US3821545A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mask alignment in manufacturing semiconductor integrated circuits
Assignee: Hitachi Ltd
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Filing: 1973-05-22
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Granted: 1974-06-28
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Expires: 1993-05-22
Abstract
Abstract A mask for manufacture of semiconductor integrated circuits provided with a position detecting pattern for alignment of the mask with a semiconductor wafer also provided with a counterpart position detecting pattern and an arrangement for the alignment capable of both coarse alignment and fine alignment. The position detecting pattern of the mask consists of a plurality of windows arranged outwardly from the center of the pattern. The coarse alignment is performed by detecting the light reflected by the detecting pattern of the semiconductor wafer through the outermost windows of the detecting pattern of the mask, while the fine alignment is performed by detecting the reflected light through all of the windows of the pattern of the mask.
Inventors
- 👤 Y Nakagawa
- 👤 N Akiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:05
CPC Classifications
G; G03; G03F; G03F9/00; G03F9/70
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
273 words
A method for aligning a mask for the manufacture of semiconductor integrated circuits with a semiconductor wafer, by overlying a reflective position detecting pattern formed on a surface of the semiconductor wafer on a light-permeable position detecting pattern formed on said mask and by detecting the amount of light which is reflected at said reflective position detecting pattern and transmitted through said light-permeable position detecting pattern, by projecting light on said reflective position detecting pattern through said lightpermeable position detecting pattern, said method comprising the steps of: a. providing said light-permeable position detecting pattern to include a pair of first and second sections each provided with a plurality of spaced window areas which are disposed in parallel with a predetermined direction and adapted to transmit light therethrough; b. providing said reflective position detecting pattern to include a plurality of spaced areas which extend in parallel to said predetermined direction and have a light reflection characteristic different from the remaining area; c. detecting, by a first detecting means, the amount of light reflected and transmitted through the window areas provided in said first section of said light-permeable position detecting pattern after being reflected at the corresponding areas of said reflective position detecting pattern; d. detecting, by a second detecting means, the amount of light reflected and transmitted through the window areas provided in said second section of said light-permeable position detecting pattern; and e. effecting a fine adjustment of the relative position between said mask and said semiconductor wafer for aligning said mask with said semiconductor in accordance with the detection of the amount of light detected by said first and second detecting means.
Claim 2
Independent Claim
273 words
A method for aligning a mask for the manufacture of semiconductor integrated circuits with a semiconductor wafer, by overlying a reflective position detecting pattern formed on a surface of the semiconductor wafer on a light-permeable position detecting pattern formed on said mask and by detecting the amount of light which is reflected at said reflective position detecting pattern and transmitted through said light-permeable position detecting pattern, by projecting light on said reflective position detecting pattern through said lightpermeable position detecting pattern, said method comprising the steps of: a. providing said light-permeable position detecting pattern to include a pair of first and second sections each provided with a plurality of spaced window areas which are disposed in parallel with a predetermined direction and adapted to transmit light therethrough; b. providing said reflective position detecting pattern to include a plurality of spaced areas which extend in parallel to said predetermined direction and have a light reflection characteristic different from the remaining area; c. detecting, by a first detecting means, the amount of light reflected and transmitted through the window areas provided in said first section of said light-permeable position detecting pattern after being reflected at the corresponding areas of said reflective position detecting pattern; d. detecting, by a second detecting means, the amount of light reflected and transmitted through the window areas provided in said second section of said light-permeable position detecting pattern; and e. effecting a fine adjustment of the relative position between said mask and said semiconductor wafer for aligning said mask with said semiconductor in accordance with the detection of the amount of light detected by said first and second detecting means.
Claim 3
Dependent Claim
139 words
A method according to claim 1, further comprising, prior to said detecting step (c), the steps of: c1. detecting, by the first detecting means, the amount of limited light reflected and transmitted through only one of the window areas provided in said first section, said one window area being the most remote window from said second section; c2. detecting, by the second detecting means, the amount of limited light reflected and transmitted through only one of the window areas provided in said second section, said one window area being the most remote window from said first section; and c3. effecting a coarse adjustment of the relative position between said mask and said semiconductor wafer for aligning said mask and said semiconductor wafer in accordance with the detection of the amount of limited light by said first and second means.
Claim 4
Independent Claim
238 words
An apparatus for aligning a mask for the manufacture of semiconductor integrated circuits with a semiconductor wafer, said wafer having a reflective position detecting pattern formed on a surface thereof, said pattern including a plurality of spaced apart areas which extend in parallel to a predetermined direction and have a light reflection characteristic different from the remainder of the pattern, comprising: a mask having a light-permeable position detecting pattern formed thereon, and including a pair of first and second sections each provided with a plurality of spaced apart window areas which are disposed in parallel with said predetermined direction and are adapted to transmit light therethrough; first means for projecting light onto said wafer, so that light will be reflected from said reflective position detecting pattern thereon toward said mask; second means detecting the amount of light reflected from said reflective position detecting pattern on said wafer and transmitted through the window areas provided in the first section of said light-permeable position detecting pattern on said mask; third means for detecting the amount of light reflected from said reflective position detecting pattern on said wafer and transmitted through the window areas provided in the second section of said light-permeable position detecting pattern on said mask; and fourth means, responsive to said second and third means, for displacing said semiconductor wafer relative to said mask in accordance with the amount of light detected by said first and second means.
