JPH0834211B2 - Plating equipment - Google Patents

Description

The present invention relates to a plating apparatus, and more particularly to a plating apparatus used for applications such as plating a bonding electrode of a semiconductor wafer or the like.

[Prior Art] A schematic configuration of a conventional apparatus used for such an application will be described with reference to FIG. 6. A circulation tank 71, which is supported on a pedestal 9 and contains a plating solution therein, is provided, and the circulation tank 71 has three sides. valve
Pump 7 is connected via 72. In the standby state, the plating solution is being circulated through the three-way valve 72 and the conduits 73 and 74.

At the center of the closed upper wall of the circulation tank 71, a plating chamber 4 is provided integrally with the tank 71. The chamber 4 is a cylindrical body that opens upward, and an anode electrode 44 is provided around the cylindrical bottom wall. The jet nozzle 41 provided is formed, and the discharge port 42 is formed on the side wall of the cylinder.

A peripheral wall 49 having a diameter slightly larger than the diameter of the wafer W is formed on the outer periphery of the opening edge of the plating chamber 4 to serve as a wafer holding portion, and a seal 17 and a cathode electrode 18 provided on the inner peripheral portion of the opening edge. The wafer W is placed with the outer peripheral lower surface in contact therewith.

When performing the plating process, the wafer W is pressed by the pressing plate 33 which moves downward by the pressing cylinder 31,
Closely adhere to the seal 17. Thereafter, a DC voltage is applied from the power source 8 between the anode electrode 44 and the cathode electrode 18, the three-way valve 72 is switched, and the plating solution discharged from the pump 7 is sent to the jet nozzle 41 via the pipe line 75. It is ejected into the plating chamber 4. The plating solution is the jet nozzle 41 described above.
Is positively charged to reach the surface to be plated on the lower surface of the wafer W to form a plating layer, and then returns to the circulation tank 71 from the discharge port 42.

The supply of the wafer W to the wafer holder 49 and the removal after the plating process are performed by the robot arm 54 also provided on the pedestal 9.

[Problems to be Solved by the Invention] In the above-described conventional plating apparatus, since the wafer holding part is completely integrated with the plating chamber or mechanically connected by bolts or the like, it is incompatible with wafers having different diameters. There is a problem that it is possible or not possible to respond promptly, and because the wafer after processing is taken out in the plating chamber, it is not possible to take it out from below, and the wafer stuck to the seal is not possible. There is a problem that the wafer may be damaged by peeling it upward with a nail or the like.

The present invention solves such a problem, and can immediately deal with wafers of different diameters, thereby improving the production efficiency, and increasing the degree of freedom in handling wafers without causing damage. An object is to provide a plating apparatus that enables handling.

[Means for Solving the Problems] The structure of the present invention will be described with reference to FIG.
A pallet 1 on which a wafer W is placed, and an opening 1a is formed to expose the plated surface of the lower surface of the wafer W in the placed state;
A position directly above the opening of the plating chamber 4 which stores the plating solution and inscribes means 41 for supplying the plating solution to the exposed surface to be plated, and the plating chamber 4 which elastically supports the pallet 1 and opens upward. And the carrier 2 that moves between a position away from the plating chamber 4 and the wafer W transferred by the carrier 2 to a position directly above the plating chamber 4.
Is pressed from above so as to liquid-tightly press the outer periphery of the lower surface of the wafer W against the edge of the pallet opening 1a and the lower surface of the outer periphery of the pallet 1 against the opening edge of the plating chamber 4, respectively.
And provided at a position away from the plating chamber 4,
Wafer take-out means 5 for passing the inside of the opening 1a of the pallet 1 transferred by the carrier 2 from below and pushing up the inner peripheral portion of the lower surface of the wafer W to separate the wafer W above the pallet 1. It is equipped with.

[Operation] In the plating apparatus having the above structure, the wafer W placed on the carrier 2 via the pallet 1 is moved to a position directly above the plating chamber 4 by the carrier 2, and is pressed downward by the pressing means 3. The wafer W and the pallet 1 are liquid-tightly pressed against each other. When a plating solution is introduced into the plating chamber 4 in this state, a plating layer is formed on the surface to be plated of the wafer W exposed in the chamber 4 through the pallet opening 1a.

