JP2011171530A - Method and device for peeling protective tape, and method of manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and device for peeling a protective tape that reliably peel the protective tape stuck on a wafer, and to provide a method of manufacturing a semiconductor device using the method for peeling the protective tape. <P>SOLUTION: After a peeling tape 24 is stuck on the surface of the protective tape 21 stuck on the surface of the wafer 21, the wafer 21 is heated by a heating unit 23a and the peeling tape 24 stuck on the peeling start end of the protective tape 22 is cooled by a cooling iron 28. The protective tape 22 is peeled from the wafer together with the peeling tape 24 with the peeling start end part cooled by the cooling iron 28 as a starting point. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a protective tape peeling method and a peeling device for peeling off a protective tape attached to a semiconductor wafer, and a semiconductor device manufacturing method using the protective tape peeling method.

  From the viewpoint of improving the mounting density by reducing the thickness of the semiconductor device and improving the performance of the power semiconductor device, in the manufacturing process of the semiconductor chip on which the semiconductor device is mounted, a semiconductor wafer (hereinafter simply referred to as “ In some cases, the back surface of the wafer is ground and thinned in a state where a protective tape is applied to the circuit pattern forming surface of the wafer).

  The thinned wafer is mounted on a dicing frame via a dicing tape with the circuit pattern forming surface facing upward, and then the protective tape attached to the circuit pattern forming surface is peeled off to form a chip in the dicing process. .

  When manufacturing a power semiconductor device, after the wafer is thinned, a diffusion layer is formed on the ground surface by an ion implantation process and a heat treatment process, and then a back electrode is formed by sputtering or the like.

  In the field of power semiconductor devices, as a semiconductor wafer, a wafer made of silicon is used. However, in recent years, a wafer made of silicon carbide is used because of its material characteristics. Also in power semiconductor devices using wafers made of silicon carbide, grinding, diffusion layer formation, and electrode formation are performed using a protective tape from the viewpoint of improving performance.

  In peeling off the protective tape, a peeling tape is used. After affixing a peeling tape on the surface of a protective tape, by peeling off, a protective tape is peeled from a wafer with a peeling tape. As a method for reliably forming the starting point of peeling, the peeling tape is peeled off by pressing the center part of the peeling tape against the surface of the protective tape with the sticking roller using a sticking roller having a width dimension shorter than that of the peeling tape. A method has been proposed (see, for example, Patent Document 1).

  In addition, as a method of improving the adhesion between the peeling tape and the protective tape at the starting point of peeling, a thermocompression bonding part between the peeling tape and the protective tape is formed over almost the entire width of the peeling tape using a thermocompression heater. Has been proposed (see, for example, Patent Document 2).

JP 2008-4712 A JP 2009-141314 A

  Along with the thinning of wafers for the purpose of reducing the thickness of semiconductor chips, in the semiconductor chip manufacturing process, wafer cracks due to the stress that the wafer receives from the grinding wheel during grinding, and the warpage and deflection of the processed wafers Increase in the number of wafers increases the number of cracks in the transfer process. In order to reduce the cracking and warping of the wafer, with respect to the protective tape, as the wafer becomes thinner, the cushioning property and rigidity tend to increase, that is, the dimension in the thickness direction of the protective tape (hereinafter referred to as “thickness dimension”) increases. There is a tendency.

  When peeling such a protective tape, if the method of forming the starting point of peeling by pressing is used as in the technique disclosed in Patent Document 1, the end portion of the wafer that becomes the starting point due to the buffering property of the protective tape However, there exists a problem that the adhesiveness of a peeling tape and a protective tape becomes inadequate. In order to improve the adhesion, it is conceivable to increase the pressing force. However, if the pressing force is too strong, there is a problem that cracks due to stress concentration occur at the edge of the wafer.

  In addition, when the technique disclosed in Patent Document 2 is used, in the pressure bonding between the peeling tape and the protective tape by the thermocompression heater, the pressure bonding between the protective tape and the peeling tape becomes insufficient due to the increase in the thickness dimension of the protective tape, There is a problem that the protective tape is overheated by the thermocompression heater and the peeling tape is cut off.

  The objective of this invention is providing the manufacturing method of the semiconductor device using the peeling method and peeling apparatus of the protective tape which can peel the protective tape affixed on the wafer reliably, and the peeling method of the said protective tape. .

  The method for peeling off a protective tape of the present invention is a method for peeling off a protective tape that is attached to the surface on one side in the thickness direction of the wafer from the wafer, on the surface on one side in the thickness direction of the protective tape. Affixing step for affixing a release tape, and heating the adhesive portion between the wafer and the protective tape by a heating means, and a predetermined peeling start end as an end of the protective tape to start peeling from the wafer; A heating and cooling step for cooling the adhesive portion with the peeling tape by a cooling means, and a peeling step for peeling the protective tape from the wafer together with the peeling tape, starting from the peeling start end portion cooled by the cooling means. It is characterized by providing.

  The method for manufacturing a semiconductor device according to the present invention includes a step of forming a circuit pattern constituting a semiconductor device on a surface portion on one side in the thickness direction of the wafer, and protecting the circuit pattern on the surface on one side in the thickness direction of the wafer. A step of applying a protective tape, a step of performing a predetermined wafer processing on a surface portion of the other side in the thickness direction opposite to the side of the wafer where the protective tape is applied, and the present invention And a step of peeling off the protective tape attached to the surface on one side in the thickness direction of the wafer using a method for peeling off the protective tape.

  The protective tape peeling device of the present invention is a protective tape peeling device for peeling a protective tape attached to the surface on one side in the thickness direction of the wafer from the wafer, on the surface on the one side in the thickness direction of the protective tape. Affixing means for affixing a release tape, a heating means for heating an adhesive portion between the wafer and the protective tape, and a peeling start end part predetermined as an end part for starting the peeling from the wafer among the protective tape, and the A cooling means for cooling an adhesive portion with the peeling tape; and a peeling means for peeling the protective tape from the wafer together with the peeling tape starting from the peeling start end cooled by the cooling means. To do.

