US5504328A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Endpoint detection utilizing ultraviolet mass spectrometry
Assignee: SUNY Polytechnic Institute
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Filing: 1994-12-09
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Granted: 1996-04-02
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Expires: 2014-12-09
Abstract
Abstract An apparatus and method for detecting the endpoint of an etch during semiconductor fabrication is provided. The endpoint detection system utilizes a mass spectrometer having an energy source located outside the vacuum chamber of the endpoint detection system, thus providing an easily replaceable energy source. The energy source may be a light source to provide photo-ionization. The energy source may be selected based upon the gas species of the etch of which an endpoint as being detected. The energy is directed into an ionization chamber of the endpoint detection system through a transparent window.
Inventors
- 👤 Douglas J. Bonser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:24
CPC Classifications
H; H01; H01J; H01J49/00; H01J49/02; H01J49/10; H01J49/16
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
100 words
An endpoint detection system for detecting an endpoint condition in a semiconductor etch apparatus comprising: a housing, said housing attachable to said etch apparatus to allow a process gas from said etch apparatus to enter said housing; an ionization chamber within said housing; a mass spectrometer filter within said housing; an ion detector for receiving ions that pass through said filter; and an ionization energy source located outside said ionization chamber for ionizing said process gas in said ionization chamber so that said ionization energy source accessed without affecting a subatmospheric pressure within said ionization chamber and said etch apparatus.
Claim 2
Dependent Claim
100 words
An endpoint detection system for detecting an endpoint condition in a semiconductor etch apparatus comprising: a housing, said housing attachable to said etch apparatus to allow a process gas from said etch apparatus to enter said housing; an ionization chamber within said housing; a mass spectrometer filter within said housing; an ion detector for receiving ions that pass through said filter; and an ionization energy source located outside said ionization chamber for ionizing said process gas in said ionization chamber so that said ionization energy source accessed without affecting a subatmospheric pressure within said ionization chamber and said etch apparatus.
Claim 3
Dependent Claim
17 words
The endpoint detection system of claim 1 wherein said ionization energy source is an electromagnetic energy source.
Claim 4
Dependent Claim
29 words
The endpoint detection system of claim 2 wherein said electromagnetic energy source is a light source, said light source causing photo-ionization of said process gas in said ionization chamber.
Claim 5
Dependent Claim
34 words
The endpoint detection system of claim 3, wherein said housing further comprises: a mounting mechanism located at one end of said housing for attaching said housing to a process chamber of said etch apparatus.
Claim 6
Dependent Claim
38 words
The endpoint detection system of claim 3, wherein said housing further comprises: a mounting mechanism located at one end of said housing for attaching said housing to a line downstream of a process chamber of said etch apparatus.
Claim 7
Dependent Claim
31 words
The endpoint detection system of claim 1, further comprising: a window attached to said housing between said ionization chamber and said ionization energy source for transmitting energy into said ionization chamber.
Claim 8
Dependent Claim
16 words
The endpoint detection system of claim 6 wherein said ionization energy source is a light source.
Claim 9
Dependent Claim
19 words
The endpoint detection system of claim 7, further comprising: focussing optics located between said light source and said window.
Claim 10
Dependent Claim
21 words
The endpoint detection system of claim 8, wherein said housing includes a flange for attaching said housing to said etch apparatus.
Claim 11
Dependent Claim
48 words
The endpoint detection system of claim 7 wherein said mass spectrometer filter is a quadrupole mass filter and said ion detector is a Faraday cup, said endpoint detection system further comprising: a focusing lens within said housing and located between said ionization chamber and said mass spectrometer filter.
Claim 12
Dependent Claim
109 words
An endpoint detection system for detecting an endpoint condition in a semiconductor etch apparatus comprising: a housing, said housing attachable to said etch apparatus to allow a process gas from said etch apparatus to enter said housing; an ionization chamber within said housing; a mass spectrometer filter within said housing; an ion detector for receiving ions that pass through said filter; and a light energy source for providing energy to photo-ionize said process gas in said ionization chamber said light energy source being located outside of said ionization chamber, so that said energy source is accessed without affecting a subatmosphere pressure within said ionization chamber and said etch apparatus.
Claim 13
Dependent Claim
109 words
An endpoint detection system for detecting an endpoint condition in a semiconductor etch apparatus comprising: a housing, said housing attachable to said etch apparatus to allow a process gas from said etch apparatus to enter said housing; an ionization chamber within said housing; a mass spectrometer filter within said housing; an ion detector for receiving ions that pass through said filter; and a light energy source for providing energy to photo-ionize said process gas in said ionization chamber said light energy source being located outside of said ionization chamber, so that said energy source is accessed without affecting a subatmosphere pressure within said ionization chamber and said etch apparatus.
Claim 14
Dependent Claim
26 words
The endpoint detection system of claim 11, further comprising: a window between said ionization chamber and said energy source for transmitting energy into said ionization chamber.
Claim 15
Dependent Claim
17 words
The endpoint detection system of claim 12 wherein said mass spectrometer filter is a quadrupole mass filter.
Claim 16
Independent Claim
89 words
A method for detecting an endpoint in an etching apparatus comprising the steps of: allowing a process gas of said etching apparatus to enter an ionization chamber of an endpoint detection system; transmitting energy into said ionization chamber from an ionization energy source outside of said ionization chamber to ionize said process gas said energy source being accessible without affecting a subatmospheric pressure within said ionization chamber and said etching apparatus; filtering ions from said ionization chamber according to a mass of said ions; and detecting said filtered ions.
Claim 17
Independent Claim
89 words
A method for detecting an endpoint in an etching apparatus comprising the steps of: allowing a process gas of said etching apparatus to enter an ionization chamber of an endpoint detection system; transmitting energy into said ionization chamber from an ionization energy source outside of said ionization chamber to ionize said process gas said energy source being accessible without affecting a subatmospheric pressure within said ionization chamber and said etching apparatus; filtering ions from said ionization chamber according to a mass of said ions; and detecting said filtered ions.
Claim 18
Dependent Claim
18 words
The method of claim 14, further comprising the step of: photo-ionizing said process gas in said ionization chamber.
Claim 19
Dependent Claim
22 words
The method of claim 14, further comprising the step of: passing said energy through a window before said energy enters said chamber.
Claim 20
Dependent Claim
39 words
The method of claim 14, further comprising the step of: focusing said ions with a lens, wherein said step of filtering is performed with a quadruple mass filter and said step of detecting is performed with a Faraday cup.
Claim 21
Dependent Claim
15 words
The method of claim 14, wherein said ionization energy source is an electromagnetic energy source.
Claim 22
Dependent Claim
33 words
The method of claim 18, wherein said ionization energy source is a light source, said method further comprising the step of: passing said energy through a window before said energy enters said chamber.
Claim 23
Dependent Claim
26 words
The method of claim 18, wherein said allowing step further comprises the step of: obtaining said process gas from a process chamber of said etching apparatus.
Claim 24
Dependent Claim
30 words
The method of claim 18, wherein said allowing step further comprises the step of: obtaining said process gas from a line downstream of a process chamber of said etching apparatus.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-04-02 | 1999-10-02 | 2000-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-04-02 | 2003-10-02 | 2004-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-04-02 | 2007-10-02 | 2008-04-02 | $7700.00 | Window Closed / Lapsed |