Crystal bar cutting method and wafer

Abstract

The invention discloses a crystal bar cutting method and a wafer, and belongs to the technical field of crystal bar machining, and the crystal bar cutting method comprises the steps that mortar is sprayed to a cutting line, the cutting line and a crystal bar are moved oppositely in the feeding direction, and the crystal bar is cut through the cutting line; the cutting process is divided into m speed changing stages in the feeding direction, the linear speed of a cutting line in each speed changing stage is Vx, x is larger than or equal to 1 and smaller than or equal to m, m is larger than or equal to 3 and smaller than or equal to 30, x is an integer, and m is an integer; and according to the cutting depth hx at the beginning of each speed change stage, the linear speed Vx in each speed change stage is determined, and along with the increase of the cutting depth hx, the linear speed Vx is firstly reduced and then increased. According to the invention, the linear speed of the cutting line in the cutting process is adjusted according to the cutting depth of the cutting line so as to change the number of the mortar particles mounted on the cutting line in the unit length, so that the cutting force of the cutting line is changed, the cutting force of the cutting line is matched with the size of the cutting part, and the flatness of the wafer is improved.

Description

Technical Field

[0001] This application belongs to the field of crystal rod processing technology, specifically relating to crystal rod cutting methods and wafers. Background Technology

[0002] A crystal rod can be cut into multiple thin-film substrates using dicing wires, and these thin-film substrates can be further processed to obtain a wafer.

[0003] However, during the cutting process of the crystal rod, cutting errors will occur, resulting in an uneven surface of the thin substrate, forming abnormal morphology areas on the wafer surface, which affects the flatness of the produced wafer. Summary of the Invention

[0004] Purpose of the invention: This application provides a method for cutting crystal rods to solve the technical problem that cutting errors result in an uneven surface of a thin-film substrate; another purpose of this application is to provide a wafer.

[0005] Technical solution: This application provides a method for cutting crystal rods, including: spraying slurry onto a cutting line, moving the cutting line and the crystal rod in opposite directions along the feed direction, and cutting the crystal rod through the cutting line;

[0006] Along the feed direction, the cutting process is divided into m speed-changing stages, and the linear velocity of the cutting line in each speed-changing stage is V. x , 1≤x≤m, 3≤m≤30, where x is an integer and m is an integer;

[0007] Based on the cutting depth h at the beginning of each speed change phase x Determine the linear velocity V within each of the aforementioned speed change stages. x And as the cutting depth h x With the increase of linear velocity V x It first decreases and then increases.

[0008] In some embodiments, based on the cutting depth h at the start of each speed-changing phase x Based on the dimensions of the crystal ingot, determine the length l along the extension direction of the cutting line at the contact position between the crystal ingot and the cutting line at the beginning of each speed-changing stage. x According to the length dimension l in each of the aforementioned speed-changing stages x Determine the linear velocity V in each of the aforementioned speed change stages. x .

[0009] In some embodiments, V x =v1-l x / a, where v1 is the initial linear velocity when the cutting line just contacts the crystal rod, l x =2(R)2 -(Rh x ) 2 ) 0.5 , a is an adjustment coefficient, a > 0; R is the radius of the crystal rod; h x =D(x-1) / m, where D is the diameter of the crystal rod.

[0010] In some embodiments, the adjustment coefficient a satisfies: 0.1D < a < D.

[0011] In some embodiments, the cutting process along the feed direction is divided into n temperature-changing stages, and the stage temperature in each temperature-changing stage is T. y , 1≤y≤n, 3≤n≤30, where y is an integer and n is an integer;

[0012] According to the cutting depth H at the beginning of each of the temperature change stages y Determine the stage temperature T within each of the temperature variation stages. y And as the cutting depth H y With the increase of [something], the stage temperature T y It first rises and then falls.

[0013] In some embodiments, based on the cutting depth H at the start of each temperature variation phase y Based on the dimensions of the crystal rod, determine the length l of the contact position between the crystal rod and the cutting line along the extension direction of the cutting line at the beginning of each temperature variation stage. y According to the length dimension l in each of the temperature variation stages y Determine the stage temperature T in each of the temperature variation stages. y .

[0014] In some embodiments, T y =t1-l y / b, where t1 is the initial stage temperature when the dicing line just contacts the crystal rod, l y =2(R) 2 -(RH y ) 2 ) 0.5 b is an adjustment coefficient, b > 0; R is the radius of the crystal rod; H y =D(y-1) / n, where D is the diameter of the crystal rod.

[0015] In some embodiments, the adjustment coefficient b satisfies: 0.2D < b < 10D.

[0016] In some embodiments, the temperature θ1 of the mortar satisfies: θ1=θ0-Δθ, where θ0 is room temperature, 0℃<Δθ≤3℃.

[0017] Accordingly, this application also provides a wafer manufactured using the ingot cutting method described in any of the above embodiments.

[0018] Beneficial effects: Compared with the prior art, the crystal rod cutting method provided in this application includes spraying slurry onto the cutting wire, moving the cutting wire and the crystal rod in opposite directions along the feed direction, and cutting the crystal rod through the cutting wire; the cutting process is divided into m speed-changing stages along the feed direction, and the linear velocity of the cutting wire in each speed-changing stage is V. x 1≤x≤m, 3≤m≤30, where x and m are integers; based on the cutting depth h at the beginning of each speed-changing stage. x Determine the linear velocity V within each speed change phase. x And as the cutting depth h x With the increase of linear velocity V x First lower, then raise. This application adjusts the linear speed of the cutting line during the cutting process according to the cutting depth of the cutting line to change the number of mortar particles adhering to the cutting line per unit length, thereby changing the cutting force of the cutting line so that the cutting force of the cutting line matches the size of the cutting part, thereby improving the flatness of the wafer made from the crystal ingot. Attached Figure Description

