TW200305004A - Multiple-pass interferometry - Google Patents

Abstract

Interferometry system including a multiple-pass interferometer having reflectors to reflect at least two beams along multiple passes through the interferometer. The multiple passes include a first set of passes and a second set of passes. The reflectors have first alignments that are normal to the directions of the paths of the beams that are reflected by the reflectors. The two beams provide information about changes in a first location on one of the reflectors after the first set of passes, and provide information about changes in the first location and changes in a second location on the reflector after the second set of passes. The paths of the beams are sheared during the first set of passes and during the second set of passes if at least one of the reflectors has an alignment other than the first alignment. The interferometry system includes optics to redirect the beams after the first set of passes and before the second set of passes so that shear imparted during the second set of passes cancels shear imparted during the first set of passes.

Description

200305004 V. Description of the invention (1) The technical field to which the invention belongs ... The present invention relates to an angle and a straight line of a dry-measuring measuring element as a photomask platform or a lithography scan. The prior art: displacement measuring interferometer The monitor moves between the measurement part and the reference. The measuring beam reflected by the measuring part generates the optical interference signal.

In many examples, this measurement is perpendicular to the polarization direction, and different by ’for example, the laser Seman split (Z

Acousto-optical modulati element. The vertical polarization allows the measurement beam and the reference beam to the reflected measurement beam and the measurement beam and the reference beam. This passes through a polarizer. The polarizer mixes the measurement light to form a mixed light beam. The mixed test beams will interfere with each other, so the beam and the reference beam's relative time-varying interferometers are particularly related to an interferometer for displacement. The measuring device can be hidden or A stepping system. Its position is based on an optical interference signal at the interferometer by overlapping and interfering-from a reference beam reflected from a reference object, the beam and the reference beam have mutual frequencies. The different frequencies can be eeman splitting), 〇n, or birefringence inside the laser to allow a polarized beam splitting to guide the measurement object and the reference object, and combine the reference beams to form overlapping ones, etc. The overlapping beams form an output beam, the beam and the polarization of the reference beam, and the intensity of the measurement beam and the reference mixed beam in the beam changes as the measurement changes. A sensor measures the ’and produces a

1057-5466-PF (Nl); Hearta.ptd Page 6 200305004 V. Description of the invention (2) Generate an electronic interference signal "Because the measuring beam and the reference light have different frequencies, the interference signal includes an " outer The difference (heter〇 ^ signal, whose frequency is equal to the frequency difference between the measurement beam and the reference beam, if the path length of the measurement beam and the reference beam is adjusted, such as by adjusting the Platform, so that the measured frequency Doppler shift is equal to 2 υηρ / λ, where the relative velocity of the y-wide measuring part and the reference object 'λ is the wavelength of the measuring beam and the reference beam' π is The refractive index of the medium through which these light beams pass, such as air or vacuum, ρ is the number of times that the reference object and the measuring device have been passed. H The phase change of the measured reference signal changes the relative position of the measuring device χ 2; The phase change of r is equal to the change of L length of / (ηρ), where l is the distance change of a circle, such as the surrounding distance of the platform including the measurement part; 0 unfortunately, the equation is indefinite Always correct. Outside the leather dagger, f Hai measurement reference The quantity of the signal may change. The amplitude of the change will reduce the accuracy of the phase change. Many interferometers will have non-linear characteristics, such as the so-called "cyclic errors". The cyclic errors can be determined by The phase or the intensity of the measured reference signal is sinusoidally dependent on the change in the long-term yield of the optical path. In particular, the first harmonic $ cycle & error has a sinusoidal dependence (2 7Γ pnL) / Again, and the period of the second harmonic

The error has a sine dependence on 2 (2 π pnL) / again. Higher harmonic errors can also be represented in this way. A may also have "non-periodic non-linear" conditions, such as the lateral displacement of the reference beam and the speculative beam in the output beam of the interferometer (such as "beam shear beam shear"). Front and measuring beam wave

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200305004 V. Description of the invention (3) When there are wavefront errors before. This phenomenon can be explained as follows. The inhomogeneities in the interferometer instrument will cause the wavefront error of the test beam and the measurement beam. When the reference beam and the star beam pass through these uneven materials in the same straight line, the same wavefront error will occur and the interference signals will cancel each other out. In addition, the reference beam and the measurement beam in the "Hai-lun" beam will be laterally displaced by each other, such as relative beam shear. This beam shear causes wavefront errors and causes errors in the interference signal obtained from the output beam.

In addition, in many interference systems, the beam shear varies with the position of the measuring element or the angular orientation of the unit. For example, a change in the angular orientation of a flat mirror measurement can cause relative beam shear. Therefore, the change of the angle of the measuring device will cause corresponding errors in the interference signal. Dry up or dry up

• The effects of beam shear and wavefront error will depend on the steps of outputting the beam according to the polarization energy ^ and the step of detecting the mixed output beam to obtain an electrical signal. The hybrid output beam can be detected by a detector, which can be detected by focusing the hybrid beam on the detector to capture the mixed beam into a single mode or multi-mode light. A mixed beam of light coming into the fiber. Beam shear and the effects of ^ also depend on the nature of the beam stop. In other words, when the optical fiber is used to guide the mixed output beam to the detector, the error of the signal involved is complex. The reference light of t’5 generated net junction interference signal amplitude change will be the sum of many mechanisms. One mechanism is, for example, caused by the rotation of the measuring part

200305004 V. Description of the invention (4) " Beam and relative beam shear of the measured beam in the output beam. In dispersion measurement, optical path measurement uses composite wavelengths, such as 532nm and 1064nm, to measure the gas in the measurement path of the dispersion measurement interferometer. The dispersion measurement can be used to convert an optical path length measured with a displacement measurement interferometer into a physical length. This conversion is important because light that is affected by airflow disturbances or uneven density can be replaced with a fixed physical length. # The above interferometer is usually an important 70 pieces of scanner or stepper system, which is used in the lithography process to form an integrated circuit on a wafer. The lithography system includes a movable flat A and fixes the wafer; a focusing device to irradiate the light to a circle; a scanning or stepping system for moving the platform close to the radiation beam; and at least An interferometer. Each interferometer guides a measuring beam to, and receives a reflected measuring beam from, a plane mirror provided on the platform. Each interferometer interferes with the reflected measurement beam and a corresponding reference beam, and the interferometers accurately measure the position of the platform relative to the radiation beam. The Xuan interferometer enables the lithography system to accurately control the exposure area of the wafer in the radiation beam. In many lithography systems and other applications, the measurement device includes at least a flat mirror to reflect the amount Measuring beam. A slight change in the angle of the measuring element, such as the height or deflection of the platform, will cause the measuring beam to change from that; the direction of the reflected beam after the mirror changes. If not compensated, the changed beam will reduce the amount Overlap of the measuring beam and the reference beam in the interferometer. In addition, the measuring beam and the reference beam will not be parallel to each other

200305004 V. Description of invention (5) The wavefront is not aligned when forming the mixed beam. Therefore, the interference between the measurement beam and the reference beam will change along the cross-section of the hybrid beam, thus damaging the interference information measured by the detector.

