Research Of Integrated MEMS Infrared Source With High Emissivity Nanostructure

Micro-electromechanical system(MEMS)infrared source based on thermal radiation has characteristics in small volume,low power consumption,high modulation frequency,wide wavelength range and long life.Recently,nanotechnology and integration nanostructure of sensors are becoming focus of attention.In this paper,high emissivity nano-structureswithin middle infrared wavelength range using plasma process are innovativelyprepared and combined with the source to greatly improve the radiation efficiency of the source.The work of this thesis is comprised of following aspects.It started with a researchstatus of MEMS infrared source at home and aboard,besides overall development of MEMS and nanotechnology.From the basic theory of infrared radiation,dynamic and static theoretical design of MEMS infrared source based on poly-silicon thermal-resistance was studied.Based on this,structural and film designs were completed using Ansys simulation and poly-silicon doping scheme also was used TCAD simulation.Nanostructure with high emissivity used for MEMSinfrared source is investigated for micro-mechanism analysis and FDTD simulation optimization.Based on this,high emissivity nanostructure based on silicon and carbon substrate were fabricated and characterized.Essential processes involved in the source were carried out after that whole process flow for integrated infrared source was designed.Finally,the dynamic and static performance of TO packaged MEMS infrared source was taking tests.The feature of the MEMS infrared source based on poly-silicon thermal-resistance is that high emissivity nanostructure within MIR is formed by that various plasma processes,besides integrated with the surface of source to substantial increase the radiation efficiency and electro-optical conversion efficiency.Compared with the common related things,it can improve the radiation intensity with narrow wave band via integrated high emissivity nanostructure of broad range.Besides numerous spectral radiations within narrow wave band can be achieved according to controlling the voltage input of the source so that high utilization ratio can be ensured and the industrialization can be easily to be accomplished.The results of tests show that,radiation spectral of MEMS infrared source covers 2~8?m,besides the emissivity can reach as high as more than 90%.Furthermore,at 631.6m W input power,the temperature of radiation zone is between 280? and 460?,and the radiation energy can increase by 101.2% than without nanostructure.The dynamic characteristic shows that the modulation depth can obtain 30% with 50 Hz modulation frequency.Overall,the performance of MEMS infrared source can all meet the demand of NDIR gas sensors.Meanwhile,other different thermal-resistance material is also studied in integrated MEMS infrared source with high emissivity nanostructure,Pt,amorphous carbon(a-C),for instance.In this way,this study establishes a solid foundation for develop various types of MEMS infrared sourcewith high emissivity nanostructure later.