JP2005116844A - Manufacturing method of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce chipping while suppressing chipping or peeling of a surface layer even when a surface layer made of a material different from that of the semiconductor substrate is formed on the surface of the semiconductor substrate.
A first laser beam 8a is scanned on the scribe line surface of the semiconductor substrate 1 from the surface side where the semiconductor element is formed while converging on the scribe line 2 on the surface where the semiconductor element is formed, A step of forming a groove and a step of scanning the second laser beam 8b while condensing the semiconductor substrate 1 along the scribe line 2 to form a modified region 10 by multiphoton absorption are included. By forming grooves on the scribe line 2 with the first laser beam 8a, chipping and cracking of the surface layer can be suppressed regardless of the surface state of the semiconductor substrate 1, and modification by multiphoton absorption can be performed with the second laser beam 8b. The cutting after forming the mass region 10 is facilitated.
[Selection] Figure 2

Description

  The present invention relates to a dicing method for dividing a semiconductor element formed on a semiconductor substrate, and more particularly, to a method for manufacturing a semiconductor device for a dicing method by laser processing that can reduce the dicing width with little chipping. Is.

  Conventionally, as a method for dicing a semiconductor substrate, a method of crushing by rotating an annular dicing saw holding diamond or CBN particles with a bonding material at a high speed has been most commonly used.

Processing with a dicing saw works to improve processing quality by improving and optimizing the diamond particle size, density, bond material and other dicing saw specifications, and rotational speed, feed speed, and cutting depth. I have been. However, there is a limit to the improvement of the processing quality by the dicing saw. In particular, with respect to the following problems, a further improvement cannot be expected in the crushing processing such as the dicing saw.
(1) Due to the crushing process, chipping occurs on the cut surface, so that the bending strength of the semiconductor substrate after dicing deteriorates.
(2) Chipping fragments become dust, which adversely affects process yield and reliability after dicing.
(3) It is necessary to make the scribe region thicker than the actual dicing width so that chipping does not enter the region of the semiconductor element.
(4) The thickness of the dicing saw needs to be about 1/10 to 1/15 of the thickness of the semiconductor substrate in order to maintain the strength. For example, when the thickness of the semiconductor substrate is 400 μm, the thickness of 25 μm to 40 μm is necessary. Become.
(5) When a module such as a process control module (PCM) or alignment mark is formed on a dicing line, the metal, protective film, or interlayer film constituting the module is peeled off due to dicing damage, and chipping is performed. Like the chip, it adversely affects the process yield and reliability after dicing.
(6) When modules such as PCM and alignment marks are formed on the surface, the module on the surface side is configured when dicing is performed by single cutting (a method of completely cutting by one dicing). Large chipping also occurs on the back side due to the influence of metal, protective film or interlayer film.

  In recent years, laser beam processing has attracted attention as a method for solving the above problems. For example, in Patent Document 1, a laser beam is focused on the upper surface of a semiconductor substrate on which a coating layer made of an oxide film, a nitride film, or a metal film is formed, and the energy is absorbed only by the coating layer, thereby the surface of the substrate. A scribe line is formed on the surface of the substrate by scanning the laser beam over a period of time, and only a part of the layer is evaporated, followed by dicing along the scribe line with a dicing saw.

  According to this method, since the front surface coating layer is removed with a laser beam and then completely cut with a dicing saw, chipping on the back surface due to the influence of the coating layer is suppressed. Furthermore, since surface chipping is not crushing, chipping can be remarkably reduced.

  However, according to this method, since the final cut uses a conventional dicing saw, chipping on the back surface occurs. Also, the dicing width depends on the thickness of the dicing saw and cannot be narrowed.

  On the other hand, in Patent Document 2, a modified region by multiphoton absorption is formed. Multiphoton absorption is a phenomenon in which absorption occurs in a material when the intensity of light is made very large even when the photon energy is smaller than the absorption bandgap of the material, that is, when it is optically transmitted. By aligning the condensing point of the laser beam inside the substrate, a phenomenon of multiphoton absorption is caused and a modified region is formed inside the semiconductor substrate. With the modified region as a starting point, the substrate can be easily divided along the dicing line, so that the substrate can be diced without causing unnecessary cracks, i.e., chipping, deviating from the dicing line.

