Crystal microstructure of PbTe/Si and PbTe/SiO2/Si thin films

A modified 'hot wall' technique (HWE) is used for growth of PbTe thin films directly on Si(100) high ohmic substrates both with and without any buffer layers. The previously formed SiO2 films have been used as buffer layers. The crystal microstructure of PbTe thin films has been studied by an etchin g pits method, SEM, RHEED and by X-ray analysis which is able to determine the X-ray rocking curve profiles and line width with high precision.. It ha s been found that these PbTe/Si and PbTe/SiO2/Si thin films have mosaic sin gle crystal structure with (100) texture without regard to the Si substrate orientation. The investigations of PbTe/Si thin films dislocation density by the etching pits method and by the analysis of X-ray reflection profiles show the average values of about 10(5)-10(7) cm(-2). The experimental resu lts of these methods have shown that PbTe/SiO2/Si thin firms had better cry stallinity perfection. The average values of dislocation density were about 5 x 10(4)-2 x 10(5) cm(-2). (C) 1998 Elsevier Science S.A. All rights rese rved.