Preparation of IZO Thin Film on Different Substrates for pH-EGFET

摘要

In this study, the IZO target (90wt%In2C>3 -10wt%ZnO) was used to prepare the indium-zinc-oxide (IZO) thin films on the different substrates, and the different sensing structures (IZO/Si, IZO/SiCVSi and IZO/ITO glass) were deposited by r.f. sputtering system. Afterwards, the new sensing structure and a commercial MOSFET device were connected, and the separative structure of the extended-gate field-effect transistor (EGFET) was fabricated. The structure of EGFET with the Keithley 236 measurement system was utilized to.measure the current-voltage (I-V) curves in the various pH buffer solutions (pH=l~ll). It was found that the different sensing structures based on IZO thin films have a high pH sensitivity and a fairly linear regression. In which, the highest pH sensitivity (57.4 mV/pH) was obtained based on IZO/Si sensing structure in pH=l~l 1 buffer solutions.