Method and apparatus for determining endpoint of semiconductor element fabricating process

• US 20060132798A1
• Filed: 01/27/2006
• Published: 06/22/2006
• Est. Priority Date: 09/06/2001
• Status: Active Grant

• Current Assignee: Hideyuki Yamamoto, Motohiko Yoshigai, Takashi Fujii, Tatehito Usui, Tetsunori Kaji
• Original Assignee: Hideyuki Yamamoto, Motohiko Yoshigai, Takashi Fujii, Tatehito Usui, Tetsunori Kaji
• Inventors: Fujii, Takashi, Yoshigai, Motohiko, Usui, Tatehito, Yamamoto, Hideyuki, Kaji, Tetsunori
• Granted Patent: US 7,126,697 B2
• Time in Patent Office: Days
• US Class Current: 356/504
• CPC Class Codes: G01B 11/0675 using interferometry
• CPC Class Codes: H01J 37/32963 End-point detection
• 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

Standard patterns of differential values of interference light that correspond to a predetermined step height of the first material being processed and standard patterns of differential values of interference light that correspond to a predetermined remaining mask layer thickness of the material are set. These standard patterns use wavelengths as parameters. Then, the intensities of interference light of multiple wavelengths are measured for a second material that has the same structure as the first material. Actual patterns with wavelength as parameter are determined from differential values of the measured interference light intensities. Based on the standard patterns and the actual patterns of the differential values, the step height and the remaining mask layer thickness of the second material are determined.

Claims

1. A method of measuring an etch quantity of a material being processed, comprising:

a) setting standard patterns (P_S) of time differential values of values relating to an interference light from a first material to be processed that respectively correspond to a plurality of predetermined etch quantities of the first material including a mask layer, the standard patterns using the wavelength as a parameter;

b) measuring values relating to an interference light of multiple wavelengths from a second material being processed of same structure as the first material and determining actual patterns of differential values of the measured values relating to the interference light, the actual patterns using the wavelength as a parameter;

c) determining an etch quantity of the second material based on the standard patterns of the first material and the actual patterns; and

d) obtaining a time change value of the etch quantity of the second material based on the etch quantity of the second material at a first time point and the etch quantity of the second material at a second time point obtained in the c) operation.