Observation of bevelled GaSb/InAs quantum wells by Raman mapping

A scanning micro‐Raman study of mechanically bevelled GaSb/InAs single quantum‐well samples was carried out with 488‐ and 514‐nm laser excitation wavelengths. The bevelling process magnifies the vertical resolution of interfaces and the quantum‐well region. We demonstrate that the depth profile of the first‐order Raman modes can be used to characterise individual layers with high spatial resolution of nanometer order. The red shift of the InAs longitudinal optical modes in the quantum well relative to that of bulk InAs provides clear evidence of compressive strain in the quantum well region. A method to estimate the quantum well thickness is also demonstrated. Copyright © 2005 John Wiley & Sons, Ltd.