Hong Kong Applied Science and Technology Research Institute Company, Limited

Ka Wah Chan

Hung Shen Chu

Yong Cai

Limin Lin

Shengmei Zheng

Li Min Lin

Sheng Mei Zheng

A method of making quasi-vertical light emitting devices includes growing semiconductor layers on a growth substrate and etching the semiconductor layers to produce device isolation trenches forming separable semiconductor devices and holes. Blind holes are drilled in the substrate at the location of each of the holes in the semiconductor layers. The drilling of the blind holes defines blind hole walls and a blind hole end in each of the blind holes. N-semiconductor metal is deposited in each of the blind holes. An n-electrode contact is formed in each of the blind holes by plating each of the blind holes with an n-electrode metal connected to the n-semiconductor metal. The substrate is thinned to expose the n-electrode metal as an n-electrode. Bonding metal is deposited to the n-electrode for packaging.

Methods for making quasi-vertical light emitting diodes

The present invention provides a method of fabricating vertical LED structures in which the substrate used for epitaxial layer growth is removed through polishing. The polishing technique used in an exemplary embodiment is chemical mechanical polishing using polish stops to provide a sufficiently level plane. Polish stops are provided in the multilayer structure before polishing the surface, the hardness of the polish stop material being greater than the hardness of the material that needs to be removed. Consequently, vertical LEDs can be produced at a lower cost and higher yield compared to either laser lift-off or conventional polishing. Exemplary vertical LEDs are GaN LEDs. The polish stops may be removed by saw dicing, laser dicing or plasma etching.

Optimization of polishing stop design

A method of making a thin gallium-nitride (GaN)-based semiconductor structure is provided. According to one embodiment of the invention, the method includes the steps of providing a substrate; sequentially forming one or more semiconductor layers on the substrate; etching a pattern in the one or more semiconductor layers; depositing a dielectrics layer; forming a photoresist on a portion of the dielectrics layer, wherein the portion of the dielectrics layer is deposited on the one or more semiconductor layers; depositing a primer; removing the photoresist layer, wherein the primer on the photoresist is also removed; depositing a superhard material, wherein the superhard material forms in the pattern; and removing the substrate. Accordingly, the superhard material may be selectively deposited in only areas where the superhard material is desired. Vertical GaN-based light emitting devices may then be formed by cutting the semiconductor structure.

Method of producing thin semiconductor structures

A quasi-vertical light emitting device is provided. According to one embodiment of the present invention, the quasi-vertical light emitting diode includes a sapphire substrate; a plurality of semiconductor layers grown on the sapphire substrate, the plurality of semiconductor layers including an n-GaN layer, an active layer, and a p-GaN layer; a plurality of holes etched in the plurality of semiconductor layers, each of the plurality of holes etched to the sapphire substrate, and a plurality of sapphire holes in the sapphire substrate, each of the plurality of holes aligned with one of the plurality of sapphire holes to form hole walls, the hole walls and bottom deposited with an n-metal and each of the plurality of holes filled with another metal to form a n-electrode contact; an n-mesa in the active layer and the p-GaN layer, the n-mesa deposited with an n-metal and a passivation layer grown over the n-metal; and a p-metal layer deposited on the p-GaN layer, and a p-electrode bonded to the p-metal.

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Hong Kong, China

Ka Wah Chan