Grwoth of (1 1 1)-oriented PbTe thin films on vicinal Si(1 1 1) and on Si(1 0 0) using fluoride buffers

摘要

High-quality PbTe films have been grown on vicinal Si(1 1 1) using both sacked BaFe_2-CaF_2 buffers and single BaF_2 laeyrs deposited directly on Si by the two-step growth method. Unlike on exactly oriented Si(1 1 1), the surface morphoogy of PbTe grown on vicinal Si(1 1 1) was undulated ue to bunched steps on the BaF_2 surface. The BaF_2 buffer laerys and the PbTe films grown on Si(1 0 0) consists of domains rotated by 90 deg C and 180 deg C around the normal to the surface, with the (1 1 1) BaF_2 and the (1 1 1) PbTe planes paralel to the (1 0 0) Si plane. Although the PbTe films grownj on Si(1 0 0) have domain structures, the mobility of carriers at 300 K is the same as in PbTe films grown on Si(1 1 1) and these heterostructures are capable of reliving the thermal mismatch strain.