JP2007194515A - Dividing method for wafer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dividing method for a wafer in which the wafer having dividing lines on a surface in a lattice shape can precisely be divided along the dividing lines. <P>SOLUTION: In the dividing method for the wafer, the wafer having a plurality of first dividing lines and a plurality of second dividing lines formed crossing each other is divided into individual chips along the first dividing lines and second dividing lines. The dividing method includes a first deterioration layer forming stage of forming deterioration layers by irradiating the inside of the wafer with a laser beam along the first dividing lines, a first dividing stage of applying an external force to the wafer along the first dividing lines to break the wafer into strips along the first dividing lines where the deterioration layers are formed, a second deterioration layer forming stage of forming deterioration layers by irradiating the inside of the wafer with a laser beam along the second dividing lines, and a second dividing stage of applying an external force to the stripped wafers along the second dividing lines to break the wafers into individual chips along the second dividing lines where the deterioration layers. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wafer dividing method for dividing a wafer having a plurality of division lines formed on a surface thereof in a lattice shape into individual chips along the division lines.

  In the semiconductor device manufacturing process, a plurality of regions are partitioned by dividing lines called streets arranged in a lattice pattern on the surface of a substantially wafer-shaped semiconductor wafer, and devices such as ICs, LSIs, etc. are partitioned in the partitioned regions. Form. Then, the semiconductor wafer is cut along the planned dividing line to divide the region where the device is formed to manufacture individual semiconductor chips. In addition, an optical device wafer in which a gallium nitride compound semiconductor or the like is laminated on the surface of a sapphire substrate is also divided into optical devices such as individual light-emitting diodes and laser diodes by cutting along a predetermined division line. Widely used.

As a method of dividing a wafer such as the above-described semiconductor wafer or optical device wafer along a planned division line, a pulse laser beam having a wavelength that is transparent to the wafer is used, and a condensing point is formed inside the region to be divided. In addition, a laser processing method for irradiating a pulsed laser beam has been proposed. The division method using this laser processing method is to divide the inside of the wafer by irradiating a pulse laser beam in the infrared region having transparency to the wafer by aligning the condensing point inside from one side of the wafer. The wafer is divided into individual chips by continuously forming a deteriorated layer along the planned line and applying an external force along the planned split line whose strength has decreased due to the formation of the deteriorated layer. . (For example, refer to Patent Document 1.)
Japanese Patent No. 3408805

  When a laser beam is irradiated along the planned division lines formed on the surface of the wafer to form a deteriorated layer, an external force is applied to the wafer on which the deteriorated layer is formed, and the wafer is divided along the planned division line. The division line is divided by meandering. As a result, there is a problem that the wafer is distorted, oblique cracks, burrs and the like are caused in the vicinity where the scheduled division lines intersect, and the quality is deteriorated.

  The present invention has been made in view of the above-mentioned facts, and the main technical problem thereof is a wafer that can accurately divide a wafer in which division lines are formed in a lattice shape on the surface along the division lines. It is to provide a dividing method.

In order to solve the main technical problem, according to the present invention, a plurality of first division lines extending in a predetermined direction and a plurality of second division lines formed intersecting with the plurality of first division lines. A wafer dividing method for dividing a wafer partitioned by a division line into individual devices along a first division line and a second division line,
A first deteriorated layer forming step of irradiating a laser beam having a wavelength transmissive to the wafer along the first scheduled dividing line and forming an altered layer along the first scheduled split line inside the wafer; ,
After performing the first deteriorated layer forming step, an external force is applied to the wafer along the first planned dividing line, and the wafer is broken along the first planned divided line where the deteriorated layer is formed. A first dividing step of dividing into a shape;
The wafer divided into strips by carrying out the first division step is irradiated with a laser beam having a wavelength that is transparent to the wafer along the second division line, and the second inside the wafer. A second deteriorated layer forming step of forming a deteriorated layer along the division line of
After performing the second deteriorated layer forming step, an external force is applied to the strip-shaped wafer along the second scheduled dividing line, and the strip is broken along the second scheduled divided line on which the deteriorated layer is formed. A second dividing step of dividing the wafer into individual chips,
A method of dividing a wafer is provided.