To cope with this problem 'many conventional interferometers have an inverted reflector retr 0ref 1 ect 0r to redirect the measurement beam back to the plane mirror, whereby the measurement beam "passes twice through" The path between the interferometer and the measuring element. The retro-reflector makes the measurement less sensitive to changes in the angular rotation of the measuring element. When used in a flat mirror interferometer, this configuration becomes generally called high High-stabi 1 it ty plane mirror interferometer (HSPMI) ° However, even with a retro-reflector, the lateral position of the measuring beam is still sensitive to changes in the angular rotation of the measuring part. In addition, the measuring beam The path passes through the optical device in the interferometer, and the path is also sensitive to changes in the angular rotation of the measurement part. In fact, the interference system is used to measure the position of the wafer platform along multiple measurement axes. E.g. setting one

Each Karst coordinate system is that the wafer platform is located in the χ-y plane. The measurement is mainly aimed at the position of the platform on the x-y axis and the angular position of the platform in the z-axis. At this time, the platform moves on the x-y plane. In addition, it can monitor the tilt of the wafer platform outside the X-y plane. For example, these skewed features can be used to calculate Abbe offset errors at the X-y position. Therefore, it can have up to five degrees of freedom for measurement. In addition, in some examples, it can also monitor the position of the platform in the z-axis direction, resulting in a sixth degree of freedom. To measure each degree of freedom, an interferometer is used to monitor the coordinate axis

1057-5466-PF (Nl); Hearta.ptd p. 10 200305004

To the displacement. For example, in a system that measures the xy position of the platform and the 1 y, z direction of rotation, at least three particularly independent measurement beams are reflected from one side of the wafer platform and at least two particularly independent measurements The light beam is reflected from the other side. Reference is made to, for example, U.S. Patent No. 5,80,8,32 " A device and method for projecting a mask pattern on a substrate using five measuring axes ", the contents of which are incorporated herein by reference. Each measurement beam is combined with a reference beam to monitor the change in optical path length in the corresponding axis. Since different measuring beams are in contact with the wafer platform at different positions, the wafer platform can be used to derive the angular orientation by the appropriate optical path length measurement results. Therefore, it can monitor every degree of freedom, and the system includes at least one measuring beam which contacts the wafer platform. In addition, as described above, each measurement beam can pass through the wafer platform twice to prevent the angle of the wafer platform from affecting the interference signal. The measurement beam can be generated by a physical separation interferometer or a multi-weight measurement beam by a multi-axis interferometer. Summary of the invention:

The invention is a multi-degree-of-freedom plane mirror interferometer group, which measures two, three or more degrees of freedom, and has zero or lower beam shearing conditions in a sensor or an optical fiber reading head (F 0 P). . In some embodiments, the reference beam or the differential beam shear of the measurement beam can be effectively reduced. The interferometer set may include a single interferometer optical set. A dual-freedom plane mirror interferometer unit with zero or low beam shear can be used to measure the linear displacement of two separate positions on a plane mirror, or to measure the linear and angular displacement of a plane mirror. Under certain settings, the reference beam and the measurement beam ’s

200305004 V. Description of the invention (7) Differential beam shear can be effectively reduced. The techniques described above can be used to measure additional degrees of freedom using the interferometer configuration disclosed in U.S. Patent Application No. 60 / 352,341. These embodiments include a three-freedom measuring plane mirror interferometer set with zero or relatively low differential beam shear, which can be used to measure three linear displacements of three independent positions on a plane mirror, or It is the linear displacement of a plane mirror and the displacement of two orthogonal angles, or the measurement of two linear displacements and an angular displacement. In some configurations, the differential beam shear of the reference beam and the measurement beam can be effectively reduced. A further embodiment includes a

Four or more free-measuring plane mirror interferometers with zero or reduced beam shear can be used to measure different combinations of straight and angular displacements.

A single plane mirror can be used as both the reference part and the measuring part to measure the change in orientation of an object. The reference beam and the measurement beam are used to measure an angle passing through the single plane. The interferometer optical element set may include a highly stable design for measuring the position f of a straight line or an angle. The interferometer optical element group may be set such that the differential beam between the reference beam and the measurement beam is cut to zero or lower. The beam of the reference beam and the beam of the measurement beam used in the angular displacement interferometer = a single plane mirror becomes zero. Two or more straight or angularly displaced output beams may have a common measurement beam path to pass through the single plane mirror. The interferometer group may be configured such that the relative reference beam and the measurement path length are the same in the glass or the same in the gas. Generally speaking, the present invention discloses a multiple degree of freedom multiple interference

1〇57.5466-PF (Nl); Hearta.ptd Page 12 200305004 V. Description of the invention (8)

The instrument is used to measure the change of the angular position and distance of a measuring part. The multiple pass interferometer includes a plurality of mirrors, and at least two light beams are reflected along the multiple passes through the interferometer. The multiple passes include a first pass and a second pass. The mirrors have a plurality of first aligners perpendicular to the beam paths reflected by the mirrors. The two beams provide information about the change in a mirror at one of the first positions after the first group passes. The two beams provide information about changes in a first position and a second position in one of the mirrors after the second group passes. When at least one of the mirrors has a calibration effect different from that of the first calibrator ', the path of the beams will be sheared when the first group passes and the second group passes. The interferometer includes optical elements to guide the beams after the first group passes and before the second group passes so that the beam shear generated when the second group passes and the beam shear generated when the first group passes Beam shear cancels each other out. Embodiments of the present invention may further include the following features. The optical elements are configured to maintain the amount and direction of beam shear between the two beams when guiding the beams. Upon completion of the first set of passes, the two light beams scattered by the optical elements will be parallel to each other. The mirrors include a plurality of planar reflecting surfaces. The beams include a reference beam ' which is directed to a mirror which is located at a stationary position relative to the interferometer. The special beam includes a measuring beam, and the mirror is preferably movable relative to the interferometer. 〃 is directed to the reference beam and the measurement beam to define an optical path difference, which indicates a change in the position of the mirror relative to the interferometer. The reflection

200305004 V. Description of the invention (9) The mirror includes a first mirror and a second mirror, and the light beams include a first light beam directed to the first mirror and a second light beam directed to the second mirror The light beam, the first mirror and the second mirror are movable relative to the interferometer. The first light beam and the second light beam define an optical path difference '. The optical path difference shows the relative position changes of the first mirror and the second mirror. The first pass consists of two passes, and each pass is reflected at least once by the reflectors. This second set of passes consists of two sets of passes, and each such beam is reflected at least once by the reflectors on each pass. The multiple pass interferometer includes a beam splitter, splits an input beam into the beams, and directs the beams to the mirrors. The beam splitter includes a polarized beam splitter. The optical element includes an odd number of reflective surfaces. The normals of the reflective surfaces are on the same plane. The reflective surfaces include planar reflective surfaces. Each light beam guided by the optical elements is reflected by the reflective surfaces 'so that the total of the incident light beam and the reflected light beam with each reflective surface is zero or an integer multiple of 360 degrees' The angle of the human beam is not in the right direction, the angle has a positive value, ΐ: in the clockwise direction, the angle has a negative value. The interferometer combines the light beams when the == the first and second groups pass by to form an overlapping light beam to exit the interferometer. The optical elements include a reflective surface. These optical elements have several reflective surfaces. These optical quasi-duplex devices include a differential plane mirror interferometer. ^ / ^ 4 The two beams have different frequencies. 200305004 V. Description of the invention (10) The rate can be used to sense the waves between the overlapping beams. It shows the measurement between the beams. An amplifier, an amplifier, and an analogue include an analyzer that is coupled to the optical path difference between the light beams to provide the light beams. The interferometer can be used to dry a wafer; a launch system to align a positioning system to adjust the level where the interferometer is used to measure the level the interferometer can be used to dry a wafer; and An emission system, a positioning system, and a lens group are radiated through the mask to generate a specific position of the mask relative to the radiation, the wafer, and the interferometer is used for measurement. The interference system includes a sensor, which optically interferes, and generates an interference path difference. The sensor includes a light-to-digital converter. The interference system detector 'calculates based on the interference signal. The interference system further includes a light source. The system includes a platform to support the wafer surface to irradiate the pattern radiation; the position of the stage relative to the pattern radiation. The system includes a platform to support a radiation source, a photomask, and a light pattern emitted by the light source when in operation. The positioning system adjusts the lens group to project the pattern radiation to the light. The position of the mask relative to the thai wafer ", Xuangan / Pedometer can be used in an interference system which includes ~ a direct-write beam for forming a pattern on a lithographic mask; waving the lithographic light sheet;- A beam guide group to direct the straight mask; and -positioning "to adjust the distance between the Ξ groups, wherein the interferometer is used to measure the light source, providing a platform to support the writing beam to the platform and the Light & J

