Plasma reactor for the treatment of large size substrates

• US 6,228,438 B1
• Filed: 09/22/1999
• Issued: 05/08/2001
• Est. Priority Date: 08/10/1999
• Status: Expired due to Term

• Current Assignee: TEL Solar AG (OC Oerlikon Corporation AG)
• Original Assignee: Unaxis Balzers AG (Oerlikon USA, Inc. (Florida))
• Inventors: Schmitt, Jacques
• Primary Examiner(s): PADGETT, MARIANNE L
• Application Number:
  US09/401,158
• Time in Patent Office: 594 Days
• Field of Search: 427/569, 427/534, 427/535, 427/488, 216/71, 118/723 E
• US Class Current: 427/569
• CPC Class Codes: C23C 16/4583 the substrate being supported substantially horizontally
• CPC Class Codes: C23C 16/509 using internal electrodes
• CPC Class Codes: H01J 37/32091 the radio frequency energy being capacitively coupled to the plasma
• CPC Class Codes: H01J 37/32192 Microwave generated discharge H01J37/32357, H01J37/32366, H01J37/32394, H01J37/32403 take precedence
• CPC Class Codes: H01J 37/32238 Windows
• CPC Class Codes: H01J 37/32348 Dielectric barrier discharge
• CPC Class Codes: H01J 37/32532 Electrodes
• CPC Class Codes: H01J 37/32541 Shape
• CPC Class Codes: H01J 37/32559 Protection means, e.g. coatings

Abstract

A radiofrequency plasma reactor (1) for the treatment of substantially large sized substrates is disclosed, comprising between the electrodes (3, 5) of the plasma reactor a solid or gaseous dielectric layer (11) having a non planar-shaped surface-profile, said profile being defined for compensating a process non uniformity in the reactor or generating a given distribution profile.

Claims

1. A process for treating at least one substrate in a radiofrequency plasma reactor, comprising the steps of:

locating the at least one substrate between two electrodes in the reactor, the two electrodes defining an internal process space there between;

circulating a reactive gas within the reactor so that the reactive gas is present in the internal process space;

connecting at least one radiofrequency generator to at least one of the electrodes at a connection location;

operating the radiofrequency generator to create a plasma discharge in at least one zone of the internal process space to expose the substrate to a processing action of the plasma discharge;

providing capacitor means having an electrical capacitance acting in series with the substrate and the plasma discharge, the capacitor means having a profile along the at least one substrate between the electrodes; and

defining the profile so that a capacitance of the capacitor means varies along the at least one substrate in a location-dependant manner along the substrate for generating a selected RF voltage distribution in the plasma discharge along the substrate.

2. A process according to claim 1, including operating the radiofrequency generator at a frequency higher than 1 MHz, the at least one substrate having a surface larger than 0.5 m², and the largest dimension of the substrate surface exposed to the plasma discharge being greater than 0.7 m.

3. A process according to claim 1 wherein the step of defining the profile of the capacitor means comprises providing at least one dielectric layer having a non-uniform thickness between the two electrodes and along the substrate, the dielectric layer having a non-planar surface.