Seoul Opto Device Co., Ltd.

Postech Foundation

Postech Academy-industry Foundation

Seoul Viosys Co., Ltd.

Pohang University of Science and Technology Foundation

Jong-Lam Lee

Ho Won Jang

Chang Min Jeon

A method for forming a metal electrode and a method for manufacturing semiconductor light emitting elements include providing a substrate having a semiconductor layer formed thereon; forming a bonding metal layer and a reflective metal layer on the semiconductor layer; and forming a metal electrode by layer inversion of the bonding metal layer and the reflective metal layer through a heat treatment process. An interface characteristic between a semiconductor layer and an electrode having a reflective metal layer is enhanced by a layer inversion phenomenon. High reflectivity can be obtained, because a reflection metal layer is uniformly distributed on a semiconductor layer. Further, out-diffusion of a reflective metal layer is prevented through layer inversion to enhance the thermal stability of an electrode. And the number of accepters for generating holes is increased through heat treatment under an oxygen atmosphere, so that contact resistance can be lowered.

Method for forming metal electrode, method for manufacturing semiconductor light emitting elements and nitride based compound semiconductor light emitting elements

The present invention relates to a method of forming an ohmic electrode in a semiconductor light emitting element, comprising: forming a semiconductor layer having a light emitting structure on a substrate, sequentially laminating a bonding layer, a reflective layer and a protective layer on the semiconductor layer, and forming an ohmic electrode by performing a heat treatment process to form ohmic bonding between the semiconductor layer and the bonding layer and to form an oxide film on at least a portion of the protective layer; and a semiconductor light emitting element using the ohmic electrode. According to the present invention, since a reflective layer is formed of Ag, Al and an alloy thereof with excellent light reflectivity, the light availability is enhanced. Further, since contact resistance between a semiconductor layer and a bonding layer is small, it is easy to apply large current for high power.

Method for forming ohmic electrode and semiconductor light emitting element

Provided are a vertical-type light emitting device and a method of manufacturing the same. The light emitting device includes a p-type semiconductor layer, an active layer, and an n-type semi-conductor layer that are stacked, a cover layer disposed on a p-type electrode layer to surround the p-type electrode layer, a conductive support layer disposed on the cover layer, and an n-type electrode layer disposed on the n-type semiconductor layer.

Light emitting device and method of manufacturing the same

The present invention relates to a gallium nitride-based compound semiconductor device and a method of manufacturing the same. According to the present invention, there is provided a gallium nitride-based III-V group compound semiconductor device comprising a gallium nitride-based semiconductor layer and an ohmic electrode layer formed on the gallium nitride-based semiconductor layer. The ohmic electrode layer comprises a contact metal layer, a reflective metal layer, and a diffusion barrier layer.

Gallium nitride-based III-V group compound semiconductor device and method of manufacturing the same

Provided are a vertical-type light emitting device and a method of manufacturing the same. The light emitting device includes a p-type semiconductor layer, an active layer, and an n-type semiconductor layer that are stacked, a cover layer disposed on a p-type electrode layer to surround the p-type electrode layer, a conductive support layer disposed on the cover layer, and an n-type electrode layer disposed on the n-type semiconductor layer.

The present invention relates to a gallium nitride (GaN) compound semiconductor light emitting element (LED) and a method of manufacturing the same. The present invention provides a vertical GaN LED capable of improving the characteristics of a horizontal LED by means of a metallic protective film layer and a metallic support layer. According to the present invention, a thick metallic protective film layer with a thickness of at least 10 microns is formed on the lateral and/or bottom sides of the vertical GaN LED to protect the element against external impact and to easily separate the chip. Further, a metallic substrate is used instead of a sapphire substrate to efficiently release the generated heat to the outside when the element is operated, so that the LED can be suitable for a high-power application and an element having improved optical output characteristics can also be manufactured. A metallic support layer is formed to protect the element from being distorted or damaged due to impact. Furthermore, a P-type electrode is partially formed on a P-GaN layer in a mesh form to thereby maximize the emission of photons generated in the active layer toward the N-GaN layer.

GaN compound semiconductor light emitting element and method of manufacturing the same

The present invention relates to a gallium nitride (GaN) compound semiconductor light emitting element (LED) and a method of manufacturing the same. The present invention provides a vertical GaN LED capable of improving the characteristics of a horizontal LED by means of a metallic protective film layer and a metallic support layer. According to the present invention, a thick metallic protective film layer with a thickness of at least 10 microns is formed on the lateral and/or bottom sides of the vertical GaN LED to protect the element against external impact and to easily separate the chip. Further, a metallic substrate is used instead of a sapphire substrate to efficiently release the generated heat to the outside when the element is operated, so that the LED can be suitable for a high-power application and an element having improved optical output characteristics can also be manufactured. A metallic support layer is formed to protect the element from being distorted or damaged due to impact. Furthermore, a P-type electrode is partially formed on a P&#x2014;GaN layer in a mesh form to thereby maximize the emission of photons generated in the active layer toward the N&#x2014;GaN layer.

A method for manufacturing a hetero-junction field effect transistor (HFET) device, which includes sequentially forming a non-doped GaN semiconductor layer and an AlGaN semiconductor layer on a substrate, separating devices from each other by etching the substrate, forming a photoresist layer pattern on the AlGaN semiconductor layer and forming gate electrodes by depositing a material on the substrate using the photoresist layer pattern, treating the surface of the AlGaN semiconductor layer, and forming a photoresist layer pattern on the substrate and forming ohmic electrodes by depositing a metal on the substrate using the photoresist layer pattern, is provided. Accordingly, it is possible to overcome a difficulty in aligning the gate electrode with the ohmic electrodes and prevent a substrate from having a step difference introduced by the ohmic electrodes because the gate electrode is formed before the ohmic electrodes are formed. It is possible to form a finer photoresist layer pattern used to form the gate electrode and improve the degree, to which the gate electrode is aligned with the ohmic electrodes. In addition, since the surface of an AlGaN semiconductor layer is treated with ICP before the ohmic electrodes are formed. Thus, it is possible to obtain ohmic characteristics without heat-treating a metal deposited on the AlGaN semiconductor layer to form the ohmic electrodes. Finally, since the maximum transconductance and maximum drain current characteristics of the AlGaN/GaN HFET device are good, the AlGaN/GaN HFET device can have improved amplification capability.

Growing community of inventors

Pohang, South Korea

Jong-Lam Lee