Ozone-treated channel diamond field-effect transistors

Diamond field-effect transistors (FETs) whose channel is partially oxidized and highly resistive are fabricated by ozone treatment. These FETs are operated in electrolyte solutions. From XPS analyses, it is evident that hydrogen-terminated (H-terminated) diamond is partially oxygen-terminated (O-terminated) by ozone treatment. The quantification of surface oxygen in ozone-treated diamond is carried out. The quantification shows that the surface oxygen increases with an increase in ozone treatment time indicating the control of oxygen coverage. The partially O-terminated diamond surface channel is much less conductive compared with the H-terminated diamond. The ozone-treated FETs were operated stably even though the channel of the FETs becomes highly resistive. For the sensing of particular ions or molecules by the immobilization of sensing components, the control of surface termination is necessary.