Wafer lifting device and semiconductor processing device

Abstract

The invention provides a lifting device which comprises an ejector pin assembly installed in a wafer chuck in a lifting mode, the ejector pin assembly is provided with an outer ejector pin and an inner ejector pin, the inner ejector pin is elastically connected with the outer ejector pin, and the inner ejector pin is used for being grounded; the outer thimble has an abutting end, and the inner thimble has a contact end. The ejector pin assembly has a first state and a second state, in the first state of the ejector pin assembly, the contact end protrudes relative to the abutting end, the contact end is used for making contact with the wafer and desorbing, meanwhile, the inner ejector pin buffers impact generated when the inner ejector pin makes contact with the wafer through elastic connection with the outer ejector pin, and the abutting end and the wafer are arranged at intervals. Therefore, the risk of collision between the wafer and the inner ejector pin can be reduced; in the second state of the ejector pin assembly, the contact end is flush with the abutting end, the abutting end and the contact end are used for abutting against the wafer at the same time, the wafer is jacked up through the outer ejector pin, and therefore the risk that the wafer slides and is damaged due to uneven elastic force can be avoided.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor equipment, and in particular relates to a wafer lifting device and a semiconductor processing device. Background Art

[0002] During the semiconductor process, the wafer is usually electrostatically adsorbed by a wafer chuck; after the semiconductor process is completed, it is necessary to apply a reverse voltage to release the wafer from the adsorption of the wafer chuck. However, in the actual process, applying a reverse voltage often cannot completely eliminate the charge between the wafer and the wafer chuck. If there is a lot of residual charge, the wafer and the wafer chuck will stick together, that is, the wafer will stick to the surface of the wafer chuck, which will cause the wafer to collide with the wafer when the wafer lifting device lifts the wafer, which will cause the wafer to be broken and cause the process to fail.

[0003] At present, the relevant technology usually adopts a conductive ejector pin to eliminate the residual charge of the wafer. However, both the ejector pin and the wafer are rigid structures. If the rising distance of the ejector pin is insufficient, the ejector pin and the wafer will not be in close contact, which will greatly reduce the effect of charge elimination. If the rising distance of the ejector pin is too long, it is easy to collide with the wafer and cause damage to the wafer. Summary of the invention

[0004] The invention provides a wafer lifting device and a semiconductor processing device, aiming to solve the problem of hard contact between the existing ejector pin and the wafer.

[0005] The present invention provides a wafer lifting device for a wafer chuck, comprising:

[0006] An ejector pin assembly is lifted and disposed in the wafer chuck; the ejector pin assembly comprises an outer ejector pin and an inner ejector pin, the inner ejector pin is used for grounding and is elastically connected to the outer ejector pin; the outer ejector pin has an abutting end, and the inner ejector pin has a contact end;

[0007] The ejector pin assembly has a first state and a second state; when the ejector pin assembly is in the first state, the contact end protrudes relative to the abutting end, the contact end is used to contact and desorb the wafer, and at the same time, the inner ejector pin buffers the impact when contacting the wafer through the elastic connection with the outer ejector pin, and the abutting end is used to be spaced apart from the wafer; when the ejector pin assembly is in the second state, the contact end is flush with the abutting end, and the abutting end and the contact end are used to abut against the wafer at the same time to lift the wafer.

[0008] Optionally, the outer ejector pin has a guide channel axially extending to the abutting end; the inner ejector pin is movably inserted in the guide channel, and in a first state of the ejector pin assembly, the contact end at least partially extends out of the guide channel, and in a second state of the ejector pin assembly, the contact end retracts into the guide channel.

[0009] Optionally, the inner ejector has a first limiting portion, which is arranged away from the contact end; a second limiting portion is arranged in the guide channel, and the second limiting portion is used to abut against the first limiting portion when the first limiting portion reaches a preset limiting position to limit the inner ejector from separating from the outer ejector.

[0010] Optionally, the ejector pin assembly further includes an elastic member connected between the outer ejector pin and the inner ejector pin, for applying an elastic force to the inner ejector pin in the axial direction that is less than the weight of the wafer, so that when the distance between the wafer and the abutting end is within a preset range, the contact end remains in abutment with the wafer.

