The epitaxial growth of mercury manganese telluride by MOVPE

The authors report the first successful growth by MOVPE of epitaxial thin films of the dilute magnetic semiconductor (Hg, Mn)Te. Epitaxial layers approximately 5 mu m thick were grown directly on (001) GaAs substrates using tricarbonyl (methyl cyclopentadienyl) manganese, di isopropyl telluride and elemental mercury. Deposition took place in a horizontal, atmospheric pressure reactor at temperatures in the range 350-400 degrees C. The layers were shown to be of good crystallinity by RHEED and double-crystal X-ray diffraction, with rocking curve widths of 400-600 seconds of arc. As-grown layers were p-type, with hole mobilities at 79 K of 2000-5500 cm 2 V -1 s -1 . Two compositions have been grown, one with x approximately=0.04, which lies below the semiconducting/semimetallic transition and x approximately=0.13, which is semiconducting. Infrared measurements of the latter show it to have a band-gap energy of approximately 0.26 eV at room temperature.