Image sensor manufacturing device, manufacturing method and image sensor

Abstract

The invention provides an image sensor manufacturing device and method and an image sensor, and relates to the technical field of semiconductor manufacturing, the image sensor manufacturing device comprises a base, a bobbin assembly and a cutting line, and the top of the base is fixedly provided with a motor box; the spool assembly comprises a pay-off shaft, a driving shaft, a tensioning structure, an auxiliary shaft and a take-up shaft which are connected with the output end of the motor box. The bobbin assembly further comprises a guide shaft, and a steering component capable of changing the winding direction of the cutting line is welded to the bottom of the guide shaft. And a horizontal cutting section and an inclined cutting section are formed when the cutting line is wound between the guide shaft and the auxiliary shaft. According to the invention, a plurality of crystal column blocks with continuously increased thickness can be obtained at the same time, the influence degree of external force on the wafer can be reduced, the phenomenon that the wafer is broken or the edge of the wafer is warped in the processing process of the back-end process of the wafer is prevented, the processing difficulty of the back-end process of the wafer is reduced, and the factory yield of the wafer is ensured.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing technology, and in particular to an image sensor manufacturing device, a manufacturing method and an image sensor. Background Art

[0002] As a semiconductor substrate, the wafer processing technology is mainly divided into front-end process and back-end process. The front-end process is responsible for manufacturing active devices such as transistors on the chip, while the back-end process is mainly divided into slicing, grinding, polishing and cleaning. In the process of implementing the back-end process on the wafer, the chemically contaminated part of the wafer can be removed and the thickness of the chip can be reduced, the resistance can be reduced, the power consumption can be reduced, and the thermal conductivity can be improved. Among them, slicing is the first step in the back-end processing of the wafer. The quality of slicing has a crucial impact on the degree of wafer damage caused during the processing and the quality of the final wafer product. At present, semiconductor wafer slicing usually adopts wire saw slicing technology, and the wafer slicing wire saw is divided into free abrasive slicing wire saw and fixed abrasive slicing wire saw according to the different cutting wire materials.

[0003] Among them, free abrasive grains are often made of mortar, while bonded abrasive wires are made of diamond wires. Diamond wires are stainless steel wires with nickel-based alloys or resins attached to the surface, and tiny hard particles are often fixed in the nickel-based alloy or resin layer as abrasive grains through electroplating, bonding or welding. Free abrasive wire saws can slice wafers made of single crystal silicon. During the slicing process, the single crystal silicon ingot moves toward the wire mesh at a certain feed speed under the action of the feed unit. At the same time, the metal wire drives the mortar to make the abrasive grains reach the processing area and exert pressure on the abrasive grains, so that the abrasive grains can be sliced ​​in the solid-liquid mixed area between the crystal 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 by wear.

[0004] However, since the thickness of the wafer after cutting and grinding is relatively small, the wafer is easily affected by external force and may break or the edge of the wafer may warp, which increases the difficulty of the wafer back-end process and is not conducive to ensuring the yield of the wafer leaving the factory. Summary of the invention

[0005] The object of the present invention is to provide an image sensor manufacturing device, a manufacturing method and an image sensor, which can cut a cylindrical wafer in half into wafers including at least one beveled surface, so that the wafer thickness can be uniformly increased in the horizontal diameter of the wafer cross section, thereby reducing the degree to which the wafer is affected by external forces. At the same time, it can effectively reduce the risk of the wafer breaking or warping during the back-end process, thereby solving the problem that the back-end process of the wafer is difficult to handle and is not conducive to improving the yield rate of wafer processing.

