Atomic layer epitaxy of GaN over sapphire using switched metalorganic chemical vapor deposition

Abstract
In this letter we report the first switched atomic layer epitaxy (SALE) of single crystalGaN over basal plane sapphire substrates. A low pressuremetalorganic chemical vapor deposition (LPMOCVD) system was used for the epilayer depositions. In contrast to conventional LPMOCVD requiring temperatures higher than 700 °C, the SALE process resulted in single crystal insulating GaN layers at growth temperatures ranging from 900 to 450 °C. The band‐edge transmission and the photoluminescence of the films from the SALE process were comparable to the best LPMOCVD films. To the best of our knowledge this is the first report of insulating GaNfilms which show excellent band‐edge photoluminescence.