HfO2 and ZrO2-Based Microchemical Ion Sensitive Field Effect Transistor (ISFET) Sensors: Simulation & Experiment

作者：Jankovic V^*; Chang J P

来源：Journal of the Electrochemical Society, 2011, 158(10): P115-P117.

DOI：10.1149/1.3623421

• hafnium compounds
• ion sensitive field effect transistors
• microfabrication
• microsensors
• pH
• silicon compounds
• zirconium compounds

Microchemical ion-sensitive field effect transistor (ISFET) sensors were designed, simulated, fabricated, and electrically characterized using SiO2, ZrO2 and HfO2 deposited by different methods as ion-sensitive gate dielectric materials. The SiO2 films showed a non-linear pH response with a low pH sensitivity (similar to 10 mV/pH) around the SiO2 point of zero charge (pzc) of 3.5 +/- 0.5 and a higher pH sensitivity (similar to 25 mV/pH) above the pzc. The ZrO2 and HfO2 films both showed linear and almost ideal (Nernstian) pH sensitivities (similar to 55 mV/pH) over a wide pH range. The pzcs of ZrO2 and HfO2 were determined to be 6.7 +/- 0.5 and 5.5 +/- 0.5 respectively. The theoretically predicted C-V responses obtained by numerically solving electroneutrality and potential continuity equations for the electrolyte oxide semiconductor (EOS) device qualitatively matched the experimental trends. This analysis offers an effective and alternative approach of determining the point of zero charge of metal oxide dielectrics.

• 出版日期2011