Image sensor manufacturing apparatus, manufacturing method, and image sensor

Abstract

The application provides an image sensor manufacturing device, a manufacturing method and an image sensor, relates to the technical field of semiconductor manufacturing, and comprises a base, a spool assembly and a cutting line, a motor box is fixed to the top of the base; the spool assembly comprises a pay-off spool, a driving shaft, a tensioning structure, an auxiliary shaft and a take-up spool which are connected with the output end of the motor box respectively; the spool assembly further comprises a guide shaft, the bottom of the guide shaft is welded with a turning part which can change the winding direction of the cutting line; when the cutting line is wound between the guide shaft and the auxiliary shaft, horizontal cutting sections and inclined cutting sections are formed. The application can obtain multiple crystal column blocks with continuously increasing thickness simultaneously, can reduce the influence degree of external force on the wafer, prevents the wafer from being broken or the edge of the wafer from being warped during the processing of the back-end process of the wafer, is favorable for reducing the processing difficulty of the back-end process of the wafer, and guarantees the yield rate of the wafer.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to an image sensor manufacturing apparatus, manufacturing method, and image sensor. Background Technology

[0002] As a semiconductor substrate, wafer fabrication processes are mainly divided into front-end and back-end processes. Front-end processes are responsible for manufacturing active devices such as transistors on the chip, while back-end processes mainly include slicing, grinding, polishing, and cleaning. Back-end processes remove chemically contaminated parts of the wafer and simultaneously reduce chip thickness, resistance, power consumption, and improve thermal conductivity. Slicing, as the first step in back-end wafer processing, has a crucial impact on the degree of wafer damage during processing and the final product quality. Currently, semiconductor wafer slicing typically uses wire sawing technology, and based on the material of the cutting wire, wafer slicing wire saws are divided into free abrasive slicing wire saws and bonded abrasive slicing wire saws.

[0003] Free abrasive grains are typically made of slurry, while bonded abrasive wires are made of diamond wire. Diamond wire is made of stainless steel wire with a nickel-based alloy or resin coating on its surface, and often tiny hard particles are fixed in the nickel-based alloy or resin layer as abrasive grains through electroplating, bonding, or welding techniques. Free abrasive wire saws can slice wafers made of monocrystalline silicon. During the slicing process, the monocrystalline silicon ingot moves towards the wire mesh at a certain feed speed under the action of the feed unit. At the same time, the metal wire carries the slurry to bring the abrasive grains to the processing area and applies pressure to the abrasive grains, so that the abrasive grains can slice in the solid-liquid mixed area between the ingot and the metal wire. During cutting, the abrasive grains are in direct contact with the surface of the ingot, and the crystal material at the cut is removed through abrasion.

[0004] However, because the wafers are thinner after cutting and grinding, they are easily affected by external forces, which can cause them to break or warp at the edges. This increases the difficulty of back-end wafer processing and makes it difficult to ensure the yield rate of wafers leaving the factory. Summary of the Invention

[0005] The purpose of this invention is to provide an image sensor manufacturing apparatus, manufacturing method, and image sensor, which can cut a cylindrical wafer in half into wafers including at least one oblique cut surface, so that the wafer thickness can be uniformly increased in the horizontal diameter of the wafer cross-section, reducing the degree of influence of external forces on the wafer, and effectively reducing the risk of wafer breakage or warping during back-end processing, thus solving the problem of difficult back-end wafer processing and the resulting low yield.

[0006] On the one hand, to achieve the above objectives, the present invention provides an image sensor manufacturing apparatus, including a base, a bobbin assembly and a cutting wire. A motor housing is fixed to the top of the base, and multiple heat dissipation holes are provided through the side of the motor housing to maintain gas exchange between the inside of the motor housing and the external environment, preventing the inside of the motor housing from overheating and affecting the normal operation of the motor inside the motor housing. Several motors are fixedly installed inside the motor housing, and the output ends of the several motors are respectively connected to a shaft-shaped component and drive the shaft-shaped component to rotate.

