JPH07299734A - Method and device for transportation of wafer - Google Patents

Abstract

PURPOSE:To automate a wafer transport means and construct it in a consolidated structure, compared with a conventional arrangement in which wafer polishing and transportation are made in separated processes to result in poor working effectiveness and risk of attachment of impurities exists because the wafer is in touch with the carrier surface. CONSTITUTION:Air is jetted from a jet provided in the center of a wafer holder 5, and thereby a wafer is held by the holding surface of the holder contactlessly, and upon polishing on a surface plate 1 rotating, air jetting is switched over to the spout of a pure wafer, and the oversurface and undersurface of the wafer are washed at the same time on a pure water shower 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic carry-out apparatus and a carry-out method for polishing and cleaning a wafer in the same apparatus, and more specifically, to a wafer while holding it in a non-contact state by alternately ejecting air or pure water. Is transferred to the polishing step and the cleaning step.

[0002]

2. Description of the Related Art In recent years, chemical mechanical polishing (CMP) has come to be known as a planarization technique for facilitating the production of an oxide film or a metal film.

Further, there are various shapes of a carrier for polishing a semiconductor wafer (hereinafter referred to as a carrier),
(1) A type in which a wafer and a plate for mounting a carrier are attached using wax, and this is mounted in a carrier to be polished, and (2) A type in which a wafer is mounted and polished in a carrier in which pure water is contained in a mat, (3) A type in which a wafer is sucked and conveyed by vacuum, then the wafer is held in pure water and polished, and the wafer is conveyed again by vacuum, (4)
A type is known in which water or air is enclosed in a bag-shaped container, a weight is placed on the container, the wafer is placed on the wafer, and the wafer is polished while applying pressure on the surface plate.

[0004]

However, in the above types (1) to (4), since the wafer and the carrier surface are always in contact with each other, there is a problem of contamination such as adhesion of particles and other impurities. It is necessary to perform reconditioning such as washing the carrier itself with pure water every time polishing is completed once, which impairs work efficiency and productivity. Further, in the above type (1), since a wafer is attached with a wax manually, there is a big problem in terms of automation and labor saving.

Regarding the method of transferring the wafer, there are known means such as a vacuum chuck for sucking and transferring and a means for carrying out by hand. The function of the carrier itself is to transfer the wafer and hold the wafer during polishing. Some have functions. However, in the current carrier, these mechanisms are separate, so that the structure of the carrier is complicated, the occurrence rate of troubles such as failure is high, and the cost of the device is high.

As described above, in the conventional carrier, since the wafer polishing and the wafer transportation are performed in separate steps, the work efficiency is not improved and there is a problem in terms of productivity. It has been desired to develop an automatic type device that can be cleaned and transported.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above problems and found that a fluid such as air or water is ejected from a hole provided at the center of a plane for holding a wafer. Wafer 6 is wafer holder 5
The present invention was found to hold the wafer 6 held in a non-contact state by arranging several retainers 7 on the outer peripheral portion of the wafer holder 5 while being attracted to the holding surface in a non-contact state. Could be provided.

That is, the first aspect of the present invention is to use a carrier composed of a wafer holder 5 for holding the wafer 6 in a non-contact manner by jetting compressed air or water and a carrier arm 12 having the tip thereof for the wafer 6 Is moved from the loading station 3 onto the polishing station 11, and then several retainers 7 provided on the outer periphery of the wafer holder 5 perform polishing while applying air pressure so that uniform pressure is applied to the wafer 6, and polishing is performed. After that, the carrier arm 12 is moved to the wafer cleaning pure water shower unit 8 while jetting water instead of the above air pressure to clean the wafer polishing surface, and then the unloading station 9 for the wafer 6 whose upper and lower surfaces have been completely cleaned. Is a wafer transfer method characterized by sequentially repeating the steps of placing on the wafer;
Second, the bottom surface forms a wafer hold surface capable of horizontally holding a floated wafer in a non-contact manner, and the center of the surface is a center where air or water for floating and holding the wafer can be individually ejected. A wafer holder 5 made of a cylindrical structure having holes and a carrier arm 12 capable of freely moving the wafer holder while keeping the wafer holding surface of the wafer holder horizontal. The third is an apparatus for transferring the wafer 6 placed in the loading station 3 to the unloading station 9 via the wafer polishing section and the wafer cleaning section, and is integrally configured. The wafer polishing unit and the wafer transfer unit are main components, and the wafer polishing unit is a polishing step in which a pad 2 is provided on a surface plate 1. The wafer holder has a plurality of vertically movable retainers 7 vertically suspended on the outer periphery of a disk-shaped solid body having an air or pure water jetting hole 4 in the center of the lower surface. 5 and the wafer holder are attached to the free ends, and the other end is composed of a carrier arm 12 rotatably fixed, and the wafer holder 5 is movable left and right and back and forth while holding the wafer 6 in a non-contact manner. The present invention relates to a wafer transfer device.

