US 6,661,039 B1Granted

Velocity-cooled hot-electron bolometric mixer/detector

AssigneeLucent Technologies Inc.

InventorsMark Lee, Loren Neil Pfeiffer, Kenneth William West

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Abstract

A hot-electron bolometric mixer/detector, which uses the nonlinearities of the heated two-dimensional electron gas medium, is described. Electrons in the illustrative embodiment of the present invention are “velocity-cooled” rather than “diffusion-cooled” or “phonon-cooled” like hot-electron bolometric mixer/detectors in the prior art. The illustrative embodiment is velocity-cooled when the elastic mean-free path of the electrons is greater than the channel length, L, of the mixer/detector. In this case, the motion of the hot electrons is more accurately modeled by their speed rather than in accordance with diffusion models. This leads to a mixer/detector with a wider modulation bandwidth at a lower power than is exhibited by mixer/detectors in the prior art.

Claims28

Dependent claims

A multilayer semiconductor structure comprising:

a first undoped compound semiconductor layer comprising at least one element from group 3 of the periodic table of the elements and at least one element from group 5 of the periodic table of the elements;
a second undoped compound semiconductor layer adjacent to said first undoped compound semiconductor layer, wherein said second undoped compound semiconductor comprises at least one element from group 3 of the periodic table of the elements and at least one element from group 5 of the periodic table of the elements, and wherein said second undoped compound semiconductor layer has a wider band gap than said first undoped compound semiconductor layer;
a third layer adjacent to said second undoped compound semiconductor layer, wherein said third layer comprises at least one element from group 4 of the periodic table of the elements;
a first ohmic contact that penetrates said third layer and said second undoped compound semiconductor layer, and makes contact with said first undoped compound semiconductor layer;
and
a second ohmic, contact spaced by a channel length L from the first ohmic contact, that penetrates said third layer and said second undoped compound semiconductor layer, and makes contact with said first undoped compound semiconductor layer;
wherein an elastic mean-free path of conduction charge carriers at a boundary between said first undoped compound semiconductor layer and said second undoped compound semiconductor layer, lμ, is greater than the channel length L.

4 more elements

A mixer for modulating or demodulating a signal, said mixer comprising:

a first undoped compound semiconductor layer comprising at least one element from group 3 of the periodic table of the elements and at least one element from group 5 of the periodic table of the elements;
a second undoped compound semiconductor layer adjacent to said first undoped compound semiconductor layer, wherein said second undoped compound semiconductor comprises at least one element from group 3 of the periodic table of the elements and at least one element from group 5 of the periodic table of the elements, and wherein said second undoped compound semiconductor layer has a wider band gap than said first undoped compound semiconductor layer;
a third layer adjacent to said second undoped compound semiconductor layer, wherein said third layer comprises at least one element from group 4 of the periodic table of the elements;
a first ohmic contact that penetrates said third layer and said second undoped compound semiconductor layer, and makes contact with said first undoped compound semiconductor layer;
a second ohmic contact, spaced by a channel length L from the first ohmic contact, that penetrates said third layer and said second undoped compound semiconductor layer, and makes contact with said first undoped compound semiconductor layer;
and
a charge carrier conducting layer having a plurality of foci, each of the foci being in contact with the first ohmic contact or the second ohmic contact;
wherein an elastic mean-free path of conduction charge carriers at a boundary between said first undoped compound semiconductor layer and said second undoped compound semiconductor layer, lμ, is greater than the channel length L.

5 more elements

Dependencies are inferred from the claim text.