High mobility electron gases in Si/Si<SUB>0.77</SUB>Ge<SUB>0.23</SUB> quantum wells at 1.7 K

Crow, GC; Abram, RA

Abstract

Calculations have been carried out to investigate the factors which limit the low temperature, low field mobilities of two dimensional electron gases formed in the X2-valley quantum wells of tensile strained Si/Si0.77Ge0.23 modulation doped structures. The electronic charge density in the system has been solved in conjunction with Poisson's equation to derive a self-consistent solution for the bound sheet charge density. Details of the self-consistent ground state wavefunction are fed into a simple calculation to derive the low field drift mobility. Remote ionized donor impurities in the supply layer and roughness at the SiGe spacer/Si well interface are found to be the main sources of electron scattering in the case of high mobility gases grown on SiGe virtual substrates at 800 °C. The comparatively poor electron mobilities observed for experimental samples produced at the lower growth temperature of 600 °C show an inverse square law dependence of mobility on sheet carrier density, the characteristic for roughness scattering.

Citation

Crow, G., & Abram, R. (1999). High mobility electron gases in Si/Si0.77Ge0.23 quantum wells at 1.7 K. Semiconductor Science and Technology, 14(8), 721-726. https://doi.org/10.1088/0268-1242/14/8/310

• Journal Article Type: Article
• Publication Date: Jan 1, 1999
• Deposit Date: Dec 16, 2010
• Journal: Semiconductor Science and Technology
• Print ISSN: 0268-1242
• Electronic ISSN: 1361-6641
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 14
• Issue: 8
• Pages: 721-726
• DOI: https://doi.org/10.1088/0268-1242/14/8/310
• Public URL: https://durham-repository.worktribe.com/output/1626214