JPS62126650A - Holding apparatus - Google Patents

Abstract

PURPOSE:To separate a thin plate from a holding surface, to avoid application of local pressure on the thin plate and to prevent breakdown of the thin plate, by applying static pressure to the thin plate, which is held by the holding surface so that it is freely attached and removed, and applying fluid pressure on the side of the holding surface. CONSTITUTION:When cutting is finished, a supporting plate 16 is turned in the direction of an arrow 23b under the state a wafer 1 is held by vacuum sucking. Positioning is performed so that a sealing body 17 becomes approximately coaxial with a holding board 5. Then the holding plate 16 is lowered in the direction of an arrow 22a, and a packing 19 is closely contacted with a holding surface 4. Then a water source 33 is operated, and water is fed to a sealed space 25, so as to fill the sealed space with the water and to compress the inside at a constant pressure. Then, on the entire surface of the wafer 1, which is sucked with vacuum, static pressure, i.e., constant pressure, is uniformly applied. A selector valve 13 is changed, and a compressed air source 15 is actuated, so that compressed air is jetted through air pipes 9.... Then wafer 1 is separated from the holding surface with air pressure. At this time, since the static pressure is applied to the wafer 1, the wafer 1 is slowly separated from the outer part.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention particularly relates to silicon (S) having a thickness of 500 μm or less.
t) A holding device suitable for holding a wafer.

[Technical background of the invention and its problems]

Generally, the back surface of a thin wafer used as a material for semiconductor devices is ground into a matte finish. This back surface grinding is performed by placing the wafer 71 on a table, vacuum suctioning it through a suction port opened on the wafer/holding surface of the table, and performing a predetermined grinding process. After the vacuum suction is released from the wafer whose back surface has been ground to a matte finish, the wafer is peeled off from the wafer holding surface of the table by blowing out water or compressed air from the suction port.

However, if the wafer had a thickness of approximately 500 μm or more, no damage such as cracks or chips would occur when the wafer was peeled from the wafer/holding surface due to water or compressed air pressure. However, the D-RAM material is 200
A finished thickness of less than μm is required.

In back grinding of such a thin wafer, damage such as cracking or chipping may occur due to air pressure, water pressure, etc. applied when the wafer is peeled off from the wafer holding surface after grinding.

[Purpose of the invention]

The present invention has been made in consideration of the above circumstances.

It is an object of the present invention to provide a holding device that does not cause damage when peeling a wafer from a holding surface.

[Summary of the invention]

The thin plate is separated from the holding surface by applying static pressure to the thin plate detachably held on the holding surface and applying fluid pressure to the holding surface side.

[Embodiments of the invention]

An embodiment of the present invention will be described below in detail with reference to the drawings.

1 and 2 show the holding device of this embodiment. This holding device consists of a wafer suction unit (2) that attaches and detaches the wafer/1 (1), and a static pressure applying unit (2) that applies static pressure to the wafer (1) held by the wafer suction unit (2). 3) It consists of. Therefore, the wafer suction part (2) has a holding surface (on which the wafer 1 (1) is directly held) (
4) and a disc-shaped holding plate (5) having the holding plate (5).
) is fitted into the upper part to hold and fix the wafer (
1) is vacuum-adsorbed and the wafer (1) is placed on the holding surface (
4) and a wafer removal mechanism (8) that blows out compressed air to separate the wafer from the wafer. The above holding plate (5)
A plurality of air holes (9) are concentrically and radially formed in the holding surface (4) at one end and opening at the lower end surface at the other end. Also, the support stand (7)
The inner bottom surface of the recess (10) into which the holding plate (5) is fitted corresponds to the opening position of the lower end of the air hole (9).

Grooves consisting of annular grooves and radial grooves are carved so as to communicate with these air holes (9). moreover.

The holding plate (5) has one end opening in the center of the groove (11).

The other end is a support base (an L-shaped ventilation hole that opens on the side of the force)
4 is drilled. However, the Weno attachment/detachment mechanism (
8) has an air pipe (gFL>) whose one end is connected to the ventilation hole (1) which is open on the side of the support base (force) and whose other end is connected to the switching valve α3; A vacuum source (14J) is connected to 131 for vacuum suction of the wafer (1) by degassing, and a vacuum source (14J) is also connected to the switching valve a3 in parallel with this vacuum source (14) and is connected to the air supply J for vacuum suction of the wafer (1). It is separate from the compressed air source 08 for releasing the.

on the other hand.

The static pressure application part (31) consists of a disk-shaped support plate f[D having approximately the same diameter as the holding plate (5), and a bottomed cylindrical support plate fixed coaxially to the lower surface of the support plate tte. A sealing body aη, for example, silicone rubber M + a ring-shaped Parakiji OI bonded to the lower end surface of the annular side wall end of the sealing body 07),
An arm (A) with a support plate (1e attached to one end),
A cylindrical support 01) with the other end of the arm supported so that this arm (A) is oriented horizontally, and this support (2)
0 in the vertical direction (in the directions of arrows (22a) and (22b)), as well as in the directions of arrows (23a) and (23b).
A sealed space (c) formed by a drive mechanism (goods) that rotates forward and backward in the direction ζ, a sealed body θD, and a holding m (41).
It consists of a water mechanism (c) that supplies water to the Therefore, the diameter of the sealing body surface is set to be slightly smaller than the diameter of the holding plate (5). In addition, through holes are evenly distributed in the bottom plate of the sealing body a7). moreover.

