JP2010258288A - Fixture, and method of manufacturing semiconductor device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixture that facilitates transferring a semiconductor wafer during a process for forming imprints by irradiating laser, and to provide a method of manufacturing a semiconductor device using the fixture. <P>SOLUTION: The fixture 1 includes a clamper 3 formed in C-shape when viewed from above; and a clamp ring 2 contacting with the periphery of the semiconductor wafer arranged on the clamper 3. A step difference 6 is provided by recessing an inner edge of the clamper 3 in a thickness direction, and the semiconductor wafer is fixed by the clamp ring 2 in the state that the semiconductor wafer is received in the step difference 6. An advantage of easily handling a semiconductor wafer during a process for imprinting is obtained, because the semiconductor wafer is fixed by the fixture 1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fixing jig and a method for manufacturing a semiconductor device using the same, and more particularly to a fixing jig for fixing a semiconductor wafer and a method for manufacturing a semiconductor device using the same.

  2. Description of the Related Art Conventionally, a semiconductor device set in an electronic device is used in a mobile phone, a portable computer, and the like, so that it is required to be downsized, thinned, and lightweight. In order to satisfy these conditions, a semiconductor device called a CSP (Chip Scale Package) having a size equivalent to a built-in semiconductor element has been developed.

  Among these CSPs, there is WLP (Wafer Level Package) as a particularly miniaturized one (see, for example, Patent Document 1 below). A general method for manufacturing WLP is to provide a semiconductor wafer with a large number of semiconductor device portions in a matrix, and after forming wirings and solder electrodes connected to the diffusion regions of each semiconductor device portion on one main surface of the semiconductor wafer, Each semiconductor device part is separated individually by dicing the semiconductor wafer into a lattice shape. Furthermore, a seal is formed on the main surface of the semiconductor device portion by laser irradiation. Alternatively, the seal may be formed by irradiating the main surface of the semiconductor wafer with a laser in the state of the semiconductor wafer.

  However, in the above general WLP manufacturing method, in order to reduce the thickness of the formed WLP to, for example, 100 μm or less, it is necessary to extremely reduce the thickness of the semiconductor wafer itself to 100 μm or less before dicing. For this reason, the mechanical strength of the semiconductor wafer after being reduced in thickness is lowered, and there are many problems that the semiconductor wafer is damaged in the transporting process or the like.

  As a method for manufacturing WLP that solves such problems, dicing before grinding (hereinafter abbreviated as DBG) has been developed (see Patent Document 2). In this method of manufacturing a semiconductor device by DBG, a semiconductor wafer on which wirings and the like are formed is half-cut from the front surface side and then ground from the back surface side, so that the semiconductor wafer is individually separated in the half-cut region. This is a method of dividing into semiconductor devices. A method of dividing a semiconductor wafer by DGB will be described with reference to FIGS.

  Referring to FIG. 11A, first, a semiconductor wafer 100 in which semiconductor device portions 108 are formed in a matrix is prepared. In the vicinity of the upper surface of each semiconductor device portion 108, an element such as a transistor is formed by a diffusion process. Further, the upper surface of the semiconductor wafer 100 is covered with an insulating layer 102 made of an oxide film, and wiring 104 connected to the element region is formed on the upper surface of the insulating film 102. Further, an external electrode 106 made of solder is formed on the wiring 104. The thickness of the semiconductor wafer 100 in this step is about 280 μm, for example.

  Referring to FIG. 11B, next, dicing is performed from the upper surface of the semiconductor wafer 100 to form a groove 110 between the semiconductor device portions 108. The dicing here does not divide the semiconductor wafer 100, and the depth of the groove 110 formed by dicing is formed to be shallower than the thickness of the semiconductor wafer 100. As an example, when the thickness of the semiconductor wafer 100 is 280 μm as described above, the depth of the groove 110 is set to about 100 μm. Therefore, the semiconductor wafer 100 that has undergone this process is not in a divided state, but presents a single plate-like body.

  Referring to FIG. 11C, after the semiconductor wafer 100 is turned upside down, the lower surface of the semiconductor wafer 100 on which the wiring 104 is formed is attached to the adhesive tape 112. Furthermore, the semiconductor wafer 100 is ground from the upper surface, and the semiconductor wafer 100 is thinned over the entire surface.

  Referring to FIG. 11D, by advancing grinding from the upper surface of semiconductor wafer 100, each semiconductor device portion 108 is individually separated at the location where groove 110 is separated.

  Referring to FIGS. 12A and 12B, next, the back surface side (surface side ground by glide) of each semiconductor device portion 108 is attached to an adhesive tape 114 made of, for example, a dicing sheet. . Further, by peeling off the adhesive tape 112, each semiconductor device portion 108 can be picked up from the front surface side (surface on which the circuit is formed) side.

