Study On The Optimization Design Of Microbolometer With Grating Structure

Infrared detectors are widely used.Microbolometer,as the core component of infrared detector,has a general problem of low infrared absorbance,which limit the detection rate of the device.In this paper,the optical excitation structure is used to improve the infrared absorptance of microbolometer,and optimize its device performance.Based on the principle of SPPs,in this paper,the effect of the grating structure on the infrared absorption rate of microbolometer is mainly studied.Choose the previously studied microbolometer as basic structure,and combined with infrared radiation characteristics,optical properties,material properties of vanadium oxide,and other theoretical basis for modeling and simulation.To adjust the basic model to a plasmon elicitation structure,thermal,optical,and electrical properties are analyzed and discussed in finite element method.First to establish an infrared bolometer simulation mode,the thermal simulation is used to optimize the model structure,and balance the mechanical and thermal properties of the device.Second to establish a plasmon optimization model,to obtain an optimized model and verify its significant effect on the performance improvement of microbolometer.According to the grating type,which located in different layer of cell structure.Three kinds of grating structure are studied successively in this paper.The effects and characteristics of each grating location are conclude by their optical simulation results.Finally,integrated the previous model data and come up with a composite grating optimization model.By the simulation results of this multi-stage grating structure,which further verify the effectiveness and theoretical feasibility of the grating trap structure.In conclusion,the composite grating optimized model,comparing to the single-stage grating,further enhances the infrared absorption rate of the pixel.And its average absorbance is over 35% at the whole band.And the above models are designed to provide data base and design idea for new type infrared bolometer.