METHODS AND APPARATUS FOR WETTING PRETREATMENT FOR THROUGH RESIST METAL PLATING

• US 20130171833A1
• Filed: 02/25/2013
• Published: 07/04/2013
• Est. Priority Date: 06/17/2009
• Status: Active Grant

• Current Assignee: Novellus Systems Incorporated (Lam Research Corporation)
• Original Assignee: Bryan L. Buckalew, Robert Rash, Steven T. Mayer, Thomas A. Ponnuswamy
• Inventors: BUCKALEW, Bryan L., MAYER, Steven T., RASH, Robert, PONNUSWAMY, Thomas A., BLACKMAN, Brian, HIGLEY, Doug
• Granted Patent: US 9,455,139 B2
• Time in Patent Office: Days
• US Class Current: 438/758
• CPC Class Codes: C25D 17/001 Apparatus specially adapted for electrolytic coating of wafers, e.g. semiconductors or solar cells
• CPC Class Codes: C25D 21/04 Removal of gases or vapours ; Gas or pressure control
• CPC Class Codes: C25D 21/12 Process control or regulation controlling or regulating in general G05
• CPC Class Codes: C25D 3/12 of nickel or cobalt
• CPC Class Codes: C25D 3/30 of tin
• CPC Class Codes: C25D 3/38 of copper
• CPC Class Codes: C25D 5/003 Electroplating using gases, e.g. pressure influence
• CPC Class Codes: C25D 5/022 using masking means
• CPC Class Codes: C25D 5/12 at least one layer being of nickel or chromium
• CPC Class Codes: C25D 5/56 of plastics
• CPC Class Codes: C25D 7/123 Semiconductors first coated with a seed layer or a conductive layer
• CPC Class Codes: H01L 21/02307 treatment by exposure to a liquid
• CPC Class Codes: H01L 21/2885 using an external electrical current, i.e. electro-deposition
• CPC Class Codes: H01L 21/321 After treatment
• CPC Class Codes: H01L 21/67051 using mainly spraying means, e.g. nozzles
• CPC Class Codes: H01L 21/67138 Apparatus for wiring semiconductor or solid state device
• CPC Class Codes: H01L 21/76861 Post-treatment or after-treatment not introducing additional chemical elements into the layer
• CPC Class Codes: H01L 21/76877 Filling of holes, grooves or trenches, e.g. vias, with conductive material
• CPC Class Codes: H01L 21/76879 by selective deposition of conductive material in the vias, e.g. selective C.V.D. on semiconductor material, plating plating on semiconductors in general H01L21/288
• CPC Class Codes: H01L 21/76885 By forming conductive members before deposition of protective insulating material, e.g. pillars, studs
• CPC Class Codes: H01L 21/76898 : formed through a semiconductor substrate

Abstract

Disclosed are pre-wetting apparatus designs and methods. In some embodiments, a pre-wetting apparatus includes a degasser, a process chamber, and a controller. The process chamber includes a wafer holder configured to hold a wafer substrate, a vacuum port configured to allow formation of a subatmospheric pressure in the process chamber, and a fluid inlet coupled to the degasser and configured to deliver a degassed pre-wetting fluid onto the wafer substrate at a velocity of at least about 7 meters per second whereby particles on the wafer substrate are dislodged and at a flow rate whereby dislodged particles are removed from the wafer substrate. The controller includes program instructions for forming a wetting layer on the wafer substrate in the process chamber by contacting the wafer substrate with the degassed pre-wetting fluid admitted through the fluid inlet at a flow rate of at least about 0.4 liters per minute.

Claims

1. An apparatus comprising:

a degasser configured to remove one or more dissolved gasses from a pre-wetting fluid to produce a degassed pre-wetting fluid;

a process chamber including;

a wafer holder configured to hold a wafer substrate and configured to rotate the wafer substrate,

a vacuum port configured to allow formation of a subatmospheric pressure in the process chamber, and

a fluid inlet coupled to the degasser and configured to deliver the degassed pre-wetting fluid onto the wafer substrate at a velocity of at least about 7 meters per second; and

a controller including program instructions for;

rotating the wafer substrate at a first rotation rate, and

forming a wetting layer on the wafer substrate at the sub-atmospheric pressure in the process chamber by contacting the wafer substrate with the degassed pre-wetting fluid from the degasser and admitted through the fluid inlet at a flow rate of at least about 0.4 liters per minute, the degassed pre-wetting fluid being in a liquid state, while rotating the wafer substrate at the first rotation rate.

2. The apparatus of claim 1, wherein the fluid inlet includes a nozzle configured to deliver the degassed pre-wetting fluid onto the wafer substrate, and wherein the nozzle is mounted on a sidewall of the process chamber.

