Processing method of large-size wafer

Abstract

The invention provides a processing method of a large-size wafer. According to the processing method, an aluminum oxide polishing solution replaces a silicon dioxide polishing solution, and wax pastepolishing replaces adsorption pad polishing. Particle size of an aluminum oxide polishing solution grinding material is 300-750 nm, and PH value is 13-13.5; particle size of the silicon dioxide polishing solution adopted in a traditional technology is 80-120 nm, and PH value is 10.5; under the same technological condition, removal rate of the aluminum oxide polishing solution reaches 8-10 mu m / h,removal rate of the silicon dioxide polishing solution is 3-4 mu m / h, and efficiency is improved by about 3 times. Uniwafer dosage of the aluminum oxide polishing solution for a four-inch wafer is about 4 g / pcs, and dosage of the silicon dioxide polishing solution is 270 g / pcs, and cost is saved by about 50%. Due to the fact that the adsorption pad polishing is affected by compression ratio of material flannelette, product surface contour is difficult to control, a wafer wax layer after the wax paste polishing is uniform and flat, and is not easily affected by external force in a chemical polishing process, wafer thickness difference after processing is smaller than or equal to 5 mu m, and LTV is smaller than 1.5 mu m.

Description

technical field [0001] The invention relates to a process method for single-sided processing of large-scale wafers (including hard and brittle material wafers such as sapphire substrates and silicon carbide substrates). Background technique [0002] Sapphire is a unique crystal with excellent optical properties, physical properties and chemical properties, and is an important basic material for modern industry. Its unique lattice structure, excellent mechanical properties, and good thermal properties make sapphire crystal an ideal substrate material for practical applications such as semiconductor lighting (LED), large-scale integrated circuits SOI and SOS, and superconducting nanostructured films. According to the statistics of French YOLE, the application of substrate materials accounts for more than 75% of the demand for sapphire, and the application of non-substrate materials accounts for about 25%. Every time the penetration rate of LED lighting increases by 1%, it wil...

AI Technical Summary

Problems solved by technology

[0007] The present invention solves the problem of yield rate, and the yield rate can be increased to more than 95% for the lamination method with wax (silicon oxide can not solve the problem of scratching the edge of wax process).

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