SEM observation and analysis of InGaN/GaN multiple quantum well structure using obliquely polished sample.

The InGaN/GaN multiple quantum well structures on sapphire substrates were observed by scanning electron microscope (SEM) using obliquely polished samples. From the contrast change across the p-n junction, piezoelectric fields were deduced. The direction of the piezoelectric field was consistent with the theoretical prediction, but the strength was smaller. Strain–stress calculation showed that st...