EP0653679B1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Mask, mask producing method and pattern forming method using mask
Assignee: Fujitsu Ltd
•
Filing: 1990-04-26
•
Granted: 2002-08-21
•
Expires: 2010-04-26
Abstract
No abstract record available.
Inventors
- 👤 Toshiaki C/O Fujitsu Ltd. Kawabata
- 👤 Kenji C/O Fujitsu Ltd. Nakagawa
- 👤 Seiichiro C/O Fujitsu Ltd. Yamaguchi
- 👤 Masao C/O Fujitsu Ltd. Taguchi
- 👤 Kazuhiko C/O Fujitsu Ltd. Sumi
- 👤 Yuichiro C/O Fujitsu Ltd. Yanagishita
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 08:48
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: 19
Claim 1
Independent Claim
152 words
A mask for use in exposure of a semiconductor
wafer, including: transparent portions (2, 31, 51) for
transmitting light used in the exposure, formed by a
transparent layer and corresponding to first areas of
said wafer, these being areas which are to be exposed; opaque portions (14, 32, 53) for masking said
light, formed by an opaque layer and corresponding to
second areas of said wafer adjacent to said first
areas; and phase shift portions (3a, 37A, 37B, 41A, 41B)
for shifting the phase of said light so as to improve
the contrast between the first and second areas, formed
by a phase shift layer (3a) formed over the transparent
layer and the opaque layer or by a phase shift region
in the transparent layer; characterized in that in at least one part of
the mask, said phase shift portions are formed only
along edges of said opaque portions (14, 32, 53).
Claim 2
Dependent Claim
31 words
The mask as claimed in claim 1, wherein the
phase shift portions (3a, 37A, 37B, 41A, 41B) produce a
phase shift of said light within a range of 180° ± 30%.
Claim 3
Dependent Claim
42 words
The mask as claimed in claim 1 or 2, wherein
a said phase shift portion (3a, 37A, 37B, 41A, 41B) is
provided at an edge portion of said opaque layer (14,
32, 53) for forming a line pattern when making the
exposure.
Claim 4
Dependent Claim
47 words
The mask as claimed in claim 1, 2, or 3,
wherein a said phase shift portion (3a, 37A, 37B, 41A,
41B) is provided at a pair of edge portions of said
opaque layer (14, 32, 53) for forming a pattern of
arbitrary width when making the exposure.
Claim 5
Dependent Claim
38 words
The mask as claimed in claim 4, wherein a
boundary between said phase shift portions (3a, 37A,
37B, 41A, 41B) and said transparent portions (2, 31,
51) is located on an inner side of a designated black
pattern.
Claim 6
Dependent Claim
36 words
The mask as claimed in any of claims 1 to 5,
wherein the phase shift portions (3a, 37A, 37B, 41A,
41B) include a first portion (3a1) and a second portion
(3a2) which have mutually different thicknesses.
Claim 7
Dependent Claim
21 words
The mask as claimed in any preceding claim,
wherein the transparent layer (2, 31, 51) is made of
quartz or glass.
Claim 8
Dependent Claim
29 words
The mask as claimed in any preceding claim,
wherein the phase shift layer (3a) is made of SiO 2 ,
Al 2 O 3 , or MgF 2 .
Claim 9
Dependent Claim
19 words
The mask as claimed in any preceding claim,
wherein the opaque layer (14, 32, 53) is made of Cr.
Claim 10
Independent Claim
108 words
A method of producing a mask as claimed in
any preceding claim, comprising the steps of: forming said opaque layer (14, 20) on said
transparent layer (2) ; forming a resist pattern (4) which is made of
a resist material, on said opaque layer; forming the phase shift layer (3a) which
transmits the light on said resist pattern layer, or
forming the phase shift region in the transparent
layer, to a predetermined thickness to form the phase
shift portions; and removing said resist pattern layer, whereby
said phase shift portions remain only along an edge
portion of said opaque layer in at least one part of
the mask.
Claim 11
Independent Claim
117 words
A method of producing a mask as claimed-in
any one of claims 1 to 9, comprising the steps of: forming said opaque layer (14, 20) on said
transparent layer (2); forming a stopper layer (21) on said opaque
layer; forming the phase shift layer (3a) on said
opaque layer to a predetermined thickness; forming a resist pattern (4) made of a resist
material, on said phase shift layer; and etching said phase shift layer using said
stopper layer as an etching stopper and said resist
pattern as an etching mask, whereby said phase shift
layer remains on said stopper layer only along an edge
portion of said opaque layer in at least one part of
the mask.
Claim 12
Dependent Claim
19 words
The method as claimed in claim 11, wherein
the stopper layer is made of Al 2 O 3 .
Claim 13
Dependent Claim
85 words
A pattern forming method for forming a
pattern on a semiconductor wafer (11) using a mask as
claimed in any of claims 1 to 9, the method comprising
illuminating the mask (1, 1A-1G) by light from a light
source, and projecting the light transmitted through
the mask onto a photoresist layer (10) formed on the
wafer by use of a lens system (9), whereby the
photoresist layer is developed in said first areas of
the wafer corresponding to the transparent portions (2)
of the mask.
Claim 14
Dependent Claim
33 words
The pattern forming method as claimed in
claim 13, wherein the light is projected at different
focal positions on the photoresist layer (10) depending
on a concavoconvex surface structure of said
photoresist layer.
Claim 15
Dependent Claim
55 words
The pattern forming method as claimed in
claim 13 or 14, wherein a black pattern (PB) is
projected on the photoresist layer (10) which has a
light intensity lower than that at other portions of
the photoresist layer, using interference generated in
the vicinity of an edge portion of said opaque layer
(14, 32, 53).
Claim 16
Dependent Claim
54 words
The pattern forming method as claimed in
claim 13 or 14, wherein a white pattern is projected on
the photoresist layer (10) which has a light intensity
higher than that at other portions of the photoresist
layer using interference generated in the vicinity of
an edge portion of the opaque layer (14, 32, 53).
Claim 17
Dependent Claim
27 words
The pattern forming method as claimed in
claim 14, 15, or 16, wherein said light is partially
coherent with a coherency in the range 0.3 to 0.7.
Claim 18
Dependent Claim
94 words
The pattern forming method as claimed in any
of claims 13 to 17, wherein the mask has mutually
adjacent phase shift portions with mutually different
phase shift quantities, the difference in phase shift
quantities being in the range 90° to 180° , and wherein
a black pattern is generated on said resist by a
boundary of the adjacent phase shift portions with a
180° phase shift quantity difference, and no pattern is
generated on said resist by a boundary of the phase
shift portions with a phase shift quantity difference
of 90° or less.
Claim 19
Dependent Claim
45 words
The pattern forming method as claimed in any
of claims 13 to 17, wherein the mask has mutually
adjacent phase shift portions with mutually different
phase shift quantities, the difference in phase shift
quantities being in the range 90° ± 30% to 180° ± -30%.
References Cited (Backward Citations)
No citation records indexed.
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