Title :
Chemical response of Si3N4/SiO2/Si structures used in pH microelectronic sensors
Author :
Moinpour, Mansour ; Cheung, Peter W. ; Liao, Eva ; Aw, Chak-Yoon ; Weiler, Edward B.
Author_Institution :
Washington Univ., Seattle, WA, USA
Abstract :
The effects of processing parameters such as annealing treatment and gas flow ratio on the chemical response of Si3N4 /SiO2/Si electrodes used in ISFET (ion-sensitive FET) pH sensors were studied. Experimental results based on capacitance-voltage measurements show that the voltage response and pH sensitivity depend on the gas flow ratio n=NH3/SiH 4 during the nitride deposition and the preoxidation anneal prior to thermal oxidation of the Si wafers. The results are interpreted in terms of chemical and physical properties of nitride and oxide layers. It is concluded that optimum performance of ISFET pH sensors requires better control and characterization of the gate insulator fabrication process
Keywords :
electric sensing devices; insulated gate field effect transistors; pH measurement; ISFET pH sensors; Si3N4-SiO2-Si; annealing treatment; capacitance-voltage measurements; chemical response; gas flow ratio; gate insulator fabrication process; nitride deposition; pH microelectronic sensors; pH sensitivity; preoxidation anneal; processing parameters; thermal oxidation; voltage response; Annealing; Capacitance measurement; Capacitance-voltage characteristics; Chemical processes; Chemical sensors; Electrodes; FETs; Fluid flow; Fluid flow measurement; Gas detectors;
Conference_Titel :
Engineering in Medicine and Biology Society, 1989. Images of the Twenty-First Century., Proceedings of the Annual International Conference of the IEEE Engineering in
Conference_Location :
Seattle, WA
DOI :
10.1109/IEMBS.1989.95740
