CN114675497A - Focusing and leveling device, photoetching machine system and defocusing amount measuring method - Google Patents
Focusing and leveling device, photoetching machine system and defocusing amount measuring method Download PDFInfo
- Publication number
- CN114675497A CN114675497A CN202011565072.2A CN202011565072A CN114675497A CN 114675497 A CN114675497 A CN 114675497A CN 202011565072 A CN202011565072 A CN 202011565072A CN 114675497 A CN114675497 A CN 114675497A
- Authority
- CN
- China
- Prior art keywords
- light spot
- detection
- mirror
- slit
- focusing
- 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.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 15
- 238000001259 photo etching Methods 0.000 title abstract description 7
- 238000001514 detection method Methods 0.000 claims abstract description 170
- 238000005286 illumination Methods 0.000 claims abstract description 41
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 27
- 229910052710 silicon Inorganic materials 0.000 claims description 27
- 239000010703 silicon Substances 0.000 claims description 27
- 230000008878 coupling Effects 0.000 claims description 16
- 238000010168 coupling process Methods 0.000 claims description 16
- 238000005859 coupling reaction Methods 0.000 claims description 16
- 238000001459 lithography Methods 0.000 claims description 9
- 230000009471 action Effects 0.000 claims description 3
- 239000000523 sample Substances 0.000 claims description 3
- 230000003321 amplification Effects 0.000 claims description 2
- 238000001914 filtration Methods 0.000 claims description 2
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 2
- 230000000644 propagated effect Effects 0.000 claims description 2
- 238000005259 measurement Methods 0.000 description 8
- 230000003287 optical effect Effects 0.000 description 7
- 238000010586 diagram Methods 0.000 description 6
- 238000000691 measurement method Methods 0.000 description 4
- 230000008569 process Effects 0.000 description 3
- 239000000463 material Substances 0.000 description 2
- 230000000903 blocking effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 150000002367 halogens Chemical class 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000013307 optical fiber Substances 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 238000002310 reflectometry Methods 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
Images
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
- G03F7/708—Construction of apparatus, e.g. environment aspects, hygiene aspects or materials
- G03F7/7085—Detection arrangement, e.g. detectors of apparatus alignment possibly mounted on wafers, exposure dose, photo-cleaning flux, stray light, thermal load
-
- 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
- G03F7/70216—Mask projection systems
- G03F7/70258—Projection system adjustments, e.g. adjustments during exposure or alignment during assembly of projection system
-
- 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
- G03F7/70691—Handling of masks or workpieces
- G03F7/70775—Position control, e.g. interferometers or encoders for determining the stage position
-
- 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
- G03F9/00—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically
- G03F9/70—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically for microlithography
- G03F9/7003—Alignment type or strategy, e.g. leveling, global alignment
- G03F9/7023—Aligning or positioning in direction perpendicular to substrate surface
- G03F9/7026—Focusing
-
- 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
- G03F9/00—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically
- G03F9/70—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically for microlithography
- G03F9/7003—Alignment type or strategy, e.g. leveling, global alignment
- G03F9/7023—Aligning or positioning in direction perpendicular to substrate surface
- G03F9/7034—Leveling
-
- 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
- G03F9/00—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically
- G03F9/70—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically for microlithography
- G03F9/7073—Alignment marks and their environment
- G03F9/708—Mark formation
-
- 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
- G03F9/00—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically
- G03F9/70—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically for microlithography
- G03F9/7088—Alignment mark detection, e.g. TTR, TTL, off-axis detection, array detector, video detection
-
- 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
- G03F9/00—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically
- G03F9/70—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically for microlithography
- G03F9/7092—Signal processing
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Health & Medical Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Epidemiology (AREA)
- Public Health (AREA)
- Multimedia (AREA)
- Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)
- Length Measuring Devices By Optical Means (AREA)
- Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)
Abstract
The invention provides a focusing and leveling device, a photoetching machine system and a defocusing amount measuring method, wherein a detection light spot provided by an illumination unit is projected onto a surface to be detected through a projection unit, is reflected by the surface to be detected to form a reflection light spot and is projected onto a detection unit. The detection slit includes a transmissive region and a reflective region. The reflected light spot forms a first light spot through the light-transmitting area, and the first detector acquires the power of the first light spot; the reflected light spot forms a second light spot through the reflecting area, and the second detector obtains the power of the second light spot. And the data processing unit calculates the defocusing amount of the surface to be measured according to the power of the first light spot and the power of the second light spot. Therefore, the power of the first light spot and the power of the second light spot are respectively obtained by arranging the light-transmitting area and the reflecting area, the defocusing amount is calculated, the scanning reflector is prevented from swinging, noise interference is reduced, and the signal-to-noise ratio of a detection signal and the measuring accuracy of the defocusing amount are improved.
