WO2002041389A2 - A method for monitoring line width of electronic circuit patterns - Google Patents
A method for monitoring line width of electronic circuit patterns Download PDFInfo
- Publication number
- WO2002041389A2 WO2002041389A2 PCT/EP2001/013305 EP0113305W WO0241389A2 WO 2002041389 A2 WO2002041389 A2 WO 2002041389A2 EP 0113305 W EP0113305 W EP 0113305W WO 0241389 A2 WO0241389 A2 WO 0241389A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- focus
- line width
- test
- pattern
- patterns
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/70—Microphotolithographic exposure; Apparatus therefor
- G03F7/70483—Information management; Active and passive control; Testing; Wafer monitoring, e.g. pattern monitoring
- G03F7/70605—Workpiece metrology
- G03F7/70616—Monitoring the printed patterns
- G03F7/70625—Dimensions, e.g. line width, critical dimension [CD], profile, sidewall angle or edge roughness
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/70—Microphotolithographic exposure; Apparatus therefor
- G03F7/70483—Information management; Active and passive control; Testing; Wafer monitoring, e.g. pattern monitoring
- G03F7/70605—Workpiece metrology
- G03F7/70616—Monitoring the printed patterns
- G03F7/70641—Focus
Definitions
- This invention relates to the production of electronic circuits on substrates and in particular to the production of conductor lines of such circuits.
- the line width of the pattern features be maintained at, or very close to, a critical dimension - defined in the circuit specification.
- the line width is a function of focus of the projected pattern, processing of the exposed substrate, and other possible variations.
- a test pattern is exposed at nominal exposure and focus conditions at several locations on a substrate. At each location there are a plurality of individual patterns, each exposed at a slightly different focus. On scanning the test pattern a series of values are obtained for line width in each of the individual patterns. These results are resolved into data which can be regressed to, for example a second order equation, or some other equation, as desired, to provide a polynomial.
- the supposed line width versus focus exhibits a convex curve, though a concave curve is also possible depending on the relative exposure dosing.
- the critical dimension is calculated for each location, and the appropriate focus. This information can be then used to control the stepper so that the ideal focus can be provided to give the critical dimension. Additionally, the line width best focus enables the user to decouple source of line width variation due to process variations from focus variations.
- the invention comprises forming a first pattern on a substrate at a normal focus, forming a test array adjacent the first pattern, the array comprising a plurality of test patterns each of a different predetermined focus, the focus range extending along the array and the focus at an intermediate position equal to the focus of the first pattern, measuring the line width in each test pattern and comparing with the line width to produce a curve indicative of line width versus focus; and to produce a focus value for an extreme line width; determining the difference between the focus for this line width and the focus for the first pattern.
- This difference can be used to program a stepper on the pattern projector to maintain a focus for an extreme line width production.
- Figure 1 illustrates diagrammatically an example layout of a substrate
- Figure 2 illustrates a curve obtained from the resolving of the scanned line width, showing line width relative to focus
- Figure 3 is a table giving an example of maximum critical dimension mapping across a wafer substrate.
- the wafer 12 is initially scanned, and the focus measured, by the scanner, at various positions 8, to determine that there is correct positioning of the wafer. This is conventional. This provides a focus value - hereafter referred to as the nominal value. No actual exposure of a pattern occurs.
- a series of set patterns 10 are exposed on the wafer at nominal exposure conditions and at the nominal focus conditions.
- a series of test arrays 14 are exposed on the wafer at positions adjacent the patterns 10.
- a plurality of test patterns I6 l -I6 'n are exposed at slightly different foci, to form what can be termed focus arrays.
- the set patterns 10 provide a nominal or datum focus as provided by the stepper for the projector.
- the focus of test pattern 16 "1 will be lower than the nominal value and at 16 " " " where the nominal focus will be higher than the value, the intermediate test patterns 16 having foci stepping from that of 16 "1 to that of 16 "n .
- the same feature is measured on both the nominal exposure set patterns 10 and the focus arrays 14. At nominal focus and exposure, the average line width and variation is calculated. For the focus arrays, the data are regressed versus focus and the critical dimension is calculated at each test pattern 16. Also, the focus at which the critical dimension is found is recorded.
