JP2006041399A - Dividing method of wafer and divider - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the dividing method of a wafer capable of dividing the wafer into individual devices without deteriorating the quality of the devices and a divider of the same. <P>SOLUTION: The wafer is divided in which a plurality of predetermined division lines are formed in a lattice, and a plurality of devices comparted by a plurality of the predetermined division lines on the surface of the wafer are cut off along the predetermined division lines while rotating a cutting blade held on a chuck table and supplying a cutting fluid thereto. The dividing method comprises a protective film forming step of forming the protective film on the surface of the wafer by coating a coating liquid having freezing point higher than the temperature of the cutting fluid on the surface of the wafer to solidify the coating liquid at a temperature lower than the freezing point; and a cutting step of cutting the wafer along the predetermined division lines while rotating the cutting blade, and supplying the freezing fluid at the temperature lower than the freezing point, with the wafer of the protective film formed on the surface of the wafer held on the chuck table. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wafer that divides a wafer in which devices such as IC, LSI, micromachine (MEMS), etc. are formed in a region partitioned by a predetermined division line formed on the surface along a predetermined division line. The present invention relates to a dividing method and a dividing apparatus.

  In the semiconductor device manufacturing process, a plurality of regions are defined by dividing lines called streets arranged in a lattice pattern on the surface of a semiconductor wafer having a substantially disk shape, and ICs, LSIs, and micromachines are defined in these partitioned regions. A device such as (MEMS) is formed. Individual devices are manufactured by cutting the semiconductor wafer formed in this way along the division line.

The above-described cutting along the semiconductor wafer division line is usually performed by a cutting device called a dicer. This cutting apparatus includes a chuck table for holding a workpiece such as a semiconductor wafer or an optical device wafer, a cutting means for cutting the workpiece held on the chuck table, and a chuck table and the cutting means. And a cutting feed means for moving it. The cutting means includes a rotary spindle, a cutting blade mounted on the spindle, and a cutting fluid supply nozzle that supplies cutting fluid to a cutting portion by the cutting blade, and the cutting fluid is supplied from the cutting fluid supply nozzle while rotating the cutting blade. While feeding, the wafer is relatively moved and cut along the planned dividing line. (For example, refer to Patent Document 1.)
JP 2002-359212 A

  Thus, when the semiconductor wafer is cut by the cutting blade, there is a problem that the cutting waste adheres to a bonding pad such as an IC or an LSI, thereby hindering wiring such as wire bonding. In addition, when a wafer on which a micromachine is formed is cut with a cutting blade, the micromachine has a fine and delicate structure, so that it is damaged by the momentum of the supplied cutting fluid, or the cutting waste is contained in the fine structure. There is a problem that the quality deteriorates significantly.

  In order to solve the above-mentioned problems, the present inventor tried to attach a protective tape to the front surface of the wafer and cut from the front surface or the back surface, but the adhesive paste of the protective tape remained on the bonding pad, wire bonding, etc. A problem similar to the conventional one occurred that hindered the wiring of this. In addition, when a protective tape is applied to the surface of the wafer on which the micromachine is formed and then cut, the micromachine may be damaged when the protective tape is peeled off, or the adhesive paste of the protective tape may remain on the bonding pad. As a result, a problem similar to that in the past has been caused, such as wire bonding and other problems.

  The present invention has been made in view of the above-described facts, and its main technical problem is to provide a wafer dividing method and a dividing apparatus that can divide a wafer into individual devices without deteriorating the quality of the device. That is.

In order to solve the above main technical problem, according to the present invention, a semiconductor wafer in which a plurality of division lines are formed in a lattice shape on the surface and a plurality of devices partitioned by the plurality of division lines are formed. Is a wafer dividing method of cutting along the planned dividing line while supplying a cutting fluid while holding the chuck table and rotating the cutting blade,
A protective film forming step of coating the surface of the wafer with a coating liquid having a freezing point higher than the temperature of the cutting liquid, and solidifying the coating liquid at a temperature below the freezing point to form a protective film on the surface of the wafer; ,
Cutting that cuts along the planned dividing line while supplying the cutting fluid at a temperature below the freezing point while rotating the cutting blade in a state where the wafer having the protective film formed on the surface is held on the chuck table. Including a process,
A method of dividing a wafer is provided.

