The proximity effect of the regrowth interface on two-dimensional electron density in strained Si

We studied the density of two-dimensional electron gas (2DEG) in SiSiGe heterostructures as a function of the distance between the substrate-epilayer interface and the 2DEG layer. The 2DEG sheet density was observed to change from 2.2× 1011 to 3.5× 1011 cm-2. Theoretical simulations are shown to be consistent with the experimental results within experimental errors. The slight deviations of the experimental results possibly come from temperature variation of the Sb dopant source during the growth of the Sb doping layer. © 2008 American Institute of Physics.