CN111624159A - Elliptical polarization measuring device and measuring method - Google Patents

Abstract

The application discloses an ellipsometry measurement device and a measurement method, including a substrate, a sample stage, a detection component, an angle switching mechanism and an angle positioning mechanism; the sample stage is fixedly installed on the base plate, and the sample stage table is flat; the angle switching mechanism is rotated and installed On the base plate, the rotation axis of the angle switching mechanism is located in the detection surface; the detection component includes a deflection arm and an analyzer arm, and the deflection arm and the analyzer arm are installed on the angle switching mechanism; the angle positioning mechanism is installed on the working platform, through the The rigid interference limit or self-locking structure defines the rotation angle of the angle switching mechanism. The ellipsometry measurement device and measurement method of the present application do not need to change the sample stage or change the orientation of the sample stage, and have the advantages of simple structure, simple operation and high repeated positioning accuracy, and can realize the same placement position for various types of samples, reducing the time required for testing. The risk of sample fragmentation can realize any point test of the sample and improve the test efficiency.

Description

A kind of ellipsometry measurement device and measurement method

technical field

The present application relates to the technical field of optical measuring instruments, and in particular, to an ellipsometric measuring device and a measuring method.

Background technique

A solar cell is a semiconductor device that converts light energy into electrical energy. The types of solar cells include: crystalline silicon solar cells, thin film solar cells, dye-sensitized solar cells, etc. Among them, crystalline silicon solar cells are the most commonly used solar cells at present. . Among them, the function of texturing is to allow the solar cell to effectively absorb sunlight; the function of the anti-reflection film is to reduce the reflection of sunlight on the surface of the solar cell, so that most of the solar energy reaches the interior of the cell and is absorbed by the semiconductor material, thereby Greatly improve the conversion of light energy.

At present, most of the textured monocrystalline silicon solar cells use the alkaline method to make texturing, which uses the anisotropy of the crystal when it is corroded to form a basic structure with a regularly arranged four-sided pyramid shape on the surface of the cell; while the textured polycrystalline silicon solar cells are mostly made of Textured by acid etching, irregular micro-undulations are formed on the surface of the battery.

At present, the commonly used instrument for detecting the thickness and refractive index of the anti-reflection film on the textured crystalline silicon solar cell is the ellipsometer. The basic principle of ellipsometer is to obtain surface information of the sample (such as the thickness of the nano-film, refractive index, etc.) by using the change of the polarization state of the light wave when it is reflected on the surface of the sample.

When the ellipsometer is used for detection, it is required that the plane where the sample detection surface is located is perpendicular to the incident surface formed by the incident optical axis and the reflected optical axis, and passes through the intersection of the two optical axes. Usually, the plane perpendicular to the incident plane formed by the incident optical axis and the reflected optical axis and passing through the intersection of the two optical axes is called the reference plane. During detection, the detection surface must be coincident with the reference surface. At this time, the incident angle of the system is equal to the reflection angle.

When using ellipsometry to measure the thickness and refractive index of anti-reflection films on different crystalline silicon (such as single-crystalline silicon, polycrystalline silicon), due to the different textured structures on crystalline silicon, it is required that different crystalline silicon be used during sample detection. The orientation relative to the reference surface is different to satisfy the coincidence of the detection surface and the reference surface.

Specifically, the acute angle between the cone surface of the tetrahedral pyramid formed on the surface of the monocrystalline silicon solar cell and the silicon substrate is about 54.7°, and the size of the pyramid is about 2-5 microns. An anti-reflection film is plated on the cone surface. In order to detect the thickness and refractive index of the anti-reflection film, the cone surface of the pyramid is required to be used as the detection surface. In order to ensure that the detection surface coincides with the reference surface, it is necessary to ensure that the inclination angle between the sample stage placement surface on which the monocrystalline silicon is placed and the reference plane is 54.7°; and the orientation of the monocrystalline silicon solar cell on the sample stage needs to be adjusted to meet the detection requirements. The face is coincident with the reference face.

The texture feature of the polycrystalline silicon solar cell using acid texturing is that there are tiny irregular undulations on the silicon surface, and the size of the undulations is in the order of microns. , the plane parallel to the silicon substrate and passing through the surface of the sample is the detection surface, so the placement surface of the sample stage where the polysilicon is placed is parallel to the reference plane.

