KR100900618B1 - Surface measurement apparatus - Google Patents

Abstract

The present invention relates to a surface measuring apparatus, and an embodiment of the present invention provides a light source for emitting a laser beam, a rotating reflecting mirror reflecting the laser beam, and a laser beam reflected by the rotating reflecting mirror to a measurement target. A scanning lens disposed on the laser beam path for scanning and a laser beam disposed on the laser beam path between the light source and the rotation reflecting mirror and reflected or scattered from the measurement object and returned to the rotation reflecting mirror The present invention provides a surface measuring apparatus including a hole mirror having a hole formed therein so as to pass through and at least one reflected beam detector for detecting a reflected beam passing through the hole mirror.

According to the present invention, it is possible to provide a surface measuring apparatus capable of measuring a large area at an extremely high speed while improving accuracy, and further capable of measuring a three-dimensional shape.

Surface Measurement, Surface Inspection, Beam Scanning, Beam Scanning, Mirror Reflector, Galvano Mirror, Polygon Mirror, Hole Mirror, Perforated Mirror

Description

SURFACE MEASUREMENT APPARATUS

1 is a schematic view for explaining a surface measuring apparatus according to the prior art.

2 is a schematic view showing a surface measuring apparatus according to an embodiment of the present invention.

3 is a schematic view showing a surface measuring apparatus according to another embodiment of the present invention.

4 is a schematic view showing a surface measuring apparatus according to an embodiment modified from the embodiment of FIG. 3.

<Description of the symbols for the main parts of the drawings>

201,301,309: beam splitter 202,302: hole mirror

203,303,310: Galvano mirror 204,304: Scanning lens

205, 305: wafer 206: reflected beam detector

207: scattering beam detection unit 308: condensing lens

403,410 polygon mirror 311 relay lens group

L: laser beam Lr: reflected beam

Ls: Scatter Beam

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface measuring apparatus for measuring foreign matters on the surface of a wafer, and more particularly, to a surface measuring apparatus having improved measurement speed and precision by using a beam scan method.

In general, semiconductor integrated circuits are manufactured by forming circuits on a wafer in accordance with photolithography processes or the like. In this case, a plurality of identical integrated circuits are arranged on the wafer, and the individual integrated circuit chips are manufactured by separating them.

If foreign matters or the like exist on the wafer in such a semiconductor integrated circuit, defects are likely to occur in the circuit pattern formed in the portion where the foreign matters and the like exist, and thus, the use of the integrated circuit may become impossible. As a result, the number of integrated circuits that can be obtained from a single wafer is reduced and yield is lowered.

In addition to semiconductor integrated circuits, advanced materials for which micrometer-sized foreign substances or defects cause defects include glass for display and substrate circuit materials.

Therefore, there is a need for equipment capable of measuring and inspecting such foreign objects or defects.

In general, a method of measuring a foreign material or a defect on a wafer is used to focus a laser on the wafer surface, to receive scattered light scattered from the focusing point, and to detect a foreign material or the like from the signal.

1 is a schematic view for explaining a surface measuring apparatus according to the prior art.

Referring to FIG. 1, the surface measuring apparatus 10 according to the related art includes a measurement object 11, such as a light source and a wafer that emit a laser beam L, and first and second beam detectors 12 and 13. It is configured by.

In this case, the first beam detector 12 detects the scattered beam Ls from the wafer 11. That is, the light scattered from the light collecting point on the wafer 11 is collected by the first beam detector 12 corresponding to the photoelectric converter using a lens. The first beam detector which collects the scattered light outputs a pulse-shaped signal according to the intensity of the beam scattered by the laser beam L by the foreign material, and determines the size of the foreign object according to the magnitude of the signal output. Can be.

In addition, the second beam detector 13 detects the beam Lr reflected by the wafer 11.

As described above, the surface measuring apparatus 10 detects both signals by the scattering beam and the reflection beam, thereby measuring the presence or absence of foreign matter on the wafer 11 and the size of the foreign matter, and further measuring the angle of the reflected beam. Three-dimensional shape can be measured.

However, in general, the surface measuring apparatus 10 is a method in which optical components such as the first and second beam detectors 12 and 13 are fixed and a stage (not shown) on which the wafer 11 is disposed is transferred. .

This stage transfer method can be pointed out as a disadvantage that the measurement speed is very slow, and furthermore, because the path of the scattered and reflected beam changes as the stage moves, there is a problem that the beam detector must move in the same manner.

