A Three-Terminal Silicon Plezotransducer: General Consideration and Estimation of Sensitivity

摘要

A general consideration of the three-terminal silicon piezotransducer (TTSP transducer) is described in the paper. The boundary problem is established and solved for the TTSP transducer with classic rectangular form of the current spread region (CSR), the analytical equations for potential distribution is obtained. The linear modal of TTSP transducer presented in the paper allows to describe the TTSP transducer as an element of external electrical circuit, to calculate the difference between output currents and voltages on output contacts as a function of strain as well as the sensitivity of transducer. The geometrical correction function is calculated in this paper for considered classic rectangular form of the CSR. The sensitivity of TTSP transducer is compared with the sensitivity of four-terminal transducer with classic rectangular form. It follows from this comparison, that the four-terminal silicon transducer can be considered as full analog of piezoresistive Wheatstone bridge, whereas the TTSP transducer can be considered as analog of half-bridge circuit only.