Analysis of a pressure sensor using n-Si/nitrogen doped diamond cathodes

The purpose of this article is to analyze the operation of a pressure senso r in a diode configuration based on field emission from n-Si/nitrogen doped diamond cathodes. The device comprises a silicon membrane, which is the pr essure sensing element. When the device emission cut-rent is kept constant? the membrane bending under external pressure modifies its operating voltag e in a linear way. A new model has been developed to characterize field emi ssion from n-Si/nitrogen doped diamond cathodes, showing good agreement wit h experimental data. The device sensitivity has been computed as function o f both the silicon membrane and diamond layer parameters. Better sensor sen sitivity is obtained for membranes with smaller dimensions and thinner, but the opposite trend allows to increase the measurable pressure range. The o btained modeling results can be further used for sensor design improvement. (C) 2000 American Vacuum Society. [S0734-211X(00)09702-X].