CN108662992B - Surface measurement method and surface measurement system - Google Patents

Abstract

A surface measurement method and a surface measurement system are provided. The surface measuring method is used for measuring the surface of a wafer to be measured, and comprises the following steps: scanning the surface of the wafer to be measured by using a surface measuring device to obtain the surface measuring information of the wafer to be measured; the white light interferometer is moved to the initial scanning position by the moving device according to one of the height data of the surface measurement information. The white light interferometer comprises a micro-actuating unit which can control the movement of the interference objective lens; the white light interferometer is arranged at the initial scanning position, and the micro-actuating unit is used for controlling the interference objective lens to move so as to carry out image acquisition operation. The unit moving step pitch of the moving device is larger than that of the micro actuating unit, and the moving speed of the moving device is larger than that of the micro actuating unit. The overall measuring speed can be greatly improved through the steps.

Description

Surface measurement method and surface measurement system

technical field

The invention relates to a surface measurement method and a surface measurement system, in particular to a surface measurement method and a surface measurement system for measuring the surface of a wafer.

Background technique

Wafer warpage is one of the important problems in the semiconductor manufacturing process. There are many factors that cause wafer warpage. The wafer warpage caused by these factors can cause component failure on the wafer, film peeling or wafer cracking. In severe cases, the wafer may even crack, so the monitoring of wafer warpage is very important to the semiconductor process. Most of the existing main surface measurement systems use white light interferometers to directly measure specific positions of the wafer. However, since the size of the wafer surface defect and the precision of the white light interferometer are very small, when using the white light interferometer for surface measurement, it takes a lot of time to perform the imaging operation, which makes the overall measurement time lengthy. , and the measurement performance is low.

SUMMARY OF THE INVENTION

The main purpose of the present invention is to provide a surface measurement method and a surface measurement system to solve the problem of low measurement efficiency in the prior art, which only uses a white light interferometer for wafer surface measurement.

In order to achieve the above purpose, the present invention provides a surface measurement method, which is used to measure the surface of a wafer to be measured. The measurement method includes the following steps: a surface information acquisition step: using a surface measurement device to measure the surface of the wafer to be measured The wafer is scanned on the surface to obtain a surface measurement information of the wafer to be tested, and the surface measurement information includes a plurality of height data; a step of moving to the starting scanning position: according to one of the height data, use a mobile device to make A white light interferometer is located at a corresponding initial scanning position; wherein, the white light interferometer includes an interference objective lens and a micro-actuating unit, and the micro-actuating unit can control the interference objective lens to move in a longitudinal direction; an image acquisition step: making At the initial scanning position of the white light interferometer, the micro-actuating unit is used to control the interferometric objective lens to move in the longitudinal direction to perform image acquisition operations; wherein, the unit movement step of the mobile device is greater than the unit movement step of the micro-actuator unit, and the movement The speed of movement of the device is greater than the speed of movement of the micro-actuating unit.

Preferably, in the step of moving to the initial scanning position, the moving device controls the white light interferometer to move in the longitudinal direction, so that the interference objective lens is positioned at the initial scanning position; wherein, the surface measuring device measures a position of the wafer to be measured. The speed of obtaining the height value corresponding to the position by measurement is faster than the speed of measuring the position by using the white light interferometer to obtain the height value corresponding to the position; in the step of moving to the starting scanning position, in addition to relying on one of the height data, Also according to a predetermined offset, the white light interferometer is positioned at the starting scanning position by the moving device.

Preferably, between the step of acquiring the surface information and the step of moving to the starting scanning position, a wafer carrying step is further included: controlling a carrying device for carrying the wafer to be measured, so that the wafer to be measured is moved from a position adjacent to the surface measurement device. Move to a predetermined position adjacent to the white light interferometer; wherein, the carrier device can move the wafer to be tested in a plane, and the longitudinal direction is the normal direction of the plane.

Preferably, after the image acquisition step, it further includes a position moving step: controlling the carrier device to move the wafer to be tested from a predetermined position to another predetermined position; wherein, the moving to the starting scanning position step, the image capturing step and the position The moving step will be repeated a predetermined number of times.

