Wafer post-processing device, back scrubbing equipment, method and processing equipment

Abstract

The invention provides a wafer post-processing device, back scrubbing equipment, a method and processing equipment. The wafer post-processing device comprises a scrubbing assembly, a supporting assembly and a clamping assembly, the scrubbing assembly comprises a scrubbing arm, a scrubbing head and a scrubbing pad, and the scrubbing pad is mounted on the scrubbing head; the supporting assembly comprises a supporting arm and a supporting head, and a plurality of supporting fluid spraying holes are distributed in the surface of the supporting head; when a wafer is processed, the clamping assembly clamps and drives the wafer to rotate, the wafer is located between the scrubbing pad and the supporting head, a gap is formed between the surface of the supporting head and the front face of the wafer, the scrubbing pad is attached to the back face of the wafer through scrubbing pressure and rotates, and the scrubbing head and the supporting head swing in a reciprocating mode and always keep aligned in the swing process. The scrubbing fluid channel supplies scrubbing fluid to the back face of the wafer, and the supporting fluid spraying holes continuously spray supporting fluid to the front face of the wafer, so that the surface of the supporting head does not make contact with the front face of the wafer; therefore, pollutants on the back surface of the wafer are removed while the front surface of the wafer is not damaged.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical mechanical polishing and is used for processing semiconductor chips. Specifically, it relates to a wafer post-processing device, a backside scrubbing device, a method, and a processing device. Background Art

[0002] Chemical mechanical polishing (CMP) equipment is currently the only equipment that can achieve global planarization of the surface of semiconductor wafers. As the process nodes of integrated circuits continue to improve, the number of CMP process steps in the entire manufacturing process is increasing, and the polishing requirements for different wafer types are also diverse.

[0003] After passing through the CMP equipment, the front side of the wafer undergoes processing processes such as polishing and cleaning, so that the roughness and particulate matter on the front side of the wafer meet the requirements of subsequent processes. However, due to possible contamination on the back side of the wafer before polishing, when polishing the front side of the wafer, the pressure applied to the back side of the wafer makes the contamination adhere more closely to the back side of the wafer, resulting in ineffective removal during subsequent cleaning, thereby affecting subsequent processes. Summary of the Invention

[0004] In view of this, the present invention provides a wafer post-processing device, a backside scrubbing device, a method, and a processing device, thereby solving or at least alleviating one or more of the above problems and other problems existing in the prior art.

[0005] A first aspect of the present invention provides a wafer post-processing device, including: a scrubbing assembly, a support assembly, and a clamping assembly; The scrubbing assembly includes a scrubbing arm, a scrubbing head, a scrubbing pad, and a scrubbing fluid channel, and the scrubbing pad is installed on the scrubbing head; The support assembly includes a support arm and a support head, and the surface of the support head has a plurality of support fluid spray holes; When processing a wafer, the clamping assembly clamps and drives the wafer to rotate, the wafer is located between the scrubbing pad and the support head, and there is a gap between the surface of the support head and the front side of the wafer, the scrubbing pad fits against the back side of the wafer with a scrubbing pressure and rotates under the drive of the scrubbing head, and the scrubbing fluid channel supplies scrubbing fluid to the back side of the wafer, the scrubbing head and the support head reciprocally swing and always maintain alignment during the swinging process, and the support fluid spray holes continuously spray the support fluid onto the front side of the wafer so that the surface of the support head does not contact the front side of the wafer; Thereby, while not damaging the front side of the wafer, the contaminants on the back side of the wafer are removed.

[0006] Optionally, the wafer post-processing device further includes a dressing component for dressing the scrubbing pad. The dressing component is arranged on the dressing swing path of the scrubbing head, and the scrubbing head moves along the dressing swing path to the dressing component; The dressing swing path does not overlap with the scrubbing swing path when the scrubbing head processes the wafer, so as to prevent contaminants generated during wafer processing from splashing onto the dressing component.

[0007] Optionally, the scrubbing component further includes a rotating and lifting element. The rotating and lifting element is connected to one end of the lower surface of the scrubbing arm, and the scrubbing head is arranged at the other end of the lower surface of the scrubbing arm; The rotating and lifting element is used to make the scrubbing arm drive the scrubbing head to swing and lift, and adjust the scrubbing pressure by lifting the scrubbing head; When processing the wafer, the scrubbing head reciprocally swings between the wafer center and the wafer edge, and adjusts the scrubbing pressure according to the position of the scrubbing head, so as to cause the wafer to deform.

[0008] Optionally, adjusting the scrubbing pressure according to the position of the scrubbing head includes: When the scrubbing head is located at the wafer center, adjust the scrubbing pressure so that the wafer center has an upward warp of 0° to 2° relative to the wafer edge, thereby guiding contaminants to flow along the arc surface formed by the upward warp to the wafer edge; and / or, When the scrubbing head is located at the wafer edge, adjust the scrubbing pressure so that the wafer is horizontal to prevent the clamping component from slipping.

[0009] Optionally, the support component further includes a rotating element coaxially arranged with the rotating and lifting element. The rotating element is connected to one end of the upper surface of the support arm, and the support head is arranged at the other end of the upper surface of the support arm; The rotating and lifting element includes a rotating motor and a coupling mechanism. The coupling mechanism drives the rotating and lifting element and the rotating element to rotate synchronously when the rotating motor rotates through coupling, and the coupling mechanism drives only the rotating and lifting element to rotate when the rotating motor rotates through decoupling.

[0010] Optionally, the clamping component includes four clamping elements evenly distributed at intervals, wherein, The first clamping element and the second clamping element are respectively installed at both ends of the first connection mechanism. The first connection mechanism and the first clamping element are located between the scrubbing arm and the support arm in the vertical direction to avoid interference with the swinging support arm; The third clamping element and the fourth clamping element are respectively installed at both ends of the second connection mechanism; The line connecting the first clamping element and the second clamping element is parallel to the line connecting the third clamping element and the fourth clamping element; The first connecting mechanism and the second connecting mechanism move relative to each other in the horizontal direction so that the four clamping elements approach or move away from each other, thereby clamping the wafer when approaching and releasing the wafer when moving away.

[0011] Optionally, the first connecting mechanism is a U-shaped plate member with an opening facing the wafer; The first clamping element and the second clamping element are respectively installed at two ends of the upper surface of the first connecting mechanism, and in the horizontal projection, the first clamping element overlaps with the swing path of the support arm, and the second clamping element does not overlap with the swing path of the support arm; The connecting mechanism support element is connected to the lower surface of the first connecting mechanism to support the first connecting mechanism, and the connecting mechanism support element is opposite to the second clamping element.

[0012] Optionally, the connecting mechanism support element can drive the first connecting structure to move horizontally relative to the second connecting structure and drive the second clamping element to rotate; The scrubbing head reciprocally swings between the center of the wafer and the second clamping element.

[0013] Optionally, the scrubbing assembly further includes a scrubbing head rotating shaft, and the scrubbing fluid channel sequentially penetrates through the scrubbing arm, the scrubbing head rotating shaft, the scrubbing head and the scrubbing pad to supply polishing fluid or cleaning fluid or pure water to the back surface of the wafer.

[0014] Optionally, the support assembly further includes a support head support shaft and a support fluid channel, and the support fluid channel sequentially penetrates through the support arm, the support head support shaft and the support head and communicates with the support fluid spray holes to supply chemical liquid and / or pure water to the support fluid spray holes.

[0015] Optionally, the surface of the support head is circular, and the width of the gap between the surface of the support head and the front surface of the wafer is 0.3 to 2 mm.

[0016] Optionally, an annular guiding portion is arranged along the circumference at the edge of the surface of the support head, the guiding portion is made of a flexible material, and the distance between the upper edge of the guiding portion and the front surface of the wafer is 0.1 to 1 mm; The guiding portion protrudes upward and outward in an arc shape from the edge of the surface of the support head and recovers inward at the end so that the support fluid forms a support fluid film on the front surface of the wafer.

[0017] Optionally, the wafer post-processing device further includes a support fluid pressure control component for controlling the flow rate and / or pressure of the supplied support fluid so that the supporting force of the support fluid on the front side of the wafer is consistent with the scrubbing pressure when the scrubbing head is located at the edge of the wafer.

[0018] Optionally, the wafer post-processing device further includes a liquid supply component, and the liquid supply component includes a cleaning liquid nozzle and a pure water nozzle for supplying cleaning liquid or pure water to the back side of the wafer.

[0019] Optionally, the dressing component includes a dressing table, a dressing member, and a dressing member cleaner; The dressing table is rotatable, and the dressing member is mounted on the upper surface of the dressing table for contacting and dressing the scrubbing pad when the scrubbing head swings from the clamping component above the dressing table; The dressing member cleaner is used for cleaning the dressing member after dressing the scrubbing pad.