After carrying out the protective tape attaching step of attaching the wafer to the protective tape attached to the annular frame, the first altered layer forming step, the first dividing step,
It is desirable to carry out the second deteriorated layer forming step and the second dividing step.

  In the wafer dividing method according to the present invention, after the first deteriorated layer forming step of forming the deteriorated layer along the first division planned line inside the wafer, the wafer is arranged along the first division planned line. When the first dividing step is performed, the first dividing step is performed in which the wafer is divided into strips by breaking along the first dividing line on which the altered layer is formed by applying an external force. Since the altered layer is not formed on the second division line that intersects the first division line, the first division line meanders when an external force is applied along the first division line. Without this, the wafer can be accurately divided along the first scheduled dividing line. In addition, after performing the second deteriorated layer forming step of forming the deteriorated layer along the second division planned line inside the wafer divided into strips by performing the first dividing step, the strip shape A second dividing step is performed in which an external force is applied to the wafer along the second division line and the wafer is broken along the second division line on which the deteriorated layer is formed to divide the wafer into individual chips. Therefore, when the second dividing step described above is performed, the wafer is divided into strips along the first division line, so that an external force acts along the second division line. Thus, the wafer is divided systematically along the second scheduled division line.

  Preferred embodiments of a wafer dividing method according to the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 is a perspective view of a semiconductor wafer as a wafer to be divided according to the wafer dividing method of the present invention. A semiconductor wafer 2 shown in FIG. 1 is made of, for example, a silicon wafer having a thickness of 300 μm, and a plurality of first division planned lines 21 extending in a predetermined direction and the plurality of first division planned lines are formed on the surface 2a. A plurality of second division lines 22 extending so as to intersect with a direction orthogonal to 21 are formed. On the surface 2 a of the semiconductor wafer 2, devices 23 such as ICs and LSIs are formed in a plurality of regions partitioned by a plurality of first division lines 21 and a plurality of second division lines 22. . Hereinafter, an embodiment of a wafer dividing method for dividing the semiconductor wafer 2 into individual devices (chips) will be described.

  The semiconductor wafer 2 shown in FIG. 1 is attached to the protective tape 4 made of a synthetic resin sheet such as polyolefin and attached to the annular frame 3 as shown in FIG. 2 (protective tape attaching step). . Accordingly, the back surface 2b of the semiconductor wafer 2 is on the upper side.

  If the above-described protective tape attaching step is performed, a laser beam having a wavelength that is transparent to the silicon wafer is irradiated along the first division line 21, and the first division line 21 is applied to the inside of the wafer. A first deteriorated layer forming step of forming a deteriorated layer along the line is performed. This first deteriorated layer forming step is performed using the laser processing apparatus 5 shown in FIG. A laser processing apparatus 5 shown in FIG. 3 has a chuck table 51 that holds a workpiece, a laser beam irradiation means 52 that irradiates a workpiece held on the chuck table 51 with a laser beam, and a chuck table 51 that holds the workpiece. An image pickup means 53 for picking up an image of the processed workpiece is provided. The chuck table 51 is configured to suck and hold a workpiece, and can be moved in a machining feed direction indicated by an arrow X and an index feed direction indicated by an arrow Y in FIG. Yes.

  The laser beam irradiation means 52 includes a cylindrical casing 521 disposed substantially horizontally. In the casing 521, a pulse laser beam oscillation means including a pulse laser beam oscillator and a repetition frequency setting means (not shown) including a YAG laser oscillator or a YVO4 laser oscillator are arranged. A condenser 522 for condensing the pulse laser beam oscillated from the pulse laser beam oscillating means is attached to the tip of the casing 521.

  In the illustrated embodiment, the image pickup means 53 mounted on the tip of the casing 521 constituting the laser beam irradiation means 52 emits infrared rays to the workpiece in addition to a normal image pickup device (CCD) that picks up an image with visible light. Infrared illumination means for irradiating, an optical system for capturing infrared light emitted by the infrared illumination means, an image pickup device (infrared CCD) for outputting an electrical signal corresponding to the infrared light captured by the optical system, and the like Then, the captured image signal is sent to a control means (not shown).

