Method of production of light emitting diodes

Claim 1

A method for preparing a plurality of light emitting diodes on a single substrate of a semiconductor material having a p or n conductivity type, and in which the resulting diodes can be separated and mechanically fixed to transmit from their substrate side rather than the junction side using otherwise conventional mounting techniques, and wherein the substrate includes an epitaxial layer of the same semiconductor material on one surface thereof in which the epitaxial layer comprises a layer of p-type material and a layer of n-type material adjacent one another and that form a p-n junction therebetween, the method comprising; etching the epitaxial layer and the substantially transparent substrate in a predetermined pattern to define individual diode precursors and wherein the etch is deep enough to form mesas in the epitaxial layer that delineate the p-n junctions in each diode precursor from one another; grooving the substrate from the side of the epitaxial layer and between the mesas of the diode precursors to a predetermined depth into the substrate to define side portions of the device precursors in the substrate while retaining enough of the substrate beneath the grooves to maintain the mechanical stability of the substrate; adding an ohmic contact to the epitaxial layer; forming a layer of an insulating material that covers the portions of the epitaxial layer that are not covered by the ohmic contact and that covers any portions of the one surface of the substrate adjacent the mesas that are not covered by the epitaxial layer and that covers portions of the side portions of the substrate for insulating the one surface, the junction and the side portions of the substrate of each diode precursor from electrical contact other than through the ohmic contact; and adding an ohmic contact to the substrate.

Claim 2

A method for preparing a plurality of light emitting diodes on a single substrate of a semiconductor material having a p or n conductivity type, and in which the resulting diodes can be separated and mechanically fixed to transmit from their substrate side rather than the junction side using otherwise conventional mounting techniques, and wherein the substrate includes an epitaxial layer of the same semiconductor material on one surface thereof in which the epitaxial layer comprises a layer of p-type material and a layer of n-type material adjacent one another and that form a p-n junction therebetween, the method comprising; etching the epitaxial layer and the substantially transparent substrate in a predetermined pattern to define individual diode precursors and wherein the etch is deep enough to form mesas in the epitaxial layer that delineate the p-n junctions in each diode precursor from one another; grooving the substrate from the side of the epitaxial layer and between the mesas of the diode precursors to a predetermined depth into the substrate to define side portions of the device precursors in the substrate while retaining enough of the substrate beneath the grooves to maintain the mechanical stability of the substrate; adding an ohmic contact to the epitaxial layer; forming a layer of an insulating material that covers the portions of the epitaxial layer that are not covered by the ohmic contact and that covers any portions of the one surface of the substrate adjacent the mesas that are not covered by the epitaxial layer and that covers portions of the side portions of the substrate for insulating the one surface, the junction and the side portions of the substrate of each diode precursor from electrical contact other than through the ohmic contact; and adding an ohmic contact to the substrate.

Claim 5

A method for preparing a plurality of blue light emitting diodes on a single substrate, and in which the resulting diodes can be separated and mechanically fixed to transmit from their substrate side rather than the junction side using otherwise conventional mounting techniques, the method comprising: forming an epitaxial layer of alpha silicon carbide on one surface of a substantially transparent silicon carbide substrate having a p or n type conductivity in which the epitaxial layer comprises a layer of p-type silicon carbide and a layer of n-type silicon carbide adjacent one another and that form a p-n junction therebetween; etching the epitaxial layer and the substrate in a predetermined pattern to define individual diode precursors and wherein the etch is deep enough to form mesas in the epitaxial layer that delineate the p-n junctions in each diode precursor from one another; grooving the substrate from the side of the epitaxial layer and between the mesas of the diode precursors to a predetermined depth into the substrate to define side portions of the device precursors in the substrate while retaining enough of the substrate beneath the grooves to maintain the mechanical stability of the substrate; adding an ohmic contact to the epitaxial layer; forming a layer of an insulating material that covers the portions of the epitaxial layer that are not covered by the ohmic contact and that covers any portions of the one surface of the substrate adjacent the mesas that are not covered by the epitaxial layer and that covers portions of the side portions of the substrate for insulating the one surface, the junction and the side portions of the substrate of each diode precursor from electrical contact other than through the ohmic contact; and adding an ohmic contact to the substrate.

Claim 6

A method for preparing a plurality of blue light emitting diodes on a single substrate, and in which the resulting diodes can be separated and mechanically fixed to transmit from their substrate side rather than the junction side using otherwise conventional mounting techniques, the method comprising: forming an epitaxial layer of alpha silicon carbide on one surface of a substantially transparent silicon carbide substrate having a p or n type conductivity in which the epitaxial layer comprises a layer of p-type silicon carbide and a layer of n-type silicon carbide adjacent one another and that form a p-n junction therebetween; etching the epitaxial layer and the substrate in a predetermined pattern to define individual diode precursors and wherein the etch is deep enough to form mesas in the epitaxial layer that delineate the p-n junctions in each diode precursor from one another; grooving the substrate from the side of the epitaxial layer and between the mesas of the diode precursors to a predetermined depth into the substrate to define side portions of the device precursors in the substrate while retaining enough of the substrate beneath the grooves to maintain the mechanical stability of the substrate; adding an ohmic contact to the epitaxial layer; forming a layer of an insulating material that covers the portions of the epitaxial layer that are not covered by the ohmic contact and that covers any portions of the one surface of the substrate adjacent the mesas that are not covered by the epitaxial layer and that covers portions of the side portions of the substrate for insulating the one surface, the junction and the side portions of the substrate of each diode precursor from electrical contact other than through the ohmic contact; and adding an ohmic contact to the substrate.