  After carrying out the cutting step, a protective film removing step is performed in which washing water having a temperature higher than the freezing point is supplied to the protective film to dissolve and remove the protective film.

  The coating liquid is made of a compound containing ethylene carbonate as a main component or a compound containing silicon oil as a main component.

According to the present invention, the chuck table for holding the wafer, the cutting means for cutting the wafer held by the chuck table, and the cutting fluid supply means for supplying the cutting fluid to the cutting portion by the cutting means, In the wafer dividing apparatus provided,
A coating liquid having a freezing point higher than the temperature of the cutting fluid is coated on the surface of the wafer before cutting, and the coating liquid is solidified at a temperature below the freezing point to form a protective coating on the surface of the wafer. A protective film forming means for forming
A wafer dividing apparatus is provided.

  The protective film forming means includes a spinner table that holds and rotates the wafer, and a coating liquid supply means that supplies the coating liquid to the surface of the wafer held on the spinner table. The protective film forming means preferably includes cleaning water supply means for supplying cleaning water having a temperature exceeding the freezing point to the surface of the wafer held on the spinner table.

  According to the present invention, the surface of the wafer is coated with a coating solution having a freezing point higher than the temperature of the cutting fluid to form a protective coating, and the wafer having the protective coating formed on the surface is rotated while the cutting blade is rotated. Since cutting is performed along the line to be divided while supplying the cutting fluid below the freezing point, cutting waste does not adhere to bonding pads of circuits such as IC and LSI. Also, even a wafer with a micromachine formed, the surface of the wafer is protected by a protective coating, so that it is not damaged by the momentum of the cutting fluid, and cutting scraps can enter and deteriorate the quality. Absent.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a wafer dividing method and a dividing apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view of a wafer dividing apparatus constructed according to the present invention.
The wafer dividing device in the illustrated embodiment includes a device housing 2 having a substantially rectangular parallelepiped shape. In the apparatus housing 2, a chuck table 3 as a workpiece holding means for holding a workpiece is disposed so as to be movable in a direction indicated by an arrow X that is a cutting feed direction. The chuck table 3 includes a suction chuck support 31 and a suction chuck 32 mounted on the suction chuck support 31, and is a workpiece on a mounting surface that is a surface of the suction chuck 32. For example, a disk-shaped semiconductor wafer is held by suction means (not shown). The chuck table 3 is configured to be rotatable by a rotation mechanism (not shown). A clamp mechanism 34 for fixing an annular frame, which will be described later, is disposed on the suction chuck support 31 of the chuck table 3 configured as described above.

  The wafer dividing apparatus in the illustrated embodiment includes a spindle unit 4 as cutting means. The spindle unit 4 is mounted on a moving base (not shown) and is adjusted to move in a direction indicated by an arrow Y that is an indexing direction and a direction indicated by an arrow Z that is a cutting direction. The rotary spindle 42 is supported, and a cutting blade 43 that is a rotary tool attached to the front end of the rotary spindle 42 is provided. A blade cover 44 that covers the upper half of the cutting blade 43 is attached to the front end of the spindle housing 41. The blade cover 44 is provided with cutting fluid supply nozzles 45 disposed on both sides of the cutting blade 43.

  The wafer dividing apparatus in the illustrated embodiment images the surface of the workpiece held on the suction chuck 32 constituting the chuck table 3 and detects an area to be cut by the cutting blade 43 or performs cutting. An imaging mechanism 5 for confirming the state of the groove is provided. The imaging mechanism 5 is composed of optical means such as a microscope and a CCD camera, and sends the captured image signal to a control means (not shown). The wafer dividing apparatus shown in the figure includes a display means 6 for displaying an image picked up by the image pickup mechanism 5.

