CN213026092U - Apparatus for holding semiconductor wafers - Google Patents

Abstract

The utility model provides an equipment for keeping semiconductor wafer, keep ware including wafer carrier and the wafer that contacts with the wafer, its characterized in that, the wafer carrier with the wafer keeps ware to be connected through shape locking connection.

Description

Apparatus for holding semiconductor wafers

Technical Field

The present invention relates to an apparatus for holding a plate-shaped workpiece, in particular a semiconductor wafer.

Background

Monocrystalline semiconductor wafers are the foundation of modern electronics. During the production of components on the semiconductor wafer, thermal processing and at the same time very complex coating steps are carried out.

However, the production of monocrystalline semiconductor wafers required for this purpose is also rather complicated due to the large number of production and processing steps.

Semiconductor wafers, in particular silicon wafers, are usually first produced by pulling a single crystal rod using the so-called float zone method (FZ) or the czochralski method (CZ). The rods produced in this way are cut into ingots using a suitable saw, for example a wire saw, a ring saw or a band saw, and then processed into semiconductor wafers, usually with a wire saw or a ring saw.

After further mechanical, chemical mechanical and/or chemical steps, the epitaxial layer may optionally be applied by CVD. These semiconductor wafers are then made available for further component processing. In all these steps, harmful metal contamination must be avoided at all times.

In many of these processing steps, robots or linear drives are used which position the semiconductor wafers quickly and with high repetitive accuracy. Special wafer handlers are used as end effectors.

WO 05010956 a2 describes a corresponding wafer handler.

For stability reasons, wafer handlers which may be made of metal are also provided with a suitable wafer contact coating (wafer holder) to reduce metal contamination. The wafer contact layer is made of a material that does not contain any metal in order to exclude possible contamination of the wafer.

Conventional systems invariably require one or more screws to attach the support (wafer holder) in contact with the wafer to the wafer handler (mounting arm on a robot or linear drive).

For example, utility model DE 202004007917U 1 describes both a wafer handler and a corresponding wafer contact support, each of which is connected to the other by means of screws.

The screws used are made of metal to withstand the high acceleration forces that occur during operation. Improper fabrication of the support (e.g., over-flattening of the screws may be reduced), improper assembly of the screws or wear (e.g., burr formation) can result in metal contamination of the wafer.

Undesirable contamination of the wafer with metal can also occur if the wafer handler is too close to the wafer to be retrieved or too close to the underlying wafer.

Due to the smaller screw size, the screw can easily be over tightened during assembly of the wafer holder or the wafer holder can be deformed due to excessive tension when fixing the wafer holder to the wafer handler.

Also for screw fixation solutions, considerable costs are required if the thread turns and/or wears or the screw head deforms. The screws must then be mechanically removed from the processing system and the entire processing system cleaned.

The use of a screwdriver always requires sufficient stability of the wafer handler or requires the operator to apply a reactive force to loosen the screws. This creates a considerable risk of permanent bending or damage (deformation, breakage, cracking) of the handling system. Furthermore, in a often confined environment (a robotic arm in a machine) it is necessary to hold the screwdriver, loosened screw and loosened wafer holder under control. If the screws, wafer holders, etc. are lost, damage can occur depending on the type of equipment, but an undesirable loss of time must occur due to metal contamination of the search and housing, which must be cleaned at great expense.

SUMMERY OF THE UTILITY MODEL

The object is to provide a device as an end effector for a robot which is not only free from additional sources of contamination for the semiconductor wafers, but at the same time is sufficiently stable to withstand the occurring acceleration forces and is easy to replace when worn.

The task of the invention is solved by the device described hereinafter.

The utility model provides an equipment for keeping semiconductor wafer, keep ware including wafer carrier and the wafer that contacts with the wafer, its characterized in that, this wafer carrier and this wafer keep ware to be connected through interlocking connection.

According to a possible embodiment of the invention, the wafer handler and the wafer holder are connected by a full-axis shape-locking and end-position-fixing connection.

According to a possible embodiment of the invention, the wafer holder in contact with the wafer is made of plastic.

According to a possible embodiment of the invention, the plastic used comprises Polyetheretherketone (PEEK).

Drawings

Fig. 1 and 2 show different forms of wafer handlers and four wafer holders.

Fig. 3 shows an interlocking connection between the wafer handler and the wafer holder.

Fig. 4 shows an interlocking connection between the wafer handler and the wafer holder.

Fig. 5 shows a full-axis form-locking connection between the wafer handler and the wafer holder.

Fig. 6 shows a full-axis form-locking connection between the wafer handler and the wafer holder.

Figure 7 shows the release apparatus in addition to the wafer handler and wafer holder.

