【作者】 高延军；

【导师】 田景全；

【作者基本信息】 长春理工大学 ， 物理电子学， 2008， 博士

【摘要】 微光夜视技术拓展了人眼的视觉范围,自上个世纪中期以来得到了迅猛的发展。新思想、新概念、新材料、新工艺和新技术的不断涌现,推动着夜视器件与技术的发展。由于光电子技术的需求牵引,二维电子倍增器件得到了很快的发展,其中微通道板(MCP)和微球板(MSP)电子倍增器就是典型的实例。微通道板电子倍增器是由大量平行堆积的单通道电子倍增器组成的具有蜂窝状结构的二维阵列,其对核中粒子和短波辐射均有响应,在微光夜视、高分辨显像管和示波管、光电倍增管、图像光子计数器以及粒子探测等领域有重要应用价值。目前,三代像管工艺成熟,四代像管已开始进入研究阶段。微通道板是像管的关键部件,也在更新换代,其相关的新技术不断涌现,性能不断提高,已引起国内外的广泛重视,这方面的研究工作对于研制新型微通道板器件,提高像管性能具有重要理论价值和实用意义。本论文结合先进技术微通道板(AT-MCP)电子倍增器,微球板电子倍增器(MSP)和硅微通道阵列电化学微加工等新技术进行了深入的理论分析和实验研究,取得了较大进展。其主要研究工作如下:1.介绍了微通道板电子倍增器的结构、特点以及发展概况,论述了微通道板新技术的主要特点、研究现状和发展背景。2.新型先进技术微通道板技术研究20世纪90年代中期美国伽利略公司提出采用半导体技术制备微通道板,称此MCP为先进技术微通道板(AT-MCP),与玻璃纤多纤维拉制工艺的还原铅硅酸微通道板(RLSG-MCP)相比具有许多优点,被认为是微通道板制作工艺技术上的新变革。硅基微孔深通道阵列的形成和连续打拿极的制作是这种AT-MCP技术的两项关键工艺技术。本文首先采用多路感应耦合等离子(ICP)刻蚀系统对硅基微孔深通道阵列的形成技术进行了系统的工艺实验研究,重点分析了一些重要的工艺参数对微孔阵列几何形貌的影响;研究了在微通道阵列结构形成过程中深通道内的气体微输运微观机制、侧壁保护以及深刻蚀产生的侧蚀等。按照工艺流程:MCP掩模版(母版)的制作→硅基片的研磨、抛光→氧化和金属膜的淀积→光刻→掩膜的形成→ICP深刻蚀→背部减薄至通透→基体绝缘化→导电层的形成→二次电子发射层的形成→镀电极→检测,流通了全部工艺,验证了AT-MCP技术的可行性。其次,本文对ICP刻蚀过程中的“刻蚀速率迟滞(lag)效应”和“钻蚀(footing)效应”进行了深入理论研究,探讨了它们与工艺参数之间的关系,尽管这些工艺问题在IC及常规MEMS领域中已经解决,但由于AT-MCP微通道阵列结构的特殊性,问题又引起了同行的重视,我们认为其结构不同于深槽结构,刻蚀过程中孔内气体的微输运只有一个自由度,其是一种封闭的结构。高长径比微孔深通道结构是微加工及MEMS领域中某些微结构的技术难题,本文作者在这方面作了探索性研究工作。在国内首次有针对性地提出了适度减小片台功率的方法,能有效地减小高长径比微孔深通道阵列制作中的footing效应的影响作用,对于改进AT-MCP制备工艺技术具有重要指导作用。最后,利用低压化学气相淀积(LPCVD)和敏化技术制作连续打拿极,探索膜层二次发射系数、体电阻与工艺参数的关系等。3.硅微通道阵列微加工技术理论及其实验研究硅微机械加工技术在大规模集成电路、光电子器件等制作中的作用已越来越引起世界各国的重视,尤其是近年来微电子机械系统(MEMS)进一步促进了新型微传感器和阵列式通道电子倍增器件等的新发展。因此,这就需要有相应的新型设备和解决最佳工艺参数选择问题,这样才能满足高长径比的深槽和微孔通道阵列的成型和质量要求。半导体电化学和光电化学(electrochemical and photoelectrochemical,EC和PEC)刻蚀在集成电路技术发展过程中起了重要的作用,集成电路制造的许多工艺过程都是基于电化学原理。1999年12月,美国纳米科学公司C P Beetz等人提出采用电化学工艺制作微通道板基体阵列的新技术,称为硅电化学刻蚀工艺。在此基础上制备的MCP称为硅微通道板(Si-MCP),其技术与AT-MCP技术基本一致,只是在硅基微孔深通道阵列的形成阶段采用了硅电化学微加工技术。实验中利用自行设计的电化学/光电化学刻蚀系统,按照如下工艺流程:材料选择→基片的研磨、抛光→氧化→光刻→诱导坑的刻蚀→微孔深通道的电化学和光电化学深刻蚀,对硅基微孔深通道阵列结构进行了初步的形成实验,刻蚀出通道直径为3.0-4.0μm,长径比大于40的微通道阵列样品。同时,对硅/HF界面结构特点、界面化学特性、物理特性以及电化学特性进行了深入的理论研究,提出了硅在HF溶液中阳极溶解的机理;并从理论上给出大孔硅成核与生长机制和高长径比通道形成的解释。研究结果对硅电化学微加工过程的工艺设计以及硅电化学理论研究具有重要意义。该项研究工作具有一定创新性。对n型硅基二维通道电子倍增器MCP微孔阵列制作工艺开展了研究工作,制作出方孔边长为3.0-4.0μm,中心距为6.0μm,长径比大于40的深通道阵列,目前还未见任何报道。针对硅/HF电化学系统,利用局部电流脉冲模型对大孔硅的成核和生长的机理进行了系统的理论研究,并且首次对p型硅基深通道阵列形成的微观机制进行了实验验证:理论计算给出了其形成电流密度J=0.58mA/cm~2;实验中在恒定电压v=1.85v时,工作电流密度J=0.60mA/cm~2,得到了理论与实验结果相符相对误差为3.4%的好结果,目前未见报导。在国内首先全面分析和系统阐述了在光电化学刻蚀n型硅基深通道阵列过程中光照强度、HF浓度以及掩膜与衬底之间晶向校准这三方面因素对其成型影响的微观机制,给出了其优化的工艺条件,得到了上述三者是形成n型硅基深通道阵列的主要决定因素的结论。这些工作对进一步深入研究与制备硅基深通道阵列和新型Si-MCP技术具有重要意义。4.介绍了微球板电子倍增器的发展概况和应用前景,以及制备微球板电子倍增器技术的主要特点和研究现状。微球板(MSP)是由直径为20-60μm的玻璃微珠构成的无规则堆积的盘片状烧结体,厚度1mm左右,其内部玻璃微珠间隙构成了不规则微型通道结构;经过处理后的微球表面具有二次电子发射特性,两端面涂覆电极后形成微球板电子倍增器。微球板电子倍增器的工作原理与微通道板相似。MSP与MCP相比具有电子增益高、无离子反馈、工作真空度要求低、强度高、寿命长等特点。制成的新型光电探测器可广泛应用于极微弱光探测和单粒子计数、质谱与能谱分析系统、快速粒子飞行时间测量、粒子成像和大屏幕显示系统等领域中。本论文研究了微球板制作过程中的一些基本理论,采用立式炉成珠设备进行了玻璃微珠的制备,设计了微球板电子倍增器制作的工艺流程,探索了微球板制备过程中玻璃微珠的分级技术,微球板电子倍增器基体成型工艺和技术,制备出满足要求的微球板电子倍增器的基体,并进行了打拿极和端面电极的探索性实验。最后对实验过程中的一些现象进行了理论分析和讨论,并给出了相应的实验结论和研究建议。由于时间短、经验不足,许多工作有待进一步完善、改进和深入。其创新点在于对微球板电子倍增器烧结速率理论进行了深入的分析,并对烧结速率库斯仲斯基理论公式进行了修正,使其更加有利于在微球板电子倍增器制备实验过程中控制其影响因素,这就对其形成提供了理论的支持更多还原

