矽單晶轉移薄膜層表面埃級平滑化之研究

An Angstrom-Scale Surface Smooth Technology for Transferred Single-Crystal Silicon Thin Film Layers

蘇雅惠(Ya-hui Su)

指導教授 ： 李天錫

國立中央大學/工學院/機械工程學系/碩士(2007年)

摘要

為製作單晶矽層具有奈米等級的SOI材料，利用氫離子聚合為基礎的單晶矽層之薄膜轉移法已被普遍應用，但由於矽單晶薄膜於轉移之後，會在其轉移層上方形成一層粉碎層，因此通常於製程後需要再多一道化學機械研磨(CMP)的拋光步驟來將此粉碎層移除。而本研究目的主要在於利用蝕刻的方式，藉由特定之蝕刻液，於特定溫度下，將以智切法轉移後之SOI薄膜表層的粉碎層去除，同時達到表面平滑的效果，避免掉CMP程序，以簡化製程。研究中成功的以多晶矽犧牲層的沉積來改善氫離子佈植時通道效應的發生，減緩氫離子植入時穿透進矽基板的深度差，使得剝離後之SOI薄膜的表面粗糙度獲得初步地改善。之後藉由蝕刻將粉碎層移除，使得表面粗糙度更進一步地降低，以此兩個階段完成矽單晶轉移薄膜層的表面平滑化。

關鍵字

矽單晶 ； 蝕刻 ； 薄膜轉移 ； 表面平滑

並列摘要

The technique of single-crystal Si layer transfer based on using Hydrogen ion implantation has been widely applied in the fabrication of SOI materials possessing nano-scale device layer with single-crystal quality. However, after Si layer transfer process, a lattice-defect region was formed near the surface of transferred Si layer. Therefore, this unwanted region usually needs an extra chemical mechanical polishing (CMP) process to remove it. The main purpose of this study is to avoid the above polishing process as well as simplify the manufacturing processes. In this study, the removal of lattice-defect region generated after layer transfer by Smart-cut® method used etching approach with specific etchants to etch out it at specific temperature. This etching process could also result in surface smooth of the Si transferred layer. Besides, depositing a polysilicon layer as a sacrificial layer has successfully improved the occurrence of channel effect during ion implantation process and then reduced the difference of ion penetration depth to initially modify the surface roughness of the as-split SOI thin film. The surface roughness could be further decreased after using etching approach to remove the lattice-defect region. The above two steps can make the final surface of the transferred single-crystal Si layer smooth and uniform.

並列關鍵字

SOI ； Surface Smooth ； Layer Transfer ； etching

參考文獻

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