JP2007294717A - Device and method for separating semiconductor wafer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To separate a semiconductor wafer from a supporting substrate by a heating method in a short processing time without totally causing a flaw on the surface of the semiconductor wafer. <P>SOLUTION: The device for separating a semiconductor wafer comprises a pair of holding mechanisms 14, 15 sandwiching the supporting substrate 3 and the semiconductor wafer 1 adhered to the supporting substrate 3 by the use of a thermoplastic adhesive agent 2, including a heater, and having a mechanism for holding the respective substrate 3 and the wafer 1; a horizontally driving mechanism 24 for sliding any one of the holding mechanisms 14, 15 by given distance in parallel with the bonding plane of the adhesive agent 2 with the agent 2 heat melted by the heater, and for sliding the slid one in a direction opposite to the slid direction to separate the substrate 3 and the wafer 1; and a removing mechanism for removing the adhered side exposed on the surface of the adhesion side of the substrate 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a semiconductor wafer separation apparatus and a separation method for separating a semiconductor wafer attached to a support substrate with a thermoplastic adhesive from the support substrate in a semiconductor device and a manufacturing method thereof.

  In some semiconductor device manufacturing methods, heat generated by the device formed on the surface of the semiconductor wafer is efficiently released to the back side to enhance the heat dissipation effect, and for high-frequency devices, etc., ground potential stability is improved. Therefore, in order to reduce the threshold current in a laser diode or the like, it is necessary to reduce the thickness of the semiconductor wafer to, for example, about 100 μm after forming the device pattern on the surface. In the process of thinning the semiconductor wafer on which the device pattern is formed in this way, and in the process of forming the electrode on the back side after the thinning, a thermoplastic adhesive such as wax is used to prevent the semiconductor wafer from cracking. For example, a semiconductor wafer is attached to a support substrate for reinforcement of about 1 mm.

  In order to separate the semiconductor wafer bonded to the support substrate as described above from the support substrate, conventionally, a dipping method in which an adhesive is dissolved using a solvent (see, for example, Patent Document 1) or heating and melting. A heating system for separation (for example, Patent Document 2) is employed.

  However, in the dipping method for dissolving the adhesive, the processing time is low due to the long time required for dissolution, and in the heating method in which it is heated and melted and separated, the stress of the semiconductor wafer generated during the separation is large, so that the semiconductor There is a problem that the wafer breaks.

  In order to solve these problems, a method for shortening the melting time by disposing a hole in the support substrate is disclosed in the immersion method (see, for example, Patent Document 3 and Patent Document 4). After the adhesive is melted in the heating method, A method of eliminating cracks in a semiconductor wafer by sliding and separating in a direction parallel to the plane of the semiconductor wafer is disclosed (for example, see Patent Document 5).

JP 2002-185109 A (page 2-4) JP-A-6-268051 (page 4-5, FIG. 1) Japanese Patent Application Laid-Open No. 5-82491 (page 2-3, FIG. 1) JP 2001-185519 A (Page 5-6, FIG. 1) Japanese Patent Laying-Open No. 2003-197724 (page 5-6, FIG. 1)

  In the backside electrode formation process after thin processing of a semiconductor wafer, if there is a non-selective film formation process such as chemical plating, a solid film is formed not only on the semiconductor wafer but also on the side surface of the adhesive and on the support substrate surface. Is done. Furthermore, in the case of using a highly permeable plating solution, in order to form a solid film by plating up to a portion that is not exposed, such as a slight adhesive crack or melted gap generated during electrode formation, These solid films cannot be easily removed physically or chemically.

  In the method disclosed in Patent Document 5, since the semiconductor wafer is slid and separated in a state where these solid films are present, the solid film remaining on the support substrate side is formed on the surface of the semiconductor wafer attached side. There is a problem of scratching.

  Although the method disclosed in Patent Document 3 or Patent Document 4 is not scratched by the solid film, the processing time is significantly longer than that of the heating method even if a hole is provided in the support substrate. There is a problem.

  An object of the present invention is to separate a semiconductor wafer from a supporting substrate without causing any scratch on the surface of the semiconductor wafer while maintaining the feature of short-time treatment by the heating method of Patent Document 5 described above.

A semiconductor wafer separation apparatus according to the present invention is:
A supporting substrate and a semiconductor wafer bonded to the supporting substrate using a thermoplastic adhesive are sandwiched, and heating means for heating and melting the thermoplastic adhesive is provided, and each of the supporting substrate and the semiconductor wafer is held. A pair of holding mechanisms having a mechanism;
In a state where the thermoplastic adhesive is heated and melted by the heating means, one of the pair of holding mechanisms is slid in a certain amount in parallel with the adhesive surface of the thermoplastic adhesive, and the one holding mechanism is slid. A horizontal driving mechanism device that separates the support substrate and the semiconductor wafer by sliding in a direction opposite to the direction in which they are moved;
A removal mechanism for removing deposits exposed on the surface of the support substrate on the bonding side;
It is equipped with.

