TWI668439B - Method of measuring surface topography - Google Patents

Abstract

The present invention provides a surface topography detecting method, the method comprising the following steps. First, test light is provided, and the test light is used to measure the surface topography of the object. On the optical path of the test ray, a spatial light modulator is provided, the spatial light modulator having a plurality of pixels. Controlling the spatial light modulator, turning on the first pixel group of the plurality of pixels in a first time interval, and turning on the second pixel group in the plurality of pixels in a second time interval. The first pixel group and the second pixel group respectively correspond to the plurality of pixels, and the first pixel group and the second pixel group have a first repeating pixel.

Description

Surface topography detection method

The invention relates to a surface topography detecting method, in particular to a surface topography detecting method capable of detecting and compensating for vibration.

After the product is manufactured, it will go through certain test procedures to control the quality of the product. In general, it is necessary to check whether the appearance of the product is defective by manpower, or to judge whether the function is normal by observing the appearance of the product. However, some products have a more detailed structure, and sometimes it is impossible to ask people to use the naked eye to check the flaws. Conventionally, the appearance of a product can be photographed, for example, using a camera, and by enlarging the captured image, the appearance of a specific area of the product can be checked.

However, if the structure of the wafer surface is to be detected, since the size of the structure is very small, the conventional surface topography detecting system is susceptible to external interference and seriously affects the accuracy of the judgment. For example, a slight vibration during shooting is likely to cause a false positive. Therefore, the industry needs a new surface topography detection method to detect small-sized objects to improve the measurement accuracy of surface topography.

The invention provides a surface topography detecting method, which sequentially turns on a plurality of pixel groups in a spatial light modulator, and designs repeated pixels in the plurality of pixel groups, thereby compensating for interference of vibration to improve Measurement accuracy of surface topography.

The present invention provides a surface topography detecting method, the method comprising the following steps. First, test light is provided, and the test light is used to measure the surface topography of the object. On the optical path of the test ray, a spatial light modulator is provided, the spatial light modulator having a plurality of pixels. Controlling the spatial light modulator, turning on the first pixel group of the plurality of pixels in a first time interval, and turning on the second pixel group in the plurality of pixels in a second time interval. The first pixel group and the second pixel group respectively correspond to the plurality of pixels, and the first pixel group and the second pixel group have a first repeating pixel.

In some embodiments, in the first time interval, the object reflects the test light to obtain the first object light, and in the second time interval, the object reflects the test light to obtain the second object light. In addition, the first object light can be detected, thereby generating a plurality of first surface topography data, each of the first surface topography data corresponding to each pixel in the first pixel group. And detecting the second object light, thereby generating a plurality of second surface topography data, each of the second surface topography data corresponding to each pixel in the second pixel group. Then, comparing the first surface topography data corresponding to the first repeated pixel with the second surface topography data corresponding to the first repeated pixel, the first vibration difference value is calculated. Finally, the second surface topography data can be compensated according to the first vibration difference value.

In some embodiments, the surface topography detection method further comprises the following steps. The spatial light modulator is controlled to turn on a third pixel group of the plurality of pixels in a third time interval. The third pixel group corresponds to the plurality of pixels, and the second pixel group and the third pixel group have a second repeating pixel, and the first repeating pixel is different from the second repeating pixel. In addition, in the third time interval, the object reflects the test light to obtain the third object light. Then, the third object light is detected, thereby generating a plurality of third surface topography data, and each of the third surface topography data respectively corresponds to each pixel in the third pixel group. And calculating a second vibration difference value by comparing the second surface topography data corresponding to the second repeated pixel with the third surface topography data corresponding to the second repeated pixel. Finally, the third surface topography data is compensated according to the first vibration difference value and the second vibration difference value.

In summary, the surface topography detecting method provided by the present invention sequentially turns on a plurality of pixel groups in the spatial light modulator, and designs repeated pixels in the plurality of pixel groups. By comparing the values obtained by repeating the pixels in two measurements, the interference of the vibration can be compensated to improve the measurement accuracy of the surface topography.

