Abstract: A small projector uses an ultra-dense array of gallium nitride (GaN) LEDs. However, epitaxial growth of GaN typically produces a GaN region that is Sum or thicker. To achieve high pixel density, the LEDs have small area, so the resulting LED structures are tall and skinny. This is undesirable because it makes further processing more difficult and has higher optical losses. As a result, it is beneficial to reduce the thickness of the GaN region. In one approach, a wafer with the GaN region on substrate is bonded to a backplane wafer containing LED driver circuits. The substrate is then separated from the GaN region, exposing a buffer layer of the GaN region. The GaN region is thinned and then patterned into individual LEDs. Typically, the buffer layer is removed entirely.

Abstract: A method according to embodiments of the invention includes providing a light emitting semiconductor structure grown on a substrate. The substrate has a front side and a back side opposite the front side. Notches are formed in the substrate. The notches extend from the front side of the substrate into the substrate. After forming notches in the substrate, the back side of the substrate is thinned to expose the notches.

Abstract: In embodiments of the invention, a passivation layer is disposed over a side of a semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region. A material configured to adhere to an underfill is disposed over an etched surface of the semiconductor structure.

Abstract: In embodiments of the invention, a passivation layer is disposed over a side of a semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region. A material configured to adhere to an underfill is disposed over an etched surface of the semiconductor structure.

Abstract: In a method according to embodiments of the invention, a light emitting structure comprising a plurality of light emitting diodes (LEDs) is provided. Each LED includes a p-contact and n-contact. A first mount and a second mount are provided. Each mount includes anode pads and cathode pads. The anode pads are aligned with the p-contacts and the cathode pads are aligned with the n-contacts. The method further includes mounting the light emitting structure on one of the first and second mounts. An electrical connection on the first mount between the plurality of LEDs differs from an electrical connection on the second mount between the plurality of LEDs. The first mount is operated at a different voltage than the second mount.

Abstract: A device according to embodiments of the invention includes a semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region. A surface of the p-type region perpendicular to a growth direction of the semiconductor structure includes a first portion and a second portion. The first portion is less conductive than the second portion. The device further includes a p-contact formed on the p-type region. The p-contact includes a reflector and a blocking material. The blocking material is disposed over the first portion and no blocking material is disposed over the second portion.

Abstract: A method according to embodiments of the invention includes growing on a first surface of a sapphire substrate a semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region. The semiconductor structure is formed into a plurality of LEDs. Cracks are formed in the sapphire substrate. The cracks extend from the first surface of the sapphire substrate and do not penetrate an entire thickness of the sapphire substrate. After forming cracks in the sapphire substrate, the sapphire substrate is thinned from a second surface of the sapphire substrate. The second surface is opposite the first surface.

Abstract: A device according to embodiments of the invention includes a semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region. A surface of the p-type region perpendicular to a growth direction of the semiconductor structure includes a first portion and a second portion. The first portion is less conductive than the second portion. The device further includes a p-contact formed on the p-type region. The p-contact includes a reflector and a blocking material. The blocking material is disposed over the first portion and no blocking material is disposed over the second portion.

Abstract: A light emitting diode (LED) structure has semiconductor layers, including a p-type layer, an active layer, and an n-type layer. The p-type layer has a bottom surface, and the n-type layer has a top surface though which light is emitted. A copper layer has a first portion electrically connected to and opposing the bottom surface of the p-type layer. A dielectric wall extends through the copper layer to isolate a second portion of the copper layer from the first portion. A metal shunt electrically connects the second portion of the copper layer to the top surface of the n-type layer. P-metal electrodes electrically connect to the first portion, and n-metal electrodes electrically connect to the second portion, wherein the LED structure forms a flip chip. Other embodiments of the methods and structures are also described.

Abstract: A light emitting diode (LED) structure has semiconductor layers, including a p-type layer, an active layer, and an n-type layer. The p-type layer has a bottom surface, and the n-type layer has a top surface though which light is emitted. A copper layer has a first portion electrically connected to and opposing the bottom surface of the p-type layer. A dielectric wall extends through the copper layer to isolate a second portion of the copper layer from the first portion. A metal shunt electrically connects the second portion of the copper layer to the top surface of the n-type layer. P-metal electrodes electrically connect to the first portion, and n-metal electrodes electrically connect to the second portion, wherein the LED structure forms a flip chip. Other embodiments of the methods and structures are also described.

Abstract: In a method according to embodiments of the invention, a light emitting structure comprising a plurality of light emitting diodes (LEDs) is provided. Each LED includes a p-contact and n-contact. A first mount and a second mount are provided. Each mount includes anode pads and cathode pads. The anode pads are aligned with the p-contacts and the cathode pads are aligned with the n-contacts. The method further includes mounting the light emitting structure on one of the first and second mounts. An electrical connection on the first mount between the plurality of LEDs differs from an electrical connection on the second mount between the plurality of LEDs. The first mount is operated at a different voltage than the second mount.

