A novel opto-mechanical uncooled infrared detector

Design of Bi-material Pixels of an Uncooled Optic Readout IR FPA

“…Taking consideration of materials property and process feasibility, Au or Al and low stress SiNx are commonly used for surface layer of the beam and reflector, and IR absorption layer of the pixel [2,3]. As the metal Al is able to react with Si, C and OH -on the surface of silicon based materials, resulting that Al and SiNx firmly adhere together each other [4].…”

“…Taking an example of Au\Cr\SiNx pixel structure [2], assuming that the bi-material beam is 2μm in width and 104 μm in equivalent length, Au, Cr and SiNx thicknesses are selected as 0.29μm, 5nm and 0.4μm respectively. Applying to ANSYS software, using the model of multi-layer shell finite element, a simulating result is given that the rotation angle of the reflector is 2.614×10 -3 rad/K under one degree change of temperature, as shown in Figure 9.…”

Novel uncooled infrared detectors

“…Between them, the most important are bimaterial microcantilevers that mechanically respond to the absorp− tion of the radiation. These sensing structures were origi− nally invented at the Oak National Laboratory (ORNL) in the mid 1990's [11][12][13][14][15], and subsequently developed by ONRL [16][17][18][19][20], the Sarnoff Corporation [21,22], Sarcon Microsystems [23][24][25] and other for imaging [26][27][28][29][30][31][32][33] and photo spectroscopic applications [34,35].…”

“…In dependence on readout techniques, the novel uncooled detectors can be devoted on: [13,15,17,19,20,[26][27][28][30][31][32][33], l piezoresistive [11,12], and l electron tunnelling [8]. …”

“…The high sensitivity of the cantilevers allows the individual pixels in the array to be shrunk from their current size of 50 μm to 20 μm while maintaining low−distortion IR imaging [25,40]. Considerable progress to reduce NEDT and time con− stant has been made in years by several research groups [20,25,[30][31][32][33]40,50,60,61,70,71]. Multispectral Imaging Inc. has developed a new class of electrically−coupled transdu− cers in which bending of the cantilever causes changing its capacitance.…”