[0020] Optionally, the wafer post-processing device further includes a cleaning component, and the cleaning component is arranged on the swinging path of the scrubbing head between the clamping component and the dressing component, and the cleaning component is used for spraying cleaning liquid or pure water to clean the scrubbing pad after dressing.

[0021] A second aspect of the present invention provides a wafer backside scrubbing device, including: a scrubbing component, a support component, and a clamping component; The scrubbing component includes a scrubbing arm, a scrubbing head, and a scrubbing pad. The scrubbing head is arranged on the scrubbing arm, the scrubbing pad is arranged on the scrubbing head, and the scrubbing head drives the scrubbing pad to rotate; The support component includes a support arm and a support head. The support head is arranged on the support arm, and a plurality of support fluid spray holes are distributed on the surface of the support head; When processing a wafer, the clamping component clamps and drives the wafer to rotate. The wafer is located between the scrubbing pad and the support head. The scrubbing pad fits against the back side of the wafer with a scrubbing pressure. There is a gap between the support head and the front side of the wafer. The scrubbing arm and the support arm swing, and during the swinging process, the scrubbing head and the support head are always opposite to each other. The support fluid spray holes continuously spray support fluid onto the front side of the wafer, and the scrubbing pressure is not greater than the supporting force of the fluid on the front side of the wafer.

[0022] A third aspect of the present invention provides a wafer backside scrubbing method for scrubbing the back side of a wafer using the wafer post-processing device as described in the first aspect or the wafer backside scrubbing device as described in the second aspect, including: Transfer the wafer to the clamping component and control the clamping component to clamp the wafer; Control the scrubbing arm to swing so that the scrubbing head is above the center of the wafer, and the support head is below the center of the wafer and opposite to the scrubbing head; Control the scrubbing arm to descend until the scrubbing pad fits against the back of the wafer, and at the same time control the support fluid to eject from the support fluid ejection holes; Supply the scrubbing fluid to the back of the wafer, and at the same time control the scrubbing arm and the support arm to swing reciprocally synchronously, control the scrubbing head to rotate, and control the clamping assembly to drive the wafer to rotate.

[0023] Optionally, the method for scrubbing the back of the wafer further includes: Control the scrubbing pressure so that when the scrubbing head is at the center of the wafer, the center of the wafer has an upward warpage of 0° to 2° relative to the edge of the wafer to prevent contaminants generated during scrubbing from accumulating on the back of the wafer; and / or, Make the wafer horizontal when the scrubbing head is at the edge of the wafer to prevent the clamping assembly from slipping.

[0024] Optionally, the method for scrubbing the back of the wafer further includes: When the scrubbing pressure when the scrubbing head is at the edge of the wafer changes with the use of the scrubbing pad, control the flow rate and / or pressure of the support fluid supplied so that the supporting force of the support fluid on the front of the wafer is consistent with the scrubbing pressure when the scrubbing head is at the edge of the wafer.

[0025] Optionally, supplying the scrubbing fluid to the back of the wafer includes: Supply polishing liquid to the back of the wafer through the scrubbing fluid channel; Stop supplying polishing liquid, and supply cleaning liquid to the back of the wafer through the scrubbing fluid channel and the cleaning liquid nozzle; Stop supplying cleaning liquid, and supply pure water to the back of the wafer through the scrubbing fluid channel and the pure water nozzle; Stop supplying pure water to the back of the wafer through the scrubbing fluid channel; Stop supplying pure water to the back of the wafer through the pure water nozzle.

[0026] Optionally, supplying the scrubbing fluid to the back of the wafer includes: Supply cleaning liquid to the back of the wafer through the scrubbing fluid channel and the cleaning liquid nozzle; Stop supplying cleaning liquid, and supply pure water to the back of the wafer through the scrubbing fluid channel and the pure water nozzle; Stop supplying pure water to the back of the wafer through the scrubbing fluid channel; Stop supplying pure water to the back of the wafer through the pure water nozzle.

[0027] Optionally, the backside scrubbing method of the wafer further includes a trimming step for trimming the scrubbing pad, including: Controlling the scrubbing arm to rise and swing until the scrubbing head is above the trimming table; Controlling the scrubbing arm to descend until the scrubbing pad fits against the trimming member; Supplying at least one of polishing liquid, cleaning liquid, and pure water to the surface of the trimming member, controlling the scrubbing arm to reciprocally swing, and controlling the scrubbing head and the trimming table to rotate.

[0028] Optionally, controlling the scrubbing arm to rise and swing until the scrubbing head is above the trimming table includes: Controlling the scrubbing arm and the support arm to stop swinging when located at the center of the wafer; Controlling the scrubbing head to stop rotating and controlling the clamping assembly to stop driving the wafer to rotate; While controlling the scrubbing arm to rise, controlling the support fluid to stop spraying from the support fluid spray holes; Controlling the coupling mechanism to decouple; Controlling the scrubbing arm to swing until the scrubbing head is above the trimming table.

[0029] Optionally, the backside scrubbing method of the wafer further includes a cleaning step for cleaning the scrubbing pad after trimming, including: Controlling the scrubbing arm to rise and swing until the scrubbing head is above the cleaning assembly; Controlling the cleaning assembly to spray cleaning liquid or pure water and controlling the scrubbing head to rotate.

[0030] Optionally, after the cleaning step, keeping the scrubbing arm stationary, transferring the next wafer to the clamping assembly, and controlling the clamping assembly to clamp the next wafer.

[0031] Optionally, controlling the support fluid to spray from the support fluid spray holes includes: controlling pure water and / or protective liquid to spray from the support fluid spray holes according to the surface film layer property of the front side of the wafer A fourth aspect of the present invention provides a wafer processing apparatus, including a controller and the wafer post-processing device as described in the first aspect, where the controller is configured to control the wafer post-processing device to execute the backside scrubbing method of the wafer as described in the second aspect.

[0032] The present invention has the following technical effects: According to the wafer post-processing device, the back scrubbing method and the processing equipment, deep residues and chemical bonding residues on the back of the wafer can be effectively removed by the scrubbing pad, and microscopic defects on the back of the wafer can be repaired, improving the surface quality of the back of the wafer. At the same time, by supporting the wafer in a non-contact manner, damage to the front of the wafer can be effectively avoided, and a fluid protection film can be formed on the front of the wafer, reducing the cleaning difficulty in subsequent processes. Finally, wafers with flatness and cleanliness on both the front and back surfaces meeting the requirements of subsequent processes can be produced, thereby improving the yield of chip manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the embodiments of the present invention, and those of ordinary skill in the art can also obtain other drawings based on these drawings.

[0034] Figure 1 is a schematic structural diagram of a polishing unit.

[0035] Figure 2 is a schematic structural diagram of an embodiment of the wafer post-processing device of the present invention.

[0036] Figure 3 is Figure 2 a schematic structural diagram of an embodiment of the support assembly of the wafer post-processing device in

[0037] Figure 4 is Figure 2 a schematic cross-sectional diagram of an embodiment of the scrubbing assembly and the support assembly of the wafer post-processing device in

[0038] Figure 5 is a schematic structural diagram of an embodiment of the wafer post-processing device of the present invention.

[0039] Figure 6 is a schematic structural diagram of an embodiment of the wafer post-processing device of the present invention.

[0040] Figure 7 is a schematic flow diagram of the wafer back scrubbing method of the present invention.

[0041] Figure 8 is a schematic structural diagram of an embodiment of the wafer processing equipment of the present invention.

[0042] Reference numerals: Scrubbing assembly 1; Scrubbing arm 11; Scrubbing head 12; Scrubbing pad 13; Rotary lifting element 14; Scrubbing fluid channel 15; Scrubbing head rotating shaft 16; Scrubbing pressure control element 17; Support component 2; Support arm 21; Support head 22; Support fluid nozzle 221; Flow guiding part 222; Rotating element 24; Support fluid channel 25; Support head support shaft 26; Fluid control component 27; Clamping component 3; Clamping element 31; First clamping element 311; Second clamping element 312; Third clamping element 313; Fourth clamping element 314; First connecting mechanism 32; Second connecting mechanism 33; Connecting mechanism support element 34; Cleaning component 4; Liquid supply component 5; Cleaning liquid nozzle 51; Pure water nozzle 52; Trimming component 6; Trimming table 61; Trimming part 62; Trimming part cleaner 63; Polishing head 10; Polishing pad 20; Polishing disc 30; Polishing liquid supply device 40; Wafer post-processing device 100; Controller 200; Wafer processing equipment 1000. Detailed implementation manners

[0043] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art shall fall within the protection scope of the embodiments of the present invention.

[0044] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0045] In addition, in the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the communication inside two elements. It can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific situations.

[0046] The wafer will sequentially pass through a polishing unit, a brushing unit, a cleaning unit, and a drying unit in the CMP equipment to perform polishing, cleaning, drying and other processing operations on the wafer.

