Wafer flatness measurement device and method

Abstract

The present invention discloses a wafer flatness measurement device and method, specifically related to the field of semiconductor technology, including a first body and a second body, wherein a moving mechanism and a measuring mechanism are arranged inside the first body, a feeding device is arranged inside the second body, and a fixing mechanism is arranged on the moving mechanism. The present invention enables the airflow in the negative pressure hole corresponding to the adsorption slot not covered by the wafer to be measured to flow normally through the arrangement of structures such as a blocking plate, a blocking plug and a sealing plate, so that the blocking plate and the blocking plug in the corresponding valve body can continue to move downward, and the blocking plug can be inserted into the sealing plate to achieve a sealed fit, so that the negative pressure airflow cannot continue to circulate, and impurities in the air are prevented from entering the negative pressure cavity through the negative pressure hole under the action of suction, and dust accumulation is avoided to affect the normal operation of the external air supply device and the negative pressure suction cup, thereby avoiding the warping phenomenon of the wafer to be measured during the measurement process caused by the reduction of suction, and improving the measurement accuracy.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and more specifically, to a wafer flatness measurement device and method. Background Art

[0002] Wafer refers to the silicon wafer used to make silicon semiconductor circuits. Its raw material is silicon. High-purity polysilicon is dissolved and doped with silicon crystal seeds, and then slowly pulled out to form cylindrical single crystal silicon. After grinding, polishing and slicing, the silicon crystal rod is formed into a silicon wafer, also known as a wafer.

[0003] As the basic material for semiconductor manufacturing, the surface flatness of wafers has a decisive influence on the performance and yield of chips. During the wafer production process, any tiny surface fluctuations may lead to the failure of processes such as lithography and etching, thereby affecting the quality and output of the final product. Therefore, achieving accurate measurement and control of wafer surface flatness has become a core link in the semiconductor industry.

[0004] During the measurement process, the wafer may warp due to factors such as temperature, humidity, air pressure and its own material. The wafer flatness measurement device in the prior art will adsorb and fix the wafer through a negative pressure suction cup and other devices when measuring the flatness of the wafer. Although the negative pressure suction cup can adsorb and fix the wafer through suction, which can reduce the wafer warping phenomenon, due to the different diameters of wafers, when the negative pressure suction cup adsorbs and fixes wafers of different diameters, the wafer with a smaller diameter cannot completely cover the negative pressure suction cup, which will cause the negative pressure of the negative pressure suction cup to leak. The smaller the wafer diameter, the more serious the negative pressure leakage, which makes the negative pressure suction cup's adsorption force on the wafer smaller, causing the wafer to shift or even fall during the movement process, which greatly reduces the effect of suppressing wafer warping and affects the measurement accuracy of wafer flatness. In addition, the negative pressure suction generated by the negative pressure suction cup when working can easily suck impurities in the air into the interior, which will affect the normal operation of the air supply device and the negative pressure suction cup after long-term accumulation.

[0005] The present invention provides a wafer flatness measurement device and method to solve the above problems. Summary of the invention

[0006] The purpose of the present invention is to provide a wafer flatness measurement device and method to solve the problem that wafers have different diameters as proposed in the above background technology, and wafers with smaller diameters cannot completely cover the negative pressure suction cup, resulting in the leakage of the negative pressure of the negative pressure suction cup, which greatly reduces the effect of suppressing wafer warping and affects the measurement accuracy of wafer flatness. In addition, the negative pressure suction force generated by the negative pressure suction cup when working can easily suck impurities in the air into the interior, which will affect the normal operation of the air supply device and the negative pressure suction cup after long-term accumulation.

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a wafer flatness measuring device comprises a first main body and a second main body, wherein a moving mechanism and a measuring mechanism are arranged inside the first main body, a feeding device is arranged inside the second main body, and a fixing mechanism is arranged on the moving mechanism; the fixing mechanism comprises a negative pressure suction cup, a plurality of adsorption grooves with diameters gradually increasing from the inside to the outside are arranged on the top of the negative pressure suction cup, a negative pressure cavity is arranged inside the negative pressure suction cup, each of the adsorption grooves is arranged with a negative pressure hole connected to the inside of the negative pressure cavity, and is used to fix the wafer to be measured by negative pressure, and a control component is arranged in each of the negative pressure holes; the control component comprises a valve body fixedly connected to the inside of the negative pressure hole, a first air suction hole is arranged on the top of the valve body, and the first air suction hole is arranged on the top of the valve body. A plurality of second air suction holes are provided at the bottom of the valve body, a sealing plate is fixedly connected to the inner wall of the valve body, a piston cavity is fixedly connected to the inner wall of the bottom of the valve body, a piston is slidably connected to the internal sealing of the piston cavity, a first piston rod is fixedly connected to the top of the piston, one end of the first piston rod extending out of the piston cavity is fixedly connected to a sealing plate for sealing the first air suction hole, a sealing plug for sealing the sealing plate is fixedly connected to the bottom of the sealing plate, the sealing plate and the sealing plug are both located above the sealing plate, and the diameter of the sealing plate is larger than the diameter of the first air suction hole and the inner diameter of the sealing plate, the sealing plug can be sealingly fitted with the sealing plate, and is used to control the switch of the negative pressure hole when the fixing mechanism adsorbs and fixes the wafer.

