CN107462167A - The pattern displacement measuring method of long stroke, high-acruracy survey - Google Patents

The pattern displacement measuring method of long stroke, high-acruracy survey Download PDF

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Publication number
CN107462167A
CN107462167A CN201710734790.XA CN201710734790A CN107462167A CN 107462167 A CN107462167 A CN 107462167A CN 201710734790 A CN201710734790 A CN 201710734790A CN 107462167 A CN107462167 A CN 107462167A
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light
grating
measurement
polarization splitting
polarization
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CN201710734790.XA
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CN107462167B (en
Inventor
李文昊
吕强
巴音贺希格
宋�莹
刘兆武
王玮
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Changchun Institute of Optics Fine Mechanics and Physics of CAS
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Changchun Institute of Optics Fine Mechanics and Physics of CAS
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    • GPHYSICS
    • G01MEASURING; TESTING
    • G01BMEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00Measuring arrangements characterised by the use of optical means
    • G01B11/02Measuring arrangements characterised by the use of optical means for measuring length, width or thickness

Abstract

The invention discloses a kind of long stroke, the pattern displacement measuring method of high-acruracy survey, comprise the following steps:The double-frequency laser that two-frequency laser sends cross-polarization is divided into two-beam by beam splitter prism and 90 ° of mirrors of turning back, and it is P light and S light to incide two polarization splitting prisms respectively by two polarization splitting prism beam splitting;The P light and S light are changed into right-circularly polarized light and left circularly polarized light after four quarter-wave plates;Dextrorotation and left circularly polarized light after the reflection of two plane mirrors, are incided on measurement grating with Littrow angle respectively;Grating movement is measured, the diffraction light of displacement information is carried by backtracking, respectively after quarter-wave plate, is changed into S light and P light respectively, is transmitted through two polarization splitting prisms, overlap the exit facet in two polarization splitting prisms, received through two receivers.The present invention can realize that accurate displacement measures, and reading head is compact-sized, small volume, the environmentally sensitive property of system are low, greatly reduces the control cost to measuring environment.

