A chip-free cutting process and device for type II superlattice wafers

Abstract

The present invention discloses a chip-free cutting process and device for Class II superlattice wafers, relating to the field of wafer cutting technology. The device comprises an operating table, a top portion of the operating table being provided with a wafer press body near one side edge, and a top portion of the operating table being provided with a rotating assembly near the center for driving the wafer to generate centrifugal force. The present invention provides double-sided protection for the wafer by first evenly coating both sides of the wafer with a certain thickness of photoresist before cutting the Class II superlattice wafer, thereby preventing the edge of the dicing blade from contacting the front edge of the wafer and compensating for the thickness difference caused by wafer warpage. During dicing, the photoresist on the back side serves as a sacrificial thickness for dicing, ensuring that the back side of the wafer remains in the middle of the cutting process, eliminating chipping on the back side. During the cutting process, the wafer is in the central area of ​​the blade cutting process. Eliminating chipping on the back side can effectively eliminate edge collapse caused by subsequent processes.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer cutting, in particular to a chip-free cutting process and device for type II superlattice wafers. Background Art

[0002] A Type II superlattice wafer is a multilayered structure formed by alternating nanometer-thin layers of two or more semiconductor materials. Electrons and holes are trapped within the different semiconductor layers, resulting in a unique band structure and excellent optoelectronic properties. An ultrasonic generator converts 50 / 60Hz current into electrical energy at 20, 30, and 40kHz. A transducer then converts this into mechanical vibrations of the same frequency. This vibration is then transmitted to the cutting blade via an amplitude modulator. The high-frequency vibrations of the blade utilize the ultrasonic energy to locally heat and melt the material being cut, achieving the desired cutting effect. This process prevents edge chipping, deformation, and wear, while also fusing and sealing the cut surface, resulting in a smooth cut surface.

[0003] In the existing technology, type II superlattice wafers are widely used in the semiconductor field and have extremely high requirements for the cutting process. The large warpage during blade cutting will seriously affect the quality of the wafer and subsequent applications. For third-generation semiconductors, the requirements for chip production and processing are even more stringent. The most important indicator of the cutting process is edge chipping, with front edge chipping ≤5um and back edge chipping ≤15um. As a new compound semiconductor material, the value of type II superlattice is constantly being explored, but it also has the problem of large surface warpage. When the surface warpage is too large, the cutting process is likely to cause inconsistent thickness, resulting in excessive edge chipping process indicators. Therefore, how to solve the cutting problem caused by warpage has become a difficult breakthrough point. In the actual dicing process, since the front side of the wafer is coated with photoresist and the front side is the blade entry point, the front edge chipping is not serious. However, the back side is the contact point of the blade tip and is not protected by photoresist, so the back edge chipping will be more serious, which will affect the subsequent normal use of the wafer.

[0004] Therefore, we propose a chip-free cutting process and device for type II superlattice wafers in order to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a chip-free cutting process and device for type II superlattice chips, so as to solve the problem raised in the above background technology that the front side of the chips is mostly protected during the cutting process, which easily leads to chipping of the back side and affects the subsequent normal use of the chips.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a chip-free cutting device for Class II superlattice wafers, comprising an operating table, a tablet press body is arranged at the top of the operating table near one side edge, a rotating assembly for driving the wafer to generate centrifugal force is arranged at the top of the operating table near the center, a protective assembly is arranged at the top of the operating table near the other side edge, the protective assembly includes a mechanical arm and a rotating frame for transferring the wafer, a sealed tank for storing photoresist is arranged at the top of the rotating frame near one side edge, a tooth row is arranged inside the rotating frame, a mobile frame is slidably connected between the relative inner walls of the tooth row, an X-ray fluorescence spectrometer for detecting the photoresist coating condition on the wafer surface is arranged at the bottom of the mobile frame, the wafer is placed inside the rotating assembly by the mechanical arm, the photoresist drips from the sealed tank to the top of the wafer, the rotating assembly causes the wafer to rotate to generate centrifugal force, so that the photoresist on the wafer surface is evenly coated, and then the X-ray fluorescence spectrometer is used to detect whether the photoresist coating is even.

[0007] Preferably, the protective component also includes a base, a solenoid valve is provided on the outer surface of the output pipe in the sealed tank, a slide groove is provided on the top of the rotating frame, a multi-stage electric telescopic rod is provided on the inner wall of the slide groove, a slider is fixed to one end of the multi-stage electric telescopic rod, a servo motor is fixed to the top of the slider by screws, an output shaft is fixed to the output end of the servo motor, a stepper motor is fixed to the outer surface of the movable frame by screws, and a driving gear is fixed on the outer surface of the active shaft part of the stepper motor.

[0008] Preferably, the bottom of the base is fixedly connected to the top of the operating table, the top of the rotating frame is movable and penetrated to the outside of the base, the outer surface of the robotic arm is fixedly connected to the outer surface of the rotating frame by a fixing bolt, the opposite outer surfaces of the slider are slidably connected to the opposite inner walls of the slide groove, the two ends of the output shaft are movable and penetrated to the opposite outsides of the slider, the inner wall of the gear row is fixedly connected to the outer surface of the output shaft, one end of the gear row penetrates to the outside of the slider, the two ends of the stepping motor driving shaft part are movable and penetrated to the opposite outsides of the moving frame, and the outer surface of the driving gear is meshed with the outer surface of the gear row.

[0009] Preferably, the rotating assembly includes a protective sleeve, the bottom of the protective sleeve is fixedly connected to the top of the operating table, the top of the operating table is fixed with a base plate, the internal rotation of the base plate is connected to the mounting shaft, the outer surface of the mounting shaft is fixed with a driven gear, the top of the base plate is fixed with a mounting bracket near one side edge, and the top of the mounting bracket is fixedly connected to the forward and reverse motors by screws.