The wafer dividing apparatus in the illustrated embodiment forms a protective film on the surface of a wafer that is a workpiece before cutting, and removes the protective film coated on the surface of the wafer after cutting. A cum washing means 7 is provided. The protective film forming / cleaning means 7 will be described with reference to FIGS.
The protective film forming / cleaning means 7 in the illustrated embodiment includes a spinner table mechanism 71 and a cleaning water receiving means 72 disposed so as to surround the spinner table mechanism 71. The spinner table mechanism 71 includes a spinner table 711, an electric motor 712 that rotationally drives the spinner table 711, and a support mechanism 713 that supports the electric motor 712 so as to be movable in the vertical direction. The spinner table 711 includes a suction chuck 711a formed of a porous material, and the suction chuck 711a communicates with suction means (not shown). Accordingly, the spinner table 711 holds the wafer on the suction chuck 711 by placing a wafer as a workpiece on the suction chuck 711a and applying a negative pressure by suction means (not shown). The spinner table 711 is provided with a clamp mechanism 714 for fixing an annular frame described later. The electric motor 712 connects the spinner table 711 to the upper end of the drive shaft 712a. The support mechanism 713 includes a plurality of support legs 713a (three in the illustrated embodiment) and a plurality of support legs 713a that are connected to the electric motor 712 by connecting the support legs 713a (three in the illustrated embodiment). ) Air cylinder 713b. The support mechanism 713 configured as described above operates the air cylinder 713b to move the electric motor 712 and the spinner table 711 to the workpiece loading / unloading position, which is the upper position illustrated in FIG. 3, and the lower position illustrated in FIG. Position to the working position that is the position.

  The cleaning water receiving means 72 includes a cleaning water receiving container 721, three support legs 722 (two are shown in FIG. 2) that support the cleaning water receiving container 721, and the electric motor 712. And a cover member 723 attached to the drive shaft 712a. As shown in FIGS. 3 and 4, the washing water receiving container 721 includes a cylindrical outer wall 721a, a bottom wall 721b, and an inner wall 721c. A hole 721d through which the drive shaft 712a of the electric motor 712 is inserted is provided at the center of the bottom wall 721b, and an inner wall 721c protruding upward from the periphery of the hole 721d is formed. Further, as shown in FIG. 2, a drainage port 721e is provided in the bottom wall 721b, and a drain hose 724 is connected to the drainage port 721e. The cover member 723 is formed in a disc shape, and includes a cover portion 723a that protrudes downward from the outer peripheral edge thereof. When the electric motor 712 and the spinner table 711 are positioned at the work position shown in FIG. 4, the cover member 723 thus configured has a gap between the cover portion 723 a and the inner wall 721 c that constitutes the cleaning water receiving container 721. Is positioned to polymerize.

  In the illustrated embodiment, the protective film forming and cleaning means 7 supplies the cutting fluid disposed on both sides of the cutting blade 43 to the surface of the wafer, which is the workpiece before cutting, held by the spinner table 711. A coating liquid supply means 74 for supplying a coating liquid made of a liquid compound having a solidification point higher than the temperature of the cutting liquid supplied from the nozzle 45 is provided. The coating liquid supply means 74 includes a coating liquid supply nozzle 741 that supplies a liquid coating liquid toward the surface of the wafer before cutting, which is held by the spinner table 711, and forward rotation that swings the coating liquid supply nozzle 741. An electric motor 742 capable of reversing is provided, and a coating liquid supply nozzle 741 is connected to a coating liquid supply source (not shown). The coating liquid resin supply nozzle 741 includes a nozzle portion 741a that extends horizontally and has a distal end bent downward, and a support portion 741b that extends downward from the base end of the nozzle portion 741a. The support portion 741b is the cleaning liquid. An unillustrated insertion hole provided in the bottom wall 721b constituting the collection container 721 is inserted and connected to a coating liquid supply source (not illustrated). Note that a coating liquid supply source (not shown) includes heating means for maintaining the coating liquid at a temperature equal to or higher than the freezing point of the coating liquid and for maintaining the coating liquid in the liquid. Further, a seal member (not shown) that seals between the support portion 741b is mounted on the periphery of an insertion hole (not shown) through which the support portion 741b of the coating liquid supply nozzle 741 is inserted.

