Effect of dielectric-semiconductor capping layer combination on the dielectric cap quantum well disordering of InGaAs/InGaAsP quantum well structure

The bandgap tuning by dielectric cap quantum well disordering (DCQWD) method has been widely used to realize the integration of optoelectronic or photonic devices without any regrowth step on a single wafer. Since the DCQWD technique has lots of merit in price and fabrication compared with the regrowth technique, there have been a lot of studies about dielectric capping layers to control QWD. In this study, we concerned the effect of dieiectric-semiconductor capping layer combination. Our study was focused to find out the effect of semiconductor capping layer on the DCQWD, and to find out optimum dielectric-semiconductor capping layer combination for a device application. The InGaAs/InGaAsP single quantum well (QW) structure used in this experiment was grown by chemical beam epitaxy (CBE) on a n-type InP substrate. In order to investigate the effect of semiconductor cap layer on DCQWD, three samples with different semiconductor cap layers (InP, InGaAs and InGaAsP(1.25Q)) were prepared.