Infrared absorption studies in proton- and deuterium-implanted Si1−xGex

✍ Scribed by R.N. Pereira; L. Dobaczewski; B. Bech Nielsen

• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 225 KB
• Volume: 340-342
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2003.09.217

✦ Synopsis

In situ-type infrared absorption measurements are carried out on bulk Si 1Àx Ge x after implantation with protons or deuterons at temperatures below 20 K. The infrared absorbance spectra recorded at 8 K after implanting the samples with protons reveal two intense and well-resolved lines located at around 2000 cm À1 . Spectra recorded at 8 K after each annealing step in an isochronal annealing sequence show that the lines disappear when the samples are heated to about 175 K. Such annealing behavior is very similar to that of the 1998 cm À1 line observed in pure Si implanted with protons under similar conditions. The dependence of the frequency of lines on the composition of the alloy and their annealing behavior demonstrates that they are produced by the Si-H stretch modes of H þ BC located between Si neighbors in two different nextneighbor configurations, where the higher frequency mode corresponds to a Si-H-Si site locally strained by a Ge atom bond to one of the Si atoms. Based on the experimental data, the formation and stability of the two defects are discussed.