In-situ Real-time Measurement Technology Study On Preparation Of Organic Semiconductors Thin Film Device

In recent years,the research and application of organic semiconductor got rapid development,forming multi-disciplinary research field across physics,chemistry,electronics and materials and so on.Compared to traditional materials,organic semiconductor materials caused wide attention in various fields such as electronics,microelectronics,solar battery and communication.According to the study,the structure,the film thickness and the interaction between film of organic thin film and so on are the important factors influencing the organic device performance.Therefore,the main propose an approach for real-time measuring the optical and electric properties of a thin film during the process of growth and then study the corresponding relations between optical signal and electric property and thin film structure.The approach is developed on the basis of two techniques: field effect transistor(FET)structure based electrical characteristics testing method and differential reflectance spectroscopy(DRS).The main works include the following aspects:1?For the demand of in-situ real-time measuring the optical and electric properties of organic semiconductor thin film during the process of growth,propose the approach of in-situ real-time measuring the optical and electric properties and set the system on the basis of two theories: field effect transistor(FET)structure based electrical characteristics testing method and differential reflectance spectroscopy(DRS).Design the software program of Labview,achieving the in-situ real-time measurement of the optical and electric properties.2?Design the new sample structure of comb teeth shape base on bottom-gate structure and the new holding device.Deposit pentacene organic thin film field-effect transistor by means of vacuum thermal evaporation.3?Optimize online electrical testing system and test performance of the system,the relative percentage of measured deviation is in the rage of + /-0.3% meeting the requirements of the experiment.Verify the feasibility of on-line electrical measurement in the vacuum environment and achieve the in-situ real-time measurement of the electric properties.And measure electric properties of organic field-effect transistor with different length-width ratio of channel and different thickness of organic thin film.4?Analyze the DRS signal of thin film during the whole process of growth,it is found that the pentacene layer forms thin film phase structure,the fluctuation amplitude of the spectrum is very sensitive to the variety of the thickness of the top most film,A good agreement between the experimental data and the computational results with a four-layer structure model of air / Pentacene/ SiO2/Si suggests that the DRS signal here is mainly contributed by the interference existing in the multilayer interfaces.And scan thin film structure of different time using AFM,it can get the corresponding relations between optical signal and electric property and thin film structure by means of analyzing contrastively the AFM figure and optical signal and electric signal of the same time.