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Mask liquid for surface roughening of LED (light emitting diode) chip or substrate as well as preparation method and application thereof

A surface roughening and masking technology, which is applied in the field of masking liquid for surface roughening of sapphire substrates, can solve problems such as the inability to guarantee the uniformity and consistency of roughened patterns, poor roughening effect, and limited ball size. Achieve the effect of improving light extraction efficiency, easy to obtain, and cheap materials

Inactive Publication Date: 2015-05-06
山东浪潮华光照明有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] Chinese patent document CN201110250041 forms polystyrene nanospheres with a certain diameter on the sapphire substrate, and the nanospheres are ordered and evenly distributed on the surface of the substrate, and then etched to form nano-scale nanospheres on the surface of the substrate. The patterned sapphire substrate improves LED luminous brightness, but the disadvantage of this patent is that the uniform distribution of polystyrene nanospheres is difficult to control and the size of the balls is limited
However, the disadvantage of this method is that the photoresist is etched by oxygen plasma, and the glue dots of the photoresist can only be at the nanometer level. Due to the poor etching resistance of the photoresist, the roughness of the film can only reach the nanometer level, or even It is still small, so the roughening effect is poor, and it hardly helps to improve the light extraction efficiency of LEDs
[0007] The roughening method of the above prior art cannot guarantee the uniformity and consistency of the roughened pattern, and the roughening effect is poor, so it is not suitable for application in large-scale production

Method used

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  • Mask liquid for surface roughening of LED (light emitting diode) chip or substrate as well as preparation method and application thereof
  • Mask liquid for surface roughening of LED (light emitting diode) chip or substrate as well as preparation method and application thereof
  • Mask liquid for surface roughening of LED (light emitting diode) chip or substrate as well as preparation method and application thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0065] Embodiment 1, masking liquid and preparation thereof

[0066] Add magnetic metal microsphere particles with a diameter of 2 to 3 μm into a positive photoresist with a viscosity of 200 centipoise, the magnetic metal microsphere particles are iron, and the positive photoresist: magnetic metal microsphere particle volume ratio = 15:1. Magnetic stirring, the stirring speed is 5 rpm, and the heating temperature is 28°C. The magnetic metal microspheres rotate under the rotating magnetic field and are evenly distributed in the photoresist. According to the routine in this field, the above-mentioned positive photoresist is contained in a brown light-shielding bottle. After adding magnetic metal microsphere particles, the mouth of the glue bottle is connected to the mouth of the magnetic stirrer with an organic solvent-resistant hose, and the air pressure pump is used to Put a certain amount of masking liquid into the magnetic stirrer bottle from the glue bottle, and pay atten...

Embodiment 2

[0068] A method for roughening the surface of an AlGaInP LED chip, such as Figure 1A ~ Figure 1E As shown, the steps are as follows:

[0069] Step 1: Growing SiO 2 layer.

[0070] SiO with a thickness of 2000 angstroms was grown on the GaP layer 104 of the AlGaInP epitaxial wafer by PECVD method 2 Layer 103.

[0071] Step 2: Apply masking fluid. The masking solution is the product prepared in Example 1.

[0072] Use compressed air to transport the masking liquid in the container to the glue spray head, and control the injection amount by adjusting the pressure of the compressed air. Generally, the injection amount is controlled at 5ml / time.

[0073] The back of the wafer is adsorbed on a rotatable vacuum rotating device. The glue spray head sprays the masking liquid onto the upper surface of the wafer. The corresponding speed is selected according to the viscosity of the photoresist and the diameter of the magnetic metal microspheres, so that the masking liquid is on the...

Embodiment 3

[0089] Preparation of a surface columnar sapphire pattern substrate, such as Figure 2A ~ Figure 2C .

[0090] Step I: prepare masking liquid, mix the masking liquid evenly and coat the masking liquid with steps 2 to 4 of Example 2, such as Figure 2A .

[0091] Step II: Plasma Etching

[0092] Since the etching ratio of the metal microsphere 201 and the photoresist 202 is very different in plasma etching, the metal microsphere 201 is basically etched and does not move. After the etching is clean, continue to etch the sapphire layer 203 under the photoresist, and stop etching when the etching reaches a depth of 1-3 μm, such as Figure 2B . ICP power is 2000W, RF power is 300W, BCl3 with Cl 2 The volume ratio is 4:1, the total gas flow rate is 100 sccm, the pressure is 20 to 50 mTorr, and the etching time is 20 minutes.

[0093] Step III: Removal of Metal Particles

[0094] After etching, use glue remover RBL3368 to remove the metal particles embedded in the photoresist,...

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Abstract

The invention relates to a mask liquid for surface roughening of an LED (light emitting diode) chip or a substrate as well as a preparation method and an application thereof. According to the mask liquid, magnetic metal microsphere particles are added into positive photoresist, and the volume ratio of the magnetic metal microsphere particles to the positive photoresist is 1 to (10-20); the component of the magnetic metal microsphere particles is made of iron or an iron alloy. The mask liquid provided by the invention is used for roughening the surface of an AlGaInP LED chip or roughening a substrate of a GaN LED chip. By spraying the mask liquid onto a wafer surface, the thickness of a mask layer is 1-2 times the diameters of the magnetic metal microsphere particles. According to the mask liquid as well as the preparation method and the application thereof provided by the invention, the shortcomings that the roughening angle and the depth of a natural roughening method are deeply limited by a crystal lattice structure and an expensive stepping photoetching machine is required for photoetching a mask plate are overcome.

Description

technical field [0001] The invention relates to a masking liquid used for roughening the surface of AlGaInP LED chips and the surface of a GaN LED sapphire substrate in the semiconductor industry and a preparation and application method thereof, belonging to the technical field of semiconductor preparation. Background technique [0002] The light extraction efficiency of LED refers to the ratio of the photons that can exit the surface of the device to the total photons generated by electron-hole recombination in the active area of ​​the epitaxial wafer. In traditional LED devices, due to the existence of factors such as total reflection of the light-emitting surface, substrate absorption, and electrode blocking, the light extraction efficiency is below 30%, and most of the photons are confined inside the device to be repeatedly absorbed, and finally in the form of heat. released, thereby affecting device reliability. [0003] The light extraction efficiency of AlGaInP LEDs ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G03F7/039G03F7/00H01L33/00H01L33/22
Inventor 申加兵夏伟李懿洲任忠祥
Owner 山东浪潮华光照明有限公司