  According to the peeling method of the protective tape of this invention, a peeling tape is affixed on the surface of the thickness direction one side of the protective tape affixed on the surface of the thickness direction one side of a wafer at the sticking process. In the heating and cooling step, the bonded portion between the wafer and the protective tape is heated by the heating means, and the bonded portion between the peeling start end portion of the protective tape and the peeling tape is cooled by the cooling means. Starting from the peeling start end cooled by the cooling means, the protective tape is peeled from the wafer together with the peeling tape in the peeling step.

  Thus, in the heating and cooling step, the bonded portion between the wafer and the protective tape is heated and the bonded portion between the peeling start end portion of the protective tape and the peeling tape is cooled. The temperature of the bonding portion can be made lower than the temperature of the bonding portion between the wafer and the protective tape. Thereby, the adhesive force between the protective tape and the peeling tape at the peeling start end can be made higher than the adhesive force between the protective tape and the wafer. Therefore, the protective tape can be reliably peeled from the wafer.

  According to the method for manufacturing a semiconductor device of the present invention, the circuit pattern constituting the semiconductor device is formed on the surface portion on one side in the thickness direction of the wafer. After the protective tape for protecting the circuit pattern is applied to the surface on the one side in the thickness direction of the wafer, it is predetermined on the surface portion on the other side in the thickness direction opposite to the side on which the protective tape of the wafer is applied. Wafer processing is performed. Then, the protective tape affixed on the surface of the thickness direction one side is peeled, and a semiconductor device is manufactured.

  When the protective tape is peeled off, the protective tape peeling method of the present invention that can reliably peel off the protective tape from the wafer as described above is used. Accordingly, the thickness of the protective tape can be increased without causing the peeling failure of the protective tape, and the buffering property and rigidity of the protective tape can be increased. Therefore, cracks and warpage of the wafer can be reduced, and the manufacturing yield of the semiconductor device can be improved.

  According to the protective tape peeling apparatus of the present invention, the peeling tape is stuck on the surface on one side in the thickness direction of the protective tape stuck on the surface on the one side in the thickness direction of the wafer by the sticking means. The bonding portion between the wafer and the protective tape is heated by the heating means, and the bonding portion between the peeling start end portion of the protective tape and the peeling tape is cooled by the cooling means. Starting from the peeling start end cooled by the cooling means, the protective tape is peeled from the wafer together with the peeling tape by the peeling means.

  In this way, the bonded portion between the wafer and the protective tape is heated by the heating means, and the bonded portion between the peeling start end of the protective tape and the peeling tape is cooled by the cooling means, so the peeling start end of the protective tape and the peeling tape Can be made lower than the temperature of the bonded portion between the wafer and the protective tape. Thereby, the adhesive force between the protective tape and the peeling tape at the peeling start end can be made higher than the adhesive force between the protective tape and the wafer. Therefore, the protective tape can be reliably peeled from the wafer.

It is a side view which shows the structure of the peeling apparatus 1 which is the 1st Embodiment of this invention. It is sectional drawing which expands and shows the stage 23 vicinity of the peeling apparatus 1 shown in FIG. 3 is a side view showing a state in which the peeling tape 24 is pasted up to a peeling end portion of the protective tape 22. It is a side view which shows the state by which the peeling start end part of the protective tape 22 was peeled. It is a side view which shows the state from which the center part of the protective tape 22 was peeled. It is a side view which shows the state by which the peeling termination | terminus part of the protective tape 22 was peeled. It is a graph which shows the temperature dependence of the adhesive force according to the sticking form of the protective tape 22 and the peeling tape 24. FIG. It is sectional drawing which shows the peeling apparatus 40 which is the 2nd Embodiment of this invention. It is sectional drawing which shows the peeling apparatus 50 which is the 3rd Embodiment of this invention.

<First Embodiment>
FIG. 1 is a side view showing a configuration of a peeling apparatus 1 according to a first embodiment of the present invention. FIG. 2 is an enlarged sectional view showing the vicinity of the stage 23 of the peeling apparatus 1 shown in FIG. In FIG. 2, in order to facilitate understanding, the peeling device 1 is shown in a simplified manner. The peeling apparatus 1 is used when peeling the protective tape 22 attached to the surface of the wafer 21 on which the circuit pattern is formed (hereinafter sometimes referred to as “circuit pattern forming surface”) from the wafer 21. The circuit pattern forming surface of the wafer 21 is a surface on one side in the thickness direction of the wafer 21, that is, a surface on the upper side toward the paper surface in FIG.

  The peeling apparatus 1 includes a stage 23, a cooling iron (hereinafter referred to as “cooling iron”) 28, a peeling tape supply / recovery mechanism 35, a vertical drive mechanism 36, a lifting mechanism 37, a transport robot (not shown), and an alignment unit (not shown). It is configured with. The cooling iron 28 corresponds to a cooling means.

  The wafer 21 to which the protective tape 22 is attached is adsorbed to the stage 23 after being appropriately positioned using an unillustrated alignment unit or the like using a transfer robot (not illustrated). Although not shown, the stage 23 has a plurality of suction holes. The wafer 21 is attracted to the stage 23 by the suction action from the suction holes.

  The surface of the wafer 21 on the other side in the thickness direction, that is, the lower surface (hereinafter also referred to as “lower surface”) toward the paper surface in FIG. For example, when the wafer 21 is attached to a dicing frame via a dicing tape, the wafer 21 is attracted to the stage 23 via the dicing frame. The stage 23 includes a heating unit 23a that is a heating unit. The heating part 23 a is formed on the surface part on one side in the thickness direction of the stage 23. The heating unit 23a is realized by, for example, a heater arranged by winding a heating wire around the stage 23. The wafer 21 can be heated by the heating unit 23a.

  Two support columns 11 are erected on the installation surfaces on both sides of the stage 23. The two support | pillars 11 are connected via the crosspiece 11a by the upper end parts which are upper edge parts toward the paper surface of FIG. The two columns 11 are each provided with column rails 12 extending in the vertical direction. Both sliders (not shown) are fitted to each column rail 12 so as to be movable up and down. A lifting frame 13 is provided integrally with both the sliders.

