Abstract
In this thesis, the principle of the MOSFET was be used for ISFET. The gate metal of the MOSFET was substituted for the insulator over the Silicon wafer such as silicon oxycarbide，which must be sensitive for the H+ and OH- in the buffer solution. Reference electrode was used to supply the reference potential for the buffer solution. The threshold voltage (VT) of the ISFET will shift in the various pH buffer solutions. Hence, the pH value of the solution can be detected by the ISFET.In this thesis the silicon oxycarbide (SiOC) membrane has been prepared by HDPCVD, High Density Plasma Chemical Vapor Deposition, method as a novel pH-sensitive layer under different gas flow rate ( trimethylsilane / oxygen, 3MS / O ) and plasma power. The silicon oxycarbide membrane was directly deposited on the p-Si substrate by ICP source to form the SiOC / Si EIS structure. The C-V measurement was used for examining the fabrication parameters and sensing properties. Moreover, the SiOC membrane was deposited on gate ISFET as the SiOC gate ISFET.Experimental results show that the fabrication parameters and characteristics of the SiOC membrane are determined at the gas flow rate 20/2(3MS/O) and the plasma power 500W via the EIS structure. There exhibits the pH response of about 52.5 mV/pH in the range of pH 1-9.