  After the above steps are completed, each semiconductor device is picked up and separated from the adhesive tape 114, and then the lower surface (the surface on which the semiconductor material is exposed) is irradiated with a laser to be stamped, and taping packaging or the like is performed.

JP 2004-172542 A JP 2005-101290 A

  In the manufacturing method described above, since productivity is poor when laser printing is performed on each divided semiconductor device, a method of performing laser printing on a semiconductor wafer before division can be considered in order to improve productivity.

  However, it has been difficult to form a seal by efficiently irradiating the main surface of each semiconductor device portion of the semiconductor wafer with a laser. Specifically, the thickness of the semiconductor wafer becomes extremely thin, for example, 100 μm or less in order to reduce the thickness of the apparatus itself. Therefore, when a thin semiconductor wafer is transported for marking by laser irradiation, the semiconductor wafer is in the middle of the transport. The problem of breaking occurs.

  Furthermore, although the above-described normal WLP manufacturing process and DBG manufacturing process may coexist in one factory, it is difficult to carry out the marking by laser irradiation in common. The reason for this is that in the normal WLP manufacturing process, laser irradiation is performed in the state of the semiconductor wafer, whereas in the DGB manufacturing process, individually separated semiconductor wafers are stamped by laser irradiation. Because it is done.

  The present invention has been made in view of the above-described problems, and a main object of the present invention is to provide a fixing jig that facilitates transport of a semiconductor wafer in a process of forming a seal by laser irradiation, and a method of manufacturing a semiconductor device using the same. It is to provide.

  The fixing jig of the present invention is a fixing jig for fixing a semiconductor wafer, and has a C shape in a plan view, and has a clamper whose inner diameter is smaller than the diameter of the semiconductor wafer, and an inner end portion of the clamper. A stepped portion that is recessed in the thickness direction; a ring-shaped clamp ring that contacts the main surface of the peripheral portion of the semiconductor wafer housed in the stepped portion; and an upper surface of the clamper that is outside the stepped portion. And a clamp block that is rotatably provided to press the clamp ring toward the clamper.

  The method of manufacturing a semiconductor device according to the present invention includes a step of mechanically fixing a semiconductor wafer on which a large number of semiconductor device portions are formed to a fixing jig in a state where a main surface of the semiconductor wafer on which a seal is formed is exposed. And holding the fixing jig, the semiconductor wafer is conveyed to a table on which laser marking is performed, and the position of the semiconductor wafer is fixed by pressing the fixing jig with the table and a pressing clamper. And a step of performing a marking by irradiating the main surface of the semiconductor wafer fixed to the table with a laser.

  According to the fixing jig of the present invention, the peripheral part of the semiconductor wafer is fixed in a state where the main surface of the semiconductor wafer irradiated with the laser is exposed, so that the fixing jig is held in the marking process by laser irradiation. As a result, the semiconductor wafer can be transferred. Therefore, even if the thickness of the semiconductor wafer on which the seal is formed is as thin as 100 μm or less, the semiconductor wafer is prevented from being cracked in the transport process.

  Further, by making the outer shape of the fixing jig for fixing the semiconductor wafer the same shape of the wafer ring used for dicing the semiconductor wafer, the marking device used for laser marking can be converted into a normal WLP manufacturing process, It can be shared with the manufacturing process of DBG. Specifically, in the case of a normal WLP manufacturing process, a laser is irradiated onto a semiconductor wafer supported by a fixing jig. Further, in the case of a DGB manufacturing process, laser beam irradiation is performed in a state where a semiconductor wafer separated into individual semiconductor devices is attached to a dicing sheet whose periphery is supported by a wafer ring.

It is a figure which shows the fixing jig of this invention, (A) is a perspective view, (B) is sectional drawing. It is a figure which shows the manufacturing method of the semiconductor device of this invention, (A) is a top view, (B) is sectional drawing. It is a figure which shows the manufacturing method of the semiconductor device of this invention, (A) and (B) are perspective views, (C) is sectional drawing. It is a figure which shows the stamping apparatus used for the manufacturing method of the semiconductor device of this invention, (A) is a perspective view which shows the whole, (B) is a perspective view which extracts and shows a part. It is a figure which shows the manufacturing method of the semiconductor device of this invention, and (A)-(C) is sectional drawing. It is a figure which shows the manufacturing method of the semiconductor device of this invention, (A) is sectional drawing, (B) is a top view. It is a figure which shows the manufacturing method of the semiconductor device of this invention, (A) and (B) are sectional drawings. It is a perspective view which shows the manufacturing method of the semiconductor device of this invention. It is a figure which shows the semiconductor device manufactured by the manufacturing method of the semiconductor device of this invention, (A) is a perspective view, (B) is sectional drawing. It is a figure which shows the manufacturing method of the semiconductor device of this invention, (A) is sectional drawing, (B) and (C) are expanded sectional drawings, (D) is an enlarged plan view. . It is a figure which shows the manufacturing method of the semiconductor device of background art, (A)-(D) is sectional drawing. It is a figure which shows the manufacturing method of the semiconductor device of background art, (A) And (B) is sectional drawing.

