Radial antenna and plasma device using it

• US 20040045674A1
• Filed: 06/18/2003
• Published: 03/11/2004
• Est. Priority Date: 08/04/2000
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Ishii, Nobuo, Shinohara, Kibatsu
• Granted Patent: US 7,296,533 B2
• Time in Patent Office: Days
• US Class Current: 156/345.48
• 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

Abstract

A plasma device includes a first conductive plate (31) in which a plurality of slots (36) are formed, a second conductive plate (32) having a microwave inlet (35) and disposed opposite to the first conductive plate (31), a ring member (34) for connecting peripheral edges of the first and second conductive plates (31, 32), and a conductive adjusting member (37) provided on said second conductive plate (32) within a radial waveguide (33) formed by the first and second conductive plates (31, 32) and serving to adjust a distance (d1, d2) up to the first conductive plate (31). With this arrangement, a desired electric field radiation distribution can be obtained without inducing abnormal discharge.

Claims

1. A radial antenna characterized by comprising

a first conductive plate in which a plurality of slots are formed,

a second conductive plate having a microwave inlet and disposed opposite to said first conductive plate,

a ring member for connecting peripheral edges of said first and second conductive plates, and

a conductive adjusting member provided on said second conductive plate in a radial waveguide formed by said first and second conductive plates and serving to adjust a distance up to said first conductive plate.

2. A radial antenna according to claim 1, characterized in that a plurality of said conductive adjusting members are disposed radially when viewed from top.

3. A radial antenna according to claim 1, characterized in that said adjusting member is disposed along the peripheral edge of said second conductive plate.

4. A radial antenna according to claim 1, characterized in that said adjusting member is set to become higher as being farther away from a center of said second conductive plate.

5. A radial antenna according to claim 1, characterized in that the slots are substantially rectangular or arcuate, and

a slot length of the slots is smaller than a length corresponding to ⅓

the wavelength of a microwave propagating in said radial waveguide.

6. A plasma device characterized by comprising

a susceptor for placing a target object thereon,

a processing vessel for accommodating said susceptor,

exhaust means for evacuating an interior of said processing vessel,

gas supply means for supplying a gas into said processing vessel, and

antenna means which is arranged to oppose that surface of said susceptor where the target object is to be placed and which supplies a microwave into said processing vessel,

wherein said antenna means comprises a radial antenna according to claim 1.