  An elevating cylinder 14 is provided on the crosspiece 11 a connecting the upper ends of the two columns 11. The cylinder shaft 14 a of the elevating cylinder 14 is connected to a fixed frame 15 that protrudes behind the elevating frame 13. The lifting frame 13 can freely move up and down along the rail 12 by the action of the lifting cylinder 14. The support 11, the rail 12, the lifting frame 13, the lifting cylinder 14 and the fixed frame 15 constitute a lifting mechanism 37.

  A unit rail (not shown) is provided in the vicinity of the lower back of the lifting frame 13 so as to extend in the vertical direction. A unit slider (not shown) is fitted to the unit rail so as to be movable up and down. A lifting unit 16 is provided integrally with the unit slider. The elevating unit 16 is connected to the cylinder shaft 14 a of the elevating cylinder 14 provided on the back surface of the elevating frame 13, and is connected to the cylinder shaft 17 a of the unit elevating cylinder 17 provided on the elevating unit 16.

  When the lifting frame 13 moves up and down along the rails 12 of the support column 11, the lifting unit 16 moves up and down accordingly. When the unit elevating cylinder 17 is operated, the elevating unit 16 moves up and down along the unit rail with respect to the elevating frame 13. The elevating unit 16, the unit elevating cylinder 17, the unit rail, and the unit slider constitute a vertical drive mechanism 36.

  The cooling iron 28 is configured to be disposed at a part where the peeling of the protective tape 22 by the peeling tape 24 is started (hereinafter sometimes referred to as “peeling start part”). Specifically, the cooling iron 28 is configured to be arranged so as to be in contact with a part of the peeling tape 24 attached to an end portion on which the protective tape 22 starts to be peeled (hereinafter referred to as “peeling start end portion”). Is done. The cooling iron 28 is provided so as to protrude through the notch portion (not shown) of the elevating frame 13 toward the front side from the elevating frame 13 toward the paper surface of FIG. The cooling iron 28 is configured to be driven in the vertical direction, in the vertical direction toward the paper surface in FIG. The cooling iron 28 is supported by the elevating unit 16 constituting the vertical drive mechanism 36.

  The cooling iron 28 moves up and down in the vertical direction toward the paper surface of FIG. The lowering unit 16 is lowered downward toward the paper surface of FIG. 1 to lower the cooling iron 28 downward toward the paper surface of FIG. Can be arranged.

  Above the stage 23, a peeling tape supply / recovery mechanism 35 for supplying and collecting the peeling tape 24 is provided. The release tape supply / recovery mechanism 35 is provided with a release tape supply side guide 25 and a release tape recovery side guide 27 in order to securely attach the release tape 24 to the protective tape 22.

  More specifically, the release tape supply / recovery mechanism 35 includes the release tape supply reel 33, the release tape supply side guide 25, the release tape application roller 26, the release tape recovery side guide 27, the first guide roller 29, and the second guide roller 30. , A pinch roller 31, a reel side guide roller 32, and a peeling tape take-up reel 34. The release tape supply side guide 25, the release tape application roller 26, and the release tape collection side guide 27 correspond to application means. Moreover, the peeling tape collection | recovery side guide 27 and the 1st guide roller 29 are equivalent to a peeling means.

  Each member constituting the release tape supply / recovery mechanism 35, that is, the release tape supply reel 33, the release tape supply side guide 25, the release tape applying roller 26, the release tape recovery side guide 27, the first guide roller 29, and the second guide roller 30. The pinch roller 31, the reel side guide roller 32, and the peeling tape take-up reel 34 are pivotally supported by the elevating frame 13. Each member constituting the peeling tape supply / recovery mechanism 35 is provided so as to protrude through the window hole (not shown) of the lifting / lowering frame 13 toward the front side of the sheet of FIG.

  The release tape supply side guide 25, the release tape application roller 26, the release tape collection side guide 27, and the first guide roller 29 are moved vertically by a vertical movement mechanism (not shown), up and down toward the paper surface in FIG. Configured to be possible. Further, the release tape supply side guide 25, the release tape application roller 26, the release tape collection side guide 27, and the first guide roller 29 are moved in the horizontal direction by a horizontal movement mechanism (not shown), and in the left and right direction in FIG. It is configured to be movable.

  The release tape 24 supplied from the release tape supply reel 33 includes a release tape supply side guide 25, a release tape application roller 26, a release tape collection side guide 27, a first guide roller 29, a second guide roller 30, a pinch roller 31, and The reel-side guide roller 32 is sequentially wound and wound by a peeling tape take-up reel 34. In the present embodiment, the peeling tape supply reel 33 rotates clockwise, and the peeling tape take-up reel 34 rotates counterclockwise. The peeling tape take-up reel 34 is driven by a take-up motor (not shown). The pinch roller 31 is driven by driving means (not shown) in conjunction with the take-up motor and rotates with the peeling tape 24 interposed therebetween.

  The tension of the peeling tape 24 is determined by detecting the positions of the peeling tape supply side guide 25, the peeling tape application roller 26, the peeling tape collection side guide 27, and the first guide roller 29 with a sensor (not shown) or the like. It can be adjusted by controlling the feeding amount and feeding speed of the peeling tape 24 and the winding amount and winding speed of the peeling tape 24 by the peeling tape take-up reel 34. Control of the winding amount and winding speed of the peeling tape 24 can be performed by a winding motor and a driving means of the pinch roller 31. On the peeling tape supply reel 34 side, a tensile resistance is applied to the peeling tape 24 with a constant tension by a winding motor or the like.

  Next, a method for peeling the protective tape 22 on the surface of the wafer 21 using the peeling apparatus 1 of the present embodiment will be described. The protective tape peeling method using the peeling apparatus 1 of the present embodiment is an embodiment of the protective tape peeling method of the present invention. First, as shown in FIG. 2 described above, the wafer 21 that has been positioned using the alignment unit or the like is sucked by the stage 23 having the heating unit 23a using a transfer robot (not shown).