[0006] On one hand, to achieve the above-mentioned purpose, the present invention provides an image sensor manufacturing device, comprising a base, a bobbin assembly and a cutting line, wherein a motor box is fixed on the top of the base, and a plurality of heat dissipation holes are provided through the side of the motor box, so as to maintain gas exchange between the inside of the motor box and the external environment, and prevent the inside of the motor box from overheating and affecting the normal operation of the motor inside the motor box, and a plurality of motors are fixedly installed inside the motor box, and the output ends of the plurality of motors are respectively connected to a shaft-shaped component and drive the shaft-shaped component to rotate; The spool assembly includes a pay-off shaft, a driving shaft, a tensioning structure, an auxiliary shaft and a take-up shaft respectively connected to the output end of the motor box, wherein the cutting wire wrapped on the surface of the pay-off shaft can be unwound during its rotation, so that the cutting wire can be tensioned and wound on the surfaces of the driving shaft, the tensioning structure, the guide shaft and the auxiliary shaft in multiple circles in sequence, and a cutting wire array is formed between the auxiliary shaft and the guide shaft. The diameter of the driving shaft is larger than that of the auxiliary shaft, which is beneficial to increase the contact length between the auxiliary shaft and the cutting wire, so as to drive the cutting wire to rotate in the vertical direction, so that the cutting wire can move relative to the surface of the crystal column, and at the same time cooperate with the feeding structure to implement pressure cutting on the crystal column, and the tensioning structure can cut the cutting wire. The cutting line applies a tensioning force in the horizontal direction, and the first tensioning shaft and the second tensioning shaft respectively apply tensioning forces of equal magnitude and opposite action directions to the cutting line, so that the cutting line wound on the first tensioning shaft and the second tensioning shaft can be tensioned and straightened, so as to maintain the cutting strength of the crystal column, and facilitate the formation of a neat incision in the process of cutting the crystal column, which is conducive to reducing the difficulty of the subsequent grinding process and saving grinding time, and is convenient for improving the processing efficiency of the crystal column. The auxiliary shaft can apply a driving force to the cutting line through the static friction contact between the auxiliary shaft and the cutting line, and cooperate with the driving shaft at the top of the spool assembly to keep the cutting line moving synchronously. The take-up shaft serves as the winding end of the cutting line and can wind up the cutting line; The spool assembly also includes a guide shaft, a steering component capable of changing the winding direction of the cutting wire is welded to the bottom of the guide shaft, a center line connecting the drive shaft, the tensioning structure, the auxiliary shaft and the guide shaft is a regular polygon, one end of the guide shaft is fixed to one side of the motor box, and the winding direction of the cutting wire can be rotated by the steering component, so as to form a crystal column block with an inclined plane-shaped incision after cutting the crystal column; When the cutting wire is wound between the guide shaft and the auxiliary shaft, a horizontal cutting section and an inclined cutting section are formed. After the inclined cutting section cuts the crystal column, a crystal column block with a bevel cut is formed. The cutting wire is wound in sequence on the surfaces of the pay-off shaft, the drive shaft, the tensioning structure, the guide shaft, the auxiliary shaft and the take-up shaft.

[0007] As a further solution of the present invention: the horizontal cutting segments and the inclined cutting segments are arranged at equal intervals and staggered in a straight direction. The staggered horizontal cutting segments and the inclined cutting segments can simultaneously perform multiple cuts on the same crystal column, so that the crystal column can be simultaneously cut into multiple oblique cylindrical crystal column blocks including a plane, an inclined surface and a cylindrical surface, which is beneficial to improve the cutting efficiency of the crystal column compared to a single oblique cutting segment and save cutting processing time. The inclined cutting segment forms an angle θ relative to the horizontal cutting segment, and the angle θ is an acute angle. The angle θ can be any one of 10°, 30°, 45° or 60° or a combination of several thereof, and can form inclined surfaces with different degrees of inclination, which is beneficial to expand the distribution area of ​​the chip, increase the amount of light absorption on the wafer, and enhance the optical image acquisition effect.

[0008] As a further solution 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 is perpendicular to the generatrix direction of the guide shaft. On the one hand, the cutting line that bypasses the first steering column and the second steering column can be steered, and on the other hand, the degree of wear of the cutting line on the surface of the first steering column or the second steering column per unit time can be reduced, which is beneficial to extending the service life and maintenance cycle of the first steering column and the second steering column.