[0019] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0020] Figure 1 A schematic diagram illustrating the change in the linear velocity of the cutting line in the crystal rod cutting method provided in the embodiments of this application;

[0021] Figure 2 This is a schematic diagram of the structure of the cutting equipment in the crystal rod cutting method provided in the embodiments of this application;

[0022] Figure 3 In the crystal rod cutting method provided in the embodiments of this application, l x and h x A diagram illustrating the annotations;

[0023] Figure 4 In the crystal rod cutting method provided in the embodiments of this application, l x A schematic diagram illustrating the changes;

[0024] Figure 5 This is a schematic diagram of the cutting equipment in the crystal rod cutting method provided in this application embodiment from another angle;

[0025] Figure 6 A schematic diagram illustrating the change in stage temperature during the crystal rod cutting method provided in this application embodiment;

[0026] Figure 7This is a schematic diagram of the structure of the cutting equipment in the crystal rod cutting method provided in the embodiments of this application;

[0027] Figure 8 In the crystal rod cutting method provided in the embodiments of this application, l y and H y A diagram illustrating the annotations;

[0028] Figure 9 In the crystal rod cutting method provided in the embodiments of this application, l y A diagram illustrating the changes.

[0029] Explanation of reference numerals in the attached figures:

[0030] 100-Crystal rod, 200-Cutting line, 300-Slurry, 400-Spindle, 500-Frame, 600-Stage, X-Extension direction of cutting line, Y-Axial direction, Z-Feed direction. Detailed Implementation

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0032] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for mutual communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. In the description of this application, "multiple" means two or more, unless otherwise expressly and specifically limited. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more features.

[0033] It should also be noted that in the accompanying drawings of the embodiments of this application, the arrows labeled X, Y, and Z respectively represent the extension direction X, axial direction Y, and feed direction Z of the cutting line. The description of this application introduces the extension direction X, axial direction Y, and feed direction Z of the cutting line to more clearly express the relative positional relationship involved in this application. The extension direction X, axial direction Y, and feed direction Z of the cutting line are three relative directions that intersect each other, rather than absolute directions. In practical applications, the extension direction X, axial direction Y, and feed direction Z of the cutting line can point to any direction in space, as long as the intersection relationship between the two is maintained.

[0034] The following disclosure provides many different implementations or examples for carrying out different structures of this application. To simplify the disclosure of this application, the components and arrangements of specific examples are described below. Of course, these are merely examples and are not intended to limit this application.

[0035] The crystal ingot 100 can be cut into multiple thin-film substrates by using the cutting line 200, and further processing of these thin-film substrates can yield a wafer.

[0036] However, during the cutting process of the crystal ingot 100, cutting errors will occur, resulting in an uneven surface of the thin substrate, forming abnormal morphology areas on the wafer surface, which affects the flatness of the wafer.

[0037] Understandably, when the crystal ingot 100 is being cut, it moves relative to the cutting line 200 along the feed direction Z. The size of the cut surface along the feed direction Z in the extension direction X of the cutting line first increases and then decreases. If the cutting force of the cutting line 200 on the crystal ingot 100 remains constant, then in the middle stage of the cutting process, due to the increase in the size of the cut area, the cutting force will be insufficient, resulting in abnormal areas on the cut surface.

[0038] To address the aforementioned technical problem of wafer flatness being affected by dicing errors, this application provides a dicing method. Please refer to [link to relevant documentation]. Figure 1 and Figure 2 The cutting method includes: spraying mortar 300 onto the cutting line 200; moving the cutting line 200 and the crystal rod 100 towards each other along the feed direction Z; and cutting the crystal rod 100 through the cutting line 200; dividing the cutting process into m speed-changing stages along the feed direction Z, wherein the linear velocity of the cutting line 200 in each speed-changing stage is V. x 1≤x≤m, 3≤m≤30, where x and m are integers; based on the cutting depth h at the beginning of each speed-changing stage. x Determine the linear velocity V within each speed change phase. x And as the cutting depth h x With the increase of linear velocity V x It first decreases and then increases.

[0039] In some embodiments, the mortar 300 contains mortar particles, and at least a portion of the mortar particles in the mortar 300 sprayed toward the cutting line 200 can be attached to the cutting line 200 to generate a cutting force when the cutting line 200 contacts the crystal rod 100 and moves relative to the crystal rod 100.

[0040] It is understandable that the faster the linear velocity of the cutting line 200, the longer the cutting line 200 can be sprayed with the same amount of mortar 300, and the fewer mortar particles carried by the cutting line 200 per unit length; the slower the linear velocity of the cutting line 200, the shorter the cutting line 200 can be sprayed with the same amount of mortar 300, and the more mortar particles carried by the cutting line 200 per unit length.

[0041] The linear velocity of the cutting line 200 first decreases and then increases. Combined with the spraying of mortar 300, the number of mortar particles carried per unit length of the cutting line 200 first increases and then decreases, and the cutting force of the cutting line 200 first increases and then decreases.

[0042] It is understandable that when the cutting line 200 is at different cutting depths, the size of the contact area between the crystal rod 100 and the cutting line 200 is different, and the required cutting force is different.

[0043] In the above embodiment, the linear velocity of the cutting line 200 is changed according to the cutting depth to change the number of mortar particles carried per unit length of the cutting line 200, thereby changing the cutting force of the cutting line 200. This allows the cutting force to match the size change of the crystal rod 100, so that the wafer cut from the crystal rod 100 can obtain better flatness.

