JP2013229467A - Method for sticking protective tape, protective tape sticking device, and method for manufacturing semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method which eliminates protrusion of a protective tape and is less likely to cause chipping at an edge of a semiconductor wafer when cutting the protective tape, and devices.SOLUTION: A method for sticking a protective tape comprises the steps of: mounting a semiconductor wafer 1 on a stage 111; covering an upper surface 1a of the semiconductor wafer 1 on the stage 111 with a protective tape 2 and sticking the protective tape 2 to the upper surface 1a; and bringing the thermal cutter 131 heated to a temperature higher than or equal to a melting point of the protective tape 2 into contact with the protective tape 2 on an edge 1c on an upper surface 1a side of the semiconductor wafer 1 or on an upper surface 1a near the edge 1c and cutting the location in contact with the thermal cutter 131 of the protective tape 2 by rotating at least one of a support unit 141 supporting the thermal cutter 131 and the stage 111.

Description

  The present invention relates to a method for attaching a protective tape to a semiconductor wafer, a protective tape attaching device, and a method for manufacturing a semiconductor device.

  Generally, in the manufacture of a semiconductor device, the thickness of a semiconductor wafer is adjusted by mechanically and chemically cutting the back surface of the semiconductor wafer with a protective tape applied to the entire front surface of the semiconductor wafer. This is done by processing. However, if the protective tape protrudes outside the edge of the semiconductor wafer, the rotation of the semiconductor wafer becomes unstable due to the flapping of the protruding portion of the protective tape when the semiconductor wafer is rotated in the subsequent process. Further, when the back surface of the semiconductor wafer is processed by a wet process, the protrusion of the protective tape tends to induce the penetration of the processing liquid between the protective tape and the semiconductor wafer. For these reasons, it is desirable that the protective tape is applied so as not to protrude from the edge of the semiconductor wafer.

  Conventionally, when affixing a protective tape on a semiconductor wafer, the protective tape is affixed to cover the entire surface of the semiconductor wafer, and the cutter blade or stage is rotated while keeping the cutter blade along the edge of the semiconductor wafer. By cutting, the protrusion of the protective tape from the edge of the semiconductor wafer was prevented (see, for example, Patent Documents 1 to 3).

Japanese Patent Laid-Open No. 1-143311 JP 2005-347644 A JP 2002-57208 A

  However, in the methods described in the above patent documents, the protective tape is cut in a state where the cutter blade is in contact with the edge of the semiconductor wafer, so that the cutter blade bites into a minute step of the edge and chipping (wafer chipping) occurs. Sometimes. When chipping occurs in a silicon wafer, wafer cracking due to cleavage starting from the chipping portion is likely to occur, and this tendency is particularly prominent in thin processed wafers and TAIKO process processed wafers.

  Therefore, the present invention provides a protective tape application method, a protective tape application device, and a semiconductor device manufacturing method that eliminates the protrusion of the protective tape and prevents chipping at the edge of the semiconductor wafer when the protective tape is cut. For the purpose.

  The protective tape attaching method according to an aspect of the present invention includes a step of placing a semiconductor wafer on a stage, a step of covering the upper surface of the semiconductor wafer on the stage with a protective tape, and attaching the protective tape to the upper surface, Support for supporting the thermal cutter while contacting the thermal cutter heated to a temperature equal to or higher than the melting point of the protective tape with the protective tape on the upper surface side edge of the semiconductor wafer or on the upper surface near the edge. And a step of rotating at least one of the section and the stage to cut a portion of the protective tape in contact with the thermal cutter.

  A protective tape attaching apparatus according to another aspect of the present invention includes a stage on which a semiconductor wafer is placed, a protective tape attaching unit that covers the upper surface of the semiconductor wafer on the stage with a protective tape, and attaches the protective tape to the upper surface. A thermal cutter that is heated to a temperature equal to or higher than the melting point of the protective tape, a thermal cutter heating unit that heats the thermal cutter to a temperature equal to or higher than the melting point of the protective tape, and an edge on the upper surface side of the semiconductor wafer or While contacting the protective tape on the upper surface in the vicinity of the edge, rotating the thermal cutter support part that supports the thermal cutter, and rotating the support part or the stage, the thermal cutter of the protective tape And a thermal cutter moving part for moving the contacted part.

