Etching liquor and mask plate forming method

Abstract

The invention relates to an etching liquor and a mask plate forming method. The etching liquor comprises perchloric acid, ceric ammonium nitrate and water in a proportion of 500mL to (2Kg-3Kg) to (12L-16L). The mask forming method comprises photoetching, developing, etching and demolding, wherein the etching is performed by using the etching liquor. The etching liquor adopts the perchloric acid with the relatively low concentration, and the content of the ceric ammonium nitrate is reduced, the amount of volatile gas is reduced from the source, and the relatively heavy odor is avoided; the etching liquor is relatively safe and relatively environmentally-friendly, and the cost is relatively reduced; by adopting the etching liquor with the proportion for etching, etching lines of a plate are good in quality, good in linearity and relatively small in defect number.

Description

technical field [0001] The invention relates to the technical field of etching technology, in particular to an etching solution and a method for forming a mask. Background technique [0002] In the manufacture of semiconductor devices, photomasks are one of the commonly used tools. The photomask is usually engraved with a designed geometric circuit diagram on a high-purity quartz or soda glass substrate. Photolithography is applied to photosensitive adhesives, which are coated on metal substrates or glass surfaces as a polymeric soluble substance, then the photoresist is baked to remove the solvent, exposed to electron beams or laser beams, and then chemically Process processing, such as developing, etching and other processes. [0003] The early etching solution was synthesized by mixing ammonia cerium nitrate, glacial acetic acid and water. Now most of them use imported stock solution with catalytic elements added. Due to the reaction time between the etching solution sy...

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Problems solved by technology

[0003] The early etching solution was synthesized by mixing ammonia cerium nitrate, glacial acetic acid and water. Now most of them use imported stock solution with catalytic elements added. Due to the reaction time between the etching solution synthesized by simply mixing ammonia cerium nitrate, glacial acetic acid and water and the chromium film Slower, uneven etching, faster reaction time of imported stock solution, uniform etching

However, the imported raw liquid is expensive. The current market price is about 200 US dollars for 3.6 liters, and about 30 pieces can be etched. Such a high price has caused a very large investment in the follow-up process of the mask plate, which greatly increases the process cost.

[0004] In addition, the existing etching solution has the following difficulties in the research and development process: 1. Etching solution volatile gas (mainly HCl and Cl 2 ) phenomenon is relatively serious, with serious odor, which will cause harm to the environment and process personnel; 2. The etching solution will have obvious crystallization after a long time of use, which will cause hidden dangers of plate scratches; 3. The number of etching sheets reaches After a certain number of tablets, the ion concentration in the solution is too high, showing that the color of the solution is too dark, which is not conducive to the reaction

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