The features, objects and functions of the present invention are further disclosed below. However, the following is only an embodiment of the present invention, and the scope of the present invention is not limited thereto, that is, the equivalent changes and modifications made by the scope of the present invention will remain the subject of the present invention. Further departures from the spirit and scope of the invention are intended to be regarded as a further embodiment of the invention.

Please refer to FIG. 1A. FIG. 1A is a schematic diagram of a surface topography detecting system according to an embodiment of the invention. As shown in FIG. 1A, the surface topography detecting method disclosed in the present invention can be applied to the surface topography detecting system 1, and the surface topography detecting system 1 can be used to detect the object DUT. Here, the object DUT may be a wafer, a die, a wafer, a panel, a circuit, or a surface having a microstructure. The foregoing examples are not intended to limit the type and size of the object DUT. In practice, the object DUT can also be any object, which is generally available to those skilled in the art. The surface topography detecting system 1 illustrated in FIG. 1A may have a light source 10, a lens 11, a beam splitting unit 12, a reference mirror 13, a spatial light modulator 14, a lens 15, and an image capturing device 16, which are described below. The optical architecture of the topography detection system 1.

The light source 10 is used to provide input light. Although the light source 10 is a point light source, the present embodiment is not limited. For example, the light source 10 may be a surface light source. In addition, the light source 10 can be a white light source or a non-coherent light source, such that the input light can be white light or a non-coordinated light. Here, the input light provided by the light source 10 enters the lens 11, and the function of the lens 11 is to convert the input light from the point source into parallel light. It will be understood by those of ordinary skill in the art that the light source 10 will generally be at the focal position of the lens 11 such that the input light passing through the lens 11 can be considered substantially as a planar light. Of course, if the light source 10 is originally a parallel surface light source, the lens 11 may not be required in practice.

The beam splitting unit 12 is located on the optical path of the input light for dividing the input light into reference light and test light, wherein the reference light is directed to the reference mirror 13 and the test light is directed to the spatial light modulator 14. In practice, the beam splitting unit 12 can be an optical beam splitter that splits the input light into two identical rays. In one example, the input ray and the test ray can be in the same direction, and the reference ray can be oriented in the direction of the vertical input ray. Of course, this embodiment does not limit the direction of the reference light and the test light. For example, it is also possible that the input light is in the same direction as the reference light, and the test light is directed in the direction of the vertical input light. In addition, the distance from the beam splitting unit 12 to the reference mirror 13 may be substantially equal to the distance from the light splitting unit 12 to the object DUT, and the embodiment is not limited thereto.

The spatial light modulator 14 can have a plurality of pixels, and the plurality of pixels can be arranged in an array. Each of the "pixels" referred to herein may be composed of liquid crystals, and the plurality of pixels can select a light-transmitting and opaque state, thereby determining whether light can pass. In other words, the spatial light modulator 14 can determine which pixels are turned on based on the control command cmd, and those pixels are turned off. Here, the spatial light modulator 14 provided in this embodiment can be divided into at least two pixel groups, which are respectively turned on in different time intervals, and at least one pixel is simultaneously classified in the two pixel groups. . Here, the pixels that are simultaneously classified in the two pixel groups are referred to as repeated pixels in this embodiment. For example, the spatial light modulator 14 of FIG. 1A may have a transmissive pixel array, and the transmissive pixel array may have a liquid crystal layer (not shown) by controlling the liquid crystal layer. The direction of rotation of the liquid crystal determines whether light is allowed to pass through a particular pixel.