[0010] Preferably, a rotating shaft is fixed to the output end of the forward and reverse motor, and both ends of the rotating shaft are movable and penetrate to the opposite outsides of the mounting frame respectively. A driving gear is fixedly sleeved near the center of the outer surface of the rotating shaft, and the outer surface of the driving gear is meshed and connected with the outer surface of the driven gear. Two telescopic tubes are provided on the top of the driven gear, and a tray is fixed between the top ends of the two telescopic tubes. A plurality of negative pressure suction cups are provided inside the tray, and a positioning frame is fixed to the top of the mounting shaft.

[0011] Preferably, a driving motor is fixedly installed on the top of the positioning frame by screws, a driving shaft is fixed to the output end of the driving motor, both ends of the driving shaft are movable and penetrate to the opposite outsides of the positioning frame, an active gear ring is fixedly sleeved near the center of the outer surface of the driving shaft, and the outer surface of the active gear ring is meshedly connected with a driven gear ring.

[0012] Preferably, the internal fixing sleeve of the driven gear ring is provided with an inner screw, the bottom end of the inner screw is movably embedded in the interior of the mounting shaft, the internal thread of the inner screw is connected to a rotating screw, the top end of the rotating screw is movably passed through the outside of the inner screw, and the top end of the rotating screw is fixedly connected to the bottom center of the tray.

[0013] Preferably, a movable component is provided on the top of the operating table, and the movable component includes a sliding rod, the bottom of the sliding rod is fixedly connected to the top of the operating table, a hydraulic rod is provided on the inner wall of one side of the sliding rod, and a supporting structure is fixed to one end of the hydraulic rod, and the opposite outer surfaces of the supporting structure are respectively slidably connected to the relative inner walls of the sliding rod, and a silicon wafer is provided inside the supporting structure.

[0014] Preferably, a relative moving mechanism is provided inside the operating table, and two auxiliary blocks are threadedly sleeved on the outer surface of the relative moving mechanism. The opposite outer surfaces of the two auxiliary blocks slide with the relative inner walls of the operating table respectively, and electric push rods are provided on the top of the two auxiliary blocks. The top ends of the two electric push rods are provided with dicing machines through auxiliary plates, and a controller is provided on the top of the operating table near the front surface.

[0015] A chip-free cutting process for a second-class superlattice wafer comprises the following steps:

[0016] S1. During the dicing process of the second-class superlattice wafer, the scribe lines are first photolithographically developed. The scribe lines are then etched with an ICP etching process to form grooves 20-50 μm deep. The etched wafers are then cleaned. The wafers are clamped to the center of the top of the tray by two grippers in the robotic arm. The gripping force of the grippers is controlled at 5-20 N. The photoresist in the sealed tank is dripped onto the center of the wafer.

[0017] S2, the drive device makes the chip rotate at high speed, the speed is rpm, the photoresist diffuses toward the edge due to the centrifugal force. The centrifugal force formula is: ,in, is the photoresist quality, is the angular velocity of rotation, The distance from the photoresist particle to the center of rotation. The centrifugal force causes the photoresist to flow toward the edge, forming a thin and uniform layer.

[0018] Splitting stage: At the beginning of high-speed rotation, a large amount of photoresist is thrown out of the edge of the wafer, and the thickness decreases rapidly.

[0019] Spreading stage: The remaining photoresist spreads evenly under the action of centrifugal force and surface tension, and the thickness gradually stabilizes.

[0020] Evaporation stage: solvent evaporates and the adhesive layer solidifies;

[0021] S3. An X-ray tube generates high-intensity primary X-rays to irradiate the photoresist layer on the wafer surface. An X-ray fluorescence spectrometer is moved omnidirectionally across the top of the wafer to measure the thickness of the photoresist on the front side of the wafer. The thickest and thinnest thicknesses are measured, and the thickness difference is calculated. This is used as a reference for the thickness of the photoresist coating on the back side of the wafer. If the photoresist coating thickness is greater than the wafer thickness difference, the wafer is then flipped 180° by a robotic arm, and the back side of the wafer is coated with photoresist.

[0022] S4. The double-sided protected wafer is bonded to the silicon wafer substrate with wax, and is pressed by a wafer pressing machine body, ensuring that the upper surface of the wafer is parallel to the surface of the silicon substrate. The mounted wafer is placed on a dicing machine for cutting and dicing. After completion, the cut chip is removed and the wax and photoresist are removed.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. When in use, before cutting the second-class superlattice wafer, a certain thickness of photoresist is first evenly applied to both sides of the wafer, thereby realizing double-sided protection for the wafer, so that the edge of the dicing knife does not contact the front edge of the wafer, compensating for the thickness difference caused by the wafer warpage. When dicing, the photoresist on the back side serves as a sacrificial thickness for dicing, ensuring that the back side of the wafer is still in the middle area of ​​dicing, eliminating back edge collapse. During the dicing process, the wafer is in the central area of ​​the blade cutting. After eliminating back collapse, the edge collapse caused by subsequent processes can be effectively eliminated. At the same time, the burrs formed in the process have no effect on the edge collapse of the front and back sides, effectively preventing the tip of the blade in the dicing machine from easily generating edge collapse due to the lack of protection on the back side of the wafer when cutting the wafer, thereby solving the problem in the prior art that the front side of the wafer is mostly protected during the dicing process, which easily leads to back edge collapse and affects the subsequent normal use of the wafer.

