TWI801661B - Wafer cutting method and wafer dividing method - Google Patents

Abstract

Suppresses the weakening of ultrasonic vibrations.

In the piezoelectric vibrating plate (24), a collar is provided around a dome that receives high-frequency voltage and vibrates to generate ultrasonic vibrations, and the collar is supported by the side wall of the water storage part (19). Therefore, since the dome is not in direct contact with the water storage (19), it is difficult for the dome to be compressed by the water storage (19). Therefore, the dome becomes easy to vibrate. In addition, compared with the structure in which the dome directly contacts the water storage part (19), the vibration of the dome part is less likely to be transmitted to the water storage part (19). Therefore, it is possible to suppress the weakening of the vibration of the dome. As a result, it is possible to suppress the weakening of the ultrasonic vibration generated by the dome.

Description

Wafer cutting method and wafer dividing method

The present invention relates to a wafer cutting method and a wafer dividing method.

The cleaning device cleans the wafer by violently spraying cleaning water from the cleaning nozzle to the wafer. In the techniques described in Patent Documents 1 and 2, in order to improve cleaning power, cleaning water that transmits ultrasonic vibrations is used to transmit ultrasonic vibrations to dust adhering to the wafer, thereby removing the dust from the wafer.

A conventional ultrasonic cleaning nozzle has, for example, a supply port for supplying washing water, a water storage part for storing washing water, a spray port provided at the front end of the water storage part, and a flat-plate ultrasonic vibrating element. The water storage unit has a volume for temporarily storing the washing water supplied from the supply port. The water storage portion is formed into a shape that tapers toward the injection port. The spray port sprays the washing water from the front end of the water storage part. The ultrasonic vibrating element is arranged in the water storage part to face the ejection port.

[Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2003-340330

[Patent Document 2] Japanese Patent Application Laid-Open No. 10-151422

The ultrasonic vibration of the water transmitted from the flat-plate-shaped ultrasonic vibrating element to the water storage part is reflected on the inner wall of the water storage part. Therefore, there are cases where the reflected ultrasonic vibration and the ultrasonic vibration oscillated from the ultrasonic vibrating member cancel each other out. In this case, there is a problem in that the ultrasonic vibration propagated by the washing water is weakened, and the washing power is reduced.

The purpose of the present invention is to suppress the weakening of ultrasonic vibrations.

The piezoelectric vibrating plate of the present invention (the present piezoelectric vibrating plate) has a dome portion, and a flange portion protruding radially outward from the outer periphery of the dome portion.

The wafer cutting method of the present invention uses an ultrasonic water jetting device (this ultrasonic water jetting device). The device includes: a cylindrical water storage part temporarily storing water supplied from a water supply source; a jetting port arranged at one end of the water storage part to spray water; and a piezoelectric The vibrating plate is arranged on the water storage part facing the injection port to generate ultrasonic vibration. The piezoelectric vibrating plate has: a domed top; protruding outward, in the ultrasonic water jet device, the dome of the piezoelectric vibrating plate The concave side of the piezoelectric vibrating plate is supported by the side wall of the water storage part toward the injection port, the ultrasonic vibration is concentrated toward the injection port, and the supersonic water is used as the water for propagating the ultrasonic vibration. The wafer is sprayed from the injection port to the workpiece, and the cutting method of the wafer includes: a process of holding the wafer as the workpiece with a clamping table; and disposing the tip of the cutting blade on the corresponding The position of the cutting depth of the wafer, so that the clamping table is relatively moved relative to the rotating cutting knife, and the process of forming a cutting groove on the wafer along the predetermined dividing line; and the formation of the cutting groove The process includes spraying the ultrasonic water from an ultrasonic water jetting device to a cutting point where the cutter enters the wafer.

The present piezoelectric vibrating plate may further include a groove provided on the flange portion so as to surround the domed portion.

The wafer splitting method of the present invention uses an ultrasonic horn (this ultrasonic horn). The ultrasonic horn is used to apply ultrasonic vibrations intensively. The ultrasonic horn is equipped with: a vibrating element, which includes the piezoelectric vibrating plate , the piezoelectric vibrating plate has a domed top; and a collar portion, which protrudes from the outer circumference of the dome toward the radially outward, and the vibrating member has a point that is intended to concentrate the ultrasonic vibration as a center to make the one point side concave forming a dome-shaped radiating surface; and a housing that holds the collar portion of the piezoelectric vibrating plate. The method for dividing the wafer includes: forming a modified layer inside the wafer along the planned division line, The process of fixing the mounting table in the water tank; the process of submerging the wafer held in the mounting table in the water tank; and moving the ultrasonic horn along the dividing line of the immersed wafer, by Ultrasonic vibration is applied to the planned dividing line from the ultrasonic horn, and the modified layer is used as the starting point to divide The project of cutting wafers.

The present piezoelectric vibrating plate may further include a groove provided on the flange portion so as to surround the domed portion.

The dome of the piezoelectric vibrating plate generates ultrasonic vibration by, for example, vibrating. Furthermore, the piezoelectric vibrating plate can be held via a flange provided around the domed portion. Therefore, the holding member for holding the piezoelectric vibrating plate, such as the side wall of the water storage portion in the ultrasonic water jet device and the casing of the ultrasonic horn, can be suppressed from being directly in contact with the dome. As a result, since the dome is difficult to be pressed by the holding member, the dome is likely to vibrate. In addition, since the vibration of the dome is less likely to be transmitted to the holding member than in the configuration in which the dome is in direct contact with the holding member, it is possible to suppress the weakening of the vibration of the dome. As a result, it is possible to suppress the weakening of the ultrasonic vibration generated by the dome.

