Patent US4467026A successfully refreshed from Google Patents.
US4467026A
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US
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Process for drawing patterns with extremely fine features in the production of VLSI, LSI and IC systems
Assignee: Panasonic Holdings Corp
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Filing: 1983-01-20
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Granted: 1984-08-21
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Expires: 2003-01-20
Abstract
Abstract In the patterning process in the fabrication of VLSI, LSI and IC systems, the electron beam is used to write a pattern over a resist layer on a wafer, but the resist layer is exposed by X-rays. More particularly, a finely focused beam of electrons writes a pattern on a thin metal film formed over a resin layer which in turn is formed over a wafer and the secondary X-rays; that is, the characteristics X-rays (such as Kα) emitted from the thin metal film when the electron beam strikes it, expose the resist layer which is sensitive to the X-rays, whereby a high degree of resolution can be obtained.
Inventors
- 👤 Kazufumi Ogawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:50
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/004; G03F7/09; G03F7/094; G03F7/20; G03F7/2051; G03F7/2059; Y; Y10; Y10S; Y10S430/00; Y10S430/167; Y10S430/168
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
138 words
A process for forming a pattern having extremely fine features, comprising the steps of: coating one major surface of a wafer with a layer comprising a resist exposable by X-rays; overcoating the exposed surface of said resist layer with a thin metal film comprising a material which emits characteristic X-rays when bombarded with an electron beam of sufficient energy; exposing said resist layer by scanning the exposed surface of said thin metal film with a finely focused beam of electrons having sufficient energy to cause said thin film to emit said characteristic X-rays, whereby at least some of said characteristic X-rays impinge upon said resist layer to expose regions of said resist layer adjacent points where said finely focused beam of electrons impinges upon said thin metal film; removing said thin metal film; and developing said resist layer.
Claim 2
Dependent Claim
138 words
A process for forming a pattern having extremely fine features, comprising the steps of: coating one major surface of a wafer with a layer comprising a resist exposable by X-rays; overcoating the exposed surface of said resist layer with a thin metal film comprising a material which emits characteristic X-rays when bombarded with an electron beam of sufficient energy; exposing said resist layer by scanning the exposed surface of said thin metal film with a finely focused beam of electrons having sufficient energy to cause said thin film to emit said characteristic X-rays, whereby at least some of said characteristic X-rays impinge upon said resist layer to expose regions of said resist layer adjacent points where said finely focused beam of electrons impinges upon said thin metal film; removing said thin metal film; and developing said resist layer.
Claim 3
Dependent Claim
16 words
A process as defined in claim 1 wherein said wafer is made of a semiconductor material.
Claim 4
Dependent Claim
14 words
A process as defined in claim 1 wherein said metal thin film comprises gold.
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) | 1987-08-21 | 1988-02-20 | 1988-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-21 | 1992-02-20 | 1992-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-21 | 1996-02-20 | 1996-08-21 | $7700.00 | Window Closed / Lapsed |