US5624791A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pattern forming method using mask
Assignee: Fujitsu Ltd
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Filing: 1995-06-05
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Granted: 1997-04-29
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Expires: 2015-06-05
Abstract
Abstract A mask includes a transparent layer which is transparent with respect to a light which is used for an exposure, and a mask pattern layer which is formed on the transparent layer. At least a portion of the mask patterns layer is made up solely of a phase shift layer for transmitting the light, so that a phase shift occurs between a phase of the light transmitted through the phase shift layer and a phase of the light transmitted through a portion of the mask having no phase shift layer.
Inventors
- 👤 Toshiaki Kawabata
- 👤 Kenji Nakagawa
- 👤 Seiichiro Yamaguchi
- 👤 Masao Taguchi
- 👤 Kazuhiko Sumi
- 👤 Yuichiro Yanagishita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:58
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/26; G03F1/32; G03F1/29; G03F1/30; G03F1/34; G03F7/00; G03F7/20; G03F7/2002; G03F7/2004; G03F7/2006; G03F1/28
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
157 words
A pattern forming method comprising the steps of: illuminating a mask with a light from a light source whereby a portion of the light is transmitted through the mask; imaging the light transmitted through the mask onto a photoresist layer on a wafer using a lens system so as to expose a pattern on the photoresist layer; and developing the exposed pattern, said mask comprising a first layer which is transparent with respect to said light and a mask pattern layer on said first layer, at least a portion of said mask pattern layer comprising a phase shift region which consists solely of a single layer phase shift material having a single thickness and adapted for transmitting light and shifting the phase of the transmitted light, whereby the pattern on the photoresist layer is exposed by an interference which occurs between light transmitted through said region and light transmitted through other portions of the mask pattern layer.
Claim 2
Dependent Claim
157 words
A pattern forming method comprising the steps of: illuminating a mask with a light from a light source whereby a portion of the light is transmitted through the mask; imaging the light transmitted through the mask onto a photoresist layer on a wafer using a lens system so as to expose a pattern on the photoresist layer; and developing the exposed pattern, said mask comprising a first layer which is transparent with respect to said light and a mask pattern layer on said first layer, at least a portion of said mask pattern layer comprising a phase shift region which consists solely of a single layer phase shift material having a single thickness and adapted for transmitting light and shifting the phase of the transmitted light, whereby the pattern on the photoresist layer is exposed by an interference which occurs between light transmitted through said region and light transmitted through other portions of the mask pattern layer.
Claim 3
Dependent Claim
42 words
A pattern forming method as set forth in claim 1, wherein the phase of the phase shift transmitted light is shifted within the range of from 150° to 210° relative to the phase of exposure light which does not impinge said region.
Claim 4
Dependent Claim
29 words
A pattern forming method as set forth in claim 1, wherein said phase shift region includes a straight edge disposed between said light portions for forming a line pattern.
Claim 5
Dependent Claim
41 words
A pattern forming method as set forth in claim 1, wherein said pattern comprises one or more of said phase shift regions presenting a pair of straight edges disposed between said light portions for forming a pattern having an arbitrary width.
Claim 6
Dependent Claim
36 words
A pattern forming method as set forth in claim 1, wherein said pattern includes at least two phase shift regions and one of said phase shift regions has a different thickness than another of said regions.
Claim 7
Dependent Claim
39 words
A pattern forming method as set forth in claim 5, wherein said imaging step comprises imaging of the pattern at different focal positions on said photoresist layer depending on a concave or convex surface structure of said photoresist layer.
Claim 8
Dependent Claim
20 words
A pattern forming method as set forth in claim 1, wherein said first layer is made of quartz or glass.
Claim 9
Dependent Claim
34 words
A pattern forming method as set forth in claim 1, wherein said phase shift region is made up of a material which comprises SiO 2 , Al 2 O 3 or MgF 2 .
Claim 10
Dependent Claim
24 words
A pattern forming method as set forth in claim 1, wherein said mask includes an opaque mask layer covering portions of the first layer.
