Manufacturing method for GaN-based LED (Light Emitting Diode) chip for increasing extraction efficiency

An LED chip and extraction efficiency technology, applied in electrical components, circuits, semiconductor devices, etc., can solve the problem of limited light extraction effect of GaN-based LEDs, and achieve the improvement of luminous optical power, increase the area of ​​the light-emitting side, and increase the escape path. Effect

CN102790158AActive Publication Date: 2012-11-21YANGZHOU ZHONGKE SEMICON LIGHTING
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2012-11-21

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Abstract

The invention provides a manufacturing method for a GaN-based LED (Light Emitting Diode) chip for increasing extraction efficiency and relates to the technical field of LED chip production. The manufacturing method is characterized in that the film thickness is d=(m+1) lambda / 4n and a multi-cycle ITO (Indium Tin Oxide) film is prepared when the ITO is taken as a GaN-based LED antireflection film, wherein the diameters of multi-cycle ITO mesh patterns are respectively 50-500nm and a distance between the adjacent multi-cycle ITO mesh patterns is 50-500nm. According to the manufacturing method provided by the invention, the lateral light emitting area is further increased, the escaping path of the light is increased and the extraction efficiency of the light is further increased.
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Description

technical field

[0001] The invention relates to the technical field of photoelectric devices, especially the production of LED chips. Background technique

[0002] ITO is used as the anti-reflection coating of GaN luminescent material, and its film thickness should be d=mλ / 4n (where n=2 is the refractive index of ITO, λ=460nm is the wavelength of blue light, and m is an integer multiple of 4). When m=4, the single-period ITO thin film has the highest transmittance at the wavelength of blue light of 460nm, and the transmittance is as high as more than 95%. The ITO film thickness at this time is about 2300?. This film thickness is currently widely used in the preparation of LED chips. However, this solution does not take into account that the GaN material has a 1 / 4 wavelength absorption for blue light. In fact, the light emitted from the quantum well needs to pass through the P-type GaN to reach the ITO. The transmittance of the GaN / ITO composite film at 460nm It has dropped...

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Embodiment Construction

[0020] 1. Making LED chips:

[0021] Step 1: Using metal-organic chemical vapor deposition (MOCVD), sequentially grow a 1 μm low-temperature GaN buffer layer 2, 1 μm undoped GaN layer 3, and 3 μm on a semiconductor substrate 1 made of sapphire, silicon, silicon carbide or metal materials N-GaN layer 4, 150nm multi-quantum well light-emitting layer 5 and 300nm P-GaN layer 6 form a GaN epitaxial wafer.

[0022] Step 2: Prepare the GaN epitaxial wafer for photolithographic patterning, use AZ4620 photoresist as a mask, and perform ICP (inductively coupled plasma) etching on one side of the GaN epitaxial wafer to remove P-GaN and quantum wells on one side And part of the N-GaN forms a mesa 41, and the etching depth of the mesa 41 is 700nm˜1500nm. ICP (Inductively Coupled Plasma) etching while using Cl 2 、BCl 3 and Ar 2 As an etching gas, where Cl 2 The flow rate is 30-100sccm, BCl 3 The flow rate is 5-20sccm, Ar 2 The flow rate is 5-25 sccm; the etching power is 300-700W; th...