In addition, for untextured crystalline silicon solar cells, the detection surface is the upper surface coated with anti-reflection film, and the sample stage placement surface is also required to be parallel to the reference plane, which is the same as the sample stage for polycrystalline silicon solar cells.

From the above analysis, it can be seen that when the monocrystalline silicon and polycrystalline silicon solar cells are tested, the placement orientation of the cell relative to the reference surface is different. angle, while the acid-fabricated polysilicon is placed with its base parallel to the reference plane.

In other words, it is required to change the dihedral angle formed by the placement surface of the sample stage and the reference plane when testing the anti-reflection films of solar cells with two different surface textured structures to meet the test requirements.

In actual testing, for example, in the production line of solar cells, it is necessary to test different types of solar cells (single crystal, polycrystalline), which requires the ellipsometer to be able to adapt to such changing testing conditions, and requires the detection of different types of solar cells. In the process, the operation is simple, time saving, high accuracy and good repeatability.

In order to meet the above requirements, existing methods include:

(1) Design sample stages with different inclination angles in the ellipsometric measurement system, and replace the required sample stage by disassembling the sample stage according to the test requirements of different samples. The inclination angle refers to the placement surface and the reference surface of the sample stage. Acute angle clamped. This method is widely used in ellipsometry systems, but its disadvantages are that the disassembly process of the sample stage is cumbersome, the replacement speed is slow, and it is inconvenient to store the disassembled sample stage. Accuracy and repeatability cannot be guaranteed during installation and require recalibration.

(2) In the ellipsometry measurement system, the method without disassembling the sample stage is designed, that is, two sets of sample stages with different inclination angles are installed, and the two sets of sample stages are connected by electric (manual) guide rails. When a certain inclination angle is required When the sample stage is selected, the sample stage is moved to the installation position through the guide rail, and the other sample stages are moved out of the installation position. However, this method of changing different types of sample stages by moving the guide rail is relatively slow and occupies a large space, and it is difficult to guarantee the accuracy and repeatability.

(3) A sample stage with two table positioning surfaces is designed in the ellipsometric measurement system, and the dihedral angle between the two table positioning surfaces is 54.7°±5°. The dihedral angle formed by the placement surface of the sample stage and the reference plane can be met under different test conditions by rotating the table top of the sample stage. However, when using this method to detect single-crystal silicon solar cells, the sample to be tested needs to be placed on the sample stage in a state inclined by 54.7°±5° from the horizontal plane, which undoubtedly increases the difficulty of taking and placing the sample, and also increases the Risk of damage to the sample to be tested.

It can be seen that in the ellipsometry system, the existing problems of the crystalline silicon solar cell sample stage used in the ellipsometer are: (1) the angle of the sample stage needs to be changed to realize the sample flat or inclined; (2) When the sample is placed obliquely, it is not easy to move the sample, so it is not conducive to the uniformity test of the sample; (3) The risk of debris is high when the sample is placed obliquely.

These problems make certain types of samples can only be tested at a fixed point, and cannot be tested at any point, and it is inconvenient to take and place test samples, which has a great impact on process improvement and test efficiency.

SUMMARY OF THE INVENTION

The purpose of this application is to provide an ellipsometric measuring device and measurement device that does not need to change the sample stage or the orientation of the sample stage, has a simple structure, simple operation, rapid replacement, high repeat positioning accuracy, and can achieve the same placement position for various types of samples. The method can meet the testing requirements of single crystal solar cells and polycrystalline solar cells at the same time, reduce the risk of fragmentation of the single crystal solar cells during the testing process, realize any point testing of samples, and improve testing efficiency.

The above-mentioned purpose one of the present application is achieved through the following technical solutions:

An ellipsometry measurement device includes a substrate, a sample stage, a detection component, an angle switching mechanism and an angle positioning mechanism; the sample stage is fixedly installed on the substrate, the sample stage table is flat, and the sample to be measured is placed on the sample stage table the detection part includes a polarizing arm for emitting incident light and an analyzing arm for receiving reflected light, the incident light axis and the reflected light axis are formed with incident surfaces; the angle switching mechanism is rotatably mounted on the substrate, The polarizing arm and the analyzing arm are installed on the angle switching mechanism, and the angle switching mechanism drives the detection component to rotate synchronously to change the angle between the incident surface of the detection component and the surface of the sample to be measured; the angle positioning mechanism is installed on the base plate On, the rotation angle of the angle switching mechanism is limited by the rigid interference limit or the self-locking structure

By adopting the above technical solution, when detecting the sample to be tested, the sample to be tested is placed on the sample stage, and the angle switching mechanism is positioned by the angle positioning mechanism, so that the incident surface of the detection component is directly perpendicular to the detection surface of the sample to be tested, Make the intersection of the two optical axes pass through the detection surface, and then perform subsequent measurement; the whole process is fast and convenient, and the sample is avoided to be placed obliquely, reducing the risk of sample damage.