Claim 11
Dependent Claim
53 words
A pattern forming method as set forth in claim 1, wherein said imaging step comprises the imaging on said photoresist layer of a black pattern at a light intensity lower than that at other portions of the photoresist layer by using phase interference generated adjacent an edge portion of the phase shift region.
Claim 12
Dependent Claim
53 words
A pattern forming method as set forth in claim 1, wherein said imaging step comprises the imaging on said photoresist layer of a white pattern at a light intensity higher than that at other portions of the photoresist layer by using phase interference generated adjacent an edge portion of the phase shift region.
Claim 13
Dependent Claim
34 words
A pattern forming method as set forth in claim 1, wherein the light utilized for illuminating the mask comprises a partially coherent light having a partial coherency within the range of 0.3 to 0.7.
Claim 14
Dependent Claim
33 words
A pattern forming method as set forth in claim 1, wherein the phase shift region comprises a portion of the first layer having a different thickness than other portions of the first layer.
Claim 15
Dependent Claim
56 words
A pattern forming method as set forth in claim 1, wherein said mask pattern includes mutually adjacent phase shift regions having mutually different phase shift quantities such that the light transmitted by one such region has a phase which differs by 90° to 180° from the phase of the light transmitted by the other such region.
Claim 16
Dependent Claim
56 words
A pattern forming method as set forth in claim 1, wherein a black pattern is generated on said resist at the boundary between the adjacent phase shift regions when the same have a 180° phase difference, and wherein no pattern is generated on said resist at said boundary when the phase difference is 90° or less.
Claim 17
Dependent Claim
56 words
A pattern forming method as set forth in claim 1, wherein said mask pattern includes mutually adjacent phase shift regions having mutually different phase shift quantities such that the light transmitted by one such region has a phase which differs by 60° to 210° from the phase of the light transmitted by the other such region.
Claim 18
Dependent Claim
181 words
A pattern forming method comprising the steps of: illuminating a mask with a light from a light source whereby a portion of the light is transmitted through the mask; imaging the light transmitted through the mask onto a photoresist layer on a wafer using a lens system so as to expose a pattern on the photoresist layer, said pattern being imaged at different focal positions on said photoresist layer depending on a concave or convex surface structure of the photoresist layer; and developing the exposed pattern, said mask comprising a first layer which is transparent with respect to said light, an opaque layer covering a portion of said first layer and having an edge portion, and a phase shift region formed adjacent said edge portion of the opaque layer, said opaque layer and said phase shift region presenting a mask pattern on said first layer, said phase shift region being adapted for transmitting light and shifting the phase of the transmitted light, whereby interference occurs between light transmitted through said region and light transmitted through other portions of the first layer.
Claim 19
Dependent Claim
181 words
A pattern forming method comprising the steps of: illuminating a mask with a light from a light source whereby a portion of the light is transmitted through the mask; imaging the light transmitted through the mask onto a photoresist layer on a wafer using a lens system so as to expose a pattern on the photoresist layer, said pattern being imaged at different focal positions on said photoresist layer depending on a concave or convex surface structure of the photoresist layer; and developing the exposed pattern, said mask comprising a first layer which is transparent with respect to said light, an opaque layer covering a portion of said first layer and having an edge portion, and a phase shift region formed adjacent said edge portion of the opaque layer, said opaque layer and said phase shift region presenting a mask pattern on said first layer, said phase shift region being adapted for transmitting light and shifting the phase of the transmitted light, whereby interference occurs between light transmitted through said region and light transmitted through other portions of the first layer.
Claim 20
Dependent Claim
20 words
A pattern forming method as set forth in claim 17, wherein said first layer is made of quartz or glass.
Claim 21
Dependent Claim
24 words
A pattern forming method as set forth in claim 17, wherein said mask includes a second opaque layer covering portions of the first layer.
Claim 22
Dependent Claim
53 words
A method as set forth in claim 17, wherein said imaging step comprises the imaging on said photoresist layer of a black pattern at a light intensity lower than that at other portions of the photoresist layer by using the interference generated in the vicinity of the edge portion of the opaque layer.