Description
Technical Field
The invention relates to the technical field of integrated circuit manufacturing, in particular to a focusing and leveling device, a photoetching machine system and a defocusing amount measuring method.
Background
A lithography machine is a device that images a mask pattern through a projection objective onto a silicon wafer surface. In order to accurately expose the mask pattern, the focusing and leveling system is required to accurately control the silicon wafer surface to be positioned at a specified position. The focusing and leveling system can calculate out-of-focus amount by detecting the height and inclination information of the silicon wafer surface in the exposure field of view, and further adjust the position of the workpiece table according to the out-of-focus amount, so that the silicon wafer surface on the workpiece table is positioned at the optimal focus to-be-measured surface of the projection objective.
Currently, a focusing and leveling device based on a scanning mirror obtains the power of detection light spots with phases of 90 ° and 270 ° respectively by adjusting the swing angle of the scanning mirror, so as to calculate the defocus amount of a silicon wafer surface relative to a projection objective. However, in the actual measurement process, the jitter of the atmosphere and the relative movement between the detector and the silicon wafer surface directly affect the detection result. And the oscillation of the scanning mirror can cause serious noise interference and can cause large measurement errors.
Therefore, a new focusing and leveling device and a defocus measurement method are needed to reduce noise interference, improve the signal-to-noise ratio of detection signals, and improve the defocus measurement accuracy.
Disclosure of Invention
The invention aims to provide a focusing and leveling device, a photoetching machine system and a defocusing amount measuring method, so as to solve the problem of how to improve the defocusing amount measuring precision of a photoetching machine.
In order to solve the above technical problem, the present invention provides a focusing and leveling device, comprising: the system comprises an illumination unit, a projection unit, a detection unit and a data processing unit; wherein,
the illumination unit is used for providing detection light spots;
the projection unit is used for projecting the detection light spot onto a surface to be detected, reflecting the detection light spot by the surface to be detected to form a reflection light spot and projecting the reflection light spot to the detection unit;
the detection unit comprises a detection slit, a first detector and a second detector; the detection slit comprises a light transmitting area and a reflecting area; the reflected light spot forms a first light spot through the light-transmitting area, and the first light spot is transmitted to the first detector; the reflected light spot forms a second light spot through the reflecting area, and the second light spot is transmitted to the second detector; the first detector obtains the power of the first light spot, and the second detector obtains the power of the second light spot;
and the data processing unit obtains the defocusing amount of the surface to be measured according to the power of the first light spot and the power of the second light spot.
Optionally, in the focusing and leveling device, an area of the light-transmitting region is equal to an area of the reflecting region.
Optionally, in the focusing and leveling device, the detection slit includes a plurality of sub detection slits arranged in an array; wherein the relationship between the size of the sub-detection slit and the size of the detection light spot is as follows:
a2＜a1a first and a second of2≤b1；
a1Detecting a length of the sub slit in a first direction;
b1detecting a length of the sub slit in a second direction;
a2the length of the reflected light spot in the first direction is;
b2is the length of the reflected light spot in the second direction; and the first direction and the second direction are perpendicular.
Optionally, in the focusing and leveling device, the illumination unit includes a light emitter, a coupling lens group, a filter, a collimating lens group, a first diaphragm, a first reflector, and a projection slit; wherein,
the illuminator is used for providing illumination, and the illumination sequentially passes through the coupling mirror group, the filter plate, the collimating mirror group, the first diaphragm, the first reflector and the projection slit and forms the detection light spot under the action of the projection slit;
the coupling lens group and the filter plate are used for modulating and selecting the wave band of the illumination;
The collimating lens group is used for adjusting the collimation of the illumination;
the first diaphragm is used for filtering illumination outside the projection slit field of view;
the first reflector is used for reflecting the illumination passing through the first diaphragm to the projection slit;
the projection slit is used for forming the illumination into the detection light spot.
Optionally, in the focusing and leveling device, the projection slit is located at an object plane of the projection unit.
Optionally, in the focusing and leveling apparatus, the position of the projection slit satisfies the following condition: tan ω ═ mtan δ; wherein,
omega is the incident angle of the detection light spot to the surface to be detected;
m is the magnification of the projection unit;
δ is the exit angle of the detection spot from the projection slit.
Optionally, in the focusing and leveling apparatus, the position of the detection slit satisfies the following condition: tan ξ ═ m1tan ω 1; wherein,
xi is the incident angle of the reflected light spot to the detection slit;
m1 is the magnification of the detection unit;
and omega 1 is an incident angle of the detection light spot to the surface to be detected.
