Patent JPS5620520A successfully refreshed from Google Patents.
US5285075A
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Electron beam lithography method
Assignee: Hitachi Ltd
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Filing: 1992-10-21
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Granted: 1994-02-08
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Expires: 2012-10-21
Abstract
Abstract A sample stage is moved so that an alignment mark on a wafer successively move on positions symmetric to the positional origin of the electron beam, and waveformes of signals obtained by scanning the alignment mark at the symmetric positions with electron beam are added each other so as to be symmetry and decrease the alignment-mark position detecting error.
Inventors
- 👤 Yoshinori Minamide
- 👤 Genya Matsuoka
- 👤 Hiroyoshi Ando
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:26
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/30; H01J37/304; H01J37/3045
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
120 words
An electron beam lithography method for positioning a sample mounted on a sample stage by detecting positions of alignment marks on the sample through electron beam scanning and lithographing a plurality of patterns on the sample on the basis of the detected positions, comprising the steps of: moving the alignment marks on the sample to positions symmetrical with respect to positional origin of the electron beam where the electron beam which is not deflected by applying deflector; detecting the waveforms of signals reflected from the alignment marks by applying the electron beam to the alignment marks at each symmetric position; and adding the detected waveforms so as to obtain a waveform reflected from the alignment mark at the positional origin.
Claim 2
Dependent Claim
120 words
An electron beam lithography method for positioning a sample mounted on a sample stage by detecting positions of alignment marks on the sample through electron beam scanning and lithographing a plurality of patterns on the sample on the basis of the detected positions, comprising the steps of: moving the alignment marks on the sample to positions symmetrical with respect to positional origin of the electron beam where the electron beam which is not deflected by applying deflector; detecting the waveforms of signals reflected from the alignment marks by applying the electron beam to the alignment marks at each symmetric position; and adding the detected waveforms so as to obtain a waveform reflected from the alignment mark at the positional origin.
Claim 3
Dependent Claim
36 words
An electron beam lithography method according to claim 1, wherein said detecting of the waveforms is performed while continuously moving the alignment marks on the sample to the positions symmetrical with respect to the positional origin.
Claim 4
Dependent Claim
25 words
An electron beam lithography method according to claim 1, wherein said positions are located at equal distances from the positional origin of the electron beam.
Claim 5
Dependent Claim
35 words
An electron beam lithography method according to claim 1, wherein said positions are composed by a plurality set of symmetrical positions which are located at equal distance from the positional origin of the electron beam.
Claim 6
Dependent Claim
36 words
An electron beam lithography method according to claim 1, wherein said applying of the electron beam to the alignment marks at each symmetric position is performed by scanning the electron beam on the each symmetric position.
Claim 7
Dependent Claim
27 words
An electron beam lithography method according to claim 5, wherein said scanning the electron beam on the each symmetric position is performed plural times towards same direction.
Claim 8
Dependent Claim
46 words
An electron beam lithography method according to claim 1, wherein said adding of the detected waveforms is performed after shifting the times of the detected waveforms so as to correspond the times to a time on which the alignment mark is detected at the positional origin.
Claim 9
Dependent Claim
40 words
An electron beam lithography method according to claim 1, wherein said adding of the detected waveforms is performed after the deflection of the electron beam is previously corrected according to the differences between the symmetric positions and the positional origin.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-02-07 | 1997-08-09 | 1998-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-02-07 | 2001-08-09 | 2002-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-02-07 | 2005-08-09 | 2006-02-08 | $7700.00 | Window Closed / Lapsed |