No abstract

A novel microchip-sized InSb photodiode infrared sensor (InSb PDS) operating at room temperature is reported. There is no power consumption on the InSb PDS itself, since it works in photovoltaic mode to output an open-circuit voltage. The InSb PDS has a typical responsivity of 1,900 V/W and an output noise of 0.15 µV/Hz 1/2 . A detectivity (D * ) of 2.8x10 8 cmHz 1/2 /W has been obtained at 300 K. The InSb PDS is finally molded with plastic on a Quad Flat Non-leaded (QFN) package, having performance high enough for applications such as mobile electronic equipments, personal computers and consumer electronics.

A microchip-sized InSb photodiode based infrared sensor (InSb PDS) that operates at room temperature was developed. The InSb PDS consists of 700 photodiodes connected in series and consumes no power, because it works in photovoltaic mode to output an open-circuit voltage. The InSb PDS has a typical responsivity of 1,900 V/W and an output noise of 0.15 μV/Hz1/2. A detectivity of 2.8×108 cmHz1/2/W was obtained at 300 K. The InSb PDS has performance high enough for applications such as mobile electronic equipment, personal computers, and consumer electronics

This paper reports the development of a novel InSb photovoltaic infrared sensor (InSb PVS) operating at room temperature. The InSb PVS consists of an InSb p + -p --n + structure grown on semi-insulating GaAs (100) substrate, with a p + -Al 0.17 In 0.83 Sb barrier layer between p + and p -layers to reduce diffusion of photo-excited electrons. Photodiodes were fabricated by wet etching process and, using a 500K blackbody, we obtained D* of 2.8x10 8 cmHz 1/2 /W and R V of 1.9 kV/W at room temperature. S/N was improved with the serial connection of 700 photodiodes patterned on a 600 x 600 µm 2 chip. Increasing the number (N) of connected photodiodes, S/N ratio was improved by a factor of N 1/2 . R V was constant for signals ranging from DC to 500Hz. From spectral response measurements a cut-off wavelength of 6.8 µm was obtained. The InSb PVS was flip-chip bonded on a pre-amplifier IC, allowing the shortest connection between the InSb PVS and the pre-amplifier, making the system immune to electromagnetic noise. The system was finally encapsulated by a Dual Flat Non-leaded (DFN) package with a window, which exposes the backside of the GaAs substrate allowing the infrared light incidence. The device external sizes are 2.2 mm x 2.7 mm x 0.7 mm and to our knowledge is the smallest uncooled sensor for the middle-infrared range reported until now.

No abstract