Wafer double-sided thinning method and system

Abstract

The invention relates to the field of wafer processing, in particular to a wafer double-sided thinning method and system, and the method comprises the steps: obtaining a pressure intensity variation P between a substrate and a wafer, a wafer position offset x and a wafer position offset rate; establishing a first compensation function model of the pressure intensity variable quantity P between the substrate and the wafer, the wafer position offset x and the liquid compensation quantity Q; and adjusting the liquid compensation amount Q of a liquid supply port based on the first compensation function model so as to enable the wafer to be centered. The invention discloses a wafer double-sided thinning method and a wafer double-sided thinning system, which achieve the effect of improving wafer centering by controlling liquid compensation.

Description

Technical Field

[0001] The present application relates to the field of wafer processing, and particularly to a method and a system for double-sided thinning of wafers. Background Art

[0002] In a double-sided thinning device, a wafer is vertically placed on an annular carrier. The carrier is arranged between two substrates. Fluids are supplied to both sides of the wafer through the substrates to balance the pressure of the wafer, and the wafer and the carrier rotate together. At the same time, grinding wheels arranged on both sides of the wafer grind two surfaces of the wafer. During the grinding process, the two grinding wheels feed axially until the wafer reaches a thickness meeting the process requirements.

[0003] In the prior art, the grinding wheels on both sides of the wafer act on the wafer. As the wafer continues to be ground and becomes thinner, a large gap is formed between the wafer and the substrate, making the wafer prone to tilt, thus affecting the quality of wafer thinning processing.

[0004] Therefore, the technical problem of the prior art is that the tilt of the wafer during the thinning process affects the processing quality. Summary of the Invention

[0005] The present application provides a method and a system for double-sided thinning of wafers, which can improve the centering effect of the wafer by controlling liquid compensation and / or inclination compensation.

[0006] On the one hand, a method for double-sided thinning of wafers provided by the present application adopts the following technical solution: A method for double-sided thinning of wafers is applied to a double-sided thinning device. The double-sided thinning device includes: a substrate assembly, the substrate assembly includes substrates, there are two groups of the substrates, and the two groups of substrates are arranged oppositely; a carrier assembly, the carrier assembly includes a carrier ring and a support member, the carrier ring is used to carry the wafer, the carrier ring is arranged between the two groups of substrates, and the support member is used to support the carrier ring so that the carrier ring and the wafer can be vertically arranged between the two groups of substrates; a grinding wheel assembly, the grinding wheel assembly includes grinding wheels, there are two groups of the grinding wheels, and the two groups of grinding wheels are respectively arranged on both sides of the carrier ring so that the grinding wheels can act axially on the wafer for grinding; and a driving assembly, the driving assembly is used to drive the carrier ring and the wafer to rotate; wherein, a liquid supply port for supplying liquid to support the wafer is arranged on the substrate; a distance sensor for detecting the offset amount of the wafer is arranged on the substrate; the method includes: obtaining the pressure change amount △P, the wafer position offset amount △x and the wafer position offset rate between the substrate and the wafer; establishing a first compensation function model of the pressure change amount △P and the wafer position offset amount △x between the substrate and the wafer with respect to the liquid compensation amount Q; and adjusting the liquid compensation amount Q of the liquid supply port based on the first compensation function model to center the wafer.

[0007] Preferably, the first compensation function model is as follows:

[0008] where K r is the proportional coefficient of △x; K p is the control coefficient for adjusting the pressure change; K x is the control coefficient for adjusting the wafer position offset; K dx is the control coefficient for adjusting the wafer position offset rate.

[0009] Preferably, the grinding wheel can rotate in the vertical direction and can also rotate in the horizontal direction so that the grinding wheel can adjust the angle relative to the wafer; the method further includes: obtaining the surface topography parameters of the previous wafer and the grinding wheel wear data; wherein, the wafer surface topography parameters include the PV curve and the BOW value; establishing a second compensation function model of the surface topography parameters of the previous wafer and the grinding wheel wear data with respect to the tilt compensation amount W; adjusting the tilt compensation amount W of the grinding wheel based on the second compensation function model to center the wafer.

[0010] Preferably, the second compensation function model is as follows:

[0011] where PV rms is the root mean square of the peak-to-valley value in the PV curve graph; K PV is the control coefficient for PV rms ; △PV 1 is the maximum amplitude of the Center-mark in the PV curve; K 1 is the control coefficient for △PV 1 ; △PV 2 is the maximum amplitude of the B-ring in the PV curve; K 2 is the control coefficient for △PV 2 ; ΔB is the BOW value; K r ’ is the proportional coefficient of ΔB; K B is the control coefficient for ΔB; △X is the grinding wheel wear amount; K X is the control coefficient for △X.

