Influence of intrinsic or extrinsic doping on charge state of carbon and its interaction with hydrogen in GaN

Abstract

It has been established that the formation of point defects and their behaviors could be regulated by growth details such as growth techniques and growth conditions. In this work, we prove that C doping approaches have great influence on the charge state of [Formula: see text], thus the interaction between H and C in GaN. For GaN with intrinsic C doping, which is realized by reducing the V/III ratio, [Formula: see text] mainly exists in the form of [Formula: see text] charged from the higher concentration of [Formula: see text] and, thus, may attract [Formula: see text] by coulomb interaction. Whereas for the extrinsically C doped GaN with propane as the doping source, the concentration of [Formula: see text] is reduced, and [Formula: see text] mainly exists in neutral charge state and, thus, nearly does not attract H ions. Therefore, we demonstrate that the interplay between H and C atoms is weaker for the extrinsically C doped GaN compared to the intrinsically doped GaN, thus gives a clear picture about the different charge states of [Formula: see text] and the formation of C–H complexes in GaN with different C doping approaches.

First Demonstration of Extrinsic C-Doped Semi-Insulating N-Polar GaN Using Propane Precursor Grown on Miscut Sapphire Substrate by MOCVD

“…Shan Wu et al [26] reported that background hydrogen [H] can affect the electrical properties of intrinsically C-doped Ga-polar GaN by forming C-H complexes. However, the same group has also shown that extrinsic C-doping using propane attracts 75% less H, thereby reducing the chance of the formation of C-H complexes [27]. Additionally, Fichtenbaum reported a background H concentration of 1.5 × 10 17 /cm 3 in an N-polar GaN film grown on a miscut sapphire substrate [28].…”