【Abstract】 Low light level night vision technology to widen human visual range appeared since 1960s.With the continuous appearance of new conceptions,new ideas,new processes and new technologies,night vision devices and technology have rapidly developed.Becaues of the requirements of photoelectron technology,two demision electron multipliers are widely applied especially such as microchannel plates(MCP) and microphere plates(MSP).The MCP is two dimension electron multiplier that has the thin slice style honeycomb shape composition gathering through thousands and hundreds passageways.It is widely used in applications of imaging multiplication.Because response to nucleus particles and other short wave radiation,the MCP has found the important applications in the field of night vision in low-level light,high resolution kinescopes,oscilloscopes,photoelectronic multiplier tube,image photon counter,and detecting particle.So far the image multipliers have experienced for three generations in its development,and the MCP in the fourth generation become appeared.That also bring about a revolution in the MCP related to the image tube.The performances of MCP have been improved on and the related new technologies have emerged continuously.The work on MCP has a relatively high theoretical and practical value to studying the new MCP devices and improving on its performances.This paper is concerned with the theoretical and experimental study on new technologies including the advanced technology of MCP(AT-MCP),the microphere plates (MSP) and the micromachining for Si microchannel array.1.The development survey and the application background of the microchannel plates electron multiplier are introduced in this paper.And the new technologies of MCP are: researched.The main characteristics and the present research situation of MCP new technology are made a systematic description.2.Study on advanced technology of microchannel platesAdvanced technology of microchannel plates,AT-MCP,is a new technology of MCP process,which has many merits compared with the old process and had be believed to be a revolution in MCP process,proposed by Galileo Co.early in 1990s.Two key technologies of AT-MCP are the formation technology of silicon micropore deep-channel array and the manufacture technology of continuous dynode.By multiplex induction coupled plasma(ICP) etching,we carried out several experimental researches and process exploration for micromaching the silicon microchannel arrays.Some important process parameters,such as gas switching time,flow rate,etching rate,were analyzed.The study results reported here had demonstrated the mechanism of lateral etching,sidewall passivation and gas micro-transport in micromaching the microchannel arrays.We had prepared the first domestic sample of AT-MCP in laboratory,and tested its electronic gain and body resistance.We had carried out all the steps in the new process flow that was the formation of MCP’s mask→wafer grinding and polishing→oxidization andd eposition→photolithography→etching mask→microchannel array etching→conducting layer→dynode layer→plating electrode→check and test,and proved the feasibility of AT-MCP.The footing effect and lag