[0044] Furthermore, in the above embodiments, by limiting the variation in the linear velocity of the cutting line 200 during the cutting process, the amount of slurry particles carried per unit length by the cutting line 200 first increases and then decreases during the cutting process. This means that during the cutting process, the cutting force of the cutting line 200 first increases and then decreases, which is the same as the trend of the dimension of the crystal ingot 100 along the extension direction X of the cutting line in the feed direction Z, which first increases and then decreases. That is, when cutting smaller areas, the cutting force of the cutting line 200 on the crystal ingot 100 is smaller, and when cutting larger areas, the cutting force of the cutting line 200 on the crystal ingot 100 is larger. The trend of the cutting force of the cutting line 200 on the crystal ingot 100 matches the trend of the dimension change of the crystal ingot 100, reducing the possibility of uneven cut surfaces and abnormal areas forming on the wafer due to insufficient cutting force, resulting in better cutting effect and higher cutting yield.

[0045] Specifically, the value of m can be one of the following: 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30.

[0046] When the value of m is small, the linear velocity of the cutting line 200 changes less frequently, making control simpler. When the value of m is large, the change in the linear velocity of the cutting line 200 is more consistent with the change in the dimension of the cutting surface along the feed direction Z in the extension direction X of the cutting line, resulting in a smoother cutting surface. When m is within the range defined in the embodiments of this application, under the premise of a relatively simple control method, the change in the linear velocity of the cutting line 200 is also more consistent with the change in the dimension of the cutting surface along the feed direction Z in the extension direction X of the cutting line.

[0047] in, Figure 1 The horizontal axis represents the shift stage x, and the vertical axis represents V. x , Figure 1 The drawing is based on an embodiment where m = 20. In the first aspect, in the above embodiment, the cutting process is divided into multiple speed-changing stages, and the cutting depth h at the beginning of each speed-changing stage is considered. x To determine the linear velocity V within each speed change phase. x That is, the linear velocity V is redefined at each speed change stage. x This can reduce the accumulation of errors and improve the overall accuracy of cutting.

[0048] Secondly, in the above embodiments, based on the cutting depth h at the beginning of each speed-changing stage... x To determine the linear velocity V within each speed change phase. x It can decompose the dynamically changing linear velocity required during the cutting process into static linear velocities V in multiple speed-changing stages. x This facilitates the control of linear velocity variations and simplifies the complexity of the control system. Furthermore, the cutting depth h is determined by selecting the moment at the beginning of each speed-changing stage. x This allows for the standardization of control logic, reducing the impact of cutting depth h in each speed-changing stage. x The possibility of other variables arising from differences in the selected time point is considered, thereby improving the robustness of this segmentation method.

[0049] Thirdly, in the above embodiments, by limiting the value of m, the cutting surface can be made relatively flat while making the control method simpler, thereby resulting in a higher cutting yield and a wafer with better flatness after being cut by the crystal ingot 100.

[0050] In some embodiments, in each speed change stage, the portion cut by the cutting line 200 has the same dimension along the feed direction Z.

[0051] In some embodiments, m = D / α, α ∈ [10, 20]; where D is the maximum dimension of the crystal rod 100 along the feed direction Z, and the unit of D is mm. The unit of α is also mm, that is, in each speed change stage, the cutting distance of the cutting line 200 along the feed direction Z is α mm.

[0052] When α is small, that is, when the cutting distance of each speed change stage is small, the linear velocity change between adjacent speed change stages is small, the linear velocity change is relatively stable, and the quality of the entire slicing process is good. When α is large, that is, when the cutting distance of each speed change stage is large, the linear velocity remains constant for a longer time, and the slicing quality within each speed change stage is good. When α is within the range defined in this application, the quality of the entire slicing process and the slicing quality within each speed change stage are both good.

[0053] In some embodiments, m = D / 10, that is, in each speed change stage, the cutting distance of the cutting line 200 along the feed direction Z is 10mm.

[0054] In the above embodiments, limiting the cutting distance to the same value in each speed-changing stage means that the step size of each speed-changing stage is fixed, making control simpler. Furthermore, the same cutting distance reduces variables, making it easier to adjust the parameters in each speed-changing stage based on the cutting results, thus facilitating the optimization of cutting parameters.

[0055] In some embodiments, please refer to Figure 3 Based on the cutting depth h at the beginning of each speed change stage x Based on the dimensions of the crystal ingot 100, determine the length l of the contact position between the crystal ingot 100 and the cutting line 200 along the extension direction X of the cutting line at the beginning of each speed change stage. x According to the length dimension l in each speed change stage x Determine the linear velocity V x .

[0056] It is understandable that when the length dimension l of the orthographic projection... x When the size is large, the cutting force required for the crystal rod 100 is also large; when the length dimension l of the orthographic projection is large... x When the force is smaller, the cutting force required for the crystal rod 100 is also smaller.

[0057] Specifically, the cutting surface swept by the cutting line 200 along the feed direction Z in each speed change stage is... Figure 3 The area enclosed by two adjacent dashed lines along the feed direction Z, or the area enclosed by the dashed line and the outline of the crystal rod 100. Figure 3 In the middle, the feed direction Z is from top to bottom, that is, the cutting line 200 cuts from top to bottom. At the beginning of the speed change stage of cutting in the shaded area, the length dimension l of the orthographic projection along the extension direction X of the cutting line is... x, is the length of the uppermost dashed line edge in the shaded area.

[0058] pass Figure 4 It can be seen that the length dimension l x The trend of change is the same as the trend of change of the dimension of the crystal rod 100 along the extension direction X of the cutting line along the feed direction Z.

[0059] in, Figure 4 The horizontal axis represents the shift stage x, and the vertical axis represents l. x , Figure 1 The example with m=20 is illustrated.

[0060] Firstly, in the above embodiments, based on the cutting depth h x The length of the contact position between the crystal ingot 100 and the dicing line 200 along the extension direction X of the dicing line is determined by the dimensions of the crystal ingot 100. x Compared to directly obtaining the length dimension l x The value of can reduce the error and cumulative error caused by the lag between the calculated value and the actual value due to the sampling delay, making the cutting more accurate.

