Annealing effects on mobility-limiting mechanisms in modulation doping Si/Si0.8Ge0.2heterostructures

✍ Scribed by T. Ueno; A. Yutani; Y. Shiraki; K. Nakagawa

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 68 KB
• Volume: 25
• Category: Article
• ISSN: 0749-6036
• DOI: 10.1006/spmi.1998.0686

✦ Synopsis

The changes in the mobility and carrier concentration in annealed modulation doping Si/Si 0.8 Ge 0.2 heterostructures with various channel thicknesses have been studied and mobility-limiting mechanisms were clarified. The dominant scattering mechanism was found to change to scattering due to uniformally doped impurities from the remote impurity scattering after annealing in samples with wider channel thickness. The thermal diffusion of both Sb and Ge caused the increase of impurity scattering and the reduction of the channel width. The channel reduction made the sample more sensitive to interface roughness scattering and gave rise to carrier localization in the extreme case. In the samples with intermediate channel width, co-operation between interface roughness and impurity scattering was observed after annealing.