The present application is further provided as follows: the height of the sample stage can be adjusted.

By adopting the above technical solution, the height of the sample stage can be adjusted in real time to correspond to different types of samples, so that the adaptability of the sample stage is better.

The present application is further provided as follows: the angle switching mechanism includes a portal frame and a bearing seat, and two bearing seats are arranged on the base plate coaxially; the end of the portal frame is fixed with a rotating shaft, and the The portal frame is rotatably connected with the bearing seat through a rotating shaft penetrating into the bearing seat; the detection component is installed on the portal frame.

By adopting the above technical solution, the portal frame provides an installation basis for the detection component, and the portal frame is rotatably mounted on the base plate through the bearing seat, so that the detection component can be adjusted in angle.

The present application further provides that: the angle positioning mechanism includes an inclined positioning member and a vertical positioning member, and the inclined positioning member and the vertical positioning member are arranged on both sides of the angle switching mechanism along the rotation direction of the angle switching mechanism; the angle switching mechanism The angle switching mechanism is positioned in the inclined state by rigid interference and cooperation with the inclined positioning member; the angle switching mechanism is in rigid interference and cooperation with the vertical positioning member to position the angle switching mechanism in the vertical state.

By adopting the above technical solution, the vertical positioning member defines the vertical state of the angle switching mechanism, and the inclined positioning member defines the inclined state of the angle switching mechanism. positioning to improve test efficiency.

The present application is further provided that: the angle switching mechanism is in interference fit with the inclined positioning member, and the angle between the incident surface of the detection component and the vertical surface is 54.7°±5°.

By adopting the above technical solution, the angle between the incident surface and the vertical surface is 54.7°, so that after the angle switching mechanism abuts the inclined positioning member, the incident surface of the detection component is directly perpendicular to the detection surface of the monocrystalline silicon solar cell, Standardized angle adjustment is achieved to increase measurement rate.

The present application is further provided as follows: the angle positioning mechanism includes a first driving member mounted on the base plate, a crank fixed on the output end of the first driving member, and an intermediate rod rotatably connected to the crank, the intermediate rod being away from the crankshaft One end is hinged with the angle switching mechanism; the first driving member is a torque motor.

By adopting the above technical solution, the driving member drives the crank to rotate, and the crank drives the angle switching mechanism to reciprocate between a certain angle by pulling the intermediate rod; when detecting different types of solar cells, only the driving member is required to drive the crank to move. to the corresponding location.

The present application is further provided as follows: the angle positioning mechanism includes a guide rail mounted on the base plate, a slider mounted on the guide rail, a connecting rod hinged with the slider, and a second driving member that drives the slider to reciprocate along the guide rail, so One end of the connecting rod away from the slider is hinged with the angle switching mechanism; the second driving member is a torque motor or an electric push rod.

By adopting the above technical solution, using the working principle of the slider linkage mechanism, the second driving member drives the slider to perform a reciprocating linear motion, and the slider drives the angle switching mechanism to swing reciprocally by pulling the connecting rod to detect different types of solar cells. At the time, it is only necessary to control the second driving member to move the slider to the corresponding position.

The present application further provides that: the angle positioning mechanism is an electric push rod, the base of the electric push rod is hinged on the base plate of the base plate, and the output end of the electric push rod is hinged on the side wall of the angle switching mechanism.

By adopting the above technical solution, the driving member is directly used to drive the angle switching mechanism to perform a reciprocating swing motion, so as to realize the angle adjustment of the angle switching mechanism, and the adjustment process is simpler and more direct.

The present application is further configured as follows: the angle positioning mechanism includes a worm wheel and a worm, the worm wheel is fixed on one side of the angle switching mechanism, and is coaxially arranged with the rotation axis of the angle switching mechanism; the worm is rotatably mounted on the base plate and is in phase with the worm wheel meshing; the end of the worm is provided with a third driving member for driving it to rotate; the third driving member is a motor or a manual crank.

