JPH0728693Y2 - Wafer holder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a holder such as a platen or a disk for holding a wafer at a predetermined position in a target chamber in an ion implantation apparatus, for example.

<Prior Art> As a conventional disk used for batch implantation in an ion implantation apparatus, as shown in FIG. 4, for example, a tapered hole 101a is formed for positioning a wafer to be held. The wafer W inserted in the hole 101a is clamped by the clamper 102.
Of the structure in which it is fixed on the support base 101 by the downward pressing force, or, as shown in FIG. 5, the support base 111 having a flat upper surface 111a is mounted on the upper surface 111a of the support base 111 and held. A positioning plate 113 having a tapered hole 113a for positioning a desired wafer, a clamper 112, and the like are provided, and the wafer W inserted into the through hole 113a of the positioning plate 113 is pressed downward by the clamper 112. By pedestal 1
11 is a structure that is fixed on top.

<Problems to be Solved by the Invention> By the way, according to the above-described two disk structures, the tapered surfaces of the holes 101a and 113a for positioning the wafer are fixed to the support bases 101 and 111, respectively. Therefore, when a part of the wafer W is caught by the tapered surface for some reason, the wafer W is damaged by the pressing force of the clamper. This wafer breakage requires downtime for cleaning the inside of the target chamber, resulting in a problem that productivity is significantly reduced.

<Means for Solving the Problems> The present invention has been made to solve the above problems, and the configuration thereof will be described with reference to FIGS. 1 to 3 corresponding to the embodiments. A clamp plate 2 for pressing the peripheral edge of the wafer W is provided above the support table (disk) 1 on which the wafer W is placed on the upper surface 1a so as to be able to move toward and away from the upper surface 1a of the support table. And support stand 1
Is provided with a plurality of positioning pins 3 at positions facing the clamp plate 2, and each of the positioning pins 3 is movable in the vertical direction with respect to the support base 1 and is made of an elastic body (spring). Part of the upper surface 1a of the support 1 is projected by the pressing force of 4, and the upper end of the protruding portion is the upper surface of the support 1.
It is configured so that it can be displaced up and down at a position having a height corresponding to the thickness of the wafer W with respect to 1a, and the wafer W is provided on the side surfaces of these positioning pins 3 respectively on the upper surface 1a of the support base.
A surface (tapered surface) 3a for positioning is formed on the clamp plate 2 and means for pressing the clamp plate 2 toward the upper surface 1a of the support base with a force larger than the pressing force of the elastic bodies 4 ... It is characterized by having 9).

<Operation> The clamp plate 2 is provided with the positioning pin 3 before pressing the wafer S.
3 hits the upper end of the clamp plate 2, and the positioning pins 3 move downward with the movement of the clamp plate 2. Therefore, when the clamp plate 2 starts pressing the wafer W, the positioning surfaces 3a 3a of the pins 3 move downward. The wafer W is being moved, so that the wafer W is pressed by the clamp plate 2 in a state where the entire surface of the wafer W is in contact with the upper surface 1a of the support 1.

Therefore, when positioning the wafer W on the support 1,
Even if a part of the wafer is caught on the positioning surface 3a of the positioning pin 3, the wafer W is not pressed against the positioning surface 3a of the pin 3 by the clamp plate 2, and the wafer W is damaged thereby. Will disappear.

<Embodiment> An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view of an essential part of an embodiment of the present invention, and FIG.
It is a II-II arrow line view. The cross section in FIG. 1 is a cross section taken along the line II in FIG.

The disk 1 is fixed to a rotary shaft 21 such as a rotary / translational driving device (not shown) by bolts 22 ... 22, and is given a rotational and translational motion.

The disk 1 has a center on a circumference L concentric with the center of rotation, and has a diameter larger than the diameter of the wafer W to be held plus the diameter of the small diameter portion of the positioning pin 3 described later. Four through holes 1c ... 1c are formed along a slightly larger circumference l. Each of the through-holes 1c ... 1c is composed of a cylindrical small-diameter portion and a large-diameter portion, and a female screw is formed in a lower part of the large-diameter portion.

Positioning pins 3 ... 3 are slidably inserted into the through holes 1b. These positioning pins 3 ... 3
Is composed of a cylindrical small-diameter portion and a large-diameter portion, and a tapered surface 3a is formed at the tip of the small-diameter portion. A spring 4 is press-inserted below the positioning pins 3 ... 3 by set screws 5 ... 5, and the positioning pins 3 ... 3 are pressed upward by the elastic force of the springs 4 and their respective tapers. The surfaces 3a ... 3a project from the disk upper surface 1a.

A clamp plate 2 supported by four connecting rods 8 ... 8 is provided above the positioning pins 3 ...
Tapered holes 2a are formed in the clamp plate 2 at positions corresponding to the circumference 1 along which the positioning pins 3 ... The lower tip diameter of the taper hole 2a is smaller than the wafer W to be held by a predetermined amount.

Each of the four connecting rods 8 ... 8 penetrates the wall of the disk 1 and projects downward, and each projecting end thereof is fixed to the bottom plate 7. The bottom plate 7 is fixed to the disk 1 by 3
It can move vertically along the guide rods 10 ... 10 of the book. A linear bearing 11 is provided at the portion where the bottom plate 7 abuts on each of the guide rods 10 ... 10 for smooth sliding between them.