[0012] Preferably, the method further includes: obtaining a liquid compensation amount Q, an inclination compensation amount W, and grinding current data; establishing a third compensation function model of the liquid compensation amount Q, the inclination compensation amount W, and the grinding current data with respect to the comprehensive compensation amount Y; and adjusting the liquid compensation amount Q of the liquid supply port and the inclination compensation amount W of the grinding wheel based on the third compensation function model to center the wafer.

[0013] Preferably, the third compensation function model is:

[0014] where is the proportionality coefficient of the liquid compensation amount; is the proportionality coefficient of the inclination compensation amount; is the proportionality coefficient of the current data in the grinding stage; is the weighted average of the difference between the reference-side current and the pressure-side current data in the grinding stage.

[0015] Preferably, a preset value θ is set, and the calculated liquid compensation amount Q is judged. If the liquid compensation amount Q < the preset value θ, the liquid compensation amount Q of the liquid supply port is adjusted based on the first compensation function model to center the wafer; if the liquid compensation amount Q > the preset value θ, the liquid compensation amount Q of the liquid supply port and the inclination compensation amount W of the grinding wheel are adjusted based on the third compensation function model to center the wafer.

[0016] On the other hand, a wafer double-sided thinning system provided by the present application adopts the following technical solution: A wafer double-sided thinning system is applied to a double-sided thinning device. The double-sided thinning device includes: a substrate assembly, the substrate assembly includes a substrate, and there are two groups of substrates, and the two groups of substrates are arranged oppositely; a carrying assembly, the carrying assembly includes a carrier ring and a support member, the carrier ring is used to carry the wafer, the carrier ring is arranged between the two groups of substrates, and the support member is used to support the carrier ring so that the carrier ring and the wafer can be vertically arranged between the two groups of substrates; a grinding wheel assembly, the grinding wheel assembly includes grinding wheels, and there are two groups of grinding wheels, and the two groups of grinding wheels are respectively arranged on both sides of the carrier ring so that the grinding wheels can act on the wafer along the axial direction for grinding; and a driving assembly, the driving assembly is used to drive the carrier ring and the wafer to rotate; wherein, a liquid supply port for supplying liquid to the wafer to support the wafer is arranged on the substrate; a distance sensor for detecting the offset amount of the wafer is arranged on the substrate; the system includes: a first parameter acquisition module, the first parameter acquisition module is used to acquire the pressure change amount △P between the substrate and the wafer, the wafer position offset amount △x, and the wafer position offset rate; a first function establishment module, the first function establishment module is used to establish a first compensation function model of the pressure change amount △P between the substrate and the wafer, the wafer position offset amount △x with respect to the liquid compensation amount Q; and a first adjustment confirmation module, the first adjustment confirmation module is used to confirm the liquid compensation amount Q of the liquid supply port based on the first compensation function model.

[0017] Preferably, the grinding wheel can rotate in the vertical direction and can also rotate in the horizontal direction so that the grinding wheel can adjust the angle with respect to the wafer; the system further includes: a second parameter acquisition module, the second parameter acquisition module is used to acquire the surface topography parameters of the previous wafer and the grinding wheel wear data; wherein, the wafer surface topography parameters include the PV curve and the BOW value; a second function establishment module, the second function establishment module is used to establish a second compensation function model of the surface topography parameters of the previous wafer, the grinding wheel wear data with respect to the inclination angle compensation amount W; and a second adjustment confirmation module, the second adjustment confirmation module is used to confirm the inclination angle compensation amount W of the grinding wheel based on the second compensation function model.

[0018] Preferably, it further includes: a third parameter acquisition module, the third parameter acquisition module is used to acquire the liquid compensation amount Q, the inclination angle compensation amount W, and the grinding current data; a third function establishment module, the third function establishment module is used to establish a third compensation function model of the liquid compensation amount Q, the inclination angle compensation amount W, the grinding current data with respect to the comprehensive compensation amount Y; and a third adjustment confirmation module, the third adjustment confirmation module is used to confirm the liquid compensation amount Q of the liquid supply port and the inclination angle compensation amount W of the grinding wheel based on the third compensation function model.

[0019] In summary, the present application includes at least one of the following beneficial technical effects: By establishing a first compensation function model for the pressure change ΔP, the wafer position offset Δx, and the liquid compensation Q between the substrate and the wafer, and adjusting the liquid supply port compensation amount based on the compensation function model, wafer centering is achieved. Description of the Drawings

[0020] Figure 1 is a schematic diagram of the double-sided thinning device described in the present application; Figure 2 is a schematic diagram of the distance measurement sensor on the substrate of the double-sided thinning device described in the present application; Figure 3 is a schematic diagram of the liquid supply port on the substrate of the double-sided thinning device described in the present application; Figure 4 is a first schematic diagram of the double-sided thinning method described in the present application; Figure 5 is a second schematic diagram of the double-sided thinning method described in the present application; Figure 6 is a schematic diagram of the PV curve in the double-sided thinning method described in the present application; Figure 7 is a third schematic diagram of the double-sided thinning method described in the present application.

