Manufacturing method of a semiconductor component with a metal layer

Abstract

Manufacturing method of a semiconductor component (21) with a metal layer (23), the manufacturing method comprising: a cutting groove forming step of causing a cutting blade (20) to cut into a first surface (11a) of a workpiece (11) having the first surface under which an electrode (15d) of a semiconductor device (21) is arranged in each of regions marked by a plurality of planned parting lines (13) arranged in a lattice shape and a second surface (11b) on a side opposite to the first surface, and forming cutting grooves (17) with a depth exceeding a final thickness of the workpiece (11) along the planned parting lines (13); a protective member adhering step of adhering a protective member (19) to the first surface of the workpiece (11) after the cutting groove forming step; a grinding step of holding the workpiece (11) on a chuck table (32) via the protective member (19) and grinding one side of the second surface until a thickness of the workpiece (11) becomes the final thickness to divide the workpiece (11) into a plurality of semiconductor devices (21); a metal layer covering step of covering a side surface (11f) of each of the plurality of semiconductor devices (21) for which the protective element (19) is adhered to a side of the first surface and the side of the second surface by a metal layer (23) after the grinding step, and a protective member removing step of removing the protective member (19) from the first surface side after the metal layer covering step.

Description

TECHNICAL BACKGROUNDTechnical field

[0001] The present invention relates to a method for producing a semiconductor device, at least a part of which is covered with a metal layer. Description of related technology

[0002] In recent years, in parts of portable radio communication equipment such as mobile phones and smartphones, the number of electronic parts such as surface acoustic wave (SAW) devices and antenna elements that configure a radio system of the portable radio communication equipment has increased, leading to improvements in functions, improvements in performance, etc. Furthermore, in order to improve the functions, improvements in performance, etc. of the portable radio communication equipment, further improvements in data transmission rates of various semiconductor devices such as dynamic random access memory (DRAM) and flash memory mounted in the portable radio communication equipment have also been promoted.There is a problem that, in connection with the improvement of the data transmission rate, electromagnetic waves generated by various semiconductor devices become noise for the radio system and adversely affect the radio system. In view of this, a technique is known in which a semiconductor device is covered with a metal layer acting as an electromagnetic wave shield to reduce the influence of electromagnetic wave noise. For example, electromagnetic wave noise can be reduced by covering the semiconductor device with a housing of a molded article made of a thermoplastic resin and a metal (see, for example, Japanese Patent Laid-Open No. 2001-44680) or a lid body made of a metal plate and a wall part made of an electrically permeable elastomer (see, for example, Japanese Patent Laid-Open No. 2004-72051).

[0003] Further prior art helpful for understanding the present invention can be found in the following documents: US 2018 / 0033737 A1 relates to a self-shielding chip comprising a substrate, an electronic device attached to the substrate, one or more electrical pads arranged on a lower surface of the substrate, and an electromagnetic interference shield. US 2018 / 0166282 A1 relates to a wafer processing method comprising a protective layer forming step, a laser beam irradiation step, a protective layer re-forming step, a plasma irradiation step, and a dividing step. JP 2016-201533 A relates to a semiconductor device manufacturing method. DESCRIPTION OF THE INVENTION

[0004] However, when a metal casing, a cover body, a metal plate, or the like is used, the space required for mounting the electromagnetic wave shield becomes comparatively large, thus hindering a reduction in size and thickness of the portable radio communication equipment. The present invention is made in consideration of such a problem and aims to reduce the space required for mounting the electromagnetic wave shield (shield).

[0005] According to one aspect of the present invention, a manufacturing method of a semiconductor device having a metal layer is provided. The manufacturing method includes a cutting groove forming step of causing a cutting blade to cut into a first surface of a workpiece having the first surface, under which an electrode of a semiconductor element is located in each region marked by a plurality of intended dividing lines arranged in a lattice shape, and a second surface on the opposite side to the first surface, and forming cutting grooves with a depth exceeding a final thickness of the workpiece along the intended dividing lines, and a protective member adhering step of adhering a protective member to the first surface of the workpiece after the cutting groove forming step.The manufacturing method also includes a grinding step of holding the workpiece on a holding table by the protective member and grinding the second surface side until the workpiece assumes a final thickness to divide the workpiece into a plurality of semiconductor devices, a metal layer covering step of covering a side surface of each of the plurality of semiconductor devices for which the protective member is adhered to the first surface side and the second surface side with a metal layer after the grinding step, and a protective member removing step of removing the protective member from the first surface side after the metal layer covering step.

[0006] Preferably, the manufacturing method of a semiconductor element having a metal layer further comprises a protective layer covering step of covering the first surface side by a protective layer before the cutting groove forming step and a protective layer removing step of removing the protective layer after the protective element removing step, and the protective element is brought into close contact with the protective layer in the protective element adhering step.

[0007] Moreover, the manufacturing method of a semiconductor device having a metal layer preferably further includes a laser-machined groove forming step of irradiating the side of the first surface of the workpiece on which the protective layer is formed with a laser beam, and forming laser-machined grooves having a width greater than the cutting grooves along the planned parting lines after the protective layer covering step and before the cutting groove forming step.

[0008] Moreover, the manufacturing method of a semiconductor device having a metal layer further includes a resist removal line forming step of forming resist removal lines obtained by removing the resist layer having a width greater than both the cutting grooves and the laser-machined grooves along the planned dividing lines by irradiating the resist layer with a laser beam having a wavelength having an absorbability with respect to the resist layer along the planned dividing lines after the resist covering step and before the laser-machined groove forming step.

[0009] In addition, the manufacturing method of a semiconductor device having a metal layer preferably further includes a dirt particle removing step of performing a treatment of the workpiece with an etching gas and removing dirt particles adhering to the laser-machined grooves and / or the cutting grooves after the laser-machined groove forming step or the cutting groove forming step and before the protective member adhering step.

[0010] Moreover, the manufacturing method of a semiconductor device having a metal layer further includes an adhesive tape adhering step of adhering an adhesive tape to the metal layer-covered second surface side of the plurality of semiconductor devices after the metal layer covering step and before the protective element removing step.

[0011] Furthermore, the protective member adhered in the protective member adhering step is preferably an adhesive tape having expandability, and the manufacturing method of a semiconductor device having a metal layer further comprises an expanding step of expanding the protective member and increasing the distance between the individual semiconductor devices after the grinding step and before the metal layer covering step.

[0012] In the manufacturing method of a semiconductor device with a metal layer according to the aspect of the present invention, the side surface of each of the semiconductor devices and the second surface ground to the final thickness are covered by the metal layer. Therefore, the space required for mounting the electromagnetic wave shield can be reduced compared to the case of using a metal-made case, a lid body made of a metal plate, or the like.

[0013] The above and other objects, features and advantages of the present invention and the mode for carrying them out will become more apparent and the invention itself will be best understood by studying the following description and the appended claims with reference to the attached drawings which show some preferred embodiments of the invention. SHORT DESCRIPTION OF THE FIGURES Fig. 1 is a perspective view showing an example of a workpiece; Fig. 2A is a diagram illustrating a cutting groove forming step (S10); Fig. 2B is a diagram illustrating a protective member adhesion step (S20); Fig. 2C is a diagram illustrating a grinding step (S30); Fig. 3A is a diagram illustrating a metal layer covering step (S40); Fig. 3B is a diagram illustrating an adhesive tape adhering step (S50); Fig. 3C is a diagram illustrating a protective element removing step (S60); Fig. 4 is a flowchart of a manufacturing method of a semiconductor device having a metal layer according to a first embodiment; Fig. 5A is a diagram illustrating a protective layer covering step (S5); Fig. 5B is a sectional view of a wafer for which a protective layer is formed on the front surface side; Fig. 5C is a diagram illustrating the cutting groove forming step (S10); Fig. 6A is a diagram illustrating the protective member adhering step (S20); Fig. 6B is a diagram illustrating the grinding step (S30); Fig. 6C is a diagram illustrating the metal layer covering step (S40), Fig. 7A is a diagram illustrating the adhesive tape adhering step (S50); Fig. 7B is a diagram illustrating the protective element removing step (S60); Fig. 7C is a diagram illustrating a protective layer removing step (S65); Fig. 8 is a flowchart of a manufacturing method of a semiconductor device having a metal layer according to a second embodiment; Fig. 9A is a diagram illustrating the protective layer covering step (S5); Fig. 9B is a partial sectional side view illustrating how to process the front surface side of the wafer by a laser beam; Fig. 10A is an enlarged view showing a laser-machined groove; Fig. 10B is an enlarged view illustrating a protective layer removal line; Fig. 10C is an enlarged view of a laser-machined groove formed in a laser-machined groove forming step (S8) after a protective layer removal line forming step (S7); Fig. 11A is a diagram illustrating a dirt particle removing step (S9); Fig. Fig. 11B is a diagram illustrating the cutting groove forming step (S10); Fig. 12A is a diagram illustrating the protective member adhering step (S20); Fig. 12B is a diagram illustrating the grinding step (S30); Fig. 13A is a diagram illustrating the metal layer covering step (S40); Fig. 13B is a diagram illustrating the adhesive tape adhering step (S50); Fig. 14 is a flowchart of a manufacturing method of a semiconductor device having a metal layer according to a third embodiment; Fig. 15A is a diagram illustrating the cutting groove forming step (S10); Fig. 15B is a diagram illustrating the dirt particle removing step (S9) according to a second modification example; Fig. 16A is a diagram illustrating the protective member adhering step (S20); Fig. 16B is a diagram illustrating the grinding step (S30); Fig. 17A is a diagram illustrating an expansion step (S35); Fig. 17B is a diagram illustrating the metal layer covering step (S40); and Fig. 18 is a flowchart of a manufacturing method of a semiconductor device having a metal layer according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Embodiments according to one aspect of the present invention will be described with reference to the accompanying drawings. Fig. Fig. 1 is a perspective view illustrating an example of a workpiece. The workpiece of the present embodiment is a wafer 11 having a circular disk shape. The wafer 11 has a semiconductor substrate 11c (see Fig. 2A), which is mainly made of silicon (Si) and formed in a circular disk shape with a thickness of substantially 500 µm to 1000 µm. There is no limitation on the material, shape, structure, size, etc. of the semiconductor substrate 11c. For example, it is also possible to use a semiconductor material other than silicon, formed of gallium arsenide (GaAs), silicon carbide (SiC), or the like, as the semiconductor substrate 11c.