[0011] Optionally, when the ejector pin assembly is in the second state, the elastic force of the elastic member is less than the ratio of the wafer gravity to the product of a preset safety factor and the number of external ejectors; wherein the preset safety factor is greater than 1.

[0012] Optionally, the outer ejector pin includes:

[0013] A sleeve having a first sub-channel running through the sleeve; the top end of the sleeve is used as the abutment end, and the second limiting portion is located in the first sub-channel;

[0014] A mounting block is connected to the bottom end of the sleeve and inserted into the sleeve; a second sub-channel is provided inside the mounting block and slidingly cooperates with the inner ejector pin; the first sub-channel is connected with the second sub-channel to form the guide channel; and the elastic member is respectively abutted against the surfaces opposite to the mounting block and the first limiting portion.

[0015] Optionally, the mounting stopper is threadedly engaged with the inner wall of the sleeve so that the distance between the mounting stopper and the second limiting portion can be adjusted by rotating the mounting stopper.

[0016] Optionally, the wafer lifting device further includes:

[0017] A pin lift tray is arranged at the bottom of the ejector pin assembly; there are multiple ejector pin assemblies, and the pin lift tray is connected to multiple external ejector pins;

[0018] A driving device is connected to the pin lift tray; the driving device is used to drive all the pin assemblies to rise synchronously during the desorption phase of the wafer to switch to the first state, and continue to drive all the pin assemblies to rise synchronously after the desorption phase is completed to switch to the second state.

[0019] Optionally, the wafer lifting device further includes:

[0020] A detection device, electrically connected to the inner ejector pin, for detecting a current value of a current generated by releasing residual charge from the wafer;

[0021] A control device, respectively connected to the driving device and the detection device for communication; the control device controls the driving device to drive the ejector assembly to switch to the first state, so as to desorb the wafer;

[0022] The control device is also used to determine whether the current value reaches a preset release completion current value; if so, control the drive device to drive the ejector assembly to switch to the second state to lift the wafer.

[0023] As another technical solution, the present invention further provides a semiconductor processing device, which includes a wafer chuck and the wafer lifting device as described above;

[0024] The wafer chuck has a bearing surface for bearing the wafer; the wafer chuck is provided with a plurality of avoidance through holes; the ejector pin assembly of the wafer lifting device can be movably arranged in the avoidance through holes.

[0025] The present invention has the following beneficial effects:

[0026] The wafer lifting device provided by the embodiment of the present invention has an outer ejector pin and an inner ejector pin which are nested, and the inner ejector pin is elastically connected to the outer ejector pin; the outer ejector pin has an abutting end, and the inner ejector pin has a contacting end. Moreover, the ejector pin assembly has a first state and a second state. In the first state of the ejector pin assembly, the contacting end protrudes relative to the abutting end, and the contacting end is used to abut against the wafer, and the abutting end is used to be spaced apart from the wafer, so as to utilize the bottom end of the inner ejector pin to desorb the wafer, and the inner ejector pin can buffer the impact when contacting the wafer through the elastic connection with the outer ejector pin, thereby avoiding hard contact between the inner ejector pin and the wafer, thereby reducing the risk of damage to the wafer caused by collision between the wafer and the inner ejector pin. In the second state of the ejector pin assembly, the contact and abutting ends are flush, so that the structural strength of the outer ejector pin can be used to support the wafer, and the supporting force of the outer ejector pin on the wafer depends on the upward driving force of the ejector pin assembly, rather than the elastic force between the inner ejector pin and the outer ejector pin, thereby avoiding the risk of damage caused by sliding of the wafer due to uneven elastic force. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of a wafer chuck in the related art;

[0028] Figure 2 It is a structural schematic diagram of an ejector pin in the related art;

[0029] Figure 3 A schematic diagram of the structure of an ejector pin assembly provided in an embodiment of the present invention;

[0030] Figure 4 A schematic diagram of a working state of the ejector assembly provided by an embodiment of the present invention in a first state;

[0031] Figure 5 A schematic diagram of a working state of the ejector assembly provided by an embodiment of the present invention in a second state;

[0032] Figure 6 An exploded view of multiple ejector pin assemblies and a pin lift tray provided in an embodiment of the present invention;

[0033] Figure 7 A schematic structural diagram of a wafer lifting device in a semiconductor processing device provided by an embodiment of the present invention when the device is in a second state;

[0034] Figure 8 A schematic diagram of charge flow during a wafer desorption process when a wafer lifting device in a semiconductor processing device provided by an embodiment of the present invention is in a first state. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0036] It should be understood that the specific embodiments and drawings described herein are only used to explain the present invention rather than to limit the present invention.

