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US 12,428,737 B2Granted
Cleaning liquid used for cleaning metal resists, and cleaning method using cleaning liquid
AssigneeTokyo Ohka Kogyo Co., Ltd.
InventorsMai Sugawara, Tomoya Kumagai
Life of this patent
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Abstract
A metal resist remover containing a solvent and a strong acid that is liquid at 20° C., in which a pH value, which is measured with a pH meter, of a liquid formed by subjecting the cleaning liquid to a 10-fold dilution with pure water is 2.5 or less.
Claims13
A metal resist remover consisting of:
- propylene glycol methyl ethyl acetate (PGMEA);
- a strong acid that is liquid at 20° C. in an amount of 0.05% to 3% by mass with respect to a total mass of the metal resist remover;
- and
- optionally, water in an amount 30% by mass or less with respect to a total mass of the metal resist remover;
- wherein a pKa of the strong acid is 2 or less;
- and
- wherein a pH value, which is measured with a pH meter, of a liquid formed by subjecting the metal resist remover to a 10-fold dilution with pure water is 2.5 or less.
4 more elements
A metal resist remover consisting of:
- propylene glycol methyl ethyl acetate (PGMEA);
- a strong acid that is liquid at 20° C. in an amount of 0.05% to 3% by mass with respect to a total mass of the metal resist remover;
- acetic acid;
- and
- optionally, water in an amount from 0.5% to 20% with respect to a total mass of the metal resist remover,
- wherein a pKa of the strong acid is 2 or less;
- and
- wherein a pH value, which is measured with a pH meter, of liquid formed by subjecting the metal resist remover to a 10-fold dilution with pure water is 2.5 or less.
5 more elements
Dependencies are inferred from the claim text.