Title |
A Study on the pH-, pNa- and pK-Sensing Properties of K and Al Coimplanted SiO_2 Thin Films |
Keywords |
Silicon dioxide ; LPCVD ; ion implantation ; ion sensitivity ; ISFET |
Abstract |
Silicon dioxide (SiO_2) layers were fabricated on Si_3N_4/SiO_2/Si layer structures by low pressure chemical vapor deposition (LPCVD). Potassium and aluminum were then coimplanted by implanting potassium ions with the energy of 100 [keY] and dose of 5x10^{16} [cm ̄^2] and 1x10^{17} [cm ̄^2] into an aluminum buffer layer on the SiO_2Si_3N4/SiO_2/Si structure. The pH, pNa, and pK ion sensitivities of the resulting layers were investigated and compared to those of as-deposited silicon dioxide layer. The pK-sensitivity of the silicon dioxide was enhanced by the K and Al coimplantation. On the contrary, the pH and pNa-sensitivities of the coimplanted silicon dioxides were quite lower than that of the as-deposited silicon dioxide. |