Arrangement for coupling microwave energy into a treatment chamber

• US 6,952,949 B2
• Filed: 12/15/2000
• Issued: 10/11/2005
• Est. Priority Date: 12/24/1999
• Status: Expired due to Fees

• Current Assignee: Tetra Laval Holdings & Finance SA (Tetra Laval Holdings BV)
• Original Assignee: Tetra Laval Holdings & Finance SA (Tetra Laval Holdings BV)
• Inventors: Essers, Wolf, Moore, Rodney
• Primary Examiner(s): Cumming, William D.
• Application Number:
  US10/169,698
• Publication Number:
  US 20030097986A1
• Time in Patent Office: 1,761 Days
• Field of Search: 455/446, 118/337, 118/723, 118/317, 73/38, 261/97, 291/121.43, 291/121.42, 291/696, 291/750, 291/97
• US Class Current: 73/38
• CPC Class Codes: H01J 37/32192 Microwave generated discharge H01J37/32357, H01J37/32366, H01J37/32394, H01J37/32403 take precedence
• CPC Class Codes: H01J 37/3222 Antennas
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01J 37/32532 Electrodes

Abstract

An arrangement for coupling microwave energy into a plasma CVD coating chamber (3) disposed in a cavity resonator (1) has a microwave feed (11) and a microwave waveguide (9, 1). So that a plastic container of a size and configuration which differ to a certain degree can be effectively coated in its interior, it is provided that the arrangement is of a substantially cylindrical structure, such that provided at the rear end is a first coaxial waveguide (in the region a) with an internal conductor in the form of an antenna (12), an approximately cylindrical waveguide (in the region b) follows in the centre of the arrangement and provided at the front end (in the region c) is a second coaxial waveguide (1) with internal conductor (13), wherein gas can be introduced through a gas feed tube (13) into the second coaxial waveguide (in the region c), which gas can be activated into the plasma state by the coupled-in microwave energy, and wherein a TM-mode is produced by the antenna (12) in the plasma region (1, c).

Claims

1. An apparatus for coupling microwave energy into a plasma chemical vapor deposition (CVD) coating chamber (3), said apparatus comprising a cavity resonator for containing the coating chamber (3), a microwave feed (11) and microwave waveguides wherein the apparatus further has a substantially cylindrical shape and is provided at one end region (a) with a first coaxial waveguide having an internal conductor in the form of an antenna (12), at a central region (b) with an approximately cylindrical waveguide and at a second end region (c) with a second coaxial waveguide (1) having an internal conductor and a gas feed tube (13) through which gas can be provided into the coating chamber to be activated into a plasma state by coupled microwave energy having a transverse magnetic field line (TM)mode within the second end region (c), produced by the antenna (12).

2. An apparatus according to claim 1 wherein the antenna (12) of the first coaxial waveguide (in the region a) is in bar form and the length of the bar antenna (12) is between 40 mm and 100 mm.

3. An apparatus according to claim 1 wherein the antenna (12) of the first coaxial waveguide (in the region a) is in the form of a conical spiral and the length of the spiral antenna (12) is between 50 mm and 70 mm.

4. An apparatus according to claim 1 wherein the internal conductor of the second coaxial conductor (in the region c) is in the form of the gas feed tube (13) and is made from metal which is surrounded by a plastic container (2) to be coated, and the container (2) is carried in a container carrier plate (5) to form the coating chamber (3).

5. An apparatus according to claim 2 wherein the internal conductor of the second coaxial conductor (in the region c) is in the form of the gas feed tube (13) and is made from metal which is surrounded by a plastic container (2) to be coated, and the container (2) is carried in a container carrier plate (5) to form the coating chamber (3).

6. An apparatus according to claim 3 wherein the internal conductor of the second coaxial conductor (in the region c) is in the form of the gas feed tube (13) and is made from metal which is surrounded by a plastic container (2) to be coated, and the container (2) is carried in a container carrier plate (5) to form the coating chamber (3).

7. An apparatus according to claim 1 wherein a quartz window (14) is disposed in the cylindrical waveguide which extends transversely with respect to a longitudinal axis of the apparatus.

8. An apparatus according to claim 2 wherein a quartz window (14) is disposed in the cylindrical waveguide which extends transversely with respect to a longitudinal axis of the apparatus.

9. An apparatus according to claim 3 wherein a quartz window (14) is disposed in the cylindrical waveguide which extends transversely with respect to a longitudinal axis of the apparatus.

10. An apparatus according to claim 4 wherein a quartz window (14) is disposed in the cylindrical waveguide which extends transversely with respect to a longitudinal axis of the apparatus.

11. An apparatus according to claim 5 wherein a quartz window (14) is disposed in the cylindrical waveguide which extends transversely with respect to a longitudinal axis of the apparatus.

12. An apparatus according to claim 6 wherein a quartz window (14) is disposed in the cylindrical waveguide which extends transversely with respect to a longitudinal axis of the apparatus.

13. An apparatus according to claim 3 wherein the spiral antenna (12) is fixed releasably by means of frictional engagement in a sleeve-shaped receiving means (21).

14. An apparatus according to claim 6 wherein the spiral antenna (12) is fixed releasably by means of frictional engagement in a sleeve-shaped receiving means (21).

15. An apparatus according to claim 9 wherein the spiral antenna (12) is fixed releasably by means of frictional engagement in a sleeve-shaped receiving means (21).

16. An apparatus according to claim 12 wherein the spiral antenna (12) is fixed releasably by means of frictional engagement in a sleeve-shaped receiving means (21).