Please use this identifier to cite or link to this item:
標題: The Study of Silicon-Surface Damage by Polishing and Related Epitaxial Growth
作者: Hsieh, Ming-Hsiung
關鍵字: silicon wafer
epitaxial growth
出版社: 材料工程學研究所
摘要: Silicon wafers have been extensively used in the microelectronic and semiconductor industry due to their unique properties and plentiful resources. First part of this work studies the effect of surface damage of test wafer by grinding. The other part concentrates at the structural characteristics and purity of epitaxial silicons on the prime or surface-ground wafers, which were prepared by ultrahigh vacuum chemical vapor deposition (UHV-CVD). The lattice strain in the surface-damaged layers was investigated by X-ray diffraction (XRD) and laser scanning techniques. The undoped epitaxial layers were studied using XRD methods. The process of high temperature (900℃) silicon-homoepitaxy was taken in an UHV-CVD reactor ,which consists of an ex situ cleaning and an in situ pre-baking. However, low temperature (550℃) silicon epitaxial growth was achieved on the hydrogen-passivated silicon-surface without using a high temperature in situ baking. Transmission electron microscopy (TEM) was employed to investigate the crystalline qualities of the epitaxial layer and the epi-layer/substrate interface prepared at different temperatures and substrates. The secondary ion mass spectroscopy (SIMS) was performed to investigate the interfacial concentrations of carbon and oxygen. The results of TEM for the sample prepared at 550℃ show the presence of stacking faults, interface, dislocations and rougher surface in the epi-layer. The stacking fault was not observed in the sample polished for three minutes. Nevertheless, all those defects were not observed for the samples prepared by the high temperature process. Chemical purity of the epi-layer was studied using SIMS and Fourier transform infrared spectrometry (FTIR), which indicated lower oxygen and carbon concentrations than those in substrate for the high temperature deposition. For silicon homoepitaxy, the in situ cleaning played a major role in reducing the amounts of surface contaminants and then the quality of epi-layer. High substrate-temperature is advantageous to the high-quality epitaxial growth.
矽晶片由於它們獨特的性質和豐富的來源,被廣泛的應用於微電子和半導體工業。在本實驗中將研究加工研磨對表面損傷之評估和不同基材及長晶條件對超高真空化學氣相沈積磊晶成長的矽薄膜層之結構性質和純度的影響。 研磨損傷層的晶格應變是利用X-光和雷射掃描的技術來評估,未摻雜矽磊晶層則利用X-光繞射來研究。高溫矽磊晶成長的清潔包括有系統外化學清潔和在腔體的系統內預熱清潔,但是低溫磊晶成長則是只有形成氫鈍化保護的系統外清潔而沒有系統內清潔。實驗中使用穿透式電子顯微鏡來研究不同溫度和基材狀況下成長磊晶層之結晶性及磊晶基材之界面。二次離子質譜儀用來研究界面的碳和氧含量。由TEM觀察發現在550℃成長之磊晶層之試片,表面較不平整且有疊差和界面出現,在研磨拋光較短時間的試片則未觀察到疊差。然而,高溫沈積之磊晶層不但沒有發現額外的缺陷和界面而且表面較平整。在二次離子質譜儀和傅立葉轉換紅外線光譜儀的分析指出高溫成長之磊晶層的碳和氧含量有較基材為低的現象。因此對矽磊晶而言,系統內預熱清潔在減低表面污染上扮演了很重要的角色,而高溫磊晶的優點是可得到高結晶品質的磊晶成長。
Appears in Collections:材料科學與工程學系



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.