<First Embodiment>
With reference to FIG. 1, the structure of the fixing jig 1 of this Embodiment is demonstrated first. FIG. 1A is a perspective view showing the fixing jig 1, and FIG. 1B is a sectional view thereof.

  1A and 1B, a fixing jig 1 includes a clamper 3 having a C-shape in a plan view, and a clamp ring 2 that contacts the periphery of a semiconductor wafer disposed on the clamper 3. And is composed mainly of. The fixing jig 1 fixes a semiconductor wafer on which a large number of semiconductor device portions are formed by a diffusion process or the like in order to perform laser marking.

  The clamper 3 is formed by molding a metal such as stainless steel into a C shape in a plan view, the inner end is circular, and the inner diameter L2 is set shorter than the diameter of the semiconductor wafer to be held. Further, a stepped portion 6 is formed in which the inner end of the clamper 3 is recessed in the thickness direction, and the distance L1 between the side surfaces of the facing stepped portions 6 is set slightly longer than the diameter of the semiconductor wafer to be held. Has been. Note that the height (thickness) of the stepped portion 6 is about the same as the length obtained by adding the semiconductor wafer to be accommodated and the thickness of the clamp ring 2.

  When the semiconductor wafer is fixed to the fixing jig 1, the peripheral portion of the main surface of the semiconductor wafer contacts the lower surface of the stepped portion 6. Further, the reason that the clamper 3 has a C shape instead of a ring shape is to secure escape of tweezers contacting the back surface of the semiconductor wafer in order to move the semiconductor wafer.

  The clamp ring 2 is formed by molding a metal such as stainless steel or a resin material into a ring shape, and its outer shape L3 is set to be smaller than the diameter L1 of the stepped portion 6 provided in the clamper 3. The lower surface of the clamp ring 2 is in contact with the periphery of the upper surface of the semiconductor wafer to be held.

  A plurality of clamp blocks 5 are arranged at equal intervals around the clamper 3 and are provided on the upper surface of the clamper 3 in a rotatable state. The longitudinal direction of each clamp block 5 is oriented in a direction perpendicular to the center of the clamper 3 until the clamp ring 2 is disposed on the clamper 3. Further, after the clamp ring 2 is accommodated in the clamper 3, the upper surface of the clamp ring 2 is pressed by the lower surface of the clamp block 5 by rotating the clamp block 5 so that the longitudinal direction of the clamp block 5 faces the center of the clamper 3. The

  The side clamp 4 is composed of a plate-like member disposed on the upper surface of the clamper 3, and is installed so as to be movable with respect to the center of the clamper 3. An inner side surface of the side clamp 4 has a function of pressing the orientation flat of the semiconductor wafer disposed on the clamper 3 from the side. This pressing force is applied by a spring disposed below the side clamp 4. Thus, by pressing the orientation flat of the semiconductor wafer with the side clamp 4, the stored semiconductor wafer can be oriented in a predetermined direction.

<Second Embodiment>
Next, a method for manufacturing a semiconductor device using the fixing jig having the above-described configuration will be described with reference to FIGS. In the manufacturing method described below, a semiconductor wafer in which a large number of semiconductor device portions are formed is prepared, and after the semiconductor wafer is fixed to a fixing jig, marking is performed by laser irradiation, and dicing is performed for each semiconductor. It is separated into the device part. That is, the fixing jig having the above-described configuration is applied to the normal WLP manufacturing method described in the background art.

  Referring to FIG. 2, first, a semiconductor wafer 22 is prepared. FIG. 2A is a plan view showing the semiconductor wafer 22, and FIG. 2B is a cross-sectional view showing a part of the semiconductor wafer 22.

  Referring to FIG. 2A, a large number (for example, several hundreds) of semiconductor device sections 24 are formed on a semiconductor wafer 22 in a matrix. Here, the semiconductor device unit 24 is a part that becomes one semiconductor device. Further, dicing lines 27 are defined in a lattice shape between the semiconductor device portions 24, and the semiconductor wafer 22 is separated into individual semiconductor devices along the dicing lines 27 in a later process.