[0008] Preferably, a partition is provided inside the negative pressure chamber, and adjustment holes are opened on the partition, the number of which is the same as that of the negative pressure holes and the positions of which are corresponding; a second piston rod is fixedly connected to the bottom of the piston, and a plug is fixedly connected to one end of the second piston rod extending to the bottom of the valve body, and the plug is used to seal the adjustment holes. When the sealing plug completely seals the sealing plate, the plug can seal the adjustment holes.

[0009] Preferably, a first conductive contact is fixedly connected to the top of the sealing plate, and a second conductive contact is fixedly connected to the bottom of the sealing plate. The second conductive contact is arranged in a ring shape on the outer peripheral side of the sealing plug. When the sealing plug completely seals the sealing plate, the second conductive contact contacts the first conductive contact and generates an electrical signal.

[0010] Preferably, a positive pressure cavity is provided inside the negative pressure suction cup, and each of the adsorption grooves is provided with a positive pressure hole connected to the inside of the positive pressure cavity; the circumferential outer wall of the negative pressure suction cup is provided with two mounting holes respectively connected to the positive pressure cavity and the negative pressure cavity, and throttle valves are installed in the two mounting holes, and the two throttle valves are connected to an external air supply device.

[0011] Preferably, the moving mechanism includes a first mounting plate fixedly connected to the first main body, a Y-axis moving component is arranged above the first mounting plate, an X-axis moving component is arranged on the Y-axis moving component, and a Z-axis moving component is arranged on the X-axis moving component for adjusting the position of the fixed mechanism.

[0012] Preferably, the Y-axis moving component includes a first support plate, on which a first screw module is arranged; the X-axis moving component includes a second support plate arranged on the first screw module, on which a second screw module is arranged, and on which a moving plate is arranged; the Z-axis moving component includes a support member fixedly connected to the top of the moving plate, in which a third screw module is arranged, and the fixing mechanism is installed on the third screw module.

[0013] Preferably, the measuring mechanism comprises a support frame fixedly connected to the first mounting plate, and the support frame is provided with a visual measuring device for measuring the flatness of the wafer.

[0014] Preferably, the feeding device includes a second mounting plate fixedly connected to the inside of the second main body, a robotic arm for feeding the wafer to be tested is arranged on the second mounting plate, a feeding port for the robotic arm to feed is opened between the first main body and the second main body, and a placement rack for placing the wafer to be tested is arranged on the outside of the second body.

[0015] Preferably, the moving mechanism, the measuring mechanism and the feeding device are all electrically connected to a controller, and the controller is capable of receiving an electrical signal generated when the first conductive contact piece contacts the second conductive contact piece.

[0016] The present invention also provides a method for measuring the flatness of a wafer, comprising the following steps:

[0017] S1. Place the tray containing the wafers to be tested on the material rack;

[0018] S2, start the robotic arm, take out the wafer to be tested through the robotic arm, and place it on the negative pressure suction cup;

[0019] S3, start the external air supply device to adsorb and fix the wafer to be tested through the negative pressure suction cup;

[0020] S4, the controller receives the electrical signal generated by the contact between the first conductive contact sheet and the second conductive contact sheet, and determines the position of the wafer to be tested and sets the moving path through the electrical signal;

[0021] S5, the controller controls the moving mechanism to adjust the initial position of the wafer to be measured;

[0022] S6. Start the visual measurement device, and control the moving mechanism through the controller to drive the wafer to be measured along the set path for measurement.

[0023] Technical effects and advantages of the present invention:

[0024] 1. The present invention arranges structures such as a blocking plate, a blocking plug and a sealing plate so that the airflow in the negative pressure hole corresponding to the adsorption slot not covered by the wafer to be tested can flow normally, thereby enabling the blocking plate and the blocking plug in the corresponding valve body to continue to move downward, and enabling the blocking plug to be inserted into the sealing plate to achieve a sealed fit, so that the negative pressure airflow cannot continue to flow, thereby avoiding negative pressure leakage in the adsorption slot not covered by the wafer to be tested, and preventing impurities in the air from entering the negative pressure cavity through the negative pressure hole under the action of suction, and preventing continuous negative pressure airflow from causing noise in the negative pressure hole, thereby avoiding dust accumulation from affecting the normal operation of the external air supply device and the negative pressure suction cup, thereby avoiding warping of the wafer to be tested during the measurement due to reduced suction, and improving the measurement accuracy.

