Fabrication of a Micro-hotplate for Application as an Infrared Emitter

The aim of this research is to design, fabricate and characterize a micro-hotplate which is suitable for application as an infrared source.For the heater material, Nichrome Ni-Cr (80/20)w t % an alloy of Ni(nickel) and Cr (chromium) is used.Nichrome exhibits high resistivity, low temperature coefficient of resistance (TCR) and is resistant to natural processes of oxidation and corrosion, these qualities make nichrome a suitable material for a microhotplate.The heater resistance versus applied voltage is measured, and a value for TCR has been obtained by using a four point probe on thermo-chuck with the temperature ranges of 20 • C to 180 • C .NiCr structures integrated on micro-hotplates are simultaneously heated and the corresponding resistance is measured using a source-meter that applies bias voltage and measures current.The calculated TCR has been found only to be valid for the temperature ranges of 20 • C to 180 • C , and the device self annealed during the testing, thus ending with a changes in TCR.The micro-hotplate heater resistance is found to be stable after it has been passed through several conditioning steps.Chapter 6 presents the testing procedure and associated results performed on the microhotplate.Lastly chapter 7 outlines the conclusion of the research work and suggestions on some of the future possibilities to improve and upgrade the micro-hotplate and the related process.