Residual stress measurement of {112}-oriented CrN layers in CrN/Cr multilayer films

Journal of Vacuum Science and Technology. B, Nanotechnology & Microelectronics : Materials, Processing, Measurement, & Phenomena : JVST B


Measurement of the residual stress in chromium nitride coatings deposited on an aluminum alloy substrate using arc ion plating method


Residual stress and bending strength of ZnO films deposited on polyimide sheet by RF sputtering system

Journal of Vacuum Science & Technology A


Influence of alkali concentration on morphology and tensile properties of abaca fibers


The Relationship between Hillock Formation Temperature and Initial Residual Stress in Copper Thin Films with Different Crystal Grain Size

結晶粒径の異なる銅薄膜のヒロック形成温度と初期残留応力の関係

We deposited copper films which have a different grain size on the silicon single crystal wafer with dc magnetron sputtering. The crystal grain size of the copper films was varied by changing the substrate temperature Ts, which is one of the sputtering deposition conditions, between 64°C and 200°C. The obtained copper films were set on an optical microscope equipped with a vacuum heating device. The films surface were observed with the microscope throughout the thermal cycling between room temperature to 800°C. Next, we examined the temperature which hillocks begin to form. As a result, we confirmed the clear relationship between the temperature which the hillocks begin to form and the initial grain size of the copper film. In the case of low substrate temperature of Ts = 64°C, the initial grain size of copper film was very small, and many hillocks were formed at low heating temperature of 300°C. On the other hand, in the case of high substrate temperature of Ts = 200°C, the initial grain size of copper film was large, and hillocks were not formed below heating temperature of 800°C.

Journal of the Society of Materials Science, Japan


Improvement of the fatigue strength of SUS304 austenite stainless steel using ultrasonic nanocrystal surface modification

An ultrasonic nanocrystal surfacemodi cation (UNSM) treatmentwas applied to improve the fatigue strength of typical SUS304 austenite stainless steel. A gradient nanocrystalline plastic deformation layer with increased hardness was created at the specimen surface after UNSM treatment. The average grain size at the top surface was re ned to a few nanometers, and the whole thickness of the plastic deformation layer was ~30 to 200 μm, depending on the various treatment conditions. The hardened surface layer was assumed to be the main reason for the improvement in the fatigue strength. The increase in the fatigue strengthwas related to theUNSMapplied static loads. In this work, it was found that a static load of 90 N was optimum to obtain a large cycle fatigue strength limit. Plastic deformation (strain)-induced martensitic transformations were also observed in the surface layer. The mechanism for further grain re nement based on martensitic transformations is discussed.


Residual Stress Development in Cu Thin Films with and without AlN Passivation by Cyclic Plane Bending

International Journal of Modern Physics B


Measurement of Micro Residual Stresses near the Grain Boundary in Copper Bicrystal


Deposition of photocatalytic TiO2 films by planar magnetron sputtering system with opposed Ti targets

e-Journal of Surface Science and Nanotechnology


Measurement of electromigration-induced stress in aluminum alloy interconnection


Effect of heating on the residual stresses in TiN films investigated using synchrotron radiation


In-situ Thermal Stress Measurement in Multi-layered Aluminum Nitride and Copper Films by Synchrotron Radiation

放射光を用いた窒化アルミニウム-銅積層膜の熱応力その場測定

The Specimen prepared in this study was multi-later aluminum nitride and copper films deposited on thermal oxidation silicon by dc sputtering. Thermal stresses in the copper layers were investigated by ultra high X-rays of synchrotron radiation in the heating and cooling process. It found from the sin^2 φ diagrams of the multi-layered film that the copper layers consisted of crystal grains which had two different orientations. One was randomly orientation, and the other was {111} orientation. The FWHM of the diffraction from the {111}-oriented crystal grains was constant regardless of heating temperature. On the other hand, the FWHM of the diffraction from the randomly-oriented crystal grains was decreased with increasing heating temperature at 1st heating cycle and it became constant regardless of heating temperature after the 1st heating cycle. The 2ϑ-sin^2 φ diagrams of the multi-layered film for the stress measurement showed non-linear. We could obtain thermal stresses in two different orientation crystal grains from the non-linear 2ϑ-sin^2 φ diagram at the same time. For both crystal grains, the thermal stress differences between the 1st heating and the 1st cooling cycles were shown as a hysteresis loop. In the case of the 2nd thermal cycles, the thermal stresses changed linearly for both crystal grains. For the 1st heating cycle, the compressive thermal stress in the {111}-oriented crystal grains was larger than that in the randomly-oriented one.

Transactions of The Japan Society of Mechanical Engineers, Series A

日本機械学会論文集(A編)


Stress-assisted atomic migration in thin copper films


Alteration of internal stresses in SiO2/Cu/TiN thin films by X-ray and synchrotron radiation due to heat treatment


Thermal stress behavior in nano-size thin aluminum films


Effect of Laser Power Density and Scanning Speed on Residual Stress in Laser-Peened Aluminum Alloy

レーザピーニング処理したアルミニウム合金の残留応力のレーザパワー密度および走査速度依存性

Laser peening has recently been developed as a surface modification technique. When a high-energy laser pulse irradiates a material surface submerged in water, high-pressure plasma is generated immediately on the surface. The plasma induces an impulse wave that penetrates into the surface layer. In the present study, a laser beam of diameter about 10mm is converged by the converging lens with focal length of 250mm, and irradiates the aluminum surface. The second harmonic generation of Yttrium-Aluminum-Garnet (YAG) laser was used at a pulse frequency of 10 Hz. The effect of laser power density and scanning speed on residual stress in the laser peened aluminum alloy surface was investigated by X-ray diffraction. The following results were obtained : (1) compressive residual stress was induced in the surface of all samples ; (2) many fused traces and many micro-cracks were formed in laser peened aluminum surface ; (3) for the series of experiments with the fixed scanning speed of 2.0mm/s, the maximum compressive residual stress was induced at the laser power density of 31MW/mm^2; and (4) for the fixed laser power density of 61 MW/mm^2, that was induced at scanning speed of 1.0mm/s.

Journal of the Society of Materials Science, Japan


動き始めた創成学習 --- 徳島大学創成学習開発センターの活動

動き始めた創成学習 --- 徳島大学創成学習開発センターの活動


Residual stress measurement in sputtered copper thin films by synchrotron radiation and ordinary X-rays


Effect of substrate temperature on crystal orientation and residual stress in RF sputtered galium nitride films


In-situ observation of thermal stress in nano-size thin aluminum films


X-ray elastic constants of chromium nitride films deposited by arc-ion plating

本論文は，アークイオンプレーティング法により成膜したCrN膜のX線的弾性定数を実験的に求めたものである．X線応力測定では，特定の回折線のひずみを測定し弾性論に基づき応力を計算するものであるから，用いる回折面に特有な弾性定数を測定によってあらかじめ求めておく必要がある．試料はステンレス鋼基板上に窒素ガス圧2.63Pa，基板温度573K，アーク電流100Aバイアス電圧-300∼-100Vで蒸着したCrN膜である．膜の配向特性は{110}であり，弾性定数の測定には220回折面を用いた．X線的弾性定数は，バイアス電圧による依存はなく，約260GPaであった．

Journal of Vacuum Science & Technology A


Effect of Substrate Temperature on Crystal Orientation and Residual Stress in Radio Frequency Sputtered Gallium-Nitride Films

The crystal orientation and residual stress in gallium nitride (GaN) films deposited on a single-crystal (0001) sapphire substrate using a sputtering system are examined through x-ray diffraction measurements as part of a study of low-temperature sputtering techniques for GaN. The rf sputtering system has an isolated deposition chamber to prevent contamination with impurities, and is expected to produce high-purity nitride films. GaN films are deposited at various substrate temperatures and constant gas pressure and input power. This system is found to produce GaN films with good crystal orientation, with the c axes of GaN crystals oriented normal to the substrate surface. The crystal size of films deposited at high temperature is larger than that deposited at low TS. All films except that deposited at 973 K exhibit compressive residual stress, and this residual stress is found to decrease with increasing temperature. Finally, the film deposited at 973 K was tinged with white, and the surface contained numerous microcracks.

