JPH1190820A - Wafer polishing template and wafer peeling method utilizing it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably and surely peel a polished wafer in a short time by providing a passage constituted of a groove, a hole, or a recessed path penetrating to the inner peripheral side from the outer peripheral side of a ring-like blank material. SOLUTION: A spout nozzle head 10 is fitted to the outer peripheral section of a template 20, then water 5 with the prescribed pressure is fed to water spout ports 8 from a water feed path 9 via a passage provided in the nozzle head 10. Since the space pinched by an O-ring 7 and the template 20 is liquid- tightly sealed, the water 5 spouted from the water spout ports 8 flows into the whole outer peripheral section of the template 20 and is spouted to the inner peripheral side of the template 20 through the passages formed in the blank material 2 of the template 20. The water 5 infiltrates between a packing pad 3 and a wafer 4, and the wafer 4 can be floated and peeled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer polishing template and a method of removing a wafer using the template, and more particularly to a method of removing a wafer adsorbed on a backing pad via a water-applied surface after polishing, in a short time. The present invention relates to the provision of a template that can be stably and reliably peeled off and a method of peeling a wafer.

[0002]

2. Description of the Related Art A wafer polishing template in which a substantially ring-shaped blank material is disposed on a backing pad and a wafer holding space (pocket) 102A is provided on the inner peripheral side of the blank material is conventionally known. As shown in FIG. 6 (B), the single-wafer type ring-shaped blank 102
The template 107 is adhered with an adhesive, water is retained on the backing pad 103 of the template 107, and the surface tension of the water and the ring-shaped blank 1
There is a method of holding and polishing the wafer 4 by using the wafer 02.

Such a template is formed of a ring-shaped blank made of a glass epoxy material or a polycarbonate material having a rectangular cross section larger than the wafer 4 on the backing pad 103.

In the actual polishing step, a wafer to be polished and water are pushed into the pockets of the template, whereby the wafer is polished while being held by the surface tension of the backing pad and water.

[0005] The wafer adsorbed and held on the water-applied surface (water-retaining surface) of the backing pad has been conventionally peeled off by the method shown in FIG. 6 after polishing is completed. That is, the conventional wafer stripping method uses a template that is about one size larger than the wafer.
When holding a wafer of mφ, the inner diameter of the blank material formed of the above-mentioned glass epoxy material or the like is set to about 303 mmφ, and the gap between the blank material and the wafer is about 1.5 mm on one side on average (actually, the wafer is offset). 0mm ~
The width is about 3 mm and there is an unevenness).
The water 5 is ejected from the nozzle 104 into the gap to allow water to enter between the wafer and the backing pad, thereby floating the wafer on the water surface formed on the pad surface, thereby removing the wafer.

[0006]

However, the method of peeling the wafer in the polishing step employs a structure in which water is jetted into a gap between the blank material and the wafer.
If the gap is not sufficient, there is a possibility that the wafer may be pressed down by the ejection of water. For this reason, in the above-mentioned conventional apparatus, a certain amount of gap is required at the water jetting position, so that the wafer is unevenly held in the pocket space in the blank material. Therefore, the offset position changes in the circumferential direction of the pocket with a width of about 0 mm to 3 mm due to the offset of the wafer. Therefore, in order to allow water to smoothly enter between the wafer and the backing pad, the nozzle position must be set to the gap. Must be set to the maximum position.

For this reason, in the conventional apparatus, it is necessary to take measures such as rotating the template, setting the nozzle ejection position at the maximum gap position and ejecting water, and it takes too much time to peel off the wafer.

Further, in the above-mentioned peeling method, even if water for peeling the wafer is spouted aiming at a gap between the glass epoxy material or the like and the end face of the wafer, a change in water amount, water pressure, etc.
In some cases, it did not normally enter the gap, but acted in the direction of holding down the wafer, making it difficult to peel it off.

On the other hand, in recent years, the polishing rate of a polishing machine has been improved,
The time for peeling the wafer from the template did not end within the processing time, and this became the rate-determining stage, which sometimes reduced the capability of the apparatus. An object of the present invention is to provide a template capable of stably and reliably peeling a wafer after polishing as described above and a wafer peeling method using the template.

