Automatic thickness measuring equipment, epitaxial layer thickness measuring system and epitaxial layer thickness measuring method

Abstract

The invention provides an automatic thickness measuring device, an epitaxial layer thickness measuring system and an epitaxial layer thickness measuring method. The automatic thickness measuring device is used for measuring the thickness of an epitaxial layer, and comprises a loading mechanism, a crystal holding mechanism, a measuring mechanism and an unloading mechanism; the loading mechanism is used for loading wafers; the crystal holding mechanism comprises a transfer component movably arranged relative to the loading mechanism, and a holding component movably arranged on the transfer component; the measuring mechanism comprises a loading component and a light control component, the loading component comprises a carrier movable relative to the light control component, the light control component has a reflection detection position for the carrier to reach, and also comprises a light guiding unit and a collecting unit; the unloading mechanism is used for unloading wafers; the position that the carrier can reach also comprises a taking position and an unloading position, and the holding component can be driven by the transfer component to pass through the loading mechanism, the taking position, the unloading position and the unloading mechanism in sequence.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor production, and in particular to an automatic thickness measuring device, an epitaxial layer thickness measuring system and an epitaxial layer thickness measuring method. Background Art

[0002] The preparation process of semiconductor wafers includes an epitaxial link, that is, an epitaxial layer is formed on a substrate formed by a wafer. After obtaining the epitaxial layer, the thickness of the epitaxial layer needs to be measured. At present, there is a method for measuring the thickness of an epitaxial layer based on spectral reflectance analysis. This method is implemented based on the reflection, refraction and absorption of the test light by the epitaxial layer. The light reflected by the epitaxial layer is detected and analyzed by a spectrometer to determine the thickness of the epitaxial layer. At present, the implementation of this method requires more manual labor. Not only do personnel have to frequently transport and transfer wafers many times, but they also have to perform measurement operations and data analysis. In addition, manual operations will inevitably lead to thickness measurement errors caused by operational errors. Summary of the invention

[0003] In view of this, the present invention provides an automatic thickness measuring device, an epitaxial layer thickness measuring system and an epitaxial layer thickness measuring method, which can replace manual operation and automatically implement the epitaxial layer thickness measurement operation.

[0004] The automatic thickness measuring device provided by the present invention is used to measure the thickness of the epitaxial layer, and includes a loading mechanism, a crystal holding mechanism, a measuring mechanism and a unloading mechanism; the loading mechanism is used to load wafers; the crystal holding mechanism includes a transfer component that can be movably arranged relative to the loading mechanism, and a holding component that is movably arranged on the transfer component; the measuring mechanism includes a loading component and a light control component, the loading component includes a carrier that can be movable relative to the light control component, the light control component has a reflection detection position for the carrier to reach, and also includes a light guiding unit and a collecting unit; the unloading mechanism is used to unload wafers; the position that the carrier can reach also includes a pick-up position and an unloading position, and the holding component can be driven by the transfer component to pass through the loading mechanism, the pick-up position, the unloading position and the unloading mechanism in sequence.

[0005] The automatic thickness measuring equipment of the present invention measures the thickness of the epitaxial layer of the wafer based on the spectral reflectance method. The wafer holding mechanism can replace the operation of manually transporting and transferring the wafer, and realizes the automatic transfer of the wafer to be measured between multiple workstations, thereby improving the degree of automation of the epitaxial layer thickness measurement operation and reducing the thickness measurement error introduced by human operation error. It is suitable for use in occasions of performing thickness detection on the epitaxial layer of a large number of wafers, which can reduce manual participation and effectively reduce labor costs.

[0006] In one embodiment, the light guiding unit includes a light guiding reflector, and the light guiding reflector is used to reflect the test light to the wafer.

[0007] With such an arrangement, it is easier for the light guide unit to transmit the test light to the wafer.

[0008] In one embodiment, the transfer assembly includes a multi-axis robotic arm, and the holding assembly is disposed at the end of the multi-axis robotic arm.

[0009] With this arrangement, the multi-axis robotic arm can control the holding component to produce movements with multiple degrees of freedom, and can accurately control the movement amplitude, movement speed and movement accuracy of the holding component, ensuring that the holding component can accurately obtain the wafer and accurately unload the wafer at the specified position.

[0010] In one embodiment, the holding component includes a suction component movably arranged on the transfer component, and also includes a negative pressure control component connected to the suction component.

[0011] With this arrangement, the holding component holds and transports the wafer by generating negative pressure and adsorbing the wafer, without causing damage to the wafer surface, especially the epitaxial layer surface, to ensure that the wafer maintains good quality after undergoing epitaxial layer thickness testing.

[0012] In one embodiment, the object-carrying component also includes a first driving member and a second driving member connected to the carrier, the first driving member is used to drive the carrier to move relative to the light control component along a first trajectory parallel to the carrier, and the second driving member is used to drive the carrier to move relative to the light control component along a second trajectory parallel to the carrier.

[0013] With such an arrangement, the first driving member and the second driving member cooperate with each other to enable the stage to produce two degrees of freedom of movement, so that the incident position of the test light irradiating the surface of the epitaxial layer of the wafer is fully distributed over the entire surface of the epitaxial layer of the wafer, which not only improves the accuracy of the epitaxial layer thickness measurement results, but also facilitates the judgment of the surface quality and thickness uniformity of the epitaxial layer of the measured wafer.

[0014] In one embodiment, the carrier assembly also includes a connected crystal moving seat and a crystal rotating axis, the carrier is connected to the crystal rotating axis, the first driving member is connected to the crystal moving seat and can drive the crystal moving seat to translate along a first trajectory, and the second driving member is connected to the crystal rotating axis and can drive the crystal rotating axis to rotate along a second trajectory.

[0015] With this arrangement, the first driving member cooperates with the second driving member to enable the platform to move with one translational degree of freedom and rotate with one rotational degree of freedom. Compared with enabling the platform to move with two translational degrees of freedom, this embodiment greatly reduces the space required for the platform to move.

[0016] In one embodiment, the carrier includes a first carrying surface for carrying the end face of the wafer, and the carrier assembly also includes a carrying portion arranged on the carrier, and the carrying portion includes a lens carrying portion for carrying a calibration lens and / or a sample carrying portion for carrying a calibration sample.

[0017] With such arrangement, the carrier assembly can also carry the calibration lens through the lens carrying part and the calibration sample through the sample carrying part. Before formally measuring the thickness of the wafer epitaxial layer, the test light is first directed to the calibration lens by the light control assembly, and then the reflection of the test light by the calibration lens is utilized, and the background spectrum information is determined by the collection unit and the spectrometer. Then, the background spectrum is excluded from the subsequent reflection spectrum of the wafer epitaxial layer, thereby eliminating the interference of environmental factors on the measurement of the epitaxial layer thickness. In addition, before formally measuring the thickness of the wafer epitaxial layer, the thickness of the calibration sample is first measured with the test light, and by comparing the actual thickness of the calibration sample with the nominal thickness of the calibration sample, it is determined whether the state of the automatic thickness measuring device itself interferes with the thickness measurement result, thereby eliminating the interference of the state factors of the automatic thickness measuring device itself on the thickness measurement result.

