CN101930180B - Method and device for detecting focal plane change of exposure machine table - Google Patents
Method and device for detecting focal plane change of exposure machine table Download PDFInfo
- Publication number
- CN101930180B CN101930180B CN 200910053374 CN200910053374A CN101930180B CN 101930180 B CN101930180 B CN 101930180B CN 200910053374 CN200910053374 CN 200910053374 CN 200910053374 A CN200910053374 A CN 200910053374A CN 101930180 B CN101930180 B CN 101930180B
- Authority
- CN
- China
- Prior art keywords
- exposure
- overlay
- focal plane
- chock
- layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Abstract
The invention discloses a method for detecting focal plane change of an exposure machine table, which comprises the following steps: carrying out exposure and development on a control wafer by using a photomask to form a first-layer overlay precise measurement mark (OVL mark); carrying out exposure and development for a second time by using the photomask with a wedge to form a second-layer OVL mark on the first-layer OVL mark, wherein the photomask with a wedge resolves the focal length Z-axis component into an X-axis component and a Y-axis component; measuring the overlay degree of the first-layer OVL mark and the second-layer OVL mark by using an overlay precise measuring instrument to obtain the overlay value of the first-layer OVL mark and the second-layer OVL mark in the X-axis direction and the Y-axis direction according to the change of the focal length variable delta Z in the second exposure; and determining whether the focal plane is changed according to the intersection point of the overlay value curve, which is formed by delta Z and X-axis direction, and the overlay value curve formed by delta Z and Y-axis direction. The invention also discloses an exposure machine table for detecting the focal plane change of the exposure machine table. The method and the device can be used for precisely determining whether the focal plane of the exposure machine table is changed with high efficiency.
Description
Technical field
The present invention relates to the technical field of lithography that semiconductor is made, particularly a kind of method and device that detects the exposure machine focal plane variation.
Background technology
At present, in the manufacture of semiconductor technology, photoetching technique is along with the improve of critical size technology, and it is more and more important to become.
The degree of stability of exposure bench is subject to very many-sided impact, impact such as aspects such as the variation of the degree of planarization of the skew of the crystal wafer platform on the exposure bench or lens, crystal column surface, optical maser wavelength and environment, the capital causes the focal plane (focal length) of exposure bench to change, the true focal length value that is exposure bench is different from initial setting value, can make like this size of wafer of exposure different from preset value with profile.
In order in time correction to be made in the variation of exposure machine focal plane, then need the variation of monitoring exposure machine focal plane.
In the prior art, at preparation focus-exposure matrix wafer (Focus Energy Matrix Wafer, FEM Wafer) afterwards, adopt critical dimension-scanning electron microscope (CriticalDemension-Scanning Electron Microscope, CD-SEM), measure the two-dimentional critical size (CD) of crystal column surface, obtain under different exposure energy points, variation relation curve between CD and the focal length value, be Bai Sang curve (Bossung Curve), from Bossung Curve, obtain the optimum focusing value.Variation for monitoring exposure machine focal plane, then need at regular intervals, obtain a pinpointed focus value according to said method, if the focal plane changes, then each pinpointed focus value that obtains is different from comparing in the past, and because need to form Bossung Curve at every turn, this Curve is relatively more responsive to environmental evolution, some are unnecessary, negligible factor changes, probably cause the Bossung Curve that forms also to change thereupon, in case seeing Bossung Curve changes, think that then the focal plane of exposure bench changes, in time exposure bench is adjusted with regard to needs, BossungCurve has reflected the variation of exposure bench unsubstantiality, this be in the concrete processing procedure do not wish to occur, therefore this method is more inaccurate and time-consuming.
Summary of the invention
In view of this, the technical matters of the present invention's solution is: detect exposure machine focal plane and change.