Furthermore, in the ultrasonic water jetting device, since the ultrasonic vibration generated by the piezoelectric vibrating plate is concentrated toward the jetting port, the ultrasonic vibration is difficult to be reflected in the water storage part. Therefore, the ultrasonic vibration can be sufficiently propagated by the water injected from the injection port. Therefore, when the workpiece is washed using the water sprayed from the injection port, the ultrasonic vibration can be sufficiently transmitted to the dirt of the workpiece, so that the detergency can be improved.

In addition, even when the workpiece is cut by the cutting device, the cutting depth of the processing point is deep, and the cutting chips in the cutting groove can be fully treated by the water sprayed from the injection port. land Transmits ultrasonic vibrations. Therefore, chips can be well discharged from the cutting groove.

Furthermore, in this ultrasonic horn, because the vibrating member has a dome-shaped radiating surface that is sunk on one side where the ultrasonic vibrations are concentrated, it is possible to concentrate the ultrasonic vibrations radiated from the vibrating member on this point. a little.

1: Wafer

3: Split the scheduled line

131: modified layer

11: Ultrasonic water jet device

13: High frequency power supply part

15: Injection device body

17: supply port

19: Water storage department

21: Injection port

23: Ultrasonic vibration parts

24: Piezoelectric vibration plate

241: round top

243: Neck

245: Ditch

25: Resonant plate

251: round top

253: Neck

26: Radiating surface

31: Wafer cleaning device

33:Rotary platform

35:Ultrasonic water jet department

41: Carrying plate loading platform

42: Adsorption surface

43:Rotary axis

45: Mounting table rotation motor

51: horizontal pipe

52: Adsorption surface

53: Rotating shaft

55: Cleansing water supply source

57:Rotary motor

L: washing water

Ls: Ultrasonic water

61: Wafer cutting device

63: cutting part

65: Carrying plate loading table

71: Shaft

73: Flange

75: Cutter

81: knife cover

83: Cutting water jet nozzle

85: Cutting water supply pipe

87: Washing water supply pipe

T: cutting tape

111: Handling device

113: Drive source

115: arm

117: source of attraction

119: Connecting components

121: Carrying mat

123: adsorption part

125: frame

141: Carrying table

151: Sink

152: nut part

153: X-axis direction movement means

155: sliding member

157: motor

159: Ball screw

161:Ultrasonic splitting device

163:High frequency power supply unit

165: Y-axis direction movement means

166: nut part

167: lifting means

169: Ultrasonic horn

171: shell

181: connected road

PT: Protective Tape

W: water

FIG. 1 is a perspective view of a wafer showing an example of a workpiece related to an embodiment.

Fig. 2 is an explanatory diagram showing the configuration of an ultrasonic water jetting device according to an embodiment.

Fig. 3 is a perspective view of the piezoelectric vibrating plate of the ultrasonic water jet device shown in Fig. 2 .

Fig. 4 is a cross-sectional view of an ultrasonic vibrating element including a piezoelectric vibrating plate.

FIG. 5 is a perspective view showing a wafer cleaning apparatus provided with the ultrasonic water jet apparatus shown in FIG. 2 .

FIG. 6 is a schematic cross-sectional view of the wafer cleaning device shown in FIG. 5 .

FIG. 7 is a schematic cross-sectional view showing a wafer cutting device equipped with the ultrasonic water jetting device shown in FIG. 2 .

FIG. 8 is an explanatory view showing a cutting portion in the wafer cutting device shown in FIG. 5 .

Fig. 9 is an explanatory view showing a modified example of the ultrasonic water jetting device.

Fig. 10 is an explanatory diagram showing a transfer process and immersion process of a division method related to another embodiment.

FIG. 11 is an explanatory diagram showing a division process of a division method related to another embodiment.

Fig. 12 is a perspective view showing a modified example of the piezoelectric vibrating plate.

Fig. 13 is a cross-sectional view of the piezoelectric vibrating plate shown in Fig. 12 .

(implementation type 1)

First, a brief description will be given of the workpiece related to this embodiment.

As shown in FIG. 1, a wafer 1, which is an example of a workpiece related to this embodiment, is formed in, for example, a disc shape. On the surface 2a of the wafer 1, a device region 5 including the device 4 and an outer peripheral remaining region 6 are formed. In the device region 5 , the devices 4 are respectively formed in the regions partitioned by the grid-like dividing lines 3 . The peripheral remaining area 6 surrounds the device area 5 . Further, on the outer peripheral edge 7 of the wafer 1, a notch 9 indicating the crystal orientation of the wafer 1 is provided. The back surface 2b of the wafer 1 does not have the device 4, and the surface to be ground is ground by a grinding stone or the like.

In this embodiment, the wafer 1 is subjected to spin cleaning using cleaning water after grinding the back surface 2b. In addition, when the cutting groove is formed along the planned dividing line 3 of the wafer 1, cleaning water is sprayed in order to remove chips from the cutting groove. The washing water used in this embodiment is super Sonic water. Ultrasonic water system is cleansing water that transmits ultrasonic vibrations.

In addition, the wafer 1 may be a semiconductor wafer in which semiconductor devices are formed on a semiconductor substrate including silicon, gallium arsenide, etc., or an optical device in which an optical device is formed on an inorganic material substrate including ceramics, glass, sapphire, etc. Wafers are also available.

Next, a device (ultrasonic water jet device) for spraying cleaning water onto the wafer 1 will be described. The ultrasonic water ejection device related to this embodiment ejects ultrasonic water as washing water from the ejection port. The ultrasonic water jet device is used for the above-mentioned rotary cleaning and removal of cutting chips.