[0009] As a further solution of the present invention: the cutting line forms a "Z"-shaped routing portion through the first steering column and the second steering column, and the minimum spacing distance between the projection contours of the first steering column and the second steering column in the vertical plane is not less than the diameter of the cutting line, which can ensure that the cutting line can pass through between the first steering column and the second steering column to 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 steering column and the second steering column during movement.

[0010] As a further solution of the present invention: the tensioning structure includes a first tensioning shaft and a second tensioning shaft, the first tensioning shaft and the second tensioning shaft are symmetrical with respect to the longitudinal bisection plane of the driving shaft, the lengths of the driving shaft, the first tensioning shaft, the second tensioning shaft, the auxiliary shaft and the guide shaft are equal to each other, the diameter of the driving shaft is not less than twice the diameter of the auxiliary shaft, the rotation speed of the auxiliary shaft is greater than twice the rotation speed of the driving shaft, the inverse of the rotation speed ratio between the driving shaft and the auxiliary shaft is equal to the diameter ratio between the two, which can keep the moving speeds of different parts of the cutting line equal, which is beneficial to keep the surface of the cutting line with a uniform degree of tension and ensure the synchronization of the crystal column cutting.

[0011] As a further solution of the present invention: the manufacturing device also includes a feeding structure, the feeding structure includes a feeding platform and a lifting component opened on the top of the base, the lifting component is fixed through the top of the feeding platform, a microporous suction cup is fixed on the top of the lifting component, the negative pressure on the top of the microporous suction cup attracts the crystal column to be cut, the microporous suction cup can attract the bottom of the crystal column, which is conducive to maintaining the stability of the crystal column placed on the surface of the microporous 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 in contact with the top surface of the microporous suction cup, and the central axis of the crystal column is parallel to the horizontal cutting section, the crystal column can be cut into multiple sections of crystal column blocks with a plane, an inclined surface and a cylindrical curved surface, and the top surface of the crystal column block with the inclined surface is an inclined elliptical surface after being processed into a wafer; When the cross-sectional diameter of the crystal column is a, the radius length r=a / 2. When the acute angle formed by the oblique section after cutting and the horizontal plane is θ=30°, the major axis of the cross-sectional ellipse is b=a / cosθ, where θ<90. Then, by calculation, we know that b>a, and we can get S 椭圆 >S 圆面 When the cylindrical crystal column is beveled and formed into an elliptical cross-section, the area of ​​the elliptical cross-section is larger than the cross-sectional area of ​​the crystal column. Therefore, a wafer with an oblique cross-section can arrange more image sensors than a wafer with a circular cross-section, which is beneficial to saving the manufacturing cost of the image sensor.

[0012] As a further solution of the present invention: the cutting wire includes a wire core, the surface of the wire core is electroplated with a coating layer and a thickening layer in sequence, 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 metal wire, the wire core is a high-strength steel wire or a tungsten wire metal wire, the high-strength tungsten wire metal wire is made of high-hardness diamond abrasive grains fixed on a carbon steel or tungsten wire substrate by electroplating, the diamonds are evenly distributed at equal intervals about the center of the wire core, and the outer contour of the cross-section of the diamond is a triangle or a pentagon.

[0013] As a further solution of the present invention: the motor box includes multiple motors, and the output ends of the multiple motors are respectively connected to one end of the pay-off shaft, the take-up shaft, the driving shaft and the auxiliary shaft. The input ends of the multiple motors installed in the motor box are respectively electrically connected to the external power supply. The external power supply can power the internal motors of the motor box. By connecting the motor box to the external power supply, each motor can be started, so that the output end of each motor drives the spool assembly to rotate, so that the cutting line rotates to cut the crystal column.