[0025] 2. The present invention arranges structures such as partitions, adjustment holes and plugs, so that the sealing plates and sealing plugs corresponding to the adsorption slots not covered by the wafers can drive the plugs to block the corresponding adjustment holes during the downward movement, thereby preventing the negative pressure airflow from passing through the adjustment holes corresponding to the adsorption slots covered by the wafers to enter the top of the partition. The overall negative pressure airflow flow and negative pressure above the partition are reduced, so that the suction of the adsorption slots can be adaptively adjusted according to the coverage of the wafers, avoiding excessive suction in the adsorption slots due to changes in the diameter of the wafers, causing deformation of the wafers, affecting the measurement results, and further improving the measurement accuracy.

[0026] 3. The present invention arranges the first conductive contact piece and the second conductive contact piece so that the second conductive contact piece corresponding to the adsorption slot not covered by the wafer to be tested contacts the first conductive contact piece and generates an electrical signal, so that the second conductive contact piece corresponding to the adsorption slot covered by the wafer to be tested cannot contact the first conductive contact piece and cannot form an electrical signal, so that the controller can determine the diameter and position of the wafer according to the electrical signal generated by the second conductive contact piece and the first conductive contact piece, so as to automatically set the moving path according to the electrical signal and measure the area where no electrical signal is generated, thereby reducing human interference and improving measurement efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0028] Figure 2 This is a schematic diagram of the internal structure of the first body and the second body of the present invention;

[0029] Figure 3 It is a schematic diagram of the structure of the moving mechanism and the measuring mechanism of the present invention;

[0030] Figure 4 It is a schematic diagram of the structure of the Y-axis moving component and the X-axis moving component of the present invention;

[0031] Figure 5 This is a schematic diagram of the structure of the Z-direction moving assembly of the present invention;

[0032] Figure 6 It is a schematic diagram of the fixing mechanism structure of the present invention;

[0033] Figure 7 This is a cross-sectional view of the internal structure of the negative pressure suction cup of the present invention;

[0034] Figure 8 For the present invention Figure 7 A magnified view of the structure of the middle part A;

[0035] Fig. 9 It is a cross-sectional view of the structure of the positive pressure chamber of the present invention;

[0036] Fig.10 This is a schematic diagram of the control component structure of the present invention;

[0037] Fig.11 A bottom view of the control assembly of the present invention;

[0038] Fig.12 This is a cross-sectional view of the control component structure of the present invention.

[0039] The accompanying drawings are marked as follows: 1. first body; 11. second body; 2. moving mechanism; 21. first mounting plate; 210. Y-axis moving assembly; 211. first support plate; 212. first screw module; 220. X-axis moving assembly; 221. second support plate; 222. second screw module; 223. moving plate; 230. Z-axis moving assembly; 231. support member; 232. third screw module; 3. measuring mechanism; 31. support frame; 32. visual measuring device; 4. feeding device; 41. second mounting plate; 42. mechanical arm; 43. feeding port; 44. unloading frame; 5 , fixing mechanism; 51, negative pressure suction cup; 52, adsorption groove; 53, negative pressure chamber; 54, negative pressure hole; 55, positive pressure chamber; 56, positive pressure hole; 57, mounting hole; 58, throttle valve; 510, control component; 511, valve body; 512, first suction hole; 513, second suction hole; 514, sealing plate; 515, piston chamber; 516, piston; 517, first piston rod; 518, sealing plate; 519, sealing plug; 520, partition; 521, adjusting hole; 522, second piston rod; 523, plug; 524, first conductive contact; 525, second conductive contact. DETAILED DESCRIPTION

[0040] 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.

[0041] Embodiment 1

[0042] refer to Figure 1 and Figure 2 A wafer flatness measuring device according to an embodiment of the present invention includes a first body 1 and a second body 11. A moving mechanism 2 and a measuring mechanism 3 are arranged inside the first body 1. A feeding device 4 is arranged inside the second body 11. A fixing mechanism 5 is arranged on the moving mechanism 2.

[0043] refer to Figures 5 to 9 The fixing mechanism 5 includes a negative pressure suction cup 51, and a plurality of adsorption grooves 52 with diameters gradually increasing from the inside to the outside are provided on the top of the negative pressure suction cup 51. A negative pressure cavity 53 is provided inside the negative pressure suction cup 51, and a negative pressure hole 54 connected to the inside of the negative pressure cavity 53 is provided in each adsorption groove 52, which is used to fix the wafer to be measured by negative pressure. A positive pressure cavity 55 is provided inside the negative pressure suction cup 51, and a positive pressure hole 56 connected to the inside of the positive pressure cavity 55 is provided in each adsorption groove 52. Two mounting holes 57 connected to the positive pressure cavity 55 and the negative pressure cavity 53 are respectively provided on the circumferential outer wall of the negative pressure suction cup 51, and throttle valves 58 are installed in the two mounting holes 57, and the two throttle valves 58 are connected to the external air supply equipment.