First, the configuration of the ultrasonic water jetting device will be described. As shown in FIG. 2, the ultrasonic water jetting device 11 includes a high-frequency power supply unit 13 for supplying a high-frequency voltage and a jetting device body 15 for jetting ultrasonic water. The injection device body 15 includes a supply port 17 for washing water L, a water storage part 19 for storing the supplied washing water L, an ultrasonic vibrating member 23 for transmitting ultrasonic waves to the stored washing water L, and The ultrasonic washing water L is the jet port 21 of the ultrasonic water Ls.

The supply port 17 is used to introduce the washing water L into the injection device main body 15 . The water storage part 19 communicates with the supply port 17, and the washing water L is supplied. The water storage unit 19 is a cylindrical member (container) that temporarily stores the washing water L supplied from the supply port 17 . The injection port 21 is provided on one end side (lower end) of the water storage portion 19 . The spray port 21 sprays the washing water L stored in the water storage unit 19 toward the outside. The water storage portion 19 is tapered toward the injection port 21 .

The ultrasonic vibrating element 23 is arranged at a position facing the injection port 21 in the water storage part 19, and is connected to the piezoelectric vibrator of the high-frequency power supply part 13. The moving plate 24 and the resonating plate 25 are arranged adjacent to the piezoelectric vibrating plate 24 .

As shown in FIGS. 3 and 4 , the piezoelectric vibrating plate 24 has a central domed portion 241 and a flange portion 243 surrounding the domed portion 241 . The dome portion 241 is configured to receive a high-frequency voltage of 1 MHz to 3 MHz from the high-frequency power supply unit 13 and vibrate to generate ultrasonic vibrations. The concave side of the dome portion 251 faces the injection port 21 (see FIG. 2 ).

The collar portion 243 is provided around the dome portion 241 so as to protrude radially outward from the outer periphery of the dome portion 24 .

The piezoelectric vibrating plate 24 having such a configuration can be formed, for example, by integral molding using a mold frame.

As shown in FIG. 4 , the resonant plate 25 has the same dome portion 251 and collar portion 253 as the piezoelectric vibrating plate 24 , and is disposed adjacently inside the piezoelectric vibrating plate 24 . The outer surface of the domed portion 251 of the resonance plate 25 is in close contact with the inner surface of the domed portion 241 of the piezoelectric vibrating plate 24 . The upper surface of the collar portion 253 of the resonance plate 25 is in close contact with the lower surface of the collar portion 243 of the piezoelectric vibrating plate 24 .

Furthermore, as shown in FIG. 2, the inner surface of the dome portion 251 of the resonant plate 25 becomes the radiation surface 26 that radiates ultrasonic vibrations toward the washing water L in the water storage portion 19, and is disposed opposite to the injection port 21. the location.

The radiation surface 26 forms a concave dome shape according to the shape of the dome 241 of the piezoelectric vibrating plate 24 and the dome 251 of the resonance plate 25 . Therefore, the ultrasonic vibration radiated from the radiation surface 26 is focused at a position (in this embodiment, the ejection port 21 ) at a specific distance from the radiation surface 26 and concentrated at this position.

In this way, one side of the ultrasonic vibrating element 23 is also the radiation surface. 26. Centering on the focal point which is a point where the ultrasonic vibration is to be concentrated, the side of the point is dented to form a dome shape.

The dome 251 of the resonance plate 25 transmits the ultrasonic vibration from the radiation surface 26 to the washing water L by resonating with the ultrasonic vibration of the dome 241 of the piezoelectric vibration plate 24 . Accordingly, the washing water L sprayed from the spray port 21 to the outside becomes the ultrasonic water Ls.

Furthermore, as shown in FIG. 2 , the flange portion 253 of the piezoelectric vibration plate 24 and the flange portion 253 of the resonance plate 25 are supported by the side wall of the water storage portion 19 .

Next, a wafer cleaning device using the ultrasonic water jetting device 11 will be described. As shown in FIG. 5 , the wafer cleaning device 31 is a rotary cleaning device and includes a turntable unit 33 and an ultrasonic water jet unit 35 .

The turntable unit 33 is configured to hold and rotate the wafer 1 . As shown in FIG. 5 , the rotary table portion 33 includes a chuck mounting table 41 for holding the wafer 1, a rotation shaft 43 of the chuck mounting table 41, and a mechanism connected to the rotation shaft 43 to rotate the chuck mounting table 41. The stage rotation motor 45 .

The pinch mounting table 41 is formed in a circular shape smaller than the wafer 1 and holds the wafer 1 . Therefore, the chuck mounting table 41 is provided with a suction surface 42 for suctioning the wafer 1 at the central portion of the upper surface. The adsorption surface 42 is formed of a porous material such as porous ceramics. The suction surface 42 is connected to a suction source (both are not shown) through the pipeline in the pinch mounting table 41 . The wafer 1 is sucked and held on the chuck mounting table 41 by the negative pressure generated on the suction surface 52 .

The upper end of the rotating shaft 43 is connected to the center of the lower surface of the pinch mounting table 41 , and the lower end is connected to the mounting table rotation motor 45 . The stage rotation motor 45 transmits the rotation driving force to the pinch plate via the rotation shaft 43 Taiwan 41. Accordingly, as shown in FIGS. 5 and 6 , the suspender mounting table 41 rotates at a high speed, for example, in the A direction around the rotation axis 43 while holding the wafer 1 .

In addition to the ultrasonic water jetting device 11 shown in FIG. A washing water supply source 55 and a rotation motor 57 . The washing water supply source 55 is an example of a water supply source.

The front end of the horizontal pipe 51 is equipped with the ultrasonic water jet device 11 . The base end of the horizontal pipe 51 is held on the upper end of the rotating shaft 53 . The rotating shaft 53 is erected to be approximately parallel to the rotating shaft 43 of the rotating table portion 33 . The rotation motor 57 rotates the rotation shaft 53 . That is, the rotating shaft 53 uses the driving force of the rotating motor 57 to rotate the horizontal pipe 51 and the ultrasonic water jetting device 11 on the chuck mounting table 41 (wafer 1 ).