[0025] 2. When in use, after the double-sided protection of the wafer is completed, a certain amount of wax is applied to the bottom surface of the wafer to adhere the silicon wafer to the wafer, and then the wafer is driven back and forth by the hydraulic rod to realize the cutting and dicing of the wafer. By pressing the wafer into the silicon wafer, the cutting of the wafer is further protected. After the dicing is completed, the staff can remove the cut wafer and remove the wax and photoresist to obtain a wafer with completely eliminated edge chipping;

[0026] 3. During use, in order to make the silicon wafer and the wafer completely parallel to each other, the combination of the silicon wafer and the wafer is pressed by the wafer press body to ensure that the upper surface of the wafer is parallel to the surface of the silicon substrate, so that the wax layer undergoes plastic deformation under high pressure, gradually filling the concave area, and finally making the upper surface of the wafer and the surface of the silicon substrate tend to be parallel under the action of pressure, thereby further ensuring the smoothness of the wafer cutting process and preventing edge collapse. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A front perspective view of a device for cutting a second type of superlattice wafer without chipping according to the present invention;

[0028] Figure 2 A partially cutaway perspective view of a protective cover of a device for cutting a second type of superlattice wafer without chipping according to the present invention;

[0029] Figure 3 For the present invention Figure 2 Enlarged view of point A in the middle;

[0030] Figure 4 A partially cutaway perspective view of a rotating assembly of a device for cutting a second type of superlattice wafer without chipping according to the present invention;

[0031] Figure 5 A partial perspective view of a protective component of a device for cutting a second type of superlattice wafer without chipping according to the present invention;

[0032] Figure 6 A perspective view of a cutaway portion of a base portion of a device for cutting a second type of superlattice wafer without chipping according to the present invention;

[0033] Figure 7 A perspective view of a slider portion of a device for cutting a second type of superlattice wafer without chipping according to the present invention;

[0034] Figure 8 A partially cutaway perspective view of a tooth row of a device for cutting a type II superlattice wafer without chipping according to the present invention;

[0035] Figure 9 A three-dimensional diagram of the supporting structure of a device for cutting a second type of superlattice wafer without chipping according to the present invention;

[0036] Figure 10 This is a partial cross-sectional perspective view of the tablet press body of a device for cutting type II superlattice wafers without chipping edges according to the present invention.

[0037] In the picture:

[0038] 1. Operating table; 2. Rotating assembly; 201. Protective cover; 202. Bottom plate; 203. Mounting shaft; 204. Driven gear; 205. Mounting frame; 206. Forward and reverse motor; 207. Rotating shaft; 208. Driving gear; 209. Telescopic tube; 210. Tray; 211. Negative pressure suction cup; 212. Rotating screw; 213. Positioning frame; 214. Driving motor; 215. Driving shaft; 216. Driving gear ring; 217. Driven gear ring; 218. Inner screw; 3. Protective assembly; 301. Base; 302. Rotating frame; 3 03. Robotic arm; 304. Sealing tank; 305. Solenoid valve; 306. Slide; 307. Multi-stage electric telescopic rod; 308. Slider; 309. Servo motor; 310. Output shaft; 311. Gear row; 312. Moving frame; 313. Stepper motor; 314. Driving gear; 315. X-ray fluorescence spectrometer; 4. Moving component; 401. Slide; 402. Hydraulic rod; 403. Support structure; 404. Silicon wafer; 5. Tablet press body; 6. Relative movement mechanism; 7. Electric push rod; 8. Dicing machine; 9. Controller. DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the implementation regulations described are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0040] Reference Figures 1-10The figure shows a device for cutting a second-class superlattice wafer without chipping, comprising an operating table 1, a tablet press body 5 is arranged at the top of the operating table 1 near one edge, a rotating assembly 2 for driving the wafer to generate centrifugal force is arranged near the center of the top of the operating table 1, a protective assembly 3 is arranged at the top of the operating table 1 near the other edge, the protective assembly 3 includes a mechanical arm 303 for transferring the wafer and a rotating frame 302, a sealed tank 304 for storing photoresist is arranged at the top of the rotating frame 302 near one edge, a tooth row 311 is arranged inside the rotating frame 302, a movable frame 312 is slidably connected between the opposite inner walls of the tooth row 311, and an X-shaped plate for detecting the photoresist coating condition on the wafer surface is arranged at the bottom of the movable frame 312. X-ray fluorescence spectrometer 315, the wafer is placed inside the rotating component 2 through the robotic arm 303, the photoresist drips from the sealed tank 304 to the top of the wafer, the rotating component 2 causes the wafer to rotate to generate centrifugal force, so that the photoresist on the wafer surface is evenly coated, and then the X-ray fluorescence spectrometer 315 is used to detect whether the photoresist coating is even. The protective component 3 also includes a base 301, an electromagnetic valve 305 is set on the outer surface of the output tube in the sealed tank 304, a slide 306 is opened on the top of the rotating frame 302, and a multi-stage electric telescopic rod 307 is set on the inner wall of the slide 306, and a slider 308 is fixed to one end of the multi-stage electric telescopic rod 307. A servo motor 309 is fixed to the top of the slider 308 by screws, and the output end of the servo motor 309 The output shaft 310 is fixed, and the outer surface of the movable frame 312 is fixedly installed with a stepper motor 313 by screws. The outer surface of the active shaft part of the stepper motor 313 is fixedly sleeved with a driving gear 314. The bottom of the base 301 is fixedly connected to the top of the operating table 1, and the top of the rotating frame 302 is movable through the outside of the base 301. The outer surface of the robotic arm 303 is fixedly connected to the outer surface of the rotating frame 302 by fixing bolts. The opposite outer surfaces of the slider 308 are respectively slidably connected to the opposite inner walls of the slide groove 306. The two ends of the output shaft 310 are respectively movable through the opposite outer sides of the slider 308. The inner wall of the gear row 311 is fixedly connected to the outer surface of the output shaft 310. One end of the gear row 311 penetrates the outside of the slider 308. The stepper motor 31 The two ends of the active shaft part are movable and penetrate to the opposite outer sides of the movable frame 312 respectively. The outer surface of the driving gear 314 is meshed with the outer surface of the gear row 311. The rotating component 2 includes a protective sleeve 201. The bottom of the protective sleeve 201 is fixedly connected to the top of the operating table 1. The top of the operating table 1 is fixed with a base plate 202. The interior of the base plate 202 is rotatably connected to the mounting shaft 203. The outer surface of the mounting shaft 203 is fixedly sleeved with a driven gear 204. The top of the base plate 202 is fixed near one side edge with a mounting frame 205. The top of the mounting frame 205 is fixedly connected to the forward and reverse motor 206 by screws. The output end of the forward and reverse motor 206 is fixed with a rotating shaft 207. The two ends of the rotating shaft 207 are movable and penetrate to the opposite outer sides of the mounting frame 205 respectively.The outer surface of the rotating shaft 207 is fixedly sleeved with a driving gear 208 near the center. The outer surface of the driving gear 208 is meshed with the outer surface of the driven gear 204. Two telescopic tubes 209 are set on the top of the driven gear 204. A tray 210 is fixed between the tops of the two telescopic tubes 209. A plurality of negative pressure suction cups 211 are set inside the tray 210. A positioning frame 213 is fixed to the top of the mounting shaft 203. A driving motor 214 is fixed to the top of the positioning frame 213 by screws. A driving shaft 215 is fixed to the output end of the driving motor 214. The two ends of the driving shaft 215 are fixed to the output end of the driving motor 214. The ends of the drive shaft 215 are respectively movable and penetrate the opposite outer parts of the positioning frame 213. The outer surface of the drive shaft 215 is fixedly sleeved with an active gear ring 216 near the center. The outer surface of the active gear ring 216 is meshedly connected with a driven gear ring 217. The inner fixed sleeve of the driven gear ring 217 is provided with an inner screw 218. The bottom end of the inner screw 218 is movably embedded in the interior of the installation shaft 203. The internal thread of the inner screw 218 is connected to the rotating screw 212. The top end of the rotating screw 212 is movable and penetrates the outside of the inner screw 218. The top end of the rotating screw 212 is fixedly connected to the bottom center of the tray 210.

