Si外延过程中图形漂移的研究

Research on Pattern Shift in Si Epitaxial Process

给出了图形漂移的定义,综合介绍了埋层外延中图形漂移的监测方法,其中包括常规的磨角染色法和无损伤测量垂直和平行于参考面两个方向上图形线宽的变化比例法。结合不同面上的原子密度的不同,分析各晶向上生长速率的差异,解释了不同晶向上不同的生长速率是造成图形漂移的根本原因。通过比对常压和减压外延的机理,明确了Si源中氯类物质的存在是导致图形漂移的必要条件。结合Si外延过程中对图形漂移的影响因素,分别指出了衬底晶向、淀积时反应室压力、生长速率和生长温度、HCl对Si片表面腐蚀量、Si源等6个参量和图形漂移的关系,并给出了6个参量的优化方向。

The definition of pattern shift was given.The measurement method of pattern shift during buried layer epitaxial process was synthetically introduced,including angular lapping stain method and measuring a ratio between the line width of a linear pattern vertical to the orientation flat and line width of a linear pattern parallel to the orientaiton flat.Combined with the diffe-rence of atomic densities on the different surfaces,the difference of growth rates was analyzed for the different orientations and the root cause of pattern shift was explained as different growth rates of different orientations.The Cl existence in Si source is a necessary condition by comparing the mechanism between the atmosphere and reduced pressure.The relationships of pattern shift and six parameters,such as substrate orientation,chamber pressure at depositing,growth rate,growth temperature,corrosion of Si surface by HCl and Si source,were pointed out and the optimal directions were given.