Effect of Graded AlxGa1-xN Interlayer Buffer on the Strain of GaN Grown on Si (111) Using MOCVD Method

Abstract

GaN film grown on Si substrate with AlN/AlxGa1-xN buffer is studied by low pressure metal organic chemical vapor deposition (MOCVD) method. The AlxGa1-xN film with Al composition varying from 0 similar to 0.66 was used. The correlation of the Al composition in the AlxGa1-xN film with the stress of the GaN film grown was studied using high resolution X-ray diffraction including symmetrical and asymmetrical omega/2 theta scans and reciprocal space maps. It is found that with proper design of the Al composition in the AlxGa1-xN buffer layer, crack-free GaN films can be successfully grown on Si (111) substrates using AlN and AlxGa1-xN buffer layers.