Al_（0．3）Ga_（0．7）As／GaAs超晶格在高能高温注入下的晶格损伤

用卢瑟福背散射／沟道技术研究了ＩＭｅＶＳｉ￣＋衬底加温注入Ａｌ_（０．３）Ｇａ_（０．７）Ａｓ／ＧａＡｓ超晶格和作为比较的ＧａＡｓ晶体后晶格的损伤积累与注入剂量的关系。实验结果表明，在注入剂量比较小的情况下，两种晶体都只有很轻微的损伤；动态退火过程的存在抑制了晶格损伤的积累。但在较高的注入剂量下，在几乎无损伤的表面下两种晶体中都形成了损伤埋层，且ＧａＡｓ中损伤峰处的损伤程度和损伤峰的宽度都大于Ａｌ_（０．３）Ｇａ_（０．７）Ａｓ／ＧａＡｓ超晶格中的情形，根据级联碰撞理论分析了晶体中的损伤积累过程，并从化学键相对强度差异的角度定性地解释了ＧａＡｓ和Ａｌ_（０．３）Ｇａ_（０．７）Ａｓ／ＧａＡｓ超晶格实验结果的不同。

Investigation of Lattice Damage Induced by High Energy Ions Irradiation at High Substrate Temperature

The dose dependence of damage accumulation in Al0.3Ga0.7As/GaAs superlattices irradiated by 1MeV Si+ at elevated substrate temperature has been investigated using Rutherford backscattering/channeling technique. For a comparison, GaAs is also irradiated at the same experimental conditions. The results show that only a slight damageaccumulationin the range of low doses is observed for the two materials. The damage accumulationis greatly inhibited by dynamic annealing. In the range of higher doses, however,a buried damage layer is formed under the almost undamaged surface for both GaAs and Al0.3Ga0.7As/GaAs superlattices,and the damage extent as well as the width of the damage peak for GaAs are larger than those for the Al0.3Ga0.7As/GaAs superlattices. The process of damage accumulation during the silicon ions implantation is analysed according to cascade collision theory. The differences of chemical bond strength between GaAs and Al0.3Ga0.7As/GaAs superlattices are proposed to be responsible for the differences of experimental results between them.