[0041] In this embodiment, before the second type superlattice wafer is cut, the second type superlattice wafer that has completed the process is first cut as follows: Figure 5 The two grippers in the robot arm 303 shown are moved to the center position of the top of the tray 210 and the two grippers are activated. Figure 6 The driving device shown in the base 301 drives the rotating frame 302 to rotate, and then drives the sealing tank 304 to rotate. When the bottom end of the output pipe part in the sealing tank 304 is aligned with the center position of the wafer, multiple negative pressure suction cups 211 are started at the same time to adsorb and fix the wafer. The solenoid valve 305 can be opened by the controller 9, so that the photoresist in the sealing tank 304 drips to the center position of the wafer, and then the driving motor 214 is started to drive the driving shaft 215 to rotate, and then the driving gear ring 216 is driven to rotate, thereby driving the driven gear ring 217 to rotate. The rotation of the driven gear ring 217 drives the inner screw 218 to move downward, wherein the two The telescopic tube 209 acts as a limit for the tray 210, thereby driving the tray 210 located at the top of the inner screw 218 to move downward until it moves to the center of the protective cover 201. The protective cover 201 prevents the photoresist on the top of the wafer from spilling outward under the action of centrifugal force during the subsequent centrifugal rotation, thereby contaminating other workpieces. Then the forward and reverse motors 206 can be started to drive the rotating shaft 207 to rotate, thereby driving the driving gear 208 to rotate, and then the driven gear 204 to rotate. The driven gear 204 drives the mounting shaft 203 to rotate, thereby rotating the tray 210, thereby driving the wafer to rotate at high speed, with a speed of rpm, the photoresist diffuses toward the edge due to the centrifugal force. The centrifugal force formula is: ,in, is the photoresist quality, is the angular velocity of rotation, is the distance from the photoresist particle to the rotation center. The centrifugal force causes the photoresist to flow to the edge, while overcoming its own viscous resistance and surface tension, and finally forming a thin and uniform adhesive layer. When the photoresist is evenly applied, the driving device in the rotating frame 302 can be started again to drive the rotating frame 302 to rotate until the X-ray fluorescence spectrometer 315 corresponds to the wafer. At this time, the multi-stage electric telescopic rod 307 can be started to extend it, driving the slider 308 to move forward, thereby pushing the gear row 311 to move forward until the slider 308 moves to one end of the slide groove 306. Then, the servo motor 309 can be started to rotate the output shaft 310, thereby driving the gear row 311 to rotate back and forth along the output shaft 310 in a certain arc, wherein the gear row 311 rotates The arc corresponds to the diameter of the wafer, and at the same time, the stepper motor 313 is started to drive the driving gear 314 to rotate, thereby causing the movable frame 312 to move back and forth along the outer surface of the tooth row 311, thereby driving the X-ray fluorescence spectrometer 315 to move back and forth along the bottom of the tooth row 311 and rotate, and comprehensively measure the thickness of the photoresist on the front side of the wafer, thereby measuring the thickest and thinnest thicknesses, and calculating the thickness difference, so as to serve as a reference for the thickness of the photoresist coating on the back side of the wafer, wherein the photoresist coating thickness is greater than the wafer thickness difference. The X-ray fluorescence spectrometer 315 generates high-intensity primary X-rays through the X-ray tube, irradiating the photoresist layer on the surface of the wafer, and can quantitatively calculate the actual thickness of the layer, which can then be measured by the driving gear 314 in the rotating frame 302. The moving device rotates the robot arm 303 to the position corresponding to the wafer, and at the same time, the drive motor 214 is started in the reverse direction to drive the drive shaft 215 to rotate in the reverse direction, thereby driving the inner screw 218 to rotate, thereby driving the tray 210 to move upward until it moves to a position where the top is flush with the top of the protective cover 201, and the multiple negative pressure suction cups 211 are closed so that they no longer produce adsorption force on the wafer. Then, the wafer can be clamped and fixed by the two clamping claws in the robot arm 303 again and then rotated 180° so that the back of the wafer faces upward, and then the wafer is put back to the center of the tray 210 by the robot arm 303, and the above steps are repeated again to drip the photoresist to the center of the other side of the wafer. At this time, the glue is irregularly accumulated on the surface of the wafer, and the thickness is thick. The photoresist is evenly covered on the surface of the wafer by the action of centrifugal force, and the speed of the driving motor 214 is controlled in real time by the controller 9 so that the thickness of the photoresist covering the wafer is consistent with the thickness of the front coating. By evenly covering the front and back sides of the wafer with photoresist, double-sided protection of the wafer is achieved, so that the edge of the dicing knife does not contact the front edge of the wafer. The back is protected by using the back glue coating method, and the thickness difference caused by the warpage of the wafer is compensated. When dicing, the photoresist on the back is used as the sacrificial thickness of dicing to ensure that the back of the wafer is still in the middle area of ​​dicing, eliminating the back edge collapse. During the dicing process, the wafer is in the central area of ​​the blade cutting. After eliminating the back collapse, the edge collapse caused by the subsequent process can be effectively eliminated.At the same time, the defects formed during the process have no effect on the chipping of the front and back sides, effectively preventing the chipping of the blade tip of the dicing machine 8 due to the lack of protection on the back side of the wafer during dicing. This solves the problem in the prior art that the front side of the wafer is often protected during dicing, which easily leads to chipping of the back side and affects the subsequent normal use of the wafer.

