Inductively and multi-capacitively coupled plasma reactor

• US 6,020,686 A
• Filed: 08/07/1997
• Issued: 02/01/2000
• Est. Priority Date: 05/08/1995
• Status: Expired due to Term

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Ye, Yan, Hanawa, Hiroji, Ma, Diana Xiaobing, Yin, Gerald Zheyao
• Primary Examiner(s): Shingleton, Michael B.
• Application Number:
  US08/908,533
• Time in Patent Office: 908 Days
• Field of Search: 315/248, 315/111.21, 315/111.51
• US Class Current: 315/111.51
• CPC Class Codes: H01J 37/32082 Radio frequency generated discharge H01J37/32357, H01J37/32366, H01J37/32394 and H01J37/32403 take precedence
• CPC Class Codes: H01J 37/32091 the radio frequency energy being capacitively coupled to the plasma
• CPC Class Codes: H01J 37/321 the radio frequency energy being inductively coupled to the plasma

Abstract

The invention is embodied in a plasma reactor for processing a semiconductor wafer, the reactor having a pair of parallel capacitive electrodes at the ceiling and base of the processing chamber, respectively, each of the capacitive electrodes capacitively coupling RF power into the chamber in accordance with a certain RF phase relationship between the pair of electrodes during processing of the semiconductor wafer for ease of plasma ignition and precise control of plasma ion energy and process reproducibility, and an inductive coil wound around a portion of the chamber and inductively coupling RF power into the chamber for independent control of plasma ion density. Preferably, in order to minimize the number of RF sources while providing independent power control, the invention includes power splitting to separately provide power from a common source or sources to the pair of electrodes and to the coil.

Claims

1. A capacitively and inductively coupled RF plasma reactor for processing a semiconductor wafer inside a vacuum chamber of said reactor, comprising:

a pair of parallel capacitive electrodes facing each other across at least a portion of the chamber;

an inductive coil wound around a portion of the chamber; and

at least one RF power source providing RF power to each of the capacitive electrodes for capacitively coupling RF power into the chamber and to said inductive coil for inductively coupling RF power into the chamber in accordance with a certain RF phase relationship between at least two of (a) a first one of the pair of electrodes, (b) a second one of the pair of electrodes and (c) said inductive coil, during processing of the semiconductor wafer for ease of plasma ignition and precise control of plasma ion energy and process reproducibility.

2. A method of capacitively and inductively coupling RF power into a vacuum chamber of a plasma reactor used for processing a semiconductor wafer so as to ignite and control a plasma within the vacuum chamber, said method comprising the steps of:

Configuring the plasma reactor to comprise a pair of parallel capacitive electrodes facing each other across at least a portion of the chamber;

configuring the plasma reactor to comprise an inductive coil wound around a portion of the chamber; and

applying RF power to each of the capacitive electrodes to capacitively couple RF power in the chamber and to said inductive coil to inductively couple RF power into the chamber during processing of the semiconductor wafer, said step of applying RF power to each of the capacitive electrodes facilitating plasma ignition and precise control of plasma ion energy and said step of applying RF power to said inductor coil facilitating precise control of plasma ion density.

3. The method of claim 2, wherein the step of applying RF power comprises:

employing a common RF source; and

separately providing power from said common RF source to at least said two of (a) a first one of the pair of electrodes, (b) a second one of the pair of electrodes and (c) said inductive coil.

4. The method of claim 3, wherein the step of separately providing power from said common RF source comprises adjustably controlling the amount of power provided to any of said first one of the pair of electrodes, said second one of the pair of electrodes and said inductive coil.

5. The method of claim 2, wherein the step of applying RF power comprises:

applying RF power to each of the capacitive electrodes and to said inductive coil in-accordance with a certain RF phase relationship between at least two of (a) a first one of the pair of electrodes, (b) a second one of the pair of electrodes and (c) said inductive coil.

6. The method of claim 2, wherein the step of applying RF power comprises:

applying RF power to each of the capacitive electrodes in accordance with a certain RF phase relationship between a first one of the pair of electrodes and a second one of the pair of electrodes, said certain phase relationship being 180 degrees out of phase.

10. The method of claim 2, wherein the step of applying RF power comprises:

employing a common RF source;

providing power from said common RF source to each of said electrodes; and

providing power from said common RF source to said inductive coil.