The present invention has been made to solve the above problems, and an object of the present invention is to measure a large area at a high speed by using a beam scan method, while improving accuracy, and furthermore, a surface measuring apparatus capable of measuring a three-dimensional shape. To provide.

In order to achieve the above object, one embodiment of the present invention,

A light source for emitting a laser beam, a rotating reflection mirror for reflecting the laser beam, a scanning lens disposed on the laser beam path to scan the laser beam reflected by the rotating reflection mirror to a measurement object, and the light source; A hole mirror disposed on the laser beam path between the rotating reflection mirrors, and having a hole formed therein so as to pass the reflected beams of the laser beams reflected or scattered from the measurement object and returned to the rotating reflection mirrors; Provided is a surface measuring apparatus including one or more reflected beam detectors for detecting a beam.

Preferably, the laser beam may be incident in a direction perpendicular to the measurement plane of the measurement object.

The apparatus may further include a beam splitter disposed on the laser beam path between the light source and the hole mirror.

In a preferred embodiment of the present invention, the reflected beam detector includes first and second reflected beam detectors, and splits the reflected beam passing through the hole mirror and provides the beams to the first and second reflected beam detectors, respectively. It may further include a splitter.

In this case, the first reflected beam detector may be a position signal detector, and the second reflected beam detector may be a reflected light amount detector.

In addition, preferably the beam transmittance of the beam splitter may be 50%.

On the other hand, in order not to have a means for physically moving the measurement object, when the rotation reflecting mirror is a first rotating reflecting mirror, the second rotating reflecting mirror reflecting the laser beam reflected from the first rotating reflecting mirror It may further include.

In this case, it is preferable that the first and second rotation reflecting mirrors have different directions of rotation axes. Further, more preferably, the first and second rotational reflection mirrors are suitable for measuring the two-dimensional surface of the measurement object that the directions of the rotation axes are perpendicular to each other.

Furthermore, the method may further include a relay lens group disposed on the laser beam path between the first and second rotational reflecting mirrors.

Meanwhile, the rotation reflecting mirror may be a galvano mirror.

Alternatively, in another embodiment of the present invention, the rotating reflection mirror may be a polygon mirror.

Preferably, the size of the hole formed in the hole mirror is greater than or equal to the size of the laser beam surface measuring apparatus.

In addition, in the case where only one rotation reflecting mirror is included, a measuring object is disposed on the upper surface and a stage for moving the measuring object in a direction different from the direction in which the laser beam is scanned to the measuring object in order to exhibit a two-dimensional scanning effect. It is preferable to further include.

In this case, the moving direction of the stage is preferably perpendicular to the direction in which the laser beam is scanned on the measurement object, as described above, as it is most preferable that the directions of the rotation axes of the two rotating reflecting mirrors are perpendicular to each other. It can be understood.

The hole mirror may reflect the laser beam scattered from the measurement object and returned to the rotation reflection mirror.

In addition, it is preferable to further include a scattering beam detector for detecting the scattering beam reflected from the hole mirror for precise surface measurement.

Furthermore, it is preferable to further include a condenser lens disposed on the scattering beam path between the hole mirror and the scattering beam detector.

Finally, the scanning lens is preferably an ftheta lens.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. Embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art. Accordingly, the shape and size of elements in the drawings may be exaggerated for clarity, and the elements denoted by the same reference numerals in the drawings are the same elements.

2 is a schematic view showing a surface measuring apparatus according to an embodiment of the present invention.

Referring to FIG. 2, the surface measuring apparatus 20 according to the present embodiment includes a light source for emitting a laser beam L, a beam splitter 201, a hole mirror 202 having a central hole, and a galvano mirror 203. And a scanning lens 204, a reflected beam detector 206, and a scattered beam detector 207. A measurement object such as a wafer 205 to be subjected to surface measurement is disposed on a stage not shown, and the stage may be moved perpendicularly to the direction in which the laser beam L is scanned onto the wafer 205, as will be described later. Can be.

Hereinafter, the components included in the surface measuring apparatus and the operating principle will be described in detail.

First, the laser beam L emitted from the light source passes through the beam splitter 201 and travels toward the hole mirror 202. In this case, although not shown regardless of the surface measurement of the wafer 205 in this embodiment, some of the laser beams L are reflected by the beam splitter 201 and are not used for surface measurement.

As described below, the beam splitter 201 reflects the laser beam Lr reflected from the wafer L to return the path to the reflected beam detector 206, and the laser beam L and The degree of transmission of the beam depends on the angle to be achieved and the degree of coating.