- the average critical dimension at best focus is a direct measurement of the machine focus effect on line width when compared to a line width exposed at normal conditions. Changes in line width at best focus are a measure of process effect, or exposure effect, independent of machine focus.
- Figure 2 illustrates one example of a program for a particular wafer substrate.
- the nominal focus for the set patterns 10 is given a focus value as 0.
- the foci for the test patterns 16 is varied from -0.2 ⁇ m to +0.02 ⁇ m.
- the critical dimension is indicated by the dotted line 20.
- the curve 22 is obtained from the data obtained from the patterns 16 resolved as above. It will be seen that the critical dimension is obtained at a slightly negative focus; almost -0.1 ⁇ m.
- This information can be applied to the stepper so that processing of wafers with the particular set up will proceed with the stepper maintaining the focus slightly reduced from the nominal. The stepper will maintain this focus independent of any other variations.
- the invention also provides information concerning other features of a process.
- the table of Figure 3 gives values for line width at various positions across a wafer, the left and top values giving Y and X positions.
- the critical dimension or line width varies from 0.191 to 0.200, but shows one locality with a major difference, 0.178. This may indicate that there is a fault in the process, such as in the coating of the substrate, or in development or some other possible variable. Any discrepancy is not caused by focus effects. Also, by looking at the values in the table, it is possible to determine whether the line width data is within specifications.
- the stepper controlling the focus of the pattern projector is programmed to maintain the best possible focus, although this may not result in the optimum line width.
- the method is to produce a first, set pattern, in the conventional manner, the stepper focusing the pattern projection at the best focus.
- the stepper focusing the pattern projection at the best focus.
- a central pattern is at the same focus as that of the first, set, pattern, the focus stepping up or down for the remaining test patterns in the array.
- the line width is measured for each test pattern in an array and from this it is possible to determine the best focus for optimum line width. This information is used to control the stepper, in effect giving a bias to the stepper control.
- the number of set patterns 10, and the number of arrays 14 can vary.
- the size of the substrate will influence the number to some extent.
- the number of test patterns 16 in an array can also vary.
- the process of the invention can be used solely to monitor a product line, to provide information, for use by an operator, for example, or it can be used to directly control the stepper, if desired.
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP01996883A EP1334407A2 (en) | 2000-11-16 | 2001-11-14 | A method for monitoring line width of electronic circuit patterns |
JP2002543692A JP2004514292A (en) | 2000-11-16 | 2001-11-14 | How to monitor line width of electronic circuit patterns |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US71324000A | 2000-11-16 | 2000-11-16 | |
US09/713,240 | 2000-11-16 |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2002041389A2 true WO2002041389A2 (en) | 2002-05-23 |
WO2002041389A3 WO2002041389A3 (en) | 2003-03-13 |
Family
ID=24865351
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP2001/013305 WO2002041389A2 (en) | 2000-11-16 | 2001-11-14 | A method for monitoring line width of electronic circuit patterns |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP1334407A2 (en) |
JP (1) | JP2004514292A (en) |
WO (1) | WO2002041389A2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
NL1028034C2 (en) * | 2004-01-16 | 2008-09-16 | Toshiba Kk | Exposure system, test mask for flash testing, method for evaluating a lithographic process, method for evaluating illuminators, method for generating a corrected mask pattern and method for manufacturing a semiconductor device. |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP6063630B2 (en) * | 2012-03-19 | 2017-01-18 | 株式会社日立ハイテクノロジーズ | Pattern measuring apparatus and semiconductor measuring system |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US990567A (en) * | 1910-08-24 | 1911-04-25 | Gustave Krieger | Corset-shoe. |
US5338630A (en) * | 1992-03-05 | 1994-08-16 | National Semiconductor Corporation | Photolithography control system and method using latent image measurements |
