Method for processing substrates and method for manufacturing chips
The method forms shield tunnels inside the substrate using a laser beam focused in the thickness direction to avoid damaging functional layers, enabling precise chip manufacturing by etching from the surface where pores open, thus preserving the functional layers.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- DISCO CORP
- Filing Date
- 2022-09-28
- Publication Date
- 2026-05-19
AI Technical Summary
Existing methods for manufacturing chips using laser beams face challenges in forming desired shield tunnels without damaging functional layers on the substrate surface, particularly when irradiating from the surface or back side, which can alter beam direction or damage the functional layer.
A method involving a laser beam with a wavelength that penetrates the substrate and is focused in a region longer in the thickness direction than the width direction, forming a shield tunnel inside the substrate with pores and amorphous portions, followed by etching from the surface where the pores open, and forming a functional layer after tunnel formation.
Enables the formation of desired shield tunnels without damaging functional layers, allowing for precise chip manufacturing by ensuring the functional layers are intact during the processing.
Smart Images
Figure 0007862271000001 
Figure 0007862271000002 
Figure 0007862271000003
Abstract
Description
Technical Field
[0001] The present invention relates to a method for processing a substrate using a laser beam that has a wavelength that can penetrate the substrate and is concentrated in a region where the length along the thickness direction of the substrate is longer than the width along the direction perpendicular to the thickness direction, and a method for manufacturing a chip from the substrate using this method for processing the substrate.
Background Art
[0002] Chips of semiconductor devices such as integrated circuits (ICs) or optical devices such as light-emitting diodes (LEDs) or laser diodes (LDs) are manufactured using, for example, a disk-shaped substrate made of a single crystal material such as silicon, silicon carbide, or sapphire.
[0003] Specifically, such chips are manufactured by forming a functional layer including a conductive film, a semiconductor film, and / or an insulating film on the surface of the substrate in order to form a plurality of devices, and then dividing the substrate along the boundaries of the plurality of devices.
[0004] As a method for dividing a substrate, a method using a laser beam that has a wavelength that can penetrate the material constituting the substrate and is concentrated in a region where the length along the thickness direction of the substrate is longer than the width along the direction perpendicular to the thickness direction is known (see, for example, Patent Document 1).
[0005] In this method, first, the laser beam is irradiated along the boundaries of a plurality of devices while positioning the region where the laser beam is concentrated inside the substrate. As a result, a shield tunnel (filament) including pores and an amorphous portion surrounding the pores is formed inside the substrate. Then, in this method, the substrate is etched so that the shield tunnel is removed. As a result, a chip is manufactured from the substrate.
Prior Art Documents
Patent Documents
[0006] [Patent Document 1] Japanese Patent Publication No. 2014-168790 [Overview of the Initiative] [Problems that the invention aims to solve]
[0007] When a laser beam is irradiated from the surface side of a substrate with a functional layer formed on its surface, the direction of the laser beam may change within the functional layer, potentially making it difficult to form the desired shielding tunnel in the substrate. Furthermore, when a laser beam is irradiated from the back side of the substrate, the functional layer may be damaged by the laser beam reaching the surface side of the substrate.
[0008] In view of these points, the object of the present invention is to provide a substrate processing method that can form a desired shield tunnel on a substrate without damaging the functional layers for constituting multiple devices, and a chip manufacturing method that uses this substrate processing method to manufacture a chip from a substrate. [Means for solving the problem]
[0009] According to one aspect of the present invention, a method for processing a substrate is provided, which involves processing the substrate using a laser beam having a wavelength that penetrates the material constituting the substrate and being focused in a region where the length along the thickness direction of the substrate is longer than the width along the direction perpendicular to the thickness direction, comprising a shield tunnel formation step of irradiating the substrate with the laser beam such that at least a portion of the region is located inside the substrate, thereby forming a shield tunnel including pores that open on at least one of the front or back surfaces of the substrate and amorphous portions surrounding the pores. Following the shield tunnel formation step, an etching step is performed to etch the shield tunnel from either the front or back surface of the substrate, whichever surface has the pores open. Applicable etching A method for processing a substrate is provided, comprising a functional layer formation step, in which a functional layer is formed on the surface of the substrate after the processing step.