[0037] It can be understood that, in the absence of conflict, the various embodiments of the present invention and the various features therein can be combined with each other.

[0038] It can be understood that, for the convenience of description, the drawings of the present invention only show the parts related to the embodiments of the present invention, while the parts unrelated to the embodiments of the present invention are not shown in the drawings.

[0039] It can be understood that, in the absence of conflict, the functions and steps marked in the flowcharts and block diagrams of the embodiments of the present invention may occur in an order different from that marked in the drawings.

[0040] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

[0041] like Figure 1 As shown, in the related art, a lift pin 01 is usually provided in the wafer chuck, so as to drive the wafer 02 on the carrying surface 04 to move up and down by making the lift pin 01 move up and down. In addition, the lift pin 01 in the related art is usually composed of a conductive inner core 011 and an insulating sleeve 012; specifically, as shown in FIG. Figure 2 As shown, the insulating sleeve 012 is fixed on the outer periphery of the conductive inner core 011 so that the top end of the conductive inner core 011 is exposed. After the process is completed, the wafer chuck stops adsorbing the wafer 02, and since there is a certain amount of static charge between the two, there is an electrostatic adsorption force between the two; in the process of desorbing the wafer 02, the driving device 03 drives the ejector pin 01 to rise, so that the driving device 03 contacts the surface of the wafer 02, so that the residual charge on the surface of the wafer 02 is introduced into the ground wire through the conductive inner core 011, until the static charge is completely eliminated, the ejector pin 01 can be controlled to continue to rise to make the wafer 02 separate from the carrying surface 04.

[0042] However, since both the wafer 02 and the ejector pin 01 are rigid parts, when the ejector pin 01 rises to the position against the wafer 02, the top of the ejector pin 01 and the wafer 02 are in rigid contact. It can be seen that in the related art, the impact force of the ejector pin 01 on the surface of the wafer 02 depends on the driving force of the driving device 03 on the ejector pin 01. The driving stroke of the driving device 03 is usually difficult to be accurately controlled. Specifically, if the stroke of the driving device 03 is lower than the ideal value, there is a risk of poor contact between the ejector pin 01 and the wafer 02, which leads to the inability to effectively remove the charge; if the running stroke of the driving device 03 is greater than the preset value, it will cause the stroke of the ejector pin 01 to overshoot, which will cause the ejector pin 01 to collide with the wafer 02, and then cause the wafer 02 to be damaged.

[0043] In order to solve the above technical problems, this embodiment provides a wafer lifting device for driving the wafer to lift. Figure 3 As shown, the wafer lifting device includes an ejector pin assembly 1, which is inserted into the wafer chuck in a liftable manner so as to lift and lower the wafer on the carrying surface. The ejector pin assembly 1 has an outer ejector pin 11 and an inner ejector pin 12; Figure 3 As shown, the inner ejector pin 12 is used for grounding, and the inner ejector pin 12 is elastically connected to the outer ejector pin 11 , the outer ejector pin 11 has an abutting end 111 ; the inner ejector pin 12 has a contact end 121 .

[0044] The ejector pin assembly 1 has a first state and a second state. Specifically, when the ejector pin assembly 1 is in the first state, the contact end 121 protrudes relative to the abutment end 111, and the contact end 121 is used to contact the wafer 2 to introduce the residual charge on the wafer 2 into the ground wire through the inner ejector pin 12, thereby desorbing the wafer 2. At the same time, the inner ejector pin 12 buffers the impact when contacting the wafer through the elastic connection with the outer ejector pin 11; and the abutment end 111 of the outer ejector pin 11 is used to be spaced from the wafer, that is, the outer ejector pin 11 does not contact the wafer 2. In this way, in the first state, only the inner ejector pin 12 abuts against the wafer 2. Therefore, the supporting force of the inner ejector pin 12 on the wafer 2 depends on the elastic force between the inner ejector pin 12 and the outer ejector pin 11, and does not depend on the upward driving force of the entire ejector pin assembly 1, so that hard contact between the inner ejector pin 12 and the wafer 2 can be avoided, thereby reducing the risk of damage to the wafer 2 caused by collision between the wafer 2 and the inner ejector pin 12 or the outer ejector pin 11.

