Apparatuses for reducing metal residue in edge bead region from metal-containing resists
Apparatuses and methods are described for removing edge bead on a wafer associated with a resist coating comprising a metal containing resist compositions. The methods can comprise applying a first bead edge rinse solution along a wafer edge following spin coating of the wafer with the metal based resist composition, wherein the edge bead solution comprises an organic solvent and an additive comprising a carboxylic acid, an inorganic fluorinated acid, a tetraalkylammonium compound, or a mixture thereof. Alternatively or additionally, the methods can comprise applying a protective composition to the wafer prior to performing an edge bead rinse. The protective composition can be a sacrificial material or an anti-adhesion material and can be applied only to the wafer edge or across the entire wafer in the case of the protective composition. Corresponding apparatuses for processing the wafers using these methods are presented.
1. A method of cleaning a substrate provided with a metal-based resist, the method comprising cleaning a substrate provided with a metal-based resist comprising at least one metal selected from the group consisting of Sn, Hf, Zr, In, Te, Sb, Ni, Co, Ti, W, Ta, and Mo using a metal resist cleaning liquid comprising an organic solvent and a carboxylic acid, thereby removing the metal-based resist from the substrate.
2. The method according to claim 1 , comprising applying the metal resist cleaning liquid along the periphery of the substrate to remove an edge bead on the substrate.
3. The method according to claim 1 wherein the organic solvent comprises a propylene glycol methyl ether (PGME), propylene glycol methyl ether acetate (PGMEA), propylene glycol butyl ether (PGBE), ethylene glycol methyl ether, cyclic esters, n-butyl acetate, ether acetate, ketones, liquid cyclic carbonates, or a mixture thereof.
4. The method according to claim 2 wherein the amount of carboxylic acid based on the total weight of the cleaning liquid is 0.1 wt % to 50 wt %.
5. The method according to claim 3 wherein the amount of carboxylic acid based on the total weight of the cleaning liquid is 0.1 wt % to 50 wt %.
6. The method according to claim 1 wherein the metal-based resist comprises Sn.
7. The method of claim 1 wherein the carboxylic acid comprises formic acid and/or acetic acid.
8. A method for removing edge bead on a wafer associated with a resist coating comprising a tin: based resist composition, the method comprising:
applying an edge bead rinse solution along a wafer edge following spin coating of the wafer with the tin organometallic resist composition, wherein the edge bead rinse solution comprises an organic solvent and an additive comprising a carboxylic acid, an inorganic fluorinated acid, a tetraalkylammonium compound, or a mixture thereof,
wherein a residual tin measurement along the wafer edge using VPD-ICP-MS is no more than about 50×10 10 atoms/cm 2 , and
wherein the carboxylic acid comprises formic acid and/or acetic acid.
9. The method of claim 8 wherein the tin organometallic resist composition comprises alkyl tin oxo/hydroxo moieties.
10. The method of claim 8 wherein the organic solvent comprises a glycol ether or ester thereof, an alcohol, a ketone, a cyclic ester, a liquid cyclic carbonate, or a mixture thereof.
11. The method of claim 8 wherein the organic solvent comprises a propylene glycol methyl ether (PGME), propylene glycol methyl ether acetate (PGMEA), 2-heptanone, or a mixture thereof.
12. The method of claim 8 wherein the additive further comprises acetic acid, citric acid, oxalic acid, 2-nitrophenylacetic acid, 2-ethylhexanoic acid, dodecanoic acid, ascorbic acid, tartaric acid, glucuronic acid, benzene sulfonic acid, p-toluenesulphonic acid, sulfuric acid (H 2 SO 4 ), or a mixture thereof.
13. The method of claim 8 wherein the edge bead rinse solution comprises 0.1 wt % to 50 wt % formic acid.
14. The method of claim 11 wherein the edge bead rinse solution comprises 0.1 wt % to 50 wt % formic acid.
15. The method of claim 8 wherein the edge bead rinse solution consists essentially of PGMEA and formic acid in a weight ratio of PGMEA:formic acid from 1:1 to 9:1.
16. The method of claim 8 wherein the edge bead rinse solution consists essentially of PGMEA and acetic acid in a weight ratio of PGMEA:acetic acid from 1:1 to 9:1.
17. A system for performing a bead edge removal comprising:
a spindle comprising a wafer support, wherein the spindle is operably connected to a motor configured to rotate the spindle;
a wafer comprising a surface layer of a tin organometallic resist composition;
a dispenser with a nozzle configured to apply fluid along an edge of the wafer mounted on the spindle; and
a reservoir comprising a fluid, wherein the reservoir is configured to deliver the fluid to the nozzle for dispensing, wherein the fluid comprises an organic solvent with an additive comprising a carboxylic acid, a sulfonic acid, sulfuric acid (H 2 SO 4 ), a phosphate ester, a phosphoric acid, an inorganic fluorinated acid, a tetraalkylammonium compound, or mixtures thereof,
wherein the fluid comprises the additive at a concentration from about 0.1 wt % to about 25 wt %,
wherein the carboxylic acid comprises formic acid and/or acetic acid.
18. The system of claim 17 wherein the organic solvent comprises a glycol ether or ester thereof, an alcohol, a ketone, a cyclic ester, a liquid cyclic carbonate, or a mixture thereof.
19. The system of claim 17 wherein the organic solvent comprises propylene glycol methyl ether (PGME), propylene glycol methyl ethyl acetate (PGMEA), propylene glycol butyl ether (PGBE), ethylene glycol methyl ether, ethanol, propanol, isobutyl alcohol, hexanol, ethylene glycol, propylene glycol, 2-heptanone, propylene carbonate, butylene carbonate, or a mixture thereof.
20. The system of claim 17 wherein the tin organometallic resist composition comprises alkyl tin oxo/hydroxo moieties.