[0061] Secondly, in the above embodiments, based on the length dimension l x To determine the linear velocity V of the cutting line 200. x This alters the amount of slurry particles carried per unit length of the cutting wire 200, thus affecting the cutting force of the cutting wire 200 on the crystal ingot 100. This ensures that the length of the portion of the cutting wire 200 in contact with the crystal ingot 100 along the cutting wire's extension direction X matches the cutting force. When the length of the portion in contact with the crystal ingot 100 along the cutting wire's extension direction X is larger, the cutting wire 200 receives a larger cutting force; conversely, when the length is smaller, it receives a smaller cutting force. This results in a smoother cut surface, a higher cutting yield, and wafers cut from the crystal ingot 100 exhibiting better flatness. Furthermore, based on the length l at the beginning of the speed-changing stage... x To determine the linear velocity V of the cutting line 200. x This simplifies the process while also increasing the linear velocity V of the cutting line 200. x The dimensions of the contact area between the actual crystal rod 100 and the cutting line 200 along the extension direction X of the cutting line are relatively consistent.

[0062] In some embodiments, the linear velocity V is determined based on the length dimension of the orthographic projection along the extension direction X of the cutting line at the end of each speed change phase. xIn some embodiments, the linear velocity V is determined based on the length of the orthographic projection along the extension direction X of the cutting line at a certain time point during the duration of each gear shift. x The same time point exists in different speed change stages. The specific time point is the moment when time S has elapsed after the start of the speed change stage. Alternatively, it can be the moment after the start of the speed change stage when the cutting line 200 and the crystal rod 100 have moved a distance of L millimeters along the feed direction Z.

[0063] In some embodiments, please refer to Figure 2 V x =v1-l x / a, where v1 is the initial linear velocity when the cutting line 200 just contacts the crystal rod 100, l x =2(R) 2 -(Rh x ) 2 ) 0.5 , a is an adjustment coefficient, a > 0; R is the radius of the crystal rod 100, h x =D(x-1) / m, where D is the diameter of the crystal rod 100.

[0064] Specifically, h x Before each speed change stage begins, the portion of the crystal rod 100 that has been cut by the cutting line 200 is defined along the feed direction Z. In the first speed change stage, x = 1, h1 = 0.

[0065] in, Figure 1 The drawing was performed using an example with v1 = 12 mm / min and m = 20.

[0066] In some embodiments, 8 mm / min ≤ v1 ≤ 25 mm / min.

[0067] Specifically, the value of v1 can be any one of the following: 8 mm / min, 9 mm / min, 10 mm / min, 11 mm / min, 12 mm / min, 13 mm / min, 14 mm / min, 15 mm / min, 16 mm / min, 17 mm / min, 18 mm / min, 19 mm / min, 20 mm / min, 21 mm / min, 22 mm / min, 23 mm / min, 24 mm / min, 25 mm / min, or any value within the range of any two values.

[0068] When the value of v1 is small, the cutting wire 200 carries relatively more slurry particles during the entire process of cutting the crystal rod 100, resulting in stronger cutting force and higher cutting quality. When the value of v1 is large, the cutting wire 200 has stronger chip removal capability and higher cutting efficiency during the entire process of cutting the crystal rod 100. When the value of v1 is within the range defined in the above embodiments, the cutting efficiency is high and the cutting success rate is also high.

[0069] In the above embodiments, due to V x It is a variable about v1. By limiting the value of the initial linear velocity v1 when the cutting line 200 just contacts the crystal rod 100, the linear velocity V in each speed-changing stage of the entire cutting process can be determined. x Limitations are imposed to ensure high cutting efficiency and success rate throughout the entire cutting process.

[0070] In the above embodiment, the cutting depth h at the start of each speed change is determined based on the diameter D of the cylindrical crystal rod 100. x Then, based on the cutting depth h x The radius R of the crystal ingot 100 determines the length l of the contact position between the cylindrical crystal ingot 100 and the dicing line 200 along the extension direction X of the dicing line. x Thus, it is possible to determine the length dimension l x To adjust the cutting force, that is, to change the linear velocity of the cutting line 200.

[0071] Furthermore, in the above embodiments, an adjustment coefficient 'a' is introduced to adjust the linear velocity variation and the length dimension 'l'. x The relationship makes V x The value of is more reasonable.

[0072] In some embodiments, the adjustment coefficient a satisfies: 0.1D < a < D.

[0073] Specifically, the value of a can be any one of 0.1D, 0.15D, 0.2D, 0.25D, 0.3D, 0.35D, 0.4D, 0.45D, 0.5D, 0.55D, 0.6D, 0.65D, 0.7D, 0.75D, 0.8D, 0.85D, 0.9D, 0.95D, 1.0D, or a value in between.

[0074] When a is small, the change in linear velocity is large, V x When the value of 'a' is small, the cutting line 200 carries more mortar particles, resulting in high cutting force and high cutting yield; when 'a' is large, the change in linear velocity is small, and V... x A larger value indicates higher chip removal efficiency and higher cutting efficiency; when a is within the range defined in the embodiments of this application, the cutting efficiency is higher and the cutting yield is higher.

[0075] In the above embodiments, by limiting the range of values ​​for 'a', the cutting efficiency and yield are improved. Simultaneously, by associating the value of 'a' with the diameter D of the cylindrical crystal rod 100, the adjustment coefficient 'a' can be applied to cylindrical crystal rods 100 of various specifications, thereby enhancing the applicability of the crystal rod 100 cutting method.

[0076] The technical solutions provided in the embodiments of this application will be described below with reference to specific examples.

[0077] Example 1: The diameter of the crystal rod 100 is D = 300 mm, R = 150 mm, m = 20, a = 2 / 3D = 200, v1 = 12 mm / min, and the speed V in each speed change stage is... x as follows.