  The protective film forming / cleaning means 7 in the illustrated embodiment includes a cleaning water supply means 75 and an air supply means 76 for cleaning the wafer, which is a workpiece after cutting, held on the spinner table 711. ing. The cleaning water supply means 75 includes a cleaning water nozzle 751 that ejects cleaning water toward the wafer after cutting held by the spinner table 711, and an electric motor that can be rotated forward and backward to swing the cleaning water nozzle 751. 752 and the cleaning water nozzle 751 is connected to a cleaning water supply source (not shown). The cleaning water nozzle 751 includes a nozzle portion 751a that extends horizontally and has a tip bent downward, and a support portion 751b that extends downward from the base end of the nozzle portion 751a. The support portion 751b is the above-described cleaning liquid collection container. An insertion hole (not shown) provided in the bottom wall 721b constituting the 721 is inserted and connected to a cleaning water supply source (not shown). A seal member (not shown) that seals between the support portion 751b and the support hole 751b is attached to the periphery of an insertion hole (not shown) through which the support portion 751b of the cleaning water nozzle 751 is inserted.

  The air supply means 76 includes an air nozzle 761 that blows air toward the cleaned wafer held by the spinner table 711, and an electric motor (not shown) that can rotate forward and reverse to swing the air nozzle 761. The air nozzle 761 is connected to an air supply source (not shown). The cleaning water nozzle 761 is composed of a nozzle portion 761a that extends horizontally and has a distal end bent downward, and a support portion 761b that extends downward from the base end of the nozzle portion 761a. The support portion 761b is the cleaning liquid collection container. An insertion hole (not shown) provided in the bottom wall 721b constituting the 721 is inserted and connected to an air supply source (not shown). A seal member (not shown) that seals between the support portion 761b is attached to the periphery of an insertion hole (not shown) through which the support portion 761b of the air nozzle 761 is inserted.

  Returning to FIG. 1, the description will be continued. The wafer dividing apparatus according to the illustrated embodiment includes a cassette mounting portion 13a on which a cassette for housing a semiconductor wafer 10 as a workpiece is placed. A cassette table 131 is arranged on the cassette mounting portion 13a so as to be movable up and down by lifting means (not shown). The cassette 13 is mounted on the cassette table 131. The semiconductor wafer 10 is affixed to the surface of a protective tape 12 attached to an annular frame 11 and is accommodated in the cassette 13 while being supported by the frame 11 via the protective tape 12. As shown in FIG. 5, the semiconductor wafer 10 is divided into a plurality of regions by a plurality of division lines 101 arranged in a lattice pattern on the surface 10a, and devices 102 such as ICs, LSIs, etc. are divided into these divided regions. Is formed. As shown in FIG. 1, the semiconductor wafer 10 thus configured has a back surface attached to a protective tape 12 mounted on an annular frame 11 with the front surface 10a, that is, the surface on which the street 101 and the device 102 are formed facing upward. Worn.

  In the wafer dividing apparatus in the illustrated embodiment, the unprocessed semiconductor wafer 10 housed in the cassette 13 is carried out to the alignment means 14 disposed in the temporary placement portion 14a, and the semiconductor wafer 10 after the cutting process. The workpiece unloading / carrying means 15 for carrying the workpiece into the cassette 13 and the unprocessed semiconductor wafer 10 carried to the alignment means 14 are conveyed to the protective film forming / cleaning means 7 and the protective film forming / cleaning means 7. The workpiece transfer means 16 for transferring the semiconductor wafer 10 whose surface is coated with the protective film onto the chuck table 36 and the semiconductor wafer 10 cut on the chuck table 36 as the protective film forming and cleaning means 7. A cleaning and conveying means 18 for conveying is provided.

