重掺硼快速退火分子束外延硅的X射线衍射研究

X-RAY DIFFRACTION STUDY OF HEAVILY BORONDOPED Si EPILAYER AFTER RAPIDTHERMAL ANNEALING

利用X射线双晶衍射,测量了经过800—1100℃快速退火处理的重掺硼的分子束外延硅中的应变情况,发现应变部分弛豫.并得出外延层与衬底硅的晶格失配与替位硼浓度(7.5×10^(29)—3.1×10^(20)cm^(-3)成正比,比例系数β为5.1.在此测量基础上,提出硼团簇的形成与分解是外延展晶格质量与电学性质变化的主要原因.

The strain of the MBE grown silicon layer doped with boron is measured by X-ray double crystal diffraction after rapid thermal annealing at 800-1100°C. It is found that the strain is partially relaxed. The lattice mismatch between the epila-yer and silicon substrate is proportional to the substitutional boron concentration (7.5×1019-3.1×1020cm-3). and the coefficient β is 5.1. Based on these results, we suggest that the generation and activation of boron clusters is the main cause of the change in lattice quality and the electrical properties of the epilayer.