GaNの低温スパッタリング技術の研究として，スパッタリングシステムを用いて(0001)単結晶サファイア基板上に堆積した窒化ガリウム(GaN)の結晶配向性と残留応力をX線回折法により調べた．高周波スパッタリングシステムは，不純物による汚染を防ぐために孤立した堆積室を持ち，高純度窒化膜を生成することが期待できる．いろいろな基板温度，一定のガス圧，一定の供給電力でGaN膜を堆積した．このシステムにより，基板面法線方向にGaN結晶のc軸が優先配向し，良い結晶配向性を有するGaN膜の生成することがわかった．高温で堆積した膜の結晶サイズは，低TSで生成したものよりも大きくなる．973Kで堆積したものを除くすべての膜で圧縮残留応力が現れ，この残留応力は温度の増加とともに減少する．最後に973Kで堆積した膜は白く着色し，表面には多数の微小クラックが含有した．


The Content and Effects of Machine Creation Laboratory Using Lego Mindstorms

Lego Mindstormsを利用した創造的ものづくり教育とその効果

A machine creation laboratory has been performed with creating robots which are called the autonomous robots. This paper describes specific examples of the laboratory which was held by using Lego Mindstorms, and then introduces the outcome of educative effects in engineering education. The purpose of this laboratory is not only the improvement of problem-creation and problem-solving ability but also that of the group activities, the writing reports and the presentations. For example, students experienced that they could create ideas for resolving problems by themselves, discuss the robot mechanism in a group through the laboratory. It can be seen that the use of these robots for engineering education is considerably effective.

創造実習は自立移動型ロボットと呼ばれる創作ロボットを利用して行われている．本報告では，Lego Mindstormsを使った創造的ものづくり教育の実施例とそれを工学教育で活用した場合に得られる教育効果について述べる．この実習の目的は，問題発見能力や問題解決能力の向上だけでなく，グループ活動能力，文章作成能力，プレゼンテーション能力などの向上も目的としている．例えば，学生は実習を通して彼ら自身で問題を解決するためのアイデアを創造したり，グループでのロボットの機構を議論することを経験できた．工学教育でこれらのロボットを利用することは相当の教育効果が期待できる．

Journal of Japanese Society for Engineering Education


Evaluation of Internal Stresses in Single-, Double- and Multi-Layered TiN and TiAlN Thin Films by Synchrotron Radiation

Residual stresses in TiN and TiAlN films on steel substrate were investigated by ultra high X-rays of synchrotron radiation. The specimens prepared in this study were single-, double- and multi-layer TiN and TiAlN films deposited on high speed steel substrate by arc-ion plating. The minimum thickness available for the residual stress measurement was 0.8 μm by in-lab equipment whereas below 0.1 μm by synchrotron radiation. Extremely large compressive residual stresses were found in the films. Residual stresses in TiAlN films were more than twice larger than those in TiN films, resulting to reduce the average residual stress in the whole film system by making double- or multi-layer film construction comparing to that in the single TiAlN film.

鉄鋼基板上のTiNおよびTiAlN膜の残留応力を放射光の高輝度X線を用いて調べた．本研究では，アークイオンプレーティングにより高速度鋼上に堆積した単層，2層および多層のTiNおよびTiAlN膜を試料として用意した．残留応力測定が可能となる最小厚さは，放射光では0.1μm以下に対し，実験室装置では0.8μmであった．非常に大きな圧縮残留応力が膜中に見つかった．TiAlN膜の残留応力はTiN膜よりも2倍大きかった．その結果，TiAlN単層膜と比較すると，2層，あるいは，多層膜構造にすることで，膜全体の系における平均残留応力の減少になる．

JSME International Journal, Series A: Solid Mechanics and Material Engineering


Residual stress and thermal stress observation in thin copper films

Internal stresses in thin copper films with or without passivation were investigated by the diffraction method using an in-lab X-ray apparatus and a synchrotron radiation system. The in-lab X-ray stress equipment primarily measures the stresses m films thicker than 100 nm, whereas the synchrotron radiation system can measure stresses in films as thin as 8 nm. The residual stresses in the copper films were tensile in all cases. Thermal stress development was investigated in the heating and cooling processes. In the case of thick films, the internal stress decreased to the compressive side in an early stage of the heating process followed by non-linear behavior. In the cooling stage, the stresses in the film changed to tensile and increased to the final state at room temperature. The stress difference between the heating and cooling cycle was shown as a hysteresis loop in thick films. A thin film exhibits neither hysteresis loop nor a non-linear relation in a thermal stress change during a thermal cycle.

保護膜を有する，または，持たない銅薄膜の内部応力を実験室X線装置および放射光システムを使った回折法により調べた．放射光システムでは，厚さ8nm程度の膜の残留応力を測定することができるが，主として厚さ100nm以上の膜の応力を実験室のX線応力装置により測定した．すべての場合，銅薄膜の残留応力は引張であった．加熱および冷却過程での熱応力を調べた．厚膜の場合，加熱過程の早い段階で初期応力は非線形なbehaviorにしたがって圧縮側へ減少した．冷却過程において，膜の応力は引張へと変化し，室温での最終段階まで増加した．加熱および冷却サイクルの間の応力差は，厚膜の場合にヒステリシスループとして現れた．薄膜の場合，熱サイクル中の熱応力変化において，ヒステリシスループもなく，非線形な関係も示さなかった．


Evaluation of internal stresses in TiN thin films by synchrotron radiation

Residual stresses in TiN films on a steel substrate were investigated with ordinary in-lab X-ray equipment and a synchrotron radiation device that emits ultra-high-intensity X-rays. Specimens prepared in this study were TiN films with different thicknesses deposited on a stainless-steel substrate by arc-ion plating. The minimum thickness that allows the residual stress measurement was 0.8 μm by in-lab equipment, but it was below 0.1 μm by synchrotron radiation. We found extremely large compressive residual stresses even in a 0.1-μm-thick film; the level of residual stress was almost constant for the films with thickness of 0.1 to 0.8 μm.

鋼基板上のTiN膜の残留応力を通常の実験室用X線装置と高輝度X線を出す放射光装置を用いて調べた．本研究では，アークイオンプレーティングによりステンレス鋼基板上に堆積した厚さの異なるTiN膜を試料として用意した．残留応力測定が可能である最小膜厚は，実験室装置で0.8μm，放射光では0.1μm以下であった．厚さ0.1μmの厚さの膜でさえ非常に大きな圧縮残留応力を有することが分かった．残留応力の大きさは，厚さが0.1から0,8μmの膜においてほとんど一定であった．


Measurement of crystal orientation and residual stress in GaN film deposited by RF sputtering with powder target

Crystal orientation and residual stress in GaN films deposited by radio frequency sputtering with gallium nitride powder target are investigated by X-ray diffraction as functions of nitrogen concentration (CN2) in the atmosphere gas consisting of argon and nitrogen. In addition, the film surfaces are observed by atomic force microscopy. The following results are obtained: (1) GaN films deposited by sputtering with the powder target attained good crystal orientation, with the c-axis oriented normal to the substrate surface; (2) film thickness decreased with increasing nitrogen concentration (CN2); (3) the film deposited at CN2=20% had the largest crystal grain size, and the film deposited at CN2=0% had the smallest; (4) the film deposited at CN2=20% had the best c-axis orientation, and that deposited at CN2=0% had the poorest; (5) tensile residual stress occurred in films deposited at CN2≦20%, and compressive residual stress over -1 GPa occurred in films deposited at CN2≧50%.

窒化ガリウム粉末ターゲットを用いた高周波スパッタリングによって堆積したGaN膜の結晶配向性と残留応力をX線回折によりアルゴンと窒素から成る雰囲気ガス中の窒素濃度(CN2)の関数として調べた．それに加えて，原子間力顕微鏡により膜表面を観察した．次の結果が得られた．(1)粉末ターゲットを用いたスパッタリングにより堆積したGaN膜は，c軸が基板面法線方向に配向した良い結晶配向性を有した．(2)膜厚は窒素濃度(CN2)の増加とともに減少した．(3) CN2=20%で堆積した膜の結晶粒サイズは最大となり，CN2=0%で堆積したものは最小となった．(4) CN2=20%で堆積した膜は最も良いc軸配向性を有し，CN2=0%で堆積したものは最も悪くなった．(5) CN2≦20%で堆積した膜には引張残留応力が発生し，CN2≧50%で堆積した膜には-1GPa以上の圧縮残留応力が発生した．


Presentation Assessment of Activities in Graduation Research and Its Development

卒業研究のプレゼンテーション評価とその展開

Graduation research is a comprehensive activity among several design subjects composed in a four-year undergraduate course. The design subject in a curriculum demand several abilities such as (1) collection and application of information, (2) creativity, (3) problem finding, (4) group activities and (5) presentation. These abilities can be assessed and promoted by practicing presentations. This paper deals with the way of presentation assessment in the activities of graduation research and its development through 2000, 2001 and 2002 academic years. A coalition consisting of five seminar groups began to develop the presentation assessment. This assessment was then extended to the whole engineering departments in Tokushima University. It was clarified that the presentation assessment in activities of graduation work is an effective method to promote presentation ability and self-studying skill of the student.