The wafer dividing apparatus in the illustrated embodiment is configured as described above, and a wafer dividing method for cutting a wafer along a planned division line using the illustrated dividing apparatus will be described below.
As shown in FIG. 1, a semiconductor wafer 10 before cutting supported on an annular frame 11 via a protective tape 12 (hereinafter simply referred to as a semiconductor wafer 10) has a surface 10a, that is, a street 101 and a device 102 formed thereon. It is accommodated in a predetermined position of the cassette 13 with its surface facing upward. The uncut semiconductor wafer 10 accommodated in a predetermined position of the cassette 13 is positioned at the unloading position when the cassette table 131 moves up and down by lifting means (not shown). Next, the workpiece unloading / loading means 15 moves forward and backward, and the semiconductor wafer 10 positioned at the unloading position is unloaded to the alignment means 14 disposed in the temporary placement portion 14a. The semiconductor wafer 10 carried out to the alignment means 14 is aligned at a predetermined position by the alignment means 14. Next, the unprocessed semiconductor wafer 10 aligned by the alignment means 14 is placed on the suction chuck 711 a of the spinner table 711 that constitutes the protective film forming and cleaning means 7 by the turning operation of the workpiece conveying means 16. It is conveyed and sucked and held by the suction chuck 711a. The annular frame 11 is fixed by a clamp mechanism 714. At this time, the spinner table 711 is positioned at the workpiece loading / unloading position shown in FIG. 3, and the resin supply nozzle 741, the washing water nozzle 751 and the air nozzle 761 are, as shown in FIGS. 2 and 3, the spinner table 711. Is positioned at a standby position separated from above.

  If the semiconductor wafer 10 before cutting is held on the spinner table 711 of the protective film forming and cleaning means 7, a protective film forming process for covering the surface 10 a of the semiconductor wafer 10 with the protective film is executed. In order to carry out the protective film forming step, first, the spinner table 711 is positioned at the working position as shown in FIG. 4, and the electric motor 742 of the film liquid supply means 74 is driven to activate the nozzle portion 741a of the film supply nozzle 741. The jet outlet is positioned above the center of the semiconductor wafer 10 held on the spinner table 711 as indicated by a two-dot chain line in the figure. Then, while rotating the spinner table 711 at a rotational speed of, for example, 100 rpm, a liquid coating solution is dropped from the jet port of the nozzle portion 741a onto the center portion of the surface 10a of the semiconductor wafer 10, so that the liquid coating solution is surrounded by the centrifugal force. And the surface of the semiconductor wafer 10 is coated.

  This liquid coating liquid is composed of a liquid compound having a freezing point higher than the temperature of the cutting liquid supplied from the cutting liquid supply nozzle 45. As such a liquid compound having a high solidification temperature, a compound mainly composed of ethylene carbonate having a solidification temperature of about 35 ° C. or a compound mainly composed of silicon oil having a solidification temperature of about 17 ° C. can be used. The name of the product manufactured and sold by Denki Kagaku Kogyo Co., Ltd. as the compound based on ethylene carbonate: The name of the product manufactured and sold by Eminent Supply Co., Ltd. as the compound based on silicon oil : Magic water can be mentioned. When a compound containing ethylene carbonate as a main component is used, the nozzle portion 741a is heated at 35 ° C. or higher to be liquefied, and when a compound containing silicon oil as a main component is used, it is liquid at room temperature (25 ° C.). Drip from the spout.

  The coating liquid covering the surface of the semiconductor wafer 10 as described above solidifies with time at room temperature (25 ° C.) when a compound containing ethylene carbonate as a main component is used, as shown in FIG. A protective film 103 is formed on the surface 10 a of the semiconductor wafer 10. In addition, when a compound containing silicon oil as a main component is used, the temperature of the clean room in which the wafer dividing apparatus is disposed is set to 17 ° C. or less to solidify with time, and the semiconductor as shown in FIG. A protective coating 103 can be formed on the surface 10 a of the wafer 10. The thickness of the protective film 103 formed on the surface 10a of the semiconductor wafer 10 may be about 100 μm.

