US5389313A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing a molding die for an information recording medium
Assignee: Canon Inc
•
Filing: 1992-12-21
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Granted: 1995-02-14
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Expires: 2012-12-21
Abstract
Abstract A method produces a molding die for an information recording medium, having a mold surface with a prescribed unevenness pattern comprising a projection; the projection having different etching velocities along its projected thickness; and defining a pair of convergent opposite inclining side slopes. Each slope of the pair forms an acute inclining angle with respect to extension of the mold surface. A pattern-forming layer is formed comprising a common metal element throughout its thickness and an additional element differing in composition from the common metal element in the thickness direction of the pattern-forming layer. The common metal element and the additional elements have different etching velocities in the thickness direction of the pattern-forming layer. The pattern-forming layer is selectively etched with a common etchant to form the projection.
Inventors
- 👤 Hiroyuki Imataki
- 👤 Tetsuya Satoh
- 👤 Mizuho Hiraoka
- 👤 Tomoyuki Tamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 21:38
CPC Classifications
B; B29; B29C; B29C33/00; B29C33/42; B29C33/424; B29C39/00; B29C39/22; B29C39/26; G; G11; G11B; G11B7/00; G11B7/24; G11B7/26; G11B7/263; Y; Y10; Y10S; Y10S425/00; Y10S425/81
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
168 words
A method of producing a molding die for an information recording medium, having a mold surface with a prescribed unevenness pattern comprising a projection; said projection having different etching velocities along its projected thickness; said projection defining a pair of convergent opposite inclining side slopes, each slope of said pair forming an acute inclining angle with respect to an extension of said mold surface; said method comprising the steps of: forming a pattern-forming layer on a substrate, said pattern-forming layer comprising a common metal element throughout the thickness of the pattern-forming layer and an additional element differing in composition from the common metal element in the thickness direction of the pattern-forming layer, the pattern-forming layer having an etching velocity which is variable in the thickness direction of the pattern-forming layer by varying a proportion of the common metal element with respect to the additional element; and etching the pattern-forming layer with an etchant having an unchanging composition to remove the pattern-forming layer selectively and to form said projection.
Claim 2
Independent Claim
168 words
A method of producing a molding die for an information recording medium, having a mold surface with a prescribed unevenness pattern comprising a projection; said projection having different etching velocities along its projected thickness; said projection defining a pair of convergent opposite inclining side slopes, each slope of said pair forming an acute inclining angle with respect to an extension of said mold surface; said method comprising the steps of: forming a pattern-forming layer on a substrate, said pattern-forming layer comprising a common metal element throughout the thickness of the pattern-forming layer and an additional element differing in composition from the common metal element in the thickness direction of the pattern-forming layer, the pattern-forming layer having an etching velocity which is variable in the thickness direction of the pattern-forming layer by varying a proportion of the common metal element with respect to the additional element; and etching the pattern-forming layer with an etchant having an unchanging composition to remove the pattern-forming layer selectively and to form said projection.
Claim 3
Independent Claim
114 words
A method of producing a molding die for an information recording medium, having a mold surface with a prescribed unevenness pattern comprising a projection; said projection defining a pair of convergent opposite inclining side slopes, each slope of said pair forming an acute inclining angle with respect to an extension of said mold surface; said method comprising the steps of: forming on a substrate a pattern-forming layer having a substantially uniform etching velocity in the thickness direction of the pattern-forming layer; and etching the pattern-forming layer according to a reactive ion etching process using an etchant gas while changing the etchant gas composition to remove the pattern-forming layer selectively and to form said projection.
Claim 4
Independent Claim
114 words
A method of producing a molding die for an information recording medium, having a mold surface with a prescribed unevenness pattern comprising a projection; said projection defining a pair of convergent opposite inclining side slopes, each slope of said pair forming an acute inclining angle with respect to an extension of said mold surface; said method comprising the steps of: forming on a substrate a pattern-forming layer having a substantially uniform etching velocity in the thickness direction of the pattern-forming layer; and etching the pattern-forming layer according to a reactive ion etching process using an etchant gas while changing the etchant gas composition to remove the pattern-forming layer selectively and to form said projection.
Claim 5
Dependent Claim
31 words
A method according to claim 1, wherein said forming step is performed by sputtering by use of a target with an atmosphere around it, while changing said atmosphere around the target.
Claim 6
Dependent Claim
42 words
A method according to claim 1, wherein said forming step is performed by sputtering by use of a Cr target with an atmosphere around it, while changing said atmosphere around the target from N 2 and O 2 to N 2 .
Claim 7
Dependent Claim
36 words
A method according to claim 2, wherein said etching step is performed using an etchant gas containing a mixture of CCl 4 and Ar, while changing the ratio of CCl 4 to Ar in said mixture.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1998-02-13 | 1998-08-15 | 1999-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-02-13 | 2002-08-15 | 2003-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-02-13 | 2006-08-15 | 2007-02-14 | $7700.00 | Window Closed / Lapsed |