Claim 23
Dependent Claim
53 words
A method as set forth in claim 17, wherein said imaging step comprises the imaging on said photoresist layer of a white pattern at a light intensity higher than that at other portions of the photoresist layer by using the interference generated in the vicinity of the edge portion of the opaque layer.
Claim 24
Dependent Claim
35 words
A pattern forming method as set forth in claim 17, wherein the light utilized for illuminating the mask comprises a partially coherent light having a partial coherency within the range of from 0.3 to 0.7.
Claim 25
Dependent Claim
177 words
A pattern forming method as set forth in claim 17, wherein the phase shift region is bounded by the opaque layer and an exposed portion of the first layer, the mask and the photoresist layer on the wafer are aligned such that portions of the mask linearly correspond with portions of the photoresist layer, when light transmitted through the mask is imbed onto the photoresist layer, a black and white boundary is created on the photoresist layer representing darkened and illuminated portions of the photoresist layer, respectively, the boundary between the opaque layer and the phase shift region is located at a first distance along a predetermined direction relative to the boundary between the phase shift region and the exposed portion of the first layer, and the black and white boundary on the photoresist layer is located at a second distance along a direction opposite to the predetermined direction relative to the portion of the photoresist layer corresponding to and aligned with the boundary between the phase shift region and the exposed portion of the first layer.
Claim 26
Dependent Claim
174 words
A pattern forming method comprising the steps of: illuminating a mask with a light from a light source whereby a portion of the light is transmitted through the mask; imaging the light transmitted through the mask onto a photoresist layer on a wafer using a lens system so as to expose a pattern on the layer; and developing the exposed pattern, said mask comprising a first layer which is transparent with respect to said light, an opaque layer covering a portion of said first layer and having an edge portion, and a phase shift region formed adjacent said edge portion of the opaque layer, said opaque layer and said phase shift region presenting a first mask pattern on said first layer, said phase shift region being adapted for transmitting light and shifting the phase of the transmitted light, whereby interference occurs between light transmitted through said region and light transmitted through other portions of the first layer, said mask including a second mask pattern which is made up solely of a phase shift region.
Claim 27
Dependent Claim
174 words
A pattern forming method comprising the steps of: illuminating a mask with a light from a light source whereby a portion of the light is transmitted through the mask; imaging the light transmitted through the mask onto a photoresist layer on a wafer using a lens system so as to expose a pattern on the layer; and developing the exposed pattern, said mask comprising a first layer which is transparent with respect to said light, an opaque layer covering a portion of said first layer and having an edge portion, and a phase shift region formed adjacent said edge portion of the opaque layer, said opaque layer and said phase shift region presenting a first mask pattern on said first layer, said phase shift region being adapted for transmitting light and shifting the phase of the transmitted light, whereby interference occurs between light transmitted through said region and light transmitted through other portions of the first layer, said mask including a second mask pattern which is made up solely of a phase shift region.
Claim 28
Dependent Claim
188 words
A pattern forming method comprising the steps of: illuminating a mask with a light from a light source whereby a portion of the light is transmitted through the mask; imaging the light transmitted through the mask onto a photoresist layer on a wafer using a lens system so as to expose a pattern on the layer; and developing the exposed pattern, said mask comprising a first layer which is transparent with respect to said light, an opaque layer covering a portion of said first layer and having an edge portion, and a phase shift region formed adjacent said edge portion of the opaque layer, said opaque layer and said phase shift region presenting a first mask pattern on said first layer, said phase shift region being adapted for transmitting light and shifting the phase of the transmitted light, whereby interference occurs between light transmitted through said region and light transmitted through other portions of the first layer, said mask including a second mask pattern which is made up solely of an opaque layer and a third mask pattern which is made up solely of a phase shift layer.