Detailed Description

Fig. 1 and 2 show different versions of a wafer handler (101, 201) and four wafer holders (102, 202), each wafer holder contacting and holding a wafer (103, 203). The diameter of the wafer is typically between 200mm and 300 mm. The number of wafer holders in contact with the wafer handler must be large enough to hold the position of the wafers, thus requiring at least three wafer holders.

Fig. 3 shows an interlocking connection between the wafer handler (301) and the wafer holder (302). The wafer holder may be inserted into an appropriate recess of the wafer handler and then secured against lateral movement in two axes. No other tools, such as screws or bolts, are required.

The wafer holder is made of plastic.

Plastic is understood to mean the following materials: PVC (polyvinyl chloride), PE (polyethylene), PP (polypropylene) or PEEK (polyetheretherketone).

Fig. 4 shows an interlocking connection between the wafer handler (401) and the wafer holder (402). The shape shown here is a dovetail groove, wherein the angle of the dovetail is greater than 90 ° and less than 180 °, preferably greater than 120 ° and less than 150 °. The wafer holder may be inserted into an appropriate recess of the wafer handler and then secured against lateral movement in two axes. No other auxiliary tools, such as screws or bolts, are required.

Fig. 5 shows an all axis form-locking connection between the wafer handler (501) and the wafer holder (502). The wafer handler has holes (snap-in openings) into which the precisely assembled wafer holder can be snapped in. In principle, the wafer holder can be exchanged without tools.

Fig. 6 shows a full-axis form-locking connection between the wafer handler (601) and the wafer holder (602). The wafer handler has drilled or milled blind holes into which the precisely assembled wafer holder can be snapped. In principle, the wafer holder can be exchanged without tools.

Fig. 7 shows a release apparatus (comprising 703, 704, 705) in addition to the wafer handler (701) and the wafer holder (702), which is adapted to assist in releasing the wafer holder (702) from the wafer handler (701). The frame (703) is pushed onto the wafer handler and wafer holder so that the first bolt-type device (704) can be guided through both the hole in the frame and the hole in the wafer handler. The wafer holder (702) may be deformed with a y-axis movement to remove a positive connection in the x-axis direction. The frame may be pulled down from the wafer handler (701) in the x-axis direction together with the wafer holder (702) using a second bolt-type fixture (705).

The present invention includes a form-locking connection between the wafer handler (101 and 201) and the wafer holder (102 and 202) that contacts the wafer to prevent lateral relative movement between the wafer holder and the wafer handler in two axes. The third axis is designed as a frictional connection by selecting a sufficiently large frictional force between the wafer carrier and the wafer holder by dimensioning the recess in the wafer carrier or dimensioning the wafer holder.

The interlocking can be designed in different ways. Examples are shown in fig. 3 and 4. The angle α in fig. 4 is greater than 90 ° and less than 180 °, preferably greater than 120 ° and less than 150 °.

Particularly preferred is a full axis, rigid and end position fixed connection between the wafer handler (501) and the wafer holder (502) contacting the wafer to prevent lateral and rotational relative motion between the wafer holder and the wafer handler.

Additional blind holes (snap-in openings or snap-in counterbores) in the wafer handler (fig. 5) and stops (counter piece) in the wafer holder prevent unintentional separation of the wafer holder from the wafer handler and prevent any relative movement in all axes during the intended operation of the apparatus.

In order to anticipate releasing the full axis interlock and the end position fixing connection, the interlock must be released in at least one axis, for example by bending a part of the device.

This may be accomplished by manually bending the wafer holder slightly along the y-axis near the space of the lock opening (fig. 5 and 6). The wafer holder may then be pulled down along the X-axis.

A suitable release device may be used to support the described bending (fig. 7).

The release apparatus for the wafer holder minimizes forces acting on the wafer handler, thus helping to prevent contamination, damage and unwanted deformation of the wafer handler.

At the same time, the release device minimizes the portion to be held under control during release. The wafer holder remains in the release apparatus and can therefore be operated with one hand.

The above description of exemplary design forms is to be understood as an example. The present disclosure enables one to understand the present invention and its related advantages on the one hand, and includes obvious modifications and variations of the described structure and process understood by the skilled person on the other hand. Accordingly, all such modifications and variations as well as equivalents are intended to be covered by the scope of the claims.

Claims (3)

1. Apparatus for holding a semiconductor wafer, comprising:

a wafer handler and a wafer holder in contact with a wafer, wherein the wafer handler and the wafer holder are connected by a full-axis shape-locking and end-position-securing connection.

2. The apparatus of claim 1, wherein the wafer holder in contact with the wafer is made of plastic.

3. The apparatus according to claim 2, wherein the plastic used comprises Polyetheretherketone (PEEK).

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