Low frequency electron cyclotron resonance plasma processor

• US 5,537,004 A
• Filed: 04/29/1994
• Issued: 07/16/1996
• Est. Priority Date: 03/06/1993
• Status: Expired due to Fees

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Fukasawa, Takayuki, Imahashi, Issei
• Primary Examiner(s): Pascal, Robert
• Assistant Examiner(s): Philogene, Haissa
• Application Number:
  US08/235,641
• Time in Patent Office: 809 Days
• Field of Search: 315/111.21, 315/111.41, 315/111.51, 315/111.71, 315/111.81, 315/111.91, 315/85, 118/723, 118/728, 118/50.1, 118/620, 118/623, 204/192 R, 204/298
• US Class Current: 315/111.21
• CPC Class Codes: H01J 37/321 the radio frequency energy being inductively coupled to the plasma
• CPC Class Codes: H01J 37/32678 Electron cyclotron resonance

Abstract

A plasma processor includes a cylindrical processing chamber storing a semiconductor wafer to be processed, a slot antenna, wound around the outside of a peripheral wall of the processing chamber, for feeding an electromagnetic wave of several tens MHz to the chamber, and an electromagnetic coil, provided on the outside of the processing chamber, for generating plasma in a plasma generating section due to electron cyclotron resonance by applying a magnetic field of 30 gausses or less to said processing chamber. The slot antenna has an elongated conductive plate having a length of about 1/2 of the wavelength of the electromagnetic wave, and an elongate slot formed in the conductive plate.

Claims

1. A plasma processor comprising:

a processing chamber having a storage section storing an object to be processed and a plasma generating section having a peripheral wall and formed continuous to the storage section;

slot antenna means wound around the peripheral wall of the plasma generating section, for radiating an electromagnetic wave into the plasma generating section of the processing chamber;

magnetic field generating mans for generating plasma in cooperation with said electromagnetic waves by applying a magnetic field to said plasma generating section; and

wherein said slot antenna means comprises an elongated belt-like antenna that is spirally wound around the outside of the peripheral wall.

2. A plasma processor according to claim 1, wherein said slot antenna means and magnetic field generating means apply the electromagnetic wave having a frequency satisfying electron cyclotron resonance condition and the magnetic field having intensity satisfying electron cyclotron resonance condition, respectively.

3. A plasma processor according to claim 2, wherein said electromagnetic wave has a frequency of 1 MHz to 200 MHz, and said magnetic field has intensity of 5 to 30 gausses.

4. A plasma processor according to claim 1, wherein said electromagnetic wave has a frequency of 1 MHz to 200 MHz.

5. A plasma processor according to claim 1, wherein said magnetic field has intensity of 5 to 30 gausses.

6. A plasma processor according to claim 1, which further includes a sheet made of ferrite-based material between the slot antenna means and the processing chamber.

7. A plasma processor comprising:

a cylindrical processing chamber having a peripheral wall and for containing an object to be processed;

a slot antenna, wound around the outside of the peripheral wall of the cylindrical processing chamber, for feeding an electromagnetic wave of several tens of MHz to the chamber; and

magnetic field applying means, provided on the outside of the processing chamber, for generating plasma in a plasma generating section due to electron cyclotron resonance by applying a magnetic field of 30 gausses or less to said processing chamber.

8. A plasma processor comprising:

a cylindrical processing chamber having a peripheral wall and for containing an object to be processed;

a slot antenna, wound around the outside of the peripheral wall of the cylindrical processing chamber, for feeding an electromagnetic wave of several tens of MHz to the chamber;

magnetic field applying means, provided on the outside of the processing chamber, for generating plasma in a plasma generating section due to electron cyclotron resonance by applying a magnetic field of 30 gausses or less to said processing chamber; and

wherein said slot antenna has an elongated conductive plate having a length of about 1/2 of the wavelength of said electromagnetic wave, and at least one slot formed in said conductive plate.

9. A plasma processor according to claim 8, wherein said slot is an elongate slot extended to portions close to both ends of the conductive plate along the conductive plate.

10. A plasma processor according to claim 9, wherein said slot has a width of 1 to 5 mm.

11. A plasma processor comprising:

a cylindrical processing chamber having a peripheral wall and for containing an object to be processed;

a slot antenna, wound around the outside of the peripheral wall of the cylindrical processing chamber, for feeding an electromagnetic wave of several tens of MHz to the chamber;

magnetic field applying means, provided on the outside of the processing chamber, for generating plasma in a plasma generating section due to electron cyclotron resonance by applying a magnetic field of 30 gausses or less to said processing chamber; and

wherein said slot antenna has an elongated conductive plate having a length of about 1/2 of the wavelength of said electromagnetic wave, and an elongated slot formed at a center of the conductive plate, extending to portions close to both ends of the conductive plate along the conductive plate, and having a width of about 1 to 5 mm, and said conductive plate has a width having the width of the slot+4 cm.

12. A plasma processor comprising:

a cylindrical processing chamber having a peripheral wall and for containing an object to be processed;

a slot antenna, wound around the outside of the peripheral wall of the cylindrical processing chamber, for feeding an electromagnetic wave of several tens of MHz to the chamber;

magnetic field applying means, provided on the outside of the processing chamber, for generating plasma in a plasma generating section due to electron cyclotron resonance by applying a magnetic field of 30 gausses or less to said processing chamber; and

wherein said slot antenna has an elongated conductive plate having a length of about 1/2 of the wavelength of said electromagnetic wave, and a plurality of slots formed with a predetermined distance along a longitudinal direction of the conductive plate.

13. A plasma processor comprising:

a processing chamber having a peripheral wall and a plasma generating section and for containing an object to be processed;

an elongated slot antenna wound around the outside of the peripheral wall of the processing chamber, for feeding an electromagnetic wave to the chamber, the slot antenna having an elongated conductive plate having first and second ends and having surfaces forming an elongated slot, said elongated slot extends to portions of the conductive plate close to the first and second ends of the elongated conductive plate; and

magnetic field applying means provided on the outside of the processing chamber in the plasma generation section for generating electron cyclotron resonance in the plasma generation section by applying a magnetic field to the processing chamber.

14. A plasma processor according to claim 13, wherein the slot has a width of 1 to 5 mm.

15. A plasma processor comprising:

a processing chamber having a peripheral wall, a plasma generation section and for containing an object to be processed, and a longitudinal axis;

an elongated slot antenna wound around the outside of the peripheral wall of the processing chamber, for feeding an electromagnetic wave to the chamber, the elongated slot antenna having an elongated conductive plate with surfaces forming a plurality of slots, each of the plurality of slots having a length along the direction of the longitudinal axis;

magnetic field applying means provided on the outside of the processing chamber in the plasma generation section for generating electron cyclotron resonance by applying a magnetic field to the processing chamber.