11. The method of claim 10, wherein the step of providing power from said common RF source comprises adjustably controlling the amount of power provided to each of said electrodes and said inductive coil.

12. The method of claim 10, wherein the step of applying RF power further comprises applying RF power to each of the capacitive electrodes in accordance with a certain RF phase relationship.

7. A capacitively and inductively coupled RF plasma reactor for processing a semiconductor wafer inside a vacuum chamber of said reactor, comprising:

a pair of parallel capacitive electrodes facing each other across at least a portion of the chamber;

an inductive coil wound around a portion of the chamber;

at least one RF power source providing RF power to each of the capacitive electrodes for capacitively coupling RF power into the chamber and to said inductive coil for inductively coupling RF power into the chamber during processing of the semiconductor wafer for ease of plasma ignition and precise control of plasma ion energy and precise control of plasma ion density.

8. The reactor of claim 7, wherein the RF power source further comprises a phase controlling means for applying RF power to each of the capacitive electrodes and to said inductive coil in accordance with a certain RF phase relationship between at least two of:

(a) a first one of the pair of electrodes, (b) a second one of the pair of electrodes and (c) said inductive coil.

9. A capacitively and inductively coupled RF plasma reactor for processing a semiconductor wafer inside a vacuum chamber of said reactor, comprising:

a pair of parallel capacitive electrodes facing each other across at least a portion of the chamber;

an inductive coil wound around a portion of the chamber; and

at least one RF power source for applying RF power to each of the capacitive electrodes for capacitively coupling RF power into the chamber and to said inductive coil for inductively coupling RF power into the chamber during processing of the semiconductor wafer for ease of plasma ignition and precise control of plasma ion energy and precise control of plasma ion density.

13. A capacitively and inductively coupled RF plasma reactor for processing a workpiece, comprising:

a pair of parallel capacitive electrodes facing each other across at least portion of the chamber;

an inductive coil wound around a portion of the chamber;

a power supply capable of producing RF power;

the power supply being coupled to each of the parallel electrodes;

the power supply being coupled to the inductive coil; and

the power supply being coupled to each of the parallel electrodes and to the inductive coil so that the RF power is adjustable therebetween so as to provide ease of plasma ignition, and precise control of plasma ion energy and plasma ion density.

14. The reactor of claim 13 wherein the power supply is coupled to each of the electrodes so as to provide a certain RF phase relationship between the electrodes.

15. A capacitively and inductively coupled RF plasma reactor for processing a semiconductor wafer inside a vacuum chamber of said reactor, comprising:

a pair of parallel capacitive electrodes facing each other across at least a portion of the chamber;

an inductive coil wound around a portion of the chamber;

power applying means for applying RF power to each of the capacitive electrodes for capacitively coupling RF power into the chamber and to said inductive coil for inductively coupling RF power into the chamber during processing of the semiconductor wafer for ease of plasma ignition and precise control of plasma ion energy and precise control of plasma ion density; and

a ceiling comprising a multi-radius dome shape, said inductive coil being conformal with said dome shape.

16. A capacitively and inductively coupled RF plasma reactor for processing a workpiece comprising:

a pair of parallel capacitive electrodes facing each other across at least a portion of the chamber;

an inductive coil wound around a portion of the chamber;

a power supply capable of producing RF power;

the power supply being coupled to each of the parallel electrodes;

the power supply being coupled to the inductive coil;

the power supply being coupled to each of the parallel electrodes and to the inductive coil so that the RF power is adjustable therebetween so as to provide ease of plasma ignition, and precise control of plasma ion energy and plasma ion density; and

a ceiling comprising a multi-radius dome shape, the inductive coil being conformal with the dome shape.

17. A RF plasma reactor for processing a workpiece, comprising:

a vacuum chamber;

a pair of parallel capacitive electrodes in a facing relationship with each other across at least a portion of the vacuum chamber facilitating ignition of a plasma within the chamber;

an inductive antenna disposed around at least a portion of the chamber facilitating precise control of an ion density of the plasma; and

a RF power source providing RF power and connected to each of the pair of parallel capacitive electrodes and the inductive antenna.

18. A plasma reactor, comprising:

a vacuum chamber;

a ceiling overlying the vacuum chamber and having a multi-radius dome shape;

a pair of capacitive electrodes in a facing relationship with each other across at least a portion of the chamber;

an inductive antenna disposed around at least a portion of the chamber and conformal with said multi-radius dome shape.