effect occurred in the ICP etching process were also systematically studied. These process problems had reappeared in the AT-MCP process though these problems had be solved in the field of integrated circuits process and microelectromechanical system (MEMS).The lag effect and the footing effect with process parameters were systematically studied in the ICP etching process.The method that platen power was moderately decreased in the process of high ratio deep-channel array can be influenced to decrease the footing effect.The continuous dynode was fabricated by LPCVD and sensitizing technology.The relationships between secondary emission coefficient and process parameters or between body resistance and process parameters were carefully studied.Our experiments and analysis results had led the author to believe that the deep pore structure with high aspect ratio and the deep trench differ greatly in etching process.The former is a closed structure for the gas transport,and the latter is a open structure,so the process of deep hole structure is a puzzle in micromaching and MEMS technology.3.Electrochemical etching for silicon microchannel arrayThe electrochemistry(EC) and photoelectrochemistry(PEC) of semicon-ductors has played an important role in the development of integrated circuit(IC) technology.Many of the processes used in IC manufacturing are based on electrochemical principles.So far Photoelectrochemical(PEC) etching researches were focus onⅢ-Ⅴsemiconductors electronic and photonic devices,silicon MEMS devices and silicon three-dimensional micromachining.In 1999,C.P.Beetz in Nanosciences Corporation of American proposed a new MCP process by EC and PEC techniques.Except that the EC or PEC etching was used to fabricate the microchannel arrays,the other.steps of new process were similar to the ones ofAT-MCP.The electrochemical etching system consisted of a potentiostat,a three electrodes electrolytic cell and a light exposure system.According to the electrochemical etching process flow that was wafer selection→grinding and polishing→oxidization→photolithography→pit precursor positioning→microchannel EC or PEC etching,several experiments for the silicon microchannel arrays were performed.The samples of silicon microchannel array with 3.0-4.0μm of pore diameters and more than 40 of aspect ratio were obtained by EC and PEC etching.We had made an attempt to deal with the structure, physical and chemical characteristics,and electrochemical properties in the interface of silicon and HF electrolyte,verify the principles of anodic corrosion in EC and PEC process, study the mechanism about nucleation and growth for macropore silicon with high aspect ratio theoretically.The obtained results were of great value in EC micromaching process design and theoretical researches.The creationary works about the new technologies in MCP process had been done in this paper,and summarized as follow:Two-dimension electron multiplier MCP’s deep micropore array on silicon substrate was attained in the paper.Lots of very perfect two-dimension deep electron multiplier channels were gained by optimizing