US5460908A
Expired / Lapsed
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Phase shifting retical fabrication method
Assignee: Micron Technology Inc
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Filing: 1994-04-13
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Granted: 1995-10-24
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Expires: 2014-04-13
Abstract
Abstract A method of fabricating a phase shifting reticle that can be used as a mask in photolithographic processes such as semiconductor wafer patterning. A transparent quartz substrate is coated with a film of an oxidizable silicon material. The silicon is then coated with a material suitable for isolating the silicon material from an oxidizing environment. A resist coating is placed atop the isolation material, developed and etched, exposing the isolation in a predetermined pattern. The isolation material is etched and the substrate placed in an oxidizing environment. The silicon material expands to a predetermined thickness, forming a phase shifter on the substrate. Next, the remaining isolation material and unoxidized silicon are removed, forming transmission regions adjacent the phase shifters. Then the remaining resist is removed to form opaque or light blocking areas on the substrate to complete formation of a phase shifting reticle.
Inventors
- 👤 Alan R. Reinberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:26
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/26; G03F1/30; G03F1/34
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
119 words
A method of forming a phase shifting reticle comprising: coating a transparent substrate with a film of an oxidizable material; coating the oxidizable material with a film of an isolation material; covering portions of the isolation material with a resist in a preselected pattern so as to leave the remaining isolation material exposed; removing the exposed isolation material thereby exposing portions of the underlying oxidizable material; removing the resist; reacting the oxidizable material with an oxidizing environment to cause the oxidizable material to expand a predetermined amount, forming phase shifters on the substrate; and removing the remaining isolation material and unoxidized oxidizable material to form a phase shifting reticle having transmission areas adjacent the phase shifters on the substrate.
Claim 2
Independent Claim
119 words
A method of forming a phase shifting reticle comprising: coating a transparent substrate with a film of an oxidizable material; coating the oxidizable material with a film of an isolation material; covering portions of the isolation material with a resist in a preselected pattern so as to leave the remaining isolation material exposed; removing the exposed isolation material thereby exposing portions of the underlying oxidizable material; removing the resist; reacting the oxidizable material with an oxidizing environment to cause the oxidizable material to expand a predetermined amount, forming phase shifters on the substrate; and removing the remaining isolation material and unoxidized oxidizable material to form a phase shifting reticle having transmission areas adjacent the phase shifters on the substrate.
Claim 3
Dependent Claim
12 words
The method of claim 1 wherein said isolation material is silicon nitride.
Claim 4
Dependent Claim
12 words
The method of claim 2 wherein said oxidizable material is amorphous silicon.
Claim 5
Dependent Claim
12 words
The method of claim 2 wherein said oxidizable material is polycrystalline silicon.
Claim 6
Dependent Claim
11 words
The method of claim 2 wherein said oxidizable material is germanium.
Claim 7
Dependent Claim
12 words
The method of claim 1 wherein said oxidizable material is amorphous silicon.
Claim 8
Dependent Claim
12 words
The method of claim 1 wherein said oxidizable material is polycrystalline silicon.
Claim 9
Dependent Claim
11 words
The method of claim 1 wherein said oxidizable material is germanium.
Claim 10
Independent Claim
146 words
A method of forming a phase shifting reticle comprising: coating a transparent substrate with a film of an oxidizable material; coating the oxidizable material with a film of an isolation material; covering a part of the isolation material with a resist in a preselected pattern so as to leave the remaining isolation material exposed; removing the exposed isolation material thereby exposing portions of the underlying oxidizable material; removing the resist; reacting the oxidizable material with an oxidizing environment to cause the oxidizable material to expand a predetermined amount, forming phase shifters on the substrate; covering a part of the remaining isolation material with a resist in a second, different preselected pattern; removing the remaining, exposed isolation material and unoxidized oxidizable material; and removing the resist to form a phase shifting reticle having opaque, light blocking areas and transmission areas adjacent the phase shifters on the substrate.
Claim 11
Independent Claim
146 words
A method of forming a phase shifting reticle comprising: coating a transparent substrate with a film of an oxidizable material; coating the oxidizable material with a film of an isolation material; covering a part of the isolation material with a resist in a preselected pattern so as to leave the remaining isolation material exposed; removing the exposed isolation material thereby exposing portions of the underlying oxidizable material; removing the resist; reacting the oxidizable material with an oxidizing environment to cause the oxidizable material to expand a predetermined amount, forming phase shifters on the substrate; covering a part of the remaining isolation material with a resist in a second, different preselected pattern; removing the remaining, exposed isolation material and unoxidized oxidizable material; and removing the resist to form a phase shifting reticle having opaque, light blocking areas and transmission areas adjacent the phase shifters on the substrate.
Claim 12
Dependent Claim
12 words
The method of claim 9 wherein said isolation material is silicon nitride.
Claim 13
Dependent Claim
12 words
The method of claim 10 wherein said oxidizable material is amorphous silicon.
Claim 14
Dependent Claim
12 words
The method of claim 10 wherein said oxidizable material is polycrystalline silicon.
Claim 15
Dependent Claim
11 words
The method of claim 10 wherein said oxidizable material is germanium.
Claim 16
Dependent Claim
12 words
The method of claim 9 wherein said oxidizable material is amorphous silicon.
Claim 17
Dependent Claim
12 words
The method of claim 9 wherein said oxidizable material is polycrystalline silicon.
Claim 18
Dependent Claim
11 words
The method of claim 9 wherein said oxidizable material is germanium.
References Cited (Backward Citations)
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