[0044] refer to Figures 2 to 4 The moving mechanism 2 includes a first mounting plate 21 fixedly connected to the first main body 1, a Y-axis moving component 210 is arranged above the first mounting plate 21, an X-axis moving component 220 is arranged on the Y-axis moving component 210, and a Z-axis moving component 230 is arranged on the X-axis moving component 220 for adjusting the position of the fixing mechanism 5, the Y-axis moving component 210 includes a first supporting plate 211, a first screw module 212 is arranged on the first supporting plate 211, the X-axis moving component 220 includes a second supporting plate 221 arranged on the first screw module 212, a second screw module 222 is arranged on the second supporting plate 221, a moving plate 223 is arranged on the second screw module 222, the Z-axis moving component 230 includes a supporting member 231 fixedly connected to the top of the moving plate 223, a third screw module 232 is arranged in the supporting member 231, and the fixing mechanism 5 is installed on the third screw module 232.

[0045] refer to Figure 2 and Figure 3The measuring mechanism 3 includes a support frame 31 fixedly connected to the first mounting plate 21 , and a visual measuring device 32 for measuring the flatness of the wafer is arranged on the support frame 31 .

[0046] refer to Figure 1 and Figure 2 The feeding device 4 includes a second mounting plate 41 fixedly connected to the inside of the second main body 11, a mechanical arm 42 for feeding the wafer to be tested is arranged on the second mounting plate 41, and a feeding claw is arranged on the mechanical arm 42. A feeding port 43 for the mechanical arm 42 to feed is opened between the first main body 1 and the second main body 11, a discharge rack 44 for placing the wafer to be tested is arranged on the outside of the second main body 11, and a feeding port for discharging is arranged above the discharge rack 44 on the outside of the second main body 11. The moving mechanism 2, the measuring mechanism 3 and the feeding device 4 are all electrically connected to the controller.

[0047] During actual operation, first place the tray containing the wafers to be tested on the unloading rack 44, start the robot arm 42, take out the wafers to be tested from the tray on the unloading rack 44 through the feeding claws on the robot arm 42, and send them into the first body 1 through the feeding port 43 between the first body 1 and the second body 11, and place the wafers to be tested on the negative pressure suction cup 51.

[0048] After placement is completed, start the external air supply device to provide negative pressure airflow into the negative pressure chamber 53 through the external air supply device. The negative pressure airflow is transmitted to the corresponding adsorption groove 52 through multiple negative pressure holes 54, so that suction is generated in the adsorption groove 52, thereby adsorbing and fixing the wafer to be tested on the negative pressure suction cup 51. The negative pressure and flow rate entering the negative pressure chamber 53 can be adjusted by the throttle valve 58.

[0049] After the fixation is completed, the moving mechanism 2 is controlled to perform preliminary position adjustment on the fixing mechanism 5 according to the thickness and diameter of the wafer to be measured, so that the position of the wafer to be measured is moved to the starting point measured by the visual measurement device 32, and the fixing mechanism 5 is driven to move by the first screw module 212 on the Y-direction moving component 210, so as to adjust the position of the wafer in the Y direction, and the fixing mechanism 5 is driven to move by the second screw module 222 on the X-direction moving component 220, so as to adjust the position of the wafer in the X direction, and the fixing mechanism 5 is driven to move by the third screw module 232 on the Z-direction moving component 230, so as to adjust the position of the wafer in the Z direction.

[0050] After the initial position adjustment is completed, the visual measurement device 32 is started, and the moving path of the moving mechanism 2 is set by the controller according to the diameter of the wafer to be measured. The moving mechanism 2 drives the wafer to be measured on the fixed mechanism 5 to move along the path set by the controller, so that the wafer to be measured is measured by the visual measurement device 32 during the movement, and the measurement data is transmitted to the controller.

[0051] After the measurement is completed, the external air supply device is controlled to stop providing negative pressure airflow into the negative pressure chamber 53, and the external air supply device is controlled to provide positive pressure airflow into the positive pressure chamber 55, and the positive pressure airflow is sprayed out through multiple positive pressure holes 56, so that it is easier to remove the wafer and avoid damage to the wafer.

[0052] Embodiment 2

[0053] During actual use, due to the different diameters of wafers, when the negative pressure suction cup 51 adsorbs and fixes wafers of different diameters, the wafer with a smaller diameter cannot completely cover the negative pressure suction cup 51, which will cause the negative pressure of the negative pressure suction cup 51 to leak. The smaller the diameter of the wafer, the more serious the negative pressure leakage, so that the adsorption force of the negative pressure suction cup 51 on the wafer is smaller, causing the wafer to shift or even fall during the movement, which greatly reduces the effect of suppressing wafer warping and affects the measurement accuracy of wafer flatness. In addition, the negative pressure suction force generated by the negative pressure suction cup 51 when working can easily suck impurities in the air into the interior, which will affect the normal operation of the air supply device and the negative pressure suction cup 51 after long-term accumulation. Therefore, this embodiment improves the device described in the above embodiment.

