Particle detection system

• US 5,467,188 A
• Filed: 08/19/1994
• Issued: 11/14/1995
• Est. Priority Date: 08/20/1993
• Status: Expired due to Fees

• Current Assignee: Anelva Corporation (Canon Inc.)
• Original Assignee: Anelva Corporation (Canon Inc.)
• Inventors: Miyashita, Haruzo
• Primary Examiner(s): Pham, Hoa Q.
• Application Number:
  US08/293,065
• Time in Patent Office: 452 Days
• Field of Search: 356/335-343, 356/244, 356/246, 250/574, 250/576, 250/492.2, 250/492.3, 250/397
• US Class Current: 356/336
• CPC Class Codes: G01N 15/14 Optical investigation techniques, e.g. flow cytometry

Abstract

A particle detecting system for detecting the number and size of particles generated in a process chamber of a semiconductor manufacturing system. The particle detecting system includes a small detection chamber and a particle detector. The small detection chamber not only has an internal space thereof provided outside a wall portion forming the process vacuum chamber so as to communicate with the process vacuum chamber, but also laser beam transmitting windows and scattered light extracting windows. The particle detector is arranged in an atmospheric environment outside the detection chamber and including a laser diode for emitting a laser beam into the detection chamber through the laser beam transmitting windows and photosensors for detecting scattered light generated within the detection chamber through the scattered light extracting windows. The detection chamber has such a structure as to be detachably attached to the process chamber. The particle detector is formed as a module, and can be attached to the detection chamber from outside the detection chamber. The particle detector has such a structure as to be detachably attached to the detection chamber.

Claims

1. A particle detection system for detecting the number and size of microscopic particles generated in a process vacuum chamber in which a semiconductor manufacturing process is performed, the process vacuum chamber being formed by an enclosure, the particle detection system comprising:

a detection chamber defining an internal space and being mounted outside the enclosure forming the process vacuum chamber so as to communicate with the process vacuum chamber, and a laser beam transmitting window means and a scattered light extracting window; and

a particle detector means arranged in an external atmospheric environment outside the detection chamber and including a light-emission means for emitting a laser beam into the detection chamber through the laser beam transmitting window means and a light-detection means for detecting scattered light generated within the detection chamber through the scattered light extracting window.

2. A particle detection system as claimed in claim 1, wherein the detection chamber has a structure which is attachable to and detachable from the process vacuum chamber.

3. A particle detection system as claimed in claim 2, wherein the particle detector means is formed as a single independent unit attachable to the detection chamber from outside the detection chamber, and has a structure which is attachable to and detachable from the detection chamber.

4. A particle detection system as claimed in claim 3, wherein the particle detector means is attachable to and detachable from the detection chamber by means of an opening formed in an enclosure of the particle detector means, the detection chamber being fitted into the opening.

5. A particle detection system as claimed in claim 1, wherein the particle detector means is formed as a single independent unit attachable to the detection chamber from outside the detection chamber, and has a structure which is attachable to and detachable from the detection chamber.

6. A particle detection system as claimed in claim 5, wherein the particle detector means is attachable to and detachable from the detection chamber by means of an opening formed in an enclosure of the particle detector means, the detection chamber being fitted into the opening.

7. A particle detection system as claimed in claim 1, wherein the light-detection means is arranged at a position where it can detect scattered light generated at an angle close to 90°

with respect to a laser beam path.

8. A particle detection system as claimed in claim 1, wherein the light-detection means is arranged at a position where it can detect scattered light generated at an angle within a range of 10 to 70 degrees with respect to the laser beam path.

9. A particle detection system as claimed in claim 8, wherein the laser beam transmitting window means includes the laser beam entrance window and a laser beam exit window, the laser beam exit window also being used as the scattered light extracting window.