電漿輔助化學氣相沉積之矽鍺薄膜再結晶處理以及材料特性研究

Abstract

經由平視野穿透式電子顯微鏡之檢視，我們求得再結晶後矽鍺薄膜結晶方 位以及晶格常數。晶粒大小與退火時間之關係告知我們晶粒成長的主要原 動力乃是晶粒內之界面能。薄膜內之晶粒成長過程主要為矽與鍺原子經由 晶粒邊界擴散而使晶粒成長。薄膜內雜質顯現出對晶粒成長的遲緩效應。 此外，晶粒成長與沉積溫度及退火溫度亦詳細地被討論。高濃度BF2 離子 佈植造成薄膜退化狀態以及矽及鍺原子擴散係數增強，使得晶粒成長較為 快速而得到較大的晶粒。非晶矽鍺氫化合金，當含有小莫爾鍺含量時，將 強烈增強非晶矽鍺薄膜電晶體P 型通道導電特性。而其N 型通道導電特性 則較之非晶矽薄膜電晶體並不會遜色太多。因此非晶矽鍺薄膜電晶體可使 得CMOS應用先天上的障礙得到解決之道。 With plane-view transmission electron microscope(TEM) inves- tigation，the crystalline orientation and lattice constantrecrystallized amorphous SiGe:H film are determined. The results of relationship between grain size and annealingtime inform us that the main driving force of the grainis the interface energy in the grains. The primarygrain growth is the diffusion of Si and Ge atomsgrain boundaries. Impurities existing in the filmeffect on grain growth. By the waytween grain growth, deposition temperature andrature are also discussed in detail. By heavy BF2 doping, the SiGe film become degenerate stateand the diffusion coefficients of Si and Ge atoms are muchced. The grain growth is more rapid and grain size isced. The amorphous SiGe:H film, with small Ge mole fraction, canstrongly enhance the P-channel conductance of amorphousTFT. Its N-channel conductance doesn't deteriorate verythe obstacle of CMOS application can be carried out amorphous SiGe:H TFT with small Ge incorporation.