[0007] The bobbin assembly includes a pay-off bobbin, a drive shaft, a tensioning structure, an auxiliary shaft, and a take-up bobbin, all connected to the output end of the motor housing. During rotation, the pay-off bobbin unwinds the cutting wire wound on its surface, allowing the wire to be wound in multiple turns sequentially and tensioned around the drive shaft, tensioning structure, guide shaft, and auxiliary shaft, forming a cutting wire array between the auxiliary shaft and guide shaft. The drive shaft has a larger diameter than the auxiliary shaft, increasing the contact length between the drive shaft and the cutting wire, enabling the cutting wire to rotate vertically and move relative to the crystal pillar surface. Simultaneously, in conjunction with the feed structure, pressure cutting is applied to the crystal pillar. The tensioning structure can... The cutting wire is tensioned horizontally. The first tensioning shaft and the second tensioning shaft apply equal and opposite tensioning forces to the cutting wire, ensuring that the cutting wire wound around the first and second tensioning shafts is taut and straight. This maintains the cutting strength of the crystal pillar, facilitates the formation of neat cuts during crystal pillar cutting, reduces the difficulty of subsequent grinding processes, saves grinding time, and improves the processing efficiency of the crystal pillar. The auxiliary shaft applies a driving force to the cutting wire through static friction contact, working in conjunction with the drive shaft at the top of the spool assembly to ensure that the cutting wire moves synchronously. The take-up shaft, as the take-up end of the cutting wire, can take up the cutting wire.

[0008] The bobbin assembly also includes a guide shaft. The bottom of the guide shaft is welded with a steering component that can change the winding direction of the cutting wire. The center line connecting the drive shaft, tensioning structure, auxiliary shaft and guide shaft is a regular polygon. One end of the guide shaft is fixed to one side of the motor housing. The winding direction of the cutting wire can be rotated by the steering component so as to form a crystal block with an inclined planar cut after cutting the crystal column.

[0009] When the cutting wire passes between the guide shaft and the auxiliary shaft, it forms a horizontal cutting section and an inclined cutting section. After the inclined cutting section cuts the crystal column, it forms a crystal column block with a beveled cut. The cutting wire is sequentially wound around the surface of the wire feeding shaft, the drive shaft, the tensioning structure, the guide shaft, the auxiliary shaft and the wire taking-up shaft.

[0010] As a further aspect of the present invention: the horizontal cutting segment and the inclined cutting segment are arranged in an alternating pattern with equal spacing in the straight direction. The alternating horizontal cutting segment and the inclined cutting segment can simultaneously perform multiple cuts on the same crystal pillar, so that the crystal pillar can be cut into multiple inclined cylindrical crystal pillar blocks, each including a plane, an inclined surface and a cylindrical surface. This is beneficial to improve the cutting efficiency of the crystal pillar compared with a single inclined cutting segment and saves cutting time. The inclined cutting segment forms an angle θ with respect to the horizontal cutting segment. The angle θ is an acute angle and can be any one or a combination of several of 10°, 30°, 45° or 60°, which can form inclined surfaces with different degrees of inclination. This is beneficial to expand the distribution area of ​​the chip, increase the light absorption on the wafer, and enhance the acquisition effect of optical images.

[0011] As a further aspect of the present invention: the steering component includes a first steering column and a second steering column, the first steering column and the second steering column are respectively cylindrical rods with a length not less than the diameter of the cutting line, and the central axis of the first steering column and the second steering column are perpendicular to the generatrix direction of the guide shaft. On the one hand, it can turn the cutting line that bypasses the first steering column and the second steering column, and on the other hand, it can reduce the degree of wear of the cutting line on the surface of the first steering column or the second steering column per unit time, which is beneficial to extending the service life and maintenance cycle of the first steering column and the second steering column.

[0012] As a further aspect of the present invention: the cutting line forms a "Z"-shaped routing section at the first and second steering columns, and the minimum interval between the projected contours of the first and second steering columns in the vertical plane is not less than the diameter of the cutting line, which can ensure that the cutting line can pass through the first and second steering columns, avoid affecting the uniform movement of the cutting line, and at the same time prevent the cutting line from exerting force on the surfaces of the first and second steering columns during the movement.

[0013] As a further aspect of the present invention: the tensioning structure includes a first tensioning shaft and a second tensioning shaft, which are symmetrical about the longitudinal bisection plane of the drive shaft. The lengths of the drive shaft, the first tensioning shaft, the second tensioning shaft, the auxiliary shaft, and the guide shaft are all equal. The diameter of the drive shaft is not less than twice the diameter of the auxiliary shaft, and the rotational speed of the auxiliary shaft is greater than twice the rotational speed of the drive shaft. The reciprocal of the ratio of the rotational speeds of the drive shaft and the auxiliary shaft is equal to the ratio of their diameters. This can maintain the same moving speed at different parts of the cutting line, which is beneficial for maintaining a uniform tension on the surface of the cutting line and ensuring the synchronization of the crystal pillar cutting.