In addition, the horizontal pipe 51 has a length extending from the upper end of the rotating shaft 53 to the center of the chuck mounting table 41 . Accordingly, the rotating shaft 53 can move the ultrasonic water jet device 11 provided at the front end of the horizontal pipe 51 from the outer periphery of the wafer 1 to the center.

The washing water supply source 55 that is connected to the upper end of the rotating shaft 53 passes through the upper end of the rotating shaft 53 and the washing water supply pipe (not shown) that is arranged inside the horizontal pipe 51. The supply port 17 (see FIG. 2 ) of the injection device 11 supplies washing water L. As shown in FIG.

Here, the cleaning process by the wafer cleaning device 31 will be described. In the cleaning process that wafer 1 is carried out, as shown in Figure 5 and Figure 6 As shown, the wafer 1 is placed on the chuck table 41 , and the back surface 2 b of the wafer 1 is sucked and held on the chuck table 41 by the negative pressure generated on the suction surface 42 . After that, the stage rotation motor 45 is driven, and the suspender stage 41 holding the wafer 1 rotates at a high speed. Furthermore, by rotating the shaft 53 , the ultrasonic water jetting device 11 moves from the retracted position outside the chuck mounting table 41 to above the wafer 1 . Then, cleaning water L is supplied from cleaning water supply source 55 to ultrasonic water jetting device 11 , and ultrasonic water Ls is jetted onto wafer 1 from jetting port 21 (see FIG. 2 ) of ultrasonic water jetting device 11 .

At this time, the ultrasonic water jetting device 11 moves back and forth along a path leading to the rotation center of the wafer 1 as indicated by arrow B in FIG. 5 . Since the chuck table 41 rotates at a high speed, the cleaning water L is sprayed to the entire area of the wafer 1 on the chuck table 41 . In this way, the wafer 1 is spin-washed by the washing water L. As shown in FIG.

As described above, the wafer cleaning device 31 includes the ultrasonic water spraying device 11 for spraying the ultrasonic water Ls for cleaning onto the wafer 1 . In the ultrasonic water jet device 11 , the radiating surface 26 that radiates ultrasonic vibrations toward the washing water L in the water storage unit 19 is formed in a concave dome shape according to the shape of the dome portion 241 of the piezoelectric vibrating plate 24 . Also, the side of the dome-shaped depression faces the injection port 21 side. Therefore, the ultrasonic vibration radiated from the radiation surface 26 is concentrated toward the injection port 21 . That is, ultrasonic vibrations are focused toward the injection port 21 . Therefore, since the ultrasonic vibration is less likely to be reflected in the water storage portion 19 , the ultrasonic vibration can be sufficiently propagated to the wafer 1 by the ultrasonic water Ls injected from the injection port 21 . Therefore, when the wafer 1 is cleaned by using the ultrasonic water Ls injected from the injection port 21, the ultrasonic vibration can be sufficiently transmitted to the The dirt on the wafer 1 can improve the cleaning power.

Next, a wafer cutting apparatus using the ultrasonic water jet apparatus 11 shown in FIG. 2 will be described. The wafer cutting device forms cutting grooves along the planned dividing lines 3 (refer to FIG. 1 ) of the wafer 1 .

As shown in FIG. 7, the wafer cutting apparatus 61 has the cutting part 63 provided with the cutting blade, and the paddle mounting table 65 which holds a wafer. The pinch mounting table 65 attracts and holds the wafer 1 through the dicing tape T. As shown in FIG. The pinch mounting table 65 moves relatively to the cutting part 63 in, for example, the arrow C direction.

The cutting part 63 has the ultrasonic water jet device 11 of the structure shown in FIG. The front end side of the rotating shaft 71 is inserted into the center of the cutting blade 75 , and the cutting blade 75 is fixed to the rotating shaft 71 by the flange 73 . The rotating shaft 71 is rotationally driven by a motor (not shown) connected to the rear end side. Along with this, the cutting blade 75 rotates at high speed. The cutting blade 75 is formed, for example, by fixing diamond abrasive grains with a resin bond and molding them into a disc shape.

As shown in FIG. 8 , the cutting portion 63 is provided with a knife cover 81 covering the cutting knife 75 in addition to the above-mentioned cutting knife 75, the cutting water spray nozzle 83 provided in the knife cover 81, and the cutting water spray nozzle 83. A cutting water supply pipe 85 for cutting water, and a washing water supply pipe 87 for supplying washing water to the ultrasonic water jetting device 11 .

The cutting water spray nozzle 83 discharges the cutting water supplied from the cutting water supply pipe 85 toward the cutting point where the cutting blade 75 cuts into the wafer 1 . The cutting blade 75 is cooled and washed by the cutting water. Wash water supply The supply pipe 87 is connected to the supply port 17 shown in FIG. 2 of the ultrasonic water jet device 11 , and supplies washing water to the ultrasonic water jet device 11 . The supersonic water jetting device 11 is configured in an inclined state so that the jetting port 21 faces the cutting point.

Here, the cutting process of the wafer 1 by the wafer cutting device 61 will be described. First, as shown in FIG. 7 , the wafer 1 is sucked and held on the chuck mounting table 65 through the dicing tape T. As shown in FIG. Next, the suspender mounting table 65 is moved, and the wafer 1 is placed under the cutting portion 63 serving as a cutting area.

