TE DOPING OF GAAS USING DIETHYL-TELLURIUM

The performance of the gaseous precursor diethyl-tellurium (DETe) for n-type doping of GaAs is studied. We report on both the properties of the molecular source DETe as well as on the suitability of the dopant element tellurium. Te is found to be an excellent dopant, comparable t o Si in the lower-doping regime and superior at highest-doping levels. DETe reveals itself to be a convenient and reproducible doping source . At substrate temperatures above 540-degrees-C, dopant desorption (mo st probably Te) is observed which limits its applications. Memory effe cts after doping up to the mid 10(18) cm-3 range can be eliminated. At still higher-doping levels an optimized technique limits unintentiona l background carrier concentrations in subsequent layers to the 10(14) cm-3 range.