[0047] Figure 1 It is a schematic diagram of a polishing unit. As shown in the figure, a polishing pad 20 covers the upper surface of a polishing platen 30. A polishing liquid supply device 40 disperses polishing liquid onto the surface of the polishing pad 20. A polishing head 10 adsorbs the wafer with its front side facing down and presses it against the polishing pad 20 with a polishing pressure. During polishing, the polishing head continuously applies pressure to the back side of the wafer and drives the wafer to rotate and move, so as to complete the removal of the material on the front side of the wafer under the combined action of chemistry and mechanics. However, the back side of the wafer may be contaminated before polishing, and there will also be contaminants generated during the polishing process remaining in the polishing head. The particulate matter therein may be embedded in the back side of the wafer under the action of mechanical pressure, forming deep residues. There are also some contaminants, such as some metal oxides or organic compounds, which will react with the material on the back side of the wafer to form chemical bond residues under the combined action of high pressure, high temperature and strong acid and strong base chemical environments during polishing.

[0048] The polished wafer is transferred to a scrubbing unit and a cleaning unit for cleaning. However, whether it is the roller brush cleaning in the scrubbing unit or the high-pressure nozzle cleaning in the cleaning unit, it can only remove the contaminants adhering to the surface of the wafer, such as residual dust particles, inorganic substances or metal ions adsorbed by electrostatic action, etc.; it cannot completely remove the deep residues embedded in the back side of the wafer, and there is no way to deal with the chemical bond residues. In addition, there may be microscopic defects on the back side of the polished wafer, including both scratches generated during the wafer processing and pits formed by the falling off of the particulate matter embedded in the back side of the wafer. Obviously, the existing CMP equipment cannot improve these microscopic defects either. Thus, wafers with deep residues, chemical bond residues or microscopic defects on the back side are transferred to subsequent process technologies, and have an increasingly serious adverse impact on the wafer yield as the process nodes are advanced. For example, in the lithography process with a process below 7nm, the contaminants at the bottom of the wafer will cause local unevenness on the surface of the wafer, resulting in local unevenness during glue coating, and causing defects such as chuck spots and focus spots after exposure, reducing the yield of chip manufacturing.

[0049] The present invention provides a wafer post-processing device for performing back-side processing on a polished wafer to improve the quality of the back side of the wafer and solve the above technical problems.

[0050] Figure 2 It is a schematic diagram of an embodiment of a wafer post-processing device 100 of the present invention. As shown in the figure, the wafer post-processing device 100 includes: a scrubbing assembly 1, a support assembly 2 and a clamping assembly 3.

[0051] The scrubbing assembly 1 includes a scrubbing arm 11, a scrubbing head 12, a scrubbing pad 13, and a scrubbing fluid channel 15. The scrubbing arm 11 is horizontally arranged and extended. The scrubbing head 12 is arranged downward on the scrubbing arm 11. The scrubbing arm 11 can drive the scrubbing head 12 to reciprocally swing around a fixed axis. A scrubbing pad 13 is arranged on the surface of the scrubbing head 12 away from the scrubbing arm 11. The scrubbing head 12 can rotate and drive the scrubbing pad 13 to rotate together when rotating. The scrubbing fluid channel 15 is used to supply scrubbing fluid to the back surface of the wafer to form a chemical environment conducive to scrubbing between the scrubbing pad and the back surface of the wafer. It can be seen that the scrubbing assembly 1 simulates the chemical mechanical polishing process by pressing the scrubbing pad 13 against the back surface of the wafer distributed with chemical liquid with a predetermined scrubbing pressure and reciprocally swinging and rotating, so as to remove a small amount of material layer on the back surface of the wafer while achieving the purpose of removing deep-layer residues and chemical bond residues, and at the same time can repair micro defects and improve the surface quality of the back surface of the wafer.

[0052] However, the object processed by the wafer post-processing device 100 is the polished wafer, that is, the front surface of the wafer has reached a predetermined flatness, and when CMP is used for advanced packaging, the front surface of the wafer may also have specific structures such as through-silicon vias (TSVs) and metal wirings. In order to ensure the scrubbing effect and scrubbing efficiency, the scrubbing pressure applied by the scrubbing pad on the back surface of the wafer cannot be too low. The typical scrubbing pressure is 0.3 to 3 psi (pounds per square inch) or 1 / 4 to 1 / 2 of the corresponding polishing pressure in the polishing unit. In order to avoid wafer fragmentation caused by the scrubbing pressure, corresponding support needs to be formed on the front surface of the wafer. If the front surface of the wafer is supported in a way that contacts the wafer, the reaction force of the support may damage the specific structure of the front surface of the wafer and destroy the flatness of the front surface of the wafer.

[0053] The support assembly 2 includes a support arm 21 and a support head 22. The support arm 21 is horizontally arranged and extended. The support head 22 is arranged upward on the support arm 21. The support arm 21 can drive the support head 22 to swing around a fixed axis together. A plurality of support fluid spray holes 221 are distributed on the surface of the support head 22 away from the support arm 21. The clamping assembly 3 can clamp the wafer and drive the wafer to rotate. When processing the wafer, the clamping assembly 3 horizontally clamps the wafer to fix the wafer at a predetermined height. The support head 22 and the scrubbing head 12 are aligned with each other across the wafer. The support head 22 does not contact the front surface of the wafer. Support fluid is sprayed onto the front surface of the wafer through the plurality of support fluid spray holes 221, so as to form a supporting force for lifting the wafer at the gap between the support head 22 and the front surface of the wafer. Ensure that when the scrubbing pad applies an appropriate scrubbing pressure, it will not damage the characteristic structure of the front surface of the wafer and will not destroy the flatness of the front surface of the wafer.

[0054] Optionally, the clamping assembly 3 includes at least three clamping elements 31 distributed at intervals. The clamping elements 31 have the same height and can move relative to each other in the horizontal direction to approach or separate from each other, so as to clamp the wafer when approaching each other and release the wafer when separating from each other. The clamping element 31 is preferably a wheel-type clamping element, and at least one clamping element 31 is used to drive the wafer to rotate.

[0055] When scrubbing the back surface of the wafer, the wafer is horizontally clamped between the scrubbing pad 13 and the support head 22 by the clamping assembly 3. The front surface of the wafer faces downwards towards the support head. While the scrubbing pad 13 presses against the back surface of the wafer with a certain scrubbing pressure, the support head 22 continuously sprays support fluid towards the front surface of the wafer. During the scrubbing process, the scrubbing fluid channel 15 supplies scrubbing fluid to the back surface of the wafer. The clamping element 31 drives the wafer to rotate, the scrubbing head 12 drives the scrubbing pad 13 to rotate, and the scrubbing arm 11 and the support arm 21 synchronously drive the scrubbing head 12 and the support head 22 to reciprocate swing respectively. During the swing process, the scrubbing head 12 and the support head 22 always maintain alignment. Thus, under the combined action of the scrubbing pad and the scrubbing fluid, a small amount of the back surface material of the wafer is removed, and the deep residue and chemical bonding residue on the back surface of the wafer are also removed together. In addition, the micro defects on the back surface of the wafer are also repaired during the process of removing the back surface material. At the same time, since the support head 22 does not directly contact the front surface of the wafer, the contact damage to the front surface of the wafer is avoided. In summary, the wafer post-processing device of this embodiment enables both the front and back surfaces of the wafer to have good surface quality, improving the yield rate of wafer processing and chip manufacturing.

[0056] In one embodiment, as Figure 3 or Figure 4 shown, the scrubbing assembly 1 further includes a scrubbing head rotating shaft 16. The scrubbing head rotating shaft 16 connects the scrubbing arm 11 and the scrubbing head 12. The scrubbing fluid channel 15 penetrates through the scrubbing arm 11, the scrubbing head rotating shaft 16 and the scrubbing head 12 in sequence to the through hole at the center of the scrubbing pad 13, so as to supply polishing liquid or cleaning liquid or pure water (DIW, deionized water) to the back surface of the wafer. Optionally, at least two of the polishing liquid, the cleaning liquid or the pure water are supplied to the back surface of the wafer in a certain order.

[0057] The support assembly 2 includes a support fluid channel 25 and a support head support shaft 26. The support fluid channel 25 penetrates through the support arm 21, the support head support shaft 26 and the support head 22 in sequence to the support fluid spray hole 221, so as to supply at least one of gas or pure water or chemical liquid to the support fluid spray hole 221.

[0058] Optionally, the contact surfaces of the scrubbing head 12 and the support head 22 with the wafer are circular and of equal size, and the scrubbing head 12 and the support head 22 are kept in alignment, that is, the centers of their respective contact surfaces with the wafer are opposite. The scrubbing fluid is directly supplied between the wafer and the scrubbing pad 13 through the scrubbing fluid channel 15, which is beneficial to reducing the usage amount of the scrubbing liquid while ensuring uniform distribution of the scrubbing liquid, so as to improve the efficiency and uniformity of removing the material layer on the back surface of the wafer.