On the other hand, the laser beam L used in the present embodiment may be used any laser capable of functioning for surface measurement, for example, YAG laser, femtosecond laser and the like.

The hole mirror 202 is a perforated mirror having a central hole and passes the laser beam L transmitted through the beam splitter 201 or the beam Lr returned from the wafer 205 through the hole. . In addition, the hole mirror 202 passes only a small portion of the beam Ls scattered from the wafer 205 and reflects most of the scattered beam Ls so that the scattered beam Ls travels in a path toward the scattering beam detector 207. .

In this case, the shape and size of the hole of the hole mirror 202 can be appropriately adjusted as necessary. If the size of the hole is large, the transmittance of the scattering beam Ls is large enough to perform the surface measurement even if it is somewhat increased. No problem This is because the intensity of the scattering beam Ls is much weaker than that of the reflective beam Lr.

However, when the reflected beam Lr is reflected by the hole mirror 202 again and provided as a signal to the scattering beam detector 207, a desired surface measurement result may not be obtained, and thus the hole mirror 202 may reflect the beam. It is preferable to transmit all Lr. Therefore, in the present embodiment, the size of the hole formed in the hole mirror 202 is greater than or equal to the size of the laser beam L and the reflection beam Lr.

On the other hand, in the present embodiment, the hole mirror 202 is formed in the center hole in the mirror that can be generally used as long as it has a high reflectance with respect to the laser beam (L) may be any shape or structure. In addition, although the position of the hole is generally formed in the center, if the selective reflection function according to the beam size required in the present embodiment can be performed, the position of the hole may not be the center.

Subsequently, the laser beam L passing through the hole mirror 202 is incident on the galvano mirror 203. The galvano mirror 203 includes a rotating part and a reflecting part, and performs a function of reflecting (scanning) the laser beam L passing through the hole mirror 202 in a straight line along one direction.

That is, the galvano mirror 203 is rotated along the axis of rotation by a rotating part that can be a motor or the like, and thus the reflection direction of the laser beam L incident on the reflecting part is changed.

Specifically, as shown in FIG. 2, as the reflector rotates, the laser beam L changes its reflection path from L1 to L2 and again from L2 to L3. In this case, since the path change is continuous, there are countless laser beams not shown between the reflected beams L1, L2, and L3. Therefore, in the present embodiment, the three reflected beams L1, L2, and L3 are described with reference to the behavior of the laser beam reflected by the galvano mirror 203, but this behavior is not shown. It may be applied to many other beams.

On the other hand, in the present embodiment, although the galvano mirror is employed as the beam scanning means, if the beam scanning function can be performed, a rotation reflecting mirror of another structure such as a polygon mirror may be employed according to the embodiment.

Subsequently, the laser beams L1, L2, and L3 reflected by the galvano mirror 203 in one direction are adjusted by the scanning lens 204 to be scanned on the wafer 205. In this case, the laser beams L1, L2, L3 are scanned in one direction on the surface of the wafer 205 as indicated by the solid line.

The scanning laser beams L1, L2, L3 are incident by the scanning lens 204 in a direction perpendicular to the measured surface of the wafer 205. As the structure is scanned in the vertical direction as described above, the beam reflected or scattered by the wafer 205 may return to the path where the laser beam L has traveled.

The scanning lens 204 preferably uses an F-theta lens to vertically scan the laser beams L1, L2, and L3. The f-theta lens 204 may perform a function of maintaining the beam scanning direction and the angle of incidence constant, and thus, the surface of the wafer 205 may be measured more precisely.

The beam passing through the scanning lens 204 is scanned onto the wafer 205 and scattered or reflected depending on the shape of the surface of the wafer 205. This scattered or reflected beam (shown in dashed lines) returns the path upon incidence of the wafer 205 as described above.

First, describing the path of the reflection beam Lr, the beams reflected from the surface of the wafer 205 return to the galvano mirror 203, and the laser beam L is scanned by the galvano mirror 203. The mirror is directed back to the hole mirror 202 by the reverse process.

As described above, since the size of the hole formed in the hole mirror 202 is greater than or equal to the size of the reflection beam Lr, the reflection beam Lr passes through the hole mirror 202 and first passes through the beam splitter ( Return to 201). The reflected beam Lr returned to the beam splitter 201 is reflected back to the beam splitter 201 and directed to the reflected beam detector 206. In this case, part of the reflected beam Lr passes through the beam splitter 201 and thus does not enter the reflected beam detector 206. On the other hand, the beam transmittance or reflectance of the beam splitter 201 is a matter that can be appropriately adjusted according to the angle formed by the laser beam (L) or the degree of coating.

