Study on the growth of crack-free Al_xGa_1-xN (0.133≥x>0.1)/GaN heterostructure With low dislocation density

摘要

ew have investigated the growth of crack-free Al_xGa_1-xN layer (0.133≥>0.1) with low dislocation density using Al_xGa_1-xN/GaN heterostructure. From the wet-etched surfaces and transmission electron microscopy (TEM) images The 2μm underlying Al_xGa_1-xN layer with low AIN molar fraction is effective in preventing the formation of cracks in Al_xGa_1-xN surface. Although the number of defects in the underlying Al_xGa_1-x layer grown on low-temperature GaN buffer are increased by the increase of AIN molar fraction, the use of the highly strained Al_xGa_1-xN/GaN/ Al_xGa_1-xN heterostructure on the underlying layer is effective in reducing the number of defects near the surface. The Possibility of the growth of crack-free Al_xGa_1-xN/GaN heterostructure with low dislocation density by controlling the AIN molar fraction and the misfit strain value is presented.