The manufacturing method of the semiconductor device which concerns on 1 aspect of this invention is the process of affixing a protective tape on the surface of the semiconductor wafer in which the semiconductor element was formed using the said affixing method of the protective tape, and the back surface of the said semiconductor wafer. And a step of applying a mechanical or chemical treatment.

  According to the present invention, when the protective tape is cut out, there is an effect that the protective tape is not protruded and chipping is hardly caused at the edge of the semiconductor wafer.

It is a side view which shows schematic structure of the masking tape sticking apparatus which concerns on 1st Embodiment of this invention. (A) And (b) is the side view and top view which show the installation step of the semiconductor wafer in the masking tape sticking method which concerns on 1st Embodiment. (A) And (b) is the side view and top view which show the sticking step of the protective tape in the protective tape sticking method which concerns on 1st Embodiment. (A) And (b) is the side view and top view which show the cutting step of the protective tape in the protective tape sticking method which concerns on 1st Embodiment. (A) And (b) is the side view and top view which show after unnecessary part removal of the protective tape in the protective tape sticking method which concerns on 1st Embodiment. 5 is a flowchart showing a method for manufacturing a semiconductor device according to the first and second embodiments. It is a side view which shows schematic structure of the masking tape sticking apparatus which concerns on the 2nd Embodiment of this invention. It is a principal part enlarged view of FIG. (A) And (b) is the side view and top view which show the installation step of the semiconductor wafer in the masking tape sticking method which concerns on 2nd Embodiment. (A) And (b) is the side view and top view which show the sticking step of the protective tape in the protective tape sticking method which concerns on 2nd Embodiment. (A) And (b) is the side view and top view which show the cutting step of the protective tape in the protective tape sticking method which concerns on 2nd Embodiment. (A) And (b) is the side view and top view which show after unnecessary part removal of the protective tape in the protective tape sticking method which concerns on 2nd Embodiment. It is a figure which shows the thermal cutter which concerns on the modification of 2nd Embodiment.

<< 1 >> First Embodiment << 1-1 >> Configuration of First Embodiment FIG. 1 is a side view showing a schematic configuration of a protective tape attaching apparatus according to a first embodiment of the present invention. The protective tape sticking apparatus which concerns on 1st Embodiment is an apparatus which can implement the protective tape sticking method which concerns on 1st Embodiment.

  The protective tape attaching apparatus according to the first embodiment covers the upper surface 1a of the semiconductor wafer 1 placed on the stage 111 with the protective tape 2 and attaches the protective tape 2 to the upper surface 1a (FIG. 3). The roller 121) in (a) and (b), a thermal cutter (hot cutter) 131 heated to a temperature equal to or higher than the melting point of the protective tape 2, and heat for heating the thermal cutter 131 to a temperature equal to or higher than the melting point of the protective tape 2. And a heater 132 as a cutter heating unit. The heat cutter 131 is preferably made of a material and a structure that store heat by being heated by the heater 132. The thermal cutter 131 has a spherical tip that contacts the protective tape 2. It is desirable that the front end portion of the thermal cutter 131 is a smooth-shaped component (for example, metal). FIG. 1 shows a case where the spherical tip portion contacts the protective tape on the upper surface 1 a near the edge 1 c of the semiconductor wafer 1. Moreover, the structure provided with the heater 132 inside the thermal cutter 131 may be sufficient. The uppermost layer of the semiconductor wafer 1 is usually coated with a heat-resistant material such as polyimide (polyimide has a heat-resistant temperature of about 400 degrees), which is the temperature at which the protective tape 2 melts (about 100 ° C. ) High enough.

  The protective tape attaching apparatus according to the first embodiment supports the thermal cutter 131 while contacting the protective tape 2 on the edge 1c on the upper surface 1a side of the semiconductor wafer 1 or on the upper surface 1a in the vicinity of the edge 1c. A thermal cutter support part 141 is provided. As shown in FIG. 1 and FIGS. 4A and 4B, the thermal cutter support portion 141 is an arm portion that supports the thermal cutter 131. However, the thermal cutter support portion 141 is fixed to, for example, a part 151 of the apparatus main body structure so as to be rotatable about the axis A1. However, the structure of the thermal cutter support 141 is not limited to the illustrated example.

