Novel sheet resistance measurement on AlGaN/GaN HEMT wafer adapted from four-point probe technique

In this paper, we present a new method of sheet resistance measurement on AlGaN/GaN wafers. Such measurements are useful for an easy monitoring of AlGaN/GaN epitaxy. Measurements were obtained by adapting the four-point probe technique to AlGaN/GaN wafers. This method is used today in the 200mm GaN-on-Si fabrication line at the CEA-LETI with a standard deviation of 2% on the sheet resistance measurement.