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 epitaxi ally grown n-GaAs. This introduced four electron traps, EHe1-EHe4, wit h discrete energy levels identical to those of the E alpha 1-E alpha 4 defects introduced during high-energy (5.4 MeV) alpha-particle irradi ation of the same n-GaAs, but in different relative concentrations. EH e3 with a level at E(c)-0.35 eV exhibits the same metastability as E a lpha(3). In addition, low-energy ion bombardment introduced a band of defects close to the GaAs surface with a continuous energy distributio n. (C) 1996 American Institute of Physics.