[0009]

The outline of the wafer transfer apparatus used in the present invention will be described with reference to FIGS. Polishing station 11 consisting of rotating surface plate 1 with pad 2 for impregnating slurry 10 in the center of this device
There is a loading station 3 on the right side of the surface plate 1.
The wafer 6 with the oriental cladding positioned is waiting.

An unloading station 9 is provided on the left side of the surface plate 1, and the wafer 6 after polishing is washed with pure water and then stored in a pure water tank (not shown).

The wafer is moved between the above stations while ejecting a fluid such as air or water from the center hole of the wafer holder 5 at the tip of the carrier arm 12 to hold the wafer 6 in a non-contact manner. While holding, the polishing of the wafer 6 and the cleaning of the hold surface and the wafer polishing surface of the wafer holder 5 can be performed simultaneously. The structure of the wafer holder 5 is as shown in FIGS. 3 is a front view, FIG. 4 is a plan view, and FIG.
Is a sectional view showing a state where the wafer holder holds and conveys the wafer, and FIG. 6 is a sectional view showing a state where the wafer held by the carrier arm is being polished.

As an operation of the apparatus of the present invention, first, the tip of the wafer holder 5 moves to the surface of the wafer 6 on the loading station 3 and stops when the tip is about 2 to 3 mm above the surface of the wafer 6.

Then, air or water (pure water) is separately supplied from the center hole provided at the center of the wafer holder 5 to about 0.5 to 3
When jetted at a pressure of kg / cm ² , the wafer 6 is attracted to the hold surface of the wafer holder 5 and held on the wafer holder 5 via a gap through which air or water passes (see FIG. 5).

Next, the wafer holder 5 holding the wafer 6 moves to the polishing station 11 and
While descending, it approaches the surface of the pad 2. At this time, the tips of several pin-shaped retainers 7 provided on the outer periphery of the wafer holder 5 come into contact with the upper surface of the pad 2 and slide upward, and at the same time, the wafer 6 is moved to the pad. It stops at the position where it contacts 2 (see FIG. 6).

At this time, when the wafer 6 is conveyed while being held by using pure water, the pure water is switched to pneumatic pressure, and when the wafer pressure is pneumatic, the wafer 6 is kept as it is until a position where a uniform and appropriate pressure is applied to the wafer 6. The tip of the holder 5 is lowered and stopped at that position.

Next, when the surface plate 1 is rotated while supplying the slurry 10, the wafer 6 is polished. During the polishing, air is ejected from the center hole of the wafer holder 5.
It holds the wafer 6 and prevents the slurry 10 from being mixed into the wafer holding surface.

After the polishing is completed, the ejected substance from the central hole of the wafer holder 5 is switched to pure water, and the wafer 6 is slid horizontally on the pad 2 and moved out of the surface plate 1. It will be held at 5.

Next, the wafer holder 5 moves to the upper surface of the cleaning pure water shower 8 while holding the wafer 6 to clean the wafer polishing surface and simultaneously clean the wafer holding surface, and the wafer 6 after cleaning is completed. Is transferred to the unloading station 9, the wafer holder 5 is moved to the loading station 3 again, and one step is completed.

As described above, in the present invention, the air or water is jetted from the central hole to hold the wafer 6 in a non-contact state, so that the contamination due to the contact between the wafer and the carrier in the conventional method is prevented. In addition, the polishing and cleaning of the wafer 6 can be automated.

[0020]

Embodiment 1 The present invention will be described with reference to FIG. 1 (a plan view of the device of the present invention). The wafers 6 to be polished were first sequentially stacked on the loading station 3.

The tip of the wafer holder 5 provided at one end of the carrier arm 12 is attached to the loading station 3.
2-3 mm above the wafer 6 surface while moving in parallel and descending
The wafer 6 was stopped at that point, and then air was ejected from the center hole of the wafer holder at a pressure of about 2 kg / cm ² to hold the wafer 6 on the wafer holder holding surface in a non-contact state.

