Gallium Nitride Epitaxial Growth on Aluminum Nitride Substrates

This program will develop a process for growth of low defect density GaN epitaxial layer on aluminum nitride substrates. Utilizing a novel high rate material transfer process, thick, low defect density, free-standing AlN substrates will be fabricated byKyma Technologies. The nitride MOVPE growth process will be employed to grow gallium nitride epitaxial layers on this substrate material. The AlN substrate has structural and thermal properties that will improve gallium nitride (GaN) and AlGaN layers inthe device structure. This will allow the production of low defect density thin films. This project will utilize parallel efforts of materials development, device fabrication and characterization. The initial focus in this program will be thedevelopment of simple p-n optoelectronic devices operating in the important wavelength range of < 450 nm, where the greatest interest for commercial and military based applications exists. The accomplishment of low-dislocation-density GaN material willincrease lifetime and brightness in optoelectronic devices. These improvements should improve the commercialization of the devices in many markets.Gallium nitride thin films are the building blocks for many commercial devices. Low defect density galliumnitride films will benefit many microelectronic and optoelectronic devices. This could lead to the commercialization of blue lasers in data storage and solid state white LED lighting. Heteroepitaxial growth of gallium nitride on single crystal aluminumnitride substrates will result in improved device performance such as increased lifetime and brightness in optoelectronics and increase power and frequency in microelectronic devices.