卒業研究は4年間の学部学生の教育過程に含まれるいくつかの創成科目の中で広範囲にわたる活動である．カリキュラム中の創成科目は，次のようないくつかの能力 (1)情報収集·活用能力，(2)創造能力，(3)問題発見能力，(4)グループ活動能力，(5)プレゼンテーション能力を要求する．本論文では，卒業研究活動におけるプレゼンテーション評価の方法と，2000，2001および2002年度を通しての進展を扱う．5つの研究グループからなるコアリションでプレゼンテーション評価の開発を始めた．その後，この評価は徳島大学の全工学科へ広げられた．卒業研究活動におけるプレゼンテーション評価は，プレゼンテーション能力と学生の自己啓発スキルを促進するための効果的な方法である．


X-Ray Evaluation of SiO2/Cu/TiN Films Deposited by Ion Plating

イオン·プレーティング法により形成したSiO2/Cu/TiN積層膜のX線的評価

ガラス基板上に2層および3層に積層した膜の残留応力をX線的に評価した研究である．基板上にまずTiN膜をイオンプレーティング法により蒸着し，その上にCu膜およびSiO2膜をコーティングした．積層膜の結晶構造を原子間力顕微鏡により，また，残留応力をX線法で測定した． SiO2膜はアモルファスであり，TiNおよびCu膜は双方とも{111}配向の結晶構造を有していた．TiN および Cu膜について2点法により残留応力を測定した．Cu膜の残留応力はほぼ200MPaの引張り応力であり，アンダーコートのTiN膜の厚さとともに増大した．TiN 膜の応力は約300MPaの引張りであった．

Journal of the Society of Materials Science, Japan


Crystal orientation and residual stress in TiN film by synchrotron radiation

The residual stresses in a TiN film, the thickness of which is less than 1μm, deposited by arc ion plating was measured using the Spring-8 synchrotron radiation facility installed at Japan Synchrotron Radiation Research Institute (JASRI). Films thicker than 300 nm have a {111} texture, whereas those with a thickness of 100 nm have a relatively random orientation. Instead of the conventional laboratory X-ray equipment, ultra-bright synchrotron radiation can be used to precisely measure the residual stress in thin films with a thickness of 100 to 800 nm. The residual stress in thicker TiN films is about 7 GPa in compression and it is not affected by the film thickness. The slightly small compressive stress in a film of 100 nm in thickness may be due to the different crystal orientation in the film.

アークイオンプレーティングによて堆積した1μm以下の厚さのTiN膜の残留応力を高輝度光科学研究センター(JASRI)のSPring-8放射光施設で測定した．300nm以上の厚膜は{111}配向を有するが，100nmの厚さのものは相対的にランダム配向を有する．100から800nmまでの厚さの薄膜の残留応力を正確に測定するために，通常の研究室のX線装置の代わりに高輝度放射光を使った．厚いTiN膜の残留応力は圧縮の約-7GPaで，膜の厚さに影響しない．厚さ100nmの膜の圧縮残留応力がわずかに小さくなったのは，膜の結晶配向性が異なるためと考えられる．


Effect of Plasma Protection Net on Crystal Orientation and Residual Stress in Sputtered Gallium Nitride Films

X-ray diffraction was carried out in order to investigate crystal orientation and residual stress in gallium nitride (GaN) films deposited on a fused quartz substrate by radio frequency (RF) planar magnetron sputtering with a net to protect against plasma exposure. GaN films were deposited at constant gas pressure, constant input power, and various substrate temperatures. The following results were obtained: (1) GaN film of good crystal orientation can be deposited by RF sputtering; (2) in all films deposited at high substrate temperature, the c-axes of GaN crystals were oriented normal to the substrate surface; (3) crystal orientation was good in films deposited at high substrate temperature Ts > 573 K, but film deposited at Ts = 873 K peeled from the substrate; (4) good crystal orientation was attained in films deposited by sputtering with the fine mesh to protect against plasma exposure; (5) compressive residual stress was found in film deposited at low Ts below 573 K; (6) compressive residual stress was found in films deposited by RF sputtering with the plasma protection net.

プラズマ露光を防止する網を有する高周波(RF)プレーナマグネトロンスパッタリング装置によって溶融石英基板上に堆積した窒化ガリウム(GaN)膜の結晶配向性および残留応力をX線回折により調べた．GaN膜は一定のガス圧，一定の供給電力，いろいろな基板温度で堆積させた．次の結果が得られた．(1)良質な結晶配向性のGaN膜は，RFスパッタリングによって堆積することができた．(2)高温で堆積したすべての膜において，GaN結晶のc軸は基板面法線方向に優先配向した．(3)573K以上の高基板温度で堆積した膜の結晶配向性は良かったが，873Kで堆積した膜は基板から剥離した．(4)プラズマ露光を防止する目の細かな網を有するスパッタリング装置により，良い結晶配向膜が形成できた．(5)573K以下の低TSで堆積した膜に圧縮残留応力が確認された．(6)プラズマ防止網を有するRFスパッタリング装置で堆積した膜に圧縮残留応力が確認された．

Materials Science Research International


A new trial of outcomes assesment based on presentation practice

プレゼンテーションの実施によるアウトカムズ評価の新しい試み

Outcomes assessment based on presentation practice is newly schemed out in this paper. In this assessment, not only teachers but students contribute to the evaluation of a few items concerning both the substance and the skill of presentation. Practicing the presentation assessment steadily enhanced the ability of students' presentation and their ability of assessment. This paper introduces examples of the results taken from the design courses of ``Practice of Elementary Creation'', ``Creation Laboratory'' and ``Graduation Thesis''.

本論文では新しく開発したプレゼンテーションによるアウトカムズ評価の方法を紹介する．この評価では，教師のみならず学生も評価に加わる．評価項目として，プレゼンテーションの内容およびプレゼンテーションの技法のそれぞれについて数項目を設定した．プレゼンテーション評価によって，表現力は向上し，また，評価能力も経験を重ねることによって高揚することが明らかになった．創成科目である「創造演習」，「創造実習」および「卒業研究」について実施した結果を紹介する．

Journal of Japanese Society for Engineering Education


Effect of sputtering gas pressure and nitrogen concentration on crystal orientation and residual stress in sputtered AlN films

The crystal orientation and residual stress in sputtered AlN films were investigated by X-ray diffraction. The AlN films were deposited on a glass substrate by direct current (DC) and radio frequency (RF) planar magnetron sputtering system at mixed gas of argon and nitrogen under various sputtering gas pressures (P) and nitrogen concentrations (CN). The following results were obtained: (1) the degree of the c-axis orientation of AlN films deposited by RF sputtering was superior to those produced by DC sputtering; (2) the degree of the c-axis orientation of AlN films was improved with decreasing P and increasing CN; (3) in-plane large compressive stress was obtained at low P, and in-plane tensile stress was obtained at high P (P>1.3 Pa); (4) film produced by DC sputtering at low P (P<1 Pa) extensively included micro-cracks; and (5) in-plane tensile stress was obtained at low CN and large compressive stress was obtained at CN (CN>40%).