[0018] In one embodiment, the first carrying surface is arranged at the end of the carrier, and the carrying portion is arranged on the outer peripheral side of the carrier. When the carrier reaches the reflection detection position, the center of the first carrying surface is located at the reflection detection position. When the carrier reaches the object picking position, the carrying surface of at least one carrying portion reaches the reflection detection position.

[0019] With this arrangement, before the carrier reaches the pick-up position so that the wafer holding mechanism can transport a new wafer to the carrier to start the epitaxial layer thickness measurement, at least one calibration lens reflects the test light, or at least one calibration sample reflects the test light. Therefore, the error calibration is completed before the epitaxial layer thickness measurement is performed on the new wafer. The error calibration can be a calibration that removes the background spectrum to eliminate interference from ambient light, and can also determine whether the automatic thickness measurement equipment's own state affects the epitaxial layer thickness measurement result.

[0020] In one embodiment, the first carrying surface is arranged at the end of the carrier, and the carrying portion is arranged on the outer peripheral side of the carrier. When the carrier reaches the reflection detection position, the center of the first carrying surface is located at the reflection detection position. When the carrier reaches the unloading position, the carrying surface of at least one carrying portion reaches the reflection detection position.

[0021] With this arrangement, when the stage reaches the unloading position so that the wafer holding mechanism can take away the wafer that has completed the epitaxial layer thickness measurement, at least one calibration lens reflects the test light, or at least one calibration sample reflects the test light. Therefore, the error calibration is completed before the epitaxial layer thickness measurement of the next wafer. The error calibration can be a calibration that removes the background spectrum to eliminate interference from ambient light, or it can determine whether the state of the automatic thickness measurement equipment itself affects the epitaxial layer thickness measurement result.

[0022] In one embodiment, the object carrier assembly includes a lens carrier portion and a sample carrier portion, and the lens carrier portion and the sample carrier portion are evenly distributed along the circumference of the carrier.

[0023] With this arrangement, the center of gravity of the whole formed by the lens carrier, the sample carrier and the stage basically coincides with the center of gravity of the stage itself, which helps to maintain the posture accuracy of the stage and the wafer and avoid introducing posture factor errors when measuring the thickness of the epitaxial layer.

[0024] In one embodiment, the picking position and the unloading position overlap to form a picking position, and the loading assembly also includes a first driving member and a second driving member connected to the carrier, the first driving member is used to drive the carrier to rotate around the axis of the carrier, and the second driving member is used to drive the axis of the carrier to move back and forth between the picking position and the unloading position and the reflection detection position.

[0025] With such arrangement, unloading of wafers on which epitaxial layer thickness measurement has been completed from the carrier and conveying of new wafers from the loading mechanism to the carrier can be carried out when the carrier is in the pick-and-place position. After the carrier obtains the new wafer, it can be moved to the reflection detection position to measure the epitaxial layer thickness of the new wafer. The carrier is driven to move by the first driving member and the second driving member in coordination with each other, so that the calibration lens or calibration sample on the carrying part can be rotated to the reflection detection position while the carrier moves to the pick-and-place position, thereby achieving the calibration error before measuring the epitaxial layer thickness of each wafer, thereby ensuring the accuracy of the epitaxial layer thickness measurement result of each wafer.

[0026] In one embodiment, the automatic thickness measuring equipment also includes a posture correction component and a code reader component, and the holding component can be driven by the transfer component to pass through the loading mechanism, the posture correction component, the picking position, the unloading position and the unloading mechanism in sequence.

[0027] With this configuration, the automatic thickness measurement equipment further integrates the wafer posture correction function and the wafer data information entry function, thereby being able to replace manual work to correct the wafer posture and enter wafer information, further improving the degree of automation of the epitaxial layer thickness measurement operation.

[0028] In one embodiment, the automatic thickness measuring device further includes a peripheral component, which includes at least a shielding unit, and the shielding unit has a test space to accommodate a loading mechanism, a crystal holding mechanism, a measuring mechanism, and a unloading mechanism.

[0029] With this arrangement, the peripheral components provide a clean measurement environment for the wafer, loading mechanism, wafer holding mechanism, measuring mechanism and unloading mechanism. The shielding unit can shield the influence of the external environment on the test space and maintain the stability of the temperature, humidity and air composition in the test space to a certain extent.

[0030] In one embodiment, the peripheral component further includes an air dispatching unit, and the air dispatching unit is used to perform air dispatching and transportation between the test space and the outside of the shielding unit.

[0031] With this arrangement, the air dispatching unit can dispatch and transport air in a timely manner according to the needs of the measurement operation, thereby maintaining a dynamic balance among the temperature, humidity and air composition in the test space.

[0032] The epitaxial layer thickness measurement system provided by the present invention includes a calibration lens, a calibration sample, a spectrometer and an automatic thickness measurement device; the carrier assembly also includes a lens carrying part and a sample carrying part arranged on the carrier, the calibration lens is arranged on the lens carrying part, and the calibration sample is arranged on the sample carrying part; the spectrometer is used to decompose the reflected light received by the collection unit; the light guide unit can transmit the test light to the calibration lens and the calibration sample, and the calibration lens and the calibration sample can reflect light to the collection unit.

[0033] On the one hand, the epitaxial layer thickness measuring system of the present invention can replace manual automatic measurement of wafer epitaxial layer thickness, reduce thickness measurement errors introduced by human operation errors, and is suitable for use in occasions where thickness detection of large quantities of wafer epitaxial layers is performed; on the other hand, the epitaxial layer thickness measuring system of the present invention is also compatible with error judgment and error calibration functions. Before formally measuring the thickness of the wafer epitaxial layer, the background spectrum of the test environment can be determined by the reflection and refraction of the test light by the calibration lens, so that the epitaxial layer reflection spectrum with the background spectrum removed can be obtained. Before formally measuring the thickness of the wafer epitaxial layer, the thickness of the calibration sample can be measured by the test light, and the actual measured thickness of the calibration sample is compared with the nominal thickness of the calibration sample to determine whether it is consistent, so as to determine whether the state of the automatic thickness measuring device itself will interfere with the epitaxial layer thickness measurement result, thereby significantly improving the thickness measurement accuracy.

[0034] The epitaxial layer thickness measurement method provided by the present invention is based on an automatic thickness measurement device, the object carrier assembly further includes a carrier portion disposed on a carrier, and the epitaxial layer thickness measurement method includes:

[0035] S10, initializing the carrier, including controlling the movement of the carrier so that the carrier reaches the object picking position and the carrying part reaches the reflection detection position;

[0036] S20, calibrating the error, including conducting the test light to the reflection detection position through the light guide unit, and receiving the light reflected from the reflection detection position through the collection unit;

[0037] S30, during the calibration error period, controlling the wafer holding mechanism to obtain the wafer from the loading mechanism, and transporting the wafer to the carrier located at the pickup position;

[0038] S40, controlling the movement of the carrier and transporting the wafer to the reflection detection position through the carrier;

[0039] S50, measuring the thickness of the epitaxial layer, including conducting the test light to the reflection detection position through the light guide unit, and receiving the light reflected from the reflection detection position through the collection unit;

[0040] S60, unloading the wafer, including controlling the carrier to transport the wafer to the unloading position, controlling the wafer holding mechanism to obtain the wafer from the unloading position and transporting the wafer to the unloading mechanism;

[0041] S70, resetting the measuring mechanism, including controlling the movement of the stage to make the stage reach the object-taking position, and making the carrying part reach the reflection detection position.