In order to achieve the above object, the present invention further provides a surface measurement system, which is used for surface measurement of a wafer to be measured, and the surface measurement system includes: a carrier device, a surface measurement device, a white light An interferometer and a mobile device. The carrier device is used for carrying a wafer to be tested, and the carrier device can move the wafer to be tested on a plane. The surface measurement device is arranged on one side of the carrier device, and the surface measurement device can measure the surface of the wafer to be tested, so as to generate a surface measurement information correspondingly, and the surface measurement information includes a plurality of height data. The white light interferometer includes a micro-actuating unit and an interferometric objective lens. The micro-actuating unit can control the interferometric objective lens to move in a longitudinal direction to acquire images of the wafer to be tested; wherein, the longitudinal direction is the normal direction of the plane. The mobile device can control the white light interferometer to move in the longitudinal direction according to each height data, so that the white light interferometer moves to a corresponding starting scanning position; wherein, the unit movement step of the mobile device is greater than the unit movement of the micro-actuating unit step distance, and the moving speed of the moving device is greater than the moving speed of the micro-actuating unit. Wherein, when the white light interferometer moves to the starting scanning position, the white light interferometer can cooperate with each other through the micro-actuating unit and the interference objective lens to acquire images of the wafer to be tested.

Preferably, the surface measurement system further includes a processing device, the processing device is electrically connected to the surface measurement device, the carrier device, the mobile device and the white light interferometer, and the processing device can be based on the plurality of height data included in the surface measurement information and the corresponding plane coordinate data to control the carrying device and the moving device, so that the white light interferometer can perform image acquisition at the corresponding position of the wafer to be tested.

Preferably, the surface measurement system further includes a calibration device for calibrating the relative positions of the surface measurement device, the carrier device, the white light interferometer and the moving device.

Preferably, the surface measuring device uses the fringe reflection method to measure the surface of the wafer to be measured; the moving device can correspondingly control the white light interferometer to move in the longitudinal direction according to each height data and a predetermined offset.

Preferably, the surface measurement system further includes an input device electrically connected to the processing device, the input device is used to provide a user to input measurement information, and the measurement information includes a plurality of wafer measurement position data; the processing device can According to the measurement position data of the plurality of wafers, the carrier device and the moving device are controlled, so that the white light interferometer performs an image acquisition operation at a position corresponding to the wafer to be measured.

Preferably, the surface measurement system further includes a robotic arm device, which is electrically connected to the processing device, and the processing device can control the robotic arm to pick and place the wafer to be tested on the carrier device.

The beneficial effect of the present invention can be that: through the mutual cooperation of the surface measuring device and the moving device, the white light interferometer can be quickly moved to the starting scanning position, so that the white light interferometer can save a lot of time to find the starting position. Scanning the position, in this way, the measurement speed of the white light interferometer can be greatly improved, and the overall measurement performance can be greatly improved.

Description of drawings

FIG. 1 is a side view of the surface measurement system of the present invention.

FIG. 2 is a top view of the surface measurement system of the present invention.

FIG. 3 is a schematic block diagram of the surface measurement system of the present invention.

FIG. 4 is a schematic flowchart of the first embodiment of the surface measurement method of the present invention.

FIG. 5 is a schematic flowchart of a second embodiment of the surface measurement method of the present invention.

FIG. 6 is a schematic diagram of the surface measurement method and the surface measurement system of the present invention for measuring the surface of a wafer.

7 to 10 are schematic diagrams of operations of the second embodiment of the surface measurement method of the present invention.

