【作者】 梁军；

【导师】 吴惠桢；

【作者基本信息】 中国科学院研究生院（上海微系统与信息技术研究所） ， 微电子学与固体电子学， 2006， 博士

【摘要】 日益增长的信息技术对超高集成度、高速、低功耗集成电路的需求，驱使晶体管的尺寸越来越小，随之而来的问题是作为MOS栅氧化物和DRAM电容介质的SiO₂迅速减薄至物理极限。另一方面，新材料的应用推动薄膜晶体管（TFT）平板显示技术迅猛发展。由此，我们对纳米ZnMgO薄膜在MOS晶体管和透明TFT的应用进行了多方面的探索研究，取得如下创新性结果： 1) ZnMgO纳米薄膜的生长与材料结构采用物理蒸发低温沉积系统（PELD）在不同衬底上，包括玻璃，石英和硅，制备了不同晶相的ZnMgO薄膜。因为生长温度低，生长的ZnMgO／衬底界面清晰，没有明显的氧化物过渡层。在氧气气氛下，经过400～700℃退火的薄膜，XRD测试半峰宽均小于0.4°，说明薄膜晶体具有良好的结晶性和热稳定性。 2) Al／C-ZnMgO／Si MIS结构电学性能和热稳定性 制备立方相C-ZnMgO MIS结构研究其电学性能。在1MHz测试频率下，C-ZnMgO材料的介电常数为10.5；大于1MHz，介电常数随频率增加而逐渐明显降低。通过电容—电压（I-V）和电流—电压（C-V）特性测试，我们研究了不同退火温度对MIS结构性能的影响。经过550～900℃退火处理的C-ZnMgO MIS结构的漏电流密度降低了3个数量级。发现550℃退火的C-ZnMgO薄膜中可动离子缺陷密度最小，这是因为退火后薄膜中的杂质缺陷得到有效的复合。高温900℃退火的薄膜有最好的界面特性结果，界面处形成了硅酸盐化合物MgSi_xO_y，进而提高了界面质量。但是薄膜中杂质缺陷增加。这可能是因为在900℃下Zn离子与O离子从ZnMgO薄膜中析出并且向表面移动，从而增加了薄膜中的缺陷，与此同时，界面处有硅酸盐化合物MgSi_xO_y的形成从而提高了界面质量。这些材料结构与电学性能的研究有助于推动C-ZnMgO在MOSFET工艺中的应用。更多还原

【Abstract】 The fast development of information technology requires integrated circuit to be greater integrated, faster functioned and lower power-consumed, which lead to continuous shrinkage of MOS and DRAM feature size and the thickness of MOS gate dielectrics （SiO₂） would soon scale down to its physical limit. Under this trend the high-K dielectrics is a promising solution for the future development of CMOS technology. Another trend is the new material systems application in TFT for next generation panel display technology. We have made a serics of investigation on fabrication and characteristics of high-K ZnMgO thin film on MOSFET and ZnMgO stacks on TFT. Main innovation results are listed as below:Highly （002） oriented Cubic ZnMgO （C-ZnMgO） films were grown in a physical evaporation low-temperature deposition system （PELD）. As-grown thin films show clear interface on the silicon. The thin films have good thermal stability and good crystal quality with smaller than 0.4° FWHM observed by XRD spectra after annealing at 400-700 ℃ in O₂ atmosphere. After fabrication into MIS structure, good dielectrics property with dielectrics constant 10.5 was attained. Permittivity is de-gradated when frequency more than 1MHz. C-ZnMgO thin film after 400℃ annealing was found to greatly reduce leakage current down to 3 orders. Of 550℃ annealing leads to high quality thin film. The reason is that at 550℃ annealing the mobile ions defect in the film were annihilated. Of 900℃ annealing shows reverse characteristics. The mobile ions defect in the film is noticeable which are attributed to Zn migrating toward surface and oxygen loss due to evaporation from the surface. But the film shows high quality interface characteristics, which could be attributed to the formation of Mg silicate layer in the interface. Those structural and electrical characteristics are helpful to MOSFET processing.Great efforts have been made for the high-K C-ZnMgO MOSFET process. The current-voltage （I-V） characteristics of MOSFET were systematically studied. The output characteristic value is lower than our Medici tool simulation result and the output curve shows insufficient in the saturation region. Those are attributed to更多还原