Method of electroplating photoresist defined features from copper electroplating baths containing reaction products of imidazole compounds, bisepoxides and halobenzyl compounds
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 compounds, bisepoxides and halobenzyl compounds to electroplate the photoresist defined features. Such features include pillars, bond pads and line space features.
1. A method 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 one or more sources of copper ions; one or more reaction products of one or more imidazole compounds, one or more bisepoxides and one or more halobenzyl compounds; 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 10%.
2. The method of claim 1 , wherein a % WID of the plurality of photoresist defined features is from 8% to 10%.
3. The method of claim 1 , wherein the one or more imidazole compounds have a formula:
where R 1 , R 2 and R 3 may be the same or different and chosen from hydrogen atom, 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 1 wherein the one or more bisepoxides are chosen from compounds having formula:
wherein R 4 and R 5 may be the same or different and are chosen from hydrogen and (C 1 -C 4 )alkyl; R 6 and R 7 may be the same of different and are chosen from hydrogen, methyl and hydroxyl; m=1-6 and n=1-20.
5. The method of claim 1 , wherein the one or more halobenzyls have a formula:
wherein R 8 , R 9 , R 10 , R 11 , R 12 and R 13 are independently chosen from hydrogen, linear or branched (C 1 -C 10 )alkyl halide, and linear or branched (C 1 -C 10 )alkyl with the proviso that at least two of R 8 , R 9 , R 10 , R 11 , R 12 and R 13 are alkyl halide in the same instance and with the proviso that R 10 , and R 12 , or R 9 , R 11 and R 13 are not methyl groups in the same instance.
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 performed 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.