Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1687936 | Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms | 2006 | 6 Pages |
Abstract
The aim of this contribution is to present a review of the results related to vacancy complexes in SiGe obtained in the positron group at Helsinki University of Technology. We have studied proton irradiated undoped and P doped SiGe layers with Ge concentration from 4% to 30%. The dominating defect after irradiation in the n-type layers is found to be the E-center, i.e. the vacancy phosphorus complex, no preferred association with either Ge or Si is found for the vacancy after irradiation. The E-center is observed to be mobile in the temperature interval 150-200 °C and to migrate until it encounters a Ge atom and forms the V-P-Ge complex. This complex anneals out in temperatures above 200 °C. We estimate that the binding energy increases by approximately 0.1-0.2 eV when a Ge atom neighbours an E-center. For the undoped irradiated samples, we find no indication of vacancies surrounded by one or several Ge atoms, i.e. the presence of Ge around a vacancy is not enough to make the defect stable at room temperature. The dominating defect in undoped irradiated samples is most likely the divacancy.
Related Topics
Physical Sciences and Engineering
Materials Science
Surfaces, Coatings and Films
Authors
J. Slotte,