[0078]

[0079]

[0080] As can be seen from the table above, in the above embodiments, V m =V 20 =11.34617mm / min, that is, v3=11.34617mm / min.

[0081] In the above embodiment, the linear velocity V of the cutting line 200 x By first decreasing the cutting speed and then increasing it, the cutting wire 200 carries fewer slurry particles per unit length when cutting the two ends of the crystal ingot 100 along the feed direction Z, resulting in a smaller cutting force. Conversely, when cutting the middle portion of the crystal ingot 100 along the feed direction Z, it carries more slurry particles per unit length, resulting in a larger cutting force. This ensures that the cutting force matches the dimension of the cut portion of the crystal ingot 100 along the extension direction X of the cutting wire, improving yield. Furthermore, dividing the crystal ingot 100 cutting process into 20 speed-changing stages simplifies control, and the cutting speed of the cutting wire 200 better matches the change in the dimension of the cut surface along the feed direction Z in the extension direction X of the cutting wire.

[0082] In some embodiments, please refer to Figure 5The cutting equipment includes a frame 500, a spindle 400, a cutting wire 200, and a stage 600. One end of the spindle 400 along the Y direction of the crystal rod 100 is rotatably connected to the frame 500. The cutting wire 200 is wound around the spindle 400, and the spindle 400 is connected to the cutting wire 200 and can drive the cutting wire 200 to move by rotation. The stage 600 is connected to the side of the frame 500 near the spindle 400. The stage 600 can move closer to or away from the spindle 400 so that the crystal rod 100 connected to the side of the stage 600 near the cutting wire 200 can move relative to the cutting wire 200 along the feed direction Z and be cut by the cutting wire 200.

[0083] Understandably, the dicing wire 200 cuts the crystal ingot 100 by rubbing against it. During the cutting process, the dicing wire 200 generates heat due to friction, causing its temperature to rise. This heat is conducted to the spindle 400, which is connected to it. The spindle 400 also experiences a temperature increase, causing it to expand and its length along the Y-axis of the crystal ingot 100 to increase. However, the increase in the length of the crystal ingot 100 along the Y-axis is less than the increase in the length of the spindle 400 along the Y-axis. This results in a relative movement between the dicing wire 200, which is wound around the spindle 400, and the crystal ingot 100 during the cutting process. This leads to an uneven cutting surface, low cutting yield, and low flatness of the wafer produced after cutting.

[0084] In some embodiments, the crystal rod 100 is a cylindrical crystal rod 100.

[0085] Specifically, during the cutting process, the size of the contact area between the cutting line 200 and the crystal rod 100 along the extension direction X of the cutting line first increases and then decreases, the heat generated by the cutting line 200 first increases and then decreases, the temperature of the spindle 400 first rises and then falls, the degree of expansion of the spindle 400 along the axial direction Y first increases and then decreases, and the size of the spindle 400 along the axial direction Y first increases and then decreases.

[0086] In some embodiments, please refer to Figure 6 Along the feed direction Z, the cutting process is divided into n temperature-changing stages, and the stage temperature of the stage 600 in each temperature-changing stage is T. y 1 ≤ y ≤ n, 3 ≤ n ≤ 30, where y is an integer and n is an integer. Based on the cutting depth H at the beginning of each temperature variation stage. y Determine the stage temperature T during each temperature change stage. y And as the cutting depth H y With the increase of [something], the stage temperature T y It first rises and then falls.

[0087] Understandably, since the stage 600 is connected to the side of the frame 500 near the spindle 400, the stage 600 will expand along the axial direction Y of the spindle 400 when the temperature rises, and the size of the stage 600 along the axial direction Y of the spindle 400 will increase. When the temperature drops, the stage 600 will contract along the axial direction Y of the spindle 400, and the size of the stage 600 along the axial direction Y of the spindle 400 will decrease.

[0088] It is understandable that when the cutting line 200 is at different cutting depths, the size of the contact area between the crystal rod 100 and the cutting line 200 is different, the heat generated by cutting is different, and the degree of expansion of the spindle 400 along the axial direction Y is different.

[0089] In the above embodiments, based on the cutting depth H y To change the stage temperature T of stage 600 y This is done to change the degree of expansion of the stage 600 along the axial direction Y, so that the expansion trend of the stage 600 along the axial direction Y is close to the expansion trend of the spindle 400, thereby making the cutting surface as flat as possible.

[0090] Furthermore, in the above embodiments, by changing the stage temperature T y This allows the stage 600 to expand and then contract during the cutting process, with its dimension along the Y-axis of the main axis 400 increasing and then decreasing. This ensures that the expansion and contraction of the stage 600 and the main axis 400 are similar, making the positional change of the cutting line 200 around the main axis 400 along the Y-axis similar to that of the crystal rod 100 connected to the stage 600. This results in a smoother cutting surface, improved cutting yield, and lower flatness of the wafer produced after cutting.

[0091] Specifically, the value of n can be one of the following: 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30.

[0092] When the value of n is small, the stage temperature T y The number of changes is relatively small, making control relatively simple; when the value of n is large, the stage temperature T... y The change in the size of the cutting surface along the feed direction Z in the extension direction X of the cutting line is more consistent, resulting in a smoother cutting surface; when n is within the range defined in the embodiments of this application, under the premise of a relatively simple control method, the stage temperature T y It also better matches the change in the dimension of the cutting surface along the feed direction Z in the extension direction X of the cutting line.

[0093] in, Figure 6 The horizontal axis represents the temperature change stage y, and the vertical axis represents T.y , Figure 6 The example with n=20 is illustrated.

[0094] Firstly, in the above embodiments, the cutting process is divided into multiple temperature-changing stages, and the cutting depth H at the beginning of each temperature-changing stage is used as the basis for the division. y To determine the stage temperature T during each temperature variation stage. y That is, the stage temperature T is readjusted during each temperature change stage. y This can reduce the accumulation of errors and improve the overall accuracy of cutting.