  Referring to FIG. 2B, in each semiconductor device portion 24, an element (diffusion region) such as a transistor is formed inside the semiconductor wafer 22 by a diffusion process. Further, a pad 56 connected to this element is formed on the upper surface of the semiconductor wafer 22. An insulating layer 54 made of an oxide film or the like is formed on the upper surface of the semiconductor wafer 22 with the pad 56 exposed. In addition, on the upper surface of the insulating layer 54, a wiring 58 connected to the pad 56 is formed from the peripheral portion of each semiconductor device portion 24 toward the central portion. An external electrode 70 made of solder is welded to the upper surface of the wiring 58 formed in a pad shape. Further, a coating layer 60 made of a resin is formed so as to cover the upper surfaces of the wiring 58 and the insulating layer 54 except for the region where the external electrode 70 is provided. The thickness of the semiconductor wafer 22 in this step varies depending on the diameter of the semiconductor wafer. For example, the thickness of the semiconductor wafer 22 having a diameter of 50 mm (2 inches) is 280 μm, and the thickness of the semiconductor wafer 22 having a diameter of 200 mm (8 inches) is 725 μm.

  Next, referring to FIG. 3, the semiconductor wafer is fixed to a fixing jig. 3A is an exploded perspective view showing a state before the semiconductor wafer 22 is fixed by the fixing jig 1, and FIG. 3B is a diagram after the semiconductor wafer 22 is fixed to the fixing jig 1. FIG. It is a perspective view which shows a state, and FIG.3 (C) is sectional drawing of the state after fixing.

  Referring to FIG. 3A, the semiconductor wafer 22 is housed in the stepped portion 6 of the clamper 3 with the surface on which the wiring or the like is formed as the upper surface. As described above, the thickness of the semiconductor wafer 22 is about 200 μm to 500 μm, and since the mechanical strength is small and it is easily broken, it is difficult to manually move the semiconductor wafer 22. In this step, the vacuum tweezers 7 are used for moving the semiconductor wafer 22. The pad provided at the tip of the tweezers 7 sucks and holds the vicinity of the center of the lower surface of the semiconductor wafer 22 where the semiconductor material is exposed. The semiconductor wafer 22 is transported to the step portion of the clamper 3 by the tweezers 7.

  As described above, the clamper 3 has a C-shape that is a ring shape with a part missing. Therefore, even if the semiconductor wafer 22 is set on the stepped portion 6 of the clamper 3, an intermediate portion of the tweezers 7 that holds the semiconductor wafer 22 from the back surface is disposed in an area where the body portion of the clamper 3 is interrupted. Therefore, the tweezers 7 do not contact the clamper 3. Further, the lower surface peripheral portion of the semiconductor wafer 22 on which the semiconductor device portion and the alignment mark are not provided is in contact with the upper surface of the step portion 6.

  Next, the clamp ring 2 is stored in the step portion 6 of the clamper 3. Since the outer shape of the clamp ring 2 is slightly smaller than the diameter of the stepped portion 6, the clamp ring 2 is accommodated in the stepped portion 6 with the lower surface in contact with the peripheral portion of the upper surface of the semiconductor wafer 22.

  Next, by sliding the side clamp 4 toward the center of the clamper 3, the side surface of the side clamp 4 is brought into contact with the orientation flat of the semiconductor wafer 22. By doing so, the orientation of the rotation direction of the semiconductor wafer 22 is fixed.

  Next, the clamp ring 2 is pressed and fixed from above by rotating the four clamp blocks 5 arranged on the upper surface of the clamper 3. Specifically, the upper surface of the clamp ring 2 is pressed by the lower surface of the clamp block 5 by rotating the clamp block 5 so that the longitudinal direction of the clamp block 5 faces the center of the clamper 3. As a result, the peripheral portion of the semiconductor wafer 22 is pressed against and fixed to the step portion 6 of the clamper 3 through the clamp ring 2.

  FIG. 3B and FIG. 3C show a state where the semiconductor wafer 22 is fixed to the fixing jig 1. As described above, the upper and lower main surfaces of the peripheral surface portion of the semiconductor wafer 22 are fixed by the clamp ring 2 and the clamper 3. The upper surface of the semiconductor wafer 22 is exposed upward from the inside of the clamp ring 2, which makes it possible to visually recognize the alignment mark provided on the upper surface of the semiconductor wafer 22. Furthermore, since the lower surface of the semiconductor wafer 22 is exposed downward from the opening of the clamper 3, the laser can be irradiated to the lower surface of the semiconductor wafer 22 from which the semiconductor material is exposed via the opening of the clamper 3. It becomes possible.

  4 to 7, next, a semiconductor wafer 22 fixed to the fixing jig 1 is irradiated with a laser to form a seal.

