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HL: Halbleiterphysik

HL 41: Heterostructures

HL 41.3: Vortrag

Donnerstag, 30. März 2006, 11:30–11:45, BEY 154

Simulated strain-energy minimization in oxygen, SiO₂ and GeO₂ monolayer quantum wells in Si(001) — •D Quinlan¹ and R Tsu² — ¹Universität Göttingen, IV. Physikalisches Institut, Germany — ²University of North Carolina at Charlotte

We simulate the hypothetical structural feasibility of three quantum wells that could be grown in bulk Si(001). The most basic QW geometry consists of a single monolayer of oxygen forming a set of “bridge bonds” separating two volumes of silicon (i.e. [Si]−O−[Si] in the 001-direction). SiO₂ or GeO₂ can be formed by two of these oxygen monolayers enclosing a single layer of germanium or silicon ([Si]−O−X−O−[Si], where X= Si or Ge). Relaxation of the QW geometry is performed using the Keating model, which defines total strain energy as a summation of contributions based on bond-length and bond-angle deviations from equilibrium values. This yields an atomic structure that defies bulk crystalline silicon symmetry. The result is consistent with knowledge of similar (001)-terminations of crystalline silicon, including clean silicon surface reconstruction and the Si-αSiO₂ interface, where the new periodicity requires a larger pattern to properly define.

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