スパッタ生成したAlN膜の結晶配向性および残留応力をX線回折により調べた．AlN膜は，いろいろなスパッタリングガス圧(P)および窒素濃度(CN)の条件下で，アルゴンと窒素の混合ガスを用いた直流(DC)および高周波(RF)プレーナマグネトロンスパッタリング法によりガラス基板上に堆積させた．以下の結果が得られた．(1)RFスパッタリングで堆積したAlN膜の結晶配向性は，DCスパッタリングで生成したものよりも優れている．(2)AlN膜のc軸配向性はPの減少およびCNの増加とともに向上する．(3)大きな平面圧縮応力は低Pで得られ，平面引張応力は高P(P<1 Pa)で得られた．(4)低P(P<1 Pa)でDCスパッタリングにより生成された膜には，微小クラックが広範囲に発生した．(5)平面引張応力は低CNで得られ，大きな圧縮応力は高CN(CN>40%)で得られた．


GaN films deposited by planar magnetron sputtering

The crystal orientation of GaN films deposited on fused quartz substrates by rf planar magnetron sputtering using a mesh to guard against plasma exposure was investigated by X-ray diffraction. Sample films were deposited at constant N2 gas pressure and input power at a range of substrate temperatures between 84℃ and 600℃. It was found that GaN films with good crystal orientation can be produced by rf sputtering with the c-axis of GaN crystals oriented normal to the substrate surface in almost all films produced. The crystal 00·2 orientation was good at substrate temperatures exceeding 300℃, however, films deposited at 600℃ peeled from the substrate. The fine mesh installed to protect the film from exposure to plasma was found to be very useful for depositing films with a good crystal orientation of 00·2, and the best crystal orientation was realized for a film deposited by sputtering with a target to mesh separation of 30 mm.

プラズマ防止網を使ったRFプレーナマグネトロンスパッタリングにより溶融石英基板上に堆積したGaN膜の結晶配向性を調べた．一定のN2ガス圧，一定の供給電力，84℃と600℃の間のいろいろな基板温度で試料の膜を堆積した．良いc軸配向性を有するGaN膜がRFスパッタリングにより生成された．また，生成したほとんどすべての膜において，基板面法線方向にGaN結晶のc軸が配向した． 300℃以上の基板温度で堆積した膜の結晶配向性は良いけれども，600℃で堆積した膜は基板から剥離した．プラズマ露光から膜を守るために取り付けた目の細かい網は，結晶配向性の良い膜を堆積させるのにたいへん有効であることが分かった．そして，ターゲットから30mmの距離に網を設置してスパッタリング生成した膜の結晶配向性が最も良かった．


Energetic oxygen ions in ZrO2 deposition by reactive sputtering of Zr

The generation of intense flux of energetic oxygen ions in the sputtering of Zr target in Ar+O2 atmosphere is investigated. The energetic negative oxygen ions were detected using a constructed probe. The photoemission intensity of sputtered Zr atoms was observed in order to monitor the surface oxidization of the Zr target. The results indicate that the surface of the Zr target undergoes rapid oxidization during sputtering. The generation of the intense flux of energetic negative oxygen ions is considered to occur as a result of sputtering the heavily oxidized Zr target.

Ar+O2雰囲気でZrターゲットスパッタリング中のエネルギを持った酸素イオンの激しい流れの発生を調べた．負のエネルギを持つ酸素イオンは，constructedプローブを用いて検出される．Zrターゲットの表面酸化を監視するために，スパッタされたZr原子の光電子放出強度を観察した．Zrターゲットの表面はスパッタリング中に急速な酸化を受けることが示された．負のエネルギを持つ酸素イオンの激しい流れの発生は，スパッタリングの結果として，Zrターゲットが激しく酸化することが考えられる．


Evaluation of Technique to Improve Pre-Design Ability and Presentation Skills

創造基礎能力とプレゼンテーション技術を高めるための教育方法

This paper repots on a technique for improving presentation skills during the education of the pre-design process to first year students. Each student was asked to investigate roots of interesting invention in mechanical engineering in a group with two other students. Each student was able to learn the process of invention and design through this investigation. It was expected that use of this technique would improve the pre-design, team working, report writing and presentation skills of each student. The results showed that presentation skills were significantly improved by the introduction of the new evaluation method.

1年生を対象とした導入教育である創造演習において，平成12年度および平成13年度に実施した課題「ルーツを探れ!」の成果について報告する．この課題は，機械工学分野のある事項に対してそのルーツを調査し，その事項がどのような背景で起こり，どのような発展経緯をとって現在に至っているかを3人のグループでまとめあげる作業を行う．この作業を通して発見や創造の過程を学ぶことができる．最終的にこの実習では，学生の創造基礎能力，グループ活動能力，報告書作成能力およびプレゼンテーション能力の向上が期待できる．とくに，プレゼンテーション能力は，学生参加型評価の導入により大きな向上が確認された．


Development of Thick TiN Film on Aluminum Substrate and Its Wear Properties

アルミニウム基材へのTiN厚膜の作製とその摩耗特性

In the industrial fields, aluminum (A1050) and aluminum alloys (A5052 and A2017) are widely used in mechanical components. However, their application is essentially restricted because of their low strength and low hardness. In the present study, TiN film deposition was tried on a surface of aluminum and aluminum alloy substrates by means of an arc ion plating. The aim is to develop thick TiN film on aluminum based materials in order to get strong wear resistance. In order to minimize an increase of the substrate temperature throughout the deposition, the process was planned to deposit TiN intermittently with cooling intervals of 120 min. Arc current, bias voltage and coating time were changed to examine their roles on hardness and wear property of TiN films. X-ray diffraction study revealed (100) preferred orientation in the film deposited under the condition of low bias voltages, whereas (111) under high bias voltages. No cracks were observed in the films deposited on the A5052 and A2017 substrates under the bias voltage below -30V, however, they occurred in the films deposited higher than -20V on A1050 substrate. Low bias voltage should be essential to obtain thick TiN films on aluminum-base materials. Wear test was made by a ball-on-disk type machine. The depth of wear traces observed in the films with the thickness of 9 μm on A1050 substrate was about 40 μm. However, no wear traces appeared in the other films deposited under low bias voltages; regardless of film thickness. Although the hardness of the film was reduced with using low bias voltage, the wear property was greatly improved by thick TiN coatings.

産業界において，アルミニウム(A1050)やアルミニウム合金(A5052およびA2017)は機械部品に幅広く使われている．しかしながら，低強度，低硬度のため，本質的に適用が制限される．本研究で，アークイオンプレーティングによってアルミニウムおよびアルミニウム合金基板の表面にTiN膜の蒸着を試みた．耐摩耗特性を得るためにアルミニウム基材料上に厚いTiN膜を堆積することを目的とする．堆積中における基板温度の上昇を最小にするため，120分間の冷却期間をともなう断続的にTiN膜を堆積させる行程を計画した．TiN膜の硬さと摩耗特性の役割を調べるために，アーク電流，バイアス電圧および成膜時間を変化させた．低バイアス電圧の条件で堆積した膜は(100)面が優先配向するが，高バイアス電圧では(111)面が優先配向することがX線回折実験より明らかになった．-30V以下のバイアス電圧でA5052およびA2017基板上に堆積したTiN膜にはクラックが観察できなかったが，-20V以上のバイアス電圧でA1050基板上に堆積した膜にはクラックが発生した．アルミ基材料上に厚いTiN膜を得るためには，低バイアス電圧が基本である．摩耗試験をボール·オン·ディスク型で行った．A1050基板上の厚さ9μmの膜において摩耗痕の深さは約40μmだった．しかしながら，膜厚に関係なく，低バイアス電圧で堆積したその他の膜では摩耗痕が現れなかった．膜の硬さが低バイアス電圧で減少するけれども，厚いTiNの被覆により摩耗特性は大きく向上した．

Journal of the Society of Materials Science, Japan


Crystal Orientation and Residual Stress in Chromium Nitride Films Deposited by Arc-Ion Plating

Chromium Nitride (CrN) films are considered to be useful as piston ring and connecting rod materials in engines because such films are very hard and durable. We investigated the hardness and roughness of CrN films deposited on steel (JIS: S50C) substrates by the arc-ion plating (AIP) method, and the crystal orientation and residual stress were investigated by X-ray diffraction. The CrN films were deposited under the following conditions. The pressure of the nitrogen atmosphere was maintained at a constant 2.66 Pa, the substrate temperature was maintained at about 573 K, the arc discharge current was 50 and 100 A in two separate tests, the bias voltage applied to the substrate was varied between -300 and 0 V, and the table-mounted substrate holder was rotated at 3 rpm. We obtained the following results: (1) the Vickers micro-hardness of the films was about 1500 HV at low bias voltage (VB=0 V) and about 2500 HV at negative bias voltages exceeding -10 V, (2) the surface of films became smoother with increasing in negative bias voltage, (3) X-ray diffraction patterns revealed that the film is {111}-oriented at low arc current (IA=50 A) and low bias voltage (VB=0 V), {100}-oriented at high arc current (IA=100 A) and low bias voltage (VB=0 V), and {110}-oriented at negative bias voltages exceeding -100 V, and (4) compressive residual stress was observed in almost all films.

