Micro Machining of a Si3N4/SiO2/Ti/Pt Hotplate and Its IR Emissivity Properties
Keywords:IR Emissivity, micro-hotplate, photolithography, platinum
This paper presents the fabrication processes for a Si3N4/SiO2/Ti/Pt membrane based micro hotplate (MHP) using photolithography (PL) micro-machining techniques. The properties of the MHP filament are investigated and overall performance characteristics with regard to infrared (IR) radiation emissivity, resistance, breakdown voltage, and temperature of the fabricated Si3N4/SiO2/Ti/Pt micro heater. During characterization, the results show the device breakdown voltage of 24.24 V corresponding to the optimum operation temperature of ~ 1730.30 K. The device also showed an emissivity value of 5.2% with ~ 7% efficiency of transforming electrical power to IR thermal radiation power. The relationship between temperature and resistance, behaviour of fourth power of temperature and thermal response time constant of IR radiation obtained from direct experimental measurements, analytical calculations and extrapolations are shown to provide practical parameters that are needed for applications of MHP in IR radiation sources.