Apparatus and method for manufacturing semiconductor crystal wafer

Abstract

The purpose of the present invention is to provide an apparatus and a method for manufacturing a semiconductor crystal wafer capable of easily and reliably manufacturing a high-quality semiconductor crystal wafer. A method for manufacturing a SiC wafer, which is an example of a semiconductor crystal wafer, includes a trench processing step (STEP100 / fig. 1), a guide line forming step (STEP110 / fig. 1), a cutting step (STEP120 / fig. 1), and a grinding step (STEP130 / fig. 1).

Description

Technical Field

[0001] The present invention relates to an apparatus and a method for manufacturing semiconductor crystal wafers by slicing a semiconductor crystal ingot (ingot) that has been ground into a cylindrical shape. Background Technology

[0002] In the past, known methods for manufacturing semiconductor wafers include, for example, the method for manufacturing SiC wafers (an example of semiconductor wafers) disclosed in Patent Document 1 below. This SiC wafer manufacturing method includes a wafer shape forming step, a subsequent processing modification layer removal step, and a final mirror polishing step. The wafer shape forming step includes: an ingot forming step of processing a single-crystal SiC block grown from crystals into a cylindrical ingot; a crystal orientation forming step of forming a notch on a portion of the outer periphery as a mark indicating the crystal orientation of the ingot; a slicing step of slicing the single-crystal SiC ingot to process it into a thin, round SiC wafer; and a method using a non-Mohs hardness (not yet modified Mohs hardness)... The planarization step involves planarizing the SiC wafer with abrasive grains (hardness); the marking step involves forming a marking; and the chamfering step involves chamfering the outer periphery; the processing modification layer removal step includes a processing modification layer removal step that incorporates the processing modification layer removal process introduced into the SiC wafer in the previous steps; the mirror polishing step includes a chemical mechanical polishing (CMP) step that involves polishing using the mechanical action of a polishing pad and the chemical action of a polishing slurry.

[0003] [Existing technical documents] [Patent Literature] [Patent Document 1] Japanese Patent Publication No.: JP2020-15646. Summary of the Invention

[0004] [The problem that the invention aims to solve] However, the well-known SiC wafer manufacturing method has the problems of many and complex manufacturing steps, complex device configuration and high manufacturing cost.

[0005] On the other hand, simplifying the manufacturing process makes it difficult to consistently achieve the required quality for SiC wafers.

[0006] Therefore, the object of the present invention is to provide an apparatus and method for manufacturing semiconductor crystal wafers that can easily and reliably produce high-quality semiconductor crystal wafers.

[0007] [Methods for solving the problem] The semiconductor wafer manufacturing apparatus of the first invention is an apparatus for slicing wafers from a semiconductor crystal ingot that has been ground into a cylindrical shape. This semiconductor wafer manufacturing apparatus includes: A guide line forming unit focuses laser light of a wavelength transmissible to the semiconductor crystal ingot to form a focusing point, and scans this focusing point along a predetermined cutting surface to form a cutting guide line; and A cutting unit cuts off the predetermined cutting surface of the semiconductor crystal ingot; The guide line forming unit forms the cutting guide line by using a scan line that is consistent with the cutting direction of the cutting unit within the predetermined cutting surface as a scan line corresponding to the cutting direction of the cutting unit.

[0008] According to the semiconductor crystal wafer manufacturing apparatus of the first invention, when the cutting unit performs cutting, the cutting guide line formed on the cutting predetermined surface becomes the cutting guide, so the semiconductor crystal ingot can be cut into slices with good precision using the cutting unit.

[0009] In other words, when the cutting unit performs the cutting, the cutting guide line becomes the guide for cutting because it is in the area with low cutting resistance.

[0010] Here, the cutting guide line is formed in a predetermined cutting surface corresponding to the cutting direction of the cutting unit as a scan line corresponding to the cutting direction of the cutting unit (for example, corresponding to the cutting direction means not only being consistent with or orthogonal to the cutting direction, but also the density of the scan line formed according to the cutting direction). Accordingly, the area with low cutting resistance when cutting with the cutting unit is formed to correspond to the cutting direction.

