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US5728253A Expired / Lapsed US ⏱️ 0.0 years remaining

Method and devices for detecting the end point of plasma process

Assignee: Tokyo Electron Ltd
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Filing: 1994-09-30
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Granted: 1998-03-17
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Expires: 2014-09-30
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Abstract

Abstract Disclosed herein is a method of detecting an end point of plasma process performed on an object, and a plasma process apparatus. The method includes the steps of detecting an emission spectrum over a wavelength region specific to C 2 in the plasma, by optical detecting means, and determining the end point of the plasma process from the emission intensity of the emission spectrum detected by the optical detector. The apparatus has a process chamber, a pair of electrodes, a light-collecting device, an optical detector, and a determining device. The chamber has a monitor window. The electrodes are located in the process chamber. The first electrode is used to support the object. A high-frequency power is supplied between the electrodes to change a process gas into plasma. The light-collecting device collects the light from the plasma through the monitor window. The optical detector detects an emission spectrum from the light collected. The determining device determines the end point of the plasma process from the emission intensity of the emission spectrum detected. The monitor window is secured to the distal end of a cylindrical member protruding from the chamber. The member has a narrow gas passage for trapping a gas generated by the plasma process.

Inventors

  • 👤 Susumu Saito
  • 👤 Kazuo Eguchi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 04:34
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/32917; H01J37/32935; B; B81; B81C; B81C1/00; B81C1/00436; B81C1/00555; B81C1/00563; B81C1/00587; B81C99/00; B81C99/0055; B81C99/0065; G; G01; G01N; G01N21/00; G01N21/62; G01N21/66; G01N21/68; H01J37/32963; H01J37/3299; B81C2201/00; B81C2201/01; B81C2201/0101; B81C2201/0128; B81C2201/013; B81C2201/0135; B81C2201/0142

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 175 words
A plasma process apparatus comprising: a process chamber having a monitor window; a pair of electrodes located in said process chamber, one of which is provided for supporting an object and between which a high-frequency power is supplied to change a process gas into plasma; light-collecting means for collecting light emanating from the plasma through said monitor window; first optical detecting means for detecting an emission spectrum from the light collected by said light-collecting means; and means for determining the end point of the plasma process from the emission intensity of the emission spectrum detected by said first optical detecting means; wherein said monitor window is secured to a distal end of a cylindrical member protruding from said process chamber, and said cylindrical member has an annular portion provided on an inner surface of said cylindrical member and a cylindrical portion provided on an end portion of said annular portion, said annular portion and said cylindrical portion constituting a narrow gas passage and defining a region for trapping a gas generated in the plasma process.
Claim 2
Dependent Claim 175 words
A plasma process apparatus comprising: a process chamber having a monitor window; a pair of electrodes located in said process chamber, one of which is provided for supporting an object and between which a high-frequency power is supplied to change a process gas into plasma; light-collecting means for collecting light emanating from the plasma through said monitor window; first optical detecting means for detecting an emission spectrum from the light collected by said light-collecting means; and means for determining the end point of the plasma process from the emission intensity of the emission spectrum detected by said first optical detecting means; wherein said monitor window is secured to a distal end of a cylindrical member protruding from said process chamber, and said cylindrical member has an annular portion provided on an inner surface of said cylindrical member and a cylindrical portion provided on an end portion of said annular portion, said annular portion and said cylindrical portion constituting a narrow gas passage and defining a region for trapping a gas generated in the plasma process.
Claim 3
Dependent Claim 13 words
An apparatus according to claim 1, wherein said cylindrical member comprises temperature-adjusting means.
Claim 4
Dependent Claim 31 words
An apparatus according to claim 1, further comprising second optical detecting means for detecting an emission spectrum over a wavelength region specific to an active species generated during the plasma process.
Claim 5
Dependent Claim 47 words
An apparatus according to claim 3, further comprising further comprising calculation means for calculating a ratio or difference between the emission intensity of the emission spectrum detected by said first optical detecting means and the emission intensity of the emission spectrum detected by said second optical means.
Claim 6
Dependent Claim 42 words
An apparatus according to claim 1, wherein a ratio (D/d) of an inside diameter D of that opening portion of said cylindrical member which communicates with said process chamber to an inside diameter d of said cylindrical member is 0.2 to 0.7.
Claim 7
Dependent Claim 18 words
An apparatus according to claim 1, wherein said cylindrical member has a length of 5 to 30 mm.
Claim 8
Dependent Claim 14 words
An apparatus according to claim 1, wherein said cylindrical member has a tapered shape.
Claim 9
Dependent Claim 34 words
An apparatus according to claim 1, wherein said process chamber is separated from said annular portion such that a shortest distance between said process chamber and said annular portion is 5 to 30 mm.
Claim 10
Dependent Claim 14 words
An apparatus according to claim 2, wherein said temperature-adjusting means is a cooling jacket.
Claim 11
Dependent Claim 13 words
An apparatus according to claim 2, wherein said temperature-adjusting means is a heater.

References Cited (Backward Citations)

US4812416A Cited
US4857136A Cited
US5322590A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2001-03-16 2001-09-15 2002-03-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2005-03-16 2005-09-15 2006-03-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2009-03-16 2009-09-15 2010-03-17 $7700.00 Window Closed / Lapsed

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