Micro-Electro-Mechanical-Systems-Based Infrared Spectrometer Composed of Multi-Slit Grating and Bolometer Array

Abstract

A micro-electro-mechanical-systems (MEMS)-based IR spectrometer has been designed and fabricated. The proposed micro-spectrometer consists of multi-slit grating and bolometric IR detector array. The grating is used for dispersion of an incident optical radiation into different wavelength components. The grating structure is patterned by reactive ion etching (RIE) of aluminum deposited on dielectric membrane, which is fabricated over silicon wafer. The IR detector part adopts a resistive bolometer that changes its resistance due to the temperature increment. The presence of IR at the specific wavelength can be detected by noticing the resistance change when temperature increases due to an incident IR ray. Vanadium oxide is adopted for resistive bolometer of IR spectrometer in this work because of its higher temperature coefficient of resistance (TCR) which is needed for the better sensitivity. Two parts that composes the MEMS-based IR spectrometer, aluminum multi-slit grating and thermal-type vanadium oxide IR detector, are processed independently and bonded as a final step.