VHF-PECVD法制备P型微晶硅锗的研究

Study of P-μ_c-Si_(1-x)Ge_x:H thin film prepared by VHF-PECVD

以SiH4和GeF4为反应气体,采用甚高频等离子体增强化学气相沉积(VHF-PECVD)方法制备了P型微晶硅锗(P-μc-Si1-xGex)薄膜。研究GeF4浓度对P型微晶硅锗材料组分、结构及电学特性的影响。随GeF4浓度的增加,薄膜中的锗含量增加,暗电导和晶化率先增加,后减小;在薄膜厚度为72 nm,GeF4浓度为4%时,得到了电导率达1.68 S/cm,激活能为0.047 eV,晶化率为60%,在长波区域的平均透过率超过0.9的P型微晶硅锗。

A series of boron doped microcrystalline hydrogenated silicon- germanium （P-μc-Sil-xGex ： H） was deposited by very high frequency plasma-enhanced chemical vapor deposition（VHF-PECVD） from SiH4 and GeF4 mixtures. The effict of GeF4 concentration on films＇ composition, structure and electrical properties was studied. The results shows that with the increasing of GeF4 concentration,the Ge fraction x increases, The dark conductivity and crystalline volume fraction increases first, then decreases, When the GC; is 4 %, P-μc-Sil-xGex ：H material with high conductivity, Iow activation energy （σ= 1.68 S/cm ,Eg =0, 047 ev） ,high crystalIine volume fraction （60%） and the average transmission coefficient over the Iong wave region reaches 0.9 at the thickness of 72 nm was achieved. The experimental results were discussed in detail.