[0015] A functional layer 15c is arranged on the semiconductor substrate 11c, which is thinner than the semiconductor substrate 11c and has a circular disk shape (see Fig. 2A). Semiconductor elements (not shown) such as an integrated circuit (IC) and a large-scale integration (LSI) are configured by a region in the semiconductor substrate 11c on the side of the functional layer 15c and the functional layer 15c. In the functional layer 15c, electrodes 15d of the semiconductor elements are arranged in electrical contact with active regions in the semiconductor substrate 11c that configures the semiconductor elements described above. Furthermore, the functional layer 15c has a low-dielectric-constant insulating layer (so-called low-k material layer) 15e acting as an intermediate insulating layer between the plurality of electrodes 15d. The top end of each electrode 15d is exposed from the low-dielectric-constant insulating layer 15e.

[0016] Meanwhile, in the present embodiment, the surface of the wafer 11 on the side of the functional layer 15c is referred to as a front surface (first surface) 11a. Furthermore, the surface of the semiconductor substrate 11c on the opposite side to the functional layer 15c is referred to as a back surface (second surface) 11b of the wafer 11. As above, the front surface 11a and the back surface 11b are arranged on different sides of the wafer 11 from each other. On the side of the front surface 11a of the wafer 11, a device region 15a including the active region of the semiconductor substrate 15c, which configures the above-described semiconductor element, and the functional layer 15c is formed in each of areas marked by a plurality of lattice-arranged planned division lines (streets) 13.

[0017] The electrode 15d is exposed in the front surface 11a of the device region 15a, and a plurality of bumps (protrusions) 15b formed in a spherical shape by a metal material such as solder are arranged on this electrode 15d. There is no limitation on the type, number, shape, structure, size, arrangement, etc. of the device regions 15a and the bumps 15b. In the present embodiment, the bumps 15b are arranged on the front surface 11a side of the wafer 11. However, the bumps 15b do not have to be arranged. Furthermore, the workpiece may be a so-called wafer-level chip-size package (WL-CSP) wafer in which the front surface 11a side is molded from a sealing resin and the bumps 15b are arranged to protrude from the sealing resin.Furthermore, the workpiece may be a plastic package substrate in the state where a plurality of components are sealed by a molded resin. The wafer 11 has, on the front surface 11a side, a component portion in which the plurality of component regions 15a are arranged, and a peripheral excess portion surrounding this component portion. A notch 11d indicating crystal orientation is formed at a peripheral end portion of the peripheral excess portion of the wafer 11. An orientation flat or the like may be formed instead of the notch 11d.

[0018] Next, a manufacturing method of a semiconductor device 21 having a metal layer according to a first embodiment using Fig. 2A to Fig. 2C, Fig. 3A to Fig. 3C and Fig. 4. In the first embodiment, a cutting groove is first formed in the wafer 11 (cutting groove forming step (S10)). Fig. 2A is a diagram illustrating the cutting groove forming step (S10). In the first embodiment, the cutting groove is formed using a cutting device (not shown). The cutting device includes a chuck table (not shown) that sucks and holds the back surface 11b side of the wafer 11. The chuck table is connected to a rotating mechanism (not shown) such as a motor and can rotate about a rotating axis substantially parallel to a Z-axis direction. Furthermore, a table moving mechanism (not shown) is disposed below the chuck table, and the chuck table can move in an X-axis direction (machining feed direction) by this table moving mechanism. An X-axis, a Y-axis (described below), and a Z-axis form an orthogonal coordinate system.A holding surface of the chuck table is connected to a suction source (not shown) via a suction path (not shown) formed inside the chuck table, etc. By causing a negative pressure of the suction source to act on the holding surface, the rear surface 11b side of the wafer 11 is sucked and held by the chuck table.

[0019] The cutting apparatus further includes a cutting unit (not shown) for cutting the wafer 11. The cutting unit includes a spindle (not shown) serving as a rotating shaft substantially parallel to a Y-axis direction (index feed direction). The spindle rotates by a rotation drive source (not shown) such as a motor connected to one end of the spindle. Furthermore, a blade attachment (not shown) having a circular ring shape is integrally attached to the other end of the spindle, located on the opposite side to the rotation drive source, in such a manner as to be rotatable.

[0020] A so-called hub-type cutting blade 20 is mounted on the spindle through the knife attachment. The cutting blade 20 of the present embodiment includes a base (not shown) having a circular ring shape and a cutting edge 22 disposed on the outer periphery of this base and having a circular ring shape. The cutting edge 22 is formed by mixing abrasive grains such as diamond, cubic boron nitride (cBN), or the like into a bonding material made of a metal, a plastic, or the like.

[0021] In the cutting groove forming step (S10), first, a dividing tape (not shown) is adhered to the back surface 11b side of the wafer 11, and the back surface 11b side of the wafer 11 is placed on the holding surface of the chuck table via this dividing tape. Thereafter, the negative pressure of the suction source is caused to act, and the wafer 11 is sucked and held by the chuck table in the state where the front surface 11a side of the wafer 11 is exposed upward. Then, the cutting unit is moved downward toward the chuck table while the cutting blade 20 is rotated at a high speed, and the cutting blade 20 is caused to cut into the front surface 11a side of the wafer 11. However, the wafer 11 is not completely cut in the cutting groove forming step (S10).

[0022] In the cutting groove forming step (S10), the cutting depth of the cutting blade 20 is adjusted to form a cutting groove 17 (see Fig. 2B) with a predetermined depth that exceeds a final thickness T1 of the wafer 11 and does not reach the back surface 11b of the wafer 11. Next, the cutting blade 20 and the chuck table are relatively moved along the X-axis direction while maintaining the cutting depth of the cutting blade 20. Thereby, the cutting groove 17 is formed in the wafer 11 from one end to the other end of a planned dividing line 13 along the X-axis direction (that is, the wafer 11 is half-cut).

[0023] After the cutting groove 17 is formed along one planned dividing line 13, the cutting unit is moved in the Y-axis direction. Then, the cutting groove 17 is similarly formed from one end to the other end of another planned dividing line 13 besides the above-described one planned dividing line 13 in the Y-axis line. After the cutting grooves 17 are formed along all the planned dividing lines 13 along one direction, the chuck is rotated 90 degrees by the rotating mechanism, and the cutting grooves 17 are similarly formed along all the planned dividing lines 13 along another direction perpendicular to the one direction. Thereby, the cutting grooves 17 with the predetermined depth are formed along all the planned dividing lines 13 arranged in a lattice shape on the front surface 11a side of the wafer 11.

