Dual band sensitivity enhancements of a VO_x microbolometer array using a patterned gold black absorber

Abstract

Infrared-absorbing gold black has been selectively patterned onto the active surfaces of a vanadium-oxide-based infrared bolometer array. Patterning by metal lift-off relies on protection of the fragile gold black with an evaporated oxide, which preserves much of gold black's high absorptance. This patterned gold black also survives the dry-etch removal of the sacrificial polyimide used to fabricate the air-bridge bolometers. For our fabricated devices, infrared responsivity is improved 22% in the long-wave IR and 70% in the mid-wave IR by the gold black coating, with no significant change in detector noise, using a 300°C blackbody and 80 Hz chopping rate. The increase in the time constant caused by the additional mass of gold black is ∼15%.

Synchrotron-Based Three-Dimensional Fourier-Transform Infrared Spectro-Microtomography of Murchison Meteorite Grain

“…In several cases where the structure is known in advance, so that the spatial index variations are known, and where the index contrast is strong and the surfaces convoluted, IR tomography has confirmed the structure without distortion. 60,[62][63][64][65][66] This gives confidence to the application of the technique to situations such as ours, where the structure and index distribution is unknown in advance, though the index variations are expected from complementary measurements to be small.…”

Designing dual-band athermal refractive-lens IR objectives

“…Сегодня уже разработан ряд матричных фотодетекторов для двойного (среднего и длинноволнового) инфракрасного (ИК) диапазона как с активным охлаждением, так и неохлаждаемых микроболометров [9 -14]. В частности, в работах [13,14] представлены результаты исследований по расширению диапазона спектральной чувствительности неохлаждаемых приёмников и достижения максимумов коэффициента поглощения в диапазонах длин волн 3 -5 мкм и 8 -14 мкм за счёт активного перестроения резонатора Фабри-Перо или за счёт нанесения абсорбирующего покрытия, выравнивающего значение коэффициента поглощения в диапазоне 3 -11 мкм. Полученные величины спектральной чувствительности показывают возможность практического применения микроболометров в двойном ИК-диапазоне.…”

Low-Cost Microbolometer Type Infrared Detectors

“…However, the most common thermistor materials like vanadium oxide (VO x ) [ 60 , 61 , 62 ] and silicon derivatives (a-Si, a-SiGe, a-Ge x Si 1−x O y , etc.,) [ 63 , 64 , 65 ], which have appropriate electrical properties, are not compatible with the CMOS process. For the CMOS-compatible microbolometer IR detector, one choice is the p-n junction diode which has acceptable properties and compatibility with CMOS process; therefore the silicon-on-insulator (SOI) diode IRFPAs have attracted continuous attention since first reported by Ishikawa et al in 1999 [ 13 ], and have been widely adopted in low-cost commercial IR detectors.…”