Afterwards, the height of the cutting portion 63 is adjusted so that the tip of the cutting blade 75 is distributed at a position corresponding to the cutting depth of the wafer 1 . After that, cutting grooves are formed along the planned dividing lines 3 of the wafer 1 by relatively moving the suspender stage 65 in the horizontal direction relative to the cutting blade 75 rotating at high speed. When forming the cutting groove, at the cutting point by the cutting blade 75, cutting water is discharged from the cutting water spray nozzle 83, and ultrasonic water Ls is sprayed from the ultrasonic water spray device 11. In this way, cutting grooves are formed along all the planned dividing lines 3 in the wafer 1 .

As mentioned above, the wafer cutting device 61 includes the ultrasonic water jetting device 11 , and the supersonic water jetting device 11 jets the supersonic water Ls to the formation part of the cutting groove in the wafer 1 . As mentioned above, in the ultrasonic water jetting device 11 , the radiating surface 26 is formed into a concave dome shape corresponding to the shape of the dome portion 241 of the piezoelectric vibrating plate 24 . Also, one side of the dome-shaped depression faces the injection port 21 side. Therefore, the ultrasonic vibration radiated from the radiation surface 26 is concentrated toward the injection port 21 . Therefore, because the ultrasonic water Ls injected through the injection port 21 can sufficiently propagate the ultrasonic vibration toward the wafer 1, that is, When the cutting depth at the cutting point is deep, ultrasonic vibration can be sufficiently transmitted to the cutting chips in the cutting groove by the ultrasonic water Ls injected from the injection port 21 . Therefore, cutting chips can be favorably discharged from the cutting groove by the ultrasonic water Ls.

Furthermore, in the piezoelectric vibrating plate 24 of the present embodiment, the flange portion 243 is provided around the dome portion 241 that receives high-frequency voltage and vibrates to generate ultrasonic vibration, and the flange portion 243 is supported by the water storage portion 19. side wall. Therefore, since the dome portion 241 is not in direct contact with the water storage portion 19 , it is difficult for the dome portion 241 to be pressed by the water storage portion 19 . Therefore, the dome portion 241 becomes easy to vibrate. Furthermore, compared with the configuration in which the dome portion 241 is in direct contact with the water storage portion 19 , the vibration of the dome portion 241 is less likely to be transmitted to the water storage portion 19 . Therefore, it is possible to suppress the weakening of the vibration of the dome portion 241 . As a result, it is possible to suppress the weakening of the ultrasonic vibration generated by the dome portion 241 .

In addition, in the ultrasonic water jetting device 11 shown in FIG. 2 , the water storage part 19 disposed inside the jetting device body 15 tapers toward the jetting port 21 . However, the configuration of the water storage unit 19 is not limited to this. Like the ultrasonic water jetting device 11a shown in FIG. 9, the water storage portion 19a may not taper toward the jetting port 21. That is, the injection device main body 15 may have a substantially cylindrical inner wall.

Furthermore, the dome shape of the dome portion 241 in the piezoelectric vibrating plate 24 related to this embodiment may be similar to the inner surface of a part of a sphere, even if it is similar to the inner surface of a mortar. Shapes are also acceptable. That is, the dome portion 241 may be configured so that ultrasonic vibrations are concentrated from the radiation surface 26 toward the injection port 21 .

[Implementation type 2]

In this embodiment, the wafer 1 shown in FIG. 1 is divided into three parts along the planned dividing line by using ultrasonic vibration without using a cutting device for the device provided with the ultrasonic vibrating element 23 shown in FIG. 4 and the like. The method is explained. By this division, the wafer 1 is divided into a plurality of wafers each including one device 4 .

(1) Modified layer formation process

In the dicing method (this dicing method) related to this embodiment mode, first, a modified layer forming process of forming a modified layer on the wafer 1 is performed using a well-known technique. In forming the modified layer, for example, an apparatus for irradiating pulsed laser light is prepared. The pulsed laser light from the device has a wavelength (such as an infrared region) that penetrates the wafer 1, and irradiates the pulsed laser light onto the wafer 1 with its focus point positioned inside the wafer 1. , one side moves along the planned dividing line 3 of the wafer 1 . Accordingly, within the wafer 1 , as shown in FIG. 10 , the modified layer 131 is formed along the planned dividing line 3 .

In addition, in the present embodiment, while changing the focusing depth, one dividing line 3 is irradiated with pulsed laser light three times, for example. Accordingly, three modified layers 131 arranged in the thickness direction of the wafer 1 are formed along one planned dividing line 3 .

(2) Handling and immersion works

Next, transfer the wafer with the modified layer 131 by the handling device 111 1. The process of transporting the mounting table 141, and the immersion process of immersing the mounting table 141 in the water tank 151. Here, the structure of the conveyance apparatus 111, the mounting table 141, and the water tank 151 used in this dividing method is demonstrated.

As shown in FIG. 10 , the transfer device 111 of the dividing method includes a transfer pad 121 for sucking and holding the wafer 1, a suction source 117 for the transfer pad 121, an arm 115 for supporting the transfer pad 121, a drive source 13 for the arm 115, and The connection member 119 which connects the conveyance mat 121 and the arm part 115.

The driving source 113 is a driving source of the arm portion 115 and supports the member. In the arm part 115 , the base end thereof is connected to the drive source 113 , and the transfer pad 121 is held on the front end thereof via the connection member 119 . The arm part 115 is rotatable on the XY plane with the drive source 113 as a rotation axis. Furthermore, the arm part 115 can be raised and lowered in the vertical direction along the Z-axis with the drive source 113 as a lifting axis.

The transfer pad 121 includes a suction portion 123 for sucking and holding the wafer 12 , and a frame 125 covering the suction portion 123 . The frame body 125 is connected to the connection member 119 and supports the adsorption part 123 . The adsorption unit 123 is made of a porous material such as porous ceramics, and is formed in a disc shape.

