JP5540062B2 - Polishing pad - Google Patents

Description

  The present invention relates to a polishing pad used for polishing a member to be polished such as a semiconductor or an electronic component. More specifically, the polishing pad of a member to be polished such as a semiconductor wafer is improved in flatness and has a long life. The present invention relates to a polishing pad that can be made simple.

  In general, when polishing a wafer, the polishing pad is held on the lower surface plate side, the wafer as the object to be polished is held on the upper surface plate side, and the wafer and the polishing pad are pressurized while supplying the polishing slurry. This is done by sliding it.

  Incidentally, as shown in FIG. 5, the conventional polishing pad has a pad main body 10, a base layer 11 laminated on the pad main body 10 with a pressure-sensitive adhesive layer 15, and a double-sided adhesive tape 14. ing. When manufacturing such a polishing pad 20, as shown in FIG. 6, the base layer 11 and the pad main body 10 are bonded to each other with a double-sided adhesive tape 15, and polishing is performed by punching this laminate into a polishing pad shape. The pad 20 is obtained.

  However, when the wafer is polished using the polishing pad 20, the slurry penetrates into the inside from the peripheral side surface of the foundation layer 11, and as a result, the physical properties such as the compressibility of the foundation layer change due to the penetration of the slurry. Thus, there is a drawback that the polishing performance is lowered, and a defect such as peeling between the adhesive layer and the underlying layer occurs due to the penetration of the slurry.

  Furthermore, in a polishing pad provided with a transparent window member through which laser light or visible light passes in order to measure the polishing rate of the wafer surface while polishing the wafer, the slurry soaks into the measurement window. For this reason, there is a disadvantage that detection failure occurs.

  The present invention has been made in order to eliminate the above-mentioned drawbacks. The object of the present invention is to prevent the slurry from penetrating into the underlayer, so that the polishing characteristics are not adversely affected, and the polishing rate is not affected. It is an object of the present invention to provide a polishing pad that can improve the detection accuracy of.

  The polishing pad according to claim 1 is a polishing pad having an underlayer and a pad body laminated on the surface of the underlayer, and a waterproof layer capable of preventing the penetration of slurry is provided on the peripheral side surface of the underlayer. This achieves the above object.

  In one embodiment, a first double-sided adhesive tape is affixed to the side of the base plate of the base layer, a second double-sided adhesive tape is affixed to the side of the base layer of the pad main body, and the periphery of the pad main body is The waterproof layer is formed by extending outward from the periphery of the base layer and bonding the first double-sided adhesive tape and the second double-sided adhesive tape at the periphery of the pad body.

  In one embodiment, the waterproof layer is formed by applying a resin, an elastomer, or rubber to at least a peripheral side surface of the base layer.

  In one embodiment, the waterproof layer is formed by increasing the density of the peripheral part of the base layer compared to the central part.

  The operation of the present invention is as follows.

  In order to impart excellent polishing characteristics to the polishing pad, the underlayer is generally formed of a porous material having elasticity. Therefore, the slurry can easily penetrate into the inside from the peripheral end surface of the underlayer. In the present invention, a waterproof layer capable of preventing the penetration of the slurry is provided on the peripheral side surface of the underlayer, thereby preventing the slurry from penetrating into the underlayer and changing the polishing characteristics (uniformity). Can be eased, thereby improving yield, improving productivity and stabilizing quality.

  According to the present invention, since the slurry can be prevented from penetrating into the underlayer, the polishing characteristics are not adversely affected, and the detection accuracy of the polishing rate can be increased. Therefore, changes in polishing characteristics (uniformity) can be moderated, thereby improving yield, improving productivity, and stabilizing quality.

Fig.1 (a) is principal part sectional drawing of one Embodiment of the polishing pad of this invention. FIG. 1B is a plan view of the polishing pad. It is use explanatory drawing of the polishing pad shown in FIG. It is the schematic explaining the manufacturing method of the polishing pad shown in FIG. It is explanatory drawing of an Example. It is sectional drawing of the conventional polishing pad. It is the schematic which shows the manufacturing method of the conventional polishing pad.

The present invention will be described in detail below.
(Embodiment)
As shown in FIG. 1, a polishing pad 1 includes a porous base layer 11 having elasticity, and a pad body 10 laminated on the surface of the base layer 11 with a pressure sensitive adhesive layer (double-sided adhesive tape) 15 interposed therebetween. Have

  The pad body 10 is usually formed of a resin layer having fine bubbles. The underlayer 11 is formed of a synthetic resin foam layer or a nonwoven fabric having elasticity compared to the pad main body 10. A release sheet (not shown) is laminated on the back surface of the base layer 11 via a pressure-sensitive adhesive layer (double-sided adhesive tape) 14, and the release sheet is peeled off to place the pressure-sensitive adhesive layer 14 on a surface plate. The polishing pad 1 is used by being attached to the surface.

  The pad body 10 can be manufactured from one or more of urethane resin, acrylic resin, polycarbonate, polyamide, polyester and the like by a known casting method, extrusion molding method, or the like. Usually, it is manufactured by a casting method or an extrusion molding method using a thermoplastic resin, but may be manufactured by heat curing using a thermosetting resin.

  The underlayer 11 can be produced from one or more of urethane resin, acrylic resin, polycarbonate, polyamide, polyester and the like by a known casting method, extrusion molding method, or the like. Usually, a thermoplastic resin is used and manufactured by a casting method or an extrusion molding method. Moreover, it can also form with the material which has air permeability like a nonwoven fabric.

