1MeV Si+衬底加温注入Al0.3Ga0.7As/GaAs超晶格和GaAs的晶格损伤研究

用卢瑟福背散射／沟道技术研究了１ＭｅＶＳｉ⁺在衬底加温和室温下以不同剂量注入Ａｌ_0.3Ｇ_0.7Ａｓ／ＧａＡｓ超晶格和ＧａＡｓ后的晶格损伤。在衬底加温下，观察到Ａｌ_0.3Ｇａ_0.7Ａｓ／ＧａＡｓ超晶格和ＧａＡｓ都存在一个动态退火速率与缺陷产生速率相平衡的剂量范围，以及两种速率失去平衡的临界剂量。超晶格比ＧａＡｓ更难以损伤，并且它的两种速率失去平衡的临界剂量也大于ＧａＡｓ中的相应临界剂量，用热尖峰与碰撞模型解释了晶格损伤积累与注入剂量和衬底温度的关系。用ＣＮＤＯ／２量子化学方法计算了ＧａＡｓ和Ａｌ_xＧａ_1-xＡｓ中化学键的相对强度，并根据计算结果解释了注入过程中Ａｌ_0.3Ｇａ_0.7Ａｓ／ＧａＡｓ超晶格和ＧａＡｓ中晶格损伤程度的差别。 关键词：

STUDIES OF LATTICE DAMAGE CAUSED BY 1MeV Si+ IMPLANTATION INTO Al0.3Ga0.7As/GaAs SUPERLATTICES AND GaAs AT ELEVATED SUBSTRATE TEMPERATURE

Rutherford backscattering/channeling technique has been used to investigate the lattice damage caused by 1MeV Si⁺ implantation into Al_0.3Ga_0.7As/GaAs superlattices and GaAs at elevated substrate temperature and room temperature for different doses. For elevated substrate temperature irradiation, a dose range for balance between defect production and dynamic annealing, and a critical dose for unbalance between them are observed for both Al_0.3Ga_0.7As/GaAs superlattices and GaAs. The superlattices are more difficult to be damaged than GaAs, and the critical dose for the former is also larger than that for the latter. The hot spot and knock-on model is used to interpret the temperature and dose dependence of damage accumulation in the two materials. The ralative bona strength in GaAs and Ａｌ_xＧａ_1-xAs are calculated using CNDO/2 quantum chemistry method to explain the differences of damage accumulation in Al_0.3Ga_0.7As/GaAs superlattices and GaAs.