[0045] When the ejector pin assembly 1 is in the second state, the contact end 121 of the inner ejector pin 12 is flush with the abutting end 111 of the outer ejector pin 11, and the abutting end 111 of the outer ejector pin 11 and the contact end 121 of the inner ejector pin 12 are used to abut against the wafer 2 at the same time to jointly lift the wafer 2; in this way, in the second state, the wafer 2 is mainly supported by the structural strength of the outer ejector pin 11, and the supporting force of the outer ejector pin 11 on the wafer 2 depends on the upward driving force of the ejector pin assembly 1, rather than the elastic force between the inner ejector pin 12 and the outer ejector pin 11, thereby avoiding the risk of the wafer 2 sliding and being damaged due to uneven elastic force of multiple ejector pins.

[0046] The elastically connected nested ejector pin assembly 1 proposed in this embodiment can realize elastic contact with the wafer 2 in the first state, and can buffer the impact force generated when contacting the wafer, so as to avoid the occurrence of "hard contact" between the ejector pin and the wafer as in the above-mentioned related art, thereby avoiding damage to the wafer 2. In addition, in the second state, the wafer 2 is supported by the outer ejector pin 11 to perform an ascending action, and the wafer 2 can be supported by the structural strength of the outer ejector pin 11 itself, thereby effectively avoiding the problem of uneven elastic force caused by the elastic connection between multiple groups of inner ejector pins 12 and outer ejector pins 11, thereby avoiding uneven force on the wafer 2 caused by uneven elastic force, and avoiding accidents such as slipping or fragments.

[0047] For example, the inner ejector pin 12 can be made of a material with good conductivity, such as aluminum alloy, graphite, etc. The outer ejector pin 11 can be made of a metal conductive material, such as aluminum alloy, which has good supporting strength, thereby providing a stable supporting force for the wafer.

[0048] In some embodiments, Figure 3As shown, the outer ejector pin 11 has a guide channel axially extending to the abutment end 111. The inner ejector pin 12 is movably inserted in the guide channel so that the inner ejector pin 12 can be extended and retracted relative to the guide channel; specifically, in the first state of the ejector pin assembly, the contact end 121 of the inner ejector pin 12 at least partially extends out of the guide channel, and in the second state of the ejector pin assembly, the contact end 121 is completely retracted into the guide channel. It should be noted that in the first state, the length of the inner ejector pin 12 extending out of the guide channel is equal to the distance between the wafer 2 and the abutment end 111, so as to ensure that the inner ejector pin 12 is in contact with the wafer 2.

[0049] In some specific embodiments, Figure 3 As shown, the inner ejector pin 12 has a first limiting portion 123, and the first limiting portion 123 is arranged away from the contact end; specifically, as Figure 3 As shown, the first limiting portion 123 is arranged on the inner ejector body 122. The guide channel is provided with a second limiting portion 113; the second limiting portion 113 is used to abut against the first limiting portion 123 when the first limiting portion 123 reaches a preset limiting position, so as to limit the inner ejector 12 from being disengaged, so that the inner ejector 12 is always movably connected with the outer ejector 11, and will not be disengaged from the ejection port of the outer ejector 11.

[0050] In some embodiments, the ejector pin assembly 1 further includes an elastic member 3, which abuts between the outer ejector pin 11 and the first limiting portion 123 to elastically connect the inner ejector pin 12 with the outer ejector pin 11. In addition, the elastic member 3 is used to apply an elastic force along the axial direction and less than the gravity of the wafer 2 to the inner ejector pin 12, so that when the distance between the wafer 2 and the abutting end 111 of the outer ejector pin 11 is within a preset range, the contact end 121 maintains abutment with the wafer 2.