[0024] After the cutting groove forming step (S10), a protective member 19 is adhered to the front surface 11a of the wafer 11 (protective member adhering step (S20)). Fig. 2B is a diagram illustrating the protective member adhering step S20. The protective member 19 includes a base layer having substantially the same diameter as the wafer 11 and is formed of, for example, a plastic. For example, the base layer has a thickness of at least 5 μm and at most 200 μm and is formed of a polymer material such as polyolefin (PO), polyvinyl chloride (PVC), polystyrene (PS), or ethylene vinyl acetate (EVA). Furthermore, the protective member 19 includes an adhesive layer on the front surface side of the base layer. The adhesive layer is a layer formed by an adhesive made of a plastic that is hardened and whose adhesive force is reduced when irradiated with, for example, heat or ultraviolet radiation.The adhesive layer may be arranged in a ring-like manner in a circular end portion of the base layer or may be arranged on the entire surface of the base layer. The adhesive layer does not need to be arranged in the protective member 19. The protective member 19 is bonded to the front surface 11a side of the wafer 11 through the adhesive layer in such a shape that it is removable. Furthermore, the protective member 19 is deformed to follow the concavo-convex structure of the bumps 15b, etc., in the device regions 15a of the wafer 11. For example, one surface of the protective member 19 bonds to the front surface 11a of the wafer 11 and the front surfaces of the bumps 15b. When the protective member 19 does not have the adhesive layer, the base layer comes into close contact with the front surface 11a side in such a manner that it is removable.

[0025] In the protective member adhering step (S20), the protective member 19 is adhered to the front surface 11a of the wafer 11 using a protective member adhering device (not shown). The protective member adhering device includes a chamber (not shown), and a suction source (not shown) for reducing the pressure inside the chamber is connected to this chamber. Furthermore, a support table (not shown) that supports the wafer 11 is arranged in the chamber. This support table is moved in a predetermined direction (e.g., an x-axis direction) by a moving mechanism such as a ball screw system. The protective member adhering device includes a supply mechanism that supplies a tape component (not shown) wound in a roll form to the upper side of the support table. The tape component is configured of the protective member and a detachable film.

[0026] Furthermore, the protective member adhering device includes a separating unit (not shown) that separates the protective member 19 from the releasable film when the tape component is fed to the upper side of the support table. The protective member 19 separated from the releasable film by the separating unit is fed to the upper side of the support table by the feed mechanism in such a manner that the adhesive layer of the protective member 19 faces the support table. The protective member adhering device further includes a pressing roller that presses the base layer side of the protective member 19 fed to the upper side of the support table. By pressing the base layer side of the protective member 19 by the pressing roller, an adhesive layer side of the protective member 19 is pressed against the support table.

[0027] In the protective member adhering step (S20), first, the rear surface 11b side of the wafer 11 is placed on the support table. Next, the pressure in the chamber is reduced by the suction source. By reducing the pressure inside the chamber, air, dust, and other foreign matter can be prevented from entering between the front surface 11a of the wafer 11 and the protective member 19. Then, while the tape component is fed in a roll form to the upper side of the support table, the detachable film is separated from the tape component by the separating unit, and the protective member 19 is adhered to the front surface 11a of the wafer 11 placed on the support table by the pressing roller. By disposing the protective member 19 on the front surface 11a of the wafer 11, damage to the front surface 11a side of the wafer 11 in subsequent processing steps can be prevented.It is not essential to use the chamber connected to the suction source and reduce the pressure inside, and the protective member adhering device can adhere the protective member 19 to the front surface 11a of the wafer 11 under atmospheric pressure. In this case, the protective member adhering device is configured from the above-described support table, a feeding mechanism, a separating unit, a pressing roller, etc.

[0028] When the adhesive layer is not formed in the protective member 19, the protective member 19 may be adhered to the wafer 11 in the protective member adhering step (S20) while the protective member 19 is softened and deformed by heating the support table. The softened protective member 19 is deformed to follow the concave-convex structure of the front surface 11a side of the wafer 11 and can therefore make close contact with the front surface 11a side of the wafer. The heating temperature can be appropriately set to become the softening point of each material according to the material of the protective member 19. Furthermore, the protective member 19 may be softened and deformed by blowing a warm flow toward the protective member 19 instead of heating the support table. In the case of blowing a warm flow, the protective member 19 is pressed against the front surface 11a side of the wafer 11 by the flow.Therefore, the protective member 19 can be brought into close contact with the front surface 11a side of the wafer 11 and adhered thereto without using the pressing roller.

[0029] After the protective element adhesion step (S20), the wafer 11 is divided into a plurality of semiconductor devices 21 by grinding the rear surface 11b side of the wafer 11 until the thickness of the wafer 11 becomes the final thickness (grinding step (S30)). Fig. 2C is a diagram illustrating the grinding step (S30). In the grinding step (S30), the wafer 11 is ground using a grinding device 30. The grinding device 30 includes a chuck table 32 that sucks and holds the front surface 11a side of the wafer 11 via the protective member 19. This chuck table 32 is connected to a rotating mechanism (not shown) such as a motor and rotates about a rotation axis substantially parallel to the Z-axis direction. A porous member having a circular disk shape is arranged on the front surface side of the chuck table 32, and the front surface of this porous member serves as a holding surface 32a of the chuck table 32.A negative pressure from a suction source (not shown) acts on the holding surface 32a via a flow path formed inside the chuck table 32, and a suction force is generated for the holding surface 32a to suck the front surface 11a side of the wafer 11.

[0030] A grinding mechanism 34 is arranged above the chuck table 32 in such a manner as to oppose the holding surface 32a. The grinding mechanism 34 includes a spindle (not shown) that rotates about a rotation axis substantially parallel to the Z-axis direction. This spindle is raised and lowered along the Z-axis direction by a raising-lowering mechanism (not shown). A disk mount (not shown) having a circular disk shape is attached to the lower end side of the spindle. A grinding wheel 36 having substantially the same diameter as the disk mount is attached to the lower surface of the disk mount. The grinding wheel 36 has an annular disk base 38a formed of a metal material such as aluminum or stainless steel.By attaching the upper surface side of the disk base 38a to the disk mount, the disk base 38a is fixed to the spindle. Furthermore, a plurality of abrasives (abrasive chips) 38b are arranged on the lower surface of the disk base 38a.

[0031] The abrasives 38b each have a substantially parallelepiped-rectangular shape and are arranged in a ring-like manner in such a way that a gap is formed between each adjacent one of the abrasives 38b over the entire circumference of the annular lower surface of the disk base 38a. The abrasives 38b are formed by mixing abrasive grains of diamond, cubic boron nitride (cBN), or the like into a binder material made of, for example, a metal, ceramic, plastic, or the like. However, there is no limitation on the binder material and the abrasive grains, and they are selected as appropriate according to the specification of the abrasives 38b.

[0032] In the grinding step (S30) of the present embodiment, first, the wafer 11 on which the protective member 19 is attached is moved from the protective member attachment device to the chuck table 32 of the grinding device 30. Thereafter, the negative pressure of the suction source (not shown) is caused to act on the holding surface 32a, and the front surface 11a side of the wafer 11 is sucked and held by the holding surface 32a via the protective member 19. Then, while the chuck table 32 and the spindle of the grinding mechanism 34 are each rotated in a predetermined direction, the spindle of the grinding mechanism 34 is lowered, and the abrasives 38b are pressed against the rear surface 11b side of the wafer 11. The rear surface 11b side of the wafer 11 is removed by a thickness T2, and the thickness of the wafer 11 becomes the final thickness T1. The cutting groove 17 is designed to be deeper than the final thickness T1.Thus, when the thickness of the wafer 11 is reduced to the final thickness T1, the semiconductor substrate 11c is divided with the cutting groove 17 as the boundary, so that the wafer 11 is divided into the plurality of semiconductor devices 21.

[0033] After the grinding step (S30), the back surface side of the wafer 11 (i.e., back surfaces 11e of the semiconductor devices 21) after being ground to the final thickness and a side surface 11f of each of the semiconductor devices 21 (i.e., each side surface of the semiconductor substrate 11c and the functional layer 15c) are covered by a metal layer (metal layer covering step (S40)). A metal layer 23 is a thin layer of a metal such as copper (Cu), aluminum (Al), nickel (Ni), or stainless steel. Fig. 3a is a diagram illustrating the metal layer covering step (S40). In the metal layer covering step (S40), the metal layer 23 is formed on the wafer 11 using a physical vapor deposition (PVD) device or a chemical vapor deposition (CVD) device. Vacuum vapor deposition, sputtering, ion plating, or the like is used as the PVD. Furthermore, plasma CVD or the like is used as the CVD.

