Grinding material for improving surface cleanliness of thinned gallium arsenide substrate, and processing method

Abstract

The invention discloses a grinding material for improving the surface cleanliness of a thinned gallium arsenide substrate, and a processing method. The preparation method comprises the following steps: mixing diethanolamide stearic acid monoglyceride, dilauryl dimethyl ammonium chloride, alkoxy polyoxyethylene sulfate and 1-sodium carboxymethyl-1-beta-hydroxyethyl-2-alkyl-imidazoline sodium hydroxide according to a ratio of 1.5-2:2-3:2-3:1 to form a regulator, such that the grinding material has characteristics of low surface activity and high dispersibility, and is suitable for the gallium arsenide substrate, and the difficult-to-remove combination of the particle surface and the substrate gallium arsenide active grinding surface due to bond breaking and the static electricity during thegrinding process is prevented. According to the invention, with the grinding material, particles can be effectively prevented from being adsorbed or remained on the surface of a thinned substrate, sothat the surface is kept clean, the subsequent coating quality is facilitated, and the quality and the yield of a chip are improved.

Description

technical field [0001] The invention relates to the technical field of LED manufacturing, in particular to an abrasive and a processing method for improving the surface cleanliness of a gallium arsenide substrate after thinning. Background technique [0002] The core structure of the LED is MQW (Multiple Quantum Well Structure), which is gradually formed by epitaxial epitaxy, and the epitaxial growth process requires a certain carrier, and the lattice structure of the carrier is required to have consistency or similarity with the structure of the epitaxial material and thermal stability. Adaptability, in order to finally grow a high-quality, high-performance LED structure. For example, a traditional blue LED uses a sapphire substrate as a substrate, and a red LED uses a gallium arsenide substrate or a silicon substrate as a substrate. Since the material of the substrate itself is relatively thick, generally around 250-450 μm, after the epitaxial epitaxy is completed, the di...

AI Technical Summary

Problems solved by technology

Due to its poor toughness and high brittleness, gallium arsenide substrates are easily broken during the chip manufacturing process and affect product quality and yield. Therefore, large-scale chip manufacturers in the industry generally use a combination of fine grinding wheels and polishing. However, ordinary small and medium-sized manufacturers use corundum abrasives for thinning. The thinning efficiency is relatively low, and the surface of the substrate after thinning is easy to absorb abrasive particles. Conventional ultrasonic cleaning, flushing, inorganic or organic solvents cannot Removal will directly affect the coating quality of the subsequent surface. For example, it will cause the coating to fall off due to poor surface cleanliness and many particles, which will seriously affect the quality of the chip.

In order to remove this kind of particulate matter, it can only be achieved by means of polishing equipment at present. The investment in raw materials, equipment, and manpower is relatively large, and the production cycle is prolonged, which is not conducive to reducing product costs.

[0004] Chinese patent literature CN102311706 publishes "Grinding Liquid for LED Substrate Processing and Preparation Method thereof" as described in which the grinding liquid is composed of solvent, additive and abrasive, wherein the main abrasive is composed of diamond micropowder and non-diamond nano-scale polishing material, according to Its composition can be seen that it is only suitable for silicon substrates, sapphire substrates, and silicon carbide substrates. The main reason is that diamond micropowder is used. Diamond itself has high hardness and cannot be used for gallium arsenide substrates. At present, there is no relevant diamond micropowder in the industry. Any information on the thinning of gallium arsenide substrates, in addition, additives are mainly used to disperse materials, and cannot simultaneously achieve the effects of the present invention to improve the surface activity of particles, static electricity and reduce the adsorption of particles on the surface of the substrate