【作者】 刘爽；

【导师】 陈艾； 宁永功； 杨家德；

【作者基本信息】 电子科技大学 ， 材料物理与化学， 2001， 博士

【摘要】 PtSi红外探测器用于红外探测具有极大优势，典型的应用主要是红外成象制导领域。其探测器量子效率、均匀性、可靠性很大程度上取决于PtSi／Si结构特性，因此改善PtSi／Si结构，提高探测器性能具有很大的学术意义和应用价值。本文在分析探测器量子效率同PtSi／Si结构关系的理论基础上，提出提高PtSi／Si结构性能的关键因素和改进途径。针对PtSi／Si肖特基势垒和研制纳米级超薄PtSi膜进行了大量相关实验，首次用低能离子注入方法将PtSi／Si势垒高度降低到0.15ev，首次在真空度不高条件下，制备出～4nm纳米级超薄膜，并将PtSi／Si红外探测器量子效率提高3～5倍。 研究得到的一些有益和有创新意义的结果归纳如下： 1、分析PtSi／Si结构测参数与膜特性的关系，用Monte Carlo方法计算了薄膜厚度、势垒高度同探测能力的关系，得到提高探测器探测能力的有效途径。考虑入射红外波的叠加，采用积分方法，首次得到用于3～5μm波长范围PtSi薄膜厚度最佳值是2～5nm。 2、详细讨论了PtSi薄膜形成热力学、动力学以及原子相互扩散机理，得到PtSi形成不是固定模式，与制备工艺条件密切相关的重要结论，并通过实验加以验证。 3、提出均匀PtSi／Si势垒。以薄膜最终物相和连续性评价势垒均匀性。通过实验测试了制备工艺参数对薄膜物相、连续性的影响，以及所引起薄膜方阻的变化。 4、研究PtIrSi膜物相结构和势垒高度，得出降低PtIrSi／Si结构势垒困难的结论。推导出掺杂衬底势垒高度的降低同杂质临界厚度和峰值浓度的关系。首次采用硅衬底低能注入B⁺、In⁺，创造性地设计调整层，将PtSi／P-Si势垒高度降低到0.15ev。 5、设计制备纳米级超薄膜新工艺方法。通过氢气预处理、真空退火、减薄等关键工艺研究，实现混合生长模式、分步退火，首次在真空度不高的设备条件下制得均匀连续超薄（～4nm）PtSi膜，并得到新型SiO_x／PtSi／Pt₂Si／Si 摘 要一微结构。 6、进行超薄Ptsi膜表征技术研究。在XRD表征单晶衬底上超薄膜物相时，采用衬底与膜分别取谱，排除衬底干扰信号等技术措施，获得准确表征超薄膜弱信号。建立XPS分析超薄Ptsi／St膜物相、含量的准确参数和方法，应用ARXPS对超薄膜均匀性、微结构和厚度进行分析测试，首次测出～4urn薄膜厚度，并观察到薄膜分层结构。用TEM观察薄膜均匀、连续性，薄膜厚度、晶粒不同取向生长状态和界面状态等显微结构。用AFM观察Ptsi薄膜表面形貌，得到退火过程中热力学、动力学变化状况。建立XPS 价带谱同Ptsi／PS 势垒关系，首次利用XPS价带谱分析势垒相对高度。 7、对超薄Ptsi膜微结构及性能进行优化。研究了物相优化、表面均匀性提高以及势垒和薄膜厚度降低，首次提出氢气处理衬底会引起薄膜形成主扩散物质改变，并利用该性质使＊x／Ptsi ／Pt。St／St变为＊x／ Pt。St／ Ptsi ／St微结构，获得高性能Ptsi／Si膜，用之研制的探测器，探测能力提高了3～5倍。更多还原

【Abstract】 PtSi infrared detector, has superb advantages in the fields of infrared detector and its typical application is in the guidance area. The quantum efficiency, uniformity and reliability of PtSi infrared detector is mainly depend on the properties of PtSi/Si structure. Hereby, it is of great academic significance and application value to improve the structure of PtSi/Si so as to enhance the performance of the detector. Based on theoretical analysis of the relationship between quantum efficiency of the detector and structure of PtSi/Si, the key factors and ways to improve PtSi/Si performance were proposed in the dissertation. The satisfactory results were obtained based on numerous experiments, which were focused on the improvement of the Schottky barriers and fabrication of nano-thinckness ultra-thin PtSi films. The barrier height was reduced to 0.15ev by injecting the low energy ions in PtSi/Si interface and the ultra-thin PtSi film with thickness of 4nm was obtained for the first time in the condition of lower vacuum, and the quantum ability of infrared detector fabricated with these films was increased about three-five times.Some helpful and new results were obtained as follows:1. The relationship between the detect parameters of PtSi/Si infrared detector and the properties of the films was derived. The dependence of detecting capability on the thickness of thin film and barrier height was simulated by the Monte Carlo method. Considering superposition of incidence infrared waves, integral methods were used to obtain the optimum thickness (2~5nm) of PtSi thin films within 3-5 u m wavelength, which is the result reported for the first time.2. The thermodynamics, kinetics and mechanism of atomic diffusion each other in the formation of PtSi thin films were discussed in detail. By theoretical study and experiment verification, an important conclusion was drawn that the formation of PtSi thin films can not be explained with single growth mode. Instead, it is closely related to fabrication processes.3. The theory of uniform PtSi/Si barrier was proposed. The uniformity ofillbarrier was evaluated by final phase and continuity of thin films. The effects of fabrication technology on phases, continuity and resistance of thin films were studied experimentally.4. Based on the experimental study of phases structure and barrier height of PtlrSi thin films, the conclusion was reached that it is difficult to reduce the barrier height of PtlrSi/Si. The dependence of the barrier height variation on the critical thickness and maximum doping concentration of impurity was deduced, and the injecting In* and ET at PtSi/Si interface by low energy level was applied for the first time, and the design of adjusted layer reduced the barrier height to 0.1 5ev creatively.5. A novel technique was designed to grow ultra-thin PtSi. Based on the study of some key processes including hydrogen pre-treatment, vacuum annealing and film thickness decreasing, an uniform and continuous ultra-thin PtSi film with thickness 4nm was obtained for the first time in the condition of lower vacuum by mixed growth model and step anneal. A new model film microstructure, SiOx/PtSi/Pt2Si/Si, was obtained at last.6. The characterization techniques of ultra-thin PtSi film were investigated. A new technique was proposed that to characterize the ultra-thin phase on the single crystal substrate, the accurate signal of ultra-thin film can be obtained by spectrum of the substrate and film respective so as to eliminate the noise of substrate. Accurate parameters of phases and content of ultra-thin PtSi/Si film were obtained by XPS. ARXPS was employed to measure the uniformity, microstructure and thickness of the film. By this technique, the thickness of the film, about 4nm, was measured and the layered structure was observed for the first time. TEM was also used to observe the uniformity, continuity, thickness and the microstructure of grain growth of the films. AFM was applied to observe the surface appearance更多还原