A first deteriorated layer forming step of forming an deteriorated layer along the first street 21 of the semiconductor wafer 2 using the laser processing apparatus 5 described above will be described with reference to FIGS.
First, the semiconductor wafer 2 is placed on the chuck table 51 of the laser processing apparatus 5 shown in FIG. 3 with the surface 2 a facing upward, and the semiconductor wafer 2 is sucked and held on the chuck table 51. In FIG. 3, the annular frame 3 to which the protective tape 4 is attached is omitted, but the annular frame 3 is held by appropriate frame holding means provided on the chuck table 51. The chuck table 51 that sucks and holds the semiconductor wafer 2 is positioned directly below the imaging means 53 by a moving mechanism (not shown).

  When the chuck table 51 is positioned immediately below the image pickup means 53, an alignment operation for detecting a processing region to be laser processed of the semiconductor wafer 2 is executed by the image pickup means 53 and a control means (not shown). That is, the image pickup means 53 and the control means (not shown) include the first division line 21 formed in a predetermined direction of the semiconductor wafer 2 and the laser beam irradiation means for irradiating the laser beam along the first division line 21. Image processing such as pattern matching for performing alignment with the 52 condensers 522 is executed, and alignment of the laser beam irradiation position is performed (alignment process). At this time, the surface 2a on which the first division line 21 of the semiconductor wafer 2 is formed is positioned on the lower side. However, as described above, the imaging unit 53 and the optical system that captures infrared rays and the infrared rays. Since the image pickup device is provided with an image pickup device (infrared CCD) or the like that outputs an electrical signal corresponding to the above, it is possible to image the first scheduled division line 21 through the back surface 2b.

  If the first division line 21 formed on the semiconductor wafer 2 held on the chuck table 51 is detected and the laser beam irradiation position is aligned as described above, (a) in FIG. As shown in FIG. 4, the chuck table 51 is moved to the laser beam irradiation region where the condenser 522 of the laser beam irradiation means 52 for irradiating the laser beam is located, and one end of the predetermined first scheduled division line 21 (at (a) in FIG. 4). (Left end) is positioned directly below the condenser 522 of the laser beam irradiation means 52. Then, the chuck table 51 is moved at a predetermined processing feed rate in the direction indicated by the arrow X1 in FIG. 4A while irradiating a pulse laser beam having a wavelength that is transmissive to the silicon wafer from the condenser 522. When the irradiation position of the condenser 522 of the laser beam irradiation means 52 reaches the position of the other end (the right end in FIG. 4B) as shown in FIG. 4B. The irradiation of the pulse laser beam is stopped and the movement of the chuck table 51 is stopped. In the first deteriorated layer forming step, the condensing point P of the pulse laser beam is matched with the vicinity of the surface 2 a (lower surface) of the semiconductor wafer 2. As a result, the deteriorated layer 210 is formed on the semiconductor wafer 20 along the first planned dividing line 21 from the surface 2a (lower surface) toward the inside. This altered layer 210 is formed as a melt-resolidified layer.

The processing conditions in the first deteriorated layer forming step are set as follows, for example.
Light source: LD excitation Q switch Nd: YVO4 laser Laser wavelength: 1064 nm pulse laser Repetition frequency: 100 kHz
Pulse width: 40 ns
Average output: 3W
Condensing spot diameter: φ1μm
Processing feed rate: 100 mm / sec

  When the thickness of the semiconductor wafer 2 is large, the first altered layer forming step described above is performed a plurality of times by changing the condensing point P stepwise as shown in FIG. Layer 210 is formed. For example, since the thickness of the deteriorated layer formed at one time is about 50 μm under the above-described processing conditions, the first deteriorated layer forming step is performed three times, for example, to form the 150 μm deteriorated layer 210. Further, six altered layers are formed on the semiconductor wafer 2 having a thickness of 300 μm, and the semiconductor wafer 2 extends from the front surface 2a to the rear surface 2b along the first division line 21 inside the semiconductor wafer 2. An altered layer may be formed. Further, the altered layer 210 may be formed only inside so as not to be exposed on the front surface 2a and the back surface 2b.