[0051] Specifically, Figure 4As shown, in the desorption stage of the wafer 2, the wafer 2 is continuously adsorbed on the carrying surface of the wafer chuck due to the residual charge. Accordingly, the wafer 2 is continuously subjected to the adsorption force and the supporting force from the carrying surface and the gravity. In this stage, the ejector pin assembly 1 can be in the first state, so that the inner ejector pin 12 supports the wafer 2 and the outer ejector pin 11 does not support the wafer 2. In this state, the external forces on the inner ejector pin 12 are: the supporting force from the elastic member 3 and the pressure from the wafer 2. Accordingly, the supporting force of the inner ejector pin 12 on the wafer 2 is determined by the compression amount of the elastic member 3. Therefore, the compression amount of the elastic member 3 depends on the retraction amount of the inner ejector pin 12 relative to the outer ejector pin 11. Since the position of the inner ejector pin 12 is fixed after the top end of the inner ejector pin 12 contacts the wafer 2, the above-mentioned retraction amount depends on the distance between the outer ejector pin 11 and the wafer 2, that is, the rising stroke of the outer ejector pin 11. In the first state, the inner ejector pin 12 remains extended and abuts against the wafer 2. Therefore, the rising stroke of the outer ejector pin 11 is sufficient not to contact the wafer 2, that is, it is within the preset range. Accordingly, as long as the driving amount of the driving component used to drive the outer ejector pin 11 to rise is within the preset range, it can be ensured that the outer ejector pin 11 will not contact the wafer 2. In this way, while ensuring that the inner ejector pin 12 is in close contact with the wafer 2 and preventing the outer ejector pin 11 from having a hard contact with the wafer 2, the ejector pin assembly 1 proposed in this embodiment has a lower driving accuracy requirement for the driving component, and can prevent the outer ejector pin 11 from having a hard contact with the wafer 2 and causing damage to the wafer 2 while grounding the wafer 2. Figure 5 As shown, after the wafer 2 is desorbed, the residual charge between the wafer 2 and the carrying surface has been completely conducted away, so the wafer 2 is no longer subjected to the adsorption force from the carrying surface of the wafer chuck, and accordingly, the wafer 2 is continuously subjected to gravity and the support force from the inner ejector pin 12; and because the elastic force applied by the elastic member 3 to the inner ejector pin 12 is less than the gravity of the wafer 2, even if the wafer 2 is no longer subjected to the adsorption force, it will not be lifted up by the inner ejector pin 12, but will remain on the carrying surface until the outer ejector pin 11 rises to the position where the abutment end 111 abuts against the wafer 2. It is well known to those skilled in the art that the relationship between the compression amount and the elastic force of the elastic member 3 is usually difficult to accurately control, so the elastic forces generated by different elastic members 3 after shortening the same compression amount may not be the same, so if the wafer 2 is supported by multiple inner ejector pins 12, the wafer 2 may be subjected to uneven force due to the inconsistent compression amounts of the multiple elastic members 3, which may cause problems such as wafer 2 slipping or fragmentation. In the present embodiment, after the desorption of the wafer 2 is completed, the wafer 2 is no longer lifted by the inner ejector pins 12, but is only supported by the outer ejector pins 11, so that the structural strength of the outer ejector pins 11 themselves can be utilized to stably support the wafer 2, thereby avoiding the problem of uneven force on the wafer 2 caused by inconsistent compression of the elastic member 3, thereby avoiding accidents such as slippage or fragmentation.

[0052] Exemplarily, the maximum length of the inner ejector pin 12 extending out of the guide channel may be in the range of 2 mm to 4 mm.

[0053] In some specific embodiments, when the ejector pin assembly is in the second state, the elastic force of the elastic member 3 is less than the ratio between the weight of the wafer 2 and the product of the preset safety factor and the number of the external ejector pins 11; that is, the elastic member 3 satisfies the following formula:

[0054]

[0055] Among them, F1 is the elastic force of the elastic member 3; G1 is the self-weight of the wafer 2; k is the preset safety factor; n is the number of the outer ejector pins 11, that is, the number of the ejector pin assembly 1. Among them, the preset safety factor k is greater than 1. The position of the ejector pin assembly 1 in the second state is the position where the inner ejector pin 12 retracts to be flush with the abutment end 111 of the outer ejector pin 11, that is, the position where the elastic force of the elastic member 3 is the largest. Therefore, the preset safety factor k is greater than 1 to ensure that after the adsorption force between the wafer 2 and the wafer chuck completely disappears, the inner ejector pin 12 will not lift the wafer 2, thereby preventing the wafer 2 from being lifted and then falling and colliding with the ejector pin assembly 1 and being damaged.