After the plating process is completed, the pressing by the pressing means 3 is released, and the carrier 2 moves to a position away from the plating chamber 4. At this time, even if the pressed state is released, the outer periphery of the lower surface of the wafer W is often in close contact with the opening 1a of the pallet 1. Here, the wafer unloading means 5 is the carrier 2
By passing through the opening 1a of the pallet 1 from below from above, and pushing up the inner peripheral portion of the lower surface of the wafer W,
The wafer W is released above the pallet 1. Since this take-out pushes up the inner peripheral portion of the lower surface of the wafer W, the wafer W is not damaged as compared with the case where the outer peripheral edge of the wafer is peeled off and taken out.

Further, by exchanging the pallets 1 mounted on the carrier 2, it is possible to immediately deal with wafers having different diameters. Furthermore, by providing a plurality of carriers 2 on which different pallets 1 are mounted, a desired carrier can be provided. 2 plating chamber 4
If you can move it up, the responsiveness will be improved.

[Embodiment] In FIG. 1, a circulation tank 71 opening upward is provided in the left half portion of a base 91 provided on a gantry 9, and the plating solution in the tank 71 is a three-way valve 72 and a pipe line. It is circulated by the pump 7 via 73 and 74. Circulation tank above
The opening of 71 is closed by the plating chamber 4. The center of the chamber 4 projects downward in a cylindrical shape, the jet nozzle 41 is opened at the projecting end face, and the discharge port 42 is formed at the upper part of the cylindrical side wall. There is. An anode electrode 44 is provided on the inner wall of the plating chamber 4 at the opening edge of the jet nozzle 41, which is connected to a power source 8 outside the chamber 4. Further, a pipe line 75 from the three-way valve 72 reaches the jet nozzle 41.

A seal ring 43 is arranged on the upper surface of the opening edge of the plating chamber 4, and a pallet 1 on which a wafer W is placed, which will be described in detail later, is pressed against the seal ring 43. Mounted on top (Fig. 2).

The carrier 2 can be moved to the right half portion of the base 91 by a mechanism described later, and FIG. 1 also shows a state in which one carrier 2 is actually at the right movement end. At the right moving end, a wafer elevating mechanism 5 which is a wafer taking-out means whose details will be described later is provided.

Hereinafter, detailed structures of the pallet 1 and the carrier 2 will be described.

The pallet 1 has a rectangular substrate 11 (Fig. 3),
A substantially circular opening 12 with a part of a straight line is formed in the center of the substrate 11, and the upper surface of the edge of the opening 12 is countersunk with a constant width (Fig. 4).
A plate-shaped seal 13 is arranged flush with each other. The shape of the opening 12 is along the wafer W and has a diameter slightly smaller than that, and the lower surface of the wafer W, which is the surface to be plated, is exposed in the opening 12 when the wafer W is placed.

Clamping mechanisms 14 are provided on the substrate 11 at opposing positions with the opening 12 interposed therebetween. Each clamping mechanism 14 has a shaft 143 that is fixed to a grip plate 141 at its tip and is biased to project by a coil spring 142. The shaft 143 is supported by a bracket 145 provided with a linear motion bearing 146, and the shaft rear end large diameter portion 144 contacts the bracket 145 and is positioned at the projecting end.

A power receiving contact 15 composed of a bolt 151 and a washer 152 is provided at an opposing position 90 degrees apart from each of the clamp mechanisms 14 with the opening 12 interposed therebetween.
A cathode electrode 16 extending upward in the radial direction and reaching the opening 12 is provided. This cathode electrode 16 is extremely thin (about 50 μm)
It is in the form of a film and adheres to the seal surface.

The carrier 2 has a rectangular frame 21 (Fig. 2) having a diameter slightly larger than that of the pallet 1, and a pair of opposed sides of the frame 21 support shafts 22 which are vertically movable by linear bearings. ing. The shaft 22 is biased to the upper end position by a coil spring 23, and a plate-like pawl 24 is fixed to the lower end of the shaft 22, and the pawls 24 of the shafts 22 project into the frame 21 to form side edges of the pallet 1. It receives the stepped part on the bottom surface.