Abstract: A device according to embodiments of the invention includes a semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region. A surface of the p-type region perpendicular to a growth direction of the semiconductor structure includes a first portion and a second portion. The first portion is less conductive than the second portion. The device further includes a p-contact formed on the p-type region. The p-contact includes a reflector and a blocking material. The blocking material is disposed over the first portion and no blocking material is disposed over the second portion.

Abstract: A device according to embodiments of the invention includes a semiconductor device structure (10) including a light emitting region (14) disposed between an n-type semiconductor region (16) and a p-type semiconductor region (12). A surface of the p-type semiconductor region (12) perpendicular to a growth direction of the semiconductor device structure (10) includes a first portion and a second portion. The first portion is less conductive than the second portion. The device further includes a p-contact (21) disposed on the p-type semiconductor region (12) and an n-contact (26) disposed on the n-type semiconductor region (16). The p-contact (21) includes a contact metal layer (20) and a blocking material layer (24). The blocking material layer (24) is disposed over the first portion and no blocking material layer (24) is disposed over the second portion.

Abstract: In a method according to embodiments of the invention, a light emitting structure comprising a plurality of light emitting diodes (LEDs) is provided. Each LED includes a p-contact and n-contact. A first mount and a second mount are provided. Each mount includes anode pads and cathode pads. The anode pads are aligned with the p-contacts and the cathode pads are aligned with the n-contacts. The method further includes mounting the light emitting structure on one of the first and second mounts. An electrical connection on the first mount between the plurality of LEDs differs from an electrical connection on the second mount between the plurality of LEDs. The first mount is operated at a different voltage than the second mount.

Abstract: In embodiments of the invention, a passivation layer is disposed over a side of a semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region. A material configured to adhere to an underfill is disposed over an etched surface of the semiconductor structure.

Abstract: A method according to embodiments of the invention includes growing on a first surface of a sapphire substrate a semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region. The semiconductor structure is formed into a plurality of LEDs. Cracks are formed in the sapphire substrate. The cracks extend from the first surface of the sapphire substrate and do not penetrate an entire thickness of the sapphire substrate. After forming cracks in the sapphire substrate, the sapphire substrate is thinned from a second surface of the sapphire substrate. The second surface is opposite the first surface.

Abstract: An LED die (40) includes an N-type layer (18), a P-type layer (22), and an active layer (20) epitaxially grown over a first surface of a transparent growth substrate (46). Light is emitted through a second surface of the substrate opposite the first surface and is wavelength converted by a phosphor layer (30). Openings (42, 44) are etched in the central areas (42) and along the edge (44) of the die to expose the first surface of the substrate (46). A highly reflective metal (50), such as silver, is deposited in the openings and insulated from the metal P-contact. The reflective metal may conduct current for the N-type layer by being electrically connected to an exposed side of the N-type layer along the inside edge of each opening. The reflective metal reflects downward light emitted by the phosphor layer to improve efficiency. The reflective areas provided by the reflective metal may form 10%-50% of the die area.

Abstract: A light emitting diode (LED) structure has semiconductor layers, including a p-type layer, an active layer, and an n-type layer. The p-type layer has a bottom surface, and the n-type layer has a top surface though which light is emitted. A copper layer has a first portion electrically connected to and opposing the bottom surface of the p-type layer. A dielectric wall extends through the copper layer to isolate a second portion of the copper layer from the first portion. A metal shunt electrically connects the second portion of the copper layer to the top surface of the n-type layer. P-metal electrodes electrically connect to the first portion, and n-metal electrodes electrically connect to the second portion, wherein the LED structure forms a flip chip. Other embodiments of the methods and structures are also described.

Abstract: A light emitting diode (LED) structure has semiconductor layers, including a p-type layer, an active layer, and an n-Type layer. The p-type layer has a bottom surface, and the n-type layer has a top surface though which light is emitted. A copper layer has a first portion electrically connected to and opposing the bottom surface of the p-type layer. A dielectric wall extends through the copper layer to isolate a second portion of the copper layer from the first portion. A metal shunt electrically connects the second portion of the copper layer to the top surface of the n-type layer. P-metal electrodes electrically connect to the first portion, and n-metal electrodes electrically connect to the second portion, wherein the LED structure forms a flip chip. Other embodiments of the methods and structures are also described.

Abstract: In a method according to embodiments of the invention, a light emitting structure comprising a plurality of light emitting diodes (LEDs) is provided. Each LED includes a p-contact and n-contact. A first mount and a second mount are provided. Each mount includes anode pads and cathode pads. The anode pads are aligned with the p-contacts and the cathode pads are aligned with the n-contacts. The method further includes mounting the light emitting structure on one of the first and second mounts. An electrical connection on the first mount between the plurality of LEDs differs from an electrical connection on the second mount between the plurality of LEDs. The first mount is operated at a different voltage than the second mount.