ANTENNA, DIELECTRIC WINDOW, PLASMA PROCESSING APPARATUS AND PLASMA PROCESSING METHOD

• US 20130008607A1
• Filed: 07/05/2012
• Published: 01/10/2013
• Est. Priority Date: 07/06/2011
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: MATSUMOTO, Naoki, YOSHIKAWA, Wataru, YOSHIKAWA, Jun, MOYAMA, Kazuki, ISHIBASHI, Kiyotaka, MORITA, Osamu, TANIKAWA, Takehiro
• Granted Patent: US 9,595,425 B2
• Time in Patent Office: Days
• US Class Current: 156/345.41
• CPC Class Codes: H01J 37/32238 Windows

Abstract

An antenna, a dielectric window, a plasma processing apparatus and a plasma processing method are capable of improving uniformity of a substrate surface processing amount in the surface of the substrate. The antenna includes the dielectric window 16; and a slot plate 20, provided on one side of the dielectric window 16, having a plurality of slots 133. The dielectric window 16 has a flat surface 146 surrounded by a ring-shaped first recess; and a plurality of second recesses 153 formed on the flat surface 146 so as to surround a center of the flat surface 146. Here, the flat surface 146 is formed on the other side of the dielectric window 16. When viewed from a thickness direction of the slot plate, a center of each second recess 153 is located within each slot 133 of the slot plate.

Claims

1. An antenna comprising:

a dielectric window; and

a slot plate, provided on one side of the dielectric window, having a plurality of slots,

wherein the dielectric window comprises;

a flat surface surrounded by a ring-shaped first recess, the flat surface being formed on the other side of the dielectric window; and

a plurality of second recesses formed on the flat surface so as to surround a center of the flat surface, and

when viewed from a thickness direction of the slot plate, a center of each second recess is located within each slot of the slot plate.

2. The antenna of claim 1,

wherein the slot plate comprises:

a first slot group located at a first distance from a center of the slot plate;

a second slot group located at a second distance from the center of the slot plate;

a third slot group located at a third distance from the center of the slot plate; and

a fourth slot group located at a fourth distance from the center of the slot plate,

the first distance, the second distance, the third distance and the fourth distance satisfy a relationship of the first distance<

the second distance<

the third distance<

the fourth distance,

angles between a straight line extended from the center of the slot plate toward a target slot in a diametrical direction and a lengthwise direction of the target slot in the first to the fourth slot groups are identical to each other,

a slot of the first slot group and a slot of the second slot group lying on a straight line extended from the center of the slot plate in the diametrical direction are elongated in different directions,

a slot of the third slot group and a slot of the fourth slot group lying on a straight line extended from the center of the slot plate in the diametrical direction are elongated in different directions,

the number of slots of the first slot group and the number of slots of the second slot group are identical to each other (N1),

the number of slots of the third slot group and the number of slots of the fourth slot group are identical to each other (N2), and

N2 is an integer multiple of N1.

3. The antenna of claim 1,

wherein each of the second recesses has a circular plate shape.

4. A plasma processing apparatus comprising:

an antenna as claimed in claim 1;

a processing chamber for accommodating the antenna therein;

a table, provided within the processing chamber so as to face the other side of the dielectric window, for mounting a processing target substrate thereon; and

a microwave inlet path that connects a microwave generator with the slot plate.

5. The plasma processing apparatus of claim 4, further comprising:

a common gas line connected to a common gas source;

a flow splitter provided on the common gas line, and configured to split the common gas line into a first split common gas line and a second split common gas line and adjust a flow rate ratio between gases flowing in the first split common gas line and the second split common gas line;

a central inlet unit, connected to the first split common gas line, having a central inlet opening positioned above a central portion of the processing target substrate mounted on the table;

a peripheral inlet unit connected to the second split common gas line, arranged along the circumferential direction of a space above the substrate and positioned under the dielectric window; and

an additive gas line that connects an additive gas source with at least one of the first split common gas line and the second split common gas line.

6. A plasma processing method for processing a substrate on the table by using a plasma processing apparatus as claimed in claim 5,

wherein the common gas source includes a rare gas,

the additive gas source includes C₅F₈, and

the method comprises:

generating plasma on the other side of the dielectric window by supplying microwave to the slot plate from the microwave generator through the microwave inlet path;

supplying the rare gas from the common gas source to the central inlet unit via the first split common gas line; and

supplying the C₅F₈ gas from the additive gas source to the peripheral inlet unit via the second split common gas line.

7. A dielectric window comprising:

a flat surface surrounded by a ring-shaped first recess, the flat surface being formed on one side of the dielectric window; and

a plurality of second recesses formed on the flat surface so as to surround a center of the flat surface,

wherein a slot plate having a plurality of slots is provided on the other side of the dielectric window,

when viewed from a thickness direction of the slot plate, a center of each second recess is located within each slot of the slot plate,

the slot plate comprises;

a first slot group located at a first distance from a center of the slot plate;

a second slot group located at a second distance from the center of the slot plate;

a third slot group located at a third distance from the center of the slot plate; and

a fourth slot group located at a fourth distance from the center of the slot plate,

the first distance, the second distance, the third distance and the fourth distance satisfy a relationship of the first distance<

the second distance<

the third distance<

the fourth distance,

angles between a straight line extended from the center of the slot plate toward a target slot in a diametrical direction and a lengthwise direction of the target slot in the first to the fourth slot groups are identical to each other,

a slot of the first slot group and a slot of the second slot group lying on a straight line extended from the center of the slot plate in the diametrical direction are elongated in different directions,

a slot of the third slot group and a slot of the fourth slot group lying on a straight line extended from the center of the slot plate in the diametrical direction are elongated in different directions,

the number of slots of the first slot group and the number of slots of the second slot group are identical to each other, and

the number of slots of the third slot group and the number of slots of the fourth slot group are identical to each other.