The effect of strain on the resistivity of indium tin oxide films prepared by pulsed laser deposition

摘要

The piezoresistivity of thin films of indium tin oxide prepared by pulsed laser deposition has been measured as a function of processing parameters. The thickness of the films ranged from 200 to 1200 nm. Resistivity and strain sensitivity measurements as a function of laser deposition parameters are reported. Gauge factors, defined as the ratio of the fractional resistance change to the applied strain, were observed to vary from approximately 0.2 for deposition in vacuum to as large as -14.7 for deposition with a residual atmosphere of 50 mTorr of oxygen. The response of gauges to strains up to the measurement limit of approximately 220 με was both linear and free of hysteresis. This fabrication strategy makes possible the direct deposition of sub-mm strain gauges onto surfaces and components, including those of micro electromechanical systems.