  With reference to FIG. 4, the structure of the marking apparatus 10 used for the manufacturing method of the semiconductor device of this embodiment will be described first. FIG. 4A is a perspective view showing the main part of the stamping apparatus 10, and FIG. 4B is a perspective view showing the configuration of the table 14 on which the semiconductor wafer is clamped.

  Referring to FIG. 4A, the stamping apparatus 10 includes a transport rail 12 on which a semiconductor wafer 22 supported by the fixing jig 1 is placed, a table 14 on which a wafer ring is fixed for marking, It mainly includes an ionizer 18 for removing the charge of the semiconductor wafer and an oscillator 20 for irradiating the semiconductor wafer with a laser. The general function of the marking apparatus 10 is to form a stamp by collectively irradiating the received semiconductor wafer 22 with a laser.

  The transport rail 12 is a part on which the received semiconductor wafer 22 is placed. Specifically, the semiconductor wafer 22 is supplied to the stamping apparatus 10 with the periphery supported by the fixing jig 1. Moreover, the conveyance rail 12 consists of two rails shape-shaped in cross section, and the fixing jig 1 is mounted on the flat surface inside this rail. In addition, the semiconductor wafer after completion of the laser irradiation marking is also placed on the transport rail 12.

  The table 14 is a movable table for fixing the fixing jig 1 for marking, and is movable in a direction parallel to the main surface of the semiconductor wafer 22 fixed to the fixing jig 1. An opening having a diameter larger than that of the semiconductor wafer is formed in the vicinity of the center of the table 14, and a laser is irradiated from below through the opening when marking is performed. The table 14 is positioned in the vicinity of the transport rail 12 when receiving the fixing jig 1, and moves below the ionizer 18 at a low speed when removing the electrification of the semiconductor wafer 22. When irradiating, it is located above the oscillator 20.

  The pressing clamper 16 is composed of two metal plates made of stainless steel or the like, and these two metal plates are arranged apart from each other on the same plane. Moreover, the curving notch is formed in the opposing side of each metal plate, and these notches form the circular opening part as a whole. Further, the pressing clamper 16 is movable in the vertical direction with respect to the table 14, and the pressing clamper 16 is spaced apart from the upper surface of the table 14 until the fixing jig 1 is placed on the upper surface of the table 14. positioned. Further, in the step of marking the semiconductor wafer 22 to which the semiconductor wafer 22 is fixed, the pressing clamper 16 presses and fixes the upper surface of the fixing jig 1 placed on the upper surface of the table 14. Further, after the stamping by the laser irradiation is completed, the pressing clamper 16 is raised again, and the fixing jig 1 is unfixed.

  The ionizer 18 has a function of artificially generating positive ions and negative ions and blowing air containing these ions to the semiconductor wafer 22. By doing so, the charge of the semiconductor wafer 22 is removed.

  The oscillator 20 has a function of irradiating the main surface of the semiconductor wafer 22 with a laser for marking. In the present embodiment, the oscillator 20 emits a YAG (Yttrium Aluminum Garnet) laser, and the wavelength of the irradiated laser is preferably 532 nm.

  As shown in FIG. 4B, the pressing clamper 16 and the table 14 are provided with openings. Specifically, the pressing clamper 16 is composed of two metal plates as described above, and the opening 16A is configured by providing a notch portion on the opposite side of both metal plates. The size of the opening 16 </ b> A is a circular shape that is smaller than the outer diameter of the fixing jig 1 and larger than the diameter of the semiconductor wafer 22. By providing the opening 16A in this manner, the semiconductor wafer 22 is exposed from the opening 16A and the position of the semiconductor wafer 22 is recognized from above even after the fixing jig 1 is fixed by the pressing clamper 16. Can do.

  Further, an opening 14A having a size equivalent to that of the above-described opening 16A is provided near the center of the table 14. When irradiating the semiconductor wafer 22 with laser, the laser is irradiated from below through the opening 14A.

  Next, referring to FIGS. 5 to 7, the main surface of each semiconductor device portion 24 included in the semiconductor wafer 22 is irradiated with a laser to form a seal. In this step, the stamping apparatus 10 having the configuration shown in FIG. 4 is used to perform stamping by irradiating each semiconductor device part included in the semiconductor wafer 22 collectively with a laser.

  Referring to FIG. 5A, first, the semiconductor wafer 22 is received on the transport rail 12 of the stamping apparatus. In this step, the semiconductor wafer 22 is received by the transport rail 12 with the periphery supported by the fixing jig 1. The fixing jig 1 placed on the transport rail 12 is transported to the table 14 while being held by the transport arm 13. Here, since the transport arm 13 holds not the semiconductor wafer 22 itself but the fixing jig 1 for fixing the semiconductor wafer 22, the semiconductor wafer 22 is prevented from being damaged by being transported by the transport arm 13. .

