Cleaning solution for a semiconductor wafer
View Patent ↗A cleaning solution for a semiconductor wafer comprises ammonia, hydrogen peroxide, a complexing agent and a block copolymer surfactant diluted in water. The cleaning solution can be used in single wafer cleaning tools to remove both particulate contaminants and metallic residues.
1. A cleaning solution for removal of particulate contaminants and metallic residues from a surface of a semiconductor wafer, the solution comprising:
an alkali;
hydrogen peroxide;
water;
a complexing agent; and
a surfactant in an amount of less than 1 wt %; wherein the surfactant is a triblock copolymer type surfactant having at least one hydrophilic copolymer block and at least one hydrophobic copolymer block.
2. A solution as claimed in claim 1 , wherein the hydrophobic copolymer block includes a polypropylene oxide group and the hydrophilic copolymer block includes a polyethylene oxide group.
3. A solution as claimed in claim 2 wherein the ratio of the polyethylene oxide groups to the polypropylene oxide groups is between 1:10 to 1 :1.
4. A solution as claimed in claim 1 wherein the block copolymer
type surfactant has a molecular weight of between about 1500 and about 15000 mwu.
5. A solution as claimed in claim 1 wherein the solution comprises between about 0.01 wt % and about 5 wt % of the alkali.
6. A solution as claimed in claim 1 wherein the solution comprises between about 0.01 wt % and about 5 wt % of hydrogen peroxide.
7. A solution as claimed in claim 1 wherein the solution comprises less than about 3 wt % of the complexing agent.
8. A method comprising:
cleaning using a cleaning solution, the cleaning solution including:
an alkali;
hydrogen peroxide;
water;
a complexing agent; and
a surfactant in an amount less than 1 wt %; wherein the surfactant is a triblock copolymer type surfactant having at least one hydrophilic copolymer block and at least one hydrophobic copolymer block.
9. A method comprising:
cleaning a semiconductor wafer using a cleaning solution, the cleaning solution including:
an alkali;
hydrogen peroxide;
water;
a complexing agent; and
a surfactant; wherein the surfactant is a triblock copolymer type surfactant having at least one hydrophilic copolymer block at least one hydrophobic copolymer block.
10. A method as claimed in claim 9 , wherein the hydrophobic copolymer block includes a polypropylene oxide group and the hydrophilic copolymer block includes a polyethylene oxide group.
11. A method as claimed in claim 10 wherein the ratio of the polyethylene oxide groups to the polypropylene oxide groups is between 1:10 to 1:1.
12. A method as claimed in claim 9 wherein the surfactant is the triblock copolymer having two of the at least one hydrophobic copolymer blocks connected by the at least one hydrophilic copolymer block.
13. A method as claimed in claim 9 wherein the surfactant is the triblock copolymer having two polypropylene oxide copolymer blocks connected by a polyethylene oxide copolymer block.
14. A method as claimed in claim 9 wherein the cleaning solution includes less than 1 wt % of the surfactant.
15. A method as claimed in claim 9 further comprising patterning gates, wherein cleaning the semiconductor wafer is performed prior to patterning gates.
16. A cleaning solution as claimed in claim 1 wherein the alkali includes ammonium hydroxide.
17. A cleaning solution as claimed in claim 6 wherein the solution comprises between about 0.01 wt % and about 0.2 wt % of the hydrogen peroxide.
18. A cleaning solution as claimed in claim 1 wherein the solution has a pH of at least 8.
19. A cleaning solution as claimed in claim 18 wherein the solution has a pH of at least 9.
20. A cleaning solution as claimed in claim 1 wherein the triblock copolymer includes two polypropylene oxide copolymer blocks connected by a polyethylene oxide copolymer block.