[0011] According to another aspect of the present invention, a method for manufacturing a chip from a substrate is provided, which involves using a laser beam having a wavelength that penetrates the material constituting the substrate and being focused in a region where the length along the thickness direction of the substrate is longer than the width along a direction perpendicular to the thickness direction, and comprising: a shield tunnel formation step of irradiating the substrate with the laser beam such that at least a portion of the region is located inside the substrate to form a shield tunnel including pores opening on at least one of the front or back surfaces of the substrate and amorphous portions surrounding the pores; an etching step of etching the shield tunnel from the front or back surface of the substrate where the pores are open, after the shield tunnel formation step; a functional layer formation step of forming a functional layer on the surface of the substrate, after the etching step; and a splitting step of splitting the substrate by applying an external force to the substrate, after the functional layer formation step.
[0012] Furthermore, in the present invention, it is preferable that the pores are open only on either the front or back surface of the substrate. [Effects of the Invention]
[0013] In the present invention, prior to the functional layer formation step in which a functional layer is formed on the surface of the substrate, a shield tunnel formation step is performed in which a shield tunnel is formed on at least one of the front or back surfaces of the substrate, which includes a pore that opens and an amorphous portion surrounding the pore.
[0014] In other words, in the present invention, a shield tunnel is formed on the substrate while no functional layer is formed on its surface. Therefore, in the present invention, it is possible to form a desired shield tunnel on the substrate without damaging the functional layers that constitute multiple devices. [Brief explanation of the drawing]
[0015] [Figure 1] Figure 1 is a schematic perspective view showing an example of a substrate used in chip manufacturing. [Figure 2]FIG. 2 is a flowchart schematically showing an example of a substrate processing method for processing a substrate using a laser beam. [Figure 3] FIG. 3(A) is a partial cross-sectional side view schematically showing the state of a shield tunnel formation process, and FIG. 3(B) is a perspective view schematically showing the shield tunnel formed inside the substrate. [Figure 4] FIG. 4(A) is a partial cross-sectional side view schematically showing the state of a functional layer formation process, and FIG. 4(B) is a cross-sectional view schematically showing a substrate having a functional layer formed on its surface. [Figure 5] FIG. 5 is a partial cross-sectional side view schematically showing the state of a shield tunnel formation process different from that in FIG. 3(A). [Figure 6] FIG. 6 is a flowchart schematically showing another example of a substrate processing method. [Figure 7] FIG. 7(A) is a partial cross-sectional side view schematically showing the state of an etching process, and FIG. 7(B) is a cross-sectional view schematically showing a substrate in which a part of the shield tunnel is etched. [Figure 8] FIG. 8 is a flowchart schematically showing an example of a chip manufacturing method. [Figure 9] Each of FIGS. 9(A) and 9(B) is a partial cross-sectional side view schematically showing the state of a dicing step. [Figure 10] FIG. 10 is a flowchart schematically showing another example of a chip manufacturing method.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view schematically showing an example of a substrate used for manufacturing a chip. The substrate 11 shown in FIG. 1 has a circular front surface 11a and a back surface 11b, and is a disk-shaped wafer made of a single crystal material such as silicon or silicon carbide, for example.
[0017] Further, a plurality of division planned lines 13 intersecting each other are set in a grid pattern on the substrate 11. The substrate 11 is partitioned into a plurality of regions 15 by the plurality of division planned lines 13, and a functional layer for forming a device is formed on the surface 11a of each region 15 as described later.
[0018] Then, chips are manufactured by dividing the substrate 11 on which the functional layer is formed in each of the plurality of division planned lines 13. Note that there are no restrictions on the material, shape, structure, size, etc. of the substrate 11. For example, the substrate 11 may be made of another single crystal material such as sapphire.