  Next, referring to FIG. 5B, the pressing clamper 16 movable in the vertical direction is lowered, and the fixing jig 1 is sandwiched and fixed between the lower surface of the pressing clamper 16 and the upper surface of the table 14. As a result, the semiconductor wafer 22 supported by the fixing jig 1 is fixed to the table 14. Further, the fixing jig 1 is held in a state of being fixed to the table 14 until the stamping process is completed. Furthermore, the pressing clamper 16 and the table 14 move together to perform marking.

  With reference to FIG. 5C, next, air containing positive ions and negative ions is blown from the ionizer 18 toward the semiconductor wafer 22. By doing so, the charge of the semiconductor wafer 22 is removed. Here, the table 14 for fixing the fixing jig 1 moves at a low speed while the ionizer 18 is fixed at a predetermined position. Specifically, the ions are sprayed over the entire area of the semiconductor wafer 22 by moving the table 14 from the right side to the left side on the paper surface while the ions are sprayed by the ionizer 18.

  Next, referring to FIG. 6, the position of the semiconductor wafer 22 is recognized. FIG. 6A is a cross-sectional view showing this step, and FIG. 6B is a plan view showing the semiconductor wafer 22 fixed to the fixing jig 1.

  Referring to FIG. 6A, after moving the table 14 so that the semiconductor wafer 22 is positioned directly below the camera 15, the semiconductor wafer 22 is photographed by the camera 15. Then, position information is extracted from the photographed image. Since the semiconductor wafer 22 is affixed to the dicing sheet 21 so that the surface on which the wiring and solder electrodes are formed is the upper surface, alignment can be performed based on these wirings and the like.

  In the present embodiment, as shown in FIG. 6B, the position of the mark 17 formed on the upper surface of the semiconductor wafer 22 is recognized. The relative positional relationship between the position of the mark 17 and the outer shape of the semiconductor wafer 22 and the position of each semiconductor device unit 24 is calculated in advance. Therefore, by recognizing the position of the mark 17, the position of the center of the semiconductor wafer 22 and the position of each semiconductor device unit 24 can be recognized.

  Four marks 17 are provided on the surface of the semiconductor wafer 22 outside the region where the semiconductor device portion 24 is formed, and are formed of, for example, the same material as the metal constituting the wiring. The number of marks 17 may be more or less than four as long as the center position of the semiconductor wafer 22 and the position of each semiconductor device portion 24 can be recognized.

  Next, referring to FIG. 7A, each semiconductor device portion 24 included in the semiconductor wafer 22 is irradiated with a laser to form a seal. First, based on the position information of the semiconductor wafer 22 obtained by the above-described method, the table 14 is moved so that a predetermined portion of the semiconductor wafer 22 is positioned above the oscillator 20. Next, a laser 28 having a predetermined wavelength is emitted from the oscillator 20 to the lower surface of the semiconductor wafer 22 where the semiconductor material is exposed. Further, the laser 28 reaches the semiconductor wafer 22 through the opening of the table 14 and the inside of the fixing jig 1. In this step, marking is performed on the lower surface of the semiconductor wafer 22 corresponding to each semiconductor device portion included in the semiconductor wafer 22.

  Next, referring to FIG. 7B, after the above-described marking is completed, the table 14 is moved to the vicinity of the transport rail 12, and then the pressing clamper 16 is raised to fix the fixing jig 1. To release. Next, the fixing jig 1 is nipped by the transport arm 13 and transported to the transport rail 12, and the fixing jig 1 is taken out from the marking device.

  After the above process is completed, the semiconductor wafer 22 on which the seal is formed is taken out from the fixing jig 1. For taking out the semiconductor wafer 22, the tweezers 7 shown in FIG.

  Referring to FIG. 8, next, the semiconductor wafer 22 is divided into semiconductor device portions. First, the semiconductor wafer 22 on which the seal is formed is stuck on the upper surface of the dicing sheet 21 whose periphery is supported by the wafer ring 23. Here, the main surface of the semiconductor wafer 22 from which the semiconductor material is exposed is bonded to the dicing sheet 21. Further, the semiconductor wafer 22 is divided into the respective semiconductor device portions 24 along the dicing lines 27 defined in a lattice shape between the semiconductor device portions 24 using the blade 26 that rotates at high speed. Each of the semiconductor device sections 24 thus divided is stored in a storage container after separating the semiconductor device section 24 from the dicing sheet 21 using an adsorption collet.

