Apparatus for plasma processing

• US 6,562,186 B1
• Filed: 02/27/2001
• Issued: 05/13/2003
• Est. Priority Date: 08/31/1998
• Status: Expired due to Term

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Saito, Susumu, Sugiyama, Norikazu
• Primary Examiner(s): Hassanzadeh, Parviz
• Application Number:
  US09/784,453
• Time in Patent Office: 805 Days
• Field of Search: 156/345.24, 156/345.25, 156/345.34, 156/345.47, 118/712, 118/715, 118/713, 118/723.E, 356/124, 348/86, 348/79, 348/87, 204/298.32, 204/192.33
• US Class Current: 156/345.24
• CPC Class Codes: H01J 37/32091 the radio frequency energy being capacitively coupled to the plasma
• CPC Class Codes: H01J 37/32623 Mechanical discharge control means
• CPC Class Codes: H01J 37/32633 Baffles
• CPC Class Codes: H01L 21/31116 by dry-etching

Abstract

A plasma etching apparatus for a semiconductor wafer generates plasma in a plasma generation space between a susceptor and a showerhead. A shield member is detachably disposed inside the sidewall of a process chamber to prevent reaction products from sticking to the sidewall. A window device is arranged to lead plasma light emitted from plasma out of the process chamber. The window device includes a quartz window plate airtightly attached to the sidewall of the process chamber. The window device also includes an aluminum light guide having a number of capillary through holes for guiding the plasma light to the window plate, and a sapphire cover plate disposed between the window plate and the light guide and covering the openings of the through holes. The light guide and the cover plate are attached to the shield member.

Claims

1. A plasma processing apparatus for a semiconductor processing system, comprising:

a process chamber enveloping a plasma generation space for generating plasma;

an exhaust mechanism configured to exhaust the process chamber and set the process chamber at a vacuum;

a process gas supply mechanism configured to supply a process gas into the process chamber;

an exciting mechanism configured to excite the process gas and turn the gas into plasma in the plasma generation space;

a shield member detachably disposed between a sidewall of the process chamber and the plasma generation space, and configured to prevent a reaction product derived from the plasma from sticking to the sidewall; and

a window device configured to lead plasma light emitted from the plasma out of the process chamber,

wherein the window device comprises

a window plate airtightly attached to the sidewall of the process chamber and consisting essentially of a material transmissible for the plasma light,

a light guide attached to the shield member at a position between the window plate and the plasma generation space and having a number of capillary through holes configured to guide the plasma light to the window plate, the through holes having respective inner openings facing and exposed to the plasma generation space and respective outer openings facing the window plate, the light guide consisting essentially of a material having a resistance against the plasma higher than the window plate and being not transmissible for the plasma light except the through holes, and

a cover plate attached to the shield member at a position between the window plate and the light guide and covering the outer openings of the through holes, the cover plate consisting essentially of a material having a resistance against the plasma higher than the window plate and being transmissible for the plasma light with transmissivity relative to the plasma light lower than that of the window plate, and the cover plate being thinner than the window plate and supported by the light guide in a state where the cover plate is in contact with and fixed onto a surface of the light guide.

2. The apparatus according to claim 1, wherein the cover plate consists substantially of sapphire.

3. The apparatus according to claim 2, wherein the cover plate has a thickness of from 0.2 to 1 mm.

4. The apparatus according to claim 2, wherein the window plate consists essentially of quartz.

5. The apparatus according to claim 2, wherein the cover plate consists essentially of single-crystalline sapphire.

6. The apparatus according to claim 1, wherein the through holes are oriented substantially perpendicular to a surface of the window plate.

7. The apparatus according to claim 1, further comprising a detector disposed outside the process chamber and configured to detect a state of the plasma based on the plasma light having passed through the window plate.

8. The apparatus according to claim 1, wherein the exciting mechanism comprises a pair of electrodes disposed in the process chamber and configured to form an electric field in a first direction in the plasma processing space, and a magnet disposed around the process chamber and configured to form a magnetic field in a second direction perpendicular to the first direction in the plasma generation space.

9. The apparatus according to claim 1, wherein the through holes have a diameter of 0.2 to 1.5 mm.

10. The apparatus according to claim 1, wherein the light guide consists essentially of aluminum or a ceramic material.

11. A plasma processing apparatus for a semiconductor processing system, comprising:

a process chamber enveloping a plasma generation space for generating plasma;

an exhaust mechanism configured to exhaust the process chamber and set the process chamber at a vacuum;

a process gas supply mechanism configured to supply a process gas into the process chamber;

an exciting mechanism configured to excite the process gas and turn the gas into plasma in the plasma generation space;

a shield member detachably disposed between a sidewall of the process chamber and the plasma generation space, and configured to prevent a reaction product derived from the plasma from sticking to the sidewall; and

a window device configured to lead plasma light emitted from the plasma out of the process chamber,

wherein the device comprises

a window plate airtightly attached to the sidewall of the process chamber and consisting essentially of a material transmissible for the plasma light,

a light guide attached to the shield member at a position between the window plate and the plasma generation space and having a number of capillary through holes configured to guide the plasma light to the window plate, the through holes having respective inner openings facing and exposed to the plasma generation space and respective outer openings facing the window plate, the light guide consisting essentially of a material having a resistance against the plasma higher than the window plate and being not transmissible for the plasma light except the through holes, and the through holes having a diameter of 0.2 to 1.5 mm and being oriented substantially perpendicular to a surface of the window plate, and

a cover plate attached to the shield member at a position between the window plate and the light guide and covering the outer openings of the through holes, the cover plate consisting essentially of a material having a resistance against the plasma higher than the window plate and being transmissible for the plasma light and cover plate is in contact with and fixed onto a surface of the light guide.

12. The apparatus according to claim 11, wherein the light guide consists essentially of aluminum or a ceramic material.

13. The apparatus according to claim 11, wherein the light guide comprises a first portion in which the through holes are formed, and a flange integrally formed with the first portion and extending laterally from the first portion, the first portion being fitted in a corresponding opening formed in the shield member, while the flange being fitted in a recess formed in the shield member adjacent to the corresponding opening.

14. The apparatus according to claim 11, wherein the cover plate is supported by the light guide in a state where the cover plate is in contact with and fixed onto a surface of the light guide.

15. The apparatus according to claim 11, further comprising a detector disposed outside the process chamber and configured to detect a state of the plasma based on the plasma light having passed through the window plate.