Description

The pattern displacement measuring method of long stroke, high-acruracy survey
Technical field
The present invention relates to the displacement measurement method based on diffraction grating, more particularly to for Precision Machining field workbench position The high-precision large-stroke pattern displacement measuring method of shift measurement.
Background technology
Accurate displacement e measurement technology is in semiconductor machining, precision optical machinery manufacture, the manufacture of large scale diffraction grating and biology The fields such as medical science play very important effect.And it is characterized in surveying in the accurate displacement e measurement technology required for these fields It is big to measure range, up to meter-sized;Measurement Resolution and precision are high, up to nanometer and sub- nano-precision.It is such as dry using scanning Relate to exposure technique and manufacture meter-sized diffraction grating, it is desirable to which workbench step distance measurement accuracy coordinates PGC demodulation precision several Individual nanometer.Because wide range and high-resolution and precision meet it is extremely difficult simultaneously, this is just accurate displacement e measurement technology Propose very high requirement.
Measuring method is all substantially two-frequency laser interferometer, but double frequency swashs used by many Precision Machining fields at present Optical interferometer environmental sensitivity is high, and measurement reproducibility is poor, and expensive, therefore to ensure its high-acruracy survey cost ratio It is larger.Pattern displacement measuring method is small by environmental constraints using grating pitch as measuring basis, and measurement reproducibility is good, and can High-acruracy survey is realized, but its range is limited by the size of measurement grating, for needing the workbench of meter level range motion Say, it is impossible to meet require in general pattern displacement measuring method.
In view of the above-mentioned problems, related work, such as Japanese Nikon company have done to solve pattern displacement in some research institutions Measuring method range problem, the said firm align shifting by the way of multiple reading heads switch on same grating and measured, Realize the increase of range.Make system bulk larger by the way of more reading heads, and install it is more difficult, due to reading head compared with More, the energy of light source can also be reduced a lot, and each reading head is required for a set of reception system, and band is handled to later data Carry out very big pressure.
The content of the invention
In view of the limitation of above-mentioned technology, the present invention provides a kind of high-precision large-stroke pattern displacement measuring method.
Long stroke of the present invention, the pattern displacement measuring method of high-acruracy survey, comprise the following steps:
The double-frequency laser that cross-polarization is sent by two-frequency laser is divided into two-beam by beam splitter prism and 90 ° of mirrors of turning back;
The two-beam incides two polarization splitting prisms respectively, incides the light of two polarization splitting prisms by two polarizations Amici prism beam splitting, wherein P light transmissions, the reflection of S light;
After four quarter-wave plates, P light is changed into right-circularly polarized light for the P light and S light, and S light is changed into left-handed circle Polarised light;
After the reflection of two plane mirrors, measurement is incided with Littrow angle respectively for the dextrorotation and left circularly polarized light On grating;
The measurement grating moves along grating vector direction, carries the diffraction light of displacement information by backtracking, passes through respectively After crossing quarter-wave plate, right-circularly polarized light is changed into S light, is reflected by two polarization splitting prisms, and left circularly polarized light is changed into P Light, transmit, the final exit facet overlapped in two polarization splitting prisms, received through two receivers by two polarization splitting prisms.
In some embodiments, the measurement grating includes three high incisure density gratings laid in triangle disposition, is located at The left end of the high incisure density grating of upside is carried on the right-hand member of the high incisure density grating positioned at left side, and right-hand member is held It is loaded in the left end of the high incisure density grating positioned at right side, and the lap of high incisure density grating described in each two In, groove is corresponding with groove, and ridge is corresponding with ridge.
In some embodiments, the three high incisure density grating is the high incisure density grating of three identicals.
In some embodiments, two-frequency laser, beam splitter prism, 90 ° of mirrors of turning back, two polarization splitting prisms, four four/ One wave plate, two plane mirrors and two receivers form reading head.
In some embodiments, the double-frequency laser for the cross-polarization that two-frequency laser is sent is by beam splitter prism and 90 ° of mirrors of turning back It is divided into parallel two-beam, incides two polarization splitting prisms respectively.
In some embodiments, two pieces of a quarters are fixed respectively in the transmission direction and reflection direction of a polarization splitting prism Wave plate, equally, two blocks of quarter-wave plates is also fixed respectively in the transmission direction of another polarization splitting prism and reflection.
In some embodiments, described two receiver alternations, long stroke displacement measurement is realized.
Compared with prior art, in pattern displacement measuring method of the invention, use three pieces high incisure density grating with " product " word arrangement forms long stroke measurement grating, and in " product " word arrangement, ensures that the cutting of grating is parallel to each other, grating slot Corresponded with grating ridge, so eliminate error in reading and data transmission error.This method has taken into account pattern displacement measurement system Unite that environmental sensitivity is low and the advantages of wide range.And required reading head is compact-sized, small volume, system is environmentally sensitive Property it is low, be easily installed, control cost to measuring environment can be substantially reduced for the measurement of Precision Machining field worktable displacement, Lifting system performance.
Brief description of the drawings
Fig. 1 is long stroke of the present invention, three high incisure densities of identical of the grating displacement measuring system of high-acruracy survey Grating is in one embodiment schematic diagram that triangle disposition is laid.
Fig. 2 is that long stroke of the present invention, reading head one embodiment of grating displacement measuring system of high-acruracy survey are shown It is intended to.
Fig. 3 is long stroke of the present invention, the flow chart of the pattern displacement measuring method of high-acruracy survey.
Embodiment
In order to make the purpose , technical scheme and advantage of the present invention be clearer, below in conjunction with accompanying drawing and specific implementation Example, the present invention will be described in further detail.It should be appreciated that specific embodiment described herein is only explaining this hair It is bright, without being construed as limiting the invention.
