Title :
A monolithic implementation of interface circuitry for CMOS compatible gas-sensor system
Author :
Afridi, M.Y. ; Suehle, J.S. ; Zaghloul, M.E. ; Berning, D.W. ; Hefner, A.R. ; Semancik, S. ; Cavicchi, R.E.
Author_Institution :
George Washington Univ., Washington, DC, USA
Abstract :
A monolithic micro-gas-sensor system, designed and fabricated in a standard CMOS process, is described. The gas-sensor system incorporates an array of four microhotplate-based gas-sensing structures. The system utilizes a thin film of tin oxide (SnO2) as a sensing material. The interface circuitry on the chip has digital decoders to select each element of the sensing array and an operational amplifier to monitor the change in conductance of the film. The chip is post-processed to create microhotplates using bulk micro-machining techniques. Measurements are presented for various portions of the interface circuitry used for the gas-sensor system.
Keywords :
CMOS integrated circuits; decoding; electric admittance; electric heating; gas sensors; integrated circuit design; integrated circuit measurement; micromachining; microsensors; operational amplifiers; thin film circuits; tin compounds; CMOS compatible gas-sensor system; CMOS process fabrication; SnO2; SnO2 gas sensor; bulk micromachining techniques; digital decoders; film conductance measurement; gas sensor interface circuitry; gas-sensor system measurements; microhotplate-based gas-sensing array structure; monolithic micro-gas-sensor system; operational amplifiers; post-processing; sensing array element selection; tin oxide thin film sensing material; Biomembranes; CMOS process; Conducting materials; Conductive films; Gas detectors; Heating; Integrated circuit interconnections; NIST; Sensor arrays; Silicon;
Conference_Titel :
Circuits and Systems, 2002. ISCAS 2002. IEEE International Symposium on
Conference_Location :
Phoenix-Scottsdale, AZ
Print_ISBN :
0-7803-7448-7
DOI :
10.1109/ISCAS.2002.1011457