  A waterproof layer 12 that can prevent the permeation of the slurry is provided on the peripheral side surface of the base layer 11.

  The waterproof layer 12 is formed as follows.

  (1) A first double-sided adhesive tape 14 is affixed to the side of the surface of the base layer 11, and a second double-sided adhesive tape 15 is affixed to the side of the base layer 11 of the pad body 10. The peripheral part of the pad main body 10 extends outward from the periphery of the base layer 11 to form an extended part 16, and the first double-sided adhesive tape 14 and the second double-sided adhesive tape 15 are formed in the peripheral part of the pad main body 10. It is glued. In this embodiment, the 1st double-sided adhesive tape 14 is extended from the lower surface of the base layer 11, and the edge part of the 1st double-sided adhesive tape 14 is stuck on the lower surface of the extension part of the pad main body 10. 2 is attached to the double-sided adhesive tape 15. The first double-sided adhesive tape 14 is along the peripheral side surface of the base layer 11, and a slight gap may or may not be formed between the peripheral side surface of the base layer 11. Moreover, you may make it affix the 2nd double-sided adhesive tape 15 to the 1st double-sided adhesive tape 14 side.

  As shown in FIG. 2, the polishing pad 1 manufactured in this way is affixed on the lower surface plate 2, and the slurry supplied between the polishing pad 1 and the wafer is surrounded by the base layer 11. Although it tries to penetrate from the side, it is blocked by the waterproof layer 12 and the slurry does not penetrate into the underlayer 11.

  An example of the manufacturing method of the polishing pad 1 is as follows.

  As shown in FIG. 3, the second double-sided adhesive tape 15 is attached to the lower surface of the pad main body 10, and the base layer 11 is attached to the lower surface of the pad main body 10 via the second double-sided adhesive tape 15. Here, the size of the base layer 11 is made slightly smaller than the size of the pad body 10. Next, as shown in the figure, the first double-sided adhesive tape 14 is attached to the lower surface (side surface of the surface plate 2) of the base layer 11, and the peripheral part of the first double-sided adhesive tape 14 is set to the peripheral part of the base layer 11. Attached to the second double-sided adhesive tape 15 along.

  Moreover, the waterproof layer 12 can also be formed as follows.

  (2) The waterproof layer 12 may be formed by applying a resin, elastomer or rubber to at least the peripheral side surface of the base layer 11. In this case, for example, it is preferable to form a waterproof layer 12 by applying a silicone sealing agent and a silicone coating agent to the peripheral surface of the base layer 11 and drying. Alternatively, the waterproof layer 12 may be formed by applying a silicon-based or fluorine-based water repellent to the peripheral side surface of the base layer 11.

  (3) When the laminated body of the pad main body 10, the second double-sided adhesive tape 15, the base layer 11, the first double-sided adhesive tape 14 and the release paper is punched with a punching blade, the blade is heated, By heating the peripheral portion, the density of the peripheral portion of the base layer 11 is made higher than that of the central portion (that is, the porosity of the peripheral portion of the base layer 11 is reduced). By configuring the base layer 11 in this way, it is possible to maintain appropriate elasticity while enhancing the waterproofness of only the peripheral portion of the base layer 11.

  The polishing pad 1 may have a transparent window member formed on a part thereof. In this case, an opening is formed in the base layer 11 at a position corresponding to the window member.

Hereinafter, the present invention will be described in detail with reference to examples.
Example 1
As shown in FIG. 4, the pad main body 10 is laminated on the upper surface of the base layer 11 via the second double-sided adhesive tape 15, and the first double-sided adhesive tape 14 is attached to the lower surface of the base layer 11. The extended end portion of the first double-sided adhesive tape 14 was adhered to the second double-sided adhesive tape 15 to constitute the polishing pad 1.

  The polishing pad 1 was immersed in the slurry under the following conditions, and the permeability of the slurry was visually observed.

Polishing pad size: 102mm diameter (pad body) x 93mm diameter (underlayer)
Immersion solution: Colored slurry immersion time: 60 ° C immersion time: 18 hours After immersion, the polishing pad was taken out of the slurry, and the base layer was peeled off from the pad body to examine the state of penetration of the slurry. It did not penetrate at all.

(Example 2)
The polishing pad 1 produced in Example 1 was attached to the lower surface plate 2 of the polishing machine, the polishing machine was operated without attaching anything to the carrier, and the permeability of the slurry was visually observed.

The test conditions are as follows.
Polishing machine: Strasbaugh's Down force: 4.3 (psi)
Platen speed: 30 (rpm)
Carrier speed: 27 (rpm)
Carrier diameter: 230 (mm)
Liquid used: Slurry Slurry flow rate: 300 (ml / min) Circulation system operation time: 480 (min)
As a result of the test, no permeation of the slurry from the end of the underlayer was observed. Furthermore, no peeling was observed between the underlayer and the pad body.

  When the conventional polishing pad was tested under the same conditions as in Example 2, the penetration of the slurry from the end of the underlayer (about 20 mm) was observed.

DESCRIPTION OF SYMBOLS 1 Polishing pad 2 Polishing machine 10 Pad main body 11 Underlayer 12 Waterproof layer 14 1st double-sided adhesive tape 15 2nd double-sided adhesive tape

Claims (1)

A polishing pad having an underlayer and a pad body laminated on the surface of the underlayer, and a waterproof layer capable of preventing the penetration of slurry without a pad body on the peripheral side surface of the underlayer. Polishing pad.

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