Long stroke of the present invention, the pattern displacement measuring method of high-acruracy survey are the light based on long stroke, high-acruracy survey What grid displacement measurement system was realized.With reference first to Fig. 1, long stroke provided in an embodiment of the present invention, the grating position of high-acruracy survey Shift measurement system, high incisure density grating 1 arrange splicing in a manner of Fig. 1, and three high incisure density grating 1 is in triangle disposition cloth If forming measurement grating, the high groove positioned at left side is carried on positioned at the left end of the high incisure density grating 1 of upside The right-hand member of density grating 1, right-hand member are carried on the left end of the high incisure density grating 1 positioned at right side, and high described in each two In the lap of incisure density grating 1, groove is corresponding with groove, and ridge is corresponding with ridge.
In one embodiment, the three high incisure density grating 1 is the high incisure density grating of three identicals.
The reading head being engaged with reference to figure 2, the high incisure density grating 1 laid with above three in triangle disposition, including 2,90 ° of mirrors 3 of turning back of beam splitter prism, polarization beam splitter prism 4, polarization beam splitter prism 5, quarter-wave plate 6,7,8 (also have one piece not Draw), plane mirror 9 and 10.The double-frequency laser for the cross-polarization that two-frequency laser (not shown) is sent is by the He of beam splitter prism 2 90 ° of mirrors 3 of turning back divide for parallel two-beam, polarization splitting prism 4 and polarization splitting prism 5 are incided respectively, in polarization spectro The transmission direction and reflection direction of prism 5 fix one block of quarter-wave plate 8 and 6 respectively;Equally, in the saturating of polarization spectroscope 4 Penetrate direction and one block of quarter-wave plate 7 and one piece of quarter-wave plate (not shown) are also fixed in reflection respectively, incide polarization The light of Amici prism 4 and 5 is by the beam splitting of polarization splitting prism 4 and 5, wherein P light transmissions, S light reflection, by quarter-wave plate P light is changed into right-circularly polarized light afterwards, and S light is changed into left circularly polarized light.Dextrorotation and left circularly polarized light pass through plane reflection respectively After mirror 9 and plane mirror 10 reflect, incided with Littrow angle on high incisure density grating, when high incisure density grating moves When, the diffraction light of displacement information is carried by backtracking, respectively after quarter-wave plate, right-circularly polarized light is changed into S light, Reflected by polarization splitting prism 4 and 5, left circularly polarized light is changed into P light, is transmitted by polarization splitting prism 4 and 5, final weight The exit facet in polarization splitting prism 4 and 5 is closed, is received through a (not shown) in two receivers.Two receiver alternatings Work.
Moved by the relative position of reading head and measurement grating, to realize that the long stroke of pattern displacement measures.In this hair In bright one embodiment, specifically, when reading head is located at Fig. 2 position, dextrorotation and left-handed that polarization splitting prism 5 projects After plane mirror 9 and plane mirror 10 reflect, high incisure density light is incided with Littrow angle respectively for circularly polarized light On grid 1, one of reception of two receivers carries the light information of displacement information backtracking, now, polarization spectro rib Dextrorotation that mirror 4 projects and left circularly polarized light after plane mirror 9 and plane mirror 10 reflect, can not be mapped to respectively Measure on grating.When measurement grating moves along grating vector direction, dextrorotation and left circularly polarized light that polarization spectroscope 5 projects Respectively after plane mirror 9 and plane mirror 10 reflect, it can not incide on measurement grating, and now polarization spectro rib Dextrorotation that mirror 4 projects and left circularly polarized light after plane mirror 9 and plane mirror 10 reflect, incide measurement respectively On grating, the other in which of two receivers receives the light information for carrying displacement information backtracking.
Referring to Fig. 3, above-mentioned measuring system is based on, pattern displacement measuring method provided in an embodiment of the present invention, including such as Lower step:
The double-frequency laser of the cross-polarization sent by two-frequency laser (not shown) is turned back mirror 3 by beam splitter prism 2 and 90 ° It is divided into parallel two-beam;
The two-beam incides polarization splitting prism 4 and polarization splitting prism 5 respectively, incides two polarization splitting prisms 4 and 5 light is by two polarization splitting prism beam splitting, wherein P light transmissions, the reflection of S light;
One block of quarter-wave plate 8 and 6 is fixed respectively in the transmission direction and reflection direction of polarization splitting prism 5;Equally, One block of quarter-wave plate 7 and one block of quarter-wave plate are also fixed respectively (not in the transmission direction of polarization spectroscope 4 and reflection Draw), the light for inciding polarization splitting prism 4 and 5 is reflected by the beam splitting of polarization splitting prism 4 and 5, wherein P light transmissions, S light, P light is changed into right-circularly polarized light after quarter-wave plate, and S light is changed into left circularly polarized light.
The dextrorotation and left circularly polarized light are respectively after plane mirror 9 and plane mirror 10 reflect, Yi Lite Incide on high incisure density grating at sieve angle;
Measurement grating along grating vector direction move when, carry the diffraction light of displacement information by backtracking, pass through respectively After quarter-wave plate, right-circularly polarized light is changed into S light, is reflected by polarization splitting prism 4 and 5, and left circularly polarized light is changed into P Light, transmitted by polarization splitting prism 4 and 5, the final exit facet overlapped in polarization splitting prism 4 and 5, through two receivers (not shown) receives.Two receiver alternations, realize long stroke displacement measurement.
The following detailed description of in grating moving process is measured, one shares three kinds of situations:
1st, the measurement light through polarization splitting prism 4 is not impinged on high incisure density grating 1, through polarization splitting prism 5 measurement light is incided on high incisure density grating 1, in this case by the measurement light by polarization splitting prism 5 Carry out displacement measurement.
2nd, the measurement light through polarization splitting prism 5 is not impinged on high incisure density grating 1, through polarization splitting prism 4 measurement light is incided on high incisure density grating 1, in this case by the measurement light by polarization splitting prism 4 Carry out displacement measurement.
3rd, by the measurement light co-incident of polarization splitting prism 4 and polarization splitting prism 5 to high incisure density grating 1 On, at this moment, two groups of measurement light can be carried out displacement measurement, and realize two by follow-up data processing system (not shown) Group measurement data is mutually linked, ensure one of which measuring beam can not the used time, another group of measuring beam can continue to measure.
The embodiment of present invention described above, is not intended to limit the scope of the present invention..Any basis Various other corresponding changes and deformation made by the technical concept of the present invention, should be included in the guarantor of the claims in the present invention In the range of shield.