Detailed ways

Please refer to FIG. 1 to FIG. 3 together, which are schematic diagrams of the surface measurement system of the present invention. The surface measuring system 1 of the present invention is used to measure the surface of a wafer W to be measured. As shown in the figure, the surface measurement system 1 includes a processing device 10 , a surface measurement device 20 , a carrier device 30 , a moving device 40 and a white light interferometer 50 . The surface measuring device 20 , the carrying device 30 , the moving device 40 and the white light interferometer 50 can be disposed on a fixed seat 60 , which is not limited, of course, and each device can be fixed in a specific position according to requirements. The processing device 10 is electrically connected to the surface measurement device 20 , the carrier device 30 , the mobile device 40 and the white light interferometer 50 , and the processing device 10 can control the surface measurement device 20 , the carrier device 30 , the mobile device 40 and the white light interferometer in sequence. 50, to perform a surface measurement operation on the wafer W to be tested. In practical applications, the processing device 10 may be, for example, a computer, a single-chip processor, etc., which is not limited herein.

Further, the surface measuring device 20 and the white light interferometer 50 can be respectively disposed at two ends of the carrier device 30 , and the carrier device 30 can carry a wafer W to be measured. The surface measurement device 20 can measure the surface of the wafer W to be measured to generate a surface measurement information 201 correspondingly, and the surface measurement device 20 can transmit the surface measurement information 201 to the processing device 10 . Specifically, the surface measurement information 201 may include a plurality of height data 2011 and a plurality of corresponding plane coordinate data 2012; that is, each height data 2011 is a Z-axis coordinate value, and each plane coordinate data 2012 That is, the X and Y axis coordinate values.

The carrying device 30 may include a carrying platform 31 and a plane moving unit 32 . The stage 31 is connected to the plane moving unit 32 . The plane moving unit 32 can be controlled by the processing device 10 to make the carrying table 31 move arbitrarily in a plane, so that the carrying table 31 can move between the surface measuring device 20 and the white light interferometer 50, and the plane moving unit 32 can The wafer W to be tested is moved to a specific position corresponding to the white light interferometer 50, so that the white light interferometer 50 performs an image acquisition operation at the specific position of the wafer W to be tested; wherein, the plane is the X-Y plane shown in the figure .

The moving device 40 and the white light interferometer 50 are connected to each other, and the moving device 40 can be controlled by the processing device 10 to move the white light interferometer 50 in a longitudinal direction (not numbered, that is, the Z-axis direction shown in the figure), so The longitudinal direction is the normal direction of the plane (the plane on which the plane moving unit 32 can control the movement of the stage 31 ), and the longitudinal direction is the Z-axis direction shown in the figure. The processing device 10 correspondingly controls the moving device 40 according to each height data 2011 in the surface measurement information 201 , so that an interference objective lens 51 of the white light interferometer 50 is located (moved to) a corresponding starting scanning position. In practical applications, the moving device 40 may directly control the movement of the entire white light interferometer 50 to move the interference objective lens 51 to the starting scanning position, or the moving device 40 may only control the movement of the interference objective lens 51 so that the It moves to the starting scanning position; of course, the moving device 40 is not limited to the above two methods, as long as the interference objective lens 51 can be located at the corresponding starting scanning position, it belongs to the scope of the present invention.

The white light interferometer 50 also includes a micro-actuating unit 52 (eg, a piezoelectric actuator PZT). When the white light interferometer 50 acquires an image of the wafer W to be tested, the micro-actuator unit 52 will control the interference objective lens 51 to move along the longitudinal direction, and cooperate with the image acquisition unit (not shown) to perform the image acquisition operation. It is worth mentioning that the unit movement step of the mobile device 40 is greater than the unit movement step of the micro-actuating unit 52 (specifically, the difference may be 1000 times), and the moving speed of the mobile device 40 is greater than the movement of the micro-actuating unit 52 . speed.

In addition, the speed at which the surface measuring device 20 measures a position of the wafer W to be tested to obtain the height value corresponding to the position is faster than that only by using the white light interferometer 50 to measure the position to obtain the position The speed of the corresponding height value; in other words, the measurement speed of the surface measurement device 20 is faster than that of the white light interferometer 50 . Specifically, the surface measurement device 20 may use the fringe reflection method to perform the surface measurement operation of the wafer W to be measured, so that the surface measurement information 201 can be obtained quickly and at one time.

