P-μc-Si1-xGex:H thin film by VHF-PECVD

Abstract:

In this paper,a series of boron doped microcrystalline hydrogenated silicon-germanium(p-μc-Si1-xGex:H)was deposited by very high frequency plasma-enhanced chemical vapor deposition(VHF-PECVD)from SiH4 and GeF4 mixtures.The effect of GeF4concentration on films'composition.structure and electrical properties was studied.The resuIts show tllat with the increase of GeF4 concentration,the Ge fraction x increases.The dark conductivity and crystalline volume fraction increase first,and then decrease.When the GC is 4%,p-μc-Si1-xGex:H matefiai with high conductivity,low activation energy(σ=1.68 S/cm,Eg=0.047 eV),high crystalline volume fraction (60%)and with an average transmission coefficient over the long wave region reaching 0.9 at the thickness of 72 am was achieved.The experimental results were discussed in detail.

Key words:experimental;results;thickness;average;transmission coefficient;long wave;region;activation energy;high;decrease;dark;conductivity;crystalline volume fraction;show;increase;concentration;structure;electrical properties;composition;effect