Optionally, in the focusing and leveling device, the projection unit includes a first lens, a second mirror, and a second lens; the detection light spot is converged by the first lens and transmitted to the second reflector, the propagation direction of the detection light spot is changed by the second reflector, the detection light spot is propagated to the second lens, and the detection light spot is converged by the second lens and projected onto the surface to be detected.
Optionally, in the focusing and leveling device, the detection unit further includes a third lens, a second diaphragm, and a fourth lens; the third lens receives the reflection light spots and converges the reflection light spots to the second diaphragm, the second diaphragm limits the size of the light beams of the reflection light spots, the reflection light spots are transmitted to the fourth lens after passing through the second diaphragm, and the fourth lens images the detection slit.
Optionally, in the focusing and leveling device, the projection unit includes a third reflecting mirror, a first concave mirror, a second concave mirror, a first convex mirror, and a fourth reflecting mirror; the detection light spot is projected to the surface to be detected through the third reflector, the first concave mirror, the first convex mirror, the second concave mirror and the fourth reflector in sequence; the third reflecting mirror and the fourth reflecting mirror are used for changing the propagation direction of the detection light spot, the first concave mirror and the second concave mirror are used for reflecting and converging the detection light spot, and the first convex mirror is used for converting the detection light spot converged by the first concave mirror into divergence the detection light spot and transmitting the divergence to the second concave mirror.
Optionally, in the focusing and leveling device, the detection unit further includes a fifth reflecting mirror, a third concave mirror, a fourth concave mirror, a second convex mirror, and a sixth reflecting mirror; the reflected light spots are imaged on the detection slit through the fifth reflecting mirror, the third concave mirror, the second convex mirror, the fourth concave mirror and the sixth reflecting mirror in sequence; the fifth reflecting mirror and the sixth reflecting mirror are used for changing the propagation direction of the reflection light spots, the third concave mirror and the fourth concave mirror are used for reflecting and converging the reflection light spots, and the second convex mirror is used for converting the reflection light spots converged by the third concave mirror into divergent reflection light spots and transmitting the divergent reflection light spots to the fourth concave mirror.
Optionally, in the focusing and leveling device, the defocus amount is calculated by using the following formula:
the delta Z is the defocusing amount;
d is the length of the detection slit in the first direction;
m is the magnification of the detection unit;
omega is the incident angle of the detection light spot to the surface to be detected;
a is the power of the first light spot;
b is the power of the second spot.
Based on the same invention concept, the invention also provides a photoetching machine system, which comprises an objective lens and the focusing and leveling device; the focusing and leveling device is used for measuring the defocusing amount of the silicon wafer and the objective lens.
Based on the same inventive concept, the invention also provides a defocus measurement method, which comprises the following steps:
the illumination unit provides detection light spots;
the detection light spot is incident on the silicon wafer through the projection unit, is reflected by the silicon wafer, is reflected to the detection slit, and forms the first light spot and the second light spot through the light-transmitting area and the reflecting area on the detection slit respectively;
the first detector obtains the power of a first light spot, and the second detector obtains the power of a second light spot;
and the data processing unit calculates the defocusing amount of the silicon wafer relative to the objective lens according to the power of the first light spot and the power of the second light spot.
Optionally, in the defocus measuring method, the defocus is calculated by using the following formula:
the delta Z is the defocusing amount;
d is the length of the detection slit in the first direction;
m is the amplification factor of the detection unit;
omega is the incident angle of the detection light spot to the silicon chip;
a is the power of the first light spot;
b is the power of the second spot.
In summary, the present invention provides a focusing and leveling apparatus, a lithography machine system and a defocus amount measuring method, wherein the focusing and leveling apparatus includes: illumination unit, projection unit, detection unit and data processing unit. Wherein, the illumination unit is used for providing a detection light spot. The projection unit is used for projecting the detection light spot onto a surface to be detected, reflecting the detection light spot by the surface to be detected to form a reflection light spot and projecting the reflection light spot to the detection unit. The detection unit includes a detection slit, a first detector, and a second detector. The detection slit includes a transmissive region and a reflective region. The reflected light spot forms a first light spot through the light-transmitting area, and the first light spot is transmitted to the first detector; the reflected light spot forms a second light spot through the reflecting area, and the second light spot is transmitted to the second detector; the first detector obtains the power of the first light spot, and the second detector obtains the power of the second light spot; and the data processing unit calculates the defocusing amount of the surface to be measured according to the power of the first light spot and the power of the second light spot. Therefore, the light transmitting area and the reflecting area are arranged in the detection slit, the reflecting light spot is divided into two parts, and the reflecting light spot passing through the light transmitting area and the reflecting area is respectively received and detected by the first detector and the second detector, so that the defocusing amount is calculated, the link of swinging the scanning reflector is avoided, the noise interference is reduced, the signal to noise ratio of a detection signal is improved, and the measurement accuracy of the defocusing amount is improved.