<Third Embodiment>
With reference to FIG. 9, the structure of the semiconductor device 50 manufactured by the above-described manufacturing method will be described. FIG. 9A is a cross-sectional view of the semiconductor device 50, and FIG. 9B is a cross-sectional view.

  Referring to FIGS. 9A and 9B, a semiconductor device 50 includes a semiconductor substrate 52, a wiring 58 formed on the lower surface of the semiconductor substrate 52, etc., and a semiconductor from which the semiconductor material is exposed. The top surface of the substrate 52 is provided with a stamp 66 by irradiating a laser. Furthermore, the semiconductor device 50 of this embodiment is a WLP in which a semiconductor material is exposed on the upper surface and side surfaces, and the external electrodes 70 made of solder are formed in a grid shape on the lower surface.

  The semiconductor substrate 52 is made of a semiconductor material such as silicon, and an element region is formed near its lower surface by a diffusion process. For example, a bipolar transistor, MOSFET, diode, IC, LSI or the like is formed inside the semiconductor substrate 52. The thickness of the semiconductor substrate 52 is, for example, about 50 μm to 100 μm. The upper surface of the semiconductor substrate 52 is a rough surface that has been ground by grinding.

  Referring to FIG. 9B, a pad 56 electrically connected to the element region (active region) formed by the diffusion process is formed on the lower surface of the semiconductor substrate 52. Except for the portion where the pad 56 is formed, the lower surface of the semiconductor substrate 52 is covered with an insulating layer 54. The insulating layer 54 is made of, for example, a nitride film or a resin film.

  A wiring 58 connected to the pad 56 is formed on the lower surface of the insulating layer 54. Here, the pad 56 is provided in the peripheral portion of the semiconductor device 50, and the wiring 58 extends from the peripheral portion to the inside. A part of the wiring 58 is formed in a pad shape, and an external electrode 70 made of a conductive adhesive such as solder is welded to the pad-shaped portion. Furthermore, the lower surfaces of the wiring 58 and the insulating layer 54 are covered with a covering layer 60 made of an insulating material such as a resin, excluding a region where the external electrode 70 is formed.

  Referring to FIG. 9A, a stamp 66 is formed on the upper surface of the semiconductor substrate 52. Here, the seal 66 includes a position mark 64 and a symbol mark 62. The position mark 64 is provided for detecting a planar position (angle) of the semiconductor device 50. Here, the position mark 64 is provided at the lower left corner of the semiconductor device 50. On the other hand, the symbol mark 62 is composed of letters, numbers, and the like, and indicates the name of the manufacturing company, the manufacturing time, the product name, the lot number, the characteristics of the built-in elements, and the like. In this embodiment, these markings 66 are provided by irradiating the upper surface of the semiconductor substrate 52 with a laser.

<Fourth embodiment>
Referring to FIG. 10, the stamping apparatus 10 shown in FIG. 4 can also be used for a semiconductor wafer 22 manufactured by a DGB process and divided into semiconductor device portions. The marking method by laser irradiation in this case will be described below. The schematic manufacturing method is the same as that of the above-described second embodiment, and therefore the following description will be focused on the differences.

  Referring to FIG. 10A, first, a separated semiconductor wafer is prepared by sticking to a dicing sheet 21 whose periphery is supported by a wafer ring 23. The outer shape of the wafer ring 23 is the same as that of the fixing jig 1 described above. Therefore, after the wafer ring 23 is placed on the upper surface of the table 14, the position of the semiconductor wafer 22 is fixed by fixing the wafer ring 23 with the pressing clamper 16 and the table 14. Furthermore, here, in order to correct bending and wrinkles of the dicing sheet 21, the dicing sheet 21 is pressed from below by the annular ring 11.

  Referring to FIG. 10B, next, laser 28 is irradiated from below to dicing sheet 21 having a plurality of semiconductor device portions 24 attached to the upper surface with adhesive layer 36 interposed therebetween. The laser 28 passes through the transparent dicing sheet 21 and the adhesive layer 36 and reaches the lower surface of the semiconductor substrate 52 of the semiconductor device unit 24.

  The laser 28 used in this step is a YAG laser, and a YAG laser having a wavelength of 532 nm is particularly preferably used. When the laser 28 having a short wavelength is irradiated in this manner, most of the laser is reflected on the upper surface of the semiconductor substrate 52, so that the laser hardly travels inside the semiconductor substrate 52 and is near the upper surface of the semiconductor substrate 52. The adverse effect of the laser is not exerted on the formed element region.

  The output of the laser 28 to be irradiated is about 6 W, for example, and the size of the irradiation region irradiated by the laser 28 is a circle having a diameter of about 30 μm. Furthermore, in the present embodiment, the output and irradiation time of the laser 28 are controlled to such an extent that the adhesive layer 36 does not vaporize due to heat generation. Therefore, the adhesive layer 36 is vaporized by heat generated by the irradiation of the laser 28, thereby preventing the semiconductor device unit 24 from being detached from the dicing sheet 21.

