ULTRA-HIGH SENSITIVITY INTRAGRAIN POLY-DIAMOND PIEZORESISTORS

Chemical vapor deposited (CVD) polycrystalline diamond is inexpensive and can become a commercially viable piezoresistive sensor material if its typical gauge factor (GF) exceeds that of crystalline Si and SE. In this paper, a study of GF of B-doped polycrystalline diamond film l eads to an intra-grain GF above 4000, which is comparable to GF of sin gle crystal p-type diamond. This result, reported for the first time, shows that large-grain (50-80 mu m) CVD diamond can be used to build i nexpensive ultra-high sensitivity piezoresistive sensors. (C) 1998 Els evier Science S.A. All rights reserved.