Performance improvement of an infrared scene generation chip by in-plane microstructures

An infrared (IR) scene generation chip based on multi-layer thin film was demonstrated. Infrared radiation was efficiently converted from visible light energy through chip absorption. We proposed that the contradictive material parameter requirements aroused by high-spatial resolution and high-frame rate of the dynamic IR scene generator could be successfully solved by a periodical microstructure fabrication. The theoretical simulation results based on a semi-one-dimensional heat transfer model illustrated that the spatial resolution of the generated IR scene was improved using a microstructure with a low contact area ratio and high fill factor, while the thermal decay time of the chip was kept unaffected. Two infrared scene generation chips with different microstructures were fabricated by lithography and site-selective deposition. Measured by non-contact thermography, the chip with low microstructure contact area ratio (0.17) showed a higher spatial resolution (13.2 lp/mm) than that with high microstructure contact area ratio of 0.46 (8.0 lp/mm). Moreover, both chips had the same thermal decay time of 20 ms. The experimental results indicated that the proposed method is an effective and economic way to improve the performance of infrared scene generation chips.