Low-energy argon ion beam treatment of a-Si : H/Si structure

The results of several surface-sensitive techniques applied to the investig ation of ion beam-treated a-Si:H/crystalline silicon structures, such as de ep-level transient spectroscopy (DLTS), photoluminescence at 6 K and room t emperature, and X-ray diffraction at grazing incidence (XRDGI) are presente d. Three important results follow from this contribution. (i) Two groups of gap states with thermal activation energies of 0.71 and 0 .84 eV were identified and found to be sensitive to illumination, this prop erty exhibiting metastable character; we suppose effects similar to those o bserved in the porous silicon/silicon and a-Si:H/silicon structures. (ii) Broader luminescence peaks were identified optically with the energies lying in the range of 0.7 to 0.95 eV, the most distinct one being at 0.85 eV. (iii) X-ray reflection at 2 theta similar to 28 degrees has been found as t he reflection suitable for tracing the structural properties of a-Si:H laye r. (C) 2000 Elsevier Science B.V. All rights reserved.