Drawings
FIG. 1 is a schematic structural diagram of a focusing and leveling device according to an embodiment of the present invention;
FIG. 2 is a schematic structural diagram of a detection slit according to an embodiment of the present invention;
FIG. 3 is a schematic structural diagram of a sub-detection slit according to an embodiment of the present invention;
FIG. 4 is a schematic structural diagram of another focusing and leveling device according to an embodiment of the present invention;
FIG. 5 is a schematic diagram of a detection spot passing through a detection slit according to an embodiment of the present invention;
FIG. 6 is a schematic structural diagram of another focusing and leveling device according to an embodiment of the present invention;
FIG. 7 is a flow chart of a defocus measurement method according to an embodiment of the present invention;
wherein the reference numbers indicate:
10-an illumination unit; 20-a projection unit; 30-a detection unit; 40-a data processing unit; 50-objective lens;
101-a light emitter; 102-a coupling mirror group; 103-a filter segment; 104-a collimating lens group; 105-a first diaphragm; 106-a first mirror; 107-projection slit;
201-a first lens; 202-a second lens; 203-a second mirror; 204-a third mirror; 205-a first concave mirror; 206-a first convex mirror; 207-a second concave mirror; 208-a fourth mirror;
301-probe slit; 3011-sub detecting slit; 302-a first detector; 303-a second detector; 304-a third lens; 305-a second diaphragm; 306-a fourth lens; 307-a fifth mirror; 308-a third concave mirror; 309-second convex mirror; 310-a fourth concave mirror; 311-sixth mirror;
M-a surface to be detected and a silicon wafer; n-detecting the light spot; a-a first spot of light; b-a second spot; c 1-light transmitting areas; c 2-reflective area.
Detailed Description
The following describes a focusing and leveling device, a lithography machine system and a defocus measurement method according to the present invention in further detail with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention. Further, the structures illustrated in the drawings are often part of actual structures. In particular, the drawings may have different emphasis points and may sometimes be scaled differently.
In order to solve the above technical problem, this embodiment provides a focusing and leveling device, as shown in fig. 1, the focusing and leveling device includes: an illumination unit 10, a projection unit 20, a detection unit 30 and a data processing unit 40. Wherein the illumination unit 10 is configured to provide a detection light spot. The projection unit 20 is configured to project the detection light spot onto a surface M to be detected, and form a reflection light spot through reflection of the surface M to be detected and project the reflection light spot to the detection unit 30. The detection unit 30 comprises a detection slit 301, a first detector 302 and a second detector 303. The detection slit 301 includes a transmissive region and a reflective region. The reflected light spot passes through the transparent region to form a first light spot a, which is transmitted to the first detector 302. And the reflected light spot forms a second light spot b through the reflection area, and the second light spot b is transmitted to the second detector 303. The first detector 302 obtains the power of the first light spot a, and the second detector 303 obtains the power of the second light spot b. The data processing unit 40 calculates the defocus amount of the silicon wafer according to the power of the first light spot a and the power of the second light spot b. Further, the first detector 302 and the second detector 303 are both photodetectors. The first detector 302 acquires the optical energy of the first optical spot a and converts the optical energy into an electrical signal, so as to obtain the corresponding optical power of the first optical spot a. Similarly, the second detector 303 obtains the light energy of the second light spot b, converts the light energy into an electrical signal, and further obtains a voltage signal difference, thereby obtaining the corresponding light power of the second light spot b.
Specifically, as shown in fig. 2 and 3, the detection slit 301 includes a plurality of sub detection slits 3011 arranged in an array. Each of the sub-detection slits 3011 is of a transflective structure, that is, the sub-detection slit includes a light-transmitting region c1 and a reflective region c 2. Wherein the light-transmitting region c1 and the reflective region c2 in each sub-detection slit 3011 are disposed adjacently, that is, the light-transmitting region c1 and the reflective region c2 have a common edge. In addition, the area of the light-transmitting region c1 is equal to the area of the reflective region c2, so that the areas of the light-transmitting region and the reflective region are equal throughout the detection slit 301. Further, the substrate of the detecting slit 301 is made of quartz material. The light beam can directly pass through the light-transmitting area c 1; the reflecting region c2 is coated with a reflecting film, the light beam will be reflected by the reflecting region c2, in this embodiment, the reflecting film can be a multilayer dielectric film for laser with the wave band of 0.5 μm-0.8 μm, and the reflectivity is more than 98%. In addition, a black blocking object is coated on the peripheral portion (non-sub-detection slit 3011 region) of the detection slit 301, so as to block the scattered energy of the detection spot. The material of the black shelter is not limited.
