Preparation Of High-aspect-ratio Hydrogen Atomic Clock Collimator And Its Performance Test

In order to solve the defects such as low dimensional accuracy,poor structure uniformity and so on in the porous structure of the collimator for the hydrogen atomic clock,which caused problems such as low constraint on particles and poor collimation efficiency,this paper presents a method for preparing a collimator for hydrogen atomic clock:At first,array groove structure was etched on the surface of quartz glass by using electron beam lithography technology combined with wet etching technology.Then,use a laser to cut the etched quartz glass to the same size.Finally,the cut pieces of quartz glass were bonded to each other to obtain a collimator with high aspect ratio.The main research contents of this article are as follows:1.Single factor experiments were designed to investigate the effects of resist thickness,exposure dose,development time and acceleration voltage on electron beam lithography,the results show that the resist thickness of 200nm,the exposure dose of 150p As/cm~2,the development time of 75s and the acceleration voltage of 30KV are better exposure parameters.Using these parameters,an array trench structure with a size of 5μm and a pitch of 120μm was exposed on the PMMA resist layer of quartz glass.2.Single factor experiments were designed to investigate the effect of etching solution temperature,concentration and composition on etching effect and design corresponding orthogonal test scheme based on single factor test results.The results show that it has suitable etching rate,low groove bottom roughness and good side wall morphology when the etching solution temperature is 35℃,etching solution concentration is 40%and the composition of the etching solution is hydrofluoric acid,hydrochloric acid and ammonium fluoride.After 5 minutes of etching,an array groove structure with depth of 4.094μm,width of 13.291μm and spacing of 120.251μm was obtained.3.The wet-etched quartz glass was cut by a laser at the same size,the collimator was obtained by bonding a single piece of quartz glass with each other and the end face was ground and polished.4.The collimator prepared in this project and the existing collimator were respectively tested for hydrogen plasma related parameters based on the plasma test platform,the results show that within a certain range of hydrogen flow,the collimator prepared by this project can obtain higher ion flow sizes,higher electron flow sizes and has better collimation effect.