[0014] As a further aspect of the present invention: the manufacturing apparatus further includes a feeding structure, which includes a feeding platform and a lifting component located on the top of the base. The lifting component is fixed to the top of the feeding platform, and a micro-perforated suction cup is fixed to the top of the lifting component. The micro-perforated suction cup attracts the crystal column to be cut by negative pressure at the top. The micro-perforated suction cup can attract the bottom of the crystal column, which helps to maintain the stability of the crystal column on the surface of the micro-perforated suction cup. The lifting component can be a telescopic cylinder, a telescopic hydraulic cylinder, or a servo feeding mechanism. When the cylindrical side of the crystal column to be cut is tangentially contacted with the top surface of the micro-perforated suction cup, and the central axis of the crystal column is parallel to the horizontal cutting segment, the crystal column can be cut into multiple crystal column blocks with a plane, a slope, and a cylindrical curved surface. After the crystal column block with the slope is processed into a wafer, its top surface is an inclined elliptical surface.

[0015] When the diameter of the cross-section of the crystal cylinder is *a*, then the radius *r* = *a* / 2. When the acute angle between the oblique section formed after cutting and the horizontal plane is θ = 30°, then the major axis of the elliptical cross-section is *b* = *a* / *cosθ*, where θ < 90°. Therefore, by calculation, *b* > *a*, and we can derive S. 椭圆 >S 圆面 When a cylindrical crystal is obliquely cut to form an elliptical cross-section, the area of ​​the elliptical cross-section is larger than the cross-sectional area of ​​the crystal. Therefore, a wafer with an oblique cross-section can accommodate more image sensors than a wafer with a circular cross-section, which helps to save on the manufacturing cost of image sensors.

[0016] As a further aspect of the present invention: the cutting wire includes a wire core, the surface of which is sequentially electroplated with a coating layer and a thickening layer, and diamonds penetrating the coating layer and the thickening layer are fixed on the surface of the wire core. The wire core is a high-strength steel wire or a tungsten wire. The high-strength tungsten wire is made by electroplating high-hardness diamond abrasive grains onto a carbon steel or tungsten wire substrate. The diamonds are evenly distributed at equal intervals around the center of the wire core, and the outer contour of the diamond cross-section is triangular or pentagonal.

[0017] As a further aspect of the present invention: the motor housing includes multiple motors, the output ends of the multiple motors are respectively connected to one end of the pay-off shaft, the take-up shaft, the drive shaft and the auxiliary shaft, and the input ends of the multiple motors installed in the motor housing are respectively electrically connected to an external power source. The external power source can supply power to the motors inside the motor housing. When the motor housing is connected to the external power source, each motor can be started, so that the output ends of each motor drive the bobbin assembly to rotate, so that the cutting wire rotates to cut the crystal pillar.

[0018] Secondly, a method for manufacturing an image sensor is also provided, the method comprising the following steps:

[0019] The front-end processes of semiconductor manufacturing are used to obtain crystal pillars from silicon ingots;

[0020] The vertically and horizontally cut section of the crystal column is placed on top of the micro-perforated chuck, so that the micro-perforated chuck applies an adsorption force to the surface of the crystal column. The surface of the micro-perforated chuck has multiple circumferentially evenly distributed adsorption micro-holes, which can adhere to the surface of the crystal column and prevent the crystal column from rolling during the vertical movement of the micro-perforated chuck, thus improving the accuracy of crystal column cutting.

[0021] Activate the lifting mechanism to raise the position of the micro-hole suction cup and bring it into contact with the inclined cutting section and the horizontal cutting section;

[0022] Continue to raise the crystal column so that the inclined cutting segment and the horizontal cutting segment cut the crystal column to form a crystal column block with an inclined surface;

[0023] After the crystal pillars are cut, grinding and etching processes are performed, and an RO / DI water bath is applied to make the surface of the wafer obtained by grinding smooth, and micro-cracks or surface damage are removed by etching the wafer.

[0024] The wafer is polished using CMP polishing technology, and then cleaned to remove organic impurities and particles from the wafer surface.

[0025] After epitaxially growing a single-crystal silicon layer on the wafer, the circuit layer is etched and then packaged.