In order to obtain all the first light spots a and all the second light spots b with a phase difference of 180 degrees, so as to improve the measurement accuracy, the relationship between the size of the sub-detection slit 3011 and the size of the detection light spot is as follows:
a2＜a1a/2, and b2≤b1；
a1Detecting a length of the slit 3011 in the first direction X for the sub;
b1detecting a length of the slit 3011 in the second direction Y for the sub;
a2the length of the reflected light spot in the first direction X is obtained;
b2is the length of the reflected light spot in the second direction Y; the first direction X is perpendicular to the second direction Y, specifically, the first direction X is a scanning direction, and the second direction Y is a non-scanning direction.
As shown in fig. 4, the illumination unit 10 includes a light emitter 101, a coupling mirror group 102, a filter 103, a collimating mirror group 104, a first diaphragm 105, a first reflector 106, and a projection slit 107. Wherein, the light emitter 101 provides illumination, and optionally, the light emitter is an incandescent lamp, an LED lamp, a halogen lamp, or the like. The illumination sequentially passes through the coupling mirror group 102, the filter plate 103, the collimating mirror group 104, the first diaphragm 105, the first reflector 106 and the projection slit 107, and forms the detection light spot under the action of the projection slit 107. Further, the coupling mirror group 102 and the filter 103 are used for modulating and selecting the wavelength band of the illumination, and are both disposed in the coupling optical path. The illumination of the illuminator 101 can be transmitted to the coupling light path through an optical fiber, and the coupling light path is acted by the coupling mirror group 102 and the filter 103 to improve the optical coupling efficiency and select the working band required by the focusing and leveling device. The collimating lens group 104 is used for adjusting the collimation of the illumination and transmitting the illumination to the first diaphragm 105. The first diaphragm 105 is used to filter the illumination outside the projection slit field of view. The first mirror 106 is used for reflecting the illumination passing through the first diaphragm 105 to the projection slit 107. The projection slit 107 is used to form the illumination into the detection spot.
With reference to fig. 4, the number of the projection slits 107 and the shape structure are not limited in this embodiment. However, the projection slit 107 is located at the object plane of the projection unit, and the positional relationship thereof satisfies the following condition:
tanω＝mtanδ；
wherein ω is an incident angle of the detection light spot incident to the side surface M; m is the magnification of the projection unit 20; δ is the exit angle of the detection spot from the projection slit 107.
In the focusing and leveling apparatus provided in the present embodiment, the projection unit 20 includes a first lens 201, a second lens 202, and a second mirror 203. The detection light spot is converged by the first lens 201 and transmitted to the second reflecting mirror 203, and is transmitted to the second lens 202 after the propagation direction is changed by the second reflecting mirror 203, and is converged by the second lens 202 and projected onto the surface M to be measured.
In the conventional focusing and leveling apparatus, the power of the reflected light spots having a phase difference of 180 °, for example, the power of the detection light spots having phases of 90 ° and 270 °, respectively, is obtained by adjusting the swing angle of the second mirror 203. As shown in fig. 5, when the phase is 90 °, half of the light waves of the reflected light spot N can be detected by the detector and corresponding power is obtained; when the phase is 270 degrees, the light wave of the other half of the reflected light spot N can be detected by the detector and corresponding power is obtained, so that the defocusing amount of the surface M (silicon wafer) to be measured relative to the projection objective lens is calculated. However, during the process of swinging the second mirror 203, factors such as atmospheric jitter, relative movement between the detector and the silicon wafer surface, and serious noise interference may occur, which may cause a large measurement error. Therefore, in order to avoid these problems, the focusing and leveling apparatus provided in this embodiment provides the transparent region c1 and the reflective region c2 in the detection slit 301, so that the power of the detection spot having a phase difference of 180 ° can be measured at one time by the detection slit 301, the first detector 302, and the second detector 303 without swinging the second mirror 203. Not only simplify the measurement process, can also acquire more accurate defocus volume, reduce the error. Therefore, in this embodiment, the second reflecting mirror 203 does not have a direct effect on detecting the defocus amount, and optionally, in other embodiments, the second reflecting mirror 203 is eliminated, and the detection light spot can be made to directly enter the surface M to be measured after passing through the first lens 201 and the second lens 202 by adjusting the incident angle of the detection light spot.
With reference to fig. 4, the detecting unit 30 further includes a third lens 304, a second diaphragm 305 and a fourth lens 306. The third lens 304 receives the reflected light spot and converges the reflected light spot to the second diaphragm 305, the second diaphragm 305 limits the size of the light beam of the reflected light spot, the reflected light spot passes through the second diaphragm 305 and then propagates to the fourth lens 306, and the reflected light spot is imaged on the detection slit by the fourth lens 306.
