氮氧锌薄膜的制备及其光电特性的研究

发布时间：2018-03-16 22:36

本文选题：ZnON薄膜　切入点：磁控溅射　出处：《电子科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：近些年以来,随着半导体工艺技术的飞速发展,半导体薄膜材料在能源、信息、国防等众多领域得到了广泛应用,尤其在平板显示和太阳能电池领域蕴含着巨大的利用价值。薄膜材料是支撑科技信息产业发展的重要基础之一,必将获得更广阔的发展空间。作为新型氧化物薄膜材料的代表之一,ZnON薄膜以其高载流子迁移率、优良的光学和电学特性、高稳定性、清洁无污染、原材料丰富等优势成为人们关注研究的焦点。本文通过制备ZnON薄膜,探究其最佳的工艺参数和制备条件,并对制备的薄膜材料进行性能表征。以ZnON薄膜为有源层制备ZnON基薄膜晶体管(ZnON-TFT),完成TFT工艺制备流程,对得到的ZnON-TFT电学特性进行测量,探究不同制备条件对ZnON-TFT电学特性的影响。具体内容分为以下三个部分:首先,采用射频磁控溅射镀膜法制备ZnON薄膜,改变氧氮比、溅射功率和靶基距等制备参数,对制备的薄膜材料进行光学特性、方阻、SEM等性能表征。结果表明氮氧比对薄膜光透过率的影响最大,随着氮气流量逐渐增加,薄膜内氮元素含量增加,透过率逐渐减少,禁带宽度降低。同时,薄膜透过率还与溅射功率和靶基距有关,溅射功率增大,透过率减小;靶基距增大,透过率增大。另外,方阻随着氮元素含量的增加而减少。SEM图表明实验制备ZnON薄膜表面比较平整。其次,以ZnON薄膜为有源层,Si作为栅极,Si02作为栅绝缘层,Mo作为源漏电极制备ZnON-TFT。以已含有Si02层的重掺杂P型Si作为衬底,先采用射频磁控溅射镀膜法制备80nm厚ZnON薄膜,再采用直流磁控溅射镀膜法制备100nm厚Mo薄膜,经过光刻、刻蚀等工艺后得到ZnON-TFT。最后,对不同制备参数下ZnON-TFT进行电学性能的测试。采用半导体测试仪测量TFT的转移特性曲线和输出特性曲线,将数据绘制成图,提取TFT特性参数。结果表明,随着氮气流量和溅射功率增加,ZnON-TFT载流子迁移率与开关比先增大后减小,亚阈值摆幅先减小后增大。随着靶基距的增加,迁移率和开关比逐渐减小,亚阈值摆幅增大。得到最佳制备工艺参数为氮气流量30sccm,溅射功率120W,靶基距9cm,此时载流子迁移率为6.12cc2/V^s,开关比1.14×105,亚阈值摆幅为1.5 V/dec,阈值电压为8.5V。阈值电压均为正值表明制备的ZnON-TFT为n沟道增强型TFT器件。
[Abstract]:In recent years, with the rapid development of semiconductor technology, semiconductor thin film materials have been widely used in many fields, such as energy, information, national defense, etc. Especially in the field of flat panel display and solar cells, there is great value in utilization. Thin film material is one of the important bases to support the development of science and technology information industry. As a representative of new oxide thin films, ZnON thin films have high carrier mobility, excellent optical and electrical properties, high stability, clean and pollution-free. The advantages of abundant raw materials have become the focus of research. In this paper, the optimal process parameters and preparation conditions of ZnON thin films are investigated. The ZnON based thin film transistors were prepared by using ZnON thin film as active layer. The preparation process of TFT was completed and the electrical properties of ZnON-TFT were measured. The effects of different preparation conditions on the electrical properties of ZnON-TFT were investigated. The specific contents were as follows: firstly, ZnON films were prepared by RF magnetron sputtering, and the preparation parameters such as oxygen to nitrogen ratio, sputtering power and target distance were changed. The optical properties of the films were characterized by SEM. The results show that the ratio of nitrogen to oxygen has the greatest influence on the optical transmittance of the films. With the increase of nitrogen flow rate, the content of nitrogen element in the films increases, and the transmittance decreases gradually. At the same time, the transmittance of the films is related to the sputtering power and the target substrate distance. The sputtering power increases and the transmittance decreases, and the target substrate distance increases and the transmittance increases. The square resistance decreases with the increase of nitrogen content. The results show that the surface of ZnON films prepared by experiments is flat. Secondly, ZnON-TFTs were prepared by using ZnON thin film as active layer and Si as gate insulator and Mo as source leakage electrode. The 80nm thick ZnON thin films were prepared by RF magnetron sputtering with heavily doped P-type Si with Si02 layer as substrate. Then 100 nm thick Mo thin films were prepared by DC magnetron sputtering. ZnON-TFTs were obtained by photolithography and etching. The electrical properties of ZnON-TFT under different preparation parameters were tested. The transfer characteristic curve and output characteristic curve of TFT were measured by semiconductor tester, and the data were drawn into a graph to extract the characteristic parameters of TFT. With the increase of nitrogen flow rate and sputtering power, the carrier mobility of ZnON-TFT decreases first and then decreases, the sub-threshold swing decreases first and then increases, and the mobility and switching ratio decrease gradually with the increase of the target base distance. The optimum preparation parameters are nitrogen flow rate 30 sccm, sputtering power 120 W, target base distance 9 cm, carrier mobility 6.12 cc2 / V ^ s, switching ratio 1.14 脳 10 5, subthreshold swing 1.5 V / deco, threshold voltage 8.5 V. the threshold voltage is positive. The ZnON-TFT is n channel enhanced TFT device.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O484

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