Claim 5
Independent Claim
238 words
An apparatus for aligning a mask for the manufacture of semiconductor integrated circuits with a semiconductor wafer, said wafer having a reflective position detecting pattern formed on a surface thereof, said pattern including a plurality of spaced apart areas which extend in parallel to a predetermined direction and have a light reflection characteristic different from the remainder of the pattern, comprising: a mask having a light-permeable position detecting pattern formed thereon, and including a pair of first and second sections each provided with a plurality of spaced apart window areas which are disposed in parallel with said predetermined direction and are adapted to transmit light therethrough; first means for projecting light onto said wafer, so that light will be reflected from said reflective position detecting pattern thereon toward said mask; second means detecting the amount of light reflected from said reflective position detecting pattern on said wafer and transmitted through the window areas provided in the first section of said light-permeable position detecting pattern on said mask; third means for detecting the amount of light reflected from said reflective position detecting pattern on said wafer and transmitted through the window areas provided in the second section of said light-permeable position detecting pattern on said mask; and fourth means, responsive to said second and third means, for displacing said semiconductor wafer relative to said mask in accordance with the amount of light detected by said first and second means.
Claim 6
Dependent Claim
79 words
An apparatus according to claim 3, further comprising: fifth means for selectively permitting only the limited light reflected and transmitted through one of the window areas provided in said first section and most remote from said second section to be detected by said second means, while permitting only the limited light reflected and transmitted through one of the window areas provided in said second section and most remote from said first section to be detected by said third means.
Claim 7
Dependent Claim
160 words
An apparatus according to claim 4, further comprising: a wafer chuck for supporting said semiconductor wafer; a carriage mechanically connected to said wafer chuck through elastic connecting means and movable by a screw mechanism; first driving means, responsive to the detection of the amount of limited light by said second and third means, for driving the screw mechanism to move said carriage until the output of said second means becomes equal to the output of said third means, to thereby effect a coarse alignment of said wafer relative to said mask; and second driving means, mounted on said carriage and responsive to the detection of the amount of light by said second and third means, for moving said wafer chuck relative to said carriage with elastic deformation of said elastic means until the output of said second means becomes equal to the output of said third means, to thereby effect a fine alignment of said wafer relative to said mask.
Claim 8
Dependent Claim
187 words
An apparatus according to claim 3, wherein said reflective position detecting pattern further includes an additional plurality of spaced apart areas which extend in parallel to a prescribed direction different from said predetermined direction and have said light reflection characteristics; said light-permeable position detecting pattern further includes a pair of third and fourth sections each provided with a plurality of spaced apart window areas which are disposed in parallel with said prescribed direction and are adapted to transmit light Therethrough; and further including fifth means for detecting the amount of light reflected from said reflective position detecting pattern on said wafer and transmitted through the window areas in said third section of said light-permeable position detecting pattern; sixth means for detecting the amount of light reflected from said reflective position detecting pattern on said wafer and transmitted through the window areas provided in the fourth section of said light-permeable detecting pattern; and wherein said fourth means is further responsive to said fith and sixth means for displacing said wafer relative to said mask in accordance with the amount of light detected by said fifth and sixth means.
Claim 9
Dependent Claim
16 words
An apparatus according to claim 6, wherein said predetermined direction is orthogonal to said prescribed direction.
Claim 10
Dependent Claim
151 words
An apparatus according to claim 6, further comprising: seventh means for selectively permitting only the limited light reflected and transmitted through one of the window areas provided in said first section and most remote from said second section to be detected by said second means, while permitting only the limited light reflected and transmitted through one of the window areas provided in said second section and most remote from said first section to be detected by said third means; and eighth means for selectively permitting only the limited light reflected and transmitted through one of the window areas provided in said third section and most remote from said fourth section to be detected by said fifth means, while permitting only the limited light reflected and transmitted through one of the window areas provided in said fourth section and most remote from said first section to be detected by said sixth means.
Claim 11
Dependent Claim
27 words
An apparatus according to claim 6, wherein the size of each window area of each section differs from those of the other window areas of that section.
Claim 12
Dependent Claim
35 words
An apparatus according to claim 9, wherein each window subtends a multiplicity of said areas the number of which corresponds to the size of that respective window when said wafer and said mask are aligned.
