Vertical FAIMS Gas Sensor Key Process Study

For the needs of portable and rapid on-site detection of gases in environmental pollution,non-invasive medical treatment,biochemical weapons,explosives,etc.,the principle of high-field asymmetric waveform ion mobility spectrometry（FAIMS technique）is that the ion mobility differs between high and low electric fields thus allowing effective target selection,and it has a wide range of application prospects.Based on this,this paper designs a vertical FAIMS gas sensor with a vertical type as the innovation point,and the multi-channel forked finger migration channel can be more sensitive and smaller than the traditional single-channel flat type.In this paper,we design a vertical FAIMS gas sensor with vertical type as the innovation point,the multi-channel forked finger migration channel can be more sensitive and smaller than the traditional single-channel flat type,and study its key process.First,the working principle of the vertical FAIMS gas sensor is studied in depth,the gas to be detected is ionized into charged ions in the ionization zone,after which the ions reach the detection zone under the action of the high field asymmetric voltage and the DC compensation voltage in the migration zone,while other ions disappear from the collision with the pole plate in the migration region,which is directly perpendicular to the migration zone and is used to detect the charged type and number of ions Tiossing the migration zone.Thus,different gas concentrations are detected.Next,the specific design of the sensor was carried out.The ionization zone was selected from a UV ionization source;the migration zone was prepared from a 300±10 μm low-resistance silicon wafer,consisting of a migration zone channel and a migration zone pole plate,and its breakdown voltage and deformation were analyzed;the detection zone was prepared from a 500 ± 10 μm BF33 glass wafer,and the detection zone pole plate was led to the outside of the sensor through an etched hole to connect the circuit.The size of the integrated migration zone-collection zone is 5.16 × 5.3 ×0.8 mm,and the assembly is designed with SOLIDWORKS software,with a radius of 5 mm and a height of 15.8 mm cylinder,so that the ionization zone,migration zone and collection zone are combined and the corresponding test system is designed.Again,the sensor was prepared using MEMS technology,and the MEMS process flow of the sensor was designed and the corresponding mask version was drawn using L-Edit software.Finally,the specific implementation methods of migration zone channel,glass through-hole,through-hole structure coated with glue,glass zone front detection zone pole plate and back electrode to achieve conduction,i.e.,for deep silicon etching,sandblasting,glue blasting,glass through-hole interconnection key process,were studied,the specific principles were also explored and the corresponding process development was carried out.