Light emitting diode bars and arrays and method of making same
First Claim
1. An LED bar comprising a row of light emitting pixel regions formed in an epitaxial thin film semiconductor structure comprising a front side cladding layer on an active p-n junction layer, on a back side cladding layer with pixel regions formed in said structure separated from adjacent pixel regions by high lateral resistivity with a thin contact film on the front side of the structure, and wherein only said contact film is removed between pixel regions, said contact film being formed on said front side cladding layer, said cladding layer having a thickness less than bout 0.5 microns thereby enhancing said high lateral resistivity between adjacent pixel regions, with metal pixel contacts formed on the back side cladding layer and remaining front side pixel contact film.
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Accused Products
Abstract
Light emitting diodes (LEDs) and LED bars and LED arrays formed of semiconductive material, such as III-V, and particularly AlGaAs/GaAs material, are formed in very thin structures using organometallic vapor deposition (OMCVD). Semiconductor p-n junctions are formed as deposited using carbon as the p-type impurity dopant. Various lift-off methods are described which permit back side processing when the growth substrate is removed and also enable device registration for LED bars and arrays to be maintained.
233 Citations
41 Claims
- 1. An LED bar comprising a row of light emitting pixel regions formed in an epitaxial thin film semiconductor structure comprising a front side cladding layer on an active p-n junction layer, on a back side cladding layer with pixel regions formed in said structure separated from adjacent pixel regions by high lateral resistivity with a thin contact film on the front side of the structure, and wherein only said contact film is removed between pixel regions, said contact film being formed on said front side cladding layer, said cladding layer having a thickness less than bout 0.5 microns thereby enhancing said high lateral resistivity between adjacent pixel regions, with metal pixel contacts formed on the back side cladding layer and remaining front side pixel contact film.
- 9. An LED array comprised of rows and columns of light emitting pixel regions formed in an epitaxial thin film semiconductor structure with pixel regions separated from adjacent pixel regions by high lateral resistivity with a thin contact film overlying said pixel regions on a front side cladding layer over a p-n junction active layer over a back side cladding layer with metal pixel contacts formed on said front side contact film and metal pixel contacts to regions of said back side cladding layer co-extensive with said pixel regions and orthogonally disposed bus bars extending across front side rows of pixel contacts and back side columns of pixel contacts and wherein said pixel regions are defined by removing only portions of said contact film between pixel regions.
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19. Apparatus for converting a first light image of wavelength λ
- 1 to a second light of wavelength λ
2 comprising;a) an array of rows and columns of individual light detectors for detecting said first light image and converting said image to electrical signals corresponding to the instantaneous light intensity of said first image as detected by said light detectors; b) an LED array comprised of rows and columns of pixel regions for emitting light of λ
2 wavelength formed in an epitaxial thin film semiconductor structure with pixel regions separated from adjacent pixel regions and front and back contacts formed on said pixel regions with front side bus bars extending along rows of front pixel contacts and back side bus bars extending along columns of back pixel contacts;c) multiplexer means for coupling the electrical signals to said contacts to cause said LED array to generate a second light image at λ
2 wavelength corresponding to said first image. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28)
- 1 to a second light of wavelength λ
- 29. A hybrid LED bar bonded to an L-shaped silicon section of a structure comprising silicon circuits on a silicon wafer connected to pixels in an LED bar by a cantilevered first contact bar extending over a second contact bar located on a surface of said wafer.
- 31. An LED comprising a light emitting pixel region formed in an epitaxial thin film semiconductor structure having a thin front contact on the front side of the structure, said front contact being formed on a front side epitaxial cladding layer formed on an active doped p-n junction layer, on a back side cladding layer with a back contact coupled to the back side cladding layer and a contact pad formed laterally adjacent said pixel region and coupled to said thin front contact.
- 35. An LED comprising a light emitting pixel region formed in an epitaxial thin film semiconductor structure having a thin front contact formed of a contact film on the front side of the structure and formed on a front side cladding layer on an active carbon doped p-n junction layer, formed on a back side cladding layer with a back contact coupled to the back side cladding layer and wherein only portions of the contact film surrounding the contact are removed to define said pixel region.
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40. An LED bar comprising a row of light emitting pixel regions formed in an epitaxial thin film semiconductor structure with pixel regions separated from adjacent pixel regions by high lateral resistivity with a thin contact film on the front side of the structure, which contact film is removed between pixel regions, said contact film being deposited on a front side epitaxial cladding layer having a thickness less than about 0.5 microns thereby enhancing said high lateral resistivity between adjacent pixel regions, said front side cladding layer being formed on an active p-n junction layer, on a back side cladding layer with metal pixel contacts formed on the back side cladding layer and remaining front side contact film and wherein said LED bar is supported on the front side by a light transparent support and is mounted with the support onto a silicon substrate and interconnected with silicon drive circuits to said metal pixel contacts.
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41. An LED comprising a light emitting pixel region formed in an epitaxial thin film semiconductor structure of less than about 3 microns thickness having a thin front contact film on the front side of the structure, said contact film being formed on a front side AlGaAs cladding layer formed on an carbon doped p-n junction AlGaAs active layer, on a back side AlGaAs cladding layer with a back contact coupled to the back side cladding layer and a contact pad formed laterally adjacent said pixel region and coupled to said thin front contact film.
Specification