A semiconductor wafer separation method according to the present invention includes:
Sandwiching a support substrate and a semiconductor wafer bonded to the support substrate using a thermoplastic adhesive;
A step of heating and melting the thermoplastic adhesive,
A step of sliding either one of the support substrate or the semiconductor wafer to expose a part of the adhesion surface on the support substrate surface in a certain amount parallel to the adhesion surface by the thermoplastic adhesive;
Removing the adhered matter on the exposed adhesive surface;
A step of separating the supporting substrate and the semiconductor wafer by sliding in the opposite direction to the sliding direction of the one slid;
It is equipped with.

  According to the semiconductor wafer separation apparatus and the separation method of the present invention, when there is a deposit on the periphery of the semiconductor wafer, the semiconductor wafer is separated from the support substrate in a short time without causing any scratch on the surface of the semiconductor wafer. be able to.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a first embodiment of a semiconductor wafer separating method according to the present invention, and a perspective view is shown at the top of each of FIGS. 1 (a) to 1 (e), and a cross-sectional view is shown at the bottom.

  FIG. 1A shows an initial state, in which the support substrate 3 and the semiconductor wafer 1 are fixed with a thermoplastic adhesive 2 such as wax, and a solid film (adhesive material) grown by plating or the like on the periphery of the semiconductor wafer. There are four.

  First, as shown in FIG. 1B, in a state where the thermoplastic adhesive 2 is heated and melted, the semiconductor wafer 1 is once slid relative to the support substrate 3 to expose the solid film 4 in one side direction of the peripheral portion. Let It is desirable that the sliding amount at this time is such that the solid film 4 entering under the semiconductor wafer 1 does not cover the device region formed on the semiconductor wafer 1.

  Next, as shown in FIG. 1C, the exposed solid film 4 is scraped off with a spatula plate 5 such as a cutting tool or a knife. Although not shown, it is preferable to wipe off the scraps or remove them with a suction machine. FIG. 1D shows a state after the solid film 4 is removed.

  Finally, as shown in FIG. 1E, the support substrate 3 and the semiconductor wafer 1 are separated by sliding the semiconductor wafer 1 in the direction opposite to the sliding direction (side from which the solid film is removed). .

  2 and 3 are a cross-sectional view (a) and a perspective view (b) showing the semiconductor wafer separation apparatus used in the semiconductor wafer separation method shown in FIG. As shown in FIG. 2, holding mechanisms 14 and 15 are provided to hold the support substrate 3 on which the semiconductor wafer 1 is fixed to the support substrate 3 with the thermoplastic adhesive 2 from above and below.

  The holding mechanisms 14 and 15 include heating means such as a heater (not shown) and have a suction groove on the holding surface and exhaust holes 7 and 11 communicating with the side surfaces as a mechanism for holding the support substrate 3 and the semiconductor wafer 1. Connecting means 8 and 12 for connecting tubes 9 and 12 of a vacuum device (not shown) to the exhaust holes 7 and 11 on the side surfaces of the blocks 6 and 10 and the heat blocks 6 and 10 are provided. 15 and the vacuum device can be controlled to be opened and closed independently from each other. In order to improve the detachability between the semiconductor wafer 1 and the support substrate 3, for example, it is desirable to have a function of puffing with dry air.

  Using the upper and lower holding mechanisms 14 and 15, the semiconductor wafer 1 and the support substrate 3 are sandwiched, the exhaust holes 7 and 11 are evacuated and the semiconductor wafer 1 and the support substrate 3 are vacuum-adsorbed, and the temperature of the heater included Is raised to heat and melt the adhesive 2. After that, as shown in FIG. 3, at least one of the upper and lower holding mechanisms 14 and 15 is slid in a small amount in the horizontal direction by the horizontal driving mechanism 24. Although the semiconductor wafer 1 or the support substrate 3 can be slid manually by an operator, it is equipped with a vertical driving mechanism in the vertical direction in addition to the horizontal driving mechanism 24 in the horizontal direction, and is automated. It is desirable.

  After sliding in a small amount in the horizontal direction, as shown in FIG. 1 (c), the exposed solid film is removed with a spatula plate 5, and after removing the exposed solid film, the direction opposite to the sliding direction (solid film) The support substrate 3 and the semiconductor wafer 1 are separated by horizontally sliding the upper and lower holding mechanisms 14, which are slid in the direction of the side from which the substrate is removed, by the horizontal driving mechanism 24.

  According to the first embodiment, a small amount of the adhesive 2 is heated and melted to slide the support substrate 3 and the semiconductor wafer 1 to expose the solid film 4, and the solid film that scratches the surface of the semiconductor wafer 1 is removed. After that, the semiconductor wafer 1 is slid and separated on the side from which the solid film 4 is removed, so that the semiconductor wafer 1 can be separated in a short time without scratching the surface.

Embodiment 2. FIG.
FIG. 4 is a perspective view showing the second embodiment. In the second embodiment, instead of the spatula plate 5 used in the semiconductor wafer separation method described in the first embodiment, as shown in FIG. 4, a motor 17 having a grindstone 16 attached to the tip is used to form a solid film. 4 is removed.

  Moreover, it is not limited to the grindstone 17 and may be a rotating body using, for example, a wire brush or a metal trimmer.