Claim 29
Dependent Claim
188 words
A pattern forming method comprising the steps of: illuminating a mask with a light from a light source whereby a portion of the light is transmitted through the mask; imaging the light transmitted through the mask onto a photoresist layer on a wafer using a lens system so as to expose a pattern on the layer; and developing the exposed pattern, said mask comprising a first layer which is transparent with respect to said light, an opaque layer covering a portion of said first layer and having an edge portion, and a phase shift region formed adjacent said edge portion of the opaque layer, said opaque layer and said phase shift region presenting a first mask pattern on said first layer, said phase shift region being adapted for transmitting light and shifting the phase of the transmitted light, whereby interference occurs between light transmitted through said region and light transmitted through other portions of the first layer, said mask including a second mask pattern which is made up solely of an opaque layer and a third mask pattern which is made up solely of a phase shift layer.
Claim 30
Dependent Claim
168 words
A pattern forming method comprising the steps of: illuminating a mask with a light from a light source whereby a portion of the light is transmitted through the mask; imaging the light transmitted through the mask onto a photoresist layer on a wafer using a lens system so as to expose a pattern on the photoresist layer; and developing the exposed pattern, said mask comprising a first layer which is transparent with respect to said light, an opaque layer covering a portion of said first layer and having an edge portion, and a phase shift region formed adjacent said edge portion of the opaque layer, said opaque layer and said phase shift region presenting a mask pattern on said first layer, said phase shift region being adapted for transmitting light and including first and second portions which have mutually different thicknesses and shifting the phase of the transmitted light, whereby interference occurs between light transmitted through said region and light transmitted through other portions of the first layer.
Claim 31
Dependent Claim
168 words
A pattern forming method comprising the steps of: illuminating a mask with a light from a light source whereby a portion of the light is transmitted through the mask; imaging the light transmitted through the mask onto a photoresist layer on a wafer using a lens system so as to expose a pattern on the photoresist layer; and developing the exposed pattern, said mask comprising a first layer which is transparent with respect to said light, an opaque layer covering a portion of said first layer and having an edge portion, and a phase shift region formed adjacent said edge portion of the opaque layer, said opaque layer and said phase shift region presenting a mask pattern on said first layer, said phase shift region being adapted for transmitting light and including first and second portions which have mutually different thicknesses and shifting the phase of the transmitted light, whereby interference occurs between light transmitted through said region and light transmitted through other portions of the first layer.
Claim 32
Dependent Claim
169 words
A pattern forming method comprising the steps of: illuminating a mask with a light from a light source whereby a portion of the light is transmitted through the mask; imaging the light transmitted through the mask onto a photoresist layer on a wafer using a lens system so as to expose a pattern on the photoresist layer; and developing the exposed pattern, said mask comprising a first layer which is transparent with respect to said light and a mask pattern layer on said first layer, at least a portion of said mask pattern layer comprising a phase shift region adapted for transmitting light and shifting the phase of the transmitted light, whereby interference occurs between light transmitted through said region and light transmitted through other portions of the mask pattern layer so that at least a portion of the pattern is formed by the interference between light transmitted through the phase shift region and light transmitted through the first layer without interaction of an opaque layer on the mask.
Claim 33
Dependent Claim
169 words
A pattern forming method comprising the steps of: illuminating a mask with a light from a light source whereby a portion of the light is transmitted through the mask; imaging the light transmitted through the mask onto a photoresist layer on a wafer using a lens system so as to expose a pattern on the photoresist layer; and developing the exposed pattern, said mask comprising a first layer which is transparent with respect to said light and a mask pattern layer on said first layer, at least a portion of said mask pattern layer comprising a phase shift region adapted for transmitting light and shifting the phase of the transmitted light, whereby interference occurs between light transmitted through said region and light transmitted through other portions of the mask pattern layer so that at least a portion of the pattern is formed by the interference between light transmitted through the phase shift region and light transmitted through the first layer without interaction of an opaque layer on the mask.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-04-28 | 2000-10-28 | 2001-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-04-28 | 2004-10-28 | 2005-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-04-28 | 2008-10-28 | 2009-04-29 | $7700.00 | Window Closed / Lapsed |