Evaluation of diamond gauge factor up to 500 °C

Gauge factors of boron-doped polycrystalline diamond films were investigated in the ranges from room temperature to 500 degrees C and from 0 to 0.07 MPa of applied pressure. AVCR fitting was used as a package for a measurement at high temperature. Undoped and boron-doped polycrystalline diamond films were deposited on a Si substrate by hot filament chemical vapor deposition (CVD) method. A chip was fabricated with bulk micro machining technique. The gauge factors were evaluated in the ranges from room temperature to 500 degrees C in furnace. The calculated values of the gauge factors were found to vary in a range of 5-241. The gauge factors decreased with increased temperature from room temperature to around 100-300 degrees C. However, with higher temperature up to 500 degrees C, it increased. (c) 2007 Elsevier B.V. All rights reserved.