The suction source 117 includes a vacuum generator, a compressor, and the like, and has a communication path 181 extending in the Z direction. The communication path 181 passes through the arm portion 115 , the connection member 119 , and the frame body 125 , and reaches the adsorption portion 123 . Therefore, the suction source 117 is connected to the suction unit 123 via the communication path 181 . The suction source 117 sucks the adsorption part 123 through the communication path 181 to generate a negative pressure on the surface of the adsorption part 123 . The suction unit 123 sucks and holds the wafer 1 by the negative pressure.

Furthermore, as shown in FIG. 10 , the stage 141 is placed on the XY plane. It has parallel loading surfaces and is arranged and fixed on the bottom of the water tank 151 . Furthermore, the stage 141 has a rotation shaft (not shown) extending in the Z-axis direction, and is rotatable in the XY plane around the rotation shaft. The mounting table 141 is centered on this rotation axis, and can rotate, for example, at least 90° in the water tank 151 .

The water tank 151 is equipped with the nut part 152 arrange|positioned in the center of a lower surface. The water tank 151 is supported by the X-axis direction moving means 153 via a sliding member 155 capable of moving in the X-axis direction. The X-axis direction moving means 153 is a member for moving the water tank 151 in the X-axis direction (direction perpendicular to the paper). The X-axis direction moving means 153 includes a ball screw 159 arranged parallel to the X-axis, and a motor 157 that rotates the ball screw 159 . The ball screw 159 is engaged with the nut portion 152 of the water tank 151 . Therefore, the ball screw 159 is rotated by the driving force of the motor 157, and the water tank 151 receives the moving force via the nut part 152, and moves along the X-axis direction.

The conveyance process and immersion process of this dividing method using the conveyance apparatus 111 and the mounting table 141 which have such a structure are demonstrated. First, the protective tape PT for protecting the device 4 is pasted on the surface 2 a of the wafer 1 . Thereafter, the arm portion 115 is rotated in the XY plane using the driving force from the driving source 113, and the transfer pad 121 is arranged above the rear surface 2b side of the wafer 1 placed at a specific position. And, by lowering the arm part 115 along the Z direction, the transfer pad 121 is brought into contact with the back surface 2b of the wafer 1 . Then, by operating the suction source 117 , the wafer 1 is sucked and held by the suction portion 123 of the transfer pad 121 .

In this state, the wafer 1 is placed on the stage 141 in the water tank 151 by rotating and lifting the arm part 115 . Moreover, by the well-known In this method, the wafer 1 is fixed on the mounting table 141 . Afterwards, the position in the XY plane of the wafer 1 is adjusted so that the direction of the planned dividing line 3 in the wafer 1 is along the X-axis direction and the Y-axis direction. This adjustment is performed by rotation in the XY plane of the stage 141 .

Next, by supplying water into the water tank 151 from a water supply source not shown, the inside of the water tank 151 is filled with a predetermined amount of water W. Accordingly, the wafer 1 held on the stage 141 held in the water tank 151 is submerged.

Thereafter, the suction force from the suction source 117 is stopped, the transfer pad 121 is separated from the wafer 1, and moved upward along the Z direction. Accordingly, the handling and immersion works are completed.

(3) Division project

Next, a division process of dividing the submerged wafer 1 into chips using ultrasonic vibration is carried out. In the dicing process, as shown in FIG. 11 , an ultrasonic dicing device 161 is placed on the submerged wafer 1 . Moreover, along the planned dividing line 3 of the wafer 1, the ultrasonic horn 169 positioned above the wafer 1 is moved to apply ultrasonic vibrations to the planned dividing line 3 on the wafer 1 in order to modify the Layer 131 is the starting point for dividing wafer 1 .

Hereinafter, the configuration of the ultrasonic segmenting device 161 used in this segmenting method will be described. As shown in FIG. 11 , the ultrasonic dividing device 161 has a high-frequency power supply unit 163 that outputs a high-frequency voltage, an ultrasonic horn 169 that radiates ultrasonic vibrations, and a Y-axis that moves the ultrasonic horn 169 along the Y-axis direction. The direction moving means 165, the lifting means 167 for making the ultrasonic horn 169 go up and down, and the Y-axis direction moving means 165 and The nut part 166 of the lifting means 167.

The high-frequency power supply unit 163 has the same configuration as the high-frequency power supply unit 13 shown in FIG. 5 , and outputs high-frequency voltage to the ultrasonic horn 169 . The Y-axis direction moving means 165 is a member for moving the ultrasonic horn 169 along the Y-axis direction, and includes a ball screw extending in the Y-axis direction. The nut 166 is engaged with the ball screw of the Y-axis direction moving means 165, and moves in the Y-axis direction as the ball screw rotates.

The lower end of the lifting means 167 holds the ultrasonic horn 169 . The upper end of the lifting means 167 is held by the nut part 166 so as to be able to move up and down in the Z direction. Therefore, the raising and lowering means 167 can move up and down along the Z-axis direction simultaneously with the ultrasonic horn 169 .

Next, the ultrasonic horn 169 will be described. As shown in FIG. 11 , the ultrasonic horn 169 includes the ultrasonic vibrating element 23 shown in FIG. 4 that radiates ultrasonic vibrations, and a case 171 that holds the outer periphery of the ultrasonic vibrating element 23 .

As mentioned above, the ultrasonic vibrating element 23 has a piezoelectric vibrating plate 24 that vibrates by receiving a high-frequency voltage of 1 MHz to 3 MHz from the high-frequency power supply unit 163 to generate ultrasonic vibrations, and a resonant vibrating plate 24 adjacent to the piezoelectric vibrating plate 24. plate 25.

