Patent US4734158A successfully refreshed from Google Patents.
US4734158A
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US
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Molecular beam etching system and method
Assignee: Raytheon Co
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Filing: 1987-03-16
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Granted: 1988-03-29
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Expires: 2007-03-16
Abstract
Abstract A particle beam etching system and method are disclosed in which ion and substantially ion-free chemical radical beams are generated separately and directed onto the same portion of a semiconductor wafer to be etched, preferably perpendicular to the wafer. The beam diameters are substantially smaller than the etching area, and the wafer is moved in an x,y plane to expose the entire etching area to the beams. The redical beam is preferably supersonic, with a flux in the approximate range of 10 19 -10 21 particles per steradian per second, while the ion beam preferably has a density of approximately 10 14 ions per cm 2 per second. The progress of the etching and the location of etching end points are continuously monitored and used to control the etching rate and wafer movement, yielding etching that is both anisotropic and selective, with an accurate and uniform etch depth.
Inventors
- 👤 Harry P. Gillis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:41
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/24; H10P50/242
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
59 words
A particle beam etching system, comprising: means for supporting a target substrate to be etched, means for generating an ion beam with a predetermined ion density, means for generating a chemical radical beam with a predetermined radical particle density, and means for directing the radical and ion beams onto a common location on a substrate in an etching operation.
Claim 2
Dependent Claim
59 words
A particle beam etching system, comprising: means for supporting a target substrate to be etched, means for generating an ion beam with a predetermined ion density, means for generating a chemical radical beam with a predetermined radical particle density, and means for directing the radical and ion beams onto a common location on a substrate in an etching operation.
Claim 3
Dependent Claim
24 words
The etching system of claim 1, the ion and radical beam directing means directing said beams onto the substrate approximately normal to the substrate.
Claim 4
Dependent Claim
54 words
The etching system of claim 2, the beam directing means comprising means for directing the radical beam onto the substrate along a substantially straight line axis, and means for initially directing the ion beam at a non-right angle to the etching surface and then deflecting the ion beam generally coaxially with the radical beam.
Claim 5
Dependent Claim
36 words
The etching system of claim 1, wherein the radical beam generating means is adapted to generate the radical beam with a flux in the approximate range of 10 19 -10 21 particles per steradian per second.
Claim 6
Dependent Claim
24 words
The etching system of claim 4, wherein the radical beam generating means is adapted to generate the radical beam as a supersonic radical beam.
Claim 7
Dependent Claim
32 words
The etching system of claim 5, wherein the ion beam generating means is adapted to generate the ion beam with a density of approximately 10 14 ions per cm. 2 per second.
Claim 8
Dependent Claim
26 words
The etching system of claim 5, wherein the ion and radical beams are generated with diameters at the substrate in the approximate range of 3-20 mm.
Claim 9
Dependent Claim
56 words
The etching system of claim 1, wherein the ion and radical beam generating means are adapted to generate their respective beams with cross-sectional areas at the substrate substantially smaller than the substrate area, and further comprising means for moving the substrate relative to the beams so that the beams traverse a desired portion of the substrate.
Claim 10
Dependent Claim
24 words
The etching system of claim 1, wherein the radical beam generating means is adapted to generate the radical beam as a supersonic radical beam.
Claim 11
Dependent Claim
66 words
A particle beam etching system, comprising: means for supporting a target substrate to be etched, means for generating an ion beam with a predetermined ion density, means independent of the ion beam generating means for generating a chemical radical beam which is substantially free of ions, and means for directing the radical and ion beams onto a common location on a substrate in an etching process.
Claim 12
Dependent Claim
66 words
A particle beam etching system, comprising: means for supporting a target substrate to be etched, means for generating an ion beam with a predetermined ion density, means independent of the ion beam generating means for generating a chemical radical beam which is substantially free of ions, and means for directing the radical and ion beams onto a common location on a substrate in an etching process.
Claim 13
Dependent Claim
23 words
The etching system of claim 10, the radical beam generating means comprising means for initially generating the radical beam substantially free of ions.
Claim 14
Dependent Claim
16 words
The etching system of claim 11, the radical beam generating means comprising a thermal type generator.
Claim 15
Dependent Claim
33 words
The etching system of claim 10, the radical beam generating means comprising means for initially generating a mixed ion and radical beam, and electrostatic deflection means for removing the ions from the beam.
Claim 16
Dependent Claim
23 words
The etching system of claim 13, the means for initially generating a mixed ion and radical beam comprising a radio frequency type generator.
Claim 17
Dependent Claim
22 words
The etching system of claim 13, the means for initially generating a mixed ion and radical beam comprising a microwave type generator.
Claim 18
Independent Claim
44 words
A method of etching a semiconductor substrate, comprising the steps of: generating and directing an ion beam onto a portion of the substrate to be etched, and generating and directing a substantially ion-free chemical radical beam onto substantially the same portion of the substrate.
Claim 19
Independent Claim
44 words
A method of etching a semiconductor substrate, comprising the steps of: generating and directing an ion beam onto a portion of the substrate to be etched, and generating and directing a substantially ion-free chemical radical beam onto substantially the same portion of the substrate.
Claim 20
Dependent Claim
18 words
The method of claim 16, wherein the ion and radical beams are directed onto the substrate generally coaxially.
Claim 21
Dependent Claim
23 words
The method of claim 17, wherein the ion and radical beams are directed onto the substrate at approximately right angles to the substrate.
Claim 22
Dependent Claim
45 words
The method of claim 18, wherein the radical beam is directed along a generally straight line axis onto the substrate, and the ion beam is initially directed at a non-right angle to the substrate but is deflected into generally coaxial alignment with the radical beam.
Claim 23
Dependent Claim
23 words
The method of claim 16, wherein the ion and radical beams are directed onto the substrate at a substantial angle to each other.
Claim 24
Dependent Claim
26 words
The method of claim 16, wherein the radical beam has a flux in the approximate range of 10 19 -10 21 particles per steradian per second.
Claim 25
Dependent Claim
22 words
The method of claim 21, wherein the ion beam has a density of approximately 10 14 ions per cm. 2 per second.
Claim 26
Dependent Claim
47 words
The method of claim 16, wherein the ion and radical beams have cross-sectional areas at the substrate substantially less than the substrate area, and further comprising the step of moving the substrate relative to the beams so that the beams traverse a desired portion of the substrate.
Claim 27
Dependent Claim
29 words
The method of claim 23, further comprising the steps of monitoring the progress of the substrate etching, and controlling the substrate movement and the beam intensities in response thereto.
Claim 28
Dependent Claim
25 words
The method of claim 24, wherein the ion and radical beams are generated with diameters at the substrate in the approximate range of 3-20 mm.
Claim 29
Dependent Claim
15 words
The method of claim 16, wherein the radical beam is generated as a supersonic beam.
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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) | 1991-03-29 | 1991-09-28 | 1992-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-29 | 1995-09-28 | 1996-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-29 | 1999-09-28 | 2000-03-29 | $7700.00 | Window Closed / Lapsed |