Highly uniform, large‐area HgCdTe layers on CdTe and CdTeSe substrates

Abstract

We report here on the growth of Hg0.8Cd0.2Te on lattice matched substrates of CdTe0.96Se0.04, by organometallic vapor phase epitaxy. Layer properties are compared with those for comparable layers grown on CdTe substrates. It is shown that the use of lattice matched substrates results in active layers of improved structural quality, as evidenced by the results of double‐crystal x‐ray diffraction measurements. A compositional uniformity of better than ±0.005 (in the Cd composition) was obtained over 1×2 cm area substrates and the thickness uniformity was better than ±0.7 μm for 12‐μm‐thick layers. These layers were deposited by the direct reaction of mercury, dimethylcadmium, and diisopropyltelluride, without the interdiffusion of separate layers of HgTe and CdTe. Both n‐ and p‐type layers have been grown, by suitable adjustment of the growth process. Mobility values in excess of 6×104 cm2/V s were obtained in n‐type material (x=0.23), with an electron concentration below 1×1015 cm−3. With p‐type layers, mobility values of 680 cm2/V s were obtained, with a hole concentration of 5×1016 cm−3.