As a new approach for contactless and non-destructive characterization method of buried multi-layer heterointerfaces, acceleration voltage-dependence of cathodoluminescence (CL) spectra is investigated for various InGaP/GaAs multi-layer heterostructures. The plot of CL intensity vs. acceleration voltage for a multi-layer heterostructure is defined as the cathodoluminescence in-depth spectrum (CLIS). Experimental CLIS spectra on InGaP/GaAs single heterostructures and quantum well structures grown on GaAs by MOVPE and by GSMBE using TBP as the P source demonstrate that CLIS technique is very powerful to obtain depth-resolved information on multi-layer heterostructures. (C) 2002 Elsevier Science B.V. All rights reserved.