  Thereafter, the lifting frame 13 shown in FIG. 1 is lowered, and the peeling tape 24 is attached to the peeling start end portion of the protective tape 22 on the surface of the wafer 21 using the peeling tape supply side guide 25. The peeling tape 24 is attached while the wafer 21 is heated by the heating unit 23 a of the stage 23. FIG. 2 shows a state in which the cooling iron 28 is in contact with the peeling tape 24 for easy understanding. Actually, however, the cooling iron 28 is used in the step shown in FIG. 3 to be described later. 24 is brought into contact.

  As the peeling tape 24, a peeling tape that is long and has a smaller dimension in the width direction than the wafer 21 is used. By using a peeling tape whose dimension in the width direction is smaller than that of the wafer 21, it is possible to prevent the peeling tape 24 from sticking to the stage 23a. Further, when the wafer 21 is adsorbed to the stage 23 via the dicing frame, the peeling tape 24 can be prevented from sticking to the dicing tape or the dicing tape. Thereby, the peeling tape 24 can be attached and the protective tape 22 can be peeled easily thereafter.

  FIG. 3 is a side view showing a state in which the peeling tape 24 is pasted to the peeling end portion of the protective tape 22. Next, as shown in FIG. 3, the peeling tape applying roller 26 is moved to the rear end side of the wafer 21, and leftward in FIG. 3 toward the paper surface, and the peeling tape 24 is opposite to the peeling start end portion of the protective tape 22. Affix to the end of the side (hereinafter referred to as “peeling end”). Also at this time, the wafer 21 is heated by the heating unit 23a. The rear end portion of the wafer 21 is an end portion on the side opposite to the front end portion when the end portion corresponding to the peeling start end portion of the protective tape 22 of the wafer 21 is the front end portion of the wafer 21. The peeling tape supply side guide 25 is moved to the left side toward the rear end side of the wafer 21, that is, the paper surface of FIG.

  The process of sticking the peeling tape 24 from the peeling start end part of the protective tape 22 to the post-peeling end part as described above corresponds to the sticking process. The affixing of the peeling tape 24 is performed while heating the wafer 21 by the heating unit 23a as described above. Thereby, since the peeling tape 24 can be heated via the wafer 21 and the protective tape 22, the adhesive force of the adhesive of the peeling tape 24 is reduced, and the peeling tape 24 can be securely attached to the protective tape 22. it can.

  Next, the cooling iron 28 is lowered by the vertical drive mechanism 36 shown in FIG. 1 and brought into contact with the peeling tape 24 attached to the peeling start end portion of the protective tape 22, whereby the peeling tape 24 at the peeling start end portion. Then, the temperature of the peeling tape 24 at the peeling start end is lowered. As a result, the bonded portion between the protective tape 22 and the peeling tape 24 at the peeling start end is cooled. The peeling start end is cooled by heating the wafer 21 with the heating unit 23 a while heating the bonding portion between the wafer 21 and the protective tape 22. This step corresponds to a heating / cooling step. Thereafter, the vertical driving mechanism 36 pulls the cooling iron 28 upward, and the cooling by the cooling iron 28 is stopped.

  4-6 is a figure which shows the process in which the protective tape 22 peels later on in order. FIG. 4 is a side view showing a state where the peeling start end portion of the protective tape 22 is peeled off. FIG. 5 is a side view showing a state where the central portion of the protective tape 22 is peeled off. FIG. 6 is a side view showing a state where the peeling end portion of the protective tape 22 is peeled off.

  Next, using the peeling tape winding mechanism 35 shown in FIG. 1 as described above, as shown in FIGS. 4 to 6, the peeling tape collecting side guide 27 is moved to the rear end side of the wafer 21, that is, in FIGS. 4 to 6. Move left toward the page. As a result, the protective tape 22 is peeled off from the wafer 21 together with the peeling tape 24 from the peeling start end of the protective tape 22 cooled by the cooling iron 28. This step corresponds to a peeling step. Specifically, the peeling tape collecting side guide 27 has an angle of peeling of the protective tape 22 that is an angle formed between the peeled protective tape 22 and the surface of the wafer 21 to which the protective tape 22 is attached to about 180 °. Moved to be held.

  Specifically, as shown in FIG. 4, first, the peeling tape collecting side guide 27 is moved, so that the peeling tape 24 and the wafer 21 are peeled in parallel to the surface on one side in the thickness direction of the wafer 21. It moves relatively along the longitudinal direction of the tape 24. Thereby, the protective tape 22 and the peeling tape 24 at the peeling start end cooled by the cooling iron 28 are folded back to form a folded portion. Specifically, the folded portion is formed so that the peeling angle of the protective tape 22 is approximately 180 °.

  Next, as shown in FIG. 5, the peeling tape 24 and the wafer 21 are relatively moved along the longitudinal direction of the peeling tape 24 while maintaining the folded state of the protective tape 22 and the peeling tape 22 in the folded portion. Specifically, the peeling tape collection side guide 27 is moved, and the peeling tape 24 is moved so that the peeling angle of the protective tape 22 is maintained at approximately 180 °. As a result, the protective tape 22 is peeled off with a peeling angle of approximately 180 ° in a state of being attached to the peeling tape 24. Further, as the peeling tape 24 and the wafer 21 move relative to each other, the peeling tape collecting reel 34 is driven to collect the protective tape 22 peeled from the wafer 21 together with the peeling tape 24.

  Finally, as shown in FIG. 6, the protective tape 22 is peeled from the wafer 21 by separating the peeling tape 24 from the wafer 21 in the vicinity of the peeling end portion opposite to the peeling start end portion of the protective tape 22. .

  FIG. 7 is a graph showing the temperature dependence of the adhesive force according to the application form of the protective tape 22 and the release tape 24. In FIG. 7, the horizontal axis represents the temperature [° C.] of the bonded portion, and the vertical axis represents the adhesive strength [Arb.Unit] (arbitrary unit). In FIG. 7, the temperature dependence of the adhesive force of the protective tape 22 attached to the surface of the wafer 21, that is, the adhesive force between the protective tape 22 and the wafer 21 is represented by a solid line indicated by a reference symbol A. Further, the temperature dependency of the adhesive force of the peeling tape 24 affixed to the surface of the protective tape 22, that is, the adhesive force between the peeling tape 24 and the protective tape 22, is represented by a broken line indicated by reference symbol B.

