【摘要】 采用催化化学气相沉积法(Cat-CVD)制备多晶硅(p-Si)薄膜的初期会形成一层比较厚的非晶硅(a-Si)孕育层。这层孕育层作为p-Si的前驱生长物,给p-Si的晶化提供晶核,同时这层薄膜又存在较多的缺陷,严重影响了p-Si器件的性能。文章采用p-Si的间断生长,对预先沉积的a-Si孕育层进行数分钟的氢原子刻蚀,目的是刻蚀掉有严重缺陷的Si—Si键,保留与晶体硅匹配的Si—Si键,促进晶核形成,抑制孕育层的再生长。经XRD和SEM测试发现,间断p-Si的生长,经若干分钟的H原子处理后多晶硅很快就形成,结晶取向在(111)面上最强,晶粒尺寸平均为80nm。而传统方法连续生长20min的硅薄膜经XRD测试未出现多晶硅特征峰。结果表明,用Cat-CVD制备p-Si薄膜,间断生长过程,用氢原子处理预先沉积的一层a-Si孕育层,可以抑制孕育层的生长,提高了p-Si薄膜的晶化速率。更多还原

【Abstract】 Polysilicon thin films are deposited by catalytic chemical vapor deposition method.The substrate temperature is 300℃ and catalytic hot wire is tungsten filament.In initial stages of the film formed,an amorphous incubation layer is formed.The amorphous incubation layer is precursor of polysilicon forming and provides nucleus for crystal.But the amorphous incubation layer has more defects and affects the characteristic of polysilicon device seriously.This article interrupts the deposition process and etches the amorphous incubation layer which is deposited beforehand with H atoms for several minutes in order to get rid of the Si—Si bonds with serious defects,keep the Si—Si bonds that are match for the crystal silicon and promote the formation of nucleus,restrict the amorphous incubation layer to grow again.By XRD and SEM testing,the characteristic peak of polysilicon is found in the(111)direction and the grain size of the film is 80 nm averagely.Whereas the film that is deposited uninterruptedly for 20 min by accustomed deposition method is not found the characteristic peak of polysilicon in XRD spectrum.It is obvious that the growing of the amorphous incubation layer can be restricted and the crystal rate of the p-Si film can be promoted by the interrupted deposition of p-Si with H atoms etching the amorphous incubation layer deposited beforehand in the Cat-CVD method.更多还原