The lower surface of the opposite side of the frame 21 is a bracket 25.
2 is connected to a rodless cylinder 26 extending in the left-right direction on the base 91, and the other side is slidably connected to a guide shaft 27 arranged on the base 91 in parallel with the cylinder 26. I am doing it. Then, the carrier 2 is moved by the cylinder 26 between the position immediately above the plating chamber 4 at the left end and the position immediately above the wafer elevating mechanism 5 at the right end.

The elevating mechanism 5 has a circular receiving plate 53 fixed to the tip of a piston rod 52 which extends from a cylinder 51 (Fig. 1) and moves up and down. When the carrier 2 reaches the right end position, the pallet opening 1a The wafer W, which coincides with the center and is placed on the pallet 1 while being raised, is pushed up and taken out, and the wafer W is placed on the pallet 1 while being lowered. It should be noted that the supply of the wafer W to the pedestal 53 that has moved up and the taking-out of the wafer W from this point onward are performed by the robot arm 54 that is swung.
To do. The presence of the wafer W on the receiving table 53 is confirmed by the photoelectric switch 55.

Immediately above the plating chamber 4, a pressing mechanism 3 fixed to a pedestal 9 is provided, and the pressing mechanism 3 includes a cylinder 31.
A thick circular press plate 33 (FIG. 2) is provided at the tip of the piston rod 32 that extends further and moves up and down. At both ends of the support arm 34 provided along the upper surface of the press plate 33, A rod-shaped feed contact 36 is provided so as to be vertically movable by being urged downward by a coil spring 35. These power supply contacts 36 are located opposite to the power supply contacts 15 of the pallet 1 which have reached the left end position, and are respectively connected to the power source 8.

The working ends of the cylinders 26, 31, 51 are detected by the position sensors 26a, 26b, 31a, 31b, 51a, 51b, respectively.

 The operation of the plating apparatus having the above structure will be described below.

The pallet 1 is placed on the pawl 24 on the carrier 2 at the right end position, and the clamp mechanism 14 on the pallet is retracted by pulling the shaft large diameter portion 144 by a pulling mechanism (not shown). In this state, the pedestal 53 of the elevating mechanism 5 rises in the opening 1a of the pallet 1 to receive the wafer W from the robot arm 54, and while lowering the outer peripheral edge of the lower surface of the wafer W onto the seal 13 of the pallet 1. To place. The pulling mechanism releases the pull of the shaft large diameter portion 144, the shaft 143 is advanced by the spring force of the coil spring 142, and the grip plate 141 fixes the wafer W from both sides. Since the wafer W has a part of the outer circumference which is a straight line, the wafer W is rotated so as to fit into the grip plate 141 during the fixing and is accurately positioned. The carrier 2 is moved to the left by the rodless cylinder 26 and reaches a position directly above the plating chamber 4.

Here, the rod 31 of the pressing mechanism 3 descends, and the feeding contact 36 comes into contact with the receiving contact 15 on the pallet 1 and conducts while descending. The lowered pressing plate 33 hits the upper surface of the wafer W, and holds the pallet substrate 11 through the wafer W and the seal 13 so that
Push down against the bearing capacity of 24. As a result, the lower surface of the substrate 11 is brought into close contact with the seal ring 43 of the plating chamber 4,
The opening 1a coincides with the opening of the chamber 4, and at the same time, the lower surface of the wafer W, which is the surface to be plated, is brought into close contact with the seal 13 to form a seal.
The cathode electrode 16 on 13 is electrically connected.

When the three-way valve 72 operates and the plating solution discharged from the pump 7 is supplied to the jet nozzle 41 via the pipe line 75, the plating solution receives a positive charge from the anode electrode 44 and is jetted into the plating chamber 4 and the wafer W A plating layer is formed on the lower surface of the.

