Organometallic Chemical Vapor Deposition Growth of Heterostructure of Wide Band Gap and Transparent Boron Phosphide on Silicon

Abstract

A boron phosphide (BP) layer was grown on the (111) Si substrate by atmospheric pressure organometallic chemical vapor deposition (MOCVD) using triethylboran ((C 2 H 5 ) 3 B) and phosphine (PH 3 ) sources. By transmission electron diffraction analysis, the transparent BP layer was found to grow on (111) Si with the following orientation: (111),<110>-Si//(111),<110>-BP. The MOCVD-grown BP layers exhibited transparency under fluorescent light illumination. Reflected light color was observed to vary depending on the thickness of the BP layer. The refractive index ( n ) of the heteroepitaxial (111) BP layer was revealed to decrease from 3.16 at a wavelength (λ) of 350 nm to 2.77 at λ of 750 nm. The extinction coefficient ( k ) corresponding to n at λ of 350 nm was 0.19. Refractive index ( n ) and k at λ of 350 nm gave 9.95 as the real part of the complex dielectric constant of the MOCVD-grown BP layer. The optical evaluation indicated that BP is applicable as a transparent III-V semiconductor layer for forming heteroepitaxial structures with Si.