[0042] The epitaxial layer thickness measurement method of the present invention is suitable for measuring the epitaxial layer thickness of a large number of wafers. During the calibration error period, the wafer holding mechanism is not idle, but the wafer is transported from the loading mechanism to the carrier, which shortens the time of the epitaxial layer thickness measurement process of the wafer and greatly improves the efficiency of epitaxial layer thickness measurement for a large number of wafers. Each wafer can be calibrated for error before receiving the epitaxial layer thickness measurement, thereby ensuring the accuracy of the epitaxial layer thickness measurement result of each wafer.

[0043] In some embodiments, the object-taking position and the object-unloading position overlap to form a pick-up and place position, the distance from the pick-up and place position to the reflection detection position is not less than the radius of the carrier, the bearing part is arranged on the outer peripheral side of the carrier, and the object-carrying assembly further includes a first driving member and a second driving member connected to the carrier;

[0044] Step - controlling the movement of the carrier to make the carrier reach the object-picking position and the carrier portion reach the reflection detection position includes:

[0045] The second driving member drives the stage to move until the axis of the stage reaches the pick-up and place position, and the first driving member drives the stage to rotate around the axis of the stage until the bearing portion reaches the reflection detection position;

[0046] Step - Controlling the stage to transport the wafer to the unloading position includes:

[0047] The second driving member drives the carrier to move until the axis of the carrier reaches the pick-up and place position;

[0048] Steps - controlling the movement of the stage and transporting the wafer to the reflective inspection position through the stage include:

[0049] The stage is driven to move by the second driving member until the axis of the stage reaches the reflection detection position.

[0050] With this arrangement, the motion control logic of the carrier is simpler and easier to implement. In the process of measuring the thickness of the epitaxial layer, the carrier only needs to be controlled to move back and forth between the pick-and-place position and the reflection detection position. When the carrier is in the pick-and-place position, the wafer that has completed the epitaxial layer thickness measurement can be unloaded, and then a new wafer can be placed on the carrier to measure the epitaxial layer thickness of the new wafer, thereby further improving the efficiency of measuring the epitaxial layer thickness of a large number of wafers.

[0051] In some implementations, the measuring mechanism is reset while the wafer holding mechanism is transferring the wafer to the loading mechanism.

[0052] Such an arrangement further shortens the time taken to measure the thickness of the epitaxial layer of the wafer, and further improves the efficiency of measuring the thickness of the epitaxial layer of a large number of wafers. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 A schematic structural diagram of an automatic thickness measuring device according to an embodiment of the present invention;

[0054] Figure 2 for Figure 1 A partial structural schematic diagram of the automatic thickness measuring device shown;

[0055] Figure 3 A partial structural schematic diagram of an automatic thickness measuring device according to an embodiment of the present invention;

[0056] Figure 4 A partial structural schematic diagram of a carrier assembly according to an embodiment of the present invention;

[0057] Figure 5 A partial structural schematic diagram of a carrier assembly according to an embodiment of the present invention;

[0058] Figure 6 A schematic diagram of the structure of a peripheral component of an embodiment of the present invention;

[0059] Figure 7 This is a first schematic diagram of the motion analysis of a stage according to an embodiment of the present invention;

[0060] Figure 8 This is a second schematic diagram of the motion analysis of a carrier according to an embodiment of the present invention.

[0061] : 10, loading mechanism; 21, posture correction component; 22, code reader component; 30, crystal holding mechanism; 31, transfer component; 311, multi-axis robot arm; 32, holding component; 40, measuring mechanism; 41, loading component; 411, stage; 412, first driving member; 413, second driving member; 414, crystal moving seat; 415, crystal rotation axis; 416, lens bearing part; 417, sample bearing part; 418, slide; 419, synchronous belt; 421, lifting driving member; 422, lifting part; 42, light control component; 50, unloading mechanism; 60, peripheral components; 61, shielding unit; 62, test space; 71, calibration lens; 72, calibration sample; 73, spectrometer; 80, base. DETAILED DESCRIPTION

[0062] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0063] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "or / and" used herein includes any and all combinations of one or more related listed items.

[0064] The present invention provides an automatic thickness measuring device for measuring the thickness of a wafer epitaxial layer, and also provides an epitaxial layer thickness measuring system including the automatic thickness measuring device. The automatic thickness measuring device and the epitaxial layer thickness measuring system of the present invention are used to implement an epitaxial layer thickness measuring method based on spectral reflection analysis. The wafer epitaxial layer has a certain light transmittance, and the epitaxial layer and the wafer substrate have a different refractive index. When the test light is incident on the epitaxial layer, it can be reflected in the epitaxial layer. The spectrometer 73 is used to perform spectral analysis on the light reflected by the epitaxial layer to reversely infer the thickness of the epitaxial layer.

[0065] See also Figure 1 The automatic thickness measuring device of the present invention comprises a loading mechanism 10, a crystal holding mechanism 30, a measuring mechanism 40 and a unloading mechanism 50. The loading mechanism 10 is used to load the wafer, the end surface of the wafer is covered with an epitaxial layer, and the wafer itself serves as the substrate of the epitaxial layer; the crystal holding mechanism 30 is used to transport and transfer the wafer, and comprises a transfer component 31 and a holding component 32, the transfer component 31 is movably arranged relative to the loading mechanism 10, and the holding component 32 is arranged on the transfer component 31 and can be driven as the transfer component 31 moves; the measuring mechanism 40 is responsible for implementing the epitaxial layer thickness measurement method based on spectral reflectance analysis, and comprises a loading component 41 and a light control component 42, and the loading component 41 comprises a carrier 411, The carrier 411 is movably arranged relative to the light control component 42, and is used to carry the wafer covered with the epitaxial layer. The light control component 42 has a reflection detection position for the carrier 411 to reach and stop, and also includes a light guiding unit and a collecting unit. The light guiding unit is used to transmit the test light emitted by the light source to the wafer so that the test light can enter the epitaxial layer. The collecting unit is used to receive the light reflected by the epitaxial layer of the wafer, and can collect data of the reflected light and transmit the collected data to the epitaxial layer thickness measurement system to obtain the epitaxial layer thickness result. The unloading mechanism 50 is used to unload the wafer.

[0066] The reflection detection position is a point position. When measuring the thickness of the epitaxial layer, the wafer follows the stage 411 to arrive at the reflection detection position synchronously. The light control component 42 transmits the test light to the reflection detection position through the light guide unit. The reflected light is reflected by the epitaxial layer of the wafer at the reflection detection position. Then, the light control component 42 receives the light reflected by the epitaxial layer of the wafer through the collection unit. Therefore, the test light incident on the epitaxial layer of the wafer and the test light reflected to the collection unit intersect at the reflection detection position.