200305004 V. Description of the invention (11) The position between the beam guiding groups. The integrated circuit can be made by using the above circle to project a specific pattern on the wafer: 1. Use a knife to support the -crystal relative position of the platform relative to the pattern radiation. The medium βΛ interferometer is used for the measurement of the integrated circuit. The above circle can be used to guide the X-ray from the light source and interfere with the system to support a 1T). The h-ray is guided to the light source through the light. Above, the special pattern of the photomask is adjusted. Qin projects the special pattern radiation onto the second middle of the wafer: "stand up" to measure the position of the photomask relative to the wafer. ‘,’ Hai interferometer worship

-The above-mentioned interference system supports the relative position of η and the light beam guiding group, wherein the interferometer; the position of the platform relative to the light beam guiding group. Looking for inside test ~

The present invention 7 also discloses a multi-degree-of-freedom interferometer, which is based on the multi-degree-of-freedom, S: measuring the distance or angular position change of a measuring part. Continued The interferometer includes a plurality of interferometer optics, including—reference parts. The interferometer optical elements are used to (1) guide a first angle measurement beam from an original incoming and outgoing beam to pass the first point on the measuring part for the first time and the reference part for the second time, (2) Guide a second angle measurement beam from the original in and out beams to pass the reference part for the first time and a second point on the measurement part for the second time, and (3) recombine the first and second angles The light beam portion is measured to generate an angle measurement output beam, which contains information about the change in the angle and orientation of the measurement element. These interferometer optics are more used in (i)

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A beam is guided from an original in and out to pass through the measuring element 1 and 以 twice: the beam distance measures the beam portion to generate first, first, and first ^ off-set measurement outputs related to the distance change of the measuring element. The light beam, which contains the interferometer, may include any of the following reference pieces, which is a plane mirror, and its incident rays. One feature. The square rotation direction is perpendicular to the light beams and the interferometer optical elements further include a polarized beam splitter, and c is used to guide the beam components to pass along its path. '—The first 丨 / 4 wavelength polarizer is set in the A polarizing beam splitter and the reference member, and a first quarter-wavelength polarizing plate are disposed between the polarizing beam splitter and one of the reference members. The interferometer optical element may further include a folded optical element for guiding the light beams back to the polarized beam splitter, and the folded optical element stone further includes a half-wave plate for receiving an angle measurement beam. First sutra ^

after that. The folded optical elements may have an odd number of reflective surfaces to guide the angle measurement beam component back to the polarization beam splitter, and the folded optical elements may have an even number of reflective surfaces to guide the distance measurement beam component Back to the polarizing beam splitter. The interferometer may further include an optical delay line for receiving the beam component of the second angle measurement, and when passing through the measuring part, an additional path length is generated to reduce the angle in the output beam of the angle measurement. Differential beam shear 0

In some embodiments, the interferometer may further include an input non-polarized light

1057-5466-PF (Nl); Hearta.ptd 200305004 V. Description of the invention (13) A beam splitter for separating the original input beam into an angle measurement input beam ^ It is guided to the polarization beam splitter to generate An angle measurement beam is t ′ and a distance measurement input beam is guided to the polarized beam splitter to generate the distance measurement beam component. For example, the interferometer may further include a mirror ' for receiving the distance measurement input beam ' from the input non-polarized beam splitter and directing it to the polarized beam splitter to generate the distance measurement wheel outgoing beam.

• In other embodiments, the polarized beam splitter may separate the original input beam into a beam component for the angle measurement, and the interferometer may further include a non-polarized beam splitter to separate a portion of the angular amount. Measure the output beam and guide it back to the polarizing beam splitter to generate the distance measurement beam: 'The component separated from the output beam measured from this angle defines the beam distance $, the input beam. For example, the interferometer may further include a retro-reflection ^ for receiving the distance measurement input from the output unpolarized beam splitter: it must be directed to the polarized beam splitter to produce the distance measurement "knife." 'The interferometer may further include a non-focal distance system provided between the output non-polarized beam splitter and the polarized beam splitter. The focal, soil systems have an amplification effect to enable the first distance measurement beam A 7-knife contact the measuring part with a normal incidence within a certain angle range. For example, the magnification effect of the non-focal distance system can be 2: 1. ^ The interferometer can further include a first optical fiber optical reading A head for coupling an off-angle measurement output beam to a sensor, and a second optical fiber optical pickup head for coupling the distance measurement output beam to the sensor. The interferometer may further include a light source , Providing the original input beam, the

200305004 V. Description of the invention (14) --- The original input beam includes linear polarization components that are perpendicular to each other. Generally speaking, in another aspect, the present invention can be a multiple degree of freedom interferometer 'including a plurality of interferometer optical elements, including a reference element. The optical element of the interferometer is used for (1) guiding a first measurement beam of a first input beam, passing a first point on a measuring device twice, and (2) guiding: the first input beam A first reference beam passes through the reference part twice, and (3) recombines the first measurement beam and the first reference beam into a first output beam, which contains the first information about the measurement part Point distance change information. The interferometer optical elements are further used to (丨) guide a second measuring beam to pass a second point on the measuring element twice, (2) guide a second measuring beam to pass the reference element twice, And (3) recombining the second measurement beam with ^, and the second meal test beam into a second output beam, which contains a change in the distance of the second point of the measurement device. The second measurement beam and the second reference beam are separated from the first output beam. The interferometer may further include any of the following features. The reference piece is a flat mirror whose direction of rotation is perpendicular to the incident rays of the beam components. The interferometer further includes a polarization beam splitter for guiding the beam components to pass along its path, a first quarter-wavelength polarizing plate disposed between the polarization beam splitter and the reference member, and a A second quarter-wavelength polarizing plate is disposed between the polarizing beam splitter and the reference member. "Hai interferometers also include a non-polarized output beam splitter to separate a portion of the first output beam to define a second incoming and outgoing beam and guide it back to the polarizing beam splitter to generate the second measurement. Beam and the ^

200305004 V. Description of the invention (15) Two reference beams. The interferometer further includes a plurality of reflective surfaces for guiding the second input beam from the output beam splitter to the polarized beam splitter, wherein the non-polarized beam splitter and the reflective surfaces reflect the second odd number of times The input beam before it reaches the polarizing beam splitter. For example, the unpolarized beam splitter reflects the second input beam, and wherein the reflective surfaces reflect the second incoming beam an even number of times. The interferometer can further include a nine-fiber optical pickup head with an output beam coupled to a sensor, and a second fiber-optic optical pickup head to couple the second output beam to the sensor.

^ The interferometer may further include a light source to provide the first input light beam: the first input light beam includes linear polarization components orthogonal to each other. In another aspect, the present invention discloses a method for forming a m3 microsecondary system on a wafer. The lithography system includes ⑴- 平 # for supporting the wafer; ⑻iH / is shot in a pattern taught by projection; Λ Λ / the interference system of the bit metal radiated relative to the pattern is used to monitor The crystal 0 is on the other hand. The present invention discloses a lithography system of a bulk circuit. Xi, forming a wafer on the circle; (2) — Zhao She Vt shirt system includes (1) a platform for placing

A positioning system, a transparent system, first, includes an illumination light source, a photomask, and guides through the photomask to ^ = and the above-mentioned interferometer. When the light source positions the pattern between the light sources, the positioning system adjusts the mask and the interference system to monitor the well = the mirror group reflects the pattern on the wafer, and the Relative position.