[0014] In a second aspect, a method for manufacturing an image sensor is also provided, the manufacturing method comprising the following steps: Implementing the front-end process of semiconductor manufacturing on the silicon ingot to obtain a crystal column; The vertical and horizontal cutting section of the crystal column is placed on the top of the microporous suction cup, so that the microporous suction cup applies adsorption force to the surface of the crystal column. The surface of the microporous suction cup is provided with a plurality of adsorption micropores evenly distributed around the circumference, which can exert adsorption force on the surface of the crystal column and prevent the crystal column from rolling when the microporous suction cup drives the crystal column to move up and down in the vertical direction, which is conducive to improving the accuracy of crystal column cutting; Start the lifting component to lift the microporous suction cup and make the microporous suction cup contact with the inclined cutting section and the horizontal cutting section; Continue to lift the crystal column so that the inclined cutting section and the horizontal cutting section cut the crystal column to form a crystal column block with an inclined surface; The cut crystal column blocks are subjected to grinding and etching processes and RO / DI water baths to make the surface of the ground wafers flat, and the wafers are etched to remove micro cracks or surface damage; The wafer is polished using CMP polishing technology, and the polished wafer is cleaned to remove organic impurities and particles on the wafer surface; After epitaxial growth of a single-crystal silicon layer on the wafer, the circuit layer is etched and packaged.

[0015] In a third aspect, an image sensor is also provided, wherein the image sensor is manufactured using the manufacturing method described in the above solution.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention uses a cutting line with multiple inclined cutting sections to cut the crystal column, so as to obtain multiple crystal column blocks with continuously increasing thicknesses at the same time, and obtain wafers with continuously increasing thicknesses, which can reduce the degree to which the wafers are affected by external forces, and prevent the wafers from breaking or edge warping during the processing of the back-end process of the wafers, which is beneficial to reducing the processing difficulty of the back-end process of the wafers and ensuring the yield rate of the wafers leaving the factory.

[0017] 2. The present invention performs bevel processing on the crystal column to form a crystal column block with an elliptical cross-section. Since the area of ​​the elliptical cross-section is larger than the cross-sectional area of ​​the crystal column, when the wafer formed by processing the crystal column block with an elliptical bevel can arrange more image sensors than the wafer with a circular cross-section, it is beneficial to save the manufacturing cost of the image sensor. At the same time, when arranging the same number of image sensor circuits, it can reduce the amount of wafers used and the time for replacing wafers, which is beneficial to improving the manufacturing efficiency of the image sensor.

[0018] 3. The present invention fixes the microporous suction cup on the top of the lifting component, and a negative pressure environment is formed inside the microporous suction cup, 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 placed on the surface of the microporous suction cup.

[0019] 4. The present invention applies tensioning forces of equal magnitude and opposite directions to the cutting line through the first tensioning shaft and the second tensioning shaft respectively, so that the cutting line wound on the first tensioning shaft and the second tensioning shaft can be tensioned and straightened to maintain the cutting strength of the crystal column, which is convenient for forming a neat incision in the process of cutting the crystal column, which is beneficial to reduce the difficulty of the subsequent grinding process and save grinding time, and is convenient for improving the processing efficiency of the crystal column. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A diagram showing the connection structure of the spool assembly of the present invention; Figure 2 This is a diagram of the connection structure of the steering component of the present invention; Figure 3 This is a diagram of a crystal column cut by an inclined cutting section of the present invention; Figure 4 It is a structural diagram of the cutting line of the present invention; Figure 5 It is a front view of the crystal column block of the present invention; Figure 6 is a structural diagram of an image sensor of the present invention; Figure 7 This is a circuit layer connection structure diagram of the present invention.

[0021] In the figure: 1. base; 2. motor box; 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. microporous suction cup; 14. crystal column block; 15. single crystal silicon layer; 16. circuit layer; 17. lifting component; 18. feeding platform. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be understood by people with general skills in the field to which the present invention belongs. "Including" and similar words used in this article mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0023] like Figure 1The figure shows a connection structure diagram of a bobbin assembly of the present invention, which provides an image sensor manufacturing device, including a base 1, a bobbin assembly and a cutting line 10. A motor box 2 is fixed on the top of the base 1. The motor box 2 includes a plurality of motors. The output ends of the plurality of motors are respectively connected to one end of a pay-off shaft 4, a take-up shaft 3, a drive shaft 5 and an auxiliary shaft 8. The input ends of the plurality of motors installed in the motor box 2 are respectively electrically connected to an external power supply. The external power supply can supply power to the internal motor of the motor box 2. When the motor box 2 is connected to the external power supply, each motor can be started, so that the output end of each motor drives the bobbin assembly to rotate, so that the cutting line 10 rotates to cut the crystal column. A plurality of heat dissipation holes are provided on the side of the motor box 2 to maintain gas exchange between the interior of the motor box 2 and the external environment, so as to prevent the interior of the motor box 2 from overheating and affecting the normal operation of the motor inside the motor box 2. A plurality of motors are fixedly installed inside the motor box 2. The output ends of the plurality of motors are respectively connected to a shaft-like component and drive the shaft-like component to rotate. The pay-off shaft 4, the take-up shaft 3, the drive shaft 5 and the auxiliary shaft 8 are all shaft-like components.

