Method and apparatus for etching a structure in a plasma chamber

• US 20070272358A1
• Filed: 05/25/2006
• Published: 11/29/2007
• Est. Priority Date: 05/25/2006
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.), Sony Electronics Inc. (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.), Sony Electronics Inc. (Sony Group Corp.)
• Inventors: Iseda, Seiji
• Granted Patent: US 7,799,237 B2
• Time in Patent Office: Days
• US Class Current: 156/345.280
• CPC Class Codes: H01J 2237/08 Ion sources
• CPC Class Codes: H01J 37/32091 the radio frequency energy being capacitively coupled to the plasma
• CPC Class Codes: H01J 37/32165 Plural frequencies
• CPC Class Codes: H01J 37/32174 Circuits specially adapted for controlling the RF discharge
• CPC Class Codes: H01J 37/32706 Polarising the substrate
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge

Abstract

A plasma processing apparatus includes a plasma reaction chamber in which a plasma is generated for processing. First and second electrodes are located in the chamber for generating the plasma. First and second RF power sources provide RF power to the first and second electrodes, respectively. The apparatus also includes first and second impedance matching circuits through which the RF power is respectively provided from the first and second RF power supplies to the first and second electrodes. A first plasma controller monitors plasma density and, in response thereto, adjusts the RF power supplied by the first RF power source to the first electrode to achieve a given plasma density. A second plasma controller monitors the ion energy of plasma species impinging on a semiconductor structure associated with the second electrode and, in response thereto, adjusts the RF power supplied by the second RF power source to the second electrode to achieve a given ion energy.

Claims

1. A plasma processing apparatus comprising:

a plasma reaction chamber in which a plasma is generated for processing;

first and second electrodes located in the chamber for generating the plasma;

first and second RF power sources for providing RF power to the first and second electrodes, respectively;

first and second impedance matching circuits through which the RF power is respectively provided from the first and second RF power supplies to the first and second electrodes;

a first plasma controller for monitoring plasma density and, in response thereto, adjusting the RF power supplied by the first RF power source to the first electrode to achieve a given plasma density; and

a second plasma controller for monitoring ion energy of plasma species impinging on a semiconductor structure associated with the second electrode and, in response thereto, adjusting the RF power supplied by the second RF power source to the second electrode to achieve a given ion energy.

2. The apparatus of claim 1 wherein said plasma is produced by capacitively coupling the RF power into the chamber.

3. The apparatus of claim 1 wherein the semiconductor structure is mounted on the second electrode.

4. The apparatus of claim 1 wherein the first plasma controller measures a resistive load experienced by the first RF power source.

5. The apparatus of claim 1 wherein the given plasma density that is achieved is a constant plasma density during an etching process.

6. The apparatus of claim 1 wherein the given ion energy that is achieved is a constant ion energy during an etching process.

7. The apparatus of claim 5 wherein the given ion energy that is achieved is a constant ion energy during etching.

8. A method for performing plasma etching on a structure, comprising:

establishing a plasma in a gaseous atmosphere that contacts a first electrode;

monitoring plasma density and adjusting an amount of RF power supplied to the first electrode to achieve a given plasma density; and

monitoring ion energy of plasma species impinging on a semiconductor structure associated with a second electrode and, in response thereto, adjusting an amount of RF power supplied to the second electrode to achieve a given ion energy.

9. The method of claim 8 wherein said plasma is produced by capacitively coupling the RF power into a chamber.

10. The method of claim 8 wherein the semiconductor structure is mounted on a second electrode.

11. The method of claim 8 wherein the step of monitoring the plasma density includes measuring a resistive load experienced by a first RF power source that establishes the plasma.

12. The method of claim 8 wherein the given plasma density that is achieved is a constant plasma density during an etching process.

13. The method of claim 8 wherein the given ion energy that is achieved is a constant ion energy during an etching process.

14. The method of claim 12 wherein the given ion energy that is achieved is a constant ion energy during an etching process.