High density plasma processing of p-Hg0.7Cd0.3Te

Reactive ion etching of HgCdTe using H₂/Ar-based gas chemistry is known to result in conductivity type conversion of exposed material and surface depletion of Hg. Secondary ion mass spectrometry has been used to investigate the compositional profile of HgCdTe material exposed to H₂/CH₄/Ar plasma in an inductively coupled plasma reactive ion etching tool, as a function of varying the plasma process pressure and temperature. The results of this profiling show that increasing the process pressure is related to an increase in the degree of Hg-depletion at the exposed surface. It has also been found that increasing the process pressure is associated with increased incorporation of C into the sample surface.