[0056] For example, the preset safety factor k may be 1.5. For example, when the weight of the wafer 2 is 1.5N and the number of ejector pin assemblies 1 is 3, the maximum elastic force of the elastic member 3 should be less than 0.33N.

[0057] Exemplarily, the elastic member 3 may be a compression spring.

[0058] Exemplarily, the elastic member 3 is sleeved on the outer circumference of the inner ejector body 122, so that the elastic member 3 can move linearly along the inner ejector body 122, thereby preventing the spring from bending during the compression process, so as to improve the service life of the elastic member 3. In addition, when the elastic member 3 abuts between the first limit portion 123 and the outer ejector 11, the elastic member 3 remains in a compressed state to continuously provide an upward elastic force to the inner ejector 12, so that the inner ejector 12 always has an upward movement trend, thereby promoting the contact between the inner ejector 12 and the wafer 2.

[0059] Exemplarily, the gap between the outer periphery of the inner ejector body 122 and the elastic member 3 may be in the range of 0.2 mm to 0.4 mm. Within this range, the elastic member 3 can be ensured to extend straight along the inner ejector 12 and the friction between the elastic member 3 and the inner ejector 12 can be reduced.

[0060] In some specific embodiments, the outer ejector pin 11 includes a sleeve and a mounting block 114. The sleeve has a first sub-channel that is arranged through the inside to form a guide channel, and the second limiting portion 113 is located in the first sub-channel; and the top of the sleeve is used as the abutment end 111 to abut against the wafer 2. The mounting block 114 is connected to the bottom end of the sleeve and inserted into the sleeve; the mounting block 114 is provided with a second sub-channel 1141 that is slidably matched with the inner ejector pin 12, and the first sub-channel and the second sub-channel 1141 are connected to form the above-mentioned guide channel; the elastic member 3 is respectively abutted against the surfaces opposite to the mounting block 114 and the first limiting portion 123, so as to install the elastic member 3 in the first sub-channel and limit the elastic member 3.

[0061] Exemplarily, the diameter of the installation stopper 114 may be 1.5 mm to 3 mm larger than the diameter of the inner ejector pin 12 , so as to protrude relative to the outer periphery of the inner ejector pin 12 , thereby abutting against the elastic member 3 .

[0062] For example, the inner ejector pin 12 is generally in the shape of an elongated strip with a length much greater than its diameter. Specifically, the length of the inner ejector pin 12 may range from 40 mm to 60 mm, and the diameter of the inner ejector pin 12 may range from 2 mm to 4 mm; accordingly, the gap between the inner periphery of the guide channel and the outer periphery of the inner ejector pin 12 may range from 0.5 mm to 0.8 mm. Within this range, the inner ejector pin 12 may be prevented from excessively tilting inside the guide channel, which may cause the inner ejector pin 12 to slide unsmoothly relative to the guide channel.

[0063] Exemplarily, the gap between the inner periphery of the second sub-channel 1141 and the outer periphery of the inner ejector pin 12 may be in the range of 0.15-0.3 mm. Within this range, the second sub-channel 1141 may guide the inner ejector pin 12 so that the inner ejector pin 12 may extend coaxially with the outer ejector pin 11 as much as possible.

[0064] Exemplarily, the roughness of the inner circumference of the second sub-channel 1141 and the outer circumference of the inner ejector pin 12 may be less than Ra0.8 to prevent the inner ejector pin 12 and the second sub-channel 1141 from being scratched and generating metal particles, thereby avoiding pollution to the process environment.

[0065] Exemplarily, the wall thickness of the sleeve may be in the range of 0.5 mm to 1 mm. Within this range, the sleeve has high supporting strength and bending strength, and its weight and volume are not too large to cause excessive driving force required for the lifting action.

[0066] In some embodiments, the mounting block 114 is threadedly engaged with the inner wall of the sleeve so that the distance between the mounting block 114 and the second limiting portion 113 can be adjusted by rotating the mounting block 114, thereby adjusting the compression amount of the elastic member 3 so that the elastic force of the elastic member 3 adapts to the process requirements.