[0026] Thirdly, an image sensor is also provided, which is manufactured using the manufacturing method described above.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] 1. This invention uses a cutting line with multiple inclined cutting segments to cut the crystal pillar, which can simultaneously obtain multiple crystal pillar blocks with continuously increasing thickness, and obtain wafers with continuously increasing thickness. This can reduce the degree of influence of external forces on the wafer, prevent the wafer from breaking or warping at the edges during the back-end processing, reduce the processing difficulty of the back-end wafer processing, and help ensure the yield rate of the wafer leaving the factory.

[0029] 2. This invention involves beveling a crystal pillar to form a crystal pillar block with an elliptical cross-section. Since the area of ​​the elliptical cross-section is larger than the cross-sectional area of ​​the crystal pillar, the wafer formed by processing the crystal pillar block with an elliptical bevel can accommodate more image sensors than a wafer with a circular cross-section. This helps to save on the manufacturing cost of image sensors. At the same time, when arranging the same number of image sensor circuits, it can reduce the amount of wafers used and the time required to replace wafers, which helps to improve the manufacturing efficiency of image sensors.

[0030] 3. The present invention fixes a microporous suction cup on the top of the lifting component, and the inside of the microporous suction cup can form a negative pressure environment, so that the top of the microporous suction cup can attract the crystal column to be cut through the negative pressure, which is beneficial to maintaining the stability and reliability of the crystal column on the surface of the microporous suction cup.

[0031] 4. The present invention applies equal and opposite tension forces to the cutting wire by means of a first tensioning shaft and a second tensioning shaft, which can keep the cutting wire wrapped around the first tensioning shaft and the second tensioning shaft taut and straight, so as to maintain the cutting strength of the crystal pillar, facilitate the formation of neat cuts during the cutting process of the crystal pillar, reduce the difficulty of the subsequent grinding process and save grinding time, and improve the processing efficiency of the crystal pillar. Attached Figure Description

[0032] Figure 1 This is a diagram showing the connection structure of the bobbin assembly of the present invention;

[0033] Figure 2 This is a diagram showing the connection structure of the steering component of the present invention;

[0034] Figure 3 This is a diagram of the crystal column cut by the inclined cutting segment of the present invention;

[0035] Figure 4 This is a structural diagram of the cutting line of the present invention;

[0036] Figure 5 This is a front view of the crystal cylinder block of the present invention;

[0037] Figure 6 This is a structural diagram of the image sensor of the present invention;

[0038] Figure 7 This is a circuit layer connection structure diagram of the present invention.

[0039] In the diagram: 1. Base; 2. Motor housing; 3. Take-up shaft; 4. Pay-off shaft; 5. Drive shaft; 6. First tensioning shaft; 7. Second tensioning shaft; 8. Auxiliary shaft; 9. Guide shaft; 10. Cutting line; 101. Horizontal cutting section; 102. Inclined cutting section; 11. First steering column; 12. Second steering column; 13. Micro-hole suction cup; 14. Crystal block; 15. Single crystal silicon layer; 16. Circuit layer; 17. Lifting component; 18. Feeding platform. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed following the word and its equivalents, but do not exclude other elements or objects.

[0041] like Figure 1 The diagram shows the connection structure of the bobbin assembly of the present invention, which provides an image sensor manufacturing apparatus including a base 1, a bobbin assembly, and a cutting wire 10. A motor housing 2 is fixed to the top of the base 1. The motor housing 2 includes multiple motors, the output ends of which are respectively connected to one end of a pay-off bobbin 4, a take-up bobbin 3, a drive shaft 5, and an auxiliary shaft 8. The input ends of the multiple motors installed in the motor housing 2 are electrically connected to an external power source. The external power source can supply power to the motors inside the motor housing 2. When the motor housing 2 is connected to the external power source, each motor can be started, causing the output ends of each motor to drive the bobbin assembly to rotate, so that the cutting wire 10 can rotate to cut the crystal pillar. Multiple heat dissipation holes are provided through the side of the motor housing 2 to maintain gas exchange between the inside of the motor housing 2 and the external environment, preventing the inside of the motor housing 2 from overheating and affecting the normal operation of the motors inside the motor housing 2. Several motors are fixedly installed inside the motor housing 2, and the output ends of the several motors are respectively connected to a shaft-shaped component and drive the shaft-shaped component to rotate. The pay-off bobbin 4, the take-up bobbin 3, the drive shaft 5, and the auxiliary shaft 8 are all shaft-shaped components.