[0054] refer to Figures 6 to 12 A control assembly 510 is provided in each negative pressure hole 54. The control assembly 510 includes a valve body 511 fixedly connected to the inside of the negative pressure hole 54. A first air suction hole 512 is provided at the top of the valve body 511. A plurality of second air suction holes 513 are provided at the bottom of the valve body 511. A sealing plate 514 is fixedly connected to the inner wall of the valve body 511. A piston cavity 515 is fixedly connected to the inner wall of the bottom of the valve body 511. A piston 516 is slidably connected to the inside of the piston cavity 515. A first piston rod 517 is fixedly connected to the top of the piston 516. The first piston rod 517 is fixedly connected to the top of the piston 516. 17 One end of the piston chamber 515 extending out is fixedly connected to a sealing plate 518 for sealing the first air suction hole 512, and the bottom of the sealing plate 518 is fixedly connected to a sealing plug 519 for sealing the sealing plate 514. The sealing plate 518 and the sealing plug 519 are both located above the sealing plate 514, and the diameter of the sealing plate 518 is larger than the diameter of the first air suction hole 512 and the inner diameter of the sealing plate 514. The sealing plug 519 can be sealed and fitted with the sealing plate 514, and is used to control the switch of the negative pressure hole 54 when the fixing mechanism 5 adsorbs and fixes the wafer.

[0055] During actual operation, the wafer to be tested is placed on the negative pressure suction cup 51, and negative pressure is generated in the negative pressure chamber 53 through an external air supply device. Due to the different diameters of the wafers to be tested, when the measured wafer diameter cannot cover all the adsorption slots 52, the adsorption slots 52 covered by the wafer to be tested are in a blocked state, and the negative pressure airflow in the negative pressure chamber 53 will enter the valve body 511 through the negative pressure hole 54 and multiple second air suction holes 513, and generate negative pressure in the valve body 511. The negative pressure will drive the sealing plate 518 and the sealing plug 519 to move downward and release the blockage of the first air suction hole 512. At this time, the negative pressure airflow passes through the first air suction hole 512 to generate suction in the adsorption slot 52, thereby adsorbing and fixing the wafer to be tested.

[0056] After the wafer to be tested is adsorbed and fixed, the airflow in the negative pressure hole 54 corresponding to the adsorption slot 52 covered by the wafer to be tested cannot flow normally, so that the sealing plate 518 and the sealing plug 519 in the corresponding negative pressure hole 54 cannot continue to move downward. The suction force always acts on the bottom of the wafer to be tested, thereby preventing the wafer to be tested from moving during the measurement process and affecting the measurement results.

[0057] At this time, the adsorption slots 52 that are not covered by the wafer to be tested are in an airflow flow state. The negative pressure airflow in the negative pressure chamber 53 will enter the valve body 511 through the negative pressure hole 54 and multiple second air suction holes 513, and generate negative pressure in the valve body 511. The negative pressure will drive the sealing plate 518 and the sealing plug 519 to move gradually downward.

[0058] Since it is not covered by the wafer, the airflow in the corresponding negative pressure hole 54 can flow normally, so that the sealing plate 518 and the sealing plug 519 in the corresponding valve body 511 can continue to move downward. When the sealing plate 518 and the sealing plug 519 move downward to the extreme position, the sealing plug 519 can be inserted into the sealing plate 514 to achieve a sealed fit, so that the negative pressure airflow cannot continue to circulate, thereby avoiding negative pressure leakage in the adsorption slot 52 that is not covered by the wafer to be tested. At the same time, it prevents impurities in the air from entering the negative pressure cavity 53 through the negative pressure hole 54 under the action of suction, and prevents continuous negative pressure airflow from causing the negative pressure hole 54 to generate noise, thereby avoiding dust accumulation from affecting the normal operation of the external air supply device and the negative pressure suction cup 51, thereby avoiding the reduction of suction and causing the wafer to be tested to warp during the measurement process, thereby improving the measurement accuracy.

[0059] It should be noted that in the present invention, when negative pressure is generated in the valve body 511 so that the sealing plate 518 and the sealing plug 519 move downward, the sealing plate 518 and the sealing plug 519 will drive the piston 516 to move downward in the piston chamber 515 through the first piston rod 517, and compress the gas in the piston chamber 515. When the negative pressure in the valve body 511 disappears, the compressed gas in the piston chamber 515 will push the piston 516 and drive the sealing plate 518 and the sealing plug 519 to move upward through the first piston rod 517, and re-seal the first suction hole 512 through the sealing plate 518, so as to prevent impurities from entering the negative pressure chamber 53 through the negative pressure hole 54 when no measurement is performed, thereby reducing the maintenance times of the fixing mechanism 5 and the external air supply device and improving the service life of the fixing mechanism 5 and the external air supply device.

