Fundamentals of micromechanical thermoelectric sensors

The thermal and electrical properties of a thin heater strip made of silicon, consisting of a low-doped electrical resistor connected to highly doped long legs, are discussed based on analytical models for the heat and the electrical current transport. Such heater strips are used, for example, as sensitive position and height sensors in local-probe storage applications. The aim of the paper is to provide a thorough understanding of the important physical mechanisms and scaling laws, and thus to establish a solid basis for the directed engineering of such sensors. In particular, the dynamic response is treated in full generality, including the intricate electrothermal coupling arising from the highly temperature-dependent resistivity of the Si heater element. © 2005 American Institute of Physics.