Study on secondary electron yield suppression of copper by micro-hole array

It is of great importance to reduce secondary electron yield (SEY) of metals in order to improve performance of electronic vacuum devices. This paper focuses on the experimental study on SEY suppression of copper. First, by using the Casino software, the SEY of square hole array surface was simulated under normal incident primary electron with energy of 0.5, 3 keV respectively. The aspect ratio and porosity dependence of the intrinsic SEY (ISEY), backscattered SEY (BSEY) and total SEY (TSEY) were obtained. Second, by using the photolithography process in semiconductor industry, various circular hole arrays were fabricated on copper foil and their surface morphology were characterized using a laser scanning microscope, their SEY were measured on SEY test platform. Simulation results show that: with increasing aspect ratio and porosity, the SEY suppression effect can be enhanced; when aspect ratio is becoming large enough, the SEY tend to be saturated; the SEY suppression effect is more obvious when incident energy is low. Measurement results show that the micro-hole array surface can effectively suppress the SEY of copper and experimental results agrees qualitatively with simulation results.