By adopting the above technical solution, the third driving member is used to rotate the worm, and the worm and the worm gear are meshed and driven to drive the worm gear to rotate synchronously, thereby driving the angle switching mechanism to rotate, realizing the angle adjustment of the angle switching mechanism; and the worm and the worm gear are multi-tooth meshing, It has the characteristics of stable transmission and low noise, and the worm gear and worm have self-locking properties. When detecting different types of solar cells, it is only necessary to control the third driving part to rotate the worm gear to the corresponding position.

The above-mentioned purpose two of the present application is achieved through the following technical solutions:

A measuring method utilizing an ellipsometric measuring device, comprising the following steps:

S1. Place the sample to be tested on the sample table;

S2. Rotate the incident surface according to the type of the sample to be tested, so that the incident surface of the detection component is perpendicular to the detection surface of the sample to be tested;

S3. Record the obtained surface information of the sample to be tested.

To sum up, the present application has the following beneficial effects: by configuring the angle switching structure for the detection part, the angle of the detection part relative to the sample stage and the sample to be tested placed on the sample stage is changed, instead of changing the angle of the sample to be tested. Angular position, by standardizing and adjusting the dihedral angle between the incident surface and the reference surface of the positioning detection component, the purpose of quickly testing the sample is finally achieved.

Description of drawings

Fig. 1 is the structural representation of the manual change angle scheme;

Fig. 2 is the front view of manual changing angle scheme;

3 is a schematic diagram of a crank-rocker mechanism scheme;

Figure 4 is a schematic diagram of the slider linkage mechanism scheme;

Figure 5 is a schematic diagram of an electric push rod scheme;

Figure 6 is a schematic diagram of a worm gear scheme.

In the figure, 1, base plate; 2, sample stage; 3, detection part; 31, deflection arm; 32, analyzer arm; 4, angle switching mechanism; 41, gantry; 42, bearing seat; 43, rotating shaft; 5. Angle positioning mechanism; 6. Inclined positioning member; 7. Vertical positioning member; 8. First driving member; 9. Crank; 10. Intermediate rod; 11. Guide rail; 12. Slider; 13. Connecting rod; 14 15, the worm gear; 16, the worm; 17, the third driving part; 20, the sample to be tested.

Detailed ways

The present application will be further described in detail below with reference to the accompanying drawings.

An ellipsometry measurement device, compared with the detachable design of the sample stage or the design of the conversion of the sample stage table and the adjustable angle of the sample stage of the ellipsometry measurement system in the prior art, the present application mainly makes the following improvements: the detection part 3 is configured with an angle Switch the structure to make the angle of the detection part 3 change relative to the sample stage 2 and the sample to be tested 20 placed on the sample stage 2. By standardizing and adjusting the dihedral angle between the incident surface and the reference surface of the positioning detection part 3, the sample can be quickly tested. the goal of.

The specific implementation is as follows: As shown in FIG. 1 , an ellipsometry measurement device includes a substrate 1 , a sample stage 2 , a detection component 3 , an angle switching mechanism 4 and an angle positioning mechanism 5 .

The top of the base plate 1 is provided with a working platform, the sample stage 2 is fixedly installed on the working platform of the base plate 1 , and the angle switching mechanism 4 is rotatably installed on the working platform of the base plate 1 . The table surface of the sample table 2 is flat, and its height can be adjusted. The height adjustment method can be lifted by a cylinder, or a mechanical lifting structure such as a scissors can be used; the sample 20 to be tested is placed flat on the table surface of the sample table 2.

The detection part 3 includes a polarization arm 31 and an analyzer arm 32 , the polarization arm 31 emits incident light, and the analyzer arm 32 receives reflected light; the polarization arm 31 and the analyzer arm 32 are installed on the angle switching mechanism 4 . The rotation axis of the angle switching mechanism 4 is located in the detection surface of the sample to be tested 20 .

When the angle switching mechanism 4 is in a vertical state, the incident surface formed by the incident optical axis and the reflected optical axis of the detection component 3 is perpendicular to the table surface of the sample stage 2 .

