Abstract: A method for fabricating a titanium nitride (TiN) sensing membrane on an extended gate field effect transistor (EGFET). The method comprises the steps of depositing a layer of aluminum on a gate terminal of the EGFET using thermal evaporation and forming the TiN sensing membrane on an exposed part of the layer of aluminum in the sensitive window as an ion sensitive sensor (pH sensor) using a radio frequency (RF) sputtering process. Because TiN is suitable for use in a standard CMOS process, all the elements in the sensing device can be mass produced and offer the benefits of low cost, high yield, and high performance.

Abstract: A method for fabricating a monolithic chip including multi-sensors that can detect pH, temperature, photo-intensity simultaneously and a readout circuit. As such, as well as the multi-sensors, the readout circuit also has a reduced chip area at low cost since selection switches are used to sequentially read pH, temperature and photo-intensity detecting values, wherein the readout action is completed within a clock cycle. The entire structure is fabricated with standard 0.5 ?m CMOS IC, Double Poly Double Metal (DPDM), n-well technology and allows the integration of the on-chip signal conditioning circuitry. The chip fabricated by the method can not only sense the Ph, temperature, photo values but also apply the extended gate field effect transistor (EGFET) on the temperature and light compensation to produce realistic pH values.

Abstract: A method for fabricating a titanium nitride (TiN) sensing membrane on an extended gate field effect transistor (EGFET). The method comprises the steps of depositing a layer of aluminum on a gate terminal of the EGFET using thermal evaporation and forming the TiN sensing membrane on an exposed part of the layer of aluminum in the sensitive window as an ion sensitive sensor (pH sensor) using a radio frequency (RF) sputtering process. Because TiN is suitable for use in a standard CMOS process, all the elements in the sensing device can be mass produced and offer the benefits of low cost, high yield, and high performance.

Abstract: A method for fabricating a monolithic chip including multi-sensors that can detect pH, temperature, photo-intensity simultaneously and a readout circuit. As such, as well as the multi-sensors, the readout circuit also has a reduced chip area at low cost since selection switches are used to sequentially read pH, temperature and photo-intensity detecting values, wherein the readout action is completed within a clock cycle. The entire structure is fabricated with standard 0.5 &mgr;m CMOS IC, Double Poly Double Metal (DPDM), n-well technology and allows the integration of the on-chip signal conditioning circuitry. The chip fabricated by the method can not only sense the Ph, temperature, photo values but also apply the extended gate field effect transistor (EGFET) on the temperature and light compensation to produce realistic pH values.