Surface state monitoring method and apparatus

• US 6,545,279 B1
• Filed: 11/18/2000
• Issued: 04/08/2003
• Est. Priority Date: 01/06/2000
• Status: Expired due to Fees

• Current Assignee: Advantest Corporation
• Original Assignee: Adramtest Corporation
• Inventors: Yoshida, Haruo, Endo, Michiaki
• Primary Examiner(s): Hannaher, Constantine
• Assistant Examiner(s): LEE, SHUN K
• Application Number:
  US09/716,863
• Time in Patent Office: 871 Days
• Field of Search: 250/341.4, 250/341.8, 250/559.36
• US Class Current: 250/341.4
• CPC Class Codes: H01L 22/26 Acting in response to an ongoing measurement without interruption of processing, e.g. endpoint detection, in-situ thickness measurement endpoint detection arrangements in CMP apparatus B24B37/013, in discharge apparatus H01J37/32

Abstract

A surface state monitoring apparatus for monitoring a surface state of semiconductor substrates by infrared spectroscopy at fabrication site of semiconductor substrates. The apparatus comprises an incidence optical system for introducing infrared radiation into a substrate-to-be-monitored, a detection optical system for detecting infrared radiation which has undergone multiple reflections inside the substrate and exited from the substrate, a surface state monitoring means for monitoring a surface state of the substrate based on the detected infrared radiation, a position detecting means for optically detecting a position of the substrate, and a control means for controlling a position and an angle at which infrared radiation to be incident on the substrate, corresponding to the position of the substrate.

Claims

1. A surface state monitoring apparatus comprising:

an incidence optical system for introducing infrared radiation into a substrate-to-be-monitored via a declined face of a peripheral edge of the substrate-to-be-monitored;

a detection optical system for detecting the infrared radiation undergoing multiple reflections inside the substrate-to-be-monitored and exiting from the substrate-to-be-monitored;

a surface state monitoring means for monitoring a surface state of the substrate-to-be-monitored, based on infrared radiation detected by the detection optical system;

a position detecting means for optically detecting a position of the substrate-to-be monitored; and

a control means for controlling a position and an angle at which the infrared radiation is incident on the substrate-to-be-monitored, corresponding to the position of the substrate-to-be-monitored detected by the position detecting means,

wherein the position detecting means optically detects a position of the substrate-to-be-monitored in consideration of a configuration of the declined face of the peripheral edge of the substrate-to-be-monitored.

2. A surface state monitoring apparatus according to claim 1, wherein

the control means controls the incidence optical system to thereby control a position and an angle at which the infrared radiation is incident on the substrate-to-be-monitored.

3. A surface state monitoring apparatus according to claim 1, wherein

the control means controls a wafer mount on which the substrate-to-be-monitored is mounted to adjust a position of the substrate-to-be-monitored to thereby control a position and an angle at which infrared radiation is incident on the substrate-to-be-monitored.

4. A surface state monitoring apparatus according to claim 1, wherein

the position detecting means is disposed above the peripheral edge of the substrate-to-be-monitored, and includes a first radiation source for applying first radiation to the peripheral edge of the substrate-to-be-monitored and a first photo detector disposed opposed to the first radiation source across the peripheral edge of the substrate-to-be-monitored, for detecting the first radiation;

and

the position detecting means detects a position of the substrate-to-be-monitored in the horizontal direction, based on a position of radiation detected by the first photo detector.

5. A surface state monitoring apparatus according to claim 4, wherein

the position detecting means includes a second radiation source for applying second radiation to the peripheral edge of the substrate-to-be-monitored and a second photo detector for detecting the second radiation reflected by the peripheral edge;

and

the position detecting means detects a vertical position of the substrate-to-be-monitored, based on a position of radiation detected by the second photo detector.

6. A surface state monitoring apparatus according to claim 5, wherein

the first radiation source and/or the second radiation source applies the first radiation and/or the second radiation to a region containing a position for the infrared radiation to be incident on the substrate-to-be-monitored.

7. A surface state monitoring apparatus according to claim 5, wherein

the first radiation source and/or the second radiation source traverses the first radiation and/or the second radiation around a position for the infrared radiation to be incident on the substrate-to-be-monitored.

8. A surface state monitoring apparatus according to claim 4, wherein

the first radiation source applies the first radiation to a region containing a position for the infrared radiation to be incident on the substrate-to-be-monitored.

9. A surface state monitoring apparatus according to claim 4, wherein

the first radiation source traverses the first radiation around a position for the infrared radiation to be incident on the substrate-to-be-monitored.

10. A surface state monitoring apparatus according to claim 4, wherein

the first radiation is radiation having a wavelength different from the wavelengths of the infrared radiation.

11. A surface state monitoring apparatus according to claim 4, wherein

the first photo detector one-dimensionally or two-dimensionally detects a position of the substrate-to-be-monitored.

12. A surface state monitoring apparatus according to claim 1, wherein

the position detecting means includes a second radiation source for applying second radiation to the peripheral edge of the substrate-to-be-monitored and a second photo detector for detecting the second radiation reflected by the peripheral edge;

and

the position detecting means detects a vertical position of the substrate-to-be-monitored, based on a position of radiation detected by the second photo detector.

13. A surface state monitoring apparatus according to claim 12, wherein

the second radiation source applies the second radiation to a region containing a position for the infrared radiation to be incident on the substrate-to-be-monitored.

14. A surface state monitoring apparatus according to claim 12, wherein

the second radiation source traverses the second radiation around a position for the infrared radiation to be incident on the substrate-to-be-monitored.

15. A surface state monitoring apparatus according to claim 12, wherein

the second radiation is radiation having a wavelength different from the wavelengths of the infrared radiation.

16. A surface state monitoring apparatus according to claim 12, wherein

the second photo detector one-dimensionally or two-dimensionally detects a position of the substrate-to-be-monitored.

17. A surface state monitoring apparatus according to claim 1, wherein

the position detecting means optically detects a position of the substrate-to-be-monitored at a plurality of positions along the peripheral edge of the substrate-to-be-monitored.

18. A surface state monitoring method for monitoring a surface state of a substrate-to-be-monitored by introducing infrared radiation into the substrate-to-be-monitored via a declined face of a peripheral edge of the substrate-to-be-monitored, detecting infrared radiation which has undergone multiple reflections inside the substrate-to-be-monitored and exited from the substrate-to-be-monitored, and analyzing the detected infrared radiation,

a position of the substrate-to-be-monitored being optically detected in consideration of a configuration of the declined face of the peripheral edge of the substrate-to-be-monitored, and a position and an angle at which infrared radiation is incident on the substrate-to-be-monitored being controlled corresponding to the detected position of the substrate-to-be-monitored.

19. A surface state monitoring method according to claim 18, wherein

when the monitoring is repeated a plurality of times with the substrate-to-be-monitored rotated to monitor a surface of the substrate-to-be-monitored substantially all over the surface, prior to the monitoring for each time, a position of the substrate-to-be-monitored is optically detected, and a position and an angle of infrared radiation to be incident on the substrate-to-be-monitored are controlled corresponding to the detected position of the substrate-to-be-monitored.