For solving the problems of the technologies described above, technical scheme of the present invention specifically is achieved in that
The invention discloses a kind of method that exposure machine focal plane changes that detects, the method comprises:
Form first cascade to accurately measuring sign OVL mark by light shield exposure imaging on wafer control slice control wafer;
By the light shield with chock, exposure imaging forms second layer OVL mark, the described component that the component of exposure bench focal length Z axis is decomposed into X-direction and Y direction with the light shield of chock at described ground floor OVL mark again;
Adopt overlay to accurately measure instrument overlay, overlay degree to described ground floor OVL mark and second layer OVL mark is measured, the variation of focal length variations amount Δ Z obtains the X-direction of described ground floor OVL mark and second layer OVL mark and the overlay overlay value of Y direction when again exposing;
According to the intersection point of the overlay value curve of the Δ Z of the overlay value curve of the Δ Z that forms and X-direction and formation and Y direction, determine whether the focal plane changes.
Described ground floor OVL mark be formed in each chip unit die that each exposing unit shot of wafer comprises around.
The ground floor OVL mark all around that is distributed in each die is four squares, comprises two little squares that are positioned at the die top, and two large squares that are positioned at the die below.
Around in the identical die of the characteristic dimension CD that the exposing unit that described second layer OVL mark is formed at center wafer comprises.
Second layer OVL mark around being distributed in the die is four squares, comprises two large squares that are positioned at the die top, and two little squares that are positioned at the die below.
An exposing unit of every formation center wafer, focal length variations amount Δ Z changes.
Whether described definite focal plane changes, and determines according to the intersection point of curve, when described intersection point departs from Δ Z=0, determines that the focal plane changes.
The invention also discloses a kind of exposure bench that exposure machine focal plane changes that detects, comprise lens, also comprise the light shield with chock, described chock is arranged on the light shield top, be used for when exposure, the component of exposure bench focal length Z-direction being resolved into the component of X-axis and Y direction.
The size of described chock is the size of a die.
The angle of described chock is that 45 degree are to 315 degree.
As seen from the above technical solutions, the present invention covers on the upper exposure imaging of wafer control slice (controlwafer) by normal optical and forms first cascade to accurately measuring sign, one chock (wedge) then is set above the light shield of exposure bench, this chock size is corresponding to the size of the chip unit on the light shield, the component of focal length Z axis can be resolved into the component of X-axis and Y-axis, carry out the exposure imaging second time by this light shield with chock, form second layer overlay and accurately measure sign, adopt overlay to accurately measure instrument, the overlay degree that described first cascade is accurately measured sign to accurately measuring sign and second layer overlay is measured, than available technology adopting CD-SEM FEM Wafer being carried out CD measures, obtain Bossung Curve, and then obtain the pinpointed focus value, then judge that from the pinpointed focus value that obtains the focal plane changes, not only detection efficiency is high, and accuracy is also higher, do not have the picture prior art in Bossung Curve very sensitive to environmental evolution, so the inaccurate defective of the information that obtains.Adopt the method can determine accurately and efficiently whether exposure machine focal plane changes.
Description of drawings
Fig. 1 is the etching system schematic diagram that exposure bench light shield top arranges a chock in the prior art.
Fig. 2 is the schematic top plan view of chock.
Fig. 3 is the schematic flow sheet of the method for the variation of detection exposure machine focal plane among the present invention.
Fig. 4 is under ideal state, the schematic diagram that OVL mark aims at fully.
Fig. 5 is that the variation of overlay value from the plane detects the curve synoptic diagram that the focal plane changes.
Embodiment
For make purpose of the present invention, technical scheme, and advantage clearer, referring to the accompanying drawing embodiment that develops simultaneously, the present invention is described in more detail.
The present invention utilizes schematic diagram to describe in detail, when the embodiment of the invention is described in detail in detail, for convenience of explanation, the schematic diagram of expression structure can be disobeyed general ratio and be done local the amplification, should be with this as limitation of the invention, in addition, in the making of reality, should comprise the three-dimensional space of length, width and the degree of depth.
In order clearly to describe structure of the present invention, omitted the part known configurations in each schematic diagram of the application.
Key of the present invention is when exposing for the second time, one chock is set above the light shield of exposure bench, this chock size resolves into the component of focal length Z axis the component of X-axis and Y-axis corresponding to the size of the chip unit on the light shield (die), thereby accurately reflects the variation of exposure machine focal plane.Every wafer (wafer) comprises a plurality of exposing units (shot), and the pattern between upper each shot of full wafer wafer is identical, is about to wafer and is divided into the shot that several have periodic structure, comprises again a plurality of die in the shot.
