The Application of a Low Temperature GaN Buffer Layer to Thick GaN Film Growth on ZnO/Si Substrate

Abstract

The effect of a low temperature GaN (LT-GaN) buffer layer on the properties of thick GaN grown on Si substrate by hydride vapor phase epitaxy (HVPE) was investigated to obtain thick GaN films of high quality. ZnO was deposited by sputtering as the first buffer layer. LT-GaN buffer layers were grown for 2 to 7 min at 600 °C. The optimization of the LT-GaN buffer layer was done using low temperature PL, AFM and XRD analysis. A Zn-related impurity peak was observed in PL spectra of LT-GaN/ZnO/Si. A strong orientation along (0002) was observed in thick GaN/LT-GaN/ZnO/Si. A red shift in PL spectra of thick GaN due to the strain was found. The LT-GaN buffer improved the crystalline and optical properties of thick GaN grown on Si substrate.