论文部分内容阅读
一、引言S做为GaAs的施主杂质是较轻的元素,容易形成良好的掺杂层。用离子注入技术制备GaAs的n型层,常选S~+做为注入的离子。但S在GaAs中的扩散系数比较大。注入后若采用常规热退火方式,其浓度分布必然要受到热扩散的影响而展宽。而且对化合物半导体而言,还有迂高温发生化学组分偏离以及热转型的问题。近年来,对离于注入后的GaAs采用激光退火的方法,已显示出比热退火好。起步稍晚的电子束退火,同样具有优于热退火的特点。从二者比较来看,在能量转换效率、退火功率的可控性、退火面积及其均匀性等方面,都显示出电子束退火更为优越。
I. INTRODUCTION S as a GaAs donor impurity is a lighter element, easy to form a good doped layer. GaAs n-type layer is prepared by ion implantation technology, S + is often selected as the implanted ions. However, the diffusion coefficient of S in GaAs is relatively large. If using conventional thermal annealing after injection, its concentration distribution will inevitably be affected by thermal diffusion and broaden. And for compound semiconductors, there are problems with chemical composition deviations and thermal transitions at elevated temperatures. In recent years, the method of laser annealing from GaAs after implantation has been shown to be better than thermal annealing. Start later electron beam annealing, also has better thermal annealing characteristics. From the comparison of the two, it shows that electron beam annealing is more superior in energy conversion efficiency, controllability of annealing power, annealing area and its uniformity.