JP2008258484A - Wafer clamp device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wafer clamp device which can prevent damage of a wafer and clamp the wafer. <P>SOLUTION: A wafer positioning device 1 is provided with a cylinder 44 and arm mechanisms 41 to 43. The cylinder 44 is vertically extended. The arm mechanisms 41 to 43 have first arms 41a, 42a, 43a, second arms 41b, 42b, 43b, and springs 41c, 42c, 43c respectively. The first arms 41a, 42a, 43a are supported on the cylinder 44 to be reciprocatably moved along a radius direction of a wafer placed above the cylinder 44. The second arms 41b, 42b, 43b fit in the first arms 41a, 42a, 43a to be moved along their radius direction, and to abut against the peripheral edge of the wafer. The springs 41c, 42c, 43c resiliently connect the first arms 41a, 42a, 43a and the second arms 41b, 42b, 43b respectively. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a wafer clamp apparatus for clamping a wafer.

  In general, a wafer is a slice of a single crystal of silicon. In the semiconductor manufacturing process, the wafer is positioned by clamping the periphery of the wafer. Various wafer clamp apparatuses that clamp such a wafer have been proposed (see, for example, Patent Document 1).

Patent Document 1 discloses a wafer centering device (wafer clamping device) that can maintain high positioning accuracy even when holding wafers having different diameters.
JP-A-9-107018

  However, the wafer clamp apparatus disclosed in Patent Document 1 has the following problems.

  In the wafer clamp device shown in Patent Document 1, there is a possibility that a large gripping force is applied to the wafer and is damaged at the moment when the wafer and the clamp roller come into contact with each other.

  Accordingly, an object of the present invention is to provide a wafer clamping device that can clamp a wafer while preventing the wafer from being damaged.

  The wafer clamp device according to the present invention includes a base portion and a plurality of arm mechanisms. The base portion extends in the vertical direction. The plurality of arm mechanisms have a first arm part, a second arm part, and an elastic member. The first arm part is supported by the base part so as to be capable of reciprocating along the radial direction of the wafer placed above the base part. The second arm portion is fitted to the first arm portion so as to be movable along the radial direction, and comes into contact with the peripheral edge of the wafer. The elastic member elastically connects the first arm part and the second arm part.

  In this configuration, after the wafer is placed between the second arm portions in each arm mechanism, the second arm moves when the first arm portion of each arm mechanism moves in a direction close to each other along the radial direction of the wafer. The part also moves together with the first arm part, and the second arm part comes into contact with the peripheral edge of the wafer. At this time, due to the elastic deformation of the elastic member, the moving distance of the second arm portion becomes smaller than the moving distance of the first arm portion, and the contact force acting on the peripheral edge of the wafer from the second arm portion is relaxed. Thereby, the contact force applied to the wafer periphery is alleviated at the moment when the second arm portion and the wafer periphery contact.

  In this configuration, the arm mechanism further includes an adjustment unit that adjusts the biasing force of the elastic member. For this reason, the elastic force of an elastic member can be adjusted.

  The second arm portion has a recess formed in parallel with the radial direction, the first arm portion has a fitting portion formed to be slidable in the radial direction within the recess, and the elastic member is A spring housed in the recess may be used. The contact force applied to the peripheral edge of the wafer can be relaxed by the elastic force of the spring.

  Further, the plurality of arm mechanisms may be arranged at equiangular intervals along the circumferential direction of the wafer when viewed from the vertical direction of the base portion. The second arm portion comes into contact with the peripheral edge of the wafer at substantially equal intervals, and the wafer can be clamped. As a result, the wafer can be positioned with high accuracy.

  The second arm portion may have a clamp claw integrally formed at an end located on the peripheral side of the wafer, and the clamp claw may abut on the peripheral edge of the wafer. The periphery of the wafer can be clamped by each clamp claw.

  The second arm portion may be formed with a bifurcated end located on the peripheral side of the wafer. The contact force acting on the wafer periphery can be further dispersed at the moment when the wafer and the clamp claws come into contact with each other when a larger number of clamp claws are brought into contact with the wafer peripheral edge than in the case where the end portion is not bifurcated.

  According to the present invention, the wafer can be clamped while preventing the wafer from being damaged.

  Hereinafter, a wafer alignment apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a side view of a wafer alignment apparatus (wafer clamp apparatus) 1. However, in FIG. 1, about the arm mechanism 41, the cut surface cut | disconnected by the AA cross section of FIG. 2 is shown typically. Moreover, about the arm mechanism 42, the cut surface cut | disconnected by the BB cross section of FIG. 2 is shown typically. (For the arm mechanism 43, the CC cross section shown in FIG. 2 is substantially the same shape as the AA cross section and the BB cross section.)
As shown in FIG. 1, the wafer alignment apparatus 1 includes a holder 3, arm mechanisms 41 to 43, a cylinder (base portion) 44, and a control unit 90, and a wafer placed above the cylinder 44. 100 is a device for positioning.

