Organometallic Vapor Phase Epitaxial Growth Of HgTe And HgCdTe Using Methylallyltelluride

Abstract

HgTe and HgCdTe layers have been grown by organometallic vapor phase epitaxy at low temperature by using methylallyltelluride (MATe), dimethylcadmium (DMCd) and elemental mercury. Use of MATe enabled us to grow layers in the 250-320°C range, which is 50°C lower than the growth temperature when diisopropyltelluride (DIPTe) is used. The layers were characterized by double crystal x-ray diffraction, low temperature Hall measurements and Fourier transform infrared spectroscopy (FTIR). Growth below 340°C resulted in featureless HgTe layers. Layers grown on CdTe are misoriented with respect to the substrate by about 60 to 150 arc-seconds whereas such tilting was not observed when lattice matched CdZnTe substrates were used. The high quality of HgTe grown at low temperature is demonstrated by the very narrow (29 arc seconds) full width at half maximum of the x-ray diffraction curve. HgCdTe layers grown at 320°C showed sharp interference fringes even for thin layers, indicating the presence of a sharp interface.