[0059] Optionally, the support fluid nozzles 221 are uniformly distributed on the surface of the support head 22 to form a uniform support fluid layer between the support head 22 and the front surface of the wafer. The width of the gap between the support head 22 and the front surface of the wafer is 0.3 to 2 mm, preferably 0.5 to 1 mm, which is beneficial to maintaining the pressure of the fluid so as to reduce the consumption of the support fluid, and at the same time can also prevent the wafer from contacting the support head 22 due to slight vibration and deformation during the scrubbing process, thereby damaging the front surface of the wafer.

[0060] Optionally, an annular diversion portion 222 protruding upward is arranged along the circumference at the edge of the surface of the support head 22. The diversion portion 222 is made of a material with a certain flexibility such as silicone rubber and polyurethane. The distance between the upper edge of the diversion portion 222 and the front surface of the wafer is 0.1 to 1 mm, preferably 0.2 to 0.5 mm. Thereby, the fluid pressure maintaining effect can be further improved without worrying about damaging the front surface of the wafer.

[0061] Optionally, as Figure 4 shown, the cross-section of the diversion portion 222 is arc-shaped, and the arc-shaped cross-section has a shape that protrudes upward, radially outward along the support head 22, and then recovers inward at the end, so that the support fluid has a flow trend as shown by the arrow in the figure when overflowing from the diversion portion 222. Thereby, while improving the fluid pressure maintaining effect again, a support fluid film will be formed on the front surface of the wafer. The support fluid film can not only serve as a protective film to prevent crystallization or dry friction on the front surface of the wafer due to water evaporation, but also make it difficult for the pollutants discharged from the back surface of the wafer and the pollutants in the atmosphere to adhere to the front surface of the wafer during the scrubbing process, thereby reducing the cleaning difficulty in subsequent processes.

[0062] In one embodiment, as Figure 1As shown, the scrubbing assembly 1 further includes a rotary lifting element 14 with rotary and lifting functions and a scrubbing pressure control element 17. The rotary lifting element 14 is connected to one end of the scrubbing arm 11 and drives the scrubbing arm 11 to swing and lift through rotation and lifting. The scrubbing head 12 is arranged at the other end of the scrubbing arm 11 away from the rotary lifting element 14. The rotary lifting element 14 adjusts the height of the scrubbing head 12 through lifting, so that the scrubbing pad 13 can press against and disengage from the back surface of the wafer. When pressing against the back surface of the wafer, the scrubbing pressure applied by the scrubbing pad 13 to the back surface of the wafer is further adjusted under the control of the scrubbing pressure control element 17. When the wafer post-processing device 100 processes the wafer, the scrubbing head 12 swings back and forth between the center and the edge of the wafer, and the scrubbing swing path of the scrubbing head 12 is as Figure 5 shown. It can be understood that the swing path of the support head 22 is the same as that of the scrubbing head 12. While rotating, the rotary lifting element 14 adjusts the scrubbing pressure applied by the scrubbing pad 13 to the back surface of the wafer according to the position of the scrubbing head 12, that is, the scrubbing head 12 can apply different scrubbing pressures to the wafer at different positions of the wafer, causing the wafer to deform during the scrubbing process, thereby improving the scrubbing effect on the back surface of the wafer.

[0063] Optionally, when the scrubbing head 12 is located at the center of the wafer, the scrubbing pressure is made less than the supporting force of the supporting fluid on the wafer, so that the center of the wafer has an upward warp of 0° to 2° relative to the edge of the wafer. The upward warp of a small angle will not damage the wafer. Instead, it is beneficial to guide the contaminants to flow along the arc surface formed by the upward warp to the edge of the wafer and be discharged from the edge of the wafer, thereby preventing the contaminants generated by scrubbing from accumulating on the back surface of the wafer and damaging the back surface of the wafer. Especially in the part where the scrubbing pad 13 contacts the back surface of the wafer, due to the continuous and small-angle warp of the wafer, a small gap will also be generated. Under the action of the scrubbing fluid, the scrubbing by-products therein can be carried out and discharged from between the scrubbing pad 13 and the back surface of the wafer, avoiding the risk of damage to the back surface of the wafer and extending the service life of the scrubbing pad 13 to a certain extent.

[0064] When the scrubbing head 12 is located at the edge of the wafer, under the dual action of the scrubbing fluid on the back surface of the wafer and the supporting fluid on the front surface of the wafer, the space between the clamping assembly 3 and the edge of the wafer is filled with fluid. If the edge of the wafer deforms, it is easy to cause the clamping to slip, which will affect the wafer scrubbing effect. Therefore, when the scrubbing head 12 swings from the center of the wafer to the edge of the wafer, the scrubbing pressure is adjusted so that the wafer is in a horizontal state, which can prevent the clamping assembly 3 from slipping.

[0065] The adjustment of the scrubbing pressure by the scrubbing pressure control element 17 can be continuous or discontinuous, which is not limited herein. Those skilled in the art can understand that by adjusting the pressure applied by the scrubbing pad 13 to the back of the wafer at the wafer center and at the wafer edge, different deformations are generated on the wafer, so that it is beneficial to discharge contaminants and avoid slipping to affect the scrubbing effect.

[0066] In one embodiment, as Figure 5 shown, the wafer post-processing device 100 further includes a fluid control assembly 27 to control the flow rate and pressure of the support fluid ejected from the support fluid ejection holes 221. Optionally, the fluid control assembly 27 synchronizes with the change in the scrubbing pressure of the scrubbing head at the wafer edge in a preset scrubbing recipe and keeps the two consistent. In particular, when the scrubbing pressure in the scrubbing recipe is set to change with the use of the scrubbing pad 13, for example, when the scrubbing pad 13 deteriorates due to use and the scrubbing pressure needs to be increased to ensure the scrubbing effect, the fluid control assembly 27 adjusts the flow rate and pressure of the support fluid so that the support force formed by the support fluid increases synchronously.

[0067] In one embodiment, the support assembly 2 includes a rotating element 24 with a rotating function. The rotating element 24 is connected to one end of the support arm 21 and drives the support arm 21 to swing through rotation. The support head 22 is provided at the other end far from the rotating element 24. The rotating lifting element 14 and the rotating element 24 are coaxially arranged, and the scrubbing arm 11 and the support arm 21 have the same length, so as to ensure that the scrubbing head 12 and the support head 22 swing synchronously and are always opposite during scrubbing.

[0068] Optionally, the shapes of the scrubbing assembly 1 and the support assembly 2 are basically the same, that is, the rotating lifting element 14 and the rotating element 24 are symmetrically arranged, the scrubbing arm 11 and the support arm 21 are symmetrically arranged, and there is a space between the scrubbing arm 11 and the support arm 21 to accommodate the opposite scrubbing head 12 and support head 22, the scrubbing head rotating shaft 16 and the support head support shaft 26, the scrubbing pad 13, and the gap between the surface of the support head 22 and the front side of the wafer for accommodating the wafer, so as to keep the overall structure stable and the control accurate and improve the scrubbing effect.

[0069] In one embodiment, as Figure 1 or Figure 5As shown, the clamping assembly 3 includes four clamping elements 31 that are equally spaced. The four clamping elements 31 are divided into two groups. The first group is the first clamping element 311 and the second clamping element 312, which are connected by a first connecting mechanism 32; the second group is the third clamping element 313 and the fourth clamping element 314, which are connected by a second connecting mechanism 33. The first connecting mechanism 32 and the second connecting mechanism 33 can move relative to each other in the horizontal direction so that the four clamping elements 31 move closer to or away from each other. Moreover, the first connecting mechanism 32 or the second connecting mechanism 33 is arranged not to interfere with the scrubbing assembly 1 or the support assembly 2 during the movement.

[0070] The first clamping element 311 and the second clamping element 312 are respectively installed at both ends of the first connecting mechanism 32, and the third clamping element 313 and the fourth clamping element 314 are respectively installed at both ends of the second connecting mechanism 33. The line connecting the first clamping element 311 and the second clamping element 312 is parallel to the line connecting the third clamping element 313 and the fourth clamping element 314 to ensure stable clamping. However, this will inevitably cause at least one coupling mechanism and at least one clamping element to overlap with the swinging paths of the scrubbing arm 11, the scrubbing head 12, and the support arm 21 and interfere. In this embodiment, interference is prevented by setting the positions of the coupling mechanism and the clamping element in the horizontal and vertical directions.

[0071] Optionally, the positions of the scrubbing assembly 1, the support assembly 2, and the clamping assembly 3 are set such that only the first connecting mechanism 32 and the first clamping element 311 overlap with the swinging path of the support arm 21 in the horizontal direction, and there is no horizontal overlap between the other parts. Then, the first clamping element 311 and the first connecting mechanism 32 are arranged to be between the scrubbing arm 11 and the support arm 21 in the vertical direction, so as not to interfere with the swinging scrubbing arm 11 and support arm 21.

