Sensing Performance of Stable TiN Extended-Gate Field-Effect Transistor pH Sensors in a Wide Short Annealing Temperature Range

摘要

In this letter, the structural properties and sensing performances of TiN sensing films deposited on a n(+)-type Si through the reactive DC sputtering method with rapid thermal annealing at a wide temperature range of 200 degrees C to 800 degrees C were investigated for extended-gate field-effect transistor (EGFET) pH sensors. We used X-ray diffraction, X-ray photoelectron spectroscopy, and atomic force microscopy to study the structural characteristics of these films. These TiN EGFET sensors exhibited almost the same sensing performances, such as pH sensitivity similar to 58 mV/pH), hysteresis voltage similar to 2 mV), and drift rate (similar to 0.45 mV/h), indicating that they contained similar or identical in the film composition and surface roughness.