In some examples, the spatial light modulator 14 can have a different design. Referring to FIG. 1B, FIG. 1B is a schematic diagram of a surface topography detecting system according to another embodiment of the present invention. 1A is the same as FIG. 1B, the light source 10, the lens 11, the beam splitting unit 12, the reference mirror 13, the lens 15, and the image capturing device 16 may be of the same design. 1A is different from FIG. 1B in that the spatial light modulator 14' of FIG. 1B can have a reflective pixel array. The reflective pixel array may also have a liquid crystal layer (not shown), and a mirror (not shown) is added after the liquid crystal layer, so that by controlling the rotation direction of the liquid crystal in the pixel, it is determined whether to let Light passes through and is reflected to the object DUT. In one example, the spatial light modulator 14' may also have no multiple liquid crystal layers and only a plurality of mirrors. For example, each "pixel" may be a small mirror, and the control command cmd may determine which pixels are reflected to the object DUT. Other pixels that are not selected can reflect light to other arbitrary, non-interfering locations.

In addition, a transmissive pixel array having a liquid crystal layer or a spatial light modulator 14 of a reflective pixel array is generally used in combination with a polarizing plate, but since the function and use of the polarizing plate are generally known in the art. It can be understood that, in addition, it is not the focus of the present invention and will not be described herein.

To illustrate the operation mode of the spatial light modulator 14, please refer to FIG. 1A and FIG. 2A to FIG. 2C. FIG. 2A is a schematic diagram of the control of the spatial light modulator in the first time interval according to an embodiment of the invention. 2B is a schematic diagram showing control of a spatial light modulator according to an embodiment of the present invention in a second time interval, and FIG. 2C is a schematic diagram showing control of a spatial light modulator in a third time interval according to an embodiment of the invention. As shown, the spatial light modulator 14 can have a plurality of pixels 140a-140o, different pixels can correspond to different locations on the surface of the object DUT, and the spatial light modulator 14 can adjust the turned-on pixels according to an external control command cmd. The example of FIG. 2A demonstrates that the first group of pixels is turned on in the first time interval, and the remaining pixels are in the off state, and the first group of pixels can be defined, for example, as the pixel 140a, the pixel 140c, the pixel 140i, and the pixel 140k. That is to say, in the first time interval, the test light that is directed to the spatial light modulator 14 can only pass through the pixels 140a, 140c, 140i, and 140k, and the test rays that are directed toward the other pixels are shielded.

Therefore, the test light passing through the four pixels can be focused by the lens 15 to the four positions on the surface of the object DUT after passing through the spatial light modulator 14 (corresponding to the pixel 140a, the pixel 140c, the pixel 140i, and the pixel 140k, respectively). . It is worth mentioning that although the present embodiment takes four pixel groups corresponding to one pixel group as an example, the purpose is only for convenience of description. In fact, the pixel group is not limited to correspond to several pixels. In addition, the embodiment defines that the light taken from the object DUT in the first time interval is the first object light, for example, the test light passes through the pixel 140a, the pixel 140c, the pixel 140i, and the pixel 140k to the four positions on the surface of the object DUT, so Four corresponding first object rays can be obtained in one time interval.

For example, when the test light passes through the pixel 140a, it is irradiated to a specific position on the surface of the object DUT through the lens 15, and then the first object light is reflected by the object DUT. The first object light may pass through the lens 15 and the pixel 140a again, reach the beam splitting unit 12, and be guided by the beam splitting unit 12 to the image capturing device 16. In one example, the image capturing device 16 can be disposed on one side of the beam splitting unit 12 for receiving reference light reflected from the reference mirror 13 and receiving the first object light reflected from a specific position on the surface of the object DUT. . In practice, the reference mirror 13 can be designed as a mirror surface that can move back and forth. When the reference mirror 13 is moved a certain distance, the image capturing device 16 can receive the highest sum of the reflected reference light and the first object light. It is considered that the reference ray and the first object ray are just constructive interference. In a physical sense, the reference light and the test light reflected back at this time are zero optical path difference. Since the first object light of the corresponding pixel 140a is fixed to the image capturing device 16, the distance of the reference mirror 13 can be inferred by finding the position of the reference mirror 13 which makes the reference light and the test light have a zero optical path difference. Thereby, the surface topography of the specific position (corresponding to the pixel 140a) of the object DUT is calculated.

