Co、Ti／Si_（1－x）Ge_x薄膜快速退火固相反应结构和组分研究

Co、 Ti/Si_(1-x)Ge_x Thin Film Solid State Reaction Using Rapid Thermal Annealing: Structure and Composition Properties

本文首次研究金属Ｃｏ与分子束外延Ｓｉ１－ｘＧｅｘ单晶薄膜快速热退火（ＲＴＡ）固相反应，并对比了ＣＯ、Ｔｉ与ＳｉＧｅ固相反应时不同的反应规律实验采用ＲＢＳ、ＡＥＳ、ＸＲＤ、ＳＥＭ等分析和测试手段对样品的组分和结构等薄膜特性进行检测．实验发现，Ｃｏ／Ｓｉ０．８Ｇｅ０，２在６５０℃热退火后形成组分为Ｃｏ（Ｓｉ０，９Ｇｅ０．１）的立方晶系结构，薄膜具有强烈择优取向；９００℃处理温度，有ＣｏＳｉ２形成，同时Ｇｅ明显地向表面分凝．ＴｉＮ／Ｔｉ／Ｓｉ０．８Ｇｅ０．２固相反应时，８５０℃处理可以形成Ｔｉ（Ｓｉ１－ｙＧｅｙ）；三元结构，并以（００４）晶面为择优取向。薄膜均匀平整，电阻率达到ＴＩＳｉ２最低值范围，高温处理未发生组分分凝．从生成物的晶体结构和形成热差异上对实验结果进行了分析．

Abstract The solid state reaction of Co with Si1-xGe. crystalline film is investigated using rapid thermal annealing for the first time, and is compared with the solid state reaction of Ti with SiGe. The SiGe films were grown by molecular beam epitaxy. The composition and structure were characterized by RBS, AES, XRD and SEM. It is found that after a rapid thermal annealing at 650℃ for 1 minute, a single phase of Co (Si0.9Ge0.1) with a cubic structure is formed. A strong preferential orientation is observed in the formed thin film. After annealing of 900℃, CoSi2,is formed with the segregation of Ge toward the surface region. In the case of TiN/Ti/SiGe, the ternary phase Ti(Si1-yGey)2 is formed at the temperature of 850℃. The preferential orientation of the film is (004). The film has a smoother surface and the resulted resistivity reached the lowest value of TiSi2. No phase separation occur ed in the film during the high temperature annealing. The results can be explained by the difference in crystalline structure and heat of formation between Co/SiGe and Ti/SiGe.