The angle positioning mechanism 5 is also installed on the working platform of the base plate 1 to limit the rotation angle of the angle switching mechanism 4. The angle positioning mechanism 5 can position the angle switching mechanism 4 at a single angle, or at certain specific angles. Positioning at any angle; for example, positioning the incident surface of the detection component 3 installed on the angle switching mechanism 4 to be parallel to the vertical surface or to form a dihedral angle of 54.7° with the vertical surface.

The working principle of the ellipsometry measuring device of the present application for measuring crystalline silicon solar cells is as follows:

When testing the sample, the detection surface must be coincident with the reference surface. Therefore, when detecting different types of samples, the sample stage needs to be adjusted to a specific height based on the detection system, and the detection part 3 is positioned and fixed to the corresponding angle, that is, the orientation of the reference surface is adjusted by the rotation of the detection part 3; When testing monocrystalline silicon solar cells, the incident surface of detection component 3 needs to be positioned at an angle of 54.7° to the vertical plane. At a parallel angle, the detection of solar cells of different types (single crystal and polycrystalline) can be realized, and finally the obtained surface information of the sample to be tested can be recorded.

Example 1: As shown in Figures 1 and 2, the angle switching mechanism 4 includes a portal frame 41 and a bearing seat 42. The number of bearing seats 42 is set to two, and is symmetrically arranged on the base plate 1 based on the central axis of the table surface of the sample stage 2. On the working platform; the portal frame 41 is composed of a horizontal bar and two vertical bars, the two vertical bars of the portal frame 41 are respectively fixed with a rotating shaft 43, and the rotating shaft 43 is rotated and installed on the bearing seat 42, so that the portal frame 41 It can rotate in a circle around the axis of the shaft 43 . The deflecting arm 31 and the analyzing arm 32 of the detection part 3 are mounted on the gantry 41 .

In this embodiment, the bearing seat 42 can be selected from angular contact ball bearings, deep groove ball bearings, rolling bearings, sliding bearings, etc., and the shaft-hub connection can be a key connection, interference fit, pin connection, expansion sleeve connection or profile fit connection Wait.

The angle positioning mechanism 5 includes an inclined positioning member 6 and a vertical positioning member 7. The inclined positioning member 6 is a mechanical part with an inclined positioning surface, and the angle between the inclined positioning surface and the vertical surface of the inclined positioning member 6 is 54.7°± 5°; the vertical positioning member 7 is a mechanical member with a vertical positioning surface. The inclined positioning member 6 and the vertical positioning member 7 are relatively arranged on both sides of the angle switching mechanism 4 along the rotation direction of the angle switching mechanism 4 , and the angle switching mechanism rigidly interferes with the inclined positioning member or the vertical positioning member.

When the angle switching mechanism 4 is turned to the vertical state, the angle switching mechanism 4 is in contact with the vertical positioning surface of the vertical positioning member 7, and the polycrystalline silicon solar cell can be tested at this time; When the inclined surfaces of the positioning member 6 are in contact with each other, the single crystal silicon solar cell is tested; the entire angle adjustment process can be completed manually.

The contact surfaces of the angle switching mechanism 4 and the angle positioning mechanism 5 are respectively fitted with magnets and magnetic steel, and the angle positioning mechanism 5 and the angle switching mechanism 4 are firmly connected by the adsorption force of the magnets, which reduces the external force factor during the measurement. The influence of the stability of the device ensures the smooth progress of the measurement process.

Embodiment 2: The difference between this embodiment and Embodiment 1 is that, as shown in FIG. 3 , the angle positioning mechanism 5 includes a first driving member 8 , a crank 9 and an intermediate rod 10 , and the first driving member 8 is fixedly installed on the base plate 1 . On the working platform, it is located on one side of the rotation direction of the angle switching mechanism 4; in this embodiment, the first driving member 8 is a motor with a holding torque, which can stop at any position and maintain the position. One end of the crank 9 is fixed on the output shaft of the motor, and the other end is rotatably connected to the end of the intermediate rod 10 ; the other end of the intermediate rod 10 is rotatably mounted on the side wall of the angle switching mechanism 4 .

The working principle of this embodiment is that the first driving member 8 drives the crank 9 to perform a rotary motion, and the crank 9 drives the angle switching mechanism 4 to reciprocate between a certain angle by pulling the intermediate rod 10 (this angle can be changed by changing the crank 9, The length of the middle rod 10 is adjusted); in this way, when detecting solar cells of different types (single crystal, polycrystalline), it is only necessary to control the first driving member 8 to drive the crank 9 to move to the corresponding position.

