Metal piezoelectric semiconductor field effect transistors for piezoelectric strain sensors

In this letter, we examine the potential of a functional device that can have good transistor and stress sensor properties. The device examined is based on the use of a thin oxide with high piezoelectric coefficients under the gate region. Channel charge and current are controlled by gate voltage or by stress. We examine the performance of two classes of heterostructures that are important semiconductor technologies: (i) Si/SiO₂/BaTiO₃ heterostructure junctions that would be an important breakthrough for silicon sensor technology and (ii) GaN/AlN/BaTiO₃ heterostructure field effect transistors. The calculations show that with a very thin piezoelectric layer we can have a highly sensitive stress sensor and transistor. For optimum performance, the piezoelectric layer thickness should be ∼30–60 Å.