[0042] like Figure 2The diagram shows the connection structure of the steering component of the present invention. The bobbin assembly includes a pay-off bobbin 4, a drive shaft 5, a tensioning structure, an auxiliary shaft 8, and a take-up bobbin 3, all connected to the output end of the motor housing 2. During rotation, the pay-off bobbin 4 unwinds the cutting wire 10 wound around its surface, allowing the cutting wire 10 to be wound in multiple loops sequentially and tensioned around the surfaces of the drive shaft 5, tensioning structure, guide shaft 9, and auxiliary shaft 8, forming a cutting wire array between the auxiliary shaft 8 and the guide shaft 9. The diameter of the drive shaft 5 is larger than that of the auxiliary shaft 8, which increases the contact length between the drive shaft 5 and the cutting wire 10, enabling the cutting wire 10 to rotate vertically and move relative to the crystal pillar surface. This increases the relative displacement speed between the cutting wire 10 and the crystal pillar, thereby accelerating the cutting speed. This, combined with the feed structure... The structure performs pressure cutting on the crystal pillar 10. The tensioning structure can apply a horizontal tension force to the cutting wire 10. The first tensioning shaft 6 and the second tensioning shaft 7 apply equal and opposite tension forces to the cutting wire 10, so that the cutting wire 10 wrapped around the first tensioning shaft 6 and the second tensioning shaft 7 can be taut and straight to maintain the cutting strength of the crystal pillar. This facilitates the formation of neat cuts during the cutting process, which helps to reduce the difficulty of subsequent grinding processes and save grinding time, thereby improving the processing efficiency of the crystal pillar. The auxiliary shaft 8 can apply a driving force to the cutting wire 10 through static friction contact with it. Together with the drive shaft 5 at the top of the spool assembly, it can keep the cutting wire 10 moving synchronously. The take-up shaft 3 serves as the take-up end of the cutting wire 10 and can take it up.

[0043] Combination Figure 1 or Figure 2 The tensioning structure includes a first tensioning shaft 6 and a second tensioning shaft 7. The first tensioning shaft 6 and the second tensioning shaft 7 are of equal length and are both cylindrical. The first tensioning shaft 6 and the second tensioning shaft 7 are symmetrical about the longitudinal bisection plane of the drive shaft 5. The lengths of the drive shaft 5, the first tensioning shaft 6, the second tensioning shaft 7, the auxiliary shaft 8, and the guide shaft 9 are all equal. The diameter of the drive shaft 5 is not less than twice the diameter of the auxiliary shaft 8. The rotational speed of the auxiliary shaft 8 is greater than twice the rotational speed of the drive shaft 5. The reciprocal of the ratio of the rotational speeds of the drive shaft 5 and the auxiliary shaft 8 is equal to the ratio of their diameters. This can keep the moving speed of different parts of the cutting line 10 equal, which is beneficial to keep the surface of the cutting line 10 uniformly tensioned and ensure the synchronization of crystal pillar cutting.

[0044] Combination Figure 2The bobbin assembly also includes a guide shaft 9. One end of the guide shaft 9 passes through the interior of the motor housing 2 and is welded and fixed to the inner wall of the motor housing 2. A steering component that can change the winding direction of the cutting line 10 is welded to the bottom of the guide shaft 9. The steering component includes a first steering column 11 and a second steering column 12. The first steering column 11 and the second steering column 12 are cylindrical rods with a length not less than the diameter of the cutting line 10. The central axis of the first steering column 11 and the second steering column 12 is perpendicular to the generatrix direction of the guide shaft 9. On the one hand, it can turn the cutting line 10 that passes around the first steering column 11 and the second steering column 12. On the other hand, it can reduce the wear of the cutting line 10 on the surface of the first steering column 11 or the second steering column 12 per unit time, and reduce the risk of breakage of the first steering column 11 or the second steering column 12.

[0045] Preferably, the center line connecting the drive shaft 5, the tensioning structure, the auxiliary shaft 8, and the guide shaft 9 is a regular polygon. One end of the guide shaft 9 is fixed to one side of the motor housing 2. The winding direction of the cutting line 10 can be rotated by the steering component so as to form a crystal block 14 with an inclined planar cut after cutting the crystal column.

