Electronic properties of defects introduced during low-energy He-ion bombardment of epitaxially grown n-GaAs

We have employed deep level transient spectroscopy to investigate the defects introduced by low-energy (5 keV) He-ion bombardment of epitaxially grown n-GaAs. This introduced four electron traps, EHe1-EHe4, with discrete energy levels identical to those of the E alpha 1-E alpha 4 defects introduced during high-energy (5.4 MeV) alpha-particle irradiation of the same n-GaAs, but in different relative concentrations. EHe3 with a level at E(c)-0.35 eV exhibits the same metastability as E alpha(3). In addition, low-energy ion bombardment introduced a band of defects close to the GaAs surface with a continuous energy distribution. (C) 1996 American Institute of Physics.