[0042] like Figure 1 and Figure 9-10 As shown, a moving component 4 is provided on the top of the operating table 1, and the moving component 4 includes a slide bar 401, the bottom of the slide bar 401 is fixedly connected to the top of the operating table 1, a hydraulic rod 402 is provided on the inner wall of one side of the slide bar 401, and a support structure 403 is fixed to one end of the hydraulic rod 402, and the opposite outer surfaces of the support structure 403 are respectively slidably connected to the relative inner walls of the slide bar 401, and a silicon wafer 404 is provided inside the support structure 403, and a relative moving mechanism 6 is provided inside the operating table 1, and two auxiliary blocks are threadedly sleeved on the outer surface of the relative moving mechanism 6, and the opposite outer surfaces of the two auxiliary blocks slide with the relative inner walls of the operating table 1 respectively, and electric push rods 7 are provided on the top of the two auxiliary blocks, and a dicing machine 8 is provided on the top of the two electric push rods 7 through an auxiliary plate, and a controller 9 is provided on the top of the operating table 1 near the front surface.

[0043] In this embodiment, after the double-sided protection of the wafer is completed, the wafer can be removed from the surface of the tray 210 by the robot arm 303, and the staff can apply a certain amount of wax on the bottom surface of the wafer, and then continue to move the wafer to the position as shown in the figure. Figure 9 As shown, at the center position of the silicon wafer 404 substrate, the silicon wafer 404 is adhered to the wafer, and at the same time, the hydraulic rod 402 is started to extend, driving the support structure 403 carrying the wafer to move forward until the wafer moves to a position corresponding to the wafer pressing machine body 5, and then the wafer pressing machine body 5 can be started to press the wafer, ensuring that the upper surface of the wafer is parallel to the surface of the silicon substrate. After the stamping is completed, the wafer can be moved to a position corresponding to the two dicing machines 8 by the action of the hydraulic rod 402, and at the same time, the relative movement mechanism 6 is started to drive the two dicing machines 8 to move relative to each other, wherein, as shown in FIG. Figure 1As shown, the relative movement mechanism 6 is composed of a driving device and a bidirectional screw. The bidirectional screw is driven to rotate by the driving device, driving the two dicing machines 8 to move along the bidirectional screw. This is an existing mature technology and will not be introduced in detail here. When the two dicing machines 8 move to the outer edge of the chip, the two electric push rods 7 can be started to shorten them, driving the two dicing machines 8 to move downward. By starting the two dicing machines 8, the chip is cut, and the chip is driven to move back and forth by the back and forth extension and contraction of the hydraulic rod 402, thereby realizing the cutting and dicing of the chip. By pressing the chip into the silicon wafer 404, the cutting of the chip is further protected. After the dicing is completed, the staff can remove the cut chip and perform dewaxing and photoresist removal treatment to obtain a chip with completely eliminated edge collapse.