1057-5466-PF (Nl); Hearta.ptd Page 20 200305004 V. Description of the Invention (16) In another aspect, the present invention discloses a beam direct writing system for making a lithographic mask. The beam direct writing system includes: (1) a light source that provides' always writing beam to form a pattern on a substrate; a platform for placing the substrate; (2)-a beam guiding group for direct writing The light beam is transmitted to the substrate; (3) a positioning system for adjusting the distance between the platform and the light beam guiding group; and the above-mentioned interferometer for monitoring the position between the platform and the light beam guiding group. Embodiments: An embodiment of the present invention has an interferometer set, which may include one or more linear displacement: interferometers and one or more angular displacement interferometers. The interferometer group may include a single, e.g., a unitary optical group. The linear displacement interferometers include a double pass interferometer, such as a high stability plane mirror interferometer (HSPMI), or a differential plane mirror interferometer (DPMI). These angle plane mirror interferometers, in which the plane mirror is simultaneously used as an angle quantity = Π t and the measuring beam element. + An embodiment of the instrument group will be said The instrument group may include one or more linear displacement interferometers and one or more angular displacement interferometers. Referring to Figure 1, the interferometer group 丨 0 in a single combination, Yigu = interferometer, and-four-channel linear displacement interferometer two beams 14 causes two passes through a first highly stable plane: almost overlapping outputs Light beam 30. This output beam 3. Second: The angle f will be measured to obtain the phase of the measuring mirror 12 in one position.

200305004 V. Description of the invention (17) A part of the output beams 30 is regarded as an input beam to the second highly stable plane mirror interferometer to form the four-channel interferometer, and the four-channel interferometer measures displacement X1 + X2 change, where X2 refers to the displacement of the measuring mirror 12 at a second position. The displacements XI and X2 can be used for linear and angular movement of the measuring mirror 2 with respect to a reference point. A mirror group 2 8 (the part surrounded by the dotted line) reduces the beam shear caused by the tilt of the mirror 12 in the measurement beam and the reference beam to produce a more accurate displacement χ 2 measurement result. The input beam 14 has mutually orthogonal linear polarization components, and it has a small frequency difference for heterodyne detection. A polarizing beam splitter 16 includes a beam splitting plane 82 which, at a point P5, separates the orthogonal components of the input beam 14 to form a reference beam 20 and a measurement beam 18. The reference beam 20 and the measurement beam 18 cause the two channels to pass through the interferometer group 10 and emit a polarized beam splitter 16 to form an emitted beam 30. The measuring beam 1 8 (passed through the surface 8 2) is mainly polarized in a direction parallel to the plane of incidence. Here, the incident plane is parallel to the plane of FIG. 1. The reference beam 20 (reflected from the surface 82) is mainly polarized perpendicular to the incident plane. The reference beam 20 passes along a first reference path and contacts a reference mirror 26. The measurement beam 18 is transmitted along a first measurement path and contacts the measurement mirror 12. The reference mirror and measuring mirror are both flat mirrors. In the figure, a light beam overlaps the path through which the light beam passes. Therefore, the light beam and the path are represented by the same line. The measuring mirror 12 can be placed on an object (such as a lithography platform).

1057-5466-PF (Nl); Hearta.ptd Page 22 200305004 V. Description of the Invention (18) Next, the measurement beam 18 and the reference beam 20 are separated at point P5 until they are recombined into the output beam 30. path. In Fig. 1, the measuring mirror 12 and the polarizing beam splitter 16 are initially arranged so that the surface of the mirror 12 is 45 degrees with respect to the beam splitting surface 82. After the point P5 is reflected by the surface 82, the reference beam 20 passes through the interferometer group 10 twice before it exits the polarized beam splitter 16 as a component of the output beam 30. During the first pass, the reference beam 20 approaches the mirror 26, passes through a quarter-wave polarizing plate 52, and is reflected by the mirror 26 at point P9. The reference beam 26 passes through the 1 / 4-wavelength polarizing plate 52 for the second time, is directed toward the reflecting mirror 22, and is reflected by the reflecting mirror 22 at points P1 3 and P14. During the first pass, the reference beam 26 is directed toward the mirror 26, and the third pass passes through the 1/4 wavelength polarizer 52, and is reflected by the mirror 26 at point P10. The reference beam 26 passes through the quarter-wave polarizing plate 52 for the fourth time, is directed toward the surface 82, is reflected by the surface 82 at point P6, and then is directed toward a sensor 24 to become a part of the output beam 30. After the point P 5 passes the surface 8 2, the measurement beam 20 passes through the interferometer group 10 twice before it exits the polarized beam splitter 16 to become a part of the output beam 30. During the first pass, the measuring beam 18 is directed to the mirror 12, passes through the 1/4 wavelength polarizing plate 54, and is reflected by the mirror 12 at the point P1. The measurement beam 1 8 passes through the quarter-wave polarizing plate 54 for the second time and is reflected by the surface 82 at the point P5. The measuring beam 18 is directed toward the reflector 22 and is reflected by the reflector 2 2 at points P1 3 and P1 4. During the second pass, the measurement beam 18 is directed toward the surface 8 2, is reflected by the surface 8 2 at the point P 6, and is directed toward the mirror 12. The measuring beam 18 passes through the 1/4 wavelength polarizing plate 5 4 for the third time, and is reflected by the mirror 12 at the point P 2. Measuring beam 1 8th

1057-5466-PF (Nl); Hearta.ptd page 23 200305004 V. Description of the invention (19) --- · Pass the 1/4 wavelength polarizing plate 5 4 four times, pass the surface 8 2 at point P 6, then It is directed to the sensor 24 and becomes a part of the output light beam 30. "The measurement beam 18 and the reference beam 20 are emitted after the polarizing beam splitter 16 is emitted", and an overlapping output beam 30 is formed and is directed to the sensor 24. A beam splitter 36 splits the light beam 30 into a light beam 32 and a light beam 34. The light beam 32 passes through a polarizing plate 62 and is sensed by the sensor 24. When the measuring mirror 12 is moved from one position 38 to another position 40, the optical path difference between the first reference path and the first measuring path will change, resulting in interference changes of the overlapping output beam 32 , Which can be sensed by the sensor 24. An analyzer can change the physical position of the nose according to the change of the optical path difference. ~ Represents the change in the average position of the points pi and p2 at the mirror 12 with respect to the polarized beam splitter 6. The beam splitter 36 is a part of the mirror group 28, which receives the beam 30 and directs a part of the beam 30 to the beam 42. The light beam 42 becomes an input light beam of the second highly stable plane mirror interferometer. The beam 42 is separated into a reference beam 44 and a measurement beam 46 by the beam splitting surface 82 at a point P7. The reference beam 44 passes along a second reference path, contacts the reference mirror 26, and the measurement beam 46 passes along a second measurement path, and contacts the measurement mirror 12. The following describes the paths between the measurement beam 46 and the reference beam 44 after they are separated at point p7 until they are recombined into the output beam 48. After being reflected by the surface 82 at the point P7, the reference beam passes through the interferometer group 10 twice before exiting the PBS16φ and becoming a part of the output beam 48. During the third pass, the reference beam 44 is directed toward the mirror 26, passes through the quarter-wave polarizing plate 52, and is reflected by the mirror 26 at the point P12. The reference beam 44 passes through the 4/4 wavelength polarizer 5 2 for the second time, and is directed to the retro-reflector 2 2, and then is reflected by the retro-reflector 5 6 at the point.

1057.5466.PF (Nl); Hearta.ptd Page 24 200305004 V. Description of the invention (20) P16 and P15 reflection. During the fourth pass, the reference beam 44 is directed to the mirror 26, and the third pass passes through the 1/4 wavelength polarizer 52 'and is reflected by the mirror 26 at point P11. The reference beam 44 passes through the 1/4 wavelength polarizer 5 2 for the fourth time, and is directed toward the surface 8 2. It is reflected by the surface 82 at the point p 8, and then is directed toward the sensor 50 to become a part of the output beam 48.