[0072] Optionally, the first connecting mechanism 32 is a U-shaped plate member with an opening facing the wafer. The first clamping element 311 and the second clamping element 312 are respectively fixed at two ends of the upper surface of the first connecting mechanism 32. The connecting mechanism support element 34 is connected to the lower surface of the first connecting mechanism 32 to support it. The connecting mechanism support element 34 is opposite to the second clamping element 312. Similarly, only the first connecting mechanism 32 and the first clamping element 311 overlap with the swinging path of the support arm 21 in the horizontal direction. Therefore, the second clamping element 312 and the connecting mechanism support element 34 do not overlap with the swinging path of the support arm 21. The connecting mechanism support element 34 serves as a support structure for the first connecting mechanism 32, so that the first clamping element 311 and the first connecting mechanism 32 are located between the scrubbing arm 11 and the support arm 21 in the vertical direction, thus preventing interference with the swinging scrubbing arm 11 and support arm 21. Preferably, the connecting mechanism support element 34 can move horizontally to drive the first connecting mechanism 32 to move relatively horizontally with respect to the second connecting mechanism 33.

[0073] Optionally, the second connecting mechanism 33 is a straight plate member. The third clamping element 313 and the fourth clamping element 314 are respectively fixed at two ends of the upper surface of the second connecting mechanism 33. The rotating element 24, the second connecting mechanism 33, and the connecting mechanism support element 34 are all connected to the chamber base of the wafer post-processing device 100. The four clamping elements 31 are arranged to have the same clamping height, so as to ensure horizontal clamping of the wafer. The second connecting mechanism 33 is arranged to be farther away from the rotating and lifting element 14 than the first connecting mechanism 32. Therefore, it is easy to prevent the second connecting mechanism 33, the third clamping element 313, and the fourth clamping element 314 from interfering with the scrubbing arm 11, the scrubbing head 12, or the support arm 21.

[0074] Preferably, all four clamping elements 31 have driving wheels for driving the wafer to rotate. Alternatively, only the first clamping element 311 has a driven wheel while the other three clamping elements all have driving wheels, so as to provide more stable frictional force and driving torque for the wafer rotation, avoid the interference of the frictional torque of the scrubbing pad on the wafer rotation speed, and ensure the uniformity of the backside scrubbing of the wafer. According to the wafer post-processing device 100 of this embodiment, the wafer is stably clamped and rotated, and the scrubbing head will not interfere with the clamping mechanism during the swinging process, making the overall structure compact and the space utilization rate high.

[0075] In one embodiment, as Figure 5 shown, the wafer post-processing device 100 further includes a liquid supply assembly 5. The liquid supply assembly 5 includes a cleaning liquid nozzle 51 and a pure water nozzle 52 for supplying cleaning liquid or pure water to the backside of the wafer. Optionally, the second connecting mechanism 33 is fixed on the base, and the liquid supply assembly 5 is arranged on the second coupling mechanism. The cleaning liquid nozzle 51 and the pure water nozzle 52 are rotatable L-shaped nozzles.

[0076] For the wafer post - processing device 100 according to this embodiment, polishing liquid is supplied to the back surface of the wafer through the scrubbing fluid channel 15. At the same time, cleaning liquid or pure water can be supplied to the back surface of the wafer through the scrubbing fluid channel 15 and the liquid supply assembly 5, preventing the limited liquid volume under the scrubbing pad due to the small area of the scrubbing pad and being unable to provide sufficient liquid volume when scrubbing a wafer much larger than the area of the scrubbing pad, thus affecting the scrubbing effect and efficiency.

[0077] As the scrubbing progresses, the surface of the scrubbing pad will deteriorate, affecting the scrubbing effect.

[0078] In one embodiment, as Figure 5 and Figure 6 shown, the wafer post - processing device 100 further includes a dressing assembly 6. The dressing assembly 6 is located at one end of the dressing swing path of the scrubbing head 12. The scrubbing arm 11 can swing the scrubbing head 12 to an appropriate position of the dressing assembly, so that the dressing assembly 6 can dress the surface of the scrubbing pad to a state suitable for scrubbing.

[0079] Optionally, the dressing assembly 6 includes a dressing table 61, a dressing member 62, and a dressing member washer 63. The dressing table 61 is rotatable, and the dressing member 62 is installed on the upper surface of the dressing table 61 and rotates with the dressing table. The dressing member 62 can be, for example, a diamond disk, so that when the scrubbing head 12 swings from the clamping assembly 3 to above the dressing table 61, it contacts and dresses the scrubbing pad 13 to dress the surface of the scrubbing pad to a state suitable for scrubbing. After the dressing is completed, there may be dressing by - products generated during the dressing process remaining on the surface of the dressing member 62. The dressing member washer 63 sprays cleaning liquid or pure water to clean the dressing member 62, thus preventing the dressing by - products from affecting the subsequent dressing effect.

[0080] As shown in the figure, in order to enable the scrubbing arm 11 with a limited length to swing to the dressing assembly 6, the dressing assembly 6 is arranged adjacent to the space where the clamping assembly 3 clamps the wafer. This results in the pollutants generated during the wafer scrubbing process possibly splashing onto the dressing assembly 6 and may also form crystals, break off, and damage the wafer.

[0081] Therefore, the scrubbing arm 11 is arranged such that the scrubbing head 12 reciprocally swings between the center of the wafer and the wafer edge far from the dressing assembly 6, that is, the scrubbing swing path and the dressing swing path of the scrubbing head 12 do not overlap, to prevent the pollutants generated by scrubbing from splashing onto the dressing assembly. At the same time, when processing the wafer, the dressing member washer 63 can continuously and slightly spray pure water to prevent crystallization through the moisturizing effect.

[0082] Optionally, the rotary lifting element 14 includes a rotary motor and a coupling mechanism (not shown). The coupling mechanism drives the rotary lifting element 14 and the rotary element 24 to rotate synchronously when the rotary motor rotates through coupling, and the coupling mechanism drives only the rotary lifting element 14 to rotate when the rotary motor rotates through decoupling. That is to say, when processing the wafer, the coupling mechanism is coupled, so that when the rotary motor rotates, it drives the rotary lifting element 14 and the rotary element 24 to rotate synchronously, ensuring that the scrubbing arm 11 and the support arm 21 rotate synchronously, so that the scrubbing head 12 and the support head 22 are always opposite. When trimming the scrubbing pad, the coupling mechanism is decoupled, so that when the rotary motor rotates, only the rotary lifting element 14 rotates, and the rotary element 24 does not rotate, so that the support assembly 2 remains stationary, and the scrubbing arm 11 drives the scrubbing head 12 to rotate to the trimming assembly 6. By sharing one motor, not only the synchronization of rotation is ensured, but also the risk of the motor being contaminated, corroded and damaged in the highly corrosive CMP environment is reduced. At the same time, the risk of reverse contamination of the wafer by pollutants such as metal ions generated by the rotation of the motor is also reduced.

[0083] In one embodiment, as Figure 6 shown, the wafer post-processing device 100 further includes a cleaning assembly 4. The cleaning assembly 4 is disposed between the clamping assembly 3 and the trimming assembly 6 and is located on the trimming swing path. Particles such as scrubbing pads, polishing liquids, and trimming parts may adhere to the surface of the scrubbing pad 13 after trimming, affecting the subsequent scrubbing effect. When the scrubbing head 12 swings above the cleaning assembly 4, the cleaning assembly 4 sprays cleaning liquid or pure water to clean the surface of the scrubbing pad 13. Optionally, the cleaning assembly 4 is a fan-shaped nozzle or a solid cone nozzle, and the cleaning assembly 4 is connected to the liquid supply assembly 5.

[0084] According to the wafer post-processing device 100 of the present invention, a trimming assembly for automatically trimming the scrubbing pad and a cleaning assembly for cleaning the scrubbing pad are integrated, effectively ensuring the wafer post-processing effect and improving the yield of chip manufacturing; at the same time, the service life of the scrubbing pad and the trimming part is improved, and the cost is saved.

[0085] The present invention also provides a method for scrubbing the back surface of a wafer using the wafer post-processing device 100, which is used to scrub and rinse deep residues and chemical bonding residues on the back surface of the wafer.

[0086] In one embodiment, as Figure 7 shown, the method includes the following steps: S1. Transfer the wafer to the clamping assembly 3 and control the clamping assembly 3 to clamp the wafer.

[0087] Optionally, the transfer can be completed by a transfer robot. Before the transfer, the scrubbing head 12 is outside the clamping working range of the clamping assembly 3 so as not to affect the transfer and clamping. After the transfer robot clamps the wafer and stays at a predetermined position, the clamping elements 31 of the clamping assembly 3 approach each other to clamp the wafer.

[0088] S2. Control the scrubbing arm 11 to swing so that the scrubbing head 12 is at a predetermined position above the wafer, and the predetermined position makes the scrubbing head 12 opposite to the support head 22.

[0089] Optionally, the support head 22 stops at a position directly opposite the center of the front side of the wafer, and the scrubbing arm 11 is controlled to swing so that the scrubbing head 12 is directly opposite the center of the back side of the wafer.