  The holder 3 includes a Bernoulli disk 30 and a support base 301. The Bernoulli disk 30 includes a plurality of air discharge ports (not shown). Then, air is discharged toward the wafer, and the wafer 100 is floated by a negative pressure due to the Bernoulli effect and a positive pressure due to the cushion effect (hereinafter simply referred to as “Bernoulli effect”). As a result, the holder 3 holds the wafer 100 in a state of being closely separated.

  The cylinder 44 is a cylindrical cylinder extending in the vertical direction. The cylinder 44 supports arm mechanisms 41 to 43, which will be described in detail later, in a state in which the mechanism can move in a horizontal direction with respect to the wafer 100. The cylinder 44 is mounted on a rotatable pedestal (not shown).

The arm mechanisms 41 to 43 are arm mechanisms for clamping and positioning the periphery of the wafer 100 shown in FIG. (Here, although not shown in FIG. 1, the arm mechanism 43 is the same arm mechanism as the arm mechanisms 41 and 42.)
As shown in FIG. 2, the arm mechanisms 41 to 43 include first arms 41a, 42a, 43a, second arms 41b, 42b, 43b, springs 41c, 42c, 43c, and adjustment units 41d, 42d, 43d, respectively. Yes. In the top view, the arm mechanisms 41 to 43 are arranged radially at equal angles around the cylinder 44. Thereby, the wafer 100 can be clamped at equal intervals by the arm mechanisms 41 to 43. For this reason, the wafer 100 can be positioned with high accuracy.

The first arms 41a, 42a, 43a are supported by the cylinder 44, and once bent in a substantially Z shape in a side view, the first arms 41a, 42a, 43a extend in the horizontal direction (that is, in a direction substantially parallel to the wafer 100). The first arms 41 a, 42 a, 43 a are held in a state movable in the horizontal direction by the cylinder 44. When the periphery of the wafer 100 is clamped, the control unit 90 moves it by a predetermined length in the direction of the rotation center 37 (that is, inside). On the other hand, when releasing the clamp of the wafer 100, the wafer is moved outward by the control unit 90. The rotation center 37 indicates the rotation axis of the wafer alignment apparatus 1. (Here, the first arms 41a, 42a, 43a and the cylinder 44 can also be expressed as forming a chuck mechanism for holding the wafer 100.)
The second arms 41b, 42b, and 43b are fitted to the first arms 41a, 42a, and 43a so as to be slidable in the longitudinal direction, and extend in the radially outward horizontal direction of the wafer 100. Further, the tip ends of the second arms 41b, 42b, 43b located in the vicinity of the periphery of the wafer 100 are bifurcated. Clamp claws 41e, 42e, and 43e are formed at the tips of the wafer 100 that contact the periphery of the wafer 100, respectively. Thereby, the wafer 100 can be clamped with more clamping claws than in the case where the tip portion is not bifurcated. For this reason, the contact force acting on the wafer 100 via each clamp claw can be reduced at the moment of clamping.

  The springs 41c, 42c, and 43c connect the adjusting portions 41d, 42d, and 43d and the first arms 41a, 42a, and 43a. This prevents a large contact force from acting on the wafer 100 when the clamp claws 41e, 42e, 43e contact the wafer 100. In the wafer alignment apparatus 1, the springs 41 c, 42 c, and 43 c are disposed at positions closer to the rotation center 37 than when the springs are disposed on the outer peripheral side of the wafer 100. For this reason, when the wafer 100 is rotated while being clamped by the clamp claws 41e, 42e, and 43e, the centrifugal force acting on the springs 41c, 42c, and 43c can be reduced. Therefore, the wafer 100 can be clamped with a smaller contact force by the springs 41c, 42c, and 43c. For this reason, the contact force with which the clamp claws 41e, 42e, 43e contact the wafer 100 can be reduced.

  Here, the configuration of the first arm 41a, the second arm 41b, and the spring 41c will be described more specifically.

  As shown in FIGS. 1 and 3, the first arm 41 a is formed such that an end located on the radially outer side of the wafer 100 protrudes in the horizontal direction and is formed in a convex shape in a side view. have. On the other hand, the second arm 41b has a concave shape in a side view so that the end portion located on the radially inner side of the wafer 100 is slidably fitted to the first arm 41a in the horizontal direction. . Furthermore, the spring 41c is disposed in the space formed in the concave shape of the second arm 41b, and connects the first arm 41a and the second arm 41b. The first arms 42a and 43a, the second arms 42b and 43b, and the springs 42c and 43c are the same as described above.

