| 摘要 |
PCT No. PCT/GB98/00100 Sec. 371 Date Sep. 14, 1999 Sec. 102(e) Date Sep. 14, 1999 PCT Filed Jan. 13, 1998 PCT Pub. No. WO98/32009 PCT Pub. Date Jul. 23, 1998A gas-sensing semiconductor device 1 is fabricated on a silicon substrate 2 having a thin silicon oxide insulating layer 3 on one side and a thin silicon layer 4 on top of the insulating layer 3 using CMOS SOI technology. The silicon layer 4 may be in the form of an island surrounded by a silicon oxide insulating barrier layer 4 formed by the known LOCOS oxidation technique, although other lateral isolation techniques may also be used. The device 1 includes at least one sensing area provided with a gas-sensitive layer 18, a MOSFET heater 6 for heating the gas-sensitive layer 18 to promote gas reaction with the gas-sensitive layer 18 and a sensor 16, which may be in the form of a chemoresistor, for providing an electrical output indicative of gas reaction with the gas-sensitive layer 18. As one of the final fabrication steps, the substrate 2 is back-etched so as to form a thin membrane 20 in the sensing area. Such a device can be produced at low cost using conventional CMOS SOI technology. |
