Transmission electron microscopy investigation of ion implantation damage in gallium arsenide and other semiconductors
The crystalline-to-amorphous transition induced by ion implantation was investigated in GaAs and GaP using transmission electron microscopy. The experiments included those performed in situ using the HVEM-Tandem Accelerator Facility at Argonne National Laboratory and also those performed using high-resolution TEM. The implantations were made with Ar$\sp+$, Kr$\sp+$, Xe$\sp+$, and Au$\sp+$ ions (energy 50 or 80 keV) at 30 and 300 K. The high-resolution experiments confirmed the amorphous nature of the damage produced in individual displacement cascades. The in situ experiments at 30 K showed that amorphous zones are produced within isolated cascades with high probability. It was found that the efficiency of production of amorphous damage increases with increasing ion mass. The probability that an individual cascade will generate an amorphous region decreases when the implantation is performed at room temperature in GaAs but remains the same for GaP. Annealing experiments in the 30-300 K range demonstrated that there is significant damage recovery below 300 K in GaAs but none in GaP. Calculations of the energy density deposited in the cascades, determined through Monte-Carlo simulations, suggest that the formation and subsequent quenching of a molten zone may be responsible for the production of the amorphous damage.
Physics, Condensed Matter, Engineering, Materials Science
University of Illinois - Urbana-Champaign
Networked Digital Library of Theses and Dissertations
University of Illinois at Urbana-Champaign