In detail, the image capturing device 16 can continuously capture multiple images in a first time interval, and each image can correspond to a position of the reference mirror 13 , and each image can simultaneously receive the reference light and the corresponding pixel 140 a The first object of light. That is to say, the reference mirror 13 can move a range in the first time interval, and the image capturing device 16 records the reference light and the first object light corresponding to the position of each of the reference mirrors 13 during the movement of the reference mirror 13. The sum of the brightness. In practice, the sum brightness can be represented by a gray scale value, that is, the image capturing device 16 can record a series of gray scale values in the first time interval. For example, when the reference mirror 13 moves by the first distance, the image capturing device 16 records the maximum grayscale value (the sum of the luminances is the highest), and the first surface can be used to estimate the surface topography of the object DUT. For example, if the surface topography of the pixel 140a corresponding to the specific position of the object DUT is a convex, the reference mirror 13 may be closer to the light splitting unit 12, and if the surface topography of the pixel 140a corresponding to the specific position of the object DUT is concave, It is possible that the reference mirror 13 is farther away from the spectroscopic unit 12. This embodiment does not limit the manner in which the surface topography is estimated from the first distance. Those skilled in the art can adjust according to the actual optical path architecture.

This embodiment does not limit how to represent the surface topography of a specific position of the object DUT. In one example, the surface topography data of the recorded object DUT can be expressed by relative values, for example, relative to a reference plane, thereby recording only the ratio. The reference plane is several units high or low. For the purpose of illustration, the present embodiment exemplifies the surface topography data (first surface topography data) of the object DUT measured in a first time interval as shown in Table 1. The different pixel representations in the table correspond to different surfaces on the object DUT. s position. However, the following numerical values are merely illustrative and are not intended to limit the actual numerical representation or calculation.   Pixel First surface topography 140a +1 140c +2 140i -1 140k +3 Table 1  

The example of FIG. 2B exemplifies that the second pixel group is turned on in the second time interval, and the remaining pixels are in the off state, and the second pixel group can be defined, for example, as the pixel 140a, the pixel 140d, the pixel 140j, and the pixel 1401. That is to say, in the second time interval, the test light that is directed to the spatial light modulator 14 can only pass through the pixels 140a, 140d, 140j, and 140l, and the test rays that are directed to the other pixels are shielded. Thus, the test ray passing through the four pixels can be focused by the lens 15 to the four positions on the surface of the object DUT after passing through the spatial light modulator 14. Among the four positions on the surface of the object DUT, in addition to the position corresponding to the pixel 140a on the surface of the object DUT, there are three new positions corresponding to the pixel 140d, the pixel 140j, and the pixel 140l. The embodiment defines that the light taken from the object DUT in the second time interval is the second object light, for example, the test light passes through the pixel 140a, the pixel 140d, the pixel 140j, and the pixel 1401 to the four positions on the surface of the object DUT, so the second Four corresponding second object rays can be obtained in the time interval.

Next, as in the foregoing example, the reference mirror 13 can also move a range in the second time interval, and the image capturing device 16 records the reference corresponding to the position of each reference mirror 13 during the movement of the reference mirror 13. The sum of the brightness of the light and the second object, and the surface topography at four locations on the surface of the object DUT can be derived. For illustrative purposes, the present embodiment exemplifies the surface topography data (second surface topography data) of the object DUT measured in the second time interval as shown in Table 2 below, and integrates the information of Table 1.   Pixel First surface topography data Second surface topography data 140a +1 +3 140c +2 140d +1 140i -1 140j +2 140k +3 140l -1 Table 2  

