Radiation-emitting semiconductor diode and method of manufacturing same
First Claim
1. A radiation-emitting semiconductor diode comprising a semiconductor body with a semiconductor substrate (1) of a first conductivity type on which a semiconductor layer structure is present which comprises in that order at least a first cladding layer (2) of the first conductivity type, an active layer (3A) which emits in the visible range of the spectrum, and a second cladding layer (4) of a second conductivity type opposite to the first, while the first and the second cladding layer (2, 4) are provided with means (5, 6, 7, 8) for electrical connection, characterized in that the active layer (3A) comprises Alx Gal-x As, the cladding layers (2, 4) comprise Aly Gaw Inl-y-w P, and the active layer (3A) has an aluminium content (x) and a thickness (d) such that the wavelength of the photoluminescence emission lies between approximately 770 and 690 nm.
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Accused Products
Abstract
Radiation-emitting semiconductor diodes are used as laser diodes or LEDs inter alia in optical disc systems, laser printers and bar code readers. The emission wavelength in these cases lies preferably in the visible range of the spectrum. Known diodes have an active layer (3A) and cladding layers (2, 4) which comprise either AlGaAs or InAlGaP. These known diodes have the disadvantage that they do not cover a portion of the visible spectrum between 880 and 600 nm.
A diode according to the invention is characterized in that the active layer (3A) comprises Alx Gal-x As and the cladding layers (2, 4) comprise Aly Gaw Inl-y-w P, while the active layer (3A) has such an aluminjure content (x) and such a thickness (d) that the wavelength of the photoluminescence emission lies between approximately 770 and 690 nm. This results in the availability of (laser) diodes covering the entire spectrum from approximately 880 nm to 600 nm which operate satisfactorily, supply a high power, and are easy to manufacture. Preferably, the active layer comprises a (multiple) quantum well structure of alternating quantum well layers and barrier layers, both comprising AlGaAs, but with different aluminium contents.
13 Citations
12 Claims
- 1. A radiation-emitting semiconductor diode comprising a semiconductor body with a semiconductor substrate (1) of a first conductivity type on which a semiconductor layer structure is present which comprises in that order at least a first cladding layer (2) of the first conductivity type, an active layer (3A) which emits in the visible range of the spectrum, and a second cladding layer (4) of a second conductivity type opposite to the first, while the first and the second cladding layer (2, 4) are provided with means (5, 6, 7, 8) for electrical connection, characterized in that the active layer (3A) comprises Alx Gal-x As, the cladding layers (2, 4) comprise Aly Gaw Inl-y-w P, and the active layer (3A) has an aluminium content (x) and a thickness (d) such that the wavelength of the photoluminescence emission lies between approximately 770 and 690 nm.
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12. A method of manufacturing a radiation-emitting semiconductor diode whereby on a semiconductor substrate are provided in that order:
- a first cladding layer (2) of a first conductivity type, an active layer (3A) of material which emits in the visible range of the emission spectrum, and a second cladding layer (4) of a second conductivity type opposed to the first, after which the cladding layers (2,
4) are provided with means (5, 6, 7,
8) for electrical connection, characterized in that Alx Gal-x As is chosen for the semiconductor material of the active layer (3A) and Aly Gaw Inl-y-w P is chosen for the semiconductor material of the cladding layers (2,
4), while the aluminium content (x) and the thickness (d) of the active layer (3A) are so chosen that the emission wavelength lies between approximately 770 and 690 nm.
- a first cladding layer (2) of a first conductivity type, an active layer (3A) of material which emits in the visible range of the emission spectrum, and a second cladding layer (4) of a second conductivity type opposed to the first, after which the cladding layers (2,
Specification