[0044] In the present invention, before the second type superlattice wafer is cut, the scribe line is firstly photolithographically developed, and the scribe line is etched into grooves by ICP etching process. Then, the second type superlattice wafer which has completed the process is processed as follows. Figure 5 The two grippers of the robot arm 303 shown in the figure move to the center position of the top of the tray 210, wherein the end effector of the robot arm 303 grasps the wafer in a manner that meets the requirements of no damage, no pollution and high stability, and clamps the wafer from the edge by means of an electrically driven gripper. The gripper is made of ceramic material and the gripping force is controlled at 5-20N to prevent the wafer from breaking. At the same time, the gripper is started as shown in FIG. Figure 6 The driving device shown in the base 301 drives the rotating frame 302 to rotate, and then drives the sealing tank 304 to rotate. When the bottom end of the output pipe part in the sealing tank 304 is aligned with the center position of the wafer, the multiple negative pressure suction cups 211 are started at the same time to adsorb and fix the wafer. The solenoid valve 305 can be opened by the controller 9, so that the photoresist in the sealing tank 304 drips to the center position of the wafer. Then the driving motor 214 is started to drive the driving shaft 215 to rotate, and then the active gear ring 216 is driven to rotate. The driven gear ring 217 is driven to rotate, and the rotation of the driven gear ring 217 drives the inner screw 218 to move downward, thereby driving the tray 210 located at the top of the inner screw 218 to move downward until it moves to the center of the protective sleeve 201. Then the forward and reverse motor 206 can be started to drive the rotating shaft 207 to rotate, thereby driving the driving gear 208 to rotate, thereby causing the driven gear 204 to rotate, and the driven gear 204 drives the mounting shaft 203 to rotate, thereby causing the tray 210 to rotate, thereby driving the wafer to rotate at high speed, with a speed of rpm, the photoresist diffuses toward the edge due to the centrifugal force. The centrifugal force formula is: ,in, is the photoresist quality, is the angular velocity of rotation, is the distance from the photoresist particle to the center of rotation. The centrifugal force causes the photoresist to flow toward the edge, while overcoming its own viscous resistance and surface tension, and finally forming a thin and uniform adhesive layer.

[0045] Splitting stage: At the beginning of high-speed rotation, a large amount of photoresist is thrown out of the edge of the wafer, and the thickness decreases rapidly.

[0046] Spreading stage: The remaining photoresist spreads evenly under the action of centrifugal force and surface tension, and the thickness gradually stabilizes.

[0047] Evaporation stage: The solvent evaporates and the glue layer solidifies. When the photoresist is evenly applied, the driving device in the rotating frame 302 can be started again to drive the rotating frame 302 to rotate until the X-ray fluorescence spectrometer 315 corresponds to the wafer. At this time, the multi-stage electric telescopic rod 307 can be started to extend, driving the slider 308 to move forward, thereby pushing the gear row 311 to move forward until the slider 308 moves to one end of the slide groove 306. Then, the servo motor 309 can be started to rotate the output shaft 310, thereby driving the gear row 311 to rotate back and forth along the output shaft 310 in a certain arc. The arc of rotation of the gear row 311 corresponds to the diameter of the wafer. At the same time, the stepper motor 313 is started, driving the drive gear 314 to rotate, thereby causing the movable frame 312 to move back and forth along the outer surface of the tooth row 311, thereby driving the X-ray fluorescence spectrometer 315 to move back and forth and rotate along the bottom of the tooth row 311, and comprehensively measuring the thickness of the photoresist on the front side of the wafer, thereby measuring the thickest and thinnest thicknesses, and calculating the thickness difference, thereby serving as a reference for the thickness of the photoresist coating on the back side of the wafer, wherein the photoresist coating thickness is greater than the wafer thickness difference. The X-ray fluorescence spectrometer 315 generates high-intensity primary X-rays through an X-ray tube, irradiating the photoresist layer on the surface of the wafer. The photoresist contains specific elements. When the energy of the primary X-rays is higher than the binding energy of the inner-shell electrons of the atoms of these elements, the inner-shell electrons are excited to a high energy level, causing the atoms to be in an excited state, generating characteristic fluorescent X-rays. The outer-shell electrons of the excited atoms quickly fill the inner-shell vacancies, releasing X-rays with a specific energy, i.e., characteristic fluorescent X-rays. As the thickness of the photoresist increases, more element atoms are excited by the X-rays, and the fluorescence signal is enhanced.However, when the thickness exceeds a certain value, the penetration depth of the X-ray is limited and the fluorescence intensity tends to saturation. By establishing a calibration curve of fluorescence intensity and thickness, the actual thickness of the adhesive layer can be quantitatively calculated. Then, the driving device in the rotating frame 302 can be used to rotate the robotic arm 303 to a position corresponding to the wafer. At the same time, the driving motor 214 is started in reverse to drive the driving shaft 215 to rotate in the opposite direction, thereby driving the inner screw 218 to rotate, thereby driving the tray 210 to move upward until the top is flush with the top of the protective cover 201. The multiple negative pressure suction cups 211 are closed so that they no longer generate adsorption force on the wafer. Then, the wafer can be clamped and fixed by the two clamps in the robotic arm 303 again and then rotated 180°, so that The back of the wafer faces upward, and the wafer is then placed back to the center of the tray 210 by the robotic arm 303. The above steps are repeated again to drip the photoresist to the center of the other side of the wafer. At this time, the glue liquid is irregularly accumulated on the surface of the wafer and the thickness is uneven. The photoresist is evenly covered on the surface of the wafer by the action of centrifugal force, and the speed of the drive motor 214 is controlled in real time by the controller 9 so that the thickness of the photoresist covering the wafer is consistent with the thickness of the front coating. When the double-sided protection of the wafer is completed, the wafer can be removed from the surface of the tray 210 by the robotic arm 303, and the staff can apply a certain amount of wax to the bottom surface of the wafer. Then, the robotic arm 303 is continued to move the wafer to the position as shown below; Figure 9At the center position of the silicon wafer 404 substrate shown, the silicon wafer 404 is bonded to the wafer, and at the same time, the hydraulic rod 402 is started to extend, driving the support structure 403 carrying the wafer to move forward until the wafer moves to a position corresponding to the wafer press body 5. Then the wafer press body 5 can be started to press the wafer, ensuring that the upper surface of the wafer is parallel to the surface of the silicon substrate. The wafer press body 5 is a pressing mechanism based on mechanical balance and plane constraint to generate and transmit pressure. The wafer press body 5 generates pressure through a hydraulic system, utilizes the incompressibility of the hydraulic oil, and converts hydraulic energy into mechanical energy through an oil pump to push the pressing plate downward, applying vertical pressure to the wafer and the silicon substrate. The pressure of the pressing head is controlled by the driving device. The pressure is evenly transmitted to the upper surface of the wafer through the pressing head, causing the middle wax layer to flow under pressure, filling the small gap between the wafer and the silicon substrate, and overcoming the deviation caused by surface unevenness. If the upper surface of the wafer is not parallel to the surface of the silicon substrate, the pressure will act preferentially on the protruding parts, causing the wax layer to undergo plastic deformation under high pressure, gradually filling the concave area, and finally making the upper surface of the wafer parallel to the silicon substrate. The substrate surface tends to be parallel under the action of pressure. After the stamping is completed, the wafer can be moved to the position corresponding to the two dicing machines 8 by the action of the hydraulic rod 402. At the same time, the relative movement mechanism 6 is started to drive the two dicing machines 8 to move relative to each other. When the two dicing machines 8 move to the outer edge of the wafer, the two electric push rods 7 can be started to shorten them, driving the two dicing machines 8 to move downward. By starting the two dicing machines 8, the wafer is cut, and the wafer is driven to move back and forth by the back and forth extension and contraction of the hydraulic rod 402, thereby realizing the cutting and dicing of the wafer. By pressing the wafer into the silicon wafer 404, the wafer cutting is further protected. After the dicing is completed, the staff can remove the cut wafer and perform wax removal and photoresist removal processing. Among them, the controller 9 is electrically connected to the forward and reverse motor 206, the negative pressure suction cup 211, the drive motor 214, the robotic arm 303, the multi-stage electric telescopic rod 307, the servo motor 309, the stepper motor 313, the X-ray fluorescence spectrometer 315, the hydraulic rod 402, the tablet press body 5, the relative movement mechanism 6, the electric push rod 7 and the dicing machine 8.

