TW201810397A - Method of manufacturing semiconductor chips - Google Patents

Abstract

A method of manufacturing semiconductor chips includes: forming grooves on a front face side of a substrate; and forming grooves on a back face side of the substrate as defined herein, and in manufacturing conditions in which a variation range of a top section of the cutting member having a tapered tip end shape with no top face in the groove width direction changes from a range included in the groove on the front face side to a range away from the groove on the front face side as wear of the cutting member advances, the use of the cutting member is stopped before the variation range changes from the range included in the groove on the front face side to the range away from the groove on the front face side.

Description

Method for manufacturing semiconductor wafer

The present invention relates to a method for manufacturing a semiconductor wafer.

A crystal cutting method has been proposed which can increase the yield of a wafer without reducing the number of wafers, by forming a first groove from the front side of a sapphire substrate using a first blade and then by using a first Two blades form a second groove wider than the first groove and deeper than the first groove from the back side, and a wafer can be obtained from a single substrate (JP-A-2003-124151). A method of increasing the number of semiconductor wafers has also been proposed. The wafers can be formed by using laser radiation to form grooves from the front side of the wafer to the middle of its thickness and then by using a blade to cut the wafer from the back side of the wafer to The position of the groove formed by the laser radiation is formed on the wafer (JP-A-2009-88252).

A known method for manufacturing a semiconductor wafer is provided with a step of forming grooves on the front side of a substrate and using a width from the back side of the substrate having an entrance portion having a width larger than that of the grooves on the front side A step of forming a groove on the back side in communication with the grooves on the front side and dicing the substrate into a semiconductor wafer by rotating the cutting member with a thickness of one thick. With this manufacturing method, the semiconductor wafer is broken in some cases when fine grooves having a width of several μm to several ten μm and formed on the front side and the back side communicate with each other, and it is not clearly understood what kind of break What is the reason Up. Therefore, it is unknown what manufacturing conditions should be used to suppress fracture, making this manufacturing method unsuitable for mass production processes.

Therefore, the present invention is intended to provide a method for manufacturing a semiconductor wafer capable of suppressing breakage of the semiconductor wafer in the above-mentioned manufacturing method.

A first aspect of the present invention is directed to a method for manufacturing a semiconductor wafer, which includes: a step of forming a groove on a front side of a substrate; One of the thicknesses of the entrance portions of the grooves is one-thick and one of the thickness of the rotary cutting member forms a groove on the back side of the substrate in communication with the grooves on the front side and cuts the substrate into a semiconductor wafer A step in which a range of variation of a top section of the cutting member having a wedge-shaped tip shape without a top surface in the width direction of the groove is included in the front side as the wear of the cutting member increases In a manufacturing condition in which a range in the groove above is changed away from a range in the groove on the front side, the range of change is changed from the range included in the groove on the front side to away from The use of the cutting member is stopped before the range of the groove on the front side.

A second aspect of the present invention is directed to a method for manufacturing a semiconductor wafer, including: a step of forming a groove on a front side of a substrate; and using a material having a lower thickness than that on the front side from a back side of the substrate. One of the thicknesses of the entrance portions of the grooves is one-thick and one of the thickness of the rotary cutting member forms a groove on the back side of the substrate in communication with the grooves on the front side and cuts the substrate into a semiconductor wafer A step in which a range of variation of a top section of the cutting member having a wedge-shaped tip shape without a top surface in the width direction of the groove is included in the front side as the wear of the cutting member increases In a manufacturing condition in which a range in the groove above is changed away from a range in the groove on the front side, a tip shape of the cutting member is formed such that a maximum stress is applied at an area of the top section and The periphery of the groove on the front side due to wear of the cutting member The use of the cutting member is discontinued before breaking a wedge shape.

A third aspect of the present invention is directed to a method for manufacturing a semiconductor crystal, including: a step of forming a groove on a front side of a substrate; and using a material having a lower thickness than that on the front side from a back side of the substrate. One of the thicknesses of the entrance portions of the grooves is one-thick and one of the thickness of the rotary cutting member forms a groove on the back side of the substrate in communication with the grooves on the front side and cuts the substrate into a semiconductor wafer A step in which a range of variation in a thickness direction center of a tip section of the cutting member becomes far away from the groove on the front side and a periphery of the groove on the front side is due to In a manufacturing condition in which abrasion is gradually reduced and one of the top section and one region of the cutting member is broken by stress, the fracture rate of the periphery of the groove on the front side starts as the wear of the cutting member increases Before raising, stop using the cutting member.

A fourth aspect of the present invention is directed to the method of manufacturing a semiconductor wafer according to any one of the first to third aspects of the present invention, wherein the method is based on the amount of the cutting member and the amount of the groove on the front side. A predetermined relationship between the fracture rates at the periphery stops the use of the cutting member.

With the first to fourth aspects of the present invention, it is possible to suppress breakage of semiconductor wafers in a method of manufacturing semiconductor wafers having the following steps: a step of forming a groove on the front side of a substrate, and a back surface of the substrate The side uses a rotating cutting member having a thickness that is thicker than the width of the entrance portion of the grooves on the front side to form grooves on the back side that communicate with the grooves on the front side and A step of dicing a substrate into a semiconductor wafer.

100‧‧‧Light-emitting element

120‧‧‧ cutting area

130‧‧‧Photoresist pattern

140‧‧‧Groove / Fine Groove on Front Side

160‧‧‧ cut crystal band

170‧‧‧Groove on the back side

180‧‧‧ ultraviolet rays

190‧‧‧extension tape

200‧‧‧ ultraviolet rays

210‧‧‧Semiconductor wafer

220‧‧‧ Fastening member

230‧‧‧Circuit Board

300‧‧‧cut crystal blade

300A‧‧‧Cutting Blade

302‧‧‧cut crystal blade

310‧‧‧ side

320‧‧‧ side

330‧‧‧ curved surface

332‧‧‧curved surface

340‧‧‧Flat / Top

350‧‧‧Chamfered Section

352‧‧‧curved surface

360‧‧‧Chamfered Section

362‧‧‧curved surface

370‧‧‧curved surface

400‧‧‧ stepped section

410‧‧‧root zone

500‧‧‧cut crystal blade

500A‧‧‧Cutting Blade

502‧‧‧cut crystal blade

502A‧‧‧Cutting Blade

504‧‧‧cut crystal blade

504A‧‧‧Cutting Blade

506‧‧‧cut crystal blade

506A‧‧‧Cutting Blade

508‧‧‧cut crystal blade

508A‧‧‧Cutting Blade

510‧‧‧ side

512‧‧‧inclined surface

514‧‧‧inclined

520‧‧‧side

522‧‧‧inclined

524‧‧‧inclined

530‧‧‧ pointed top section

532‧‧‧ flat surface

532A‧‧‧ flat surface

534‧‧‧ pointed top section

534A‧‧‧flat surface

536‧‧‧ pointed top section

536A‧‧‧ flat surface

600‧‧‧ flat support base

610‧‧‧Shaped Plate

620‧‧‧Motor

630‧‧‧cut crystal blade

640‧‧‧chuck

700‧‧‧ dotted line

710‧‧‧solid line

720‧‧‧ fracture

800‧‧‧fine groove

800A‧‧‧Fine groove

800B‧‧‧Fine groove

800C‧‧‧fine groove

810‧‧‧First groove part

820‧‧‧Second groove part

830‧‧‧ Rectangular second groove part

840‧‧‧Second groove part

900‧‧‧Photoresist

910‧‧‧ opening

920‧‧‧protective film

D1‧‧‧ Depth of the first groove part

D2‧‧‧Second groove part depth

Ds‧‧‧Position deviation

F‧‧‧ Force exerted by the crystal cutting blade

H‧‧‧face

K‧‧‧ Center of thickness

M‧‧‧ Margin

Q‧‧‧ axis

r‧‧‧curvature radius

S‧‧‧constant space

Sa‧‧‧Fine groove width

Sa1‧‧‧The first groove part width

Sa2‧‧‧Second groove part width

Sb‧‧‧cut width

T‧‧‧ Required thickness of stepped section

W‧‧‧ semiconductor substrate

Wh‧‧‧Width of stepped section

Wt‧‧‧step width

X‧‧‧ direction

Y‧‧‧ direction

Z‧‧‧ direction

θ‧‧‧ inclination

Illustrative specific examples of the present invention will be described in detail based on the following drawings, wherein: FIG. 1 is a flowchart showing an example of a semiconductor wafer manufacturing process according to an example of the present invention; FIGS. 2A, 2B, 2C, and 2D are schematic cross-sectional views, each showing a semiconductor wafer according to an example of the present invention Semiconductor substrate in the manufacturing process; FIGS. 3E, 3F, 3G, 3H, and 3I are schematic cross-sectional views, each showing a semiconductor substrate in a semiconductor wafer manufacturing process according to an example of the present invention; and FIG. 4 is a display A schematic plan view of a semiconductor substrate (wafer) when circuit formation is completed; FIG. 5A is a cross-sectional view illustrating a cutting operation of a crystal cutting blade, and FIGS. 5B, 5C, 5D, 5E, and 5F are shown according to this An enlarged cross-sectional view of a tip section of an example of a crystal cutting blade, and FIG. 5G is an enlarged cross-sectional view showing a tip section of a cutting blade for general full-cutting; FIG. 6A is a view illustrating a cutting blade for simulation FIG. 6B is an enlarged cross-sectional view of the tip section. FIG. 6B is a cross-sectional view showing the shape of a groove formed in the semiconductor substrate when the dicing blade shown in FIG. 6A is used, and FIGS. 6C and 6D are shown for simulation. The tip of the dicing blade The enlarged sectional view of the segment, the radius of curvature of the tip segment is r = 0.5 and r = 12.5; Figure 7 shows the radius of curvature of the tip segment of the crystal cutting blade and the corner segment generated in the stepped segment during simulation A graph showing the relationship between the stress values in the graph; Figure 8 is a graph showing the relationship between the radius of curvature of the tip section of the crystal cutting blade and the maximum stress value during the simulation; Figure 9A is a diagram illustrating the application to the stepped region A cross-sectional view of the stress of a corner section of a segment, and FIG. 9B is a cross-sectional view illustrating an example where the stepped section is broken due to the stress generated in the corner section of the stepped section; FIG. 10 is a view illustrating when FIG. 5B is used Applied to the stepped section when the dicing blade shown in FIG. 11A is a cross-sectional view showing a stepped section when the center of the groove 140 is consistent with the center of the groove 170, and FIG. 11B is a view showing when a position deviation has occurred in the center and the groove of the groove 140 A cross-sectional view of a stepped section when between the centers of the grooves 170; FIGS. 12A, 12B, 12C, and 12D are views illustrating four kinds of crystal cutting blades used for simulation of position deviation; FIG. 13 is a view showing A graph of the results of the simulation of the effect of the position deviation amount and the cut width on the stepped section; FIG. 14 shows an example where the maximum stress occurs when the cut width Sb is narrow and the position deviation Ds is large. View; FIG. 15 is a view showing the results of an experiment when the actual substrate is cut using various dicing blades having different cutting widths Sb and a radius of curvature of the tip corner section; FIG. 16 is a view showing confirmation of a groove on the front side A view of the results of experiments conducted on the effect of the difference in the width of the stepped section and the effect of the difference in the thickness of the stepped section on the stepped section; FIG. 17 is a diagram illustrating an example of the present invention. Design available FIG. 18 is a flowchart illustrating a method of setting the width of a groove on the front side according to an example of the present invention; FIG. 19 is a flowchart illustrating a method according to the present invention; A flowchart of a method of selecting a manufacturing device according to an example of the invention; FIG. 20 is a flowchart illustrating another example of a method of setting a width of a groove on the front side and a method of selecting a manufacturing device according to an example of the invention; 21B, 21C, 21D, and 21E are enlarged cross-sectional views showing an example of a tip section of a crystal cutting blade according to an example of the present invention; 22 is a flowchart illustrating a first processing method for processing a tip shape of a crystal cutting blade according to an example of the present invention; FIG. 23A is a diagram illustrating an example of a tip shape for processing a crystal cutting blade and applicable to the present invention. A schematic plan view of an example of a processing device, and FIG. 23B is a schematic cross-sectional view showing the processing device; FIGS. 24A, 24B, and 24C are shown in FIGS. 21A, 21B, 21C, 21D, and 21E. View of an example in which the top section of the dicing blade is processed so that its degree of taper becomes smaller; FIG. 25 is a diagram illustrating a second processing method for processing the tip shape of the dicing blade according to an example of the present invention Flow chart; FIG. 26 is a cross-sectional view illustrating the relationship between the wear of the tip section of the crystal cutting blade and the fracture of the stepped section; FIG. 27A, FIG. 27B, FIG. 27C, and FIG. A cross-sectional view of a typical configuration of a fine groove; FIG. 28 is a flowchart illustrating a manufacturing method of forming a fine groove according to an example of the present invention; and FIGS. 29A and 29B show manufacturing by using an example according to the present invention Method to make fine A schematic sectional view of a groove of the processes.

A method of manufacturing a semiconductor wafer according to the present invention is applied to a method of manufacturing individual semiconductor wafers by dividing (cutting) a substrate-shaped member such as a semiconductor wafer having a plurality of semiconductor elements formed thereon, for example. The semiconductor element formed on the substrate is not particularly limited and includes a light emitting element, an active element, a passive element, etc. In a preferred mode, the manufacturing method according to the present invention is applied to take out light from a substrate containing light. The method of semiconductor wafer of the device, and the light-emitting device may be, for example, a surface-emitting semiconductor laser, a light-emitting diode, and a light-emitting gate fluid. A single semiconductor wafer may contain a single light emitting element or may include a plurality of light emitting elements arranged in an array, and may further include a driving circuit for driving the single light emitting element or a plurality of light emitting elements. In addition, the substrate may be a substrate made of, for example, silicon, SiC, compound semiconductor, and sapphire, and a substrate made of other materials may be used, provided that the substrate contains at least a semiconductor (hereinafter collectively referred to as a semiconductor substrate). Preferably, the substrate is a semiconductor substrate made of a III-V compound (such as GaAs), on which a light emitting element such as a surface emitting semiconductor laser, a light emitting diode is formed.

A method of forming a plurality of light emitting elements on a semiconductor substrate and taking out individual semiconductor wafers from the semiconductor substrate will be described below with reference to the drawings. Since the proportions and shapes shown in the drawings are emphasized for easy understanding of the characteristics of the present invention, it should be noted that the proportions and shapes of the devices shown in the drawings may not be the same as those of the actual devices.

FIG. 1 is a flowchart showing an example of a semiconductor wafer manufacturing process according to an example of the present invention. As shown in FIG. 1, the method of manufacturing a semiconductor wafer according to this example includes a step (S100) of forming a light emitting element, a step (S102) of forming a photoresist pattern, and forming a fine groove on a front surface of a semiconductor substrate. One step (S104), one step of removing the photoresist pattern (S106), one step of attaching all crystal ribbons to the front surface of the semiconductor substrate (S108), one of performing half-cutting crystals from the back surface of the semiconductor substrate Step (S110), one step of irradiating ultraviolet (UV) rays to the dicing tape and attaching an extension tape to the back surface of the semiconductor substrate (S112), removing the dicing tape and irradiating ultraviolet rays to the One step of expanding the tape (S114) and one step of selecting a semiconductor wafer and performing die mounting on a circuit board or the like (S116). The cross-sectional views of the semiconductor substrate shown in FIGS. 2A to 2D and FIGS. 3E to 3I correspond to steps S100 to S116, respectively.

In the step (S100) of forming a light emitting element, as shown in FIG. 2A, a plurality of Each light emitting element 100 is formed on the front surface of a semiconductor substrate W made of, for example, GaAs. The light-emitting element 100 is a surface-emitting semiconductor laser, a light-emitting diode, a light-emitting gate fluid, or the like. Although it is referred to as a single area of the light emitting element 100 in the figure, it should be noted that the single light emitting element 100 as an example represents an element included in a single semiconductor wafer, and is not only a single light emitting element, a plurality of light emitting elements, Other circuit elements may be included in the area of the single light-emitting element 100.

FIG. 4 is a plan view showing an example of the semiconductor substrate W when the step of forming a light emitting element is completed. In the figure, for convenience, only the light emitting element 100 located at the center portion is shown as an example. On the front surface of the semiconductor substrate W, a plurality of light emitting elements 100 are formed in an array in a matrix direction. The flat regions of the single light-emitting element 100 have an approximately rectangular shape, and the individual light-emitting elements 100 are arranged in a grid shape so as to be separated by a cutting region 120 separated by a cutting track or the like separated by a constant space S.

Next, when the formation of the light emitting element is completed, a photoresist pattern is formed on the front surface of the semiconductor substrate W (at S102). As shown in FIG. 2B, the photoresist pattern 130 is processed to expose a cutting area 120 on the front surface of the semiconductor substrate W defined by a dicing track or the like. The photoresist pattern 130 is processed in a photolithography step.

Next, a fine groove is formed on the front surface of the semiconductor substrate W (at S104). As shown in FIG. 2C, a fine groove having a constant width (hereinafter referred to as a fine groove or a groove on the front side for convenience) 140 is formed on the semiconductor substrate W by using the photoresist pattern 130 as a mask. On the front. These kinds of grooves can be formed, for example, by anisotropic etching, and preferably can be formed by anisotropic plasma etching (reactive ion etching) serving as anisotropic dry etching. Although thin dicing blades or isotropic etching can also be used to form grooves, anisotropic dry etching can form narrower and deeper grooves on the front side than isotropic etching, and can be more effective than using dicing blades Method to more effectively suppress vibration, stress, etc. For the influence of the light emitting element 100 around the fine groove, it is preferable. The width Sa of the fine groove 140 is almost equal to the width of an opening formed in the photoresist pattern 130 and is in a range of, for example, several μm to several ten μm. Preferably, the width Sa is approximately 3 μm to approximately 15 μm. Further, the depth of the groove is, for example, in a range of approximately 10 μm to approximately 100 μm, and the depth is made at least deeper than a depth at which a functional element such as a light emitting element is formed. Preferably, the depth of the micro-groove 140 is approximately 30 μm to approximately 80 μm. In the case where the fine groove 140 is formed by using an ordinary crystal cutting blade, the space S of the cutting area 120 (that is, the total groove width obtained by the crystal cutting blade itself and the margin width considering the peeling amount ) Becomes large, at most approximately 40 to 80 μm. On the other hand, in the case where the fine groove 140 is formed in a semiconductor process, the groove width can be made narrower, and the margin width for cutting can be made narrower than that in the case where a dicing blade is used. . In other words, the space of the dicing region 120 can be made smaller, so that the light-emitting elements can be arranged on the wafer at a high density and the number of semiconductor wafers to be obtained can be increased. The "front side" in this example refers to the side of the face on which a functional element such as a light emitting element is formed, and the "back side" refers to the side of the face on the opposite side of the "front side".

Next, the photoresist pattern is removed (at S106). As shown in FIG. 2D, when the photoresist pattern 130 is removed from the front surface of the semiconductor substrate, the fine grooves 140 formed along the cutting area 120 are exposed on the front surface. Details of the shape of the fine groove 140 will be described later.