[0021] Description of the Reference Numerals: 100, substrate assembly; 110, substrate; 120, liquid supply port; 130, distance sensor; 200, carrier assembly; 210, carrier ring; 220, support member; 300, grinding wheel assembly; 310, grinding wheel; 400, wafer. Detailed Description of the Embodiments

[0022] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the described objects and do not have any sequential or technical meaning. The terms "connection" and "coupling" used in the present application, unless otherwise specified, both include direct and indirect connection (coupling). In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application 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 application.

[0023] In this application, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may mean that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0024] An embodiment of this application provides a method and system for double-sided thinning of a wafer 400. By controlling liquid compensation and tilt compensation, the centering effect of the wafer 400 is improved.

[0025] To better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings of the specification and specific implementation manners. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit this application.

[0026] This application provides a method for double-sided thinning of a wafer 400, which is applied to a double-sided thinning device, such as Figure 1-3 As shown, the double-sided thinning device includes: a substrate assembly 100, a carrier assembly 200, a grinding wheel assembly 300, and a driving assembly (the driving assembly is not shown). The substrate assembly 100 includes a substrate 110, and there are two groups of substrates 110, which are arranged oppositely; the carrier assembly 200 includes a carrier ring 210 and a support member 220. The carrier ring 210 is used to carry the wafer 400, and the carrier ring 210 is arranged between the two groups of substrates 110. The support member 220 is used to support the carrier ring 210, so that the carrier ring 210 and the wafer 400 can be vertically arranged between the two groups of substrates 110. The support member 220 can rotate, so that the carrier ring 210 can rotate while being supported by the support member 220; the grinding wheel assembly 300 includes a grinding wheel 310, and there are two groups of grinding wheels 310, which are respectively arranged on both sides of the carrier ring 210, so that the grinding wheel 310 can act on the wafer 400 axially for grinding; the driving assembly is used to drive the carrier ring 210 and the wafer 400 to rotate.

[0027] It should be noted that the substrate assembly 100, the carrier assembly 200, the grinding wheel assembly 300, and the driving assembly are all existing double-sided thinning structures, and will not be elaborated in this embodiment.

[0028] Among them, as Figure 2 、 3As shown, a liquid supply port 120 for supplying liquid to the wafer 400 to support the wafer 400 is provided on the substrate 110; a distance sensor 130 for detecting the offset of the wafer 400 is provided on the substrate 110; specifically, the liquid supply port 120 is used to connect to an external liquid supply source, such as a water tank, etc., and liquid is supplied from the water tank to the liquid supply port 120 through a water pump, so that the liquid flows out of the liquid supply port 120 to support the wafer 400; in one embodiment, a plurality of liquid supply ports 120 may be provided on each substrate 110; the distance sensor 130 may adopt a pneumatic measuring instrument, and a pneumatic measuring instrument detection port is provided on the substrate 110 to detect the position of the wafer 400; in one embodiment, a plurality of pneumatic measuring instruments (distance measuring sensors) may be provided on each substrate 110.

[0029] Based on the above-mentioned double-sided thinning equipment, this embodiment proposes the following method: Figure 4 As shown, S1.1: obtaining the pressure change △P, wafer position offset △x and wafer position offset rate between the substrate 110 and the wafer 400; S1.2: establishing a first compensation function model of the pressure change △P, wafer position offset △x between the substrate 110 and the wafer 400 with respect to the liquid compensation amount Q; S1.3: adjusting the liquid compensation amount Q of the liquid supply port 120 based on the first compensation function model to center the wafer 400.

[0030] In other words, the calculation of the fluid compensation amount Q is based on the pressure change ΔP and the wafer position offset Δx. Q is related to ΔP and Δx, and the parameters required to achieve liquid dynamic compensation can be calculated by combining the correlation functions. It should be noted that the changes of ΔP and Δx are monitored in real time, and the flow rate and pressure of the fluid are dynamically adjusted according to the calculation results to achieve accurate liquid compensation.

[0031] The first compensation function model is:

[0032] Among them, K r is the proportionality coefficient of △x; K p is the control factor used to adjust the pressure change; K x is a control coefficient for adjusting wafer position offset; K dx is the control coefficient used to adjust the wafer position deviation rate.

[0033] In one embodiment, the pneumatic measuring instrument monitors the distance between the wafer 400 and the substrate 110 in real time, with 3 monitoring points on each side, for a total of 6 raw data. The wafer position offset Δx at each pneumatic measuring instrument monitoring port ij (i=1, 2, 3, j=1, 2, 3) = x 基ij -x加ij , j 1 , j 2 , j 3 correspond to the values at the tool changing position, the start of the fine grinding stage, and the start position of the optical grinding stage respectively.

