铟镓锌氧化物半导体器件制备与性能研究

发布时间：2018-02-23 20:52

本文关键词： IGZO 薄膜晶体管氧含量电学性能电极双层结构　出处：《郑州大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着大尺寸的显示器和有机发光二极管的发展,传统的晶体硅薄膜和有机薄膜晶体管已经满足不了现代显示的要求。作为薄膜晶体管的核心组成,特别是现代透明显示技术,非晶态铟镓锌氧化物(a-IGZO)薄膜作为薄膜晶体管的沟道层成分正越来越受到广泛的关注。由于其优越的性能:高迁移率、均一性好、制备温度低和良好的光学透过性,被选为下一代主流的晶体管沟道层材料。为了制备出性能优异的薄膜晶体管,本文着重分以下几个部分探讨以a-IGZO为沟道层的薄膜晶体管的制备与性能研究。采用磁控溅射的方法在室温下超高真空(Ultra-high Vacuum)中制备出一系列不同氧含量的IGZO薄膜并对薄膜进行一系列表征:XRD结果表明室温下不同氧含量下磁控溅射制备出的IGZO薄膜均为非晶结构;不同工艺下制备出的IGZO薄膜其在可见光波段透过率均超过80%,并且得知在纯Ar下制备出的IGZO薄膜其光学禁带宽度为3.20eV,在氧含量为10%的气氛下制备出的IGZO薄膜光学禁带宽度为3.47eV;通过氧含量的改变实现了IGZO薄膜电阻率由10-4-106(?·cm)的变化,载流子浓度由1019(cm-3)降低至1011(cm-3)。进一步地,我们采用底栅顶接触结构制备出了“FTO-HfO2-IGZO-Al”薄膜晶体管器件。研究了不同氧含量制备的IGZO薄膜对薄膜晶体管性能的影响。研究表明对于不同IGZO薄膜晶体管,其10%氧含量下制备出的晶体管拥有低的关闭电流10-9A,高的饱和迁移率10.4cm2/V·s,阈值电压更接近0V。实验对比了不同的沟道宽长比对器件性能的影响,实验表明,采用掩膜版的方法在衬底上固定有特定图案的金属掩膜版,形成小面积的沟道层,有效防止了电极边缘电场对沟道层电子传输的影响,减小了不同宽长比对薄膜晶体管性能的影响。实验还对比了不同漏源电极(Cu、Al、ITO)对器件性能的影响,实验结果表明ITO、Al电极作为IGZO薄膜晶体管的漏源电极其器件性能最优。为得到高性能的薄膜晶体管,本文采用双层IGZO结构,在载流子浓度低的IGZO层下沉积一层载流子浓度高的IGZO薄膜,形成了载流子浓度不同的双层IGZO薄膜,然后研究了高载流子浓度IGZO层对器件性能的影响。实验表明IGZO半导体晶体管采用双层IGZO结构可以显著提高器件电学性能,器件开启电流明显提升至1.3mA,迁移率提升至54cm2/V·s,其阈值电压达到0.4V,开关电流比达到106。
[Abstract]:With the development of large-sized displays and organic light-emitting diodes (OLEDs), traditional crystalline silicon thin films and organic thin film transistors can not meet the requirements of modern display. Amorphous indium gallium zinc oxide (a-gallium zinc oxide) thin films have attracted more and more attention as the channel layer composition of thin film transistors. Due to their excellent properties, such as high mobility, good uniformity, low temperature and good optical transmittance, amorphous indium gallium zinc oxide thin films are widely used in the fabrication of thin film transistors. The transistor channel layer material selected as the mainstream of the next generation. In order to produce thin film transistors with excellent performance, In this paper, the fabrication and performance of a-IGZO thin film transistors with channel layer are discussed. A series of IGZO thin films with different oxygen content have been prepared by magnetron sputtering in ultra-high vacuum ultrahigh vacuum at room temperature. A series of characterization results showed that the IGZO films prepared by magnetron sputtering at room temperature were amorphous. The transmittance of IGZO films prepared under different conditions is over 80 in the visible light band, and the optical band gap of IGZO thin films prepared under pure ar is 3.20eV, and the optical gap of IGZO films prepared in the atmosphere of 10% oxygen content is found to be 3.20eV. The band width is 3.47eV, and the resistivity of IGZO thin films can be changed from 10-4-106? 路cm), the carrier concentration decreased from 1019 to 1011 cm-3. Further, We have fabricated "FTO-HfO2-IGZO-Al" thin film transistor devices using bottom gate top contact structure. The effect of IGZO thin films prepared with different oxygen content on the performance of thin film transistors is studied. The results show that for different IGZO thin film transistors, The transistor with 10% oxygen content has a low closing current of 10-9A, a high saturation mobility of 10.4cm2 / V 路s, and a threshold voltage closer to 0V. the effects of different channel width ratios on the performance of the device are compared experimentally. A metal mask plate with a specific pattern is fixed on the substrate by using a mask plate to form a small channel layer, which effectively prevents the influence of the electrode edge electric field on the electron transport in the channel layer. The effects of different aspect ratios on the performance of thin film transistors are reduced. The experimental results show that Ito Al electrode is the best drain source electrode for IGZO thin film transistors. In order to obtain high performance thin film transistors, a double layer IGZO structure is used in this paper. A layer of IGZO thin films with high carrier concentration was deposited under the IGZO layer with low carrier concentration, and a double layer IGZO film with different carrier concentration was formed. Then the influence of high carrier concentration IGZO layer on the device performance is studied. It is shown that the double-layer IGZO structure of IGZO semiconductor transistor can improve the electrical performance of the device. The threshold voltage of the device is 0.4V and the switching current ratio is 106.The threshold current is raised to 1.3 Ma, the mobility is increased to 54 cm ~ 2 / V 路s, and the threshold voltage is 0.4 V.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN303

【相似文献】