[0019] FIG. 2 is a flowchart schematically showing an example of a substrate processing method for processing the substrate 11 using a laser beam. In this method, first, a shield tunnel including pores opening on the back surface 11b of the substrate 11 and an amorphous portion surrounding the pores is formed (shield tunnel forming step S1).
[0020] FIG. 3(A) is a partial cross-sectional side view schematically showing the state of the shield tunnel forming step S1. Specifically, in FIG. 3(A), the state of forming the shield tunnel 19 inside the substrate 11 in the laser processing apparatus 2 is shown.
[0021] The laser processing apparatus 2 has a disk-shaped holding table 4. This holding table 4 has, for example, a circular upper surface (holding surface). Further, the holding table 4 has a disk-shaped porous plate (not shown) whose upper surface is exposed on this holding surface.
[0022] Furthermore, this porous plate communicates with a suction source (not shown) such as an ejector through a flow path or the like formed inside the holding table 4. When this suction source operates, a suction force acts on the space near the holding surface of the holding table 4. Thereby, for example, the substrate 11 placed on the holding surface can be held by the holding table 4.
[0023] Furthermore, the holding table 4 is connected to a horizontal movement mechanism (not shown). This horizontal movement mechanism includes, for example, a ball screw and a motor. When this horizontal movement mechanism operates, the holding table 4 moves along the horizontal direction.
[0024] Furthermore, a head 6 of the laser beam irradiation unit is provided above the holding table 4. The laser beam irradiation unit also has a laser oscillator (not shown). This laser oscillator has, for example, Nd:YAG as the laser medium.
[0025] The laser oscillator then irradiates the substrate 11 with a pulsed laser beam LB (for example, a laser beam with a pulse width of 10 ps and a frequency of 50 kHz) having a wavelength that penetrates the material constituting the substrate 11 (for example, a wavelength of 1064 nm).
[0026] This laser beam LB is irradiated directly downward from the head 6 through an optical system (not shown) including a focusing lens 6a, etc., after its output (power) has been adjusted by an attenuator (not shown) (for example, the average output has been set to 2W).
[0027] Furthermore, the laser beam LB is subjected to aberrations (particularly longitudinal aberrations) by this optical system, for example. As a result, the laser beam LB is focused in a region R where the length along its propagation direction (the thickness direction of the substrate 11) is longer than the width along the direction perpendicular to the propagation direction.
[0028] Furthermore, the head 6 of the laser beam irradiation unit is connected to a vertical movement mechanism (not shown). This vertical movement mechanism includes, for example, a ball screw and a motor. When this vertical movement mechanism operates, the head 6 moves along the vertical direction.
[0029] When forming a shield tunnel inside the substrate 11 in the laser processing apparatus 2, first, the substrate 11, with protective tape 17 attached to its surface 11a, is placed on the holding table 4 with its back surface 11b facing upwards. This protective tape 17 is made of, for example, resin and has a disc shape with a diameter approximately equal to that of the substrate 11.
[0030] Furthermore, in the shield tunnel formation process S1, the protective tape 17 does not need to be attached to the surface 11a of the substrate 11. That is, the substrate 11 may be placed on the holding table 4 such that its surface 11a is in direct contact with the holding surface of the holding table 4.
[0031] Next, a suction source communicating with the porous plate exposed on the holding surface of the holding table 4 is activated. This causes the substrate 11 to be held by the holding table 4. Then, the position of the holding table 4 and / or the head 6 is adjusted so that one end of any of the multiple division lines 13 on the substrate 11 overlaps with the area where the laser beam LB is focused.
[0032] Next, while irradiating the head 6 with a laser beam LB, the holding table 4 is moved along the direction in which the planned division line 13 extends (see Figure 3(A)). This forms a shield tunnel 19 in the region of the substrate 11 along the planned division line 13.