After the point P7 passes through the surface 82, the measurement beam 46 passes through the interferometer group 10 twice before it exits the PBS 16 and becomes a part of the output beam 48. During the third pass, the measurement beam 46 is directed toward the mirror 12, passes through the 1/4 wavelength polarizing plate 5 4 ', and is reflected by the mirror 12 at the point P 4. The measuring beam 18 passes through the 1/4 wavelength polarizing plate 54 a second time and is reflected by the surface 82 at the point P7. The measurement beam 18 is directed toward the retro-reflector 56 and is reflected by the retro-reflector 56 at points P16 and P15. At the fourth pass, the measurement beam 8 is directed toward the surface 82, and is reflected by the surface 82 at point p8, and is directed toward the mirror 12. The measuring beam 18 passes through the 1/4 f long polarizing plate 54 for the third time and is reflected by the mirror 12 at the point P3. The measuring beam is passed through the quarter-wave polarizing plate 54 for the fourth time, passes through the surface 82 at the point P8, and is directed toward the sensor 50 to become a part of the output beam 48.

The back measuring beam 46 and the reference beam 44 are emitted from the polarizing beam splitter 16 to form an overlapping output beam 48 and are directed toward the sensor 50. The light beam 48 passes through the polarizing plate 64 and is sensed by the sensor 50. When the measuring mirror 12 is moved from one position 38 to another position 40, the optical path difference between the second reference path and the second measuring path will change, resulting in interference changes of the overlapping output beams 48, It can be sensed by the sensor 50. An analyzer can calculate the physical change △ = ~ according to the optical path difference = change. ~ Is obtained by subtracting ~ from △. Δζ represents the average position of points P3 and P4 on mirror 12 with respect to pBS16

200305004

The change. By guessing ~ and ~, it can be calculated by (the average linear displacement of Δ mirror 12 relative to PBS16. It can also be two ~) / "decision-△ 2) to determine the change in orientation, when divided by one : "Different? 1 1) The distance from the middle point (between P3 and P4) is closer to the rotation angle of the mirror relative to PBS16.

Referring to FIG. 2, when the mirror 12 is rotated from a position 58 to, a relative shear (51 is generated by placing the DU charcoal 18 and the DU charcoal 18 with H two components (measurement between light. Mirror group 28) Bow 丨 beam 34

The relative shear 52 is formed between the two components of the light beam 42 (which will become the first beams 44 and 46). In reflection, group 28 is designed to be relatively shear 52, which is basically equivalent to relative shear 31. At the passing point P7, the measuring beam 46 passes through the PBS16 a third time and a fourth time. Track the beam shear between the measurement beam 46 and the ideal measurement path (the measurement beam path when the mirror 2 is at position 58). The shear that is dispersed during the first pass and the second pass of the stomach is between The third and fourth passes of the measuring beam pass through the interferometer group at 10 o'clock.

The advantage of using the interferometer group 10 is that when the mirror 12 is tilted, the relative (or different) beam of the components of the output beam 48 emitted from the second highly stable plane mirror interferometer is cut to zero. The overall beam shear (relative to the beam path when the mirror 12 is not tilted) of the output beam component 48 from the second high-stability plane mirror interferometer is also zero. The two components that make up the output beam 30 are parallel to each other. The two components making up the output beam 48 are also parallel to each other.

1057-5466-PF (Nl); Hearta.ptd Page 26 200305004 V. Description of the Invention (22) Next, the configuration of the mirror group 28 will be described. In addition to the beam splitter 36 ', the mirror group includes mirrors 66 and 68. The beam splitter 36 and the mirrors 66 and 68 can be arranged in several different ways. Figures 3 and 4 show the configuration of two suitable mirror groups 28. The beam splitter 36 and the mirrors 66 and 68 are set such that the sum of the angles between the incident light beam and the reflected light beam is zero or a multiple of 360 degrees. Light beam 30 is reflected by beam splitter 36 into light beam 34, which is reflected by mirror 66 into light beam 70, and which is reflected by mirror 68 into light beam 42. Referring to FIG. 2, the angle α has a negative value (clockwise from beam 30 to beam 34), the angle cold has a positive value (counterclockwise from beam 34 to beam 70), and the angle r has a positive value. The beam splitter 36 and the mirrors 66 and 68 are arranged. In Figure 3, the angles α, 0, and 7 have negative values (clockwise from the incident beam to the reflected beam). The beam splitter 36 and the mirrors 66 and 68 are configured as a + / 5 + r = 360 degrees. The mirrors can be configured in different ways so that the sum of α, zhao, and 7 is zero or a multiple of 360 degrees. In Figures 3 and 4, the beam splitter and the mirror have their normals on the same plane (Figures 3 and 4). In the design, the normal of the beam splitter and the mirror can also be located on different planes, but it can also compensate the beam shear caused by the measuring mirror. For example, in Figure 5, a mirror group 80 includes a beam splitter 36, mirrors 66 and 68, and a pyramid inverted reflector 72, which has six reflective surfaces (the normals of the reflective surfaces are not On the same plane). The beam splitter 36 and the mirrors 66 and 68 are configured as a beam

1057-5466-PF (Nl); Hearta.ptd Page 27 200305004 V. Description of the invention (23) 74 (produced after being reflected by the beam splitter 36 and mirrors 66 and 68) Parallel to the beam 30, and the beam 3 〇 and 74 pass in the same direction. The retro-reflector 72 directs the light beam 74 into the light beam 42. The light beam 42 is parallel to the light beam 30 but passes in the opposite direction. The mirror group 80 has the same transmission characteristics as the mirror group 28 in FIG. 3 or FIG. 4, so the amount of beam shear and the direction of the beam 42 are equal to the amount of beam shear of the beam 30. And direction. In the example in Figs. 1-4, the mirror group 28 includes three planar reflecting surfaces (one forming the beam splitter 36 and the other two forming the mirrors 66 and 68 respectively). In other examples, another odd (greater than three) plane mirror may be used. The odd reflections from the beam splitter with the normal line on the same plane and the mirror will make the amount and direction of the beam shear between the beams entering the mirror group equal to the beam shear between the beams reflected by the mirror group. Quantity and direction, where the beam shear is caused by the tilt of the measuring mirror. The mirror group in Figs. 1-5 can compensate for the variable rotation of the measuring mirror, for example, 'rotate around an axis orthogonal to each other and orthogonal to the normal of the measuring mirror. Regardless of the amount and direction of the beam shear caused by the tilt of the measuring mirror, the beam shear that disperses the measuring beam during the first and second passes will be passed by the second person and the fourth pass The beam shearing of the time-dispersed measuring beam is offset by the time. Variations of the above interferometer system may include additional linear or angular displacement interferometers, in an interferometer group or in a single interferometer group to become an interference system capable of measuring three or more degrees of freedom Where the output beam of the additional interferometer can have zero or reduced beam to the sensor

1057-5466-PF (Nl); Hearta.ptd page 28 200305004 V. Description of the invention (24) Shear. Deformation of the interference system may also include one or more moving away + & > compensating for any tilt of the measuring element. For example, a dynamic can be used; == the change in direction of the beam due to the change in the angle of the measuring element. : == Unveiled in the United States. _.S. Nqs. 6,271, 923, and 6313 moving 9iG parts The above-mentioned interference system provides high-precision measurement. This system is specific to lithography applications for making large-size integrated circuits, such as computer chips. Lithography is a key technology for the semiconductor manufacturing industry. Overlay improvement ^ The important challenge of reducing the line width to below 100nm, refer to Semiconductor,

Industry Roadmap, p82 (1997). Overlay is directly related to, for example, the accuracy of distance measurement interferometers that position wafers and mask platforms. Since a lithography tool can produce a production value of $ 50-1 0 0M per year, the economic value of improving the bow-off measurement interferometer is huge. Every 1% improvement in lithography tools can generate an economic benefit of about $ 1M for the fabrication of integrated circuits and the sales of lithography tools. The lithography tool's function is to guide the mask pattern to a photoresist-coated wafer. The process includes determining the position of the wafer and irradiating the radiation onto the photoresist. In order to accurately set the wafer, the wafer includes alignment marks on the wafer 'which can be measured by a dedicated sensor. The measurement _ position of the alignment mark defines the position of the wafer in the tool. With this information, the positions of the crystal circle and the pattern radiation are calibrated. According to this information, a movable platform 'coated with a photoresist is used to move the wafer so that the radiation can be accurately irradiated onto the wafer.

