Growth and characterization of Si-doped cubic GaN

We grew Si-doped cubic GaN layers having Si concentrations in the range between 5x10¹⁸ and 1x10²⁰ cm^-3. The electron mobility and carrier concentration were 95 cm²V^-1s^-1 and 6.7x10¹⁹ cm^-3, respectively, when the Si concentration was 9.2x10¹⁹cm^-3. This mobility is almost equal to that of hexagonal GaN with high Si concentration. The sheet resistance was highly anisotropic when the Si concentration of the specimen was lower than 2x10¹⁹ cm^-3. The number of stacking faults in the (111) plane in the [110] direction was higher than that in [ https://www.w3.org/1998/Math/MathML"> 1 1 ¯ 0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003063100/ce4a879a-688a-4c77-a95b-e9b91ed32a4e/content/inline-math98.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ]. Since the stacking faults of (111) are hexagonal GaN phase, we think the sheet resistance anisotropy was caused by barriers between the cubic and hexagonal GaN phases.