[0095] Secondly, in the above embodiments, based on the cutting depth H at the beginning of each temperature change stage... y To determine the stage temperature T during each temperature variation stage. y It can decompose the dynamically changing stage temperature during the cutting process into a static stage temperature T in multiple temperature-changing stages. y To facilitate the temperature of the platform T y Controlling the variations simplifies the complexity of the control system. Simultaneously, the cutting depth H is determined by selecting the moment at the beginning of each temperature-changing stage. y This allows for the standardization of control logic, reducing the impact of varying cutting depths (H) during each temperature change stage. y The possibility of other variables arising from differences in the selected time point is considered, thereby improving the robustness of this segmentation method.

[0096] Thirdly, in the above embodiments, by limiting the value of n, the cutting surface can be made relatively flat while making the control method simpler, thereby resulting in a higher cutting yield and a wafer with better flatness after being cut by the crystal ingot 100.

[0097] In addition, in the above embodiments, by simultaneously changing the linear speed of the cutting line 200 and the stage temperature of the stage 600 during the cutting of the crystal rod 100, the cutting quality can be further improved.

[0098] In some embodiments, in each temperature variation stage, the portion cut by the cutting line 200 is the same along the feed direction Z.

[0099] In some embodiments, n = D / β, β ∈ [5, 20]; where D is the maximum dimension of the crystal rod 100 along the feed direction Z, and the unit of D is mm. The unit of β is also mm, that is, in each speed change stage, the cutting distance of the cutting line 200 along the feed direction Z is β mm.

[0100] When β is small, that is, when the cutting distance of each speed change stage is small, the stage temperature T in adjacent temperature change stages can be reduced. y The variation between them is small, stage temperature T yThe change in β is relatively stable, and the overall slicing process has good quality; when β is large, that is, when the cutting distance at each speed change stage is large, the stage temperature T y The longer the temperature remains constant, the better the slice quality is within each temperature change stage; when β is within the range defined in this application, the quality of the entire slicing process and the slice quality within each temperature change stage are both good.

[0101] In some embodiments, n = D / 10, that is, in each temperature change stage, the cutting distance of the cutting line 200 along the feed direction Z is 10 mm.

[0102] In the above embodiments, limiting the cutting distance to the same value in each temperature-changing stage means that the step size of each temperature-changing stage is fixed, making control simpler. Furthermore, the same cutting distance reduces variables, making it easier to adjust the parameters in each temperature-changing stage based on the cutting results, thus facilitating the optimization of cutting parameters.

[0103] In some embodiments, m = n, meaning the number of temperature-changing stages and speed-changing stages is equal, which facilitates control. In some embodiments, one of m and n is greater than the other; a larger m allows for more precise control, while a smaller m reduces the difficulty of control.

[0104] In some embodiments, please refer to Figure 8 According to the cutting depth H at the beginning of each temperature change stage y Based on the dimensions of the crystal ingot 100, the contact position between the crystal ingot 100 and the cutting line 200 at the beginning of each temperature variation stage has a length dimension l along the extension direction X of the cutting line. y According to the length dimension l in each temperature change stage y Determine the stage temperature T in each temperature variation stage. y .

[0105] It is understandable that when the length dimension l of the orthographic projection... y When the diameter is large, the heat generated by cutting the 100mm crystal rod is relatively large; when the length dimension of the orthographic projection is l y When the size is small, less heat is generated during the cutting of the crystal rod 100.

[0106] Specifically, the cutting surface swept by the cutting line 200 along the feed direction Z in each temperature variation stage is... Figure 8 The area enclosed by two adjacent dashed lines along the feed direction Z, or the area enclosed by the dashed line and the outline of the crystal rod 100. Figure 8 In the middle, the feed direction Z is from top to bottom, that is, the cutting line 200 cuts from top to bottom. At the beginning of the temperature change stage of cutting in the shaded area, the length of the orthographic projection along the extension direction X of the cutting line is l. y , is the length of the uppermost dashed line edge in the shaded area.

[0107] pass Figure 9 It can be seen that the length dimension l y The trend of change is the same as the trend of change of the dimension of the crystal rod 100 along the extension direction X of the cutting line along the feed direction Z.

[0108] in, Figure 9 The horizontal axis represents the temperature change stage y, and the vertical axis represents l. y The example with n=20 is drawn.

[0109] Firstly, in the above embodiments, based on the cutting depth H y The contact position between the crystal ingot 100 and the dicing line 200 is determined by the dimensions of the crystal ingot 100 and the length dimension l along the extension direction X of the dicing line. y Compared to directly obtaining the length dimension l y The value of can reduce the error and cumulative error caused by the lag between the calculated value and the actual value due to the sampling delay, making the cutting more accurate.

[0110] Secondly, in the above embodiments, based on the length dimension l y Determine the stage temperature T y This alters the degree of expansion of the stage 600 along the axial Y direction, ensuring that the expansion of the stage 600 along the axial Y direction matches that of the spindle 400 along the axial Y direction. When the length dimension along the cutting line extension direction X of the part in contact with the crystal ingot 100 is large, more heat is generated during cutting, resulting in a larger expansion of the spindle 400 along the axial Y direction and a higher stage temperature T of the stage 600. y As the expansion of the stage 600 along the axial direction Y increases, the length dimension along the cutting line extension direction X at the contact point with the crystal ingot 100 is smaller, resulting in less heat generated during cutting. Consequently, the expansion of the spindle 400 along the axial direction Y is smaller, and the stage temperature T of the stage 600 is lower. y The stage 600 expands less along the axial Y direction to result in a smoother cut surface. Furthermore, the length dimension l at the beginning of the temperature change phase is adjusted accordingly. y To determine the stage temperature T of stage 600. y This simplifies the process while also maintaining the stage temperature T of the 600 stage. y The dimensions of the contact area between the actual crystal rod 100 and the cutting line 200 along the extension direction X of the cutting line are relatively consistent.

