Composite technique for polishing sapphire by using green and ultraviolet laser

Abstract

The invention relates to a composite technique for polishing sapphire by using green and ultraviolet laser, which comprises the following steps:1) scanning and polishing the surface of a sapphire wafer by green laser; 2) polishing the green laser polished surface of the sapphire wafer by ultraviolet laser. The green laser and the ultraviolet laser are pulsed laser. In the composite technique, the green laser is firstly used for polishing, and then the ultraviolet laser is used for precision polishing. Polishing by pulsed green laser replaces the traditional grinding, and by the light and heat coupling generated on the sapphire surface radiated by the laser, materials are removed mainly by evaporation, melting and other forms in company with tiny smashing and photochemical reaction so as to obtain a relatively flat surface in macroscopic view with a hump of curved surface in microscopic view. The complex technique has high polishing efficiency, and uneven areas and defects on the polished surface in microscopic view are easy to remove in the subsequent polishing processes. The composite technique can reduce and even eliminate the effects of heat on sapphire materials, and obtain polishing surfaces with low surface roughness and subsurface damage degree.

Description

technical field [0001] The invention is a composite process method for laser polishing sapphire with green light and ultraviolet light, which belongs to the innovative technology of the process method for laser polishing sapphire. Background technique [0002] Sapphire single crystal is an excellent multifunctional material with the characteristics of high hardness, high melting point, good light transmission, excellent electrical insulation, and stable chemical properties. In terms of optics, sapphire single crystal is used in the mirror window of high-energy lasers due to its good light transmission and wear resistance. At the same time, it is also one of the key materials for infrared guided weapons. In terms of electronics, it can be used as a substrate for heteroepitaxial growth of semiconductor materials or metal materials, such as epitaxial substrates for semiconductor silicon and epitaxial substrate materials for semiconductor GaN. As a semiconductor substrate mater...

AI Technical Summary

Problems solved by technology

At present, sapphire is mainly processed by mechanical polishing, chemical mechanical polishing and other methods. These traditional contact polishing methods often cause problems such as brittle failure during the material removal process. After polishing, there are often surface scratches, pits and so on on the surface of sapphire. Defects such as subsurface cracks, polishing fog spots may also appear on the chemically polished surface, it is difficult to obtain a high-quality optical surface, and the polishing efficiency and yield are low