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Patent US5347138A successfully refreshed from Google Patents.
US5347138A
Expired / Lapsed
US
⏱️ 0.0 years remaining
In situ real time particle monitor for a sputter coater chamber
Assignee: Hach Co
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Filing: 1993-04-01
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Granted: 1994-09-13
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Expires: 2013-04-01
Abstract
Abstract A structure and a method use a non-invasive particle monitor to detect particles in a process chamber for a "down sputtering" metal deposition process. In one embodiment, only non-spherical particles are detected using a single laser beam of a predetermined polarization is used, and the phase shift in the polarization due to the passing of a particle through the laser beam is measured. In another embodiment, two closely spaced orthogonally polarized laser beams are used, and the differential intensity of the laser beams is measured when a particle passes through one of the laser beams. In another embodiment, shield tubes for housing optical components are used to prevent coating of the optical components and to prevent deposition to take place outside the shielded area. Internal electric and magnetic fields are used to drive particles through the laser beams for particle detection.
Inventors
- 👤 Derek G. Aqui
- 👤 Peter G. Borden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 03:27
CPC Classifications
G; G01; G01N; G01N15/00; G01N15/02; G01N15/0205; G01N2015/0238; G01N21/00; G01N21/17; G01N21/47; G01N2021/4792; G01N21/84; G01N21/88; G01N21/94
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
91 words
An apparatus for monitoring particles in a process chamber for a sputter deposition process using plasma, said process chamber having first and second ports allowing access to said plasma in said process chamber, comprising: a laser source for providing an incident laser beam; a set of optical components for collimating, polarizing and focussing said laser beam through said first and second ports on said plasma; and a detector for detecting from a measurement of the phase of said incident laser beam particles in said plasma passing through said incident laser beam.
Claim 2
Independent Claim
91 words
An apparatus for monitoring particles in a process chamber for a sputter deposition process using plasma, said process chamber having first and second ports allowing access to said plasma in said process chamber, comprising: a laser source for providing an incident laser beam; a set of optical components for collimating, polarizing and focussing said laser beam through said first and second ports on said plasma; and a detector for detecting from a measurement of the phase of said incident laser beam particles in said plasma passing through said incident laser beam.
Claim 3
Dependent Claim
80 words
An apparatus as in claim 1, further comprising: a first shield tube attached to said first port of said process chamber, said first shield tube allowing said incident laser beam to pass into said process chamber thereby allowing said incident laser beam to pass through said plasma; and a second shield tube attached to said second port of said process chamber, said second shield tube allowing said incident laser beam, having passed through said plasma, to exit said process chamber.
Claim 4
Dependent Claim
33 words
An apparatus as in claim 1, wherein said incident laser beam having a predetermined polarization, and wherein said detector detects a phase shift in polarization in said incident laser beam of predetermined polarization.
Claim 5
Dependent Claim
100 words
An apparatus as in claim 1, wherein said set of optical components split said incident laser beam into orthogonally polarized first and second laser beams, said first and second laser beam being spaced in a predetermined distance, such that both said first and second laser beam pass into said process chamber through said first shield tube, pass through said plasma and exit from said process chamber through said second shield tube; and wherein said detector detects a difference in intensity between said first and second laser beams when a particle passes through one of said first and second laser beams.
Claim 6
Dependent Claim
35 words
An apparatus as in claim 1, wherein said laser beam has an oval cross section oriented such that the major axis of said cross section is aligned substantially perpendicular to a direction of particle flow.
Claim 7
Dependent Claim
37 words
An apparatus as in claim 2, wherein said first and second shield tubes each a length greater than three mean free paths of said particles and a width less than one mean free path of said particles.
Claim 8
Dependent Claim
18 words
An apparatus as in claim 1, wherein internal electric and magnetic fields drive particles through the laser beam.
Claim 9
Dependent Claim
41 words
An apparatus as in claim 1, wherein said detector comprises a beam splitter for splitting said incident laser beam into orthogonally polarized laser beams, said detector having photocells placed to detect the intensity of each of said orthogonally polarized laser beams.
Claim 10
Dependent Claim
14 words
An apparatus as in claim 1, wherein said incident laser beam is linearly polarized.
Claim 11
Independent Claim
109 words
A method for detecting particles in a process chamber for a sputter deposition process using plasma, said process chamber having first and second ports allowing access to said plasma in said process chamber, comprising the steps of: providing an incident laser beam; providing a set of optical components for collimating, polarizing and focussing said incident laser beam, so as to allow said incident laser beam to enter said process chamber through said first port, passing through said plasma and exiting said process chamber through said second port; and providing a detector for detecting from said laser beam whether or not particles in said plasma pass through said laser beam.
Claim 12
Independent Claim
109 words
A method for detecting particles in a process chamber for a sputter deposition process using plasma, said process chamber having first and second ports allowing access to said plasma in said process chamber, comprising the steps of: providing an incident laser beam; providing a set of optical components for collimating, polarizing and focussing said incident laser beam, so as to allow said incident laser beam to enter said process chamber through said first port, passing through said plasma and exiting said process chamber through said second port; and providing a detector for detecting from said laser beam whether or not particles in said plasma pass through said laser beam.
Claim 13
Dependent Claim
81 words
A method as in claim 10, further comprising the steps of: providing a first shield tube attached to said first port of said process chamber, said first shield tube allowing said laser beam to pass into said process chamber thereby allowing said laser beam to pass through said plasma; providing a second shield tube attached to said second port of said process chamber, said second shield tube allowing said laser beam, having passed through said plasma, to exit said process chamber;
Claim 14
Dependent Claim
50 words
A method as in claim 10, wherein said step of providing an incident laser beam provides said incident laser beam in a predetermined polarization, and wherein said step of providing a detector provides a detector for detecting a phase shift in the polarization in said laser beam of predetermined polarization.
Claim 15
Dependent Claim
115 words
A method as in claim 11, where, in said step of providing a set of optical components, said optical components split said laser beam into orthogonally polarized first and second laser beams, said first and second laser beams being spaced in a predetermined distance, such that both said first and second laser beams pass into said process chamber through said first shield tube, pass through said plasma and exit from said process chamber through said second shield tube; and wherein said step of providing a detector, provides a detector for detecting a difference in intensity between said first and second laser beams when a particle passes through one of said first and second laser beams.
Claim 16
Dependent Claim
44 words
A method as in claim 10, wherein said step of providing an incident laser beam provides a laser beam of an oval cross section oriented such that the major axis of said cross section is aligned substantially perpendicular to a direction of particle flow.
Claim 17
Dependent Claim
45 words
A method as in claim 11, wherein said steps of providing first and second shield tubes each provides a shield tube of a length greater than three mean free paths of said particles and a width less than one mean free path of said particles.
Claim 18
Dependent Claim
28 words
A method as in claim 10, further comprising the step of positioning said laser beam such that internal electric and magnetic fields drive particles through the laser beam.
Claim 19
Dependent Claim
44 words
A method as in claim 10, wherein said step of providing a detector provides a beam splitter for splitting said incident laser beam into orthogonally polarized laser beams, and provides photocells placed to detect the intensity of each of said orthogonally polarized laser beams.
Claim 20
Dependent Claim
14 words
A method as in claim 10, wherein said incident laser beam is linearly polarized.
References Cited (Backward Citations)
US4707133A
Cited
US5061070A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-09-12 | 1998-03-14 | 1998-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-09-12 | 2002-03-14 | 2002-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-09-12 | 2006-03-14 | 2006-09-13 | $7700.00 | Window Closed / Lapsed |