Light emitting diode chip having electrode pad

Abstract

Disclosed herein is an LED chip including electrode pads. The LED chip includes a semiconductor stack including a first conductive type semiconductor layer, a second conductive type semiconductor layer on the first conductive type semiconductor layer, and an active layer interposed between the first conductive type semiconductor layer and the second conductive type semiconductor layer; a first electrode pad located on the second conductive type semiconductor layer opposite to the first conductive type semiconductor layer; a first electrode extension extending from the first electrode pad and connected to the first conductive type semiconductor layer; a second electrode pad electrically connected to the second conductive type semiconductor layer; and an insulation layer interposed between the first electrode pad and the second conductive type semiconductor layer. The LED chip includes the first electrode pad on the second conductive type semiconductor layer, thereby increasing a light emitting area.

Description

technical field [0001] The invention relates to a light emitting diode chip, more specifically, to a light emitting diode chip with electrode pads. Background technique [0002] Gallium nitride (GaN)-based light-emitting diodes (LEDs) have been used in a wide range of applications including natural-color LED displays, LED traffic lights, and white LEDs. In recent years, high-efficiency white LEDs are expected to replace fluorescent lamps, specifically, white LEDs whose efficiency reaches that of typical fluorescent lamps. [0003] GaN-based LEDs are generally formed by growing epitaxial layers on a substrate such as a sapphire substrate, and GaN-based LEDs include an n-type semiconductor layer, a p-type semiconductor layer, and an active layer disposed between the n-type semiconductor layer and the p-type semiconductor layer. In addition, an n-electrode pad is formed on the n-type semiconductor layer, and a p-electrode pad is formed on the p-type semiconductor layer. The L...

AI Technical Summary

Problems solved by technology

Therefore, the formation of n-electrode pads and n-electrode extensions results in a reduction in light-emitting area, resulting in deterioration of light-emitting efficiency.

[0006] Meanwhile, since the electrode pad and the electrode extension are formed of metal, the electrode pad and the electrode extension absorb light generated in the active layer, resulting in optical loss

Furthermore, although the use of electrode extensions enhances current spreading, current crowding still occurs at regions near the electrode extensions, resulting in electrode extension-induced optical losses

In addition, since the electrode pad and the electrode extension use a material such as Cr exhibiting low reflectivity as an underlying layer, optical loss becomes serious

[0007] Additionally, as the size of LEDs increases, the likelihood of defects in the LED increases

For example, defects such as threading dislocations and pin holes provide pathways along which current flows rapidly, thereby interfering with current spreading in LEDs

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