[0048] The wiring diagrams of the forward and reverse motor 206, negative pressure suction cup 211, drive motor 214, robotic arm 303, multi-stage electric telescopic rod 307, servo motor 309, stepper motor 313, X-ray fluorescence spectrometer 315, hydraulic rod 402, tablet press body 5, relative movement mechanism 6, electric push rod 7, dicing machine 8 and controller 9 in the present invention are common knowledge in the field, and their working principles are already well-known technologies. The models are selected according to actual use. Therefore, the control mode and wiring layout of the forward and reverse motor 206, negative pressure suction cup 211, drive motor 214, robotic arm 303, multi-stage electric telescopic rod 307, servo motor 309, stepper motor 313, X-ray fluorescence spectrometer 315, hydraulic rod 402, tablet press body 5, relative movement mechanism 6, electric push rod 7, dicing machine 8 and controller 9 are no longer explained in detail.

[0049] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A device for cutting a second-class superlattice wafer without chipping, comprising an operating table (1), a tablet press body (5) being arranged near one side edge of the top of the operating table (1), and a rotating assembly (2) for driving the wafer to generate centrifugal force being arranged near the center of the top of the operating table (1), characterized in that: A protective component (3) is provided on the top of the operating table (1) near the other side edge; A protective component (3), the protective component (3) comprising a mechanical arm (303) for transferring a wafer and a rotating frame (302), a sealed tank (304) for storing photoresist being provided at the top of the rotating frame (302) near one side edge, a tooth row (311) being provided inside the rotating frame (302), a movable frame (312) being slidably connected between opposite inner walls of the tooth row (311), an X-ray fluorescence spectrometer (315) for detecting the photoresist coating condition on the wafer surface being provided at the bottom of the movable frame (312), the wafer being placed inside the rotating component (2) by the mechanical arm (303), the photoresist dripping from the sealed tank (304) to the top of the wafer, the rotating component (2) causing the wafer to rotate to generate centrifugal force, so that the photoresist coating on the wafer surface is uniform, and then the X-ray fluorescence spectrometer (315) is used to detect whether the photoresist coating is uniform; The protection component (3) further comprises a base (301), a solenoid valve (305) is provided on the outer surface of the output tube in the sealed tank (304), a slide groove (306) is provided on the top of the rotating frame (302), a multi-stage electric telescopic rod (307) is provided on the inner wall of the slide groove (306), a slider (308) is fixed to one end of the multi-stage electric telescopic rod (307), a servo motor (309) is fixed to the top of the slider (308) by screws, an output shaft (310) is fixed to the output end of the servo motor (309), a stepping motor (313) is fixed to the outer surface of the movable frame (312) by screws, and a driving gear (314) is fixedly provided on the outer surface of the driving shaft of the stepping motor (313); The bottom of the base (301) is fixedly connected to the top of the operating table (1), the top of the rotating frame (302) is movable and penetrates to the outside of the base (301), the outer surface of the mechanical arm (303) is fixedly connected to the outer surface of the rotating frame (302) by a fixing bolt, the opposite outer surfaces of the slider (308) are respectively slidably connected to the opposite inner walls of the slide groove (306), the two ends of the output shaft (310) are respectively movable and penetrate to the opposite outer sides of the slider (308), the inner wall of the gear row (311) is fixedly connected to the outer surface of the output shaft (310), one end of the gear row (311) penetrates to the outside of the slider (308), the two ends of the driving shaft part of the stepping motor (313) are respectively movable and penetrate to the opposite outer sides of the moving frame (312), and the outer surface of the driving gear (314) is meshed and connected with the outer surface of the gear row (311); A relative moving mechanism (6) is provided inside the operating table (1), and two auxiliary blocks are provided on the outer surface of the relative moving mechanism (6), and the outer surfaces of the two auxiliary blocks are respectively slid with the inner walls of the operating table (1). Electric push rods (7) are provided on the tops of the two auxiliary blocks, and dicing machines (8) are provided on the tops of the two electric push rods (7) through auxiliary plates. A controller (9) is provided on the top of the operating table (1) near the front surface.