[0067] The carrier component 41 and the light control component 42 are movably arranged relative to each other. On the one hand, the carrier component 41 can move relative to the light control component 42 so that the test light transmitted to the epitaxial layer is successively shot into the epitaxial layer from different positions on the surface of the epitaxial layer, so that the incident position of the test light entering the epitaxial layer is distributed throughout the entire surface of the epitaxial layer. On the other hand, the carrier component 41 can change the position of the carrier 411 relative to the light control component 42 by moving relative to the light control component 42, so that the crystal holding mechanism 30 can more conveniently take and place the wafer. The position of the carrier 411 relative to the light control component 42 includes a pick-up position and an unloading position, that is, the carrier 411 can move relative to the light control component 42 to reach the pick-up position and the unloading position, and the carrier 411 can also The holding component 32 can move relative to the light control component 42 to reach the reflection detection position. The holding component 32 can be driven by the transfer component 31 to pass through the loading mechanism 10, the carrier 411 at the picking position, the carrier 411 at the unloading position and the unloading mechanism 50 in sequence. The holding component 32 first passes through the loading mechanism 10 under the control of the transfer component 31 to obtain the wafer, and then passes through the carrier 411 at the picking position to place the wafer on the carrier 411. After the measuring mechanism 40 completes the measurement of the epitaxial layer thickness, the holding component 32 passes through the carrier 411 at the unloading position under the control of the transfer component 31 to obtain the wafer again, and finally passes through the unloading mechanism 50 and places the wafer on the unloading mechanism 50 to complete the unloading.

[0068] In some embodiments, both the loading mechanism 10 and the unloading mechanism 50 can be used to place a wafer box, which is a container for storing wafers. The loading mechanism 10 includes a sensor for detecting protrusions on the wafers in the wafer box. The holding component 32 can map the number of wafers in the wafer box and position the wafers. The unloading mechanism 50 includes a wafer box, which is used to receive wafers that have completed epitaxial layer thickness measurement.

[0069] In some embodiments, the light guiding unit is a reflective light path component, and the reflective light path component and the collecting unit are matched with the spectrometer 73 and used in conjunction with each other. The reflective light path component includes a light guiding reflector, which is used to reflect the test light to the epitaxial layer of the wafer. The epitaxial layer thickness measurement system includes a light source for generating the test light, and the light source can be an infrared light source capable of generating infrared test light.

[0070] See also Figure 1~Figure 2 In some embodiments, the automatic thickness measurement equipment also includes a posture correction component 21 and a barcode reader component 22. The posture correction component 21 is used to align and position the wafer before the wafer is transported to the carrier 411 to ensure that the wafer can maintain a consistent posture state in the subsequent epitaxial layer thickness measurement process. The barcode reader component 22 is used to read, identify and record the identification code or barcode on the wafer so that the epitaxial layer thickness measurement system can confirm the type, batch and other information of the wafer undergoing epitaxial layer thickness measurement for subsequent tracking and management of the wafer.

[0071] Specifically, the posture correction component 21 can drive the wafer to rotate to adjust the posture of the wafer in the circumferential direction of the wafer, and the flat edge or notch on the circumferential side of the wafer is aligned with the preset correction reference position through the correction of the posture correction component 21, and the code reader component 22 completes the reading of the identification code or barcode on the wafer. The holding component 32 can be driven by the transfer component 31 and pass through the loading mechanism 10, the posture correction component 21, the carrier 411 at the picking position, the carrier 411 at the unloading position and the unloading mechanism 50 in sequence. After the holding component 32 obtains the wafer from the loading mechanism 10, it first places the wafer on the posture correction component 21 under the control of the transfer component 31. After the posture of the wafer is corrected by the posture correction component 21 and the barcode reader component 22 reads the wafer information, the holding component 32 obtains the wafer from the posture correction component 21 under the control of the transfer component 31, and then brings the wafer to the carrier 411 in the picking position.

[0072] In some embodiments, see Figure 6 The automatic thickness measuring device also includes a peripheral component 60, which at least includes a shielding unit 61 in a hollow thin-walled structure. The shielding unit 61 has a test space 62. The shielding unit 61 can surround and accommodate the feeding mechanism 10, the posture correction component 21, the code reader component 22, the crystal holding mechanism 30, the measuring mechanism 40 and the unloading mechanism 50 through the test space 62. Although the holding component 32 moves under the control of the transfer component 31, the entire crystal holding mechanism 30 is always located in the test space 62. The shielding unit 61 provides a clean measurement environment for the epitaxial layer thickness measurement operation, can shield the influence of the external environment on the test space 62, and to a certain extent maintain the stability of environmental parameters such as temperature, humidity, and air composition in the test space 62. For example, the shielding unit 61 can prevent external dust from entering the test space 62 and adhering to the epitaxial layer, ensuring the accuracy of the epitaxial layer thickness measurement, and can prevent misjudgment of the surface quality of the epitaxial layer.

[0073] Furthermore, in some embodiments, the peripheral component 60 also includes an air scheduling unit, which is used to perform air scheduling and transportation between the test space 62 and the outside of the shielding unit 61, so that environmental parameters such as temperature, humidity and air composition in the test space 62 maintain dynamic balance to a certain extent, thereby avoiding large fluctuations in environmental parameters and interfering with the measurement results of the epitaxial layer thickness.

[0074] See also Figure 1~Figure 2 In some embodiments, the transfer assembly 31 includes a multi-axis robot arm 311, and the holding assembly 32 is disposed at the end of the multi-axis robot arm 311. Specifically, the holding assembly 32 includes a suction member and a negative pressure control member. The suction member is disposed at the end of the multi-axis robot arm 311 and can move with the movement of the multi-axis robot arm 311. The negative pressure control member is connected to the suction member. When the holding assembly 32 needs to obtain a wafer, the negative pressure control member is used to generate negative pressure when the suction member contacts the wafer so that the suction member fixes the wafer. When the wafer needs to be removed from the holding assembly 32, the negative pressure control member releases the negative pressure to release the suction and fixation of the wafer by the suction member.

[0075] In other embodiments, the holding assembly 32 may further include a pick-and-place robot disposed at the end of the multi-axis robot arm 311 , and the pick-and-place robot picks up or unloads the wafer by controlling the movement of the pick-and-place fingers.

[0076] See also Figure 4~Figure 5 In some embodiments, the object carrier assembly 41 further includes a bearing portion disposed on the carrier 411, the bearing portion includes a lens bearing portion 416 and a sample bearing portion 417, and the epitaxial layer thickness measurement system further includes a calibration lens 71, a calibration sample 72, and a spectrometer 73. The end of the carrier 411 includes a first bearing surface, which serves as the table of the carrier 411 and is used to carry the end face of the wafer with the epitaxial layer. The holding assembly 32 can place the wafer on the carrier 411 under the control of the transfer assembly 31, and can obtain the wafer from the carrier 411 under the control of the transfer assembly 31; the lens bearing portion 416 is fixedly disposed on the outer peripheral side of the carrier 411, including a second bearing surface for carrying the calibration lens 71, and the sample bearing portion 417 is fixedly disposed on the outer peripheral side of the carrier 411, including a third bearing surface for carrying the calibration sample 72.