[0090] S3. Control the scrubbing arm 11 to press down so that the scrubbing pad 13 fits against the back side of the wafer, and at the same time control the support fluid to spray out from the support fluid spray holes 221.

[0091] Optionally, control the flow rate and pressure of the fluid sprayed out from the support fluid spray holes 221 so that the fluid pressure for supporting the front side of the wafer is small initially and gradually increases as the scrubbing head 12 presses down, thereby avoiding excessive pressure on any side of the wafer and causing fragmentation. After the scrubbing is completed, when the scrubbing head 12 rises away from the wafer, control the flow rate and pressure of the fluid sprayed out from the support fluid spray holes 221 in the opposite way.

[0092] S4. Supply scrubbing fluid to the back side of the wafer, and at the same time control the scrubbing arm 11 and the support arm 21 to swing reciprocally synchronously, and control the scrubbing head 12 and the clamping assembly 3 to drive the wafer to rotate.

[0093] During the scrubbing process, the wafer and the scrubbing head 12 rotate in the same direction but at different speeds. The scrubbing arm 11 drives the scrubbing head 12 to swing reciprocally along the radial direction of the wafer, and the support arm 21 also drives the support head 22 to swing synchronously, keeping the scrubbing head 12 and the support head 22 always opposite. At the same time, according to the needs of scrubbing, supply scrubbing fluid to the back side of the wafer to remove deep residues and chemical bonding residues on the back side of the wafer without damaging the front side of the wafer.

[0094] Optionally, controlling the support fluid to spray out from the support fluid spray holes in step S3 further includes controlling the type of the support fluid according to the surface film layer property of the front side of the wafer, specifically including: For a surface film layer with hydrophilic property on the front side of the wafer and low risk of corrosion by contacting pure water, control pure water to spray out from the support fluid spray holes; For a surface film layer with hydrophobic property or high risk of corrosion by contacting pure water on the front side of the wafer, control the protective liquid to spray out from the support fluid spray holes; For a surface film layer with medium risk of corrosion by contacting pure water, control the protective liquid and pure water to spray out alternately from the support fluid spray holes.

[0095] The protective liquid includes at least one of a protective liquid with a specific pH value, a protective liquid added with an antioxidant to prevent local electrochemical corrosion of the metal interconnection layer, and a protective liquid added with a trace amount of surfactant to reduce the surface tension. According to this embodiment, special protection can be formed on the front side of the wafer with different surface film layer properties, while reducing the usage cost of the protective liquid.

[0096] Optionally, by controlling the specific sequence of supplying the scrubbing fluid to the back side of the wafer in step S4, the scrubbing effect can be further improved, and at the same time, the back side of the wafer can be rinsed to improve the cleaning efficiency in subsequent processes. The specific steps are as follows: S411. Supply polishing liquid to the back side of the wafer through the scrubbing fluid channel 15. The polishing liquid is used to quickly remove a small amount of material layer on the back side of the wafer, thus providing convenient conditions for quickly and thoroughly removing deep - layer residues and chemical - bonding residues.

[0097] S412. Stop supplying the polishing liquid, and supply cleaning liquid to the back side of the wafer through the scrubbing fluid channel 15 and the cleaning liquid nozzle 51. The cleaning liquid helps to strengthen the cleaning effect to quickly remove and discharge the contaminant particles. At the same time, the cleaning liquid nozzle 51 can increase the supply amount of the cleaning liquid and provide a rinsing effect, thereby preventing the contaminants from adhering to the back side of the wafer again during the movement of the scrubbing pad 13.

[0098] S413. Stop supplying the cleaning liquid, and supply pure water to the back side of the wafer through the scrubbing fluid channel 15 and the pure water nozzle 52. Optionally, the flow rate and pressure of the pure water are much greater than those of the cleaning liquid, so as to provide a better rinsing effect and remove all the remaining contaminant particles, polishing liquid, and cleaning liquid on the back side of the wafer.

[0099] S414. Stop supplying pure water to the back side of the wafer through the scrubbing fluid channel 15. After stopping the water supply, control the scrubbing arm 11 to rise to a predetermined height, and control the scrubbing arm 11 to swing until the scrubbing head 12 leaves above the wafer.

[0100] S415. Stop supplying pure water to the back side of the wafer through the pure water nozzle 52. Continuously supply pure water to the back side of the wafer through the pure water nozzle 52 during the process of the scrubbing head 12 leaving above the wafer, so as to rinse the remaining contaminants under the scrubbing pad 13 and the contaminants dripping from the scrubbing head 12 clean.

[0101] In one embodiment, it is also possible not to use polishing liquid when supplying the scrubbing fluid to the back side of the wafer in step S4, so as to reduce the use and pollution caused by the polishing liquid. However, the scrubbing time can be appropriately increased to mainly remove the material layer on the back side of the wafer through mechanical action. The steps include: S421. Supply cleaning liquid to the back side of the wafer through the scrubbing fluid channel 15 and the cleaning liquid nozzle 51; S422. Stop supplying the cleaning liquid, and supply pure water to the back side of the wafer through the scrubbing fluid channel 15 and the pure water nozzle 52; S423. Stop supplying pure water to the back side of the wafer through the scrubbing fluid channel 15; S424. Stop supplying pure water to the back side of the wafer through the pure water nozzle 52.

[0102] Compared with the cleaning using a roller brush in the brushing unit, this embodiment can apply a greater scrubbing pressure to the wafer to remove part of the material layer on the back side of the wafer, effectively improving deep layer residues, chemical bonding residues or micro-defects, without damaging the front side of the wafer, and at the same time reducing the cost increase and the increased pollution risk caused by the use of polishing fluid.

[0103] In one embodiment, the method for scrubbing the back side of the wafer according to the present invention further includes the following steps: S5. Control the scrubbing pressure so that when the scrubbing head is located at the center of the wafer, the center of the wafer has an upward warpage of 0° to 2° relative to the edge of the wafer to prevent contaminants generated by scrubbing from accumulating on the back side of the wafer; And when the scrubbing head is located at the edge of the wafer, the wafer is in a horizontal state to prevent the clamping assembly from slipping.

[0104] Optionally, when the scrubbing head 12 and the support head 22 are at the center position of the wafer, synchronously increase the scrubbing pressure, the pressure and flow rate of the support fluid. After the scrubbing pressure reaches the scrubbing pressure in the scrubbing formula, maintain it, and continue to increase the support force of the support fluid until it is greater than the scrubbing pressure until the center of the wafer has an upward warpage of 0° to 2° relative to the edge of the wafer. During the swinging process of the scrubbing head 12, keep the support force of the support fluid unchanged, and periodically control the scrubbing pressure applied by the scrubbing head 12 to the wafer: during the process of the scrubbing head 12 swinging from the center of the wafer to the edge of the wafer, the scrubbing pressure gradually increases, and when the scrubbing head 12 is located at the edge of the wafer, the wafer is in a horizontal state; and during the process of the scrubbing head 12 swinging from the edge of the wafer to the center of the wafer, the scrubbing pressure gradually decreases, so that when the scrubbing head 12 is located at the center of the wafer, the support force of the support fluid lifts the center of the wafer relative to the edge of the wafer upward again to have an upward warpage of 0° to 2°.

[0105] It can be seen that in this embodiment, by controlling the scrubbing pressure applied by the scrubbing head to the back side of the wafer, it is possible to effectively prevent contaminants generated by scrubbing from accumulating on the back side of the wafer, so that the contaminants do not affect the scrubbing effect; and it avoids the slipping of the clamping assembly when clamping the wafer and affecting the scrubbing effect.

[0106] In one embodiment, as the scrubbing pad is used, it may be necessary to change the scrubbing pressure to maintain the scrubbing effect. For example, when it deteriorates due to use, it may be necessary to increase the scrubbing pressure. The method for scrubbing the back side of the wafer according to the present invention further includes the following steps: S6. When changing the scrubbing pressure according to the scrubbing requirement, control the flow rate and pressure of the support fluid supplied to the support fluid nozzles so that the support force formed by the support fluid is consistent with the scrubbing pressure when the scrubbing head is at the edge of the wafer.

[0107] It can be seen that in this embodiment, by synchronously controlling the flow rate and pressure of the supplied support fluid, even if the scrubbing pressure changes during the continuous production process, the periodic micro-deformation of the wafer can still be maintained to ensure the scrubbing effect of the scrubbing method of the present invention.

[0108] In one embodiment, the scrubbing method of the present invention further includes a scrubbing pad trimming step S7 for trimming the scrubbing pad 13 that has processed the wafer to a state suitable for scrubbing, including: S71. Control the scrubbing arm 11 to rise and swing until the scrubbing head 12 is above the trimming table 61.

[0109] S72. Control the scrubbing arm 11 to descend until the scrubbing pad 13 fits against the trimming member 62.