窒化クロム(CrN)膜は非常に硬く，高強度のために，エンジンのピストンリングや連結ロッドとしての使用が考えられている．我々はアークイオンプレーティング(AIP)法により炭素鋼(JIS:S50C)基板上に堆積したCrN膜の硬さと粗さを調べた．また，X線回折を用いて結晶配向性および残留応力も調べた．次の条件でCrN膜を堆積した．窒素雰囲気ガスの圧力を2.66Paに固定し，基板温度を約573Kに保持し，アーク電流は50Aと100Aの2つの状態に設定し，基板に供給するバイアス電圧は-300Vと0Vの間で変化させ，試料台を設置するテーブルを約3rpmで回転させた．我々は以下の結果を得た．(1)膜のヴィッカース微小硬さは，低バイアス電圧(VB=0 V)で約1500HV，-10Vを超える負のバイアス電圧で約2500であった．(2)膜表面は負のバイアス電圧の増加とともに滑らかになった．(3)X線回折線図より，低アーク電流(IA=50 A)低バイアス電圧(VB=0 V)で{111}配向，高アーク電流(IA=100 A)低バイアス電圧(VB=0 V)で{100}配向，-100Vを超える負のバイアス電圧で{110}配向となることが明らかになった．(4)ほとんどすべての膜において圧縮残留応力が確認された．

Materials Science Research International, Special Technical Publication


X-Ray Evaluation of Laser-Peened Aluminum Surface

Shot peening is a technique that improves the surface properties of materials by inducing compressive residual stress and work hardening in the surface layer. It has been practiced in a broad range of engineering fields, in particular for machine parts that are subject to cyclic loading. Laser peening has recently been developed as a new surface modification technique. When a high-energy pulse laser irradiates a material surface submerged in water, high pressure plasma is generated immediately in front of the surface. The plasma induces impulse waves that penetrate into the surface layer. In the present study, a second harmonic generation of Yttrium-Aluminum-Garnet (YAG) laser passing through water was used irradiate the surface of aluminum specimens. The effect of pulse energy and laser focus point on surface modification was investigated. The residual stress that developed as a result of laser peening was evaluated by X-ray stress measurement. The following results were obtained: (1) high laser power, 7.0, developed plastic deformation and residual stress; (2) when the laser beam was converged in front of the surface, compressive residual stress was induced, whereas tensile residual stress was induced when the focus was beyond the surface; (3) the surface roughness was higher for focusing in front of the surface than for beyond; (4) the hardened depth was estimated to be about 10 μm at the laser power of 7.0.

ショットピーニングは，表面層に圧縮残留応力を発生させ，硬くすることによって材料の表面特性を改善する技術である．これは幅広い工学分野，特に，繰り返し負荷を受ける機械部品に実施された．近年，レーザピーニングは新しい表面改質技術として開発された．高エネルギパルスレーザを水中に設置した材料表面に照射すると，直ちに高圧プラズマが材料表面に生成される．プラズマは表面層から内部へ浸透する衝撃波を誘起する．本研究ではYAGレーザ第2高調波を使用し，水中に固定した試料に照射した．表面特性のパルスエネルギおよび焦点位置依存性を調べた．ピーニングの結果発生する残留応力をX線応力測定により評価した．次の結果が得られた．(1)7.0の高レーザ出力で塑性変形と残留応力が発生した．(2)表面前方でレーザビームを集光させたとき，圧縮応力が増加した．一方，表面後方で集光させたときには引張残留応力が発生した．(3)表面粗さは，表面後方で焦点を結ぶよりも前方で結ぶ方が大きくなる．(4)硬化の深さは，7.0のレーザ出力で約10μmであると評価した．


X-ray Stress Measurement and Mechanical Properties of TiN Films Coated on Aluminum and Aluminum Alloy Substrates by Arc Ion Plating and Ion Beam Mixing

TiN coatings on cutting tools have greatly succeeded in prolongation of tool lives. In the present study, TiN film deposition was tried on a surface of aluminum and aluminum alloy substrates by means of an arc ion plating (AIP) method and an ion beam mixing (IBM) method. The aim is to develop aluminum-based materials having strong wear resistance. In order to examine the hardness and residual stress of TiN films, the bias the voltage and N2 gas pressure were varied in the AIP treatment and the titanium deposition rate was changed in the IBM treatment. Vickers hardness test revealed high values (HV=1800∼2400). The TiN films coated by the AIP and the IBM methods exhibited very high {111} and {110} preferred orientations, respectively. The two-exposure X-ray stress measuring method was used to measure residual stresses in the TiN film. Large compressive residual stresses of -6.3∼ -2.3 GPa were developed at lower N2 gas pressures for the AIP method and at higher Ti deposition rates for the IBM method. A wear experiment was also made with a ball-on-disk type wear testing machine. The depth and the width of wear traces on the surface of specimens were greatly reduced when TiN coatings were applied.

工具上のTiNの被覆は工具寿命のprolongationに大きく成功した．本研究で，アークイオンプレーティング(AIP)法およびイオンミキシング(IBM)法によってアルミニウムおよびアルミニウム合金の表面にTiN膜の堆積を試みた．アルミニウム基の材料に耐摩耗特性を持たせることを目的とする．TiN膜の硬さおよび残留応力を調べるために，AIP処理においてバイアス電圧およびN2ガス圧を変化させ，IBM処理において堆積率を変化させた．ヴィッカース硬さ試験において高い値(HV=1800~2400)を示した．AIPおよびIBM法によって被覆されたTiN膜は，それぞれ高い{111}および{110}優先配向を示した．TiN膜の残留応力を測定するために2点傾斜X線応力測定法を用いた．-6.3∼-2.3 GPaの大きな圧縮残留応力が，AIP法においては低いN2ガス圧で，IBM法においては高いTi堆積率で発生した．ボール·オン·ディスク型磨耗試験機を用いて磨耗試験もまた行った．TiN皮膜を付けたとき，試料表面の磨耗痕の深さと幅は著しく減少した．

Materials Science Research International


Effect of Input Power on Crystal Orientation and Residual Stress in AlN Film Deposited by dc Sputtering

The crystal orientation and residual stress development in AlN films deposited by dc planar magnetron sputtering on a glass substrate were investigated by atomic force microscopy (AFM) and X-ray diffraction. The microscopic surface morphology, the film thickness and the crystal orientation were investigated for films that were deposited at a constant N2 gas pressure and a constant heating temperature of the substrate at various input powers. The following results were obtained: (1) the crystal grain size and the film thickness increased with increasing input power; (2) c-axis orientation was slightly good at high input power; (3) tensile residual stresses were obtained at low input power and large compressive stresses were obtained at high input powers of P=154 and 180 W.

ガラス基板上DCプレーナマグネトロンスパッタリングによって堆積したAlN膜の結晶配向性と残留応力を原子間力顕微鏡(AFM)観察およびX線回折法により調べた．一定のN2ガス圧，一定の基板温度，いろいろな供給電力で堆積した膜の顕微鏡表面形態，膜厚および結晶配向性を調べた．次の結果が得られた．(1)結晶粒サイズと膜厚は供給電力の増加とともに増加した．(2)c軸配向性は高い供給電力でわずかに良くなった．(3)低供給電力で引張残留応力が，P=154および180Wの高供給電力で大きな圧縮応力が得られた．


Residual Stress in TiN Film Deposited by Arc Ion Plating

TiN films were deposited on aluminum and stainless steel substrates by arc ion plating (AIP). Bias voltages, nitrogen gas pressures and arc currents were changed to examine their role on the hardness and residual stress of a TiN film. Vickers microhardness tests revealed high hardness value (HV = 2250 ∼ 2500) which depends on both nitrogen gas pressures and arc currents. From the X-ray diffraction pattern, it was found that the crystal orientation of the TiN film markedly varied with the bias voltage. Residual stresses in the TiN film were measured by the two-exposure X-ray stress analysis as a function of the nitrogen gas pressure, arc current. Very high compressive residual stresses, -5 GPa in the films on aluminum substrates and -7 GPa in the film on a stainless steel substrate, were observed.