In this embodiment, the resonance plate 25 radiates ultrasonic vibrations through the water W from the radiation surface 26 by resonating with the ultrasonic vibrations of the piezoelectric vibrating plate 24 . As described above, the radiation surface 26 is formed into a dome shape so that the ultrasonic vibrations radiated from the radiation surface 26 are focused at a position with a certain distance from the radiation surface 26 and concentrated at the position.

Furthermore, in the present embodiment, the flange portion 253 of the piezoelectric vibrating plate 24 and the flange portion 253 of the resonance plate 25 are held by the case 171 .

Furthermore, the ultrasonic dicing device 161 has an alignment camera (not shown) capable of penetrating the wafer 1 from the back surface 2b of the wafer 1 and photographing the surface 2a of the wafer 1 . The alignment camera is, for example, an infrared camera. By using this alignment camera, it is possible to photograph the planned dividing lines 3 formed on the front surface 2 a from the back surface 2 b side of the wafer 1 .

The division process of this division method using the ultrasonic division device 161 having such a configuration will be described. After the immersion process is performed, the ultrasonic splitting device 161 is placed on the rear surface 2 b of the submerged wafer 1 maintained on the stage 141 .

Next, using the X-axis direction moving means 153 and the Y-axis direction moving means 165, the relative position of the ultrasonic horn 169 is controlled with respect to the wafer 1 in the XY plane. By this control, the focal point of the ultrasonic vibrating element 23 (the focal point of the radiation surface 26 ) of the ultrasonic horn 169 is arranged above the first planned dividing line 3 extending in the X direction in the wafer 1 . In addition, the above-mentioned alignment camera is used in this control.

Next, the lifting means 167 is controlled to control the position of the ultrasonic horn 169 in the Z-axis direction. By this control, the height of the focal point of the ultrasonic vibrator 23 becomes the height of the back surface 2 b of the wafer 1 . Accordingly, the focal point of the ultrasonic vibrating element 23 is arranged on the planned dividing line 3 on the rear surface 2 b of the wafer 1 . In this state, the high-frequency power supply unit 163 is driven to output a high-frequency voltage to the ultrasonic vibrator 23 , and ultrasonic vibrations are radiated from the ultrasonic vibrator 23 . According to this, the ultrasonic vibration is directed towards the planned dividing line 3 of the wafer 1, passing through the water tank 151 The inner water W is concentratedly irradiated.

And, while radiating ultrasonic vibrations from the ultrasonic vibrating member 23 of the ultrasonic horn 169 toward the planned dividing line 3, the ultrasonic horn 169 is opposed to the wafer 1 along the planned dividing line 3 extending in the X-axis direction. to move. That is, the motor 157 of the X-axis direction moving means 153 holding the water tank 151 is driven to move the mounting table 141 together with the water tank 151 in the X-axis direction. After radiating ultrasonic vibrations to the entire area of a predetermined dividing line 3, use the moving means 165 in the Y-axis direction and the lifting means 167 to align the focus of the ultrasonic vibrating element 23 on another planned dividing line 3 extending along the X-axis direction , along the planned division line 3, the ultrasonic horn 169 is relatively moved.

In this way, ultrasonic vibrations are radiated to the entire area of all the planned dividing lines 3 parallel to one direction in the wafer 1 . Thereafter, the mounting table 141 is rotated by 90°, and ultrasonic vibrations are similarly radiated to the planned dividing line 3 perpendicular to the planned dividing line 3 to which the ultrasonic vibration has been irradiated.

In this way, ultrasonic vibration is applied to the entire area of all the planned dividing lines 3 in the wafer 1 . In the wafer 1 , an external force due to ultrasonic vibration is applied to the line 3 to be divided, and cracks are generated starting from the weak modified layer 131 formed along the line 3 to be divided. Therefore, the wafer 1 is divided along the planned dividing line 3 . In this way, the wafer 1 is divided into small pieces to produce a plurality of wafers.

As described above, in the ultrasonic horn 169 used in this division method, the radiation surface 26 is formed in a dome shape by denting the focal point which is a point where ultrasonic vibrations are to be concentrated. According to this, the ultrasonic vibration radiated from the ultrasonic vibrating member 23 can be concentrated in one point.

Furthermore, in this dividing method, the modified layer 131 having weak strength is formed along the planned dividing line 3 of the wafer 1 . Furthermore, the ultrasonic horn 169 applies ultrasonic vibrations to the upper surface of the wafer 1 through the water W while moving along the planned dividing line 3 of the wafer 1 . Therefore, in this splitting method, ultrasonic vibration can be applied intensively to each modified layer 131 on all modified layers 131 of the wafer 1 . Therefore, since the wafer 1 can be favorably divided along the modified layer 131 , it is possible to suppress the occurrence of division residue.

Furthermore, in the piezoelectric vibrating plate 24 of this embodiment, the collar portion 243 provided around the dome portion 241 that receives high-frequency voltage and vibrates to generate ultrasonic vibration is held by the case 171 . Therefore, since the dome portion 241 is not in direct contact with the housing 171 , it is difficult for the dome portion 241 to be pressed by the housing 171 . Therefore, the dome 241 vibrates easily. Furthermore, compared with the structure in which the dome 241 directly contacts the housing 171 , the vibration of the dome 241 is less likely to be transmitted to the housing 171 . Therefore, it is possible to suppress the weakening of the vibration of the dome portion 241 . As a result, it is possible to suppress the weakening of the ultrasonic vibration generated by the dome portion 241 .

In addition, either one of the transfer device 111 and the ultrasonic splitting device 161 may be configured to rotationally drive the water tank 151 so as to be arranged on the wafer 1 in the water tank 151 . Alternatively, the water tank 151 moves planarly (for example, linearly) in such a manner that the wafer 1 is arranged below any one of the transfer device 111 and the ultrasonic splitting device 161 arranged parallel to the XY plane direction. Can.