[0034] In the present embodiment, the metal layer 23 is formed by using a high-frequency magnetron sputtering apparatus (not shown, hereinafter abbreviated to sputtering apparatus). The sputtering apparatus includes a treatment chamber (not shown), and a holding table (not shown) that holds the wafer 11 by an electrostatic system or other method is arranged inside this treatment chamber. Furthermore, above the holding table, a target (not shown) serving as the material for the metal layer 23 is arranged in the state of being supported by an excitation element (not shown). A high-frequency power supply (not shown) is connected to this target.In addition, an introduction port (not shown) from which a sputtering gas of argon or the like is introduced and an exhaust port (not shown) connected to a pressure reduction source (not shown) are formed in the treatment chamber.

[0035] In the metal layer covering step (S40), first, the wafer 11, for which the protective member 19 is adhered to the front surface 11a side, is placed in the processing chamber via the protective member 19 on the holding table, and the wafer 11 is held by an electrostatic system or other method. That is, the back surfaces 11e of the semiconductor devices 21 are aligned with the target after grinding. Next, the processing chamber is sealed, and the interior of the processing chamber is evacuated from the exhaust port to reduce the pressure. Next, high-frequency power is supplied from the high-frequency power supply to the target magnetized by the excitation element, and the sputtering gas is introduced from the introduction port to generate plasma.When ions of the sputtering gas in the plasma impact the target, metal particles are sputtered out of the target and the material is deposited on the back surfaces 11e and the side surfaces 11f of the semiconductor devices 21.

[0036] For example, the thickness of the metal layer 23 is at least 2 µm and at most 10 µm, and preferably at least 3 µm and at most 8 µm. The metal layer 23 functions as an electromagnetic wave shield that blocks electromagnetic wave noise emitted from the semiconductor devices 21. As above, in the present embodiment, the metal layer 23 is formed on the order of micrometers directly on the back surfaces 11e and the side surfaces 11f of the semiconductor devices 21 as the electromagnetic wave shield. Therefore, the space required for attaching the electromagnetic wave shield can be reduced compared to the case where a case made of a metal, a lid body made of a metal plate, or the like is employed as in the related art.Furthermore, in the metal layer covering step (S40), the metal layer 23 can be formed simultaneously for all of the plurality of semiconductor devices 21 adhered to the protective member 19. For this reason, the semiconductor devices 21 can be covered by the electromagnetic wave shield more efficiently compared to the case of individually covering each semiconductor device with a casing made of a metal or the like as in the related art.

[0037] After the metal layer covering step (S40), an adhesive tape 27 is adhered to the plurality of semiconductor devices 21 and a frame 25 formed of a metal and having a ring shape to form a frame unit 29 (adhesive tape adhering step (S50)). Fig. 3B is a sectional view of the frame unit 29 in the adhesive tape adhesion step (S50). In the adhesive tape adhesion step (S50), first, the plurality of semiconductor devices 21 and the protective element 19 are arranged in the opening of the frame 25 in such a manner that the metal layer 23 is arranged on the upper side. Meanwhile, the frame unit 29 is Fig. 3B is shown reversed. Next, the circular adhesive tape 27, which has a larger diameter than the opening of the frame 25 and is made of a plastic, is adhered to the frame 25, the plurality of semiconductor devices 21, and the protective member 19. Thereby, the adhesive tape 27 is adhered to the rear surface 11e side of the semiconductor devices 21 covered by the metal layer 23, and the protective member 19, the plurality of semiconductor devices 21, and the frame 25 are integrated by the adhesive tape 27 to form the frame unit 29.

[0038] After the adhesive tape adhesion step (S50), the protective member 19 is removed from the front surface 11a side of the wafer 11 (protective member removal step (S60)). Fig. 3C is a sectional view of the frame unit 29 in the protective member removal step (S60). When the protective member 19 has an adhesive layer, in the protective member removal step (S60), the adhesive force of the protective layer of the protective member 19 is reduced using an ultraviolet irradiation device or a heating device, and then the protective member 19 is peeled off from the front surface 11a side of the wafer 11. When the protective member 19 does not have the adhesive layer, the protective member 19 can be peeled off from the front surface 11a side without treating the protective member 19 with an ultraviolet ray or the like. After the protective member 19 is removed, the individual semiconductor devices 21 are removed from the adhesive tape 27 using a pickup device or the like (not shown).

[0039] Fig. 4 is a flowchart of the manufacturing method of the semiconductor device 21 having the metal layer 23 according to the first embodiment. As described above, in the present embodiment, the metal layer 23 can be directly formed on the back surfaces 11e and the side surfaces 11f of the semiconductor devices 21, and therefore, the space required for attaching the electromagnetic wave shield can be reduced. Furthermore, the metal layer 23 is formed for all the semiconductor devices 21 simultaneously, and therefore, the semiconductor devices 21 can be more efficiently covered by the electromagnetic wave shield.

[0040] Next, a second embodiment using Fig. 5A to Fig. 8. The second embodiment further includes a protective layer covering step (S5) of covering the front surface 11a side of the wafer 11 with a protective layer before the cutting groove forming step (S10). Fig. 5A is a diagram illustrating the protective layer covering step (S5), and Fig. 5B is a sectional view of the wafer 11 for which a protective layer 45 is formed on the front surface 11a side. In the protective layer covering step (S5), the protective layer 45 is formed on the front surface 11a side of the wafer 11 by using a protective layer forming device 40. The protective layer forming device 40 includes a turntable mechanism (not shown) and a liquid receiving mechanism (not shown) arranged, for example, to surround the periphery and the lower part of the turntable mechanism.

[0041] The turntable mechanism includes a circular turntable (not shown), a support member (not shown) that rotates the turntable and has a circular column shape, and an electric motor (not shown) that rotatably drives the turntable through the support member. When the electric motor is rotatably driven, the turntable rotates in the direction of the arrow in Fig. 5A. The turntable includes a suction holding portion formed of a porous material, and this suction holding portion is connected to a suction source (not shown). The wafer 11 placed on the suction holding portion of the turntable is sucked and held on the suction holding portion by negative pressure from the suction source. The above-described liquid receiving mechanism includes a liquid receiving container (not shown) surrounding the periphery and bottom portion of the turntable mechanism, and a cover member (not shown) attached to the support member.

[0042] The protective layer forming apparatus 40 further includes a liquid-state resin dispensing unit (not shown) that dispenses a resin in a liquid state to the front surface 11a side of the wafer 11 held by the turntable. The liquid-state resin dispensing unit includes an arm having a substantially L-shape, a liquid-state resin dispensing nozzle 42 disposed at the tip of this arm and dispensing the liquid-state resin, and an electric motor that swings the arm. The liquid-state resin dispensing nozzle 42 is connected to a liquid-state resin supply source (not shown) via the arm. The protective layer forming apparatus 40 is also used as a cleaning device that cleans the wafer 11.The protective layer forming apparatus 40 includes a cleaning liquid dispensing unit (not shown) for cleaning the wafer 11 held by the turntable in a different position from the liquid-state resin dispensing unit. Similar to the liquid-state resin dispensing unit, the cleaning liquid dispensing unit includes an arm having a substantially L-shape, a cleaning liquid dispensing nozzle 46 (see FIG. Fig. 7C) located at the tip of this arm and dispensing a cleaning fluid 48, and an electric motor that pivots the arm. The cleaning fluid dispensing nozzle 46 is connected via the arm to a cleaning fluid supply source (not shown).

[0043] The procedure of the protective layer covering step (S5) will be described. First, the wafer 11 is placed on the suction holding part of the turntable in such a manner that the front surface 11a side of the wafer 11 faces the liquid-state resin discharge nozzle 42. Then, the rear surface 11b side of the wafer 11 is sucked and held by the turntable based on the negative pressure from the suction source. Next, the electric motor is driven to rotate the wafer 11 together with the turntable. At this time, the cleaning liquid discharge nozzle 46 has been evacuated from the upper side of the turntable.

[0044] Then, as in Fig. As shown in Figure 5A, with the rotation of the turntable in the direction of the arrow at a low speed (for example, 30 rpm to 50 rpm), a liquid-state resin 44 is dropped onto the wafer 11 from the liquid-state resin dispensing nozzle 42 while the liquid-state resin dispensing nozzle 42 is swung in a circular arc shape above the turntable in such a manner as to pass through the center of rotation of the turntable. The resin in the liquid state spreads evenly over the front surface 11a of the wafer 11 and over the front surfaces of the bumps 15b due to centrifugal force. The protective layer 45 is formed with a thickness of, for example, substantially 1 µm to 20 µm to follow concavities and convexities on the side of the front surface 11a of the wafer 11 to reflect concavities and convexities of the bumps 15b, etc. (see Fig. 5B).