[0011] Furthermore, according to the semiconductor wafer manufacturing apparatus of the first invention and the semiconductor wafer manufacturing method of the fifth invention, the cutting guide line is formed by scanning lines that are consistent with the cutting direction of the cutting unit. Accordingly, when the cutting unit is actually cutting, the cutting guide line in the region with low cutting resistance is continuously formed along the cutting direction and becomes the guide for cutting.

[0012] As described above, the semiconductor crystal wafer manufacturing apparatus according to the first invention can precisely cut semiconductor crystal ingots into slices, and can easily and reliably manufacture high-quality semiconductor crystal wafers.

[0013] The semiconductor wafer manufacturing apparatus of the second invention is in the first invention. The cutting unit is a wire discharge processing device that rotates and advances the wire while cutting the predetermined surface and discharges electricity from the wire.

[0014] According to the semiconductor crystal wafer manufacturing apparatus of the second invention, it is preferable that the cutting unit is a wire discharge machining apparatus, which can cut the semiconductor crystal ingot into slices with good precision.

[0015] As described above, the semiconductor crystal wafer manufacturing apparatus according to the second invention can practically and accurately cut semiconductor crystal ingots into slices, and can easily and reliably manufacture high-quality semiconductor crystal wafers.

[0016] The semiconductor wafer manufacturing apparatus of the third invention is described in the first invention. The cutting unit is a cutting device that makes the cutting blade travel on the predetermined cutting surface.

[0017] In the semiconductor crystal wafer manufacturing apparatus of the third invention, it is preferable that the cutting unit is a cutting device, which can cut the semiconductor crystal ingot into slices with good precision.

[0018] As described above, the semiconductor crystal wafer manufacturing apparatus according to the third invention can practically and accurately cut semiconductor crystal ingots into slices, and can easily and reliably manufacture high-quality semiconductor crystal wafers.

[0019] The fourth invention is a semiconductor wafer manufacturing apparatus that cuts wafers from a semiconductor crystal ingot that has been ground into a cylindrical shape into slices. This semiconductor wafer manufacturing apparatus includes: The grooved grinding stone is a drum-shaped grinding stone used to form multiple grooves around the entire side of the semiconductor crystal ingot, and has multiple protrusions on the side corresponding to the multiple grooves. A wire saw device that causes multiple wires arranged in the plurality of grooves to advance while rotating, thereby cutting the semiconductor crystal ingot into slices; and The guide line forming unit focuses a laser beam of a wavelength that is transmissible to the semiconductor crystal ingot on each predetermined cutting surface containing grooves formed on the side of the semiconductor crystal ingot to form a focusing point and scans the focusing point along the predetermined cutting surface to form a cutting guide line. The guide wire forming unit forms the cutting guide wire using a scanning direction consistent with the traveling direction of the wire in the wire saw device, as the scanning direction corresponding to the traveling direction of the wire.

[0020] The semiconductor crystal wafer manufacturing apparatus according to the fourth invention comprises a grooved grinding stone with a plurality of protrusions corresponding to the plurality of grooves formed on the side of the semiconductor crystal ingot, and corresponding auxiliary materials.

[0021] The first auxiliary equipment is a wire saw, which causes multiple wires arranged in multiple grooves formed on the entire side of a semiconductor crystal ingot to rotate.

[0022] The second auxiliary component is a guide line forming unit, which focuses a laser beam of a transmissive wavelength on each predetermined cutting surface containing each groove to form a focal point and scans the focal point along the predetermined cutting surface to form a cutting guide line.

[0023] In the above configuration, multiple grooves are correctly arranged in multiple grooves formed on the entire side of the semiconductor crystal ingot by the grooved grinding stone, and the cutting guide line formed on each predetermined cutting surface during the cutting is made to guide the cutting. Therefore, the semiconductor crystal ingot can be cut into slices with good precision using multiple lines.

[0024] In other words, as the wire positioned in the groove moves forward while rotating during the cutting process, the groove and the cutting guide wire in the part before cutting form an area with low cutting resistance, thus becoming a guide for cutting.

[0025] Furthermore, by aligning the cutting guide line with the direction of the line's travel, a region with low cutting resistance can be continuously provided to the line during its travel.