In other words, the surface measuring device 20 with a relatively fast measurement speed and relatively rough measurement accuracy firstly scans the height of the entire surface of the wafer W to be tested quickly, and then uses the height data 2011 obtained by scanning, The white light interferometer 50 can quickly reach the corresponding starting scanning position, so that the white light interferometer 50 can quickly start the image acquisition operation. In this way, the overall measurement speed can be greatly improved, and the measurement can be greatly improved. efficiency.

Compared with the prior art that only uses a white light interferometer to measure the surface of the wafer to be tested, the surface of the wafer to be tested may be uneven due to warpage or various reasons. In the prior art, the white light interferometer needs a lot of time to reach the above-mentioned starting scanning position, and then the image acquisition operation can be performed, which will result in low measurement performance. In addition, as the dimensions of the components on the wafer W to be measured become increasingly finer, the existing devices for surface measurement using the fringe reflection method have poor precision, so only the surface measurement device using the fringe reflection method is used. The device will not be able to effectively perform fine image acquisition of the components on the wafer W to be tested.

In a special application, the surface measurement device 20 and the white light interferometer 50 can be arranged on the same side, and are not limited to the positions shown in the figure; even in a better application, the surface measurement is performed by the fringe reflection method Part of the components of the surface measurement device 20 may be shared with the components inside the white light interferometer 50, and are not limited to the aforementioned two independent devices.

It is particularly noted that, in practical applications, the surface measurement system 1 may also include a robotic arm device 70 (as shown in FIG. 2 ), which is used to transfer the wafer W to be measured, so as to measure the unmeasured wafer W to be measured. The wafer W to be tested is placed on the carrier device 30, or the wafer W to be tested that has been measured is unloaded from the carrier device 30; and the robotic arm device 70 may be electrically connected to the processing device 10, and the processing device 10. After the measurement of the wafer to be measured W is completed, the robot arm device 70 can be controlled to transfer the wafer to be measured W on the carrier device 30, so as to achieve the effect of automatic measurement. Of course, the number of the robot device 70 and the carrier device 30 can be increased according to the demand. In this way, when one of the carrier device 30 and the robot device 70 is performing the unloading operation of the wafer W to be tested, the other carrier device 30 The installation of another wafer W to be tested can be performed simultaneously with the robotic arm device 70 , and even at the same time, another wafer W to be tested can be subjected to a measurement operation.

It is worth mentioning that, the surface measurement system 1 further includes a calibration device (not shown), which can be selectively disposed on the carrier device 30 . When the calibration device is installed on the carrier device 30, the processing device 10 can control the surface measurement device 20 to measure the surface, and then control the carrier device 30 to carry it to the white light interferometer 50, so that the mobile device 40 can match the white light The interferometer 50 performs surface measurements of the correction device. In this way, the processing device 10 or related personnel can calibrate the surface measurement device 20 , the carrier device 30 , the white light interferometer 50 and the movement correspondingly according to the measurement results of the surface measurement device 10 and the white light interferometer 50 on the calibration device. The relative positions of the devices 40 are so that the carrier device 30 can correctly move the wafer W to be tested from a position adjacent to the surface measurement device 20 to a predetermined position adjacent to the white light interferometer 50, and through the calibration device, the white light The interferometer 50 and the mobile device 40 can accurately perform related image acquisition operations according to the surface measurement information 201 . In addition, as shown in FIG. 2 , the calibration device 80 may be used to calibrate the measurement value of the white light interferometer 50 itself.

In a specific implementation, the surface measurement system 1 may further include an input device 90 which is electrically connected to the processing device 10 . The input device 90 is used to provide a user to input measurement information (not shown), the measurement information Contains multiple wafer measurement position data (not shown). In this way, the processing device 10 can control the carrier device 30 and the moving device 40 according to the wafer measurement position data, so that the white light interferometer 50 can perform image acquisition at the position corresponding to the wafer W to be measured. More specifically, the user can input the actual positions of the wafer W to be measured that are prone to warping, and input the measurement position data for these wafers through the input device 90, so that the white light interferometer 50 is prone to warping according to the inputted position. position for surface measurement.