  The adhesive force between the protective tape 22 and the wafer 21 and the adhesive force between the peeling tape 24 and the protective tape 22 are rapidly reduced in the process of increasing the temperature of the adhesive portion. This is because the temperature has exceeded the glass transition temperature Tg of the adhesive applied to each base tape of the protective tape 22 and the release tape 24.

  As shown in FIG. 7, the adhesive force between the protective tape 22 and the wafer 21 has a sharper adhesive force at a lower temperature than the adhesive force between the peeling tape 24 and the protective tape 22. A decline begins to occur. Therefore, there is a range where the adhesive force between the peeling tape 24 and the protective tape 22 exceeds the adhesive force between the protective tape 22 and the wafer 21, that is, a range where the broken line B is located above the solid line A. Within this range, the protective tape 22 attached to the surface of the wafer 21 can be peeled off by the peeling tape 24.

  According to FIG. 7, only when the temperature of the bonding part between the protective tape 22 and the wafer 21 and the temperature of the bonding part between the peeling tape 24 and the protective tape 22 are around 90 ° C., the peeling tape 24 and the protective tape 22 The adhesive strength between them exceeds the adhesive strength between the protective tape 22 and the wafer 21. Therefore, if the temperature of both adhesion parts is around 90 degreeC, it is thought that the protective tape 22 can be stably peeled with the peeling tape 24, but actually, the temperature of both adhesion parts is Even at around 90 ° C., the protective tape 22 may not be peeled off by the peeling tape 24 due to variations in the production of the protective tape 22 and the peeling tape 24.

  Further, as the thickness of the wafer 21 is reduced, it is required to perform the wafer process with the protective tape 22 still attached from the viewpoint of securing the support of the wafer 21 and protecting the wafer 21. This tendency is particularly strong in the field of power semiconductor devices. Development of a tape material with improved heat resistance is underway so that the wafer process can be performed with the protective tape 22 still attached. Along with this, the glass transition temperature Tg of the adhesive of the protective tape 22 tends to increase.

  When the glass transition temperature Tg of the adhesive of the protective tape 22 is increased, the temperature of the adhesive portion when the adhesive force between the protective tape 22 and the wafer 21 starts to rapidly decrease is increased. In FIG. Shifts toward the broken line B. Therefore, there is almost no range where the adhesive strength between the peeling tape 24 and the protective tape 22 exceeds the adhesive strength between the protective tape 22 and the wafer 21, and the protective tape 22 may not be peeled off by the peeling tape 24. Arise.

  In the present embodiment, the bonding portion between the peeling tape 24 and the protective tape 22 is cooled from the peeling tape 24 side using the cooling iron 28 shown in FIG. It is possible to raise only the temperature of the bonding portion between the protective tape 22 and the wafer 21 while lowering the temperature of the bonding portion. Therefore, as described above, even when the protective tape 22 and the peeling tape 24 have manufacturing variations and when the glass transition temperature Tg of the adhesive of the protective tape 22 is high, the peeling tape 24 and the protective tape 22 The adhesive force between the protective tape 22 and the wafer 21 can be made higher than the adhesive force between the protective tape 22 and the wafer 21. Therefore, the protective tape 22 can be reliably peeled from the wafer 21 by the peeling tape 24.

  The protective tape peeling method of the present embodiment is suitable when the material of the wafer 21 is silicon carbide. Since silicon carbide has a thermal conductivity approximately twice as high as that of silicon widely used as a wafer material for semiconductor devices, when the material of the wafer 21 is silicon carbide, the material of the wafer 21 is silicon. Compared with a case, the heat of the heating unit 23 a of the stage 23 is easily transmitted to the protective tape 22 through the wafer 21. Accordingly, the difference between the temperature at the bonding portion between the peeling tape 24 and the protective tape 22 and the temperature at the bonding portion between the protective tape 22 and the wafer 21 is less likely to occur. It becomes difficult to control the force and the adhesive force between the protective tape 22 and the wafer 21.

  In the present embodiment, the bonding part between the peeling tape 24 and the protective tape 22 is cooled from the side of the peeling tape 24 using the cooling iron 28 shown in FIG. 2 described above, so the material of the wafer 21 is silicon carbide. Even in this case, the temperature of the bonded portion between the peeling tape 24 and the protective tape 22 can be made lower than the temperature of the bonded portion between the protective tape 22 and the wafer 21. Accordingly, the adhesive force between the peeling tape 24 and the protective tape 22 can be made higher than the adhesive force between the protective tape 22 and the wafer 21, so that the protective tape 22 is reliably secured from the wafer 21 by the peeling tape 24. Can be peeled off.

  In the present embodiment, since the cooling iron 28 is used as the cooling means, the temperature of the bonded portion between the peeling tape 24 and the protective tape 22 can be protected more reliably than when other cooling means are used. The temperature can be lower than the temperature at the bonding portion between the tape 22 and the wafer 21. Thereby, the adhesive force between the peeling tape 24 and the protective tape 22 can be more reliably increased than the adhesive force between the protective tape 22 and the wafer 21. Therefore, the protective tape 22 can be more reliably peeled from the wafer 21.

  The cooling iron 28 may be configured to be movable to the left in the direction in which the protective tape 22 is folded, that is, toward the paper surface of FIGS. By configuring the protective tape 22 to be movable in the direction in which the protective tape 22 is folded back, the cooling iron 28 can continue to cool the bonding portion between the protective tape 22 and the peeling tape 24 even during the peeling of the protective tape 22. In this way, the cooling iron 28 is configured so that the bonded portion between the protective tape 22 and the peeling tape 24 can be cooled while the protective tape 22 is peeled off from the wafer 21, and is cooled even when the protective tape 22 is peeled off. By continuing cooling with the iron 28, the temperature of the bonded portion between the peeling tape 24 and the protective tape 22 can be maintained in a low state. Therefore, since the adhesive force between the peeling tape 24 and the protective tape 22 can be maintained in a high state, the protective tape 22 can be more reliably peeled from the wafer 21.