Next, an ultraviolet-cured dicing tape is attached (at S108). As shown in FIG. 3E, the dicing tape 160 having an adhesive layer is attached to the side of the light emitting element. Next, a half-cut crystal is performed along the fine groove 140 using a dicing blade from the back side of the substrate (at S110). The crystal cutting blade is indirectly detected by using an infrared camera disposed above the back side of the substrate and the position of the fine groove 140 is indirectly using infrared rays transmitted through the substrate. The camera is disposed above the front side of the substrate. And the position of the fine groove 140 is straight Use detection methods or locate by other known methods. Based on such positioning, as shown in FIG. 3F, the half-cut crystal system is performed using a dicing blade and the groove 170 is formed on the back side of the semiconductor substrate. The groove 170 has a depth reaching the fine groove 140 formed on the front surface of the semiconductor substrate. The width of the fine groove 140 may be narrower than the width of the groove 170 formed on the back side by a crystal cutting blade. This is because the number of semiconductor wafers that can be obtained from a single wafer under the condition where the fine grooves 140 having a narrower width than the width of the grooves 170 on the back side is formed, compared with the semiconductor substrate system using only dicing blades The state of cutting is increased. First, if a fine groove having a depth in a range of several μm to a dozen μm shown in FIG. 2C can be formed from the front surface to the back surface of the semiconductor substrate, it is not necessary to use a dicing blade to form the groove on the back surface side. . However, it is not easy to form a fine groove having this depth. Therefore, as shown in FIG. 3F, the half-cut crystal system from the back surface using the dicing blade is combined with etching.

Next, ultraviolet (UV) rays are irradiated to the dicing tape and an extended tape is attached (at S112). As shown in FIG. 3G, the ultraviolet ray 180 is irradiated to the dicing tape 160, and the adhesive layer of the tape is thereby hardened. Next, the extension tape 190 is attached to the back surface of the semiconductor substrate.

Next, the cut band is removed and ultraviolet rays are irradiated to the extended band (at S114). As shown in FIG. 3H, the dicing tape 160 is removed from the front surface of the semiconductor substrate. In addition, the ultraviolet ray 200 is irradiated to the extension tape 190 on the back surface of the substrate, and the adhesive layer of the tape is thereby hardened. The expansion band 190 having elasticity of the base material is stretched to facilitate picking up of individualized semiconductor wafers after dicing, thereby extending the space between the light emitting elements.

Next, individual semiconductor wafer selection and die mounting are performed (at S116). As shown in FIG. 3I, the semiconductor wafer 210 that has been selected from the expansion tape 190 is mounted on the circuit board 230 via a fastening member 220 (for example, a conductive paste such as an adhesive or solder). on.

Next, details of the half-cut crystal using the dicing blade will be described below. FIG. 5A is a cross-sectional view when a half-cut crystal is performed as shown in FIG. 3F using a crystal cutting blade.

As described above, a plurality of light-emitting elements 100 are formed on the front surface of the semiconductor substrate W, and the individual light-emitting elements 100 are separated by the cutting regions 120 defined by the cutting lines separated by a constant interval S, for example. In the cutting region 120, the fine groove 140 having a width Sa is formed by anisotropic etching. On the other hand, the dicing blade 300 is a disc-shaped cutting member that rotates about the axis Q as shown in FIG. 5A and has a thickness corresponding to the cut width Sb of the groove 170. The dicing blade 300 is positioned outside the semiconductor substrate W in a direction parallel to the rear surface of the semiconductor substrate W. In addition, the dicing blade 300 is moved by a predetermined amount in a direction Y perpendicular to the back surface of the semiconductor substrate W, thereby being positioned in the thickness direction of the semiconductor substrate W so that the stepped section 400 has a desired thickness T. In addition, after positioning, at least the dicing blade 300 or the semiconductor substrate W moves in a direction horizontal to the back surface of the semiconductor substrate W while the dicing blade 300 rotates, whereby the groove 170 is formed in the semiconductor substrate W. Since the cut width Sb is greater than the width Sa of the fine groove 140, when the groove 170 reaches the fine groove 140, a cantilevered eaves-shaped stepped section 400 having a thickness T is formed due to the difference between the width Sb and the width Sa . If the center of the dicing blade 300 is exactly the same as the center of the fine groove 140, the length of the stepped section 400 extending in the horizontal direction is (Sb-Sa) / 2.

A) Explanation of the tip section

5B to 5F are enlarged sectional views showing the tip section A of the crystal cutting blade 300 as an example of an example according to the present invention, and FIG. 5G is showing the tip section A of the crystal cutting blade used for general full crystal cutting Enlarged sectional view. For general complete cutting The tip section of the crystal cutting blade 300A has a side surface 310 on one side, a side surface 320 on the opposite side thereof, and a flat surface 340 almost orthogonal to the side surfaces 310 and 320 as shown in FIG. 5G. In other words, viewed from the direction of rotation, the tip section has a rectangular cross section. On the other hand, the tip section of the dicing blade 300 has a wedge shape, in which the thickness of the dicing blade 300 gradually becomes thinner toward the top section of the tip section of the dicing blade 300, for example, As shown in Figures 5B to 5F.

In the example, the "top section" is the topmost part of the dicing blade, and in the cases shown in Figs. 5B, 5D, and 5E, the top section is the topmost point. In addition, in the case of the shapes shown in FIG. 5C and FIG. 5F, the top section is a flat surface except for small irregularities, and the flat surface is referred to as a "top surface". The shape of the portion having the tip portion of the dicing blade 300 that becomes smaller toward the top portion is referred to as a "wedge shape" shape. 5B to 5F all show examples of the wedge shape.

The respective shapes shown in FIGS. 5B to 5G are initial shapes when the cutting of the semiconductor substrate is performed in a mass production process. In other words, the dicing blade 300 according to the example shown in FIGS. 5B to 5F initially has these shapes as an initial shape in a mass production process. In addition, although the tip section having a rectangular shape as shown in FIG. 5G and used for general complete dicing has a rectangular shape in its initial state, the tip section is ground as the dicing blade is continuously used as shown in FIG. 5B The wedge-shaped shape having such curved surfaces 330 shown in Fig. 5D.

The example shown in FIG. 5B has a pair of side surfaces 310 and 320 and a curved surface 330 disposed between the pair of side surfaces 310 and 320. More specifically, the distance between the pair of sides 310 and 320 is a width corresponding to the cut width Sb, and the tip section has a semicircular curved surface 330 between the side 310 and the side 320, but does not have The top surfaces 340 shown in FIGS. 5C and 5F. The example shown in FIG. 5C is shown in FIGS. 5B and 5G. The shape shown is intermediate between the shapes and has a top surface 340 and a curved surface 330 at its tip corner section. The example shown in FIG. 5D does not have a top surface 340, but has curved surfaces 330, which have a radius of curvature greater than the radius of curvature of the tip corner section shown in FIGS. 5B and 5C, and have a radius smaller than the curved surface 330. The curved surface 370 of the radius of curvature is formed at the position of the top section. In the curved surface 330 shown in FIGS. 5B to 5D, the thickness of the dicing blade 300 becomes smaller toward the top section of the dicing blade 300.

In the example shown in FIG. 5E, a curved surface 370 is formed between the two chamfered sections 350 and 360. In this case, the top section 340 is not formed as in the case of FIG. 5D. In the example shown in FIG. 5F, the opposite side surfaces 310 and 320 are formed, the top surface 340 is disposed between the side surface 310 and the side surface 320, and the chamfered sections 350 and 360 are formed on the top surface 340 and the side surfaces 310 and 320. between. In addition, a curved surface 352 is formed at a corner section between the chamfered section 350 and the top surface 340, and a curved surface 362 is formed at a corner section between the chamfered section 360 and the top surface 340.

Unless otherwise stated, the tip section of the crystal cutting blade according to the example may have only a wedge shape instead of the rectangular shape of the tip section shown in FIG. 5G and may not have a top surface. In addition, the tip section of the dicing blade 300 according to the example shown in FIGS. 5B to 5F has a shape that is linearly symmetrical with respect to the center K of the thickness of the dicing blade 300 shown in FIG. 5D. However, unless otherwise stated, the tip section does not always need to have a linearly symmetric shape, and the position of the top section (top surface) may be deviated in the thickness direction of the crystal cutting blade 300.

B) Explanation of simulation and results of experiments

Next, in the case where fine grooves having a width in a range of several μm to a dozen μm are connected to each other, the following will be described as confirming what kind of fracture system is caused by which Caused simulations and experiments.

B-1) Explanation of simulation of tip shape

FIGS. 6A to 6D, FIG. 7 and FIG. 8 are used for explaining the simulation performed for grasping the relationship between the radius of curvature of the tip corner section of the cutting blade and the stress applied to the stepped section, and for explaining the simulation View of the results. FIG. 6A shows an example of a dicing blade 302 for simulation. FIG. 6A shows the cross-sectional shape of the tip section viewed from the rotation direction of the self-cutting crystal blade 302. As shown in FIG. 6A, the tip section of the dicing blade 302 has sides 310 and 320, a top surface 340 having a constant length, and a curved surface 330 having a radius of curvature r and formed between the top surface 340 and the sides 310 and 320. And the tip section is configured so that it is symmetrical to a line orthogonal to the axis of rotation.

FIG. 6B shows the shape of a groove formed in the semiconductor substrate in the case where the dicing blade 302 having a tip shape shown in FIG. 6A is used. As shown in the figure, due to the difference between the position of the side of the groove 140 on the front side of the substrate and the position of the groove 170 on the back side of the substrate, a step having a width Wt is generated on the front side Between the vertical side of the groove 140 and the vertical side of the groove 170 on the back side, an eaves-shaped region having a thickness T (ie, the stepped section 400) is formed by this step. In other words, the stepped section 400 is a portion between the step formed at the connection section of the groove 140 on the front side and the groove 170 on the back side and the front surface of the semiconductor substrate.

In this simulation, when the curvature radius r (μm) of the curved surface 330 in the crystal cutting blade 302 becomes r = 0.5, r = 2.5, r = 5.0, r = 7.5, r = 10.0, and r = 12.5, borrow The value of the stress applied to the stepped section 400 is calculated by simulation. The thickness of the dicing blade 302 is 25 μm. FIG. 6C shows the shape of the tip section at r = 0.5, and FIG. 6D shows the shape of the tip section at r = 12.5. The tip section shown in FIG. 6D has a semi-circular shape, The radius of curvature of the tip corner section is 1/2 of the thickness of the dicing blade 302. The substrate to be processed is a GaAs substrate. The width of the groove 140 on the front side is 5 μm, the thickness T of the stepped section 400 is 40 μm, and the setting is performed so that a load of 2 mN is applied in a direction from the groove 170 on the back side to the front side of the substrate To the stepped section 400. In addition, the simulation is performed in a state where the center of the width of the groove 140 on the front side is aligned with the center of the thickness of the dicing blade 302.

The graph shown in FIG. 7 shows the results of the simulation and shows the change in the value of the stress applied to the stepped section 400 when the radius of curvature of the tip corner section is changed. In this graph, the vertical axis represents the stress value [Mpa], and the horizontal axis represents the X coordinate when the center of the groove 140 on the front side shown in FIG. 6B is used as the origin. According to the graph, in each radius of curvature r, the stress becomes larger as the X coordinate becomes closer to 12.5 μm, that is, the stress changes with the tip corner section from the center of the groove 170 on the back surface It becomes larger near the root side of the stepped section 400. In addition, it was found that as the value of the radius of curvature r becomes larger, the stress applied to the root side of the stepped section 400 decreases and the increase in stress becomes more gradual. In other words, in the range of the tip shape used in the simulation performed at this time, that is, in the case where the tip shape has a taper degree smaller than that of the semicircular tip section shown in FIG. 6D The maximum stress occurs on the root side of the stepped section 400. Further, the stress applied to the root side of the stepped section 400 in the case where the tip shape is semicircular as shown in FIG. 6D is smaller than the stress in the case where the tip shape is almost rectangular as shown in FIG. 6C. In other words, the stress applied to the root side of the stepped section 400 becomes smaller as the degree of taper becomes larger. In addition, in a case where the tip shape is almost rectangular as shown in FIG. 6C (for example, in the case of r = 0.5, in the range of X coordinate up to approximately 11 μm), the stress is smaller than the case where the radius of curvature r is large Under stress. However, in a range exceeding the above range (that is, in a portion closer to the root), the stress suddenly becomes larger, and It was found that the stress was concentrated at a portion of the X coordinate close to 12.5 μm.

Next, FIG. 8 shows the relationship between the radius of curvature on the horizontal axis and the maximum stress value on the vertical axis. In this graph, in addition to the values of the curvature radius r shown in FIG. 7, simulations are performed at r = 25 μm and r = 50 μm, and the results of the simulation are also included and displayed. In the case where the radius of curvature r is larger than the radius of curvature of the semicircular shape 12.5 (for example, 25 μm or 50 μm), the tip shape has a large degree of taper as shown in FIG. 5D, for example. According to this graph, as the radius of curvature r is smaller, that is, as the tip shape becomes closer to a rectangular shape, the maximum stress value becomes higher, and the degree of change in the maximum stress depending on the change in the radius of curvature r suddenly changes. Get bigger. Conversely, the maximum stress value decreases as the radius of curvature r increases, and the degree of change in the maximum stress depending on the change in the radius of curvature r becomes lower. In the range of the curvature radii of 12.5 μm and 50 μm, that is, in the range of the top surface where the wedge shape does not have the top surface as shown in FIGS. 6D and 5D, it can be found that the change in the maximum stress value is almost constant.

The mechanism of how the semiconductor wafer is broken will be described with reference to FIGS. 9A, 9B, 11A, and 11B based on the results of the above simulation. As shown in FIG. 9A, in the case where the tip section has a rectangular shape as in the crystal cutting blade 300A (in the case where the value of the curvature radius r is small), the top surface 340 of the crystal cutting blade 300A has a cutout. When the groove 170 having the width Sb is formed from the back surface of the semiconductor substrate, the semiconductor substrate is pressed. Although the force F applied by the dicing blade 300A is completely applied to the stepped segment 400, it is assumed that the force F applied to the stepped segment 400 is concentrated on the root side region (the root region 410) of the stepped segment 400 due to the principle of leverage. )on. Next, when the stress concentrated on the root region 410 exceeds the fracture stress of the wafer, the stress causes the root region 410 of the stepped section 400 as shown in FIG. 9B to break (peel, crack, or pry). If the fracture occurs at the stepped section 400, the margin M for cutting of the stepped section 400 needs to be ensured; this means the space S of the cutting area 120 Need to be equal to or greater than the margin M. According to the results of the simulation shown in FIG. 8, when the stress in the case of r = 0.5 and the stress in the case of r = 12.5 are compared, the root region 410 of the stepped section 400 is applied in the former case. The stress system is different, that is, almost four times that in the latter case. This means that in a range where the value of the radius of curvature r is smaller than the radius of curvature of this semi-circular tip as shown in FIGS. 5B and 6D, that is, in a range where the tip shape has a top surface, it is applied to the stepped section. The stress in the root region 410 of 400 changes significantly depending on the value of the radius of curvature r of the tip corner section. In the case where the stepped portion parallel to the surface of the substrate is formed by using the tip shapes of the top surfaces having the top surfaces as shown in FIGS. 5C, 5F, and 5G, the "root region in this example It is assumed to be a region closer to the side of the vertical side of the groove 170 on the back side than the 1/2 position of the width Wh of the stepped portion parallel to the surface of the substrate, the side being formed in a recess on the front side On each of the two sides of the slot. FIG. 6B shows the relationship between the width Wh and the width Wt. Further, in the case where a stepped portion parallel to the surface of the substrate is not formed, for example, when a wedge-shaped tip shape (such as the tip shapes shown in FIGS. 5B, 5D, and 5E) without a top surface is used, In this case, the region is assumed to correspond to the crystal cutting blade on each of both sides of the center region of the crystal cutting blade in a case where the crystal cutting blade is equally divided into three regions in the thickness direction. Areas of stepped sections 1/3 of their thickness.

FIG. 10 is a cross-sectional view illustrating the application of stress to the stepped section 400 when the groove 170 is formed by the crystal cutting blade 300 according to the example shown in FIG. 5B. FIG. 10 shows an example in which the tip section of the dicing blade 300 has a semi-circular shape. In this case, the shape of the groove 170 also becomes semicircular so as to follow the shape of the tip section. The result is that the force F applied to the stepped section 400 by the tip section of the dicing blade 300 is distributed in a direction along the semicircular shape of the groove. Therefore, it is assumed that the restraint stress is concentrated on the root region 410 of the stepped section 400 unlike the case shown in FIG. 9A, whereby the stepped section Peeling and cracking of 400 will be suppressed.

B-2) Simulation of position deviation

Next, the amount of positional deviation of the crystal cutting blade in the groove width direction will be described below. 11A and 11B are views illustrating a positional relationship between a width Sa of a groove 140 formed on a front side of a front surface of a substrate and a cut width Sb of a groove 170 formed by a dicing blade. It is desirable that the center of the cut width Sb coincides with the center of the width Sa of the groove 140 on the front side. However, actually, due to the variation at the time of manufacture, the center of the cut width Sb deviates from the center of the width Sa of the groove 140 on the front side, as shown in FIG. 11B. In addition, due to the positional deviation, a difference between the widths Wt of the left and right stepped sections 400 may occur. It is assumed here that the difference between the center of the width Sa of the groove 140 on the front side and the center of the cut width Sb is the position deviation amount Ds. Changes in manufacturing are mainly determined by manufacturing conditions such as the positioning accuracy of the manufacturing equipment used (including the accuracy of alignment marks and the like) and the degree of deformation of the cutting blade (bending and Amount of warping).

Next, simulations are performed to grasp the relationship between the position deviation amount Ds of the crystal cutting blade in the groove width direction and the stress applied to the stepped section 400, and to grasp the cutting width Sb of the crystal cutting blade and the application The simulation performed on the relationship between the stresses to the stepped section 400 will be described as follows. In these simulations, four values of Sb = 25, Sb = 20.4, Sb = 15.8, and Sb = 11.2 are used as the cut-off width Sb (μm) at the position of 12.5 μm from the top section of the dicing blade, The stress values at the respective section widths when the position deviation amount Ds (μm) from the groove 140 on the front side becomes Ds = 0, Ds = 2.5, and Ds = 7.5 are calculated by these simulations. Although the shape of the tip used in this simulation is different from the shape of the tip used in the simulations related to FIG. 6, the simulation is similar to the simulations related to FIGS. 6A to 6D. It is intended to be common to use a plurality of tip shapes having different degrees of tapering. The substrate to be processed is a GaAs substrate, the thickness of the dicing blade is set to 25 μm, each of the radius of curvature of the tip corner section is set to r = 5 μm, and the width Sa of the groove 140 on the front side of the semiconductor substrate is set to r = 5 μm, and the thickness T of the stepped section 400 is set to 40 μm. In addition, the setting is performed such that a total load of 10 mN is applied in the normal direction of the side surface of the stepped section 400 and the groove 170 on the back side. The load incorporated into the side of the groove 170 on the back side takes into consideration the horizontal vibration of the crystal cutting blade during actual cutting.

FIGS. 12A to 12D show the shapes of the grooves in a state where the position deviation amount Ds is zero in the case of the four kinds of cut widths (corresponding to the tip shape of the cutting blade) used in the simulation. FIG. 12A shows the shape under Sb = 25 μm, FIG. 12B shows the shape under Sb = 20.4 μm, FIG. 12C shows the shape under Sb = 15.8 μm, and FIG. 12D shows the shape under Sb = 11.2 μm. In each shape, the surface of the tip corner section other than the curved surface is straight, and in the case of Sb = 11.2 μm in FIG. 12D, the radius of curvature at the region of the top section is set to 5 μm, as shown in the figure. Shown so that the shape does not have a sharp corner section.

FIG. 13 shows the results of a simulation on the effects of the position deviation amount Ds and the cut width Sb on the stepped section. The vertical axis represents the maximum stress value applied to the stepped section 400, and the horizontal axis represents the section width Sb. The cross-section width Sb on the horizontal axis is the width at a position 12.5 μm away from the top section of the dicing blade, and it is marked when the position deviation Ds (μm) is Ds = 0, Ds = 2.5, and Ds = 7.5 The results obtained.