1057-5466-PF (Nl); Hearta.ptd p. 29 200305004

Description of the invention When a radiation source illuminates a reticle with a pattern during exposure, it scatters the radiation to generate the patterned radiation. The reticle can be a photomask. The following two terms can be used interchangeably. In the case of reduced lithography, a reducing lens collects the scattered radiation and forms a reduced image. In proximity transfer, the scattered radiation passes through a short distance (usually on the order of micrometers) and contacts the wafer to produce a 1: 1 shadow. The radiation starts a chemical reaction in the photoresist and transfers the pattern into the photoresist. The interference system is an important component of the positioning mechanism, which can control the position of the wafer and the scribe, and record the reduced image on the wafer. If the 4 interference system includes the above-mentioned features, the periodic error of the distance measurement can be minimized and the accuracy can be improved.

The positioning system line, for example, as well as a graph with a derivative can be included on top. The position of the irradiation system position system, wafer positioning position system. In terms of. The ultraviolet ray scribing or projecting lens group has a pattern and also includes a system package for adjusting the volume of electricity. The micro-imaging system is visible as a mask ray. A system for radiating a photomask to rectify the light, including a crystal to rectify the crystal path, includes an irradiating system and a crystal n includes a radiation light source 'for providing radiation light, X-rays, electron beams or ion beams, In order to impart the radiation pattern, i In addition, for reducing the lithography, the irradiation is to print the patterned radiation onto the photoresist on the wafer when the crystal line is placed on the wafer. A language platform is used to support the photomask, and a position of the 5 mask platform relative to the radiation. $ A round platform for holding the wafer and one; = the platform relative to the patterned radiation 矣 k may include a plurality of exposure steps. Available

200305004 V. Description of the invention (26) J.R. Sheets and BW Smith, in Micro1ithography: Science and Technology (Marcel Dekker, Inc, New York, 1998) ° The above interference system can be used to accurately measure the wafer The position of the platform and the delta reticle platform relative to other elements of the exposure system, such as a lens group's radiation source, or a bearing structure. In each example, the interference system can be set on a static structure, and the measurement device can be set on a movable element, such as a photomask or a wafer platform. This situation can also be converted into that the interference system is provided on a movable element and the measurement element is provided on a static element.

More generally, the interference system can be used to measure the position of any component of an exposure system relative to any other component. An example of a lithography scanner for an interference system 1 1 2 6 is shown in FIG. 6. The interference system is used to accurately measure the wafer position in an exposure system. Here, the platform 11 2 2 is used to carry and position the wafer. The scanner 1100 includes a frame 1102 that supports other branch structures and various elements on these structures. An exposure base 1104 is provided above with a lens housing 1106, which is provided with a reticle or photomask platform Hu to support the reticle or photomask. A positioning system is used for positioning the position of the photomask relative to the exposure device, and is represented by element 丨 丨 丨 7. The positioning system 111 7 may include, for example, a piezoelectric transducer element and corresponding electronic parts. Although it is not included in the above embodiment, the above-mentioned interference system can be used to accurately measure the position of the photomask platform or other movable elements that need to be accurately positioned (see SUpra Sheats and Smith).

Microlithography: Science and Technology).

200305004 V. Description of the invention (27) Hanging under the exposure foundation 1104 is the support foundation 1113, which carries the wafer platform 1122. The platform 1122 includes a plane mirror 1128 for reflecting a measurement beam 11 5 4 guided to the platform by the interference system 11 2 6. A positioning system for positioning the platform 1122 is represented by element 1Π9. The positioning system 1119 may include ' for example, a piezoelectric transducer element and corresponding control electronics. The measurement beam is reflected back to the interference system, which is set above the exposure base 110 4. The interference system may be any one of the above embodiments.

In operation, the radiation beam 111, such as ultraviolet light, passes through a light beam to form an optical group 1112 and is transmitted downward after being reflected by a mirror 1114. Therefore, the radiation beam passes through a photomask (not shown) received by the photomask platform 1116. The photomask is reflected on a wafer (not shown) on a wafer platform 1122 through a lens group 1108. The foundation 1 104 and the various components it supports utilize springs 1 1 2 0 to be independent of environmental vibrations. In another embodiment of the lithography scanner, the previously described interference system can be used to measure distances and angles along multiple axes, but is not limited to the wafer or the reticle (or mask) platform . Similarly, in addition to the ultraviolet light beam ', other light beams such as X-rays, electron beams, ion beams, and light can be used.

In some embodiments, the interference system 1126 guides the reference light (not shown) along an external reference path and contacts a reference mirror (not shown) provided on some structures to guide the radiation beam, such as the lens housing 11 〇6. The "reflected" reference beam returns to the interference system. The + reference system generates an interference signal with the measurement beam 11 54 and the reference beam, indicating the current displacement relative to the radiation beam. In addition, in other embodiments,

200305004 V. Description of the invention (28) The related system 11 26 can be used to measure changes in the reticle or photomask platform η 16 or change the position of other movable components of the literacy system. After the interference system is placed, Can be used for similar lithography systems, two, or scanners. The inclusion of a stepper and lithography as a difficult part of the method for making a semiconductor device. Second, U.S. Patent No. 5,483,343 outlines this manufacturing step. The steps are described here using FIGS. 7 and 8. The figure 7 is a manufacturing flow chart of a semiconductor device, such as a semiconductor wafer, a liquid coupler. Step 11 51 is a f-process designed for: / or a circuit with a charge ^. Step 1152 is a process of manufacturing a photomask in the circuit diagram 荦 = ^. Step 1153 is to make a wafer using materials such as Shi Xi: The basic t 5 5 is 4 is a wafer process. It is called pre-processing, and a pre-circle circuit is formed on the wafer through lithography. The = degree circuit is on the wafer, and the lithography tool is better than the wafer to improve the lithography effect. Extra strong 1 is a combination step, which is called post-processing, in which the step is combined and packaged; 56Γ; ί conductor wafer. This step includes group 1157). A loaded + conductor device can be completed and shipped (step Figure 8 is a flowchart showing the details of the wafer process. Steps