Claims (7)

1. the pattern displacement measuring method of a kind of long stroke, high-acruracy survey, it is characterised in that comprise the following steps:
The double-frequency laser that cross-polarization is sent by two-frequency laser is divided into two-beam by beam splitter prism and 90 ° of mirrors of turning back;
The two-beam incides two polarization splitting prisms respectively, incides the light of two polarization splitting prisms by two polarization spectros Prism beam splitting, wherein P light transmissions, the reflection of S light;
After four quarter-wave plates, P light is changed into right-circularly polarized light for the P light and S light, and S light is changed into Left-hand circular polarization Light;
After the reflection of two plane mirrors, measurement grating is incided with Littrow angle respectively for the dextrorotation and left circularly polarized light On;
The measurement grating moves along grating vector direction, the diffraction light of displacement information is carried by backtracking, respectively by four After/mono- wave plate, right-circularly polarized light is changed into S light, is reflected by two polarization splitting prisms, and left circularly polarized light is changed into P light, Transmit, the final exit facet overlapped in two polarization splitting prisms, received through two receivers by two polarization splitting prisms.
2. the method for pattern displacement as claimed in claim 1 measurement, it is characterised in that the measurement grating is in including three The high incisure density grating that triangle disposition is laid, the left end positioned at the high incisure density grating of upside are carried on positioned at left side The high incisure density grating right-hand member, right-hand member is carried on the left end of the high incisure density grating positioned at right side, and often In the lap of two high incisure density gratings, groove is corresponding with groove, and ridge is corresponding with ridge.
3. the method for pattern displacement as claimed in claim 2 measurement, it is characterised in that the three high incisure density grating is The high incisure density grating of three identicals.
4. the method for pattern displacement as claimed in claim 3 measurement, it is characterised in that two-frequency laser, beam splitter prism, 90 ° Turn back mirror, two polarization splitting prisms, four quarter-wave plates, two plane mirrors and two receivers form reading head.
5. the method for pattern displacement measurement as claimed in claim 1, it is characterised in that the cross-polarization that two-frequency laser is sent Double-frequency laser parallel two-beam is divided into by beam splitter prism and 90 ° of mirrors of turning back, incide two polarization splitting prisms respectively.
6. the method for pattern displacement measurement as claimed in claim 1, it is characterised in that in the transmission side of a polarization splitting prism To two blocks of quarter-wave plates are fixed respectively with reflection direction, equally, transmission direction and reflection in another polarization splitting prism Also two blocks of quarter-wave plates are fixed respectively.
7. the method for pattern displacement measurement as claimed in claim 1, it is characterised in that described two receiver alternations, Realize long stroke displacement measurement.
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Cited By (3)

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CN108254819A (en) * 2017-12-26 2018-07-06 中国科学院长春光学精密机械与物理研究所 A kind of production method of Chinese character pin-shaped displacement measurement grating
CN108444389A (en) * 2017-12-26 2018-08-24 中国科学院长春光学精密机械与物理研究所 A kind of production method of Chinese character pin-shaped displacement measurement grating
CN109632010A (en) * 2019-01-23 2019-04-16 中国科学院长春光学精密机械与物理研究所 It is a kind of to be displaced and angle method for synchronously measuring

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CN105823422A (en) * 2016-03-01 2016-08-03 清华大学 Two-degree-of-freedom heterodyne grating interferometer displacement measurement system and method
CN106289068A (en) * 2016-07-22 2017-01-04 清华大学 A kind of two degrees of freedom heterodyne grating interferometer displacement measurement method

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108254819A (en) * 2017-12-26 2018-07-06 中国科学院长春光学精密机械与物理研究所 A kind of production method of Chinese character pin-shaped displacement measurement grating
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CN109632010A (en) * 2019-01-23 2019-04-16 中国科学院长春光学精密机械与物理研究所 It is a kind of to be displaced and angle method for synchronously measuring
CN109632010B (en) * 2019-01-23 2020-07-17 中国科学院长春光学精密机械与物理研究所 Displacement and angle synchronous measurement method

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