[0026] Furthermore, according to the semiconductor wafer manufacturing apparatus of the fourth invention, the cutting guide line is formed in the same direction as the line's travel direction, thereby practically providing a region with low cutting resistance to the line continuously during its travel.

[0027] As described above, the semiconductor crystal wafer manufacturing apparatus according to the fourth invention can precisely cut semiconductor crystal ingots into slices, and can easily and reliably manufacture high-quality semiconductor crystal wafers.

[0028] The semiconductor wafer manufacturing apparatus of the fifth invention is in any of the first to fourth inventions. The guide line forming unit causes the laser beam to enter from the end face of the semiconductor crystal ingot.

[0029] According to the semiconductor crystal wafer manufacturing apparatus of the fifth invention, a laser beam for forming a cutting guide line is injected from the end face of the semiconductor crystal ingot, and the laser beam is scanned along the direction of line travel while the distance between the laser beam and the focal point is determined and maintained, thereby forming the cutting guide line easily and reliably.

[0030] As described above, the semiconductor crystal wafer manufacturing apparatus according to the fifth invention can easily and reliably form dicing guide lines and accurately dice semiconductor crystal ingots into slices, thereby easily and reliably manufacturing high-quality semiconductor crystal wafers.

[0031] The sixth invention discloses a method for manufacturing semiconductor crystal wafers, which involves slicing a semiconductor crystal ingot, ground into a cylindrical shape, into a wafer. This method includes: The guide line forming step involves focusing a laser beam of a wavelength transmissible to the semiconductor crystal ingot to form a focusing point, and then scanning this focusing point along a predetermined cutting surface to form a cutting guide line; and The cutting step involves cutting the predetermined cutting surface of the semiconductor crystal ingot; The guide line forming step uses a scan line within the predetermined cutting surface that is aligned with the cutting direction of the cutting step as the scan line corresponding to the cutting direction of the cutting step to form the cutting guide line.

[0032] According to the semiconductor crystal wafer manufacturing method of the sixth invention, the cutting guide line formed on the predetermined cutting surface during the cutting step will become the cutting guide, so the semiconductor crystal ingot can be cut into slices with good precision by the cutting step.

[0033] In other words, during the cutting process, the cutting guide line serves as a guide for cutting in areas with low resistance.

[0034] Here, the cutting guide line is formed in the predetermined cutting surface corresponding to the cutting direction of the cutting step as a scan line corresponding to the cutting direction of the cutting step (for example, corresponding to the cutting direction means not only being consistent with or perpendicular to the cutting direction, but also the density of the scan line formed according to the cutting direction). Based on this, the area with low cutting resistance during the cutting step can be formed corresponding to the cutting direction.

[0035] Furthermore, according to the semiconductor crystal wafer manufacturing method of the sixth invention, the cutting guide line is formed by scanning lines that are consistent with the cutting direction of the cutting step. Accordingly, when the cutting is actually performed by the cutting step, the cutting guide line in the region with low cutting resistance is continuously formed along the cutting direction and becomes the guide for cutting.

[0036] As described above, the semiconductor crystal wafer manufacturing method according to the sixth invention can precisely cut semiconductor crystal ingots into slices, and can easily and reliably manufacture high-quality semiconductor crystal wafers.

[0037] The seventh invention discloses a method for manufacturing semiconductor crystal wafers, which involves slicing a semiconductor crystal ingot, ground into a cylindrical shape, into a wafer. This method includes: The trenching process forms multiple grooves around the entire side of the semiconductor crystal ingot; In the guide line forming step, a laser beam of a wavelength transmissible to the semiconductor crystal ingot is focused onto each predetermined cutting surface containing grooves formed on the side of the semiconductor crystal ingot via the trenching step to form a focusing point, and the focusing point is scanned along the predetermined cutting surface to form a cutting guide line; and The cutting step involves moving multiple lines arranged in the multiple grooves formed in the trenching step while rotating to cut the semiconductor crystal ingot into slices. The guide line forming step uses a scanning direction consistent with the travel direction of the line in the cutting step as the scanning direction corresponding to the travel direction of the line to form the cutting guide line.