  In this embodiment, when the protective tape 22 is peeled off, it is first cooled by the cooling iron 28 by the action of the peeling tape collecting side guide 27 and the first guide roller 29 as shown in FIG. The protective tape 22 and the peeling tape 24 at the peeling start end are folded back to form a folded portion. Then, as shown in FIG. 5 described above, the peeling tape 24 is moved while maintaining the folded state of the protective tape 22 and the peeling tape 22 in the folded portion, and the peeling tape 24 removes the protective tape 22 peeled from the wafer 21. Collect with. Finally, as shown in FIG. 6 described above, the peeling tape 24 is separated from the wafer 21 in the vicinity of the peeling end portion on the opposite side of the peeling start end portion of the protective tape 22, and the protective tape 22 is peeled off from the wafer 21. To do.

  Since the protective tape 22 is peeled in this way, when the protective tape 22 is peeled off, the force applied in the direction perpendicular to the surface on the one side in the thickness direction of the wafer 21, that is, in the thickness direction of the wafer 21 can be reduced. it can. In particular, in the present embodiment, the protective tape 22 is peeled off with a peeling angle of about 180 ° in a state of being attached to the peeling tape 24, so that the wafer 21 is on one side in the thickness direction of the wafer 21. A force is applied in a direction parallel to the surface of the wafer 21, and a force applied in a direction perpendicular to the surface on one side in the thickness direction of the wafer 21 is substantially zero. Therefore, even when the thickness dimension of the wafer 21 is extremely small, damage such as chipping due to the lifting of the protective tape 22 can be prevented.

<Second Embodiment>
FIG. 8 is a cross-sectional view showing a peeling apparatus 40 according to the second embodiment of the present invention. The peeling device 40 of the present embodiment is similar to the peeling device 1 of the first embodiment described above, and the other configuration except for the cooling iron 28 is the same as that of the peeling device 1 of the first embodiment. Therefore, only different parts will be described, and the same reference numerals are given to the same components, and the common description will be omitted. In FIG. 8, the vicinity of the stage 23 of the peeling apparatus 40 is shown in an enlarged manner as in FIG.

  In the peeling apparatus 1 of the first embodiment described above, the cooling iron 28 is provided as a cooling means. However, in the peeling apparatus 40 of the present embodiment, a cooling fan 41 is used instead of the cooling iron 28. Is provided.

  The cooling fan 41 is provided on the side of the portion where the peeling start end portion of the protective tape 22 is located in a state where the wafer 21 to which the protective tape 22 is attached is attracted to the stage 23. The cooling fan 41 is provided so that air can be sent out toward the peeling start end of the protective tape 22. When the cooling fan 41 is activated, air is sent out from the side of the peeling start end of the protective tape 22 and from the right in FIG. Thereby, the peeling start end portion of the protective tape 22 is cooled, and the bonding portion between the peeling start end portion of the protective tape 22 and the peeling tape 24 is cooled.

  Using such a peeling apparatus 40 of the present embodiment, a method for peeling a protective tape that is an embodiment of the present invention is executed. Since the method for peeling off the protective tape in the present embodiment is the same as the method for peeling off the protective tape in the first embodiment described above, different steps will be described and common description will be omitted.

  In this embodiment, after the peeling tape 24 is pasted from the peeling start end to the peeling end of the protective tape 22 while heating the wafer 21 by the heating unit 23a of the stage 23 in the same manner as in the first embodiment. Then, air is sent out from the cooling fan 41 to cool the peeling start end portion of the protective tape 22, and consequently the bonding portion between the peeling start end portion of the protective tape 22 and the peeling tape 24. While air is sent out from the cooling fan 41, the wafer 21 is heated by the heating unit 23a.

  After the cooling of the protective tape 22 by the cooling fan 41 and the heating of the wafer 21 by the heating unit 23a are stopped, or in a state where the heating is continued, the protective tape 22 together with the peeling tape 24 in the same manner as in the first embodiment. Peel off.

  As described above, in the present embodiment, the wafer 21 is heated by the heating unit 23a, and the peeling start end portion of the protective tape 22 is cooled by the cooling fan 41, so that the adhesive force between the peeling tape 24 and the protective tape 22 is increased. While maintaining, the adhesive force between the protective tape 22 and the wafer 21 can be reduced. Therefore, the protective tape 22 can be stably and reliably peeled from the wafer 21 by the peeling tape 24.

  In the present embodiment, since the cooling fan 41 is used as the cooling means, the peeling device 40 can be realized with a simple configuration as compared with the case where other cooling means are used, and the peeling tape 24 and the protective tape. 24 can be easily cooled.

  A discharge mechanism may be provided on the air delivery side of the cooling fan 41, that is, the side facing the peeling start end of the protective tape 22. By providing the discharge mechanism, it becomes possible to send out ions together with air, so that electrostatic breakdown of elements on the surface of the wafer 21 due to the protective tape 22 during peeling can be suppressed.

  In the present embodiment, the cooling fan 41 is provided on the side of the portion where the peeling start end portion of the protective tape 22 is located in a state where the wafer 21 is attracted to the stage 23, so that the protective tape 22 is removed from the wafer 21. Even during peeling, it is possible to cool the bonded portion between the protective tape 22 and the peeling tape 24. Therefore, the cooling by the cooling fan 41 may be continued while the protective tape 22 is peeled off. Thereby, since the adhesive force between the peeling tape 24 and the protective tape 22 can be maintained in a high state, the protective tape 22 can be more reliably peeled from the wafer 21.

<Third Embodiment>
FIG. 9 is a cross-sectional view showing a peeling apparatus 50 according to the third embodiment of the present invention. The peeling device 40 of the present embodiment is similar to the peeling device 1 of the first embodiment described above, and the other configuration except for the cooling iron 28 is the same as that of the peeling device 1 of the first embodiment. Therefore, only different parts will be described, and the same reference numerals are given to the same components, and the common description will be omitted. 9, the vicinity of the stage 23 of the peeling apparatus 50 is shown in an enlarged manner, as in FIG.

  In the peeling device 1 of the first embodiment described above, the cooling iron 28 is provided as a cooling means. However, in the peeling device 50 of the present embodiment, an organic solvent discharge is used instead of the cooling iron 28. A mechanism 51 is provided. The organic solvent discharge mechanism 51 corresponds to an organic solvent supply unit.

