MOCVD法制备锌锡氧薄膜及其特性研究

发布时间：2018-03-14 04:37

  本文选题：金属有机化学气相沉积　切入点：锌锡氧薄膜　出处：《山东大学》2011年硕士论文　论文类型：学位论文

【摘要】：在科学技术日新月异的今天,半导体材料的发展经历了第一代以锗、硅为代表的元素半导体,第二代以砷化镓、磷化铟为代表的化合物半导体,第三代半导体材料则以氮化镓、碳化硅、氧化锌等宽禁带半导体为代表,它们一般具有更高的击穿电场、热导率、电子饱和速率和更高的抗辐射能力,因而更适合于制作高温、高频及大功率器件,其中的ZnO和SnO2等宽禁带半导体氧化物材料都是重要的光电子信息材料,在透明导电氧化物方面有很多的应用。透明导电氧化物(transparent conductive oxide简称TCO)薄膜主要包括In、Sb、Zn和Cd的氧化物及其复合多元氧化物薄膜材料。 在透明导电氧化物薄膜的不同应用领域,对透明导电氧化物薄膜的性能提出了不同的要求。目前应用较多的是单掺杂的薄膜,用途有些局限,性能比较单一。每一种透明导电氧化物材料都具有各自的特性,不可能满足所有的应用要求。为了开发适合特殊用途的TCO薄膜,一些研究小组将各种TCO材料进行组合,制备出一些具有新特点的TCO薄膜。一些二元TCO材料(如ZnO、SnO2等)可以按各种比例组合、采用多种方法制成TCO薄膜,其性能与化学组分密切相关。Zn-Sn-O薄膜可以同时具有ZnO和SnO2的优点,它的化学稳定性与易刻蚀性及相关光电和结构等性质随组分的改变而改变。在一定的条件和一定的比例下,Zn-Sn-0可以形成新的三元TCO材料锡酸锌。锡酸锌根据不同的Zn和Sn的比例,有两种不同结构的晶体,分别是属于斜方六面体结构的ZnSnO3和立方相尖晶石结构的Zn2SnO4。 本论文的研究工作及结果如下： 1.MOCVD方法,以高纯(C2H5)4Sn作为锡源,高纯(C2H5)2Zn作为锌源,高纯02作为氧化剂,高纯N2作为载气,在蓝宝石(0001)衬底上制备了一定生长温度下Sn与Zn不同比例(原子比)的Zn-Sn-O薄膜。随后在锡锌比1：1的条件下进行了变温实验,温度范围为550-700℃。X射线衍射(XRD)测试结果显示,在特定的温度下,锡锌比分别为1：5、1：10和1：20时,只出现了ZnO(002)一个衍射峰,制备的薄膜为氧化锌六方纤锌矿结构；当锡锌比为1:1时,Zn-Sn-O薄膜呈现的是ZnSnO3(303)衍射峰,其晶体结构属三方晶系斜方六面体。分别对样品进行了扫描电子显微镜(SEM)、透过率和霍尔效应等测试,详细研究了薄膜的结构形貌特征、光学性质和电学性质。2.特定温度下,锌锡比1：10时生成ZnO薄膜,锌锡比1：1时生成ZnSnO3薄膜,分别对锌锡比为1：10和1：1的样品在空气中进行退火处理,退火温度为650℃和800℃。ZnO薄膜随退火温度的升高薄膜的晶体质量有所提高。ZnSnO3薄膜在退火温度为650℃时开始分解,退火温度为800℃时完全分解成Zn2SnO4和SnO2,这与ZnSnO3的热分解化学方程式是完全符合的,即2ZnSnO3(?)Zn2SnO4+SnO2
[Abstract]:Today, with the rapid development of science and technology, the development of semiconductor materials has experienced the first generation of element semiconductors represented by germanium and silicon, the second generation of compound semiconductors represented by gallium arsenide and indium phosphide, and the third generation semiconductor materials by gallium nitride. Silicon carbide, zinc oxide and other wide band gap semiconductors are generally more suitable for high temperature, high frequency and high power devices due to their higher breakdown electric field, thermal conductivity, electron saturation rate and higher radiation resistance. Both ZnO and SnO2 semiconductor oxide materials are important optoelectronic information materials. Transparent conductive oxide thin films mainly include the oxides of Zn and CD and their composite multicomponent oxide films. In different applications of transparent conductive oxide films, different requirements are put forward for the properties of transparent conductive oxide films. Each transparent conductive oxide material has its own characteristics and cannot meet all the application requirements. In order to develop TCO films suitable for special purposes, some research groups combine various TCO materials. Some TCO thin films with new characteristics have been prepared. Some binary TCO materials (such as ZnO- Sno _ 2, etc.) can be combined in various proportions to make TCO thin films. The properties of TCO thin films are closely related to the chemical composition. Zn-Sn-O thin films can have the advantages of both ZnO and SnO2. The chemical stability, etch resistance, related photoelectric and structural properties of Zn-Sn-0 change with the change of composition. A new ternary TCO material, zinc stannate, can be formed under certain conditions and a certain proportion of Zn-Sn-0. Zinc Stannate varies according to the ratio of Zn and Sn. There are two kinds of crystals with different structures: ZnSnO3 with oblique hexahedron and Zn _ 2SnO _ 4 with cubic spinel structure. The research work and results of this thesis are as follows:. 1. Using high purity C _ 2H _ 5H _ 4Sn as tin source, high purity C _ 2H _ 5H _ 2Zn as zinc source, high purity 02 as oxidant and high purity N _ 2 as carrier gas by MOCVD. Zn-Sn-O thin films with different ratio of Sn to Zn (atomic ratio) were prepared on sapphire sapphire (0001) substrates at a certain growth temperature. The temperature variation experiments were carried out at the ratio of Sn to Zn at 1: 1. The temperature range was 550-700 鈩，

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