The reflected beam detector 206 for detecting the reflected beam Lr performs a function of converting an optical signal into an electrical signal and analyzing the same as the scattered beam detector 207. As described in the related art, the surface of the wafer 205 may be precisely measured by analyzing the signals of the reflected beam detector 206 and the scattered beam detector 207 together. Let's explain.

In addition, as described above, the path of the reflection beam Lr to be used for detection may be kept constant. Therefore, it is not necessary to move the reflected beam detector 206 in accordance with the movement of the incident beam as in the prior art. In addition, as will be described in the embodiment shown in FIG. 3, if the path of the reflected beam to be used for detection is constant, various signals can be analyzed through the plurality of detection units by dividing them. When a plurality of detection units are appropriately arranged, more accurate surface state can be measured, and three-dimensional three-dimensional information can be obtained.

Next, looking at the path of the scattered beams from the wafer 205, the scattered beams Ls1, Ls2, and Ls3 pass through the galvano mirror 203 through the hole mirror 202, as in the case of the reflective beam described above. Go back to However, the scattered beams Ls1, Ls2, and Ls3 each have a larger divergence angle than the scanned beams L1, L2, L3 and the reflected beams corresponding thereto. That is, since the scattering beams Ls1, Ls2, and Ls3 may have a large degree of change in path due to foreign matters on the surface of the wafer 205, the scattering beams Ls1, Ls2, and Ls3 may spread widely. In addition, since the specific gravity of the foreign matter and the like that scatters compared to the total surface area of the wafer 205 is very small, the intensity of the scattering beams (Ls1, Ls2, Ls3) is generally very small compared to the reflected beam.

Except for the difference in divergence angle and intensity, the path of the scattering beam Ls until it reaches the hole mirror 202 again may be understood to be the same as the path of the reflection beam Lr described above.

The scattering beam Ls reaching the hole mirror 202 is reflected by the hole mirror 202 and is incident to the scattering beam detector 207. Since the scattering beam Ls spreads out more broadly than the reflecting beam, it passes through the hole of the hole mirror 202 made for the reflection beam Lr transmission. In addition, since the intensity of the scattering beam Ls itself is very small compared to that of the reflective beam Lr, a part of the scattering beam Ls passes through the hole mirror 202 and is reflected like the reflective beam Lr. Incident at 206 also does not significantly affect surface measurement.

The scattering beam detector 207, in which the scattering beam Ls reflected from the reflection surface of the hole mirror 202 is received, converts an optical signal into a current signal and analyzes the wafer as in the reflection beam detector 206 described above. The position of 205 can be determined, and can also be used to correct the output of the reflected beam detector 206.

That is, the scattering beam detector 207 is for detecting the noise signal Ls diffusely reflected by the beam Ls scattered from the wafer 205, that is, the foreign matter present on the surface. When there is no foreign matter or scratches in the process of scanning the beam on the wafer 205 surface, most of the beams are reflected without being scattered and received by the reflected beam detector 209, but when there is a foreign matter or the like, the scattering beam is instantaneously. The intensity of Ls is increased, and the signal and the reflected beam can be analyzed together to find out the location of the foreign material or the size of the foreign material.

However, the scattering beam detection unit 207 is not essential in the present invention, and surface measurement performance may be degraded, but in some cases, the surface state of the wafer may be measured only by the reflection beam Lr.

On the other hand, the wafer 205 is disposed on a movable stage (not shown), it can be seen that the beam is scanned in two dimensions. That is, in the surface measuring apparatus according to the prior art, the method of fixing the laser beam and moving the wafer from side to side, but the surface measuring apparatus according to the present embodiment, the laser beam (L) incident at a fixed point (0 dimension) ) Can be scanned in one dimension by the galvano mirror 203, and furthermore, by moving the wafer 205 in a direction different from the direction in which the beam is scanned, the two-dimensional beam scanning effect can be more easily seen. It is.

In this case, as illustrated in FIG. 2, the wafer 205 is most preferably moved in a direction perpendicular to the direction in which the laser beam is scanned. However, the present invention is not limited thereto, and the two-dimensional beam is not limited thereto. Another direction of movement may be chosen that may have an injection effect.

Next, another embodiment of the present invention will be described with reference to FIG. 3.

3 is a schematic view showing a surface measuring apparatus according to another embodiment of the present invention.

