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

摘要

GaN film grown on Si substrate with AlN/Al_xGa_(1-x)N buffer is studied by low pressure metal organic chemical vapor deposition (MOCVD) method. The Al_xGa_(1-x)N film with Al composition varying from 0～ 0.66 was used. The correlation of the Al composition in the Al_xGa_(1-x)N film with the stress of the GaN film grown was studied using high resolution X-ray diffraction including symmetrical and asymmetrical ω/2θscans and reciprocal space maps. It is found that with proper design of the Al composition in the Al_xGa_(1-x)N buffer layer, crack-free GaN films can be successfully grown on Si (111) substrates using A1N and Al_xGa_(1-x)N buffer layers.