[0046] like Figure 3 The diagram shows the crystal pillar cut by the inclined cutting segment of the present invention. When the cutting line 10 passes between the guide shaft 9 and the auxiliary shaft 8, it forms a horizontal cutting segment 101 and an inclined cutting segment 102. After the inclined cutting segment 102 cuts the crystal pillar, it forms a crystal pillar block 14 with a beveled cut. The cutting line 10 is sequentially wound around the surface of the pay-off shaft 4, the drive shaft 5, the tensioning structure, the guide shaft 9, the auxiliary shaft 8 and the take-up shaft 3, and the cutting line 10 passing over the surface is tensioned by the drive shaft 5, the tensioning structure, the guide shaft 9, the auxiliary shaft 8 and the take-up shaft 3.

[0047] Preferably, the horizontal cutting segment 101 and the inclined cutting segment 102 are arranged in a staggered pattern with equal spacing in the straight direction. The staggered arrangement of the horizontal cutting segment 101 and the inclined cutting segment 102 can simultaneously perform multiple cuts on the same crystal cylinder, so that the crystal cylinder can be cut into multiple oblique cylindrical crystal cylinder blocks 14, each including a plane, an inclined surface, and a cylindrical surface. This is beneficial for improving the cutting efficiency of the crystal cylinder compared to a single inclined cutting segment 102, and saving cutting time. The inclined cutting segment 102 forms an angle θ with respect to the horizontal cutting segment 101. This angle θ is an acute angle with an angle of 30°. By using a cutting line 10 with multiple inclined cutting segments 102 to cut the crystal cylinder, multiple crystal cylinder blocks 14 with continuously increasing thickness can be obtained simultaneously, and a continuously increasing thickness can be achieved. The addition of wafers reduces the impact of external forces on the wafers, preventing breakage or edge warping during back-end processing. This reduces the difficulty of back-end processing and helps ensure wafer yield. On the other hand, by beveling the crystal pillars to form crystal pillar blocks 14 with elliptical cross-sections, the wafers formed by the elliptical cross-section blocks 14 can accommodate more image sensors than wafers with circular cross-sections. This helps save on image sensor manufacturing costs. Furthermore, when arranging the same number of image sensor circuits, it reduces the amount of wafers used and the time required for wafer replacement, thus improving image sensor manufacturing efficiency.

[0048] Combination Figure 1 The manufacturing apparatus also includes a feeding structure, which includes a feeding platform 18 and a lifting component 17 located on the top of the base 1. The lifting component 17 is fixed to the top of the feeding platform 18. A micro-perforated suction cup 13 is fixed to the top of the lifting component 17. The micro-perforated suction cup 13 attracts the crystal column to be cut by negative pressure. The micro-perforated suction cup 13 can attract the bottom of the crystal column, which helps to maintain the stability of the crystal column on the surface of the micro-perforated suction cup 13. The lifting component 17 can be a telescopic cylinder, a telescopic hydraulic cylinder, or a servo feeding mechanism. When the cylindrical side of the crystal column to be cut is in tangential contact with the top surface of the micro-perforated suction cup 13 and the central axis of the crystal column is parallel to the horizontal cutting section 101, the crystal column can be cut into multiple crystal column blocks 14 with a plane, a slope, and a cylindrical curved surface. After the crystal column block 14 with the slope is processed into a wafer, its top surface is an inclined elliptical surface.

[0049] Combination Figure 2The cutting line 10 forms a "Z"-shaped routing section at the first steering column 11 and the second steering column 12. At least one section of the cutting line 10 in the "Z"-shaped routing section forms an acute angle with the central axis of the crystal pillar to be cut at the top of the micro-hole chuck 13. The minimum interval between the projection contours of the first steering column 11 and the second steering column 12 in the vertical plane is not less than the diameter of the cutting line 10. This ensures that the cutting line 10 can pass through the first steering column 11 and the second steering column 12, avoiding affecting the uniform movement of the cutting line 10. This effectively prevents the crystal pillar from being cut without force, which is beneficial to improving the yield of crystal pillar cutting.

