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一、引言 报导C·Z法和F·Z法生长无位错Si单晶的早期作者,都未报导过外形表征,如鼓棱(ridge-like bulges)。后来,国内外有关文献虽然也叙述了外形特征和现象,但对于结晶过程的微观机理都未讨论过。到了七十年代,西泽润一寺崎健等人对Si(111)原子排列优先方向的讨论,和T.F.Ciszek对F.Z晶体鼓棱的分析,才初步对微观机理问题有了一些认识。国内,近年来对此问题也有些看法,认为鼓棱是倾斜的(111)小平面的生长、合适的应力作用等等。迄今为止,国内外对此问题并无文献系统地分析和总结,同时在实际工作中又出现许多现象,用现有文献的分析结论是无法解释的。例如,无位错Si单晶有时无鼓棱、有时鼓棱处又呈晶带状、有时晶体呈蛇形,而且有时鼓棱有一条、两条或三条,甚至有六条之多。以上这些现象,仅用目前的观点对(111)上Si原子排列结晶动力学的特性是无法解释的。本文则是考虑〔111〕生长对(111)上各晶向Si
I. INTRODUCTION None of the earlier authors of the C.Z. and F.Z. method of growing dislocated Si monocrystals reported the appearance of features such as ridge-like bulges. Later, although the relevant literature at home and abroad also described the appearance features and phenomena, the microscopic mechanism of the crystallization process has not been discussed. By the seventies, the discussions on the preferential orientation of Si (111) atoms and the analysis of F.F.Ciszek’s drumming of F.Z crystals gave some insight into the microscopic mechanism problems. In China, there have also been some opinions on this issue in recent years, believing that the growth of the tilted (111) facet, proper stressing, and the like are considered. So far, there is no systematic and systematic analysis and summary of this issue both at home and abroad. At the same time, many phenomena appear again in actual work. The conclusions drawn from the existing literature can not be explained. For example, dislocation-free Si single crystals are sometimes not drummed, sometimes drum-shaped and band-shaped, and sometimes the crystal is serpentine, and sometimes one, two or three drums, or even six. All of these phenomena can not be explained by the present viewpoint of the character of the kinetics of Si atom alignment on (111). In this paper, we take into account the growth of [111] to (111) each orientation Si