[0077] With such arrangement, the automatic thickness measuring device of the present invention and the epitaxial layer thickness measuring system are also compatible with the error judgment and error calibration functions. Specifically, since in the process of measuring the thickness of the epitaxial layer, not only the test light is incident on the epitaxial layer, but also the ambient light is incident on the epitaxial layer, before formally measuring the thickness of the epitaxial layer, the background spectrum of the test environment can be determined by the reflection and refraction of the test light by the calibration lens 71, so that the background spectrum can be eliminated to obtain the epitaxial layer reflection spectrum of the test light. In addition, before formally measuring the thickness of the epitaxial layer, the thickness of the calibration sample 72 can be measured by the test light, and the measured thickness of the calibration sample 72 can be compared with the nominal thickness of the calibration sample 72, so as to judge whether the state of the automatic thickness measuring device itself interferes with the accuracy of the epitaxial layer thickness measurement result. The consistency between the measured thickness of the calibration sample 72 and the nominal thickness of the calibration sample 72 indicates that the state of the automatic thickness measuring device itself is good.

[0078] In some embodiments, when the stage 411 reaches the reflection detection position, the center of the first bearing surface is located at the reflection detection position, and when the stage 411 reaches the object-taking position, the bearing surface of at least one bearing portion reaches the reflection detection position, which may be the second bearing surface of the lens bearing portion 416 or the third bearing surface of the sample bearing portion 417. When the second bearing surface reaches the reflection detection position, the calibration lens 71 reflects the test light from the light guide unit to the collection unit, and when the third bearing surface reaches the reflection detection position, the calibration sample 72 reflects the test light from the light guide unit to the collection unit.

[0079] With such arrangement, before the carrier 411 reaches the picking position so that the wafer holding mechanism 30 can transport the new wafer to the carrier 411 for epitaxial layer thickness measurement, at least one calibration lens 71 reflects the test light, or at least one calibration sample 72 reflects the test light. Therefore, error calibration is completed before the epitaxial layer thickness measurement is performed on the new wafer. The error calibration can be based on the calibration lens 71 reflecting the test light to eliminate the background spectrum, or it can be based on the calibration sample 72 reflecting the test light to determine the self-state factors of the automatic thickness measurement equipment.

[0080] In some embodiments, when the stage 411 reaches the reflection detection position, the center of the first bearing surface is located at the reflection detection position, and when the stage 411 reaches the unloading position, the bearing surface of at least one bearing portion reaches the reflection detection position, which may be the second bearing surface of the lens bearing portion 416 or the third bearing surface of the sample bearing portion 417. When the second bearing surface reaches the reflection detection position, the calibration lens 71 reflects the test light from the light guide unit to the collection unit, and when the third bearing surface reaches the reflection detection position, the calibration sample 72 reflects the test light from the light guide unit to the collection unit.

[0081] With such arrangement, when the carrier 411 reaches the unloading position so that the wafer holding mechanism 30 can take away the wafer that has undergone the measurement of the epitaxial layer thickness, at least one calibration lens 71 reflects the test light, or at least one calibration sample 72 reflects the test light. Therefore, the error calibration is completed before the epitaxial layer thickness measurement is performed on the next wafer. The error calibration can be based on the calibration lens 71 reflecting the test light to eliminate the background spectrum, or it can be based on the calibration sample 72 reflecting the test light to determine the self-state factors of the automatic thickness measurement equipment.

[0082] See also Figure 4 The stage 411 is a disc-shaped flat plate structure, the lens bearing part 416 is provided with a lens groove, the groove wall of the lens groove forms a second bearing surface, the calibration lens 71 is fixedly installed in the lens groove and fixedly matched with the second bearing surface, the sample bearing part 417 is provided with a sample groove, the groove wall of the sample groove forms a third bearing surface, the calibration sample 72 is fixedly installed in the sample groove and fixedly matched with the third bearing surface. The lens bearing part 416 and the sample bearing part 417 are both fixedly arranged on the outer peripheral side of the stage 411 and are evenly arranged along the circumference of the stage 411. The number of lens bearing parts 416 can be one or more, and the number of sample bearing parts 417 can be one or more. When the lens supporting part 416 on which the calibration lens 71 is fixed and the sample supporting part 417 on which the calibration sample 72 is fixed are evenly distributed along the circumference of the carrier 411, the center of gravity position of the whole formed by the carrier 411, the lens supporting part 416 and the sample supporting part 417 is basically consistent with the center of gravity position of the carrier 411 itself, which can maintain the posture balance of the carrier 411 and will not cause the epitaxial layer to be skewed.

[0083] See also Figure 3 and Figure 5 In some embodiments, the object carrier component 41 also includes a first driving member 412 and a second driving member 413 connected to the carrier 411, the first driving member 412 is used to drive the carrier 411 to move relative to the light control component 42 along a first trajectory parallel to the carrier 411, and the second driving member 413 is used to drive the carrier 411 to move relative to the light control component 42 along a second trajectory parallel to the carrier 411, the first trajectory and the second trajectory do not overlap with each other, no matter the carrier 411 is driven by the first driving member 412, the second driving member 413, or the first driving member 412 and the second driving member 413 are driven at the same time, the table posture of the carrier 411 always remains unchanged, optionally, the first trajectory and the second trajectory are both parallel to the horizontal plane, the table surface of the carrier 411 and the wafer placed on the carrier 411 always maintain a posture parallel to the horizontal plane.

[0084] With such arrangement, the first driving member 412 and the second driving member 413 respectively control the stage 411 to produce two degrees of freedom of movement, and the composite motion formed by the superposition of the two degrees of freedom of movement can achieve the following effect: the position of the stage 411 relative to the test light is continuously changed under the drive of the first driving member 412 and the second driving member 413, and thus the incident position of the test light entering the epitaxial layer changes accordingly, and eventually all the incident positions of the test light entering the epitaxial layer can be spread over the entire surface of the epitaxial layer, which can not only improve the accuracy of the epitaxial layer thickness measurement results, but also determine the thickness uniformity and surface quality of the measured epitaxial layer.

[0085] Furthermore, in some embodiments, the picking position and the unloading position overlap to form a picking position, the first driving member 412 is used to drive the platform 411 to rotate around the axis of the platform 411, and the second driving member 413 is used to drive the platform 411 to move so that the axis of the platform 411 moves back and forth between the picking position and the unloading position and the reflection detection position.

[0086] With such arrangement, wafers whose epitaxial layer thickness has been measured are unloaded from the carrier 411 and new wafers are transported from the loading mechanism to the carrier 411 both when the carrier is in the pick-and-place position. After the carrier 411 obtains the new wafer, it can move to the reflection detection position to measure the epitaxial layer thickness of the new wafer. The first driving member 412 and the second driving member 413 cooperate to drive the carrier 411 to move, so that the calibration lens 71 or the calibration sample on the carrying part can be rotated to the reflection detection position while the carrier 411 moves to the pick-and-place position, thereby achieving the calibration error before measuring the epitaxial layer thickness of each wafer, thereby ensuring the accuracy of the epitaxial layer thickness measurement result of each wafer.

[0087] Specifically, see Figure 3 The automatic thickness measuring device further comprises a base 80, a spectrometer 73, a loading assembly 41 and a light control assembly 42 are all arranged on the base 80, see Figure 5 The carrier assembly 41 also includes a crystal moving seat 414, a crystal rotating shaft 415 and a slide 418. The slide 418 is fixed to the base 80. The crystal moving seat 414 and the slide 418 are slidably connected. The crystal rotating shaft 415 is rotatably arranged on the crystal moving seat 414. The carrier 411 is coaxially connected with the crystal rotating shaft 415. The first driving member 412 is drivingly connected to the crystal moving seat 414 so as to drive the crystal moving seat 414 to move relative to the slide 418 along the Figure 5 The first track is the track of the translation of the carrier 411 relative to the base 80. The crystal rotation axis 415 and the carrier 411 can follow the crystal moving base 414 synchronously along the Figure 5 X-axis translation shown.