It can be seen from Table 2 that the present embodiment is provided with a repeating pixel 140a (first repeating pixel) between the first pixel group and the second pixel group. Since the pixel 140a scans the position on the surface of the object DUT is fixed, it is possible to calculate the degree of vibration interference received in the second time interval. For example, Table 2 exemplifies the position of the pixel 140a corresponding to the surface of the object DUT, the surface topography data in the first time interval is +1, and the surface topography data in the second time interval is +3, which can infer the vibration difference. The value (first vibration difference) is +2. In other words, all the second surface topography data measured in the second time interval are interfered by the first vibration difference value, and the second surface topography data after compensating/deducting the first vibration difference value can be compared with the first The surface topography data has the same benchmark. For the sake of explanation, the corrected second surface topography data in this embodiment is shown in Table 3 below, and the information of Table 1 is integrated.   Pixel first surface topography data second surface topography data compensated second surface topography data 140a +1 +3 +1 140c +2 140d +1 -1 140i -1 140j +2 +0 140k +3 140l - 1 -3 Table 3  

The example of FIG. 2C demonstrates that the third pixel group is turned on in the third time interval, and the remaining pixels are in the off state, and the third pixel group can be defined, for example, as the pixel 140b, the pixel 140d, the pixel 140m, and the pixel 140o. That is to say, in the third time interval, the test light that is directed to the spatial light modulator 14 can only pass through the pixels 140b, the pixels 140d, the pixels 140m, and the pixels 140o, and the test rays that are directed to the other pixels are shielded. Thus, the test ray passing through the four pixels can be focused by the lens 15 to the four positions on the surface of the object DUT after passing through the spatial light modulator 14. Among the four positions on the surface of the object DUT, in addition to the position corresponding to the pixel 140d on the surface of the object DUT, there are three new positions corresponding to the pixel 140b, the pixel 140m, and the pixel 140o. This embodiment defines that the light taken from the object DUT in the third time interval is the third object light. For example, the test light passes through the pixel 140b, the pixel 140d, the pixel 140m, and the pixel 140o to the four positions on the surface of the object DUT, so the third time Four corresponding third object rays can be obtained in the interval.

Next, as in the foregoing example, the reference mirror 13 can also move a range in the third time interval, and the image capturing device 16 records the reference corresponding to the position of each reference mirror 13 during the movement of the reference mirror 13. The sum of the brightness of the light and the third object, and the surface topography at four locations on the surface of the object DUT can be derived. For illustrative purposes, the present embodiment exemplifies the surface topography data (third surface topography data) of the object DUT measured in the third time interval as shown in Table 4 below, and integrates the information of Table 2.   Pixel Second surface topography data Third surface topography 140a +3 140b +3 140d +1 +2 140j +2 140l -1 140m +4 140o +2 Table 4  

It can be seen from Table 4 that the present embodiment provides a repeating pixel 140d (second repeating pixel) between the second pixel group and the third pixel group. Since the position of the pixel 140d on the surface of the scanned object DUT is fixed, the degree of vibration interference received in the third time interval can be calculated. It is worth mentioning that although the third pixel group illustrated in FIG. 2C does not include the pixel 140a, it does not mean that the third pixel group cannot select the pixel 140a (the first repeated pixel). For example, in practice, the pixel 140a, the pixel 140b, the pixel 140m, and the pixel 140o may be selected as the third pixel group, so that the repeated pixel between the second pixel group and the third pixel group may be the first The repeating pixels between the pixel group and the second pixel group are the same.

Returning to the example illustrated in FIG. 2C, Table 4 demonstrates that the pixel 140d corresponds to the position on the surface of the object DUT, the surface topography data in the second time interval is +1, and the surface topography data in the third time interval is +2, it can be inferred that the vibration difference (second vibration difference) is +1. However, because the second surface topography data is interfered by the first vibration difference, it can be known that all the third surface topography data measured in the third time interval are affected by the first vibration difference value and the second vibration difference value. The third surface topography data after compensating/deducting the first shock difference value (+2) and the second vibration difference value (+1) can have the same reference as the first surface topography data. The deformed and third surface topography materials in this embodiment are shown in Table 5 below.   The third surface topography data after compensation of the second surface topography data compensated by the first surface topography data of the pixel 140a +1 +1 140b +0 140c +2 140d -1 -1 140i -1 140j +0 140k +3 140l -3 140m +1 140o -1 Table 5  