A disc-shaped recess is provided on the lower surface of the support plate (le).

The upper ends of the through holes C2 to C2 are arranged to communicate with each other.

Further, a through hole (to) with one end opening in four parts is coaxially bored in the center of the support plate Oe. On the other hand, the water supply mechanism (
C) is a water injection device connected to the upper end of the through hole (0])
A flexible water supply pipe 02, one end of which is connected to this water injection tool 6υ, and the other end of this water supply pipe G are connected to the sealed space (c) to apply a static pressure of 10 It consists of a water supply source (c) that supplies water.

Next, the operation of the holding device configured as described above will be described.

First, move the support plate (I6) with the arrow (2) using the drive mechanism (2).
3b) Rotate in the direction. Next, the wafer (1) is placed on the holding surface (4) with its back side facing up. Next, operate the vacuum source A4 and open the switching valve (131 air pipe 0 x 6 vent 0).

By degassing through the grooves (11) and the air holes (9), the waeno (1) is vacuum-adsorbed and fixed to the holding surface (4). Then, by a grinding mechanism (not shown), the back surface of the wafer (1) is ground into a matte finish. Then, when this grinding process is completed, while maintaining the vacuum suction of the wafer (1), move the support plate + [9 to the arrow (23).
&) direction, and position it so that the sealing body aη is approximately coaxial with the holding plate (5). Next, support plate 06)
is lowered in the direction of the arrow (22a) to bring the gasket (11) into close contact with the holding surface (4).Thus, the water supply source on the 13th floor is activated.

Water is supplied to the closed space (2) through the water supply pipe 0, the water filler 01) 9 through hole (30), the recess and the through hole (c), and the water is supplied to the closed space ρ. Along with filling,
Apply constant pressure. Then, static pressure, that is, a constant pressure, acts uniformly on the entire surface of the wafer (1) that is vacuum-adsorbed. Then, switch the switching valve 0.

The compressed air source 09 is operated to blow out compressed air from the air pipes (9) through the switching valve 0, the air pipe 05, the ventilation hole 0'IJ, and the groove αυ. Then, wafer (1).

It is peeled off from the holding surface (4) by air pressure. At this time.

Since static pressure is acting on the wafer (1), the wafer (1) is gradually peeled off from the outer periphery. In other words, water gradually penetrates from the outer periphery of the wafer (1), and rapid peeling does not occur. Thus, the holding surface of the wafer (1) (
4) Once the stripping work is completed, the compressed air source (as well as stopping the supply of compressed air from the country).

The drive mechanism (2) raises the support plate 0[9 in the direction of the arrow (22b) and rotates it in the direction of the arrow (23b).

The wafer (1) after the grinding process is then recovered.

As described above, the holding device of this embodiment, when peeling the vacuum-adsorbed wafer (1) from the holding surface (4),
Since static pressure is applied, the compressed air pressure acts locally on the wafer (1) and does not cause unreasonable peeling, thereby preventing damage such as cracking or chipping of the wafer (1). There is nothing to prevent. Furthermore, there is an advantage that the grinding surface can be simultaneously cleaned by supplying water to the sealed space θ.

In the above embodiment, water is supplied to the sealed space (C), but compressed air may be supplied to apply static pressure to the wafer (1). Also.

Although compressed air is used as a peeling force for peeling the wafer (1) from the holding surface (4), the peeling may be performed by supplying pressurized water. moreover.

The present invention can also be applied to an electrostatic chuck method for fixing the wafer (1).

〔Effect of the invention〕

The holding device of the present invention separates the thin plate from the holding surface by applying static pressure to the thin plate removably held on the holding surface and applying fluid pressure to the holding surface. , local pressure is not applied to the thin plate, and damage to the thin plate can be prevented. Therefore 1
The present invention is.

When applied to holding wafers of 200 μm or less for D-FLAM and C-MOS, a remarkable effect is produced.

[Brief explanation of drawings]

FIG. 1 is a front view with main parts cut away of a holding device according to an embodiment of the present invention, and FIG. 2 is a plan view of FIG. 1. (1): Wafer (thin plate). (2): Wafer adsorption section (N plate holding section). (3): Static pressure applying part, (4): Holding surface. (9): Air hole (lth fluid hole), Q7+: Sealing body. (C): Sealed space, (C): Through hole (second fluid hole). c! 1: Part 4.

Claims (1)

[Claims] The holding surface has a holding surface to which the thin plate is attracted, and a first fluid hole opening in the holding surface, and the thin plate is removably adsorbed on the holding surface, and fluid is ejected from the first fluid hole to the holding surface. A thin plate holding part that applies a peeling force to separate the thin plate being attracted from the holding surface, a recess that forms a sealed space that seals the thin plate when the thin plate is in close contact with the holding surface, and a second fluid that opens into the recess. The sealing body is provided with a hole and is movable relative to the holding surface, and when the sealed space is formed, static pressure is applied almost uniformly to the thin plate adsorbed to the holding surface. A holding device comprising: a static pressure applying section that supplies fluid via the second fluid hole.