INVESTIGATION OF MERCURY INTERSTITIALS IN HG1-XCDXTE ALLOYS USING RESONANT IMPACT-IONIZATION SPECTROSCOPY

A technique for studying low concentrations of trap levels in narrow-gap Hg1-xCdxTe has been combined with the deliberate introduction of defects to determine the activation energies of these impurities in this ternary material. In this investigation, mercury (Hg) interstitials, believed to be responsible for dark current in metal-insulator-semiconductor devices, were deliberately introduced into samples with x almost-equal-to 0.22 and x almost-equal-to 0.24. Each sample was divided into two parts with the second part of each slice used as a control. The results from these samples provide direct evidence that Hg interstitials create trap levels near 45 and 60 meV above the valence-band edge for these x-value samples.