[0088] Furthermore, the carrier assembly 41 also includes a synchronous belt 419, and the second driving member 413 is fixedly connected to the crystal moving seat 414, and is driven to connect the crystal rotating shaft 415 through the synchronous belt 419, so that the second driving member 413 can drive the crystal rotating shaft 415 and the carrier 411 to rotate relative to the crystal moving seat 414 and the base 80 around the axis of the crystal rotating shaft 415, and the second trajectory is the trajectory of the rotation of the carrier 411 relative to the base 80. Figure 5 In the illustrated embodiment, the stage 411 is suspended on the side of the base 80 away from the ground, the table surface of the stage 411 is parallel to the table surface of the base 80, the X-axis direction is parallel to the horizontal plane, the crystal rotation axis 415 extends in the vertical direction, and the table surface of the stage 411 is always parallel to the horizontal plane. The driving operation of the first driving member 412 and the driving operation of the second driving member 413 do not affect each other, and the two can be operated simultaneously or separately.

[0089] It can be understood that in other embodiments, the second driving member 413 can also be configured as: installed on the crystal moving seat 414 and driving the connected carrier 411, used to drive the carrier 411 to translate along a straight line direction parallel to the base 80 and the carrier 411 and perpendicular to the X-axis direction, the second trajectory is a straight line trajectory of the carrier 411 moving relative to the crystal moving seat 414, the first trajectory and the second trajectory are perpendicular to each other, and both are parallel to the carrier 411.

[0090] Compared with the first driving member 412 and the second driving member 413 controlling the stage 411 to produce a compound motion with two mutually perpendicular degrees of freedom of movement, Figure 5 The embodiment shown can further reduce the space required for the movement of the stage 411. Specifically, by controlling the stage 411 to rotate relative to the base 80 around the crystal axis 415, the stage 411 can be moved perpendicular to the crystal axis 415. Figure 5 The movement range in the horizontal straight line direction of the X-axis direction shown is reduced, so the space required for the stage 411 to move in the vertical direction along the X-axis direction is simplified.

[0091] Further, see Figure 5 In some embodiments, the carrier assembly 41 also includes a lifting drive 421 installed on the crystal moving base 414 and a lifting portion 422 connected to the lifting drive 421. The lifting portion 422 can move in the vertical direction and pass through the table top of the carrier 411 under the control of the lifting drive 421. When the measuring mechanism 40 completes the measurement of the thickness of the epitaxial layer, the carrier 411 is in the unloading position, and the lifting drive 421 drives the lifting portion 422 to move up in the vertical direction, thereby lifting the wafer placed on the table top of the carrier 411 to facilitate the holding assembly 32 to obtain the wafer. Then, the holding assembly 32 moves the wafer away from the carrier 411 in the unloading position under the control of the transfer assembly 31, and then transports the wafer to the unloading mechanism 50.

[0092] On the one hand, the automatic thickness measuring device and epitaxial layer thickness measuring system of the present invention can replace manual automatic measurement of wafer epitaxial layer thickness, reduce thickness measurement errors introduced by human operation errors, and are suitable for use in thickness detection of large quantities of wafer epitaxial layers; on the other hand, the epitaxial layer thickness measuring system of the present invention is also compatible with error judgment and error calibration functions. Before formally measuring the thickness of the wafer epitaxial layer, the background spectrum of the test environment can be determined by the reflection and refraction of the test light by the calibration lens 71, so as to obtain the epitaxial layer reflection spectrum with the background spectrum removed. Before formally measuring the thickness of the wafer epitaxial layer, the thickness of the calibration sample 72 can be measured by the test light, and the actual measured thickness of the calibration sample 72 can be compared with the nominal thickness of the calibration sample 72 to determine whether it is consistent, so as to determine whether the state of the automatic thickness measuring device itself will interfere with the epitaxial layer thickness measurement result, thereby significantly improving the thickness measurement accuracy.

[0093] The present application also provides an epitaxial layer thickness measurement method based on an automatic thickness measurement device, the automatic thickness measurement device being the automatic thickness measurement device of the present invention, the epitaxial layer thickness measurement method is to measure the thickness of the epitaxial layer according to the principle of spectral reflection analysis, and is suitable for measuring the thickness of the epitaxial layer of a large number of wafers, comprising the following steps:

[0094] S10, initializing the carrier, including controlling the movement of the carrier so that the carrier reaches the object picking position and the carrying part reaches the reflection detection position;

[0095] S20, calibrating the error, including conducting the test light to the reflection detection position through the light guide unit, and receiving the light reflected from the reflection detection position through the collection unit;

[0096] S30, during the calibration error period, controlling the wafer holding mechanism to obtain the wafer from the loading mechanism, and transporting the wafer to the carrier located at the pickup position;

[0097] S40, controlling the movement of the carrier and transporting the wafer to the reflection detection position through the carrier;

[0098] S50, measuring the thickness of the epitaxial layer, including conducting the test light to the reflection detection position through the light guide unit, and receiving the light reflected from the reflection detection position through the collection unit;

[0099] S60, unloading the wafer, including controlling the carrier to transport the wafer to the unloading position, controlling the wafer holding mechanism to obtain the wafer from the unloading position and transporting the wafer to the unloading mechanism;

[0100] S70, resetting the measuring mechanism, including controlling the movement of the stage to make the stage reach the object-taking position, and making the carrying part reach the reflection detection position.

[0101] The reflection detection position is an inherent position of the light control component 42, which is constructed by the light guiding unit and the collecting unit. By controlling the movement of the carrier 411 relative to the light control component 42, the carrier 411 can be made to reach the reflection detection position, the lens carrying part 416 can be made to reach the reflection detection position, and the sample carrying part 417 can be made to reach the reflection detection position.

[0102] When the carrier 411 reaches the reflection detection position, the center of the first carrying surface is located at the reflection detection position. At this time, the wafer can reflect the test light from the light guide unit to the collecting unit to complete the measurement of the epitaxial layer thickness. When the lens carrying part 416 reaches the reflection detection position, the calibration lens 71 is located at the reflection detection position and can reflect the test light from the light guide unit to the collecting unit to complete the calibration to eliminate the interference of ambient light. When the sample carrying part 417 reaches the reflection detection position, the calibration sample 72 is located at the reflection detection position and can reflect the test light from the light guide unit to the collecting unit to complete the calibration to eliminate the interference of the automatic thickness measurement equipment's own state.

[0103] Specifically, in step S10, controlling the movement of the carrier 411 so that the carrier 411 reaches the object-picking position and the carrying portion reaches the reflection detection position includes:

[0104] S11, driving the carrier 411 to move by the second driving member 413 until the axis of the carrier 411 reaches the object picking position, and controlling the first driving member 412 to drive the carrier 411 to rotate around the axis of the carrier 411 until the bearing portion reaches the reflection detection position.