Please refer to FIG. 4 and FIG. 5 together, which are schematic diagrams of two embodiments of the surface measurement method for measuring the surface morphology of a wafer according to the present invention; in the following description, the specific settings of each device and component The position and linkage relationship can be referred to the foregoing embodiments, which will not be repeated below; however, the method steps defined in the following embodiments are not limited to the use of these devices and components in the foregoing embodiments, and any device that can achieve the same effect and purpose. The components and components are all variations of this embodiment.

As shown in Figure 4, it is the first embodiment of the surface measurement method, which includes the following steps:

A surface information acquisition step S11 : using the surface measurement device 20 to scan the surface of the wafer W to be tested to obtain the surface measurement information 201 of the wafer W to be tested; wherein the surface measurement information 201 includes a plurality of heights Data 2011.

1. Move to the starting scanning position. Step S12: According to one of the height data 2011 (ie, the Z-axis coordinate value), use the moving device 40 to move the white light interferometer 50, so that the interference objective lens 51 of the white light interferometer 50 is located at a corresponding one The starting scanning position (that is, the position where the interference objective lens 51 corresponds to the Z-axis coordinate value); wherein, the white light interferometer 50 has a micro-actuating unit 52 inside, which is used for the measurement of the white light interferometer 50 , the interferometric objective lens 51 is controlled to move along a longitudinal direction, and the moving device 40 is not a component used to control the interferometric objective lens 51 to move when the white light interferometer 50 performs the image acquisition operation; wherein, the steps described in this step The height data 2011 may include a predetermined offset D (as shown in FIG. 6 ) set by the user (or set by a related processing device); in an actual implementation, the mobile device 40 may be used to control The white light interferometer 40 moves along the Z axis (the longitudinal direction), and the wafer W to be tested is controlled by the carrier device 30 to move in the X-Y plane, or the moving device 40 can control the white light interferometer 50 to move in the X, Y, and Z axes.

An image acquisition step S13 : the white light interferometer 50 is placed at the starting scanning position, and the micro-actuating unit 52 is used to control the interferometric objective lens 51 to move in the longitudinal direction, so as to perform the image acquisition operation.

In a specific implementation, the surface measurement device 20 , the mobile device 40 and the white light interferometer 50 may be electrically connected to each other, and the surface measurement information 201 and related control signals may be performed with each other in a wired or wireless manner. transmission. Of course, the surface measuring device 20 , the moving device 40 and the white light interferometer 50 may all be connected to the processing device 10 , and the related information and signals are transmitted through the processing device 10 . It is particularly noted that the above-mentioned step S12 of moving to the initial scanning position and the step S13 of image acquisition are to measure the surface state of a single position on the wafer W to be tested. In practical applications, the above-mentioned step of moving to the initial scanning position S12 and the image acquisition step S13 may be repeated several times according to user requirements; for example, the user may predetermine to measure the surface states of N positions on the wafer W to be tested, and the above moves to the start The scanning position step S12 and the image acquisition step S13 are repeated for N times correspondingly.

As shown in FIG. 5 to FIG. 10, it is the second embodiment of the surface measurement method, which includes the following steps:

A surface information acquisition step S21 : using the surface measurement device 20 to scan the surface of the wafer W to be measured to obtain surface measurement information 201 of the wafer to be measured, the surface measurement information 201 includes a plurality of height data 2011 ; For example, as shown in FIG. 6, the height data 2011 (Z-axis coordinate value) obtained by the surface measuring device 20 and a predetermined offset D can be calculated to obtain the starting scan line shown in the figure. ISL; wherein, the predetermined offset D may be set by the user according to the heights of the components P1, P2, P3, and P4 on the wafer W to be measured, or may be determined by the processing device 10 according to the surface measurement information 201; or That is to say, the predetermined offset D can be manually set or automatically set by a computer, which is not limited herein. It is particularly noted that the initial scanning line ISL is determined based on the topography of the wafer W to be tested and the predetermined offset D, and the scanning direction and scanning distance of the white light interferometer 50. Therefore, when the white light interferometer 50 When 50 scans downward, the start scan line ISL is basically located above the wafer W to be tested.

