US 8,554,356 B2 · Processing end point detection method, polishing method, and polishing apparatus

Abstract

A processing end point detection method detects a timing of a processing end point (e.g., polishing stop, changing of polishing conditions) by calculating a characteristic value of a surface of a workpiece (an object of polishing) such as a substrate. This method includes producing a spectral waveform indicating a relationship between reflection intensities and wavelengths at a processing end point, with use of a reference workpiece or simulation calculation, based on the spectral waveform, selecting wavelengths of a local maximum value and a local minimum value of the reflection intensities, calculating the characteristic value with respect to a surface, to be processed, from reflection intensities at the selected wavelengths, setting a distinctive point of time variation of the characteristic value at a processing end point of the workpiece as the processing end point, and detecting the processing end point of the workpiece by detecting the distinctive point during processing of the workpiece.

Drawings

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Drawings

Claims9

Dependent claims

A processing end point detection method for detecting a processing end point based on a characteristic value with respect to a surface of a workpiece, the characteristic value being calculated using a spectral waveform of reflected light obtained by applying light to the surface of the workpiece, said method comprising:

producing a reference spectral waveform indicating a relationship between reflection intensities and wavelengths at a processing end point of a surface of a reference workpiece;
based on the reference spectral waveform, selecting wavelengths of a local maximum value and a local minimum value of the reflection intensities at the processing end point of the reference workpiece prior to processing a workpiece;
calculating a characteristic value with respect to the surface of the reference workpiece from the reflection intensities at the selected wavelengths;
setting a distinctive point of time variation of the characteristic value at the processing end point of the reference workpiece as a processing end point of a workpiece;
processing a surface of the workpiece that corresponds to the surface of the reference workpiece while monitoring a characteristic value of the surface of the workpiece;
and
detecting the processing end point of the workpiece by detecting the distinctive point of time variation during the processing of the workpiece.

4 more elements

A processing apparatus comprising:

a light source configured to apply light to a surface of a workpiece;
a light-receiving unit configured to receive reflected light from the surface of the workpiece;
a spectroscope unit configured to divide the reflected light received by said light-receiving unit into a plurality of light rays and convert the light rays into electrical information;
and
a processor configured to process the electrical information from said spectroscope unit,
wherein said processor is configured to
average reflection intensities at each of a plurality of wavelengths over a processing time of a surface of a reference workpiece to determine an average reflection intensity at each of the wavelengths,
produce a reference spectral waveform by dividing each of the reflection intensities, obtained at a processing end point of the reference workpiece, by a corresponding one of the average reflection intensities,
select wavelengths of a local maximum value and a local minimum value of the reference spectral waveform at the processing end point of the reference workpiece,
calculate a characteristic value with respect to the surface of the reference workpiece from the reflection intensities at the selected wavelengths,
set a distinctive point of time variation of the characteristic value at the processing end point of the reference workpiece as a processing end point of the workpiece, and
detect the processing end point of the workpiece by detecting the distinctive point of time variation during processing of a surface of the workpiece that corresponds to the surface of the reference workpiece.

9 more elements

Dependencies are inferred from the claim text.

Description17,709 words

Summary4,054 words

#The present invention relates to a processing end point detection method for detecting a timing of a processing end point (e.g., polishing stop, changing of polishing conditions, etching stop, film-formation stop, and the like) by calculating a characteristic value of a surface of a workpiece (an object of polishing) such as a substrate.

#The present invention also relates to a polishing method and polishing apparatus for polishing a substrate, such as a semiconductor wafer, to planarize the substrate.

#The trend of recent years in a semiconductor device has been a highly integrated structure, which requires fine interconnects and multi-layered structure. To realize the fine interconnects and the multi-layered structure, it is necessary to planarize a surface of a substrate. Chemical mechanical polishing (CMP) is conventionally used to remove irregularities from the surface of the substrate to thereby planarize the surface.

Brief description of the drawings27 figures

#FIG. 2 is a diagram showing the operation of light-receiving elements in a spectroscope unit in a case where a pulsed light source is used in the polishing state monitoring apparatus shown in FIG. 1;

#FIG. 3 is a diagram showing the operation of light-receiving elements in a spectroscope unit in a case where a continuous light source is used in the polishing state monitoring apparatus shown in FIG. 1;

Detailed description12,936 words

#Embodiments of the present invention will be described in detail below with reference to the drawings.

#FIG. 1 is a schematic view showing an overall arrangement of a polishing apparatus capable of performing a method of detecting a polishing end point according to an embodiment of the present invention. As shown in FIG. 1, the polishing apparatus has a polishing table 12 with a polishing pad 10 attached to an upper surface thereof, and a top ring 14 for holding a substrate W, which is a workpiece (object to be polished) and pressing the substrate W against an upper surface of the polishing pad 10. The upper surface of the polishing pad 10 serves as a polishing surface providing a sliding contact with the substrate W. An upper surface of a fixed abrasive plate containing fine abrasive particles (made of CeO2 or the like) fixed by a binder, such as resin, may be used as a polishing surface.

#The polishing table 12 is coupled to a motor (not shown) disposed therebelow, and is rotatable about its own axis as indicated by arrow. A polishing liquid supply nozzle 16 is disposed above the polishing table 12 and supplies a polishing liquid Q onto the polishing pad 10.

Facts

Application

12/311,560Filed 5 Oct 2007

Priority

JP 2006-2746226 Oct 2006

Published

US 2010/0015889 A121 Jan 2010

Granted

8 Oct 2013

Term ends

22 Sep 2030

Estimated · how

20 years from earliest known nonprovisional domestic filing plus recorded patent term adjustment, including 1,083 days of adjustment. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification17 codes

B24B 49/04
According to the instantaneous size and required size of the workpiece acted upon, the measuring or gauging being continuous or intermittent:…
B24B 37/013
Control means for lapping machines or devices: devices or means for detecting lapping completion
B24B 49/12
Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring…
B24D 7/12
Bonded abrasive wheels, or wheels with inserted abrasive blocks, designed for acting otherwise than only by their periphery, e.g. by the front…:…

Timeline

6 Oct 2006Priority claimedJP 2006-274622
5 Oct 2007Application filedUS 12/311,560
3 Apr 2009Assigned to Ebara Corporation, Kabushiki Kaisha Toshibaassignment of assignor's interest
21 Jan 2010PublishedUS 2010/0015889 A1
8 Oct 2013GrantedUS 8,554,356 B2
11 Sep 2017Assigned to Toshiba Memory Corporationassignment of assignor's interest
23 Dec 2021Assigned to K.K. Pangeamerger
23 Dec 2021Assigned to Toshiba Memory Corporationchange of name
23 Dec 2021Assigned to Kioxia Corporationchange of name
12 Oct 2026TodayWithin its term
22 Sep 2030Term endsEstimated, includes 1,083 days of adjustment

Processing end point detection method, polishing method, and polishing apparatus

Life of this patent

Processing end point detection method, polishing method, and polishing apparatus

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims9

Description17,709 words

Drawings

Classification17 codes

Life of this patent

Description17,709 words