| Microchannel plates(MCP) is the key component of the image intensifier. In recent years, with the development of low-light-level night vision technology and photoelectronic imaging devices, traditional MCP fabricated by reduced lead silicate glass don’t satisfy MCP requirements for performance because of existing some defects. So the new technology of fabricating MCP become a popular subject of study in China and other countries. Compared with the traditional MCP, the Si MCP fabricated by MEMS technologies not only overcomes the shortcomings in processing, but also has a great improvement on the performance.The technology of fabricating Si MCP with pore lOμm, pitch 5μm, aspect ratio 2.0:1, is focused in this paper. The lithography process, the patterning process of mask, and RIE process are used to fabricate it. Compared with electrochemical etching, this method is simply, it is unnecessary to fabricate Ohmic contact, and the process of etching is controlled simply. In the process of fabricating Si MCP, the fabricating method and parameters both have effects on the last result. So it is necessary to study every process. The main focus as follows:1) The lithography result is influenced by the exposed time, reversing temperature, and development time. Through controlling variable specifically, it is found the size of the lithography pattern is bigger with more exposure time; the result of reversing pattern is better with higher reversing temperature; the lines of the pattern is more distinct with more development time, but the size of the pattern will become smaller with longer development time. Though optimizing parameters, the best parameter of the lithography is got:exposure time 10s, reversing temperature 115℃, development time 55s.2) The etching result is effected by the size of the pattern of the film, so it is necessary to focus on the patterning process of mask. As the film is array micropore with pore 10μm and pitch 5μm, the air film is arising which makes difficult for effecting between the corrosive liquid and Al film. Though focusing on the corrosive concentration, temperature and the etching time, the mask of satisfying size requirement is got at last. As the micro-channel array is a big area, and the nμmber of the micro-channel array is millions, the randomness of etching is inevitable. And the etching process is harder to manipulate. Based on the lithography and magnetron sputtering, lift-off can obtain better micro-channel array compared with wet etch. But lift-off has strict requirement on both thickness. Using lift off, the mask, which is satisfying the requirement of the size and the pattern, is got.3) The etching processes of the micro-channel array in Si are focused. The influences of the process parameters on the etching rate and sidewall verticality, such as oxygen flow, the pressure and the ICP power, are focused. The results shows the etching rate becomes larger and larger with the increasing of the pressure and ICP power. And the oxygen contribute to etching. But the sidewall verticality is worse with increasing oxygen flow. Though optimizing parameters, the best etching parameter is got:the pressure 12mTorr, the ICP power 500W, the oxygen flow 5sccm.Finally, it is successful to fabricate the micro-channel array in a inch silicon wafer using the parameters to etch Si. And it meets the requirement for the subject. Compared with the current process, the aspect ratio is improved. |
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