<title>Large bandgap shift in InGaAs(P)/InP multi-quantum well structure obtained by impurity-free vacancy diffusion using SiO<formula><inf><roman>2</roman></inf></formula> capping and its application to photodetectors</title>

Abstract

In this paper, we have investigated the bandgap tuning in the InGaAs InP multiquantum well structure obtained by impurity-free vacancy diffusion using low temperature photoluminescence (PL). The MQW intermixing was performed in a rapid thermal annealer (RTA) using the dielectric capping materials, SiO2 and SiNx. The SiO2 capping was successfully used with InGaAs cap layer to cause a large bandgap tuning effect in the InGaAs/InP MQW material. The blue shift of bandgap energy after RTA treatment was as much as 185 and 230 meV at 750 degrees C and 850 degrees C, respectively, with its value controllable using annealing time and temperature. Samples with SiO2-InP or SiNx- InGaAs cap layer combinations, on the other hand, did not show any significant energy shifts. The absorption spectra taken from the same samples confirmed the energy shifts obtained using PL. The process development can be readily applied to fabrication of photodetectors that are sensitive to wavelength and/or polarization.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.