  Accordingly, it is possible to suppress a decrease in bending strength due to chipping and generation of dust. Further, unlike the crushing process, the dicing width does not have a physical cutting width in the plane direction, so that the dicing area can be extremely narrowed.

  The laser processing method in Patent Document 2 will be described with reference to the drawings.

  FIG. 8 is a plan view showing a scribe line and its periphery of a semiconductor substrate which is a laser workpiece, and FIG. 9 is a c-c ′ cross-sectional view shown in FIG. 8 during laser processing.

  8 and 9, 101 is a semiconductor substrate, 102 is a scribe line, 102a is the center of the scribe line, 103 is a laser beam, 104 is a modified region, 105 is a cut portion (crack generated from the modified region 104 as a starting point) ).

First, the laser beam 103 is focused on the inside of the semiconductor substrate 101 to cause multiphoton absorption. Next, the modified region 104 along the scribe line 102 is formed inside the semiconductor substrate 101 by scanning along the center 102a of the scribe line while continuously or intermittently generating multiphoton absorption. Is done. Since the cut portion 105 is formed starting from the modified region 104, the semiconductor substrate 101 can be easily broken with a relatively small external force. In particular, when the semiconductor substrate 101 is thin, it can be naturally cracked in the thickness direction without applying an external force. Even when the semiconductor substrate 101 is thick, for example, if a plurality of modified regions 104 are formed in parallel in the thickness direction (not shown), they can be easily cut.
JP 2002-329686 A Japanese Patent No. 3408805

However, Patent Document 2 has the following problems.
(1) When the surface of the semiconductor substrate has a surface layer formed of a material different from that of the semiconductor substrate, such as a PCM made of a metal, an oxide film, a nitride film, etc., the band gap or refraction of each material Due to the difference in rate, it is very difficult to collect sufficient light intensity to cause multiphoton absorption inside the semiconductor substrate. Furthermore, in the case where each material is not formed in the same state over the entire scribe line and is scattered in an island shape, it is practically impossible to control.
(2) As a solution to the above problem, when a laser beam is transmitted from the back surface direction where the surface layer of the semiconductor substrate is not formed, a ductile material is applied to the dicing line, such as a metal layer. It is possible to cut from the modified region, but the metal layer is not cut along the dicing line, but is torn off or peeled off, so that the surface dicing trace contains metal burrs and dust. Many remain. Further, when a foreign thin film layer such as an oxide film or a nitride film is formed on a semiconductor substrate, it causes interface peeling and causes dust.
(3) In general, the dicing process is performed in a state where the semiconductor substrate is attached to a holding tape such as a dicing tape so that the semiconductor substrate after dicing is not scattered and the handling property is improved. Due to its own weight, deflection caused by the weight of the semiconductor substrate, and damage during the pick-up process after dicing, the edges of the dicing surfaces facing each other rub against each other and the edges are missing, resulting in bending strength. Cause a decline. In the case of dicing with a conventional dicing saw or the like, there is no gap between the semiconductor substrates separated after dicing because the gap exceeds the width of the dicing saw. In the case of cutting using the quality layer as a starting point, this problem occurs because there is no physical width in the plane direction.

  Therefore, even if a surface layer made of a material different from that of the semiconductor substrate is formed on the surface of the semiconductor substrate, the object of the present invention is to enable cutting from the modified region by multiphoton absorption while suppressing chipping or peeling of the surface layer. And a method of manufacturing a semiconductor device that realizes a method of dicing a semiconductor substrate that can prevent chipping due to edge-to-edge rubbing of the dicing surface after dicing.

  In order to solve the above problems, a method of manufacturing a semiconductor device according to claim 1 of the present invention is a method of manufacturing a semiconductor device in which a semiconductor element formed on a semiconductor substrate is divided along a scribe line. A step of forming a groove by scanning a first laser beam on the surface of the scribe line from the side of the surface on which the semiconductor element is formed on the scribe line of the surface of the substrate on which the semiconductor element is formed. And scanning along the scribe line while condensing the second laser light inside the semiconductor substrate to form a modified region by multiphoton absorption.