[0038] According to the semiconductor crystal wafer manufacturing method of the seventh invention, the following steps are performed: a trenching step, a guide line forming step, and a cutting step; the trenching step forms grooves corresponding to a plurality of protrusions of a trenching drum on the entire side of the semiconductor crystal ingot; the guide line forming step forms cutting guide lines on each predetermined cutting surface containing the grooves formed in the trenching step; the cutting step causes the plurality of lines disposed in the plurality of grooves formed in the trenching step to advance while rotating to cut the semiconductor crystal ingot into slices.

[0039] Here, in addition to correctly arranging multiple lines in multiple grooves formed on the entire side of the semiconductor crystal ingot by using a grooved grinding stone, the cutting guide lines formed on each predetermined cutting surface will become the cutting guide in the cutting process performed by the lines. Therefore, the semiconductor crystal ingot can be cut into slices with good precision using multiple lines.

[0040] In other words, as the wire positioned in the groove moves forward while rotating during the cutting process, the groove and the area with low cutting resistance formed by the cutting guide wire both become guides for the cutting.

[0041] Furthermore, since the cutting guide line is formed in accordance with the direction of the line's travel, it can continuously provide the line with a region of low cutting resistance during the line's travel.

[0042] As described above, the semiconductor crystal wafer manufacturing method of the seventh invention can precisely cut semiconductor crystal ingots into slices, and can easily and reliably manufacture high-quality semiconductor crystal wafers. Attached Figure Description

[0043] [ Figure 1 The flowchart shows the various steps of the manufacturing method of SiC wafer (semiconductor crystal wafer) according to this embodiment.

[0044] [ Figure 2 ]show Figure 1 A diagram illustrating the trenching process in the manufacturing method of SiC wafers.

[0045] [ Figure 3 ]show Figure 1 A diagram illustrating the lead wire formation and cutting steps in the manufacturing process of SiC wafers.

[0046] [ Figure 4 ]show Figure 1 A diagram illustrating the grinding steps in the manufacturing process of SiC wafers.

[0047] [ Figure 5 ]show Figure 1 An illustrative diagram illustrating variations in the guide wire formation step during the manufacturing process of SiC wafers.

[0048] [ Figure 6 ]show Figure 1 An illustrative diagram illustrating variations in the guide wire formation step during the manufacturing process of SiC wafers. Detailed Implementation

[0049] like Figure 1 As shown, in this embodiment, a method for manufacturing a SiC wafer, an example of a semiconductor crystal wafer, involves obtaining a SiC wafer sliced ​​into a slice shape from a SiC ingot that has been ground into a cylindrical shape. This method includes: a trenching step (STEP 100 / Figure 1 ), Guide line formation steps (STEP110 / Figure 1 Cutting steps (STEP120 / ) Figure 1 ) and grinding process steps (STEP130 / Figure 1 ).

[0050] Reference Figures 2 to 5 This section will explain the details of each step and the SiC wafer manufacturing apparatus of this embodiment.

[0051] First, the trenching process (STEP100 / Figure 1 A groove is used to process a drum-shaped grinding stone 20, forming multiple grooves 11 around the entire side of the SiC ingot 10 in one go.

[0052] The grooved grinding drum 20 is a drum-shaped grinding stone used to form multiple grooves 11 around the entire side of the SiC ingot 10, and its side has multiple protrusions 21 corresponding to the multiple grooves 11.

[0053] Specifically, the trenching steps (STEP100 / Figure 1 The grooves 11 are formed by pressing a drum-shaped grinding stone 20, which has multiple protrusions 21 corresponding to multiple grooves 11, onto the SiC ingot 10 while rolling around parallel rotation axes.

[0054] At this point, the SiC ingot 10 is supported in a state where its two ends are protected by a pair of protective plates 15, 15, allowing it to rotate freely.

[0055] The protective plate 15 is made of a synthetic resin such as polyvinyl chloride, and is optionally bonded to the SiC ingot 10 by an adhesive or the like.

[0056] The pair of protective plates 15, 15 can protect the two ends of the SiC ingot 10, preventing the ends from chipping or cracking. Therefore, multiple grooves 11 can be formed very close to the two end faces, thereby allowing for the cutting of more SiC wafers 100, which will be described later.