[0024] like Figure 2 The figure shows the connection structure diagram of the steering component of the present invention, the spool assembly includes a pay-off shaft 4, a driving shaft 5, a tensioning structure, an auxiliary shaft 8 and a take-up shaft 3 respectively connected to the output end of the motor box 2, wherein the pay-off shaft 4 can unwind the cutting wire 10 wound on its surface during rotation, so that the cutting wire 10 can be tensioned and wound on the surfaces of the driving shaft 5, the tensioning structure, the guide shaft 9 and the auxiliary shaft 8 in multiple circles, and a cutting wire array is formed between the auxiliary shaft 8 and the guide shaft 9. The diameter of the driving shaft 5 is larger than that of the auxiliary shaft 8, which is beneficial to increase the contact length between the auxiliary shaft 8 and the cutting wire 10, so as to drive the cutting wire 10 to rotate in the vertical direction, so that the cutting wire 10 can move relative to the surface of the crystal column, and the cutting speed is accelerated by increasing the relative displacement speed between the cutting wire 10 and the crystal column, and at the same time, the feeding structure is used to increase the contact length between the auxiliary shaft 8 and the cutting wire 10. The structure is used to implement pressure cutting on the crystal column 10. The tensioning structure can apply a tensioning force in the horizontal direction to the cutting line 10. The first tensioning shaft 6 and the second tensioning shaft 7 respectively apply tensioning forces of equal magnitude and opposite action directions to the cutting line 10, so that the cutting line 10 wound on the first tensioning shaft 6 and the second tensioning shaft 7 can be tensioned and straightened to maintain the cutting strength of the crystal column, which is convenient for forming a neat incision in the process of cutting the crystal column, which is beneficial to reduce the difficulty of the subsequent grinding process and save grinding time, and is convenient for improving the processing efficiency of the crystal column. The auxiliary shaft 8 can apply a driving force to the cutting line 10 through the static friction contact between the auxiliary shaft 8 and the cutting line 10, and cooperate with the driving shaft 5 at the top of the spool assembly to keep the cutting line 10 able to move synchronously. The take-up shaft 3 serves as the winding end of the cutting line 10 and can wind up the cutting line 10.

[0025] Combination Figure 1 or Figure 2The tensioning structure includes a first tensioning shaft 6 and a second tensioning shaft 7. The lengths of the first tensioning shaft 6 and the second tensioning shaft 7 are equal and both are cylindrical. The first tensioning shaft 6 and the second tensioning shaft 7 are symmetrical with respect to the longitudinal bisection plane of the driving shaft 5. The lengths of the driving shaft 5, the first tensioning shaft 6, the second tensioning shaft 7, the auxiliary shaft 8 and the guide shaft 9 are equal to each other. The diameter of the driving shaft 5 is not less than twice the diameter of the auxiliary shaft 8. The rotation speed of the auxiliary shaft 8 is greater than twice the rotation speed of the driving shaft 5. The inverse of the rotation speed ratio between the driving shaft 5 and the auxiliary shaft 8 is equal to the diameter ratio between the two. This can keep the moving speeds of different parts of the cutting line 10 equal, which is beneficial to keep the surface of the cutting line 10 with a uniform degree of tension and ensure the synchronization of the crystal column cutting.

