Plasma processing apparatus

• US 6,000,360 A
• Filed: 07/02/1997
• Issued: 12/14/1999
• Est. Priority Date: 07/03/1996
• Status: Expired due to Term

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Koshimizu, Chishio
• Primary Examiner(s): Breneman, Bruce
• Assistant Examiner(s): ALEJANDRO MULERO, LUZ L
• Application Number:
  US08/887,084
• Time in Patent Office: 895 Days
• Field of Search: 118/723 E, 118/723 I, 118/723 AN, 118/723 MA, 156/345, 315/111.21, 315/111.41, 315/111.51, 204/298.06, 204/298.16, 204/298.34, 204/298.37
• US Class Current: 118/723.00E
• CPC Class Codes: H01J 37/32623 Mechanical discharge control means
• CPC Class Codes: H01J 37/3266 Magnetic control means

Abstract

The plasma processing apparatus according to the present invention comprises a processing chamber in which an object to be processed is processed, a lower electrode provided at a lower portion in the processing chamber, having a mount surface where the object is mounted, and applied with a bias voltage, gas introduce tube for introducing a processing gas into the processing chamber, an upper electrode provided fixedly on a roof portion of the processing chamber and supplied with a high-frequency power, to form plasma from the processing gas in the processing chamber, and a magnetic field formation portion provided fixedly on the roof portion of the processing chamber, for forming a magnetic field in the processing chamber. The the upper electrode and the magnetic field formation portion are arranged such that a force for moving circularly electrons in the plasma is generated in the processing chamber and such that two or more circular flows of electrons which are coaxial with each other and have turning radii different from each other are generated by the force.

Claims

1. A plasma processing apparatus comprising:

a processing chamber in which an object to be processed is processed;

gas introduce means for introducing a processing gas into the processing chamber;

an upper electrode comprising a part of an upper wall portion of the processing chamber and supplied with a high-frequency power, to form plasma from the processing gas in the processing chamber;

magnetic field formation means provided fixedly on the upper wall portion of the processing chamber, for forming a magnetic field in the processing chamber; and

a lower electrode provided at a lower portion in the processing chamber, having a mount surface where the object is mounted, and applied with a bias voltage;

wherein the upper electrode and the magnetic field formation means are positioned in such a way that a force for moving circularly in the plasma is generated in the processing chamber and such that two or more circular flows of electrons which are substantially coaxial with each other and have turning radii different from each other are generated by the force.

2. A plasma processing apparatus according to claim 1, wherein the upper electrode consists of a plurality of electrode portions and the high-frequency powers are controlled individually for each of the electrode portions and the phases of the high frequency powers are relatively controlled.

3. A plasma processing apparatus according to claim 1, wherein the upper electrode comprises a plurality of circular members which are arranged substantially concentric with each other.

4. A plasma processing apparatus according to claim 1, wherein the magnetic field formation means and the upper electrode are parts of the upper chamber wall of the processing chamber.

5. A plasma processing apparatus according to claim 1, wherein the upper electrode and the lower electrode are plate-shaped, and located parallel to each other and opposite to each other.

6. A plasma processing apparatus according to claim 1, wherein:

the upper electrode comprises a plurality of circular members which are arranged substantially concentric with each other;

high frequency powers to be supplied to the circular members are controlled individually, and phases of the high frequency powers are relatively controlled; and

the upper electrode and the lower electrode are plate-shaped, and located parallel to each other and opposite to each other.

7. A plasma processing apparatus comprising:

a processing chamber in which an object to be processed is processed;

gas introduce means for introducing a processing gas into the processing chamber;

an upper electrode provided fixedly on a roof portion of the processing chamber and supplied with a high-frequency power, to form plasma from the processing gas in the processing chamber; and

magnetic field formation means provided fixedly on the roof portion of the processing chamber, for forming a magnetic field in the processing chamber; and

wherein the upper electrode and the magnetic field formation means are positioned in such a way that a force for moving circularly electrons in the plasma is generated in the processing chamber and such that two or more circular flows of electrons which are substantially coaxial with each other and have turning radii different from each other are generated by the force; and

wherein the upper electrode consists of a plurality of ring-like electrode portions arranged to be substantially coaxial with each other, the magnetic field formation means consists of a plurality of ring-like magnets arranged to be substantially coaxial with each other, and the magnets are individually provided between the electrodes or inside the electrodes, to be substantially coaxial with the electrodes, such that poles of adjacent magnets which face each other have polarities different from each other.

8. A plasma processing apparatus according to claim 7, comprising:

a lower electrode provided at a lower portion in the processing chamber, having a mount surface where the object is mounted, and applied with a bias voltage.

