Reactive Ion Etching chamber design for flip chip interconnections

• US 6,531,069 B1
• Filed: 06/22/2000
• Issued: 03/11/2003
• Est. Priority Date: 06/22/2000
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Griffith, Jonathan H., Brearley, William H., Wade, Peter C., Srivastava, Kamalesh K.
• Primary Examiner(s): KORNAKOV, MIKHAIL
• Application Number:
  US09/599,761
• Time in Patent Office: 992 Days
• Field of Search: 113/723.R, 156/345, 204/298.07, 204/298.08, 204/298.11, 204/298.31, 216/67, 216/70, 438/707, 438/9, 438/710
• US Class Current: 216/67
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01J 37/32623 Mechanical discharge control means

Abstract

RIE processing chambers includes arrangements of gas outlets which force gas-flow-shadow elimination. Means are provided to control and adjust the direction of gases to the outlet to modify and control the direction of plasma flow at the wafer surface during processing. Means are provided to either move the exhaust paths for exhaust gases or to open and close exhaust paths sequentially, in a controlled manner, to modify flow directions of ions in the etching plasma. A combination of rotation/oscillation of a magnetic field imposed on the RIE chamber can be employed by rotation of permanent magnetic dipoles about the periphery of the RIE chamber or by controlling current through a coil wrapped around the periphery of the RIE process chamber to enhance the removal of the residues attributable to gas-flow-shadows formed by linear ion paths in the plasma.

Claims

1. A method of performing Reactive Ion Etching (RIE) comprising:

providing an RIE chamber,

providing a work supporting surface comprising a first electrode,

providing a second electrode confronting the first electrode combined therewith to form an ionization space above the work supporting surface in the chamber,

providing a plurality of peripheral exhaust openings arranged on the periphery of the ionization space,

supplying a reactive species into the ionization space,

forming a plasma of the reactive species in the ionization space between the inlet electrode and the first electrode provided by the work supporting surface, and

imparting vector forces to the plasma of said reactive species diverting the paths thereof with continuously varying vectors by imparting vector forces directing the reactive species along non-linear paths along continuously changing direction as a function of time by sequentially rotating access to the peripheral exhaust openings about the ionization space mechanically,

whereby the reactive species follow non-linear paths continuously changing direction with time thereby counteracting shadow effects of the RIE process relative to tall structures and asperities on workpiece surfaces.

5. The method of claim 1 wherein:

inlet gases arc directed through a plurality of widely dispersed inlet openings formed through the second electrode, the inlet openings being directed towards the work supporting surface, and

the vectors are applied by sequential rotation of opening and closing of access to the peripheral exhaust openings.

6. The method of claim 1 wherein the vectors are applied sequentially by rotation of a shutter thereby opening and closing access to and through the peripheral exhaust openings.

13. The method of claim 1 wherein the inlet gases are directed through a plurality of widely dispersed inlet openings formed through the second electrode, directed through means formed through the second electrode, the inlet means being directed towards the work supporting surface.

14. The method of claim 1 wherein the exhaust openings are arranged substantially uniformly along an arc.

2. A method of performing Reactive Ion Etching (RIE) comprising:

providing an RIE chamber,

providing a work supporting surface comprising a first electrode,

providing a second electrode confronting the first electrode combined therewith to form an ionization space above the work supporting surface in the chamber,

providing peripheral exhaust openings on the periphery of the ionization space,

supplying a reactive species into the ionization space,

forming a plasma of the reactive species in the ionization space,

imparting vector forces to the plasma of said reactive species diverting the paths thereof with continuously varying vectors by a method for imparting vector forces, directing the reactive species along non-linear paths thereby continuously changing the direction thereof as a function of time,

with the step of imparting vector forces by mechanically rotating access to the peripheral exhaust openings about the ionization space, and

the step of rotation of access to the peripheral exhaust openings is provided along a limited arc,

whereby the reactive species follow non-linear paths continuously changing direction with time thereby counteracting shadow effects of the RIE process relative to tall structures and asperities on workpiece surfaces.

3. The method of claim 2 wherein the vectors are applied by rotation of access to and through the peripheral exhaust openings.

4. The method of claim 2 wherein the rotation of access to and through the peripheral exhaust openings is provided by sequential operation of valves or shutters to control access to and through the exhaust openings along a limited are.

7. A Reactive Ion Etching (RIE) system comprising:

an RIE chamber,

a work supporting surface comprising a first electrode located in the RIE chamber,

a second electrode located in the chamber and confronting the first electrode combined therewith to form an ionization space above the work supporting surface in the RIE chamber,

a plurality of peripheral exhaust openings located on the periphery of the ionization space,

distribution means for supplying a reactive species into the ionization space,

plasma means for forming a plasma of the reactive species in the ionization space between the first and second electrodes thereby directing the reactive species along non-linear paths that continuously change direction as a function of time,

vector means for imparting vector forces to the plasma of the reactive species diverting the paths thereof with continuously varying vector, directing the reactive species along non-linear paths along continuously changing direction as a function of time, the means for imparting vector force being mechanical means for sequentially providing rotation of access to the peripheral exhaust openings about the ionization space mechanically,

whereby the reactive species follow non-linear paths continuously changing direction with time thereby counteracting shadow effects of the RIE process relative to tall structures and asperities on workpiece surfaces.

8. The system of claim 7 wherein the rotation of access to and through the peripheral exhaust openings is provided along a limited arc.

9. The system of claim 8 wherein the vectors are applied by rotation of access to and through the peripheral exhaust openings.

10. The system of claim 8 wherein the rotation of access to and through the peripheral exhaust openings is provided by sequential operation of valve or shutter means along a limited arc.

11. The system of claim 7 wherein the vectors are applied by access means for sequential rotation of opening and closing of access to the peripheral exhaust openings.

12. The system of claim 7 wherein the vectors are applied sequentially by rotation of a shutter thereby opening and closing access to and through the peripheral exhaust openings.

15. The system of claim 7 wherein the inlet gases are directed through a plurality of widely dispersed inlet openings formed through the second electrode, directed through means formed through the second electrode, the inlet means being directed towards the work supporting surface.

16. The system of claim 7 wherein the exhaust openings are a arranged substantially uniformly along an arc.