[0060] To sum up, through the setting of structures such as the sealing plate 518, the sealing plug 519 and the sealing plate 514, the airflow in the negative pressure hole 54 corresponding to the adsorption slot 52 not covered by the wafer to be tested can flow normally, so that the sealing plate 518 and the sealing plug 519 in the corresponding valve body 511 can continue to move downward, and the sealing plug 519 can be inserted into the sealing plate 514 to achieve a sealed fit, so that the negative pressure airflow cannot continue to circulate, thereby avoiding negative pressure leakage in the adsorption slot 52 not covered by the wafer to be tested, and preventing impurities in the air from entering the negative pressure cavity 53 through the negative pressure hole 54 under the action of suction, and preventing continuous negative pressure airflow from causing the negative pressure hole 54 to generate noise, thereby avoiding dust accumulation from affecting the normal operation of the external air supply device and the negative pressure suction cup 51, thereby avoiding the reduction of suction force and causing the wafer to be tested to warp during the measurement process, thereby improving the measurement accuracy.

[0061] Embodiment 3

[0062] During actual use, the fixing mechanism 5 corresponding to the adsorption slot 52 not covered by the wafer will block the corresponding negative pressure hole 54, which will increase the negative pressure in the negative pressure chamber 53. These negative pressures will act on the wafer through the adsorption slot 52 covered by the wafer. The more negative pressure holes 54 are blocked, the greater the negative pressure in the negative pressure chamber 53, and the greater the suction force acting on the wafer. Excessive suction may cause deformation of the wafer and affect the measurement accuracy. Therefore, this embodiment improves the device described in the above embodiment.

[0063] refer to Figures 7 to 12A partition 520 is provided inside the negative pressure chamber 53, and adjustment holes 521 of the same number and corresponding positions as the negative pressure holes 54 are opened on the partition 520. A second piston rod 522 is fixedly connected to the bottom of the piston 516, and a plug 523 is fixedly connected to one end of the second piston rod 522 extending below the valve body 511. The plug 523 is used to block the adjustment holes 521. When the sealing plug 519 completely blocks the sealing plate 514, the plug 523 can block the adjustment holes 521.

[0064] During actual operation, the negative pressure airflow in the negative pressure chamber 53 will preferentially enter the top of the partition 520 through the multiple adjustment holes 521, and then enter the corresponding valve body 511 through the multiple negative pressure holes 54. When the negative pressure suction cup 51 adsorbs and fixes the wafer to be tested, the sealing plate 518 and the sealing plug 519 in the valve body 511 corresponding to the adsorption groove 52 covered by the wafer cannot move downward to the extreme position. Therefore, during the downward movement of the sealing plate 518 and the sealing plug 519, the first piston rod 517, the piston 516 and the second piston rod 522 cannot drive the plug 523 to seal the corresponding adjustment hole 521. At this time, the negative pressure airflow can still enter the top of the partition 520 through the adjustment hole 521 corresponding to the adsorption groove 52 covered by the wafer.

[0065] Since the sealing plate 518 and the sealing plug 519 in the valve body 511 corresponding to the adsorption slot 52 not covered by the wafer will move downward to the extreme position, the sealing plate 518 and the sealing plug 519 will drive the plug 523 to block the corresponding adjusting hole 521 through the first piston rod 517, the piston 516 and the second piston rod 522 during the downward movement. At this time, the negative pressure airflow cannot enter the top of the partition 520 through the adjusting hole 521 corresponding to the adsorption slot 52 covered by the wafer, so that the overall negative pressure airflow flow and negative pressure above the partition 520 are reduced. The more the adsorption slot 52 is covered, the less the adjusting hole 521 is blocked, and the less the adsorption slot 52 is covered, the more the adjusting hole 521 is blocked. Therefore, the suction force of the adsorption slot 52 can be adaptively adjusted according to the coverage of the wafer to avoid excessive suction force in the adsorption slot 52 due to changes in the diameter of the wafer, causing deformation of the wafer and affecting the measurement result, thereby further improving the measurement accuracy.

[0066] To summarize, through the arrangement of structures such as the partition 520, the adjustment hole 521 and the plug 523, the sealing plate 518 and the sealing plug 519 corresponding to the adsorption slot 52 not covered by the wafer can drive the plug 523 to block the corresponding adjustment hole 521 during the downward movement, so that the negative pressure airflow cannot pass through the adjustment hole 521 corresponding to the adsorption slot 52 covered by the wafer to enter the top of the partition 520, so that the overall negative pressure airflow flow and negative pressure above the partition 520 are reduced, so that the suction force of the adsorption slot 52 can be adaptively adjusted according to the coverage of the wafer, so as to avoid excessive suction in the adsorption slot 52 due to changes in the diameter of the wafer, causing deformation of the wafer, affecting the measurement results, and further improving the measurement accuracy.

[0067] Embodiment 4

[0068] During actual use, the moving path during wafer measurement needs to be manually changed according to the diameter of the wafer. Manual changes are troublesome and prone to carelessness and errors, which affect the measurement efficiency. The moving path needs to be set and saved in the controller. If the moving path saved in the controller does not match the wafer diameter, it is necessary to pick up the points and set the path again, which will further affect the measurement efficiency. Therefore, this embodiment improves the device described in the above embodiment.

