Flow stability control in drying liquid between plates
AssigneeTokyo Electron Limited
InventorsDerek Bassett, Rencheng Dong
Life of this patent
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Abstract
A method of flow control is provided. The method includes injecting a liquid onto a wafer via a dispense system. The dispense system includes a plate and an injection hole in the plate. The plate is positioned away from the wafer at a distance and has a diameter equal to or larger than the wafer. A drying gas is injected onto the wafer via the dispense system to push out the liquid. While injecting the drying gas onto the wafer via the dispense system, at least one parameter selected from the group consisting of an inlet flow pressure of the injection hole, the distance and an injection sequence is adjusted so that an interface between the drying gas and the liquid is stable.
Claims18
A method of flow control, the method comprising:
- injecting a liquid onto a wafer via a dispense system, wherein the dispense system comprises a plate and an injection hole in the plate, and the plate is positioned away from the wafer at a distance and has a diameter equal to or larger than the wafer;
- injecting a drying gas onto the wafer via the dispense system to push out the liquid;
- and
- while injecting the drying gas onto the wafer via the dispense system, adjusting at least one parameter selected from the group consisting of an inlet flow pressure of the injection hole, the distance and an injection sequence of the drying gas so that an interface between the drying gas and the liquid is substantially circular, wherein:
- the inlet flow pressure is adjusted based on equations,
- p
- i
-
- n
- (
- r
- )
- =
- 1
-
- 2
-
- r
-
- u
- h
- 2
-
- (
- μ
- 1
-
- ln
-
- (
- γ
- R
- i
-
- n
- )
- +
- μ
- 2
-
- ln
-
- (
- R
- out
- r
- )
- )
- +
- γ
- h
- ,
- and
- u
- =
- (
- 3
-
- h
-
- ω
-
- (
- μ
- 2
- +
- μ
- 1
- )
- 4
- )
- 2
- /
- 3
-
- γ
- 1
- /
- 3
- μ
- 2
- -
- μ
- 1
- ,
- where pin(r) is the inlet flow pressure,
- r is an average radius of the interface,
- u is an average velocity of the interface,
- h is the distance,
- μ1 is a viscosity of the drying gas,
- μ2 is a viscosity of the liquid,
- Rin is a radius of an inlet of the injection hole,
- Rout is a radius of the wafer,
- γ is a surface tension of the liquid, and
- ω is an instability growth rate.
Dependencies are inferred from the claim text.