[0034] By curve fitting the above 9 data, the overall skew state of the wafer 400 and the wafer position offset Δx are obtained; at the same time, Δx is sampled every 1 second ij The numerical values in the grinding stage are fitted to obtain the wafer position offset rate ; record the pressure P adjusted manually each time ij (i = 1 - 8 corresponds to 8 liquid supply ports 120, j = 1, 2 corresponds to two substrates 110), and the weighted average of each group of data is obtained , ΔP = - Ps (Ps is the standard value of 0.2 MPa).

[0035] Record the above Δx, , and ΔP numerical values into the first compensation function model ; at the same time, K r takes values in 1 / 2 steps, verifies the deviation value between the subsequent data and the model, and continuously tries to take the K r value. After obtaining more accurate numerical values, the steepest gradient confirms K p , K x , K dx and other control coefficients. So far, the first compensation function model is established.

[0036] Data fitting: The offset data is directly read and calculated through each pneumatic gauge monitoring port; for the data of 3 monitoring points in the same stage (such as the tool changing stage), cubic polynomial fitting is used to obtain the overall offset function , where t is time. For example, the offset function in the tool changing stage can be expressed as:

[0037] Among them, the coefficients a 1 , b 1 , c 1 , d 1 are determined by least squares fitting.

[0038] Offset rate calculation: By taking the derivative of the fitting function with respect to time, the offset change rate is obtained:

[0039] For example, in the fine grinding stage (j = 2), if the fitting result is , then the rate is:

[0040] Pressure deviation calculation: In one embodiment, the pressure data P of 8 water support ports is collected ij (i = 1 - 8 corresponds to 8 liquid supply ports 120, j = 1, 2, corresponding to two substrates 110), and the weighted average value is calculated:

[0041] where the weight w i is set according to the distribution symmetry of the support positions (for example, the weight of the central support position is 0.3, and the weight of the edge support position is 0.1); the pressure deviation is:

[0042] The first compensation function model is:

[0043] Initial trial value: Set K r = 0.5, and other coefficients K p = K x = K dx = 1.

[0044] Gradient descent optimization: Define the loss function: , calculate the partial derivatives of the loss with respect to each coefficient: , and similarly calculate 、 .

[0045] Update the coefficients: , where α is the learning rate (for example, α = 0.01); iterate until the loss function converges, such as L < 10 −4 .

[0046] Exemplarily: Suppose the monitoring data for a certain time is △P = 0.05 MPa, △x = 0.8 μm, = 0.2 μm / s, and the model output under the initial coefficients is: Q 模型 = 1×0.05 + 1×0.8 0.5 + 1×0.2 = 1.144; If the actual compensation amount Q 实际 = 1.5, then the loss is L = (1.5 - 1.144) 2 = 0.127; adjust the coefficients through gradient descent iteration, and finally obtain K p = 2.1, K x = 1.6, K dx = 0.5 。

[0047] However, limited by the mechanical structure, when the adjustment amount of Q is small (Q ≤ θ), liquid compensation can meet the requirements for adjusting the posture of the wafer 400; but when Q ≥ θ, the inclination compensation of the grinding wheel 310 needs to be combined: By combining the Wrap3D image obtained from the calibration wafer on the detection equipment (viewing the overall topography of the simulated wafer 400), the PV curve graph and values (viewing the unevenness degree and amplitude of the Center-mark and B-ring regions, the uniformity and values of the overall PV curve), the BOW curve and values (viewing how the wafer 400 bends on the overall level), and simultaneously comprehensively combining the current monitoring conditions on both sides of the grinding wheel 310 during each wafer grinding and the tooth consumption data of the grinding wheel 310, to adjust the small horizontal angles of the grinding wheel 310 on both sides and the left and right micron-level movement of the tool-changing position of the grinding wheel 310 in the axial direction, so as to accurately adjust the grinding upright state of the wafer 400 and the warping degree of the wafer 400, and to control the parameters of the wafer 400.

[0048] Furthermore, the grinding wheel 310 can be rotated in the vertical direction and can also be rotated in the horizontal direction, so that the grinding wheel 310 can adjust the angle relative to the wafer 400; in other words, the grinding wheel 310 can be adjusted relative to the wafer 400, so that the wafer 400 can be aligned and centered by adjusting the position of the grinding wheel 310. As Figure 5 shown, the method further includes: S2.1: Obtaining the surface topography parameters of the previous wafer and the grinding wheel wear data; wherein, the wafer surface topography parameters include the PV curve and the BOW value; S2.2: Establishing a second compensation function model of the surface topography parameters of the previous wafer and the grinding wheel wear data with respect to the inclination compensation amount W; S2.3: Adjusting the inclination compensation amount W of the grinding wheel 310 based on the second compensation function model to align the wafer 400.