2. The chip-free cutting device for type II superlattice wafers according to claim 1, characterized in that: The rotating assembly (2) includes a protective sleeve (201), the bottom of the protective sleeve (201) is fixedly connected to the top of the operating table (1), a bottom plate (202) is fixed to the top of the operating table (1), the interior of the bottom plate (202) is rotatably connected to a mounting shaft (203), the outer surface of the mounting shaft (203) is fixedly sleeved with a driven gear (204), a mounting frame (205) is fixed to the top of the bottom plate (202) near one side edge, and the top of the mounting frame (205) is fixedly connected to a forward and reverse motor (206) by screws; A rotating shaft (207) is fixed to the output end of the forward and reverse motor (206), and both ends of the rotating shaft (207) are movable and extend through opposite exteriors of the mounting frame (205). A driving gear (208) is fixedly sleeved near the center of the outer surface of the rotating shaft (207), and the outer surface of the driving gear (208) is meshedly connected with the outer surface of the driven gear (204). Two telescopic tubes (209) are provided on the top of the driven gear (204), and a tray (210) is fixed between the top ends of the two telescopic tubes (209). A plurality of negative pressure suction cups (211) are provided inside the tray (210), and a positioning frame (213) is fixed to the top of the mounting shaft (203).

3. The chip-free cutting device for type II superlattice wafers according to claim 2, characterized in that: A driving motor (214) is fixedly mounted on the top of the positioning frame (213) by screws, a driving shaft (215) is fixed to the output end of the driving motor (214), and both ends of the driving shaft (215) are movable and penetrate the opposite exteriors of the positioning frame (213), and a driving gear ring (216) is fixedly sleeved on the outer surface of the driving shaft (215) near the center, and a driven gear ring (217) is meshedly connected to the outer surface of the driving gear ring (216); The internal fixed sleeve of the driven gear ring (217) is provided with an inner screw (218), the bottom end of the inner screw (218) is movably embedded in the interior of the mounting shaft (203), the internal thread of the inner screw (218) is connected to the rotating screw (212), the top end of the rotating screw (212) is movably passed through the outside of the inner screw (218), and the top end of the rotating screw (212) is fixedly connected to the bottom center of the tray (210).

4. The chip-free cutting device for type II superlattice wafers according to claim 3, characterized in that: A moving assembly (4) is provided on the top of the operating table (1), and the moving assembly (4) includes a slide bar (401), the bottom of the slide bar (401) is fixedly connected to the top of the operating table (1), a hydraulic rod (402) is provided on the inner wall of one side of the slide bar (401), a support structure (403) is fixed to one end of the hydraulic rod (402), the opposite outer surfaces of the support structure (403) are respectively slidably connected to the opposite inner walls of the slide bar (401), and a silicon chip (404) is provided inside the support structure (403).

5. A chip-free cutting process for type II superlattice wafers, characterized in that: The chip-free cutting device for the second-class superlattice wafer according to claim 4 is used, comprising the following steps: S1. During the cutting process of the second-class superlattice wafer, the scribe line is first photolithographically developed, and a groove is etched on the scribe line by an ICP etching process to a depth of 20-50 μm. The etched wafer is then cleaned, and the wafer is clamped to the center of the top of the tray (210) by two clamps in the robot arm (303). The clamping force of the clamps is controlled at 5-20 N, and the photoresist in the sealing tank (304) is dripped to the center of the wafer. S2, the drive device makes the chip rotate at high speed, the speed is rpm, the photoresist diffuses toward the edge due to the centrifugal force. The centrifugal force formula is: ,in, is the photoresist quality, is the angular velocity of rotation, The distance from the photoresist particle to the center of rotation. The centrifugal force causes the photoresist to flow toward the edge, forming a thin and uniform layer. Splitting stage: At the beginning of high-speed rotation, a large amount of photoresist is thrown out of the edge of the wafer, and the thickness decreases rapidly. Spreading stage: The remaining photoresist spreads evenly under the action of centrifugal force and surface tension, and the thickness gradually stabilizes. Evaporation stage: solvent evaporates and the adhesive layer solidifies; S3, generating high-intensity primary X-rays through an X-ray tube to irradiate the photoresist layer on the surface of the wafer, and moving an X-ray fluorescence spectrometer (315) on the top of the wafer in all directions to measure the thickness of the photoresist on the front side of the wafer, measuring the thickest and thinnest thicknesses, and calculating the thickness difference, which is used as a reference for the thickness of the photoresist coating on the back side of the wafer, wherein the photoresist coating thickness is greater than the wafer thickness difference, and then the wafer is flipped 180 degrees by a robotic arm (303), and the back side of the wafer is coated with glue; S4. The double-sided protected wafer is bonded to the silicon wafer (404) substrate by wax and pressed by the wafer pressing machine body (5), ensuring that the upper surface of the wafer is parallel to the surface of the silicon substrate. The mounted wafer is placed on the dicing machine (8) for dicing. After completion, the diced chip is removed and the wax and photoresist are removed.

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