SHOWERHEAD ASSEMBLY FOR PLASMA PROCESSING CHAMBER

• US 20110088847A1
• Filed: 10/15/2010
• Published: 04/21/2011
• Est. Priority Date: 10/15/2009
• Status: Active Grant

• Current Assignee: KLA Corporation
• Original Assignee: Orbotech LT Solar LLC (KLA Corporation)
• Inventors: Law, Robin K. F., Can, Linh, LAW, Kam S., Blonigan, Wendell Thomas, Toshima, Masato
• Granted Patent: US 8,617,349 B2
• Time in Patent Office: Days
• US Class Current: 156/345.34
• CPC Class Codes: C23C 16/45565 Shower nozzles
• CPC Class Codes: C23C 16/45578 Elongated nozzles, tubes with holes
• CPC Class Codes: C23C 16/50 using electric discharges generation and control of plasma in discharge tubes for surface treatment H01J37/32, H01J37/34
• CPC Class Codes: H01J 37/32091 the radio frequency energy being capacitively coupled to the plasma
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01J 37/32449 Gas control, e.g. control of the gas flow
• CPC Class Codes: Y10T 29/49428 Gas and water specific plumbing component making
• CPC Class Codes: Y10T 29/496 Multiperforated metal article making
• CPC Class Codes: Y10T 408/03 Processes

Abstract

A showerhead for a plasma process apparatus for processing substrates, comprising a showerhead body comprising a top plate and a bottom plate defining a cavity in between; a gas inlet formed in the top plate; a perforated plate positioned between the top plate and the bottom plate and dissecting the cavity into an upper gas compartment and a lower gas compartment; and, wherein the bottom plate comprises a plurality of elongated diffusion slots on its lower surface and a plurality of diffusion holes on its upper surface, each of the diffusion holes making fluid connection from the lower gas compartment to more than one of the diffusion slots.

Claims

1. A showerhead assembly for a plasma process apparatus for processing substrates, comprising:

a top plate having gas inlet;

a perforated plate positioned below the top plate and distanced from the top plate so as to define an upper gas compartment with the top plate;

a gas distribution plate positioned below the perforated plate and distanced from the perforated plate so as to define a lower gas compartment, the gas distribution plate facing the substrate to be processed; and

,

wherein the gas distribution plate comprises a plurality of elongated gas distribution slots on its lower surface and a plurality of gas distribution holes on its upper surface, each of the gas distribution holes having a diameter larger than holes in the perforated plate, and each of the gas distribution holes making fluid connection from the lower gas compartment to more than one of the gas distribution slots.

2. The showerhead assembly of claim 1, wherein the gas distribution holes are arranged in a plurality of rows and each gas distribution slot intersects all holes in one row.

3. The showerhead assembly of claim 2, wherein the plurality of rows are staggered in the direction of the gas distribution slots, such that each row of gas distribution holes is offset from the rows that are immediately next to it.

4. The showerhead assembly of claim 2, wherein the plurality of rows are shifted in a direction perpendicular to the gas distribution slots, such that holes in a row of gas distribution holes overlap at least one gas distribution slot connected to holes from an immediately neighboring row.

5. The showerhead assembly of claim 3, wherein the plurality of rows are shifted in a direction perpendicular to the gas distribution slots, such that holes in a row of gas distribution holes overlap at least one gas distribution slot connected to holes from an immediately neighboring row.

6. The showerhead assembly of claim 1, wherein the gas distribution plate comprises a single plate of metal having its bottom surface machined to form the gas distribution slots and its top surface drilled to form the rows of gas distribution holes.

7. The showerhead assembly of claim 1, wherein the perforated plate is configured to provide a uniform gas distribution into the lower gas compartment.

8. The showerhead assembly of claim 1, wherein the perforated plate is configured to provide a non-uniform gas distribution into the lower gas compartment.

9. The showerhead assembly of claim 1, wherein the gas distribution slots are configured to support gas ionization inside the gas distribution slots.

10. The showerhead assembly of claim 9, wherein the gas distribution slots are of width of 0.010″

to 1.000″

, a depth of 0.010″

to 1.000″

, and a slot pitch of 0.015″

to 3.000″

.

11. The showerhead assembly of claim 9, wherein the gas distribution holes are of diameter 0.025″

to 6.000″

.

12. A showerhead assembly for a plasma process apparatus for processing substrates, comprising:

a showerhead body comprising a top plate and a bottom ionization plate, defining a cavity in between;

a gas inlet formed in the top plate;

a gas restriction plate positioned between the top plate and the ionization plate and dissecting the cavity into an upper gas compartment and a lower gas compartment and restricting flow such that the upper gas compartment supports a higher gas pressure than the lower gas compartment; and

,

wherein the bottom ionization plate comprises a single metallic plate having plurality of elongated ionization slots machined on its lower surface and a plurality of diffusion holes drilled on its upper surface, each of the diffusion holes making fluid connection from the lower gas compartment to more than one of the ionization slots.

13. The showerhead assembly of claim 12, wherein the diffusion holes are arranged in a plurality of rows and each ionization slot intersects all holes in one row.

14. The showerhead assembly of claim 12, wherein the plurality of rows are staggered such that each row of holes is offset from the rows that are immediately next to it.

15. The showerhead assembly of claim 12, wherein the plurality of rows are shifted in a direction perpendicular to the ionization slots, such that holes in one row overlap at least one ionization slot connected to holes from an immediately neighboring row.

16. The showerhead assembly of claim 12, wherein the gas restriction plate comprises perforations configured to provide a uniform gas distribution into the lower gas compartment.

17. The showerhead assembly of claim 12, wherein the gas restriction plate comprises perforations configured to provide a gradient gas distribution into the lower gas compartment.

18. The showerhead assembly of claim 12, wherein the ionization slots are of width 0.010″

to 1.000″

, a depth of 0.010″

to 1.000″

, and a slot pitch of 0.015″

to 3.000″

.

19. The showerhead assembly of claim 12, wherein the gas diffusion holes are of diameter 0.025″

to 6.000″

.

20. A method for fabricating a gas ionization plate for use in a showerhead assembly of a plasma processing chamber, comprising:

fabricating a plate;

using gang cutter to form a plurality of gas ionization slots on the lower surface of the plate; and

,

drilling a plurality of gas distribution holes from the top surface of the plate such that each holes reaches and opened to a plurality of the gas ionization slots.

21. The method of claim 20, wherein each gas ionization slot is cut to a depth of 0.010″

to 1.000″ and

width of 0.010″

to 1.000″

.

22. The method of claim 20, wherein each gas distribution hole is drilled to a depth of 0.010″

to 10.000″ and

diameter of 0.025″

to 6.000″

.