Patterning of visible/infrared dual-band microstrip filter arrays for multispectral imaging application

• Published in: Journal of micromechanics and microengineering Vol. 19; no. 8; pp. 085004 - 085004 (8)
• Main Authors: Lai, Jian-Jun, Liang, Hua-Feng, Zhou, Zhi-Ping, Fang, Guo-Jia, Li, Li
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.08.2009; Institute of Physics
• Subjects: Applied sciences; Electronics; Exact sciences and technology; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Mechanical engineering. Machine design; Mechanical instruments, equipment and techniques; Microelectronic fabrication (materials and surfaces technology); Micromechanical devices and systems; Physics; Precision engineering, watch making; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Infrared thermography; Patterning; Thick film device; Ion beam sputtering; Measurement sensor; Thermomechanical properties; High temperature; Optical measurement; Lift off; Sapphire; Germanium; Zinc oxide; Passband; Double layers; Bilayers
• ISSN: 0960-1317; 1361-6439
• DOI: 10.1088/0960-1317/19/8/085004

Visible/infrared dual-band microstrip filter arrays have been developed to be integrated with 512 X 512 PtSi CCD imaging sensor chips for multispectral imaging when it operates in the front-illumination mode. A high visible transmittance and high infrared reflectance ZAO (ZnO:Al) based coating for visible passband and an interference absorbing filter film for a mid-infrared passband have been designed and deposited on sapphire substrates. An effective double-layer lift-off technique that is compatible with high temperature deposition has been developed to create thick microstrip infrared film. The infrared passband film using germanium and yttrium fluoride as high and low refractive indices materials have been deposited by ion-beam-assisted electron beam evaporation. Tested optical performance results reveal that the visible and near-infrared transmittance of the infrared passband film is very low, which makes it ideal for mid-infrared imaging. Environmental durability testing shows that the microstrip arrays have good mechanical and thermal performances for practical applications.