Suspended-Gate- and Lundstrom-FET integrated on a CMOS-chip

A Lundstrom-FET and a SGFET with Pt suspended gate have been integrated together on a single chip in CMOS technology, and operated as a hydrogen sensor. Sensor sensitivities have been determined and the reactions to target gases have been measured. While the Lundstrom-FET is more sensitive at low H2 concentrations, the SGFET's measuring range extends to higher concentrations. So the paired setup enlarges the sensitivity range of the sensor. At the same time the signal reliability, e.g. in security applications, is increased due to different cross sensitivities of the two devices. A modified CMOS process is used which allows the integration of operation and evaluation electronics.