MOCVD growth of high quality crack-free GaN on Si(III) substrates

High quality crack free GaN epilayers were grown on Si(111) substrates. Low temperature AlN interlayer grown under low V/III ratio was used to effectively eliminate the formation of micro-cracks. It is found that tensile stress in the GaN epilayer decreases as the N/Al ratio decreases used for AlN interlayer growth. The high optical and structural qualities of the GaN/Si samples were characterized by RBS, PL and XRD measurements. The RT-PL FWHM of the band edge emission is only 39.5meV The XRD FWHM of the GaN/Si sample is 8.2arcmin, which is among the best values ever reported.

Characterization of GaSb substrate wafers for MOCVD III-V antimonides

The qualities of GaSb substrates commonly used for the preparation of III-V antimonide epilayers were studied before and after growing GaInAsSb multi-layers by MOCVD using PL, FTIR and DCXD together with the electrical properties and EPD value. The correlation between the substrate qualities and epilayer properties was briefly discussed. The good property epilayers of GaInAsSb and, then, the high preformance of 2.3 um photodetectors were achieved only using the good quality GaSb wafers as the substrates.