  The method for manufacturing a semiconductor device according to claim 2 is the method for manufacturing a semiconductor device according to claim 1, wherein a surface layer made of a material different from the semiconductor substrate is formed on the scribe line. When forming the groove, the surface layer is removed to expose the semiconductor substrate.

  A method for manufacturing a semiconductor device according to a third aspect is the method for manufacturing a semiconductor device according to the second aspect, wherein the surface layer material includes a metal layer.

  According to a fourth aspect of the present invention, there is provided a method of manufacturing a semiconductor device according to the first, second, or third aspect, wherein the groove is continuously formed on the scribe line.

  The method for manufacturing a semiconductor device according to claim 5 is a method for manufacturing a semiconductor device in which a semiconductor element formed on a semiconductor substrate is divided along a scribe line, wherein the surface of the semiconductor substrate on which the semiconductor element is formed is formed. On the back surface, from the back surface side, scanning while condensing the first laser beam on the back surface, forming a groove continuously along the scribe line of the semiconductor substrate, along the scribe line, Scanning while condensing the second laser beam inside the semiconductor substrate to form a modified region by multiphoton absorption.

  A method for manufacturing a semiconductor device according to claim 6 is a method for manufacturing a semiconductor device in which a semiconductor element formed on a semiconductor substrate is divided along a scribe line, the surface of the semiconductor substrate having the semiconductor element formed thereon. Scanning the first laser beam from the rear surface side while condensing the first laser beam on the rear surface to form a first groove continuously along the scribe line of the semiconductor substrate; and On the scribe line of the surface on which the semiconductor element is formed, scanning is performed while condensing the second laser light on the surface of the scribe line from the surface side on which the semiconductor element is formed, thereby forming a second groove. And a step of forming a modified region by multiphoton absorption by scanning along the scribe line while condensing a third laser beam inside the semiconductor substrate.

  According to the method of manufacturing a semiconductor device of the first aspect of the present invention, the first laser beam is scribed from the surface side on which the semiconductor element is formed on the scribe line on the surface of the semiconductor substrate on which the semiconductor element is formed. Scanning while condensing on the surface of the line to form a groove, and scanning along the scribe line while condensing the second laser beam inside the semiconductor substrate to form a modified region by multiphoton absorption Forming a groove on the scribe line with the first laser light, thereby suppressing chipping and cracking of the surface layer regardless of the surface state of the semiconductor substrate, and multiphoton with the second laser light. Cutting after forming the modified region by absorption is facilitated.

  That is, even if PCM made of metal, oxide film, or the like is formed on the surface layer on the scribe line of the semiconductor substrate, a semiconductor is formed by forming a groove with a laser beam along the scribe line on the front surface or the back surface of the semiconductor substrate. It is possible to easily cut the semiconductor substrate from the modified region formed by the excitation of multiphoton absorption by condensing the laser beam inside the substrate.

  In claim 2, at least one or more surface layers made of a material different from the semiconductor substrate are formed on the scribe line, and when forming the groove, the surface layer is removed to expose the semiconductor substrate. Even if a surface layer made of an oxide film or a nitride film is formed on the surface, the surface layer on the scribe line is completely removed by the first laser light, and the semiconductor substrate is exposed. A modified region by multiphoton absorption can be formed, and it is possible to eliminate the occurrence of burrs and chipping in the surface layer such as an oxide film and a nitride film in the subsequent cutting process.

  In claim 3, since the surface layer material includes a metal layer, for example, even if a metal such as Al or Cu of the semiconductor substrate is formed in the surface layer, the first laser beam causes Since the semiconductor layer is completely removed and the semiconductor substrate is exposed, a modified region by multiphoton absorption can be formed by the second laser beam, and the surface layer containing metal is used in the subsequent cutting process. It is possible to eliminate the occurrence of burrs and chipping.

