DAMAGE DISTRIBUTION IN GAAS IMPLANTED AT ELEVATED-TEMPERATURE

Wafers of (100) GaAs have been implanted with 140 keV Zn+ ions at off- channeling direction up to a fluence of 1 x 10(14) cm-2. The target te mperature was kept at 110 +/- 10-degrees-C. The defect clusters and th e damage depth distributions were investigated by planar and cross-sec tional high-resolution transmission electron microscopy (HRTEM and XHR TEM) and were modelled by a MAR-LOWE-based computer code. The experime ntal mean depth of the damage profile located at about 85 nm exceeds t he calculated deposited energy and vacancy distributions by more than 50%. The correlation between the deposited energy density within the c ascade and the inner structure of the observed defect clusters is disc ussed.