[0069] refer to Figures 10 to 12 A first conductive contact 524 is fixedly connected to the top of the sealing plate 514, and a second conductive contact 525 is fixedly connected to the bottom of the sealing plate 518. The second conductive contact 525 is arranged in a ring shape on the outer peripheral side of the sealing plug 519. When the sealing plug 519 completely blocks the sealing plate 514, the second conductive contact 525 contacts the first conductive contact 524 and generates an electrical signal. The controller can receive the electrical signal generated when the second conductive contact 525 contacts the first conductive contact 524.

[0070] During actual operation, when the negative pressure suction cup 51 is adsorbed and fixed, the sealing plate 518 and the sealing plug 519 corresponding to the adsorption slot 52 not covered by the wafer to be tested will move downward to the limit position, and the second conductive contact piece 525 will be driven to move downward during the downward movement of the sealing plate 518. When the sealing plate 518 and the sealing plug 519 move downward to the limit position inside the valve body 511, the sealing plate 518 will drive the second conductive contact piece 525 to contact the first conductive contact piece 524 and generate an electrical signal, while the sealing plate 518 and the sealing plug 519 corresponding to the adsorption slot 52 not covered by the wafer to be tested cannot move downward to the limit position, so the corresponding second conductive contact piece 525 cannot contact the first conductive contact piece 524 and no electrical signal is generated. Therefore, the controller can determine the diameter and position of the wafer according to the electrical signal generated by the second conductive contact piece 525 and the first conductive contact piece 524, so as to automatically set the moving path according to the electrical signal and measure the area where no electrical signal is generated, thereby reducing human interference and improving measurement efficiency.

[0071] To summarize, by setting the first conductive contact piece 524 and the second conductive contact piece 525, the second conductive contact piece 525 corresponding to the adsorption slot 52 not covered by the wafer to be tested contacts the first conductive contact piece 524 and generates an electrical signal, so that the second conductive contact piece 525 corresponding to the adsorption slot 52 covered by the wafer to be tested cannot contact the first conductive contact piece 524 and cannot form an electrical signal, so that the controller can determine the diameter and position of the wafer according to the electrical signal generated by the second conductive contact piece 525 and the first conductive contact piece 524, so as to automatically set the moving path according to the electrical signal and measure the area where no electrical signal is generated, thereby reducing human interference and improving measurement efficiency.

[0072] Embodiment 5

[0073] The present invention also provides a method for measuring the flatness of a wafer, comprising the following steps:

[0074] S1, placing a tray containing wafers to be tested on a material placement rack 44;

[0075] S2, start the robot arm 42, take out the wafer to be tested through the robot arm 42, and place it on the negative pressure suction cup 51;

[0076] S3, start the external air supply device to adsorb and fix the wafer to be tested through the negative pressure suction cup 51;

[0077] S4, the controller receives the electrical signal generated by the contact between the first conductive contact piece 524 and the second conductive contact piece 525, and determines the position of the wafer to be tested and sets the moving path through the electrical signal;

[0078] S5, the controller controls the moving mechanism 2 to adjust the initial position of the wafer to be measured, so that the position of the wafer to be measured is adjusted to the starting point measured by the visual measuring device 32;

[0079] S6, start the visual measurement device 32, and control the moving mechanism 2 through the controller to drive the wafer to be measured along the set path for measurement.

[0080] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A wafer flatness measuring device, comprising a first body (1) and a second body (11), characterized in that: A moving mechanism (2) and a measuring mechanism (3) are arranged inside the first body (1), a feeding device (4) is arranged inside the second body (11), and a fixing mechanism (5) is arranged on the moving mechanism (2); The fixing mechanism (5) comprises a negative pressure suction cup (51), a top of the negative pressure suction cup (51) is provided with a plurality of adsorption grooves (52) whose diameters gradually increase from the inside to the outside, a negative pressure cavity (53) is provided inside the negative pressure suction cup (51), each of the adsorption grooves (52) is provided with a negative pressure hole (54) connected to the inside of the negative pressure cavity (53) for fixing the wafer to be measured by negative pressure, and each of the negative pressure holes (54) is provided with a control component (510); The control assembly (510) comprises a valve body (511) fixedly connected to the inside of the negative pressure hole (54); a first air suction hole (512) is formed at the top of the valve body (511); a plurality of second air suction holes (513) are formed at the bottom of the valve body (511); an annular sealing plate (514) is fixedly connected to the inner wall of the valve body (511); a piston chamber (515) is fixedly connected to the inner wall of the bottom of the valve body (511); a piston (516) is sealingly and slidably connected to the inside of the piston chamber (515); a first piston rod (517) is fixedly connected to the top of the piston (516); the first piston rod (517) extends out of the piston chamber (515). ) is fixedly connected to one end thereof with a blocking plate (518) for blocking the first air suction hole (512), and a sealing plug (519) for blocking the sealing plate (514) is fixedly connected to the bottom of the blocking plate (518), the blocking plate (518) and the sealing plug (519) are both located above the sealing plate (514), and the diameter of the blocking plate (518) is larger than the diameter of the first air suction hole (512) and the inner diameter of the sealing plate (514), and the sealing plug (519) can be sealingly fitted with the sealing plate (514) and is used to control the switch of the negative pressure hole (54) when the fixing mechanism (5) adsorbs and fixes the wafer; A partition plate (520) is provided inside the negative pressure chamber (53), and the partition plate (520) is provided with adjustment holes (521) having the same number as the negative pressure holes (54) and corresponding positions; A second piston rod (522) is fixedly connected to the bottom of the piston (516); one end of the second piston rod (522) extending below the valve body (511) is fixedly connected to a plug (523); the plug (523) is used to seal the regulating hole (521); when the sealing plug (519) completely seals the sealing plate (514), the plug (523) can seal the regulating hole (521).

