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 ((C2H5)3B) and phosphine (PH3) 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.