TCCT match circuit for plasma etch chambers

• US 9,059,678 B2
• Filed: 01/25/2013
• Issued: 06/16/2015
• Est. Priority Date: 04/28/2011
• Status: Active Grant

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Long, Maolin, Marsh, Ricky, Paterson, Alex
• Primary Examiner(s): Owens, Douglas W
• Assistant Examiner(s): Sathiraju, Srinivas
• Application Number:
  US13/751,001
• Publication Number:
  US 20130135058A1
• Time in Patent Office: 872 Days
• Field of Search: 315/111.21, 311/112.1
• US Class Current: 1/1
• CPC Class Codes: H03H 7/38 Impedance-matching networks
• CPC Class Codes: H03H 7/40 Automatic matching of load impedance to source impedance

Abstract

A match circuit includes the following: a power input circuit coupled to an RF source; an inner coil input circuit coupled between the power input circuit and an input terminal of an inner coil, the inner coil input circuit including an inductor and a capacitor coupled in series to the inductor, the inductor connecting to the power input circuit, and the capacitor connecting to the input terminal of the inner coil, a first node being defined between the power input circuit and the inner coil input circuit; an inner coil output circuit coupled between an output terminal of the inner coil and ground, the inner coil output circuit defining a direct pass-through connection to ground; an outer coil input circuit coupled between the first node and an input terminal of an outer coil; and an outer coil output circuit coupled between an output terminal of the outer coil and ground.

Claims

1. A match circuit coupled between an RF source and a plasma chamber, the match circuit comprising:

a power input circuit, the power input circuit coupled to an RF source;

an inner coil input circuit coupled between the power input circuit and an input terminal of an inner coil, the inner coil input circuit including an inductor and a first variable capacitor coupled in series to the inductor, the inductor connecting to the power input circuit, and the capacitor connecting to the input terminal of the inner coil, a first node being defined between the power input circuit and the inner coil input circuit, wherein the inductor has a value of 0.3 uH to 0.5 uH;

an inner coil output circuit coupled between an output terminal of the inner coil and ground, the inner coil output circuit defining a direct pass-through connection that does not include an inductor or capacitor and is a direct connection to ground;

an outer coil input circuit coupled between the first node and an input terminal of an outer coil, the outer coil input circuit having a second variable capacitor, the outer coil input circuit further coupled to the power input circuit via the first node;

an outer coil output circuit coupled between an output terminal of the outer coil and ground, wherein the outer coil output circuit includes a third capacitor having a value of about 80 pF to about 120 pF;

wherein the first node splits power from the power input circuit for distribution to the inner coil input circuit and the outer coil input circuit, the first and second variable capacitors providing for tuning of a ratio of currents between the inner coil and the outer coil.

2. The match circuit of claim 1,

wherein the first variable capacitor having a rating of between about 150 pF to about 1500 pF.

3. The match circuit of claim 1, wherein the second variable capacitor having a rating of about 150 pF to about 1500 pF.

4. The match circuit of claim 1, wherein the power input circuit includes a fourth capacitor coupled to the RF source, a second inductor coupled to the inner coil input circuit, a fifth capacitor coupled between the fourth capacitor and the second inductor, a second node being defined between the ec-end fourth capacitor and the fifth capacitor, and a sixth capacitor coupled between the second node and ground.

5. The match circuit of claim 4,

wherein the fourth capacitor has a rating of about 5 pF to about 500 pF;

wherein the fifth capacitor has a rating of about 50 pF to about 500 pF;

wherein the second inductor has a value of 0.3 uH to 0.5 uH;

wherein the sixth capacitor has a value of about 200 pF to about 300 pF.

6. A match circuit, comprising:

a power input circuit, the power input circuit coupled to an RF source;

an inner coil input circuit coupled between the power input circuit and an input terminal of an inner coil, the inner coil input circuit including an inductor and a first capacitor coupled in series to the inductor, the inductor connecting to the power input circuit, and the first capacitor connecting to the input terminal of the inner coil, a first node being defined between the power input circuit and the inner coil input circuit, wherein the first capacitor is a variable capacitor having a rating of between about 150 pF to about 1500 pF, and wherein the inductor has a value of about 0.3 uH to about 0.5 uH;

an inner coil output circuit coupled between an output terminal of the inner coil and ground, the inner coil output circuit defining a direct pass-through connection to ground;

an outer coil input circuit coupled between the first node and an input terminal of an outer coil;

an outer coil output circuit coupled between an output terminal of the outer coil and ground, the outer coil output circuit including a second capacitor having a value greater than 85 pF;

wherein the power input circuit includes a third capacitor coupled to the RF source, a second inductor coupled to the inner coil input circuit, a fourth capacitor coupled between the third capacitor and the second inductor, a second node being defined between the third capacitor and the fourth capacitor, and a fifth capacitor coupled between the second node and ground.

7. The match circuit of claim 6, wherein the outer coil input circuit includes a third capacitor.

8. The match circuit of claim 7, wherein the third capacitor is a variable capacitor having a rating of about 150 pF to about 1500 pF.

9. The match circuit of claim 6,

wherein the third capacitor has a rating of about 5 pF to about 500 pF;

wherein the fourth capacitor has a rating of about 50 pF to about 500 pF;

wherein the second inductor has a value of about 0.3 uH to about 0.5 uH;

wherein the fifth capacitor has a value of 200 pF to 300 pF.

10. A match circuit coupled between an RF source and a plasma chamber, the match circuit comprising:

a power input circuit, the power input circuit coupled to an RF source;

an inner coil input circuit coupled between the power input circuit and an input terminal of an inner coil, the inner coil input circuit including an inductor and a first variable capacitor coupled in series to the inductor, the inductor connecting to the power input circuit, and the capacitor connecting to the input terminal of the inner coil, a first node being defined between the power input circuit and the inner coil input circuit, wherein the inductor has a value of 0.3 uH to 0.5 uH;

an inner coil output circuit coupled between an output terminal of the inner coil and ground, the inner coil output circuit defining a direct pass-through connection that does not include an inductor or capacitor and is a direct connection to ground;

an outer coil input circuit coupled between the first node and an input terminal of an outer coil, the outer coil input circuit having a second variable capacitor, the outer coil input circuit further coupled to the power input circuit via the first node;

an outer coil output circuit coupled between an output terminal of the outer coil and ground, wherein the outer coil output circuit includes a third capacitor having a value of about 80 pF to about 120 pF;

wherein the first node splits power from the power input circuit for distribution to the inner coil input circuit and the outer coil input circuit, the first and second variable capacitors providing for tuning of a ratio of currents between the inner coil and the outer coil;

wherein the power input circuit includes a fourth capacitor coupled to the RF source, a second inductor coupled to the inner coil input circuit, a fifth capacitor coupled between the fourth capacitor and the second inductor, a second node being defined between the fourth capacitor and the fifth capacitor, and a sixth capacitor coupled between the second node and ground;

wherein the fourth capacitor has a rating of about 5 pF to about 500 pF;

wherein the fifth capacitor has a rating of about 50 pF to about 500 pF;

wherein the second inductor has a value of 0.3 uH to 0.5 uH;

wherein the sixth capacitor has a value of about 200 pF to about 300 pF.

11. The match circuit of claim 10,

wherein the first variable capacitor having a rating of between about 150 pF to about 1500 pF.

12. The match circuit of claim 10, wherein the second variable capacitor having a rating of about 150 pF to about 1500 pF.