Method and apparatus for trimming IR/CCD mosaic sensors

A threshold level trimming apparatus for IR/CCD mosaic sensors comprising in combination:

• a scanning electron microscope for irradiating a specimen, said scanning electron microscope producing an electron beam output, said scanning electron microscope including a cathode ray tube unit for visual observation of said specimen,
• an IR/CCD sensor unit comprising a plurality of IR/CCD mosaic sensors, said IR/CCD sensor unit being positioned in said scanning electron microscope for exposure to said electron beam output, said IR/CCD sensor unit being registered within the scanning electron microscope coordinate system to permit any region of said IR/CCD sensor unit to be irradiated, a bias level being applied to each of said plurality of IR/CCD mosaic sensors, some of said plurality of IR/CCD mosaic sensors producing an output signal, said bias level being increased until each of said plurality of IR/CCD mosaic sensors produce an output signal, the bias level which produces an output signal in each of said plurality of IR/CCD mosaic sensors being the established threshold level, and,
• a readout unit connected to said IR/CCD sensor unit to indicate the output signal in each of said plurality of IR/CCD mosaic sensors, each of said plurality of IR/CCD mosaic sensors having an input gate which is positioned on an insulating region, said scanning electron microscope irradiating the insulating region of each of said IR/CCD mosaic sensors whose threshold level is below the established threshold level to introduce a positive charge into said insulating region and bring all input gates to the same threshold level for a no-signal condition.