200305004 V. Description of the invention (29) 1161 is-oxidation step, used to oxidize the wafer surface, and a vapor deposition process is used to form wafers on the surface of the wafer. Step 1U4 is an ion implantation process, == 2 = 0, a round shape. Step 1165 is a -photoresist process, which is used to apply a crystal. Step 11 66 is an exposure process' using an exposure mask: ^ The pattern is transferred using the exposure device described above. ^ The circuit description on the mask can be improved using this interference system and method; the step t is -㈣ step, which is used to remove the pass; the process is used to remove the borrow. It is formed by repeating this process' circuit pattern and superimposed on the crystal. This interference system can be used for other applications when the position between objects needs accurate summer measurement. For example, the direct writing beam is laser, X-ray, ion beam. Or an electron beam, marking the pattern on a substrate, and the interference system can be used to measure the relative motion of the substrate and the write-through beam. For example, the schematic diagram of the 'beam write-through system 12 00' is shown in Figure θ: .- Light source 1210 produced all the time The light beam 1212 and a beam focusing combination 121 4 guide the radiation beam to a substrate 1216, which is supported by a movable platform 1 2 1 8. In order to determine the relative position of the platform, the interference system 1 220 guides a reference beam 丨222 to a mirror 1 224, and guide a measuring beam 1226 to a mirror 1228. Since the reference beam contacts a mirror set on the beam focusing combination, the beam writing system is an example using an array reference. 1057- 5466-PF (Nl); Hearta.ptd Page 34 200305004 V. Description of the invention (30) The dry f system 1220 can be any of the above-mentioned interference systems. The position change measured by the interference system corresponds to the direct writing beam 1212 and the change of position of the substrate 1216. The interference system 1220 transmits a measurement signal 1 232 to the controller 1 230, which guides the relative position between the write-through beam 1212 and the substrate 1216. The controller 1230 transmits an output Signal 1234 to a base 1236, which supports and positions the platform 1218. In addition, the controller 1230 sends a signal 1238 to the light source 1210 to change the intensity of the direct writing beam 1212 so that the direct writing beam is sufficient The intensity touches the substrate. In some embodiments, the controller 1230 may cause the beam focusing group 1 2 1 4 to scan the write-through beam in an area of the substrate, for example, using the "4". Therefore, the controller 123. The other elements of the system are guided to pattern! I: =: The action of transferring the pattern is based on the electronic pattern stored in the controller. In some applications +, the direct photoresistor is a photoresistor on the substrate, or it can be used carefully: bamboo mouth system. Use 5 mysterious straight writing first beam direct money to engraving the basic system-an important application is to make a photomask. In order to make a lithographic photomask, an electron beam can be used. It is used for transferring patterns to a chrome substrate. In this example, when the direct writing beam is a direct writing system, the electron beam path is enclosed in a vacuum. Straight write beams such as' an electron beam or ions; 氺 gui: r includes an electron field generator, such as the outer line of a dynamic quadrupole, or visible light, the beam is focused on two U, such as X-ray, purple to focus Guide the radiation to the substrate. Optical elements of ...

200305004 V. Description of the invention (31) Although the present invention has been disclosed as above in the preferred embodiment, it is not intended to: determine the present invention 'anyone skilled in the art, without departing from the spirit and scope β, can still make some Changes and Runs: The scope of the month's intensive care shall be determined by the scope of the attached patent application. " Mingzhibao

1057-5466-PF (Nl); Hearta.ptd

Page 36 200305004

Brief description of the drawings Figure 1 shows an interference system; Figure 2 shows an interference system; Figures 3-5 show a mirror group; Figure 6 shows a lithography system for making integrated circuits Figures 7-8 are flowcharts showing the steps of making integrated circuits; Figure 9 is a schematic diagram of a beam direct writing system. Explanation of symbols: 1 〇 ~ interferometer group 1 4 ~ input beam 1 8 ~ measurement beam 22 ~ reflector 26 ~ reference mirror 30 ~ output beam 34 ~ beam 44 ~ reference mirror 48 ~ output beam 5 2 ~ 1/4 wavelength Polarizing sheet 56 ~ reflector 64 ~ polarizing sheet 72 ~ corner retroreflector 82 ~ beam splitting plane 1 2 0 0 ~ beam direct writing system 1 2 ~ measurement mirror 16 ~ polarizing beam splitter 20 ~ reference beam 2 4 ~ Sensor 28 ~ Mirror group 32 ~ Beam 3 6 ~ Beam splitter 46 ~ Measuring beam 5 0 ~ Sensor 5 4 ~ 1/4 Wavelength polarizer 62 ~ Polarizer 7 0 ~ Beam 74 ~ Beams 1151, 1152, ..., 1157 ~ Steps 1161, 1162, ..., 1169 ~ Steps

1057-5466-PF (Nl); Hearta.ptd Page 37 200305004 Brief description of the drawings 1210 ~ Light source 1212 ~ Direct writing beam 1214 ~ Beam focusing combination 1216 ~ Substrate 1218 ~ Mobile platform 1220 ~ Interference system 1222 ~ Reference beam 1224 ~ Mirror 1226 ～ Measuring beam 1228 ～ Mirror 1230 ～ Controller 1232 ～ Measurement signal 1234 ～ Output signal 1236 ～ Basic 1238 ～ Signal 1244 ～ Signal

1057-5466-PF (Nl); Hearta.ptd page 38

Claims (1)

