Journal article
Piezoresistance in p-type silicon revisited
Department of Micro- and Nanotechnology, Technical University of Denmark1
Technical University of Denmark2
Theoretical Nanoelectronics Group, Theory Section, Department of Micro- and Nanotechnology, Technical University of Denmark3
Theory Section, Department of Micro- and Nanotechnology, Technical University of Denmark4
Silicon Microtechnology Group, MicroElectroMechanical Systems Section, Department of Micro- and Nanotechnology, Technical University of Denmark5
MicroElectroMechanical Systems Section, Department of Micro- and Nanotechnology, Technical University of Denmark6
Center for Individual Nanoparticle Functionality, Centers, Technical University of Denmark7
Center for Nanoteknologi, Centers, Technical University of Denmark8
We calculate the shear piezocoefficient pi44 in p-type Si with a 6×6 k·p Hamiltonian model using the Boltzmann transport equation in the relaxation-time approximation. Furthermore, we fabricate and characterize p-type silicon piezoresistors embedded in a (001) silicon substrate. We find that the relaxation-time model needs to include all scattering mechanisms in order to obtain correct temperature and acceptor density dependencies.
The k·p results are compared to results obtained using a recent tight-binding (TB) model. The magnitude of the pi44 piezocoefficient obtained from the TB model is a factor of 4 lower than experimental values; however, the temperature and acceptor density dependencies of the normalized values agree with experiments.
The 6×6 Hamiltonian model shows good agreement between the absolute value of pi44 and the temperature and acceptor density dependencies when compared to experiments. Finally, we present a fitting function of temperature and acceptor density to the 6×6 model that can be used to predict the piezoresistance effect in p-type silicon. ©2008 American Institute of Physics
Language: | English |
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Publisher: | American Institute of Physics |
Year: | 2008 |
Pages: | 023715 |
ISSN: | 10897550 and 00218979 |
Types: | Journal article |
DOI: | 10.1063/1.2960335 |
ORCIDs: | Brandbyge, Mads , Thomsen, Erik Vilain and Hansen, Ole |