Conference Publication Details
Mandatory Fields
Murphy-Armando F.;Fahy S.
2012 13th International Conference on Ultimate Integration on Silicon, ULIS 2012
Very large piezoresistance in Si 1-xGe x alloys
Optional Fields
ab inito Piezoresistance Silicon-germanium
First-principles electronic structure methods are used to predict the piezoresistance of n-type Si 1-xGe x at various alloy compositions and strain configurations. We report very large gauge factors, G = d/de/, where is resistivity and e is strain: for compositions x 0.90 under uniaxial strain in the <111> direction, G > 500. These gauge factors are over three times larger than the best values for single crystalline bulk Si. This large change in resistance due to strain is explained by the change in the occupancy of the higher-conductance L valley relative to the lower-conductance valley, coupled to a change in inter-valley alloy and phonon scattering. 2012 IEEE.
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