A wafer carrying step S22 : controlling the carrying device 30 carrying the wafer W to be measured, so that the wafer W to be measured is moved from a position adjacent to the surface measurement device 20 to a predetermined position; wherein, the predetermined position is white light interference Specifically, as shown in FIG. 6 , when the surface inspection system 1 wants to perform an image acquisition operation on the component P1 on the wafer W to be tested, the processing device 10 will According to the plane coordinate data 2012 of the component P1 (which may be selected by the user), the carrying device 30 is controlled to move so that the component P1 is located approximately below the white light interferometer 50 (ie, the position where the white light interferometer 50 can perform image acquisition) .

1. Move to the starting scanning position. Step S23: According to one of the height data 2011 (corresponding to the plane coordinate data 2012 in step 23), use the moving device 40 (driving the white light interferometer 50 to move in the longitudinal direction) to make the white light interferometer 50 (The interference objective lens 51) is located at a corresponding starting scanning position; wherein, the white light interferometer 50 has a micro-actuating unit 52 inside, which is used to control the interference objective lens 51 to perform an image acquisition operation when the white light interferometer 50 performs an image acquisition operation. The moving device 40 is not a component used to control the movement of the interference objective lens 51 when the white light interferometer 50 performs scanning and image acquisition. Specifically, please refer to FIG. 6 to FIG. 8 together. When the processing device 10 (as shown in FIG. 3 ) controls the carrying device 30 to move in the X-Y plane to move below the white light interferometer 50 , the processing device 10 will According to one of the height data 2011 (Z-axis coordinate value) and a predetermined offset D, the white light interferometer 50 will be controlled to move to an initial scanning position ISP1 corresponding to the component P1; that is, the processing device 10 will The plane coordinate data 2012 (which can be determined by the processing device 10, or the X and Y axis coordinate values selected by the user), look for the corresponding height data 2011 (Z axis coordinate value) in the surface measurement information 201 , and selectively superimpose (or subtract) a predetermined offset D according to the scanning direction and scanning distance of the white light interferometer 50, so as to obtain the Z-axis coordinate value of the starting scanning position ISP1, thereby making The white light interferometer 50 is correspondingly moved to the starting scanning position ISP1. In practical applications, each height data 2011 output by the surface measurement device 20 may directly include the predetermined offset D; or, each height data 2011 may also not include the predetermined offset D, Then, the processing device 10 or the mobile device 40 calculates each height data 2011 according to the predetermined offset D defined by the user or calculated by the processing device 10 to obtain the start scan position ISP1.

An image acquisition step S24 : the white light interferometer 50 is positioned at the start scanning position, and the micro-actuating unit 52 is used to control the interferometric objective lens 51 to move in the longitudinal direction, so as to perform the image acquisition operation. Specifically, please refer to FIG. 6 to FIG. 9 together. The processing device 10 (as shown in FIG. 3 ) controls the moving device 40 to move the white light interferometer 50 to the starting scanning position ISP1, and the processing device 10 makes the white light The micro-actuating unit 52 of the interferometer 50 operates to drive the interferometric objective lens 51 to move longitudinally, so that the white-light interferometer 50 can perform image acquisition operations; wherein, the dotted frame R shown in FIG. 6 corresponds to the micro-actuator The unit 52 controls the operation of the interference objective lens 51 to enable the white light interferometer 50 to perform a longitudinal scanning range of the image acquisition of the wafer W to be tested.

A position moving step S25 : controlling the carrier device 30 to move the wafer W to be tested from a predetermined position to another predetermined position; specifically, the carrier device 30 will carry the wafer to be tested according to different plane coordinate data 2012 W moves, so that different positions of the wafer W to be tested are correspondingly located at positions where the white light interferometer 50 can perform the image acquisition operation. Wherein, the step of moving to the starting scanning position, the step of acquiring the image and the step of moving the position will be repeated for a predetermined number of times, and the predetermined number of times is less than the number of these height data. Specifically, as shown in FIG. 6 , FIG. 9 and FIG. 10 , if the surface inspection system 1 wants to scan and acquire the positions of the four components P1 , P2 , P3 , and P4 on the wafer W to be tested, and then process the When the white light interferometer 50 is at the initial scanning position ISP1, the device 10 will execute the position moving step S25 after completing the image acquisition step S24, so as to control the carrier device 30 to move the wafer W to be tested according to the plane coordinate value corresponding to the component P2. Move to the bottom of the white light interferometer 50, and then perform the step S23 of moving to the initial scanning position again, so that the white light interferometer 50 is moved to the initial scanning position ISP2, and perform the image acquisition step S24 again. Similarly, the measurement of the components P3 and P4 follows the same steps as above.