It can be seen from Table 5 that the original second surface topography data and the third surface topography data have the influence of vibration, so if the surface topography data without vibration compensation is taken, the surface shape of the object DUT cannot be truly reflected. appearance. The surface topography detecting system 1 to which the surface topography detecting method disclosed in the present invention is applied can sequentially reflect light at different positions on the surface of the object DUT after sequentially opening different pixel groups on the spatial light modulator 14. The surface topography of each position is judged to achieve the purpose of completely scanning the surface topography of the designated area of the object DUT. Moreover, after the vibration compensation, the surface topography data corresponding to different pixel groups can be integrated, so that a complete and correct surface topography of the designated area of the object DUT can be obtained.

In order to illustrate the steps of the surface topography detecting method of the present invention, please refer to FIG. 1A, FIG. 2A to FIG. 2C and FIG. 3 together. FIG. 3 illustrates the flow of steps of the surface topography detecting method according to an embodiment of the present invention. Figure. In step S30, the beam splitting unit 12 can split the input light into reference light and test light, and the test light can be used to scan the surface topography of the object DUT. In step S32, a spatial light modulator 14 is disposed on the optical path through which the test ray travels, and the spatial light modulator 14 has a plurality of pixels 140a-140o. In step S34, an external computer workstation or server may be used to issue a control command cmd, and the spatial light modulator 14 may be controlled by the control command cmd to open a first pixel group of the plurality of pixels in a first time interval ( For example, the pixel 140a, the pixel 140c, the pixel 140i, and the pixel 140k) turn on the second pixel group (for example, the pixel 140a, the pixel 140d, the pixel 140j, and the pixel 140l) of the plurality of pixels in the second time interval. The pixel corresponding to the first pixel group and the second pixel group has at least one repeated pixel (for example, the pixel 140a). The details of other steps of the surface topography detecting method of the present invention have been described in detail in the foregoing embodiments, and are not described herein.

Of course, the present invention does not limit the surface topography detecting system 1 to only use the optical architecture illustrated in FIG. 1A. Please refer to FIG. 1A and FIG. 4 together. FIG. 4 is a schematic diagram of a surface topography detecting system according to another embodiment of the present invention. Similarly, the surface topography detecting method disclosed in the present invention can also be applied to the surface topography detecting system 4. Similar to FIG. 1A, the surface topography detecting system 4 also has a light source 40, a lens 41, a spatial light modulator 42, a lens 43, and an image capturing device 44. The functions of the light source 40, the lens 41, the lens 43, and the image capturing device 44 are very similar to those of the foregoing embodiment, and are not described herein. Different from the previous embodiment, the surface topography detecting system 4 of the present embodiment uses a confocal optical structure, and the spatial light modulator 42 can guide the object light reflected by the object DUT to the image capturing device 44, so that The surface topography detection system 4 can also be used to detect the object DUT.

In addition, the control mode of each pixel in the spatial light modulator 42 is the same as that of the previous embodiment. Similarly, a plurality of pixels can be divided into a plurality of pixel groups, and there are repeated pixels between the two pixel groups. Thereby, the surface topography detecting system 4 can also scan the surface topography of the designated area of the object DUT after sequentially opening different pixel groups on the spatial light modulator 42. Moreover, after the vibration compensation, the surface topography data corresponding to different pixel groups can be integrated, so that a complete and correct surface topography of the designated area of the object DUT can be obtained.

In summary, the surface topography detecting method provided by the present invention sequentially turns on a plurality of pixel groups in the spatial light modulator, and designs repeated pixels in the plurality of pixel groups. By comparing the values obtained by repeating the pixels in two measurements, the interference of the vibration can be compensated to improve the measurement accuracy of the surface topography.

