This paper reviews characteristics and performance of the amorphous silicon microbolometers with a pixel-pitch of 25 μm. We first present the advantages of amorphous silicon uncooled microbolometer technology which enables the production of high volume and low cost uncooled IRFPA. The 25 μm pixel architecture profits from the low thermal time constant of 45 μm pixel detector, to design higher thermal insulated pixel. It enables the development of a 25 μm pixel-pitch detector which has high performance despite the pixel pitch reduction. Thanks to this new pixel design and by pushing the design rules even further, high fill factor has been kept, without the use of complex, as well as expensive, two-level structure. IRFPAs are then described in terms of ROIC architecture, packaging, operability and electro-optical performances. New readout integrated circuit structure has been specially developed for this pixel pitch. High level functions like gain, offset correction, image flip and windowing could be operated through a serial link to simplify the electrical interface.
At a 60Hz frame rate, focal planes with less than 50mK (f/1) NETD are now achieved with high stability regarding environmental temperature.