アークイオンプレーティング(AIP)法によりアルミニウムおよびステンレス鋼上にTiN膜を堆積した．TiN膜の硬さと残留応力の役割を調べるために，バイアス電圧，窒素ガス圧およびアーク電流を変化させた．ヴィッカース微小硬さ試験により，窒素ガス圧とアーク電流ともに依存する高硬度値(HV=2250~2500)が明らかとなった．X線回折線図より，TiN膜の結晶配向性はバイアス電圧に著しく依存することが分かった．窒素ガス圧およびアーク電流の関数として，TiN膜の残留応力を2点傾斜X線応力解析により測定した．アルミニウム基板上の膜には-5GPa，ステンレス鋼基板上の膜には-7GPaの非常に高い圧縮残留応力が得られた．


Abnormal Residual Stress State in ZnO Films Synthesized by Planar Magnetron Sputtering System with Two Facing Targets

The structure and residual stresses of ZnO films synthesized by a planar magnetron sputtering system with two facing targets were investigated by X-ray diffraction. ZnO films were deposited onto a sheet of Corning 7059 glass. The X-ray diffraction pattern shows that the film has high [00·1} orientation. Residual strains were measured on various diffraction lines that appear at special angles from the surface normal. The strains taken from positive and negative differed from each other. This behavior is deduced from the existence of a shear stress component in a cross-section of the film. The magnitude of the shear stress increased with increasing current density of the Zn target as well as with decreasing argon gas pressure.

対向ターゲット式プレーナマグネトロンスパッタリングによって生成したZnO膜の構造と残留応力をX線回折によって調べた．ZnO膜をはコーニング#7059ガラス上に堆積した．X線回折線図から，膜が高い{00·1}配向性を有することが明らかになった．残留応力は基板法線から特別な角度ψで現れるいろいろな回折線により測定される．+ψおよび-ψから得られるひずみは互いに異なっていた．このふるまいは膜の断面にせん断応力成分の存在が推定される．アルゴンガス圧を減少させることとZnターゲットの供給電流を増加させるとともに，せん断応力の大きさは増加する．


Mechanical Properties of TiN Films Deposited on Aluminum Substrates by Arc Ion Plating Method

アークイオンプレーティング法によるアルミニウム基板へのTiN膜の形成とその機械的特性

TiN film, 3μm in thickness, was deposited on aluminum (JIS A 1050) and aluminum alloy (JIS A 2017 and JIS A 5052) substrates by an Arc Ion Plating (AIP) method. Bias voltage and N2 gas pressure were changed to examine their role on hardness and residual stress of TiN film. Wear experiment was also conducted using a ball-on-disk type wear apparatus. Vickers hardness tests revealed high value (HV = 2100~2400) which depends on both bias voltage and N2 gas pressure. The TiN films exhibited very high {111} preferred orientation. Residual stresses in the TiN film were measured by the two-exposure X-ray stress measuring method as a function of N2 gas pressure. Very high compressive residual stresses, -6.3~-4.6 GPa, were observed. The depth of wear scars on the substrate of the processed specimens were greatly shallow.

アークイオンプレーティング(AIP)法によって，アルミニウム(JIS A 1050)およびアルミニウム合金(JIS A 2017 and JIS A 5052)基板上に膜厚さ3μmのTiN膜を堆積した．TiN膜の硬さと残留応力の役割を調べるために，バイアス電圧およびN2ガス圧を変化させた．ボール·オン·ディスク摩耗装置を使った摩耗実験もまた行った．ヴィッカース硬さ試験により，バイアス電圧と窒素ガス圧ともに依存する高硬度値(HV=2100∼2400)が明らかとなった．非常に高い{111}．窒素ガス圧の関数として，TiN膜の残留応力を2点傾斜X線応力解析により測定した．-6.3~-4.6 GPaの高い圧縮残留応力が観測された．処理された試料の基板上の摩耗痕は非常に浅かった．

Transactions of The Japan Society of Mechanical Engineers, Series A

日本機械学会論文集(A編)


Effect of External Magnetic Field on c-axis Orientation and Residual Stress in AlN Films

Crystal orientation and residual stress development in AlN films on borosilicate glass (the thermal expansion coefficient of which is nearly equal to that of AlN) substrate were investigated by atomic force microscopy (AFM) observation and X-ray diffraction method. The AlN films were prepared by a planar magnetron sputtering system with two opposite targets under the condition of constant nitrogen gas pressure, constant substrate temperature, various deposition time and various external magnetic field (EM) between 63 and 128 gauss. We obtain the following results: (1) the size of crystal grains was large and the value of FWHM of 00·2 diffraction line was small at large EM; (2) the c-axis orientation was good for all films; (3) the large tensile residual stresses were obtained at large EM and decreased with decreasing the EM because of ion peening.

ホウ珪酸ガラス基板上に堆積したAlN膜の結晶配向性と残留応力を原子間力顕微鏡(AFM)観察およびX線回折法により調べた．一定の窒素ガス圧，一定の基板温度，いろいろな堆積時間，63と128ガウスの間のいろいろな外部磁場(EM)の条件の下，対向ターゲット式プレーナマグネトロンスパッタリングによってAlN膜を用意した．我々は次の結果を得た．(1)大EMで結晶粒の大きさが大きくなり，00·2回折線の半価幅値は小さくなる．(2)すべての膜でc軸配向性は良い．(3)大きな引張残留応力が大EMで発生し，EMの減少にともないイオン衝撃のために引張残留応力が減少する．


Influence of target shape on properties of AlN sputtered film

AlN films were deposited by reactive magnetron sputtering with a roof-shaped Al target and conventional planar target. The c-axis orientation and the grain growth of AlN films were improved and the defects in the film were decreased, when the ion flux bombarding the film decreased. This trend was confirmed by depositing AlN films under various N2 gas pressures or external magnetic fields. These data indicate that there remains a considerable influence of ion bombardment in conventional planar magnetron sputtering, but the use of a roof-type target is effective for decreasing the exposure of the film to plasma as a result of a decrease in ion bombardment.

屋根型アルミニウムターゲットおよび従来型平板ターゲットを有する反応性スパッタリングによりAlN膜を堆積した．膜に衝突するイオン流が減少したとき，c軸配向性およびAlN膜の粒成長は向上し，膜中の欠陥が減少する．この傾向はいろいろなN2ガス圧や磁場でAlN膜を堆積させることで確認される．これらのデータは，従来型平板マグネトロンスパッタリングではイオン衝撃の影響を残すが，屋根型ターゲットの使用はイオン衝撃の軽減の結果として膜のプラズマ露光を減少させる効果があることを示す．

Japanese Journal of Applied Physics, Part 1 (Regular Papers & Short Notes)


Magnetic Field Dependence of AlN Films in DC Planar Magnetron Sputtering with Opposed Targets

AlN films were deposited on glass substrates by planar magnetron sputtering with opposed targets. Two kinds of target holders with different magnetic field distributions were used. We investigated how magnetic field configuration in a plasma region affects AlN film properties such as c-axis orientation, optical transmittance spectrum and internal stress. It was found that degree of c-axis orientation of AlN films has a close relation with the magnetic field distribution in the facing target system. When magnetic field distribution in the chamber was designed so that electrons could escape outward from the plasma region, AlN films could be deposited with little damage.

対向ターゲット式プレーナマグネトロンスパッタリングによってAlN膜を堆積した．磁場分布の異なる2種類のターゲットホルダーを用いた．我々はプラズマ領域中の磁場分布が，c軸配向性，光透過率，内部応力などのAlN膜特性にどのような影響を及ぼすかを調べた．AlN膜のc軸配向性が対向ターゲット間の磁場分布に密接な関係があることが分かった．チャンバー内の磁場分布は，電子がプラズマ領域から外へ逃れることができ，AlN膜が損傷なく堆積することができるように設計させる．


Residual Stress Measurement in AlN Film Deposited by Alternating Sputtering Method

交替式スパッタリング法によるAlN膜の残留応力測定

Crystal orientation and residual stress development in AlN films deposited on BLC glass (Borosilicate glass; the thermal expansion coefficient of which is nearly equal to that of AlN) substrates were investigated by X-ray diffraction method. The AlN films were prepared by an alternating planar magnetron sputtering system under the condition of constant substrate temperature, various nitrogen gas pressures between 0.17 Pa and 1.1 Pa and various switching time to alternate the anodic and cathodic polarity of two target electrodes between 30sec and 600sec. The measurement of intensity from 00·2 diffraction showed that c-axis orientation of AlN film was improved when the film was deposited at low nitrogen gas pressure below 0.5 Pa and large switching time over 300sec. The tensile residual stresses were found in the films deposited at low nitrogen gas pressure below 0.3 Pa or high nitrogen gas pressure over 0.8 Pa and short switching time below 120sec.