[0050] like Figure 5 The figure shown is a front view of the crystal cylinder block of the present invention. When the diameter of the cross-section of the crystal cylinder block 14 is a, the radius r = a / 2. When the acute angle θ formed by the oblique section after cutting and the horizontal plane is 30°, the major axis of the elliptical surface of the cross-section is b = a / cosθ, where θ < 90°. Therefore, it can be calculated that b > a, and S can be obtained. 椭圆 >S 圆面 When a cylindrical crystal is obliquely cut to form an elliptical cross-section, the area of ​​the elliptical cross-section is larger than the cross-sectional area of ​​the crystal. Therefore, a wafer with an oblique cross-section can accommodate more image sensors than a wafer with a circular cross-section, which helps to save on the manufacturing cost of image sensors. On the other hand, it can increase the amount of light absorbed by the image sensor and enhance the acquisition effect of optical images.

[0051] like Figure 4 The diagram shows the structure of the cutting wire of the present invention. The cutting wire 10 includes a wire core 103. The surface of the wire core 103 is sequentially electroplated with a coating layer 104 and a thickening layer 106. Diamonds 105 are fixed to the surface of the wire core 103, penetrating the coating layer 104 and the thickening layer 106. The wire core 103 is a high-strength steel wire or a tungsten wire. The high-strength tungsten wire is made by fixing high-hardness diamond abrasive grains on a carbon steel or tungsten wire substrate by electroplating. The diamonds 105 are evenly distributed at equal intervals around the center of the wire core 103. The outer contour of the cross-section of the diamonds 105 is triangular or pentagonal. The thickening layer 106 is a nickel plating layer.

[0052] Combination Figure 1 Furthermore, a method for manufacturing an image sensor is provided, the method comprising the following steps:

[0053] S1: The front-end process of semiconductor manufacturing of silicon ingots is used to obtain crystal pillars, which are cylindrical silicon ingots processed by crystal pulling process;

[0054] S2: Place the vertical and horizontal cutting section 101 of the crystal column on top of the micro-hole chuck 13, so that the micro-hole chuck 13 applies an adsorption force to the surface of the crystal column. The surface of the micro-hole chuck 13 has multiple circumferentially evenly distributed adsorption micro-holes, which can adsorb the surface of the crystal column and prevent the crystal column from rolling during the vertical movement of the micro-hole chuck 13, which is beneficial to improving the accuracy of crystal column cutting.

[0055] S3: Activate the lifting component 17 to raise the position of the micro-hole suction cup 13 and make the micro-hole suction cup 13 contact the inclined cutting section 102 and the horizontal cutting section 101. The lifting component 17 can be a hydraulic telescopic cylinder, a telescopic cylinder or a servo motor lifting mechanism. The lifting component 17 can pull the micro-hole suction cup 13 upward or downward in the vertical direction so that the crystal pillar placed on the top of the micro-hole suction cup 13 can contact the cutting line 10.

[0056] S4: Continue to raise the crystal column 10 so that the inclined cutting section 102 and the horizontal cutting section 101 cut the crystal column to form a crystal column block 14 with an inclined surface. By adjusting the number of pairs of the inclined cutting section 102 and the horizontal cutting section 101, the number of crystal column blocks 14 obtained after cutting the crystal column can be adjusted synchronously, which is beneficial to improving the cutting efficiency of the crystal column block 14 and ensuring that each crystal column block 14 includes at least one inclined surface. A thin plate-shaped pad is welded to the bottom of the crystal column block 14.

[0057] S5: After the crystal pillar block 14 is cut, a grinding and etching process is performed and an RO / DI water bath is applied to make the surface of the wafer obtained by grinding flat, and micro cracks or surface damage are removed by etching the wafer, which helps to ensure the quality of the wafer.

[0058] S6: The wafer is polished using CMP polishing technology. The polished wafer surface is smoother, avoiding the impact of protruding impurities on the etched circuit. The polished wafer is then cleaned to remove organic impurities and particles from the wafer surface, improving the purity of the wafer itself and reducing the adverse effects of impurity particles on the etched circuit on the wafer.

[0059] like Figure 7 The diagram shown is a circuit layer connection structure diagram of the present invention. After growing a single crystal silicon layer 15 on the wafer, the circuit layer 16 is etched and packaged to obtain a sensor element capable of acquiring optical images.

[0060] like Figure 6 The diagram shown is a structural diagram of the image sensor of the present invention. An image sensor is also provided, which is manufactured by the manufacturing method of the above embodiment. It can arrange more image sensors than a wafer with a circular cross-section, which helps to save the manufacturing cost of the image sensor and improve the acquisition effect of optical images.