Unlike the case of FIG. 2, the surface measuring apparatus 30 according to the present exemplary embodiment has a structure having two galvano mirrors, a light source emitting the laser beam L, first and second beam splitters 301 and 309, Hall mirror 302, first and second galvano mirrors 303 and 310 having a central hole, scanning lens 304, reflected beam detectors 306a and 306b, scattered beam detector 307, relay lens group ( 311) and a condenser lens 308.

In this case, the components described in the same terms may be understood as the same elements as in the embodiment of FIG. In contrast, the description will be made based on the reflection beam detectors 306a and 306b for dividing the reflection beam signal into two.

First, the surface measuring apparatus 30 according to the present embodiment can measure a two-dimensional surface by arranging two beam scanning means, specifically, galvano mirrors 303 and 310, without moving the wafer 305. .

In detail, first, the laser beam L emitted from the light source and passed through the first beam splitter 301 is reflected (scanned) in one direction by the first galvano mirror 303. Although not shown in detail in the relation shown in two dimensions in FIG. 3, it may be understood that the scanning direction by the first galvano mirror 303 is a direction perpendicular to the direction (indicated by a line) scanned on the wafer 305. have.

As in FIG. 2, the beam passing through the first galvano mirror 303 is scanned by changing the path to L1, L2, and L3 by the rotation of the second galvano mirror 310. Thereafter, the paths of the beams reflected by the wafer 305 through the scanning lens 304 and the scattered beams Ls1, Ls2, and Ls3 take the same manner as described with reference to FIG. 2.

The laser beam L emitted as one point may be scanned in two dimensions while passing through two galvano mirrors 303 and 310. To this end, the rotation axes of the first and second galvano mirrors 303 and 310 are preferably different from each other, and more preferably, the rotation axes are perpendicular to each other.

As such, the surface measuring apparatus 30 according to the present embodiment provides an advantage that the moving means of the wafer 305 does not need to be used for the two-dimensional beam scanning, unlike the embodiment of FIG. 2.

In addition, a relay lens group 311 is disposed between the first and second galvano mirrors 303 and 310. The relay lens group 311 is for adjusting the focus position of the laser beam L, the size of the beam, and the like, and can be obtained by appropriately disposing two or three or more lenses.

The scattering beam Ls is reflected by the hole mirror 302 and is incident on the scattering beam detector 307 via the condenser lens 308 as in the embodiment of FIG. 2. In addition, as in the present embodiment, a condenser lens 208 is disposed between the scattered beam detector 207 and the wafer 205 so as to focus the scattered beam Ls to be detected and provide the scattered beam detector 207 to the scattered beam detector 207. Can be.

In the case of the reflected beam Lr passing through the hole mirror 302, it is reflected by the first beam splitter 301 and is directed toward the reflected beam detectors 306a and 306b. Even in this case, part of the reflected beam Lr passes through the first beam splitter 301 and is not used as a detection signal.

The reflected beam Lr reflected by the first beam splitter 301 is divided by the second beam splitter 309 and incident on the first and second reflected beam detectors 306a and 306b, respectively.

Here, the first and second reflected beam detectors 306a and 306b are the position signal detector 306a and the reflected light amount detector 306b, respectively, and vice versa.

In this case, the light transmittance of the beam splitter 309 may be 50%, and the light transmittance may be appropriately adjusted according to the required beam intensity of each detector.

The change in the reflected beam angle may be measured using the position signal detector PSD (306a), and a three-dimensional shape may be measured by a triangulation method based on the measured values. Accordingly, the three-dimensional shape according to the change in morphology can be measured. In addition, it may be understood that the reflected light amount detector 306b performs the same function as the reflected beam detector described in the embodiment of FIG. 2.

In the present embodiment, one beam splitter 309 and two reflection beam detectors 306a and 306b have been described. However, by arranging a plurality of beam splitters according to the number required for detection, a plurality of beam splitters are arranged. You might want to split it up to detect it.

Finally, FIG. 4 is a schematic diagram showing a surface measuring apparatus according to an embodiment modified from the embodiment of FIG. 3.

In the embodiment of FIG. 3, the surface measuring apparatus according to the present embodiment is a form in which a galvano mirror is replaced with polygon mirrors 403 and 410 consisting of hexagonal bodies.

That is, in this embodiment, polygon mirrors 403 and 410 are used as the beam scanning means. As in the embodiment of FIG. 3, the surface measuring apparatus includes a light source for emitting the laser beam L, first and second beam splitters 301 and 309, a hole mirror 302 and a scanning lens 304 having a central hole. And the reflected beam detectors 306a and 306b and the scattered beam detector 307, and the first and second polygon mirrors 403 and 410 are used instead of the first and second galvano mirrors 303 and 310.