[0057] Additionally, when clamping and fixing the SiC ingot 10 to the rotating shaft, the protective plates 15, 15 can optionally be machined (e.g., drilled) for fixation. In this case, since no machining is performed on the SiC ingot 10 body, the SiC ingot 10 will not be damaged.

[0058] Next, as Figure 3 As shown in part (a), a guide wire forming step (STEP 110 / ) is performed before cutting using wire 40. Figure 1 This is used to form a cutting guide line on the predetermined cutting surface.

[0059] Cutting off a predetermined surface includes the trenching process (STEP100 / Figure 1 The surfaces of each groove 11 formed (shown as circular surfaces with diameters after the groove depth is reduced from the outer radial direction of the ingot, as indicated by imaginary lines in the figure) are used to form focal points by focusing laser light of a wavelength that is transmissible to the SiC ingot 10 and positioning the focal points on the predetermined cutting surface, thereby locally forming modified regions of SiC crystals on the SiC ingot 10. Furthermore, the desired cutting guide lines are formed by scanning lines that scan the focal points on the predetermined cutting surface.

[0060] A laser oscillator that generates the aforementioned laser light and a lens that focuses the laser light into the interior of the SiC ingot 10 can be used as the guide wire unit for forming the cutting guide wire.

[0061] Specifically, scan lines such as Figure 3 As shown in the cross-sectional view of the cut-off plane in part (b), multiple cut guide lines are formed by scanning multiple times along the direction of travel of line 40 indicated by the arrow in the figure. The spacing between these cut guide lines can be equal or can be sparse and dense, with the spacing narrowing towards the center and widening towards the left and right sides.

[0062] By setting the density of the cutting lines in this way, the cutting speed in the central part, where the cutting volume is larger, is slower (conversely, the cutting speed on both sides is faster), thus causing the line 40 to become arc-shaped. By periodically setting areas of low cutting resistance from both sides to the central part, it is possible to achieve... Figure 3 As shown in section (c), this prevents line 40 from becoming arc-shaped, keeping the line straight.

[0063] In the cutting step (STEP120 / ) where the wire 40 is cut. Figure 1 The wire cutting device used in the process (various devices can be used) causes multiple wires 40 suspended between wire bobbins to rotate and advance while applying high voltage (high frequency and high voltage) to the wires to discharge the SiC ingot 10, thereby cutting the SiC ingot 10 into slices.

[0064] As the wire 40, positioned in the groove 11, moves forward while rotating and discharging during cutting, in addition to the groove 11 (where the outer diameter of the SiC ingot 10 becomes smaller), the cutting guide wire also makes the cutting surface a region with low cutting resistance, allowing the wire 40 to cut as if it were sliding across the cutting surface.

[0065] Therefore, the SiC ingot 10 can be precisely cut into slices in one operation using multiple lines 40 arranged in multiple grooves 11. That is, high-speed cutting processing can be achieved by the lines 40, and the surface flatness of the cut surface can be achieved with low damage. In addition, for SiC ingots 10 with poor crystallinity in the whole or specific areas, the thickness can be specified to form slices, regardless of the crystal orientation.

[0066] In addition, because the cutting resistance is small, the wire diameter of wire 40 can be reduced, thereby minimizing the amount of material removed and increasing the yield.

[0067] Next, as Figure 4 As shown, in the grinding process step (STEP130 / Figure 1In the first surface processing step (STEP130(1)), one side 110 of the cut surface on both sides is used as the support surface, and mechanical polishing (high precision grinding) is performed on the other side 120.

[0068] Specifically, the first surface processing step (STEP130(1)) is performed by grinding using a mechanical polishing device 50 (ultra-high precision grinding device) that performs mechanical polishing.

[0069] The mechanical polishing device 50 includes a spindle 51 and a diamond polishing stone 53 on a platen 52.

[0070] First, one side 110 is facing upwards and is held by the vacuum porous suction cup 54 of the spindle 51, which acts as an adsorption plate, while the other side 120 is facing downwards and is ground by the diamond grinding stone 53.

