Noncontact thickness and composition assessment of a strained AIGaAs/AIAs/InGaAs double barrier multiple quantum well structure

Abstract

By using a contactless double crystal x-ray diffraction technique with either photoluminescence or infrared intersubband absorption and theoretical calculations, it is possible to determine the dimensions and composition of a three layered multiple quantum well (MQW) structure accurately. A strained AlGaAs/AlAs/InGaAs double barrier (DB) three layered MQW structure was used to demonstrate this. Moreover, it is shown that this structure is well suited for infrared photodetection in the 3 μm wavelength region, based on intersubband absorption. The compositions and thicknesses evaluated are in good agreement, and transmission electron microscopy is utilized to confirm the thicknesses. © 1996 American Institue of Physics.