  In addition, in the protective tape attaching apparatus according to the first embodiment, the thermal cutter moving unit 140 that rotates at least one of the thermal cutter support unit 141 or the stage 111 and moves the contact portion between the protective tape 2 and the thermal cutter 131. Have In the first embodiment, the thermal cutter moving unit 140 rotates the thermal cutter support unit 141 in the D141 direction. As shown in FIGS. 1 and 4A and 4B, the thermal cutter moving unit 140 includes, for example, a motor 144, a gear 143 that rotates by receiving the rotational driving force of the motor 144, and a thermal cutter support unit. 141 includes a gear 142 coupled to the vertical arm 141 and meshing with the gear 143, and an apparatus main body structure 151 that rotatably supports the vertical arm of the thermal cutter support 141. However, the thermal cutter moving unit 140 may have another structure such as one that rotates the stage 111.

<< 1-2 >> Operation of First Embodiment FIGS. 2A and 2B are a side view and a plan view showing a semiconductor wafer installation step in the protective tape attaching method according to the first embodiment. FIGS. 3A and 3B are a side view and a plan view showing a protective tape attaching step in the protective tape attaching method according to the first embodiment. FIGS. 4A and 4B are a side view and a plan view showing a protective tape cutting step in the protective tape attaching method according to the first embodiment. FIGS. 5A and 5B are a side view and a plan view showing a state after removing unnecessary portions of the protective tape in the protective tape attaching method according to the first embodiment.

  In the protective tape attaching method according to the first embodiment, first, as shown in FIGS. 2A and 2B, the semiconductor wafer 1 is staged by the wafer moving unit 112 that holds and moves the semiconductor wafer 1. 111 is placed at a predetermined position. At this time, the surface of the semiconductor wafer on which the elements are formed is the upper surface 1 a, and the semiconductor wafer 1 is placed with the back surface 1 b on the opposite side facing the mounting surface of the stage 111.

  Next, as shown in FIGS. 3A and 3B, the upper surface 1a of the semiconductor wafer 1 on the stage 111 is covered with the protective tape 2, and the protective tape 2 is attached to the upper surface 1a. The protective tape 2 is attached by, for example, spreading the protective tape 2 with a pair of rolls (not shown) above the upper surface 1a of the semiconductor wafer 1 and rotating the protective tape 2 with a protective tape attaching roller 121 supported rotatably. This is performed by pressing from above toward the upper surface 1 a of the semiconductor wafer 1.

  Next, as shown in FIGS. 4A and 4B, the thermal cutter 131 heated to a temperature equal to or higher than the melting point of the protective tape 2 is applied to the protective tape 2 on the upper surface 1 a near the edge 1 c of the semiconductor wafer 1. , The support portion 141 that supports the thermal cutter 131 is rotated in the direction D141 to cut the portion of the protective tape 2 in contact with the thermal cutter 131. The thermal cutter 131 can also be brought into contact with the protective tape 2 on the edge 1c on the upper surface side of the semiconductor wafer 1. By the rotation of at least one of the thermal cutter 131 or the stage 111, the protective tape 2 is cut once along the edge 1c of the semiconductor wafer 1.

  Next, the unnecessary portion of the protective tape 2, that is, the portion of the protective tape 2 other than the upper surface 1 a of the semiconductor wafer 1 is peeled off and removed. As a result, the protective tape 2 is affixed to the upper surface 1a of the semiconductor wafer 1 as shown in FIGS.

  FIG. 6 is a flowchart illustrating the method for manufacturing the semiconductor device according to the first embodiment. The manufacturing method of the semiconductor device according to the first embodiment includes the semiconductor wafer 1 after the step of attaching the protective tape 2 to the upper surface 1a of the semiconductor wafer 1 described with reference to FIGS. A step of performing mechanical or chemical treatment (for example, cutting or grinding) on the back surface 1b of the semiconductor wafer (step S6), and thereafter a step of peeling off and removing the protective tape 2 on the upper surface 1a of the semiconductor wafer 1 (step S6). S7).