[0033] Figure 3(B) is a schematic perspective view showing a shield tunnel 19 formed inside the substrate 11. This shield tunnel 19 includes pores 19a that open on both the front surface 11a and the back surface 11b of the substrate 11, and amorphous portions 19b surrounding the pores 19a.
[0034] Furthermore, the above operation is repeated until shield tunnels 19 are formed in all regions along the multiple planned division lines 13. This results in a substrate 11 in which shield tunnels 19 are formed in a grid pattern when viewed from above.
[0035] Following the shield tunnel formation process S1, a functional layer is formed on the surface 11a of the substrate 11 (functional layer formation process S2). In this functional layer formation process S2, for example, a functional layer consisting of a single metal film is formed on the surface 11a of the substrate 11 using physical vapor deposition (PVD). This functional layer is used, for example, as a back electrode for a power device.
[0036] Figure 4(A) is a schematic partial cross-sectional side view showing the functional layer formation process S2. Specifically, Figure 4(A) shows the formation of a metal film on the surface 11a of the substrate 11 in the sputtering apparatus 8. Note that in Figure 4(A), some of the components of the sputtering apparatus 8 are shown as blocks.
[0037] The sputtering apparatus 8 has a housing 10 that defines the chamber C. A through hole is formed in the bottom wall of the housing 10, and a support member 12 passes through the through hole. The support member 12 supports a holding table 14 on which an electrostatic chuck is provided on the upper side.
[0038] Furthermore, a target 16 made of a metal material is provided above the holding table 14, and this target 16 is attached to the electrode 18. In addition, an excitation member 20 for exciting the target 16 is provided near the target 16. The target 16 is also connected to a high-frequency power supply 22 via the electrode 18.
[0039] Furthermore, the side wall of the housing 10 is formed with an inlet 10a that can communicate with a sputtering gas supply source (for example, argon, etc.) via a valve (not shown), and an exhaust port 10b that can communicate with a suction source for reducing the pressure in the chamber C.
[0040] When forming a metal film on the surface 11a of the substrate 11 in the sputtering apparatus 8, first, the protective tape 17 attached to the surface 11a of the substrate 11 is peeled off, and a protective tape 21 similar to the protective tape 17 is attached to the back surface 11b.
[0041] Next, the substrate 11 is placed on the holding table 14 via the protective tape 21 so that the exposed surface 11a faces upward. Then, the electrostatic chuck provided on the upper side of the holding table 14 is activated. This holds the substrate 11 in place on the holding table 14.
[0042] Next, the suction source connected to the exhaust port 10b is activated to evacuate the chamber C, and its internal pressure is 10 -2 Pa~10 -4 The pressure in chamber C is reduced to Pa. Then, the high-frequency power supply 22 is operated so that a high-frequency power of, for example, 40 kHz is applied to the target 16, which has been magnetized by the excitation member 20, via the electrode 18, and sputtering gas is supplied to chamber C from the supply source via the valve and the inlet 10a, etc.
[0043] As a result, a plasma containing ions from the sputtering gas is generated in chamber C, and these ions collide with the target 16. Then, metal particles ejected from the target 16 by the collision of sputtering gas ions are deposited on the surface 11a of the substrate 11, forming a metal film.
[0044] Figure 4(B) is a schematic cross-sectional view showing a substrate 11 on which a functional layer 23 consisting of a single metal film is formed on the surface 11a. Note that this functional layer 23 may be composed of multiple thin films. Specifically, this functional layer 23 is formed by repeatedly forming a thin film by physical vapor deposition (PVD) or chemical vapor deposition (CVD), and patterning the thin film using photolithography and etching.
[0045] In the substrate processing method shown in Figure 2, prior to the functional layer formation step S2 in which a functional layer 23 is formed on the surface 11a of the substrate 11, a shield tunnel formation step S1 is performed to form a shield tunnel 19 that includes pores 19a that open on both the surface 11a and the back surface of the substrate 11, and amorphous portions 19b surrounding the pores 19a.
[0046] In other words, in this method, the shield tunnel 19 is formed on the substrate 11 while the functional layer 23 is not formed on its surface 11a. Therefore, in this method, it is possible to form the desired shield tunnel 19 on the substrate 11 without damaging the functional layer 23 that constitutes multiple devices.
[0047] It should be noted that the above-described content is one aspect of the present invention, and the present invention is not limited to the above-described content. For example, in the shield tunnel formation step S1 of the present invention, the shield tunnel 19 does not need to be formed so as to penetrate the substrate 11 in the thickness direction, as long as the substrate 11 can be divided in a dividing step or the like which will be described later.
[0048] Figure 5 is a schematic partial cross-sectional side view showing a different shield tunnel formation process S1 than that shown in Figure 3(A). The shield tunnel formation process S1 shown in Figure 5 is carried out in the same way as the shield tunnel formation process S1 shown in Figure 3(A), but the shield tunnel 19 is formed so as not to penetrate the substrate 11.
[0049] Specifically, the shield tunnel 19 includes a pore 19a that opens only on the back surface 11b of the substrate 11 and an amorphous portion 19b surrounding the pore 19a. Alternatively, the shield tunnel 19 may include a pore 19a that opens only on the front surface 11a of the substrate 11 and an amorphous portion 19b surrounding the pore 19a.
[0050] Furthermore, the structure of the laser processing apparatus used in the shield tunnel formation process S1 of the present invention is not limited to the structure of the laser processing apparatus 2 described above. For example, the shield tunnel formation process S1 may be carried out using a laser processing apparatus that is equipped with a vertical movement mechanism for moving the holding table 4 along the vertical direction and a horizontal movement mechanism for moving the head 6 of the laser beam irradiation unit along the horizontal direction.
[0051] Alternatively, the shield tunnel formation step S1 of the present invention may be carried out using a laser processing apparatus in which a scanning optical system capable of changing the direction of the laser beam LB irradiated from the head 6 is provided in the laser beam irradiation unit. This scanning optical system includes, for example, a galvanometer scanner, an acousto-optic element (AOD), and / or a polygon mirror.
[0052] In other words, in the shield tunnel formation process S1 of the present invention, it is sufficient that the substrate 11 held by the holding table 4 and the region where the laser beam LB irradiated from the head 6 is focused can move relative to each other along the horizontal and vertical directions, and there are no limitations on the structure for this purpose.
[0053] Furthermore, in the present invention, prior to the functional layer formation step S2, a portion of the shield tunnel 19, for example, 60% to 75%, may be removed. Figure 6 is a schematic flowchart showing an example of a substrate processing method in which a portion of the shield tunnel 19 is removed.
[0054] In the substrate processing method shown in Figure 6, the shield tunnel 19 is etched from the back surface 11b of the substrate 11 between the shield tunnel formation step S1 and the functional layer formation step S2 (etching step S3).
[0055] Figure 7(A) is a schematic partial cross-sectional side view showing the etching process S3. Specifically, Figure 7(A) shows the etching of a portion of the shield tunnel 19, which is formed to penetrate the substrate 11, for example, a portion on the back surface 11b side, by the etching agent E in the etching apparatus 24.
[0056] The etching apparatus 24 has a holding table 26 similar to the holding table 4 shown in Figure 3(A). Furthermore, the porous plate of the holding table 26 communicates with a suction source (not shown), such as an ejector, via a channel formed inside the holding table 26.
[0057] When this suction source is activated, an attractive force acts on the space near the holding surface of the holding table 26. This allows, for example, the substrate 11 placed on the holding surface to be held by the holding table 26.
[0058] Furthermore, the holding table 26 is connected to a rotation mechanism (not shown). This rotation mechanism includes, for example, a spindle and a motor. When this rotation mechanism operates, the holding table 26 rotates with a rotation axis that passes through the center of the holding surface and is aligned vertically.
[0059] Furthermore, a nozzle 28 is provided above the holding table 26 to supply an etching agent E to the substrate 11 held by the holding table 26. This etching agent E includes, for example, hydrofluoric acid.
[0060] When etching a portion of the shield tunnel 19 with the etching agent E in the etching apparatus 24, first, the substrate 11, with protective tape 17 attached to the surface 11a, is placed on the holding table 26 so that the back surface 11b faces upward.
[0061] Furthermore, in etching step S3, the protective tape 17 does not need to be attached to the surface 11a of the substrate 11. That is, the substrate 11 may be placed on the holding table 26 such that its surface 11a is in direct contact with the holding surface of the holding table 26.
[0062] Next, a suction source communicating with the porous plate exposed on the holding surface of the holding table 26 is activated. This causes the substrate 11 to be held by the holding table 26. Then, while supplying etching agent E to the back surface 11b of the substrate 11, the rotation mechanism is operated to rotate the substrate 11 for a predetermined period of time.
[0063] As a result, a portion of the back surface 11b of the shield tunnel 19 is etched. Figure 7(B) is a schematic cross-sectional view showing the substrate 11 with a portion of the shield tunnel 19 etched.
[0064] This etching process creates grooves 11c on the back surface 11b of the substrate 11 in areas along multiple planned division lines 13. It should be noted that during this etching process, the portion of the substrate 11 where the shield tunnel 19 is not formed, i.e., the portion overlapping with region 15, may be slightly etched.
[0065] Furthermore, in etching step S3, etching may be continued until all shield tunnels 19 are removed, that is, until the substrate 11 is divided along the multiple planned division lines 13.
[0066] Furthermore, in etching step S3, a portion of the surface 11a side of the shield tunnel 19 may be removed. That is, in etching step S3, the shield tunnel 19 may be etched from the surface 11a that is exposed by peeling off the protective tape 17.
[0067] Furthermore, the present invention may also be a method for manufacturing a chip that includes the substrate processing method described above. Figure 8 is a flowchart schematically showing an example of such a chip manufacturing method. In the method shown in Figure 8, the shield tunnel formation step S1, etching step S3, and functional layer formation step S2 described above are carried out in order.
[0068] Then, after the functional layer formation step S2, the substrate 11 is divided by applying an external force to it (dividing step S4). Figures 9(A) and 9(B) are schematic partial cross-sectional side views showing the dividing step S4.
[0069] Specifically, Figures 9(A) and 9(B) show how the expanding device 30 divides the substrate 11 and functional layer 23 along multiple planned division lines 13 by applying an external force to the substrate 11 and functional layer 23 that expands them along their radial direction.
[0070] Prior to the splitting process S4, the protective tape 21 is peeled off from the back surface 11b of the substrate 11, and the central region of a disc-shaped dicing tape 25, which has a larger diameter than the substrate 11, is attached. In addition, an annular frame 27, which has a circular opening with a larger diameter than the substrate 11, is attached to the outer periphery of this dicing tape 25.
[0071] The expanding device 30 has a cylindrical drum 32. A support unit 34 is provided around the drum 32. This support unit 34 has an annular support base 34a that surrounds the upper end of the drum 32.
[0072] Furthermore, multiple gripping portions 34b are provided on the upper surface of the support base 34a at approximately equal angular intervals along the circumferential direction of the support base 34a. When the substrate 11, which is integrated with the frame 27 via the dicing tape 25, is brought into the expander 30, the frame 27 is placed on the support base 34a via the dicing tape 25, and the frame 27 is gripped by the support base 34a and the multiple gripping portions 34b.
[0073] Furthermore, a plurality of rods 34c are provided on the lower surface of the support base 34a at approximately equal angular intervals along the circumferential direction of the support base 34a. Each of the plurality of rods 34c is, for example, a rod of an air cylinder and is movable up and down. When the plurality of rods 34c move up and down, the support base 34a and the plurality of gripping parts 34b also move up and down together with the plurality of rods 34c.
[0074] When dividing the substrate 11 along multiple division lines 13 in the expanding device 30, first, multiple rods 34c are raised and lowered so that the upper surface of the support base 34a is positioned on the same plane as the upper end of the drum 32.
[0075] Next, the substrate 11, which is integrated with the frame 27 via the dicing tape 25, is brought into the expander 30 so that the functional layer 23 faces upward, and the frame 27 is gripped by the support base 34a and the multiple gripping parts 34b (see Figure 9(A)). Then, the support base 34a and the multiple gripping parts 34b are lowered together with the multiple rods 34c.
[0076] As a result, the dicing tape 25 expands by the amount of the separation between the upper end of the drum 32 and the support base 34a. At this time, an external force acts on the substrate 11 and the functional layer 23, causing them to expand. Consequently, the substrate 11 and the functional layer 23 are divided along multiple planned division lines 13 (see Figure 9(B)).
[0077] In the chip manufacturing method of the present invention, the functional layer 23 may be divided along a plurality of planned division lines 13 prior to the division step S4. Figure 10 is a flowchart schematically showing an example of such a chip manufacturing method.
[0078] In the method shown in Figure 10, between the functional layer formation step S2 and the splitting step S4, the functional layer 23 is patterned to remove the region overlapping with the shield tunnel 19 of the functional layer 23 (patterning step S5). This patterning step is carried out, for example, using photolithography and etching.
[0079] Furthermore, the structures and methods of the embodiments described above can be modified as appropriate without departing from the scope of the present invention. [Explanation of symbols]
[0080] 2: Laser processing equipment 4: Holding Table 6: Head 8: Sputtering equipment 10: Housing 11: Substrate (11a: front side, 11b: back side, 11c: groove) 12: Support member 13: Planned division line 14: Holding Table 15: Area 16: Target 17: Protective tape 18: Electrode 19: Shield tunnel (19a: pores, 19b: amorphous region) 20: Excitation component 21: Protective tape 22: High frequency power supply 23: Functional Layer 24: Etching equipment 25: Dicing Tape 26: Holding Table 27: Frame 28: Nozzle 30: Expanding device 32: Drums 34: Support unit (34a: support base, 34b: gripping part, 34c: rod)
Claims
1. A method for processing a substrate, comprising processing the substrate using a laser beam having a wavelength that penetrates the material constituting the substrate, and being focused in a region where the length along the thickness direction of the substrate is longer than the width along the direction perpendicular to the thickness direction, A shield tunnel formation step involves irradiating the substrate with a laser beam such that at least a portion of the region is positioned inside the substrate, thereby forming a shield tunnel that includes pores opening on at least one of the front or back surfaces of the substrate and amorphous portions surrounding the pores. Following the shield tunnel formation step, an etching step is performed to etch the shield tunnel from either the front or back surface of the substrate, whichever surface has the pores open. Following the etching process, a functional layer formation process is performed to form a functional layer on the surface of the substrate. A method for processing a substrate that includes the following.
2. The method for processing a substrate according to claim 1, wherein the pores are opened only on either the front or back surface of the substrate.
3. A method for manufacturing a chip from a substrate, which involves using a laser beam having a wavelength that penetrates the material constituting the substrate, and which is focused in a region where the length along the thickness direction of the substrate is longer than the width along the direction perpendicular to the thickness direction, A shield tunnel formation step involves irradiating the substrate with a laser beam such that at least a portion of the region is positioned inside the substrate, thereby forming a shield tunnel that includes pores opening on at least one of the front or back surfaces of the substrate and amorphous portions surrounding the pores. Following the shield tunnel formation step, an etching step is performed to etch the shield tunnel from either the front or back surface of the substrate, whichever surface has the pores open. Following the etching process, a functional layer formation process is performed to form a functional layer on the surface of the substrate. After the functional layer formation step, a splitting step is performed in which the substrate is split by applying an external force to the substrate, A method for manufacturing a chip equipped with the following features.
4. The method for manufacturing a chip according to claim 3, wherein the pore is opened only on either the front or back surface of the substrate.