Structural and sensing properties of high-k PrTiO3 sensing membranes for pH-ISFET applications.
We describe an electrolyte-insulator-semiconductor (EIS) device for biomedical engineering applications prepared from high-k PrTiO(3) sensing membranes deposited on Si substrates by means of reactive radio-frequency sputtering. We used X-ray diffraction, X-ray photoelectron spectroscopy, and atomic force microscopy to investigate the structural and morphological features of these films after they had been subjected to annealing at various temperatures. The EIS device incorporating a high-k PrTiO(3) sensing film that had been annealed at 800 degrees C exhibited a higher sensitivity (56.8 mV/pH, in the solutions from pH 2 to 12), a smaller hysteresis voltage (2.84 mV in the pH loop 7 --> 4 --> 7 --> 10 --> 7), and a lower drift rate (1.77 mV/h in the pH 7 buffer solution) than did those prepared at the other annealing temperatures, presumably because of its thinner low-k interfacial layer at the oxide-Si interface and its higher surface roughness.
Pan
Tung-Ming
TM
Department of Electronics Engineering, Chang Gung University, Taoyuan 333, Taiwan. tmpan@mail.cgu.edu.tw
Liao
Kao-Ming
KM
D015374:Biosensing Techniques / Q000295:instrumentation*; D006863:Hydrogen-Ion Concentration; D008567:Membranes, Artificial; D018625:Microscopy, Atomic Force; D011221:Praseodymium / Q000737:chemistry*; D012680:Sensitivity and Specificity; D012822:Silicon Dioxide / Q000737:chemistry; D013052:Spectrometry, X-Ray Emission; D013696:Temperature; D013997:Time Factors; D014025:Titanium / Q000737:chemistry*; D014961:X-Ray Diffraction
D008567:Membranes, Artificial; C009495:titanium dioxide; D012822:Silicon Dioxide; D014025:Titanium; D011221:Praseodymium