HG1-XCDXTE - ELECTRICAL AND STRUCTURAL-CHANGES INDUCED BY RAPID THERMAL ANNEALING

The combined electrical and structural characterization of encapsulate d HgCdTe annealed in a rapid thermal processor under different tempera tures and times is presented. Hall effect measurements are used for th e determination of the changes in carrier concentration and mobility p roduced during the annealing, while structural changes due to the ther mal treatment are deduced from channelled proton-induced X-ray emissio n measurements. The results indicate that both the carrier concentrati on and mobility change homogeneously throughout the crystal, reaching equilibrium values that are only a function of the annealing temperatu re. The evolution towards equilibrium of each parameter can be fitted to exponential laws, the time constants being a function of the anneal ing temperature. However, the time required to reach the equilibrium m obility is always longer (by about X3.5) than that needed to saturate the carrier concentration, for the same temperature. The crystallinity of the samples also shows a dependence on the annealing temperature. These changes are explained on the basis of generation and annihilatio n of mercury vacancies through the interaction with tellurium precipit ates.