[0061] While embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of the invention as set forth in the claims. Furthermore, the invention described herein may have other embodiments and can be implemented or carried out in various ways.

Claims

1. An image sensor manufacturing apparatus, characterized in that, include: A base, on the top of which a motor housing is fixed; A bobbin assembly, comprising a pay-off bobbin, a drive shaft, a tensioning structure, an auxiliary shaft, and a take-up bobbin, all connected to the output end of the motor housing. The bobbin assembly also includes a guide shaft, the bottom of which is welded with a steering component that can change the winding direction of the cutting wire; The cutting line, when passing between the guide shaft and the auxiliary shaft, forms horizontal cutting segments and inclined cutting segments. The horizontal cutting segments and inclined cutting segments are arranged alternately at equal intervals in the straight direction. After the inclined cutting segments cut the crystal pillar, they form a crystal pillar block with an elliptical bevel. Since the area of ​​the elliptical cross section is larger than the cross-sectional area of ​​the crystal pillar, a larger number of image sensors can be arranged when the crystal pillar block with the elliptical bevel is processed into a wafer.

2. The image sensor manufacturing apparatus according to claim 1, characterized in that: The inclined cutting segment forms an angle θ with respect to the horizontal cutting segment.

3. The image sensor manufacturing apparatus according to claim 2, characterized in that: The steering component includes a first steering column and a second steering column, wherein the first steering column and the second steering column are cylindrical rods with a length not less than the diameter of the cutting line.

4. The image sensor manufacturing apparatus according to claim 3, characterized in that: The cutting line forms a "Z"-shaped routing section at the first and second steering columns, and the minimum interval between the projected contours of the first and second steering columns in the vertical plane is not less than the diameter of the cutting line.

5. The image sensor manufacturing apparatus according to claim 1, characterized in that: The tensioning structure includes a first tensioning shaft and a second tensioning shaft, which are symmetrical about the longitudinal bisecting plane of the drive shaft. The lengths of the drive shaft, the first tensioning shaft, the second tensioning shaft, the auxiliary shaft, and the guide shaft are all equal. The diameter of the drive shaft is not less than twice the diameter of the auxiliary shaft, the rotational speed of the auxiliary shaft is greater than twice the rotational speed of the drive shaft, and the reciprocal of the ratio of the rotational speeds of the drive shaft and the auxiliary shaft is equal to the ratio of their diameters.

6. The image sensor manufacturing apparatus according to claim 1, characterized in that: The manufacturing apparatus further includes: The feeding structure includes a feeding platform and a lifting component located on the top of the base; The lifting component is fixed to the top of the feeding platform. A micro-perforated suction cup is fixed to the top of the lifting component. The negative pressure at the top of the micro-perforated suction cup attracts the crystal column to be cut.

7. The image sensor manufacturing apparatus according to claim 1, characterized in that: The cutting wire includes a wire core, the surface of which is sequentially electroplated with a coating layer and a thickening layer, and a diamond penetrating the coating layer and the thickening layer is fixed on the surface of the wire core.

8. The image sensor manufacturing apparatus according to claim 1, characterized in that: The motor housing includes multiple motors, the output ends of which are respectively connected to one end of the pay-off shaft, the take-up shaft, the drive shaft, and the auxiliary shaft. The input ends of the multiple motors installed inside the motor housing are respectively electrically connected to an external power source, which can supply power to the motors inside the motor housing.

9. A method for manufacturing an image sensor, applied to the image sensor manufacturing apparatus as described in claim 6, characterized in that, The manufacturing method comprises the following steps: The front-end processes of semiconductor manufacturing are used to obtain crystal pillars from silicon ingots; The crystal column is placed perpendicular to the horizontal cut section on top of the microporous chuck, so that the microporous chuck applies an adsorption force to the surface of the crystal column; Activate the lifting mechanism to raise the position of the micro-hole suction cup and bring it into contact with the inclined cutting section and the horizontal cutting section; Continue to raise the crystal column so that the inclined cutting segment and the horizontal cutting segment cut the crystal column to form a crystal column block with an inclined surface; After the crystal blocks are cut, they are subjected to grinding and etching processes and then RO / DI water bath is applied. The wafer is polished using CMP polishing technology, and then cleaned after polishing. After epitaxially growing a single-crystal silicon layer on the wafer, the circuit layer is etched and then packaged.

10. An image sensor, characterized in that: The image sensor is manufactured using the manufacturing method described in claim 9.

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