[0010]

According to the first aspect of the present invention,
In a wafer polishing template in which a substantially ring-shaped blank material is disposed on a backing pad and a wafer holding space is provided on an inner peripheral side of the blank material, grooves and holes penetrating from the outer peripheral side to the inner peripheral side of the ring-shaped blank material are provided. Alternatively, a polishing template characterized by providing a flow path composed of a recessed path or the like is proposed. This channel may be one, but is preferably 5 ° to 5 ° radially from the center of the template (wafer).
Provided at 90 ° intervals.

Although the fluid generally uses water, a liquid other than water, a gas such as clean air, or a gas-liquid mixed fluid may be used. Therefore, the backing pad is not necessarily limited to the water retention pad, and includes a case where the backing pad is peeled off with clean air using a dry pad.

A second aspect of the present invention is a method of removing a wafer using such a template, wherein the wafer held in a template having a substantially ring-shaped blank material on a backing pad is polished, and then the wafer is removed. A flow path penetrating from the outer peripheral side to the inner peripheral side of the blank material is provided, and a fluid is ejected from the outer peripheral side of the flow path toward the inner peripheral side so that the fluid enters between the backing pad and the wafer ( It is characterized in that the wafer is lifted off).

According to a third aspect of the present invention, there is provided a method for suitably implementing the wafer peeling method according to the second aspect, wherein the backing pad is a water-applied pad having water retained thereon, and In a wafer peeling method in which the wafer is held through, a plurality of the flow paths are provided radially from the center direction at predetermined intervals in the blank material circumferential direction, and water is ejected from the plurality of flow paths, The method is characterized in that a portion between the pad-water-applied surface and the wafer is peeled off.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, and are merely illustrative examples. Only. 1 to 3 are configuration diagrams of a template according to an embodiment of the present invention. FIG.
FIG. 2 is a sectional view taken along line AA of FIG. 1. FIG. 3 is an enlarged perspective view of the template showing the drilling position of the flow path as viewed from the direction indicated by the arrow B in FIG.

In these figures, a ring-shaped blank 2 made of a glass epoxy material or the like and having a rectangular cross section is bonded to a backing pad 3, and a flow path 1 is provided in the blank 2. The flow path 1 is formed of a groove, a hole, or a recessed path penetrating from the outer peripheral side to the inner peripheral side of the ring-shaped blank material 2. A plurality is formed. The size of the flow path (groove) 1, the number of grooves to be provided, the shape of the groove, and the like are appropriately determined according to the size, thickness, and thickness and strength of the blank of the target wafer. Is formed by a substantially circular or elliptical through hole having an opening diameter of the flow channel 1 of about 0.3 mm to 0.8 mm, and a through hole having a rectangular cross section.

Specifically, as shown in FIG. 3, when the blank 1 is 770 μm thick, the flow path 1 has a wide elliptical through-hole having a circumferential length (width) of 1.0 mm and a thickness of 700 μm. 12 channels (grooves) were provided. The penetration direction may be horizontal or slightly downward toward the inner peripheral side,
In any case, the position, the direction, and the diameter of the water 5 that can enter between the backing pad 3 and the wafer are set, and the inner peripheral opening position of the through hole is set in advance on the backing pad 3 side (where the wafer is attached). (A side near the side where the light is emitted), the penetration effect is further increased.

Accordingly, the shape of the flow path 1 is not particularly limited, and a U-shaped groove penetrating from the outer peripheral side to the inner peripheral side,
It may be a hole or a recessed path. The position where the flow path 1 is provided is formed over the entire circumference at an interval of 5 ° to 90 °. In the case of the present embodiment, about 12 points are set at intervals of 30 °.