[0071] At this time, the spindle 51 and the diamond grinding stone 53 rotate under the drive of a drive device (not shown), and the spindle 51 is pressed against the diamond grinding stone 53 by an air compressor (not shown) to perform grinding on the other side 120.

[0072] After grinding, the diamond grinding stone 53 can be dressed using a dresser or similar tool.

[0073] In addition, the mechanical polishing unit 50 may optionally have a functional water supply piping to enable the use of various functional waters during processing.

[0074] Next, in the second surface machining step (STEP130(2)), the other surface 120, which has undergone high-precision grinding in the first surface machining step, is turned upwards, and the same high-precision grinding process as in the first surface machining step is performed on the surface 110.

[0075] That is, the other side 120 is facing upwards and is held by the vacuum porous suction cup 54 of the main shaft 51, which acts as an adsorption plate, while the other side 110 is facing downwards and is ground by the diamond grinding stone 53.

[0076] The same applies here; you can choose to press the dressing tool or similar device onto the diamond polishing stone 53 to perform the dressing.

[0077] According to the mechanical polishing (high-precision grinding) process of the first surface processing step (STEP130(1)) and the second surface processing step (STEP130(2)) mentioned above, one side of the cut surface with high flatness and no transfer effect obtained by the cutting and grinding steps is used as the support surface (the surface held by the suction cup), and then the other side is mechanically polished (high-precision grinding) is performed in sequence. This can prevent so-called transfer and obtain high-quality SiC wafers, and can greatly simplify the complex manufacturing steps of traditional free abrasive processing, such as multiple fine grinding (lapping) one to four times.

[0078] More specifically, without the need to change grinding stones for rough grinding and multiple fine grinding operations, grinding can be performed directly in one pass using grinding stones of grit ♯30000 or higher. This not only makes the process simple but also significantly ensures the availability of intrinsic semiconductor layers from SiC wafers 100.

[0079] In the high-precision grinding process of the first surface processing step (STEP130(1)) and the second surface processing step (STEP130(2)), the size of the SiC wafer 100 is currently up to 8 inches (up to 12 inches). Wafers of various diameters are set according to the area of ​​the grinding head, and then high-precision grinding process (up to 12 inches) is performed.

[0080] The above is a detailed description of the SiC wafer manufacturing method of this embodiment. As detailed above, according to the SiC wafer manufacturing method and apparatus of this embodiment, regions with low cutting resistance are actively formed by the grooves 11 and cutting guide lines. These serve as cutting guides, and the SiC ingot 10 can be cut into slices with good precision in one step using multiple lines 40.

[0081] Next, refer to Figure 5 To illustrate the changes caused by cutting the guide wire.

[0082] Specifically, such as Figure 5 As shown in part (a), cutting the guide wire is not limited to allowing the laser beam to enter from the end face of the SiC ingot 10; the laser beam can also enter from the side, and as... Figure 5 As shown in the cross-sectional view of part (b) on the cut-off plane, multiple cutting guide lines are formed in a concentric circle on the cut-off plane. For example, by rotating the SiC ingot 10 around the axis, concentric cutting guide lines can be easily formed.

[0083] Similarly, as the line 40 positioned in the groove 11 advances while rotating during the cutting process, the cutting guide line becomes a region of low cutting resistance, except for the non-cutting area of ​​the groove 11, thus guiding the cutting. Furthermore, in this case, the multiple concentric circular cutting guide lines become denser towards the center of the SiC ingot 10, so... Figure 5 As shown in section (c), this prevents line 40 from becoming arc-shaped and keeps the line straight.

[0084] In the above embodiments, it is not limited to forming the cutting guide line in the same direction as the travel of line 40 or forming it in a concentric circle shape. The cutting guide line can be formed as long as the travel direction of line 40 is taken into account. For example, the cutting guide line can be formed in a radial scanning direction from the cutting endpoint of line 40 to the advancing or retreating direction of the line (in this case, the retreating direction).

[0085] In this case, the cutting guide lines are also denser in the center of the SiC ingot than on the left and right sides. Therefore, the area with low cutting resistance is set to have a step difference from the sides to the center, which can also prevent the line 40 from becoming bow-shaped and keep the line straight.