  In this way, when removing the solid film with a rotating body, scraping scraps are likely to scatter, so as a countermeasure against this, shield the scattered foreign matter by attaching a hood to the rotating body or installing an air curtain using an air nozzle. The foreign matter is sucked and removed using a suction nozzle.

  According to the second embodiment, since there is no problem such as blade skipping and the solid film can be surely removed in a short time, the semiconductor wafer 1 and the semiconductor wafer 1 can be removed in a short time without scratching the surface of the semiconductor wafer 1 at all. In addition to being able to separate from the support substrate 3, the product throughput is improved and quality maintenance management is facilitated.

Embodiment 3 FIG.
FIG. 5 is a perspective view showing the third embodiment, and FIG. 6 is a cross-sectional view showing the internal structure of the adhesion removing mechanism 18 in FIG.

  In the third embodiment, instead of the spatula plate 5 used in the semiconductor wafer separation method described in the first embodiment, an adhesive roller 19 is used as shown in FIG. The solid film 4 is peeled off and removed.

  Moreover, it is not limited to the adhesive roller 19, and any member having an adhesive material on the front surface such as an adhesive tape may be used.

  When the adhesive roller 19 is used, as shown in FIG. 6, the transfer roller 20 that rotates in the reverse direction in synchronization with the rotation of the adhesive roller 19 and the supply that supplies the strong adhesive sheet 21 by the rotation of the transfer roller 20. A roller 22 is provided. The adhesive roller 19 has a function of self-cleaning the roller surface with a constantly strong strong adhesive sheet 21 supplied from the supply roller 22.

  According to the third embodiment, it is possible to remove the solid film without scattering scraping scraps, preventing foreign matter adhesion to the semiconductor wafer 1 and contamination in the apparatus, and scratching the surface of the semiconductor wafer 1 at all. The semiconductor wafer 1 and the support substrate 3 can be separated in a short time without being attached.

  INDUSTRIAL APPLICABILITY The semiconductor wafer separating apparatus and the separating method according to the present invention can be used in a semiconductor device and a manufacturing method thereof for separating a semiconductor wafer attached to a supporting substrate with a thermoplastic adhesive without damaging it.

It is a figure which shows Embodiment 1 of the semiconductor wafer separation method which concerns on this invention. It is sectional drawing (a) and perspective view (b) which show the semiconductor wafer separation apparatus used for the semiconductor wafer separation method shown in FIG. It is sectional drawing (a) and perspective view (b) which show the semiconductor wafer separation apparatus used for the semiconductor wafer separation method shown in FIG. FIG. 6 is a perspective view showing a second embodiment. FIG. 6 is a perspective view showing a third embodiment. It is sectional drawing which shows the internal structure of the adhesion removal mechanism 18 in FIG.

Explanation of symbols

1 semiconductor wafer, 2 adhesive, 3 support substrate, 4 solid film, 5 spatula plate,
6 Upper heat block, 7 Exhaust hole, 8 Connector, 9 Tube,
10 Lower heat block, 11 Exhaust hole, 12 Connector, 13 Tube,
14 upper holding mechanism, 15 lower holding mechanism, 16 grindstone, 17 motor,
18 adhesive removal mechanism, 19 adhesive roller, 20 transfer roller, 21 strong adhesive sheet,
22 Supply roller, 23 Cover, 24 Horizontal drive mechanism.

Claims (5)

A supporting substrate and a semiconductor wafer bonded to the supporting substrate using a thermoplastic adhesive are sandwiched, and heating means for heating and melting the thermoplastic adhesive is provided, and each of the supporting substrate and the semiconductor wafer is held. A pair of holding mechanisms having a mechanism;
In a state where the thermoplastic adhesive is heated and melted by the heating means, one of the pair of holding mechanisms is slid in a certain amount in parallel with the adhesive surface of the thermoplastic adhesive, and the one holding mechanism is slid. A horizontal driving mechanism device that separates the support substrate and the semiconductor wafer by sliding in a direction opposite to the direction in which they are moved;
A removal mechanism for removing deposits exposed on the surface of the support substrate on the bonding side;
A semiconductor wafer separating apparatus comprising: 2. The semiconductor wafer separating apparatus according to claim 1, wherein the removing means is a spatula-like plate. 2. The semiconductor wafer separating apparatus according to claim 1, wherein the removing means is a rotating grindstone, a brush or a metal trimmer. 2. The semiconductor wafer separating apparatus according to claim 1, wherein the removing means is a member having an adhesive material on a surface thereof. Sandwiching a support substrate and a semiconductor wafer bonded to the support substrate using a thermoplastic adhesive;
A step of heating and melting the thermoplastic adhesive,
A step of sliding either one of the support substrate or the semiconductor wafer to expose a part of the adhesion surface on the support substrate surface in a certain amount parallel to the adhesion surface by the thermoplastic adhesive;
Removing the adhered matter on the exposed adhesive surface;
A step of separating the supporting substrate and the semiconductor wafer by sliding in the opposite direction to the sliding direction of the one slid;
A method for separating a semiconductor wafer, comprising:

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