RUTHERFORD BACKSCATTERING ANALYSIS OF DAMAGE IN ION-IMPLANTED GAAS AL0.44GA0.56AS/

The system 65 nm GaAs/940 nm Al<INF>0.44</INF>Ga<INF>0.56</INF>As was implanted with 600 keV Se<SUP>+</SUP> ions at 80 and 300 K. The concen tration and distribution of defects was analysed by RES and the DICADA 2 code. The neglect of the deviating stoichiometry in the cap layer ca uses only a small overestimate of the relative defect concentration of approximate to 0.03 within the Al<INF>0.44</INF>Ga<INF>0.56</INF>As l ayer. When the implantation was performed at 80 Ii, amorphization of A l<INF>0.44</INF>Ga<INF>0.56</INF>As at the maximum of the distribution occurs at about 0.42 dpa, but the profiles deviate from that of the p rimary nuclear energy deposition, suggesting an enhanced defect diffus ion and annealing around the interface between the implanted region an d the underlying crystalline Al<INF>0.44</INF>Ga<INF>0.56</INF>As. Aft er implantation at 300 K, most of the defects were point defects and p oint defect clusters, which were preferably trapped around the project ed range of the implanted ions, thus resulting in the formation of dis locations by further irradiation, which was proved by cross-sectional TEM observations. No amorphization could be observed up to an ion dose of 5 x 10<SUP>16</SUP> cm<SUP>-2</SUP>.<SUP></SUP> (C) 1998 Elsevier Science B.V.