Al_(2)O_(3)/MgO复合膜层对微通道板性能的影响  

Effect of Al_(2)O_(3)/MgO Composite Layer on the Properties of Microchannel Plate

作　　者：张正君[1] 邱祥彪 乔芳建 丛晓庆[1] 李婧雯[1] 任玲[1] 王鹏飞 ZHANG Zheng-jun;QIU Xiang-biao;QIAO Fang-jian;CONG Xiao-qing;LI Jing-wen;REN Ling;WANG Peng-fei(North Night Vision Tech Corp Ltd.,Nanjing 211106,China)

机构地区：[1]北方夜视技术股份有限公司,南京211106

出　　处：《表面技术》2021年第6期199-205,共7页Surface Technology

摘　　要：目的大幅提高微通道板增益,延长寿命。方法采用原子层沉积技术(ALD)在微通道板(MCP)大长径比(40:1)通道内壁沉积Al_(2)O_(3)/MgO复合膜层材料,对通道内壁二次电子发射层进行增强,改善其二次电子发射特性。通过设计复合膜层结构,采用Al_(2)O_(3)膜层保护易潮解的MgO膜层,提高复合膜层的稳定性。研究MgO膜层沉积工艺,基于SEM检测,实现在大长径比通道内制备出厚度均匀(不均匀性为3.8%)的膜层。研究MgO膜层厚度、沉积温度对MCP增益以及双片叠加增益达到10~7时工作电压的影响,确定最佳的复合膜层制作工艺。结果通过采用20 cycles Al_(2)O_(3)膜层进行封装保护,使表面制备复合膜层MCP在氮气柜中可稳定存储14 d。试验MgO最佳的膜层沉积工艺:沉积温度为210℃,膜层厚度为50 cycles(6.1 nm)。优化的"三明治"型复合膜层结构Al_(2)O_(3)/MgO/Al_(2)O_(3),沉积循环次数分别为5/50/20。在550 V电压下,复合膜层的MCP增益较常规MCP提高了3.9倍,应用于微通道板型光电倍增管(MCP-PMT)中,工作电压从1880V降低至1740 V,同时能量分辨率与峰谷比性能得到提升,寿命达到10 C/cm^(2)以上。结论在MCP上制作Al_(2)O_(3)/MgO复合膜层材料,能够有效提高其增益,降低应用器件的工作电压,同时延长MCP寿命。采用Al_(2)O_(3)膜层进行封装保护,对于MgO材料应用于MCP等光电探测元器件有非常重要的作用,同时MgO材料的应用可拓展MCP在探测活性离子等方面的应用。To improve the performance of microchannel plate(MCP)such as gain and lifetime,in this paper,Al_(2)O_(3)/MgO composite layer materials are deposited by Atomic Layer Deposition(ALD)technique in MCP.The composite layer deposited in the channel wall with large aspect ratio(40:1)can increase the second electron emission coefficient of the channel wall.Magnesium oxide has a high secondary electron yield and has good application prospect in photoelectric detection devices.However,magnesium oxide is easy to deliquesce in air and has poor stability,which is an urgent problem to be solved.In this paper,ALD-MCP with Al_(2)O_(3)/MgO/Al_(2)O_(3) composite layer was proposed so that MgO layer can be protected by Al_(2)O_(3) layer.The thickness nonuniformity of MgO film in the channel with large aspect ratio can reach 3.8%by optimizing the deposition process.The effects of film thickness and deposition temperature on the gain of MCP and the operating voltage of MCP-PMT(gain@107)were studied to obtain the best film fabrication process.The ALD-MCP with Al_(2)O_(3)/MgO/Al_(2)O_(3) composite layer can be stable storage for 14 days in the nitrogen cabinet by the surface protection of 20 cycles Al_(2)O_(3).The optimum film deposition process of MgO:deposition temperature is 210℃,thickness of 50 cycles(6.1 nm).The gain(@550 V)of the ALD-MCP with Al_(2)O_(3)/MgO/Al_(2)O_(3)(5/50/20)composite layer deposited by ALD can be increased by 3.9 times.When the ALD-MCP coated with Al_(2)O_(3)/MgO/Al_(2)O_(3) composite layer is used in MCP-PMT,the performance of MCP-PMT improved significantly,including the operating voltage,the peak-valley ratio,pulse height resolution and lifetime.The operating voltage decrease from 1880 V to 1740 V and the output charge can reach 10 C/cm^(2).Applied Al_(2)O_(3)/MgO composite layer in MCP can effectively improve the gain,reduce the operating voltage of the device and extend the lifetime.The use of Al_(2)O_(3) film layer for encapsulation protection is very important for the application of MgO materials in MC

关 键 词：微通道板(MCP) 氧化镁 氧化铝 封装 复合膜层 原子层沉积(ALD) 高增益 长寿命 

分 类 号：TN223[电子电信—物理电子学]