Strain control and electrical properties of stripe-patterned Si/Si1−xGex/Si(1 0 0) heterostructures

Abstract

In a Si/Si1−xGex/Si(1 0 0) heterostructure patterned into a shape striped in the ⟨1 1 0⟩ direction, strain control of capping Si and Si1−xGex layers is investigated. The Raman scattering analysis of the stripe-patterned Si/Si1−xGex/Si(1 0 0) heterostructure indicates strain relaxation in the Si1−xGex layer and introduction of tensile strain into the capping Si layer by submicron stripe patterning. It is found that the degree of strain relaxation in the Si1−xGex layer is strongly dependent on the stripe width, the capping Si layer thickness and the Si1−xGex layer thickness. Four-terminal resistivity measurement of the strain-controlled Si/Si1−xGex/Si(1 0 0) heterostructure shows an increase of the electron and hole conductivity for the tensile strained capping Si layer and a decrease of the hole conductivity for the partially relaxed Si1−xGex layer.