MEMS-Based Planar Incandescent Microfilaments With Low Voltage Operation

In this article, we report the design and fabrication for planar-type incandescent microfilaments on the silicon on insulator (SOI) wafer. The micro-electro-mechanical systems (MEMS) process with XeF₂ etching is used to construct the suspension structure for the reduction of thermal conduction. The fabricated line-type microfilament has a low operation voltage of 4 V. Besides, the operation voltages for the $1\times 4$ , $5\times 5$ , $6\times 6$ , and $7\times 7$ arrays at 50 mtorr are 4.0, 9.0, 9.5, and 9.5 V, respectively. The $1\times 4$ array filament exhibits the measured lifetime of 200 hrs and the predicted lifetime of about 570 hrs. The microfilament has a continuous broadband spectrum that covers from visible light extended to over $3~{\mu }\text{m}$ , which is a suitable light source for near-infrared spectroscopy.