[0067] Specifically, during the actual installation process, Figure 6 As shown, the inner ejector pin 12 can be inserted into the sleeve first, and then the elastic member 3 can be sleeved on the outer periphery of the inner ejector pin 12 from the bottom end of the inner ejector pin 12, and then the second sub-channel 1141 in the mounting block 114 can be aligned with the inner ejector pin 12, and then the mounting block 114 can be installed in the sleeve by rotating the mounting block 114. In the debugging stage after the installation is completed, the compression amount of the corresponding elastic member 3 can be adjusted by rotating the mounting block 114. Specifically, the mounting blocks 114 of multiple ejector pin assemblies 1 need to be adjusted so that the difference in elastic force of the elastic members 3 of the multiple ejector pin assemblies 1 is within a preset error range. Exemplarily, the difference in elastic force of the elastic member 3 can be ±0.02N.

[0068] In some embodiments, Figure 7 As shown, the wafer lifting device also includes a lifting pin tray 4 and a driving device 5. Moreover, there are multiple ejector pin assemblies 1. The lifting pin tray 4 is arranged on the bottom wafer chuck 9 bearing surface 91 of the multiple ejector pin assemblies 1, that is, the lifting pin tray 4 is arranged below the wafer chuck 9. Figure 8 As shown, the needle lift tray 4 is connected to a plurality of external ejector pins 11 , and the driving device 5 is drivingly connected to the needle lift tray 4 , so that the needle lift tray 4 is used to synchronously lift and lower a plurality of ejector pin assemblies 1 .

[0069] like Figure 4 As shown, the driving device 5 is used to drive all the ejector pin assemblies 1 to rise synchronously to the first state during the desorption stage of the wafer 2, so that all the inner ejector pins 12 abut against the wafer 2, thereby introducing the residual charge on the wafer 2 into the ground line; Figure 5 As shown, the driving device 5 is also used to continue to drive all ejector pin assemblies 1 to rise synchronously to the second state after the desorption stage is completed, so that all external ejector pins 11 abut against the wafer 2 to push the wafer 2 to rise.

[0070] Exemplarily, the mounting block 114 may be made of conductive materials such as stainless steel.

[0071] For example, Figure 4 and Figure 5 As shown, the mounting block 114 is fixedly connected to the pin lift tray 4 so that the ejector assembly 1 is integrally mounted on the pin lift tray 4 .

[0072] Please refer to Figure 8 In the desorption stage of the wafer 2, the extraction path of the residual charge is as follows: the residual charge enters the inner ejector pin 12, and then enters the lift pin tray 4 through the mounting block 114, and then enters the power output shaft 51 of the driving device 5 connected to the lift pin tray 4, and then enters the interface disk 7 through the mounting bracket 6, so as to be electrically connected to the process chamber wall 8 through the interface disk 7, and finally grounded through the process chamber wall 8.

[0073] In some embodiments, the wafer lifting device further includes a detection device and a control device (not shown in the figure). The detection device is electrically connected to the inner ejector pin 12 and is used to detect the current value of the current generated by releasing the residual charge of the wafer 2.

[0074] The control device is communicatively connected with the driving device 5 and the detection device respectively; the control device controls the driving device 5 to drive the ejector pin assembly 1 to rise so as to switch to the first state, thereby desorbing the wafer 2; the control device is also used to determine whether the current value reaches a preset release completion current value; if so, it means that the residual charge on the wafer 2 has been released, and the control device controls the driving device 5 to drive the ejector pin assembly 1 to rise so as to switch to the second state, thereby using the external ejector pin 11 to lift the wafer 2.

[0075] Exemplarily, the preset release completion current value may be 0 to ensure that after the residual charge is completely released and the adsorption force on the wafer 2 completely disappears, the ejector pin assembly 1 is controlled to rise, thereby preventing the outer ejector pin 11 from colliding with the wafer 2 .

[0076] As another technical solution, this embodiment also provides a semiconductor processing device, which includes a wafer chuck 9 and the wafer lifting device as described above. Figure 7 and Figure 8 As shown, the wafer chuck 9 has a carrying surface 91 for carrying the wafer; a plurality of avoidance through holes 92 are provided on the carrying surface 91; and the ejector pin assembly of the wafer lifting device can be movably disposed in the avoidance through holes 92.

