Method and its apparatus for detecting floating particles in a plasma processing chamber and an apparatus for processing a semiconductor device

• US 6,712,928 B2
• Filed: 02/26/2001
• Issued: 03/30/2004
• Est. Priority Date: 08/07/2000
• Status: Expired due to Fees

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Hitachi, Ltd.
• Inventors: Nakano, Hiroyuki, Nakata, Toshihiko
• Primary Examiner(s): Hassanzadeh, Parviz
• Application Number:
  US09/791,677
• Publication Number:
  US 20020016068A1
• Time in Patent Office: 1,128 Days
• Field of Search: 156/345.24, 156/345.25, 118/715, 118/712, 204/298.03, 204/298.32, 204/192.13, 204/192.33, 356/947, 356/948, 356/949, 356/337
• US Class Current: 156/345.24
• CPC Class Codes: C23C 14/564 Means for minimising impurities in the coating chamber such as dust, moisture, residual gases
• CPC Class Codes: C23C 16/4401 Means for minimising impurities, e.g. dust, moisture or residual gas, in the reaction chamber
• CPC Class Codes: H01J 2237/0225 Detecting or monitoring foreign particles
• CPC Class Codes: H01J 37/3299 Feedback systems

Abstract

The following operations are performed in order to allow particles suspended in a processing chamber to be detected using a single observation window and an optical system formed as a single unit and in order to provide precise detection of very weak particle-scattered light: when a desired film-forming/processing operation is being performed on a body being processed in a processing chamber, a beam that is P-polarized and that is intensity amplified at a frequency different from an excitation source frequency and integer multiples thereof is passed through an observation window sloped to form a Brewster angle relative to the P-polarized entry beam; back-scattered light scattered by particles in the processing chamber passes through the same observation window and received and imaged by a detection optical system; the frequency component described above and the intensity-modulated beam wavelength component are detected from the received light signal; and these detected components and the image information imaged as described above is used to determine the quantity, sizes, and distribution of the particles.

Claims

1. A device for detecting particles suspended in a device for processing semiconductor devices comprising:

a laser light source module outputting a laser;

a laser illumination optical system receiving a laser emitted by said laser light source and scanning a laser to illuminate inside said device for processing semiconductor devices;

a scattered light detection optical system detecting a laser scattered by a particle suspended inside said device for processing semiconductor devices and illuminated by said scanning performed by said laser illumination optical system; and

a signal processing module processing a detection signal from said scattered light detection optical system and outputting information relating to said particle suspended in said device for processing semiconductor devices;

wherein said laser light source module and said laser illumination optical system are connected by an optical fiber.

2. A device as claimed in claim 1, wherein said laser illumination optical system and said scattered light detection optical system are formed as a single unit.

3. A device as claimed in claim 1, wherein said laser light source module includes a heat sink.

4. A device as claimed in claim 1, wherein said scattered light detection optical system includes a light blocker for blocking light reflected from inner wall surfaces of said device for processing semiconductor devices.

5. A device as claimed in claim 1, wherein said scanned laser illuminating inside said device for processing semiconductor devices is intensity modulated at a desired frequency.

6. A device as claimed in claim 1, wherein said signal processing module outputs information about quantity, sizes, and distribution of particles suspended inside said device for processing semiconductor devices.

7. A device for detecting particles suspended in a processing chamber for processing semiconductor devices, comprising:

a laser light source module for outputting a laser;

a monitoring optical system for receiving a laser emitted by said laser light source, scanning a laser to illuminate inside said processing chamber, and detecting scattered light scattered by a particle suspended inside said processing chamber; and

a signal processing module for processing a detection signal from said monitoring optical system detecting said scattered light;

wherein said monitoring optical system is connected to said laser light source module and said signal processing module by optical fibers.

8. A device as claimed in claim 7, wherein said laser light source module outputs an excitation laser and said excitation laser output from said laser light source module excites a laser from said monitoring optical system that illuminates inside said processing chamber.

9. A device as claimed in claim 7, wherein said monitoring optical system can be attached to and removed from an observation window of said processing chamber.