Further, the position of the detection slit 301 satisfies the following condition:
tanξ＝m1tanω1；
where ξ is the incident angle of the reflected light spot incident on the detection slit 301. m1 is the magnification of the detection unit 30. And ω 1 is an incident angle of the detection light spot incident to the surface M to be measured.
The present embodiment also provides another structure of the projection unit 20 and the detection unit 30. Referring to fig. 6, the projection unit 20 further includes a third mirror 204, a first concave mirror 205, a second concave mirror 207, a first convex mirror 206, and a fourth mirror 208. The detection light spot is reflected to the waiting side surface M sequentially by the third reflecting mirror 204, the first concave mirror 205, the first convex mirror 206, the second concave mirror 207 and the fourth reflecting mirror 208. Wherein the third mirror 204 and the fourth mirror 208 are used for changing the propagation direction of the detection light spot. The first concave mirror 205 and the second concave mirror 207 are used for reflecting and converging the detection light spot. The first convex mirror 206 is configured to convert the detection light spot converged by the first concave mirror 205 into a divergent detection light spot and transmit the divergent detection light spot to the second concave mirror 207.
The detection unit 30 further comprises a fifth mirror 307, a third concave mirror 308, a fourth concave mirror 310, a second convex mirror 309 and a sixth mirror 311. The detection light spot is reflected to the detection slit 301 by the fifth reflecting mirror 307, the third concave mirror 308, the second convex mirror 309, the fourth concave mirror 310 and the sixth reflecting mirror 311 in sequence. The fifth reflecting mirror 307 and the sixth reflecting mirror 311 are configured to change a propagation direction of the reflected light spot, the third concave mirror 308 and the fourth concave mirror 310 are configured to reflect and converge the reflected light spot, and the second convex mirror 309 is configured to convert the reflected light spot converged by the third concave mirror 308 into a divergent reflected light spot and transmit the divergent reflected light spot to the fourth concave mirror 310.
Based on the same inventive concept, the present embodiment further provides a lithography system, and the lithography system described with reference to fig. 4 and 6 includes: an objective lens 50 and the focusing and leveling device. The focusing and leveling device is used for measuring the defocusing amount between the silicon wafer M and the objective lens 50. And the silicon wafer is placed on the surface M to be tested.
Based on the same inventive concept, the present embodiment further provides a defocus amount measuring method, please refer to fig. 4 and 7, the defocus amount measuring method includes:
Step one S10: the illumination unit 10 provides a detection light spot;
the light emitter 101 provides light, and the light enters the projection slit 107 after sequentially passing through the coupling light path, the collimator set 104, the first diaphragm 105 and the first reflector 106, and forms a detection light spot through the projection slit 107.
Step two S20: the detection light spot is incident on the silicon wafer M through the projection unit 20, is reflected by the silicon wafer M, is reflected to the detection slit 301, and forms the first light spot a and the second light spot b through the light-transmitting area and the reflecting area on the detection slit 301.
After being reflected by the silicon wafer M, the detection light spot optionally passes through the third lens 304, the second diaphragm 305, and the fourth lens 306 in sequence, and enters the detection slit 301. The transmitted light spot passing through the transmissive region in the detection slit 301 is directly transmitted and transmitted to the first detector 302, and the reflected light spot passing through the reflective region in the detection slit 301 is reflected to the second detector 303.
Step three S30: the first detector 302 obtains the power of the first light spot a, and the second detector 303 obtains the power of the second light spot b.
Step four S40: the data processing unit 40 calculates the defocus amount Δ Z of the silicon wafer M relative to the objective lens 50 according to the power of the first light spot a and the power of the second light spot b.
The defocus amount is calculated as follows:
the delta Z is the defocusing amount;
d is the length of the detection slit 301 in the first direction X;
m is the magnification of the detection unit 30;
omega is an incident angle of the detection light spot to the silicon wafer M;
a is the power of the first light spot a;
b is the power of the second spot B.
In summary, the present embodiment provides a focusing and leveling device, a lithography machine system, and a defocus amount measuring method, wherein the focusing and leveling device includes: an illumination unit 10, a projection unit 20, a detection unit 30 and a data processing unit 40. In the present embodiment, the detection unit 30 is provided with a detection slit 301, a first detector 302 and a second detector 303. A light-transmitting area and a reflecting area are arranged in the detection slit 301, a detection light spot provided by the illumination unit 10 is divided into two parts, and the detection light spot of the light-transmitting area and the detection light spot of the reflecting area are respectively received and detected by the first detector 302 and the second detector 303, so that the defocusing amount is calculated, the link of swinging the scanning reflector is avoided, noise interference is reduced, the signal-to-noise ratio of a detection signal is improved, and the measurement accuracy of the defocusing amount is improved.