[0026] Combination Figure 2 The spool assembly also includes a guide shaft 9, one end of which passes through the interior of the motor box 2 and is welded and fixed to the inner wall of the motor box 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, the cutting line 10 that bypasses the first steering column 11 and the second steering column 12 can be steered. On the other hand, the degree of wear of the cutting line 10 on the surface of the first steering column 11 or the second steering column 12 per unit time can be reduced, thereby reducing the risk of breaking the first steering column 11 or the second steering column 12.

[0027] 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 box 2, and the winding direction of the cutting wire 10 can be rotated through the steering component to form a crystal column block 14 with an inclined planar incision after cutting the crystal column.

[0028] like Figure 3 The figure shows a diagram of the inclined cutting section cutting a crystal column according to the present invention. When the cutting line 10 passes through the guide shaft 9 and the auxiliary shaft 8, a horizontal cutting section 101 and an inclined cutting section 102 are formed. After the inclined cutting section 102 cuts the crystal column, a crystal column block 14 with a bevel cut is formed. The cutting line 10 is sequentially wound around the surfaces 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 around the surface thereof is tensioned by the drive shaft 5, the tensioning structure, the guide shaft 9, the auxiliary shaft 8 and the take-up shaft 3.

[0029] Preferably, the horizontal cutting segments 101 and the inclined cutting segments 102 are arranged in an equidistant and staggered manner in a straight line direction. The staggered horizontal cutting segments 101 and the inclined cutting segments 102 can simultaneously perform multiple cuts on the same crystal column, so that the crystal column can be simultaneously cut into multiple oblique cylindrical crystal column blocks 14 including a plane, an inclined surface and a cylindrical surface, which is beneficial to improve the cutting efficiency of the crystal column compared with a single oblique cutting segment 102 and save cutting time. The inclined cutting segment 102 forms an angle θ with respect to the horizontal cutting segment 101, and the angle θ is an acute angle, and the angle θ is 30°. By using a cutting line 10 with multiple oblique cutting segments 102 to cut the crystal column, multiple crystal column blocks 14 with continuously increasing thickness can be obtained at the same time, and a continuously increasing thickness can be obtained. The added wafer can reduce the degree to which the wafer is affected by external forces, prevent the wafer from breaking or edge warping during the back-end processing of the wafer, which is beneficial to reducing the processing difficulty of the wafer back-end process, and at the same time is beneficial to ensuring the yield rate of the wafer leaving the factory. On the other hand, by beveling the crystal column and forming a crystal column block 14 with an elliptical cross-section, since the area of ​​the elliptical cross-section is larger than the cross-sectional area of ​​the crystal column, when the wafer formed by the crystal column block 14 with an elliptical bevel is processed, a larger number of image sensors can be arranged than a wafer with a circular cross-section, which is beneficial to saving the manufacturing cost of the image sensor. At the same time, when the same number of image sensor circuits are arranged, the amount of wafers used and the time for replacing wafers can be reduced, which is beneficial to improving the manufacturing efficiency of the image sensor.

[0030] Combination Figure 1 The manufacturing device also includes a feeding structure, which includes a feeding platform 18 and a lifting component 17 opened on the top of the base 1. The lifting component 17 is fixed on the top of the feeding platform 18. A microporous suction cup 13 is fixed on the top of the lifting component 17. The negative pressure on the top of the microporous suction cup 13 attracts the crystal column to be cut. The microporous suction cup 13 can attract the bottom of the crystal column, which is beneficial to maintain the stability of the crystal column placed on the surface of the microporous 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 tangentially in contact with the top surface of the microporous 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 sections of crystal column blocks 14 with a plane, a slope and a cylindrical curved surface. After the crystal column block 14 with a slope is processed into a wafer, its top surface is an inclined elliptical surface.

[0031] Combination Figure 2The cutting line 10 passes through the first steering column 11 and the second steering column 12 to form a "Z"-shaped routing portion. At least one section of the cutting line 10 in the "Z"-shaped routing portion forms an acute angle with the central axis of the crystal column to be cut at the top of the microporous suction cup 13. The minimum spacing distance 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, which can ensure that the cutting line 10 can pass through between the first steering column 11 and the second steering column 12 to avoid affecting the uniform movement of the cutting line 10, and can effectively prevent the situation where the crystal column is unable to be cut, which is beneficial to improving the yield rate of crystal column cutting.

