Analytical features of K+-sensitive membrane obtained by implantation in silicon dioxide films

Potassium (K+) ion-sensitive membranes produced by the ion implantation technique are investigated. The sensing layers are fabricated by implanting K+ and Al+ ions into silicon dioxide on silicon with low energy in order to reduce the damage to the substrate during the process of implantation. The ion sensitivity of such ion-implanted layers was investigated by using C–V measurements. All devices tested have shown good sensitivities and linear responses over at least four decades of potassium activity, with good selectivity in the presence of interfering ions like NH4+, Li+ and Mg2+.