FIGS. 4 and 5 are conceptual diagrams of the wafer peeling method according to the above-described embodiment. FIG. 4 shows a state in which the wafer peeling water 5 is ejected from the flow path 1, and FIG. 5 shows an apparatus for supplying the wafer peeling water 5. It is a conceptual diagram showing an example. In FIG.
Is a processing head, which fixes the template 20 by bonding the back surface of the backing pad 3. (Template 2
Reference numeral 0 denotes a backing pad 3 and a blank 2. )

In FIG. 5, reference numeral 7 denotes an O-ring, 10 denotes an injection nozzle head having a water outlet 8 and a water supply port 9, and the nozzle head main body 10a comprises a processing head 6 and a template 20.
A ring column is formed around the outer circumference through a predetermined clearance, and a ring piece 10b for contacting the lower surface of the blank material 2 for liquid-tightness is provided on the inner circumferential side of the bottom surface, and an O-ring 7 is interposed on the processing head 6 side. In this way, the space on the inner peripheral side of the nozzle head 10 between the water jet port 8 and the flow path 1 has a liquid-tight structure.

It is preferable that the water outlets 8 are provided at 12 positions in the circumferential direction at intervals of 30 ° at a position facing the flow path 1 and face the opening of the flow path 1. Since the space between the templates 20 and the like is sealed in a liquid-tight manner, the water 5 flows into the entire outer peripheral portion of the template 20 and passes through the respective flow paths 1 formed in the blank material 2, and enters the inside of the template 20. It may be configured to eject. Therefore, it is sufficient to provide at least one water jet port 8 for jetting water 5 when the wafer is peeled off, but it is preferable to provide a plurality of water jet ports.

A plurality of water supply ports 9 are provided on the lower surface side of the nozzle head body 10a at predetermined intervals in the circumferential direction, and water 5 of a predetermined pressure is supplied to each water jet port 8 through a passage 10c provided in the nozzle head. Is configured to be supplied.

Next, a method of peeling a wafer according to the embodiment will be described. After polishing the wafer 4 held on the backing pad 3 holding water through the processing head 6,
As shown in FIG. 5, after the injection nozzle head 10 is attached to the outer peripheral portion of the template 20, water 5 of a predetermined pressure is supplied from the water supply port 9 to each water ejection port 8 through a passage provided in the nozzle head 10. As a result, the water 5 spouted from the water spout 8 flows into the entire outer peripheral portion of the template 20 because the space between the O-ring 7 and the template 20 and the like is sealed in a liquid-tight manner. The fluid passes through the respective flow paths 1 formed in the blank material 2 and is jetted toward the inner peripheral side of the template 20, whereby the fluid can enter between the backing pad 3 and the wafer to lift and separate the wafer 4.

The water 5 flows from right beside the wafer as shown in FIG. 4, and the effect of peeling the wafer is enhanced. Therefore, by providing the position where the flow path 1 is formed in advance near the backing pad 3 side (the side to which the wafer is attached), this effect is further enhanced.
By ejecting the water 5 from the side of the wafer, the wafer can be easily peeled off.

In this manner, the structure is such that the entire outer peripheral portion of the template 20 can be filled with the water 5, and the water 5 is ejected from all the channels 1 provided over the entire circumference of the blank material 2 in the circumferential direction. It can be more stably peeled off and can be easily automated. Note that the wafer peeling method of the present invention is not limited to this. For example, as another method, it is also possible to manually apply a nozzle to one or a plurality of portions of the flow path 1 and eject water 5. It is possible to peel it off.

Therefore, the peeling method according to the present embodiment eliminates the problem of pressing down the wafer 4 due to the ejection of the water 5 which was a problem in the conventional method, and makes it easy to peel the wafer 4 (easy to float).

For this reason, in the past, a certain gap 30a was required between the blank material and the wafer in order to peel the wafer, but in the present invention, the gap 30a can be eliminated, and the wafer 4 Since the wafer 2 can be stored exactly in the wafer 2, sag around the processed wafer can be prevented at the same time.

