Metalorganic vapour phase epitaxy of GaN-based structures grown on etched and non-etched Si(115) substrates for piezoelectric component separated devices

Abstract

We propose the application of an Si(115) substrate for the growth of the GaN semi-polar layer, the c-axis of which is inclined by an angle of 40 degrees. The calculations concerning built-in polarization fields in AlGaN/GaN heterostructures of various crystal orientations will be presented, focusing on the separation of piezoelectric and spontaneous components for high electron mobility transistor (HEMT) type structures that are insensitive to the applied stress. Two potential ways of growing semi-polar GaN by means of the metalorganic vapor phase epitaxy (MOVPE) technique will be presented, including etched (patterned) and non-etched Si(115) substrates. The selected optimized etching solution will be presented along with the GaN growth procedure. Scanning electron microscope (SEM) imaging supported by high resolution X-ray diffraction (HRXRD) characterization results of semi-polar GaN will be discussed.