[0049] The second compensation function model is:

[0050] Wherein, is the root mean square of the peak-to-valley values in the PV curve graph, reflecting the microscopic unevenness of the surface of the wafer 400; is its corresponding control coefficient; is the maximum amplitude of the Center-mark in the PV, is the maximum amplitude of the B-ring in the PV; are their corresponding control coefficients respectively; is the BOW value (including positive and negative), K r ’ is related to the coefficient ratio, is its corresponding control coefficient; is the grinding wheel wear amount during this wafer grinding, is its corresponding control coefficient; As Figure 6 shown, in the PV curve graph, collect the PV values corresponding to every 25 coordinates of the abscissa from 25 to 250 in the 1st - 4th curves i (1 ≤ i ≤ 11), and obtain the root mean square of these data .

[0051] Select the maximum / minimum value within the abscissa range of 100 - 200 to obtain , and select the maximum / minimum value within the abscissa ranges of 0 - 50 and 250 - 300 to obtain .

[0052] For each lapping, import the above , , , as well as the aforementioned , data into the W model. Take K r ’ as 1.5 for trial, and temporarily take the other coefficient ratios as 1. Verify the deviation value between the subsequent data and the model, and continuously trial the value of K r . After obtaining a more accurate value, confirm the steepest gradient , , , , and other control coefficients. Thus, the second compensation function model is established.

[0053] Specific process for determining model parameters: The PV curve reflects the peak - valley height difference at different positions on the surface of the wafer 400 during the grinding process, and is used to evaluate the surface flatness; obtain the maximum protrusion (Peak) and depression (Valley) values to form the PV curve.

[0054] The root mean square value of PV (PVrms) refers to the root mean square value of the PV curve in a specific area, and is used to quantify the surface micro - unevenness; in the range of the abscissa from 25 to 250 of the PV curve, take a point every 25, a total of 11 points (coordinates 25, 50, 75,..., 250); record the PV value (peak - valley difference) of each point, denoted as PV 1 , PV 2 ,.., PV 11 , then

[0055] Example: If the PV values of 11 points are 2, 3, 4,..., 12 μm respectively, then:

[0056] Regional peak - valley difference (△PV 1With △PV 2 ): △PV 1 : The difference between the maximum PV value and the minimum PV value is taken within the range of 100 - 200 on the abscissa:

[0057] Example: If the maximum PV value in this area is 10 μm and the minimum is 4 μm, then △PV 1 = 6 μm.

[0058] △PV 2 : The differences between the maximum and minimum PV values are taken respectively within the ranges of 0 - 50 and 250 - 300 on the abscissa, and then comprehensively calculated:

[0059] Example: If the maximum PV in the range of 0 - 50 is 8 μm and the minimum is 2 μm; the maximum PV in the range of 250 - 300 is 7 μm and the minimum is 3 μm, then: △PV 2 = max(8, 7) - min(2, 3) = 8 - 2 = 6 μm.

[0060] The BOW value (wafer 400 curvature) refers to the overall curvature degree of the wafer 400 analyzed through the Wrap3D image. The BOW value is the height difference between the center and the edge of the wafer 400; if the Wrap3D image shows that the center depression depth is +5 μm and the edge warpage is -3 μm, then: ; The wheel wear amount (ΔX) refers to the thickness reduction amount of the wheel 310 during the grinding process, which is monitored in real time by a tooth profile sensor; if the thickness of the wheel 310 is reduced by 0.1 mm after a certain grinding, then: .

[0061] The second compensation function model is: ; Set K r ’ = 1.5, and the other coefficients K PV = 1, K1 = 1, K 2 = 1, K B = 1, K X = 1; Gradient descent method optimization: Define the loss function:

[0062] Calculate the partial derivatives and update the coefficients: For example, if the PV rms term is the maximum value, then update K PV : , where β is the learning rate, such as β=0.001.

[0063] The data of three dimensions, namely PV curve, BOW curvature and grinding wheel wear, comprehensively reflect the reasons for abnormal wafer 400 posture. The max function is used to automatically select the parameters that have the greatest impact on the current state to avoid the limitations of a single factor. The exponential term of BOW and the square root term of grinding wheel wear enhance the adaptability of the model to complex processes.

[0064] When the fluid compensation reaches the limit value θ, the grinding wheel 310 tilt compensation W is further introduced. The adjustment of W is based on the microscopic roughness (rms PV) of the surface of the wafer 400, the concave and convex degree of the center-mark and B-ring areas (PV1 and PV2), the uniformity and value of the overall PV curve, the BOW value, and the grinding wheel wear ΔX. By constructing a function model of W and collecting relevant data, the optimal grinding wheel 310 tilt compensation can be calculated.

