APPARATUS FOR ETCHING HIGH ASPECT RATIO FEATURES

• US 20070256786A1
• Filed: 05/31/2006
• Published: 11/08/2007
• Est. Priority Date: 05/03/2006
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Zhou, Xiaoping, Dietz, Jeffrey
• Granted Patent: US 8,440,049 B2
• Time in Patent Office: Days
• US Class Current: 156/345.340
• CPC Class Codes: H01J 37/32477 characterised by the means for protecting vessels or internal parts, e.g. coatings
• CPC Class Codes: H01L 21/02002 Preparing wafers
• CPC Class Codes: H01L 21/67069 for drying etching
• CPC Class Codes: H01L 21/67109 mainly by convection
• CPC Class Codes: H01L 21/67253 Process monitoring, e.g. flow or thickness monitoring
• CPC Class Codes: H01L 21/6831 using electrostatic chucks

Abstract

Embodiments of the invention provide a method and apparatus, such as a processing chamber, suitable for etching high aspect ratio features. Other embodiments include a showerhead assembly for use in the processing chamber. In one embodiment, a processing chamber includes a chamber body having a showerhead assembly and substrate support disposed therein. The showerhead assembly includes at least two fluidly isolated plenums, a region transmissive to an optical metrology signal, and a plurality of gas passages formed through the showerhead assembly fluidly coupling the plenums to the interior volume of the chamber body.

Claims

1. A showerhead assembly, comprising:

a gas distribution plate having an outer set of gas flow holes, an inner set of gas flow holes, and a set of optical metrology holes;

an upper section coupled to the gas distribution plate and having a first plenum fluidly coupled to the outer set of gas flow holes and a second plenum fluidly coupled to the inner set of gas flow holes, the plenums being fluidly isolated within the upper section; and

a ceramic plug disposed through the upper section and having an optically transmissive region aligned with the optical metrology holes.

2. The showerhead assembly of claim 1 further comprising:

a window disposed through the upper section and aligned with the plug.

3. The showerhead assembly of claim 2, wherein the window further comprises:

a material transmissive to a signal utilized by an optical monitoring system.

4. The showerhead assembly of claim 2, wherein the window further comprises quartz.

5. The showerhead assembly of claim 2, wherein the upper section further comprises:

a base having a recess formed therein, the gas distribution plate covering the recess, wherein the window is disposed in the recess.

6. The showerhead assembly of claim 1, wherein the gas distribution plate is fabricated from bulk Yttria.

7. The showerhead assembly of claim 1, wherein the optically transmissive region further comprises a plurality of high aspect ratio holes.

8. The showerhead assembly of claim 1 further comprising:

concentric rings of adhesive coupling the gas distribution plate to the upper section, wherein the concentric rings form radially isolated concentric plenums defined between gas distribution plate and the upper section.

9. The showerhead assembly of claim 8 further comprising:

beads of adhesive disposed between concentric rings of adhesive, wherein gases present between the gas distribution plate, the upper section and a pair of adhesive rings may flow around the beads.

10. The showerhead assembly of claim 1, wherein the upper section further comprises:

a base having a stepped recess;

a first plate disposed in the recess;

a second plate disposed in the recess between the first place and the base; and

a barrier wall disposed between the first and second plates and separating the first and second plenums.

11. The showerhead assembly of claim 10, wherein the upper section further comprises:

a plurality of pins spacing the first plate from the second plate.

12. The showerhead assembly of claim 11, wherein the pins are press fit into the first and second plates.

13. The showerhead assembly of claim 11, wherein the first plate comprises a pluarity of gas passages, wherein each gas passage further comprises:

an orifice hole disposed between a first bore hole and a second bore hole, wherein bore holes have substantially greater diameter and depth relative to the orifice hole.

14. A showerhead assembly, comprising:

an upper section having a plurality of gas flow passages separating an upper plenum from a lower plenum;

a gas distribution plate coupled to the upper section and having a plurality of gas flow holes fluidly coupled to the lower plenum; and

an optically transmissive passage defined though the upper section and the gas distribution plate.

15. The showerhead assembly of claim 14, wherein the optically transmissive passage further comprises:

a sealed window; and

a member disposed between the window and the gas distribution plate; and

a plurality of high aspect ratio holes formed in the member.

16. The showerhead assembly of claim 14, wherein the high aspect ratio holes have an aspect ratio (height to diameter) of at least about 10:

1.

17. The showerhead assembly of claim 14, wherein the high aspect ratio holes have a diameter of less than or comparable at least one of a DEBYE length and/or the electron mean free path.

18. The showerhead assembly of claim 14, wherein the high aspect ratio holes have a diameter less than about 1.5 mm.

19. The showerhead assembly of claim 14, wherein the high aspect ratio holes define an open area of up to about 60 percent open area.

20. The showerhead assembly of claim 14, wherein the high aspect ratio holes have 37 holes.

21. The showerhead assembly of claim 14, wherein the member further comprises ceramic.

22. The showerhead assembly of claim 14, wherein the upper section further comprises:

a base having a stepped recess;

a first plate disposed in the recess;

a second plate disposed in the recess between the first place and the base; and

a barrier wall disposed between the first and second plates and separating the first and second plenums.

23. The showerhead assembly of claim 22, wherein the upper section further comprises:

a plurality of pins spacing the first plate from the second plate.

24. The showerhead assembly of claim 22, wherein the pins are press fit into the first and second plates.

25. The showerhead assembly of claim 22, wherein the first plate comprises a pluarity of gas passages, wherein each gas passage further comprises:

an orifice hole disposed between a first bore hole and a second bore hole, wherein bore holes have substantially greater diameter and depth relative to the orifice hole.

26. The showerhead assembly of claim 14, wherein the gas distribution plate is fabricated from bulk Yttria.

27. The showerhead assembly of claim 14, wherein the optically transmissive region further comprises a plurality of high aspect ratio holes.

28. The showerhead assembly of claim 14 further comprising:

concentric rings of adhesive coupling the gas distribution plate to the upper section, wherein the concentric rings form radially isolated concentric plenums defined between gas distribution plate and the upper section.

29. The showerhead assembly of claim 28 further comprising:

beads of adhesive disposed between concentric rings of adhesive, wherein gases present between the gas distribution plate, the upper section and a pair of adhesive rings may flow around the beads.

30. A showerhead assembly, comprising:

a base having a stepped recess;

a first plate disposed in the recess;

a second plate disposed in the recess between the first place and the base;

a ceramic plug having a plurality a high aspect ratio holes formed therethrough, the high aspect ratio holes have a diameter less than about 1.5 mm and an aspect ratio (height to diameter) of at least about 10;

1;

a barrier wall disposed between the first and second plates and separating a first and second plenums defined the first and second plates;

a gas distribution plate coupled to the first plate by a plurality of concentric adhesive lines and having a plurality of gas flow holes aligned between adhesive lines; and

an optically transmissive passage defined though the base, plates, and ceramic plug and the gas distribution plate.