BLCガラス基板上に堆積させたAlN膜の結晶配向性および残留応力をX線回折法により調べた．交替式プレーナマグネトロンスパッタリング法を用いて，一定の基板温度，0.17Paと1.1Paの間のいろいろな窒素ガス圧，30秒と600秒の間のいろいろなスイッチ切り換え時間(2つの電極の正極と陰極を切り換える時間)でAlN膜を用意した．0.5Pa以下の窒素ガス圧，300秒以上の長スイッチ切り換え時間で膜を堆積したとき，AlN膜のc軸配向性は良くなる．0.3Pa以下の低窒素ガス圧，0.8Pa以上の高窒素ガス圧，120秒以下のスイッチ切り換え時間で堆積させた膜には，引張残留応力が発生する．

Journal of the Society of Materials Science, Japan


Effect of Plasma Protection Net on Residual Stress in AlN Films Deposited by a Magnetron Sputtering System

Crystal orientation and residual stress development in AlN films deposited on borosilicate glass (the thermal expansion coefficient of which is nearly equal to that of AlN) substrates were investigated by X-ray diffraction method. The AlN films were prepared by a conventional planar magnetron sputtering system with a plasma protection net under the condition of constant substrate temperature and various nitrogen gas pressures between 0.8 Pa and 13 Pa. We found that the residual stresses show the same qualitative tendency against the nitrogen gas pressure independent of the use of the plasma protection net. Large tensile residual stress was observed at high nitrogen gas pressure and large compressive residual stress was observed at low gas pressure. When the plasma protection net was used, residual stresses in the AlN film were shifted to the compressive side.

BLCガラス基板上に堆積したAlN膜の結晶配向性と残留応力をX線回折法により調べた．一定の基板温度，0.8Paから13Paの間のいろいろな窒素ガス圧の条件の下，従来型プレーナマグネトロンスパッタリングによりAlN膜を堆積した．プラズマ防止網の使用に関して，窒素ガス圧に対して同じ定性的な傾向を示す．高窒素ガス圧で大きな引張残留応力が，低窒素ガス圧で大きな圧縮残留応力が発生した．プラズマ防止網を使用した場合，AlN膜の残留応力は圧縮側へ移行した．


Residual Stress and in-situ Thermal Stress Measurement of Aluminum Film Deposited on Silicon Wafer

Residual stresses in aluminum film deposited on a silicon wafer were measured after annealing and quenching. In all cases, residual stresses were tensile, but slow cooling produced lager stresses than quenching. Residual stresses of slow-cooled samples became relaxed after annealing above 300℃. Film passivation by carbon deposition retarded the relaxation of residual stress. In-situ X-ray stress measurement revealed that compressive stresses developed in a heating stage and tensile stresses in a cooling stage. From a scanning electron microscopy observation, it becomes clear that the former contributes to nucleation of hillocks and the latter to void formation and growth.

焼鈍および急冷後，シリコンウエハ上に堆積させたアルミニウム膜の残留応力を測定した．すべての場合において残留応力は引張となるが，除冷は急冷よりも大きな応力を形成する．除冷試料の残留応力300℃以上での焼鈍後に緩和する．炭素の保護膜は残留応力の緩和に関係する．加熱段階で圧縮応力が，冷却段階で引張残留応力が形成されることがX線応力その場測定により明らかになった．走査型電子顕微鏡観察より，ヒロックの核が形成され，その後，ボイドが形成し成長することが明らかになった．


Gas pressure dependence of AlN film properties in alternating sputtering system

AlN films were prepared in N2 and N2/Ar gas by the alternating DC sputtering method wherein two Al targets facing each other were sputtered alternately, and the mechanism of film damage in AlN film preparation was investigated. When the gas pressure was lower than 3 mTorr, the crystalline orientation of the film inclined slightly toward the direction of incidence of depositing atoms. In this system, the influence of plasma exposure on the film properties was decreased. This was due to the decrease of electron flow into the substrate. Degradation of the c-axis orientation was ascribed to both the tilt of the growth direction of the (00·2) plane at low gas pressures and film bombardment by positive ions with energies above 60 eV.

2つの対向させたアルミニウムターゲットが交互にスパッタされる交替式DCスパッタリング法によりN2およびN2/Arガス中でAlN膜を作成し，AlNの成膜における膜損傷のメカニズムを調べた．ガス圧が3mTorrより低い場合，膜の結晶方位は堆積原子の入射方向に沿ってわずかに傾く．このシステムで膜特性に対するプラズマ露光の影響は減少した．これは基板に入る電子流が減少したためである．c軸配向性の悪化は，(00·2)面の成長方向の傾きと60eV以上のエネルギを有する正イオンによる膜衝撃の両方に帰する．


Effect of Nitrogen Gas Pressure on Residual Stress in AlN Films Deposited by the Planar Magnetron Sputtering System

The crystal orientation and residual stress development in AlN films deposited on borosilicate (BLC) glass substrates were investigated by X-ray diffraction. Deposition was performed using two kinds of planar magnetron sputtering system: a conventional system (CPM system) and a special system with two facing targets (FTPM system). The nitrogen gas pressure (PN) was varied over a suitable range for each system. The diffraction patterns of the AlN films showed that the c-axis orientation was improved when the films were deposited using the CPM system at a nitrogen gas pressure lower than 1 Pa. For the CPM system, compressive residual stress was found in films deposited at PN ≦ 2 Pa and tensile residual stress at PN > 2 Pa/ For the FTPM system, tensile residual stress was found in films deposited at PN < 0.8 Pa and compressive residual stress at PN > 0.8 Pa.

BLCガラス基板上に堆積したAlN膜の結晶配向性および残留応力をX線回折法により調べた．従来型システム(CPMシステム)と対向ターゲット式システム(FTPMシステム)の2種類のプレーナマグネトロンスパッタリング法により成膜を行った．それぞれのシステムにおいて窒素ガス圧(PN)を変化させた． CPMシステムにより1Pa以下の低窒素ガス圧で堆積させたとき，AlN膜の回折線図形からc軸配向性が向上することが明らかになった．CPMシステムにおいて，2Pa以下のPNで堆積させた膜で圧縮残留応力が，2Pa以上のPNで堆積させた膜で引張残留応力が発生する．FTPMシステムにおいて，0.8Pa以下のPNで堆積させた膜で圧縮残留応力が，0.8Pa以上のPNで堆積させた膜で引張残留応力が発生する．


TiN films prepared by unbalanced planar magnetron sputtering under controle of photoemission of Ti

TiN films have been prepared by unbalanced planar magnetron sputtering, where the flux of sputtered Ti atoms was maintained constant by adjusting N2 gas flow during sputtering. At a set point of 75% of the Ti signal in the pure Ar gas, the film resistivity has a minimum, the film stress becomes a minimum and the appearance is most gold-like. With an increase in ion bombardment, the internal stress increases, whereas the film resistivity decreases. These results confirm that stoichiometric TiN films are prepared at the set point of 75%, where the target surface is not fully covered by TiN. The energetic ions appear to improve the properties of the TiN films.

