Growth of high quality gan on si (111) substrate by using two-step growth method for vertical power devices application

Abstract

A crack-free GaN film grown on 4-inch Si (111) substrate is proposed using two-step growth methods simply controlled by both III/V ratio and pressure. Two-step growth process is found to be effective in compensating the strong tensile stress in the GaN layer grown on Si substrate. The high-resolution X-ray diffraction (XRD) rocking curves of (002) and (102) planes for the GaN epitaxial layer with two-step growth method are 317 and 432 arcsec, while the corresponding values for the reference sample without two-step growth method are 550 and 1207 arcsec, respectively. The reduced threading dislocation of GaN film with two-step growth method is obtained to be ~2 × 108/cm2, which is attributed to effectively annihilate and bend threading dislocation.