Strain control and electrical properties of stripe-patterned Si/Si_(1-x)Ge_x/Si(l00) heterostructures

摘要

In a Si/Si_(1-x)Ge_x/Si(100) heterostructure patterned into a shape striped in the 〈110〉 direction, strain control of capping Si and Si_(1-x)Ge_x layers is investigated. The Raman scattering analysis of the stripe-patterned Si/Si_(1-x)Ge_x/Si(100) heterostructure indicates strain relaxation in the Si_(1-x)Ge_x 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 Si_(1-x)Ge_x layer is strongly dependent on the stripe width, the capping Si layer thickness and the Si_(1-x)Ge_x layer thickness. Four-terminal resistivity measurement of the strain-controlled Si/Si_(1-x)Ge_x/Si(100) 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 Si_(1-x)Ge_x layer.