[0105] Optionally, in step S10, controlling the movement of the carrier 411 so that the carrier 411 reaches the object-picking position and controlling the carrying portion to reach the reflection detection position are completed simultaneously. Figure 7 Looking down at the stage 411 that has reached the reflection detection position in a line of sight parallel to the axis of the stage 411, Figure 8 The carrier 411 reaching the object-taking position is viewed from a direction parallel to the axis of the carrier 411. At least a portion of the light control component 42 is Figure 7 and Figure 8 The geometric center of the rectangle is the reflection detection position. The stage 411 is Figure 7 and Figure 8 The center of the table surface of the stage 411 is represented by K. The center of the table surface of the stage 411 refers to the intersection of the axis of the stage 411 and the first bearing surface, so the K point is also used to represent the axis of the stage 411. Figure 7 and Figure 8When the second driving member 413 drives the stage 411 to move, the trajectory formed by the movement of the axis of the stage 411 is represented by a line segment T, and the straight line where the line segment T is located passes through the reflection detection position.

[0106] like Figure 7 As shown, when the carrier 411 reaches the reflection detection position, the center K of the surface of the carrier 411 is located at the reflection detection position, and a line from a bearing portion to the center of the surface of the carrier 411 is perpendicular to the moving track of the axis of the carrier 411, and the vertical foot position is exactly the center of the surface of the carrier 411; Figure 8 As shown, the second driving member 413 drives the stage 411 to move until the center K of the stage 411 is located at the object-taking position, and the first driving member 412 drives the stage 411 to rotate until one of the bearing parts reaches the reflection detection position. Figure 7 to Figure 8 , the moving distance of the stage 411 is the radius of the stage 411, and the stage 411 rotates clockwise by 90°.

[0107] Optionally, in step S20, conducting the test light to the reflection detection position through the light guiding unit and receiving the light reflected from the reflection detection position through the collecting unit includes:

[0108] S21, transmitting the test light to the calibration lens located at the reflection detection position through the light guide unit, and receiving the light reflected by the calibration lens through the collection unit;

[0109] S22, transmitting the test light to the calibration sample located at the reflection detection position through the light guiding unit, and receiving the light reflected by the calibration sample through the collecting unit.

[0110] In step S40, controlling the movement of the carrier and transporting the wafer to the reflection detection position through the carrier includes:

[0111] S41, driving the stage to move by the second driving member until the axis of the stage reaches the reflection detection position.

[0112] In step S50, conducting the test light to the reflection detection position through the light guide unit and receiving the light reflected from the reflection detection position through the collection unit includes:

[0113] S51, transmitting the test light to the wafer located at the reflection detection position through the light guiding unit, and receiving the light reflected from the wafer located at the reflection detection position through the collecting unit.

[0114] In step S60, controlling the stage to transport the wafer to the unloading position, controlling the wafer holding mechanism to obtain the wafer from the unloading position and transporting the wafer to the unloading mechanism includes:

[0115] S61, controlling the second driving member to drive the carrier to move until the axis of the carrier reaches the unloading position.

[0116] In step S70, controlling the movement of the stage 411 so that the stage 411 reaches the object-picking position and the carrying part reaches the reflection detection position includes:

[0117] S71, driving the stage 411 to move by the second driving member 413 until the axis of the stage 411 reaches the object picking position, and controlling the first driving member 412 to drive the stage 411 to rotate around the axis of the stage 411 until the bearing portion reaches the reflection detection position.

[0118] Compared with the existing wafer epitaxial layer thickness measurement method, the epitaxial layer thickness measurement method of the present invention is suitable for efficient epitaxial layer thickness measurement of a large number of wafers. Step S30 is executed simultaneously with step S20. The wafer holding mechanism is not idle during the error calibration period, but transports the wafer from the loading mechanism to the carrier, which shortens the time for measuring the epitaxial layer thickness and improves the efficiency of epitaxial layer thickness measurement for a large number of wafers. Moreover, before measuring the epitaxial layer thickness of any wafer, the error can be calibrated to eliminate the influence of ambient light or the automatic thickness measurement equipment's own factors on the epitaxial layer thickness measurement result, thereby ensuring that the epitaxial layer thickness measurement result of each wafer is more accurate.

[0119] Specifically, in some embodiments, the object taking position and the object unloading position overlap and form a pick-and-place position, and the second driving member 413 is used to drive the stage 411 to move back and forth, so that the center of the table surface of the stage 411 moves back and forth between the reflection detection position and the pick-and-place position, and the distance from the pick-and-place position to the reflection detection position is greater than or equal to the radius of the stage 411. Both the lens bearing part 416 and the sample bearing part 417 are fixedly arranged on the outer peripheral side of the stage 411, and the radius of the stage 411 is equivalent to the shortest distance from the bearing part to the axis of the stage 411;

[0120] In step S10, controlling the movement of the carrier 411 so that the carrier 411 reaches the object-picking position and the carrying part reaches the reflection detection position includes:

[0121] S12, driving the stage 411 to move by the second driving member 413 until the axis of the stage 411 reaches the pick-and-place position, and driving the stage 411 to rotate around the axis of the stage 411 by the first driving member 412 until the bearing portion reaches the reflection detection position;

[0122] In step S60, controlling the carrier 411 to transport the wafer to the unloading position includes:

[0123] Step S62, driving the carrier 411 to move by the second driving member 413 until the axis of the carrier 411 reaches the pick-up and place position;

[0124] During the wafer holding mechanism 30 transporting the wafer to the lower feeding mechanism 50 , step S70 is executed to reset the measuring mechanism 40 .

[0125] With such arrangement, the driving control logic of the carrier 411 is simpler, the space required for the movement of the carrier 411 is smaller, and the layout space required for the carrier assembly 41 can be reduced. The pick-and-place position serves as both the position for the carrier 411 to obtain the wafer sent by the crystal holding mechanism 30 and the position for the carrier 411 to unload the wafer so that the crystal holding mechanism 30 can take the wafer away. When the control of the carrier 411 in step S60 is completed to transport the wafer to the unloading position, it is equivalent to executing the control of the movement of the carrier 411 in step S70 to make the carrier 411 reach the pick-up position, thereby further shortening the time for measuring the thickness of the epitaxial layer of the wafer, which is beneficial to improving the efficiency of measuring the thickness of the epitaxial layer of the wafer.

[0126] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0127] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention. As long as they are within the spirit of the present invention, appropriate changes and modifications to the above embodiments are within the scope of protection claimed by the present invention.

Claims

1. An automatic thickness measuring device, characterized in that: include A loading mechanism (10) for loading wafers; The crystal holding mechanism (30) comprises a transfer component (31) movably arranged relative to the feeding mechanism (10), and a holding component (32) movably arranged on the transfer component (31); A measuring mechanism (40) comprises a carrier component (41) and a light control component (42), wherein the carrier component (41) comprises a carrier (411) movable relative to the light control component (42) and a bearing portion arranged on the carrier (411), wherein the carrier (411) comprises a first bearing surface for bearing an end face of a wafer, and the light control component (42) has a reflection detection position for the carrier (411) to reach, and further comprises a light guide unit and a collection unit; A material unloading mechanism (50) for unloading wafers; The positions that the carrier (411) can reach also include a pick-up position and an unloading position, and the holding component (32) can be driven by the transfer component (31) to sequentially pass through the loading mechanism (10), the pick-up position, the unloading position and the unloading mechanism (50); When the carrier (411) reaches the reflection detection position, the center of the first carrier surface is located at the reflection detection position, and When the carrier (411) reaches the object-taking position and / or the object-unloading position, the carrying surface of at least one of the carrying parts reaches the reflection detection position.

