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US 2007/0190676 A1Published application
Light emitting diodes (leds) with improved light extraction by roughening
AssigneeSemiLEDs Corporation
InventorsChen-Fu Chu, Hao-Chun Cheng, Feng-Hsu Fan, Wen-Huang Liu, Chao-Chen Cheng
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Abstract
Systems and methods are disclosed for fabricating a semiconductor light-emitting diode (LED) device by forming an n-doped gallium nitride (n-GaN) layer on the LED device and roughening the surface of the n-GaN layer to extract light from an interior of the LED device.
Claims20
A method comprising:
- providing a light-emitting diode (LED) wafer assembly having a plurality of LED stacks disposed above a conductive substrate, each of the LED stacks comprising:
- a p-doped layer disposed above the conductive substrate;
- an active layer for emitting light disposed above the p-doped layer;
- and
- an n-doped layer disposed above the active layer;
- applying a protective layer covering a selected portion of a surface of the n-doped layer for each of the plurality of LED stacks;
- altering the surface of the n-doped layer by at least one of roughening and texturing, wherein the protective layer shields the selected portion of each of the plurality of LED stacks during the altering;
- and
- removing the protective layer.
6 more elements
A method comprising:
- providing a light-emitting diode (LED) wafer assembly having a plurality of LED stacks disposed above a conductive substrate, each of the LED stacks comprising:
- a p-doped layer disposed above the conductive substrate;
- an active layer for emitting light disposed above the p-doped layer;
- and
- an n-doped layer disposed above the active layer;
- applying a protective layer covering a selected portion of a surface of the n-doped layer for each of the plurality of LED stacks;
- immersing the surface of the n-doped layer having the protective layer applied in an electrolytic solution;
- applying an electrical bias to the conductive substrate;
- and
- illuminating the surface of the n-doped layer such that photoelectrochemical (PEC) oxidation and etching occurs to roughen the surface of the n-doped layer, wherein the protective layer shields the selected portion of each of the plurality of LED stacks during the illuminating.
7 more elements
A method comprising:
- providing a light-emitting diode (LED) wafer assembly comprising a plurality of LED dies;
- and
- selectively altering a desired portion of a light-emitting surface of each of the plurality of LED dies by at least one of roughening and texturing, wherein each of the plurality of LED dies has a remaining portion of the light-emitting surface that is excluded from the altering.
Dependencies are inferred from the claim text.