US5005075A
Expired / Lapsed
US
⏱️ 0.0 years remaining
X-ray mask and method of manufacturing an X-ray mask
Assignee: Hoya Corp
•
Filing: 1990-01-30
•
Granted: 1991-04-02
•
Expires: 2010-01-30
Abstract
Abstract In a method of manufacturing an X-ray mask comprising a substrate, an X-ray transmission layer on the substrate, an X-ray absorption layer on the X-ray transmission layer, the X-ray transmission layer is flattened to remove undulation and to make roughness of the X-ray transmission layer smaller than 100 angstroms. The X-ray transmission layer may be formed by silicon carbide or silicon nitride. Alternatively, the X-ray transmission layer may have a multilayer structure of sandwiched structure comprising either a silicon carbide film or a silicon nitride film.
Inventors
- 👤 Masato Kobayashi
- 👤 Yoh-Ichi Yamaguchi
- 👤 Minoru Sugawara
- 👤 Kazuhide Yamashiro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:54
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/22
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
83 words
A method of manufacturing an X-ray mask which is for use in an X-ray lithography and which comprises a substrate having a principal surface, an X-ray transmission layer on said principal surface, and an X-ray absorption layer on said X-ray transmission layer, said method comprising the steps of: determining conditions of depositing said X-ray transmission layer on said principal surface under said conditions, said X-ray transmission layer having undulation; flattening the undulation of said X-ray transmission layer; and depositing said X-ray absorption layer.
Claim 2
Independent Claim
83 words
A method of manufacturing an X-ray mask which is for use in an X-ray lithography and which comprises a substrate having a principal surface, an X-ray transmission layer on said principal surface, and an X-ray absorption layer on said X-ray transmission layer, said method comprising the steps of: determining conditions of depositing said X-ray transmission layer on said principal surface under said conditions, said X-ray transmission layer having undulation; flattening the undulation of said X-ray transmission layer; and depositing said X-ray absorption layer.
Claim 3
Dependent Claim
18 words
A method as claimed in claim 1, wherein said X-ray transmission layer is formed by silicon carbide (SiCx).
Claim 4
Dependent Claim
17 words
A method as claimed in claim 1, wherein said X-ray transmission layer is formed by silicon nitride.
Claim 5
Dependent Claim
48 words
A method as claimed in claim 1, wherein said flattening step comprises the steps of: coating a dummy layer on said X-ray transmission layer; and etching said dummy layer and a part of said X-ray transmission layer to remove said undulation and to flatten said X-ray transmission layer.
Claim 6
Dependent Claim
24 words
A method as claimed in claim 4, wherein said X-ray transmission layer is etched at an etching rate substantially equal to said dummy layer.
Claim 7
Dependent Claim
68 words
A method as claimed in claim 1, wherein said X-ray transmission layer depositing step comprises the steps of: depositing a first X-ray transmission film of silicon carbide on said principal surface, said first X-ray transmission film having the undulation; removing said undulation of the first X-ray transmission film to form a flattened transmission film; depositing a second X-ray transmission film of silicon oxide on said flattened transmission film.
Claim 8
Dependent Claim
117 words
A method as claimed in claim 6, said substrate having a back surface opposite to said principal surface, wherein said X-ray transmission layer depositing step further comprises the steps of: depositing a back X-ray transmission film of silicon carbide simultaneously with said first X-ray transmission film; selectively etching said back X-ray transmission film to expose a part of said back surface of the substrate; etching said part of the substrate from said back surface of the substrate to said first X-ray transmission film; depositing an underlying transmission film of silicon oxide on said first X-ray transmission film so as to interpose said first X-ray transmission film by said second X-ray transmission film and said underlying transmission film.
Claim 9
Dependent Claim
87 words
A method as claimed in claim 1, said substrate having a back surface opposite to said principal surface, wherein said X-ray transmission layer depositing step comprises the steps of: depositing first and second X-ray transmission films of silicon nitride on said principal and said back surfaces of the substrate; forming a dummy layer on said first X-ray transmission film; and etching said dummy layer and a part of said first X-ray transmission film to flatten the first X-ray transmission film and to form a flattened transmission film.
Claim 10
Dependent Claim
89 words
A method as claimed in claim 8, wherein said X-ray transmission layer depositing step further comprises the steps of: depositing an intermediate X-ray transmission film of silicon oxide on said flattened transmission film; depositing an overlying X-ray transmission film of silicon nitride on said intermediate X-ray transmission film; coating an additional dummy layer on said overlying X-ray transmission film; and etching said additional dummy layer and a part of said overlying X-ray transmission film to flatten said overlying X-ray transmission film and to form an additional flattened transmission film.
Claim 11
Dependent Claim
45 words
An X-ray mask comprising a substrate having a principal surface, an X-ray transmission layer on said principal surface, and an X-ray absorption layer on said X-ray transmission layer, said X-ray transmission layer being subjected to a flattened process and having roughness smaller than 100 angstroms.
Claim 12
Dependent Claim
45 words
An X-ray mask comprising a substrate having a principal surface, an X-ray transmission layer on said principal surface, and an X-ray absorption layer on said X-ray transmission layer, said X-ray transmission layer being subjected to a flattened process and having roughness smaller than 100 angstroms.
Claim 13
Dependent Claim
27 words
An X-ray mask as claimed in claim 10, wherein said X-ray transmission layer further has a tensile stress between 1×10 8 and 8×10 8 dyn/cm 2 .
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) | 1994-04-01 | 1994-10-01 | 1995-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-04-01 | 1998-10-01 | 1999-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-04-01 | 2002-10-01 | 2003-04-02 | $7700.00 | Window Closed / Lapsed |