[0065] Therefore, if Figure 7 As shown, the method also includes: S3.1: obtaining liquid compensation amount Q, inclination compensation amount W and grinding current data; S3.2: establishing a third compensation function model of liquid compensation amount Q, inclination compensation amount W, and grinding current data regarding comprehensive compensation amount Y; S3.3: adjusting the liquid compensation amount Q of the liquid supply port 120 and the inclination compensation amount W of the grinding wheel 310 based on the third compensation function model to center the wafer 400.

[0066] The third compensation function model is:

[0067] in is the integration proportional coefficient of the liquid compensation amount, is the integration proportional coefficient of the tilt compensation amount, is the proportional coefficient of the current data in the grinding stage; The weighted average of the difference between the reference current and the current on the pressurized side, which is sampled every second during the grinding stage; the Q, W, Data, imported into the Y model, Try 0.7, and temporarily set the other coefficients to 1. Confirm the fastest gradient , The third compensation function model is now established.

[0068] Current difference calculation: collect the current data of the reference side and the pressurized side every second. 基 (t) and I 加 (t), where the pressurized side and the reference side correspond to the two substrates 110, and the weighted average is calculated: =

[0069] The weight w(t) can be set according to time decay (e.g., w(t)=e −0.1t ).

[0070] For the third compensation function model:

[0071] Initial trial value: Set K q = 0.7, K w = 1, K i = 1; Define the total loss function ; Update the coefficients through partial derivatives: ; Similarly, update K w and K i .

[0072] Exemplarily: Assume that in a certain adjustment, Q = 7.2, W = 30.14, = 0.5, and the model output under the initial coefficients is:

[0073] If the actual requirement Y 实际 = 38, then the loss is (38 - 35.68)^2 = 5.38, and gradually approach the target value by adjusting the coefficients.

[0074] Preferably, set a preset value θ, calculate the liquid compensation amount Q, and judge: If the liquid compensation amount Q < the preset value θ, adjust the liquid compensation amount Q of the liquid supply port 120 based on the first compensation function model to align the wafer 400; if the liquid compensation amount Q > the preset value θ, adjust the liquid compensation amount Q of the liquid supply port 120 and the inclination compensation amount W of the grinding wheel 310 based on the third compensation function model to align the wafer 400.

[0075] In other words, when Q < θ: Only adjust the liquid compensation amount Q through the first compensation function model; when Q ≥ θ: Activate the third compensation function model and adjust Q and the inclination compensation amount W of the grinding wheel 310 simultaneously.

[0076] This embodiment also provides a double-sided thinning system for a wafer 400, which is applied to a double-sided thinning device. The double-sided thinning device includes a substrate assembly 100, a carrier assembly 200, a grinding wheel assembly 300, and a driving assembly. The substrate assembly 100 includes substrates 110, and there are two groups of substrates 110 arranged oppositely; the carrier assembly 200 includes a carrier ring 210 and a support member 220. The carrier ring 210 is used to carry the wafer 400, and the carrier ring 210 is arranged between the two groups of substrates 110. The support member 220 is used to support the carrier ring 210, so that the carrier ring 210 and the wafer 400 can be vertically arranged between the two groups of substrates 110. The support member 220 can rotate, so that the carrier ring 210 can rotate while being supported by the support member 220; the grinding wheel assembly 300 includes grinding wheels 310, and there are two groups of grinding wheels 310 respectively arranged on both sides of the carrier ring 210, so that the grinding wheels 310 can act on the wafer 400 axially for grinding; the driving assembly is used to drive the carrier ring 210 and the wafer 400 to rotate.

[0077] It should be noted that the substrate assembly 100, the carrier assembly 200, the grinding wheel assembly 300, and the driving assembly are all existing double-sided thinning structures, and will not be elaborated in this embodiment.

[0078] Among them, a liquid supply port 120 for supplying liquid to the wafer 400 to support the wafer 400 is arranged on the substrate 110; a distance sensor 130 for detecting the offset of the wafer 400 is arranged on the substrate 110; specifically, the liquid supply port 120 is used to connect to an external liquid supply source, such as a water tank, etc. The water tank supplies liquid to the liquid supply port 120 through a water pump, so that the liquid flows out from the liquid supply port 120 to support the wafer 400; in one embodiment, multiple liquid supply ports 120 can be arranged on each substrate 110; the distance sensor 130 can adopt a pneumatic gauge, and a pneumatic gauge detection port is arranged on the substrate 110 to detect the position of the wafer 400; in one embodiment, multiple pneumatic gauges (distance measuring sensors) can be arranged on each substrate 110.

