US4680084A
Expired / Lapsed
US
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Interferometric methods and apparatus for device fabrication
Assignee: Nokia Bell Labs
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Filing: 1984-08-21
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Granted: 1987-07-14
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Expires: 2004-08-21
Abstract
Abstract The invention involves new etch monitoring and thickness measurement techniques which are more accurate than previous techniques. In accordance with the invention, the etch depth of a substrate region undergoing etching is monitored, or the thickness of the region is measured, by impinging the region with light and detecting the intensity of the reflected light. In contrast to the previous techniques, the incident light is chosen so that a substrate region underlying, and/or a patterned substrate region overlying the substrate region of interest is substantially opaque to the incident light, which precludes the formation of signals unrelated to etch depth or thickness.
Inventors
- 👤 Peter A. Heimann
- 👤 Joseph M. Moran
- 👤 Ronald J. Schutz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:36
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/02; G01B11/06; G01B11/0616; G01B11/0683
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
118 words
A method for fabricating a device, comprising the steps of: etching at least a portion of a first region of a substrate, which first region overlies a second region of said substrate; monitoring said etching by illuminating an area of said first region being etched with light and detecting the intensity of at least a portion of the light reflected from said first region; terminating said etching based on the detected intensity; and completing the fabrication of said device, Characterized In That said illuminating light includes nonvisible light which is chosen in relation to said first and second regions so that said first region is substantially transparent, and said second region is substantially opaque, to said nonvisible light.
Claim 2
Independent Claim
118 words
A method for fabricating a device, comprising the steps of: etching at least a portion of a first region of a substrate, which first region overlies a second region of said substrate; monitoring said etching by illuminating an area of said first region being etched with light and detecting the intensity of at least a portion of the light reflected from said first region; terminating said etching based on the detected intensity; and completing the fabrication of said device, Characterized In That said illuminating light includes nonvisible light which is chosen in relation to said first and second regions so that said first region is substantially transparent, and said second region is substantially opaque, to said nonvisible light.
Claim 3
Dependent Claim
16 words
The method of claim 1 wherein said first region is removed subsequent to said terminating step.
Claim 4
Dependent Claim
16 words
The method of claim 1 wherein said second region is removed subsequent to said terminating step.
Claim 5
Independent Claim
134 words
A method for fabricating a device, comprising the steps of: forming a sacrificial coating overlying a substrate, said coating including a first region overlying a second region; etching at least a portion of said first region; monitoring said etching by illuminating an area of said first region being etched with light and detecting the intensity of at least a portion of the light reflected from said first region; terminating said etching based on the detected intensity; and completing the fabrication of said device, said completing step including the step of removing said sacrificial coating, Characterized In That said illuminating light is chosen in relation to said first and second regions so that said first region is substantially transparent, and said second region is substantially opaque, to at least a portion of the illuminating light.
Claim 6
Independent Claim
134 words
A method for fabricating a device, comprising the steps of: forming a sacrificial coating overlying a substrate, said coating including a first region overlying a second region; etching at least a portion of said first region; monitoring said etching by illuminating an area of said first region being etched with light and detecting the intensity of at least a portion of the light reflected from said first region; terminating said etching based on the detected intensity; and completing the fabrication of said device, said completing step including the step of removing said sacrificial coating, Characterized In That said illuminating light is chosen in relation to said first and second regions so that said first region is substantially transparent, and said second region is substantially opaque, to at least a portion of the illuminating light.
Claim 7
Independent Claim
100 words
A method for fabricating a device, comprising the steps of: measuring a thickness of a first region of a substrate overlying a second region of said substrate by illuminating an area of said first region with light and detecting the intensity of at least a portion of the light reflected from said first region; and completing the fabrication of said device, Characterized In That said illuminating light includes nonvisible light which is chosen in relation to said first and second regions so that said first region is substantially transparent, and said second region is substantially opaque, to said nonvisible light.
Claim 8
Independent Claim
100 words
A method for fabricating a device, comprising the steps of: measuring a thickness of a first region of a substrate overlying a second region of said substrate by illuminating an area of said first region with light and detecting the intensity of at least a portion of the light reflected from said first region; and completing the fabrication of said device, Characterized In That said illuminating light includes nonvisible light which is chosen in relation to said first and second regions so that said first region is substantially transparent, and said second region is substantially opaque, to said nonvisible light.
Claim 9
Dependent Claim
37 words
The method of claim 5 wherein said completing step includes the step of etching at least a portion of said first region, the etching time being determined, in part, by the measured thickness of said first region.
Claim 10
Dependent Claim
23 words
The method of claim 6 wherein said completing step further includes the step of removing said first region subsequent to said etching step.
Claim 11
Dependent Claim
19 words
The method of claim 7 wherein said completing step still further includes the step of removing said second region.
Claim 12
Dependent Claim
26 words
The method of claim 5 wherein said completing step includes the step of altering a thickness of said first region in response to the measured thickness.