[0045] The protective layer 45 is a plastic layer having heat resistance and chemical resistance, and is, for example, a vinyl chloride layer. Although the protective layer 45 is formed using the turntable in the present embodiment, the protective layer 45 may instead be adhered in a film shape to the front surface 11a side of the wafer 11. In the case of adhering the film-shaped protective layer 45 to the front surface 11a side, the thickness of the protective layer 45 can be adjusted in advance before it is adhered to the front surface 11a side. For this reason, the thickness of the protective layer 45 can be easily adjusted compared to the case of forming the protective layer 45 using the turntable mechanism.For example, the thickness of the protective layer 45 can be set larger, specifically, to substantially 5 µm to 200 µm, compared with the state of forming the protective layer 45 using the turntable mechanism.

[0046] After the protective layer covering step (S5), the cutting groove forming step (S10) is carried out. Fig. 5C is a diagram illustrating the cutting groove forming step (S10). In the cutting groove forming step (S10) of the second embodiment, the above-described cutting device is used to cut the protective layer 45 and form the cutting groove 17 in the wafer 11 similarly to the first embodiment (see Fig. 6A). After the cutting groove forming step (S10), the protective element adhering step (S20) is performed. Fig. 6A is a diagram illustrating the protective member adhering step (S20). In the protective member adhering step (S20) of the second embodiment, the above-described protective member adhering device is also used to adhere the protective member 19 to the front surface 11a side of the wafer 11 and bring the protective member 19 into close contact with the protective layer 45. As above, in the second embodiment, the protective member 19 is disposed on the front surface 11a side of the wafer 11 via the protective layer 45. Therefore, even if the adhesive layer of the protective member 19 remains over the front surface 11a of the wafer 11 and the bumps 15b after the protective member 19 is separated from the wafer 11, this adhesive layer can also be removed together when the protective layer 45 is removed. For this reason, the adhesive layer of the protective member 19 can be prevented from remaining above the front surface 11a of the semiconductor devices 21.

[0047] After the protective element adhesion step (S20), the grinding step (S30) is carried out. Fig. 6B is a diagram illustrating the grinding step (S30). Also in the grinding step (S30) of the second embodiment, the back surface 11b side of the wafer 11 is removed by the thickness T2, and the wafer 11 is machined to the final thickness T1. This divides the semiconductor substrate 11c with the cutting groove 17 as the boundary, so that the wafer 11 becomes the plurality of semiconductor devices 21. After the grinding step (S30), the metal layer covering step (S40) is performed. Fig. 6C is a diagram illustrating the metal layer covering step (S40). Also in the metal layer covering step (S40) of the second embodiment, the metal layer 23 is formed on the back surfaces 11e and the side surfaces 11f of the semiconductor devices 21 by PVD or CVD.

[0048] After the metal layer covering step (S40), the adhesive tape adhesion step (S50) is carried out. Fig. 7A is a diagram illustrating the adhesive tape adhesion step (S50). In the adhesive tape adhesion step (S50), the frame unit 29 is configured similarly to the first embodiment. After the adhesive tape adhesion step (S50), the protective member 19 is removed from the front surface 11a side of the wafer 11 (protective member removal step (S60)). Fig. 7B is a diagram illustrating the protective element removal step (S60). The protective layer 45 is in close contact with the front surface 11a side of the wafer 11, and the protective layer 45 is not completely peeled off from the front surface 11a side in the protective element removal step (S60).

[0049] In view of this, in the manufacturing method of the semiconductor device 21 having the metal layer 23 according to the second embodiment, a protective layer removing step (S65) of removing the protective layer 45 is performed after the protective element removing step (S60). In the protective layer removing step (S65), the protective layer 45 is removed using the protective layer forming device 40, which has a second function as a cleaning device. Fig. 7C is a diagram illustrating the protective layer removal step (S65). The method of removing the protective layer 45 will be described. First, the surface of the adhesive tape 27 on the opposite side of the semiconductor devices 21 (i.e., the rear surface 27b side) is placed on the suction holding part of the turntable in such a manner that the upper surface 11a side is positioned toward the upper side. Then, the rear surface 27b side of the adhesive tape 27 is sucked and held by the turntable based on the negative pressure of the suction source. Next, the electric motor is driven to rotate the frame unit 29 integrally with the turntable. At this time, the liquid-state resin discharge nozzle 42 has been removed from the upper side of the turntable.

[0050] Then, with rotation of the turntable at, for example, 800 rpm, the cleaning liquid 48 (for example, isopropyl alcohol (IPA)) is dropped onto the wafer 11 while the cleaning liquid discharge nozzle 46 is swung in a circular arc shape above the turntable. As shown in Fig. As shown in Fig. 7C, the protective layer 45 is dissolved in the cleaning liquid 48 to become used liquid A. The used liquid A is blown outside the semiconductor device 21 by centrifugal force and is collected by the liquid collecting container. In this way, the protective layer 45 is removed from the front surface 11a side of the wafer 11 by the cleaning liquid 48. When the protective layer 45 is adhered to the front surface 11a in a layered form, the protective layer 45 can be peeled off in the protective member removing step (S60) like peeling off the protective member 19.

[0051] Fig. 8 is a flowchart of the manufacturing method of the semiconductor device 21 with the metal layer 23 according to the second embodiment. In the second embodiment, the protective member 19 is disposed via the protective layer 45 on the front surface 11a side of the wafer 11, and therefore, the adhesive layer of the protective member 19 can be prevented from remaining above the front surface 11a of the semiconductor devices 21. Furthermore, in the second embodiment, similar to the first embodiment, the metal layer 23 can be directly formed on the back surfaces 11e and the side surfaces 11f of the semiconductor devices 21, and the space required for attaching the electromagnetic wave shield can be reduced. Furthermore, the metal layer 23 is formed for all the semiconductor devices 21 simultaneously, and therefore, the semiconductor devices 21 can be efficiently covered by the electromagnetic wave shield.

[0052] Next, a third embodiment using Fig. 9A to Fig. 14. In the third embodiment, first, the protective layer 45 is formed on the front surface 11a side of the wafer 11 using the protective layer forming apparatus 40 similarly to the second embodiment (protective layer covering step (S5)). Fig. 9A is a diagram illustrating the protective layer covering step (S5). In the third embodiment, after the protective layer covering step (S5) and before the cutting groove forming step (S10), the side of the front surface 11a of the wafer 11 for which the protective layer 45 is formed is irradiated with a laser beam L, and laser-machined grooves 51, etc., are formed on the planned dividing lines 13.

[0053] Fig. 9B is a partial sectional side view illustrating how to process the front surface 11a side of the wafer 11 by the laser beam L. For example, by irradiation with the laser beam L, the protective layer 45 and the fusion layer 15c are ablated, and the laser-processed groove 51 is formed (laser-processed groove forming step (S8)). Fig. 10A is an enlarged view showing the laser-machined groove 51. Fig. 10A represents an area B in Fig. 9B.

[0054] The laser-machined groove forming step (S8) is performed using a laser machining apparatus 50. The laser machining apparatus 50 includes a chuck table (not shown) that sucks and holds the back surface 11b side of the wafer 11. Furthermore, a machining head 52 is arranged at a position opposite to the chuck table and pulse-irradiates the laser beam L onto the front surface 11a side of the wafer 11 held by the holding table. The laser beam L has a wavelength that has absorbability with respect to the protective layer 45 and the wafer 11 (i.e., a wavelength so as to be absorbed by the protective layer 45 and the wafer 11), for example, a wavelength of 355 nm. A holding surface of the chuck table is connected to a suction source (not shown) via a suction path (not shown) formed inside the chuck table, and so forth.By causing a negative pressure of the suction source to act on the holding surface, the back surface 11b side of the wafer 11 is sucked and held by the chuck table. Furthermore, a support table (not shown) is arranged below the chuck table, and this support table moves along a predetermined direction (for example, an X-axis direction) by a moving mechanism of a ball screw system.

[0055] For example, when the protective layer 45 and the wafer 11 are machined by the laser beam L, a planned dividing line 13 is arranged parallel to the X-axis direction in which the chuck table moves. Then, the machining head 52 and the chuck table are relatively moved in the X-axis direction while irradiating the front surface 11a side of the wafer 11 with the laser beam L. The irradiation with the laser beam L can be performed once or more times along a planned dividing line 13, although it also depends on the width of the laser beam L. Thereby, the protective layer 45 and the functional layer 15c are subjected to ablation processing and removed along the planned dividing line 13, and the laser-machined groove 51 reaching the semiconductor substrate 11c is formed along the planned dividing line 13.