In this way, when the first deteriorated layer forming step is performed along all the first planned dividing lines 21 extending in a predetermined direction of the semiconductor wafer 2, the semiconductor wafer 2 is divided into the first divided schedule. An external force is applied along the line 21, and a first division step is performed in which the wafer is broken into strips by breaking along the first division line 21 on which the altered layer 210 is formed. This first dividing step is performed using a dividing device 6 shown in FIG.
The dividing device 6 shown in FIG. 6 includes a base 61 and a moving table 62 arranged on the base 61 so as to be movable in the direction indicated by the arrow Y. The base 61 is formed in a rectangular shape, and two guide rails 611 and 612 are arranged in parallel to each other in the direction indicated by the arrow Y on the upper surface of both side portions. A moving table 62 is movably disposed on the two guide rails 611 and 612. The moving table 62 is moved in the direction indicated by the arrow Y by the moving means 63. Frame holding means 64 for holding the annular frame 3 is disposed on the moving table 62. The frame holding means 64 includes a cylindrical main body 641, an annular frame holding member 642 provided at the upper end of the main body 641, and a plurality of clamps 643 as fixing means disposed on the outer periphery of the frame holding member 642. It is made up of. The frame holding means 64 configured as described above fixes the annular frame 3 placed on the frame holding member 642 with the clamp 643. Further, the dividing device 6 shown in FIG. 6 includes a rotating means 65 for rotating the frame holding means 64. The rotating means 65 is wound around a pulse motor 651 disposed on the moving table 62, a pulley 652 mounted on the rotation shaft of the pulse motor 651, and the pulley 652 and a cylindrical main body 641. It consists of an endless belt 653. The rotation means 65 configured as described above rotates the frame holding means 64 via the pulley 652 and the endless belt 653 by driving the pulse motor 651.

  The dividing device 6 shown in FIG. 6 applies a tensile force to the semiconductor wafer 2 supported by the annular frame 3 held by the annular frame holding member 642 via the protective tape 4 in the direction perpendicular to the division line. There is provided tension applying means 66 to be applied. The tension applying means 66 is disposed in the main body 641 of the annular frame holding member 64. The tension applying means 66 includes a first suction holding member 661 and a second suction holding member 662 each having a rectangular holding surface that is long in a direction orthogonal to the arrow Y direction. The first suction holding member 661 has a plurality of suction holes 661a, and the second suction holding member 662 has a plurality of suction holes 662a. The plurality of suction holes 661a and 662a communicate with suction means (not shown). Further, the first suction holding member 661 and the second suction holding member 662 can be moved in the arrow Y direction by a moving means (not shown).

  The dividing device 6 shown in FIG. 6 has a detecting means 67 for detecting a division line of the semiconductor wafer 2 supported on the annular frame 3 held by the annular frame holding member 642 via the protective tape 4. It has. The detection means 67 is attached to an L-shaped support column 671 disposed on the base 61. The detection means 6 is composed of an optical system, an image sensor (CCD), and the like, and is disposed above the tension applying means 66. The detection means 67 configured in this manner images the planned division line of the semiconductor wafer 2 supported by the annular frame 3 held by the annular frame holding member 642 via the protective tape 4, It is converted into an electric signal and sent to a control means (not shown).

A first dividing step performed using the dividing device 6 described above will be described with reference to FIGS. 6 and 7.
An annular frame 3 that supports the semiconductor wafer 2 on which the above-described first deteriorated layer forming step has been performed via a protective tape 4 is placed on a frame holding member 642 as shown in FIG. The frame holding member 642 is fixed by a clamp 643. Next, the moving means 63 is operated to move the moving table 62 in the direction indicated by the arrow Y (see FIG. 6), and the altered layer 21 of the semiconductor wafer 2 is formed as shown in FIG. The first scheduled dividing line 21 (the leftmost scheduled dividing line in the illustrated embodiment) of the holding surface of the first suction holding member 661 and the second suction holding member 662 constituting the tension applying means 66. Position it between the holding surface. At this time, the first dividing line 21 is imaged by the detection unit 67 and the holding surface of the first suction holding member 661 and the holding surface of the second suction holding member 662 are aligned. In this way, if one first scheduled division line 21 is positioned between the holding surface of the first suction holding member 661 and the holding surface of the second suction holding member 662, suction (not shown) is performed. By operating the means to apply a negative pressure to the suction holes 661a and 662a, the semiconductor wafer 2 is placed on the holding surface of the first suction holding member 661 and the holding surface of the second suction holding member 662 via the protective tape 4. Is sucked and held (holding step).