[0086] Of course, the cutting guide line can also be formed by scanning in a radial pattern from the cutting start point of line 40 in the forward and backward direction of the wire saw (in this case, the forward direction), or by scanning in both a radial pattern from the cutting end point of line 40 and a radial pattern from the cutting start point of line 40.

[0087] As described above, by setting radial cutting guide lines starting from the cutting start point or the cutting end point, cutting at the cutting start point and the cutting end point can be carried out with almost no cutting resistance, which can significantly improve the cutting efficiency at the cutting start point and the cutting end point.

[0088] The guide wire forming step of this embodiment (STEP110 / Figure 1 It can be applied to the processing of thin films formed on the backside for the purpose of wafer regeneration.

[0089] In the SiC wafer manufacturing method of this embodiment, after the series of processes described above, a chemical mechanical polishing (CMP) step and a wafer washing step may be optionally performed.

[0090] Although this embodiment describes a method for manufacturing semiconductor crystal wafers by manufacturing SiC wafers from SiC ingots, the semiconductor crystal is not limited to SiC and may also be gallium arsenide (GaAs), indium phosphide (InP), silicon, or other compound semiconductors.

[0091] Furthermore, although this embodiment is aimed at the trenching step (STEP100 / Figure 1 In this description, the SiC ingot 10 is supported in a state where its two end faces are protected by a pair of protective plates 15, 15, allowing it to rotate freely, but this is not a limitation. For example, the pair of protective plates 15, 15 may be omitted, and the SiC ingot 10 may be directly fixed to the rotation axis.

[0092] Additionally, in the trenching process (STEP100 / Figure 1 Steps other than ) such as cutting step (STEP120 / Figure 1 In addition, the SiC ingot 10 can also be processed while the two ends of the SiC ingot 10 are protected by a pair of protective plates 15, 15.

[0093] Furthermore, although this embodiment is aimed at the trenching step (STEP100 / Figure 1 In the example, the case of forming multiple grooves 11 around the entire side of the SiC ingot 10 by processing a drum-shaped grinding stone 20 using a common groove is described. However, the groove processing step of STEP 100 can also be omitted, and the grooves 11 are not formed.

[0094] Furthermore, although this embodiment uses an electrical discharge machining device, which is a type of wire saw, as an example of a cutting unit, the cutting unit is not limited to this. In addition to wire saw devices without electrical discharge function, it can also be a cutting device (including the case of electrical discharge function). In this case, the shape of the cutting blade can be a disc-shaped ring blade or a saw blade of a hacksaw, etc.

[0095] Furthermore, this embodiment primarily uses a scan line aligned with the cutting direction as an example of a scan line corresponding to the cutting direction to illustrate the guide line formation step (STEP110 / Figure 1 Examples of forming a cutting guide line in the image are shown, but the scan line corresponding to the cutting direction is not limited to this. It can also be a scan line orthogonal to the cutting direction. In addition, the scan line can be set to be sparse and dense in relation to the cutting direction.

[0096] For example, it can also be like Figure 6 As shown, a cutting guide line is formed, which radiates outwards from the cutting endpoint of the cutting unit (the wire saw device) in the cutting direction (the direction of wire travel). By forming the scanning line radially, and by providing areas of low cutting resistance in stages from both sides to the center during cutting, it is possible to prevent the central part of the wire from traveling in an arc shape during cutting. Furthermore, because the final cut is at the radial point (where cutting can be performed without cutting resistance), the cutting efficiency of the final cut is excellent.

[0097] Furthermore, such radial scanning lines can start from either the cutting endpoint of the cutting unit (the wire saw's wire) or the cutting starting point, or they can start from the cutting starting point instead of the cutting endpoint of the cutting unit. In this case, because the cutting starting point is a radial point (it can cut without cutting resistance), the cutting efficiency at the cutting starting point will be excellent.

[0098] Explanation of reference numerals in the attached figures 1. SiC crystallization (semiconductor crystallization) 4. Wire saw device (electrical discharge machining device) 10. SiC ingot (semiconductor crystal ingot) 11. Groove, 15, 15... A pair of protective plates, 20. Grooving of drum-shaped grinding stones, twenty one. . . convex part, 40. Line 50. Mechanical polishing equipment (ultra-high precision grinding equipment) 51. Spindle 52. Platform 53. Diamond polishing stone, 54. Vacuum porous suction cup (adsorption plate) 100... SiC wafers (semiconductor crystal wafers) 110. ... ... One side, 120. The other side.

