1.55MeV^3He离子辐照单晶Si引起的损伤效应研究

Damage production in silicon induced by 1.55 MeV^3He ion implantation

室温下使用1.55 MeV、5×1015×1016/cm2注量的3He离子注入单晶Si,采用透射电子显微镜(TEM)观测分析了高温退火后单晶Si中由注入引起的损伤形貌,同时使用核反应分析(NRA)技术研究了3He气体原子的热解吸。结果显示,低注量3He离子注入在Si中产生的缺陷主要为一些小尺寸的位错或位错环;在中等照射剂量,退火导致了气泡和气泡团簇的形成并伴随着高密度的位错环从这些气泡团簇中发射出来;而对于较高的照射剂量,3He离子注入加上随后的高温退火则在离子射程附近产生了一个具有确定边界的空腔带。结合NRA结果对实验现象进行了分析。

Crystalline silicon samples were implanted at room temperature with 1.55MeV 3He ions at different doses ranging from 5 × 1015 to 5 × 1016 /cm2. Damage production after subsequent high temperature annealing was studied by using cross-sectional transmission electron microscopy (XTEM). Meanwhile, nuclear reaction analysis (NRA) was used to study the behavior of 3He desorption from the implanted samples. Our results show that at low dose range, the He implantation followed by high temperature annealing only induces the creation of small dislocations, and at intermediate dose range, clusters of bubbles accompanied with high density of dislocation loops were observed, while for the higher implanted dose, a well defined cavity band was formed at the depth corresponding to the projected 3He range. The phenomena were discussed in combination with NRA results.