The growth of N-face GaN by MOCVD: effect of Mg, Si, and In

The MOCVD growth of N-face GaN on Ga-face GaN has been investigated using excess Mg to produce inversion of the polar axis. Characterization of the inverted material by AFM, TEM, optical microscopy and chemo-mechanical polishing indicates complete inversion and the ability to grow N-face films. Growth of N-face GaN is accompanied by higher oxygen incorporation as well as higher background electron concentrations than growth of the Ga-face material under similar conditions. Silicon can be incorporated during the growth of the N-face material and acts as an n-type dopant as is the case for growth of the Ga-face. InGaN layers can be deposited on the N-face and exhibit typical emission in the 380-450 nm range with an additional emission in the red likely caused by defect levels in the InGaN. Conditions for growing high-quality inverted layers are discussed. (C) 2004 Elsevier B.V. All rights reserved.