  If the protective film 103 is formed on the surface 10a of the semiconductor wafer 10 by the protective film forming process described above, the spinner table 711 is positioned at the workpiece loading / unloading position shown in FIG. The suction holding of the semiconductor wafer 10 is released, and the fixation of the annular frame 11 by the clamp mechanism 714 is released. Then, the semiconductor wafer 10 on the spinner table 711 is transferred onto the suction chuck 32 of the chuck table 3 by the workpiece transfer means 16, and the protective tape 12 side is sucked and held by the suction chuck 32. The annular frame 11 is fixed by the clamp mechanism 34. The chuck table 3 that sucks and holds the semiconductor wafer 10 in this manner is moved to a position directly below the imaging mechanism 5. When the chuck table 3 is positioned immediately below the image pickup mechanism 5, the cutting line 101 formed on the semiconductor wafer 10 is detected by the image pickup mechanism 5, and the spindle unit 4 is moved and adjusted in the arrow Y direction as an indexing direction for cutting. A precision alignment operation between the line and the cutting blade 43 is performed.

  Next, a cutting step of cutting the semiconductor wafer 10 along the planned dividing line while supplying cutting fluid below the freezing point of the compound forming the protective coating 103 from the cutting fluid supply nozzle 45 while rotating the cutting blade 43. carry out. That is, the cutting blade 43 is cut and fed by a predetermined amount in the direction indicated by the arrow Z (see FIG. 1), and positioned at a position where the lower end of the cutting blade 43 reaches the protective tape 12 held by the chuck table 3 as shown in FIG. . Then, the rotary spindle 42, that is, the cutting blade 43 is rotated in a direction indicated by an arrow in FIG. 7 and moved in a direction perpendicular to the paper surface in FIG. 7 (direction indicated by an arrow X in FIG. 1) at a predetermined cutting feed speed. Thus, the semiconductor wafer 10 held on the chuck table 3 is cut along the predetermined cutting line 101 by the cutting blade 43. At the time of cutting with the cutting blade 43, the cutting fluid is supplied from the cutting water supply nozzles 45, 45 to the cutting portion with the cutting blade 43. The temperature of the cutting fluid supplied from the cutting water supply nozzles 45, 45 is set to be equal to or lower than the solidification temperature of the compound that forms the protective coating 103. That is, when the protective coating 103 is formed of a compound containing ethylene carbonate as a main component (solidification temperature is 35 ° C.), the temperature of the cutting fluid may be generally set to 22 ° C. When the protective coating 103 is formed of a compound containing silicon oil as a main component (solidification temperature is 17 ° C.), the temperature of the cutting fluid is set to 15 ° C. or less, for example. By setting the temperature of the cutting fluid in this way, the protective coating 103 is not dissolved even if the cutting fluid is supplied to the cutting portion by the cutting blade 43.

  In the cutting process described above, cutting waste is generated by cutting with the cutting blade 43. However, since the protective film 103 is formed on the surface of the semiconductor wafer 10, the cutting waste is formed on the bonding pad of the circuit 102 such as an IC or LSI. Will not adhere. In the cutting step, the cutting fluid is supplied from the cutting water supply nozzles 45, 45 to the cutting portion by the cutting blade 43 at a considerable flow rate. However, since the protective film 103 is formed on the surface of the wafer, even if the wafer has a micromachine, it will not be damaged by the momentum of the cutting fluid, and cutting chips will enter and the quality will deteriorate. There is nothing.

  When the cutting process is executed along the predetermined cutting line 101 formed on the semiconductor wafer 10 as described above, the spindle unit 4 as the cutting means is moved in the direction indicated by the arrow Y in FIG. The indexing movement is performed (indexing process), and the cutting process is performed. When the cutting process and the indexing process are performed for all the cutting lines 101 extending in a predetermined direction in this way, the chuck table 3 and thus the semiconductor wafer 10 held on the chuck table 3 are rotated by 90 degrees to The semiconductor wafer 10 is divided into individual devices by executing the cutting process and the indexing process along the streets extending at right angles to a predetermined direction. The divided devices do not fall apart due to the action of the protective tape 12, and the state of the semiconductor wafer 10 supported by the annular frame 12 is maintained.