Embodiment 3: The difference between this embodiment and Embodiment 1 is that, as shown in FIG. 4 , the angle positioning mechanism 5 includes a guide rail 11 , a slider 12 , a connecting rod 13 and a second driving member 14 , and the guide rail 11 is fixedly installed on the base plate 1 . On the working platform, the length direction of the guide rail 11 is arranged in the same direction as the rotation direction of the angle switching mechanism 4; The second driving member 14 is also mounted on the base plate 1 to drive the slider 12 to reciprocate linearly on the guide rail 11 .

Specifically, the guide rail 11 can be set as a polished rod, the sliding block 12 is slidably connected with the guide rail 11, and the second driving member 14 is an electric push rod; the output end of the electric push rod is connected with the sliding block 12, and directly drives the sliding block 12 on the sliding rail. Reciprocating motion; the guide rail 11 can also be set as a screw rod, the two ends of which are rotatably fitted with bearing seats, and the bearing seats are fixed on the base plate 1. Correspondingly, the slider 12 is threadedly connected with the guide rail 11, and the second driving part 14 uses a motor, and the motor The output end of the screw is connected with the screw; the motor drives the screw to rotate forward and reverse, so as to drive the slider 12 to reciprocate on the screw.

This embodiment utilizes the working principle of the linkage mechanism of the slider 12, and drives the slider 12 to perform a reciprocating linear motion through the second driving member 14. The slider 12 drives the angle switching mechanism 4 to swing back and forth by pulling the connecting rod 13 (the swing angle can be determined by Change the length of the connecting rod 13 for adjustment, or change the stroke of the reciprocating motion of the slider 12 for adjustment). The second drive 14 chosen for this embodiment has a holding torque that can stop at any position and hold that position.

When detecting solar cells of different types (single crystal and polycrystalline), it is only necessary to control the second driving member 14 to move the slider 12 to the corresponding position.

Embodiment 4: The difference between this embodiment and Embodiment 1 is that, as shown in Figure 5, the angle positioning mechanism 5 is an electric push rod, the base of the electric push rod is hinged on the working platform of the base plate 1, and its output end is hinged at the angle switch. on the side wall of the mechanism 4. When the electric push rod does telescopic motion, it drives the angle switching mechanism 4 to do a reciprocating swing motion (this angle can be adjusted by selecting electric push rods with different strokes). The electric actuator chosen for this embodiment has a holding torque that can stop at any position and hold that position.

When testing solar cells of different types (single crystal, polycrystalline), it is only necessary to control the electric push rod to move to the corresponding position.

Embodiment 5: The difference between this embodiment and Embodiment 1 is that, as shown in FIG. 6 , the angle positioning mechanism 5 includes a worm wheel 15 , a worm screw 16 and a third driving member 17 , wherein the worm wheel 15 is coaxially fixed to the angle switching mechanism 4 . On the rotating shaft 43 at the end, the worm 16 is rotatably installed on the top of the base plate 1 through the bearing seat 42, and the worm wheel 15 and the worm 16 are engaged; the third driving member 17 can be a motor or a manual crank, which is arranged at one end of the worm 16, and is connected by the third driving member 17. The driving member 17 drives the worm 16 to rotate. When the worm 16 rotates, it drives the worm wheel 15 to rotate synchronously, thereby driving the angle switching mechanism 4 to perform a reciprocating swing motion (the angle can be adjusted by the rotation of the worm wheel 15 ).

When detecting solar cells of different types (single crystal and polycrystalline), it is only necessary to control the worm gear 15 to move to the corresponding position.

This specific embodiment is only an explanation of the application, and it does not limit the application. Those skilled in the art can make modifications to the embodiment without creative contribution as needed after reading this specification, but as long as the rights of the application are All claims are protected by patent law.