[0077] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A wafer lifting device, characterized in that: include: An ejector pin assembly is lifted and disposed in the wafer chuck; the ejector pin assembly comprises an outer ejector pin and an inner ejector pin, the inner ejector pin is used for grounding and is elastically connected to the outer ejector pin; the outer ejector pin has an abutting end, and the inner ejector pin has a contact end; The ejector pin assembly has a first state and a second state; in the first state of the ejector pin assembly, the contact end protrudes relative to the abutting end, the contact end is used to contact and desorb the wafer, and at the same time, the inner ejector pin buffers the impact when contacting the wafer through the elastic connection with the outer ejector pin, and the abutting end is used to be spaced apart from the wafer; in the second state of the ejector pin assembly, the contact end is flush with the abutting end, and the abutting end and the contact end are used to abut against the wafer at the same time to lift the wafer.

2. The wafer lifting device according to claim 1, characterized in that: The outer ejector pin has a guide channel axially extending to the abutting end; the inner ejector pin is movably inserted in the guide channel, and in the first state of the ejector pin assembly, the contact end at least partially extends out of the guide channel, and in the second state of the ejector pin assembly, the contact end retracts into the guide channel.

3. The wafer lifting device according to claim 2, characterized in that: The inner ejector pin has a first limiting portion, which is arranged away from the contact end; a second limiting portion is arranged in the guide channel, and the second limiting portion is used to abut against the first limiting portion when the first limiting portion reaches a preset limiting position, so as to limit the inner ejector pin from being separated from the outer ejector pin.

4. The wafer lifting device according to claim 3, characterized in that: The ejector pin assembly further comprises: An elastic member is abutted between the first limiting portion and the outer ejector pin, and is used to apply an elastic force along the axial direction and less than the weight of the wafer to the inner ejector pin, so that when the distance between the wafer and the abutting end is within a preset range, the contact end and the wafer remain in abutment.

5. The wafer lifting device according to claim 4, characterized in that: In the second state of the ejector pin assembly, the elastic force of the elastic member is less than the ratio of the wafer weight to the product of a preset safety factor and the number of external ejectors; wherein the preset safety factor is greater than 1.

6. The wafer lifting device according to claim 4, characterized in that: The outer ejector pin comprises: A sleeve having a first sub-channel axially penetrating therein; the top end of the sleeve is used as the abutment end, and the second limiting portion is located in the first sub-channel; A mounting block is connected to the bottom end of the sleeve and inserted into the sleeve; a second sub-channel that slidably cooperates with the inner ejector pin is provided inside the mounting block, and the first sub-channel is connected to the second sub-channel to form the guide channel; the elastic member is respectively abutted against the surfaces opposite to the mounting block and the first limiting portion.

7. The wafer lifting device according to claim 6, characterized in that: The installation stopper is threadedly matched with the inner wall of the sleeve, so that the distance between the installation stopper and the second limiting portion can be adjusted by rotating the installation stopper.

8. The wafer lifting device according to claim 1, characterized in that: Also includes: A pin lift tray is arranged at the bottom of the ejector pin assembly; there are multiple ejector pin assemblies, and the pin lift tray is connected to multiple external ejector pins; A driving device is connected to the pin lift tray; the driving device is used to drive all the pin assemblies to rise synchronously during the desorption phase of the wafer to switch to the first state, and continue to drive all the pin assemblies to rise synchronously after the desorption phase is completed to switch to the second state.

9. The wafer lifting device according to claim 8, characterized in that: Also includes: A detection device, electrically connected to the inner ejector pin, for detecting a current value of a current generated by releasing residual charge from the wafer; A control device, respectively connected to the driving device and the detection device for communication; the control device controls the driving device to drive the ejector assembly to switch to the first state, so as to desorb the wafer; The control device is also used to determine whether the current value reaches a preset release completion current value; if so, control the drive device to drive the ejector assembly to switch to the second state to lift the wafer.

10. A semiconductor processing device, characterized in that: It comprises a wafer chuck and a wafer lifting device as claimed in any one of claims 1 to 9; The wafer chuck has a bearing surface for bearing the wafer; the wafer chuck is provided with a plurality of avoidance through holes; the ejector pin assembly of the wafer lifting device can be movably arranged in the avoidance through holes.

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