[0032] like Figure 5 The figure shows a front view of the crystal column block of the present invention. When the cross-sectional diameter of the crystal column block 14 is a, the radius length r=a / 2. When the acute angle θ formed by the oblique section formed after cutting and the horizontal plane is 30°, the major axis of the cross-sectional elliptical surface is b=a / cosθ, where θ<90. Then, by calculation, it can be known that b>a, and S can be obtained. 椭圆 >S 圆面 When the cylindrical crystal column is beveled and formed into an elliptical cross-section, the area of ​​the elliptical cross-section is larger than the cross-sectional area of ​​the crystal column. Therefore, the wafer with an oblique cross-section can arrange more image sensors than the wafer with a circular cross-section, which is beneficial to saving the manufacturing cost of the image sensor. On the other hand, it can increase the amount of light absorbed by the image sensor and enhance the optical image acquisition effect.

[0033] like Figure 4 The cutting wire structure diagram of the present invention is shown, the cutting wire 10 includes a wire core 103, the surface of the wire core 103 is electroplated with a coating layer 104 and a thickening layer 106 in sequence, the surface of the wire core 103 is fixed with diamonds 105 penetrating the coating layer 104 and the thickening layer 106, the wire core 103 is a high-strength steel wire or a tungsten wire metal wire, the high-strength tungsten wire metal wire is made of high-hardness diamond abrasive grains fixed on a carbon steel or tungsten wire substrate by electroplating, the diamonds 105 are evenly distributed at equal intervals about the center of the wire core 103, the outer contour of the cross section of the diamond 105 is a triangle or a pentagon, and the thickening layer 106 is a nickel-plated layer.

[0034] Combination Figure 1 , and also provides a method for manufacturing an image sensor, the manufacturing method having the following steps: S1: Applying the front-end process of semiconductor manufacturing to the silicon ingot to obtain a crystal column, which is a cylindrical silicon ingot processed by a crystal pulling process; S2: placing the vertical and horizontal cutting section 101 of the crystal column on the top of the microporous suction cup 13, so that the microporous suction cup 13 applies an adsorption force to the surface of the crystal column. The surface of the microporous suction cup 13 is provided with a plurality of adsorption micropores evenly distributed around the circumference, which can exert an adsorption force on the surface of the crystal column and prevent the microporous suction cup 13 from driving the crystal column to roll in the process of moving the crystal column up and down in the vertical direction, which is conducive to improving the accuracy of cutting the crystal column; S3: Start the lifting component 17, so that the lifting component 17 lifts the position of the micropore suction cup 13 and makes the micropore suction cup 13 contact with 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 micropore suction cup 13 upward or downward in the vertical direction, so that the crystal column placed on the top of the micropore suction cup 13 can contact with the cutting line 10; S4: Continue to lift 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 synchronously adjusted, which is conducive 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 at the bottom of the crystal column block 14; S5: grinding and etching the crystal column block 14 after cutting and applying RO / DI water bath to make the surface of the ground wafer flat, and remove micro cracks or surface damage by etching the wafer, which is conducive to ensuring the quality of the wafer; S6: The wafer is polished using CMP polishing technology. The surface of the polished wafer is smoother to prevent protruding impurities from affecting the etched circuit. The polished wafer is then cleaned to remove organic impurities and particles on the surface of the wafer, thereby improving the purity of the wafer itself and reducing the adverse effects of impurity particles on the etched circuit on the wafer. like Figure 7 It is a circuit layer connection structure diagram of the present invention. After the single crystal silicon layer 15 is epitaxially grown on the wafer, the circuit layer 16 is etched and packaged to obtain a sensor element capable of collecting optical images.

[0035] like Figure 6 The image sensor structure diagram of the present invention is shown. An image sensor is also provided, which is manufactured using the manufacturing method of the above embodiment. A larger number of image sensors can be arranged on a wafer with a circular cross-section, which is beneficial to saving the manufacturing cost of the image sensor and improving the optical image acquisition effect.

