AlN/sapphire上のAlGaN のMOVPE成長と発光特性

摘要

減圧MOVPE法によりAlN/sapphire基板を下地としたAlGaN膜の成長を，反射光を用いたその場によって成長形態を観測しながら行うことで，さらなる膜の高品質化と膜厚の制御を行った.AlGaNのAl組成は成長温度で制御できる.Al組成を変化させることで対応した発光波長の紫外光を観測した.また得られたサンプルから電子線励起による紫外光源試作管を作製し，評価を行った.界面組成制御，Si-dope，成長条件の最適化により発光強度は飛躍的に向上し，試作管から波長247nmの深紫外光を観測した.%We performed growth of AlGaN on AlN/sapphire substrate as an underlying layer by low-pressure MOVPE with in-situ monitoring system, in order to fabricate a further high-quality and well-thickness controlled film, and controlled the film thickness. The Al content in AlGaN can be controlled by the growth temperature. Ultraviolet light of luminescence with wavelength that corresponded by changing the Al content was observed. Moreover, we fabricate the prototype ultraviolet-light source tube with the AlGaN film as a target for the electronic beam excitation. Luminous intensity was significantly improved by Si-doping, and optimization of the growth condition, and 247 nm deep-ultraviolet light was observed from the tube.