  As shown in FIG. 1, the adjusting portions 41d, 42d, and 43d are provided through the second arms 41b, 42b, and 43b located on the peripheral side of the wafer 100, and the lengths of the springs 41c, 42c, and 43c. It is an adjustment mechanism that adjusts. As shown in FIG. 3, the adjusting portions 41d, 42d, and 43d include spring force adjusting screws 51a, 52a, and 53a and adjusting blocks 51b, 52b, and 53b.

  By rotating the spring force adjusting screws 51a, 52a, 53a to move the horizontal positions of the adjusting blocks 51b, 52b, 53b, the springs 41c, 42c, 43c connected to the adjusting blocks 51b, 52b, 53b are moved. Change the length. Thereby, the lengths of the springs 41c, 42c, and 43c can be adjusted according to the size of the diameter of the wafer 100, the degree of variation in diameter, and the like.

  Here, the operation of the arm mechanisms 41 to 43 when clamping the wafer 100 will be described more specifically.

  As shown in FIG. 3A, it is a diagram showing a positional relationship between the wafer 100 before clamping and the arm mechanisms 41 to 43. The wafer 100 is placed with a gap G between the clamp claws 41e, 42e, and 43e.

  When clamping the wafer 100, the control unit 90 drives the arm mechanisms 41 to 43 to a predetermined length (here, a length corresponding to the gap G + the gap H) in the horizontal direction radially inward of the cylinder 44. ) Move the first arms 41a, 42a, 43a. Then, until the gap G disappears, the second arms 41b, 42b, 43b move in the same manner in the horizontal direction on the radially inner side of the cylinder 44. However, when the clamp claws 41e, 42e, and 43e come into contact with the peripheral edge of the wafer 100, the second arms 41b, 42b, and 43b stop at the positions. Then, the springs 41c, 42c, 43c connecting the first arms 41a, 42a, 43a and the second arms 41b, 42b, 43b extend by the length of the gap H, and the state shown in FIG. . As described above, when the clamp claws 41e, 42e, 43e come into contact with the wafer 100, the springs 41c, 42c, 43c extend to prevent a large contact force from acting on the periphery of the wafer 100 via the first arm 41a. is doing.

  For this reason, according to the wafer alignment apparatus 1, it is possible to prevent damage to the wafer even when positioning a thin wafer such as a recycled wafer or when positioning a wafer having a variation in diameter.

  In addition, according to the wafer alignment apparatus 1, it is possible to obtain an effect that the wafer 100 can be rotated while being clamped by the arm mechanisms 41 to 43 in order to detect the notch position.

  As shown in FIG. 1, the wafer alignment apparatus 1 has been described with an example in which arm mechanisms 41 to 43 are provided. However, the present invention is not limited to this. For example, the wafer alignment apparatus 1 may further include an arm mechanism. Also in this case, the same effect as the wafer alignment apparatus 1 according to the above embodiment can be obtained.

It is a side view which shows the whole structure of a wafer alignment apparatus. It is a figure which shows typically the positional relationship of each arm mechanism and a wafer in the top view of a wafer alignment apparatus. It is a schematic diagram explaining operation | movement of each arm mechanism at the time of clamping a wafer.

Explanation of symbols

1-wafer alignment device (wafer clamp device), 100-wafer,
41-43-arm mechanism, 41a, 42a, 43a-first arm, 41b, 42b, 43b-second arm, 41c, 42c, 43c-spring, 41d, 42d, 43d-adjusting part, 41e, 42e, 43e- Clamp claw, 44-cylinder (base part),
51a, 52a, 53a-spring force adjusting screw, 51b, 52b, 53b-adjusting block,
Gap-G, Gap-H

Claims (6)

A base portion extending in the vertical direction;
A first arm part supported by the base part so as to be able to reciprocate along the radial direction of a wafer placed above the base part, and movably fitted along the radial direction to the first arm part. A plurality of arm mechanisms having a second arm portion that contacts the peripheral edge of the wafer, and an elastic member that elastically connects the first arm portion and the second arm portion;
A wafer clamping device. The arm mechanism further includes an adjustment unit that adjusts an urging force of the elastic member.
The wafer clamp apparatus according to claim 1. The second arm portion has a recess formed in parallel with the radial direction,
The first arm portion has a fitting portion formed to be slidable in the radial direction in the recess,
The elastic member is a spring housed in the recess.
The wafer clamp apparatus according to claim 1 or 2. A plurality of the arm mechanisms are arranged at equiangular intervals along the circumferential direction of the wafer as viewed from the vertical direction of the base portion.
The wafer clamp apparatus of any one of Claim 1 to 3. The second arm portion is integrally formed with an end portion located on the peripheral edge side of the wafer, and a clamp claw that comes into contact with the peripheral edge of the wafer.
The wafer clamp apparatus of any one of Claim 1 to 4. The second arm portion is formed with a bifurcated end.
The wafer clamp apparatus according to claim 5.

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