Furthermore, in this embodiment, the conveying device 111 will After the wafer 1 is placed on the mounting table 141 , water is supplied to the water tank 151 , and then the transfer device 111 separates it from the wafer 1 . However, the present invention is not limited thereto, and the transfer pad 121 of the transfer device 111 may be cut off from the wafer 1 after the wafer 1 is placed on the mounting table 141 , and water may be supplied to the water tank 151 thereafter.

Furthermore, in this embodiment, the wafer 1 is placed on the mounting table 141 previously arranged in the water tank 151 by the transfer device 111 , and then water is supplied in the water tank 151 . However, it is not limited thereto, and the wafer 1 may be placed on the stage 141 in the water tank 151 for storing water. Alternatively, the mounting table 141 arranged outside the water tank 151 may place the wafer 1 by the transfer device 111, and then the mounting table 141 holding the wafer 1 may be arranged in the water tank 151 for storing water.

Furthermore, in Embodiments 1 and 2, the piezoelectric vibrating plate 24a shown in FIGS. 12 and 13 may be used instead of the piezoelectric vibrating plate 24 shown in FIG. 3 . The piezoelectric vibrating plate 24a has a groove portion 245 in addition to the dome portion 241 and the flange portion 243 shown in FIG. 3 . The groove portion 245 is provided on the top side surface of the dome portion 241 at the portion of the flange portion 243 that is in contact with the dome portion 241 . That is, the groove portion 245 is provided on the collar portion 243 so as to surround the dome portion 241 .

In this configuration, the presence of the groove portion 245 reduces the cross-sectional area of the portion of the collar portion 243 that is in contact with the dome portion 241 . Therefore, it is possible to suppress the vibration generated in the dome portion 241 from being transmitted to the flange portion 243 .

Therefore, in this configuration, it is possible to suppress the ultrasonic vibration from being transmitted to the side wall of the water storage unit 19 or the casing 171 via the collar portion 243 . Therefore, in this configuration, the vibration of the dome portion 241 of the piezoelectric vibration plate 24 can be efficiently transmitted to the dome portion 251 of the resonance plate 25 .

Furthermore, in Embodiments 1 and 2 above, the ultrasonic vibration 23 includes the piezoelectric vibration plate 24 and the resonance plate 25 , and the resonance plate 25 has the radiation surface 26 . However, the present invention is not limited thereto, and the ultrasonic vibrating element 23 may not include the resonance plate 25 even if it includes the piezoelectric vibrating plate 24 . In this configuration, the dome portion 241 of the piezoelectric vibrating plate 24 has a dome-shaped radiation surface formed by indenting one point around a point where ultrasonic vibrations are to be concentrated, and ultrasonic vibrations are oscillated from the radiation surface. That is, the piezoelectric vibrating plate 24 is arranged in the water storage part 19 to face the injection port 21, and oscillates ultrasonic vibration.

11: Ultrasonic water jet device

13: High frequency power supply part

15: Injection device body

17: supply port

19: Water storage department

21: Injection port

23: Ultrasonic vibration parts

24: Piezoelectric vibration plate

25: Resonant plate

26: Radiating surface

L: washing water

Ls: Ultrasonic water

Claims (4)

A wafer cutting method, which uses an ultrasonic water jetting device, the ultrasonic water jetting device sprays water that propagates ultrasonic vibrations to a workpiece, and the ultrasonic water jetting device includes: a cylindrical water storage unit, It temporarily stores the water supplied from the water supply source; the injection port is arranged at one end side of the water storage part and injects water; and the piezoelectric vibrating plate faces the injection port And be arranged in this water storage part, produce ultrasonic vibration, this piezoelectric vibrating plate has: dome top; In the device, the concave side of the dome portion of the piezoelectric vibration plate faces the injection port, the flange portion of the piezoelectric vibration plate is supported by the side wall of the water storage portion, and the ultrasonic vibration is concentrated toward the injection port, as The ultrasonic water of the water propagating the ultrasonic vibration is sprayed from the injection port to the workpiece, and the cutting method of the wafer includes: a process of holding the wafer as the workpiece with a chuck table; and Cutter The tip of the cutter is arranged at a position corresponding to the cutting depth of the wafer, and the clamping table is relatively moved with respect to the rotating cutter, and the wafer is formed along the planned dividing line. The process of cutting trenches; and the process of forming the cutting trenches comprising jetting the ultrasonic water jets from an ultrasonic water jetting device to a cutting point where the cutting blade cuts into the wafer engineering. The wafer cutting method according to claim 1, wherein the piezoelectric vibrating plate further has a groove provided on the collar so as to surround the domed portion. A method for dividing a wafer, which uses an ultrasonic horn, and the ultrasonic horn applies ultrasonic vibrations intensively, and the ultrasonic horn is provided with: a vibrating member, which includes a piezoelectric vibrating plate, and the piezoelectric vibrating plate has a domed top and the flange part, which protrudes radially outward from the outer circumference of the dome, and the vibrating member has a dome-shaped radiating surface that is centered on a point where the ultrasonic vibration is to be concentrated; and the case, which holds the collar portion of the piezoelectric vibrating plate, and the method of dividing the wafer includes: fixing the wafer with the modified layer along the planned dividing line on the mounting table in the water tank ; the process of immersing the wafer held on the stage in the water tank; and moving the ultrasonic horn along the dividing line of the submerged wafer by dividing the dividing line from the ultrasonic horn A process in which ultrasonic vibration is applied to the wire and the wafer is split from the modified layer as the starting point. The wafer dividing method as claimed in claim 3, wherein, The piezoelectric vibrating plate further has a groove provided on the collar so as to surround the dome.

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