  After the semiconductor wafer 10 is divided into individual devices in this way, the chuck table 3 holding the semiconductor wafer 10 is first returned to the position where the semiconductor wafer 10 is sucked and held. Here, the semiconductor wafer 10 is sucked. The holding is released and the fixing of the annular frame 11 by the clamp mechanism 34 is released. Then, the semiconductor wafer 10 is transported onto the suction chuck 711a of the spinner table 711 constituting the protective film forming and cleaning means 7 by the cleaning transport means 18, and sucked and held by the suction chuck 711a. The annular frame 11 is fixed by a clamp mechanism 714. At this time, the resin supply nozzle 741, the washing water nozzle 751 and the air nozzle 761 are positioned at a standby position separated from the upper side of the spinner table 711 as shown in FIGS.

  If the semiconductor wafer 10 after the cutting process is held on the spinner table 711 of the protective film forming and cleaning means 7, a protective film removing step for dissolving and removing the protective film is performed. That is, as shown in FIG. 4, the spinner table 711 is positioned at the working position, and the electric motor 752 of the cleaning water supply means 75 is driven so that the outlet of the nozzle portion 751a of the cleaning water supply nozzle 751 is indicated by a two-dot chain line in the drawing. As shown, it is positioned above the center of the semiconductor wafer 10 held on the spinner table 711. Then, cleaning water, which may be pure water, is ejected from the ejection port of the nozzle portion 751a while rotating the spinner table 711 at a rotational speed of, for example, 300 rpm. This washing water is set to a temperature of, for example, 50 to 60 ° C., which is higher than the solidification temperature of the compound forming the protective coating 103, and is supplied at about 2 liters per minute. At this time, from the position where the electric motor 752 is driven and the washing water ejected from the nozzle 751a of the washing water supply nozzle 751 hits the center of the semiconductor wafer 10 held by the spinner table 711 to the position hitting the outer peripheral part. It can be swung within the required angle range. As a result, the protective film 11 coated on the surface 10a of the semiconductor wafer 10 is washed away and removed together with the cutting waste that has dissolved and adhered in the cutting process.

  When the protective film removal process described above is completed, a drying process is performed. That is, the cleaning water supply nozzle 741 is positioned at the standby position, and the jet port of the nozzle portion 761a constituting the air nozzle 761 of the air supply means 76 is positioned above the central portion of the semiconductor wafer 10 held on the spinner table 711. Then, while rotating the spinner table 711 at a rotational speed of, for example, 2000 rpm, air is ejected from the ejection port of the nozzle portion 761a for about 15 seconds. At this time, the air nozzle 761 is swung in a required angle range from a position where the air ejected from the nozzle portion 761 a hits the center of the semiconductor wafer 10 held by the spinner table 711 to a position where it hits the outer peripheral portion. As a result, the surface of the semiconductor wafer 10 is dried. In the case of a wafer on which a micromachine is formed, it is desirable to perform the drying process by reducing the rotation speed of the spinner table 711 to about 1000 rpm.

  If the protective film removing step and the drying step are performed as described above, the rotation of the spinner table 711 is stopped and the air nozzle 761 of the air supply means 76 is positioned at the standby position. Then, the spinner table 711 is positioned at the workpiece loading / unloading position shown in FIG. 3 and the suction and holding of the semiconductor wafer 10 held on the spinner table 711 is released. Next, the processed semiconductor wafer 10 on the spinner table 711 is carried out by the workpiece transfer means 16 to the alignment means 14 provided in the temporary placement portion 14a. The processed semiconductor wafer 10 unloaded to the alignment means 14 is stored in a predetermined position of the cassette 13 by the workpiece unloading means 15.

  As described above, the protective film forming / cleaning means 7 in the illustrated embodiment includes the spinner table mechanism 71, the coating liquid supply means 74, the cleaning water supply means 75, and the air supply means 76. A protective film forming process for covering the surface of the wafer 10 with the protective film 103, a protective film removing process after cutting, and a drying process can be performed.

