Influence of substrate misorientation on carbon impurity incorporation and electrical properties of p-GaN grown by metalorganic chemical vapor deposition

Abstract

The influence of substrate misorientation angle on carbon impurity incorporation and electrical properties of p-GaN grown at a low temperature of 900 °C has been explored. Secondary ion mass spectrometry results reveal that the concentration of unintentionally incorporated carbon impurity decreases remarkably (from 2 ×1017 cm-3 to 7 ×1016 cm-3) with the increasing misorientation angle. The step motion model is introduced to explain the reason for decreasing carbon concentration with increasing misorientation angle. It has also been found the hole concentration of p-GaN increases and the resistivity of p-GaN decreases with the increasing misorientation angle since carbon acts as compensating donor in p-GaN.