TiN膜はアンバランスドプレーナマグネトロンスパッタリングによって準備された．ここで，スパッタリング中のN2ガス流量を調整することで，スパッタされたTi原子の量が一定に保たたれた．純アルゴンガス中でTi信号の75%のセットポイントで，得られる膜の抵抗が最小となり，膜応力が最小となり，外観が金のようになる．イオン衝撃の増加とともに膜抵抗が減少するにも関わらず，内部応力が増加する．これらの結果は，化学量論組成のTiN膜が75%のセットポイントで作製されることを示す．ここで，ターゲット表面はTiNで完全には覆われていない．エネルギを持ったイオンは，TiN膜の特性の向上に現れる．


Effects of Nitrogen Pressure and Ion Flux on the Properties of Direct Current Reactive Magnetron Sputtered Zr-N Films

Zr-N films have been deposited by direct current reactive magnetron sputtering using a plasma emission monitoring (PEM) control system, where a signal proportional to the light emitted by the sputtered Zr in the plasma created by the electrical discharge was used to control the admission of the reactive nitrogen into the system. The Zr line set point for PEM control, φ, was used as a parameter; as the partial pressure of nitrogen rises the Zr line emission falls due to target poisoning. The influence of the nitrogen partial pressure on the Zr-N film structure, reflectivity, resistivity, and internal stress was investigated. The effect of ion flux during film deposition on the film properties was also investigated. The Zr-N films deposited at the Zr line set point φ=60%-70% revealed the minimum resistivity and gold-like reflectivity spectra. These films showed a ZrN single phase. The internal stress of the films showed a maximum at φ=60%-70%, which corresponds to the condition for depositing minimum resistivity films. The external magnetic field scarcely affected the optical and the electrical properties of the deposited Zr-N films. The internal stress of the films deposited at the lower φ (higher nitrogen partial pressure) was only dependent on the ion flux.

本論文は，表面保護膜や装飾用，拡散バリアなどの用途を持つ窒化ジルコン膜を，金属ジルコンターゲットをアルゴン窒素の混合ガス中で反応性スパッタを行い作製する際，PEM法といわれる手法で行ったものである．この手法は，ターゲット表面の窒化物生成の割合を一定に保つようにして膜作製ができ，安定な条件設定が可能である．組成比の評価から，化学量論的窒化ジルコン膜は窒素分圧の非常に狭い範囲の制御で作製可能なことを示した．また，膜の抵抗率，内部応力についても評価を行い，これらへのプラズマの影響について調べた．

Journal of Vacuum Science & Technology A


Film Degradation in AlN Preparation by Facing Target System

In AlN films prepared by the facing target system, a decrease in degree of c-axis orientation, film coloring and film cracking or peeling from the substrate were observed. This film degradation is thought to be related to insulative films in general. In order to clarify how these phenomena are induced, we prepared samples under various sputtering conditions; i.e., by changing target holders, placing a ground mesh in front of the substrate and using a positively biased electrode. It is confirmed that plasma exposure severely influences c-axis orientation of AlN films. To decrease this influence, it is important that electrons flow adequately into the anode.

対向ターゲットシステムにより用意したAlN膜には，c軸配向性の悪化，膜の着色，割れ，基板からの剥離が観察された．この膜汚染は一般に絶縁膜に関係すると考えられている．これらの現象を解明するために，我々は種々のスパッタリング条件，すなわち，ターゲットホルダーの改造，基板前方にアースされた網の設置および正のバイアス電極の使用によって試料を準備した．プラズマ露光がAlN膜のc軸配向性に厳密に影響することが確認された．この影響を減少するために電子を適当に陽極へ流すことが重要である．

Japanese Journal of Applied Physics, Part 1 (Regular Papers & Short Notes)


Effects of Plasma Contamination on Crystal Orientation and Residual Stress in AlN Films Deposited by Planar Magnetron Sputtering

プレーナマグネトロンスパッタリング生成によるAlN膜の結晶配向性と残留応力のプラズマ汚染の影響

Crystal orientation and residual stress development in AlN films deposited on BLC glass (Borosilicate glass; the thermal expansion coefficient of which is nearly equal to that of AlN) substrate were investigated by an X-ray diffraction. Deposition was made by a conventional planar magnetron sputtering system under the nitrogen gas pressure of 0.65 Pa at the substrate temperature between 423K and 523K. In order to investigate the effect of plasma contamination, the distance between the target and the substrate holder (target distance dT) was chosen at 30 mm and 60 mm. The intensity of 00·2 diffraction showed that the c-axis orientation of AlN films was improved by the deposition with a short target distance (dT=30 mm). However, in all the AlN films deposited with dT=30 mm, fine cracks were observed probably due to the effect of plasma contamination. In the films deposited with a long target distance (dT=60 mm), large tensile residual stress greater than 1 GPa was found at every substrate temperature used in the present investigation. In the film deposited with dT=30 mm, tensile residual stress became larger with increasing substrate temperature. As compared with the AlN films deposited with dT=60 mm, the tensile residual stress in AlN films deposited with dT=30 mm considerably decreased because of the effect of ion bombardment.

X線回折法を用いてBLCガラス基板上に堆積したAlN膜の結晶配向性と残留応力を調べた．従来型プレーナマグネトロンスパッタリング法により窒素ガス圧0.65Pa，基板温度423Kおよび523Kで成膜を行った．プラズマ汚染の影響を調べるために，ターゲットと基板間距離dTを30∼60mmに変化させた．00·2回折強度の測定より，短dTで堆積したAlN膜のc軸配向性が良くなることが分かった．しかし，dT=30mmで用意したすべての膜は，プラズマ汚染の影響により細かな割れが観察された．dT=60mmで形成した膜には，本実験で行った両基板温度において1GPa以上の大きな引っ張り残留応力が発生した．dT=30mmで形成した場合，基板温度の増加とともに引張残留応力が増加した．dT=60mmで形成した膜に比べて，dT=30mmで形成した膜の引張残留応力はイオン衝撃の効果のために減少した．

Journal of the Society of Materials Science, Japan


Dependence of Substrate and Its Temperature on Residual Stress in AlN Films Deposited by Sputtering

スパッタリング生成によるAlN薄膜の残留応力の基板および基板温度依存性

Crystal orientation and residual stress development in AlN films deposited on BLC glass and quartz substrates were investigated by an X-ray diffraction method. The deposition was made by a planar magnetron sputtering system with two facing targets under the nitrogen gas pressure of 0.39Pa in the substrate temperature range between 373K and 553K. The measurement of diffraction intensity from (00·2) plane showed that the c-axis orientation of AlN films was improved when deposited at higher substrate temperatures than 523K. Large tensile residual stresses, 0.9 ∼ 1.4 GPa for the BLC substrate and 1.4 ∼ 2.7 GPa for the quartz substrate, were found in the films deposited at low substrate temperatures ( ≦ 523K). Especially, the residual stress in the film on a quartz substrate showed a large increase with substrate temperature, whereas that on a BLC substrate showed a small increase. A very small stress was found in the film deposited at high substrate temperatures (> 523K) for both substrates. The role of intrinsic and thermal residual stresses on residual stress development was discussed.

BLCガラスおよび石英基板上に堆積したAlN膜の結晶配向性と残留応力をX線回折法により調べた．成膜は対向ターゲット式プレーナマグネトロンスパッタリング法で行い，堆積条件として窒素ガス圧を0.39Pa，基板温度を373Kから553Kの間で変化させた．(00·2)面からの回折強度の測定より，523K以上の基板温度で堆積したAlN膜のc軸配向性が向上することが明らかになった．523K以下の低基板温度で堆積させたBLCガラス基板上のAlN膜には0.9∼1.4GPa，石英基板上の膜には1.4∼2.7GPaの大きな引張残留応力が形成される．特に，石英基板上の膜中の残留応力は基板温度の増加とともに大きくなる．両基板において523Kより高い基板温度で堆積した膜中の残留応力は，非常に小さい応力が形成される．真応力と熱応力の発生について検討を行った．


TiNおよびTiAlN膜の応力のX線的評価

TiNおよびTiAlN膜の応力のX線的評価

AIP法によりステンレス鋼基板に成膜したTiN およびTiAlNの積層膜の残竜王りょっくをシンクロトロン放射光により測定した研究である．厚さ1ミクロン以下0.01ミクロンまでのTiN薄膜の結晶配向性および残留応力を測定した．通常のX線装置では薄膜の厚さが0.5ミクロン以下のときは測定が不可能であるが，シンクロトロン放射光を用いることで薄い薄膜の残留応力測定が可能になった．また，積層膜の各層の残留応力測定もシンクロトロンにより初めて測定可能になった．TiN 膜には-2∼-4GPaの応力，TiAlN膜には-8GPaの応力が観測された．


ナノサイズアルミニウム配線のエレクトロニクスマイグレーション誘起応力の挙動

ナノサイズアルミニウム配線のエレクトロニクスマイグレーション誘起応力の挙動

SPring-8ナノテクノロジー研究

SPring-8ナノテクノロジー研究


Development of green nanocomposites reinforced by cellulose nanofibers extracted from paper sludge