photo-electrochemical technics parameters,of which side length of square hole was 3.0-4.0μm and ratio of length to diameter of MCP-channel was more than 40 and this had no other internal report.According to Si/HF ethcing system,based on the local current burst theory,the authors had developed a variational method to explain the hole nucleation and growth in the process of electrochemical etching for silicon microchannel arrays.And firstly the process micromechanism of deep-channel array on p-type silicon was obtained by experimental verification.The process current density J is 0.58mA/cm~2 theoretically,but in this experiment the practical current density J is 0.60mA/cm~2 at the constant voltage of 1.85v. The consentaneous conclusion between theory and practical was obtained that the relative error is 3.4%and this had no oilier report.It is a key step to adjust the direction of the micropore array to the crystal orientation of Si substrate during the process of forming pre-determinate square patterns before PEC etching process.The electrochemical reaction strongly depends on the light intensity and HF concentration.These optimized experimental conditions were obtained and the three factors was very key to process deep-channel array on n-type silicon.It is demonstrated that these works were very valuable to further study and fabricate the deep micropore channel array of MCP.4.The development survey and the application background of the MSP electron multiplier are introduced in this paper.The main characteristics of MSP and the present research situation of process technology are made a systematic description.The MSP is a sintered plate of 20-60μm-diameter glass beads.The electron multiplicationprocess takes place in the interstices between these beads when a voltage is applied between the front and rear surfaces,which are covered with thin layers of nichrome. Despite the similarity in operating principle there are some significant differences between MCPs and MSPs.Advantages of MSPs are higher gain and less stringent vacuum requirements.The absence of long electron travel paths inside MSPs minimizes ionic feedback.A disadvantage of MSPs is lower spatial resolution due to the spreading out of the electron avalanche within the MSP,and also due to the randomness of the sphere stacking within the plate,as well as the larger unit sizea.Another disadvantage is the lower geometrical open area ratio than MCPs’.In this paper,we analyze thick cumulus,sintering phenomenon,dynamics and the law of mass transfer in the process of MSP body formation.Base on the theory of predecessor, we eatablish twin-ball mode of sintering speed rate and deduce rate equation of sintering.We make experiments MSP green body,manufacture MSP body and meet the demands basically. In the end,we analyse and discussed some phenomena in the course of experiment and the conclusion of the experiment.To the existing problem in the experiment,we put forward our idea and suggestion.The innovation point is that the process thoery of MSP is systematically analyzed and modified so that it is beneficial to the process technology of MSP.更多还原