System and method for testing mark size of photomask substrate

Abstract

The invention discloses a photomask substrate mark size testing system which comprises a three-dimensional moving platform, a light source, a focusing lens, a camera, a computer and a controller. A transparent and light-transmitting fixed plate is arranged in the middle of the three-dimensional mobile platform; a photomask substrate to be tested is mounted on the fixing plate; the light source is located below the fixing plate, and the focusing lens is located above the photomask substrate; the camera lens directly faces the focusing lens; the camera and the controller are respectively connected with the computer, and the controller is connected with the three-dimensional mobile platform and controls the movement of the three-dimensional mobile platform. The invention further provides a photomask substrate mark size testing method. Compared with the prior art, the method has the advantages that based on a machine vision method, the position of a specific area of the mark angle when imaging is clear is found, the size of the mark angle is obtained through position difference comparison, the quality area of the photomask substrate is not contacted in the measurement process, scratches are avoided, and the measurement cost is low.

Description

technical field [0001] The invention relates to the technical field of semiconductor photomask substrate production and manufacturing, in particular to a photomask substrate marking size testing system and method. Background technique [0002] In the semiconductor manufacturing process, one of the more important links is the manufacturing process from layout to wafer, which is usually called photolithography. Photolithography is a key part of the process connection, the most expensive part of the process, and one of the bottlenecks that restricts the minimum line width. The layout used in lithography is called a photomask, and common photomasks include four types: chrome, dry, letterpress, and liquid letterpress. The photomask is mainly composed of a photomask substrate and a light-shielding film. The photomask substrate is usually quartz glass with high purity, low reflectivity, and low thermal expansion coefficient. The technical barriers to the production of photomask s...

AI Technical Summary

Problems solved by technology

At present, vernier calipers can be used to measure these appearance dimensions. Vernier calipers are cheap, but they are easy to introduce scratches and cause the substrate to be scrapped, and the accuracy is low; high-end optical inspection equipment can also be used. Although the accuracy can meet the requirements, the equipment cost is high. conducive to promotion and utilization

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