Method of fabricating a trapping-mode
AssigneeSanta Barbara Research Center
InventorPaul R. Norton
Life of this patent
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Abstract
Photodetectors that produce detectivities close to the theoretical maximum detectivity include an electrically insulating substrate carrying a body of semiconductor material that includes a region of first conductivity type and a region of second conductivity type where the region of first conductivity type overlies and covers the junction with the region of second conductivity type and where the junction between the first and second regions separates minority carriers in the region of second conductivity type from majority carriers in the region of first conductivity type. These photodetectors produce high detectivities where radiation incident on the detectors has wavelengths in the range of about 1 to about 25 microns or more, particularly under low background conditions.
Claims20
A method for making a photoconductive photodetector comprising epitaxially growing a body of semiconductor material on an electrically insulating substrate;
- annealing the resulting body of semiconductor material attached to said substrate for a time sufficient to form a region of first conductivity type substantially completely overlying a region of second conductivity type within said body of semiconductor material, and said photodetector having a detectivity of at least about 2.times.10.sup.17 .lambda..eta./Q.sub.B).sup.1/2 cmHz.sup.1/2 /Watt where the radiation incident on said photodetector is in the range of about 1 to about 25 microns or more, and where .lambda. is the wavelength of radiation incident on said photodetector, Q.sub.B is the background photon flux, and .eta. is the quantum efficiency.
A method for making a photoconductive photodetector having a detectivity of at least about 2.times.10.sup.17 .lambda.(.eta./Q.sub.B).sup.1/2 cmHz.sup.1/2 /Watt, where .lambda. is the wavelength of radiation incident on said photodetector, Q.sub.B is the background photon flux, and .eta. is the quantum efficiency, and where the radiation incident on said photodetector is in the range of about 1 to a bout 25 microns, and comprising an electrically insulating substrate attached to a body of semiconductor material comprising a region of first conductivity type and a region of second, opposite conductivity type, said region of first conductivity type substantially completely overlying said region of second conductivity type, said region of second conductivity type tending to trap, and to separate minority carriers from majority carriers in said region of first conductivity type, said method comprising the steps of:
- epitaxially growing said body on said substrate;
- and annealing said body attached to said substrate for a time sufficient to form said regions of first and second conductivity types.
Dependencies are inferred from the claim text.