As clearly shown in the graph of FIG. 13, it can be found that in each section width Sb, the maximum stress applied to the stepped section 400 is larger with the position deviation Ds of the cutting blade in the groove width direction And become larger. Further, although not shown in FIG. 13, the maximum stress is generated in the root region 410 on the side where the width Wt of the stepped section 400 is large due to the positional deviation of the cutting blade. Suppose this happens because of being in office When the position deviation Ds becomes larger, a larger stress is easily applied to the root region 410 of the stepped section 400 on the side where the step becomes larger according to the principle of leverage.

In addition, the maximum stress value tends to become smaller on the side where the cut width Sb is narrower (the side where the degree of tapering is greater), and it is assumed that this occurs because it is used to compact the stepped section 400 to the front side of the substrate The stress on the side becomes weaker due to the large degree of taper, whereby the stress is hardly concentrated on the root region 410 of the stepped section 400. In addition, when the cut width Sb is narrow (Sb = 11.2μm) and the position deviation Ds is large (Ds = 7.5μm), it can be found that the location where the maximum stress value occurs suddenly changes, and the stress value (approximately 7.2) increases . It is assumed that this occurs because in the case where the cutting blade has a wide cutting width Sb (the cutting blade has a small degree of tapering), a wide surface is used to apply stress to the stepped section 400, but in the cutting blade In the case where the cutting width Sb is very narrow (the dicing blade has a large degree of tapering) and when the top section (apex) deviates from the range of the groove 140 on the front side of the semiconductor substrate, the stress is concentrated on On the area of the wedge-shaped top section (apex). Although not shown in Fig. 13, according to the simulation results, the maximum stress when the cut width Sb is narrow (Sb = 11.2μm) and the position deviation Ds is large (Ds = 7.5μm) is generated in the top section (apex) Area, and this position is indicated by P in FIG. 14. The “region of the top section” according to the example is a region including the top section and located on the side of the center of the groove on the back side, rather than the root region 410 of the stepped section 400.

B-3) Explanation of the results of the first experiment

FIG. 15 shows the results of an experiment of preparing a plurality of dicing blades having different degrees of tapering and cutting an actual substrate. In this experiment, the tip of a dicing blade having a thickness of 25 μm was processed to prepare a radius of curvature r in the range of 1 μm to 23 μm at the tip corner section and 5 μm at a position 5 μm away from the top section. And 25 A plurality of dicing blades with a cut width in the range of μm. A specific combination of the radius of curvature and the width of the cut is shown in FIG. 15, and a plurality of dicing blades are prepared so that the degree of taper is distributed almost equally. In addition, using a GaAs substrate, the width of the groove 140 on the front side is set to approximately 5 μm, the thickness T of the stepped section 400 is set to approximately 40 μm, and the positional deviation Ds of the cutting blade in the groove width direction is set to Less than ± 7.5μm. Since the thickness of the dicing blade is 25 μm, in a range where the radius of curvature of the tip corner section is 12.5 μm or more, the tip section has a wedge shape without a top surface. On the other hand, in a range where the radius of curvature is less than 12.5 μm, the degree of tapering becomes smaller as the radius of curvature becomes smaller, and in the case where the radius of curvature is 1 μm, the tip section has a nearly rectangular tip shape.

The “o” mark in FIG. 15 indicates that the fracture of the stepped section 400 is sufficiently suppressed and the degree of tapering corresponding thereto can be used in a mass production process, and the “x” mark indicates that the fracture of the stepped section 400 is not sufficiently suppressed and The corresponding degree of shrinkage cannot be used in mass production processes. In FIG. 15, the unavailable range appears between a small degree of tapering (curvature radius r is 8 μm or less) and a large degree of tapering (curvature radius r is 22 μm or more), and the degree of tapering is appropriate The range exists between the two ranges. This is based on the following reasons. In the range of small taper, stress is concentrated on the root region 410 of the stepped section 400 and the stepped section 400 is broken; in the range of large taper, stress is concentrated on the top section of the cutting blade ( Vertex) and the stepped section 400 breaks, as described in the results of the simulation described above. It can be said that the range where the radius of curvature r is 8 μm or less is a range where the stepped section is broken due to a small degree of tapering, and the range where the radius of curvature r is 22 μm or more is a stepped section which is broken due to a large degree of tapering. Range.

As described in the description of the simulation shown in FIG. 8, the maximum stress experienced by the stepped section 400 varies significantly depending on the degree of tapering of the tip section. Therefore, it can be found Even if the fracture occurs in the case of using a rectangular tip shape or any other tip shape, the extent of the taper is determined by determining the range of the appropriate taper degree and by controlling the tip shape as indicated in the experiment shown in FIG. 15 Within the range, there is no need to change the manufacturing conditions, that is, it is not necessary to increase the thickness T of the stepped section 400 (widening and deepening the width of the groove 140 on the front side) to increase the strength of the stepped section, Fracture can be suppressed to a level that does not cause problems in mass production.

B-4) Explanation of the results of the second experiment

FIG. 16 shows the results of experiments performed to confirm the effect of the difference in the width of the grooves on the front side on the fracture of the stepped section and the effect of the difference in the thickness of the stepped section on the fracture of the stepped section. In this experiment, a GaAs substrate was used, the thickness T of the stepped section 400 was set to 25 μm and 40 μm, and a dicing blade having a cut width of 16.7 μm at a position 5 μm from the tip section was used. Next, for each width Sa of the groove 140 on the front side and for each thickness T of the stepped section 400, in order to suppress the breakage of the stepped section 400 and use a crystal cutting blade in a mass production process, Check the allowable position deviation of the crystal cutting blade in the groove width direction. “A” to “D” in FIG. 16 indicate the range of the position deviation amount Ds obtained from the result that the fracture of the stepped section 400 is sufficiently suppressed.

For example, in the case where the thickness T of the stepped section is 25 μm and the width Sa of the groove on the front side is 7.5 μm, the range is “B”, and this means that In the case of deviations from ± 5 μm to less than ± 7.5 μm, the fracture of the stepped section 400 is sufficiently suppressed and the crystal cutting blade can be used in a large-scale production process, and it also indicates that the position deviation is ± 7.5 μm or more Next, the fracture of the stepped section 400 is not sufficiently suppressed. In addition, the thickness T in the stepped section 400 is 45 μm and In the case where the width Sa of the groove on the front side is 5 μm, the range is “A”, and this means that even in a state where the crystal cutting blade deviates from the groove width direction by ± 7.5 μm or more, the stepped section The breakage of 400 is sufficiently suppressed and the crystal cutting blade can be used in mass production processes. In addition, in the case where the thickness T of the stepped section 400 is 25 μm and the width Sa of the groove on the front side is 5 μm, the range is “D”, and this means that only the dicing blade in the groove width direction In the case where the deviation is less than ± 3 μm, the fracture of the stepped section 400 is sufficiently suppressed, and in the case where the deviation is ± 3 μm or more, the fracture of the stepped section 400 is not sufficiently suppressed.

The results of the experiment shown in FIG. 16 show that as the width of the groove 140 on the front side becomes larger, the stepped section 400 is stronger against the positional deviation of the cutting blade in the groove width direction. In other words, the stepped section 400 is less likely to break due to the stress from the dicing blade, because the width Sa of the groove 140 on the front side is wider. It is assumed that this is because the principle of leverage hardly works because the width Wt of the stepped section 400 becomes narrower as the width Sa of the groove 140 on the front side becomes wider. In addition, the results show that the stepped section is stronger when resisting the positional deviation of the cutting blade in the groove width direction, because the thickness T of the stepped section 400 is thicker. In other words, since the thickness T of the stepped section 400 is thick, the stepped section 400 is unlikely to be broken due to the stress from the crystal cutting blade. This is because the strength against stress becomes higher due to the thicker thickness T of the stepped section 400.

C) Method of designing the tip section

Next, a method of designing the tip shape of a dicing blade and a method of manufacturing a semiconductor wafer will be described based on the results of the simulation and experiments described above. Unless otherwise stated, the respective examples described below are based on a manufacturing process according to the example shown in FIG. 1.

17 is a flowchart illustrating a method of designing a tip shape of a dicing blade used in a method of manufacturing a semiconductor wafer according to an example of the present invention. One series of steps in FIG. 17 may be performed using an actual semiconductor substrate and an actual dicing blade or may be performed using simulation without using an actual semiconductor substrate and an actual dicing blade.

According to the flowchart of FIG. 17, first, in S200, a plurality of dicing blades are prepared, and the shapes of the tip shapes of the dicing blades are different from each other. For example, as in the experiment shown in FIG. 15, a plurality of dicing blades are prepared and the degree of taper is made with a constant interval difference. The shape of the tip used in a complete cut as a general cut method is a rectangular shape as shown in FIG. 5G. Therefore, in order to prepare a plurality of crystal cutting blades having different degrees of taper by using the crystal cutting blades having this rectangular shape, the crystal cutting blades having this rectangular shape need to be processed in advance. For example, a plurality of dicing blades having a rectangular shape are obtained and used for practically dicing a part such as a dummy wafer for tip processing, thereby abrading the tip shape due to cutting The degree may be different only for every crystal blade. The details of the method of sharpening the dicing blade will be described later.

At S200, the plurality of dicing blades can be prepared by obtaining a plurality of dicing blades having different degrees of tapering from other entities (others) instead of processing the tip shape internally. In addition, step S200 can be regarded as a step of preparing a plurality of crystal cutting blades that apply different degrees of stress to the root region 410 of the stepped section 400. Furthermore, the dicing blades need not be prepared collectively at one time. For example, the following method can be used. A single-type tapered blade with a tapered degree can be prepared first, and the process in the process can be performed up to S204 described below, and a chip with other tapered degrees can be prepared, and then the process in the process can be performed again until S204. In addition, the plurality of dicing blades do not necessarily have to be separated, and a plurality of dicing blades having different degrees of taper can be prepared by gradually changing the tip shape of a monolithic crystalline blade.

The "degree of tapering" in the example is determined by, for example, the radius of curvature of the tip corner section of the crystal cutting blade, the radius of curvature of its top section (apex) and the thickness of the blade at a predetermined distance from the top section. For example, the degree of taper becomes larger because the radius of curvature of the tip corner section is larger and the radius of curvature of the top section (apex) is smaller. In addition, since the degree of taper becomes larger as the thickness of the blade at a predetermined distance from the top section becomes thinner, the degree of taper can be correlated with the thickness of the blade at a predetermined distance from the top section. Moreover, when the cutting blade is worn and the thickness of the tip corner section becomes thinner, the degree of tapering also becomes larger. The degree of taper may be correlated with the degree of stress applied to the root region 410 of the stepped section 400, and the degree of stress applied to the root region 410 of the stepped section 400 becomes smaller as the degree of taper becomes larger. Unless otherwise stated, the degree of tapering refers to the degree of tapering of the shape on the tip side in a range from the top section of the dicing blade to a distance corresponding to approximately twice the thickness of the dicing blade.

Next, in S202, in order to confirm the broken state of the stepped section in the case of using a plurality of dicing blades prepared in S200, a semiconductor substrate having a plurality of grooves having the same shape is prepared, and the grooves are formed On the front side and suitable for mass production processes. The pitch of the grooves on the front side may be a pitch used for a mass production process or may be a different pitch. In other words, the pitch can be set only so that the state of the fracture of the stepped section in a mass production process can be estimated for each degree of tapering. In addition, in S202, in the case of a semiconductor substrate without a groove, the preparation of the semiconductor substrate can be performed by forming a groove on the front side of the substrate as in the case of S104 in FIG. 1, or can be obtained from other entities ( Others) obtain the semiconductor substrate in which the groove has been formed. "Identical shape" does not mean that the shapes are exactly the same, but means substantially the same shape, which has an error or the like that may occur in the case where grooves are formed in order to have the same shape.

Next, by using the plurality of dicing blades prepared in S200 Each of them forms a groove 170 on the back side in the semiconductor substrate prepared in S202. Next, the state of fracture of the stepped section when each of the plurality of dicing blades was used was confirmed. In other words, it is confirmed whether the state of the fracture causes a problem in the mass production process. Use a microscope or the like to confirm the presence and extent of spalling, cracking, etc. around the stepped section. The formation of the groove on the back side and the confirmation of the state of the fracture should be performed multiple times for each tip shape, in order to determine the degree of tapering of the stepped section without fracture (fracture is suppressed to the extent that the cutting blade can be used in large quantities Shape of the production process). In addition, considering the change in the position of the crystal cutting blade, it is preferable to perform the confirmation under the condition that the stepped section is easily broken. Therefore, through the above confirmation, the degree of tapering of each crystal blade and the determination of whether the stepped section is broken due to the degree of tapering (whether the degree of tapering can be used in a large-scale production process) can be taken as an example shown in FIG. Listed.

Next, in S206, it is determined whether or not both the tapered degree of the stepped segment fracture and the tapered degree of the stepped segment non-fracture are included in the plurality of crystal cutting blades prepared in S200. For example, in the case of FIG. 15, since both the tapered degree of the stepped section breaking and the tapered degree of the stepless section not broken are included, the flow proceeds to S210. The case of including two degrees of taper as described above means that at least part of a range of degree of taper that can be used in a mass production process and at least part of a range of degree of taper that cannot be used in a mass production process can be specified. For example, in the case where the stepped section is broken at a small taper and the stepped section is not broken at a large taper, it can be assumed that the fracture at the small taper is caused by the root applied to the stepped section Area stress. Therefore, it can be judged that the range of the degree of taper smaller than the small degree of taper is an unusable range. In addition, it can be judged that at least the degree of taper that the stepped section does not break is the degree of taper that can be used. Conversely, in the case where the stepped section is broken at a large taper and the stepped section is not broken at a small taper, it can be assumed that the fracture at the large taper is caused by the stress in the wedge-shaped top section. region Caused by concentration. Therefore, it can be judged that the range of the degree of taper that is larger than the large degree of taper is an unusable range. In addition, it can be judged that at least the degree of taper that the stepped section does not break can be used. In the case of using a crystal cutting blade with an arbitrary tip shape, the narrow and shallow grooves can cause the stepped section to break; as described above, in S206, the stepped section breaks down and the stepped section is included. The fact that the degree of tapering of the segment does not break means that at least part of the range of the degree of tapering that can be used in the mass production process and at least part of the range of tapering that is not available for the mass production process can be targeted at the narrow side And shallow grooves are specified.

On the other hand, the fact that all of the tapering degree of the sliced blade prepared by S200 is broken in the stepped section means that the degree of tapering that can be used for mass production is completely unspecified. Therefore, in this case, the flow advances to S208. In addition, in the case where the stepped section does not break at all degrees of tapering, manufacturing conditions may be inappropriate. For example, the groove on the front side is unnecessarily wide and deep, so the strength of the stepped section is Set it unnecessarily high. Therefore, the flow also proceeds to S208 in this case.

At S208, design conditions such as the shape (width, depth, etc.) of the groove 140 on the front side are changed. According to the results of the experiment shown in FIG. 16, the strength of the stepped section becomes lower and the stepped section is more likely to break because the groove 140 on the front side is shallower and the depression on the front side is shallower. The width Sa of the groove 140 is narrow. In other words, in the case where all the tapering degree of the sliced blade prepared by S200 in the stepped section is broken, it can be assumed that the groove 140 on the front side is too shallow or too narrow, so the stepped section is too weak . Therefore, in this case, the strength of the stepped section is made higher by changing the shape of the groove 140 on the front side. More specifically, at least the width Sa of the groove 140 on the front side is made wider or the depth of the groove is deeper.

In addition, according to the results of the simulations shown in FIG. 12 and FIG. 13, since the tip section of the crystal cutting blade in the groove width direction is formed when the groove 170 on the back side is formed. Position accuracy is lower and stepped sections are more likely to break. Therefore, the manufacturing conditions that influence the position accuracy can be changed to improve the position accuracy of the tip section of the cutting blade in the groove width direction. For example, the existing crystal cutting device can be changed to a crystal cutting device with high accuracy for positioning the crystal cutting blade. As described above, changing these conditions, by changing at least the shape of the groove 140 on the front side or the position accuracy of the cutting blade in the groove width direction, makes the stepped section break hardly occur.

In addition, in the case that the stepped section does not break at all the degree of taper of the crystal cutting blade prepared by S200, it can be assumed that the groove 140 on the front side is unnecessarily wide and deep, so the strength of the stepped section It is set to be unnecessarily high. In this case, the groove width can be changed to be narrower, thereby increasing the number of semiconductor wafers that can be obtained from a single semiconductor substrate. When the groove width is made narrow, it is difficult to form deep grooves, and the strength of the stepped section becomes weak. However, as shown in FIG. 8, the stress varies significantly depending on the degree of tapering. Therefore, by specifying an appropriate degree of tapering, the groove 170 on the back side can be formed without causing the stepped section of the narrower and shallower groove 140 on the front side to break. Therefore, in the case where all the degrees of tapering of the dicing blade prepared in step S206 are not broken, the design conditions are changed so that the number of semiconductor wafers that can be obtained from a single semiconductor substrate The groove 140 is narrower (or narrower and lighter) and increases, and the process from S200 is performed again, and the process from S200 to S208 is repeated until the process reaches S210. If the groove 140 is narrow, it becomes difficult to form a deep groove, as described above. This is because, for example, in the case where the groove 140 on the front side is formed by dry etching, if the groove is narrow, the etching gas hardly penetrates into the groove. The progress of the etching is interrupted, and in the case where the groove formation is performed using a thin dicing blade, the blade is easily broken.

In addition, for example, the number of types of the cutting blade prepared in S200 is In the case where the degree of taper is not balanced and thus is too large or too small, the state including both the degree of taper of the stepped section breaking and the degree of taper of the stepped section not breaking does not hardly occur in S206. Therefore, in this case, the design conditions may be changed in S208 so that the number of types of the tip shape of the dicing blade to be prepared in S200 is increased.

As described above, the design conditions are changed in S208, and the flow from S200 is executed again. Then, the process from S200 to S208 is repeated until the process reaches S210.

In S210, an initial tip shape of a crystal cutting blade for a mass production process is selected from a tip shape having a tapered degree of non-breaking of a stepped section. In addition, the degree of tapering of the stepped section fracture is excluded from the objects to be selected, so that of course such a degree of tapering is not used during mass production periods. In other words, the degree of tapering is excluded from the range of objects to be selected. However, a tip shape having the same degree of taper as that used in experiments is not necessarily selected as the tip shape for a mass production process. It is possible to estimate the range of the degree of taper in which the stepped section does not break, and the degree of taper included in the estimated range can be selected. For example, in the results of the experiment in FIG. 15, it can be estimated that the range of the radius of curvature r of the tip corner section 13 μm to 21 μm corresponds to the range of the degree of tapering of the stepped section without breaking, and the choice corresponds to 14.5 μm or 18.5 The tip shape of the curvature radius r of μm is used as the initial tip shape of the crystal cutting blade to be used in the mass production process, and control is performed so that the curvature radius does not deviate from the range of 13 μm to 21 μm in the mass production period. In other words, in the case where the number of the tapered extents that the stepped section does not break is plural, the range of these degrees can be estimated as the range that the stepped section does not break, and it is only possible to select to include in the range A tapered tip shape.

In the range of the degree of taper in which the stepped section does not break, preferably, a tip shape having a degree of taper that is smaller than the degree of taper at the center of the range should be selected as a crystal cutting blade to be used in a mass production process The initial tip shape. For example, according to Figure 15 As a result of the experiment shown, a tip shape in which the radius of curvature r of the tip corner section is in a range of 13 μm to 17 μm should be selected instead of a tip shape in which the radius of curvature r is in a range of 17 μm to 21 μm. The state where the degree of taper is small is that the tip section is not worn more than the state where the tip section has a large degree of taper; in other words, the life of the crystal blade with a small degree of taper is longer. In addition, in the case where a crystal chip having a generally rectangular shape is used and the tip shape of the crystal chip is processed, the time required to form the tip shape in advance to a shape having a desired degree of tapering can be reduced.

