Activated nitrogens in ECR-plasma and its effects on growth of cubic GaN

Summary form only given. Recently, the market for short wavelength laser diodes attracts many groups to focus on growing the GaN system material. However growing of GaN on GaAs substrates and processing of the devices concerned have to be carried out under the low temperature conditions of less than 800/spl deg/ C. So it´s necessary to provide a highly activated nitrogen source for PA-MOCVD. By use of a homemade cavity-coupling ECR plasma generator-MEP to deliver activated nitrogens, excellent cubic GaN epilayers have been grown on [001]GaAs under low temperature(/spl sim/600 degree) and low pressure (/spl sim/1 Pa) by ECR-PAMOCVD. The experiment results showed that the initial nitridation of GaAs substrates and the growth of buffer layer are very important for the combination of the interface and the crystal quality of GaN. So one of the most important growth parameters is the chemical species in the nitrogen plasma,especially nitrogen radicals. The optical emission spectra of nitrogen plasma in MEP were investigated as functions of the operating pressure Po (or N/sub 2/ gas flow rate) and microwave power Pw. It was found that the quantity of nitrogen radicals were increased with Po and Pw, and the MEP plasma generator was a good candidate for growing cubic GaN.