Cree Gmbh

Wolfspeed, Inc.

Harshad Golakia

Matthew Donofrio

John Adam Edmond

Eric Mayer

Sten Heikman

Yuvaraj Dora

Pritish Kar

Rajeev Acharya

A crystalline material processing method includes forming subsurface laser damage at a first average depth position to form cracks in the substrate interior propagating outward from at least one subsurface laser damage pattern, followed by imaging the substrate top surface, analyzing the image to identify a condition indicative of presence of uncracked regions within the substrate, and taking one or more actions responsive to the analyzing. One potential action includes changing an instruction set for producing subsequent laser damage formation (at second or subsequent average depth positions), without necessarily forming additional damage at the first depth position. Another potential action includes forming additional subsurface laser damage at the first depth position. The substrate surface is illuminated with a diffuse light source arranged perpendicular to a primary substrate flat and positioned to a first side of the substrate, and imaged with an imaging device positioned to an opposing second side of the substrate.

Laser-assisted method for parting crystalline material

A method for processing a crystalline substrate to form multiple patterns of subsurface laser damage facilitates subsequent fracture of the substrate to yield first and second substrate portions of reduced thickness. Multiple (e.g., two, three, or more) groups of parallel lines of multiple subsurface laser damage patterns may be sequentially interspersed with one another, with at least some lines of different groups not crossing one another. Certain implementations include formation of multiple subsurface laser damage patterns including groups of parallel lines that are non-parallel to one another, but with each line remaining within &#xb1;5 degrees of perpendicular to the &#x3c;110&#x3e; direction of a hexagonal crystal structure of a material of the substrate. Further methods involve formation of initial and subsequent subsurface laser damage patterns that are centered at different depths within an interior of a substrate, with the subsurface laser damage patterns being registered with one another and having vertical extents that are overlapping.

Simplified LED chip architectures or chip builds are disclosed that can result in simpler manufacturing processes using fewer steps. The LED structure can have fewer layers than conventional LED chips with the layers arranged in different ways for efficient fabrication and operation. The LED chips can comprise an active LED structure. A dielectric reflective layer is included adjacent to one of the oppositely doped layers. A metal reflective layer is on the dielectric reflective layer, wherein the dielectric and metal reflective layers extend beyond the edge of said active region. By extending the dielectric layer, the LED chips can emit with more efficiency by reflecting more LED light to emit in the desired direction. By extending the metal reflective layer beyond the edge of the active region, the metal reflective layer can serve as a current spreading layer and barrier, in addition to reflecting LED light to emit in the desired direction. The LED chips can also comprise self-aligned and self-limiting features that simplify etching processes during fabrication.

High efficiency LEDs and methods of manufacturing

Growing community of inventors

Morrisville, NC, United States of America

Harshad Golakia