  According to the fourth aspect of the present invention, since the grooves are continuously formed on the scribe line, the groove is simply formed continuously along the scribe line without specifying the location of the groove. It is possible to save the labor required for specifying the location.

  According to the method for manufacturing a semiconductor device according to claim 5 of the present invention, scanning is performed while condensing the first laser beam on the back surface from the back surface side of the surface on which the semiconductor element of the semiconductor substrate is formed, A step of continuously forming a groove along the scribe line of the semiconductor substrate, and scanning along the scribe line while condensing the second laser beam inside the semiconductor substrate, thereby forming a modified region by multiphoton absorption. Forming the chip, preventing chipping due to edge-to-edge rubbing of the dicing surface after dicing, thereby reducing chipping and making the scribe line narrow.

  That is, since the groove is formed on the back surface side of the semiconductor substrate along the scribe line by the first laser beam, the groove is cut from the modified region formed by causing the multiphoton absorption by the second laser beam. The edge on the back side of the surface has a chamfered shape, and unnecessary chipping does not occur during pickup after the dicing process.

  According to the method for manufacturing a semiconductor device according to claim 6 of the present invention, scanning is performed while condensing the first laser beam on the back surface from the back surface side of the surface on which the semiconductor element of the semiconductor substrate is formed, A step of continuously forming a first groove along the scribe line of the semiconductor substrate, and a second side of the semiconductor element on the scribe line of the surface of the semiconductor substrate on which the semiconductor element is formed, Scanning while condensing the laser beam on the surface of the scribe line, forming the second groove, and scanning along the scribe line while condensing the third laser beam inside the semiconductor substrate And a step of forming a modified region by absorption, the semiconductor substrate can be easily cut from the modified region formed by excitation of multiphoton absorption as in the first aspect. Like 5 Ping is extremely small, to allow a narrow width of the scribe line.

  That is, since the groove is formed on the back surface side of the semiconductor substrate along the scribe line by the first laser beam, the groove is cut starting from the modified region formed by causing the multiphoton absorption by the second laser beam. The edge on the back side of the surface has a chamfered shape, and unnecessary chipping does not occur during pickup after the dicing process. Furthermore, since the groove is formed on the scribe line on the surface side by the second laser beam, the modified region by multiphoton absorption is formed by the third laser beam regardless of the surface state of the semiconductor substrate. It is intended to facilitate cutting.

  A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a plan view showing a scribe line and its periphery of a semiconductor substrate that is a laser workpiece in the first embodiment of the present invention, and FIG. 2 is a process using the aa ′ cross-sectional view shown in FIG. FIG.

  1 and 2, 1 is a semiconductor substrate, 2 is a scribe line, 2a is the center of the scribe line, 3 is a protective film, 4 is a metal pad, 5 is an interlayer film, 6 is a protective film 3, metal pad 4, and interlayer Surface layer portion made of a material different from the semiconductor substrate such as the film 5, 7 is a dicing tape, 8a is a first laser beam, 8b is a second laser beam, 9a is a condensing point of the first laser beam 8a, 9b Is a condensing point of the second laser beam 8b, and 10 is a modified region.

  The semiconductor substrate 1 has a scribe line 2. The scribe line 2 is a virtual line for cutting. An active element such as a semiconductor element, a passive element such as a resistance element, a wiring, a pad electrode, and the like (not shown) are formed on the semiconductor element formation surface on the semiconductor substrate 1, and also on the scribe line 2. Further, a PCM (process control module) composed of an interlayer film 5, a metal pad 4, a protective film 3, and the like, and a surface layer portion 6 such as an alignment mark are formed. Here, examples of the constituent material of the surface layer portion 6 include a nitride film, an oxide film, a high dielectric film, a low dielectric film, an organic film, and a metal film, and the thickness of each film is 10 nm to several μm. Further, the thickness of the entire surface layer portion 6 is about 10 μm at most, except for special cases such as when a resin coat is formed.