  Similar to the cooling iron 28 in the first embodiment, the organic solvent discharge mechanism 51 is supported by the elevating unit 16 that constitutes the vertical drive mechanism 36 shown in FIG. That is, it is configured to be driven in the vertical direction toward the paper surface of FIG. The organic solvent discharge mechanism 51 is configured to be able to cool the bonding portion between the protective tape 22 and the peeling tape 24 while the protective tape 22 is peeled from the wafer 21. Specifically, the organic solvent discharge mechanism 51 is configured to be movable leftward in the direction in which the protective tape 22 is folded, that is, in FIG.

  The organic solvent discharge mechanism 51 is disposed above the release tape 24 in a state where the release tape 24 is attached to the protective tape 22 on the surface of the wafer 21. The organic solvent discharge mechanism 51 is provided so that an organic solvent can be supplied to the part of the peeling tape 24 attached to the peeling start end of the protective tape 22. As a result, the bonded portion between the peeling start end portion of the protective tape 22 and the peeling tape 24 is cooled. The organic solvent discharge mechanism 51 supplies the organic solvent by discharging, specifically, dropping or spraying the organic solvent toward the peeling tape 24 from the upper side to the lower side in FIG. .

  As the organic solvent, the protective tape 22 and the release tape 24 are not dissolved without dissolving the base tapes of the protective tape 22 and the release tape 24, and without eroding the circuit pattern formed on the pattern forming surface of the wafer 21 and the wafer 21. An organic solvent capable of cooling the bonded portion with 24 is used. Specifically, a volatile organic solvent such as isopropyl alcohol is used.

  In this way, by supplying the organic solvent from the organic solvent discharge mechanism 51 toward the part of the peeling tape 24 attached to the peeling start end of the protective tape 22, the protective tape 22 at the peeling start end of the protective tape 22 is supplied. And the adhesive part of the peeling tape 24 can be cooled.

  Using such a peeling apparatus 40 of the present embodiment, a method for peeling a protective tape that is an embodiment of the present invention is executed. Since the method for peeling off the protective tape in the present embodiment is the same as the method for peeling off the protective tape in the first embodiment described above, different steps will be described and common description will be omitted.

  In this embodiment, after the peeling tape 24 is pasted from the peeling start end to the peeling end of the protective tape 22 while heating the wafer 21 by the heating unit 23a of the stage 23 in the same manner as in the first embodiment. Then, the organic solvent is supplied from the organic solvent discharge mechanism 51, and the bonded portion between the protective tape 22 and the peeling tape 24 is cooled at the peeling start end of the protective tape 22. While the organic solvent is supplied from the organic solvent discharge mechanism 51, the wafer 21 is heated by the heating unit 23a. After the supply of the organic solvent from the organic solvent discharge mechanism 51 and the heating of the wafer 21 by the heating unit 23a are stopped, the protective tape 22 is peeled off together with the peeling tape 24 in the same manner as in the first embodiment.

  As described above, in this embodiment, the wafer 21 is heated by the heating unit 23 a and the peeling start end portion of the protective tape 22 is cooled by the organic solvent discharge mechanism 51, so that the adhesion between the peeling tape 24 and the protective tape 22 is achieved. The adhesive force between the protective tape 22 and the wafer 21 can be reduced while maintaining the force. Therefore, the protective tape 22 can be stably and reliably peeled from the wafer 21 by the peeling tape 24.

  Further, in this embodiment, the peeling start end portion of the protective tape 22 is eroded by the organic solvent supplied from the organic solvent discharge mechanism 51, and therefore, compared with the first and second embodiments, at the peeling start end portion. The adhesive force between the protective tape 22 and the wafer 21 can be further reduced. Therefore, the protective tape 22 can be more reliably peeled from the wafer 21.

  Further, in the present embodiment, even when the adhesive of the protective tape 22 adheres to the surface of the stage 23, the protective tape 22 attached to the surface of the stage 23 by the organic solvent supplied from the organic solvent discharge mechanism 51. The pressure-sensitive adhesive can be dissolved. Therefore, it is possible to prevent the wafer 21 from being stressed by the transfer arm adsorbing the wafer 21 while the wafer 21 and the stage 23 are adhered to each other with the adhesive of the protective tape 22 attached to the surface of the stage 23. Therefore, damage to the wafer 21 can be prevented.

  Further, in the present embodiment, the organic solvent discharge mechanism 51 is configured to be movable in the direction in which the protective tape 22 is folded back, that is, to the left in FIG. Cooling of the adhesive portion between the tape 22 and the release tape 24 can be continued. Thereby, since the adhesive force between the peeling tape 24 and the protective tape 22 can be maintained in a high state, the protective tape 22 can be more reliably peeled from the wafer 21.

  Next, a method for manufacturing a semiconductor device according to an embodiment of the present invention will be described. The manufacturing method of the semiconductor device of the present embodiment is a protective tape 22 attached to the circuit pattern forming surface of the wafer 21 using the protective tape peeling method in any of the first to third embodiments described above. A step of peeling the wafer from the wafer 21.

  Specifically, in the method for manufacturing a semiconductor device according to the present embodiment, first, after a circuit pattern constituting the semiconductor device is formed on the surface portion on one side in the thickness direction of the wafer 21, the circuit pattern of the wafer 21 is formed. The protective tape 22 is affixed to the circuit pattern formation surface which is the surface of the done side. Then, a predetermined wafer processing is performed on the surface portion of the wafer 21 opposite to the side to which the protective tape 22 is attached, that is, the surface portion on the other side in the thickness direction. The predetermined wafer processing is, for example, a process in which the wafer 21 is thinned by grinding the surface of the wafer 21 opposite to the circuit pattern forming surface. The predetermined wafer processing process includes a process of forming a diffusion layer on the ground surface by ion implantation and heat treatment after the process of thinning the wafer 21, and then forming a back electrode by sputtering or the like. But you can.

