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Method for improving luminous efficiency of AlGaN-based ultraviolet LED (Light-Emitting Diode)

A technology of luminous efficiency and high temperature, applied in electrical components, circuits, semiconductor devices, etc., can solve the problems of increased difficulty, easy wear and tear of thin films, and high production costs, to reduce stress and dislocation density, and not easy to wear and fall off. , simple in design and craftsmanship

Inactive Publication Date: 2013-01-02
ZHEJIANG EUVILEDS TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although people can realize ultraviolet LEDs in the 210-400nm band by adjusting the Al composition, but with the increase of the Al composition, the difficulty from material growth to device preparation has also increased accordingly.
The 210nm DUV-LED is driven by 40mA DC, the luminous power is only 0.02mW, and its external quantum efficiency is lower than 10-5%
However, the surface roughening treatment only improves the light extraction efficiency by increasing the scattering of light at the interface, and its effect is not very obvious, and the outgoing light is relatively divergent.
Coating Bragg gratings on the surface can improve the output of light, but the design of this film system is limited by the refractive index of the material, and the coated film is easy to wear and fall off, and it is not good for heat dissipation
Photonic crystals guide light based on the photonic band gap, which can improve the extraction rate of light, but the preparation cost is relatively high, most of the outgoing light is polarization-related, and there are also disadvantages of wear and shedding

Method used

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  • Method for improving luminous efficiency of AlGaN-based ultraviolet LED (Light-Emitting Diode)
  • Method for improving luminous efficiency of AlGaN-based ultraviolet LED (Light-Emitting Diode)
  • Method for improving luminous efficiency of AlGaN-based ultraviolet LED (Light-Emitting Diode)

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Embodiment 1

[0055] A method for improving the luminous efficiency of an AlGaN-based ultraviolet LED by using a double-sided patterned sapphire substrate, the operation is as follows:

[0056] First, a 200nm silicon dioxide film 2 is deposited on a 2-inch c-plane sapphire substrate 1 using chemical vapor deposition (CVD) technology, and then a periodic photoresist pattern display 3 is made using conventional photolithography technology, and the pattern unit is rectangular , the spacing is 500nm, the cross-sectional view after photolithography is as follows figure 1 shown;

[0057] Next, using the photoresist pattern array as a mask, using a mixture of hydrofluoric acid and ammonium fluoride solution (mixing volume ratio is 1:7), etch a silicon dioxide film 2 with a pattern structure (such as figure 2 shown);

[0058] Then, using the silicon dioxide film 2 with a pattern structure as a mask plate, the c-plane sapphire substrate 1 is etched at 450°C for 10 minutes with a mixture of sulfur...

Embodiment 2

[0065] A method for improving the luminous efficiency of an AlGaN-based ultraviolet LED by using a double-sided patterned sapphire substrate, the operation is as follows:

[0066] First, a 1.0-micron silicon dioxide film 2 is deposited on a 2-inch c-plane sapphire substrate 1 using chemical vapor deposition (CVD) technology, and then a periodic photoresist pattern display 3 is made using conventional photolithography technology. The pattern unit is Rectangular, with a pitch of 1.0 microns, the cross-sectional view after photolithography is as follows figure 1 shown;

[0067] Next, using the photoresist pattern array as a mask, using a mixture of hydrofluoric acid and ammonium fluoride solution (mixing volume ratio is 1:7), etch a silicon dioxide film 2 with a pattern structure (such as figure 2 shown);

[0068] Then, using the silicon dioxide film 2 with a pattern structure as a mask plate, the c-plane sapphire substrate 1 is etched at 450°C for 10 minutes with a mixture of...

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Abstract

The invention belongs to the technical field of semiconductors, and in particular relates to a method for improving luminous efficiency of an AlGaN-based ultraviolet LED (Light-Emitting Diode). According to the method, the crystal quality of an AlNBuffer layer is improved by etching a triangularly prism-shaped graph on the surface of a C-side sapphire along the direction of [10-10], and the surface topography of an AlN layer is improved by a high-temperature pulse type atomic layer epitaxy. The traditional AlGaN-based LED with a flipchip structure can improve the light extraction rate by adopting a plated bragg grating, and the method not only is limited by the refractive index of materials and high in cost, but also is easy to wear and fall off. The method disclosed by the invention and adopting etching of a subwavelength grating not only is simple in design and process, but also is not easy to wear and fall, and is beneficial to heat dissipation, so that the luminous efficiency of the device can be improved.

Description

technical field [0001] The invention belongs to the technical field of semiconductors, in particular to a method for improving the luminous efficiency of an AlGaN-based ultraviolet LED by using a double-sided patterned sapphire substrate. Background technique [0002] Ultraviolet Light Emitting Diode (LED) is a semiconductor device that emits ultraviolet wavelengths under current drive. The research and development of such devices has become a focus in the field of wide-bandgap semiconductor optoelectronic devices, and it is also a research hotspot in the use of wide-bandgap semiconductor materials to realize ultraviolet light sources. At present, commonly used ultraviolet light sources include mercury lamps, xenon lamps, and fluorescent lamps. However, these lamps are bulky, have high operating voltage and are not very environmentally friendly, so they are not very convenient to use. On the contrary, AlGaN-based ultraviolet LED is a semiconductor solid light source, which...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01L33/00H01L33/20
Inventor 胡斌卢细中
Owner ZHEJIANG EUVILEDS TECH
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