RF induction plasma source generating apparatus

• US 6,073,578 A
• Filed: 12/04/1998
• Issued: 06/13/2000
• Est. Priority Date: 10/09/1998
• Status: Expired due to Term

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Shim, Kyu-Hwan, Cho, Kyoung-Ik, Paek, Mun-Cheol
• Primary Examiner(s): Dang, Thi
• Assistant Examiner(s): Zervigon, Rudy
• Application Number:
  US09/205,617
• Time in Patent Office: 557 Days
• Field of Search: 422/186.29, 422/186, 118/733, 118/723 MP
• US Class Current: 118/723.00I
• CPC Class Codes: C23C 14/0026 Activation or excitation of reactive gases outside the coating chamber
• CPC Class Codes: H01J 37/321 the radio frequency energy being inductively coupled to the plasma
• CPC Class Codes: H05H 1/30 using applied electromagnetic fields, e.g. high frequency or microwave energy H05H1/28 takes precedence

Abstract

The object of the present invention is to provide a RF induction plasma source generating apparatus which generates a stabilized plasma and sustains the stabilized plasma by maintaining the plasma pressure from several hundreds Torr to several thousands Torr with attachment a buffer nozzle cap, upper metallic blocking films and lower metallic blocking films to a nozzle cap, plasma tube and RF induction coils, respectively for separating the plasma source generating apparatus from the chamber. To accomplish the object of the invention, the plasma source generating apparatus comprising PBN tube, RF induction coils, a nozzle, and a nozzle cap is characterized by a buffer nozzle cap for locating between the nozzle cap and the plasma tube and modulating the flow of the gas to modulate the difference between the chamber pressure and the plasma pressure; sealing films formed by sealing the lips of the buffer nozzle cap, the nozzle cap and the plasma tube for preventing the leakage of gas; and upper blocking films and lower blocking films for blocking the spread out of the RF electric field induced in the RF induction coils and converging the plasma source.

Claims

1. A RF induction plasma source generating apparatus including a PBN tube for supplying gas a plasma tube, a RF induction coil for inducing RF electric field and forming the gas supplied to said the plasma tube as a plasma source, a nozzle for spraying the plasma source formed in said plasma tube, and a nozzle cap, comprising:

a buffer nozzle cap for locating between said nozzle cap and said plasma tube and modulating the flow of the gas to modulate the difference between the chamber pressure and the plasma pressure;

sealing films formed by sealing the lips of said buffer nozzle cap, said nozzle cap and said plasma tube for protecting the leakage of gas; and

upper blocking films and lower blocking films for blocking the spread out of the RF electric field induced by said the RF induction coils and converging said plasma source.

2. A RF induction plasma source generating apparatus as set forth in claim 1, wherein said buffer nozzle cap comprises a lip formed with circular plate;

and a tube having a predetermined length and a predetermined diameter, the top toward said plasma tube of said tube being closed and the bottom being coupled with the center of said lip.

3. A RF induction plasma source generating apparatus as set forth in claim 2, a plurality of nozzles are asymmetrically formed in a predetermined location of the top of said tube.

4. A RF induction plasma source generating apparatus as set forth in claim 1, wherein said sealing films are formed by coating the lips of said buffer nozzle cap, said nozzle, and said plasma tube with metal type such as Al, Ga and In, and thermal processing said members in a connected state in a high temperature furnace thereby to bond with each other.

5. A RF induction plasma source generating apparatus as set forth in claim 4, wherein said sealing films are formed of nitride thin films such as AIN, GaN, InN by causing said high temperature furnace to be maintained at the temperature of 700-900°

C., the atmosphere of said high temperature furnace to be NH₃ gas, and said NH₃ gas to be reacted with said metal for a few hours.

6. A RF induction plasma source generating apparatus as set forth in claim 1, wherein said upper metallic blocking films comprises a lip of a circular plate and a tube provided with slits in both side, the top of said tube being opened and the bottom being coupled with the center of said lip.

7. A RF induction plasma source generating apparatus as set forth in claim 1, wherein said upper metallic blocking films are located in direction of said RF induction coils by a predetermined length longer than said buffer nozzle cap in order for separating the converging plasma from said buffer nozzle cap.

8. A RF induction plasma source generating apparatus as set forth in claim 1, wherein said lower metallic blocking films comprises a cylindrical tube formed with the both sides thereof being opened;

and slits formed in said both sides in a predetermined length from one side of said tube.

9. A RF induction plasma source generating apparatus as set forth in claims 6, wherein said slits prevent the current from inducing by RF electric field of said RF induction coils.

10. A RF induction plasma source generating apparatus as set forth in claims 6, wherein said upper metallic films and said lower metallic films are formed with metal type such as tantalum or molybdenum having a high melting point so that even when used in a high temperature, the outgassing is sustained at minimum.