  A method for dicing the semiconductor substrate will be described. As shown in FIG. 2A, the semiconductor substrate 1 is first attached to a holding material such as a dicing tape 7 so as to handle and not scatter after being cut into individual pieces. Here, the holding material may be a dicing tape or a high-rigid body such as glass that is temporarily bonded via a resin or the like.

  Next, as shown in FIG. 2B, the surface of the semiconductor substrate 1 is irradiated from the semiconductor element formation surface side along the center 2a of the scribe line 2 with the first laser light 8a having a wavelength absorbed by the surface layer portion 6. The surface layer portion 6 located at the position is scanned while being condensed to form a groove. At this time, the wavelength of the laser beam 8a may be 100 nm to 100 μm, which is a wavelength generally used for processing. In particular, when the groove is surely formed regardless of the material of the surface layer portion, the wavelength is 200 nm. It is desirable to use an ultraviolet to visible region laser of about ˜500 nm. Furthermore, the laser beam 8a is preferably pulsed irradiation in order to suppress an increase in the substrate temperature. Further, the depth of the groove is preferably about 5 μm to 30 μm, and particularly the depth at which the surface layer portion 6 is completely removed and the semiconductor substrate 1 is exposed is preferable. On the other hand, the width of the groove is desirably 50 μm or less. The first laser beam 8a forms a groove along the center 2a of the scribe line 2, but this groove may be selectively formed only in the region where the surface layer portion 6 is formed. 2 may be formed continuously along the entire center 2a. Further, the laser beam 8a is condensed on the surface layer portion 6, but the condensing does not mean a state where the laser beam 8a is completely focused, but the laser beam 8a is absorbed at the condensing point 9a and melted into the material. This means that microcracks are generated by sublimation, thermal shock, and the crystal structure is changed.

  Next, as shown in FIG. 2C, the second laser light 8 b having a wavelength that is hardly absorbed by the surface of the semiconductor substrate 1 is moved from the semiconductor element formation surface side along the center 2 a of the scribe line 2. Scanning is performed so that the light condensing point 9b is located inside 1, thereby forming a modified region 10 by multiphoton absorption shown in FIG. For example, when the semiconductor substrate 1 is a Si wafer, the wavelength of the laser light 8b is desirably 1 μm or more, which is a wavelength that is difficult to be absorbed by Si.

  Finally, as shown in FIG. 2 (e), by applying an external force to stretch the dicing tape 7, cracks progress in the thickness direction of the semiconductor substrate 1 starting from the modified region 10, and the semiconductor substrate 1 Is divided into pieces. As a method of stretching the dicing tape 7, a method of sticking to the expanding ring using an expander may be used, or a method of pushing up from the bottom of the semiconductor substrate where the push-up pin is desired to be divided as in a normal pick-up process may be used. .

  A second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a process diagram of the second embodiment of the present invention, and is a sectional view corresponding to the a-a ′ section shown in FIG. 1.

  In FIG. 3, 1 is a semiconductor substrate, 2 is a scribe line, 2a is the center of the scribe line, 3 is a protective film, 4 is a metal pad, 5 is an interlayer film, 6 is a protective film 3, metal pad 4, interlayer film 5, etc. The surface layer portion made of a material different from that of the semiconductor substrate, 7 is a dicing tape, 8a is a first laser beam, 8b is a second laser beam, 9a is a condensing point of the first laser beam 8a, and 9b is a second laser beam. The condensing point 10 of the laser beam 8b is a modified region.

  This embodiment is different from the first embodiment in that, as shown in FIG. 3C, the second laser light 8b having a wavelength that is hardly absorbed by the surface of the semiconductor substrate 1 is dicing tape 7 from the back surface side. 3 is a point in which the modified region 10 shown in FIG. 3D is formed by scanning along the center 2a of the scribe line 2 with the condensing point 9b inside the semiconductor substrate 1. . Other configurations are the same as those of the first embodiment. Here, the dicing tape 7 is attached to the back surface side of the semiconductor substrate 1, but after the processing with the first laser light 8 a, it is peeled off once, and is again attached to the semiconductor element formation surface of the semiconductor substrate 1, and the second You may process with the laser beam 8b.