9. A plasma process apparatus comprising:

a processing chamber in which an object to be processed is processed;

gas introduce means for introducing a processing gas into the processing chamber;

an upper electrode provided fixedly on a roof portion of the processing chamber and supplied with a high-frequency power, to form plasma from the processing gas in the processing chamber; and

magnetic field formation means provided fixedly on the roof portion of the processing chamber, for forming a magnetic field in the processing chamber;

wherein the upper electrode and the magnetic field formation means are positioned in such a way that a force for moving circularly electrons in the plasma is generated in the processing chamber and such that two or more circular flows of electrons which are substantially coaxial with each other and have turning radii different from each other are generated by the force; and

wherein the upper electrode is formed such that a surface of the upper electrode facing the processing chamber constitutes curved surface extending along a direction of a line of magnetic force of the magnetic field generated in the processing chamber.

10. A plasma processing apparatus comprising:

a processing chamber in which an object to be processed is processed;

a lower electrode provided at a lower portion in the processing chamber, having a mount surface where the object is mounted, and applied with a bias voltage;

gas introduce means for introducing a processing gas into the processing chamber;

a first ring-like upper electrode provided fixedly on a roof portion of the processing chamber and supplied with a high-frequency power for forming plasma from the processing gas in the processing chamber;

a second ring-like upper electrode provided fixedly on the roof portion of the processing chamber outside the first ring-like upper electrode, to be substantially coaxial with the first ring-like upper electrode, and supplied with a high-frequency power for forming plasma from the processing gas in the processing chamber;

a first ring-like magnet provided fixedly on the roof portion of the processing chamber inside the first ring-like upper electrode, to be substantially coaxial with the first ring-like upper electrode, for generating a magnetic field in the processing chamber;

a second ring-like magnet provided fixedly between the first and second ring-like upper electrodes on the roof portion of the processing chamber, to be substantially coaxial with the first and second ring-like upper electrodes, for generating a magnetic field in the processing chamber; and

a third ring-like magnet provided fixedly on the roof portion of the processing chamber and positioned outside the second ring-like upper electrode, to be substantially coaxial with the second ring-like upper electrode, for forming a magnetic field in the processing chamber, wherein

the first, second, and third ring-like magnets are arranged such that any adjacent two of the magnets have poles facing each other, polarities of which are different from each other, and

the magnetic field generated in the processing chamber by the magnets generates a force for moving circularly electrons in the plasma and generates two circular flows of electrons which have turning radii different from each other and which are substantially coaxial with each other.

11. A plasma processing apparatus according to claim 10, wherein the high-frequency powers are controlled individually for each of the first and second ring-like upper electrodes and the phases of the high frequency powers are relatively controlled.

12. A plasma processing apparatus according to claim 10, wherein the first and second ring-like upper electrodes are formed such that a surface of each of the upper electrodes facing the processing chamber constitutes a curved surface extending along a direction of a line of magnetic force of the magnetic field generated in the processing chamber.

13. A plasma processing apparatus according to claim 10, wherein the two circular flows of electrons have one same turning direction.

14. A plasma processing apparatus according to claim 10, wherein the two circular flows of electrons have turning directions opposite to each other.

15. A plasma processing apparatus comprising:

a processing chamber in which an object to be processed is processed;

a lower electrode provided at a lower portion in the processing chamber, having a mount surface where the object is mounted, and applied with a bias voltage;

gas introduce means for introducing a processing gas into the processing chamber;

a first ring-like upper electrode provided fixedly on a roof portion of the processing chamber and supplied with a high-frequency power for forming plasma from the processing gas in the processing chamber;

a second ring-like upper electrode provided fixedly on the roof portion of the processing chamber outside the first ring-like upper electrode, to be substantially coaxial with the first ring-like upper electrode, and supplied with a high-frequency power for forming plasma from the processing gas in the processing chamber;

a first magnet provided fixedly on the roof portion of the processing chamber, to be positioned inside the first ring-like upper electrode, for generating a magnetic field in the processing chamber;

a first ring-like magnet provided fixedly between the first and second ring-like upper electrodes on the roof portion of the processing chamber, to be substantially coaxial with the first and second ring-like upper electrodes, for generating a magnetic field in the processing chamber; and

a second ring-like magnet provided fixedly on the roof portion of the processing chamber and positioned outside the second ring-like upper electrode, to be substantially coaxial with the second ring-like upper electrode, for forming a magnetic field in the processing chamber, wherein

the first magnet and the first and second ring-like magnets are arranged such that any adjacent two of the magnets have poles facing each other, polarities of which are different from each other, and

the magnetic field generated in the processing chamber by the magnets generates a force for moving circularly electrons in the plasma and generates two circular flows of electrons which have turning radii different from each other and which are substantially coaxial with each other.

16. A plasma processing apparatus according to claim 15, wherein the high-frequency powers are controlled individually for each of the first and second ring-like upper electrodes and the phases of the high frequency powers are relatively controlled.

17. A plasma processing apparatus according to claim 15, wherein the two circular flows of electrons have turning directions opposite to each other.