  Referring to FIG. 10C, in this step, a stamp is formed by repeatedly irradiating a laser 28 with a shot (pulse). When the irradiated laser 28 passes through the dicing sheet 21 and the adhesive layer 36 and reaches the lower surface of the semiconductor substrate 52, the region irradiated with the laser 28 is excavated locally to form a concave portion 38A. In addition, due to the irradiation of the laser 28, the concave portion 38 </ b> A and its peripheral portion are heated at the lower surface of the semiconductor substrate 52, and the adhesive layer 36 attached to these regions is carbonized. And the carbide | carbonized_material 68 which consists of the carbonized contact bonding layer 36 adheres to the concave part 38A and its peripheral part (carbonization area | region 40A shown to FIG. 10 (D)). In this step, the above-described shot irradiation of the laser 28 is performed along the shape of the seal to be formed.

  FIG. 10D shows the concave portions 38 </ b> A- 38 </ b> D and the carbonized regions 40 </ b> A- 40 </ b> D formed by the laser 28. By irradiating the laser 28, concave portions 38A-38D are formed at equal intervals, and carbonized regions 40A-40D concentric with the concave portions 38A-38D are formed. The adjacent carbonized regions (for example, the carbonized region 40A and the carbonized region 40B) are partially overlapped to form a line-shaped seal by the continuous carbonized regions 40A-40D.

DESCRIPTION OF SYMBOLS 1 Fixing jig 2 Clamp ring 3 Clamper 4 Side clamp 5 Clamp block 6 Step part 7 Tweezers 10 Stamping device 11 Ring 12 Transport rail 13 Transport arm 14 Table 14A Opening part 15 Camera 16 Pressing clamper 16A Opening part 17 Mark 18 Ionizer 20 Oscillator 21 Dicing sheet 22 Semiconductor wafer 23 Wafer ring 24 Semiconductor device part 26 Blade 27 Dicing line 28 Laser 32 Adhesive layer 36 Adhesive layers 38, 38A, 38B, 38C, 38D Concave part 40, 40A, 40B, 40C, 40D Carbonized region 42 Carbide 44 groove 50 semiconductor device 52 semiconductor substrate 54 insulating layer 56 pad 58 wiring 60 covering layer 62 symbol mark 64 position mark 66 stamp 68 carbide 70 external electrode

Claims (8)

A fixing jig for fixing a semiconductor wafer,
A clamper having a C-shape in plan view and having an inner diameter smaller than the diameter of the semiconductor wafer;
A stepped portion provided by recessing the inner end of the clamper in the thickness direction;
A ring-shaped clamp ring that contacts the main surface of the peripheral portion of the semiconductor wafer housed in the stepped portion;
A clamp block which is rotatably provided on the upper surface of the clamper outside the stepped portion and presses the clamp ring toward the clamper;
A fixing jig for a semiconductor wafer, comprising:   The fixing jig according to claim 1, further comprising a side clamp that presses a side surface of the semiconductor wafer on which the orientation flat is formed from a side.   3. The fixing jig according to claim 2, wherein the outer shape of the clamper is the same shape as a wafer ring used when dicing a semiconductor wafer.   The fixing jig according to claim 3, wherein a length obtained by adding a thickness of the semiconductor wafer to be fixed and a thickness of the wafer ring is equal to a height of the stepped portion. A step of mechanically fixing a semiconductor wafer on which a large number of semiconductor device portions are formed to a fixing jig in a state where a main surface of the semiconductor wafer on which a stamp is formed is exposed;
The process of conveying the semiconductor wafer to a table on which laser marking is performed by holding the fixing jig, and fixing the position of the semiconductor wafer by pressing the fixing jig with the table and a pressing clamper. When,
Irradiating a laser to the main surface of the semiconductor wafer in a state fixed to the table and performing a seal;
A method for manufacturing a semiconductor device, comprising:   6. The method of manufacturing a semiconductor device according to claim 5, wherein the semiconductor wafer fixed to the fixing jig is transported to the table by a transport arm holding the fixing jig.   The semiconductor device according to claim 6, wherein the table is provided with an opening that is larger than the semiconductor wafer, and each semiconductor device portion of the semiconductor wafer is irradiated with a laser through the opening. Method.   The position of the alignment mark arrange | positioned on the said semiconductor wafer is recognized, and alignment with the irradiation apparatus which irradiates the said laser, and each said semiconductor device part contained in the said semiconductor wafer is performed. The manufacturing method of the semiconductor device of description.

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