Claim 13
Independent Claim
253 words
A method for aligning a first article relative to a second article comprising the steps of: a. forming, on a first surface of said first article, a reflective position detecting pattern including a first plurality of spaced apart groups of areas aligned in parallel with a first predetermined direction and having a light reflection characteristic different from the remainder of the pattern; b. forming, in said second article, a light-permeable position detecting pattern including a pair of first and second sections each provided with a plurality of spaced apart window areas which are disposed in parallel with said first predetermined direction and are adapted to transmit light therethrough; c. positioning said second article with respect to said first article, so that light reflected from at least a portion of said reflective position detecting pattern on said first article will pass through at least a portion of the light-permeable position detecting pattern in said second article; d. detecting the amount of light reflected from said reflective position detecting pattern on said first article and transmitted through the window areas provided in the first section of said light-permeable detecting pattern in said second article; e. detecting the amount of light reflected from said reflective position detecting pattern on said first article and transmitted through the window areas provided in the second section of said light-permeable detecting pattern in said second article; and f. displacing said second article relative to said first article in accordance with the amount of light detected by steps (d) and (e).
Claim 14
Independent Claim
253 words
A method for aligning a first article relative to a second article comprising the steps of: a. forming, on a first surface of said first article, a reflective position detecting pattern including a first plurality of spaced apart groups of areas aligned in parallel with a first predetermined direction and having a light reflection characteristic different from the remainder of the pattern; b. forming, in said second article, a light-permeable position detecting pattern including a pair of first and second sections each provided with a plurality of spaced apart window areas which are disposed in parallel with said first predetermined direction and are adapted to transmit light therethrough; c. positioning said second article with respect to said first article, so that light reflected from at least a portion of said reflective position detecting pattern on said first article will pass through at least a portion of the light-permeable position detecting pattern in said second article; d. detecting the amount of light reflected from said reflective position detecting pattern on said first article and transmitted through the window areas provided in the first section of said light-permeable detecting pattern in said second article; e. detecting the amount of light reflected from said reflective position detecting pattern on said first article and transmitted through the window areas provided in the second section of said light-permeable detecting pattern in said second article; and f. displacing said second article relative to said first article in accordance with the amount of light detected by steps (d) and (e).
Claim 15
Dependent Claim
139 words
A method according to claim 11, wherein said step (d) includes the step of d1. detecting the amount of light reflected from said position detecting pattern on said first article and transmiTted only through that window of said first section of said light-permeable detecting pattern which is the most remote from the second section thereof; said step (e) includes the step of e1. detecting the amount of light reflected from said position detecting pattern on said first article and transmitted only through that window of said second section of said light-permeable detecting pattern which is the most remote from the first section thereof; and said step (f) includes the step of f1. effecting a coarse adjustment of the relative position between said first and second articles in accordance with the amount of light detected in steps (d1) and (e1).
Claim 16
Dependent Claim
27 words
A method according to claim 11, wherein the size of each window area of each section differs from those of the other window areas of that section.
Claim 17
Dependent Claim
39 words
A method according to claim 13, wherein the number of areas in each group of areas corresponds to the size of the window subtending that respective group of areas when said first article is aligned with said second article.
Claim 18
Dependent Claim
197 words
A method according to claim 11, wherein said reflective position detecting pattern formed in step (a) further includes a second plurality of spaced apart groups of areas aligned in parallel with a second predetermined direction different from said first predetermined direction and having said light reflection characteristic, and said light-permeable position detecting pattern formed in step (b) further includes a pair of third and fourth sections each provided with a plurality of spaced apart window areas which are disposed in parallel with said section predetermined direction and are adapted to transmit light therethrough; and further including the steps of g. detecting the amount of light reflected from said reflective position detecting pattern on said first article and transmitted through the window areas provided in the third section of said light-permeable detecting pattern in said second article; h. detecting the amount of light reflected from said reflective position detecting pattern on said first article and transmitted through the window areas provided in the fourth section of said light-permeable detecting pattern in said second article; and i. further displacing said second article relative to first article in accordance with the amount of light detected by steps (g) and (h).
Claim 19
Dependent Claim
18 words
A method according to claim 15, wherein said first predetermined direction is orthogonal to said second predetermined direction.
Claim 20
Dependent Claim
271 words
A method according to claim 15, wherein said step (d) includes the step of d1. detecting the amount of light reflected from said position detecting pattern on said first article and transmitted only through that window of said first section of said light-permeable detecting pattern which is the most remote from the second section thereof; said step (e) includes the step of e1. detecting the amount of light reflected from said position detecting pattern on said first article and transmitted only through that window of said second section of said light-permeable detecting pattern which is the most remote from the first section thereof; and said step (f) includes the step of f1. effecting a coarse adjustment of the relative position between said first and second articles in accordance with the amount of light detected in steps (d1) and (e1); said step (g) includes the step of g1. detecting the amount of light reflected from said position detecting pattern on said first article and transmitted only through that window of said third section of said light-permeable detecting pattern which is the most remote from the fourth section thereof; said step (h) includes the step of h1. detecting the amount of light reflected from said position detecting pattern on said first article and transmitted only through that window of said fourth section of said light-permeable detecting pattern which is The most remote from said third section thereof; and said (i) includes the step of i1. effecting a further coarse adjustment of the relative position between said first and second articles in accordance with the amount of light detected in steps (g1) and (h1).
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-27 | 1981-12-27 | 1982-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-27 | 1985-12-27 | 1986-06-28 | $7700.00 | Window Closed / Lapsed |