[0111] In some embodiments, please refer to Figure 7 T y =t1-l y / b, where t1 is the initial stage temperature when the cutting line 200 just contacts the crystal rod 100, l y =2(R) 2 -(RH y )2 ) 0.5 b is an adjustment coefficient, b > 0; R is the radius of the crystal rod 100, H y =D(y-1) / n, where D is the diameter of the crystal rod 100.

[0112] Specifically, H y In each temperature variation stage, the dimension of the portion of the crystal rod 100 that has been cut by the cutting line 200 along the feed direction Z is: in the first temperature variation stage, y = 1 and H1 = 0.

[0113] in, Figure 6 The diagram is drawn using an example where t1 = 24℃ and n = 20.

[0114] In some embodiments, 20℃≤t1≤25℃.

[0115] Specifically, the value of v1 can be any one of 20℃, 20.5℃, 21℃, 21.5℃, 22℃, 22.5℃, 23℃, 23.5℃, 24℃, 24.5℃, and 25℃, or any one of any two values ​​within the range of 20℃, 20.5℃, 21℃, 21.5℃, 22℃, 22.5℃, 23℃, 23.5℃, 24℃, 24.5℃, and 25℃.

[0116] When the value of t1 is small, the stage 600 can more easily absorb the frictional heat generated by the crystal rod 100 during the cutting process, which can significantly reduce the overall temperature of the crystal rod 100, reduce the dimensional changes of the crystal rod 100 due to thermal expansion, and improve the cutting accuracy. When the value of t1 is large, it can reduce the temperature difference between the crystal rod 100 and the stage 600, reduce the possibility of the crystal rod 100 cracking or deforming due to thermal stress, and improve the cutting yield. When the value of t1 is within the range defined in the embodiments of this application, it can improve both the cutting accuracy and the cutting yield.

[0117] In the above embodiments, due to T y It is a variable about t1. By limiting the value of the initial stage temperature t1 when the cutting line 200 just comes into contact with the crystal rod 100, the stage temperature T in each temperature-changing stage of the entire cutting process can be controlled. y Limitations are imposed to improve the cutting accuracy and yield of the entire cutting process.

[0118] In the above embodiment, the cutting depth H at the start of each temperature change is determined based on the diameter D of the cylindrical crystal rod 100. y Then, based on the cutting depth H y The radius R of the crystal ingot 100 determines the length l of the contact position between the cylindrical crystal ingot 100 and the dicing line 200 along the extension direction X of the dicing line. y Thus, it is possible to determine the length dimension l y To adjust the stage temperature T y .

[0119] Furthermore, in the above embodiments, an adjustment coefficient b is introduced to adjust the change in stage temperature and length dimension l. y The relationship makes T y The value of is more reasonable.

[0120] In some embodiments, the adjustment coefficient b satisfies: 0.2D < b < 10D.

[0121] Specifically, the value of b can be 0.2D, 0.4D, 0.6D, 0.8D, 1.0D, 1.2D, 1.4D, 1.6D, 1.8D, 2.0D, 2.2D, 2.4D, 2.6D, 2.8D, 3.0D, 3.2D, 3.4D, 3.6D, 3.8D, 4.0D, 4.2D, 4.4D, 4.6D, 4.8D, 5.0D, 5.2D, A value within the range of any one of 5.4D, 5.6D, 5.8D, 6.0D, 6.2D, 6.4D, 6.6D, 6.8D, 7.0D, 7.2D, 7.4D, 7.6D, 7.8D, 8.0D, 8.2D, 8.4D, 8.6D, 8.8D, 9.0D, 9.2D, 9.4D, 9.6D, 9.8D, and 10.0D, or any value between any two of them.

[0122] When b is small, the temperature change of the stage is large, T y When the value of b is small, the energy consumption is small; when b is large, the change in stage temperature is small, T y When the value of b is large, the deformation degree of the stage 600 along the Y-axis of the crystal rod 100 is closer to that of the main axis 400, the cutting surface is flatter, the cutting yield is higher, and the flatness of the wafer produced after cutting is lower; when b is within the range defined in the embodiments of this application, the energy consumption is smaller, the deformation degree of the stage 600 along the Y-axis of the crystal rod 100 is closer to that of the main axis 400, the cutting surface is flatter, the cutting yield is higher, and the flatness of the wafer produced after cutting is lower.

[0123] In the above embodiments, by limiting the range of values ​​for b, the deformation of the stage 600 along the Y-axis of the ingot 100 is closer to that of the spindle 400 while maintaining low energy consumption, resulting in a smoother cutting surface, higher cutting yield, and lower flatness of the wafers produced after cutting. Simultaneously, the value of b is correlated with the diameter D of the cylindrical ingot 100, allowing the adjustment coefficient b to be applied to cylindrical ingots 100 of various specifications, thereby improving the applicability of the ingot 100 cutting method.

[0124] The technical solutions provided in the embodiments of this application will be described below with reference to specific examples.

[0125] Example 2: Crystal rod 100 has a diameter D = 300 mm, R = 150 mm, n = 20, b = 2 / 3D = 200, t1 = 24℃, and a temperature change rate T for each temperature stage. y as follows.

[0126]

[0127]

[0128] As can be seen from the table above, in the above embodiments, T n =T 20 =24.65383℃, that is, t3 =24.65383℃.

