Abstract
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
Original language | English |
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Journal | Journal of Applied Physics |
Volume | 104 |
Issue number | 2 |
Pages (from-to) | 023715 |
ISSN | 0021-8979 |
DOIs | |
Publication status | Published - 2008 |