10. A device as claimed in claim 7, wherein said signal processing module outputs information about quantity, sizes, and distribution of particles suspended inside said processing chamber.

11. A device as claimed in claim 7, wherein said monitoring optical system illuminates circularly polarized light inside said processing chamber.

12. A device as claimed in claim 7, wherein said monitoring optical system detects light scattered by particles suspended inside said processing chamber while blocking light illuminated in said processing chamber and reflected from inner wall surfaces of said processing chamber.

13. A device as claimed in claim 7, wherein said laser light source module includes a heat sink.

14. A device as claimed in claim 7, wherein said scanning laser illuminating inside said processing chamber is intensity modulated at a desired frequency.

15. A device for processing semiconductor devices comprising:

a processing chamber having an observation window allowing observation inside said processing chamber, a mounting module for mounting a substrate to be processed in said processing chamber, and a pressure setting module for maintaining a predetermined pressure inside said processing chamber;

plasma processing means for processing plasma inside said processing chamber in which said predetermined pressure is maintained, and processing said substrate mounted on said mounting module;

a laser light source module disposed outside of said processing chamber;

a laser illumination optical system for receiving a laser emitted by said laser light source by way of an optical fiber, and scanning a laser through said observation window to illuminate inside said processing chamber;

a scattered light detection optical system for detecting, through said observation window, scattered light scattered by a particle suspended inside said processing chamber and illuminated by said scanning performed by said laser illumination optical system, while said plasma processing means is processing said substrate mounted on said mounting module; and

a signal processing module for receiving and processing, by way of an optical fiber, a detection signal from said scattered light detection optical system, and outputting information relating to said particle suspended in said processing chamber.

16. A device as claimed in claim 15, wherein said laser light source module outputs an excitation laser and said excitation laser output from said laser light source module excites a laser from said laser illumination optical system that illuminates inside processing chamber.

17. A device as claimed in claim 15, wherein said laser illumination optical system and said scattered light detection optical system are formed as a single unit.

18. A device as claimed in claim 15, wherein said laser light source module includes a heat sink.

19. A device as claimed in claim 15, wherein said scattered light detection optical system includes a light blocker for blocking light reflected from inner wall surfaces of said processing chamber.

20. A device as claimed in claim 15, wherein said signal processing module outputs information about quantity, sizes, and distribution of particles suspended inside said processing chamber.

21. A device for processing semiconductor devices comprising:

a processing chamber having an observation window allowing observation inside said processing chamber, a mounting module for mounting a substrate to be processed in said processing chamber, and a pressure setting module for maintaining a predetermined pressure inside said processing chamber;

means for processing plasma inside said processing chamber in which said predetermined pressure is maintained, and processing said substrate mounted on said mounting module;

a laser light source module disposed outside of said processing chamber;

a monitoring optical system for receiving a laser emitted by said laser light source by way of an optical fiber, scanning a laser through said observation window to illuminate inside said processing chamber, and detecting, through said observation window, scattered light scattered by a particle suspended inside said processing chamber in which said plasma processing means is processing said substrate mounted on said mounting module and illuminated by said scanning performed by said laser illumination optical system; and

a signal processing module for receiving and processing, by way of an optical fiber, a detection signal from said scattered light detection optical system, and outputting information relating to said particle suspended in said processing chamber.

22. A device as claimed in claim 21, wherein said laser light source module outputs an excitation laser and said excitation laser output from said laser light source module excites a laser from said monitoring optical system that illuminates inside said processing chamber.

23. A device as claimed in claim 21, wherein said monitoring optical system can be attached to and removed from said observation window of said processing chamber.

24. A device as claimed in claim 21, wherein said monitoring optical system detects light scattered by particles suspended inside said processing chamber, while blocking light illuminated in said processing chamber and reflected from inner wall surfaces of said processing chamber.

25. A device as claimed in claim 21, wherein said laser light source module includes a heat sink.

26. A device as claimed in claim 21, wherein said signal processing module outputs information about quantity, sizes, and distribution of particles suspended inside said processing chamber.