[0129] In the above embodiment, the stage temperature T of the stage 600 is... y By first increasing and then decreasing the temperature, the stage 600 expands and then contracts during the cutting process. The dimension along the Y-axis of the spindle 400 increases and then decreases, making the expansion and contraction of the stage 600 and the spindle 400 similar. This ensures that the positional change of the cutting line 200 around the spindle 400 along the Y-axis is similar to that of the crystal ingot 100 connected to the stage 600, resulting in a smoother cutting surface, improved cutting yield, and lower wafer flatness. Furthermore, dividing the crystal ingot 100 cutting process into 20 temperature-varying stages simplifies control. Simultaneously, with this simplified control method, the stage temperature more closely matches the change in the dimension of the cutting surface along the feed direction Z and the extension direction X of the cutting line.

[0130] In some embodiments, the temperature θ1 of mortar 300 satisfies: θ1=θ0-Δθ, where θ0 is room temperature, 0℃<Δθ≤30℃.

[0131] In some embodiments, the value of θ0 can be measured and obtained using a thermometer.

[0132] In some embodiments, θ0 is obtained as follows:

[0133] Place the thermometer in the room where the cutting equipment is located, turn on the cutting equipment to cut the crystal rod 100, and after the first preset time, read the thermometer reading and record it as θ0.

[0134] In some embodiments, the first preset time is the time required for the cutting device to cut a crystal rod 100.

[0135] In the above embodiment, since Δθ is a constant and the value of θ1 is lower than the value of θ0, that is, the temperature of the slurry 300 is lower than room temperature, the slurry 300 sprayed onto the cutting line 200 can cool the cutting line 200, and remove the heat from the cutting line 200 more quickly, thereby reducing the degree to which the heat generated during the cutting process causes the spindle 400 to expand along the Y-axis of the crystal rod 100, thus improving the cutting yield of the crystal rod 100. At the same time, the lower temperature of the slurry 300 can also improve the ability of the slurry 300 to adhere to the cutting line 200, making the cutting force of the cutting line 200 more stable, further reducing the possibility of abnormal surface morphology of the thin sheet-like substrate after the crystal rod 100 is cut due to fluctuations in cutting force, and improving the cutting yield.

[0136] The value of θ1 can be read by the temperature sensor in the mortar 300 spraying system.

[0137] Accordingly, this application also provides a wafer manufactured using the ingot 100 cutting method as described in any of the above embodiments.

[0138] The foregoing has provided a detailed description of a crystal rod cutting method and a wafer provided in the embodiments of this application. Specific examples have been used in this application to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for cutting crystal rods, characterized in that, include: Slurry (300) is sprayed onto the cutting line (200), and the cutting line (200) and the crystal rod (100) are moved towards each other along the feed direction (Z), and the crystal rod (100) is cut through the cutting line (200); Along the feed direction (Z), the cutting process is divided into m speed-changing stages, and the linear velocity of the cutting line (200) in each speed-changing stage is V. x , 1≤x≤m, 3≤m≤30, where x is an integer and m is an integer; Based on the cutting depth h at the beginning of each speed-changing stage x Determine the linear velocity V within each of the aforementioned speed change stages. x And as the cutting depth h x With the increase of the linear velocity V x It first decreases and then increases.

2. The crystal rod cutting method according to claim 1, characterized in that, Based on the cutting depth h at the beginning of each speed change phase x Based on the dimensions of the crystal ingot (100), determine the length of the contact position between the crystal ingot (100) and the cutting line (200) at the beginning of each speed change phase, along the extension direction (X) of the cutting line. x According to the length dimension l in each of the aforementioned speed-changing stages x Determine the linear velocity V in each of the aforementioned speed change stages. x .

3. The crystal rod cutting method according to claim 2, characterized in that, V x =v1-l x / a, where v1 is the initial linear velocity when the cutting line (200) just contacts the crystal rod (100), l x =2(R) 2 -(Rh x ) 2 ) 0.5 , a is an adjustment coefficient, a > 0; R is the radius of the crystal rod (100); h x =D(x-1) / m, where D is the diameter of the crystal rod (100).

4. The crystal rod cutting method according to claim 3, characterized in that, The adjustment coefficient a satisfies: 0.1D < a < D.

5. The crystal rod cutting method according to claim 1, characterized in that, Along the feed direction (Z), the cutting process is divided into n temperature-changing stages, and the stage temperature of the stage (600) in each temperature-changing stage is T. y , 1≤y≤n, 3≤n≤30, where y is an integer and n is an integer; Based on the cutting depth H at the beginning of each of the temperature change stages y Determine the stage temperature T within each of the temperature variation stages. y And as the cutting depth H y As the temperature T of the platform increases, y It first rises and then falls.

6. The crystal rod cutting method according to claim 5, characterized in that, Based on the cutting depth H at the beginning of each of the temperature change stages y Based on the dimensions of the crystal rod (100), determine the length of the contact position between the crystal rod (100) and the cutting line (200) at the beginning of each temperature variation stage along the extension direction (X) of the cutting line. y According to the length dimension l in each of the temperature variation stages y Determine the stage temperature T in each of the temperature variation stages. y .

7. The crystal rod cutting method according to claim 6, characterized in that, T y =t1-l y / b, where t1 is the initial stage temperature when the cutting line (200) just contacts the crystal rod (100), l y =2(R) 2 -(RH y ) 2 ) 0.5 b is an adjustment coefficient, b > 0; R is the radius of the crystal rod (100); H y =D(y-1) / n, where D is the diameter of the crystal rod (100).

8. The crystal rod cutting method according to claim 7, characterized in that, The adjustment coefficient b satisfies: 0.2D < b < 10D.

9. The crystal rod cutting method according to claim 1, characterized in that, The temperature θ1 of the mortar (300) satisfies: θ1=θ0-Δθ, where θ0 is room temperature, 0℃<Δθ≤3℃.

10. A wafer, characterized in that, It is manufactured by the method of cutting the crystal rod (100) as described in any one of claims 1 to 9.

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