摘要
防离子反馈膜是一种覆盖在微通道板输入端的Al2O3或SiO2连续超薄膜,该膜对延长微光像管的使用寿命具有重要的作用。首先采用射频磁控溅射方法在0.5～1μm的有机载膜上制备Si薄膜,然后在4～6Pa氧气下放电使其贴敷到微通道板上,同时使Si膜氧化和有机载膜分解,最后在微通道板输入面上形成满足设计要求的SiO2防离子反馈膜。该制膜方法工艺稳定,重复性好,成品率超过90%。给出了有、无薄膜时微通道板的电子透过特性曲线和膜层厚度与死电压间关系曲线。对相同厚度为5nm的SiO2和Al2O3防离子反馈膜的电子透过特性进行了分析和比较,得出了SiO2比Al2O3薄膜对电子透过稍好,相应的死电压分别为220V和255V的结论。结合对膜层电子透过和离子阻止特性的综合分析可以看出,SiO2也是制作微通道板防离子反馈膜较为理想的材料之一。为了定量表征微通道板防离子反馈膜的离子阻止能力,最后指出了防离子反馈膜离子透过率的测量是今后该项研究工作的当务之急。
Microchannel plate （MCP） is a key component in the low-level-light image intensifier. When the intensifier is working, positive ion feedback will be produced in front of the output surface of MCP. On the one hand, the ion feedback destroy the hnear operation characteristics of the MCP; on the other hand, electron emission produced by these feedback ions results in the appearance of ion spots on the screen; furthermore, these positive ions can bombard the photo-electrical cathode and shorten the operating life of the cathode. At present, the effective method for minimizing the ion feedback phenomenon is to fabricate a super-thin M2 03 or SiO2 thin film on the input surface of MCP. This thin film allows some electrons with certain energy and stop effectively positive ions to pass though it, thus the cathode can avoid the bombard from the feedback ions and prolong the operation life of image tube.
In this paper, the silicon thin film with the thickness of 0.5 - 1 μm was firstly formed on an organic selfsustaining thin film using radio-frequency magnetron sputtering method. Next, the silicon thin fihn was attached on the MCP by discharging oxygen gas under a vacuum of 4 -6 Pa. At the same time, silicon thin film was oxidized and the organic film was discomposed in this process. Finally a thin layer of SiO2 ion-preventive feedback thin film satisfied the requirement was formed on the input surface of MCP. This fabrication method is very stable, and with a good reproducibility, the yield of this method is well above 90%. The technological parameters in the fabrication of sputtered Si thin film on the self-sustaining organic thin fihn were also reported in this paper. The structure and operating method of vacuum-discharge attaching was introduced and the advantage of ion-preventive feedback thin film fabricated by this method was shown.
After the measurement, the electron transmittance characteristics though the ion-preventive feedback thin film for unfilmed and filmed MCPs were shown. The relationship between the thickness of the ion-preventive feedback thin film and the dead-voltage （characterize the electron transmittance propertied through the film） was given. The electron transmittance characteristics for SiO2 ion-preventive feedback thin film was compared with that for Al2O3 thin film. The electron transmittance characteristic of SiO2 ion-preventive feedback thin film is better than that of Al2O3 film （ the dead-voltage is 220 V for SiO2 thin film and 255 V for Al2O3 film with the same film＇s thickness of 5 nm）.
At the end, it was pointed out that the emphasis of this project should be placed on the measurement of ion transmittance characteristics.
出处
《发光学报》
EI
CAS
CSCD
北大核心
2008年第6期1096-1100,共5页
Chinese Journal of Luminescence
关键词
微通道板
SIO2
防离子反馈膜
电子透过特性
microchannel plate
silicon oxide
ion-preventive feedback thin film
electron transmission characteristic