Exposure bench light shield of the prior art top is arranged a chock, and etching system comprises light shield 101 and lens 102 with chock as shown in Figure 1.Wafer (wafer) is placed on the below of lens 102, the pattern on the light shield 101 (pattern), and the exposure through light source 103 has copied on the wafer.The chock size is corresponding to the size of the chip unit on the light shield (die), that is to say when using light shield 101 with chock to expose, and only the die among the selected shot need to be exposed and just can reach purpose of the present invention.Be positioned over the schematic top plan view of the chock on the light shield as shown in Figure 2.The angle 2 of chock also has multiple, generally value between 45 degree are spent to 315.
Fig. 3 shows the schematic flow sheet of the method for the variation that detects exposure machine focal plane among the present invention.
In the specific embodiment of the invention, choose 9 shot at wafer, expose, form second layer pattern area and OVL mark.Wherein, OVL mark still be formed in each die around.Certainly, the quantity of the shot that gets is more, and the variation of reflection focal plane is more accurate, chooses 9 shot just for the present invention clearly is described.The interference that changes in order not to be subject to wafer itself, the position of 9 shot that get all concentrates on the center of wafer.This is to comprise that mainly wafer amplifies, wafer rotates and the wafer orthogonality because affect the parameter of wafer itself, and the center of wafer is subjected to the impact of above-mentioned parameter minimum, along with the increase interference of radius is also more serious, the focal plane is changed.The object of the invention is to detect the variation of focal plane, i.e. the variation of focal length, so the interference that above-mentioned wafer itself changes is not wished to detect, the position of the shot that therefore gets all is in the center of wafer basically.Need to prove, the size of light shield is the size of a shot, because only corresponding to the size of a die on the light shield, other zones do not have chock on the light shield for chock size, and during exposure, wafer need to be moved 9 times, so when choosing upper 9 shot of wafer and exposing, specifically refer to an identical die of critical size (CD) among each shot of 9 shot, expose through chock, and other die remain direct and expose through light shield.Shot of every exposure among the present invention, the focal length of exposure bench Z-direction is changing the described component that the component of exposure bench focal length Z axis is decomposed into X-direction and Y direction with the light shield of chock.
During exposure, on move or move down wafer distance be the length of half die, make the large square OVL mark of the second layer in the little square OVL mark alignment procedures 32 of ground floor in the step 31, make simultaneously the little square OVL mark of the second layer in the large square OVL mark alignment procedures 32 of ground floor in the step 31.
Owing to choosing 9 shot on the wafer, so take 200 nanometers (nm) as the interval, the change Delta Z that makes focal length is from value between the-800nm to 800nm, namely when exposing the second time, shot of every exposure, Δ Z value changes.Certainly, the value of Δ Z and interval can specifically be chosen as the case may be, take 200nm as the interval, and from value between the-800nm to 800nm, the present invention's one specific embodiment just.The figure that obtains as shown in Figure 5, horizontal ordinate is Δ Z, the value of Δ Z is respectively-800nm,-600nm,-400nm,-200nm, 0nm, 200nm, 400nm, 600nm and 800nm, ordinate is the value of overlay on directions X and the Y-direction, take Δ Z=-800nm as example, corresponding X value be changed to 120nm, being changed to-150nm of corresponding Y value, when measuring the value of 9 corresponding overlay of shot, along with the variation of Δ Z value, the X value changes like this, match forms a dimension curve, equally, along with the variation of Δ Z value, Y value changes, match forms a dimension curve again, article two, the point of crossing of a dimension curve is the variation of focal length, as can be seen from the figure, focal length has departed from 0 point, Δ Z=-80nm, this explanation focal length changes off center position-80nm.