The above description is only for the purpose of describing the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention, and any variations and modifications made by those skilled in the art based on the above disclosure are within the scope of the appended claims.
Claims (15)
1. A focusing and leveling device, comprising: the system comprises an illumination unit, a projection unit, a detection unit and a data processing unit; wherein,
the illumination unit is used for providing detection light spots;
the projection unit is used for projecting the detection light spot onto a surface to be detected, reflecting the detection light spot by the surface to be detected to form a reflection light spot and projecting the reflection light spot to the detection unit;
the detection unit comprises a detection slit, a first detector and a second detector; the detection slit comprises a light transmitting area and a reflecting area; the reflected light spot forms a first light spot through the light-transmitting area, and the first light spot is transmitted to the first detector; the reflected light spot forms a second light spot through the reflecting area, and the second light spot is transmitted to the second detector; the first detector obtains the power of the first light spot, and the second detector obtains the power of the second light spot;
And the data processing unit obtains the defocusing amount of the surface to be measured according to the power of the first light spot and the power of the second light spot.
2. The focusing and leveling device according to claim 1 wherein the area of the light transmitting area is equal to the area of the reflecting area.
3. The focusing and leveling device according to claim 1 wherein the probe slit comprises a plurality of sub-probe slits arranged in an array; wherein the relationship between the size of the sub-detection slit and the size of the detection light spot is as follows:
a2＜a1a/2, and b2≤b1；
a1Detecting a length of the sub slit in a first direction;
b1detecting a length of the sub slit in a second direction;
a2the length of the reflected light spot in the first direction is;
b2is the length of the reflected light spot in the second direction; and the first direction and the second direction are perpendicular.
4. The focusing and leveling device according to claim 1, wherein the illumination unit comprises a light emitter, a coupling mirror group, a filter, a collimating mirror group, a first diaphragm, a first reflecting mirror, and a projection slit; wherein,
the illuminator is used for providing illumination, and the illumination sequentially passes through the coupling mirror group, the filter plate, the collimating mirror group, the first diaphragm, the first reflector and the projection slit and forms the detection light spot under the action of the projection slit;
The coupling mirror group and the filter are used for modulating and selecting the wave band of the illumination;
the collimating lens group is used for adjusting the collimation of the illumination;
the first diaphragm is used for filtering illumination outside the projection slit field of view;
the first reflector is used for reflecting the illumination passing through the first diaphragm to the projection slit;
the projection slit is used for forming the illumination into the detection light spot.
5. The focusing and leveling device of claim 4 wherein the projection slit is located at an object plane of the projection unit.
6. The focusing and leveling device according to claim 4 wherein the position of the projection slit satisfies the following condition: tan ω ═ m tan δ; wherein,
omega is the incident angle of the detection light spot to the surface to be detected;
m is the magnification of the projection unit;
δ is the exit angle of the detection spot from the projection slit.
7. The focusing and leveling device according to claim 1 wherein the position of the detection slit satisfies the following condition: tan ξ ═ m1 tan ω 1; wherein,
xi is the incident angle of the reflected light spot to the detection slit;
m1 is the magnification of the detection unit;
And omega 1 is an incident angle of the detection light spot to the surface to be detected.
8. The focusing and leveling device according to claim 1 wherein the projection unit comprises a first lens, a second mirror and a second lens; the detection light spot is converged by the first lens and transmitted to the second reflector, the propagation direction of the detection light spot is changed by the second reflector, the detection light spot is propagated to the second lens, and the detection light spot is converged by the second lens and projected onto the surface to be detected.
9. The focusing and leveling device according to claim 1 wherein the detection unit further comprises a third lens, a second diaphragm and a fourth lens; the third lens receives the reflected light spot and converges the reflected light spot to the second diaphragm, the second diaphragm limits the size of the light beam of the reflected light spot, the reflected light spot is transmitted to the fourth lens after passing through the second diaphragm, and the reflected light spot is imaged on the detection slit through the fourth lens.
10. The focusing and leveling device according to claim 1 wherein the projection unit comprises a third mirror, a first concave mirror, a second concave mirror, a first convex mirror, and a fourth mirror; the detection light spot is projected to the surface to be detected through the third reflector, the first concave mirror, the first convex mirror, the second concave mirror and the fourth reflector in sequence; the third reflecting mirror and the fourth reflecting mirror are used for changing the propagation direction of the detection light spot, the first concave mirror and the second concave mirror are used for reflecting and converging the detection light spot, and the first convex mirror is used for converting the detection light spot converged by the first concave mirror into divergence the detection light spot and transmitting the divergence to the second concave mirror.