3. The apparatus of claim 2, wherein the nozzle is a fan nozzle configured to deliver the degassed pre-wetting fluid onto the wafer substrate such that the degassed pre-wetting fluid that impinges the wafer substrate has a shape of a line.

4. The apparatus of claim 1, wherein the fluid inlet includes a manifold including at least one nozzle configured to deliver the degassed pre-wetting fluid onto the wafer substrate, and wherein the nozzle is located over the wafer substrate.

5. The apparatus of claim 4, wherein the at least one nozzle includes a fan nozzle configured to deliver the degassed pre-wetting fluid onto the wafer substrate such that the degassed pre-wetting fluid that impinges the wafer substrate has a shape of a line.

6. The apparatus of claim 4, wherein the process chamber includes a cover and a body, wherein the cover remains stationary and the body is configured to move in a substantially vertical manner to bring the body into contact with the cover and to form a vacuum seal, and wherein the nozzle is attached to the cover.

7. The apparatus of claim 4, wherein the nozzle is configured to deliver the degassed pre-wetting fluid onto the wafer substrate from an edge of the wafer substrate to substantially the center of the wafer substrate.

8. The apparatus of claim 1, wherein the wafer holder is configured to hold the wafer substrate in a substantially face-up orientation.

9. The apparatus of claim 1, wherein the degasser includes a membrane contactor degasser.

10. The apparatus of claim 1, wherein the degasser is configured to produce degassed pre-wetting fluid for contacting the wafer substrate having about 0.5 ppm or less dissolved atmospheric gas.

11. The apparatus of claim 1, wherein the pre-wetting fluid is at least one of deionized water and a chemical solution that aids in dislodging and removing particles from the wafer substrate.

12. The apparatus of claim 1, wherein the vacuum port is located below the wafer holder.

13. The apparatus of claim 1, wherein the process chamber is configured to maintain the subatmospheric pressure of less than about 50 Torr during forming the wetting layer on the wafer substrate.

14. The apparatus of claim 1, wherein the program instructions further include instructions for:

after forming the wetting layer on the wafer substrate, stopping delivery of the degassed pre-wetting fluid, and

after stopping the delivery of the degassed pre-wetting fluid, rotating the wafer substrate at a second rotation rate to remove excess surface entrained degassed pre-wetting fluid from the wafer substrate.

15. The apparatus of claim 14, wherein the program instructions further include instructions for:

increasing pressure in the process chamber to atmospheric pressure or to above atmospheric pressure after stopping the delivery of the degassed pre-wetting fluid and prior to removal of the excess surface entrained pre-wetting fluid.

16. The apparatus of claim 1, wherein the program instructions further include instructions for:

reducing pressure in the process chamber to the subatmospheric pressure prior to forming the wetting layer on the wafer substrate.

17. The apparatus of claim 1, wherein the program instructions further comprise instructions for:

initiating forming the wetting layer on the wafer substrate when a pressure in the process chamber is reduced to less than about 50 Torr.

18. The apparatus of claim 1, wherein the program instructions further comprise instructions for:

contacting the wafer substrate with the degassed pre-wetting fluid for about 10 seconds to 120 seconds.

22. A system comprising the apparatus of claim 1 and a stepper.

19. A method comprising:

(a) providing a wafer substrate having an exposed metal layer on at least a portion of a surface of the wafer substrate to a process chamber;

(b) reducing pressure in the process chamber to a subatmospheric pressure;

(c) degassing a pre-wetting fluid;

(d) rotating the wafer substrate; and

(e) contacting the rotating wafer substrate with the degassed pre-wetting fluid at the subatmospheric pressure in the process chamber to form a wetting layer on the wafer substrate, the degassed pre-wetting fluid contacting the wafer substrate at a velocity of at least about 7 meters per second and at a flow rate of at least about 0.4 liters per minute.

20. The method of claim 19, further comprising:

applying photoresist to the wafer substrate;

exposing the photoresist to light;

patterning the resist and transferring the pattern to the wafer substrate; and

selectively removing the photoresist from the work piece.

21. A non-transitory computer machine-readable medium including program instructions for control of an apparatus, the program instructions including code for operations comprising:

(a) providing a wafer substrate having an exposed metal layer on at least a portion of a surface of the wafer substrate to a process chamber;

(b) reducing pressure in the process chamber to a subatmospheric pressure;

(c) degassing a pre-wetting fluid;

(d) rotating the wafer substrate; and

(e) contacting the rotating wafer substrate with the degassed pre-wetting fluid at the subatmospheric pressure in the process chamber to form a wetting layer on the wafer substrate, the degassed pre-wetting fluid contacting the wafer substrate at a velocity of at least about 7 meters per second and at a flow rate of at least about 0.4 liters per minute.