Detection method of subsurface defect of optical glass

Abstract

The invention relates to a detection method of a subsurface defect of optical glass. The detection method comprises the steps: preparing a glass sample of the subsurface defect in an asphalt or polyurethane polishing mode; reasonably determining a sampling point of the sample, so as to comprehensively evaluate the subsurface defect of the sample; manufacturing a removal function of a removal area which is in a regular shape according to the sampling point, and convolving with the value of the dwell time, so as to obtain a plurality of sampling areas which are in regular shapes; uniformly removing the sampling areas with different depths by utilizing the removal function and ion beam machining; and observing the sampling areas by using surface morphology observation equipment, so as to obtain the morphology of the subsurface defect of the optical glass. According to the detection method, surface hydrolysis layers of the different sampling points in a full field of the optical glass are removed by adopting the ion beam machining, and surface microtopography detection equipment is used for observation. The detection method has the characteristics of being simple in principle, accurate and visual in measurement results and the like, hydrofluoric acid is not used, and the detection method is a safe and effective measuring method of the subsurface defect.

Description

technical field [0001] The invention relates to the field of optical processing and detection, in particular to a method for detecting subsurface defects of optical glass. Background technique [0002] The photolithography machine used in the manufacture of large-scale integrated circuits can expose and produce tens of nanometer feature size patterns to meet the needs of smaller and smaller chip sizes and higher integration. As the most important part of the lithography machine, the projection lithography objective lens is currently the most complicated optical system, and its manufacturing process puts forward extremely high requirements on optical design, processing, inspection and assembly. For optical processing, there will still be subsurface defects in optical glass after polishing. The existence of these defects, especially microcracks, will enhance the local field under high-energy laser irradiation, reducing the ability of optical materials to resist laser damage, ...

AI Technical Summary

Problems solved by technology

Since silicon dioxide only reacts with hydrofluoric acid, hydrofluoric acid can only be used as the acid for corrosion. Hydrofluoric acid itself is very corrosive, and the reaction between the two produces silicon fluoride gas, which is a colorless and poisonous gas, so hydrogen Protection is more important during the use of hydrofluoric acid and corrosion; magnetorheological processing is a non-destructive processing method, but it, like other processing methods using polishing fluid, will produce a hydrolyzed layer on the surface of optical glass, although it is thinner tha

Images