Method of electroplating photoresist defined features from copper electroplating baths containing reaction products of imidazole and bisepoxide compounds
View Patent ↗Electroplating methods enable the plating of photoresist defined features which have substantially uniform morphology. The electroplating methods include copper electroplating baths with reaction products of imidazole and bisepoxides to electroplate the photoresist defined features. Such features include pillars, bond pads and line space features.
1. A method of electroplating photoresist defined features comprising:
a) providing a substrate comprising a layer of photoresist, wherein the layer of photoresist comprises a plurality of apertures;
b) providing a copper electroplating bath comprising a source of copper ions, one or more reaction products of one or more imidazole compounds and one or more bisepoxides; an electrolyte; one or more accelerators; and one or more suppressors;
c) immersing the substrate comprising the layer of photoresist with the plurality of apertures in the copper electroplating bath; and
d) electroplating a plurality of copper photoresist defined features in the plurality of apertures, the plurality of photoresist defined features comprise an average % TIR of 5% to 8%.
2. The method of claim 1 , wherein a % WID of the plurality of photoresist defined features is from 5% to 12%.
3. The method of claim 1 , wherein the one or more imidazole compounds have a formula:
wherein R 1 , R 2 and R 3 are independently chosen from a hydrogen, linear or branched (C 1 -C 10 )alkyl, hydroxyl, linear or branched alkoxy, linear or branched hydroxy(C 1 -C 10 )alkyl, linear or branched alkoxy(C 1 -C 10 )alkyl, linear or branched, carboxy(C 1 -C 10 )alkyl, linear or branched amino(C 1 -C 10 )alkyl, and substituted or unsubstituted phenyl.
4. The method of claim 3 , wherein R 1 , R 2 and R 3 are independently chosen from hydrogen and (C 1 -C 3 )alkyl.
5. The method of claim 1 , wherein the one or more bisepoxide compounds have a formula:
wherein R 4 and R 5 are independently chosen from hydrogen and (C 1 -C 4 )alkyl; R 6 and R 7 are independently chosen from hydrogen, methyl and hydroxyl; m=1-6 and n=1-20.
6. The method of claim 1 , wherein the reaction product is in amounts of 0.25 ppm to 20 ppm.
7. The method of claim 1 , wherein electroplating is done at a current density of 0.25 ASD to 40 ASD.
8. The method of claim 1 , wherein the one or more copper photoresist defined features are pillars, bond pads or line space features.