Furthermore, in the case where the degree of tapering of the stepped section fracture exists on the side where the degree of tapering is greater than the degree of tapering of the stepped section without breaking, it is preferable to perform control during mass production so that The tip section of the crystal cutting blade does not form a shape having such a degree of taper as the wear of the tip section of the crystal cutting blade increases. For example, in FIG. 15, the tapered degree of the fracture of the stepped section (that is, the radius of curvature is in the range of 22 μm to 23 μm) exists in the radius of curvature of the tip corner section greater than the tapered of the stepped section. On the side of the range of 13 μm to 21 μm (out of the range of 21 μm). Therefore, in the case of the results of the experiment shown in FIG. 15, it is preferable to perform control in a large-scale production process so that the radius of curvature of the tip corner section does not exceed the wear of the tip section of the crystal cutting blade. 21 μm. More specifically, before the degree of tapering reaches this degree of tapering, it is preferable that the use of the dicing blade should be stopped and the dicing blade should be replaced. It should be noted that "replacement" in the example means not only replacing the crystal cutting blade with a completely independent crystal cutting blade, but also reprocessing (trimming) the tip shape of the same crystal cutting blade.

The flow of a method for designing the tip shape of a crystal cutting blade according to an example has been described above. With this design method, when deciding the tip shape of a dicing blade used in a mass production process, it is possible to determine in a mass production process a relationship having a ratio of tapering of the tip shape and the breakage of the semiconductor wafer in the mass production process. Shallow depth Degree of groove 140 on the front side. Traditionally, in the case where fine grooves having a width of several μm to a dozen μm are connected to each other, it is not clear what kind of failure is caused by what cause. Therefore, in the actual mass production process, it is difficult to adopt the manufacturing process shown in FIG. 1. In addition, if an attempt is made to use the manufacturing process shown in FIG. 1, the grooves on the front side become unnecessarily wide and deep. On the other hand, in the case of the method of designing the tip shape of the crystal cutting blade according to the example, the fact that the stress to the stepped section changes significantly as shown in FIG. 7 and FIG. 8 is noticed, In S200 in FIG. 17, a plurality of dicing blades having different degrees of tapering are prepared. In addition, in S206 in FIG. 17, the selection of the tip shape is performed only in a case where both the tapered degree of the stepped section fracture and the tapered degree of the stepless section not fracture are included. Therefore, narrower and shallower grooves 140 on the front side can be used during mass production, although the time and effort required for the design is greater than that required when using a crystal cutting blade with an arbitrary tip shape Time and workload.

Next, a specific method of preparing a plurality of dicing blades having different degrees of tapering at S200 in FIG. 17 will be described below. First, a diamond blade or a blade in which a diamond blade and an aluminum substrate are integrated can be used as a dicing blade for cutting, for example, a GaAs compound semiconductor. Roughly, the tips of commercially available dicing blades are, for example, formed in a rectangular shape without a curved surface at the tip section, as shown in FIG. 5G. For this reason, in the case where the crystal cutting blade has a rectangular shape but does not have a desired shape, the tip section of the crystal cutting blade needs to be processed.

This process includes the following steps. That is, for example, a commercially available crystal cutting blade is obtained, and a material for processing the tip section of the obtained crystal cutting blade is selected. For example, a substrate made of Si, SiC, or another compound semiconductor material may be selected as the material for processing use. Other materials have to be used as long as they can process the tip section into the desired shape.

Next, the dicing blade is used to repeat the cutting of the processed semiconductor substrate, and the tip section is thus worn to form a desired shape. The angle formed by the substrate to be processed and the dicing blade, the rotational speed of the dicing blade, the polishing time, the polishing agent, etc. may be appropriately selected to obtain a desired curved surface. As described above, before the dicing step, the dicing blade is formed into a desired wedge shape using a material prepared for processing purposes for processing the tip section. With this method, even a rectangular shape dicing blade for general complete dicing can be commonly used as a dicing blade prepared in S200 in FIG. 17.

Next, details of what degree of tapering should be made in S200 in FIG. 17 will be explained as follows.

As a first mode, it is preferable to include at least one type of crystal cutting blade that is tapered more than a crystal cutting blade having a semi-circular tip section. In other words, it should preferably include at least one dicing blade having a tapered degree of maximum stress generated in the root region of the stepped section that is smaller than the maximum stress in the dicing blade with a semicircular tip section. As clearly shown in FIG. 8, the maximum stress is saturated at a low level in a range where the tip section tapers more than the semicircular tip section (r is greater than 12.5 μm). In other words, whether or not the stepped section is broken under conditions close to the condition that the maximum stress applied to the root region is minimized by preparing at least one crystal cutting blade having a degree of tapering included in the range can be performed. confirm. In addition, for example, in the case where the stepped section is broken, it can be easily determined in S208 that the width and depth of the groove 140 on the front side need to be changed so that the stepped section is hardly broken, instead of changing the design conditions to This increases the number of kinds of tip shapes prepared.

As the second mode, it is preferable to include, in addition to the chip-cutting blade having a more tapered tip section than the semi-circular tip section, a chip with a smaller tip section than the semi-circular tip section. Slicing blade. In other words, it should preferably include that the maximum stress generated in the root region of the stepped section is less than the maximum Both the dicing blade with a tapered degree of stress and the dicing blade with a tapered degree with a larger maximum stress. As clearly shown in FIG. 8, the maximum stress is saturated at a low level in a range where the tip section tapers more than the semicircular tip section (r is greater than 12.5 μm). On the other hand, the change in the maximum stress is large in a range (r is 12.5 μm or less) in which the tip section shrinks less than the semicircular tip section. In other words, in the case of preparing a crystalline blade having a degree of taperedness included in each range, the crystalline blade is very likely to have a tapered degree of stepped section breakage and also a tapered degree of stepped section not broken. . Therefore, the flow easily progresses from S206 in FIG. 17 to S210 in FIG. 17. In other words, it helps to choose the shape of the tip.

As a third mode, it is preferable to include a plurality of dicing blades having a degree of taper smaller than a degree of taper of a cutting section having a semi-circular tip section. In other words, it should preferably include a plurality of crystalline blades having a degree of tapering in which the stress greater than the stress generated in the crystalline blade having a semicircular tip section is generated in the root region of the stepped section. As clearly shown in FIG. 8, the maximum stress is in a range (r is less than 12.5 μm) in a range (r is less than 12.5 μm) in which a stress greater than a stress generated in a crystal cutting blade having a semicircular tip section is generated in a root region of the stepped section. The change with respect to the degree of tapering is larger than the change in a range (r is 12.5 μm or more) in which the degree of tapering becomes larger than the degree of tapering in the range. Therefore, in the case of preparing a plurality of crystal cutting blades within a range where the maximum stress varies greatly, it is helpful to confirm whether or not the stepped section does not break even when the degree of tapering is reduced.

As a fourth mode, it is preferable to include three or more dicing blades having a degree of taper smaller than that of a cutting section having a semi-circular tip section. In other words, it should preferably include at least three types of crystal cutting blades having a degree of tapering that is greater than the stress generated in the crystal cutting blade having a semi-circular tip section, resulting in a tapered degree in the root region of the stepped section. As clearly shown in FIG. 8, a range in which a stress greater than a stress generated in a crystal cutting blade having a semicircular tip section is generated in a root region of the stepped section (r is 12.5 μm or less), the change in the maximum stress is large, and the change in stress is non-linear but non-linear. Therefore, in the case of using at least three kinds of crystal cutting blades within a range where the stress is changed non-linearly, compared with the case of using two kinds of crystal cutting blades, it is helpful to reduce the stepped section even if the degree of tapering Confirm whether the case does not break.

As the fifth mode, it is preferable that the prepared crystal cutting blade includes all crystal cutting blades having a wedge-shaped tip shape without a top surface at the top section and having a crystal cutting blade when a groove on the back side is formed. In the case where the position of the top section in the groove width direction is far from the width of the groove on the front side, the maximum stress is generated in a degree of tapering in the region of the top section away from the width of the groove on the front side. Unless such a crystal cutting blade is included, in the case where the position of the top section in the groove width direction becomes far away from the width of the groove on the front side, it is impossible to perform the stepped section even if the degree of tapering increases. In this case, it is confirmed that there is no break. In addition, in the case where a plurality of these crystal cutting blades are included, compared with the case where only one type of crystal cutting blade is used, it is helpful to confirm that the stepped section does not break even if the degree of tapering increases. . In the case where it is known that the top section of the dicing blade does not become far away from the width of the groove on the front side, it is not necessary to include such a dicing blade.

As the sixth mode, it is preferable to prepare the dicing blades having the degree of tapering as shown in FIG. 15 arranged at almost equal intervals. In addition, although S200 in FIG. 17 is required to prepare a dicing blade having at least two degrees of tapering, in order to use narrower and shallower grooves on the front side, it should preferably be prepared as shown in FIG. 15 There are as many types of tapered blades as possible.

D) An example based on the relationship between the position of the blade and the width of the groove D-1) Relationship between cutting accuracy and grooves on the front side

Next, the relationship between the variation range of the tip section of the crystal cutting blade in the groove width direction and the width Sa of the groove 140 on the front side will be described below, and the design of the crystal cutting blade will also be described below. A method of a tip shape and a method of manufacturing a semiconductor wafer based on this relationship. The range of variation of the tip section of the cutting blade in the groove width direction is the range in which the position of the cutting section of the cutting blade changes in the groove width direction due to manufacturing differences in the mass production period. The range is determined by manufacturing conditions including, for example, the positioning accuracy of the manufacturing apparatus used and the degree of deformation (amount of bending and warping) of the crystal cutting blade. In addition, the positioning accuracy of the manufacturing device includes the detection accuracy of a camera or the like for detecting alignment marks and the like, and also includes the accuracy gradually accumulated when cutting is performed along a plurality of lines. The bending and warping of the cutting blade will occur depending on the thickness of the cutting blade, the accuracy of the surface holding the cutting blade and the method of fixing, the stress during cutting, the rotation speed of the device, and the like.

As described with reference to FIG. 13, in a dicing blade having a large degree of tapering, a range in which a wedge-shaped top section without a top surface is far from a groove 140 on a front side of a semiconductor substrate in a groove width direction Down, stress can be concentrated on the area of the top section and the stepped section will break in some cases. In other words, in the case of using a crystalline blade having a tapered degree of stress concentrated on the area of the wedge-shaped top section without the top surface, it is preferable to determine the shape of the tip of the crystalline blade and the groove 140 on the front side. Shape (width and depth) ... etc. such that even if the top section is in the top section away from the groove 140 on the front side of the semiconductor substrate, the manufacturing conditions in the range of the groove width direction and the groove 140 on the front side In the relationship between the widths, the stepped sections do not break.

On the other hand, even in a crystal chip with a large degree of tapering, the stress applied to the stepped section does not become far away from the positive section due to manufacturing differences. The manufacturing conditions of the width of the grooves 140 on the front side do not change abruptly. In other words, in the case where there is no manufacturing condition in which the wedge-shaped top section of the top surface is included in the width of the groove 140 on the front side, even with a large degree of tapering (that is, the tip corner region shown in FIG. 15 When the curvature radius of the segment is, for example, 22 μm or 23 μm), the stepped segment does not break. Conversely, the maximum stress applied to the stepped section becomes smaller because the degree of tapering of the dicing blade is larger. Therefore, from the viewpoint of minimizing the maximum stress, a dicing blade having a large degree of tapering is preferred.

In addition, since the wedge-shaped top section without the top surface is usually formed at the center of the thickness of the dicing blade, the manufacturing condition of the wedge-shaped top section without the top surface does not become far from the width of the groove 140 on the front side. It is a manufacturing condition that the variation range of the thickness center of the dicing blade in the groove width direction is included in the width of the groove 140 on the front side. However, in some cases, due to the partial wear depending on the conditions when the tip shape is pre-treated, and the wear condition in the actual manufacturing process, the wedge-shaped top section without the top surface may become far away from the cutting blade The thickness of the center. In other words, the position of the wedge-shaped top section without the top surface and the center of the thickness of the dicing blade do not always coincide with each other.

From the viewpoint of accuracy, it is better to consider whether the actual position of the top section becomes far away from the width of the groove 140 on the front side. However, since the top section is usually formed at the center of the thickness of the crystal cutting blade as described above, when the center position of the thickness of the crystal cutting blade is considered, compared with the case where nothing is considered, the stepped area Accidental fracture of the segment will be suppressed. Regardless of the above-mentioned differences, since the accidental fracture of the stepped section is similarly suppressed, according to the example, the "variation range of the thickness center of the crystalline blade in the groove width direction is included in the width of the groove 140 on the front side" (Or the manufacturing conditions that become farther away from the width of the groove 140 on the front side) can be regarded as "the range of variation of the wedge-shaped top section without the top surface in the groove width direction includes the groove 140 on the front side" Width Medium (or getting away from the width of the groove 140 on the front side), unless otherwise stated and there is no technical contradiction.

In this example, the term "including" in the example also includes the case where the position of the top section exactly matches the width of the groove. In addition, whether the variation range of the top section of the cutting blade in the groove width direction or the center of the thickness of the tip section is included in the width of the groove 140 on the front side depends on whether the state far from the width includes a large number of Factors of time-lapse factors in the production period appear to judge. The range of variation of the center of the top section or thickness is determined by, for example, including the positional accuracy of the manufacturing apparatus used as described above and the degree of deformation (amount of bending and warping) of the cutting blade. However, for the purpose of grasping the amount of bending and warping of the crystal cutting blade, these amounts need to be grasped through actual experiments or the like, and this requires time and effort. On the other hand, according to the specifications or the like described in the catalog or the like, the position accuracy of the manufacturing device can be relatively easily grasped. Therefore, in a case where the amount of bending and warping is not grasped, for example, in a case where it is difficult to grasp the amount of bending and warping, only the positional accuracy of the manufacturing device may be considered. In other words, in the example, the judgment as to whether the range of the positional accuracy of the manufacturing device used is included in the width of the groove 140 on the front side may be made depending on the conditions, rather than the range of variation of the top section or the cutting blade A condition for determining whether the center of the thickness of the tip section is included in the width of the groove 140. In this case, as described above, the values described in the catalogue of the products used or the like can be used as a range of the position accuracy of the manufacturing apparatus. However, in cases where specifications are not described in the catalog or the like or specifications cannot be obtained from the manufacturer, actual measurement is required. In this case, taking into account the environmental conditions and other conditions, the actual measurement will be performed multiple times. The average value and standard deviation of the accuracy are calculated based on the measurement results, and three times the standard deviation (3 standard The value obtained by adding a value in a range from a difference) to a quadruple value (4 standard deviations) to the average value is set as a range of the position accuracy of the manufacturing apparatus. Accurate in location In the case where the degree depends on the accuracy level of a plurality of devices, a square average of the accuracy levels of the respective devices is used.

Regarding the width of the groove on the front side required for judging whether the top section is included in the width of the groove 140 on the front side, the width of the groove on the front side is not as shown in FIG. 27A To the constant case shown in FIG. 27D, the maximum width from the position of the bottom section of the groove on the front side to the position reached by the top section of the dicing blade can be used as the width. For example, in a case where it is difficult to make a judgment as to whether the top section is included in the width of the groove 140 on the front side and it is impossible to make a judgment, even if an example in which the top section should be included or the top section should not be included In any of the other examples (away from the width), it is also assumed that there is no significant difference in the degree of fracture at the stepped section therebetween. Therefore, only any one of them can be arbitrarily selected.

D-2) In the case where the top section of the blade is included in a groove on the front side

Next, a method of designing the tip shape of the dicing blade and a method of manufacturing a semiconductor wafer will be described based on the relationship between the position of the dicing blade in the groove width direction and the width of the groove 140 on the front side. First, an illustrative specific example of manufacturing conditions in the variation range of the thickness center of the dicing blade in the groove width direction included in the width of the groove 140 on the front side will be described.

As a first mode, in a manufacturing condition in which a variation center of the thickness of the crystal blade in the groove width direction is included in the width of the groove 140 on the front side, the tip of the crystal blade can be designed as follows shape. For example, when the tip shape of the dicing blade is designed according to the process shown in FIG. 7, it is not necessary to prepare a dicing blade having a large degree of tapering at S200. Based on the results of the simulation shown in FIG. 8, in the range of the radius of curvature r of 25 μm or more, the maximum stress only changed by 0.1 MPa. So the preparation has the tip A tapered blade having a degree of curvature of the corner section of 25 μm or more (the radius of curvature of the tip corner section is not less than the thickness of the chip blade) is almost meaningless. In other words, the plurality of dicing blades to be prepared may include only a tapering in the root region of the stepped section with a stress greater than the stress generated by the radius of curvature of the tip corner section not less than the thickness of the dicing blade. Degree of at least everything crystal blade. A crystal blade having a degree of tapering of a stress less than the stress generated in the root region of the stepped section may not be included.

As a second mode, in the manufacturing conditions in which the variation range of the thickness center of the dicing blade in the groove width direction is included in the width of the groove 140 on the front side, a manufacturing method described below can be used to manufacture a semiconductor Wafer. In the flow shown in FIG. 17, the range of the tapered degree of fracture of the stepped section due to the small tapered shape of the tip shape of the crystal cutting blade is confirmed. A dicing blade having a tip shape having a degree of tapering greater than a degree of tapering included in this range is used. In contrast, a dicing blade having a tip shape having a degree of taper smaller than a degree of taper included in this range is not used. This is because in manufacturing conditions in which the center of the thickness of the dicing blade is included in the width of the groove 140 on the front side, even if the degree of tapering is large, the stress applied to the stepped section does not change suddenly, unlike As shown in FIG. 13, the width of the cutout is narrow (Sb = 11.2) and the position deviation Ds is large (Ds = 7.5μm), so that only the range on the side with a smaller degree of taper can be considered in the design .

According to FIG. 15, the range of the tapered degree of fracture of the stepped section due to the small tapered degree is a range in which the radius of curvature of the tip corner section is not greater than 8 μm. In addition, in the manufacturing conditions in which the variation center of the thickness of the dicing blade in the groove width direction is included in the width of the groove 140 on the front side, the stepped section is formed due to the formation of the groove on the back side. In the case of fracture, this means that the stress on the root region of the stepped section is too great. Therefore, in the case where the stepped section is broken due to the formation of a groove on the back side by using a crystalline blade having a certain degree of tapering, it is possible to simply not use a tape having a degree of tapering smaller than the tapering degree. Shredded blade.

As a third mode, in a manufacturing condition in which the variation range of the center of the thickness of the dicing blade in the groove width direction is included in the width of the groove 140 on the front side, a condition having a ratio greater than that shown in FIG. 6D is used. The shape of the semi-circular tip section of the semi-circular tip section which is the initial tip shape at the time of cutting tapers the shape of the more-shaped tip. As clearly shown in FIG. 8, in a range (r <12.5 μm) where the degree of taper is smaller than that of the semi-circular tip section (r = 12.5 μm), the maximum stress is the case when the degree of taper changes. Significantly changed. On the other hand, in a range (r> 12.5 μm) in which the degree of tapering is larger than that of the semicircular tip section, the maximum stress is saturated at a low level. When it is assumed that the tip shape which is tapered more than the tip section having a semicircular shape is the initial tip shape at the time of cutting, the state that the stress on the stepped section during the mass production period is suppressed at a low level even in The condition that the cutting blade is worn afterwards can be maintained. In addition, in the case where the shape of the area where the stress is saturated at a low level is formed as the initial tip shape, the change in the stress applied to the stepped section can be suppressed and the narrower and shallower groove can be more easily on the front side It is adopted on the side, even when the tip shape is changed when preparing a crystal cutting blade having an initial shape. As a result, as compared with the case where a tip shape having a degree of taper smaller than that of the semicircular tip section is used as the initial tip shape, as a result, the stepped section is suppressed from being broken.