  A third embodiment of the present invention will be described with reference to FIG. FIG. 4 is a process diagram of the third embodiment of the present invention, and is a cross-sectional view corresponding to the a-a ′ cross section shown in FIG. 1.

  In FIG. 4, 1 is a semiconductor substrate, 2 is a scribe line, 2a is the center of the scribe line, 3 is a protective film, 4 is a metal pad, 5 is an interlayer film, 6 is a protective film 3, metal pad 4, interlayer film 5, etc. The surface layer portion made of a material different from that of the semiconductor substrate, 7 is a dicing tape, 8a is a first laser beam, 8b is a second laser beam, 9a is a condensing point of the first laser beam 8a, and 9b is a second laser beam. 10 is a modified region, and 11 is a crack that enters the thickness direction of the semiconductor substrate starting from the modified region 10.

  This embodiment is different from the second embodiment in that, as shown in FIGS. 4B to 4D, the second laser beam is formed before the grooves are formed by the first laser beam 8a. In 8b, the modified region 10 is formed inside the semiconductor substrate 1. By reversing the process in this manner, the first laser beam 8a can form an external force to the modified region 10 at the same time as forming the groove, so that the crack 11 advances from the modified region 10. It is possible to make it. Other configurations are the same as those of the first embodiment.

  A fourth embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a plan view showing a scribe line and its periphery of a semiconductor substrate which is a laser workpiece in the fourth embodiment of the present invention, and FIG. 6 is a process using the bb ′ sectional view shown in FIG. FIG.

  5 and 6, 1 is a semiconductor substrate, 2 is a scribe line, 2a is the center of the scribe line, 7 is a dicing tape, 8a is a first laser beam, 8b is a second laser beam, and 9a is a first laser beam. A condensing point of the laser beam 8a, 9b is a condensing point of the second laser beam 8b, 10 is a modified region, and 12 is a protective tape on the element surface side of the semiconductor substrate.

The semiconductor substrate 1 has a scribe line 2. The scribe line 2 is a virtual line for cutting. An active element such as a semiconductor element, a passive element such as a resistance element, a wiring, a pad electrode, and the like (not shown) are formed on the semiconductor element formation surface on the semiconductor substrate 1. Is not particularly formed, and the semiconductor substrate 1 is exposed.
Here, the processing of the semiconductor substrate after the element formation generally proceeds in the order of applying the protective tape on the element surface, polishing the back surface, removing the protective tape, applying the dicing tape, and dicing. The protective tape 12 is, for example, brought into this process without peeling off the protective tape to be applied to protect the element surface during the back surface polishing process.

  A method for dicing the semiconductor substrate will be described. As shown in FIG. 6 (b), the first laser beam 8 a having a wavelength that is easily absorbed by the semiconductor substrate 1 is condensed from the back surface side to the back surface of the semiconductor substrate 1 along the center 2 a of the scribe line 2. Scan and form grooves. At this time, the wavelength of the laser beam 8a may be 100 nm to 100 μm, which is generally used for processing. In particular, when the semiconductor substrate is made of Si, it is easily absorbed by Si and is about 200 nm to 500 nm. It is desirable to use laser light having a wavelength in the ultraviolet to visible range. Furthermore, the laser beam 8a is preferably pulsed irradiation in order to suppress an increase in the substrate temperature. The depth of the groove is preferably about 10 μm to 50 μm, and the surface of the groove is preferably melted and solidified. On the other hand, the width of the groove is desirably 10 μm or more. Moreover, it is preferable to form continuously along the center 2a of the scribe line 2. Further, the laser beam 8a is condensed on the surface layer portion 6, but the condensing does not mean a state where the laser beam 8a is completely focused, but the laser beam 8a is absorbed at the condensing point 9a and melted into the material. This means that microcracks are generated by sublimation, thermal shock, and the crystal structure is changed.

  Next, as shown in FIG. 6C, the protective tape 12 is peeled off, and the dicing tape 7 is attached to the back surface of the semiconductor substrate 1. At this time, the dicing tape 7 after peeling off the protective tape 12 may be applied, or the protective tape 12 may be peeled off after applying the dicing tape 7.

