【作者】 吴跃波；

【导师】 吴孙桃；

【作者基本信息】 厦门大学 ， 测试计量技术及仪器， 2008， 博士

【摘要】 随着紫外探测技术越来越广泛地被应用于众多领域,大大推动了宽禁带半导体的发展。ZnO是一种直接带隙宽禁带半导体材料,在光电器件领域有着光明的应用前景,近年来已成为国际上半导体光电材料的研究热点。目前,高质量的ZnO薄膜一般是利用MOCVD或MBE在蓝宝石衬底上制备。生产成本高,限制了ZnO材料的潜在应用。而磁控溅射技术是一种简便应用广泛且技术成熟的薄膜制备技术,生产成本低廉,与集成电路平面工艺兼容性好,通过调节磁控溅射的工艺参数制备出高质量的ZnO薄膜是很有意义的工作。同时ZnO具有良好的抗高能射线辐射能力,相比其它宽禁带半导体在制作紫外探测器方面具有独特的优势。本论文主要工作是研究如何利用简便的射频磁控溅射技术在SiO₂/Si和石英玻璃衬底上制备高质量的ZnO及其掺Al（AZO）薄膜。在薄膜制备的研究基础上,在以SiO₂/Si为衬底的ZnO薄膜上研制MSM结构的紫外光电探测器,研究了器件的制作工艺和性能。所开展的研究工作对ZnO薄膜在光电领域的器件应用开发具有重要的意义,主要工作内容如下:利用JC500-3/D磁控溅射镀膜机在SiO₂/Si和石英玻璃衬底上制备具有C轴择优取向的ZnO和AZO晶柱薄膜。结合XRD、AFM、SEM、霍耳效应测量和透射谱的测量,研究了溅射气体氩氧比、溅射气压、溅射功率和衬底温度对薄膜结构、形貌、光电特性的影响,为制作性能良好的紫外探测器探索较佳的工艺参数。对在较佳溅射工艺参数下在SiO₂/Si衬底上制备的ZnO和AZO薄膜样品进行退火处理。随着退火温度的升高,ZnO和AZO薄膜的结晶性能得到改善。在以SiO₂/Si为衬底900℃下退火的ZnO薄膜样品上制作了Ag-ZnO-Al和Au-ZnO-Al方框结构,研究金属Ag、Au与ZnO的接触特性。结果表明,Ag与ZnO薄膜形成了良好的肖特基接触,Au与ZnO薄膜形成了欧姆接触。采用单步反剥离技术制备金属电极,在以SiO₂/Si为衬底退火后的ZnO薄膜上制作了Ag-ZnO-Ag MSM结构肖特基型和Au-ZnO-Au MSM结构光电导型的紫外光电探测器,并对所制备的探测器进行I-V、C-V及光谱响应的测试分析。结果表明所制备的器件在紫外波段有较高的响应度,光谱响应峰在370nm附近。本论文从材料制备、器件设计流片到测试分析,做了大量的实验探索与理论研究工作,创新性地解决了一些科学与技术上的难题:利用简便的射频磁控溅射技术在SiO₂/Si和石英玻璃衬底上制备出C轴择优取向、颗粒均匀、致密的ZnO和AZO晶柱薄膜;结合Kajikawa提出的ZnO薄膜生长模型和所制备样品的SEM截面图讨论了我们利用磁控溅射制备的多晶ZnO薄膜的生长过程;根据我们采用的JC500-3/D磁控溅射镀膜机的参数调节范围,研究了溅射工艺参数和退火对薄膜特性的影响;结合Burstein-Moss效应分析了AZO薄膜的光学带隙变化;设计了Ag-ZnO-Ag MSM结构肖特基型和Au-ZnO-Au MSM结构光电导型的紫外光电探测器,开发了完整可行的制备工艺流程。更多还原

【Abstract】 Wide band semiconductors has been greatly developed with ultraviolet photodetectors applied more and more widely in many aeras. ZnO, as a direct and wide band gap semiconductor, has promising applications on optoelectronic devices. In recent years ZnO has been a hotspot in the area of semiconductor optoelectronic material. At present, high quality ZnO film is grown on sappire by MOCVD or MBE, which is expensive and limits potential applications of ZnO material. Magnetron sputtering is a simple technique which has been widely applied on film deposition. It is cheap and has a good compatibility with integrate circuit technology. It is a very significant task that high quality ZnO film is prepared by adjusting the technology parameters of magnetron sputtering. ZnO is resistant to high energy proton irradiation, which makes it have particular advantages over other wide gap semiconductors on fabrication of ultraviolet photodetector. In this dissertation, high quality ZnO and AZO films were deposited on SiO₂/Si and quartz glass substrates by RF magnetron sputtering. Based on the study of the films, MSM structure ultraviolet photodetects were fabricated on ZnO films on SiO₂/Si substrate. The work is of a great significance in application of ZnO film on optoelectronic devices. The main contents of this dissertation are summarized as follow:The ZnO and AZO films with c-axis preferred orientation were deposited on SiO₂/Si and quartz glass substrates by RF magnetron sputtering. The effects of sputtering parameters on the properties of the films were investigated by XRD, AFM, SEM, Hall effect and transmission spectra. The ZnO and AZO films on SiO₂/Si under better sputtering parameters were annealed. The quality of the films was improved with annealing temperature raising.Ag-ZnO-Al and Au-ZnO-Al quadrate structures were fabricated on the ZnO films on SiO₂/Si annealed at 900℃. The results indicate that schottky contact is achieved by Ag-ZnO contact and ohmic contact is achieved by Au-ZnO contact. Ag-ZnO-Ag and Au-ZnO-Au MSM photodetectors were fabricated on the annealed ZnO films on SiO₂/Si. Metal electrodes were achieved by a lift-off process. I-V, C-V and photoresponsivity characteristics of the photodetectors were analyzed. The photoresponsivity was high in the ultraviolet range and exhibited a maximum value around 370nm.In the dissertation, A lot of experiments and theory research have been conducted. Some technical problems are solved innovatively: The compact ZnO and AZO films with c-axis preferred orientation and uniform grains were deposited on SiO₂/Si and quartz glass substrates by RF magnetron sputtering; We discussed ZnO film growth process by ZnO film growth model and cross section image of the ZnO sample; The effects of sputtering parameters and annealing on the properties of the films were investigated; Optical band gap of the AZO films was analyzed by Burstein-Moss effect; Ag-ZnO-Ag MSM schottky photodetectors and Au-ZnO-Au MSM Photoconductive detectors were designed and fabricated.更多还原