Research On Micro-nano Mask Fabrication Method Based On Fluid Spinnability Direct Writing

Micro-nano mask fabrication is the main processing prior to micro-nano processing such as etching,deposition,and modification,and is a key step and foundation in micro-nano processing.Therefore,the fabrication method of micro-nano mask with high quality,high efficiency,low cost is very important for scientific research and production in micro/nano electromechanical systems(MEMS/NEMS),micro-nanotechnology,micro/nanoelectronic chips,and semiconductor devices.At present,the direct-write masking method is a kind of mask pattern manufacturing method which could not rely on mask stencil and impression,and its fabrication process is simple with high accuracy and flexibility of mask production.Therefore,the direct-write masking method is an important development direction for micro-nano mask fabrication.However,the current direct-write masking method has problems in direct writing principle and mechanism,equipment,mask materials and processes that restrict its further development towards low cost,high quality,and green environmental protection.These are also the key issues that direct-write masking method can be used in a large number of applications for micro-nano fabrication.This paper proposes a direct-write masking method base on fluid spinnability,and researches are conducted on the principle and mechanism of direct writing,direct writing equipment,mask materials and micro-nano processing technology,further,in-depth study of the influencing factors of its principle,micro-nano fabrication processes after direct-write masking,and micro-nano device manufacturing method based on the direct-write masking method.Therefore,this lays the foundation for achieving the goal of low-cost,high-quality,green-friendly direct write mask and micro-nano device manufacturing.The main research work is as follows:(1)A principle of direct-write method base on fluid spinnability was proposed,and based on the related theories of fluid's tensile flow,shear flow,spinnability and fracture,and the correctness of this principle is proved by simulation calculations.At the same time,based on this principle,a material with suitable spinning characteristics,low cost,and environmental protection is selected as a mask material in the direct write mask method.(2)Based on the principle of direct-write masking method base on fluid spinnability,the preparation method of filament microstructure was studied.At the same time,direct writing of sub-micron mask patterns on hydrophilic and hydrophobic substrates is achieved based on the filament microstructure.Furthermore,an automatic write-through mask experiment system was developed,and automatic mask writing was realized.In addition,the preparation process and parameters of the tungsten probe base on electrochemical method were also studied,and the preparation of a tungsten probe with a smooth and clean surface and a submicron tip was realized.(3)The micro-nano processing technology was studied on a sample directly written with a maltose syrup mask(abbreviated as sugar mask)through the principle of direct-write masking method base on fluid spinnability,and micro-structures such as micro-gold electrodes and graphite micro-structures were prepared.At the same time,these microstructures were tested and characterized by atomic microscopy,scanning electron microscopy,and a built-up test system,all of which gave good results.In addition,through the comparative study with the photoresist mask,it is concluded that the sugar mask has the characteristics of high quality,environmental protection,easy removal,and no residue.(4)A graphite mesa micro-nano devices manufacturing method base on the direct-write masking method of fluid spinnability is proposed.At the same time,through scanning electron microscopy characterization and self-recovery test experiments,proved that the graphite mesa micro-nano devices fabricated on this method have important characteristics such as smooth surface and no residue.More importantly,the graphite mesa micro-nano devices manufactured by this method have the same self-recovery phenomenon,maximum friction force,maximum self-recovery displacement and speed with the graphite mesa micro-nano devices manufactured by the method of manufacturing the graphite mesa micro-nano devices based on the electron beam direct writing mask,which demonstrated the reliability of the graphite mesa micro-nano devices fabricated by the micro-nano manufacturing method based on the direct-write masking method of fluid spinnability.It also shows that the micro-nano manufacturing method based on this direct writting mask method is characterized by high quality,environmental protection,low cost,simplicity,.Through the fluid spinnability direct-write masking method proposed in this paper,and in-depth study of the influencing factors of its principle,micro-nano fabrication processes after direct-write masking,and micro-nano device manufacturing method based on the direct-write masking method.We have initially achieved low-cost,high-quality,green and minimal sub-micron mask write-through.Moreover,the direct-write masking method can also be applied to the fabrication of micro-nano processing and micro-nano devices with high quality,and therefore,it is of great significance to the development of micro-nano fabrication.