Calibration and Applications of Scanning Capacitance Microscopy: n-Type GaN

Abstract

TO understand the basic mechanisms of scanning capacitance microscopy (SCM) four GaN-based test structures were grown on sapphire. These have been designed to test the carrier concentration and spatial detection limits of the technique, and it has been noted that SCM reliably distinguished between different carrier concentrations for levels >= 5 x 10(17)cm(-3) and for layers equal to or thicker than 25nm. The response of SCM is seen to be highly dependent on the particular probe used, necessitating the use of calibration standards for the quantification of unknown samples.