<< 1-3 >> Effects of the First Embodiment As described above, if the method for applying a protective tape, the apparatus for applying a protective tape, or the method for manufacturing a semiconductor device according to the first embodiment is used, the tip is formed. Without using a sharp blade, the protective tape 2 that does not protrude from the outside of the semiconductor wafer 1 can be attached without causing the semiconductor wafer 1 to chip.

  Further, since the melting temperature of the protective tape 2 is lower than the heat resistant temperature of the polyimide on the surface of the semiconductor wafer 1, the temperature of the thermal cutter 131 can be set to a temperature that does not damage the semiconductor wafer 1. The quality of the apparatus can be maintained well.

<< 2 >> Second Embodiment << 2-1 >> Configuration of Second Embodiment FIG. 7 is a side view showing a schematic configuration of a protective tape attaching apparatus according to a second embodiment of the present invention. FIG. 8 is an enlarged view of a main part of FIG. The protective tape sticking apparatus which concerns on 2nd Embodiment is an apparatus which can implement the protective tape sticking method which concerns on 2nd Embodiment.

  The protective tape attaching apparatus according to the second embodiment covers the upper surface 3a of the semiconductor wafer 3 placed on the stage 113 with the protective tape 4 and attaches the protective tape 4 to the upper surface 3a (FIG. 10). The roller 121) in (a) and (b), a thermal cutter (hot cutter) 133 heated to a temperature equal to or higher than the melting point of the protective tape 4, and heat for heating the thermal cutter 133 to a temperature equal to or higher than the melting point of the protective tape 4. And a heater 134 as a cutter heating unit. The heat cutter 133 is preferably made of a material and a structure that store heat by being heated by the heater 134. The thermal cutter 133 is a cylindrical member (for example, metal) whose side surface is in contact with the protective tape 4. It is desirable that the cylindrical side surface of the thermal cutter 133 is a component having a smooth shape. 7 and 8 show a case where the cylindrical heat cutter 133 contacts the protective tape 4 on the edge 3c of the semiconductor wafer 3. FIG. Moreover, although the structure which equips the inside of the heat cutter 133 with the heater 134 is shown, the heater 134 may be provided in another place. The uppermost layer of the semiconductor wafer 3 is usually coated with a heat-resistant material such as polyimide (polyimide has a heat-resistant temperature of about 400 degrees), which is the melting temperature of the protective tape 4 (about 100 ° C.). High enough. As shown in FIG. 8, the thermal cutter 133 is supported in the vicinity of the tip of the thermal cutter support portion 141 so as to be rotatable in the direction of arrow D148 about the support shaft 148. In addition, the thermal cutter 133 is applied with a force that draws it in the direction D145 in the radial center direction of the semiconductor wafer 3 by an elastic member 145 such as a spring.

  The protective tape attaching apparatus according to the second embodiment has a thermal cutter support portion 141 that supports the thermal cutter 133 while being in contact with the protective tape 4 on the edge 3c on the upper surface 3a side of the semiconductor wafer 3. As shown in FIGS. 7 and 8, the thermal cutter support portion 141 is an arm portion that supports the thermal cutter 133. However, the structure of the thermal cutter support 141 is not limited to the illustrated example.

  In addition, in the protective tape attaching apparatus according to the second embodiment, at least one of the thermal cutter support unit 141 or the stage 113 is rotated, and the thermal cutter moving unit 140 that moves the portion of the protective tape 4 in contact with the thermal cutter 133 is moved. Have In the second embodiment, the thermal cutter moving unit 140 rotates the thermal cutter support unit 141 in the direction of D141 about the support shaft A1. As shown in FIGS. 7 and 11A and 11B, the structure of the thermal cutter moving unit 140 is the same as that in the first embodiment.

<< 2-2 >> Operation of the Second Embodiment FIGS. 9A and 9B are a side view and a plan view showing a semiconductor wafer installation step in the protective tape attaching method according to the second embodiment. FIGS. 10A and 10B are a side view and a plan view showing a protective tape attaching step in the protective tape attaching method according to the second embodiment. FIGS. 11A and 11B are a side view and a plan view showing a protective tape cutting step in the protective tape attaching method according to the second embodiment. FIGS. 12A and 12B are a side view and a plan view showing a state after removing unnecessary portions of the protective tape in the protective tape attaching method according to the second embodiment.

