Si_(1-x-y)Ge_xC_y的淀积工艺和材料特性

Deposition Process and Material Characteristic of Si_(1-x-y)Ge_xC_y

研究了利用减压外延的方法制备Si1-x-yGexCy薄膜的特性及与工艺参数之间的关系,给出了改善表面粗糙度、减少有源区关键尺寸(CD)减少量的方法。在单晶硅、图形硅片α-Si和光片α-Si表面Si1-x-yGexCy上淀积的Si1-x-yGexCy薄膜的表面形貌不同,在单晶硅上成长的是单晶态的Si1-x-yGexCy,在除单晶硅之外的材料上成长的都是多晶态的Si1-x-yGexCy,多晶态Si1-x-yGexCy的淀积速率高于单晶态Si1-x-yGexCy的淀积速率。多晶态Si1-x-yGexCy的淀积速率高于单晶态Si1-x-yGexCy的淀积速率,造成了淀积工艺完成后有源区CD的减少。利用低温淀积工艺和控制浅沟槽隔离(STI)凹陷的深度,可以有效减少由于淀积Si1-x-yGexCy薄膜造成的有源区CD减少量。同时,研究了碳组分对硼扩散的抑制作用,碳组分越高,对硼扩散的抑制作用越大。

Deposition process and material characteristic of Si1-x-yGexCy by low pressure epitaxial growth were studied. The dependence of material characteristic and substrate materials were also studied. The method to improve surface roughness and mitigate critical dimersion （CD） loss of active area was suggested. Si, _~_yG%Cydeposited on single crystal silicon isof single crystal status, and Si1-x-yGexCy deposited on other materials except single crystal silicon is of polysilicon status. Deposition ratio of polysilicon Si1-x-yGexCy is higher than that of single crystalSi1-x-yGexCy, therefore, active area is lost after Si, deposition. The amount of loss can be mitigated by taking low temperature deposition process and by controlling shallow trench isolation （STI） divot height. The impact of carbon concentration to boron diffusion was also studied, the higher the carbon concentration, the less the boron diffusion was observed.