Copper diffusion into silicon substrates through TaN and Ta/TaN multilayer barriers

A study of copper (Cu) diffusion into silicon substrates through Ta nitride (TaN) and tantalum (Ta/TaN) layers was investigated based on an experimental approach. TaN _x and Ta/TaN _x thin films were deposited by radiofrequency sputtering under argon (Ar) and Ar-nitrogen (N) plasma. The influence of the N₂ partial pressure on the microstructure and the electrical properties is reported. X-ray diffraction patterns showed that the increase of the N₂ partial pressure, from 2 to 10.7%, induces a change in the composition of the δTaN phase, from TaN to TaN_1.13, as well as an evolution of the dominant crystallographic orientation. This composition change is related to a drastic increase of the electrical resistivity over a N₂ partial pressure of 7.3%. The efficiency of TaN layers and Ta/TaN multilayer diffusion barriers was investigated after annealing at temperatures between 600 and 900 °C in vacuum. Secondary ion mass spectrometry profiles showed that Cu diffuses from the surface layer through the TaN barrier from 600 °C. Cu diffusion mechanisms are modified in the presence of a Ta sublayer. This article was presented at the Multicomponent-Multiphase Diffusion Symposium in Honor of Mysore A. Dayananda, which was held during TMS 2006, the 135th Annual Meeting and Exhibition, March 12–16, 2006, in San Antonio, TX. The symposium was organized by Yongho Sohn of the University of Central Florida, Carelyn E. Campbell of National Institute of Standards and Technology, Richard D. Sisson, Jr., of Worcester Polytechnic Institute, and John E. Morral of Ohio State University.     

Ti衬底层对FePt颗粒膜的微结构和磁特性的影响

在室温下,应用对靶直流磁控溅射设备在普通玻璃基片上制备了FePt(30nm)/Ti(tnm)颗粒膜样品,随后,在真空中进行了原位退火.详细研究了Ti衬底层对FePt颗粒膜的微结构和磁特性的影响.X射线衍射图谱表明样品形成了较有序的L10织构,Ti和FePt形成了三元FePtTi合金.当Ti层厚度t=5 nm、退火温度Ta=500℃时,样品具有高度有序的L10织构、小的颗粒尺寸和优异的磁特性.矫顽力超过了6.7 kOe,饱和磁化强度为620emu/cc.并且具有较小的开关场分布.结果表明FePt/Ti颗粒膜系统可作为超高密度磁记录介质的候选者.     

Characterization and optimization of magnetic garnet films for magneto-optical visualization of magnetic field distributions

Rare-earth iron garnet films with in-plane anisotropy grown on (111)-oriented substrates can be used as magneto-optical indicator films for visualization of magnetic leakage fields in nondestructive evaluation. The influence of Faraday rotation, Faraday ellipticity, absorption and film thickness on the performance of a magneto-optical indicator film is investigated. A new optimization method is introduced and compared with the method of contrast optimization. The theory is experimentally verified and an application example is presented.     

溅射NiCrAlY渗Al涂层的高温氧化行为

用SEM、XRD和EPMA等手段,研究了溅射NiCrAlY涂层渗Al前后在1000℃和1100℃的高温氧化行为.结果表明,溅射涂层在1000℃形成了单相的α-Al2O3,具有优异的抗氧化性能;但在1100℃由于Al的过度消耗而失去保护作用.渗Al涂层在1000℃快速增长θ-Al2O3相,使其抗氧化性能稍逊于溅射涂层;在1100℃表面形成了以α-Al2O3为主的保护膜,抗氧化性能优于溅射涂层.     

INTERFACIAL REACTIONS OF METAL FILMS WITH AlN SUBSTRATE

ＩＮＴＥＲＦＡＣＩＡＬＲＥＡＣＴＩＯＮＳＯＦＭＥＴＡＬＦＩＬＭＳＷＩＴＨＡｌＮＳＵＢＳＴＲＡＴＥＨｅＸｉａｎｇｊｕｎ；ＴａｏＫｕｎ；ＦａｎＹｕｄｉａｎ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｅｒｉａｌｓＳｃｉｅｎｃｅａｎｄＥｎｇｉｎｅｅｒｉｎｇ，Ｔｓｉｎｇｈ...     

Preparation and characterization of GaN films grown on Ga-diffused Si （111） substrates

Hexagonal GaN films were prepared by nitriding Ga2O3 films with flowing ammonia. Ga2O3 films were deposited on Ga-diffused Si (111) substrates by radio frequency (r.f.) magnetron sputtering. This paper have investigated the change of structural properties of GaN films nitrided in NH3 atmosphere at the temperatures of 850, 900, and 950℃ for 15 min and nitrided at the temperature of 900℃ for 10, 15, and 20 rain, respectively. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were used to analyze the structure, surface morphology and composition of synthesized samples. The results reveal that the as-grown films are polycrystalline GaN with hexagonal wurtzite structure and GaN films with the highest crystal quality can be obtained when nitrided at 900℃ for 15 min.     

反应溅射制备AlN薄膜中沉积速率的研究

通过对浅射过程中辉光放电现象及薄膜沉积速率的研究，发现随着氮浓度的增大，靶面上形成一层不稳定的AlN层，由于AlN的溅射速率远小于Al，从而使薄膜的沉积速率显著下降。同时还研究了其它溅射参数对薄膜沉积速率的影响。结果表明：随靶基距的增大靶功率的减小，不同程度引起沉积速率的下降；随着溅射气压的增大，最初沉积速率不断增大，当溅射气压增大到一定程度时，沉积速率达到最大值，之后随溅射气 压的增大，又不断减小。     

氮化硅陶瓷刀具表面涂覆高硬耐磨氮化钛涂层研究

用高能量密度脉冲等离子体于室温下在氮化硅陶瓷刀具上成功沉积了高硬耐磨的氮化钛涂层。薄膜厚度用光学显微镜和俄歇电子能谱仪测定，薄膜元素和相组成与分布分别用俄歇电子能谱仪、X光电子能谱以及X光衍射仪测定，薄膜微观结构用扫描电镜观察，薄膜表面粗糙度用光学显微镜测定，薄膜力学性能由纳米压痕实验和纳米划痕实验确定，薄膜的磨损性能用上业条件下的切削实验评价。实验结果表明，在最优化条件下，涂层与基体的结合力很好，纳米划痕实验临界载荷达80mN以上；氮化钛涂层具有很高的硬度和杨氏模量，分别达28GPa和350GPa以上。涂层刀具用于HB达2200MPa—2300MPa的HT250钢切削实验表明，刀具耐磨损能力增强，寿命明显提高。     

离子束增强沉积Si─N膜

用离子束增强沉积方法制备了ＳｉＮ薄膜，其中Ｓｉ由一束Ａｒ离子从Ｓｉ靶上溅射下来，在溅射沉积的同时，以一束Ｎ离子轰击正在沉积的膜层，于是获得了ＳｉＮ膜。采用卢瑟福背散射、红外光谱和透射电镜对膜层的成分和结构进行了分析，结果表明：膜面平整，膜层为非晶或微晶结构，由Ｓｉ和βＳｉ３Ｎ４组成