Claims

1. A semiconductor wafer manufacturing apparatus is an apparatus for slicing wafers from a semiconductor ingot that has been ground into a cylindrical shape into wafers, the semiconductor wafer manufacturing apparatus comprising: A guide line forming unit focuses laser light of a wavelength transmissible to the semiconductor crystal ingot to form a focusing point, and scans this focusing point along a predetermined cutting surface to form a cutting guide line; and A cutting unit cuts off the predetermined cutting surface of the semiconductor crystal ingot; The guide line forming unit forms the cutting guide line by using a scan line that is consistent with the cutting direction of the cutting unit within the predetermined cutting surface as a scan line corresponding to the cutting direction of the cutting unit.

2. The semiconductor wafer manufacturing apparatus according to claim 1, wherein, The cutting unit is a wire discharge processing device that moves the wire around the predetermined cutting surface while simultaneously discharging electricity from the wire.

3. The semiconductor wafer manufacturing apparatus according to claim 1, wherein, The cutting unit is a cutting device that makes the cutting blade travel on the predetermined cutting surface.

4. A semiconductor wafer manufacturing apparatus is an apparatus for slicing a semiconductor wafer from a semiconductor ingot that has been ground into a cylindrical shape into a wafer in a slicing manner, the semiconductor wafer manufacturing apparatus comprising: The grooved grinding stone is a drum-shaped grinding stone used to form multiple grooves around the entire side of the semiconductor crystal ingot, and has multiple protrusions on the side corresponding to the multiple grooves. A wire saw device that causes multiple wires arranged in the plurality of grooves to rotate and advance while cutting the semiconductor crystal ingot into slices; and The guide line forming unit focuses a laser beam of a wavelength that is transmissible to the semiconductor crystal ingot on each predetermined cutting surface containing grooves formed on the side of the semiconductor crystal ingot to form a focusing point and scans the focusing point along the predetermined cutting surface to form a cutting guide line. The guide wire forming unit forms the cutting guide wire using a scanning direction consistent with the traveling direction of the wire in the wire saw device, as the scanning direction corresponding to the traveling direction of the wire.

5. The semiconductor wafer manufacturing apparatus according to any one of claims 1 to 4, wherein, The guide line forming unit causes the laser beam to enter from the end face of the semiconductor crystal ingot.

6. A method for manufacturing a semiconductor crystal wafer is a method for slicing a semiconductor crystal ingot, which has been ground into a cylindrical shape, into a wafer in a slicing manner, the method comprising: The guide line forming step involves focusing a laser beam of a wavelength that is transmissible to the semiconductor crystal ingot to form a focusing point, and then scanning the focusing point along the predetermined cutting surface to form a cutting guide line. as well as The cutting step involves cutting the predetermined cutting surface of the semiconductor crystal ingot; The guide line forming step uses a scan line within the predetermined cutting surface that is aligned with the cutting direction of the cutting step as the scan line corresponding to the cutting direction of the cutting step to form the cutting guide line.

7. A method for manufacturing a semiconductor crystal wafer is a method for slicing a semiconductor crystal ingot, which has been ground into a cylindrical shape, into a wafer in a slicing manner, the method comprising: The trenching process forms multiple grooves around the entire side of the semiconductor crystal ingot; In the guide line forming step, a laser beam of a wavelength that is transmissible to the semiconductor crystal ingot is focused on each predetermined cutting surface containing grooves formed on the side of the semiconductor crystal ingot by the trench processing step to form a focusing point, and the focusing point is scanned along the predetermined cutting surface to form a cutting guide line. as well as The cutting step involves moving multiple lines arranged in the multiple grooves formed in the trenching step while rotating to cut the semiconductor crystal ingot into slices. The guide line forming step uses a scanning direction consistent with the travel direction of the line in the cutting step as the scanning direction corresponding to the travel direction of the line to form the cutting guide line.

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