磁控溅射法制备MgAlSnO薄膜及其特性的研究

发布时间：2018-02-02 12:56

  本文关键词： 薄膜晶体管 磁控溅射 金属氧化物半导体 MgAlSnO　出处：《深圳大学》2017年硕士论文　论文类型：学位论文

【摘要】：当今电子信息化产业发展日新月异,显示技术在这其中更是扮演了十分重要的角色。在现有的显示技术中,无论是已规模化量产的TFT-LCD,还是作为最具潜力的下一代显示技术AM-OLED,TFT阵列都是其核心技术。近年来,氧化物半导体TFT因其具有高迁移率、可见光区域透明、可低温制备等特性而受到了广泛关注,是值得进一步研究和开发的新型TFT技术。本论文首次进行了采用磁控溅射方法制备MgAlSnO三元复合金属氧化物薄膜的研究,并对其作TFT有源层的应用进行了初步的实验探索,主要研究工作及结果如下:1、首先寻找最佳的磁控溅射工艺;针对磁控溅射设备工艺参数对制备MgAlSnO薄膜的影响进行了详细的实验研究,发现溅射气压为0.6Pa、溅射功率为100W时,薄膜的生长速度最快,表面形貌最好,并在120nm的厚度下保持良好的非晶态。2、对锡酸镁进行不同化学配比的Al掺杂,探索MgAlSnO在不同Al元素掺杂比(Mg:Sn:Al=16:7:1/8:3:1/4:1:1/1:1:2)下对薄膜的表面形貌、光学透过率和电学性能的影响。实验结果表明:随着Al元素比例的增加,薄膜表面粗糙度减小,表面更为光滑致密,可见Al元素的掺入有利于改善薄膜质量;不同配比的MgAlSnO薄膜在可见光波段的透过率不尽相同,但都保持在92%以上;对其MSM结构的电学性能测试发现电流密度和电压基本保持线性关系,说明MATO系列薄膜与Al电极和ITO电极之间形成良好的欧姆接触,Mg_2SnO_4和大比例掺Al的MATO(1:1:2)薄膜的导电性较好;3、利用EDS定性分析所制备的MATO系列薄膜上物质元素的组成成分时,发现薄膜成分与靶材的的配比有一定的差距,但当靶材中Al元素低掺杂时,薄膜中还是能含有接近匹配含量的Al;4、在Mg_2SnO_4和MgAlSnO薄膜制备过程中通入少量氧气(O_2/Ar=2/48)时,薄膜透过率都得到了提高,达到93%以上,部分比例薄膜导电性降低,说明通氧情况下,断裂氧键的金属原子会继续被氧化,透过率得到提高,薄膜中氧空位减少,用于导电的载流子浓度降低,导电性变差;5、300℃退火处理后Mg_2SnO_4和MgAlSnO薄膜仍保持非晶结构,薄膜表面光滑致密,导电性有所降低,主要是由于高温退火后薄膜中原子重组一次,氧空位缺陷减少,载流子浓度降低;6、在前期探索的良好的薄膜性能基础上,将MATO薄膜应用到TFT有源层,并结合光刻工艺进行了制备小尺寸TFT器件的初步试验。
[Abstract]:With the rapid development of electronic information industry, display technology plays a very important role in this field. In the existing display technology, whether it is a large-scale production of TFT-LCD. It is the core technology of AM-Ole TFT array, which is the most promising next generation display technology. In recent years, oxide semiconductor TFT is transparent in visible region because of its high mobility. Low temperature preparation and other properties have attracted wide attention. It is a new TFT technology worthy of further research and development. In this thesis, the preparation of MgAlSnO ternary composite metal oxide thin films by magnetron sputtering method was first studied. The application of TFT as active layer is studied. The main research work and results are as follows: 1. First, the best magnetron sputtering technology is found. The effects of the process parameters of magnetron sputtering equipment on the preparation of MgAlSnO thin films were studied in detail. It was found that the sputtering pressure was 0.6 Pa and the sputtering power was 100W. The film has the fastest growth rate, the best surface morphology, and maintains a good amorphous state. 2 at the thickness of 120nm. The magnesium Stannate is doped with different chemical ratios of Al. To explore the surface morphology of MgAlSnO films at different Al doping ratios (mg: SnW: 16: 7: 1 / 8: 3: 1 / 4: 1 / 1 / 1 / 1: 2). The influence of optical transmittance and electrical properties. The experimental results show that with the increase of Al element ratio, the surface roughness decreases and the surface becomes smoother and denser. It can be seen that the addition of Al element can improve the film quality. The transmittance of MgAlSnO films with different ratios is different in the visible band, but all of them remain above 92%. The electrical properties of the MSM structure show that the current density and voltage have a linear relationship, indicating that the ohmic contact between the MATO series films and Al and ITO electrodes is good. The conductivity of Mg_2SnO_4 and Al doped MATLAB 1: 1: 2) thin films is better. 3. When EDS qualitative analysis was used to analyze the composition of material elements in MATO series films, it was found that there was a certain gap between the composition of the films and the target materials, but when Al elements in the target materials were low doping. The film can still contain Al close to the matching content; 4. The transmittance of Mg_2SnO_4 and MgAlSnO films increased to more than 93% when a small amount of oxygen was added into the thin films. The partial reduction of the electrical conductivity of the films indicates that the metal atoms with broken oxygen bonds will continue to be oxidized, the transmittance will be increased, the oxygen vacancies in the films will be reduced, and the carrier concentration for conducting electricity will be reduced. Poor conductivity; After annealing at 5,300 鈩，

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