The innovative AlN-ISFET based pH sensor

Abstract

This innovative pH-ISFET sensor used nanocrystalline-AlN thin film as ion-sensitive membrane which prepared by reactive gas-timing r.f, magnetron sputtering without heating substrate and post annealing. The technique of gas-timing r.f. magnetron sputtering purposed by us, the feeding gas is on-off controlled periodically in such a way that the deposited AlOxNy film has a quite stable composition of aluminum, nitrogen and oxygen (A1:O:N=52:18:30 %) all over the entire film. The AlN-ISFET devices were structured. The pH-sensitivity characteristics show increasing sensitivity depended on film thickness. The highest sensitivity is 54.50 mV/pH achieved from 80 nm of AlN thin film which is comparable to our previous report Si3N4-ISFET devices. © 2008 IEEE.