Wherein, the wafer carrying step S22 may be performed by, for example, the aforementioned carrying device 30 , so that the wafer to be measured can be moved between the surface measuring device 20 and the white light interferometer 50 . In the step of moving the position, the carrier device 30 can also be used to move the wafer W to be measured to the next predetermined measurement position, so that the white light interferometer can perform measurement. In practical applications, the carrying device 30 may be an X-Y axis linear moving device, a robotic arm, etc., which is not limited herein.

To sum up the above, please refer to FIG. 6 , in the surface measurement system and surface measurement method of the present invention, a plurality of starting scanning positions ISP1 , ISP2 , ISP3 , and ISP4 shown in the figure are first obtained through the surface measurement device 20 , Then, through the cooperation of the carrying device 30 and the moving device 40, after the white light interferometer 50 reaches the starting scanning position (ISP1, ISP2, ISP3, ISP4), the micro-actuating unit 52 is used to drive the interference objective lens 51 to move longitudinally, so that the white light interferes The instrument 50 performs an image acquisition operation. Since these starting scanning positions (ISP1, ISP2, ISP3, ISP4) are calculated by the surface measuring device 20 after measuring the surface topography of the wafer W to be measured (selectively adding or subtracting predetermined offsets) Therefore, after the white light interferometer 50 reaches the starting scanning position (ISP1, ISP2, ISP3, ISP4), the micro-actuating unit 52 can be used to drive the interference objective lens 51 to move longitudinally, so that the white light interferometer 50 can The wafer W to be tested at this position performs related image acquisition operations.

Compared with the present invention, the existing wafer surface measurement system that directly uses the white light interferometer to perform image scanning has the following problems: since the user controls the specific position of the wafer to be measured by the white light interferometer, before the image acquisition operation is performed , the user does not know the surface topography of the wafer to be tested. Therefore, in the prior art, the relevant user must set the white light interferometer at the same predetermined Z-axis height based on past experience, and start to measure different position for image acquisition. In this way, the white light interferometer will take a lot of time (the unit movement step of the micro actuation unit is very small) to reach the starting scanning position of the present invention, so that the image scanning and acquisition operations can be performed (based on white light interference Due to the optical characteristics of the instrument, the white light interferometer must be moved to the correct scanning position before the micro-actuating unit can be effectively used for image acquisition). In extreme cases, when the Z-axis height set by the user cannot match the warpage value at different positions of the wafer to be tested, it will cause the white light interferometer to spend a lot of time scanning and still cannot find the starting point The scanning position, and the user must adjust the initial Z-axis height again, so that the white light interferometer can scan again.

Claims (9)