[0110] S73. Supply at least one of polishing liquid, cleaning liquid, and pure water to the surface of the trimming member 62, control the scrubbing arm 11 to swing back and forth, and control the scrubbing head 12 and the trimming table 61 to rotate.

[0111] Optionally, step S71 includes the following steps: S711. Control the scrubbing arm 11 and the support arm 21 to stop swinging when they are at the center of the wafer; S712. Control the scrubbing head 12 to stop rotating and control the clamping assembly 3 to stop driving the wafer to rotate; S713. Control the scrubbing fluid to stop spraying from the support fluid nozzles 221, and control the scrubbing arm 11 to rise; S714. Control the coupling mechanism to decouple; S715. Control the scrubbing arm 11 to swing until the scrubbing head 12 is above the trimming table 61.

[0112] In one embodiment, the backside scrubbing method of the wafer of the present invention further includes a scrubbing pad cleaning step S8 for cleaning the trimmed scrubbing pad 13, specifically including: S81. After completing the trimming of the scrubbing pad 13, control the scrubbing arm 11 to rise and swing until the scrubbing head 12 is above the cleaning assembly 4, and the cleaning assembly 4 is on the trimming swing path between the clamping assembly 3 and the trimming assembly 6.

[0113] S82. Control the cleaning assembly 4 to spray cleaning liquid or pure water, and at the same time control the scrubbing head 12 to rotate to wash away various contaminant particles attached to the scrubbing pad 13 during the trimming step through the liquid.

[0114] Meanwhile, the trim part washer 63 starts to clean and moisturize the trim part 62 to wash away various contaminant particles adhering to the trim part 62 during the trimming step and prevent crystallization due to water evaporation.

[0115] In one embodiment, the wafers are transferred to the wafer post-processing device 100 according to the production rhythm. After the backside scrub cleaning of one wafer is completed and after step S72 is executed, the transfer manipulator and the clamping assembly 3 cooperate to enable the transfer manipulator to clamp the wafer and leave the clamping assembly 3 and transfer it to the chamber of the next process flow. Then, after the cleaning step S8 is completed, the scrubbing arm 11 is again controlled to swing so that the scrubbing head 12 is located above the trimming table 61, so as to execute step S1 again, that is, the transfer manipulator transfers the next wafer to be processed to the clamping assembly 3, and the clamping assembly 3 is controlled to clamp the wafer.

[0116] The wafer backside scrubbing method of the present invention can efficiently clean the contaminant particles on the backside of the wafer, ensure that the quality of both the front and back surfaces of the wafer meets the requirements of subsequent processes, and can adapt to the existing wafer processing rhythm without affecting the production efficiency of the wafer.

[0117] The present invention also provides a wafer processing device 1000, including a controller 200 and a wafer post-processing device 100. The controller 200 is used to control the wafer post-processing device 100 to execute the wafer backside scrubbing method of the present invention.

[0118] In one embodiment, as Figure 8 shown, the wafer post-processing device 100 is located after the polishing unit and before the brushing unit, the cleaning unit and the drying unit. After the controller controls the polishing unit to complete the front-side polishing of the wafer, the polished wafer is transferred to the wafer post-processing device 100, and the wafer backside scrubbing method of the present invention is executed in the wafer post-processing device 100. Then, the scrubbed wafer is sequentially transferred to the brushing unit, the cleaning unit and the drying unit to perform processes such as brushing, cleaning and drying on the wafer, so that the quality of both the front and back surfaces of the wafer processed by the wafer processing device 1000 meets the requirements of subsequent processes, and the yield of chip manufacturing is improved.

[0119] Those skilled in the art can understand that the wafer post-processing device 100 of the present invention can also be used as an independent wafer backside scrubbing equipment station, and transfer the wafers that need to improve the backside quality of the wafer to the wafer backside scrubbing equipment, so as to process the backside of the wafer to a state that meets the requirements of subsequent processes without damaging the front side of the wafer.

[0120] In one embodiment, the wafer backside scrubbing device of the present invention includes: a scrubbing assembly, a support assembly, and a clamping assembly; the scrubbing assembly includes a scrubbing arm, a scrubbing head, and a scrubbing pad, the scrubbing head is arranged on the scrubbing arm, the scrubbing pad is arranged on the scrubbing head, and the scrubbing head drives the scrubbing pad to rotate; the support assembly includes a support arm and a support head, the support head is arranged on the support arm, and a plurality of support fluid spray holes are distributed on the surface of the support head; when processing a wafer, the clamping assembly clamps and drives the wafer to rotate, the wafer is located between the scrubbing pad and the support head, the scrubbing pad fits against the backside of the wafer with a scrubbing pressure, there is a gap between the support head and the front side of the wafer, the scrubbing arm and the support arm swing, and the scrubbing head and the support head are always opposite to each other during the swinging process, the support fluid spray holes continuously spray support fluid onto the front side of the wafer, and the scrubbing pressure is not greater than the support force of the fluid on the front side of the wafer.

[0121] The above embodiments are only used to illustrate the embodiments of the present invention, rather than limiting the embodiments of the present invention. Those of ordinary skill in the relevant technical field can also make various changes and modifications without departing from the spirit and scope of the embodiments of the present invention. Therefore, all equivalent technical solutions also belong to the scope of the embodiments of the present invention, and the patent protection scope of the embodiments of the present invention shall be defined by the claims.

Claims

1. A wafer post-processing device, characterized in that: include: a scrubbing assembly, a supporting assembly, and a clamping assembly; The scrubbing assembly includes a scrubbing arm, a scrubbing head, a scrubbing pad, and a scrubbing fluid passage, wherein the scrubbing pad is mounted on the scrubbing head; The support assembly comprises a support arm and a support head, and the surface of the support head has a plurality of support fluid spray holes; When processing wafers, The clamping assembly clamps and drives the wafer to rotate, the wafer is located between the scrubbing pad and the supporting head, and there is a gap between the surface of the supporting head and the front side of the wafer. The scrubbing pad is attached to the back of the wafer with scrubbing pressure and rotates under the drive of the scrubbing head. The scrubbing fluid channel supplies scrubbing fluid to the back of the wafer. The scrubbing head and the supporting head swing back and forth and always keep aligned during the swinging process, and the supporting fluid spray hole continuously sprays the supporting fluid toward the front side of the wafer so that the surface of the supporting head does not contact the front side of the wafer; Thus, deep residual contaminants, chemically bonded residual contaminants or microscopic defects on the back side of the wafer are removed without damaging the front side of the wafer.

2. The wafer post-processing device according to claim 1, characterized in that: Also included is a dressing assembly for dressing the scrubbing pad, the dressing assembly being disposed on a dressing swing path of the scrubbing head, and the scrubbing head moving along the dressing swing path to the dressing assembly; The trimming swing route does not overlap with the scrubbing swing route of the scrubbing head when processing the wafer, so as to prevent the contaminants generated when processing the wafer from sputtering to the trimming component.

3. The wafer post-processing device according to claim 1, characterized in that: The scrubbing assembly further includes a rotary lifting element connected to one end of the lower surface of the scrubbing arm, and the scrubbing head is disposed at the other end of the lower surface of the scrubbing arm; The rotating lifting element is used to make the scrubbing arm drive the scrubbing head to swing and lift, and adjust the scrubbing pressure by lifting the scrubbing head; When processing a wafer, the scrubbing head swings back and forth between the center of the wafer and the edge of the wafer, and the scrubbing pressure is adjusted according to the position of the scrubbing head to cause the wafer to deform.

4. The wafer post-processing device according to claim 3, characterized in that: Adjusting the scrubbing pressure according to the position of the scrubbing head comprises: When the scrubbing head is located at the center of the wafer, the scrubbing pressure is adjusted so that the center of the wafer has an upward warping of 0° to 2° relative to the edge of the wafer, thereby guiding the contaminants to flow toward the edge of the wafer along the arc surface formed by the upward warping; and / or, When the scrubbing head is located at the edge of the wafer, the scrubbing pressure is adjusted to make the wafer level to prevent the clamping assembly from slipping.

5. The wafer post-processing device according to any one of claims 3 or 4, characterized in that: The support assembly further includes a rotating element coaxially arranged with the rotating lifting element, the rotating element is connected to one end of the upper surface of the support arm, and the support head is arranged at the other end of the upper surface of the support arm; The rotary lifting element comprises a rotary motor and a coupling mechanism. The coupling mechanism drives the rotary lifting element and the rotary element to rotate synchronously when the rotary motor rotates through coupling. The coupling mechanism drives only the rotary lifting element to rotate when the rotary motor rotates through decoupling.

6. The wafer post-processing device according to any one of claims 1 to 4, characterized in that: The clamping assembly comprises four clamping elements distributed at equal intervals, wherein: The first clamping element and the second clamping element are respectively mounted at two ends of the first connecting mechanism, and the first connecting mechanism and the first clamping element are located between the scrubbing arm and the supporting arm in the vertical direction to avoid interference with the swinging supporting arm; The third clamping element and the fourth clamping element are respectively mounted at two ends of the second connecting mechanism; A line connecting the first clamping element and the second clamping element is parallel to a line connecting the third clamping element and the fourth clamping element; The first connecting mechanism and the second connecting mechanism move relatively in the horizontal direction, so that the four clamping elements move closer to or farther from each other, thereby clamping the wafer when they move closer and releasing the wafer when they move farther from each other.