2. The wafer flatness measurement device according to claim 1, characterized in that: A first conductive contact piece (524) is fixedly connected to the top of the sealing plate (514), and a second conductive contact piece (525) is fixedly connected to the bottom of the sealing plate (518). The second conductive contact piece (525) is arranged in a ring shape on the outer peripheral side of the sealing plug (519). When the sealing plug (519) completely seals the sealing plate (514), the second conductive contact piece (525) contacts the first conductive contact piece (524) and generates an electrical signal.

3. The wafer flatness measuring device according to claim 2, characterized in that: A positive pressure cavity (55) is provided inside the negative pressure suction cup (51), and each of the adsorption grooves (52) is provided with a positive pressure hole (56) which is connected to the inside of the positive pressure cavity (55); The circumferential outer wall of the negative pressure suction cup (51) is provided with two mounting holes (57) which are respectively connected to the positive pressure chamber (55) and the negative pressure chamber (53); a throttle valve (58) is installed in each of the two mounting holes (57); and the two throttle valves (58) are connected to an external air supply device.

4. The wafer flatness measuring device according to claim 3, characterized in that: The moving mechanism (2) comprises a first mounting plate (21) fixedly connected to the first main body (1); a Y-direction moving component (210) is arranged above the first mounting plate (21); an X-direction moving component (220) is arranged on the Y-direction moving component (210); and a Z-direction moving component (230) is arranged on the X-direction moving component (220), for adjusting the position of the fixing mechanism (5).

5. The wafer flatness measuring device according to claim 4, characterized in that: The Y-direction moving assembly (210) comprises a first support plate (211), and a first screw module (212) is arranged on the first support plate (211); The X-direction moving assembly (220) comprises a second support plate (221) arranged on the first screw module (212), a second screw module (222) being arranged on the second support plate (221), and a moving plate (223) being arranged on the second screw module (222); The Z-direction moving assembly (230) comprises a support member (231) fixedly connected to the top of the moving plate (223), a third screw module (232) is arranged in the support member (231), and the fixing mechanism (5) is mounted on the third screw module (232).

6. The wafer flatness measuring device according to claim 5, characterized in that: The measuring mechanism (3) comprises a support frame (31) fixedly connected to the first mounting plate (21), and a visual measuring device (32) for measuring the flatness of a wafer is arranged on the support frame (31).

7. The wafer flatness measurement device according to claim 6, characterized in that: The feeding device (4) comprises a second mounting plate (41) fixedly connected to the inside of the second body (11); a mechanical arm (42) for feeding the wafer to be tested is arranged on the second mounting plate (41); a feeding port (43) for the mechanical arm (42) to feed is provided between the first body (1) and the second body (11); and a placing rack (44) for placing the wafer to be tested is arranged on the outside of the second body (11).

8. The wafer flatness measurement device according to claim 7, characterized in that: The moving mechanism (2), the measuring mechanism (3) and the feeding device (4) are all electrically connected to a controller, and the controller is capable of receiving an electrical signal generated when the first conductive contact piece (524) contacts the second conductive contact piece (525).

9. A method for measuring the flatness of a wafer, wherein the method uses the wafer flatness measuring device according to claim 8 for measurement, characterized in that: The following steps are involved: S1, placing a tray containing wafers to be tested on a material placement rack (44); S2, starting the robotic arm (42), taking out the wafer to be tested through the robotic arm (42), and placing it on the negative pressure suction cup (51); S3, starting the external air supply device to adsorb and fix the wafer to be tested through the negative pressure suction cup (51); S4, the controller receives an electrical signal generated by the contact between the first conductive contact sheet (524) and the second conductive contact sheet (525), and determines the position of the wafer to be tested and sets a moving path through the electrical signal; S5, the controller controls the moving mechanism (2) to adjust the initial position of the wafer to be measured; S6, starting the visual measurement device (32), and controlling the moving mechanism (2) through the controller to drive the wafer to be measured along a set path for measurement.

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