Photomask used for color filter technology

Abstract

The invention discloses a photo mask which comprises a first pair of site marks set symmetrically and a second pair of site marks. The first and second pairs of marks have plural different graphs, but the graphs of the first and the second pairs of marks are corresponding to each other, and the corresponding graphs have actual asymmetrical distances to the photo mask reference symmetrical center; when the photo masks on the same plane, after rotating 180 degree, different graphs corresponds to the same site, which make it easy to identify that the photo mask is placed in wrong direction and to modify.

Description

technical field [0001] The invention relates to a photomask used in the color filter process, in particular to a photomask with alignment marks used in the color filter process. Background technique [0002] Liquid crystal display has the advantages of power saving, light weight, low radiation and easy to carry. It has become the mainstream product on the market and is widely used in TVs, computer screens, notebook computers, car navigation systems, mobile communication devices, etc., gradually replacing traditional display. One of the key components is the color filter. [0003] Generally speaking, the color filter adopts a proximity exposure process in a photolithography process. Currently, leading manufacturers using proximity exposure machines include Topcon, Seiko, Hitachi DECO, Orc Manufacturing and DNS. In the photolithography process, in order to ensure that the exposure position of the substrate under the photomask is correct, a plurality of detection points for ...

AI Technical Summary

Problems solved by technology

On-site operators obtain the photomask with alignment marks and expose the color filter; in terms of this highly repeatable and technically uncomplicated step, on-site operators usually work at a lower standard For the exposure procedure, if the alignment mark "BGR" is taken as an example, on the same plane, the on-site operator is very likely to invert the photomask 10 by 180 degrees, and the result will be as follows image 3 shown

It can be seen from the figure that even if the photomask is inverted, the second scanner at the fixed position will still display the word "G". (Especially under long hours of work and heavy workload) It is very difficult to identify the difference between the front and back of the font, detect the error, and correct it immediately; the operator seems to have a mistake in the correct position of the photomask 10 It will cause subsequent operators to mistakenly think that it is correct to carry out subsequent exposure procedures, resulting in wrong lithography results

[0006] Furthermore, the undetected photomask inversion in the above-mentioned production line actually comes from the fact that the operator only observes the same words through the scanner, which is judged to be correct alignment, although the exposure The program will not be hindered, but in fact, the pixel pattern (pixel pattern) has been seriously shifted from the original expected position due to the inversion of the corresponding exposure position, making the exposed product completely unusable

What's more, because the photomask inversion phenomenon is not easy to detect in the process, it is possible to continue the production and manufacture until a certain inspection station, or even until the final product is obtained, the product defect is not found. and a serious waste of manpower

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