pH-sensitive ISFETs based on titanium nitride and their application to battery monitor

A novel pH-sensitive ISFET (ion-sensitive field effect transistor) based on titanium nitride (TiN), which is an electron conducting material, was fabricated by a plasma-enhanced chemical vapor deposition, (CVD) method. The TiN ISFETs showed a linear response from pH 1.68 to 10.01 of standard pH solutions with 59 mV per decade change. The TiN ISFETs had no alkaline error from pH 1.68 to 10.01. Since TiN films have superior mechanical and chemical characteristics in the strongly acidic region, the basic application to a lead battery monitor was investigated. The TiN ISFETs showed a fairly linear correlation with the specific gravity of electrolytic solution in a battery.<
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