EMISSION CHANNELING STUDIES IN SEMICONDUCTORS

Emission channeling allows the determination of the lattice location of radioactive impurities in crystalline solids at very low impurity concentrations of typically 10(17) cm-3 by measuring the channeling effects of electrons, positrons or alpha-particles emitted in the nuclear decay. Lattice sites of ion implanted dopants in semiconductors and subsequent recovery of implantation defects can be studied after implantation without amorphizing the lattice. An introduction to the emission channeling technique and experiments for the investigation of defect recovery and impurity lattice location after implantation of In, Cd and Te into III-V semiconductors in the temperature range 50 K to 600 K are presented. The alpha-emitting isotope Li-8 offers a novel access to study the behavior of vacancy-like defects via lattice site changes of implanted Li probe atoms. Alpha-emission channeling experiments in GaP and GaAs are compared to results from heavy ion implantation.