A technique based on infrared microscopy and the automatic fitting of the transmissivity curves has been developed to measure the composition and thickness distributions of HgCdTe wafers grown by molecular beam epitaxy (MBE). This technique has the ability to handle many measuring points, provides high spatial resolution, and can be used for the routine characterization of the uniformity of HgCdTe grown on CdZnTe and Si-based substrates. The mapping measurements both are helpful for infrared detector fabrication and can help MBE growers adjust growth conditions and optimize equipment configurations to grow large area uniform HgCdTe material. The reason that limits the enhancement of uniformity was also discussed. (c) 2005 Elsevier B.V. All rights reserved.