Study of dislocations in HgCdTe epilayers at (1Â 1Â 1)B and (1Â 1Â 0) surfaces using modified defect etchant

A new etchant, based on the modification of standard Chen etchant has been developed for revealing etch pits in HgCdTe epilayer at (1 1 1)B and (1 1 0) planes. We have optimized the oxidizing and dissolving agents in the solution by systematic experimentation to obtain the new etchant. By using this etchant we revealed the etch pits reliably and consistently in several HgCdTe epilayers grown on (1 1 1)B face CdZnTe substrates using LPE (liquid phase epitaxy) technique, The new etchant is not sensitive to the sample orientation and works equally well for both (1 1 1) and (1 1 0) planes. The dislocations revealed by the modified etchant were investigated by the study of etch pits at (1 1 1)B surface and at the cleaved plane, i.e., (1 1 0) face. Different types of etch pits have been observed and investigated. The etch pits were found to be dependent on the CdZnTe substrate and the stress induced during the growth itself.