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 (Δx) 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(Δx) was 0.010, and the mean value (x) was 0.264 over the full surface of the 3 in. diam wafer. The thickness variation (Δd) was 0.7 μm, and the mean value (d) 5.7 μm. An evaluation of the surface morphology showed a specular surface with small triangular pits. The etch pit density was 2.6–7.4×106 cm−2.