[0056] Furthermore, by moving the chuck table in the Y-axis direction and rotating it, the laser-machined grooves 51 are formed along all the planned parting lines 13. The laser-machined groove 51 has a width W1 that is larger than a width W4 of the cutting groove 17 formed in the following cutting groove forming step (S10) (ie, W4 < W1) (see Fig. 11B). In the present embodiment, the laser-machined groove 51 having the width W1 is formed by the laser beam L. Then, in the following cutting groove forming step (S10), the cutting blade 20 is positioned at this width W1, and the semiconductor substrate 11c is cut by the cutting blade 20. Due to this, compared with the case of cutting the functional layer 15c and the protective layer 45 by the cutting blade 20, film separation, etc., of the functional layer 15c can be prevented, and therefore, cutting processing with higher quality is enabled. Furthermore, dirt particles generated at the time of ablation processing can be prevented from adhering to the device regions 15a by the protective layer 45.

[0057] Meanwhile, in the subsequent metal layer covering step (S40), the metal layer 23 is formed in the laser-machined groove 51. At this time, the metal layer 23 is also formed on side portions 57 of the protective layer 45 exposed to the inside of the laser-machined groove 51. However, the protective layer 45 is finally removed in the protective layer removing step (S65). Thus, the metal layer 23 formed on the side portions 57 of the protective layer 45 assumes a state of protruding into the space, and the metal layer 23 formed on the side surfaces of the functional layer 15c exposed to the inside of the laser-machined groove 51 becomes easily peelable due to a slight trigger. Therefore, the electromagnetic wave shielding effect of the metal layer 23 may be reduced.In view of this, in a first modification example of the third embodiment, a step part is formed by exposing a part of the functional layer 15c from the protective layer 45. In this first modification example, after the shield covering step (S5) and before the laser-machined groove forming step (S8), the protective layer 45 is irradiated with the laser beam L along the planned parting line 13. The protective layer 45 is ablated and is removed along the planned parting line 13, and a protective layer removal line 53 is formed (protective layer removal line forming step (S7)).

[0058] This protective layer removal line 53 has a width W2 that is larger than both a width W3 of a laser-machined groove 55 formed in the laser-machined groove forming step (S8) and the width W4 of the cutting groove 17 formed in the cutting groove forming step (S10). Fig. 10B is an enlarged view of the protective layer removal line 53. Fig. 10B represents an area B in Fig. 9B. For example, after the spot of the laser beam L on the protective layer 45 is adjusted to a wide width shape corresponding to the width W2, the front surface 11a side of the wafer 11 is irradiated with the laser beam L along the planned dividing lines 13. This can form the protective layer removal line 53. Moreover, instead of adjusting the spot to the wide width shape on the protective layer 45, the spot of the laser beam L may be adjusted to a circular shape. In this case, the front surface 11a side of the wafer 11 is irradiated with the laser beam L in such a manner that the loci of the laser beam L partially overlap in the width direction of the width W2 (i.e., a direction perpendicular to the planned dividing line 13).

[0059] After the protective layer removal line forming step (S7), the functional layer 15c arranged within the width W2 is irradiated with the laser beam L from the front surface 11a side of the wafer 11, and the laser-machined groove 55 is formed (laser-machined groove forming step (S8)). The laser-machined groove 55 has the width W3, which is larger than the width W4 of the cutting groove 17 and smaller than the width W2 of the protective layer removal line 53 (ie, W4 < W3 < W2). For example, in the laser-machined groove forming step (S8) of the first modification example, the power density W / cm 2) is set higher by focusing the laser beam L compared to the resist removal line forming step (S7), and the functional layer 15c located within the width W2 is ablated. This can form the laser-machined groove 55 having the width W3 smaller than the resist removal line 53 and reaching the semiconductor substrate 11c.

[0060] Fig. 10C is an enlarged view illustrating the laser-machined groove 55 formed in the laser-machined groove forming step (S8) of the first modification example after the protective layer removal line forming step (S7). Fig. 10C represents an area B in Fig. 9B. As in Fig. 10C, in the first modification example, step portions 59b each formed from a side portion 59a of the functional layer 15c exposed within the laser-machined groove 55 and the upper surface of the functional layer 15c of the area from which the protective layer 45 has been removed are formed. In the following metal layer covering step (S40), the metal layer 23 is formed in contact with the step portions 59b of the functional layer 15c. Specifically, the metal layer 23 is formed on the upper surface of the functional layer 15c. Thus, the metal layer 23 can be formed more evenly than in the case of forming the metal layer 23 in the Fig. 10A, the laser-machined groove 51 comes into closer contact with the functional layer 15c. Therefore, the metal layer 23 is Fig. 10A, it is less easy to remove it from the side parts 59a of the functional layer 15c.

[0061] In the third embodiment, a dirt particle removal step (S9) is performed after the laser-machined groove forming step (S8) or after the protective layer removal line forming step (S7) and the laser-machined groove forming step (S8), and before the protective member adhering step (S20). This removes dirt particles of the functional layer 15c adhering to the laser-machined groove 55. Fig. 11A is a diagram illustrating the dirt particle removal step (S9). Hereinafter, the wafer 11 that has undergone the resist removal line formation step (S7) and the laser-machined groove formation step (S8) described as the first modification example of the third embodiment will be illustrated in the drawings.

[0062] The contaminant removal step (S9) is performed using a plasma etching apparatus 60. The plasma etching apparatus 60 of the present embodiment is a remote plasma etching apparatus that converts an etching gas into a plasma state and then introduces this etching gas in the plasma state into a vacuum chamber. The plasma etching apparatus 60 includes the vacuum chamber (not shown) having a processing space inside. Furthermore, a table base (not shown) for supporting the wafer 11 is arranged in the processing space. On the upper surface of a circular disk portion of the table base, an electrostatic chuck table (not shown) having a circular disk shape with a smaller diameter than the circular disk portion is arranged.The electrostatic chuck table includes a table main body formed of an insulating material and a plurality of electrodes embedded in the table main body. The table adsorbs and holds the wafer 11 by static electricity generated in each electrode. Each electrode is connected to a DC power source capable of generating a high voltage of, for example, approximately 5 kV.

[0063] A supply nozzle (not shown) that supplies a source gas in a plasma state to the wafer 11 held by the electrostatic chuck table is arranged in an upper wall of the vacuum chamber. On the upstream side of a flow path connected to the supply nozzle, each of one or more gas supply sources (not shown) is connected in parallel via a valve (not shown), a flow rate controller (not shown), etc. The number of gas types supplied from the one or more gas supply sources can be changed according to the contaminants to be removed. The contaminants mainly originate from the functional layer 15c.For example, when the low-dielectric-constant insulating layer 15e in the functional layer 15c is an oxide of a carbon-containing silicon oxide-based substance (SiOCH-based substance), a gas containing perfluorocyclobutane (C4F8) or sulfur hexafluoride (SF6) is supplied from the gas supply source. Furthermore, for example, when the low-dielectric-constant insulating layer 15e in the functional layer 15c is an organic substance other than a carbon-containing silicon oxide-based substance, a gas containing hydrogen (H2) is supplied from a first gas supply source, and a gas containing nitrogen (N2) is supplied from a second gas supply source.

[0064] An electrode for applying a high-frequency voltage to a mixed gas flowing in the supply nozzle is arranged between a supply port formed at the downstream end of the supply nozzle and the gas supply source. A high-frequency power source is connected to this electrode. The high-frequency power source supplies power of substantially 0.5 to 5 kW to the electrode at a high-frequency voltage of substantially 450 kHz to 2.45 GHz (e.g., 13.56 MHz). By causing the high-frequency voltage to act on the mixed gas flowing in the supply nozzle using the high-frequency power source, etc., the mixed gas can be converted into plasma (typically into radicals or ions). The mixed gas in the plasma state is supplied from the supply port of the supply nozzle to the treatment chamber.

[0065] In the contaminant removal step (S9) of the present invention, first, the wafer 11 is conveyed into the processing space of the vacuum chamber of the above-described remote plasma etching apparatus, and the rear surface 11b side of the wafer 11 is placed on the upper surface of the electrostatic chuck table in such a manner that the front surface 11a side of the wafer 11 is exposed upward. Thereafter, a DC voltage is applied to the electrodes of the electrostatic chuck table, and the wafer 11 is adsorbed and held by the electrostatic chuck table based on static electricity. Furthermore, the processing space is evacuated, and the processing space is exhausted to, for example, substantially 200 Pa.