[0079] The double-sided thinning system includes: A first parameter acquisition module, which is used to acquire the pressure change amount △P, the wafer position offset amount △x, and the wafer position offset rate between the substrate 110 and the wafer 400; A first function establishment module, which is used to establish a first compensation function model of the pressure change amount △P, the wafer position offset amount △x, and the liquid compensation amount Q between the substrate 110 and the wafer 400; and A first adjustment confirmation module, which is used to confirm the liquid compensation amount Q of the liquid supply port 120 based on the first compensation function model.

[0080] Further, the grinding wheel 310 is rotatable in the vertical direction and also in the horizontal direction, so that the angle of the grinding wheel 310 relative to the wafer 400 can be adjusted; the system further includes: A second parameter acquisition module, which is used to acquire the surface topography parameters of the previous wafer and the grinding wheel wear data; wherein, the wafer surface topography parameters include the PV curve and the BOW value; A second function establishment module, which is used to establish a second compensation function model of the surface topography parameters of the previous wafer, the grinding wheel wear data, and the inclination compensation amount W; and A second adjustment confirmation module, which is used to confirm the inclination compensation amount W of the grinding wheel 310 based on the second compensation function model.

[0081] Further, the system further includes: a third parameter acquisition module, which is used to acquire the liquid compensation amount Q, the inclination compensation amount W, and the grinding current data; A third function establishment module, which is used to establish a third compensation function model of the liquid compensation amount Q, the inclination compensation amount W, the grinding current data, and the comprehensive compensation amount Y; and A third adjustment confirmation module, which is used to confirm the liquid compensation amount Q of the liquid supply port 120 and the inclination compensation amount W of the grinding wheel 310 based on the third compensation function model.

[0082] Although the preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications once they learn the basic creative concepts. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present application.

[0083] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these modifications and variations.

Claims

1. A double-sided wafer thinning method, applied to a double-sided wafer thinning device, characterized in that: The double-sided thinning device comprises: A substrate assembly (100), the substrate assembly (100) comprising substrates (110), the substrates (110) having two groups, the two groups of substrates (110) being arranged opposite to each other; A carrying assembly (200), the carrying assembly (200) comprising a carrying ring (210) and a supporting member (220), the carrying ring (210) being used to carry a wafer (400), the carrying ring (210) being arranged between two groups of substrates (110), and the supporting member (220) being used to support the carrying ring (210), so that the carrying ring (210) and the wafer (400) can be arranged vertically between the two groups of substrates (110); A grinding wheel assembly (300), the grinding wheel assembly (300) comprising a grinding wheel (310), the grinding wheel (310) having two groups, the two groups of grinding wheels (310) being respectively arranged on both sides of the carrier ring (210), so that the grinding wheel (310) can act on the wafer (400) in an axial direction for grinding; and a driving component, the driving component being used to drive the carrier ring (210) and the wafer (400) to rotate; The substrate (110) is provided with a liquid supply port (120) for supplying liquid to the wafer (400) to support the wafer (400); the substrate (110) is provided with a distance sensor (130) for detecting the offset of the wafer (400); The method comprises: Obtaining a pressure change ΔP between the substrate (110) and the wafer (400), a wafer position offset Δx, and a wafer position offset rate; Establishing a first compensation function model of the pressure change ΔP between the substrate (110) and the wafer (400) and the wafer position offset Δx with respect to the liquid compensation amount Q; The liquid compensation amount Q of the liquid supply port (120) is adjusted based on the first compensation function model to center the wafer (400).

2. A wafer double-sided thinning method according to claim 1, characterized in that: The first compensation function model is: Among them, K r is the proportionality coefficient of △x; K p is the control factor used to adjust the pressure change; K x is a control coefficient for adjusting wafer position offset; K dx is the control coefficient used to adjust the wafer position deviation rate.

3. A double-sided wafer thinning method according to claim 2, characterized in that: The grinding wheel (310) is capable of rotating in a vertical direction and in a horizontal direction, so that the grinding wheel (310) can be adjusted in angle relative to the wafer (400); The method further comprises: Obtaining the surface morphology parameters of the previous wafer and the grinding wheel wear data; wherein the surface morphology parameters of the wafer include a PV curve and a BOW value; Establish a second compensation function model of the surface morphology parameters of the previous wafer and the grinding wheel wear data with respect to the tilt angle compensation amount W; The tilt compensation amount W of the grinding wheel (310) is adjusted based on the second compensation function model to center the wafer (400).

4. A wafer double-sided thinning method according to claim 3, characterized in that: The second compensation function model is: Among them, PV rms K is the root mean square of the peak and valley values ​​in the PV curve; PV For PV rms The control coefficient of △PV1 is the maximum value of Center-mark in PV curve; K1 is the control coefficient of △PV1; △PV2 is the maximum amplitude of B-ring in the PV curve; K2 is the control coefficient of △PV2; ΔB is the BOW value; K r ' is the proportionality coefficient of ΔB; K B is the control coefficient of ΔB; △X is the wear of the grinding wheel; K X is the control coefficient of △X.