A crystal chip having a shape that tapers more than a crystal chip having a semi-circular tip section can be prepared by processing a rectangular crystal chip as described in S200 in FIG. 17 or can be obtained from other entities ( Others) obtained this dicing blade instead of performing the process in-house to prepare it. In addition, it is possible to confirm whether the range of variation of the center of the thickness of the crystalline blade in the groove width direction is included in the width of the groove on the front side, and if the range is included in the width, A determination is made to use, for example, a tapered blade having a shape that is previously tapered rather than having a semi-circular tip section as an initial tip shape at the time of cutting. Multi-shaped cut crystal blades.

As a fourth mode, in the manufacturing conditions in which the variation range of the center of the thickness of the dicing blade in the groove width direction is included in the width of the groove 140 on the front side, it is possible to use the manufacturing method described below Manufacture of semiconductor wafers. For example, in the case where the stepped section has a strength such that the stepped section breaks when using a crystal cutting blade having a rectangular tip shape in section as viewed from the direction of rotation, a step having a larger fracture than the stepped section is used. A tapered tip-shaped dicing blade having a tapered degree range to form a groove 170 on the back side. In other words, in the case as described above, the back surface is formed using a tip-shaped dicing blade having a tapered shape having a stress that is tapered so that a stress equal to or greater than the stress capable of breaking the stepped section is not applied to the root region of the stepped section. The side groove 170. With these manufacturing conditions, even if the shape of the grooves on the front side is narrow and shallow, the stepped section may be broken under the condition of using a regular and frequently used rectangular crystal cutting blade, and the semiconductor substrate may be crystallized so that The stepped section of the semiconductor wafer does not break from the stress applied by the dicing blade.

As clearly shown in Figure 8, the stress experienced by the stepped section changes four or more times depending on the degree of tapering of the tip section. Therefore, this illustrative specific example is based on two discoveries: one was found to be the extent to which the stepped section might break even if the shape of the groove on the front side is narrow and shallow to the stepped section, using a crystal tip with a rectangular tip shape, There is still a degree of taper in which the stepped section does not break, and another finding is that the range in the groove width direction is included in the width of the groove 140 on the front side even if the degree of tapering is in the center of the thickness of the crystal cutting blade. The manufacturing conditions become larger, and the stress applied to the stepped section does not change suddenly.

By using a chisel blade with a tapered tip section that tapers more than a semi-circular tip section or by using a stress that has less stress than the semi-circular tip section A tapered cutting blade generated in the root region of the stepped section can use a region where the stress applied to the stepped section is saturated at a low level. Therefore, the use of these crystal cutting blades is preferable from the viewpoint of stress.

D-3) When the top section of the blade becomes far away from the groove on the front side

The exemplary specific examples of the manufacturing conditions in the width of the center of the dicing blade in the groove width direction included in the width of the groove 140 on the front side have been described above. Next, an illustrative specific example in the manufacturing conditions in which the variation range of the center of the thickness of the dicing blade in the groove width direction becomes farther from the width of the groove 140 on the front side will be described below.

First, as a first mode, when a chip blade having a wedge-shaped tip shape without a top surface at the top section is used, and the range of variation of the top section in the groove width direction becomes far from the width of the groove on the front side Among the manufacturing conditions, semiconductor wafers can be manufactured by using the manufacturing method described below. For example, a groove on the back side is formed using a dicing blade and its tip shape has a range of taper that is smaller than the range of taper where the maximum stress is applied at the region of the top section and the stepped section is broken. In other words, a dicing blade having a shape as described above is used in a mass production period.

With this manufacturing method, even in a manufacturing condition in which the variation range of the wedge-shaped top section without the top surface in the groove width direction becomes far away from the groove width on the front side, it is possible to avoid an inadvertently used dicing blade A scenario with a degree of tapering where maximum stress would be applied at the area of the top section and the stepped section could eventually break. As a result, accidental fracture can be suppressed, and the fracture of the stepped section can be suppressed by this, compared with the case of using a tip-shaped crystal chip having a stepped section broken at the maximum stress applied to the region of the top section. Effectively suppressed. The degree of tapering of the maximum stress applied to the stepped section In the case where the range needs to be confirmed, the confirmation can be performed, for example, by performing such a stress simulation as shown in FIGS. 12 and 13 or by actually forming a groove on the back side and by checking the state of its fracture . In a case where the groove is actually formed on the back side and a broken state is confirmed, for example, in a case where the groove is actually formed on the back side for a narrow and shallow groove on the front side, and in a stepped shape In the case of a segmental fracture, it is only necessary to confirm whether a fracture has occurred in the region or the root region of the top segment.

As a second mode, a manufacturing method is used in which a chip blade having a wedge-shaped tip shape without a top surface at the top section is used and the range of variation of the top section in the groove width direction becomes far from the width of the groove on the front side In the condition, the crystal cutting blade is replaced before the degree of tapering becomes in a range where the maximum stress is applied to the top section and the stepped section is broken (due to the wear of the crystal cutting blade). With this method, the maximum stress caused by the abrasion of the crystal cutting blade at the region of the top segment is prevented from breaking. Further, in the case of using such a manufacturing method, by using the design method shown in FIG. 17, it is possible to use a groove having a position in the groove width direction of each top section that becomes farther away from the front side A plurality of dicing blades having tip shapes with different degrees of tapering in the state of width are formed with grooves on the back side. The degree of tapering that can be used and the tapering that should not be used are confirmed based on the results of the grooves on the back side And the replacement of the dicing blade and the dicing blade should not be used until the degree of taper reaches the degree of taper obtained from the confirmed result.

As a third mode, a manufacturing method is used in which a crystal cutting blade having a wedge-shaped tip shape without a top surface at the top section is used, and the range of variation of the top section in the groove width direction becomes far from the width of the groove on the front side. Among the conditions, a semiconductor wafer can be manufactured by using a manufacturing method described below. For example, in a manufacturing condition using a cutting blade having a wedge-shaped tip shape without a top surface, and in the cutting blade having the top section in a groove In a manufacturing condition in which the degree of tapering of the stepped section at the area where the maximum stress is applied to the top section when the position in the width direction becomes far away from the groove on the front side, the shape of the groove on the front side is manufactured (Width and depth) and the depth reached by the top section are set so that the stepped section does not break due to the maximum stress when the position of the top section in the groove width direction becomes far away from the groove width on the front side Conditions. With this manufacturing method, in a manufacturing condition where the position of the top section of the dicing blade in the groove width direction becomes far from the width of the groove on the front side, even when the top section is inadvertently applied with the maximum stress In the case of a tip-shaped dicing blade in the stepped section in the region, breakage of the stepped section is suppressed. If the above setting has not been performed, in the case where the position of the top section of the crystal cutting blade in the groove width direction becomes far away from the groove width on the front side, an unexpected fracture may occur. Since the shape of the stepped section is determined by the shape (width and depth) of the groove on the front side and the depth reached by the top section and the strength of the stepped section is determined by the shape of the stepped section It can be assumed that the strength of the stepped section is set by setting the shape (width and depth) of the groove on the front side and the depth reached by the top section.

As a fourth mode, a manufacturing method is used in which a crystal cutting blade having a wedge-shaped tip shape having no top surface at the top section is used, and the range of variation of the top section in the groove width direction becomes far from the width of the groove on the front side Among the conditions, a semiconductor wafer can be manufactured by using a manufacturing method described below. For example, in the case where the tip section is worn so as to have a degree of tapering of the stepped section in the region where the maximum stress is applied to the top section during the use period of the crystal cutting blade, the grooves on the front side are manufactured. The shape and the depth to which the top section reaches are set so that the stepped section does not break under conditions of maximum stress. With this manufacturing method, in a manufacturing condition where the position of the top section of the dicing blade in the groove width direction becomes far away from the groove width on the front side, even if it is inadvertently used In the case of a dicing blade having a tip shape of the stepped section at the region where the maximum stress is applied to the stepped section, the stepped section is prevented from breaking. If the above settings are not performed, unexpected breakage may occur.

As a fifth mode, in a manufacturing condition in which the variation range of the center of the thickness of the dicing blade in the groove width direction becomes far from the width of the groove 140 on the front side, it can be achieved by using a manufacturing method described below Manufacture of semiconductor wafers. For example, in a manufacturing condition in which the center of thickness of the crystal blade has a variation range in the groove width direction away from the width of the groove on the front side, the stepped section can be confirmed only by confirming the tip of the crystal blade The range of the degree of tapering of the shape is small, and the range of the degree of gradual breakage of the stepped segment is the range of the degree of gradation of the tip shape of the crystal cutting blade, and the range of the degree of tapering of the fracture is as follows: (Indicated in the results) and then a semiconductor wafer is manufactured by forming a groove on the back side using a tip shape having a degree of tapering in a range of degrees of tapering included between the above two ranges.

The reason for this is that the tip shape of the crystalline blade is judged regardless of the thickness of the crystalline blade without confirming the range of the degree of tapering of the stepped section due to the large tapering of the crystalline tip shape. The variation range of the center of the groove in the width direction of the groove becomes far from the manufacturing conditions of the width of the groove 140 on the front side, and accidental fracture may occur. Further, the range of the degree of tapering in which the maximum stress is generated in the root region of the stepped section and the range of the degree of tapering in the region where the maximum stress is generated in the top section are included in the range between the two ranges. In this case, the groove on the back surface side should preferably be formed using a cutting member having a tip shape having a tapered degree included in a range of tapered degree in which the maximum stress is generated in the root region of the stepped section. This is because the life of the cutting member becomes longer, and its amount corresponds to the use of a tip shape having a degree of tapering in a range including a degree of tapering included in the root region of the stepped section where the maximum stress is generated. Compared to the case of cutting members, the degree of tapering is reduced.

D-4) Method for setting width of groove on front side and method for setting manufacturing conditions

Next, the setting on the front side will be described below considering the relationship between the width of the groove on the front side and the range of fluctuation of the top section (or thickness center) of the dicing blade in the groove width direction. Method of groove width and method of setting manufacturing conditions.

FIG. 18 is a view illustrating a method of setting a width of a groove on a front side according to an example of the present invention. First, at S300, the range of variation of the center of the thickness direction of the dicing blade in the groove width direction is confirmed. For example, the variation range of the thickness direction center of the dicing blade in the groove width direction is grasped by referring to a product catalog or confirmation by actual measurement. Next, in S310, it is determined that the width of the groove on the front side is one of the widths included in the fluctuation range confirmed in S300. A groove having this width is then formed. With this setting method, unlike the case where the cut width shown in Figure 13 is narrow (Sb = 11.2) and the position deviation Ds is large (Ds = 7.5μm), the stress will not be concentrated in the top section Fracture of the upper and stepped sections will be suppressed. The "setting" of the groove width includes the determination of the groove width and the formation of a groove having the groove width in an actual substrate.

In addition, in S300 in FIG. 18, when a crystal cutting blade having a wedge-shaped top section without a top surface is used, the range of variation of the top section in the groove width direction can be confirmed, and the concave on the front side The width of the groove can be determined to include the range. In addition, the range of the positional accuracy of the manufacturing device used can be confirmed and the width of the groove on the front side can be determined to include the range. The width including this variation range should preferably be determined to be as narrow as possible. This is because in a case where the width of the groove on the front side is too wide, the number of semiconductor wafers obtained from a single substrate may be reduced. For example, In the case where the variation range of the center in the groove width direction is ± 3 μm, the width of the groove on the front side can be preferably set to only approximately 6 μm to 9 μm, that is, the variation range of the thickness direction center of the crystal cutting blade Rather than setting the width of the groove on the front side to 10 μm or more. However, in the case where a groove having a constant width is not used as shown in FIGS. 27A to 27D described later, the groove shape may be formed only so that the position and cutout of the bottom section of the groove on the front side The maximum width between the positions where the top section of the blade reaches includes this range of variation.

FIG. 19 is a view illustrating a method of setting manufacturing conditions according to an example of the present invention. First, at S400, confirm the width of the groove on the front side. More specifically, the maximum width between the position of the bottom section of the groove on the front side and the position where the top section of the dicing blade is reached is confirmed. The maximum width can be confirmed only by, for example, actually measuring a groove formed on the front side in the substrate as a confirmation method. Next, in order to include the variation range of the center of the thickness direction of the crystalline blade in the groove width direction in the confirmed width on the front side, manufacturing conditions that affect the variation range are set in S410. More specifically, selecting a manufacturing device (such as a crystal cutting device) having a range of variation in the thickness direction center of the crystal cutting blade in the groove width direction including accuracy in the confirmed width of the groove on the front side, Chips with less warp and less warpage, and an optimal rotation speed. Next, a manufacturing system (manufacturing line) that meets the manufacturing conditions selected and determined as described above is constructed and a semiconductor wafer is manufactured using the manufacturing system. "Setting" of manufacturing conditions herein means selecting a device, determining other conditions, and preparing a manufacturing system based on the selection and the determination. Using the manufacturing condition setting method described above, unlike the case where the cut width as shown in FIG. 13 is narrow (Sb = 11.2) and the position deviation Ds is large (Ds = 7.5 μm), the area of the top section The verifiability of the stress concentration on the surface becomes low, and the fracture of the stepped section is suppressed. In addition, not only the accuracy of the manufacturing apparatus, but also manufacturing conditions such as Thickness, precision and method of fixing the fixed surface of the dicing blade, the stress during cutting, and the rotation speed of the device), and these can be used to prevent the range of variation from moving away from the width of the groove on the front side conditions of. In other words, the fracture of the stepped section caused by the stress concentration on the top section is achieved by setting the manufacturing conditions that affect the range of variation of the cutting blade (i.e., including the accuracy range of the manufacturing equipment used) And manufacturing conditions of the range of changes caused by the deformation (bending and warping) of the cutting blade) so that the variation range of the thickness center of the cutting blade in the groove width direction includes the depression on the front side The width of the slot.

In addition, in S410 in FIG. 19, in the case of using a crystal cutting blade having a wedge-shaped top section without a top surface, manufacturing conditions that affect the range of variation of the cutting blade can be set so that the top section is concave The variation range in the groove width direction is included in the confirmed width. Especially in some cases, the deformation (bending and warping) of the crystal cutting blade may not be considered, such as a case where the thickness of the crystal cutting blade is thick or a case where the cutting depth is shallow. However, in the case where the thickness of the dicing blade is thin or the cutting depth is deep, it is preferable to consider setting these conditions.

FIG. 20 is a view illustrating another example of a method of setting a width of a groove on a front side and a method of setting a manufacturing condition according to an example of the present invention. First, at S500 and S510, confirm the width of the groove on the front side and the range of variation of the cutting blade in the groove width direction. The confirmed details are similar to those shown in FIGS. 18 and 19. Next, in S520, a confirmation is made as to whether the variation range of the center (or top section) of the dicing blade in the groove width direction becomes far from the width of the groove on the front side. In the case where the range of variation does not become far from the width of the groove, the flow proceeds to S540, and the groove width and manufacturing conditions are set. On the other hand, in the case where the range of variation becomes far away from the width of the groove, the flow advances to S530, and at least the width of the groove on the front side or the opposite change is changed. The moving range exerts influence on the manufacturing conditions so that the variation range of the thickness center (or top section) of the dicing blade in the groove width direction does not become far from the width of the groove on the front side. For example, the crystal cutting device is replaced with a crystal cutting device having a higher position accuracy, the blade is warped by making the blade thicker, or other conditions such as the rotation speed are optimized. With this change, unlike the case where the cut width as shown in FIG. 13 is narrow (Sb = 11.2) and the position deviation Ds is large (Ds = 7.5 μm), the stress is not concentrated on the area of the top section and the step Fracture of the shaped section is suppressed. Also in this example, when confirming whether the center of the crystal cutting blade becomes far away from the width of the groove on the front side, only the accuracy range of the manufacturing apparatus used may be considered, or the accuracy range may be considered And both the range of variation caused by the deformation (bending and warping) of the cutting blade.

A method for designing a tip shape of a dicing blade, a method for manufacturing a semiconductor wafer, and a setting of a groove on the front side based on the relationship between the position of the dicing blade in the groove width direction and the width of the groove on the front side The method of the width, the method of setting the manufacturing conditions, and the like have been described above. In these examples, unless otherwise stated and there is no technical contradiction, "the variation range of the center of the thickness of the crystalline blade in the groove width direction is included in the width of the groove 140 on the front side (Or the manufacturing conditions that become farther away from the width of the groove 140 on the front side) can be regarded as "the range of variation of the wedge-shaped top section without the top surface in the groove width direction includes the groove 140 on the front side" Of the width (or the width of the groove 140 on the front side that becomes farther away). In addition, these manufacturing conditions can also be regarded as "the range of position accuracy of the manufacturing device used is included in the width of the groove 140 on the front side (or becomes farther away from the width of the groove 140 on the front side). Manufacturing conditions. " In addition, unless otherwise stated, these conditions are not required to be satisfied during the period from the start of the use of the dicing blade until the replacement of the dicing blade, and may only be required to be satisfied during a part of the usage period. Furthermore, unless otherwise stated, may be provided or may be A step of confirming whether the center of the thickness of the dicing blade or the range of variation of the top section is included in the width of the groove 140 on the front side is not provided. Still further, the composition and conditions of the individual examples can be combined with each other without technical contradiction.

E) Examples of steps for pre-processing the shape of the tip

Next, the steps of preparing the crystal cutting blades used in the actual mass production process will be described below. This processing step may or may not be applied to the individual examples described above. In this processing step, before forming the grooves on the back side in the actual mass production process, it is necessary to prepare a desired tip shape selected by a design flow such as shown in FIG. 17. The preparation method may be similar to the method described at S200 in FIG. 17. In other words, for example, a dicing blade having a rectangular tip shape is prepared, and a processing step of forming the tip shape into a desired tip shape in advance is provided. In this processing step, the obtained dicing blades are processed until a tapered degree in which the stepped section does not break is obtained. The desired tip shape obtained by this processing step may be a shape determined by the flow shown in FIG. 17 or may be a shape determined by a method different from the method shown in the flow of FIG. 17. Furthermore, this processing step may or may not be applied to the individual examples described above.

Next, another preferred specific example of the processing step of forming the tip shape in advance into a desired tip shape will be described below. As a first mode, although a rectangular tip shape or other arbitrary tip shape is used for general cutting, in the processing step according to this example, a stress having a stress not less than that for breaking the stepped section is applied to the stepped region. The tip shape of the root region of the segment, such as a rectangular shape or a shape close to a rectangular shape, is tapered so that the tip shape is processed in advance so as to have a tapered degree in which the stepped section does not break. For example, the tip section is abraded in advance until a tapered degree in which the stepped section does not break is obtained. With this process, even if the crystal cutting blade has no less than breaking the stepped section The stress of the cracking stress is applied to the tip shape of the root region of the stepped section, and the crystal cutting blade can also be used as a crystal cutting blade capable of suppressing the fracture of the stepped section. However, in the case where the stepped section is not broken due to the wide and deep grooves on the front side, even if a crystal cutting blade having a rectangular tip section is used, this pre-processing step in this example is not required. However, in the case where the width of the groove on the front side is narrow and shallow, that is, when a rectangular tip shape or any other tip shape is used, a stress not less than the stress that breaks the stepped section is applied to the stepped shape In the case of the root region of a segment, it is preferable to provide the step of pre-processing the tip segment as in this example.

