Abstract Heteroepitaxial InGaAs layers on (100) GaAs and InAs substrates are characterized by micro-Raman spectroscopy. The samples are angle-lapped to observe depth profiles of phonon frequency. The GaAs-like LO frequency is shifted upward near the interface in InGaAs / GaAs and downward in InGaAs / InAs. The shift is believed to be due to residual misfit strain, and it is larger in InGaAs / InAs than in a GaAs / InAs structure where the mismatch degree is larger. The results of Raman measurements are compared with results of X-ray diffraction and transmission electron microscope.