2. The automatic thickness measuring device according to claim 1, characterized in that: The light guide unit includes a light guide reflector, and the light guide reflector is used to reflect the test light to the wafer; and / or, The transfer component (31) comprises a multi-axis mechanical arm (311), and the holding component (32) is arranged at the end of the multi-axis mechanical arm (311); and / or, The holding component (32) comprises a suction component movably arranged on the transfer component (31), and also comprises a negative pressure control component connected to the suction component.

3. The automatic thickness measuring device according to claim 1, characterized in that: The object-carrying component (41) further comprises a first driving member (412) and a second driving member (413) connected to the carrier (411), wherein the first driving member (412) is used to drive the carrier (411) to move along a first track parallel to the carrier (411) relative to the light-controlling component (42), and the second driving member (413) is used to drive the carrier (411) to move along a second track parallel to the carrier (411) relative to the light-controlling component (42).

4. The automatic thickness measuring device according to claim 3, characterized in that: The carrier assembly (41) also includes a crystal moving seat (414) and a crystal rotating shaft (415) connected to each other, the carrier (411) is connected to the crystal rotating shaft (415), the first driving member (412) is connected to the crystal moving seat (414) and can drive the crystal moving seat (414) to translate along the first trajectory, and the second driving member (413) is connected to the crystal rotating shaft (415) and can drive the crystal rotating shaft (415) to rotate along the second trajectory.

5. The automatic thickness measuring device according to any one of claims 1 to 4, characterized in that: The carrier (411) includes a first carrying surface for carrying the end face of the wafer, and the object carrier assembly (41) also includes a carrying portion arranged on the carrier (411), and the carrying portion includes a lens carrying portion (416) for carrying a calibration lens (71) and / or a sample carrying portion (417) for carrying a calibration sample (72).

6. The automatic thickness measuring device according to claim 5, characterized in that: The first bearing surface is arranged at the end of the carrier (411), and the bearing portion is arranged on the outer peripheral side of the carrier (411).

7. The automatic thickness measuring device according to claim 6, characterized in that: The object carrier assembly (41) comprises the lens carrier portion (416) and the sample carrier portion (417), and the lens carrier portion (416) and the sample carrier portion (417) are evenly distributed along the circumference of the carrier (411); and / or, The object picking position and the object unloading position overlap to form a pick-and-place position, and the object carrying assembly (41) also includes a first driving member (412) and a second driving member (413) connected to the carrier (411), the first driving member (412) being used to drive the carrier (411) to rotate around the axis of the carrier (411), and the second driving member (413) being used to drive the axis of the carrier (411) to move back and forth between the pick-and-place position and the reflection detection position.

8. The automatic thickness measuring device according to any one of claims 1 to 4, characterized in that: The automatic thickness measuring device further comprises a posture correction component (21) and a code reader component (22), and the holding component (32) can be driven by the transfer component (31) to sequentially pass through the loading mechanism (10), the posture correction component (21), the picking position, the unloading position and the unloading mechanism (50).

9. The automatic thickness measuring device according to any one of claims 1 to 4, characterized in that: The automatic thickness measuring device further comprises a peripheral component (60), wherein the peripheral component (60) comprises at least a shielding unit (61), and the shielding unit (61) has a test space (62) for accommodating the loading mechanism (10), the crystal holding mechanism (30), the measuring mechanism (40), and the unloading mechanism (50).

10. The automatic thickness measuring device according to claim 9, characterized in that: The peripheral component (60) further comprises an air dispatching unit, wherein the air dispatching unit is used for performing air dispatching and transportation between the test space (62) and the outside of the shielding unit (61).

11. An epitaxial layer thickness measurement system, characterized in that: It comprises a calibration lens (71), a calibration sample (72), a spectrometer (73) and an automatic thickness measuring device according to any one of claims 1 to 10; The object carrier assembly (41) further comprises a lens carrying portion (416) and a sample carrying portion (417) arranged on the carrier (411); the calibration lens (71) is arranged on the lens carrying portion (416); and the calibration sample (72) is arranged on the sample carrying portion (417); The spectrometer (73) is used to decompose the reflected light received by the collection unit; The light guide unit can transmit the test light to the calibration lens (71) and the calibration sample (72), and the calibration lens (71) and the calibration sample (72) can reflect the light to the collection unit.

12. A method for measuring the thickness of an epitaxial layer, based on the automatic thickness measuring device according to any one of claims 1 to 10, wherein the object carrier assembly (41) further comprises a carrier portion disposed on the carrier (411); It is characterized in that The method comprises: Initializing the carrier (411), including controlling the movement of the carrier (411) so that the carrier (411) reaches an object-picking position, and the carrier portion reaches a reflection detection position; The calibration error includes conducting the test light to the reflection detection position through the light guide unit and receiving the light reflected from the reflection detection position through the collection unit; During the calibration error period, the wafer holding mechanism (30) is controlled to obtain the wafer from the loading mechanism (10), and the wafer is transported to the carrier (411) located at the object taking position; Controlling the movement of the carrier (411) and transporting the wafer to the reflection detection position via the carrier (411); Measuring the thickness of the epitaxial layer includes transmitting the test light to the reflection detection position through the light guide unit and receiving the light reflected from the reflection detection position through the collection unit; Unloading the wafers, including controlling the carrier (411) to transport the wafers to the unloading position, controlling the wafer holding mechanism (30) to obtain the wafers from the unloading position and transporting the wafers to the unloading mechanism (50); Resetting the measuring mechanism (40) includes controlling the movement of the carrier (411) so that the carrier (411) reaches an object-taking position and the carrying portion reaches a reflection detection position.

13. The epitaxial layer thickness measurement method according to claim 12, characterized in that: The object-pickup position and the object-unloading position overlap to form a pick-up and placement position, the distance from the pick-up and placement position to the reflection detection position is not less than the radius of the carrier (411), the bearing portion is arranged on the outer peripheral side of the carrier (411), and the object-carrying assembly (41) further comprises a first driving member (412) and a second driving member (413) connected to the carrier (411); The step of controlling the movement of the carrier (411) so that the carrier (411) reaches the object-picking position and the carrier reaches the reflection detection position comprises: The second driving member (413) drives the carrier (411) to move until the axis of the carrier (411) reaches the pick-and-place position, and the first driving member (412) drives the carrier (411) to rotate around the axis of the carrier (411) until the bearing portion reaches the reflection detection position; Step - controlling the carrier (411) to transport the wafer to the unloading position includes: The carrier (411) is driven to move by a second driving member (413) until the axis of the carrier (411) reaches a pick-and-place position; The step of controlling the movement of the carrier (411) and transporting the wafer to the reflection detection position through the carrier (411) includes: The carrier (411) is driven to move by the second driving member (413) until the axis of the carrier (411) reaches the reflection detection position.

14. The epitaxial layer thickness measurement method according to claim 12, characterized in that: The measuring mechanism (40) is reset while the wafer holding mechanism (30) transports the wafer to the lower feeding mechanism (50).

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