Chip manufacturing method

Abstract

To provide a chip manufacturing method capable of reliably producing a chip having a desired shape from a substrate having a crystal structure.SOLUTION: A method for manufacturing a chip is a method for manufacturing a chip having a desired shape from a substrate having a crystal structure, and includes a division-scheduled line setting step 1 of setting, on a substrate, an outline of a chip to be generated and linear division assisting lines which are adjacent to the outline of the chip and assist the division of the substrate, a division start point forming step 2 of locating a focusing point of a laser beam having a wavelength transmissive to the substrate at a predetermined position from the upper surface of the substrate, and irradiating light along the outline of the chip and the division assisting lines to form a division start point in the substrate, and a dividing step 3 of dividing the substrate by applying an external force to the substrate in which the division start point is formed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a chip. [Background technology]

[0002] When manufacturing chips of a desired shape from a plate-like object such as a glass substrate, a laser processing device capable of irradiating a laser beam along the contour of the chip is used. Examples of the laser processing device include one that positions the focal point of a laser beam with a wavelength that is transparent to the plate-like object inside the plate-like object and irradiates the laser beam to form a modified layer (see Patent Document 1), and one that positions the focal point of a laser beam with a wavelength that is transparent to the plate-like object at a required position and forms a shield tunnel consisting of a pore and an amorphous material surrounding the pore (see Patent Document 2).

[0003] However, even if a dividing point is formed for cutting out a circular part, the outside and inside of the dividing point are closely attached in a curved line, making it difficult to divide the two parts efficiently and reliably, and there is a problem that it is necessary to rely on manual work by an experienced worker, resulting in poor processing efficiency.

[0004] Therefore, the present inventors developed a dividing tool that can reliably and efficiently divide a plate-like object having a circular dividing starting point (see Patent Document 3). By using the dividing tool, it has become possible to reliably divide a substrate that does not have crystallinity, such as glass. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 3408805 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-221483 [Patent Document 3] Japanese Patent Application Publication No. 2017-202589 Summary of the Invention [Problem to be solved by the invention]

[0006] On the other hand, when substrates have a crystalline structure such as silicon carbide, even if the above-mentioned dividing tool is used, there is a very high probability that they will crack along the crystal orientation during division, highlighting a new issue in that it is difficult to cut out chips of the desired shape.

[0007] The present invention has been made in view of the above problems, and its object is to provide a method for manufacturing chips that can reliably produce chips of a desired shape from a substrate having a crystalline structure. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems and achieve the object, the chip manufacturing method of the present invention is a chip manufacturing method for producing chips of a desired shape from a substrate having a crystalline structure, and includes a dividing line setting step of setting, on the substrate, an outline of the chip to be produced and a linear dividing auxiliary line that is tangent to the outline of the chip and assists in dividing the substrate; a dividing origin forming step of positioning a focusing point of a laser beam of a wavelength that is transparent to the substrate at a predetermined position from the upper surface of the substrate and irradiating the laser beam along the outline of the chip and the dividing auxiliary line, thereby forming dividing origins inside the substrate; and a dividing step of applying an external force to the substrate with the dividing origins formed thereon to divide the substrate, is not parallel to any of the edges that connect the grid points that make up The line is also a tangent to the contour of the chip to be generated.

[0009] In the chip manufacturing method of the present invention, the auxiliary dividing line is preferably set on the upper surface of the substrate so as to intersect perpendicularly with one side of a unit cell constituting the crystal structure of the substrate.

[0010] In the chip manufacturing method of the present invention, the substrate may be made of SiC. [Effects of the Invention]