As a second mode, in the step of pre-processing the tip section, the dicing blade can be more tapered than a dicing blade having a semi-circular tip section. For example, even when the stepped section is not broken when the tip section is not more tapered than the tip section with a semicircular shape, the tip section may be tapered more than the semicircular tip section . This is because, as clearly shown in FIG. 8, in a range where the degree of tapering of the tip section is larger than that of the semi-circular cutting blade, the change in the maximum stress is small and the stress is sufficiently suppressed, whereby even the tip The shape changes and becomes different from the desired shape in the processing step, and changes in stress in the root region of the stepped section are suppressed. As a result, the stress change in the root region of the stepped section changes even when the tip shape is changed in the processing step, as compared to a case where the chip is not tapered more than a chip with a semicircular tip This situation can also be suppressed.

As a third mode, in the case where the step of pre-processing the tip section is a step of processing the tip section into a wedge-shaped tip shape having no top surface at the top section, the pre-processed top section is in the groove width direction The relationship between the fluctuation range on the front side and the groove width on the front side is preferably the relationship in which the fluctuation range in the groove width direction of the pre-treated top section is included in the groove width on the front side. Pre-treated in the tip section In the case of processing, the position of the top section may deviate from the center of the thickness direction of the dicing blade in some cases. Therefore, even if the change in the shape of the tip in the processing step is taken into account, if the top section is included in the width of the groove on the front side, the fracture of the stepped section caused by the stress concentrated on the region of the top section even at the tip The shape is also suppressed when it is changed in the processing step.

As a fourth mode, in the case where a crystal cutting blade having a previously processed tip section is used, a variation range of the thickness direction center of the crystal cutting blade in the groove width direction is between the width of the groove on the front side The relationship is preferably a relationship in which the variation range of the center of the thickness direction of the dicing blade in the groove width direction is included in the groove width on the front side. In the case where the processing steps of the crystal cutting blade have been tapered in this example, the wedge-shaped top section is easily formed at the center in the thickness direction of the crystal cutting blade. Therefore, in the case where the variation range of the center of the thickness direction of the crystal cutting blade is included in the groove width on the front side, even if the tip section is processed so as to have a tapered degree of stress concentration on the area of the top section In this case, as compared with the case where the variation range is not included in the groove width, the fracture of the stepped section caused by the stress concentrated on the stepped section region is also suppressed. In addition, even if the tip section is not tapered to such an extent that the stress is concentrated on the area of the top section, the stress is concentrated on the step when the tip section is tapered due to wear during mass production. Fracture of the stepped section caused by the region of the shaped section is also suppressed.

As a fifth mode, as the tip shape of the crystal cutting blade before the crystal cutting blade is processed in advance, it is preferable to prepare a crystal cutting blade having a substantially rectangular cross section when viewed from the rotation direction. This is because a crystal cutting blade having a substantially rectangular shape in cross section is often used for complete crystal cutting and easy to obtain, and the crystal cutting blade is easy to be processed so as to have an arbitrary degree of tapering by the processing steps. In addition, in the case of using a crystal cutting blade having a substantially rectangular shape, it is preferable to make a decision as to whether or not the stepped section will be provided with a pre-design step. Confirmation of fracture of the substantially rectangular shaped crystal cutting blade. If the stepped section does not break and the shape of the groove on the front side is not desired to be changed, for example, in a mass production process, a crystal cutting blade having a substantially rectangular shape may be used without modification. Then, the step of pre-treating the tip can be simply performed only on the tip shape where the stepped section is broken. Using this example, it is confirmed whether the stepped section is broken due to the tip shape used in the mass production process, and the processing step is performed only when the stepped section is not broken, so that the processing step is not required. . The "substantially rectangular shape" includes a shape having a slightly curved surface formed at a corner section of the tip, which is attributed to variations in manufacturing and the like as a result of the manufacturing of the tip shape into a rectangular shape. For example, a cutting blade that has been manufactured to be formed in a rectangular shape and has been sold and described in a catalog or the like is included in a cutting blade having a "substantially rectangular shape" according to this example, regardless of the tip corner area What is the size of the curved surface at the segment.

Next, as a sixth mode, the top section (thickness-direction center) of the dicing blade having a tapered degree in a region where the maximum stress is generated in the top section becomes away from the groove on the front side of the semiconductor substrate In the case of a groove width of 140, the process performed when the crystal cutting blade has a tapered degree of fracture of the stepped section due to the maximum stress will be described as follows. As shown in the results of the simulation in FIG. 13, when the top section (thickness-direction center) of the dicing blade having a large tapering degree becomes farther away from the width of the groove 140 on the front side of the semiconductor substrate, the stress is concentrated On the area of the top section of the dicing blade, instead of focusing on the root area of the stepped section of the semiconductor wafer. In the case where the strength of the stepped section in the processed semiconductor substrate cannot withstand the stress at the region of the top section at this time, the stepped section may be broken. The determination of whether the degree of taper is the maximum stress applied to the region of the top section and the degree of taper of the stepped section breaking depends not only on the tip shape, but also, for example, on the stepped section in the semiconductor substrate being processed. Strong degree. Therefore, the degree of taper is grasped by actually processing the semiconductor substrate to be processed or by performing, for example, another simulation. The strength of the stepped section depends on the shape of the groove 140 on the front side, such as the width and depth of the groove 140 on the front side. 21A to 21E show examples of the dicing blades 500, 502, 504, 506, and 508 having the tip shape of the stepped section at the region where the maximum stress is applied to the top section. In the case of obtaining a crystal chip having such a tip shape, when an attempt is made to use a crystal chip having an initial state without modification and in a mass production process, the strength of the tip shape and the stepped section or the like are broken. The relationship between them appears in the stepped section. Therefore, it is necessary to suppress this fracture.

The crystal cutting blade 500 shown in FIG. 21A has a pair of side surfaces 510 and 520 and a pair of inclined surfaces 512 and 522 inclined and linearly extending from the pair of side surfaces 510 and 520. A pointed top section 530 is formed at the intersection of the pair of inclined surfaces 512 and 522. The angle of inclination θ of the pointed top section 530 is the angle between the plane H orthogonal to the sides 510 and 520 and the inclined planes 512 and 522 or the plane H parallel to the axis of rotation of the cutting blade and the angles of the inclined planes 512 and 522 Define. In addition, the distance between the pair of side surfaces 510 and 520 corresponds to the cut width Sb.

The dicing blade 502 shown in FIG. 21B has a flat surface (top surface) 532 formed at the pointed top section 530 shown in FIG. 21A. In this case, the angle between the surface H parallel to the flat surface 532 and the inclined surfaces 512 and 522 is the inclination angle θ of the top section (top surface). In the dicing blade 504 shown in FIG. 21C, the inclined surfaces 514 and 524 extending from the pair of sides 510 and 520 are curved, and a pointed top section 534 is formed at the intersection of the inclined surfaces 514 and 524. In the dicing blade 506 shown in FIG. 21D, the side surface 510 having a straight shape intersects with the inclined surface 522 extending obliquely from the other side 520, and a pointed top section 536 is formed at the intersection. The dicing blade 508 shown in FIG. 21E has a flat surface (top surface) formed at the top section 536 of the tip of the dicing blade shown in FIG. 21D. 532.

The dicing blade shown in FIGS. 21A to 21E (where the maximum stress is applied at the region of the top section) is taken as an example and may have a configuration other than the configuration described above. For example, in the range of the shape at the region where the maximum stress is applied to the top section, the inclination angle θ of the top section may be arbitrarily set, and the inclined surfaces 512 and 522 shown in FIG. 21A may have different inclination angles (in other words, The inclined surfaces may not be linearly symmetrical with respect to the centerline of the thickness). In addition, in the range of the shape at the region where the maximum stress is applied to the top section, the flat surface 532 shown in FIG. 21B may be bent into a convex shape, or the flat surface may be formed in the top section shown in FIG. 21C. 534 places.

In the case where a crystal cutting blade which will have a wedge shape at the tip section (where the maximum stress is applied at the top section) is used in a mass production process, and at the top section (thickness-direction center) of each crystal blade In the case where the width of the groove 140 on the front side of the semiconductor substrate becomes far away and the stepped section cannot withstand the stress, a fracture occurs at the stepped section. More specifically, in the case where the top section (thickness-direction center) of the dicing blade is included in the width of the groove 140 on the front side of the semiconductor substrate, no breakage occurs at the stepped section. However, in the case where the top section becomes farther away from the width of the groove 140 on the front side due to manufacturing variations, a fracture occurs at the stepped section. Therefore, compared with, for example, the case where the manufacturing variation is small and the top section (thickness center in the thickness direction) of the dicing blade is always included in the width of the groove 140 on the front side, the breakage ratio in the throughput is increased.

Therefore, in this example, in the case where such a crystal cutting blade is to be mass-produced, the tip shape of the crystal cutting blade is pre-processed so that the stepped section caused by the stress generated in the region of the top section The fracture is suppressed. FIG. 22 is a flowchart illustrating a first processing method according to an example. First, proceed to the top section (thickness direction) Confirmation of whether the fluctuation range in the groove width direction is included in the groove width on the front side (at S600). For example, the range of variation of the top section or the center of its thickness is determined by manufacturing conditions including the position accuracy of the manufacturing device (crystal cutting device) used and the degree of deformation (amount of bending and warping) of the crystal cutting blade. However, for the purpose of grasping the amount of bending and warping of the crystal cutting blade, such amount needs to be grasped through actual experiments or the like, and this requires time and effort. On the other hand, according to specifications or the like described in the catalog or the like, the position accuracy of the manufacturing device can be relatively easily grasped. Therefore, when it is difficult to grasp the amount of bending and warping, only the accuracy of the position of the manufacturing device can be considered. This confirmation is made by the person responsible for the handling of the tip shape.

In the case where the range of variation is included in the groove width, the flow advances to S610, and it is judged that the dicing blade having a wedge-shaped tip shape as shown in one of FIGS. 21A to 21E has been unmodified from the beginning. For mass production. In the manufacturing condition in which the top section of the crystal cutting blade is included in the groove width, the stress applied to the stepped section does not change suddenly even if the crystal cutting blade having a wedge-shaped tip section is continuously used, which is different from As shown in FIG. 13, in the case where the cut width is narrow (Sb = 11.2) and the position deviation Ds is large (Ds = 7.5 μm), the stepped section fracture is thereby suppressed. However, step S610 does not intend to completely prohibit the processing of the tip shape of the tip section of the crystal cutting blade, but the tip section may be processed so as to form a shape with an arbitrary degree of taper as needed, provided that the shape does not cause Fracture of stepped section.

On the other hand, in the case where the top section is not included in the groove width on the front side, the flow advances to S620, and the tip shape is processed so that the degree of tapering of the tip section of the dicing blade becomes smaller. (To ease the degree of tapering). In other words, the tip section is processed so as to have a tapered degree where the maximum stress is not applied to the region of the top section of the cutting blade and the stepped section is not broken. If the top section becomes wider away from the groove on the front side In the manufacturing conditions of the degree of use of the crystal chip with a large degree of tapering, the fracture rate of the stepped section becomes higher as the crystal continues. On the other hand, when the degree of tapering of the tip section becomes smaller, the stress applied by the top section is dispersed and applied to a point of the stepped section without large stress concentration, and the stepped section is broken The probability becomes lower.

Next, a specific processing method for changing the degree of tapering will be described below. The crystal cutting blade can cut various types of substrates made of GaAs, sapphire, glass, silicon and the like. These dicing blades include electroformed blades in which diamond abrasive particles or the like are bonded to the side of a substrate made of aluminum or the like by metal plating, and resin-like blades in which diamond abrasive particles or the like are Bonded with resin adhesive) and metal blades (where diamond abrasive particles or the like are baked and cured with a metal adhesive). The structure of the crystal cutting blade depends on the type of the substrate to be cut. When the crystal cutting blade is repeatedly used for cutting, the tip section of the crystal cutting blade gradually wears out and becomes a shape that is not suitable for cutting in some cases. For example, the tip section of the dicing blade becomes excessively tapered or unevenly worn, thereby forming an unexpected shape in some cases. In such a case, the reprocessing (trimming) of the tip section of the dicing blade is called a method of returning the shape of the tip of the dicing blade to a desired shape. In this example, this technique for reprocessing the deformed tip section as described above is used to process the tip shape of the dicing blade where the maximum stress is applied at the region of the top section.

23A and 23B show an example of a typical processing apparatus for processing a tip section of a dicing blade. FIG. 23A is a schematic plan view of the processing apparatus, and FIG. 23B is a schematic cross-sectional view of the processing apparatus. The processing device has a shaping plate 610 mounted on a flat support base 600 for processing the tip shape of a crystal cutting blade, a motor 620 movable in three dimensions above the shaping plate 610, and a cutting blade 630 The chuck 640 is detachably mounted on a rotation shaft of the motor 620.

The shaping plate 610 is a so-called trimming plate for processing the tip shape of a crystal cutting blade and is made of a material suitable for the processing of the crystal cutting blade. For example, the shaping plate 610 is made of an adhesive harder than that of a crystal cutting blade and is formed of abrasive particles larger than the abrasive particles of the crystal cutting blade. The motor 620 can be moved in the X, Y, and Z directions by a driving mechanism (not shown). Therefore, the crystal cutting blade 630 fixed to the motor 620 is positioned on the shaping plate 610 and cuts the shaping plate 610 when the motor 620 moves in the Z direction.

In the case where the degree of tapering of the tip section of the crystal cutting blade 630 becomes smaller, first, this crystal cutting blade as shown in one of FIGS. 21A to 21E is mounted on the rotation shaft of the motor 620 . Next, the cutting blade 630 is positioned on the shaping plate 610 by moving the motor 620 in the X and Y directions, and the motor 620 rotates at a constant speed. Next, the motor 620 is lowered in the Z direction so that the crystal cutting blade 630 cuts the shaping plate 610 with a constant cutting depth. The cutting depth is, for example, approximately several μm. Next, the motor 620 moves in the X direction (in a direction parallel to the rotation axis of the motor 620), and the motor 620 is further lowered in the Z direction, thereby causing the crystal cutting blade 630 to perform cutting with a cutting depth of several μm. By repeating cutting in the Z and X directions as described above, the degree of tapering of the tip section of the dicing blade 630 becomes smaller.

Figures 24A to 24C show the cutting edge of the cutting blade of the cutting blade shown in Figures 21A to 21E after being processed so that the degree of tapering of the cutting edge of the cutting blade becomes smaller. status. The dicing blades 500A and 502A shown in FIG. 24A correspond to the dicing blades 500 and 502 shown in FIGS. 21A and 21B, respectively. At the tip section of each of the crystal cutting blades 500A and 502A, inclined surfaces 512 and 522 are formed, and a flat surface (top surface) 532A is formed by making the degree of tapering of the tip section smaller. Between the inclined planes. When the degree of tapering further becomes smaller, the inclined surfaces 512 and 522 are removed, and the tip shape may be formed into this almost rectangular shape as shown in FIG. 5G. Figure 24B The dicing blade 504A shown in FIG. 2 corresponds to the dicing blade 504 shown in FIG. 21C. The flat surface 534A is formed between the inclined surfaces 514 and 524 by making the degree of tapering of the tip section smaller. The dicing blades 506A and 508A shown in FIG. 24C correspond to the dicing blades 506 and 508 shown in FIGS. 21D and 21E, respectively. The flat surface 536A is formed at the top section by making the degree of tapering of the tip section smaller.

The shapes shown in FIGS. 24A to 24C are examples of shapes in which the degree of tapering of the tip section becomes smaller, but the shapes are not limited to these shapes. For example, depending on the material and processing conditions of the shaping plate 610 (cutting depth in the Z direction, number of cuts in the X direction, setting angle of the shaping plate, etc.), the thickness of the flat surfaces 532A, 534A, and 536A can be appropriately adjusted. The width, the distance between the inclined surfaces 512 and 522, and the like change the degree of taper. In addition, if the degree of tapering of the tip section becomes too small (that is, the shape of the tip section is formed to be too close to a rectangular shape), although the maximum stress does not occur in the region of the top section, the maximum stress occurs In the root region of the stepped section, and in some cases stress can cause fractures at the root region of the stepped section. In this case, only the degree of tapering can be made small to the extent that fracture does not occur at the root region of the stepped section. For example, after the tip section is formed into the shape shown in one of FIGS. 24A to 24C, the tip section may be further formed to have a shape as shown in FIG. 5B by using the aforementioned semiconductor substrate for processing a tip section. This shape of this curved surface is shown. In addition, the tip section can be formed into a desired shape by using only a semiconductor substrate for processing of the tip section instead of using the processing method described with reference to FIGS. 23A and 23B.

In the case where a cutting blade having a tapered degree at which the maximum stress is applied to the area of the top section is used for mass production, a step can be obtained by making the tapered degree of the tip section smaller if necessary. The fracture rate of the shaped section is suppressed so as to be suitable for mass-produced crystal cutting blades. In the above first processing method, the bar at S600 in FIG. 22 The conditional branch step may be a judgment step in which the person responsible for the processing of the tip shape actually makes a "yes" or "no" judgment, or a simple conditional branch in which the person responsible for the processing of the tip shape does not make any judgment. In other words, in each conditional branch, a "yes" or "no" judgment can be a judgment as to whether the conditions in the branch have finally been satisfied, and it is not always necessary to be judged by the person responsible for the processing of the tip shape.

Next, in the crystal chip having a degree of taperedness at the region where the maximum stress is applied to the top section of the crystal chip, and it is assumed that the top section (the center in the thickness direction) of the crystal chip becomes away from the semiconductor substrate In the case of the width of the groove 140 on the front side, a second processing method in the case of using a crystal cutting blade having a tapered degree of stepped section fracture due to the maximum stress will be described as follows. FIG. 25 is a flowchart illustrating the second processing method. Different from the first processing method, in this second processing method, it is assumed that the top section is not included in the groove width on the front side regardless of whether the top section (thickness center) of the dicing blade is included in the groove width on the front side. In the groove width on the front side, and the top section is processed to make the degree of taper smaller, thereby obtaining a degree of taper where the maximum stress is not provided at the region of the top section and the stepped section does not break (At S700) and use this method for mass production. As an example, in the case where a crystal blade having such a tip shape as shown in one of FIGS. 21A to 21E is used, the tip section is formed, for example, by using a method similar to the first processing method as It has the shape of this curved surface as shown in FIG. 5B, and the crystal cutting blade is used in a mass production process. As described above, with the second processing method, it is not necessary to confirm whether the top section (thickness direction center) of the dicing blade is included in the groove width on the front side.

In the above first and second processing methods, in the case where the tip section of the crystal cutting blade obtained from other entities has been tapered, the shape of the tip of the crystal cutting blade described above is processed to make the shape suitable for large batches. Examples of production. However, the first and second processing The method is not limited to this example, but can also be applied to a process of making the degree of taper smaller again when the degree of taper of the tip section becomes larger as the crystal cutting blade is continuously used. In that case, for example, the above-mentioned processing method may be applied only to the timing of replacing the cutting blade as described below. In addition, these processing steps may not be performed internally, but may be performed by other entities.

F) Examples of blade replacement

Next, the replacement timing of the dicing blade will be described below. When the crystal cutting blade is continuously used, the crystal cutting blade is gradually worn and the tip of the crystal cutting blade is formed into a wedge shape as shown in FIG. 26. Even in a case where the tip is worn into this wedge shape, in a manufacturing condition in which the top section at the tip of the dicing blade does not become far away from the width of the groove 140 on the front side of the semiconductor substrate, even if the worn In the dicing blade, the fracture of the stepped section is also suppressed, as can be understood from the results of the simulation shown in FIG. 13. However, in the case of manufacturing conditions regarding the positional accuracy of the top section at the tip of the dicing blade becoming far away from the width of the groove on the front side of the semiconductor substrate, the fracture rate of the stepped section varies with the dicing Continuously executed to become higher.