Claims (10)

1. An ellipsometry measuring device, characterized in that: comprising a substrate (1), a sample stage (2), a detection component (3), an angle switching mechanism (4) and an angle positioning mechanism (5); The sample stage (2) is fixedly mounted on the base plate (1), the surface of the sample stage (2) is flat, and the sample to be tested (20) is placed on the surface of the sample stage (2); The detection component (3) comprises a polarizing arm (31) for emitting incident light and an analyzing arm (32) for receiving reflected light, and incident surfaces are formed on the incident optical axis and the reflected optical axis; The angle switching mechanism (4) is rotatably mounted on the base plate (1), the polarizing arm (31) and the analyzing arm (32) are mounted on the angle switching mechanism (4), and the angle switching mechanism (4) The detection part (3) is driven to rotate synchronously, so as to change the angle between the incident surface of the detection part (3) and the surface of the sample to be tested (20); The angle positioning mechanism (5) is installed on the base plate (1), and the rotation angle of the angle switching mechanism (4) is limited by a rigid interference limit or self-locking structure. 2 . The ellipsometry measuring device according to claim 1 , wherein the height of the sample stage ( 2 ) can be adjusted. 3 . 3. An ellipsometry measuring device according to claim 1, characterized in that: the angle switching mechanism (4) comprises a portal frame (41) and a bearing seat (42), and the bearing seat (42) is provided with The two are arranged coaxially on the base plate (1); the end of the portal frame (41) is fixed with a rotating shaft (43), and the portal frame (41) passes through the bearing seat (42) The rotating shaft (43) of the rotary shaft (43) is rotatably connected with the bearing seat (42); the detection component (3) is mounted on the portal frame (41). 4. An ellipsometric measuring device according to claim 1 or 3, characterized in that: the angle positioning mechanism (5) comprises an inclined positioning member (6) and a vertical positioning member (7), and the inclined positioning The vertical positioning member (6) and the vertical positioning member (7) are arranged on both sides of the angle switching mechanism (4) along the rotation direction of the angle switching mechanism (4); the angle switching mechanism (4) is rigidly interfered with the inclined positioning member (6). , the angle switching mechanism (4) is positioned to the inclined state; the angle switching mechanism (4) is rigidly interfered with the vertical positioning member (7) to position the angle switching mechanism (4) to the vertical state. 5. An ellipsometric measuring device according to claim 4, characterized in that: the angle switching mechanism (4) is in conflict with the inclined positioning member (6), and the incident surface of the detection member (3) is in contact with the vertical The angle between the faces is 54.7°±5°. 6. An ellipsometry measuring device according to claim 1 or 3, characterized in that: the angle positioning mechanism (5) comprises a first driving member (8) mounted on the base plate (1), fixed on the A crank (9) at the output end of the first driving member (8), and an intermediate rod (10) rotatably connected to the crank (9), the intermediate rod (10) being away from the crank (9) and the angle switching mechanism (4) ) are hinged; the first driving member (8) is a torque motor. 7. An ellipsometry measuring device according to claim 1 or 3, characterized in that: the angle positioning mechanism (5) comprises a guide rail (11) installed on the base plate (1), a guide rail (11) installed on the guide rail (11) The sliding block (12) on the upper part, the connecting rod (13) hinged with the sliding block (12), and the second driving member (14) which drives the sliding block (12) to reciprocate along the guide rail (11), the connecting rod ( 13) One end away from the slider (12) is hinged with the angle switching mechanism (4); the second driving member (14) is a torque motor or an electric push rod. 8. An ellipsometry measuring device according to claim 1 or 3, characterized in that: the angle positioning mechanism (5) is an electric push rod, and the base of the electric push rod is hinged on the base plate (1) of the base plate (1). The output end of the electric push rod is hinged on the side wall of the angle switching mechanism (4). 9. An ellipsometric measuring device according to claim 1 or 3, characterized in that: the angle positioning mechanism (5) comprises a worm wheel (15) and a worm (16), and the worm wheel (15) is fixed on the One side of the angle switching mechanism (4) is arranged coaxially with the rotation axis of the angle switching mechanism (4); the worm (16) is rotatably mounted on the base plate (1) and is engaged with the worm wheel (15); the worm (16) ) end is provided with a third driving member (17) for driving it to rotate, and the third driving member (17) is a motor or a manual crank. 10. A measuring method utilizing the ellipsometry measuring device according to any one of claims 1-9, characterized in that: comprising the following steps: S1. Place the sample to be tested (20) flat on the surface of the sample table (2); S2, according to the type of the sample to be tested (20), rotate the incident surface, so that the incident surface of the detection component (3) is perpendicular to the detection surface of the sample to be tested (20); S3. Record the obtained surface information of the sample to be tested (20).

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