[0066] Next, the source gas, an inert gas, etc., are supplied from the respective gas supply sources at predetermined flow rates. Furthermore, a high-frequency voltage is supplied from the high-frequency power supply to the electrode, and a mixed gas of the source gas and the inert gas is converted into plasma (converted into radicals, ions, or the like). This can supply an etching gas P in a plasma state from the supply port of the supply nozzle to the treatment space. The etching gas P in a plasma state supplied from the supply port is supplied to the front surface 11a side of the wafer 11 located below the supply port and removes dirt particles existing in the laser-processed groove 55. This allows the metal layer 23 formed in the subsequent metal layer covering step (S40) to come into closer contact with the functional layer 15c compared to the case where the dirt particles are not removed by the etching gas P.In the contaminant removal step (S9), the contaminants can be removed by supplying a reactive gas that is not converted into plasma to the laser-machined groove 55. For example, chlorine trifluoride (ClF3), xenon difluoride (XeF2), or the like are used as the reactive gas. Furthermore, the contaminants can be removed by supplying a mixed gas of the reactive gas and an inert gas, such as nitrogen (N2), argon (Ar), or helium (He).

[0067] After the dirt particle removal step (S9), the cutting groove formation step (S10) is carried out. Fig. 11B is a diagram illustrating the cutting groove forming step (S10). In the cutting groove forming step (S10), the cutting groove 17 with the width W4 is formed within the laser-machined groove 55 using the cutting device described above. After the cutting groove forming step (S10), the protective member adhering step (S20) is performed. Fig. 12A is a diagram illustrating the protective member adhering step (S20). In the protective member adhering step (S20), the protective member 19 is disposed on the front surface 11a side of the wafer 11 using the above-described protective member adhering device. The protective member 19 comes into close contact with the protective layer 45, but does not come into contact with the front surface 11a of the wafer 11. Therefore, a space is formed between the upper surface of the functional layer 15c at the step portions 59b and the surface of the protective member 19 on the wafer 11 side.

[0068] After the protective element adhesion step (S20), the grinding step (S30) is carried out. Fig. 12B is a diagram illustrating the grinding step (S30). For example, the wafer 11 is processed to the final thickness T1 using the above-described grinding apparatus 30. This divides the wafer 11 into the semiconductor devices 21. After the grinding step (S30), the metal layer covering step (S40) is performed. Fig. 13A is a diagram illustrating the metal layer covering step (S40). For example, the metal layer 23 is formed on the back surfaces 11e, the side surfaces 11f, and the top surfaces of the step portions 59b in the semiconductor devices 21 by a high-frequency magnetron sputtering method using the sputtering apparatus described above.

[0069] As described above, the metal layer 23 is formed on the upper surface of the functional layer 15c at the step portions 59b. Therefore, even when the protective layer 45 is removed, the metal layer 23 is less easily peeled off from the side surfaces of the functional layer 15c (ie, surfaces of the side portions 59a). Due to this, the metal layer 23 is less easily peeled off from the side surfaces 11f of the semiconductor devices 21 even by the protective layer removal step (S65).

[0070] After the metal layer covering step (S40) and before the protective element removing step (S60), the adhesive tape adhering step (S50) is carried out. Fig. 13B is a diagram illustrating the adhesive tape adhesion step (S50). In the adhesive tape adhesion step (S50), the protective member 19 and the plurality of semiconductor devices 21 are integrated with the annular frame 25 and the circular adhesive tape 27 to form the frame unit 29. Due to the formation of the frame unit 29, handling of the plurality of semiconductor devices 21 in the respective subsequent steps is simplified compared to the case where the frame unit 29 is not formed.

[0071] After the adhesive tape adhesion step (S50), the protective member removal step (S60) is performed. As described above, in the protective member removal step (S60), the adhesive force of the adhesive layer of the protective member 19 is reduced using an ultraviolet irradiation device or a heating device, and then the protective member 19 is peeled off from the front surface 11a side of the wafer 11. If the protective member 19 does not have the adhesive layer, the protective member 19 can be peeled off from the front surface 11a side without treating the protective member 19 with an ultraviolet ray or the like. After the protective member removal step (S60), the protective layer removal step (S65) is performed. As described above, in the protective layer removal step (S65), the protective layer 45 is removed using the protective layer forming device 40, which has a second function as a cleaning device.Furthermore, after the protective layer removal step (S65), the individual semiconductor devices 21 can be removed from the adhesive tape 27 using the above-described pickup device (not shown) or the like. This can achieve the semiconductor devices 21 having the metal layer 23 on the order of micrometers as an electromagnetic wave shield.

[0072] Fig. 14 is a flowchart of the manufacturing method of the semiconductor device 21 having the metal layer 23 according to the third embodiment. In the third embodiment, when the resist removal lines 53 are formed (YES in S6), the resist removal line forming step (S7) and the laser-machined groove forming step (S8) are performed sequentially, and the process proceeds to the debris removal step (S9). In comparison, when the resist removal line 53 is not formed (NO in S6), only the laser-machined groove forming step (S8) is performed, and the process proceeds to the debris removal step (S9).

[0073] Next, a second modification example of the third embodiment will be described. In the second modification example, after the laser-machined groove forming step (S8), the cutting groove removing step (S10) and the debris removing step (S9) are performed in this order. The second modification example differs from the first modification example in this point. In the second modification example of the third embodiment, the cutting groove removing step (S10) is performed using the cutting device described above after the laser-machined groove forming step (S8). Fig. 15A is a diagram illustrating the cutting groove forming step (S10). Then, after the cutting groove forming step (S10) and before the subsequent protective member adhering step (S20), the wafer 11 is treated with the etching gas P converted into plasma, and dirt particles adhering to the laser-machined groove 55 and the cutting groove 17 are removed (dirt particle removing step (S9)). Fig. 15B is a diagram illustrating the dirt particle removing step (S9) according to the second modification example.

[0074] In the second modification example of the third embodiment, in addition to the dirt particles generated due to laser ablation of the functional layer 15c in the cutting groove 17, dirt particles generated are removed by the etching gas P. Due to this, compared with the case where treatment with the etching gas P is not performed, the metal layer 23 formed in the subsequent metal layer covering step (S40), for example, can be brought into more intimate contact with the semiconductor substrate and the functional layer 15c. The protective member adhesion step (S20) is performed after the dirt particle removal step (S9). The following steps are the same as in the third embodiment.As described above, in the dirt particle removing step (S9), the dirt particles may be removed by supplying a reactive gas not converted into plasma to the laser-processed groove 55, or the dirt particles may be removed by a mixed gas of the reactive gas and an inert gas.

[0075] Next we will present a fourth embodiment using Fig. 16A to Fig. 18. The difference between the third embodiment and the fourth embodiment will be mainly described below. In the fourth embodiment, too, first, steps from the protective layer covering step (S5) to the cutting groove forming step (S10) are performed similarly to the third embodiment. After the cutting groove forming step (S10), the protective member adhering step (S20) is performed. However, the protective member 19 adhered to the front surface 11a side of the wafer 11 in the protective member adhering step (S20) of the fourth embodiment is an adhesive tape that expands (that is, has expandability) in the radial direction by an external force.

[0076] In the protective member adhering step (S20), in the state where the wafer 11 with the protective layer formed on the front surface 11a side is arranged in the opening part of the metal-made annular frame 25, the protective member 19 is adhered to the frame 25 and the front surface 11a side of the wafer 11 using the above-described protective member adhering device (not shown). Thereby, the frame unit 29 in which the wafer 11, the frame 25, the protective member 19, etc. are integrated is formed. Fig. 16A is a diagram illustrating the protective element adhesion step (S20). After the protective element adhesion step (S20), the grinding step (S30) is performed using the above-described grinding apparatus 30, and the wafer 11 is divided into the plurality of semiconductor devices 21. Fig. 16B is a diagram illustrating the grinding step (S30).

[0077] After the grinding step (S30) and before the metal layer covering step (S40), the protective element 19 is expanded to increase the distance between the individual semiconductor devices 21 (expanding step (S35)). In the expanding step (S35), the protective element 19 is expanded in the radial direction, for example, by using an expanding device 70. Fig. 17A is a diagram illustrating the expanding step (S35). The expanding device 70 includes a drum 72 having a larger diameter than the diameter of the wafer 11 and a circular cylindrical shape. A plurality of rollers 74 are arranged at the upper part of this drum 72 along the circumferential direction. The frame unit 29 is placed on the drum 72 in such a manner that a rear surface 19b of the protective member 19 arranged on the opposite side of the semiconductor elements 21 is in contact with the rollers 74.