1. A surface measurement method, wherein the surface measurement method is used to measure the surface of a wafer to be measured, and the surface measurement method comprises the following steps: A surface information acquisition step: using a surface measurement device to scan the surface of the wafer to be tested to obtain a surface measurement information of the wafer to be tested, the surface measurement information includes a plurality of height data; A step of moving to the starting scanning position: according to one of the height data and a predetermined offset, use a moving device to control a white light interferometer to move in a longitudinal direction, so that an interference objective lens included in the white light interferometer is located at a start The initial scanning position; wherein, the white light interferometer further includes a micro-actuating unit, the micro-actuating unit can control the interference objective lens to move in the longitudinal direction; and An image acquisition step: making the white light interferometer at the starting scanning position, and using the micro-actuating unit to control the interferometric objective lens to move in the longitudinal direction, so that the white light interferometer performs an image acquisition operation on the wafer to be tested; Wherein, the unit moving step of the mobile device is greater than the unit moving step of the micro-actuating unit, and the moving speed of the mobile device is greater than the moving speed of the micro-actuating unit; Wherein, the speed at which the surface measuring device measures a position of the wafer to be measured to obtain the height value corresponding to the position is faster than only using the white light interferometer to measure the position to obtain the height value corresponding to the position. The velocity of the altitude value. 2 . The surface measurement method according to claim 1 , wherein between the step of acquiring the surface information and the step of moving to the starting scanning position, a wafer carrying step is further included: controlling the wafer carrying the wafer to be measured. 3 . a carrier device to move the wafer to be tested from a position adjacent to the surface measurement device to a predetermined position adjacent to the white light interferometer; wherein the carrier device can move the wafer to be tested in a plane, The longitudinal direction is the normal direction of the plane. 3 . The surface measurement method according to claim 2 , further comprising a position moving step after the image acquisition step: controlling the carrier device to move the wafer to be measured from the predetermined position to another. 4 . a predetermined position; wherein, the step of moving to the starting scanning position, the step of acquiring the image and the step of moving the position will be repeated for a predetermined number of times. 4. A surface measurement system, wherein the surface measurement system is used to perform the surface measurement method of claim 2, to perform surface measurement on a wafer to be measured, and the surface measurement The system includes: the carrier device for carrying the wafer to be tested, the carrier device can move the wafer to be tested on the plane; The surface measurement device is disposed on one side of the carrier device, and the surface measurement device can measure the surface of the wafer to be measured, so as to generate the surface measurement information correspondingly, and the surface measurement information includes multiple such height data; The white light interferometer is disposed on the other side of the carrying device, the white light interferometer includes the micro-actuating unit and the interference objective lens, and the micro-actuating unit can control the interferometric objective lens to move in the longitudinal direction, so as to An image acquisition operation is performed on the wafer to be tested; wherein, the longitudinal direction is the normal direction of the plane; and The mobile device can control the white light interferometer to move along the longitudinal direction according to the height data, so that the white light interferometer is located at the corresponding starting scanning position; wherein, the unit moving step of the mobile device is greater than the The unit moving step of the micro-actuating unit, and the moving speed of the mobile device is greater than the moving speed of the micro-actuating unit; Wherein, when the white light interferometer is located at the starting scanning position, the white light interferometer can cooperate with each other through the micro-actuating unit and the interference objective lens to acquire images of the wafer to be tested. 5 . The surface measurement system of claim 4 , wherein the surface measurement system further comprises a processing device, and the processing device is electrically connected to the surface measurement device, the carrier device, the moving device and the White light interferometer, the processing device can control the carrying device and the moving device according to the height data and the corresponding plane coordinate data included in the surface measurement information, so that the white light interferometer can operate on the crystal to be measured. Image acquisition is performed at the position corresponding to the circle. 6 . The surface measurement system of claim 4 , wherein the surface measurement system further comprises a calibration device for calibrating the surface measurement device, the carrier device, the white light interferometer and the movement. 7 . The relative position of the devices to each other. 7 . The surface measurement system of claim 4 , wherein the surface measurement device uses a fringe reflection method to measure the surface of the wafer to be measured; the mobile device can measure the surface of the wafer to be measured according to the height data and a The predetermined offset corresponds to controlling the white light interferometer to move along the longitudinal direction. 8 . The surface measurement system according to claim 4 , wherein the surface measurement system further comprises an input device, which is electrically connected to a processing device, and the input device is used for providing a user to input measurement information. 9 . , the measurement information includes a plurality of wafer measurement position data; the processing device can control the carrier device and the moving device according to the wafer measurement position data, so that the white light interferometer is located on the wafer to be measured. The image acquisition operation is performed at the position corresponding to the circle. 9 . The surface measurement system according to claim 4 , wherein the surface measurement system further comprises a robotic arm device, which is electrically connected to a processing device, and the processing device can control the robotic arm device to take The wafer to be tested is placed on the carrier device.

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