Crystalline properties of BP epitaxially grown on Si substrates using B 2H 6-PH 3-H 2 system

Abstract

Boron monophosphide (BP) was epitaxially grown on Si substrates with (100) face and slightly off-oriented (100) faces by the thermal decomposition of a diborane and phosphine mixture in a hydrogen atmosphere. In the early growth layer of BP, characteristic crystalline imperfections such as {211} and {111} twinnings and {111} planar defects were present. The generation of {211} twinnings depended on the substrate off-orientation. The optimum orientation for minimizing the imperfections was a 2° off-oriented (100) face in the direction of a (110) plane. The twinnings and other defects were found to be contained within a thickness of several hundred angstroms. In spite of the existence of defects in the early growth layer, moiré diffraction patterns and fringes from the BP-Si double layers were observed. Removal of the imperfect layer by etching resulted in BP films with a high crystalline perfection.