  In the above-described embodiment, an example in which the protective film forming process is performed by the protective film forming and cleaning unit 7 has been described. However, the protective film forming process may be performed on the chuck table 3. In this case, the protective film forming / cleaning means 7 may have any cleaning function.

1 is a perspective view of a wafer dividing apparatus constructed according to the present invention. FIG. The perspective view which fractures | ruptures and shows a part of protective film formation and washing | cleaning means with which the laser processing apparatus shown in FIG. 1 is equipped. Explanatory drawing which shows the state which located the spinner table of the protective film formation and washing | cleaning means shown in FIG. 2 in the workpiece carrying in / out position. Explanatory drawing which shows the state which located the spinner table of the protective film formation and washing | cleaning means shown in FIG. 2 in the working position. The perspective view of the semiconductor wafer divided according to the present invention. Explanatory drawing which shows the state in which the protective film removal process in the division | segmentation method of the wafer by this invention was implemented. Explanatory drawing of the cutting process in the division | segmentation method of the wafer by this invention.

Explanation of symbols

2: Device housing 3: Chuck table 4: Spindle unit 41: Spindle housing 42: Rotating spindle 43: Cutting blade 44: Blade cover 45: Cutting water supply nozzle 5: Imaging mechanism 6: Display means 7: Protective film formation / cleaning means 71: Spinner table mechanism 711: Spinner table 712: Electric motor 72: Washing water receiving means 721: Washing water receiving container 723: Cover member 74: Coating liquid supply means 742: Film supply nozzle 742: Electric motor 75: Cleaning water supply means 751: Washing water nozzle 752: Electric motor 76: Air supply means 761: Air nozzle 10: Semiconductor wafer 101: Street 102: Circuit 103: Protective coating 11: Ring frame 12: Protective tape 13: Cassette 14: Positioning means 1 : Workpiece unloading-loading means 16: workpiece conveying means 18: cleaning conveying means

Claims (7)

A wafer on which a plurality of division lines are formed in a lattice shape on the surface and a plurality of devices defined by the plurality of division lines are formed is held on a chuck table and a cutting blade is rotated while rotating a cutting blade. A wafer dividing method for cutting along a line to be divided while supplying,
A protective film forming step of coating the surface of the wafer with a coating liquid having a freezing point higher than the temperature of the cutting liquid, and solidifying the coating liquid at a temperature below the freezing point to form a protective film on the surface of the wafer; ,
Cutting that cuts along the planned dividing line while supplying the cutting fluid at a temperature below the freezing point while rotating the cutting blade in a state where the wafer having the protective film formed on the surface is held on the chuck table. Including a process,
A wafer dividing method characterized by the above.   The method of dividing a wafer according to claim 1, wherein after the cutting step is performed, a protective coating removing step is performed in which cleaning water having a temperature higher than the freezing point is supplied to the protective coating to dissolve and remove the protective coating. .   3. The method for dividing a wafer according to claim 1, wherein the coating solution is made of a compound containing ethylene carbonate as a main component.   The coating solution is made of a compound mainly composed of silicon oil. 3. The wafer dividing method according to claim 1 or 2. In a wafer dividing apparatus comprising: a chuck table for holding a wafer; a cutting means for cutting a wafer held on the chuck table; and a cutting fluid supply means for supplying a cutting fluid to a cutting portion by the cutting means.
A coating liquid having a freezing point higher than the temperature of the cutting fluid is coated on the surface of the wafer before cutting, and the coating liquid is solidified at a temperature below the freezing point to form a protective coating on the surface of the wafer. A protective film forming means for forming
A wafer dividing apparatus characterized by the above.   6. The protective coating forming means comprises a spinner table that holds and rotates the wafer, and a coating liquid supply means that supplies the coating liquid to the surface of the wafer held on the spinner table. The wafer dividing apparatus as described.   7. The wafer dividing apparatus according to claim 6, wherein the protective film forming means comprises cleaning water supply means for supplying cleaning water having a temperature exceeding the freezing point to the surface of the wafer held by the spinner table.

Images