  When the holding step described above is performed, the moving means (not shown) constituting the tension applying means 66 is operated, and the first suction holding member 661 and the second suction holding member 662 are shown in FIG. Move them away from each other. As a result, the first division planned line 21 positioned between the holding surface of the first suction holding member 661 and the holding surface of the second suction holding member 662 is orthogonal to the first division planned line 21. A tensile force acts in the direction in which the semiconductor wafer 2 is broken, and the semiconductor wafer 2 is broken along the first scheduled dividing line 21 (first dividing step). By performing this first division step, the protective tape 4 is slightly extended. In this dividing step, the semiconductor wafer 2 has the deteriorated layer 210 formed along the first scheduled dividing line 21 and the strength thereof is lowered. Therefore, the first suction holding member 661 and the second suction holding member 662 are reduced. Are moved about 0.5 mm in directions away from each other, the semiconductor wafer 2 can be broken along the first scheduled dividing line 21.

  If the 1st division | segmentation process fractured | ruptured along the 1st division | segmentation line 21 formed in the predetermined direction as mentioned above is implemented, the 1st suction holding member 661 and the 2nd suction | attraction mentioned above will be carried out. The suction holding of the semiconductor wafer 2 by the holding member 662 is released. Next, the moving means 63 is operated to move the moving table 62 in the direction indicated by the arrow Y (see FIG. 6) by an amount corresponding to the interval between the first scheduled dividing lines 21, and the first dividing step is performed. The first planned division line 21 adjacent to the first planned division line 21 is between the holding surface of the first suction holding member 661 and the holding surface of the second suction holding member 662 constituting the tension applying means 66. Position. And the said holding process and a 1st division | segmentation process are implemented. As described above, by carrying out the holding process and the first dividing process on all the first planned dividing lines 21 formed in the predetermined direction, the semiconductor wafer 2 has the first planned dividing lines 21. Are divided into strips.

  In addition, when an altered layer is formed on both the first planned division line 21 and the second planned division line 22 in the division step, the second force is applied when an external force is applied along the first planned division line 21. Since an external force is also propagated to the altered layer formed in the planned division line 22, the division planned line meanders, and distortion and oblique cracking occur in the vicinity where the first division planned line 21 and the second planned division line 22 intersect. And burrs occur. However, in the first division step described above, no alteration layer is formed on the second planned division line 22 that intersects the first planned division line 21, so that it is orthogonal to the first planned division line 21. The semiconductor wafer 2 can be accurately divided along the first scheduled dividing line 21 without the first scheduled dividing line 21 meandering when a tensile force acts in the direction.

,
If the first dividing step described above is performed, a laser beam having a wavelength that is transmissive to the silicon wafer is applied to the semiconductor wafer 2 that has been divided into strips by performing the first dividing step. A second deteriorated layer forming step of irradiating along the planned division line 22 and forming a deteriorated layer along the second planned division line 22 inside the wafer is performed. This second deteriorated layer forming step is performed using the laser processing apparatus 5 shown in FIG. When the second deteriorated layer forming step is performed, as shown in FIG. 8, the semiconductor wafer 2 (divided into strips along the first division planned line 21) is used in the laser processing apparatus 5. The semiconductor wafer 2 is placed on the chuck table 51 with a phase angle of 90 degrees with that in the first alteration step, and the semiconductor wafer 2 is sucked and held on the chuck table 51. If the semiconductor wafer 2 is sucked and held on the chuck table 51 in this way, the alignment process described above is performed.

