Gray mask defect checking method

Abstract

PURPOSE: A method for inspecting defects of a gray tone mask is provided to determine whether a gray tone part has defects or not in exposure and transfer precisely with high accuracy. CONSTITUTION: A method for inspecting defects of a gray tone mask includes the steps of composing image data of a gray tone part, carrying out image processing on the basis of the image data for distinguishing defects of the gray tone part, and carrying out the defect inspection of the gray tone part on the basis of the data after the image processing. The image processing is to be fading or highlighting. The gray tone part is an area formed with a light shield pattern below a resolution threshold of an exposure using the gray tone mask and the defect inspection is carried out on the basis of an allowance range of shading of color preset for the data after the image processing.

Description

technical field [0001] The present invention relates to a device having a gray-tone portion having an adjusted light transmittance area for selectively changing the film thickness of a photoresist film by reducing the light transmittance of the area. A defect inspection (judgment) method, a defect correction method, etc. of a gray tone portion of a gray tone mask. Background technique [0002] In recent years, in the field of masks for large LCDs, an attempt has been made to reduce the number of masks using a gray tone mask (Non-Patent Document 1). [0003] Here, a gray tone mask such as Figure 5 As shown in (1), a light-shielding portion 1 , a light-transmitting portion 2 , and a gray tone portion 3 are provided on a transparent substrate. The gray tone portion 3 is, for example, an area where a light-shielding pattern 3a below the limit resolution limit resolution of a large-scale LCD exposure machine using a gray tone mask is formed, and the amount of light transmitted ...

AI Technical Summary

Problems solved by technology

[0012] First, when correcting to a figure that has the same shape as a normal figure (within the CD allowable accuracy of the normal figure), although a comparison check can be performed by comparing the normal figures with each other, but in the case of a figure whose shape is similar to the normal figure (Except for the CD allowable precision of the normal pattern) When correction is performed, and when correction is performed on a pattern that is different from the normal pattern shape, there is a problem that it is not easy to check because the usual comparison check cannot be performed.

[0013] The 2nd, when removing black defect with laser repairing device, because glass substrate is easily damaged, therefore even if the shading pattern 3a after being corrected satisfies the technical specification (pattern line width and shape) under the situation of setting, in fine When the light-transmitting part (glass part) 3b is damaged, the light transmittance of the fine light-transmitting part (glass part) 3b will also decrease, which will cause problems in the user's exposure and transfer processing

In this case, there is a problem that only checking the shape of the figure is insufficient

[0014] Third, even if it is a normal pattern that satisfies the set technical specifications (line width and shape of the pattern) in order to meet the user's requirements (when the user exposes, retain the specified resist film thickness) (of course, within the allowable accuracy of CD) The correction pattern within the CD allowable accuracy of the normal pattern, due to the existence of the exposure conditions when the user actually uses a gray tone mask to obtain the transferred pattern on the resist film of the transferred substrate, depends on the optical conditions of the exposure device used for transfer. Depending on the setting conditions, problems may occur in the user's exposure and transfer processing

Specifically, there are cases where the exposure conditions of the gray tone mask used by the user are not normal conditions (for example, the light irradiation amount conditions are not normal conditions (excessive irradiation conditions, etc.)), and the gray tone pattern is intentionally confused. like conditions

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