  Next, as shown in FIG. 6 (d), the second laser light 8 b having a wavelength that is hardly absorbed by the surface of the semiconductor substrate 1 is passed along the center 2 a of the scribe line 2 from the back side of the semiconductor substrate 1. Scanning is performed so that the light condensing point 9b is located inside 1, thereby forming a modified region 10 by multiphoton absorption shown in FIG. 6 (e). Here, the laser beam 8b is scanned from the back surface side of the semiconductor substrate 1, but it is of course possible to scan from the semiconductor element formation surface side as in the first embodiment. For example, when the semiconductor substrate 1 is a Si wafer, the wavelength of the laser light 8b is desirably 1 μm or more, which is a wavelength that is difficult to be absorbed by Si.

  Finally, as shown in FIG. 6 (f), by applying an external force to stretch the dicing tape 7, a crack progresses in the thickness direction of the semiconductor substrate 1 starting from the modified region 10, and the semiconductor substrate 1 Is divided into pieces. As a method of stretching the dicing tape 7, a method of sticking to the expanding ring using an expander may be used, or a method of pushing up from the bottom of the semiconductor substrate where the push-up pin is desired to be divided as in a normal pick-up process may be used. .

  A fifth embodiment of the present invention will be described with reference to FIG. FIG. 7 is a process diagram of the fifth embodiment of the present invention, and is a sectional view corresponding to the a-a ′ section shown in FIG. 1.

  In FIG. 7, 1 is a semiconductor substrate, 2 is a scribe line, 2a is the center of the scribe line, 3 is a protective film, 4 is a metal pad, 5 is an interlayer film, 6 is a protective film 3, metal pad 4, interlayer film 5, etc. The surface layer portion made of a material different from that of the semiconductor substrate, 7 is a dicing tape, 8a is a first laser beam, 8b is a second laser beam, 9a is a condensing point of the first laser beam 8a, and 9b is a second laser beam. The condensing point of the laser beam 8b, 10 is a modified region, and 12 is a protective tape on the semiconductor element surface side of the semiconductor substrate.

  A method for dicing the semiconductor substrate will be described. First, as in the fourth embodiment, the first laser beam having a wavelength that is easily absorbed by the semiconductor substrate 1 as shown in FIG. 7B in a state where the protective tape 12 is attached to the semiconductor element surface side. After scanning 8a along the center 2a of the scribe line 2 from the back surface side while condensing on the back surface of the semiconductor substrate 1 to form a groove, the protective tape 12 is peeled off as shown in FIG. Then, the dicing tape 7 is attached to the back surface of the semiconductor substrate 1.

  Thereafter, in the same manner as in the second embodiment, as shown in FIG. 7 (d), the second laser light 8b having a wavelength absorbed by the surface layer portion 6 is transmitted along the center 2a of the scribe line 2 to the semiconductor. After condensing from the element forming surface side to the surface layer portion 6 located on the surface of the semiconductor substrate 1 to scan and forming a groove, the wavelength of the wavelength hardly absorbed by the surface of the semiconductor substrate 1 as shown in FIG. The third laser beam 8c is scanned from the back side through the dicing tape 7 along the center 2a of the scribe line 2 so that the condensing point 9b is located inside the semiconductor substrate 1, and FIG. The modified region 10 by multiphoton absorption shown in FIG.

  Finally, as shown in FIG. 7G, by applying an external force to stretch the dicing tape 7, a crack progresses in the thickness direction of the semiconductor substrate 1 starting from the modified region 10, and the semiconductor The substrate 1 is divided into individual pieces. Here, the third laser beam 8c is scanned from the back surface side, but may be scanned from the semiconductor element formation surface side as in the first embodiment. In this embodiment, the groove is formed on the back surface side of the semiconductor element 1, the groove is formed on the semiconductor element surface side, and finally the modified region 10 is formed inside the semiconductor substrate 1. This order is not necessary, and a modified region may be formed inside the semiconductor substrate 1 before forming the groove on the semiconductor element surface side as in the third embodiment.

