Compositions for cleaning ion implanted photoresist in front end of line applications
View Patent ↗A front end of the line (FEOL) stripping and cleaning composition for cleaning unashed ion-implanted photoresist from a wafer substrate comprises: a) at least one organic stripping solvent, b) fluoride ions from at least one of ammonium fluoride, ammonium bifluoride or hydrogen fluoride, c) at least one acidifying agent selected from inorganic or organic acids, and d) water, with an oxidizing agent optionally also being present in the composition.
1. A FEOL stripping and cleaning method for stripping/cleaning unashed ion-implanted photoresist from a wafer substrate, the process comprising conducting the process without supercritical CO 2 and comprises contacting the unashed ion-implanted photoresist on a wafer substrate with a FEOL stripping/cleaning composition for a time sufficient to clean the wafer substrate of the unashed ion-implanted photoresist, wherein the FEOL stripping/cleaning composition comprises:
a) at least one organic stripping solvent,
b) fluoride ions from at least one of ammonium fluoride, ammonium bifluoride and hydrogen fluoride,
c) at least one acidifying agent selected from inorganic or organic acids other than HF,
d) water, and
e) at least one oxidizing agent:
wherein the at least one acidifying agent selected from inorganic or organic acids other than HF is present in an amount to produce an overall acidic solution of pH>5.
2. A FEOL stripping and cleaning method according to claim 1 wherein the at least one oxidizing agent in the composition comprises hydrogen peroxide.
3. A FEOL stripping and cleaning method according to claim 1 wherein the at least one organic solvent in the composition is selected from the group consisting of dialkyl sulfones of the formula R 1 —S(O)(O)—R 2 where R 1 and R 2 are alkyl of 1 to 4 carbon atoms, dimethyl sulfoxide (DMSO), tetrahydrothiophene-1,1-dioxide compounds, dimethylacetamide and dimethylformamide.
4. A FEOL stripping and cleaning method according to claim 2 wherein the at least one organic solvent in the composition is selected from the group consisting of dialkyl sulfones of the formula R 1 —S(O)(O)—R 2 where R 1 and R 2 are alkyl of 1 to 4 carbon atoms, dimethyl sulfoxide (DMSO), tetrahydrothiophene-1,1-dioxide compounds, dimethylacetamide and dimethylformamide.
5. A FEOL stripping and cleaning method according to claim 3 wherein the at least one organic solvent in the composition comprises sulfolane.
6. A FEOL stripping and cleaning method according to claim 4 wherein the at least one organic solvent in the composition comprise sulfolane.
7. A FEOL stripping and cleaning method according to claim 5 wherein the at least one acid in the composition comprises hydrochloric acid.
8. A FEOL stripping and cleaning method according to claim 6 wherein the at least one acid in the composition comprises hydrochloric acid.
9. A FEOL stripping and cleaning method according to claim 1 wherein the composition comprises from about 45 to about 82 wt % of sulfolane, about 0.1 to about 2.0 wt % ammonium fluoride, about 0.8 to about 3 wt % hydrochloric acid, about 15 to about 50 wt % water, and the hydrogen peroxide is present in an amount such that the weight ratio of the other components to the hydrogen peroxide component is about 2:1 to about 5:1.