US5747202A (en) * | 1993-06-07 | 1998-05-05 | Canon Kabushiki Kaisha | Projection exposure method |
US5989764A (en) * | 1991-03-04 | 1999-11-23 | Lucent Technologies Inc. | Method of adjusting lithography tool through scattered energy measurement |
-
2001
- 2001-11-14 WO PCT/EP2001/013305 patent/WO2002041389A2/en not_active Application Discontinuation
- 2001-11-14 EP EP01996883A patent/EP1334407A2/en not_active Withdrawn
- 2001-11-14 JP JP2002543692A patent/JP2004514292A/en active Pending
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US990567A (en) * | 1910-08-24 | 1911-04-25 | Gustave Krieger | Corset-shoe. |
US5989764A (en) * | 1991-03-04 | 1999-11-23 | Lucent Technologies Inc. | Method of adjusting lithography tool through scattered energy measurement |
US5338630A (en) * | 1992-03-05 | 1994-08-16 | National Semiconductor Corporation | Photolithography control system and method using latent image measurements |
US5747202A (en) * | 1993-06-07 | 1998-05-05 | Canon Kabushiki Kaisha | Projection exposure method |
Non-Patent Citations (1)
Title |
---|
DIRKSEN P ET AL: "FOCUS AND EXPOSURE DOSE DETERMINATION USING STEPPER ALIGNMENT" PROCEEDINGS OF THE SPIE, SPIE, BELLINGHAM, VA, US, vol. 2726, 1996, pages 799-808, XP001016402 * |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
NL1028034C2 (en) * | 2004-01-16 | 2008-09-16 | Toshiba Kk | Exposure system, test mask for flash testing, method for evaluating a lithographic process, method for evaluating illuminators, method for generating a corrected mask pattern and method for manufacturing a semiconductor device. |
Also Published As
Publication number | Publication date |
---|---|
WO2002041389A3 (en) | 2003-03-13 |
JP2004514292A (en) | 2004-05-13 |
EP1334407A2 (en) | 2003-08-13 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
KR100733546B1 (en) | Method and System for Selective Linewidth Optimization During a Lithographic Process | |
KR102081271B1 (en) | Lithographic Apparatus and Device Manufacturing Method | |
US5436097A (en) | Mask for evaluation of aligner and method of evaluating aligner using the same | |
KR100563157B1 (en) | Duv scanner linewidth control by mask error factor compensation | |
US6248485B1 (en) | Method for controlling a process for patterning a feature in a photoresist | |
US5805866A (en) | Alignment method | |
US5448333A (en) | Exposure method | |
KR100844809B1 (en) | Production method of semiconductor device and production system of semiconductor device | |
KR20030007935A (en) | Method and apparatus for using scatterometry to perform feedback and feed-forward control | |
US20060160037A1 (en) | Automated sub-field blading for leveling optimization in lithography exposure tool | |
KR20070080573A (en) | Lithographic apparatus, calibration method, device manufacturing method and computer program product | |
US5928822A (en) | Method for confirming optimum focus of stepper | |
US7507508B2 (en) | Method for manufacturing a semiconductor device | |
US6426174B1 (en) | Method for manufacture semiconductor devices | |
KR100271048B1 (en) | Alignment method | |
US6536130B1 (en) | Overlay mark for concurrently monitoring alignment accuracy, focus, leveling and astigmatism and method of application thereof | |
KR900001506B1 (en) | Correcting method of electron beam devices | |
WO2002041389A2 (en) | A method for monitoring line width of electronic circuit patterns | |
GB2321316A (en) | Forming a pattern on a semiconductor substrate including heating or cooling the substrate to adjust its size | |
JPH06232028A (en) | Positioning method | |
US6493063B1 (en) | Critical dimension control improvement method for step and scan photolithography | |
US20020082789A1 (en) | Calibration plate having accurately defined calibration pattern | |
JP2822229B2 (en) | Positioning method and apparatus | |
Slonaker et al. | Enhanced global alignment for production optical lithography | |
TW202232232A (en) | Lithographic method |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A2 Designated state(s): JP |
|
AL | Designated countries for regional patents |
Kind code of ref document: A2 Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2001996883 Country of ref document: EP |
|
ENP | Entry into the national phase in: |
Ref country code: JP Ref document number: 2002 543692 Kind code of ref document: A Format of ref document f/p: F |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWP | Wipo information: published in national office |
Ref document number: 2001996883 Country of ref document: EP |
|
WWW | Wipo information: withdrawn in national office |
Ref document number: 2001996883 Country of ref document: EP |