  In the protective tape attaching method according to the second embodiment, first, as shown in FIGS. 9A and 9B, the semiconductor wafer 3 is placed on the stage 113 by the wafer moving unit 112 that moves the semiconductor wafer 3. Put. At this time, the surface of the semiconductor wafer 3 on which the elements are formed is the upper surface 3 a, and the semiconductor wafer 3 is placed with the back surface 3 b on the opposite side facing the mounting surface of the stage 113. The stage 113 may have an annular groove 113 a that prevents the tip of the cylindrical heat cutter 133 from hitting the stage 113.

  Next, as shown in FIGS. 10A and 10B, the upper surface 3a of the semiconductor wafer 3 on the stage 113 is covered with the protective tape 4, and the protective tape 4 is attached to the upper surface 3a. The protective tape 4 is attached by, for example, spreading the protective tape 4 above the upper surface 3a of the semiconductor wafer 3 using a pair of rolls (not shown), and then applying the protective tape 4 from above to the semiconductor with the protective tape application roller 121. This is performed by pressing the wafer 3 toward the upper surface 3a.

  Next, as shown in FIGS. 11A and 11B, the thermal cutter 133 heated to a temperature equal to or higher than the melting point of the protective tape 4 is brought into contact with the protective tape 4 on the edge 3 c of the semiconductor wafer 3. However, the support portion 141 that supports the thermal cutter 133 is rotated in the direction of D 141, and the portion of the protective tape 4 that is in contact with the thermal cutter 133 is cut in a range corresponding to one round of the semiconductor wafer 3.

  Next, unnecessary portions of the protective tape 4, that is, portions other than the upper surface 3 a of the semiconductor wafer 3 are peeled off and removed. As a result, the protective tape 4 is affixed to the upper surface 3a of the semiconductor wafer 3 as shown in FIGS.

  FIG. 6 shows a flowchart of a method for manufacturing a semiconductor device according to the second embodiment. In the method for manufacturing a semiconductor device according to the second embodiment, after the step (steps S1 to S5) of attaching the protective tape 4 to the upper surface 3a of the semiconductor wafer 3 described with reference to FIGS. A step of performing mechanical or chemical treatment (for example, cutting or grinding) on the back surface 3b of the semiconductor wafer 3 (step S6), and thereafter a step of peeling off and removing the protective tape 4 on the upper surface 3a of the semiconductor wafer 3 (step S6). S7).

<< 2-3 >> Effect of Second Embodiment As described above, if the method for applying a protective tape, the apparatus for applying a protective tape, or the method for manufacturing a semiconductor device according to the second embodiment is used, the tip is Without using a sharp blade, the protective tape 4 that does not protrude outside the semiconductor wafer 3 can be attached without causing the semiconductor wafer 3 to chip.

  In addition, since the melting temperature of the protective tape 4 is lower than the heat resistant temperature of the polyimide on the surface of the semiconductor wafer 3, the temperature of the thermal cutter 133 can be set to a temperature that does not damage the semiconductor wafer 3. The quality of the apparatus can be maintained well.

<< 2-4 >> Effect of Second Embodiment As described above, according to the second embodiment, the tape can be cut out in the range of the edge edge of the wafer surface, and the cutter in contact with the wafer edge is sharp. It is not so difficult to chip.

<< 3 >> Modified Example FIG. 13 is a diagram illustrating a thermal cutter according to a modified example of the second embodiment. In FIG. 13, the thermal cutter 133 is rotatable about the shaft body 146 in the arrow D146 direction, and the shaft body 146 and the thermal cutter 133 are rotatable about the shaft 147 in the arrow D147 direction. is there. Accordingly, when the contact portion is moved while the thermal cutter 133 is applied to the protective tape 4 on the edge 3c of the semiconductor wafer 3, the thermal cutter 133 rotates in the direction of the arrow D146, so that the sliding with respect to the protective tape 4 does not occur. Since there are few and it contacts the protective tape 4 in the perimeter of the heat cutter 133, the load of the motor 144 becomes small and heat conduction efficiency is also good.

