P-TYPE DOPING WITH ARSENIC IN (211)B HGCDTE GROWN BY MBE

Arsenic incorporation and doping in HgCdTe layers grown by molecular b eam epitaxy (MBE) were examined in this paper. Arsenic incorporation i nto MBE-HgCdTe was carried out in two different ways: (1)ex-situ arsen ic ion-implantation on indium-doped n-type HgCdTe layers, and (2) thro ugh a new approach called arsenic planar doping. We report on ex-situ arsenic diffusion on indium-doped MBE-HgCdTe layers at 450 degrees C. In the investigated layers, arsenic redistribution occurs with a multi -component character. We obtained a diffusion coefficient of D-As = (1 -3) x 10(-13) cm(2)/s at 450 degrees C. Results of differential Hall a nd fabricated p-n junctions suggest that during high temperature annea ling, arsenic preferentially substitutes into Te sublattices and acts as acceptor impurities. In the second case, arsenic has been successfu lly incorporated during the MBE growth as an acceptor in the planar do ping approach. Without ex-situ annealing, as-grown layers show up to 5 0% activation of arsenic during the growth. These results are very pro mising for in-situ fabrication of infrared devices using HgCdTe materi al.