US4430151A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of monitoring status of a silicon layer by detecting, emission spectra variable during etching
Assignee: Canon Anelva Corp
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Filing: 1983-06-09
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Granted: 1984-02-07
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Expires: 2003-06-09
Abstract
Abstract In a monitoring method of monitoring status of a silicon layer etched in a hollow space by plasma, a chlorine including gas is introduced into a hollow space to cause CCl-radical to occur in the hollow space. A first spectrum region is selected to detect first emission spectra of the CCl-radical which are variable in intensity only during the etching and which may include a wavelength of 307 nm. Preferably, a second spectrum region is selected to second emission spectra invariable even during the etching and to indicate the beginning and the end of the etching by monitoring a relationship between the first and the second emission spectra. The second spectrum region may include a wavelength of 396 nm. Alternatively, emission spectra of OH-radical which results from water remaining in the hollow space may be monitored as the first emission spectra.
Inventors
- 👤 Tsutomu Tsukada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 08:07
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/24; H10P50/242; G; G01; G01N; G01N21/00; G01N21/62; H01; H01J; H01J37/00; H01J37/32; H01J37/32917; H01J37/32935
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
129 words
A method for use in etching a layer of silicon by plasma in a chlorine including gas filled in a hollow space, to distinguish between a first and a second duration which said layer is being etched and not, respectively, said plasma producing CCl- and OH-radicals whch result from said chlorine including gas and from water remaining as a remnant in said hollow space, respectively, said method coprising the steps of: selecting emission spectra which result from a preselected one of said CCl- and said OH-radicals and which are variable in intensity at a transition time instant between said first and said second durations; and monitoring said intensity of said emission spectra to detect said transition time instant and to, thereby, distinguish between said first and said second durations.
Claim 2
Independent Claim
129 words
A method for use in etching a layer of silicon by plasma in a chlorine including gas filled in a hollow space, to distinguish between a first and a second duration which said layer is being etched and not, respectively, said plasma producing CCl- and OH-radicals whch result from said chlorine including gas and from water remaining as a remnant in said hollow space, respectively, said method coprising the steps of: selecting emission spectra which result from a preselected one of said CCl- and said OH-radicals and which are variable in intensity at a transition time instant between said first and said second durations; and monitoring said intensity of said emission spectra to detect said transition time instant and to, thereby, distinguish between said first and said second durations.
Claim 3
Dependent Claim
27 words
A method as claimed in claim 1, wherein said preselected radical is said OH-radical, the emission spectra of said OH-radical being laid in a predetermined spectrum region.
Claim 4
Dependent Claim
18 words
A method as claimed in claim 2, wherein said predetermined spectrum region includes a wavelength of 307 nm.
Claim 5
Dependent Claim
27 words
A method as claimed in claim 1, wherein said preselected radical is said CCl-radical, the emission spectra of said CCl-radical being laid in a prescribed spectrum region.
Claim 6
Dependent Claim
18 words
A method as claimed in claim 4, wherein said prescribed spectrum region includes a wavelength of 307 nm.
Claim 7
Dependent Claim
15 words
A method as claimed in claim 1, wherein said chlorine including gas comprises carbon tetrachloride.
Claim 8
Dependent Claim
34 words
A method as claimed in claim 6, wherein said chlorine including gas further comprises at least one additional gas selected from a group consisting of inert gases, an oxygen gas, and a nitrogen gas.
Claim 9
Dependent Claim
15 words
A method as claimed in claim 7, wherein said additional gas comprises a helium gas.
Claim 10
Dependent Claim
16 words
A method as claimed in claim 8, wherein said additional gas further comprises said oxygen gas.
Claim 11
Dependent Claim
13 words
A method as claimed in claim 1, wherein said layer comprises polycrystalline silicon.
Claim 12
Dependent Claim
24 words
A method as claimed in claim 10, wherein said layer comprises at least one of phosphorus, boron, and arsenic doped in said polycrystalline silicon.
Claim 13
Dependent Claim
60 words
A method as claimed in claim 1, further comprising the step of: further selecting additional spectra invariable in intensity at said transition time instant; said monitoring step comprising the steps of: detecting a relationship between the intensities of said emission spectra and said additional emission spectra; and distinguishing between said first and said second durations in consideration of said relationship.
Claim 14
Dependent Claim
22 words
A method as claimed in claim 12, wherein said additional emission spectra comprises a spectrum region including a wavelength of 396 nm.
References Cited (Backward Citations)
US4289188A
Cited
US4367044A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-02-06 | 1987-08-08 | 1988-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-06 | 1991-08-08 | 1992-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-06 | 1995-08-08 | 1996-02-07 | $7700.00 | Window Closed / Lapsed |