Elements indicated by the same numerals and terms constituting the surface measuring apparatus have the same arrangement structure and function as previously described, and the first and second polygon mirrors 403 and 410 will be described below.

The polygon mirrors 403 and 410 are connected to a motor (not shown) and the like so as to rotate about a rotation axis, similar to the galvano mirrors employed in the previous embodiment. The laser beam L incident in a predetermined direction through the mirror 302 is reflected in one direction. The laser beam reflected or scanned in one direction by the first polygon mirror 403 is incident on the second polygon mirror 410 via the relay lens group 311, and the wafer is rotated according to the rotation of the second polygon mirror 410. 305 can be scanned in two dimensions. Accordingly, in the present embodiment, the surface state can be measured without adding a moving means for moving the wafer 305 as in the embodiment of FIG. 3.

However, in addition to the case where the polygon mirrors 403 and 410 are hexagonal, in another embodiment, a polygon mirror made of a tetrahedron or a polyhedron having a different number of surfaces may be employed.

The present invention is not limited by the above-described embodiment and the accompanying drawings, but is intended to be limited by the appended claims. Accordingly, various forms of substitution, modification, and alteration may be made by those skilled in the art without departing from the technical spirit of the present invention described in the claims, which are also within the scope of the present invention. something to do.

As described above, according to the present invention, it is possible to provide a surface measuring apparatus capable of measuring a large area at an extremely high speed while improving accuracy, and further capable of measuring a three-dimensional shape.

Claims (19)

A light source for emitting a laser beam; A rotating reflection mirror reflecting the laser beam; A scanning lens disposed on the laser beam path to scan the laser beam reflected by the rotating reflection mirror to a measurement object; A hole is disposed on the laser beam path between the light source and the rotating reflection mirror, and a hole is formed to pass the reflected beam among the laser beam emitted from the light source and the laser beam reflected or scattered from the measurement object and returned to the rotating reflection mirror. Formed hole mirror; And At least one reflected beam detector for detecting a reflected beam passing through the hole mirror; Surface measuring apparatus comprising a. The method of claim 1, And the laser beam is incident in a direction perpendicular to the measurement plane of the measurement object. The method according to claim 1 or 2, And a beamsplitter disposed on the laser beam path between the light source and the hole mirror. The method according to claim 1 or 2, The reflected beam detector includes first and second reflected beam detectors, And a beam splitter which splits the reflected beam passing through the hole mirror and provides the split beams to the first and second reflected beam detectors, respectively. The method of claim 4, wherein And the first reflected beam detector is a position signal detector, and the second reflected beam detector is a reflected light amount detector. The method of claim 4, wherein And the beam transmittance of the beam splitter is 50%. The method according to claim 1 or 2, When the rotation reflecting mirror is referred to as a first rotating reflecting mirror, the surface measuring apparatus further comprises a second rotating reflecting mirror reflecting the laser beam reflected from the first rotating reflecting mirror. The method of claim 7, wherein The first and the second reflecting mirror is a surface measuring device, characterized in that the direction of the rotation axis is different. The method of claim 8, The first and the second reflecting mirror is a surface measuring device, characterized in that the direction of the rotation axis is perpendicular to each other. The method of claim 7, wherein And a relay lens group disposed on the laser beam path between the first and second rotational reflecting mirrors. The method according to claim 1 or 2, The rotating reflection mirror is a surface measuring device, characterized in that the galvano mirror. The method according to claim 1 or 2, The rotating reflection mirror is a surface measuring device, characterized in that the polygon mirror. The method according to claim 1 or 2, The size of the hole formed in the hole mirror is greater than or equal to the size of the laser beam surface measuring apparatus. The method according to claim 1 or 2, And a stage for disposing a measurement object on an upper surface and moving the measurement object in a direction different from a direction in which the laser beam is scanned onto the measurement object. The method of claim 14, The moving direction of the stage is a surface measuring apparatus, characterized in that the perpendicular to the direction in which the laser beam is scanned to the measurement object. The method according to claim 1 or 2, And the hole mirror reflects the laser beam scattered from the measurement object and returned to the rotating reflection mirror. The method of claim 16, And a scattering beam detector for detecting the scattered beams reflected from the hole mirror. The method of claim 17, And a condenser lens disposed on the scattering beam path between the hole mirror and the scattering beam detector. The method according to claim 1 or 2, And the scanning lens is an f-theta lens.

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