When the pressing plate 33 is raised after the plating process is completed, the feeding contact 36 and the receiving contact 15 are separated and cut off, and the pallet 1 is pulled upward by the claw plate 24 as the pressing plate 33 rises. Carrier 2 is moved back to the right end again,
After the gap between the grip plates 141 is expanded by the pulling mechanism, the pedestal 53 of the elevating mechanism 5 is lifted to push up the inner peripheral portion of the lower surface of the wafer W and take out the wafer W from the pallet 1.

According to this embodiment, when the shape of the wafer W is changed, it can be dealt with immediately by replacing the pallet 1, and it is not necessary to provide dedicated equipment for each wafer W. Can be significantly reduced, and also the setup time for coping with the change of the wafer W can be significantly reduced.

Since the wafer W is taken out at a position apart from the plating chamber 4 by pushing up the inner peripheral portion of the wafer W from below by the elevating mechanism 5, it is possible to effectively prevent the wafer from being damaged.

Further, since the cathode electrode 16 that requires periodical inspection is provided on the pallet 1, it is not necessary to stop the entire apparatus during electrode maintenance.

In the above embodiment, one carrier 2 is provided, but a plurality of carriers 2 are provided so as to be sequentially moved onto the plating chamber 4, and pallets 1 for wafers W having different diameters may be provided in advance. The setup time when changing the wafer W can be shortened. In this case, the pallet 1 does not necessarily have to have a structure that can be easily separated from the carrier 2.

The structure of the plating chamber may be as shown in FIG. In the figure, a plating solution introducing pipe 46 is inserted into the plating chamber 4 from below, and a porous nozzle 45 is vapor-deposited at the tip of the introducing pipe 46. The liquid tightness of the chamber 4 is
It is secured by a bellows 47 that connects the periphery of the through-hole through which the introduction pipe 46 is inserted and the tip of the introduction pipe 46. The above-mentioned introduction space 46 is linked to a motor 48 and operates links 484, 485 and a gear 48.
1,482,483 can reciprocate about 90 degrees.

In this state, the plating solution supplied into the introduction pipe 46 passes through the through hole of the anode electrode 44 provided in the introduction pipe 46, reaches the upper porous nozzle 45, and is ejected in a shower shape.

[Advantages of the Invention] As described above, the plating apparatus of the present invention can deal with wafers having different diameters with the same equipment, and can quickly deal with the same, which can reduce the equipment cost and significantly improve the work efficiency. It is an improvement.

Further, since it is not necessary to take out the wafer on the plating chamber, it is possible to take out the wafer by pushing it up from below, and thereby effectively prevent the wafer from being damaged.

[Brief description of drawings]

1 to 4 show an embodiment of the present invention, FIG. 1 is an overall side view of an essential part of the device, FIG. 2 is a cutaway perspective view of the essential part of the device, and FIG. 3 is a plan view of a pallet. , Fig. 4 of Fig. 3
IV-IV line sectional drawing, FIG. 5 is a broken perspective view showing another example of the plating chamber, and FIG. 1 ... Pallet 1a ... Opening 2 ... Carrier 3 ... Pressing mechanism (pressing means) 4 ... Plating chamber 41 ... Jet nozzle (plating solution supply means) 5 ... Elevating mechanism (wafer taking-out means) 7 ... Pump 8 ... Power supply W ... Wafer

Claims (1)

[Claims] 1. A pallet on which a wafer is placed, an opening for exposing a surface to be plated on the lower surface of the wafer is formed, and a plating solution is stored, and the plating solution is supplied to the exposed surface to be plated. A plating chamber having means inside, a carrier that elastically supports the pallet and moves between a position directly above the opening of the plating chamber that opens upward, and a position separated from the plating chamber; Pressing means for pressing the wafer transferred to a position directly above the plating chamber from above so as to liquid-tightly contact the outer periphery of the lower surface of the wafer with the pallet opening edge and the outer peripheral lower surface of the pallet with the plating chamber opening edge, respectively; It is provided at a position away from the chamber and passes from below through the opening of the pallet transferred by the carrier, and is transferred to the bottom of the wafer. Push up the inner peripheral surface,
And a wafer take-out means for separating the wafer above the pallet.