Patent ID: 7205173

Claim:
A method of fabricating a micro-electromechanical system (MEMS) incorporating a sensing element and a junction field-effect transistor (JFET) electrically connected to the sensing element, the method comprising the steps of: (a) forming a first layer of electrically insulating barrier material on a surface of a substrate; (b) patterning the first layer so as to expose a first region of the substrate; (c) doping by ion implantation the first region of the substrate to form a well region of the JFET; (d) forming a second layer of barrier material on the surface of both the first layer and the first region of the substrate; (e) patterning the second layer of barrier material so as to expose a part of the first region of the substrate; (f) doping by ion implantation the exposed part of the first region of the substrate to form source and drain contact areas of the JFET; (g) patterning the second layer of barrier material so as to expose a second region of the substrate; and (h) doping by ion implantation the second region of the substrate to form gate and substrate contact areas of the JFET in a single implantation step.