Study on the Preparation, Measurement and Readout Circuit of the Bio-medicine Sensor by the Spttering of Ruthenium

• Main Authors: Shih-i Liu, 劉適意
• Other Authors: Jung Chuan Chou
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/75339830482756027405

碩士 === 國立雲林科技大學 === 電子與資訊工程研究所碩士班 === 92 === In this paper, Ruthenium is one kind of noble metals, of which oxide has the characteristics of super-high capacity for storage charge. One of the reasons is double layer mechanism and another is pseudo-capacitance due to redox action on the surface of ruthenium oxide with the solution. The latter is ten times to the former in storing charge. Ruthenium dioxide is as metal because of low resistivity (less to 10-4 ohm•cm) and high surface area (about 800-1000 m2/g). The reasons why are studied for this paper are 1.high conductance, 2. high surface area, 3. multi-redox-active pairs [Ru(II)-Ru(III)-Ru(IV)-Ru(V)-Ru(VI)-Ru(VII)], 4.excellent adhesion of the enzymes and compounds, 5. excellent reversibility in electrochemistry, 6. very stable in the acid solution, 7.good pH sensing membrane. In this paper, R.F. sputtering technology is presented in fabricating thin film of ruthenium oxide and ruthenium nitride for the sensing electrode in pH Values. This film structure can be simulated as sensing electrode of semiconductor process. ISFET ( Ion Sensitive Field Effect Transistor) can be replaced with the EGFET (Extended Gate Field Effect Transistor), which can be saved for the cost in fabrication and measurement of the devices. In this paper, the ruthenium is studied in pH-ion measuring application of the sensing film by the R.F. sputtering with oxygen and nitrogen. In sputtering process, the preparation of ruthenium oxide film is the main work for the optimums, which is deposited by R.F. sputtering in the low pressure. The sensing membrane of ruthenium oxide presents a linear response from pH 1 to pH 12 of standard pH solutions with 56.52 mV/pH at the room temperature. If using nitrogen instead of oxygen, the sensing membrane of ruthenium nitride presents a linear response from pH 1 to pH 13 of standard pH solutions with 58.52 mV/pH at the room temperature. There exist superior mechanical and chemical characteristics in two kinds of sensing membranes of ruthenium, therefore they can be the good material in detecting the pH values and application of wide sensing, rapid response time, selection and so on. By a series of Scanning Electron Microscope (SEM), Atomic Force Microscope (AFM), Electron Spectroscope for Chemical Analysis (ESCA), Energy Dispersive Spectrometer (EDS), and X-Ray Diffraction (XRD) measurements, the compositions and structures of thin films can be obtained. The I-V (Current Voltage) measurement can be used by Keithley 236 with CD4007, and C-V (cyclic voltammetry) can be proven that the circuit structure of current measurement can be applied for detesting H+ ion in the sensing film of ruthenium composition. By the temperature effect, enzyme, response time, hystersis and so on, the characteristics of both films can be obtained for the development of semiconductor process, can be connected with MEMS (Micro-Electro-Mechanical Systems) in the application of biosensor measurement.