A method for wet roughening of gallium phosphide window layer of light-assisted red LED

A gallium phosphide and window layer technology, applied in semiconductor devices, electrical components, circuits, etc., can solve the problems of unfavorable light extraction, cumbersome steps, and high cost of corrosion structures, and achieve improved light extraction efficiency, large processing area, and easy operation Effect

Inactive Publication Date: 2011-12-14
SHANDONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantages of using etching to roughen the light-emitting surface of LEDs are: (1) etching is very destructive to the carrier transport properties of semiconductor materials, which significantly reduces the electrical properties of LEDs; (2) ) The cost of purchasing and using etching equipment is extremely high, which greatly increases the cost of LEDs; (3) There is no way to control and optimize the shape and size of the roughened LED light-emitting surface by etching
(4) The processing time is longer and the production efficiency is lower
The shortcomings of this method for roughening the light-emitting surface of LEDs are: (1) an external voltage is required for assistance, and an additional electrode preparation process is introduced; (2) the obtained corrosion structure is not conducive to the light extraction of LEDs
This method needs to use PS microspheres as a mask, the steps are cumbersome, the cost is high, and it is difficult to ensure a uniform coarsening structure with a large area
[0008] To sum up, the above technologies and patents do not have the characteristics of high controllability, low cost, easy integration with existing LED technology, non-toxicity, and no damage to the electrical properties of LED chips.

Method used

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  • A method for wet roughening of gallium phosphide window layer of light-assisted red LED
  • A method for wet roughening of gallium phosphide window layer of light-assisted red LED

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] Taking a 2-inch GaAs-based front-mounted red LED epitaxial wafer as an example to illustrate the implementation method of the present invention:

[0030] (1) The structure of the GaAs-based front-loading red LED epitaxial wafer from bottom to top is GaAs substrate, n-GaAs confinement layer, multi-quantum well active light-emitting region, p-GaAs confinement layer, and GaP window layer.

[0031] (2) Put the GaP layer of the red LED epitaxial wafer upwards into the polytetrafluoroethylene reaction vessel.

[0032] (3) Turn on the 532nm light source so that the power density irradiated on the surface of the epitaxial wafer is 1 μW / cm 2 .

[0033] (4) Add a mixed solution of 1% hydrofluoric acid and 0.1% hydrogen peroxide into the reaction vessel until the liquid level is above the surface of the epitaxial wafer.

[0034] (5) Stand for reaction for 3 hours.

[0035] (6) The cleaning process after the corrosion is completed is ultrasonic cleaning with high-purity water fo...

Embodiment 2

[0038] Take the 2-inch AlGaInP-based front-loading red LED epitaxial wafer as an example to illustrate the realization method of the present invention, the 2nd and 7th steps are the same as the example 1, the difference is:

[0039] (1) The structure of the AlGaInP-based front-loading red LED epitaxial wafer from bottom to top is gallium arsenide substrate, n-AlGaInP confinement layer, multi-quantum well active light-emitting region, p-AlGaInP confinement layer, and GaP window layer.

[0040] (2) Turn on the 450nm light source so that the power density irradiated on the surface of the epitaxial wafer is 100mW / cm 2 .

[0041] (3) Add a mixed solution of 40% hydrofluoric acid and 50% potassium ferricyanide into the reaction vessel until the liquid level is above the surface of the epitaxial wafer.

[0042] (4) Stand for reaction for 3 minutes.

[0043] (5) The cleaning process after the corrosion is completed is ultrasonic cleaning with high-purity water for 15 minutes, ultrason...

Embodiment 3

[0045] 2-inch AlGaInP-based front-loading red LED epitaxial wafer is taken as an example to illustrate the realization method of the present invention, and the first, second, and seventh steps are the same as in Example 2, except that:

[0046] (1) Turn on the 480nm light source so that the power density irradiated on the surface of the epitaxial wafer is 20mW / cm 2 .

[0047] (2) Add a mixed solution of 10% hydrofluoric acid and 20% potassium permanganate into the reaction vessel until the liquid level is above the surface of the epitaxial wafer.

[0048] (3) Stand for reaction for 12 minutes.

[0049] (4) The cleaning process after the corrosion is completed is ultrasonic cleaning with high-purity water for 20 minutes, ultrasonic cleaning with acetone for 20 minutes, and ultrasonic cleaning with ethanol for 10 minutes.

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Abstract

The invention, which belongs to the LED technology field, relates to a coarsening method of a wet method of a gallium phosphide window layer of a photo-assisted red light LED. A mixed solution of hydrofluoric acid and an oxidizing agent is utilized and light irradiation is utilized; a gallium phosphide window layer can be corroded without a mask layer and a conical composition array is obtained, so that a surface coarsening of the red light LED is realized. A size and a height of the conical composition caused by corrosion can be controlled by controlling corrosion time and a concentration ofcorrosive liquid. According to the invention, a problem of coarsening of the gallium phosphide window layer of the red light LED can be effectively solved and an extraction efficiency of a red light LED chip can be improved more than double. The method has advantages of good coarsening effect, low cost and rapid speed and the like and thus has great application potential in production of a large power red light LED.

Description

technical field [0001] The invention relates to a wet roughening method for a gallium phosphide window layer of a light-assisted red LED, and belongs to the technical field of light-emitting diode manufacturing. Background technique [0002] In the 1950s, with the efforts of many well-known research institutions represented by IBM Thomas J. Watson Research Center, III-V semiconductors represented by GaAs rose rapidly in the field of semiconductor light emitting. Later, with the emergence of metal oxide chemical vapor deposition (MOCVD) technology, the growth of high-quality III-V semiconductors broke through the technical barrier, and semiconductor light-emitting diode devices with various wavelengths flooded into the market one after another. Compared with the current light-emitting devices, semiconductor light-emitting diodes have the characteristics of high theoretical efficiency, long life, and mechanical shock resistance, and are regarded as a new generation of lighting...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01L33/00
Inventor 刘铎左致远王瑞军于谦冯兆斌徐现刚
Owner SHANDONG UNIV
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