Development of MEMS IR source by compound release process with nano-scale silicon forest radiation layer

Based on the previous work, we continued a study on improving the emissivity of radiation layer and the perfection of release process developed for electrical modulation pulsed MEMS infrared (IR) source used in NDIR gas sensors. Two different fabrication processes of nano-scale silicon forests were produced by reactive-ion etching (RIE) dry etching poly silicon beneath the aluminum wire bonding pad and plasma immersion ion implantation (PIII) etching both poly silicon and single crystal silicon. Various surface topography and characteristic of absorptivity were investigated by scanning electron microscope (SEM) and Fourier transform infrared (FTIR) spectrometer, respectively. Besides, compound release processes by backside KOH wet etch and XeF2 dry etch were employed as a result of improved yield rate and uniformity. The fabrication process, results and analysis were then carried out.