Utilizing overlay to accurately measure instrument among the present invention measures OVL mark, detect the method that the focal plane changes, than available technology adopting CD-SEM FEM Wafer being carried out CD measures, obtain Bossung Curve, and then obtain the pinpointed focus value, then judge that from the pinpointed focus value that obtains the focal plane changes, not only detection efficiency is high, and accuracy is also higher, do not have the picture prior art in Bossung Curve very sensitive to environmental evolution, so the inaccurate defective of the information that obtains.Above described detection efficiency high, refer to the CD-SEM that the OVL that utilizes among the present invention utilizes in the prior art, the quantum of output of board itself is high.OVL adopts optical principle, does not need when wafer is measured to vacuumize, and the measurement time of every wafer is very short, is approximately 2 minutes.And in semiconductor manufacturing factory (Fab), belonging to more idle board, the wafer that therefore just gets off from exposure bench can measure at once.And therefore CD-SEM needs to keep in the wafer reaction chamber certain vacuum tightness because be by the secondary electron imaging.Therefore every a slice wafer board all needs to vacuumize.Therefore frequent heap goods on the board, the wafer that just gets off from exposure bench just can not measure at once, and exposure bench such as needs at the result of (MONITOR) to be monitored, so the time of answering a pager's call of exposure bench will stop over because of the heap goods of CD-SEM.And the measurement time of every wafer of CD-SEM is greatly about 5 minutes.As can be seen from the above, use OVL to save the more measurement time than CD-SEM, greatly improved detection efficiency.
The above is preferred embodiment of the present invention only, is not for limiting protection scope of the present invention.Within the spirit and principles in the present invention all, any modification of doing, be equal to and replace and improvement etc., all should be included within protection scope of the present invention.
Claims (9)
1. one kind is detected the method that exposure machine focal plane changes, and the method comprises:
Form first cascade to accurately measuring sign by light shield exposure imaging on wafer control slice;
By the light shield with chock, exposure imaging again, accurately measure sign, the described component that the component of exposure bench focal length Z axis is decomposed into X-direction and Y direction with the light shield of chock at described first cascade to accurately measuring the overlay of the sign formation second layer;
Adopt overlay to accurately measure instrument, the overlay degree that described first cascade is accurately measured sign to accurately measuring sign and second layer overlay is measured, the variation of focal length variations amount △ Z when again exposing obtains described first cascade and accurately measures the X-direction of sign and the overlay value of Y direction to accurately measuring sign and second layer overlay;
Intersection point according to the overlay value curve of the △ Z of the overlay value curve of the △ Z that forms and X-direction and formation and Y direction, determine whether the focal plane changes, whether described definite focal plane changes, intersection point according to curve is determined, when described intersection point departs from △ Z=0, determine that the focal plane changes.
2. the method for claim 1 is characterized in that, described first cascade to accurately measure sign be formed in each chip unit that each exposing unit of wafer control slice comprises around.
3. method as claimed in claim 2, it is characterized in that, the first cascade all around that is distributed in each chip unit is designated four squares to accurately measuring, and comprises two little squares that are positioned at the chip unit top, and two large squares that are positioned at the chip unit below.
4. the method for claim 1 is characterized in that, described second layer overlay accurately measure sign be formed in the identical chip unit of characteristic dimension CD that the exposing unit at wafer control slice center comprises around.
5. method as claimed in claim 4, it is characterized in that, second layer overlay around being distributed in the chip unit accurately measures and is designated four squares, comprises two large squares that are positioned at the chip unit top, and two little squares that are positioned at the chip unit below.
6. method as claimed in claim 4 is characterized in that, an exposing unit at every formation wafer control slice center, and focal length variations amount △ Z changes.
7. one kind is detected the exposure bench that exposure machine focal plane changes, and comprises lens, it is characterized in that, also comprise the light shield with chock, described chock is arranged on the light shield top, is used for the component of exposure bench focal length Z-direction being resolved into the component of X-axis and Y direction when exposure.
8. exposure bench as claimed in claim 7, the size of described chock is the size of a chip unit.
