US5227269A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for fabricating high density DRAM reticles
Assignee: Texas Instruments Inc
•
Filing: 1990-06-22
•
Granted: 1993-07-13
•
Expires: 2010-06-22
Abstract
Abstract A method of reticle fabrication is disclosed which will reduce e-beam write time by two orders of magnitude for a 64 megabit DRAM. The method involves the mix of using both e-beam and optical lithography on a single reticle.
Inventors
- 👤 David B. Scott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:40
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70425; G03F7/70433; G03F7/70458
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
60 words
A method of fabricating DRAM reticles comprising: patterning and etching a periphery pattern onto a first reticle glass using an e-beam; patterning and etching an array pattern onto a second reticle glass using an e-beam; placing an optical photoresist over said first reticle; and stepping and repeating said array pattern of said second reticle glass onto said first reticle glass.
Claim 2
Independent Claim
60 words
A method of fabricating DRAM reticles comprising: patterning and etching a periphery pattern onto a first reticle glass using an e-beam; patterning and etching an array pattern onto a second reticle glass using an e-beam; placing an optical photoresist over said first reticle; and stepping and repeating said array pattern of said second reticle glass onto said first reticle glass.
Claim 3
Dependent Claim
32 words
A method as recited in claim 1 wherein said periphery pattern is of a first predetermined scale multiple size and wherein said array pattern is of a second predetermined scale multiple size.
Claim 4
Dependent Claim
28 words
A method as recited in claim 2 which further includes reducing said array pattern to said first predetermined scale multiple size prior to said stepping and repeating step.
Claim 5
Dependent Claim
27 words
A method as recited in claim 3 wherein wafer fabrication from the resulting method of claim 3 uses the same stepper from which said reticles are made.
Claim 6
Dependent Claim
41 words
A method as recited in claim 3 wherein said pattern and etch step includes: depositing a first material on a second material; placing a photo resist over said first material; and exposing portions of said resist according to a predetermined scheme.
Claim 7
Dependent Claim
27 words
A method as recited in claim 5 wherein said pattern and etch step further includes removing said exposed resist and said first material underlying said exposed resist.
Claim 8
Dependent Claim
26 words
A method as recited in claim 5 wherein said pattern and etch step further includes removing unexposed resist and said first material underlying said unexposed resist.
Claim 9
Dependent Claim
20 words
A method as recited in claim 5 wherein said first material includes chrome and wherein said second material includes glass.
Claim 10
Dependent Claim
30 words
A method as recited in claim 2 wherein said first predetermined scale multiple size is 25 times scale and wherein said second predetermined scale multiple size is 5 times scale.
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) | 1996-07-12 | 1997-01-11 | 1997-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-07-12 | 2001-01-11 | 2001-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-07-12 | 2005-01-11 | 2005-07-13 | $7700.00 | Window Closed / Lapsed |