Metalorganic chemical vapor deposition of silver thin films for future interconnects by direct liquid injection system

Deposition of Ag films by direct liquid injection-metal organic chemical vapor deposition (DLI-MOCVD) was chosen because this preparation method allows precise control of precursor flow and prevents early decomposition of the precursor as compared to the bubbler-delivery. Silver(I)-2,2-dimethyl-6,6,7,7,8,8,8-heptafluoro-3,5-octanedionato-triethylphosphine [Ag(fod)(PEt₃)] as the precursor for Ag CVD was studied, which is liquid at 30 °C. Ag films were grown on different substrates of SiO₂/Si and TiN/Si. Argon and nitrogen/hydrogen carrier gas was used in a cold wall reactor at a pressure of 50–500 Pa with deposition temperature ranging between 220 °C and 350 °C. Ag films deposited on a TiN/Si diffusion barrier layer have favorable properties over films deposited on SiO₂/Si substrate. At lower temperature (220 °C), film growth is essentially reaction-limited on SiO₂ substrate. Significant dependence of the surface morphology on the deposition conditions exists in our experiments. According to XPS analysis pure Ag films are deposited by DLI-MOCVD at 250 °C by using argon as carrier gas.     

Barrier layer effect of tantalum on the electromigration in sputtered copper films on hydrogen silsesguioxane and SiO2

As IC devices scale down to the submicron level, the resistance-capacitance (RC) time delays are the limitation to circuit speed. A solution is to use low dielectric constant materials and low resistivity materials. In this work, the influence of underlying barrier Ta on the electromigration (EM) of Cu on hydrogen silsesquioxane (HSQ) and SiO₂ substrates was investigated. The presence of a Ta barrier not only improves the adhesion between Cu and dielectrics, but also enhances the crystallinity of Cu film and improves the Cu electromigration resistance. The activation energy obtained suggests a grain boundary migration mechanism and the current exponent calculated indicates the Joule heating effect.     

钨金属化与氧化铝陶瓷高温共烧

阐述了钨金属化与氧化铝陶瓷高温共烧工艺的特点,分析了烧结过程中温度曲线和露点等工艺参数对钨金属化与瓷件结合强度、密封气密性和收缩率的影响。通过反复的试验和烧结机理分析对比,给出了最佳的控制参数。     

激光冲击诱发相变的实验研究

本对激光冲击是否可以诱发相变进行了试验研究。用功率密度为１．０６×１０＾８Ｗ／ｃｍ＾２的激光器冲击Ｔ８钢表面。实验结果表明激光冲击处理使Ｔ８钢的表面显微硬度有所提高并可以发生马氏体相变。冲击处理后材料表面硬度提高了两倍，认为相变是Ｔ８钢表面硬度提高的原因之一。     

New antenna design approach – 3D polymer printing and metallization. experimental test at 14–18 GHz

This paper proves a new approach for rapid prototyping of radio antennas through 3D printing and chemical metallization. For this purpose, a standard metal pyramidal horn prototype is compared with its 3D printed replica. Three different 3D polymer printers are tested. The printed samples are assessed nondestructively by an X-ray Industrial Computed Tomography (CT) scanner, and then metalized via chemical deposition and chemical-electrochemical deposition. Copper with two different layer thicknesses and nickel materials are deployed and verified as a metallization opportunity. Again the CT scanner, X-ray fluorescent analysis and nanoindentation technique were used to perform the metallization quality estimation. As a result, a qualitative polymer prototype was produced having weight of 13 g – ten times lighter than the original. The prototype was successfully metalized and was able to be soldered. The radio-measurement comparison with the metal original for frequencies 14–18 GHz showed no significant differences. Finally, a simple dynamometric test confirmed the bonding between the metal and the polymer. To the best of our knowledge this is the first known comprehensive analysis of the possibility to print 3D lightweight wideband polymer antenna prototypes with a stable chemical metallization and radio properties very close to the original at 14–18 GHz.     

高速脊波导激光器寄生电容的分析

高速调制半导体激光器光源是光纤通信系统、相控阵雷达等的关键器件。高速激光器的寄生电容是影响其调制带宽的因素之一。为了减小寄生电容,针对脊波导结构激光器的电容,采用计算机模拟与实际测试相结合的方法,进行了理论分析和实验验证。结果表明,其寄生电容大小不仅与电极金属化面积有关,还与隔离沟的腐蚀深度有关。当腐蚀至波导层时,寄生电容减小到10pF以下。这一结论对实现激光器的高速调制是非常有意义的。     

The effect of composition on the barrier height and contact resistance of Tixw1-x/si contacts

Barrier height is an important parameter for metal/silicon rectifying contacts. In this paper the barrier heights of Ti_xW{1-x}/Si contacts have been studied and found to range from 0.54 eV for high Ti content to 0.66 eV for pureW. Interpretation is made in terms of the parallel Schottky diode model of Tu. Ohmic contact measurements of Ti_xW_1-x/ Si metallization after heat treatment at 500° C have also been made and specific contact resistances of less than 10⁻⁶ ohm-cm² obtained in shallow implanted junction devices.     

The effect of Ti:W barrier metal on characteristics of palladium-silicide Schottky barrier diodes

The values of diode-quality factor and reverse-current leakage of Au/Pd/Ti:W/Pd₂Si/nSi unguarded Schottky barrier diodes are much higher than expected from silicide/silicon junction-radius induced highfield effects. Experimental Ti-, W-, and Ti:W-MIS structures were built and tested to show that Ti is responsible for the formation of a parasitic Ti-MIS structure around the unguarded-diode perimeter. This parasitic structure is responsible for excessive current leakage and also for an additional unguarded-diode degradation induced by annealing at 400 °C.     

超大规模集成电路的一些材料物理问题（I）——Cu互连和金属化

21世纪初，超大规模集成电路（ULSI）的特征尺寸将由150nm逐代缩至50nm。文章以100nmULSI器件为主，简要介绍与互连相关的一些材料物理问题，其中包括Cu互连、金属化及低介电常数介质。