  Next, after attaching a dicing tape to the ground surface of the wafer 21, that is, the surface opposite to the circuit pattern forming surface, the protective tape peeling method according to any one of the first to third embodiments described above is used. Then, the protective tape 22 attached to the circuit pattern forming surface of the wafer 21 is peeled off from the wafer 21. Thereafter, the wafer 21 is diced into chips to obtain a semiconductor device.

  As described above, in the protective tape peeling method according to the first to third embodiments, the bonding portion between the peeling tape 24 and the protective tape 22 is cooled by the cooling means. The adhesive force between the protective tape 22 and the wafer 21 can be reduced while maintaining the adhesive force between the two. Thereby, the protective tape 22 can be reliably peeled from the wafer 21.

  In the manufacturing method of the semiconductor device according to the present embodiment, the protective tape 22 is peeled off by using the protective tape peeling method according to any one of the first to third embodiments. Without causing a defect, the thickness of the protective tape 22 can be increased to increase the cushioning property and rigidity of the protective tape 22. Therefore, cracks and warpage of the wafer 21 can be reduced, and the manufacturing yield of the semiconductor device can be improved.

  1, 40, 50 Peeling Device, 21 Wafer, 22 Protection Tape, 23 Stage, 24 Peeling Tape, 25 Peeling Tape Supply Side Guide, 26 Peeling Tape Application Roller, 27 Peeling Tape Collection Side Guide, 28 Cooling Trowel, 29 First Guide roller, 30 Second guide roller, 41 Cooling fan, 51 Organic solvent discharge mechanism.

Claims (14)

A protective tape peeling method for peeling off the protective tape attached to the surface on one side of the thickness direction of the wafer from the wafer,
A sticking step of attaching a release tape to the surface on one side of the thickness direction of the protective tape;
While heating the adhesion part of the said wafer and the said protective tape with a heating means, the adhesion part of the peeling start end part predetermined as an edge part which starts peeling from the said wafer and the said peeling tape among the said protective tape is cooled. A heating and cooling step of cooling by means;
And a peeling step of peeling the protective tape from the wafer together with the peeling tape, starting from the peeling start end cooled by the cooling means. In the attaching step, an elongated release tape as the release tape is attached to the surface on one side in the thickness direction of the protective tape,
The peeling step includes
The peeling start edge cooled by the cooling means by moving the peeling tape and the wafer relatively in parallel with the surface on one side in the thickness direction of the wafer and along the longitudinal direction of the peeling tape. Folding back the protective tape and the peeling tape to form a folded portion;
While maintaining the folded state of the protective tape and the peeling tape in the folded portion, the peeling tape and the wafer are relatively moved along the longitudinal direction of the peeling tape, and the peeled from the wafer. Recovering the protective tape together with the release tape;
The method for peeling off the protective tape according to claim 1, further comprising a step of separating the peeling tape from the wafer in the vicinity of the peeling end portion opposite to the peeling start end portion of the protective tape.   The cooling means is a cooling iron, and contacts the surface on one side in the thickness direction of the peeling tape to cool the peeling tape, thereby bonding the peeling start end of the protective tape and the peeling tape. The method according to claim 1 or 2, wherein the protective tape is cooled.   The cooling means is a cooling fan, and cools an adhesive portion between the peeling start end of the protective tape and the peeling tape by sending air toward the peeling start end of the protective tape. The method for peeling off the protective tape according to claim 1 or 2.   3. The protection according to claim 1, wherein the cooling unit is an organic solvent supply unit that supplies an organic solvent to cool an adhesive portion between the peeling start end of the protective tape and the peeling tape. Tape peeling method.   In the said peeling process, while the adhesion part of the said protective tape and the said peeling tape is cooled by the said cooling means, the said protective tape is peeled from the said wafer, It is any one of Claims 1-5 characterized by the above-mentioned. The peeling method of the protective tape as described.   The method for peeling off a protective tape according to claim 1, wherein the material of the wafer is silicon carbide. Forming a circuit pattern constituting the semiconductor device on a surface portion on one side in the thickness direction of the wafer;
A process of attaching a protective tape for protecting the circuit pattern to the surface on one side in the thickness direction of the wafer;
A step of performing a predetermined wafer processing on the surface portion on the other side in the thickness direction opposite to the side where the protective tape of the wafer is attached;
Using the method for peeling off a protective tape according to any one of claims 1 to 7, comprising a step of peeling off the protective tape attached to the surface on one side in the thickness direction of the wafer. A method for manufacturing a semiconductor device. A protective tape peeling apparatus that peels off the protective tape attached to the surface on one side in the thickness direction of the wafer from the wafer,
Affixing means for affixing a release tape to the surface on one side of the thickness direction of the protective tape;
Heating means for heating an adhesive portion between the wafer and the protective tape;
Among the protective tape, a cooling means for cooling an adhesive portion between the peeling start end portion and the peeling tape, which is predetermined as an end portion for starting peeling from the wafer,
An apparatus for peeling off a protective tape, comprising: a peeling means for peeling the protective tape from the wafer together with the peeling tape, starting from the peeling start end cooled by the cooling means. The affixing means is configured to be able to affix an elongated release tape as the release tape to the surface on one side in the thickness direction of the protective tape,
The peeling means is configured to be capable of relatively moving the peeling tape and the wafer parallel to the surface on one side in the thickness direction of the wafer and along the longitudinal direction of the peeling tape. The peeling apparatus of the protective tape of Claim 9.   11. The protective tape peeling apparatus according to claim 9 or 10, wherein the cooling means is a cooling iron that cools the peeling tape by contacting a surface on one side in the thickness direction of the peeling tape.   The said cooling means is a cooling fan which sends out air toward the said peeling start end part of the said protective tape, The peeling apparatus of the protective tape of Claim 9 or 10 characterized by the above-mentioned.   The protection according to claim 9 or 10, wherein the cooling means is an organic solvent supply means for cooling an adhesive portion between the peeling start end of the protective tape and the peeling tape by supplying an organic solvent. Tape peeling device.   The cooling unit is configured to be capable of cooling an adhesive portion between the protective tape and the peeling tape while the protective tape is being peeled from the wafer by the peeling unit. The peeling apparatus of the protective tape as described in any one of 13.

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