5. A wafer double-sided thinning method according to claim 4, characterized in that: The method further comprises: Obtain liquid compensation amount Q, inclination compensation amount W and grinding current data; Establishing a third compensation function model of liquid compensation amount Q, inclination compensation amount W, and grinding current data with respect to comprehensive compensation amount Y; Based on the third compensation function model, the liquid compensation amount Q of the liquid supply port (120) and the tilt compensation amount W of the grinding wheel (310) are adjusted to center the wafer (400).

6. A wafer double-sided thinning method according to claim 5, characterized in that: The third compensation function model is: in, is the proportional coefficient of liquid compensation; is the proportional coefficient of the inclination compensation; is the proportional coefficient of the current data in the grinding stage; It is the weighted average of the difference between the baseline current measured during the grinding phase and the current on the pressurized side.

7. A double-sided wafer thinning method according to claim 5 or 6, characterized in that: Set the preset value θ, calculate the liquid compensation amount Q, and judge: If the liquid compensation amount Q is less than a preset value θ, adjusting the liquid compensation amount Q of the liquid supply port (120) based on the first compensation function model to center the wafer (400); If the liquid compensation amount Q>preset value θ, the liquid compensation amount Q of the liquid supply port (120) and the tilt compensation amount W of the grinding wheel (310) are adjusted based on the third compensation function model to center the wafer (400).

8. A wafer double-sided thinning system, applied to a double-sided thinning device, characterized in that: The double-sided thinning device comprises: A substrate assembly (100), the substrate assembly (100) comprising substrates (110), the substrates (110) having two groups, the two groups of substrates (110) being arranged opposite to each other; A carrying assembly (200), the carrying assembly (200) comprising a carrying ring (210) and a supporting member (220), the carrying ring (210) being used to carry a wafer (400), the carrying ring (210) being arranged between two groups of substrates (110), and the supporting member (220) being used to support the carrying ring (210), so that the carrying ring (210) and the wafer (400) can be arranged vertically between the two groups of substrates (110); A grinding wheel assembly (300), the grinding wheel assembly (300) comprising a grinding wheel (310), the grinding wheel (310) having two groups, the two groups of grinding wheels (310) being respectively arranged on both sides of the carrier ring (210), so that the grinding wheel (310) can act on the wafer (400) in an axial direction for grinding; and a driving component, the driving component being used to drive the carrier ring (210) and the wafer (400) to rotate; The substrate (110) is provided with a liquid supply port (120) for supplying liquid to the wafer (400) to support the wafer (400); the substrate (110) is provided with a distance sensor (130) for detecting the offset of the wafer (400); The system comprises: A first parameter acquisition module, the first parameter acquisition module being used to acquire a pressure change ΔP between the substrate (110) and the wafer (400), a wafer position offset Δx, and a wafer position offset rate; A first function establishment module, the first function establishment module being used to establish a first compensation function model of a pressure change ΔP between a substrate (110) and a wafer (400), and a wafer position offset Δx with respect to a liquid compensation amount Q; and A first adjustment confirmation module, the first adjustment confirmation module is used to confirm the liquid compensation amount Q of the liquid supply port (120) based on the first compensation function model.

9. A wafer double-sided thinning system according to claim 8, characterized in that: The grinding wheel (310) is capable of rotating in a vertical direction and in a horizontal direction, so that the grinding wheel (310) can be adjusted in angle relative to the wafer (400); The system further comprises: A second parameter acquisition module, the second parameter acquisition module is used to obtain the surface morphology parameters of the previous wafer and the wear data of the grinding wheel; wherein the surface morphology parameters of the wafer include a PV curve and a BOW value; A second function establishment module, the second function establishment module is used to establish a second compensation function model of the surface morphology parameters of the previous wafer and the grinding wheel wear data with respect to the inclination compensation amount W; and A second adjustment confirmation module, the second adjustment confirmation module is used to confirm the inclination compensation amount W of the grinding wheel (310) based on the second compensation function model.

10. A wafer double-sided thinning system according to claim 9, characterized in that: Also includes: A third parameter acquisition module, the third parameter acquisition module is used to obtain liquid compensation amount Q, inclination compensation amount W and grinding current data; A third function establishment module, the third function establishment module is used to establish a third compensation function model of liquid compensation amount Q, inclination compensation amount W, and grinding current data with respect to comprehensive compensation amount Y; and A third adjustment confirmation module, the third adjustment confirmation module is used to confirm the liquid compensation amount Q of the liquid supply port (120) and the inclination compensation amount W of the grinding wheel (310) based on the third compensation function model.

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