Claim 13
Independent Claim
143 words
A method for fabricating a device, comprising the steps of: forming a sacrificial coating overlying a substrate, said coating including a first region overlying a second region; measuring a thickness of said first region by illuminating an area of said first region with light and detecting the intensity of at least a portion of the light reflected from said first region; etching at least a portion of said first region, the etching time being determined, in part, by the measured thickness of said first region; and completing the fabrication of said device, said completing step including the step of removing said sacrificial coating, Characterized In That said illuminating light is chosen in relation to said first and second regions so that said first region is substantially transparent, and said second region is substantially opaque, to at least a portion of the illuminating light.
Claim 14
Independent Claim
143 words
A method for fabricating a device, comprising the steps of: forming a sacrificial coating overlying a substrate, said coating including a first region overlying a second region; measuring a thickness of said first region by illuminating an area of said first region with light and detecting the intensity of at least a portion of the light reflected from said first region; etching at least a portion of said first region, the etching time being determined, in part, by the measured thickness of said first region; and completing the fabrication of said device, said completing step including the step of removing said sacrificial coating, Characterized In That said illuminating light is chosen in relation to said first and second regions so that said first region is substantially transparent, and said second region is substantially opaque, to at least a portion of the illuminating light.
Claim 15
Independent Claim
125 words
A method for fabricating a device, comprising the steps of: forming a patterned first region of a substrate, which first region overlies a second region of said substrate; etching said second region while using said patterned first region as an etch mask; monitoring the etching of said second region by illuminating at least a portion of said second region being etched with light, and detecting the intensity of at least a portion of the light reflected from said second region; terminating said etching based on the detected intensity; and completing the fabrication of said device, Characterized In That said illuminating light includes nonvisible light which is chosen in relation to said first region so that said first region is substantially opaque to said nonvisible light.
Claim 16
Independent Claim
125 words
A method for fabricating a device, comprising the steps of: forming a patterned first region of a substrate, which first region overlies a second region of said substrate; etching said second region while using said patterned first region as an etch mask; monitoring the etching of said second region by illuminating at least a portion of said second region being etched with light, and detecting the intensity of at least a portion of the light reflected from said second region; terminating said etching based on the detected intensity; and completing the fabrication of said device, Characterized In That said illuminating light includes nonvisible light which is chosen in relation to said first region so that said first region is substantially opaque to said nonvisible light.
Claim 17
Dependent Claim
17 words
The method of claim 11 wherein said completing step includes the step of removing said first region.
Claim 18
Independent Claim
134 words
A method of fabricating a device, comprising the steps of: forming a patterned sacrificial coating overlying a substrate, said coating including a material substantially free of metallic atoms in their zero oxidation state; etching said substrate while using said patterned coating as an etch mask; monitoring said etching by illuminating at least a portion of the substrate being etched with light, and detecting the intensity of at least a portion of the light reflected from the substrate; terminating said etching based on the detected intensity; and completing the fabrication of said device, said completing step including the step of removing said patterned sacrificial coating, Characterized In That said illuminating light is chosen in relation to said sacrificial coating so that said coating is substantially opaque to at least a portion of the illuminating light.
Claim 19
Independent Claim
134 words
A method of fabricating a device, comprising the steps of: forming a patterned sacrificial coating overlying a substrate, said coating including a material substantially free of metallic atoms in their zero oxidation state; etching said substrate while using said patterned coating as an etch mask; monitoring said etching by illuminating at least a portion of the substrate being etched with light, and detecting the intensity of at least a portion of the light reflected from the substrate; terminating said etching based on the detected intensity; and completing the fabrication of said device, said completing step including the step of removing said patterned sacrificial coating, Characterized In That said illuminating light is chosen in relation to said sacrificial coating so that said coating is substantially opaque to at least a portion of the illuminating light.
Claim 20
Dependent Claim
47 words
An etching machine, comprising: an etching reactor; first means for illuminating a substrate within said reactor with light; second means for sensing at least a portion of the light reflected from said substrate, Characterized In That at least a portion of the illuminating light is nonvisible light.
Claim 21
Dependent Claim
47 words
An etching machine, comprising: an etching reactor; first means for illuminating a substrate within said reactor with light; second means for sensing at least a portion of the light reflected from said substrate, Characterized In That at least a portion of the illuminating light is nonvisible light.
Claim 22
Dependent Claim
13 words
The etching machine of claim 14 wherein said nonvisible light is UV light.
References Cited (Backward Citations)
US4454001A
Cited
US4482424A
Cited
USPTO Annuity & Maintenance Windows
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| 3.5 Years (Year 4) | 1990-07-13 | 1991-01-12 | 1991-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-13 | 1995-01-12 | 1995-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-13 | 1999-01-12 | 1999-07-14 | $7700.00 | Window Closed / Lapsed |