CHEMICAL PREPARATION OF CDTE(100) AND CDTE(110) SURFACES USING ATOMIC-HYDROGEN

We present the results of an AES, XPS, LEED and photoluminescence stud y of the reaction of oxide and contaminant overlayers on CdTe(100) and (110) surfaces with atomic hydrogen. For both surfaces exposure of an oxide overlayer to a flux of atomic hydrogen produced by 'cracking' a mbient molecular hydrogen on a hot tungsten filament results, in contr ast to the case of GaAs substrates, in a rapid, quantitative removal o f the oxide overlayer at substrate temperatures as low as 300 K. This process results in surfaces free of contaminants which have sufficient surface order to produce clear LEED patterns characteristic of well k nown reconstructions of these surfaces. Additionally in situ photolumi nescence spectroscopy allows direct correlation of surface cleaning wi th reduced nonradiative carrier recombination.