Cleaning solution and manufacturing method for semiconductor device
View Patent ↗A method of manufacturing a semiconductor device forms an interlayer insulating film on a nickel silicide layer formed on a substrate, and forms a through hole by performing dry etching using a resist pattern, formed on the interlayer insulating film, as a mask and then removing the resist pattern by ashing. A wafer after an ashing process is cleaned using a cleaning solution comprised of aqueous solution having a content of the fluorine-containing compound of 1.0 to 5.0 mass %, a content of chelating agent of 0.2 to 5.0 mass %, and a content of the organic acid salt of 0.1 to 3.0 mass %.
1. An aqueous cleaning solution consisting of:
1.0 to 5.0 mass % of a fluorine-containing compound;
0.2 to 5.0 mass % of a chelating agent;
0.1 to 3.0 mass % of an organic acid salt; and
water, and
wherein said cleaning solution is capable of cleaning a substrate on which a nickel silicide layer is formed,
wherein said fluorine-containing compound is at least one compound selected from the group consisting of hydrofluoric acid, ammonium fluoride, and amine fluoride,
wherein said chelating agent is selected from a group consisting of chelating agents having an acid dissociation constant pKa n of 8.0 or greater at 25° C. when a dissociation stage for a basic acid having a valence of n, wherein n being an integer of 1 or greater, is n-th stage, and
wherein said organic acid salt is selected from carboxylic ammonium salt having an acid dissociation constant pKa n of 2.5 or greater at 25° C. when a dissociation stage for a basic acid having a valence of n, wherein n being an integer of 1 or greater, is n-th stage.
2. The cleaning solution according to claim 1 , wherein the chelating agent is selected from the group consisting of acetylacetone, catechol, and pyrogallol, and the organic acid salt is selected from the group consisting of ammonium malonate, ammonium lactate, ammonium glycolate, ammonium citrate, and ammonium tartarate.
3. The cleaning solution according to claim 1 , wherein the content of the fluorine-containing compound is 2.0 to 3.0 mass %, the content of the chelating agent is 0.5 to 2.5 mass %, and the content of the organic acid salt is 0.3 to 1.5 mass %.
4. The cleaning solution according to claim 1 , having a pH of 7.0 or less.
5. The cleaning solution according to claim 1 , wherein a thickness of the nickel silicide layer is 50 nm or less.
6. The cleaning solution according to claim 1 , wherein at least one kind of metal selected from the group consisting of Ta, Zr, Co, and V is contained in the nickel silicide layer.
7. The cleaning solution according to claim 1 , wherein the nickel silicide layer is doped with an impurity.