9. exposure bench as claimed in claim 7, the angle of described chock are that 45 degree are to 315 degree.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200910053374 CN101930180B (en) | 2009-06-18 | 2009-06-18 | Method and device for detecting focal plane change of exposure machine table |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200910053374 CN101930180B (en) | 2009-06-18 | 2009-06-18 | Method and device for detecting focal plane change of exposure machine table |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101930180A CN101930180A (en) | 2010-12-29 |
| CN101930180B true CN101930180B (en) | 2013-01-23 |
Family
ID=43369425
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200910053374 Expired - Fee Related CN101930180B (en) | 2009-06-18 | 2009-06-18 | Method and device for detecting focal plane change of exposure machine table |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101930180B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105223784B (en) * | 2015-10-29 | 2018-01-26 | 上海华力微电子有限公司 | A kind of method for detecting litho machine focus offset |
| CN105547655A (en) * | 2016-01-29 | 2016-05-04 | 上海华虹宏力半导体制造有限公司 | Method for detecting optimal focal length of product through optical measurement |
| DE102017115365B4 (en) * | 2017-07-10 | 2020-10-15 | Carl Zeiss Smt Gmbh | Semiconductor lithography mask inspection device and process |
| CN109188855B (en) * | 2018-10-15 | 2022-03-18 | 上海华力集成电路制造有限公司 | Focal length monitoring photomask and method of photoetching machine |
-
2009
- 2009-06-18 CN CN 200910053374 patent/CN101930180B/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN101930180A (en) | 2010-12-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11022900B2 (en) | Inspection apparatus and methods, substrates having metrology targets, lithographic system and device manufacturing method | |
| US10725386B2 (en) | Metrology method and apparatus, lithographic system and device manufacturing method | |
| US10042268B2 (en) | Method, apparatus and substrates for lithographic metrology | |
| US9714827B2 (en) | Metrology method and apparatus, lithographic system, device manufacturing method and substrate | |
| TWI431439B (en) | Level sensor arrangement for lithographic apparatus and device manufacturing method | |
| US9134256B2 (en) | Metrology method and apparatus, lithographic system and device manufacturing method | |
| KR101826651B1 (en) | Method of determining critical-dimension-related properties, inspection apparatus and device manufacturing method | |
| US10416577B2 (en) | Position measuring method of an alignment target | |
| KR20180124109A (en) | Determination of stack difference and correction technique using stack difference | |
| JP2008021984A (en) | Method and device of analyzing characteristics of spectroscopy lithography which is angle-resolved | |
| JP2014529903A (en) | Method for determining focus correction, lithographic processing cell and device manufacturing method | |
| KR20190112787A (en) | Metrology methods and devices and associated computer products | |
| CN101930180B (en) | Method and device for detecting focal plane change of exposure machine table | |
| TWI604276B (en) | Method of determining edge placement error, inspection apparatus, patterning device, substrate and device manufacturing method | |
| TW202013060A (en) | Metrology apparatus | |
| CN109509738B (en) | Method for manufacturing alignment mark on wafer and structure of alignment mark | |
| JP6945010B2 (en) | How to measure targets, metrology equipment, lithographic cells and targets | |
| KR20070014585A (en) | Apparatus for aligning a semiconductor substrate | |
| US20180356742A1 (en) | Method and apparatus for processing a substrate in a lithographic apparatus | |
| US20090107399A1 (en) | System and Method of Measuring Film Height on a Substrate | |
| EP4202550A1 (en) | Substrate comprising a target arrangement, associated patterning device, lithographic method and metrology method | |
| EP3951500A1 (en) | A fabrication process deviation determination method, calibration method, inspection tool, fabrication system and a sample | |
| KR20230044204A (en) | Methods for determining manufacturing process deviations, calibration methods, inspection tools, manufacturing systems and samples | |
| TW202321838A (en) | Metrology method and apparatus | |
| CN117970740A (en) | Photomask of large-size spliced product and on-line measuring and positioning method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| ASS | Succession or assignment of patent right |
Owner name: SEMICONDUCTOR MANUFACTURING INTERNATIONAL (BEIJING Effective date: 20121116 |
|
| C41 | Transfer of patent application or patent right or utility model | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20121116 Address after: 201203 Shanghai City, Pudong New Area Zhangjiang Road No. 18 Applicant after: Semiconductor Manufacturing International (Shanghai) Corporation Applicant after: Semiconductor Manufacturing International (Beijing) Corporation Address before: 201203 Shanghai City, Pudong New Area Zhangjiang Road No. 18 Applicant before: Semiconductor Manufacturing International (Shanghai) Corporation |
|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130123 Termination date: 20200618 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |