CN107452678B - Method for processing wafer - Google Patents
Method for processing wafer Download PDFInfo
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- CN107452678B CN107452678B CN201710325604.7A CN201710325604A CN107452678B CN 107452678 B CN107452678 B CN 107452678B CN 201710325604 A CN201710325604 A CN 201710325604A CN 107452678 B CN107452678 B CN 107452678B
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- 238000000034 method Methods 0.000 title claims description 14
- 238000003672 processing method Methods 0.000 claims abstract description 10
- 230000001681 protective effect Effects 0.000 claims description 6
- 230000001678 irradiating effect Effects 0.000 claims description 3
- 230000015572 biosynthetic process Effects 0.000 abstract description 9
- 230000007547 defect Effects 0.000 abstract description 7
- 238000003754 machining Methods 0.000 description 12
- 230000003287 optical effect Effects 0.000 description 6
- 239000004065 semiconductor Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 239000004820 Pressure-sensitive adhesive Substances 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- JBRZTFJDHDCESZ-UHFFFAOYSA-N AsGa Chemical compound [As]#[Ga] JBRZTFJDHDCESZ-UHFFFAOYSA-N 0.000 description 1
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 229910010293 ceramic material Inorganic materials 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- 239000011147 inorganic material Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 229910052594 sapphire Inorganic materials 0.000 description 1
- 239000010980 sapphire Substances 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
- H01L21/77—Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate
- H01L21/78—Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate with subsequent division of the substrate into plural individual devices
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02002—Preparing wafers
- H01L21/02005—Preparing bulk and homogeneous wafers
- H01L21/02008—Multistep processes
- H01L21/0201—Specific process step
- H01L21/02013—Grinding, lapping
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/26—Bombardment with radiation
- H01L21/263—Bombardment with radiation with high-energy radiation
- H01L21/268—Bombardment with radiation with high-energy radiation using electromagnetic radiation, e.g. laser radiation
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
- H01L21/683—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping
- H01L21/6835—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping using temporarily an auxiliary support
- H01L21/6836—Wafer tapes, e.g. grinding or dicing support tapes
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
- H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
- H01L21/76—Making of isolation regions between components
Abstract
Provided is a wafer processing method capable of dividing a wafer so that defects do not occur in corners of device chips. A laser beam having a wavelength which is transparent to a wafer (W) is positioned inside the wafer from the back surface (W2) of the wafer and is irradiated along a 1 st street (L1) and a 2 nd street (L2) to form a modified layer (R) inside the wafer. After the formation of the modified layer, the wafer is divided into Device Chips (DC) along the 1 st street and the 2 nd street by a grinding operation of grinding from the back surface of the wafer with the modified layer as a starting point. In the formation of the modified layer, when the 1 st street is positioned in the X-axis direction and irradiated with a laser beam, the modified layer is formed in the 1 st street at a predetermined interval in the Y-axis direction for each of the adjacent devices (D). Thus, corners of adjacent device chips do not rub on the diagonal line when divided.
Description
Technical Field
The present invention relates to a method for processing a wafer, which divides the wafer into a plurality of device chips.
Background
For example, when a wafer having a relatively thick thickness of 300 [ μm ] or more is cut with a cutting tool, there is a problem that chipping of the back surface becomes large. Therefore, a method using SDBG (Stealth Before Grinding) in which laser processing and Grinding are combined has been proposed (for example, see patent document 1). In the SDBG, a laser beam having a wavelength that is transparent to the wafer is irradiated along the planned dividing line of the wafer, and a modified layer having a reduced intensity is formed at a position at a predetermined depth of the wafer. Thereafter, the wafer is thinned to a finished thickness by grinding the back surface of the wafer, and the wafer is divided into individual device chips with the modified layer as a division start point using grinding pressure.
Patent document 1: international publication No. 2003/077295
However, when the modified layer is formed inside the wafer by the SDBG and then the wafer is divided into the individual chips, there is no space between the corners of the chips adjacent to each other in the diagonal direction, and therefore, there is a problem that the corners of the chips rub against each other, and hence the corners are likely to be chipped.
Disclosure of Invention
The present invention has been made in view of the above problems, and an object of the present invention is to provide a wafer processing method capable of dividing a wafer so as not to cause defects at corners of each device chip.
A method for processing a wafer according to the present invention, the wafer having on a front surface thereof a plurality of devices divided by a plurality of 1 st streets formed in one direction and a plurality of 2 nd streets formed in a direction perpendicular to the 1 st streets, the method for processing the wafer dividing the wafer into device chips along the 1 st streets and the 2 nd streets by a laser processing apparatus, the laser processing apparatus comprising: a holding table for holding a wafer; a laser beam irradiation member that irradiates a laser beam to the wafer held on the holding table; a processing feeding component which carries out processing feeding in the X-axis direction relative to the holding workbench and the laser beam irradiation component; an index feeding member that performs index feeding in the Y-axis direction in correspondence with the interval of the streets so as to oppose the holding table and the laser beam irradiation member; and a control member for controlling each component, the wafer processing method is characterized by comprising the following steps: a holding step of holding the wafer having the protective tape bonded to the front surface side on a holding table; a modified layer forming step of forming a modified layer in the wafer by positioning a laser beam having a wavelength that is transparent to the wafer from the back surface of the wafer into the wafer and irradiating the laser beam along the 1 st street and the 2 nd street; and a dividing step of thinning the wafer to a finished thickness by grinding the wafer from the back surface of the wafer by a grinding member after the modified layer forming step is performed, and dividing the wafer along the 1 st street and the 2 nd street by a grinding operation with the modified layer as a starting point, wherein in the modified layer forming step, at least when the 1 st street is positioned in the X-axis direction and a laser beam is irradiated, the modified layer is formed by shifting every adjacent device in the 1 st street by a predetermined interval in the Y-axis direction so that corners of adjacent device chips do not rub against each other on diagonal lines at the time of dividing.
According to this configuration, in the modified layer forming step, since the modified layer is formed discontinuously with the adjacent devices shifted by a predetermined interval in the index direction, an interval can be formed between the corners of the device chip adjacent in the diagonal direction of the chip. Thus, rubbing of the corners of the device chip against each other in the dividing step can be reduced, and defects at the corners can be reduced.
According to the present invention, the wafer can be divided so that defects do not occur at the corners of the device chip.
Drawings
Fig. 1 is a schematic perspective view of a workpiece according to the present embodiment.
Fig. 2 is a schematic perspective view of the laser processing apparatus according to the present embodiment.
Fig. 3 is an explanatory diagram showing a holding step in the present embodiment.
Fig. 4 is an explanatory view showing a modified layer forming step of the present embodiment.
Fig. 5 is an explanatory view showing a modified layer forming step of the present embodiment.
Fig. 6 is an explanatory view showing a modified layer forming step of the present embodiment.
Fig. 7 is an explanatory diagram showing a dividing procedure in the present embodiment.
Fig. 8 is an explanatory diagram showing a dividing procedure in the present embodiment.
Description of the reference symbols
10: a laser processing device; 13: a holding table; 20: an indexing feed member; 21: a machining feed member; 40: a processing head (laser beam irradiation member); 51: a control member; c: an angle; d: a device; DC: a device chip; l1: the 1 st interval channel; l2: the 2 nd spacing channel; r: a modified layer; t: protecting the belt; w: a wafer; w1: a front side; w2: and a back surface.
Detailed Description
Hereinafter, a method for processing a wafer according to the present embodiment will be described with reference to the drawings. First, a wafer processed by the wafer processing method according to the present embodiment will be described with reference to fig. 1. Fig. 1 is a schematic perspective view of a wafer according to the present embodiment.
As shown in fig. 1, the wafer W is formed into a substantially disk shape, and the device layer WA is provided on the front surface W1. A 1 st street L1 extending in one direction and a plurality of 2 nd streets L2 extending in a direction perpendicular to the 1 st street L1 are formed on the front surface W1 of the wafer W. A plurality of devices D are formed in the region defined by the 1 st and 2 nd streets L1 and L2. A protective tape T for protecting the devices D is bonded to the front surface of the wafer W. As shown in fig. 2, the lower surface side of the wafer W is bonded to a pressure-sensitive adhesive sheet S, and the pressure-sensitive adhesive sheet S is bonded to and held by an annular frame F.
The wafer W has a thickness of, for example, 300 [ μm ] or more, and the SDBG obtained by combining laser processing and grinding is divided into device chips. In this case, after the modified layer is formed in the wafer W by laser processing, the wafer W is ground to a finish thickness by grinding processing, and the wafer W is divided with the modified layer as a division starting point. The wafer W may be a semiconductor wafer having semiconductor devices such as ICs and LSIs formed on a semiconductor substrate such as silicon and gallium arsenide, or may be an optical device wafer having optical devices such as LEDs formed on an inorganic material substrate such as sapphire and silicon carbide.
Next, a laser processing apparatus used in the wafer processing method according to the present embodiment will be described with reference to fig. 2. Fig. 2 is a schematic perspective view of the laser processing apparatus according to the present embodiment. The laser processing apparatus according to the present embodiment is not limited to the configuration shown in fig. 2. The laser processing apparatus may have any structure as long as the modified layer can be formed on the wafer.
As shown in fig. 2, the laser processing apparatus 10 is configured to process the wafer W by relatively moving a laser processing unit 12 and a holding table 13, wherein the laser processing unit 12 emits a laser beam and the holding table 13 holds the wafer W on the upper surface thereof.
The laser processing apparatus 10 has a rectangular parallelepiped base 11. A chuck table moving mechanism 14 is provided on the upper surface of the base 11, and the chuck table moving mechanism 14 performs machining feed in the X-axis direction and indexing feed in the Y-axis direction with respect to the holding table 13. A standing wall portion 16 is provided upright behind the chuck table moving mechanism 14. The arm 17 protrudes from the front surface of the standing wall 16, and the laser processing unit 12 is supported on the arm 17 so as to face the holding table 13.
The chuck table moving mechanism 14 includes: an index feed member 20 that relatively moves the holding table 13 and the laser processing unit 12 in an index feed direction (Y-axis direction); and a processing feed member 21 that relatively moves the holding table 13 and the laser processing unit 12 in a processing feed direction (X-axis direction).
The indexing-feed member 20 has: a pair of guide rails 23 parallel to the Y-axis direction and disposed on the upper surface of the base 11; and a motor-driven Y-axis table 24 provided slidably on the pair of guide rails 23. On the lower surface side of the Y-axis table 24, nut portions, not shown, are formed, and these nut portions are screwed with the ball screw 25. Then, by rotationally driving a drive motor 26 coupled to one end portion of the ball screw 25, the Y-axis table 24, the machining feed member 21, and the holding table 13 move in the Y-axis direction along the guide rail 23.
The processing feed member 21 has: a pair of guide rails 30 parallel to the X-axis direction and disposed on the upper surface of the Y-axis table 24; and a movable portion 31 movable in the machining feed direction (X-axis direction) via the guide rail 30. The movable portion 31 has: an X-axis table 32 whose sliding movement in the X-axis direction is guided by the guide rail 30; and a linear motor (motor) 33 provided at a lower portion of the X-axis table 32. The linear motor 33 has an electromagnetic coil (not shown) facing a magnetic plate 35 disposed along the X-axis direction between the guide rails 30. The electromagnetic coil is energized in sequence by, for example, shifting the phase of the three-phase alternating current, and forms a moving magnetic field that moves the linear motor 33 itself and the X-axis table 32 in the reciprocating direction, which is the X-axis direction. The machining feed member 21 is not limited to the above configuration, and may be configured using a rotationally driven ball screw, such as the indexing member 20.
A holding table 13 is held on the upper surface of the X-axis table 32. The holding table 13 is formed in a disc shape, and is rotatably provided on the upper surface of the X-axis table 32 via a θ table 38. An adsorption surface is formed of a porous ceramic material on the upper surface of the holding table 13. Around the holding table 13, 4 clip portions 39 are provided via support arms. The 4 clamp portions 39 are driven by an air actuator (not shown) to clamp and fix the ring frame F around the wafer W from all sides.
The laser processing unit 12 has a processing head 40 as a laser beam irradiation member provided at the front end of the arm 17. The arm 17 and the machining head 40 are provided with optical systems of the laser machining unit 12. The machining head 40 focuses a laser beam oscillated from an oscillator, not shown, by a condenser lens, and irradiates the wafer W held on the holding table 13 with the laser beam to perform laser machining. In this case, the wavelength of the laser beam, which is adjusted to be positioned inside the wafer W in the optical system, has transparency to the wafer W.
The modified layer R (see fig. 4 and 5) is formed as a division starting point inside the wafer W by the irradiation of the laser beam. The modified layer R is a region in which the density, refractive index, mechanical strength, or other physical properties of the inside of the wafer W are different from those of the surroundings and the intensity is lower than those of the surroundings by irradiation with the laser beam. The modified layer R may be, for example, a melt-processed region, a crack region, an insulation breakdown region, a refractive index change region, or a region in which these regions are mixed. The laser beam irradiated from the processing head 40 can control the height of the condensed position where the modified layer R is formed.
The laser processing apparatus 10 is provided with a control means 51 for collectively controlling the respective components of the apparatus. The control means 51 is constituted by a processor that executes various processes. Detection results from various detectors, not shown, are input to the control means 51. Control signals are output from the control means 51 to the drive motor 26, the linear motor 33, the machining head 40, and the like.
Hereinafter, a method of processing a wafer will be described with reference to fig. 3 to 7. Fig. 3 is an explanatory view showing a holding step of the present embodiment, fig. 4 to 6 are explanatory views showing a modified layer forming step of the present embodiment, and fig. 7 and 8 are explanatory views showing a dividing step. In the present embodiment, an example in which the wafer processing method is applied to the SDBG has been described, but the present invention can also be applied to another processing method in which the wafer is divided inside from the modified layer as a starting point.
As shown in fig. 3, the holding step is first performed. In the holding step, the wafer W to which the protective tape T is pasted is sucked and held on the holding table 13 via the protective tape T.
As shown in fig. 4 and 5, the modified layer forming step is performed after the holding step is performed. In the modified layer forming step, the holding table 13 is first moved and rotated to position the wafer W so that, for example, the 1 st street L1 is parallel to the X-axis direction and the 2 nd street L2 is parallel to the Y-axis direction. Next, the processing head 40 is positioned in the 1 st street L1 parallel to the X-axis direction with respect to the wafer W on the holding table 13. Thereafter, the holding table 13 and the processing head 40 are relatively moved in parallel to the X-axis direction (processing feed) while irradiating the back surface W2 side of the wafer W with a laser beam. Thereby, the laser beam is irradiated along the 1 st street L1, and the modified layer R along the 1 st street L1 is formed inside the wafer W.
After the modified layer R is formed along the 1 st street L1 of the object, the irradiation of the laser beam is stopped, and the holding table 13 and the processing head 40 are relatively moved (indexed) in the Y-axis direction in correspondence with the spacing of the 1 st street L1. This allows the machining head 40 to be aligned with the 1 st street L1 adjacent to the 1 st street L1 to be processed.
Next, the same modified layer R is formed along the adjacent 1 st street L1. This operation is repeated to form the modified layer R along all the 1 st streets L1 extending in the X-axis direction, and thereafter, the holding table 13 is rotated by 90 ° about the rotation axis to form the modified layer R along the 2 nd streets L2 extending in the Y-axis direction.
The modified layer R is modified at a pulse pitch based on the wavelength of the laser beam, and is formed such that longitudinal ellipses in a cross-sectional view are continuously arranged in the machine feed direction (X-axis direction). The formation of the modified layer R by the laser beam may be repeated a plurality of times, for example, in the case of performing the formation twice, in the first formation of the modified layer R1, the laser beam is irradiated with the converging point positioned at the position closer to the front surface W1 of the optical device wafer W in the vertical position in fig. 4. After the first modified layer R1 is formed along all of the streets L1 and L2 at the upper and lower positions of the focal point, the focal point is moved upward stepwise. Then, the formation of the modified layer R2 was performed for the 2 nd time in the same manner as the formation of the first modified layer R1. The formation position is set at a position spaced apart from the rear surface W2 side (upper side) of the first modified layer R1 by a predetermined distance. Thus, two modified layers R1 and R2 are formed in the region from the front surface W1 side to the rear surface W2 side of the wafer W, in other words, the starting points of division along the streets L1 and L2 are formed inside the wafer W.
Here, in the modified layer forming step, as shown in fig. 6, the 1 st street L1 parallel to the X-axis direction is not formed in a straight line and is not formed continuously. Regarding the formation of the 1 st street L1, first, in the positioning of the processing head 40 with respect to the 1 st street L1, for example, a converging point is set so that the position in the Y-axis direction is at the position Y1 of fig. 6. During the machining feed of the wafer W, the irradiation of the laser beam and the stop of the irradiation are repeated every 1 device D in the X-axis direction. Thus, at the Y-axis direction position Y1 in the 1 st street L1, a region where the modified layer R is formed and a region where the modified layer R is not formed are alternately provided for each device D adjacent in the X-axis direction.
After the modified layer R is formed at the Y-axis position Y1, the wafer W is indexed so that the converging point is shifted by the interval a in the Y-axis direction in the 1 st street L1 to set the converging point at the Y-axis position Y2. Then, while the wafer W is being processed and fed in the X-axis direction, the laser beam is irradiated at the Y-axis position Y2 in the region where the modified layer R is not formed at the Y-axis position Y1. Therefore, in the irradiation of the laser beam, the irradiation of the laser beam and the stop of the irradiation are also repeated every 1 device D in the X-axis direction. In other words, at the Y-axis direction position Y2, a region where the modified layer R is formed and a region where the modified layer R is not formed are alternately provided for each device D adjacent in the X-axis direction. Thus, the modified layer R formed at the Y-axis position Y1 and the modified layer R formed at the Y-axis position Y2 are combined, and the modified layers R are formed in the 1 st lane L1 adjacent to each other in the X-axis direction while being shifted by the interval a in the Y-axis direction.
After such modified layers R are formed along all of the 1 st streets L1 extending in the X-axis direction, the modified layers R are formed along the 2 nd streets L2 extending in the Y-axis direction as described above. By forming the modified layer R of the 2 nd street L2 to be a continuous straight line as shown in the drawing, the corners (corner portions) C of the devices D adjacent in the Y-axis direction are arranged at substantially the same position in fig. 6, and the corners C of the devices D adjacent in the X-axis direction are positioned apart from each other in the Y-axis direction at the interval a. The corners C of the devices D adjacent in the diagonal direction of the devices D are located apart from each other without being at the same position.
Here, the interval a is preferably wide within the range of the 1 st lane L1. The Y-axis direction positions Y1 and Y2 at which the modified layer R is formed are preferably the same distance from the center of the 1 st segment L1 in the width direction, and examples thereof may include the distance a being 10 to 40 [ μm ] and the distance from the center of the 1 st segment L1 in the width direction to the Y-axis direction positions Y1 and Y2 being 5 to 20 [ μm ].
In the present embodiment, the modified layer R formed on the 2 nd street L2 is formed at the widthwise center position of the 2 nd street L2. Therefore, the distances between the upper and lower ends of the device D in fig. 6 and the modified layers R of the 2 nd street L2 adjacent thereto are substantially the same. Therefore, pads and the like for electrical connection to the device D are formed along the upper and lower ends of the device D in fig. 6, so that the mounting at the upper end and the mounting at the lower end can be performed in the same manner, and the workability can be maintained well.
As shown in fig. 7 and 8, the dividing step is performed after the modified layer forming step is performed. In the dividing step, the wafer W is held on the chuck table 61 of the grinding apparatus 60 via the protective tape T. The grinding wheel (grinding member) 62 is brought close to the chuck table 61 while rotating, and the grinding wheel 62 is brought into rotational contact with the back surface W1 of the wafer W to grind and thin the wafer W to a finished thickness. By this grinding operation, a grinding pressure is applied from the grinding wheel 62 to the modified layers R1 and R2, and the crack is extended in the thickness direction of the wafer W from the modified layers R1 and R2. Thereby, the wafer W is divided along the 1 st street L1 and the 2 nd street L2 to form the device chips DC (not shown in fig. 7).
According to such an embodiment, since the modified layer R of the 1 st street L1 is formed as described above and the corners C adjacent in the diagonal direction of the device D are positioned apart from each other, the corners of the adjacent device chips DC can be prevented from rubbing against each other in the diagonal direction in the dividing step. Here, for example, in particular, when the wafer W having a crystal direction inclined at 45 ° to the streets L1 and L2 is used, defects tend to occur in the diagonal direction of the device chip DC due to the grinding pressure. In the present embodiment, since the corners C of the devices D adjacent in the diagonal direction are separated from each other without rubbing, even if the crystal direction is inclined as described above, the occurrence of defect or crack of the corners C can be prevented. This enables the wafer W to be divided into the device chips DC along the streets L1 and L2.
The present invention is not limited to the above embodiments, and various modifications can be made. In the above-described embodiments, the size, shape, orientation, and the like shown in the drawings are not limited to these, and can be appropriately modified within the range in which the effects of the present invention are exhibited. In addition, appropriate modifications can be made without departing from the scope of the object of the present invention.
For example, in the above embodiment, the modified layer R of the 1 st street L1 is formed discontinuously for each of the adjacent devices D, but the 2 nd street L2 may be formed discontinuously in the same manner. In this case, the corners C adjacent in the diagonal direction of the device D can also be separated from each other. In the device D, when the bonding pad is formed at a position along only one of the 1 st street L1 and the 2 nd street L2, the modified layer R is formed and divided as described above in the other street L1 and L2 in which the bonding pad is not formed. Thus, the distance between the bonding pad and the outer edge of the device chip is kept constant, and bonding can be performed without changing the processing conditions such as the bonding position from the bonding pad.
As described above, the present invention has an effect of favorably dividing a wafer without causing cracks or defects in the divided device chips, and is particularly useful for a method of processing a wafer for dividing a semiconductor wafer or an optical device wafer into individual chips.
Claims (1)
1. A processing method of a wafer having on a front surface thereof a plurality of devices divided by a plurality of 1 st streets formed in one direction and a plurality of 2 nd streets formed in a direction perpendicular to the 1 st streets, the processing method of the wafer dividing the wafer into device chips along the 1 st streets and the 2 nd streets by a laser processing apparatus, the laser processing apparatus having: a holding table for holding the wafer; a laser beam irradiation member that irradiates a laser beam to the wafer held on the holding table; a processing feeding member that performs processing feeding in the X-axis direction relative to the holding table and the laser beam irradiation member; an index feeding member that performs index feeding in the Y-axis direction in correspondence with the interval of the space track relatively to the holding table and the laser beam irradiation member; and a control member for controlling each component, the wafer processing method is characterized by comprising the following steps:
