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AssigneeU.S. Philips Corporation
InventorsAdriaan Valster, Coen T. H. F. Liedenbaum
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Radiation-emitting semiconductor diodes in the form of a laser diode or an LED form important components in information processing systems. There is a particular demand for diodes emitting in the visible range of the spectrum and having a high permissible operating temperature. A radiation-emitting diode including a semiconductor body with a semiconductor substrate on which a lower cladding layer, an active layer, and an upper cladding layer are present, the active layer and the two cladding layers each including different semiconductor materials which form a mixed crystal, partly fulfill the above requirements. According to the invention, such a diode is characterized in that the mixed crystal of the active layer is more strongly ordered than that of the two cladding layers. This makes the difference in bandgap between these layers greater than in the known diode. The diode thus has a comparatively high T.sub.o value and accordingly a high maximum operation temperature. The invention also relates to a method of manufacturing such a diode. In this method, a difference in the degree of ordering between the active layer and the cladding layers is achieved through a change in the growing temperature or in the ratio of the quantities of the offered elements during providing of the semiconductor layers. Thus diodes--for example in the InGaP/InAlGaP material system-with the required characteristics are obtained.
A radiation-emitting semiconductor diode comprising a semiconductor body with a semiconductor substrate of a first conductivity type on which are present at least, in that order, a lower cladding layer of the first conductivity type, an active layer, and an upper cladding layer of a second conductivity type, said active layer and at least one of said cladding layers, to be called first cladding layer hereinafter, comprising mutually differing semiconductor materials which each comprise a mixed crystal of at least two binary compounds with two sub-lattices, atoms of different elements being present side by side on at least one of said sub-lattices, to be called first sub-lattice hereinafter, characterized in that the distribution of the atoms of different elements over said first sub-lattice in said active layer is ordered to a greater extent than it is in said first cladding layer, and in that the different in the degree of ordering between said active layer and said first cladding layer results in an increased different between the bandgap of said active layer and the bandgap of said first cladding layer.
Dependencies are inferred from the claim text.