[0011] The present invention can reliably produce chips of a desired shape from a substrate having a crystalline structure. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a flowchart showing the flow of a chip manufacturing method according to an embodiment. [Figure 2] FIG. 2 is a plan view schematically showing the substrate after the dividing line setting step shown in FIG. [Figure 3] FIG. 3 is a perspective view schematically showing one state of the division starting point forming step shown in FIG. [Figure 4] FIG. 4 is a perspective view schematically showing the substrate after the division starting point forming step shown in FIG. [Figure 5] FIG. 5 is a cross-sectional view showing a portion of the substrate of FIG. [Figure 6] FIG. 6 is an enlarged cross-sectional view of a part of FIG. [Figure 7] FIG. 7 is a perspective view schematically showing a shield tunnel formed in the substrate of FIG. [Figure 8] FIG. 8 is a side view schematically showing one state of the dividing step shown in FIG. [Figure 9] FIG. 9 is a side view schematically showing a state after FIG. 8 of the dividing step shown in FIG. [Figure 10] FIG. 10 is a perspective view schematically showing the substrate in one state of the dividing step shown in FIG. [Figure 11] FIG. 11 is a plan view schematically showing the substrate divided along the division auxiliary lines of the first comparative example. [Figure 12] FIG. 12 is a plan view schematically showing the substrate divided along the division auxiliary lines of the second comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0013] Modes (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by a person skilled in the art and those that are substantially the same. Furthermore, the configurations described below can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the configuration can be made within the scope of the gist of the present invention.

[0014] [Embodiment] A method for manufacturing a chip according to an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a flow chart showing the flow of the method for manufacturing a chip according to an embodiment. The method for manufacturing a chip according to the embodiment includes a step 1 for setting a division line, a step 2 for forming a division start point, and a step 3 for dividing.

[0015] (Step 1: Setting the planned division line) Fig. 2 is a plan view schematically showing the substrate 10 after the dividing line setting step 1 shown in Fig. 1. The dividing line setting step 1 is a step of setting, on the substrate 10, the outlines 21 of the chips 20 to be produced and linear dividing auxiliary lines 30 that are in contact with the outlines 21 of the chips 20 and that assist in dividing the substrate 10.

[0016] The substrate 10 is a plate-like object made of, for example, silicon carbide (SiC). The substrate 10 has a crystalline structure. The substrate 10 of the embodiment shown in FIG. 2 has a hexagonal unit cell 12 formed by connecting six lattice points 11 when viewed from above. The substrate 10 has, for example, an orientation flat or a notch indicating the crystal orientation.

[0017] In step 1 of setting planned dividing lines, first, the outline 21 of the chip 20 to be produced is set on the upper surface of the substrate 10. In the embodiment, the outline 21 of the chip 20 to be produced is circular. Note that, although the shape of the chip 20 is circular in the embodiment, it is not limited to a circular shape in the present invention and may be any desired shape.

[0018] In the dividing line setting step 1, dividing auxiliary lines 30 are next set on the upper surface of the substrate 10. The dividing auxiliary lines 30 are straight lines that assist in dividing the substrate 10 into chips 20. The dividing auxiliary lines 30 are tangent lines that are tangent to the outlines 21 of the chips 20 to be produced. The dividing auxiliary lines 30 are set so as not to be parallel to the lines connecting the lattice points 11 that constitute the unit lattices 12 of the crystal structure, i.e., to none of the sides 13 of the unit lattices 12. In other words, the dividing auxiliary lines 30 are set so as to intersect with all of the sides 13 of the unit lattices 12 through which the dividing auxiliary lines 30 pass, or with extensions of the sides 13. In this embodiment, the dividing auxiliary lines 30 are set so as to intersect perpendicularly with one of the sides 13 of the unit lattices 12 that constitute the crystal structure of the substrate 10.

[0019] (Splitting point formation step 2) Fig. 3 is a perspective view schematically showing one state of the dividing start point forming step 2 shown in Fig. 1. Fig. 4 is a perspective view schematically showing the substrate 10 after the dividing start point forming step 2 shown in Fig. 1. Fig. 5 is a cross-sectional view showing a part of the substrate 10 of Fig. 4. Fig. 6 is a cross-sectional view showing an enlarged part of Fig. 5. Fig. 7 is a perspective view schematically showing a shield tunnel 50 formed in the substrate 10 of Fig. 4.

[0020] The division starting point forming step 2 is a step of forming a division starting point for dividing the substrate 10 into chips 20 inside the substrate 10. In the embodiment, the division starting point is a shield tunnel 50. In the division starting point forming step 2 of the embodiment, the shield tunnel 50 is formed using a laser processing device. The laser processing device includes a support table (not shown) that supports the substrate 10, a laser beam irradiation unit 40, and a movement unit (not shown) that moves the support table and the laser beam irradiation unit 40 relative to each other.

[0021] The laser beam irradiation unit 40 irradiates the substrate 10 supported on the holding table of the laser processing device with a laser beam 41. The laser beam 41 has a wavelength that allows the substrate 10 to transmit the laser beam 41.

[0022] In the division starting point forming step 2, first, the support table that supports the substrate 10 and the laser beam irradiation unit 40 are moved relatively to position the focal point of the laser beam 41 at a predetermined position from the upper surface of the substrate 10. Next, the laser beam 41 is irradiated into the substrate 10 while the substrate 10 and the focal point of the laser beam 41 are moved relatively to each other so that the laser beam 41 is irradiated along the outline 21 of the chip 20 and the division auxiliary line 30.

[0023] As a result, pores 52 and amorphous modified regions 51 surrounding pores 52 grow along contour 21 of chip 20 and auxiliary dividing line 30 from near the focal point of laser beam 41 positioned inside substrate 10 toward the upper surface of substrate 10, forming shield tunnels 50 at predetermined intervals. The inner diameter 53 of pore 52 is about 1 μm, the outer diameter 54 of modified region 51 is about 5 μm, and the interval between adjacent modified regions 51 is about 10 μm.

[0024] (Split Step 3) Fig. 8 is a side view schematically showing one state of dividing step 3 shown in Fig. 1. Fig. 9 is a side view schematically showing one state of dividing step 3 shown in Fig. 1 after Fig. 8. Fig. 10 is a perspective view schematically showing substrate 10 in one state of dividing step 3 shown in Fig. 1.

[0025] The dividing step 3 is a step of dividing the substrate 10, on which the dividing starting points (shield tunnels 50) have been formed, into chips 20. In the dividing step 3 of the embodiment, the substrate 10 is divided by applying an external force to the substrate 10 using an expansion device 60. The expansion device 60 includes a clamp member 61 and a push-up member 62.

[0026] In the dividing step 3, first, the expanding tape 71 is attached to the annular frame 70, and the expanding tape 71 is attached to the substrate 10, and the substrate 10 is fixed in the opening of the frame 70. Next, the outer periphery of the frame 70 that holds the substrate 10 is fixed with the clamping members 61. At this time, the tip of the push-up member 62 abuts against the expanding tape 71 between the inner peripheral edge of the frame 70 and the outer peripheral edge of the substrate 10. It is preferable that the tip of the push-up member 62 includes a roller member.

[0027] In dividing step 3, push-up members 62 are then raised relative to clamp members 61. Because the outer periphery of expanding tape 71 is fixed by clamp members 61 via frame 70, the portion between the inner peripheral edge of frame 70 and outline 21 of chip 20 on substrate 10 is expanded in the planar direction. A radial tensile force acts on expanding tape 71, dividing chip 20 on substrate 10 and the portion outside chip 20 separated by dividing auxiliary line 30, with outline 21 of chip 20 and dividing auxiliary line 30 as boundaries.

[0028] (First Comparative Example) 11 is a plan view schematically showing a substrate 10-1 of the first comparative example divided along division auxiliary lines 31. The division auxiliary lines 31 of the first comparative example are normal lines that are tangent to the outlines 21 of the chips 20 to be produced on the upper surface of the substrate 10-1 and extend outside the chips 20.

[0029] In the first comparative example, in the dividing line setting step 1, the outline 21 of the chip 20 to be generated and the dividing auxiliary lines 31 are set on the upper surface of the substrate 10-1. Thereafter, in the first comparative example, the dividing start point forming step 2 and the dividing step 3 are performed in the same manner as in the embodiment. As shown in Fig. 11, in the first comparative example, an extended crack 22 occurs in the divided chip 20, extending from the intersection of one of the dividing auxiliary lines 31 and the outline 21 of the chip 20, and extending inward from the dividing auxiliary line 31.

[0030] (Second Comparative Example) 12 is a plan view schematically showing a substrate 10-2 of a second comparative example divided by division auxiliary lines 32. The division auxiliary lines 32 of the second modified example are tangent lines that contact the outlines 21 of the chips 20 to be produced on the upper surface of the substrate 10-2 and are parallel to one side 13 of the unit cell 12 that constitutes the crystal structure.

[0031] In the second comparative example, in the dividing line setting step 1, the outline 21 of the chip 20 to be generated and a dividing auxiliary line 32 are set on the upper surface of the substrate 10-2. Thereafter, in the second comparative example, the dividing start point forming step 2 and the dividing step 3 are performed in the same manner as in the embodiment. As shown in Fig. 12, in the second comparative example, a crack 23 was generated in the divided chip 20, intersecting with the dividing auxiliary line 32 and extending across the inside of the chip 20.

[0032] As described above, in the chip manufacturing method of the embodiment, in order to obtain a chip 20 of the desired shape from the substrate 10, the division auxiliary line 30 formed outside the outline 21 of the chip 20 to be generated is set taking into account the crystal orientation of the substrate 10.

[0033] For example, in the embodiment, in the step 1 of setting the intended dividing lines, the auxiliary dividing lines 30 are set at right angles to the diagonals of the hexagon of the unit lattice 12, i.e., the lines connecting the farthest lattice points 11, but if the substrate 10 is a hexagonal crystal, they may be set at angles greater than 60° and less than 120° relative to the diagonals of the hexagon. Note that if the substrate is a tetragonal crystal, they may be set at angles greater than 0° and less than 180° relative to the diagonals of the quadrangle.

[0034] In this way, by forming the chip 10 at an ideal angle for splitting relative to the crystal orientation of the substrate 10, the probability that cracks 22, 23 will extend into the interior of the chip 20 during splitting can be significantly reduced, thereby ensuring that chips 20 of the desired shape can be obtained.

[0035] The present invention is not limited to the above-described embodiment, and can be implemented in various modifications without departing from the gist of the present invention.

[0036] For example, etching may be performed after the division starting point forming step 2 and before the division step 3. In addition, in the division step 3, although the division is performed by expanding using the expansion device 60 in the embodiment, the division may be performed using a division tool such as that described in Patent Document 3.

[0037] Furthermore, although the embodiment has been described with reference to an example in which one chip 20 is formed on one substrate 10, the present invention may also form multiple chips 20 on one substrate 10. In this case, it is preferable to form a set of the outline 21 of the chip 20 and the corresponding division auxiliary line 30, and form a new division auxiliary line that separates each set into separate regions. This makes it possible to prevent each chip 20 from being influenced by adjacent chips 20 and division auxiliary lines 30, which would otherwise cause cracks to propagate inside the chip 20. [Explanation of symbols]

[0038] 10, 10-1, 10-2 board 11 grid points 12 Unit Cell 13 sides 20 chips 21 Contour 22, 23 cracks 30, 31, 32 dividing extension line 41 Laser Beam

Claims

1. A method for producing a chip having a desired shape from a substrate having a crystalline structure, comprising: a dividing line setting step of setting, on the substrate, an outline of a chip to be produced and a linear dividing auxiliary line that is in contact with the outline of the chip and that assists in dividing the substrate; a division starting point forming step of positioning a focal point of a laser beam having a wavelength that is transparent to the substrate at a predetermined position from the upper surface of the substrate and irradiating the laser beam along the outline of the chip and the division assist line, thereby forming a division starting point inside the substrate; a dividing step of dividing the substrate by applying an external force to the substrate on which the dividing start points are formed; Including, The dividing auxiliary line is the dividing auxiliary line is a tangent line that is not parallel to any of the sides that are lines connecting lattice points constituting a unit lattice on the upper surface of the substrate and is in contact with the outline of the chip to be generated. How chips are manufactured.

2. The dividing auxiliary line is On the upper surface of the substrate, the alignment film is set to perpendicularly intersect with one side of a unit cell constituting the crystal structure of the substrate. A method for manufacturing the chip according to claim 1 .

3. The substrate is Characterized in that it is SiC, A method for manufacturing the chip according to claim 1 .

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