Gan-on-Si process defect detection and analysis for HB-LEDs and power devices

The race to gallium-on-silicon (GaN-on-Si) has been a heated one simply because growth of defect-free GaN-on Si is not an easy problem. The main impetus for this stack comes from a combination of factors, including the ability to use large and cheaper substrates and access to automated back-end manufacturing tools in depreciated IC fabs. Study of the different types of defects during GaN epitaxy is the main goal of this paper. In order to do so, we use scatterrometry is used to analyze different signals. Setting the correct thresholds between signal and noise is key in detecting the defects of interest.