a holding step of holding the wafer having the protective tape bonded to the front surface side on a holding table;
a modified layer forming step of forming a 1 st modified layer and a 2 nd modified layer in the wafer by positioning a laser beam having a wavelength that is transparent to the wafer from the back surface of the wafer into the wafer and irradiating the laser beam along the 1 st street and the 2 nd street, respectively, after the holding step is performed; and
a dividing step of thinning the wafer to a finished thickness by grinding the wafer from the back surface thereof by a grinding member after the modified layer forming step is performed, and dividing the wafer along the 1 st street and the 2 nd street by a grinding operation with the 1 st modified layer and the 2 nd modified layer as starting points,
in the modified layer forming step, at least when the 1 st street is positioned in the X-axis direction and irradiated with a laser beam, the 1 st modified layer connected to the 2 nd modified layer is formed in the Y-axis direction at a predetermined interval in the 1 st street for each of the adjacent devices so that corners of the adjacent device chips do not rub against each other on a diagonal line in a process of being divided along the 1 st street and the 2 nd street from the 1 st modified layer and the 2 nd modified layer connected to each other by grinding from the back surface of the wafer by a grinding member.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2016096972A JP6636384B2 (en) | 2016-05-13 | 2016-05-13 | Wafer processing method |
| JP2016-096972 | 2016-05-13 |
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| Publication Number | Publication Date |
|---|---|
| CN107452678A CN107452678A (en) | 2017-12-08 |
| CN107452678B true CN107452678B (en) | 2021-07-09 |
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| CN201710325604.7A Active CN107452678B (en) | 2016-05-13 | 2017-05-10 | Method for processing wafer |
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| JP (1) | JP6636384B2 (en) |
| KR (1) | KR102226645B1 (en) |
| CN (1) | CN107452678B (en) |
| TW (1) | TWI721152B (en) |
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| US20190363017A1 (en) * | 2018-05-24 | 2019-11-28 | Semiconductor Components Industries, Llc | Die sawing singulation systems and methods |
| JP7120904B2 (en) | 2018-10-30 | 2022-08-17 | 浜松ホトニクス株式会社 | LASER PROCESSING APPARATUS AND LASER PROCESSING METHOD |
| WO2020090894A1 (en) | 2018-10-30 | 2020-05-07 | 浜松ホトニクス株式会社 | Laser processing device and laser processing method |
| CN112775539A (en) * | 2019-11-07 | 2021-05-11 | 大族激光科技产业集团股份有限公司 | Laser processing method and apparatus |
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| JPH06275714A (en) * | 1993-03-22 | 1994-09-30 | Mitsubishi Electric Corp | Semiconductor laser element board and manufacture of semiconductor laser |
| JP2003072090A (en) * | 2001-09-06 | 2003-03-12 | Ricoh Co Ltd | Liquid drop ejection head and its manufacturing method, micro device, ink cartridge, and ink jet recorder |
| ES2377521T3 (en) | 2002-03-12 | 2012-03-28 | Hamamatsu Photonics K.K. | Method to divide a substrate |
| JP4240362B2 (en) * | 2002-12-02 | 2009-03-18 | 住友電気工業株式会社 | Cleaving method of compound semiconductor wafer |
| JP4634089B2 (en) * | 2004-07-30 | 2011-02-16 | 浜松ホトニクス株式会社 | Laser processing method |
| JP5090897B2 (en) * | 2007-12-28 | 2012-12-05 | 株式会社ディスコ | Wafer dividing method |
| JP5395411B2 (en) * | 2008-11-20 | 2014-01-22 | 株式会社ディスコ | Wafer laser processing method |
| JP2011108708A (en) * | 2009-11-13 | 2011-06-02 | Disco Abrasive Syst Ltd | Method of processing wafer |
| JP2013089714A (en) * | 2011-10-17 | 2013-05-13 | Disco Abrasive Syst Ltd | Chip formation method |
| JP6053381B2 (en) * | 2012-08-06 | 2016-12-27 | 株式会社ディスコ | Wafer dividing method |
| JP5598801B2 (en) * | 2012-12-18 | 2014-10-01 | 株式会社レーザーシステム | Laser dicing method, chip manufacturing method, and laser processing apparatus |
| JP6045361B2 (en) * | 2013-01-17 | 2016-12-14 | 株式会社ディスコ | Wafer processing method |
| JP2015201585A (en) * | 2014-04-10 | 2015-11-12 | 株式会社ディスコ | Processing method of wafer |
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