全水溶液工艺的高k介电薄膜的低温制备及TFT器件的集成

Because of the demands of low-energy consumption and high-mobility electronic devices, the development of high dielectric constant (k) thin film and the research of the MOS devices based on high-k dielectrics are becoming more and more important. The research of this project is to develop ultra-thin, nontoxic, environmentally-friendly, and low-cost high-k dielectric thin films with low leakage current density and relatively high k value, which will provide the clues for high-efficiency and low-cost materials for large-scale MOS integrated circuits. This research includes three parts: 1) "water-inducement" sol-gel technology and low-temperature UV-decomposition processes are used to prepared ultrathin high-k dielectric film (T<300 oC). The film quality can be optimized by doping and post treatment. 2) "water-inducement" sol-gel technology is used to prepare InMZnO channel layer (M: transition metal) at low temperature. The defect density of MOS devices can be analyzed by fitting the experimental results with theoretical calculation. The final goal is to obtain the high-mobility thin-film transistors with low defect density. 3) Depending on the TFT difference based on various channel layer and dielectric layer, we will find the possible applications in the field of biological detection. Compared to the traditional silicon-based MOS detector, the low voltage characteristics of the TFTs are very important in science and have broad applications.

在低能耗和高迁移率电子器件的需求中，高介电常数(k)薄膜及基于高k介电薄膜的MOS器件的研究具有极其重要的意义。本项目以开发无毒、环境友好、低成本的超薄高k介电材料为研究基础，以低漏电流和较高介电常数为性能目标，为大规模MOS集成电路提供高效低成本材料提供依据。研究包括三部分：1)利用“水性”溶胶-凝胶技术和“紫外光分解”低温工艺制备超薄高k介电薄膜(T＜300oC)，通过设计掺杂实验和后处理工艺优化薄膜质量。2)利用“水性”溶胶-凝胶技术低温制备InMZnO半导体沟道层（M：过渡金属元素），结合理论计算和实验结果分析MOS器件的缺陷态，最终获得具有低缺陷密度和高迁移率的薄膜晶体管(TFT)。3)根据TFT沟道层和介电层的不同，拓展其在生物探测领域的应用。相比于传统硅基MOS探测器件，该TFT器件的低压操作特征具有重要的科学价值和广阔的应用前景。

非晶氧化物半导体(AOS)薄膜晶体管(TFT)具有迁移率高、室温制备、适合大面积生产、成本低等优点，引起了学术界和工业界浓厚的兴趣。一个影响比较大的因素是介电层的选取和制备，溶液法制备介电层更是工作中的难点。本项目采用的水性溶胶技术成功制备了多种超薄高k介电薄膜（AlOx, ScOx, ZrOx, HfO2等），并成功集成到了场效应器件中。该技术保证了在薄膜制备过程中没有任何有毒的有机成分加入，并且显著的降低了器件的制备温度。在此基础上，我们利用成熟的水溶液技术成功制备了全水溶液工艺的TFT器件，该系列研究成本廉价，过程环保对大面积制备绿色器件和实现柔性衬底上的器件集成具有重要的指导意义。不仅如此，在完成基本的目标之外，我们还研究了基于纳米纤维的场效应器件的制备和电解质晶体管在神经仿生领域的应用，拓展了水性溶胶技术的应用。