Next, the wafer holder 5 holding the wafer 6 moves to the polishing station 11 and descends to approach the surface of the pad 2. At this time, the eight pin-shaped retainers 7 provided on the outer circumference of the wafer holder 5 are provided. While the tip of the pad contacts the upper surface of the pad 2 and slides upward, the descent of the wafer holder 5 stops while the wafer 6 is in contact with the upper surface of the pad 2.

Next, while supplying the slurry 10, the surface plate 1
When the wafer 6 is rotated, the wafer 6 is polished. During the polishing, air jetting from the central hole of the wafer holder holds the wafer 6 in a non-contact state, and also allows the slurry 10 to enter the wafer holding surface. It works to prevent it.

After the polishing is completed, the air jet from the central hole of the wafer holder is switched to the jet of pure water, while the wafer 6 is held in the non-contact state as described above, the wafer holder 5 is slid horizontally over the pad 2. It was moved from the surface plate 1 onto the clean pure water shower 8.

Then, the polishing surface of the lower surface of the wafer 6 is cleaned by the cleaning pure water shower 8, and the upper surface of the wafer 6 is simultaneously cleaned with pure water from the central hole of the wafer holder.

After the cleaning, the wafer 6 is moved to the unloading station 9 while being held by the wafer holder 5, and is transferred into the unloading station 9.

After the transfer, the carrier arm 12 is rotated to move the wafer holder portion 5 to the loading station 3 again.
By moving up, one step of polishing / cleaning according to the present invention is completed. By repeating these steps in sequence, a required amount of wafer 6 can be polished / cleaned.

[0028]

As described above, according to the present invention, since the wafer can be held in a non-contact state and the ejection can be switched by air or pure water, the wafer surface is not damaged unlike the conventional method. Moreover, it has become possible to automate and integrate the transfer means for polishing and cleaning.

[Brief description of drawings]

FIG. 1 is a plan view of a device of the present invention.

FIG. 2 is a schematic sectional view of the device of the present invention.

FIG. 3 is a front view of a wafer holder in the device of the present invention.

FIG. 4 is a plan view of a wafer holder in the device of the present invention.

FIG. 5 is a cross-sectional view showing a state where a wafer holder holds and conveys a wafer.

FIG. 6 is a cross-sectional view showing a state in which a wafer held by a wafer holder is being polished.

[Explanation of symbols]

 1 Surface Plate 2 Pad 3 Loading Station 4 Air or Pure Water Jet 5 Wafer Holder 6 Wafer 7 Retainer 8 Cleaning Pure Water Shower 9 Unloading Station 10 Slurry 11 Polishing Station 12 Carrier Arm

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshitaka Kudo 1-8-2 Marunouchi, Chiyoda-ku, Tokyo Dowa Mining Co., Ltd.

Claims (3)

[Claims] 1. A wafer (6) is provided by using a carrier composed of a wafer holder (5) for holding a wafer (6) in a non-contact manner by ejecting compressed air or water and a carrier arm (12) having this at its tip. ) Is moved from the loading station (3) onto the polishing station (11), and then several retainers (7) provided on the outer periphery of the wafer holder (5) exert a uniform pressure on the wafer (6). Thus, polishing is performed while applying air pressure, and after polishing, the carrier arm (12) is moved to the wafer cleaning pure water shower section (8) while water is jetted instead of the above air pressure to clean the wafer polishing surface, Next, a wafer transfer method characterized in that the operation of placing the wafer (6) whose upper and lower surfaces have been cleaned in the unloading station (9) is sequentially repeated. Law. 2. A bottom surface forms a wafer hold surface capable of horizontally holding a levitated wafer in a non-contact manner, and air or water for levitating and holding the wafer can be individually ejected at the center of the surface. A wafer holder (5) made of a cylindrical structure having a central hole and a carrier arm (12) capable of freely moving the wafer holder while keeping the wafer holding surface of the wafer holder horizontal. A wafer transfer device characterized in that 3. An apparatus for transporting a wafer (6) placed in a loading station (3) to an unloading station (9) via a wafer polishing section and a wafer cleaning section, which is an integrated wafer. The polishing section and the wafer transfer section are main components, and the wafer polishing section includes a polishing station (11) in which a pad (2) is provided on a surface plate (1). A wafer holder (5) in which a plurality of vertically movable retainers (7) are vertically suspended and arranged on the outer periphery of a disk-shaped structure having a pure water ejection hole (4) in the center of the lower surface, The carrier arm (12) is attached to the free end and rotatably fixed to the other end, and the wafer holder (5) holds the wafer (6) in a non-contact manner. A wafer transfer device having a structure capable of moving to the left and right and back and forth.