The dashed line 700 in the figure indicates an example of the initial shape of the dicing blade 300 according to the example, and the solid line 710 in the figure indicates the wedge shape of the worn dicing blade 300. In the case of the shape 700 of the dicing blade 300, even in a case where the top section of the dicing blade 300 becomes far away from the width of the groove 140 on the front side of the semiconductor substrate W due to manufacturing variations and the like, stress Also dispersed by the curved surface of the tip section. Therefore, large stress is not concentratedly applied to one point of the stepped section, and the possibility of fracture of the stepped section is low. On the other hand, in the case of a worn dicing blade shape 710, although the tip section has a curved surface, the tip section gradually shrinks. Therefore, stress is easily concentratedly applied to A point of the stepped section, and the break 720 easily appears at the stepped section around the part.

Therefore, in this example, before the tip section is formed into a wedge shape where the maximum stress is applied to the top section and the stepped section is broken due to the wear of the crystal blade, the use of the crystal blade is stopped and a new one is used. Replaces the dicing blade. In other words, in the case where the stress applied to the stepped section during dicing reaches a predetermined stress due to the abrasion of the dicing blade, even before the life of the dicing blade expires, the dicing blade is replaced with a new dicing blade. As an example, in the case of manufacturing conditions regarding the position accuracy of the width of the top section at the tip of the dicing blade away from the groove on the front side of the semiconductor substrate, the life time of the dicing blade is different from that of the dicing blade. The above timing is full to replace the crystal cutting blade. In the ordinary full-cut crystal, in a state where the tip section is tapered due to abrasion, cracks such as spalling may occur, for example, due to vibration when the crystal is cut and impact generated when the crystal-cutting blade passes through the semiconductor substrate. Therefore, in ordinary complete cutting, the timing is grasped experimentally and empirically, the expiration of the life of the cutting blade is determined, and the cutting blade is replaced based on the life. On the other hand, in this example, the dicing blade is replaced even before the life of the dicing blade based on the fracture judgment such as flaking is expired.

In addition, for the judgment as to whether the tip shape has reached the predetermined wedge shape and the judgment as to whether the stress has reached the predetermined stress, grasp the allowable degree of fracture (fracture rate or the like) in the mass production process and the shape of the tip section. And the relationship between the degree of fracture and the stress, and the manufacturing conditions (the number of cutting blades to be used) are obtained in advance through prior experiments, simulations, etc., including, for example, the total crystal cutting time, the total distance of the crystals and the requirements The total number of semiconductor substrates required to perform the dicing until the shape and stress of the tip section are reached. Then, in a large-scale production process, if the manufacturing conditions indicate that the degree of wear of these crystal cutting blades has reached a predetermined condition, it can be judged only that the tip shape has reached To a predetermined wedge shape and the stress has reached a predetermined stress.

In addition, without grasping the specific shape of the tip section and the specific stress corresponding to the allowable fracture rate in mass production without prior experiments, simulations, etc., the degree of wear (such as the total time), the cut can be obtained through experiments. The relationship between the total distance in the crystal, the total number of substrates, and the manufacturing conditions of the broken state, and the timing of replacement can be judged based on the obtained relationship. Furthermore, as another method, when the actual tip shape is measured in the middle of a mass production process, a judgment can be made as to whether a predetermined wedge shape has been reached. In this case, only the judgment can be made by measuring the thickness at a predetermined distance from the top section of the dicing blade, the angle of the tip section, and the like.

In the case of selecting a manufacturing condition in which the top section at the tip of the dicing blade does not become far away from the width of the groove on the front side of the semiconductor substrate or when the top section does not break even if the top section becomes far away from the width In the case of the thickness of the stepped section, the fracture of the stepped section is further suppressed. In this case, the dicing blade can be replaced based only on the life of the dicing blade. Furthermore, in order that the top section of the dicing blade does not become far away from the width of the groove on the front side, only the manufacturing conditions and semiconductor substrates that affect the variation range of the dicing blade in the groove width direction can be selected. The relationship between the width of the grooves on the front side of the grooves in order to obtain a combination of these manufacturing conditions and the width of the grooves where the dicing blade does not become far away from the width of the grooves. For example, in the case where the accuracy of the manufacturing device is low, only the width of the groove on the front side of the semiconductor substrate can be made wider, and in the case where the accuracy of the manufacturing device is high, only the groove can be made according to the accuracy The width is narrow.

In addition, without knowing whether the manufacturing condition to be used is a manufacturing condition in which the top section becomes far from the width of the groove, it can be assumed that the manufacturing condition to be used is a manufacturing condition in which the top section becomes far from the width of the groove , And can replace the cutting blade regardless of the life of the cutting blade. In other words, the maximum stress is applied to the top section at the degree of taper. At the region and before the tapered extent of the stepped section breaks, the use of the cutting blade can be stopped and the cutting blade can be replaced with a new cutting blade.

Next, the timing of replacement in the case where the top section at the tip of the cutting blade becomes farther away from the width of the groove on the front side as the cutting blade wear increases will be described below. It is assumed that the top section of the dicing blade becomes away from the width of the groove on the front side in both cases. In the first case, the top section is far from this width at the start of the use of the dicing blade. In the second case, the state of the top section of the dicing blade is changed from a state where the top section is not far from the width to a state where the top section is distant from the width as the wear of the dicing blade increases. The former case corresponds to the case where the range of position accuracy is far from the groove width on the front side at the start time of use of the cutting blade, because, for example, the position accuracy of the manufacturing apparatus is low or the groove width on the front side is narrow . The latter case corresponds to the case where the top section becomes farther away from the width of the groove on the front side in the use of the cutting blade, because the thickness of the cutting blade becomes thinner as the wear of the cutting blade increases. Therefore, due to the stress during cutting, the strength of the crystal cutting blade becomes weaker and the warpage amount of the crystal cutting blade gradually becomes larger.

Therefore, when the state changes from a state where the top section is not far from the width to a state where the top section is away from the width as the wear of the crystal cutting blade increases, the use of the crystal cutting blade can be stopped and the top section can be stopped. The dicing blade can be replaced with a new dicing blade before becoming farther from the width. In this case, the use of the crystal cutting blade can be stopped under the condition that the shape of the tip section of the crystal cutting blade has been formed into a wedge shape in which the maximum stress is applied to the region of the top section and the stepped section is broken, or The use of the dicing blade can be stopped before the top section becomes farther away from that width, regardless of the shape of the tip section of the dicing blade. The timing from the state where the top section is not far from the width to the state where the top section is far from the width may be based only on, for example, the frequency of use of the cutting blade and the time around the groove on the front side The relationship between the fracture rates at the periphery is obtained in advance. At this time, a confirmation can be made as to whether the top section of the dicing blade is actually far from the width of the groove on the front side. The "perimeter" of the groove on the front side in this example is the range in which the stress is received directly or indirectly from the crystalline blade.

In the method of manufacturing a semiconductor wafer according to this example, although the stepped section is in a state where it is not broken at the start time of use of the dicing blade, the stepped section also becomes due to the dicing blade being as described above In some cases the state of wear and tear. In this case, for a certain time after the use of the dicing blade, the fracture rate of the semiconductor wafer is stable and belongs to a constant range. This is because the fracture of the semiconductor wafer occurs only due to factors other than the wear of the crystalline blade . However, when the same dicing blade is continuously used, the degree of tapering reaches a range in which the stepped section breaks or the top section becomes farther away from the width of the groove on the front side, whereby the breaking rate gradually increases. Then, the fracture rate can finally reach the fracture rate that is not allowed during mass production.

Therefore, considering that the breakage rate described above changes with the timing of replacement of the slicing blade, the slicing blade can be replaced, for example, before the breakage rate (breakage rate of the stepped section) of the semiconductor wafer starts to rise, or After the break rate of the wafer starts to rise and before the break rate reaches a break rate that is not allowed during mass production, the dicing blade can be replaced.

The instructions for blade replacement have been presented above, and they are summarized below. That is, as a first mode regarding the replacement of the blade, a step of forming a groove on the front side of a substrate is provided and using an entrance portion having a groove on the front side from the back side of the substrate A step of forming a groove on the back side in communication with the grooves on the front side and dicing the substrate into a semiconductor wafer, and cutting the substrate into a semiconductor wafer; and The range of the thickness direction center of the tip section in the groove width direction becomes far away from the groove on the front side and the front side In manufacturing conditions where the periphery of the groove on the side is broken due to stress from the area of the top section of the cutting member that is tapered due to abrasion, the tip shape of the cutting member is formed as the recess on the front side. Before the wedge of the groove breaks due to abrasion, the use of the cutting member can be stopped and the cutting member can be replaced with a new cutting member.

As a second mode, a step of forming a groove on a front side of a substrate and a rotation from the back side of the substrate using a thickness having a thickness greater than a width of an entrance portion of the grooves on the front side are provided. A step in which the cutting member forms a groove on the back side communicating with the grooves on the front side and crystallizes the substrate into a semiconductor wafer; and a change in the thickness direction center of the tip section of the cutting member In manufacturing conditions where the range becomes farther away from the groove on the front side and the periphery of the groove on the front side is broken due to stress from the area of the top section of the cutting member that is tapered due to wear, in Before the break rate of the periphery of the groove on the front side starts to increase as the cutting member wears, the use of the cutting member can be stopped and the cutting member can be replaced with a new cutting member.

As a third mode, a step of forming a groove on a front side of a substrate and a rotation from the back side of the substrate using a thickness having a thickness greater than a width of an entrance portion of the grooves on the front side are provided. A step in which the cutting member forms a groove on the back side that communicates with the grooves on the front side and crystallizes the substrate into a semiconductor wafer, and is located at a center position in the thickness direction of the tip section of the cutting member In a manufacturing condition where the range of variation becomes far away from the groove on the front side and the periphery of the groove on the front side is broken due to stress from a region of the top section of the cutting member that is tapered due to wear, After the fracture rate of the periphery of the groove on the front side starts to increase as the cutting member wears, and before the fracture rate reaches a fracture rate that is not allowed in a large number of production processes, the cutting can be stopped. Use of the component and the cutting component can be replaced with a new cutting component. Leave here The increase in the break rate of these semiconductor wafers in manufacturing is attributed to the wear of the dicing blades mainly in two cases. In the first case, in the case where the center (top section) of the thickness of the dicing blade can be moved away from the width of the groove on the front side from an early stage of use of the dicing blade (for example, in In the case where the groove width on the front side is narrow or the positional accuracy of the crystal cutting device is low), the tip shape having a tapered degree of stepped section not breaking is formed to have a stepped section with the wear of the crystal cutting blade Increasing the shape of the tapered fracture. In the second case, the amount of warpage and bending of the crystal cutting blade is increased, and the state of the crystal cutting blade is not far from the width of the groove on the front side from the center (top section) of the thickness of the crystal cutting blade. The state of is changed from the width to the center of the thickness as the wear of the cutting blade increases. The second and third models are based on these findings.

As a fourth mode, a step of forming a groove on a front side of a substrate and a rotation from the back side of the substrate using a thickness having a thickness greater than a width of an entrance portion of the grooves on the front side are provided. A step of the cutting member forming a groove on the back side communicating with the grooves on the front side and dicing the substrate into a semiconductor wafer, and the periphery of the groove on the front side being broken In manufacturing conditions where the abrasion of the cutting member increases as the abrasion of the cutting member increases, the use of the cutting member can be stopped before the fracture rate reaches a fracture rate that is not allowed in a large number of production processes.

As a fifth mode, after the fracture rate starts to increase and before the fracture rate reaches a fracture rate that is not allowed in a large number of production processes in the fourth mode, the use of the cutting member can be stopped and replaced with a new cutting member The cutting member.

As a sixth mode, the tip shape of the cutting member is formed at a region where the maximum stress is applied to the top section and the periphery of the groove on the front side follows the cutting member in the fourth mode and the fifth mode. Before the wear increases and a wedge shape is broken, the use of the cutting member can be stopped and the cutting member can be replaced with a new cutting member.

As a seventh mode, the variation range of the thickness direction center of the tip section of the cutting member in the groove width direction is included in the front side as the wear of the cutting member increases in the fourth mode and the fifth mode. Before the range in the groove changes to the range far from the groove on the front side, the use of the cutting member can be stopped and the cutting member can be replaced with a new cutting member.

As an eighth mode, the range of variation of the top section of the cutting member that does not have a top surface in the groove width direction is included on the front side as the wear of the cutting member increases in the fourth and fifth modes. Before the range in the groove changes to the range far from the groove on the front side, the use of the cutting member can be stopped and the cutting member can be replaced with a new cutting member.

As a ninth mode, a step of forming a groove on the front side of a substrate and a rotation from the back side of the substrate using one of the thicknesses that is thicker than the width of the entrance portion of the grooves on the front side are provided. A step in which the cutting member forms a groove on the back side communicating with the grooves on the front side and crystallizes the substrate into a semiconductor wafer, and the center of the cutting member in the thickness direction of the cutting member is concave The variation range of the groove width direction increases with the abrasion of the cutting member from the range included in the groove on the front side to a manufacturing condition far from the range of the groove on the front side. Before the range of change changes from the range included in the groove on the front side to the range far from the groove on the front side, the use of the cutting member may be stopped and the cutting may be replaced with a new cutting member member.

As a tenth mode, a step of forming a groove on a front side of a substrate is provided, and one of a thickness having a thickness greater than a width of an entrance portion of the grooves on the front side is rotated from the back side of the substrate. A step of cutting the member to form a groove on the back side in communication with the grooves on the front side and dicing the substrate into a semiconductor wafer, and The range of variation of the top section of the cutting member that does not have a top surface in the groove width direction increases as the wear of the cutting member increases from the range in the groove included on the front side to away from the front side In the manufacturing conditions of the range of the groove above, the variation range may be stopped before the range of change from the range included in the groove on the front side to the range far from the groove on the front side The cutting member can be used and replaced with a new cutting member.

As the eleventh mode, a step of forming a groove on a front side of a substrate and a rotation from the back side of the substrate using a thickness having a thickness larger than a width of an entrance portion of the grooves on the front side are provided. A step in which the cutting member forms a groove on the back side communicating with the grooves on the front side and crystallizes the substrate into a semiconductor wafer, and the center of the cutting member in the thickness direction of the cutting member is concave The variation range of the groove width direction increases with the abrasion of the cutting member from the range included in the groove on the front side to a manufacturing condition far from the range of the groove on the front side. The cutting section of the cutting member having a wedge shape and having no top surface at the top section is formed so that the maximum stress is applied at the area of the top section and the stepped section is broken, and the cutting can be stopped Use of the component and the cutting component can be replaced with a new cutting component.

As a twelfth mode, a step of forming a groove on the front side of a substrate and a rotation from the rear side of the substrate using a thickness having a thickness larger than the width of the entrance portion of the grooves on the front side are provided. A step of forming a cutting member on the back side in communication with the grooves on the front side and dicing the substrate into a semiconductor wafer; and the cutting member having a wedge-shaped tip shape and having no top surface The variation range of the top section in the groove width direction increases with the abrasion of the cutting member from the range included in the groove on the front side to the range far from the groove on the front side In the manufacturing conditions, the tip shape of the cutting member is formed such that the maximum stress is applied to the top section Before the wedge shape of the stepped section is broken, the use of the cutting member can be stopped and the cutting member can be replaced with a new cutting member. According to the twelfth mode, for example, the top section of the dicing blade having this wedge-shaped tip section without a top surface as shown in FIG. 5B is worn and formed so that maximum stress is applied to the top section as shown in FIG. 14 The use of the dicing blade is stopped before the wedge shape of the stepped section is broken in the region of the segment.

As the thirteenth mode, in the first to twelfth modes, the cutting can be stopped based on the relationship between the usage amount of the cutting member as a predetermined relationship and the breakage rate at the periphery of the groove on the front side. Use of the component and the cutting component can be replaced with a new cutting component. In other words, a change in the fracture rate at the periphery of the groove on the front side caused by a change in the usage amount of the cutting member can be obtained in advance, and the stopping of the cutting member can be determined by using the obtained relationship. When to use it. The "break rate" is the ratio of the amount of damaged product to the production amount of the semiconductor wafer obtained without the occurrence of breaks. In this example, the breaking rate includes not only the breaking rate itself, but also other characteristics that change in proportion to the breaking rate and indirectly change in synchronization with the breaking rate.

In the above-mentioned first to third modes, "manufacturing conditions for the peripheral fracture of the groove on the front side" indicates the life of the crystal blade under the assumption that a cutting member such as a crystal blade is continuously used. A manufacturing condition in which the periphery of the groove on the front side is broken before expiration (before a break such as peeling occurs). Further, in the eighth to twelfth modes described above, "the range of change from the range included in the groove on the front side to the manufacturing conditions of the range far from the groove on the front side" is expressed in Assuming that a cutting member such as a dicing blade is used continuously, the range of variation becomes far from the manufacturing conditions of the groove on the front side before the life of the dicing blade expires (before a break such as spalling occurs). .

G) Examples of processing for thinning substrates

Next, a process for thinning a semiconductor substrate will be described below. Unlike the case of general complete crystal cutting, in the case of the above-mentioned crystal cutting method according to the example, even if the position of the top section of the crystal cutting blade is only deviated from the groove width direction by about 1.2 μm, it is applied to the stepped section. Stress also changes significantly in some cases. For example, when the groove on the back side is formed, as the thickness of the substrate is thicker, the stress from the substrate becomes larger during the dicing, the dicing blade is easily deformed (for example, warped), and the The position of the tip section is deviated in the groove width direction, whereby the stress applied to the stepped section becomes larger.

Therefore, the thinning process for making the thickness of the substrate thinner can be performed before the grooves on the back side are formed to reduce the stress applied to the stepped section. As one example of the processing, back surface grinding is performed to make the thickness of the substrate thinner in the direction from the back surface to the front surface of the substrate as a whole before any step S110 in FIG. 1. In back grinding, the substrate is placed in such a way that the back of the substrate can be seen in the case of half-cut crystals according to the example described earlier, and, for example, a rotary grinding machine moves in the horizontal and vertical directions, whereby the substrate The thickness becomes thinner as a whole until the fine grooves on the front side are exposed. In the case where the strength of the substrate becomes a problem after the back surface grinding, the substrate can be formed into a so-called rib-structured substrate by not only grinding the periphery of the substrate.

As described earlier, the range in which the stress applied to the stepped section in the top section (center of thickness) of the dicing blade in the groove width direction becomes far away from the groove on the front side Significantly changed. Therefore, the range of variation in the groove width direction at the center of the thickness direction of the tip section of the dicing blade is assuming that the grooves on the back surface side have been formed without performing back surface grinding, away from the front surface side. In the manufacturing conditions of the width of the groove, only the back grinding can be performed. In addition, the substrate can be ground to the top section (center of thickness) of the dicing blade in the groove width direction only by back grinding. The moving range becomes thinner by including the thickness in the width of the groove on the front side.

The above examples can be summarized and described as follows. That is, this example is a method of manufacturing a semiconductor wafer in which a step of forming grooves on the front side of a substrate is provided and using an entrance having grooves on the front side from the back side of the substrate A step of forming a groove on the back side in communication with the grooves on the front side and dicing the substrate into a semiconductor wafer; and The variation range of the thickness direction center of the tip section in the groove width direction is assumed to be away from the case where it is assumed that the groove on the back side is formed without performing a process for making the thickness of the substrate thin. In the manufacturing conditions of the groove on the front side, a process for making the thickness of the substrate thinner is performed so that the range includes the area on the front side before the groove on the back side is formed. In width.

