GROWTH OF UNIFORM HGCDTE BY METALORGANIC CHEMICAL VAPOR-DEPOSITION SYSTEM

Hg1-xCdxTe growth was studied, evaluating the uniformity in terms of the composition, thickness, and surface morphology. Growth was done on a 3 in. GaAs substrate in a vertical reactor using metalorganic chemical vapor deposition featuring a rotating susceptor with multiple nozzles. In a simulation based on the results of our experiment, we found that eight nozzles are needed to grow an epilayer having a compositional variation (DELTA-x) within 0.002. Hg1-xCdxTe was grown using eight nozzles after a CdTe (111) B buffer layer was grown on a 3 in. GaAs (100) wafer. The maximum variation in x(DELTA-x) was 0.010, and the mean value (xBAR) was 0.264 over the full surface of the 3 in. diam wafer. The thickness variation (DELTA-d) was 0.7-mu-m, and the mean value (dBAR) 5.7-mu-m. An evaluation of the surface morphology showed a specular surface with small triangular pits. The etch pit density was 2.6-7.4 X 10(6) cm-2.