摘要
作者首次用Ｘ射线双晶衍射技术对注入Ａｓ＋的Ｓｉ０．５７Ｇｅ０．４３合金的晶格损伤消除和应变弛豫进行了研究，并与未注入ＡＳ＋的Ｓｉ０．５７Ｇｅ０．４３合金的应变弛豫进行了比较．结果表明，退火后，注入ＡＳ_的Ｓｉ１－ｘＧｅｘ外延层中的应变分布不同于未注入ＡＳ＋的应变分布．对于未注入Ａｓ＋的Ｓｉ０．５７Ｇｅ０．４３样品，其Ｘ射线衍射峰的半宽度ＦＷＨＭ由于退火引起应变弛豫导致镶嵌结构的产生而展宽．对于注入Ａｓ＋的Ｓｉ０．５７Ｇｅ０．４３样品，９５０℃的快速退火过程可以有效地消除晶格损伤，使晶格得以恢复，且其退火后的Ｘ射线衍射峰的半宽度比未注入Ａｓ＋的Ｓｉ０．５７Ｇｅ０．４３样品的半宽度窄，甚至比部分弛豫的原生样品的半宽度窄．这可能是退火后一部分Ｇｅ的晶格位置被Ａｓ原子占据，导致晶格体积收缩，应变弛豫，因而失配位错密度低的缘故．
Abstract We report the first study of strain relaxation in As+ implanted Si0.57Ge0.43 epilayers, and compare strain relaxation in As+ implanted Si0.57Ge0.43 epilayers to that in non-implanted Si0.57Ge0.43 epilayers using X-ray double crystal diffractometry (DCXRD). Experimental results show that after rapid thermal annealing (RTA) the full width at half maximum (FWHM) of X--ray peak of As+ implanted Si0.57Ge0.43 epilayers is narrower than that of non-implanted epilayers, and even than that of the partially relaxed as-grown samples.This may be due to low densities of misfit dislocations which originate from that a portion of As atoms are incorporated into the Ge lattice site along with the host atoms after RTA,so that lattice contracts and strain relaxes in Si1-xGex epilayers, and the broadening of Xray peak of non-implanted Si0.57Ge0.43 epilayers is due primarily to mosaic structure from misfit dislocations generated by the relaxation. The results show that the RTA process athigher than 950℃ can result in complete removal of irradiation damage from As+ implanted Si1-xGex samples.
基金
国家自然科学基金