This example can also be described as follows. That is, this example is a method of manufacturing a semiconductor wafer, in which a step of forming grooves on the front side of a substrate is provided and using a process having grooves on the front side from the back side of the substrate A step of rotating the cutting member with a thickness of a thick one at the entrance portion to form a groove on the back side communicating with the grooves on the front side and dicing the substrate into a semiconductor wafer, and without the top The range of variation in the groove width direction of the top section of the wedge-shaped cutting member of the surface is changed assuming that the groove on the back side is formed without performing a process for making the thickness of the substrate thin. In a manufacturing condition away from the groove on the front side, a process for making the thickness of the substrate thinner is performed so that the range is included on the front side before the groove on the back side is formed. Of that width.

In the case where the thinning process according to the example is performed as described above, as compared with the case where the thinning process is not performed, the fracture of the stepped section is suppressed. In the thinning process according to the example, the top of the dicing blade can be performed without performing the thinning process. Confirmation of whether the center of the partial section or thickness deviates from the width of the groove on the front side, and the thinning process can be performed only when the top section deviates, or by knowing in advance the thickness of the substrate without deviation and without The substrate is made thinner by confirming whether a deviation occurs without performing a thinning process. In other words, without performing the thinning process, the state where the center of the top section or thickness of the dicing blade deviates from the width of the groove on the front side by performing the thinning process and finally can simply become the top section or center Does not deviate from the state of the groove width on the front side. In addition, the timing for performing the thinning process may be any time before the grooves on the back side are formed. For example, in FIG. 1, the thinning process may be performed before the light emitting element is formed or after the light emitting element is formed and before the fine grooves are formed.

H) Modification of fine grooves on the front side

Next, a modification of the fine groove formed on the back side of the substrate will be described below. Although the fine grooves 140 shown in FIG. 2D are formed as straight grooves having sides extending from the front surface of the substrate in an almost vertical direction by anisotropic dry etching, the fine grooves may be formed in other shapes.

27A to 27D show other configuration examples of the fine groove according to this example. These grooves are formed so that the lower side of the groove becomes wider, so that the stepped section of the groove hardly receives stress, even if the position of the top section of the cutting blade changes in the groove width direction. The fine groove 800 shown in FIG. 27A has a first groove portion 810 (which includes straight side surfaces forming an almost uniform width Sa1 and a depth D1) and also has a second groove portion 820 (which has a depth D2 and a bottom portion). The spherical side of the surface), the second groove portion 820 is connected to the lower portion of the first groove portion 810. The width Sa2 of the second groove portion 820 is an inner diameter between the sidewalls facing each other in a direction parallel to the front surface of the substrate, and a relationship of Sa2> Sa1 is established. In the example shown in the figure, the width Sa2 is in the second groove portion There is a maximum near the center of 820.

The fine groove 800A shown in FIG. 27B has a first groove portion 810 (which includes straight side surfaces forming an almost uniform width Sa1 and a depth D1) and also has a rectangular second groove portion 830 (which has a depth D2 Almost straight side), the second groove portion 830 is connected to the lower portion of the first groove portion 810. The second groove portion 830 is obtained by changing the spherical side surface and the spherical bottom surface of the second groove portion 820 shown in FIG. 27A into a linear shape. The width Sa2 of the second groove portion 830 is a distance between the side walls facing each other in a direction parallel to the front surface of the substrate, and the distance is almost constant (Sa2> Sa1). The shape of the second groove portion shown here is regarded as an example, and the shape of the second groove portion can only be a shape having a width larger than the width Sa1 of the first groove portion. For example, the shape may be simply an intermediate shape between the second groove portion 820 shown in FIG. 27A and the second groove portion 830 shown in FIG. 27B, that is, the shape may be simply an oval shape. Further, the second groove portion may simply have a shape of a space wider than the width of the groove (the width of the groove at the depth D1) at the boundary portion between the first groove portion and the second groove portion.

The fine groove 800B shown in FIG. 27C has a first groove portion 810 (which has a side forming an almost uniform width Sa1 and a depth D1) and also has a second groove portion 840 (which has a reverse wedge shape with a depth D2) Shape), the second groove portion 840 is connected to a lower portion of the first groove portion 810. The sides of the second groove portion 840 are inclined so that the width between the sides gradually increases toward the bottom section. The width Sa2 of the second groove portion 840 is the distance between the sides facing each other in a direction parallel to the front surface of the substrate, and the distance is near the lowest section of the second groove portion 840 (near the lower end). Has the maximum value.

The fine groove 800C shown in FIG. 27D has a shape whose width gradually increases from the opening width Sa1 on the front surface of the substrate to the width near the lowest section. Sa2. In other words, the fine groove 800C is a reverse wedge-shaped groove having a depth D2. The fine groove 800C is obtained by making the depth D1 of the first groove portion 810 shown in FIG. 27C as small as possible. In the shapes shown in FIGS. 27A to 27C, the angles of the sides of the first groove portion and the second groove portion are changed at the boundary between the first groove portion and the second groove portion. However, in the shape shown in FIG. 27D, the angle of the side surface does not change, and the width of the lower section of the groove is wider than the width of the upper section, so that the fine groove has the first groove portion (the upper section ) And a second groove portion (lower section) wider than the first groove portion.

As the shape of the first recessed portion, such vertical shapes as shown in FIG. 27A to FIG. 27C such as those shown in FIG. 27D which gradually become wider in width from the front surface to the back surface of the substrate (reverse wedge shape) Shape) is more advantageous in order to suppress the remaining portion of the adhesive layer of the dicing tape 160 generated when the dicing tape is removed. This is based on the following reasons. In the case of a groove having a reverse wedge shape, ultraviolet rays are difficult to transmit to the adhesive layer which has penetrated into the groove, and the adhesive layer is difficult to harden. Even if the adhesive layer is hardened, stress is easily applied to the root portion of the adhesive layer that has penetrated into the groove, and the adhesive layer is more easily broken into multiple pieces when removed than when the groove has a vertical shape.

In addition, from the viewpoint of suppressing the remaining portion of the adhesive layer, the shape of the side surface of the first groove portion should preferably be a shape that gradually becomes narrower from the front side to the back side of the substrate (forward wedge shape), rather The vertical shapes shown in FIGS. 27A to 27C. In other words, the shape of the first groove portion should preferably be a shape that does not have a portion (reverse wedge shape) whose width becomes wider from the front surface to the back surface of the substrate.

The fine grooves 800, 800A, 800B, and 800C shown in FIGS. 27A to 27D are preferably configured so that they are linearly symmetrical with respect to a center line orthogonal to the substrate. In addition, the fine grooves shown in FIGS. 27A to 27D are drawn using straight lines and curved surfaces to easily understand the characteristics of the fine grooves. However, it should be noted that the side of the fine groove to be formed The surface may actually have steps or concave and convex portions, and the corners may not necessarily be formed into angular shapes in the strict sense, but may be formed into curved surfaces. Further, the fine grooves shown in FIGS. 27A to 27D are merely examples and may have other shapes, provided that a second groove portion wider than the first groove portion is formed under the first groove portion so that Connect with it. For example, the individual shapes shown in FIGS. 27A to 27D may be combined, or the shapes may be combined and then further modified. Furthermore, the corners of the forward / reverse mesa shapes shown in FIG. 27C and FIG. 27D are merely examples. The shape may have only a surface inclined with respect to a surface perpendicular to the surface of the substrate, and the degree of the tilt is not important.

Next, a method of manufacturing a fine groove according to an example will be described below. FIG. 28 is a flowchart illustrating a method of manufacturing a fine groove according to an example. A method of manufacturing such fine grooves as shown in FIGS. 27A to 27D includes a step of forming a first groove portion having a width Sa1 by performing a first etching (S800), and by performing a second etching A step (S810) of forming a second groove portion having a width Sa2 wider than the width Sa1 below the first groove portion. The intensity of the second etch is higher than that of the first etch. A case where an anisotropic etching is used as the first etching and an isotropic etching is used as the second etching will be described below as an example.

29A and 29B are schematic cross-sectional views illustrating a process of manufacturing the fine groove 800 shown in FIG. 27A. A photoresist 900 is formed on the front surface of the GaAs substrate W. The photoresist is an i-ray resist having a viscosity of 100 cpi and is coated to a thickness of, for example, about 8 μm. The opening 910 is formed in the photoresist 900 by a known photolithography process using, for example, an i-ray stepper and a TMAH 2.38% developer solution. The width of this opening 910 is set to the width Sa1 of the first groove portion.

The first groove portion 810 is formed on the front surface of the substrate by anisotropic etching using the photoresist 900 as an etching mask. In a preferred mode, an induction coupling plasma (ICP) is used as a reactive ion etching (RIE) device. For example, the etching conditions are as follows: 500W inductively coupled plasma (ICP) power; 50W bias power; 3Pa pressure; an etching gas composed of Cl ₂ = 150 sccm, BCl ₃ = 50 sccm, and C ₄ F ₈ = 20 sccm; and 20 minute etching time. A protective film 920 is formed on the sidewall of the groove while performing etching by adding a CF-based gas using a known method. Free radicals and ions are generated from the plasma of the reactive gas. Although the sidewall of the groove is only attacked by free radicals, the sidewall is not etched because the protective film 920 is provided for protection. On the other hand, the protective film is removed from the bottom section of the groove by ions incident at the bottom section in the vertical direction, and the removed portion of the protective film is etched by radical etching. Therefore, the anisotropic etching is completed.

Next, the etching conditions are changed and isotropic etching is performed. In this case, for example, the supply of C ₄ F ₈ for forming a protective film 920 to protect the sidewall is stopped. The etching conditions are as follows: 500W inductively coupled plasma (ICP) power; 50W bias power; 3Pa pressure; an etching gas composed of Cl ₂ = 150 sccm and BCl ₃ = 50 sccm; and an etching time of 10 minutes. Since the supply of C ₄ F ₈ is stopped, the protective film 920 for protecting the sidewall is not formed. Therefore, isotropic etching is completed at the bottom section of the first groove portion 810. Therefore, the second groove portion 820 is formed under the first groove portion 810. The second groove portion 820 has a spherical side surface and a spherical bottom surface that further expands to the side and downward from the width Sa1 of the first groove portion 810. The above-mentioned etching conditions are merely examples and the width, depth, shape, etc. of the fine grooves may be appropriately changed.

This shape shown in FIG. 27C is formed by making the etching strength only in the direction of the side wall when forming the second groove portion is lower than when forming the second groove portion shown in FIG. 27A. The etching strength in the direction of the sidewall can be changed by changing the etching conditions such as the output of the etching device and the type of the etching gas. More specifically, for example, the supply of C ₄ F ₈ serving as a gas for protecting the side wall may not be completely stopped, but the flow rate of the gas may be made lower than that when the first groove portion is formed, or may be Increasing, for example, the flow rate of Cl ₂ serving as a gas for performing etching, or these conditions may be combined. In other words, in both the case where the first groove portion is formed and the case where the second groove portion is formed, although both the gas for protecting the sidewall and the gas for performing etching contained in the etching gas are supplied, the concave The groove portions can be formed only by changing the respective flow rates. In addition, by setting the aforementioned flow rate in advance before the formation of the first groove portion, the first groove portion and the second groove portion may be formed in a series of successive etching steps. In the case where the first groove portion is formed into a shape (forward wedge shape) so as to be narrow from the front surface to the back surface of the substrate to suppress the remaining portion of the adhesive layer, only C ₄ F ₈ and Cl can be optimized The flow rate of ₂ and the output of the etching device may be switched only to obtain such a shape. Further, this shape as shown in FIG. 27D can be formed by omitting the formation of the first groove portion shown in FIG. 27C. It should be noted that such etching is substantially completed as isotropic etching.

Although the method of manufacturing a fine groove according to the example has been described above, other methods may be used as long as a first groove portion and a second groove portion wider than the first groove portion can be formed. For example, a combination of dry etching and wet etching may be used to form the groove portion. In addition, the first groove portion is not required to be formed only by the first etching, and the second groove portion is not required to be formed only by the second etching. In other words, if the first etching is the main etching for the first groove portion, it may include etching other than the first etching, and if the second etching is the main etching for the second groove portion, it may include removing Etching outside the second etch. In addition, since only at least the first groove portion and the second groove portion may need to be formed, for example, the third groove portion and the fourth groove portion may also be disposed between the first groove portion and the second groove portion. Occasionally, the position is closer to the back surface side of the substrate than the position of the second groove portion, and these groove portions can be formed by the third etching and the fourth etching.

The exemplary embodiment according to the present invention has been described in detail above. The "stepped section due to the difference between the width of the groove on the front side and the width of the groove on the back side" in each example includes not only the width of the groove on the back side than the front side The stepped section in a state where the width of the groove on the side is wide, and also includes when the width of the groove on the front side is formed so as to be wider than the width of the groove on the back side (for example, when using FIG. 27A Up to the stepped section formed by this groove shown in each of FIG. 27D (that is, in the case of a groove having a non-constant width on the front side). In addition, in each example, "the groove on the back side communicating with the groove on the front side is formed using a one-rotation cutting member having a thickness thicker than the width of the groove on the front side" in the description of " The width of the groove on the front side "is the width of the entrance portion of the groove on the front side. In other words, the "width of the groove on the front side" is used to clearly describe the configuration for increasing the number of semiconductor wafers that can be obtained from a single substrate compared to the case of a complete cut. This is because the number of semiconductor wafers that can be obtained from a single substrate is the width of the groove on the front side of the substrate on which the functional element is formed, rather than the width of the groove on the back side below the groove on the front side (Ie, the width of the entrance portion of the groove on the front side). On the other hand, the width of the groove on the front side required for the judgment as to whether the top section includes or becomes away from the width of the groove on the front side is from the position of the bottom section of the groove on the front side to The maximum width at which the top section of the dicing blade reached as described earlier. In addition, the suppression of fracture in the present specification is not limited to the suppression of peeling, cracking, and the like to such an extent that the peeling, cracking, and the like cannot be visually recognized, but the suppression includes the suppression for suppressing the fracture to a certain degree and the ability to crack. A certain degree of suppression that reduces the likelihood of occurrence. The degree of suppression is not important.

The method of designing the tip shape of the dicing blade as described above with reference to FIG. 17 can also be described as follows. That is, this method is a method of manufacturing a semiconductor wafer, It is provided with a rotary cutting member having a thickness that is thicker than the width of the grooves on the front side from the back side of a substrate to form grooves on the back side that communicate with the grooves on the front side and A step of dicing the substrate into a semiconductor wafer having a stepped section formed due to a difference between the width of the grooves on the front side and the width of the grooves on the back side, wherein the step The process is a process in which a recess on the back side is formed using a plurality of tip-shaped dicing blades having different tapering degrees for grooves on the front side having a shape to be adopted in a mass production process. Groove, and as a result of the formation of grooves on the back side, the first tapered degree range and the tapered degree of the stepped section being broken due to the small tapered degree of the tip shape are larger than those in the first tapered degree range In the case where both the second tapered degree range of the tapered degree and the stepped section does not break, by using a cutting structure having a tapered degree included in the second tapered degree range in a mass production process, The grooves are formed on the back surface side.

In addition, the present invention is not limited to the specific exemplary embodiments, but may be variously modified and changed within the scope of the gist of the present invention described in the scope of the patent application. For example, the present invention can also be applied to a case where the element is individualized from a substrate made of glass, polymer, or the like that does not contain a semiconductor. For example, the present invention can also be applied to a substrate for a semiconductor-free MEMS. In addition, as long as there is no contradiction in order, at least some of the individual steps in the exemplary embodiment of the present invention may be performed in the design phase during mass production, or all such steps may be performed as part of the mass production process. . Furthermore, the respective steps according to the exemplary embodiment of the present invention may be performed by a plurality of entities (others). For example, the first entity forms a groove on the front side of the substrate, the first entity supplies the substrate (where the groove on the front side has been formed) to the second entity, thereby preparing a substrate, and the second entity forms a prepared substrate Groove on the back side and then the substrate is cut (divided). In other words, the first entity can prepare a substrate (where a groove on the front side has been formed) or the second entity itself can prepare a substrate.

Claims (11)

A method for manufacturing a semiconductor wafer, comprising: forming a first groove on a front side of a substrate; and forming a second groove on a back side of the substrate by using a rotating cutting member, the cutting member having a A tip section having a cutting width wider than a width of each of the first grooves, and the second grooves are respectively opened to the first grooves; A stepped section of a semiconductor wafer, the stepped sections are formed due to the difference between the widths of the first grooves and the second grooves; before forming the second grooves, pre-treat a The untreated tip section forms the tip section, the tip section has a first degree of tapering that does not break the stepped sections, and the untreated tip section has the stepped One of the second degree of tapered section fracture. The method of manufacturing a semiconductor wafer as claimed in claim 1, wherein the first grooves are formed by dry etching. The method of manufacturing a semiconductor wafer as claimed in claim 1, wherein the cutting member is a crystal blade. A method of manufacturing a semiconductor wafer, comprising: forming a first groove on a front side of a substrate; and forming a second groove on a back side of the substrate by using a rotating cutting member having a warp Processing a tip section having a cutting width wider than the width of each of the first grooves, and the second grooves are opened to the first grooves respectively; Crystallized into a semiconductor wafer with stepped sections, which are formed due to the difference between the widths of the first grooves and the second grooves; Before forming the second grooves, an untreated tip section is pre-processed to form the tip section, and the processed tip section is formed by tapering the untreated tip section. , So that the processed tip section is formed to have a tapering degree, the taper degree exerts less stress on the root region of the stepped section than a yield stress that breaks the stepped section, and The stress applied to the root regions by the untreated tip section is not less than the yield stress that fractures the stepped section. The method of manufacturing a semiconductor wafer as claimed in claim 4, wherein the pre-processing step includes making the untreated cutting member more tapered than a cutting member having a semicircular tip section. The method of manufacturing a semiconductor wafer as claimed in claim 4, wherein said pre-processing step includes processing the untreated tip section into a wedge-shaped tip shape which does not have a top surface on its top section And the position of the top section is within the range of the first grooves in a width direction of the first grooves. The method of manufacturing a semiconductor wafer according to claim 4, wherein the center of the cutting width is within the range of the first grooves. The method of manufacturing a semiconductor wafer as claimed in claim 4, the method further comprising: preparing a cutting member having a substantially rectangular shape in section when viewed from the direction of rotation; and forming the first and second cutting members on the back surface side using the prepared cutting member When there are two grooves, the state of fracture of the stepped sections is confirmed, wherein when the prepared cutting member breaks a stepped section, the pre-processing step is performed. A method for manufacturing a semiconductor wafer, comprising: forming a first groove on a front side of a substrate; and forming a second groove on a back side of the substrate by using a rotating cutting member, the cutting member having a A tip section having a cutting width wider than a width of each of the first grooves, and the second grooves are respectively opened to the first grooves; A stepped section of a semiconductor wafer, the stepped sections are formed due to the difference between the widths of the first grooves and the second grooves; before forming the second grooves, pre-treat a The untreated tip section forms the tip section, the untreated tip section has a degree of tapering to form a top section of the untreated tip section, and the top section applies the One of the maximum stresses of the stepped section fracture, wherein the degree of tapering of the untreated tip section is made smaller, so that the cutting member has a degree of tapering to form a top section of the cutting member , The top section applies no So that one of said stepped sections maximum breaking stress. The method of manufacturing a semiconductor wafer as claimed in claim 9, wherein the pre-processing step is performed in a manufacturing condition in which the position of the top section of the cutting member is in the first groove A width direction is not included in the range of the first grooves. If the method of manufacturing a semiconductor wafer according to claim 9, the method further comprises: confirming the presence or absence of a condition in which the position of the top section of the cutting member is not in a width direction of one of the first grooves Is included in the scope of the first grooves, wherein the pre-processing step is performed in a manufacturing condition in which the position is not included in the scope of the first grooves.