7. The wafer post-processing device according to claim 6, characterized in that: The first connecting mechanism is a U-shaped plate with an opening facing the wafer; The first clamping element and the second clamping element are respectively mounted on two ends of the upper surface of the first connecting mechanism, and in the horizontal projection, the first clamping element overlaps with the swing path of the support arm, while the second clamping element does not overlap with the swing path of the support arm; A connecting mechanism supporting member is connected to a lower surface of the first connecting mechanism to support the first connecting mechanism, and the connecting mechanism supporting member is opposite to the second clamping member.

8. The wafer post-processing device according to claim 7, characterized in that: The connecting mechanism supporting element can drive the first connecting mechanism to move in a horizontal direction relative to the second connecting mechanism, and drive the second clamping element to rotate; The scrubbing head reciprocates between the center of the wafer and the second clamping element.

9. The wafer post-processing device according to any one of claims 1 to 4, characterized in that: The scrubbing assembly also includes a scrubbing head shaft, and the scrubbing fluid channel sequentially passes through the scrubbing arm, the scrubbing head shaft, the scrubbing head and the scrubbing pad to supply polishing liquid or cleaning liquid or pure water to the back side of the wafer.

10. The wafer post-processing device according to any one of claims 1 to 4, characterized in that: The support assembly also includes a support head support shaft and a support fluid channel, wherein the support fluid channel sequentially passes through the support arm, the support head support shaft and the support head, and is connected to the support fluid spray hole to supply protective liquid and / or pure water to the support fluid spray hole.

11. The wafer post-processing device according to claim 10, characterized in that: The surface of the support head is circular, and the width of the gap between the surface of the support head and the front side of the wafer is 0.3 to 2 mm.

12. The wafer post-processing device according to claim 11, characterized in that: An annular guide portion is provided on the edge of the surface of the support head along the circumferential direction, the guide portion is made of a flexible material, and the distance between the upper edge of the guide portion and the front side of the wafer is 0.1 to 1 mm; The guide portion protrudes upward and outward in an arc shape from the edge of the surface of the supporting head, and is retracted inward at the end, so that the supporting fluid forms a supporting fluid film on the front side of the wafer.

13. The wafer post-processing device according to claim 10, characterized in that: It also includes a supporting fluid pressure control component for controlling the flow rate and / or pressure of the supporting fluid so that the supporting force of the supporting fluid on the front side of the wafer is consistent with the scrubbing pressure when the scrubbing head is located at the edge of the wafer.

14. The wafer post-processing device according to any one of claims 1 to 4, characterized in that: It also includes a liquid supply component, which includes a cleaning liquid nozzle and a pure water nozzle, and is used to supply cleaning liquid or pure water to the back side of the wafer.

15. The wafer post-processing device according to claim 2, characterized in that: The trimming assembly includes a trimming table, a trimming piece, and a trimming piece washer; The dressing table is rotatable, and the dressing member is mounted on the upper surface of the dressing table for contacting and dressing the scrubbing pad when the scrubbing head swings from the clamping assembly to above the dressing table; The trimming piece cleaning device is used to clean the trimming piece after trimming the scrubbing pad.

16. The wafer post-processing device according to claim 2 or 15, characterized in that: It also includes a cleaning component, which is arranged on the trimming swing path between the clamping component and the trimming component of the scrubbing head, and is used to spray cleaning liquid or pure water to clean the trimmed scrubbing pad.

17. A wafer backside scrubbing device, characterized in that: include: a scrubbing assembly, a supporting assembly, and a clamping assembly; The scrubbing assembly comprises a scrubbing arm, a scrubbing head and a scrubbing pad, wherein the scrubbing head is arranged on the scrubbing arm, the scrubbing pad is arranged on the scrubbing head, and the scrubbing head drives the scrubbing pad to rotate; The support assembly comprises a support arm and a support head, wherein the support head is arranged on the support arm, and a plurality of support fluid spray holes are distributed on the surface of the support head; When processing the wafer, the clamping assembly clamps and drives the wafer to rotate, and the wafer is located between the scrubbing pad and the supporting head. The scrubbing pad adheres to the back of the wafer with scrubbing pressure, and there is a gap between the supporting head and the front of the wafer. The scrubbing arm and the supporting arm swing, and the scrubbing head and the supporting head are always opposite to each other during the swinging process. The supporting fluid nozzle continuously sprays supporting fluid toward the front of the wafer, and the scrubbing pressure is not greater than the supporting force of the fluid on the front of the wafer, so as to remove deep residual contaminants, chemically bonded residual contaminants or microscopic defects on the back of the wafer.

18. A method for scrubbing the back side of a wafer, characterized in that: Using the wafer post-processing device as claimed in any one of claims 1 to 16 to scrub the back side of the wafer, comprising: Transferring the wafer to the clamping assembly, and controlling the clamping assembly to clamp the wafer; Controlling the scrubbing arm to swing until the scrubbing head is located above the center of the wafer and opposite to the supporting head located below the center of the wafer; Controlling the scrubbing arm to descend until the scrubbing pad is attached to the back side of the wafer while controlling the supporting fluid to be sprayed out from the supporting fluid spray hole; The scrubbing fluid is supplied to the back side of the wafer, and at the same time, the scrubbing arm and the supporting arm are controlled to swing back and forth synchronously, the scrubbing head is controlled to rotate, and the clamping assembly is controlled to drive the wafer to rotate.

19. The wafer backside scrubbing method according to claim 18, characterized in that: Also includes: Controlling the scrubbing pressure so that when the scrubbing head is located at the center of the wafer, the center of the wafer has an upward warping of 0° to 2° relative to the edge of the wafer to prevent contaminants generated by scrubbing from accumulating on the back of the wafer; and / or, When the scrubbing head is located at the edge of the wafer, the wafer is level to prevent the clamping assembly from slipping.

20. The wafer backside scrubbing method according to claim 19, wherein: Also includes: When the scrubbing pressure when the scrubbing head is located at the edge of the wafer changes with the use of the scrubbing pad, the flow rate and / or pressure of the supporting fluid is controlled so that the supporting force of the supporting fluid on the front side of the wafer is consistent with the scrubbing pressure when the scrubbing head is located at the edge of the wafer.

21. The wafer backside scrubbing method according to any one of claims 18 to 20, characterized in that: The step of supplying a scrubbing fluid to the back side of the wafer comprises: supplying polishing liquid to the back side of the wafer through the scrubbing fluid channel; Stop supplying the polishing liquid, and supply a cleaning liquid to the back side of the wafer through the scrubbing fluid channel and the liquid supply component of the wafer post-processing device; Stop supplying the cleaning liquid, and supply pure water to the back side of the wafer through the scrubbing fluid channel and the liquid supply assembly; stopping supplying pure water to the back side of the wafer through the scrubbing fluid channel; Stop supplying pure water to the back side of the wafer through the liquid supply assembly.

22. The wafer backside scrubbing method according to any one of claims 18 to 20, characterized in that: The step of supplying a scrubbing fluid to the back side of the wafer comprises: supplying cleaning liquid to the back side of the wafer through the scrubbing fluid channel and the liquid supply component of the wafer post-processing device; Stop supplying the cleaning liquid, and supply pure water to the back side of the wafer through the scrubbing fluid channel and the liquid supply assembly; stopping supplying pure water to the back side of the wafer through the scrubbing fluid channel; Stop supplying pure water to the back side of the wafer through the liquid supply assembly.

23. The wafer backside scrubbing method according to claim 21, characterized in that: Also included is a dressing step for dressing the scrubbing pad and a cleaning step for cleaning the trimmed scrubbing pad; In the trimming step, the scrubbing arm rises and swings until the scrubbing head is located at a trimming assembly of the wafer post-processing device; In the cleaning step, the scrubbing arm rises and swings until the scrubbing head is located at a cleaning assembly of the wafer post-processing device; and, After the cleaning step, the scrubbing arm is kept stationary, the next wafer is transferred to the clamping assembly, and the clamping assembly is controlled to clamp the next wafer.

24. The wafer backside scrubbing method according to any one of claims 18 to 20, characterized in that: Controlling the supporting fluid to be ejected from the supporting fluid ejection hole comprises: According to the surface film properties of the front side of the wafer, pure water and / or protective liquid is controlled to be sprayed out from the supporting fluid spray hole.

25. A wafer processing device, characterized in that: It comprises a controller and a wafer post-processing device as described in any one of claims 1-16, wherein the controller is used to control the wafer post-processing device to execute the wafer back side scrubbing method as described in any one of claims 18-24.

Images