[0036] Although the embodiments of the present invention are described in detail above, it is obvious 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 are within the scope and spirit of the present invention as described in the claims. Moreover, the present invention described herein may have other embodiments and may be implemented or realized in a variety of ways.

Claims

1. An image sensor manufacturing device, characterized in that: include: A base, with a motor box fixed on the top of the base; A bobbin assembly, the bobbin assembly comprising a pay-off shaft, a drive shaft, a tensioning structure, an auxiliary shaft and a take-up shaft respectively connected to the output end of the motor box; The spool assembly also includes a guide shaft, and a steering component capable of changing the winding direction of the cutting line is welded to the bottom of the guide shaft; A cutting line is formed when the cutting line passes between the guide shaft and the auxiliary shaft to form a horizontal cutting section and an inclined cutting section. After the inclined cutting section cuts the crystal column, a crystal column block with an inclined cut is formed.

2. The image sensor manufacturing device according to claim 1, characterized in that: The horizontal cutting segments and the inclined cutting segments are arranged alternately and at equal intervals in a straight line direction, and the inclined cutting segments form an angle θ with respect to the horizontal cutting segments.

3. The image sensor manufacturing device according to claim 2, characterized in that: The steering component comprises 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 device according to claim 3, characterized in that: The cutting line passes through the first steering column and the second steering column to form a "Z"-shaped routing portion, and the minimum spacing distance between the projection contours of the first steering column and the second steering column on the vertical plane is not less than the diameter of the cutting line.

5. The image sensor manufacturing device according to claim 1, characterized in that: The tensioning structure comprises a first tensioning shaft and a second tensioning shaft, wherein the first tensioning shaft and the second tensioning shaft are symmetrical with respect to a longitudinal bisecting plane of the driving shaft; The lengths of the driving shaft, the first tensioning shaft, the second tensioning shaft, the auxiliary shaft and the guide shaft are equal in any two; The diameter of the driving shaft is not less than twice the diameter of the auxiliary shaft, the rotation speed of the auxiliary shaft is greater than twice the rotation speed of the driving shaft, and the inverse of the rotation speed ratio between the driving shaft and the auxiliary shaft is equal to the diameter ratio between the two.

6. The image sensor manufacturing device according to claim 1, characterized in that: The manufacturing device also includes: A feeding structure, the feeding structure comprising a feeding platform and a lifting component opened on the top of the base; The lifting component is fixed through the top of the feeding platform, and a microporous suction cup is fixed on the top of the lifting component. The negative pressure on the top of the microporous suction cup attracts the crystal column to be cut.

7. The image sensor manufacturing device according to claim 1, characterized in that: The cutting wire comprises a wire core, a coating layer and a thickening layer are electroplated in sequence on the surface of the wire core, and diamonds penetrating the coating layer and the thickening layer are fixed on the surface of the wire core.

8. The image sensor manufacturing device according to claim 1, characterized in that: The motor box includes multiple motors, and 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. The input ends of the multiple motors installed in the motor box are respectively electrically connected to an external power supply, and the external power supply can power the internal motors of the motor box.

9. A method for manufacturing an image sensor, the method comprising the following steps: Implementing the front-end process of semiconductor manufacturing on the silicon ingot to obtain a crystal column; Place the vertical and horizontal cut sections of the crystal column on top of the microporous suction cup, so that the microporous suction cup applies an adsorption force to the surface of the crystal column; Start the lifting component to lift the microporous suction cup and make the microporous suction cup contact with the inclined cutting section and the horizontal cutting section; Continue to lift the crystal column so that the inclined cutting section and the horizontal cutting section cut the crystal column to form a crystal column block with an inclined surface; The cut crystal column blocks are subjected to grinding and etching processes and RO / DI water baths are applied; The wafer is polished using CMP polishing technology, and the polished wafer is cleaned; After epitaxial growth of a single-crystal silicon layer on the wafer, the circuit layer is etched and packaged.

10. An image sensor, characterized in that: The image sensor is manufactured by the manufacturing method according to claim 9.

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