Metallization method
View Patent ↗Disclosed herein is a metallization method, comprising (a) providing a photoresist layer on a first surface of a substrate, wherein the photoresist layer is formed from a photoresist composition comprising: a polymer comprising acid-labile groups; a photoacid generator; an organic phosphonic acid; and a solvent; (b) pattern-wise exposing the photoresist layer to activating radiation; (c) developing the exposed photoresist layer with a basic developer to form a photoresist pattern; and (d) after forming the photoresist pattern, plating a metal on the first surface of the substrate using the photoresist pattern as a plating mask.
1 . A metallization method, comprising:
(a) providing a photoresist layer on a first surface of a substrate, wherein the photoresist layer is formed from a photoresist composition comprising: a polymer comprising acid-labile groups; a photoacid generator; an organic phosphonic acid; a solvent; and a basic compound;
(b) pattern-wise exposing the photoresist layer to activating radiation;
(c) developing the exposed photoresist layer with a basic developer to form a photoresist pattern; and
(d) after forming the photoresist pattern, plating a metal on the first surface of the substrate using the photoresist pattern as a plating mask, wherein the organic phosphonic acid is selected from the group consisting of butyl phosphonic acid, pentyl phosphonic acid, hexyl phosphonic acid, octyl phosphonic acid, n-decyl phosphonic acid, n-dodecylphosphonic acid, n-hexadecylphosphonic acid, n-hexylphosphonic acid, n-octadecylphosphonic acid, n-octylphosphonic acid, n-tetradecylphosphonic acid, phenyl phosphonic acid, benzylphosphonic acid, (4-aminobenzyl) phosphonic acid (4-aminophenyl) phosphonic acid, (4-hydroxyphenyl) phosphonic acid, benzhydryl phosphonic acid, (2-phenylethyl) phosphonic acid, 4-methoxyphenyl phosphonic acid, (pyridin-3-ylmethyl) phosphonic acid, or a combination thereof, and
wherein the basic compound is selected from the group consisting of 2,8-dimethyl-6H,12H-5,11-methanodibenzo [b,f][1,5]diazocine (Troger's Base), ethyl-3-(morpholino) propionate, 4-(p-tolyl) morpholine, or a combination thereof.
2 . The metallization method of claim 1 , wherein the photoresist pattern has an undercut profile.
3 . The metallization method of claim 1 , further comprising (e) removing the photoresist pattern after plating the metal.
4 . The metallization method of claim 1 , wherein the photoresist layer is disposed directly on a metal layer.
5 . The metallization method of claim 1 , wherein the photoresist layer has a thickness of greater than 2 microns.
6 . The metallization method of claim 1 , wherein the organic phosphonic acid is a phenyl phosphonic acid.
7 . The metallization method of claim 1 , wherein the organic phosphonic acid is present in the photoresist layer in an amount of 0.01 to 0.50 parts by weight per 100 parts of the polymer that comprises acid-labile groups.
8 . The metallization method of claim 1 , wherein the acid-labile groups are chosen from tertiary ester groups, acetal groups, or a combination thereof.
9 . The metallization method of claim 1 , wherein the polymer further comprises a repeat unit formed from a vinyl aromatic monomer.
10 . The metallization method of claim 1 , wherein the photoresist composition further comprises a basic compound having a pKa of less than 7.
11 . The metallization method of claim 10 , wherein the basic compound is selected from tertiary amine compounds.