200305004 VI. Scope of patent application 1. A device including: a multiple-pass interferometer, including a plurality of reflectors, reflecting at least two light beams through the interferometer along the multiple-pass, the multiple passes include a first group of passes and a The second group passes, the mirrors have a plurality of first calibrators, which are perpendicular to the beam paths reflected by the mirrors; the two far beams provide information about Information about changes after the first group passes; the two beams provide information about changes at a first position and the second position at one of the mirrors after the second group passes; ΐί: When the mirror has a calibration effect different from that of the first calibrator, a shear will be generated when the first group passes and the second path; and The group guides these light beams so that before the second heart group passes, it cuts off with the light beam generated when the first and second groups pass. 2. As described in item 1 of the scope of application, the _ item is set to When such light guide 'beam amount of such an optical element in the direction of shear. , To hold the light between the two beams 3. When one of the groups described in the application scope item 1 passes, the two beams are passed by the W, where, after completing the first mutual flat h # 先 学 Element 所The scattered light beam will include a plurality of planar reflective surfaces as described in item 丨 of the scope of application. ,, Bazhong, these mirrors 200305004 6. Scope of patent application 5. The device as described in item 1 of the scope of application, wherein the light beams include a reference light beam 'which is directed to a mirror' and which is located at a static position relative to the interferometer. 6. The device according to item 5 of the scope of application, wherein the light beams include a measuring beam which is directed to a mirror which is movable relative to the interferometer. 7. The device according to item 6 of the application scope, wherein the reference beam and the measurement beam define an optical path difference, and the optical path difference shows a change in the position of the mirror relative to the interferometer. 8. The device as described in item 1 of the declaration scope, wherein the mirrors include a first mirror and a second mirror, and the light beams include a first light beam directed to the first mirror and A second light beam 'guided to the second mirror', the first mirror and the second mirror are movable relative to the interferometer. '° 9 · The device according to item 8 of the application scope, wherein the first light beam and the second light beam define an optical path difference, and the optical path difference shows the first mirror and the second mirror. Relative position changes. 1 0 · The device according to item 1 of the scope of application, wherein the first group is composed of two groups of passes, and each of these beams is reflected by the reflectors at least once each time. 11. The device according to item 10 of the scope of application, wherein the second pass is composed of two passes, and each of these beams is reflected at least once by the reflectors on each pass. The multiple passes 1057-5466-PF (Nl); Hearta.ptd Page 40 200305004 VI. Patent Application Interferometer includes a beam splitter that splits an input beam into the beams and directs the beams to the Reflector. 1 3. The device according to item 2 of the application, wherein the beam splitter comprises a polarized beam splitter. 1 4 · The device according to item 1 of the scope of application, wherein the optical elements include an odd number of reflective surfaces. 1 5 · The device according to item 4 of the scope of application, wherein the normals of the reflective surfaces lie on the same plane. 16. The device according to item 14 of the scope of application, wherein the reflective surfaces include planar reflective surfaces. 1 7 · The device according to item 14 of the scope of application, wherein each light beam guided by the optical elements is reflected by the reflective surfaces, so that the total of the incident light beam and the reflected light beam with each reflective surface is Zero or an integer multiple of degrees. The angle is measured from the incident beam to the reflected beam. When the counterclockwise direction is used, the angle has a positive value. When the clockwise direction is used, the angle has a negative value. . 18. The device according to item 丨 of the scope of application, wherein the interferometer combines the light beams when the light beams pass through the first and second groups to form an overlapping light beam and emits the interferometer. 19. The device according to item 18 of the scope of application, further comprising a sensor for sensing optical interference between the overlapping light beams and generating an interference signal that displays light between the light beams Cheng poor. 2 0. The device according to item 19 of the scope of application, wherein the sensor includes a light sensor, an amplifier, and an analog-to-digital converter. 200305004 VI. Application for patent scope 21. 'kp T LV analyzer, coupled to the sensor, its root device' where, device, where, where t search range 21 · As described in item 20 of the application range The device > set ^ Qigu 'also includes a meter, mixed with the poor m, which calculates the optical path difference between the beams according to the interference signal 2 2 · As the first item of the scope of application includes a Reflective surface. 2 3. The item described in item 1 of the scope of application includes an even number of reflective surfaces. # 置 24 · As described in item 23 of the scope of application, the element includes a cone-shaped mirror. 25. A source as described in item 1 of the scope of application to provide such beams. 2 6 Include a differential plane mirror interferometer as described in item 1 of the scope of application. 2 7 · Different frequencies as described in item 1 of the scope of application. u 〇0, • The device of “ten.” It further includes a platform, / month dry sibling 1 shell ”to illuminate the surface of the wafer to support a wafer; a launch system, M, t ⑴ Oral tea radiation; and-positioning system to adjust the position of the pattern, where the interferometer is used to measure 瘰 0 0 L rb /, ten [the device also includes a platform, 29. If the scope of application The second item σσ,, ν described in Item I, includes a round light source and a support to support a wafer; and an emission system flat front cover'-positioning system and-lens, the light source The emitted radiation passes through the mask to generate a specific .2 ′, M sense position system adjusts the position f of the mask with respect to the radiation. The lens group lightly shoots the pattern into the I device, where the device is a device, where δ Hei Xun Optical Element 5 Hei Optical Element 'These optics also include a light, the interferometer, and the two beams 1057-5466-PF (Nl); Hearta.ptd 200305004 6. Scope of patent application Projected onto the wafer, and the interferometer is used to measure the position of the photomask relative to the wafer. 30. The device according to item 1 of the application scope, further comprising: a light source for providing a constant writing beam for forming a pattern on a lithographic mask; a platform 'to support the lithographic mask; a light beam A guide group for transmitting the direct writing beam to the lithographic mask; and A positioning system is used to adjust the distance between the platform and the beam guiding group. The interferometer is used to measure the position of the platform relative to the beam guiding group. 3 1 · — A method for making integrated circuits, including .... using a device as described in item 28 of the patent application to support a wafer 'projecting a specific pattern onto the wafer, and adjusting The relative position of the platform relative to the pattern, wherein the interferometer is used to measure the position of the platform. 32 · —A method for making integrated circuits, including: Use the device described in the scope of patent application No. 29 to support a wafer, guide radiation from the light source, pass through the photomask to generate a special pattern of radiation on the light source, and adjust the position of the photomask relative to the radiation And projecting the special pattern radiation onto the wafer, wherein the interferometer is used to measure the position of the photomask relative to the wafer. 33 · —A method for making a lithographic mask, comprising: using a device as described in Item 30 of the scope of patent application to support a lithographic mask l〇57-5466-PF (Nl); Hearta.ptd page 43 200305004 VI. Patent application scope Guangjun, passing the light beam to the relative position of the light beam guiding group of the lithography mask, where the stage is relative to The beam guides the position of the group. 34. A device comprising: a multi-axis interferometer 'for changing the position of the multi-axis; the interferometer is configured to receive a first measurement beam separated from an input beam and the first measurement element, The combination of a first spot measurement beam on the measuring element and the separated from the input beam to generate a first output beam containing a change in separation; and the interferometer is further configured to guide the first The first-first I measurement beam 'uses the first and second points on the measurement device, and then, a second reference light and an output beam separated from the input beam include information about the second Point in it that the interferometer includes a part of the first output beam that is reflected by a folded optical element, so that the second measurement beam and the second input beam are separated. 35 · —Multiple-degree-of-freedom interferometer, including: a plurality of interferometer optical elements, the interferometers, and the interferometer to adjust the platform and a measuring element beam used to measure the flatness degree to guide the input light from the input light One pass and the second pass' Then, the first reference beam is bound to the first point and the distance between the incoming beam and the second pass is combined with the second distance beam, and the amount separated by the first The test piece is used to measure the light beam and from it to generate a first change; to reflect the second input light beam an odd number of times; the reference light beam is used to guide the 200305004 optical element of the first instrument. A first measuring beam passes through a first point on a measuring element twice, a first reference beam guiding the first input beam passes through the reference element twice, and passes the first measuring beam And the first reference beam is recombined into a first output beam, which contains distance change information about the first point of the measuring element; the interferometer optical elements are further used to guide a second The measuring beam passes through a second point on the measuring element twice, guides a second reference beam through the reference element twice, and recombines the second measuring beam and the second meal test beam into a second An output beam containing a change in distance with respect to a second point of the measuring element; Among them, the second measurement beam and the second reference beam are separated from the first output beam. ^ 36. The interferometer according to item 35 of the scope of patent application, wherein the interferometer optical element further includes a polarizing beam splitter for guiding the transmission of these beam components along its path, a first 1/4 A wavelength polarizer is disposed between the polarizing beam splitter and the reference member, and a second ¼ / 4 wavelength polarizer is disposed between the polarizing beam splitter and the reference member. 37. The interferometer according to item 36 of the patent scope of Shenying, wherein the f test piece is a flat mirror whose rotation direction is perpendicular to the incident rays of the beam components. 38. The interferometer as described in item 36 of the scope of patent application, which further comprises: a non-biased, output beam splitter to separate one of the first output beam and a second input and output beam and guide it to return Go to the polarization beam splitter to generate the second measurement beam and the second reference beam. 200305004 6. Application patent scope 39. The interferometer according to item 38 of the patent application scope, further comprising a plurality of reflective surfaces for guiding the second input beam from the wheel-out beam splitter to guide the polarized beam splitter. Where 'the non-polarized beam splitter and the reflective surfaces reflect the second input beam an odd number of times before it reaches the polarized beam splitter. 40. The interferometer according to item 39 of the scope of the patent application, wherein the non-polarized beam splitter reflects the second input beam 'and wherein the reflecting surfaces reflect the second input beam an even number of times. 4 1 · The interferometer according to item 35 of the scope of patent application, further comprising a first optical fiber optical read head to couple the first output beam to a sensor and a second optical fiber An optical pickup head for consuming the second output beam to the sensor. 4 2 · — a lithography system for making integrated circuits on a wafer, the system includes: a platform to support the wafer; a launch system to project a specific pattern to the crystal Above the circle; a positioning system to adjust the position of the platform relative to the pattern radiation, and an interference system as described in item 35 of the patent application scope, to monitor the position of the k wafer relative to the pattern radiation . 4 3 · — a lithography system for forming an integrated circuit on a wafer, the system including: a platform for placing the wafer; 200305004 VI. Patent application scope-An illumination system includes an illumination source ', a hood, a positioning system', a lens group, and a device such as the 35th patent scope, where the light source guides light through the light When the mask is used to generate a pattern, the position system adjusts the position between the mask and the light source, the lens group reflects the pattern on the wafer, and the interference system monitors the distance between the mask and the light source. relative position. 44. A beam direct writing system for manufacturing a lithographic mask, the system includes: a light source 'provides a writing beam to form a pattern on a substrate; two platforms for placing the substrate; A guide group for transmitting the direct writing beam to the substrate; a positioning system 'for adjusting the distance between the platform and the beam guide group; and a device such as the scope of patent application No. 35 for monitoring the platform And the beam steering group. 1057-5466-PF (Nl); Hearta.ptd p. 47