EXAMPLE A 335 mm diameter (outer diameter) template was prepared for a 300 mm diameter wafer. The blank 2 of the template 20 is formed of a glass epoxy material, has a thickness of 770 μm, a frame width of 16 mm, and an inner diameter of 303 m.
m. The glass epoxy material (frame) has a width of 1.0
12 mm square, 700 μm thick rectangular channels (through holes)
Places. Using the template 20, a 300 mmφ wafer having a finished thickness of 775 μm was polished. At this time, about 1.5 m on average between the blank 2 and the wafer
There is a gap 30a of m (actually, there is a bias in the width of about 0mm-3mm)

After completion of the polishing, water 5 was jetted from the entire outer periphery of the flow path (groove) formed in the blank 2 of the template 20 at a pressure of 1 kgf / cm ^{2 by} the apparatus shown in FIG. Peeling was possible in about 40 seconds per wafer.

(Comparative Example) As a conventional template, a template 107 in which the rectangular flow path (through hole) was not provided in the blank material 102 was prepared, and the wafer 4 was polished using the template 107. In order to peel off the wafer 4 and the blank 10 as shown in FIG.
Water was sprayed obliquely from the nozzle into the gap 102A (pocket) 102A. At this time, since a gap 102A between the blank 102 and the wafer is selected at a position of about 3 mm and water is ejected, it is relatively easy to peel off the wafer 4, but the nozzles in the gap 102A are aligned. Therefore, it was necessary to rotate the template to a position where it could be easily peeled off.

In such a case, the peeling time varies greatly from 50 seconds to 240 seconds per wafer, and a long peeling time is required as a whole. In this case, the size of the template 20 made of the blank material 2 was set to be the same as that of the comparative example for a comparative experiment with the conventional example. However, in the case of the present invention, it is possible to further reduce the size according to the wafer diameter. . For example, using the template 20 in which the width of the blank 2 is set to 17 mm and the inner diameter is set to 301 mm in the above embodiment, the gap 30a between the blank 2 and the wafer is used.
Even when the average was narrowed to about 0.5 mm, the wafer 4 could be smoothly and stably peeled off, and in this case, the peripheral sag of the wafer could be suppressed during the polishing.

[0031]

As described above, according to the present invention, the time for peeling the wafer is reduced and stabilized, and the productivity is improved.
In addition, there are various effects such as the gap between the template and the wafer can be reduced as much as possible, whereby the sag around the wafer during polishing can be suppressed.

[Brief description of the drawings]

FIGS. 1 to 3 are configuration diagrams of a template according to an embodiment of the present invention, and FIG. 1 is a central longitudinal sectional view.

FIG. 2 is a sectional view taken along line AA of FIG. It is the figure which looked at the template of this invention from the top.

FIG. 3B shows a template of FIG.
It is a perspective view enlarged on arrow.

FIG. 4 and FIG. 5 are conceptual diagrams of a wafer peeling method according to the embodiment, and FIG. 4 is a conceptual diagram showing a state of jetting wafer peeling water from a flow path.

FIG. 5 is a conceptual diagram illustrating an example of a wafer peeling water supply device of FIG. 4;

FIG. 6 is a conceptual diagram of a wafer peeling method using a template according to a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flow path 20 Template 2 Blank material 3 Backing pad 30 Wafer storage space 30a Gap between wafer and blank material 4 Wafer 5 Water (flow of water) 6 Processing head 7 O-ring 8 Water outlet 9 Water supply port 10 Injection nozzle head

Claims (3)

[Claims] 1. A wafer polishing template in which a substantially ring-shaped blank material is disposed on a backing pad and a wafer holding space is provided on an inner circumferential side of the blank material. A polishing template provided with a flow path composed of a penetrating groove, hole, concave path, or the like. 2. A method of polishing a wafer held in a template having a substantially ring-shaped blank material on a backing pad and then removing the wafer from the outer peripheral side of the blank material through a flow path penetrating from the outer peripheral side to the inner peripheral side. A wafer peeling method, wherein a fluid is ejected from an outer peripheral side to an inner peripheral side of the flow path, and the fluid is caused to enter between the backing pad and the wafer to be peeled off. 3. The wafer peeling method according to claim 2, wherein the backing pad is a water-applied water-pad, and the wafer is held via a water-applied surface of the pad. A wafer peeling method, wherein a plurality of wafers are radially provided from a center direction at predetermined intervals in a circumferential direction, and water is ejected from the plurality of flow paths to peel off a portion between the pad-water-applied surface and the wafer.