  Next, as shown in FIG. 9A, the chuck table 51 is moved to the laser beam irradiation area where the condenser 522 of the laser beam irradiation means 52 for irradiating the laser beam is located, and the predetermined second division line 22 is moved. One end (the left end in FIG. 9A) is positioned directly below the condenser 522 of the laser beam irradiation means 52. Then, the chuck table 51 is moved at a predetermined processing feed rate in the direction indicated by the arrow X1 in FIG. 9A while irradiating a pulse laser beam having a wavelength that is transmissive to the silicon wafer from the condenser 522. Then, as shown in FIG. 9B, when the irradiation position of the condenser 322 of the laser beam irradiation means 52 reaches the position of the other end of the second scheduled division line 22 (the right end in FIG. 9B). The irradiation of the pulse laser beam is stopped and the movement of the chuck table 51 is stopped. Also in the second deteriorated layer forming step, the condensing point P of the pulse laser beam is matched with the vicinity of the surface 2a (lower surface) of the semiconductor wafer 2. As a result, the altered layer 220 is formed on the semiconductor wafer 20 from the surface 2a (lower surface) to the inside along the second scheduled dividing line 22. This altered layer 220 is formed as a melt-resolidified layer. The processing conditions for the second deteriorated layer forming step may be the same as the processing conditions for the first deteriorated layer forming step.

  In this way, if the second deteriorated layer forming step is executed along all the second scheduled division lines 22 formed on the semiconductor wafer 2, the second wafer layer 2 formed on the semiconductor wafer 2 is formed into a second shape. A second dividing step is performed in which an external force is applied along the predetermined dividing line 22 and the wafer is broken along the second dividing line on which the deteriorated layer 220 is formed to divide the wafer into individual chips. This second dividing step is performed using the dividing device 6 shown in FIG. That is, the annular frame 3 for supporting the semiconductor wafer 2 divided into strips through the protective tape 4 after the second deteriorated layer forming step is held as shown in FIG. It is placed on the member 642 and fixed to the frame holding member 642 by a clamp 643. Next, the moving means 63 is actuated to move the moving table 62 in the direction indicated by the arrow Y (see FIG. 6), and the altered layer 22 of the semiconductor wafer 2 is formed as shown in FIG. The second scheduled split line 22 (the leftmost scheduled split line in the illustrated embodiment) of the first suction holding member 661 and the second suction holding member 662 constituting the tension applying means 66. Position it between the holding surface. At this time, the second planned dividing line 22 is imaged by the detection means 67, and the holding surface of the first suction holding member 661 and the holding surface of the second suction holding member 662 are aligned. In this way, if one second scheduled dividing line 22 is positioned between the holding surface of the first suction holding member 661 and the holding surface of the second suction holding member 662, suction (not shown) is performed. By operating the means and applying a negative pressure to the suction holes 661a and 662a, the first suction holding member 661 and the second suction holding member 662 are formed in a strip shape on the holding surface of the second suction holding member 662 via the protective tape 4. The divided semiconductor wafer 2 is sucked and held (holding process).

  When the holding step described above is performed, the moving means (not shown) constituting the tension applying means 66 is operated, and the first suction holding member 661 and the second suction holding member 662 are shown in FIG. Move them away from each other. As a result, the second division line 22 positioned between the holding surface of the first suction holding member 661 and the holding surface of the second suction holding member 662 is orthogonal to the second division line 22. The semiconductor wafer 2 divided into strips is broken along the second scheduled division line 22 (second dividing step). By performing this second dividing step, the protective tape 4 is slightly extended. In the second dividing step, the semiconductor wafer 2 has the deteriorated layer 220 formed along the second scheduled dividing line 22 and the strength thereof is lowered, so that the first suction holding member 661 and the second suction are reduced. By moving the holding member 662 about 0.5 mm away from each other, the semiconductor wafer 2 divided into strips can be broken along the second scheduled dividing line 22.

  As described above, if the second dividing step of breaking along one second scheduled dividing line 22 is performed, the semiconductor wafer by the first suction holding member 661 and the second suction holding member 662 described above is used. Release suction hold of 2. Next, the moving means 63 is actuated to move the moving table 62 in the direction indicated by the arrow Y (see FIG. 6) by an amount corresponding to the interval between the second scheduled division lines 22, and the second dividing step is performed. The second scheduled division line 22 adjacent to the second scheduled division line 22 is between the holding surface of the first suction holding member 661 and the holding surface of the second suction holding member 662 constituting the tension applying means 66. Position. Then, the holding step and the second dividing step are performed. As described above, by performing the holding step and the second dividing step on all the second scheduled dividing lines 22 formed in the predetermined direction, the semiconductor wafer 2 divided into strips can be It is broken along the two scheduled division lines 22 and divided into individual chips 20.