1‧‧‧Surface topography detection system

10‧‧‧Light source

11‧‧‧ lens

12‧‧‧Distribution unit

13‧‧‧Reference mirror

14‧‧‧Spatial Light Modulator

140a~140o‧‧‧ pixels

15‧‧‧ lens

16‧‧‧Image capture equipment

4‧‧‧Surface topography detection system

40‧‧‧Light source

41‧‧‧ lens

42‧‧‧Spatial Light Modulator

43‧‧‧ lens

44‧‧‧Image capture equipment

S30~S34‧‧‧Step procedure

Cmd‧‧‧Control Instructions

1A is a schematic diagram of a surface topography detecting system in accordance with an embodiment of the present invention.

1B is a schematic view showing a surface topography detecting system according to another embodiment of the present invention.

2A is a schematic diagram of control of a spatial light modulator in a first time interval according to an embodiment of the invention.

2B is a schematic diagram showing control of a spatial light modulator in a second time interval according to an embodiment of the invention.

2C is a schematic diagram showing control of a spatial light modulator in a third time interval according to an embodiment of the invention.

3 is a flow chart showing the steps of a surface topography detecting method according to an embodiment of the invention.

4 is a schematic view showing a surface topography detecting system according to another embodiment of the present invention.

Claims (11)

A surface topography detecting method comprising: providing a test light for measuring a surface topography of an object; and providing a spatial light modulator on an optical path of the test light, the spatial light modulator having a plurality of pixels; and controlling the spatial light modulator to turn on a first pixel group of the pixels in a first time interval, and to activate a second pixel group of the pixels in a second time interval; The first pixel group and the second pixel group respectively correspond to the pixels, and the first pixel group and the second pixel group have a first repeating pixel. The surface topography detecting method of claim 1, wherein in the first time interval, the object reflects the test light to obtain a first object light, and in the second time interval, the object reflects the test light And to obtain a second object light. The method for detecting a surface topography according to claim 2, further comprising: detecting the light of the first object, thereby generating a plurality of first surface topography data, each of the first surface topography data respectively corresponding to the first Each of the pixels in the pixel group; detecting the second object light to generate a plurality of second surface topography data, each of the second surface topography data respectively corresponding to each of the second pixel groups a first pixel; and a first surface difference value calculated by comparing the first surface topography data corresponding to the first repeated pixel with the second surface topography data corresponding to the first repeated pixel. The method for measuring a surface topography according to claim 3, further comprising: compensating the second surface topography data according to the first vibration difference value. The surface topography detecting method of claim 4, further comprising: combining the first surface topography data and the compensated second surface topography data. The surface topography detecting method of claim 3, further comprising: providing a beam splitting unit for dividing an input light into a reference light and the test light; comparing the first object light with the reference light Generating the first surface topography data; and comparing the second object light to the reference light to generate the second surface topography data. The method for detecting a surface topography according to claim 1, further comprising: controlling the spatial light modulator to enable a third pixel group of the pixels in a third time interval; wherein the third pixel group corresponds to a portion of the pixels, and a second repeating pixel between the second group of pixels and the third group of pixels. The surface topography detecting method of claim 7, wherein the first repeating pixel is different from the second repeating pixel. The surface topography detecting method of claim 7, wherein in the third time interval, the object reflects the test light to obtain a third object light. The method for detecting a surface topography according to claim 9, further comprising: detecting the light of the third object, thereby generating a plurality of third surface topography data, each of the third surface topography data respectively corresponding to the third surface topography data Calculating a second vibration difference value for each of the pixels in the pixel group; and the third surface topography data corresponding to the second surface topography data corresponding to the second repeated pixel and the second surface topography data . The surface topography detecting method of claim 10, further comprising: compensating the third surface topography data according to the first vibration difference value and the second vibration difference value.