[0078] Furthermore, the expander 70 includes an inner ring 76 disposed on the rear surface 19b side of the protective member 19 and made of a metal in a circular ring shape. The lower end portion of the inner ring 76 is supported in such a manner that the radial direction thereof is horizontal, and the inner ring 76 is configured in such a manner that the upper end portion thereof comes into contact with the rear surface 19b of the protective member 19. The expander 70 further includes an outer ring 78 disposed on the semiconductor device 21 side (i.e., a front surface 19a side) with respect to the protective member 19 and made of a metal in a circular ring shape whose inner diameter is larger than the outer diameter of the inner ring 76.The outer ring 78 is configured in such a manner that the lower end portion thereof comes into contact with the front surface 19a of the protective member 19 and the upper end portion thereof is pressed. The inner ring 76 and the outer ring 78, each having the circular ring shape, are arranged coaxially and are relatively movable in a direction such that they come closer to each other. Moreover, the difference between the outer diameter of the inner ring 76 and the inner diameter of the outer ring 78 is smaller than the thickness of the protective member 19. When the inner ring 76 and the outer ring 78 move relatively and reach the same height position, the protective member 19 is clamped and fixed between the outer periphery of the inner ring 76 and the inner periphery of the outer ring 78.

[0079] The expanding device 70 further includes a frame holding unit (not shown). The frame holding unit includes a frame support base (not shown) arranged to surround the upper end part of the drum 72 from the outer peripheral side. The frame support base has an opening with a diameter larger than the diameter of the drum 72 and is arranged at the same height as the upper end part of the drum 72. Furthermore, clamps (not shown) are arranged at a plurality of locations on the outer peripheral side of the frame support base. When the frame support unit 29 is arranged on the drum 72 in such a manner that the frame 25 is arranged on the frame support base and the frame 25 is fixed by the clamps, the frame unit 29 is fixed by the frame support base. The frame support base is supported by a plurality of rods (not shown) extending along the vertical direction.At the lower end portion of each rod, an air cylinder (not shown) is mounted on a base (not shown) having an annular disc shape, which lifts and lowers the rod. When each air cylinder is retracted, the frame support base is lowered relative to the drum 72.

[0080] In the expansion step (S35), first, the air cylinders are actuated to adjust the height of the frame support base in such a way that the height of the upper end of the drum 72 corresponds to the height of the upper surface of the frame support base. Next, the frame unit 29 is arranged on the drum 72 and the frame support base. After that, the frame 25 is fixed to the frame support base by the clamps. Next, the air cylinders are actuated to lower the frame support base of the frame holding unit relative to the drum 72. This expands the protective member 19 in the radial direction, as shown in Fig. 17A is shown.

[0081] When the protective element 19 is expanded in the radial direction, the distance between the semiconductor devices 21 supported by the protective element 19 is expanded. Due to this, the metal is more easily deposited on the semiconductor devices 21 in the following metal covering step (S40) compared to the case where the expanding step (S35) is not performed. In particular, the metal is more easily deposited on the side surfaces 11f of the semiconductor devices 21 (i.e., side surfaces of the semiconductor substrate 11c and the functional layer 15c) and the upper surfaces of the step parts 59b (see Fig. 10C, the upper surfaces of the step parts 59b are in Fig. 17A pointing downwards).

[0082] After the protective member 19 has been expanded, the inner ring 76 and the outer ring 78 are relatively moved to be brought closer to each other, and the protective member 19 is clamped between the outer periphery of the inner ring 76 and the inner periphery of the outer ring 78. Thereby, the protective member 19 is fixed by the inner ring 76 and the outer ring 78 in the expanded state. Thereafter, the protective member 19 is cut into a circular shape at a position between the outer ring 78 and the rollers 74 along the outer periphery of the outer ring 78, so that a ring unit 80 (see Fig. 17B). This completes the expansion step (S35).

[0083] After the expanding step (S35), the metal layer covering step (S40) is performed using the above-described sputtering apparatus or the like. In the metal layer covering step (S40), the ring unit 80 is arranged on the support table of the sputtering apparatus in such a manner that, for example, the rear surface 19b of the protective member 19 makes contact with the surface of the support table. Then, the metal layer 23 is formed on the rear surfaces 11e, the side surfaces 11f, etc., of the semiconductor devices 21 using the sputtering apparatus. Fig. 17B is a diagram illustrating the metal layer covering step (S40). A flowchart of the manufacturing method of the semiconductor device 21 having the metal layer 23 according to the fourth embodiment is shown in Fig.18. In the fourth embodiment, the adhesive tape adhering step (S50) and the following steps are sequentially performed after the metal layer covering step (S40) similarly to the third embodiment.

[0084] Moreover, structures, methods, etc. according to the embodiments described above can be carried out with appropriate changes without departing from the scope of the present invention. For example, the expanding step (S35) in the fourth embodiment can be applied to the first and second embodiments. Moreover, in the first embodiment to the fourth embodiment and the first and second modification examples of the third embodiment, the semiconductor devices 21 having the metal layer 23 are formed from the workpiece including the semiconductor substrate 11c and the functional layer 15c. However, when the workpiece is a WL-CSP wafer or a plastic package board, a semiconductor package device having the metal layer 23 from the workpiece can be manufactured.

Claims

[1] Manufacturing method of a semiconductor device (21) with a metal layer (23), the manufacturing method comprising: a cutting groove forming step of causing a cutting blade (20) to cut into a first surface (11a) of a workpiece (11) having the first surface under which an electrode (15d) of a semiconductor device (21) is arranged in each of regions marked by a plurality of planned parting lines (13) arranged in a lattice shape and a second surface (11b) on a side opposite to the first surface, and forming cutting grooves (17) with a depth exceeding a final thickness of the workpiece (11) along the planned parting lines (13); a protective member adhering step of adhering a protective member (19) to the first surface of the workpiece (11) after the cutting groove forming step; a grinding step of holding the workpiece (11) on a chuck table (32) via the protective member (19) and grinding one side of the second surface until a thickness of the workpiece (11) becomes the final thickness to divide the workpiece (11) into a plurality of semiconductor devices (21); a metal layer covering step of covering a side surface (11f) of each of the plurality of semiconductor devices (21) for which the protective element (19) is adhered to a side of the first surface and the side of the second surface by a metal layer (23) after the grinding step, and a protective member removing step of removing the protective member (19) from the first surface side after the metal layer covering step. [2] A manufacturing method of a semiconductor device (21) having a metal layer (23) according to claim 1, the manufacturing method further comprising: a protective member covering step of covering the first surface side with a protective layer before the cutting groove forming step; and a protective layer removing step of removing the protective layer after the protective element removing step, wherein the protective element (19) is brought into close contact with the protective layer in the protective element adhesion step. [3] A manufacturing method of a semiconductor device (21) having a metal layer (23) according to claim 2, the manufacturing method further comprising: a laser-machined groove forming step of irradiating the side of the first surface of the workpiece (11) on which the protective layer is formed with a laser beam and forming laser-machined grooves having a greater width than the cutting grooves (17) along the planned parting lines (13) after the protective layer covering step and before the cutting groove forming step. [4] A manufacturing method of a semiconductor device (21) having a metal layer (23) according to claim 3, the manufacturing method further comprising: a protective layer removal line forming step of forming protective layer removal lines obtained by removing the protective layer having a width greater than both the cutting grooves (17) and the laser-machined grooves along the planned parting lines (13) by irradiating the protective layer with a laser beam having a wavelength with an absorbability with respect to the protective layer along the planned parting lines (13) after the protective layer covering step and before the laser-machined groove forming step. [5] A manufacturing method of a semiconductor device (21) having a metal layer (23) according to claim 3 or 4, the manufacturing method further comprising: a dirt particle removing step of performing a treatment of the workpiece (11) with an etching gas and removing dirt particles adhering to the laser-machined grooves and / or the cutting grooves (17) after the laser-machined groove forming step or the cutting groove forming step and before the protective member adhering step. [6] A method of manufacturing a semiconductor device (21) having a metal layer (23) according to any one of the preceding claims, the method further comprising: an adhesive tape adhering step of adhering an adhesive tape to the side of the second surface covered by the metal layer (23) in the plurality of semiconductor devices (21) after the metal layer covering step and before the protective element removing step. [7] A manufacturing method of a semiconductor device (21) having a metal layer (23) according to any one of the preceding claims, wherein the protective element (19) adhered in the protective element adhering step is an adhesive tape having an expandability, the manufacturing method further comprising: an expanding step of expanding the protective element (19) and increasing a distance between the individual semiconductor components (21) after the grinding step and before the metal layer covering step.

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