  1, 3 semiconductor wafer, 1a, 3a upper surface, 1b, 3b back surface, 1c, 3c edge, 2, 4 protective tape, 111, 113 stage, 121 roller, 131, 133 heat cutter, 132 heater (heat cutter heating part), 140 thermal cutter moving unit, 141 thermal cutter support unit, 142, 143 gear, 144 motor, 145 spring, 151 arm support structure.

Claims (15)

Placing the semiconductor wafer on the stage;
Covering the upper surface of the semiconductor wafer on the stage with a protective tape, and affixing the protective tape on the upper surface;
Support for supporting the thermal cutter while contacting the thermal cutter heated to a temperature equal to or higher than the melting point of the protective tape with the protective tape on the upper surface side edge of the semiconductor wafer or on the upper surface near the edge. And a step of rotating at least one of the part or the stage to cut a portion of the protective tape that contacts the thermal cutter.   The said thermal cutter contains the spherical-shaped front-end | tip part which contacts the said protective tape, The protective tape sticking method of Claim 1 characterized by the above-mentioned.   The method for applying a protective tape according to claim 2, wherein, in the step of cutting the protective tape, the spherical tip portion contacts the protective tape on the upper surface in the vicinity of the edge of the semiconductor wafer. .   The method according to claim 1, wherein the thermal cutter includes a cylindrical body that contacts the protective tape.   5. The protective tape attaching method according to claim 4, wherein in the step of cutting the protective tape, a side surface of the cylindrical body is in contact with the protective tape on an edge on the upper surface side of the semiconductor wafer.   In the step of cutting the protective tape, the cylindrical body is brought into contact with the cylindrical body by a spring connected to the cylindrical body so that the side surface of the cylindrical body is in contact with the protective tape on the upper surface side edge of the semiconductor wafer. The method for applying a protective tape according to claim 5, wherein a radially inward force is applied to the semiconductor wafer. The cylindrical body is rotatably supported by the support portion by a support shaft passing through its central axis.
In the step of cutting the protective tape, the cylindrical body is rotated around the support shaft as at least one of the support portion and the stage is rotated. The method for applying a protective tape according to item 1. A stage on which a semiconductor wafer is placed;
Covering the upper surface of the semiconductor wafer on the stage with a protective tape, and a protective tape attaching part for attaching the protective tape to the upper surface;
A thermal cutter heated to a temperature equal to or higher than the melting point of the protective tape;
A thermal cutter heating section for heating the thermal cutter to a temperature equal to or higher than the melting point of the protective tape;
A thermal cutter supporting portion for supporting the thermal cutter while contacting the protective tape on the upper surface side edge of the semiconductor wafer or on the upper surface near the edge;
A protective tape attaching apparatus, comprising: a thermal cutter moving unit that rotates at least one of the support unit or the stage to move a portion of the protective tape that contacts the thermal cutter.   The said thermal cutter contains the spherical-shaped front-end | tip part which contacts the said protective tape, The protective tape sticking apparatus of Claim 8 characterized by the above-mentioned.   10. The protective tape attaching device according to claim 9, wherein the spherical tip portion contacts the protective tape on the upper surface in the vicinity of the edge of the semiconductor wafer.   The said thermal cutter contains the cylindrical body which contacts the said protective tape, The protective tape sticking apparatus of Claim 8 characterized by the above-mentioned.   The side surface of the said cylindrical body contacts the said protective tape on the edge of the said semiconductor wafer, The protective tape sticking apparatus of Claim 11 characterized by the above-mentioned.   A radially inward force of the semiconductor wafer on the cylindrical body by a spring connected to the cylindrical body so that a side surface of the cylindrical body is in contact with the protective tape on an edge on the upper surface side of the semiconductor wafer. The protective tape affixing device according to claim 12, wherein:   The cylindrical body of the thermal cutter is rotatably supported with respect to the support portion, and in the step of cutting the protective tape, the cylindrical body of the thermal cutter is accompanied with the rotation of at least one of the support portion or the stage. 14. The protective tape attaching device according to claim 11, wherein the body rotates. The process of sticking a protective tape on the surface of the semiconductor wafer in which the semiconductor element was formed using the method of sticking the protective tape according to any one of claims 1 to 7,
And a step of subjecting the back surface of the semiconductor wafer to mechanical or chemical treatment.

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