Study of silicon–germanium interdiffusion from pure germanium deposited layers

✍ Scribed by Mathieu Gavelle; El Mehdi Bazizi; Emmanuel Scheid; Claude Armand; Pier Francesco Fazzini; Olivier Marcelot; Yves Campidelli; Aomar Halimaoui; Fuccio Cristiano

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 532 KB
• Volume: 154-155
• Category: Article
• ISSN: 0921-5107
• DOI: 10.1016/j.mseb.2008.09.015

✦ Synopsis

We have studied the Ge-Si interdiffusion from structures in which ∼300 nm-thick pure Ge(:B) layers were grown on Si 200 mm substrates by CVD at 450 • C. As-grown samples were capped with SiO 2 and then annealed in the 750-900 • C range for various times. Using the secondary ion mass spectrometry (SIMS) MCs 2 + methodology, we measures precisely the Ge diffused profiles. Boltzmann-Matano analysis was used to extract the interdiffusion coefficients. Si-Ge interdiffusion is found to be strongly dependent on the Ge concentration. Also, an effect of dislocations near the Ge/Si original interface is suggested by our results. A physical model including the various observed effects is proposed, that gives a very good agreement with experiments. Finally, we show that the effect of the in situ B doping of the pure Ge layer is to reduce the interdiffusion.