11. The focusing and leveling device according to claim 10 wherein the detection unit further comprises a fifth mirror, a third concave mirror, a fourth concave mirror, a second convex mirror, and a sixth mirror; the reflected light spot is imaged on the detection slit through the fifth reflecting mirror, the third concave mirror, the second convex mirror, the fourth concave mirror and the sixth reflecting mirror in sequence; the fifth reflecting mirror and the sixth reflecting mirror are used for changing the propagation direction of the reflection light spot, the third concave mirror and the fourth concave mirror are used for reflecting and converging the reflection light spot, and the second convex mirror is used for converting the reflection light spot converged by the third concave mirror into divergence the reflection light spot and transmitting the divergence to the fourth concave mirror.
12. The focusing and leveling device according to claim 1 wherein the defocus amount is calculated using the following formula:
delta Z is defocus;
d is the length of the detection slit in the first direction;
m is the amplification factor of the detection unit;
omega is an incident angle of the detection light spot to the surface to be detected;
a is the power of the first light spot;
b is the power of the second spot.
13. A lithography system, characterized in that the lithography system comprises an objective and a focusing and leveling device according to any one of claims 1-11; the focusing and leveling device is used for measuring the defocusing amount of the silicon wafer and the objective lens.
14. A defocus amount measuring method using the lithography system according to claim 13, comprising:
the illumination unit provides detection light spots;
the detection light spot is incident on the silicon chip through the projection unit, is reflected by the silicon chip, is reflected to the detection slit, and forms the first light spot and the second light spot through the light-transmitting area and the reflection area on the detection slit respectively;
the first detector obtains the power of a first light spot, and the second detector obtains the power of a second light spot;
and the data processing unit calculates the defocusing amount of the silicon wafer relative to the objective lens according to the power of the first light spot and the power of the second light spot.
15. The defocus amount measuring method of claim 14, wherein the defocus amount is calculated by using the following formula:
delta Z is defocus;
d is the length of the detection slit in the first direction;
m is the magnification of the detection unit;
omega is the incident angle of the detection light spot to the silicon chip;
a is the power of the first light spot;
b is the power of the second spot.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011565072.2A CN114675497A (en) | 2020-12-25 | 2020-12-25 | Focusing and leveling device, photoetching machine system and defocusing amount measuring method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011565072.2A CN114675497A (en) | 2020-12-25 | 2020-12-25 | Focusing and leveling device, photoetching machine system and defocusing amount measuring method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114675497A true CN114675497A (en) | 2022-06-28 |
Family
ID=82071116
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011565072.2A Pending CN114675497A (en) | 2020-12-25 | 2020-12-25 | Focusing and leveling device, photoetching machine system and defocusing amount measuring method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114675497A (en) |
-
2020
- 2020-12-25 CN CN202011565072.2A patent/CN114675497A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5510892A (en) | Inclination detecting apparatus and method | |
| KR970004887B1 (en) | Method for aligning photomasks | |
| JP2008171960A (en) | Position detection device and exposure device | |
| US4566795A (en) | Alignment apparatus | |
| TWI534558B (en) | Detection device, exposure apparatus, and device manufacturing method using same | |
| KR20090004776A (en) | Exposure apparatus and method for manufacturing device | |
| JPH04215015A (en) | Surface position detecting device | |
| JPH0580497A (en) | Surface state inspecting device | |
| TW201107905A (en) | Measurement apparatus, exposure apparatus, and device fabrication method | |
| CN102043352B (en) | Focusing and leveling detection device | |
| JP3634558B2 (en) | Exposure apparatus and device manufacturing method using the same | |
| JP2020012892A (en) | Exposure apparatus and method for manufacturing article | |
| JP3335126B2 (en) | Surface position detecting apparatus and scanning projection exposure apparatus using the same | |
| TWI358529B (en) | Shape measuring apparatus, shape measuring method, | |
| JP2003007601A (en) | Method of measuring interval between two objects, method of exposing semiconductor using the same, interval measuring instrument, and semiconductor exposure system | |
| JPH07130636A (en) | Position detector and manufacture of semiconductor element using same | |
| CN114675497A (en) | Focusing and leveling device, photoetching machine system and defocusing amount measuring method | |
| JP2000012445A (en) | Position detecting method and apparatus, and aligner equipped with the apparatus | |
| CN111090223B (en) | Optical measurement system | |
| JPH104055A (en) | Automatic focusing device and manufacture of device using it | |
| WO2009093594A1 (en) | Surface position detecting device, exposure apparatus, and device manufacturing method | |
| KR20190064450A (en) | Exposure apparatus, exposure method, and method of manufacturing article | |
| CN113433800B (en) | Vertical measurement system and exposure device | |
| CN214896205U (en) | Focus detection device, detection device and photoetching machine | |
| JP3376291B2 (en) | Exposure apparatus and device manufacturing method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |