Method for cutting substrate and method for manufacturing substrate pieces

Abstract

To cut a substrate having a first layer (cleavable layer) made of semiconductor single crystals and a second layer (non-cleavable layer) of glass formed on the surface of the first layer, using fewer processes and without requiring complex equipment adjustments.SOLUTION: A method for cutting a substrate S having a first layer LA1 consisting of a cleavable layer and a second layer LA2 consisting of a non-cleavable layer formed on the first layer LA1 includes the steps of forming a scribe line SL for the second layer LA2 only and cutting the substrate S along the scribe line SL.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a method for cutting a substrate having a first layer made of a semiconductor single crystal and a glass layer formed on the surface of the first layer, and a method for producing substrate pieces from the substrate. [Background technology]

[0002] A known method for cutting a laminated substrate in which a glass layer is formed on the surface of a substrate made of a semiconductor single crystal such as Si is to irradiate both the semiconductor single crystal substrate and the glass layer thereon with laser light, form modified layers along a planned processing line on both the semiconductor single crystal substrate and the glass layer, and cut the laminated substrate along the planned processing line using the modified portion as the cutting starting point due to thermal stress generated by applying a local temperature change to the laminated substrate (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-23215 Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional cutting method described above, in order to form modified layers on both the semiconductor single crystal substrate and the glass layer, it is necessary to perform the modified layer formation process (laser light irradiation) multiple times along the same planned processing line. Furthermore, in order to irradiate the semiconductor single crystal substrate with laser light, it is necessary to align the focus of the laser light with the surface of the semiconductor single crystal substrate through the glass layer. Adjusting the focus position through the glass layer is difficult due to variations in the thickness of the glass layer and differences in the refractive index of the medium through which the laser light passes. In other words, conventional cutting methods require many processes and complex equipment adjustments.

[0005] An object of the present invention is to cut a substrate having a first layer made of a semiconductor single crystal and a glass layer formed on the surface of the first layer with fewer processes and without the need for complex adjustment of equipment. [Means for solving the problem]

[0006] Below, several aspects will be described as means for solving the problems. These aspects can be arbitrarily combined as necessary. A method for cutting a substrate according to one aspect of the present invention is a method for cutting a substrate having a first layer made of a semiconductor single crystal and a second layer that is a glass layer formed on the first layer, comprising the following steps: A step of forming scribe lines only on the second layer. A step of cutting the substrate along the scribe lines.

[0007] In the above-described substrate cutting method, a process of forming a scribe line only in the second layer, which is a glass layer, is performed, and then the substrate is cut along the scribe line from the first layer side or the second layer side. It is preferable to cut the substrate from the second layer side. When cutting the substrate along the scribe line by pushing the scribe line, the scribe line can be pushed from the first layer side to cut the substrate from the second layer side. In a substrate having a first layer made of a semiconductor single crystal and a second layer, which is a glass layer, if a scribe line is formed in the second layer, when cutting the substrate, the first layer is cut by cleavage in accordance with the cutting of the second layer. As such, the above-described cutting method does not require forming a scribe line in the first layer, and therefore can cut the substrate with fewer processes than conventional methods and without the need for complex adjustments such as adjusting the focal position through the glass layer. That is, the present invention can also be understood as a method for cutting a substrate having a cleavable layer and a cleavable layer formed on the cleavable layer, for example, a layer not extending from the first layer side when the substrate is cut along the scribe line by pressing the scribe line. The scribe line may be a modified layer of a predetermined thickness formed along a plane extending from the front side to the back side of the layer on which the scribe line is formed (a plane perpendicular to the main surface of the layer on which the scribe line is formed). The scribe line may also be accompanied by a vertical crack (a crack extending perpendicular to the main surface of the layer on which the scribe line is formed) extending from the front side to the interior or back side of the layer on which the scribe line is formed.

[0008] The substrate may have a third layer, which is a glass layer, formed on the side of the first layer opposite to the side on which the second layer is formed. In this case, scribe lines may be formed in the second and third layers. This allows scribe lines to be formed in both the second and third glass layers, making it easier to cut the substrate when breaking. The scribe lines in the third layer can be formed in the same manner as the scribe lines in the second layer.

[0009] A method for cutting a substrate according to another aspect of the present invention is a method for cutting a substrate having a first layer having cleavability and a second layer having no cleavability formed on the first layer, comprising the following steps: A step of forming scribe lines only on the second layer. A step of cutting the substrate along the scribe lines.

[0010] In the above-described substrate cutting method, a process of forming a scribe line only in the non-cleavable second layer is performed, and then the substrate is cut along the scribe line from the first layer side or the second layer side. In a substrate having a cleavable first layer and a non-cleavable second layer, if a scribe line is formed in the non-cleavable second layer, when the substrate is cut, the first layer is cut by cleavage in accordance with the cutting of the second layer. In this way, the above-described cutting method does not require forming a scribe line in the first layer, and therefore can cut the substrate with fewer processes than conventional methods and without the need for complex adjustments such as adjusting the focal position through the second layer.

[0011] The substrate may have a non-cleavable third layer formed on the side of the first layer opposite to the side on which the second layer is formed. In this case, scribe lines may be formed in the second and third layers. This allows scribe lines to be formed in both the non-cleavable second and third layers, making it easier to cut the substrate when breaking. After forming scribe lines in the second and third layers, the substrate can be cut by pressing the scribe lines from the second layer side or the third layer side.

[0012] In the cutting step, the substrate may be cut along the scribe line by pushing the scribe line, thereby making it possible to cut the substrate by simply pushing the scribe line.

[0013] In a substrate having a second layer and a third layer, the thickness of the second layer may be smaller than the thickness of the third layer. In this case, the substrate may be cut by pushing the substrate from the second layer side. This makes it easier to cut the substrate along the scribe line.

[0014] In the step of forming the scribe line, the scribe line may be formed by irradiating the second layer with laser light having a pulse width on the order of picoseconds (e.g., 0.1 picoseconds or more and 100 picoseconds or less, particularly 1 picoseconds or more and 50 picoseconds or less). This allows for selective formation of a scribe line (e.g., a scribe line made of a modified layer) in the second layer, which is a glass layer.

[0015] The laser light may have a wavelength in the infrared region (e.g., 750 nm or more and 4000 nm or less, particularly 750 nm or more and 2500 nm or less, specifically the fundamental wave of a YAG laser). This allows for appropriate formation of scribe lines (e.g., scribe lines made of the modified layer) in the second layer, which is a glass layer.

[0016] The first layer may be a silicon substrate, which allows the first layer to be cut using the cleavage properties of the silicon substrate, thereby allowing the substrate to be cut appropriately.

[0017] A manufacturing method according to yet another aspect of the present invention is a method for manufacturing a substrate piece from a substrate having a first layer made of a semiconductor single crystal and a second layer that is a glass layer formed on the first layer. The manufacturing method for the substrate piece includes the following steps. A step of forming scribe lines only on the second layer. A step of cutting the substrate along the scribe lines.

[0018] In the above-described method for manufacturing substrate pieces, the process of forming scribe lines on a substrate having a first layer made of semiconductor single crystal and a second layer made of glass is performed only on the second layer, which is a glass layer. Then, the substrate is cut along the scribe lines by pushing the scribe lines from either the first layer side or the second layer side, thereby cutting the substrate into substrate pieces. In a substrate having a first layer made of semiconductor single crystal and a second layer made of glass, if a scribe line is formed in the second layer, when the substrate is cut, the first layer is cut by cleavage in accordance with the cutting of the second layer. Thus, the above-described method for manufacturing substrate pieces does not require forming scribe lines on the first layer, and therefore substrate pieces can be manufactured with fewer processes than conventional methods and without the need for complex adjustments such as adjusting the focal position through the glass layer.

[0019] The substrate may have a third layer, which is a glass layer, formed on the side of the first layer opposite to the side on which the second layer is formed. In this case, scribe lines may be formed in the second and third layers. This makes it easier to cut the substrate when breaking, as scribe lines are formed in both the second and third glass layers.

[0020] A method for manufacturing a substrate piece according to yet another aspect of the present invention is a method for manufacturing a substrate piece from a substrate having a first layer made of a layer having cleavability and a second layer that is a layer having no cleavability formed on the first layer. The method for manufacturing a substrate piece comprises the following steps: A step of forming scribe lines only on the second layer. A step of cutting the substrate along the scribe lines.

[0021] In the above-described method for manufacturing substrate pieces, a process for forming scribe lines on a substrate having a first layer made of a cleavable layer and a second layer made of a non-cleavable layer is performed only on the second layer made of a non-cleavable layer. Then, the substrate is cut along the scribe lines by pushing the scribe lines from either the first layer side or the second layer side, thereby cutting the substrate into substrate pieces. In a substrate having a first layer made of a cleavable layer and a second layer made of a non-cleavable layer, if a scribe line is formed in the second layer, the first layer is cut by cleavage in accordance with the cutting of the second layer when the substrate is cut. Thus, the above-described method for manufacturing substrate pieces does not require forming scribe lines on the first layer, and therefore substrate pieces can be manufactured with fewer processes than conventional methods and without the need for complex adjustments such as adjusting the focal position through the second layer.

[0022] The substrate may have a third layer that does not have cleavability formed on the side of the first layer opposite to the side on which the second layer is formed. In this case, scribe lines may be formed in the second and third layers. This makes it easier to cut the substrate when breaking, as scribe lines are formed in both the second and third layers that do not have cleavability. [Effects of the Invention]

[0023] A substrate having a first layer made of a semiconductor single crystal and a second layer of glass formed on the surface of the first layer, or a substrate having a first layer having cleavability and a second layer having no cleavability formed on the surface of the first layer, can be cut with fewer processes and without the need for complex adjustments of equipment. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. [Figure 2] FIG. 1 is a schematic diagram of a scribe line forming device. [Figure 3] FIG. 2 is a diagram showing the configuration of a transmission optical system. [Figure 4] FIG. 2 is a schematic diagram showing the configuration of a breaking device. [Figure 5]10 is a flowchart showing a method for cutting a substrate. [Figure 6] 5A to 5C are diagrams illustrating a method for cutting a substrate. [Figure 7] Microscope image of a cross section of a small piece of substrate. DETAILED DESCRIPTION OF THE INVENTION

[0025] 1. First embodiment (1) Circuit board A method for manufacturing substrate pieces SS by cutting them out from a substrate S according to the present disclosure will be described below. The substrate S from which the substrate pieces SS are cut has a plurality of structures (e.g., MEMS devices) arranged vertically and horizontally in a plan view. The substrate piece SS has a rectangular shape containing a predetermined number of these structures.

[0026] Meanwhile, the cross section of the substrate S has a structure as shown in Fig. 1. Note that the substrate piece SS cut out from the substrate S also has a similar cross section structure. Fig. 1 is a diagram showing the cross section structure of the substrate. The substrate S is a laminated substrate having a first layer LA1, a second layer LA2, and a third layer LA3.

[0027] The first layer LA1 is a substrate having cleavage properties. Specifically, the first layer LA1 is a plate-shaped substrate made of a semiconductor single crystal. The first layer LA1 is, for example, a silicon (Si) substrate. The crystal orientation of the first layer LA1, which is a silicon substrate, is (111), and it has the property of easily breaking in a specific direction (cleavage properties). The second layer LA2 is a layer that does not have cleavage properties and is stacked by being fixed on the first surface SU1 of the first layer LA1. The second layer LA2 is, for example, a plate-shaped substrate made of glass. Generally, glass substrates do not have cleavage properties.

[0028] The third layer LA3 is a non-cleavable layer that is laminated by being fixed on the second surface SU2 of the first layer LA1, opposite the first surface SU1. The third layer LA3 is, for example, a glass plate-shaped substrate. The thickness of the second layer LA2 is smaller than the thickness of the third layer LA3.

[0029] As described above, the substrate S to be processed in this disclosure has a structure in which a cleavable, plate-like first layer LA1 is sandwiched between non-cleavable, plate-like second and third layers LA2 and LA3 (glass layers). When cutting out substrate pieces SS from this substrate S, a process of forming scribe lines SL along the boundary lines of the substrate piece SS is carried out only in the second and third layers LA2 and LA3, which are glass layers. In other words, the process of forming scribe lines SL is not carried out in the first layer LA1. The substrate S is then broken along the formed scribe lines SL, allowing the substrate pieces SS to be cut out from the substrate S.

[0030] The scribe lines SL are modified layers of a predetermined thickness formed along a plane (a plane perpendicular to the main surface of the layer on which the scribe lines SL are formed) extending from the front surface to the back surface of the layer on which the scribe lines SL are formed (second layer LA2, third layer LA3). The scribe lines SL may also include vertical cracks extending from the front surface to the interior or back surface of the layer on which the scribe lines SL are formed (i.e., cracks extending perpendicular to the main surface of the layer on which the scribe lines SL are formed).

[0031] (2) Scribe line forming device A scribe line forming apparatus 100 that forms scribe lines SL on the second layer LA2 and third layer LA3 of the substrate S will be described below with reference to Fig. 2. Fig. 2 is a schematic diagram of the scribe line forming apparatus. The scribe line forming apparatus 100 is an apparatus that forms scribe lines SL on the second layer LA2 and third layer LA3, which are glass layers, by irradiating the second layer LA2 and third layer LA3 with laser light. The scribe line forming apparatus 100 includes a laser system 1, a processing table 3, a table driving unit 5, and a control unit 7.

[0032] The laser system 1 outputs laser light (referred to as processing laser light L1) for forming a scribe line SL on the substrate S. Specifically, the laser system 1 includes a laser device 11, a transmission optical system 13, and a drive mechanism 15. The laser device 11 outputs laser light L2 to be incident on the transmission optical system 13. The laser device 11 includes a laser oscillator 11a and a laser control unit 11b. The laser oscillator 11a outputs pulsed laser light L2 having a wavelength in the infrared region at a predetermined irradiation period. The laser oscillator 11a is, for example, a YAG laser oscillator. The laser oscillator 11a outputs a fundamental wave of a YAG laser as the laser light L2. The wavelength output from the laser oscillator 11a is, for example, 750 nm or more and 4000 nm or less. More preferably, it is 750 nm or more and 2500 nm or less.

[0033] The above-mentioned irradiation period refers to the time from when one laser light pulse is output until when the next laser light pulse is output.

[0034] The pulse width of the laser light L2 from the laser oscillator 11a is set to the order of picoseconds. Specifically, the pulse width of the laser light L2 (processing laser light L1) is set to 100 femtoseconds or more and 100 picoseconds or less. More preferably, it is set to 1 picoseconds or more and 50 picoseconds or less. The processing laser light L1 having such a pulse width on the order of picoseconds has a wavelength range that transmits through glass and has high peak energy, making it possible to form a processing mark (i.e., a scribe line SL) that is a modified layer throughout the entire thickness direction of the glass layer. On the other hand, silicon absorbs the processing laser light L1 having a pulse width on the order of picoseconds at the incident surface, so no processing mark is formed inside the silicon. Therefore, by using the processing laser light L1 having a pulse width on the order of picoseconds in the process of forming the scribe line SL, processing marks that become the scribe line SL are easily formed in the glass layer, but processing marks (scribe lines SL) are less likely to be formed in the first layer LA1. That is, by using the processing laser light L1 having a pulse width on the order of picoseconds, the scribe lines SL can be formed only in the glass layer.

[0035] The laser control unit 11b controls the laser oscillator 11a in accordance with the conditions for generating the laser light L2 (such as the irradiation period and the intensity of the laser light L2).

[0036] Transmission optical system 13 receives laser light L2 output from laser device 11 and outputs laser light L2 with an adjusted beam diameter on substrate S. Specifically, as shown in Fig. 3, transmission optical system 13 has an axicon lens 131 and a reduction optical system 133. Fig. 3 is a diagram showing the configuration of the transmission optical system.

[0037] The axicon lens 131 receives the laser beam L2 and converts it into a ring beam L3 having a constant ring width w in the propagation direction of the laser beam. The reduction optical system 133 receives the ring beam L3 and reduces the ring beam L3 to form a processing laser beam L1 whose beam diameter on the substrate S is adjusted. The reduction optical system 133 is composed of, for example, multiple lenses.

[0038] The transmission optical system 13 having the above configuration can convert the laser light L2 output from the laser device 11 into processing laser light L1 that is optimal for forming the scribe line SL.

[0039] In addition to axicon lens 131 and reduction optical system 133, transmission optical system 13 may include other optical members such as a λ / 4 wave plate, a beam expander, a prism, and the like.

[0040] The driving mechanism 15 changes the position of the lenses (axicon lens 131, reduction optical system 133) provided in the transmission optical system 13 in the optical axis direction (propagation direction of the laser light L2) in order to adjust the beam diameter of the processing laser light L1 on the substrate S.

[0041] The processing table 3 is a table on which the substrate S is placed. The table driving unit 5 (an example of a driving unit) moves the processing table 3 relative to the laser system 1 (transmission optical system 13). The table driving unit 5 is a known mechanism having, for example, guide rails, a motor, etc.

[0042] The control unit 7 is a computer system having a processor (e.g., a CPU), a storage device (e.g., a ROM, RAM, HDD, SSD, etc.), and various interfaces (e.g., an A / D converter, a D / A converter, a communication interface, etc.). The control unit 7 performs various control operations in the scribe line forming apparatus 100 by executing programs stored in the storage device (corresponding to part or all of the storage area of ​​the storage device). The control unit 7 may be composed of a single processor, or may be composed of multiple processors independent for each control.

[0043] The control unit 7 outputs, for example, setting values ​​of the output conditions of the laser light L2 to the laser control unit 11b. The control unit 7 also controls the drive mechanism 15 to adjust the beam diameter of the processing laser light L1 on the substrate S.

[0044] Furthermore, the control unit 7 controls the table driving unit 5 to move the processing table 3 in the horizontal direction, thereby moving the substrate S relative to the processing laser beam L1. That is, the control unit 7 moves the substrate S relative to the processing laser beam L1, causing the processing laser beam L1 to scan the substrate S. The control unit 7 also controls the scanning speed of the processing laser beam L1 on the substrate S by adjusting the horizontal movement speed of the processing table 3.

[0045] Although not shown, the control unit 7 is connected to sensors that detect the size, shape, and position of the substrate S, sensors and switches that detect the state of each part of the scribe line forming device 100, and an information input device.

[0046] (3) Break device Next, a breaking device 200 for breaking the substrate S along the scribe line SL will be described with reference to Figure 4. Figure 4 is a schematic diagram showing the configuration of the breaking device. The breaking device 200 is a device that cuts the substrate S by three-point bending break. That is, the breaking device 200 is a device that cuts the substrate S along the scribe line SL by pressing the portion of the substrate S where the scribe line SL is formed. It has a break plate 21 and a pair of receiving blades 23.

[0047] The break plate 21 is a member for pressing the portion of the substrate S where the scribe line SL is to be formed toward the pair of receiving blades 23 to cut the substrate S along the scribe line SL. The break plate 21 is a member made of, for example, zirconia. The pair of receiving blades 23 are arranged with a predetermined gap (for example, about several mm) between them and are members for holding the substrate S. In the breaking device 200, the substrate S is aligned so that the scribe line SL is located in the gap between the pair of receiving blades 23.

[0048] When the substrate S is broken using the breaking device 200, the surface of the substrate S facing the break plate 21 is protected by the wafer tape WT. On the other hand, the surface of the substrate S facing the pair of receiving blades 23 is protected by the protective film F disposed between the wafer ring WR and the pair of receiving blades 23.

[0049] (4) How to cut the board 5 and 6, a method for cutting the substrate S along the planned processing line to cut out substrate pieces SS will be described. FIG. 5 is a flowchart showing the substrate cutting method. FIG. 6 is a diagram schematically showing the substrate cutting method. First, the substrate S to be processed is placed on the processing table 3 so that the second layer LA2, which is a non-cleavable glass layer, is the irradiation surface of the processing laser light L1.

[0050] Thereafter, in step S1, laser device 11 generates laser light L2 at a predetermined irradiation cycle, and transmission optical system 13 emits processing laser light L1 having a predetermined beam diameter toward the surface of second layer LA2 of substrate S. While emitting processing laser light L1, table drive unit 5 is driven to move processing table 3 in the horizontal direction, thereby scanning processing laser light L1 along a planned processing line for cutting out substrate pieces SS on substrate S. Specifically, processing laser light L1 is scanned in two directions corresponding to the vertical and horizontal sides of substrate piece SS.

[0051] As described above, the processing laser beam L1 is a laser beam in the infrared region having a pulse width on the order of picoseconds. Therefore, as shown in Fig. 6(1), the processing laser beam L1 can form a scribe line SL on the second layer LA2, which is a non-cleavable glass layer, but hardly forms a scribe line SL on the first layer LA1, which is a cleavable silicon substrate.

[0052] After forming the scribe line SL in the second layer LA2, the substrate S is turned over to make the third layer LA3 the irradiation surface of the processing laser beam L1, and the processing laser beam L1 is irradiated onto the surface of the third layer LA3, as shown in (2) of Fig. 6. This forms the scribe line SL in the third layer LA3, which is a layer of glass that does not have cleavage properties.

[0053] The order of forming the scribe lines SL is not limited to the above, and the processing laser light L1 may be irradiated onto the third layer LA3 first to form the scribe lines SL, and then the processing laser light L1 may be irradiated onto the second layer LA2 to form the scribe lines SL.

[0054] After forming scribe lines SL on the second layer LA2 and the third layer LA3, in step S2, the breaking device 200 is used to cut the substrate S along the scribe lines SL, thereby cutting out substrate pieces SS from the substrate S. Specifically, the breaking plate 21 presses the scribe lines SL of the substrate S toward the pair of receiving blades 23, thereby cutting the substrate S along the scribe lines SL.

[0055] When breaking the substrate S using the breaking device 200, it is preferable to press the substrate S from the side of the second layer LA2, which is a thinner glass layer, as shown in (3) and (4) of Figure 6. It is also possible to break the substrate S by pressing the substrate S from the side of the third layer LA3, which is a thicker glass layer, but the inventors have discovered that, in general, the substrate S tends to be more easily cut by breaking the substrate S from the side of the second layer LA2, which has a smaller thickness, rather than from the side of the third layer LA3, which is thicker.

[0056] (5) Example An example of cutting substrate pieces SS from a substrate S using the above-described method of cutting a substrate S will be described below. In this example, a laminated substrate in which a glass layer (second layer LA2), a silicon substrate (first layer LA1), and a glass layer (third layer LA3) are sequentially laminated is used as the substrate S to be processed. The thicknesses of the glass layer (second layer LA2), the silicon substrate (first layer LA1), and the glass layer (third layer LA3) are 300 μm, 150 μm, and 500 μm, respectively.

[0057] The processing laser light L1 used was infrared light with a wavelength of 1060 nm and a pulse width of 15 picoseconds or less. The energy per pulse of the processing laser light L1 was 340 μJ. This processing laser light L1 was output 22,500 times per second and was output along the scribe line SL at a scanning speed of 100 mm per second. The processing laser light L1 was scanned along the scribe line SL only once.

[0058] To cut out rectangular substrate pieces SS from the substrate S, the second layer LA2 and the third layer LA3 were irradiated with processing laser light L1 along the vertical and horizontal sides of the substrate piece SS. Thereafter, the substrate S was cut along the vertical and horizontal scribe lines SL using a breaking device 200 to cut out the substrate pieces SS. The substrate S was broken from the second layer LA2 side, which was thinner.

[0059] Note that, for example, if the second layer LA2 and / or the third layer LA3, which are non-cleavable glass layers, are thick and the scribe line SL formed by scanning the processing laser light L1 only once makes it difficult for the breaking device 200 to cut the substrate S, the scribe line SL may be formed by scanning the processing laser light L1 multiple times. This makes it possible to form a scribe line SL that is further extended in the thickness direction of the second layer LA2 and / or the third layer LA3, making it easier to cut the substrate S with the breaking device 200.

[0060] Figure 7 shows a microscope image of a cut surface of the substrate piece SS after it has been cut out from the substrate S. Figure 7 (1) shows a cut surface along one of the vertical or horizontal sides of the substrate piece SS, and Figure 7 (2) shows a cut surface of the substrate piece SS along the other side of the substrate piece SS. Figure 7 is a microscope image of the cut surface of the substrate piece.

[0061] As shown in Figure 7, the substrate S was successfully cut in both the vertical and horizontal directions of the substrate piece SS. However, the state of the cut surface of the first layer LA1 differed between the vertical and horizontal directions. Specifically, no uncut portions were observed on one cut surface, while some uncut portions were observed on the other cut surface. This is thought to be due to the cleavage properties of the first layer LA1, which is made of a semiconductor single crystal, which resulted in differences in the susceptibility of the first layer LA1 to cracking along the vertical and horizontal directions, as well as the relative positions of the cracking positions and the scribe lines SL.

[0062] As described above, in the method for cutting the substrate S according to the present disclosure, the substrate S can be cut simply by irradiating the processing laser light L1 only onto the second layer LA2 and the third layer LA3, which are glass layers, and breaking the substrate S along the scribe lines SL thus formed. In other words, in the method for cutting the substrate S according to the present disclosure, the substrate S can be cut with fewer processes and without the need for complex adjustments of the device.

[0063] 2. Other Embodiments Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible within the scope of the gist of the invention. In particular, the multiple examples and modifications described in this specification can be arbitrarily combined as necessary. (A) The first layer LA1 may be a substrate made of a semiconductor single crystal other than a silicon substrate, or may be a substrate having cleavage properties other than a silicon substrate.

[0064] (B) The substrate S may have only the second layer LA2 as a glass layer or a layer without cleavage. That is, a glass layer or a layer without cleavage may be formed on only one side of the first layer LA1. In this case, the scribe line SL may be formed (irradiated with the processing laser light L1) only on the second layer LA2. In this case, cutting of the substrate S by breaking is preferably performed from the side of the first layer LA1 that does not have cleavage. When cutting the substrate S along the scribe line SL by pushing the scribe line SL, cutting of the substrate S can be performed from the side of the second layer LA2 by pushing the scribe line SL from the side of the first layer LA1.

[0065] (C) The scribe lines SL may be formed in the second layer LA2 and / or the third layer LA3, which are glass layers or non-cleavable layers, by a method other than irradiation with a laser beam having a pulse width on the order of picoseconds. For example, the scribe lines SL may be formed by a method using a scribe wheel.

[0066] (D) The breaking of the substrate S is not limited to three-point bending breaking. For example, other breaking methods such as table breaking (a breaking method in which a substrate S placed on a table is cut by pressing a break plate along a scribe line SL formed on the substrate S) can be used. [Industrial Applicability]

[0067] The present invention is widely applicable to cutting a substrate having a first layer made of a semiconductor single crystal and a glass layer formed on the surface of the first layer, and also to cutting a substrate having a first layer with cleavability and a layer without cleavability formed on the surface of the first layer. [Explanation of symbols]

[0068] 100 Scribe line forming device 1. Laser system 11 Laser device 11a Laser oscillator 11b Laser control unit 13 Transmission optics 131 Axicon Lens 133 Reduction optical system 15 Drive mechanism L1 Processing laser light L2 laser light L3 Ring Beam 3 Processing table 5 Table drive unit 7 Control Unit 200 Break Device 21 Break Plate 23 Receiving blade F. Protective film WR wafer ring WT wafer tape S board SS board small piece SU1 1st surface SU2 Second Surface LA1 1st layer LA2 2nd layer LA3 3rd layer SL Scribe Line

Claims

1. A method for cutting a substrate having a first layer made of a semiconductor single crystal, a second layer which is a glass layer formed on the first layer, and a third layer which is a glass layer formed on the side of the first layer opposite to the side on which the second layer is formed, comprising: forming scribe lines only on the second layer and the third layer; cutting the substrate along the scribe lines; Equipped with the thickness of the second layer is smaller than the thickness of the third layer; A cutting method, wherein the substrate is cut by pushing the substrate from the second layer side.

2. A method for cutting a substrate having a first layer having cleavability, a second layer having no cleavability formed on the first layer, and a third layer having no cleavability formed on a side of the first layer opposite to a side on which the second layer is formed, comprising: forming scribe lines only on the second layer and the third layer; cutting the substrate along the scribe lines; Equipped with the thickness of the second layer is smaller than the thickness of the third layer; A cutting method, wherein the substrate is cut by pushing the substrate from the second layer side.

3. The cutting method according to claim 1 or 2, wherein in the cutting step, the substrate is cut along the scribe line by pushing the scribe line.

4. 4. The cutting method according to claim 1, wherein in the step of forming the scribe line, the scribe line is formed by irradiating a layer in which the scribe line is to be formed with laser light having a pulse width on the order of picoseconds.

5. The cutting method according to claim 4 , wherein the laser light has a wavelength in the infrared region.

6. The cutting method according to any one of claims 1 to 5, wherein the first layer is a silicon substrate.

7. A method for producing a substrate piece from a substrate having a first layer made of a semiconductor single crystal, a second layer which is a glass layer formed on the first layer, and a third layer which is a glass layer formed on the side of the first layer opposite to the side on which the second layer is formed, comprising: forming scribe lines only on the second layer and the third layer; cutting the substrate along the scribe lines; Equipped with the thickness of the second layer is smaller than the thickness of the third layer; A method for manufacturing substrate pieces, wherein cutting of the substrate is carried out by pushing the substrate from the second layer side.

8. A method for producing a substrate piece from a substrate having a first layer made of a layer having cleavability, a second layer being a layer having no cleavability formed on the first layer, and a third layer having no cleavability formed on the side of the first layer opposite to the side on which the second layer is formed, comprising: forming scribe lines only on the second layer and the third layer; cutting the substrate along the scribe lines; Equipped with the thickness of the second layer is smaller than the thickness of the third layer; A method for manufacturing substrate pieces, wherein cutting of the substrate is carried out by pushing the substrate from the second layer side.

Images