以電漿表面氮化處理及碳離子佈植技術降低淺接面EOR缺陷之研究

Abstract

經鍺離子非晶化佈植後之矽單晶片退火後會產生EOR缺陷(End-of- Range Defects)分佈於非晶層和結晶層界面處，EOR缺陷通常為格隙型差 排環(Interstitial Dislocation Loop)。本實驗以微波電漿表面處理在 矽表面上形成氮化矽層以探討其消除EOR缺陷之效應，結果顯示氮化矽可 提供空孔擴散的來源而降低EOR差排環之數目及大小。 本實驗另一部份為研究碳離子佈植以降低硼的增益擴散(Enhanced Diffusion)所致的影響。在退火後，矽非晶層固相磊晶成長時所形成之 EOR缺陷可由碳離子佈植來消除，但本實驗亦觀察到退火後有髮夾狀差排 出現。結果顯示，髮夾狀差排的出現與碳離子佈植的能量有關，當碳離子 佈植之Rp(Projected Range)與鍺非晶層/結晶層位置愈接近時，髮夾狀差 排出現的機率愈高。 The end-of-range (EOR) defects were obserced in germanium implantated Si single crystal wafer after thermal annealing. Most of the EOR defects were found to be dislocation loops of interstitial type confined to amorphous-crystalline interface. In this work, we studied the effect of plasma surface nitridation to reduce the EOR defects. Experimental resultsindicated that the Si nitride layer was able to serve as a vacancy source which, in turn, effectively reduced the size and number of the EOR dislocation loops. Another part of this work is to study the effect of carbon implantation to reduce the transient diffusion (TED) of implanted boron. It was foundthat the carbon implantation could effectively remove the EOR defects. However, hair-pin dislocations were also observed after annealing. Thehair-pin dislocations were most likely formed when the projected range (Rp) of carbon implantation was located in the vicinity of the amorphous/crystalline (a/c) interface created by Ge implantation.