| Crystal Research and Technology |
Hydrogen detection and analysis was carried out on the undoped semi-insulating (S.I.) gallium arsenide (GaAs) single crystal using conventional elastic recoil detection analysis (ERDA) technique with high energy, heavy ion beam. Presence of hydrogen (nearly 3 x 1020 atoms/cc) has been observed on the as-grown samples and further high concentration of atomic hydrogen (total concentration of 7 x 1020 atoms/cc) was found at the surface and was found to be decreasing with depth after 100 nm. Further the low energy hydrogen and oxygen ions implanted separately in GaAs at room temperature were also analysed by ERDA technique. From the analysis, the projected range (Rp) of 100 keV hydrogen and oxygen ions in GaAs was determined to be 891 nm (with Delta Rp equal to 320 nm), 170 nm (with Delta Rp equal to 120 nm) respectively. The experimentally determined values of both Rp and Delta Rp are more as compared with the values obtained using the TRIM theoretical program. Low temperature (4K) photoluminescence (PL) measurements of un-implanted and H+ implanted samples show the passivation of intrinsic deep level defect EL2 and shallow acceptor impurity carbon by the low energy implanted hydrogen ions. The low energy hydrogen implantation may be used as a method of hydrogenation for passivation.
Keywords: hydrogen analysis, GaAs, ERDA, low energy ion implantation, passivation
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