原子层沉积钌/氧化铝复合纳米薄膜的制备与电阻调控OA北大核心CSTPCD

Applying atomic layer deposition (ALD) technology to fabricate the functional layer of a microchannel plate (MCP) has been verified to be an effective approach to enhancing MCP performance. However, the conduction layer inside the MCP device faces the issues of a narrow range of adjustable resistance and poor stability. The work aims to propose a method of utilizing ALD to fabricate Ru/Al2O3 composite nanofilm as the MCP conduction layer since Al2O3 has good environmental stability and excellent dielectricity and Ru possesses the properties of excellent thermal stability and high-temperature corrosion resistance. In order to explore the process parameters, Al2O3 and Ru nanofilms were deposited on Si wafers by ALD technology with different ALD cycle numbers. The cross-section thickness of the nanofilms was obtained by scanning electron microscopy (SEM), and the relative elemental composition of the nanofilms was obtained by energy-dispersive X-ray spectroscopy (EDS). The SEM characterization showed that applying ALD technology for the deposition of nanofilm resulted in high film quality, compact layer structure, and dense atomic arrangement. Moreover, the film thickness showed only a slight deviation from the estimated thickness, and the selected process parameters met the expected experimental objectives. On this basis, the Ru/Al2O3 composite nanofilm was fabricated by depositing two materials sequentially with ALD technology. A series of Ru/Al2O3 composite films were fabricated by maintaining a constant number of ALD cycles for Al2O3 and varying the ALD cycles for Ru, aiming to control the bulk resistance of the conduction layer. The bulk resistance of the MCP conduction layers was tested, and the stability of the bulk resistance was tested under different bias voltages. From the SEM and EDS results, it could be concluded that the process of preparing Al2O3 and Ru nanofilms with ALD was stable. The bulk resistance significantly decreased with the increase of ALD cycles of Ru according to the bulk resistance test results. The process parameters applicable to the preparation of the MCP conduction layer were Ru with an ALD cycle number of 28～40 and Al2O3 with an ALD cycle number of 10. In this case, the MCP bulk resistance was controlled in the range from 709 to 3.98 MΩ. The MCP bulk resistance was then tested under different bias voltages, namely, post-deposition without/with baking and extending purge time during deposition followed by natural cooling. The MCP bulk resistance showed preferable stability under different bias voltages by employing the process of extending purge time followed by natural cooling. With ALD technology, controlling the MCP bulk resistance from several to several hundred megohms has been achieved. Moreover, the optimized process for the conduction layer exhibits excellent stability regarding MCP bulk resistance. This work holds engineering application value in extending the range of conduction layer materials, and also makes significant sense for improving MCP performance.