  The method for manufacturing a semiconductor device according to the present invention can eliminate unnecessary chipping in dicing a silicon substrate or a compound semiconductor substrate, reduce the cutting width, and provide a high-quality semiconductor device. In particular, it is useful as a high-quality dicing process for a semiconductor substrate or the like in which a different material such as a metal layer or a fragile film is formed on a dicing line.

It is a top view which shows the scribe line of the semiconductor substrate which is a to-be-lased workpiece in the 1st Embodiment of this invention, and its periphery. It is process sectional drawing which shows the dicing method of the semiconductor substrate concerning the 1st Embodiment of this invention. It is process sectional drawing which shows the dicing method of the semiconductor substrate concerning the 2nd Embodiment of this invention. It is process sectional drawing which shows the dicing method of the semiconductor substrate concerning the 3rd Embodiment of this invention. It is a top view which shows the scribe line of the semiconductor substrate which is a to-be-lased workpiece, and its periphery concerning the 4th Embodiment of this invention. It is process sectional drawing which shows the dicing method of the semiconductor substrate concerning the 4th Embodiment of this invention. It is process sectional drawing which shows the dicing method of the semiconductor substrate concerning the 5th Embodiment of this invention. It is a top view which shows the scribe line of the semiconductor substrate which is a to-be-lased workpiece, and its periphery in the conventional dicing method of a semiconductor substrate. It is sectional drawing which shows the dicing method of the conventional semiconductor substrate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101 Semiconductor substrate 2,102 Dicing line 2a, 102a Center of dicing line 3 Protective film 4 Metal pad (metal layer)
DESCRIPTION OF SYMBOLS 5 Interlayer film 6 Surface layer 7 Dicing tape 8a, 8b, 8c, 103 Laser beam 9a, 9b, 9c The condensing point of a laser beam 10,104 Modified area | region 11,105 Crack from the modified area | region 12 Protection tape

Claims (6)

  A method of manufacturing a semiconductor device in which a semiconductor element formed on a semiconductor substrate is divided along a scribe line, wherein the semiconductor element is formed on the scribe line on a surface of the semiconductor substrate on which the semiconductor element is formed. The first laser beam is scanned from the surface side while condensing on the surface of the scribe line to form a groove, and the second laser beam is collected inside the semiconductor substrate along the scribe line. Scanning with light, and forming a modified region by multiphoton absorption.   2. The semiconductor according to claim 1, wherein a surface layer made of a material different from that of the semiconductor substrate is formed on the scribe line, and the surface layer is removed to expose the semiconductor substrate when the groove is formed. Device manufacturing method.   The method for manufacturing a semiconductor device according to claim 2, wherein the material of the surface layer includes a metal layer.   The method of manufacturing a semiconductor device according to claim 1, wherein the groove is continuously formed on the scribe line.   A method of manufacturing a semiconductor device in which a semiconductor element formed on a semiconductor substrate is divided along a scribe line, wherein a first laser is formed on the back surface of the surface of the semiconductor substrate on which the semiconductor element is formed from the back surface side. Scanning while condensing light on the back surface, forming a groove continuously along the scribe line of the semiconductor substrate, and passing a second laser beam along the scribe line into the semiconductor substrate A method of manufacturing a semiconductor device including a step of scanning while collecting and forming a modified region by multiphoton absorption.   A method of manufacturing a semiconductor device in which a semiconductor element formed on a semiconductor substrate is divided along a scribe line, wherein a first laser is formed on the back surface of the surface of the semiconductor substrate on which the semiconductor element is formed from the back surface side. Scanning while condensing light on the back surface, forming a first groove continuously along the scribe line of the semiconductor substrate, and on the scribe line on the surface of the semiconductor substrate on which the semiconductor element is formed And scanning the second laser beam from the surface side on which the semiconductor element is formed while condensing on the surface of the scribe line to form a second groove, along the scribe line, And a step of scanning while condensing the laser beam inside the semiconductor substrate to form a modified region by multiphoton absorption.

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