  When performing the above-described second division step, the semiconductor wafer 2 is divided into strips along the first division line 21, so that the direction is perpendicular to the second division line 22. When the tensile force acts on the semiconductor wafer 2, the semiconductor wafer 2 is divided along the second scheduled division line 22 with high accuracy.

  Although the present invention has been described based on the embodiments, the present invention is not limited only to the embodiments, and various modifications can be made within the scope of the gist of the present invention. For example, if the first deteriorated layer forming step and the first dividing step are performed to divide the wafer into strips, the second deteriorated layer is formed for each of the wafers formed in strips. You may implement a formation process and a 2nd division | segmentation process. In this way, the first dividing step is performed to divide the wafer into strips, so that even if the second scheduled lines formed on the strip-shaped wafers are slightly displaced, In the second deteriorated layer forming step, the deteriorated layer can be reliably formed along the second scheduled division line.

The perspective view of the semiconductor wafer divided | segmented into each chip | tip by the wafer division | segmentation method by this invention. The perspective view which shows the state which affixed the semiconductor wafer shown in FIG. 1 on the surface of the protective tape with which the cyclic | annular flame | frame was mounted | worn. The principal part perspective view of the laser processing apparatus for implementing the 1st deteriorated layer formation process and the 2nd deteriorated layer formation process in the division | segmentation method of the wafer by this invention. Explanatory drawing of the 1st deteriorated layer formation process in the division | segmentation method of the wafer by this invention. FIG. 5 is an explanatory diagram illustrating a state in which a deteriorated layer is stacked and formed inside a semiconductor wafer in the first deteriorated layer forming step illustrated in FIG. 4. The perspective view of the dividing apparatus for implementing the 1st division process and the 2nd division process in the division method of the wafer by the present invention. Explanatory drawing of the 1st division | segmentation process in the division | segmentation method of the wafer by this invention. Explanatory drawing of the 2nd deteriorated layer formation process in the division | segmentation method of the wafer by this invention. Explanatory drawing of the 2nd deteriorated layer formation process in the division | segmentation method of the wafer by this invention. Explanatory drawing of the 2nd division | segmentation process in the division | segmentation method of the wafer by this invention.

Explanation of symbols

2: Semiconductor wafer 20: Chip 21: First division planned line 22: Second division planned line 23: Device
210: Altered layer 220: Altered layer 3: Circular frame 4: Protective tape
5: Laser processing apparatus 51: Chuck table of laser processing apparatus 52: Laser beam irradiation means 53: Imaging means 6: Dividing apparatus 61: Base of dividing apparatus 62: Moving table 63: Moving means 64: Frame holding means 65: Rotation Means 66: Tension applying means 67: Detection means

Claims (2)

A wafer that is partitioned by a plurality of first division lines that extend in a predetermined direction and a plurality of second division lines that are formed to intersect the plurality of first division lines. A method of dividing a wafer into individual chips along a line and a second scheduled division line,
A first deteriorated layer forming step of irradiating a laser beam having a wavelength transmissive to the wafer along the first scheduled dividing line and forming an altered layer along the first scheduled split line inside the wafer; ,
After performing the first deteriorated layer forming step, an external force is applied to the wafer along the first planned dividing line, and the wafer is broken along the first planned divided line where the deteriorated layer is formed. A first dividing step of dividing into a shape;
The wafer divided into strips by carrying out the first division step is irradiated with a laser beam having a wavelength that is transparent to the wafer along the second division line, and the second inside the wafer. A second deteriorated layer forming step of forming a deteriorated layer along the division line of
After performing the second deteriorated layer forming step, an external force is applied to the strip-shaped wafer along the second scheduled dividing line, and the strip is broken along the second scheduled divided line on which the deteriorated layer is formed. A second dividing step of dividing the wafer into individual chips,
A wafer dividing method characterized by the above.   After carrying out the protective tape attaching step for attaching the wafer to the protective tape attached to the annular frame, the first altered layer forming step, the first dividing step, the second altered layer forming step, and The wafer dividing method according to claim 1, wherein the second dividing step is performed.

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