Further, springs 9 ... 9 are narrowly provided around the lower portions of the four connecting rods 8 ... 8 and between the lower surface 1b of the disc 1 and the upper surface 7a of the bottom plate 7, respectively. The bottom plate 7 is pressed downward by the elastic force. That is, the clamp plate 2 is pressed toward the upper surface 1a of the disc. Further, the clamp plate 2 can be raised by pushing the bottom plate 7 upward against the elastic force of each spring 9 ... The spring 9
.. 9 is set to such an extent that the clamp plate 2 can press the positioning pins 3 ... 3 downward and can sufficiently press the wafer W.

The disk 1 also has a circumference of 4 concentric with the circumference l.
The individual through holes 1d ... 1d are drilled, and the through holes 1d ... 1d are formed.
Clamp-up pins 6 ... 6 are slidably inserted therein. The lower end of each of the clamp-up pins 6 ... 6 is fixed to the bottom plate 7, and when the bottom plate 7 is pushed upward, a part of the clamp-up pin 6 is projected from the upper surface 1a of the disc.

The four positioning pins 3 ... 3, which are configured as described above,
Clamp plate 2 and four clamp-up pins 6 ... 6
Are provided at a plurality of locations along the circumference L of the disk 1 so as to be rotationally symmetrical.

A known clamp-up bar 12 is arranged at a predetermined position in a vacuum chamber (not shown) for pushing up the clamp plate 2, that is, the bottom plate 7 when the wafer W is mounted on the disk 1. ing.

Next, the operation will be described together with the wafer mounting procedure with reference to FIG.

First, the bottom plate 7 is pushed up by the clamp up bar 12, and the clamp plate 2 is released upward. In this state, as shown in FIG. 3 (a), the positioning pins 3 ... 3 and the clamp-up pins 6 ... 6 project from the upper surface 1a of the disc, and the wafer W is clamped to the clamp-up pins 6 ...
It is placed on the upper end of 6 so that its position is directly below the tapered hole 2a of the clamp plate 2.

Then, when the clamp-up bar 12 is gradually lowered downward, the wafer W is moved to the tapered surfaces 3a of the positioning pins 3 ...
.. 3a, and when the tips of the clamp-up pins 6 ... 6 are below the upper surface 1a of the disc, as shown in FIG. 3 [b], the positioning pin 3 ... Positioned by 3. When the clamp up bar 12 is further lowered, the clamp plate 2
3 first abuts on the upper ends of the positioning pins 3 ... 3 and then on the peripheral edge of the wafer W.
When is separated from the bottom plate 7, it is pressed toward the disc 1 by the elastic force of the spring 9. As a result, the wafer W is held on the upper surface 1a of the disk. Then, by performing the above procedure every time the disk 1 is rotated by a predetermined pitch, a plurality of wafers W ...
W can be held in place on the upper surface 1a of the disc.

Here, when the wafer W is positioned on the upper surface 1a of the disk, even if a part of the wafer W is caught by the tapered surface 3a of the positioning pin 3 for some reason, the wafer W is pressed by the clamp plate 2. At that time, the positioning pin 6 is moved downward by the clamp plate 2, and the wafer W is pressed by the clamp plate 2 with the entire surface of the wafer W in contact with the upper surface 1a of the disk.
As a result, the wafer W is not damaged by the pressing force of the clamp plate 2.

In the above, an example in which the present invention is applied to a batch type disk has been shown, but the present invention is not limited to this, and it is needless to say that the present invention can also be applied to a single-wafer platen.

<Effect of Device> As described above, according to the wafer holder of the present invention,
Plural positioning pins arranged below the clamp plate,
It is movable up and down with respect to the support table and part of it protrudes from the upper surface of the support table due to the pressing force of the elastic body, and the upper and lower parts of the position where the upper end of the protrusion is at a height corresponding to the wafer thickness with respect to the upper surface of the support table. Since the side faces of each positioning pin are formed with a surface for positioning the wafer, the clamp plate hits the upper end of the positioning pin before pressing the wafer, and the clamp plate moves. Since the positioning pins move downward together with the positioning pins, the clamping plate does not press the wafer against the positioning surfaces of the pins even when a part of the wafer is caught on the positioning surfaces of the positioning pins. As a result, there is no risk of wafer damage, and productivity is improved.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an essential part of an embodiment of the present invention, FIG. 2 is a sectional view taken along the line II-II, and FIG. 3 is a longitudinal sectional view of an essential part for explaining the operation, FIGS. FIG. 7 is a cross-sectional view showing an example of a conventional structure of a batch type disc. 1 …… Disk 1a …… Top surface 2 …… Clamp plate 3… 3 …… Positioning pin 3a… 3a …… Tapered surface 4,9 …… Spring W… W …… Wafer

Claims (1)

[Scope of utility model registration request] 1. A holder for holding a wafer at a predetermined position in an ion implantation apparatus or the like, wherein a clamp plate for holding a peripheral portion of the wafer is provided above the support table on which the wafer is placed. , Is arranged so as to be able to move toward and away from the upper surface of the support base, and a plurality of positioning pins are arranged on the support base at positions where the clamp plates face each other. A position that is movable in the vertical direction with respect to the support table and partially protrudes from the upper surface of the support table due to the pressing force of the elastic body, and the upper end of the protrusion has a height corresponding to the wafer thickness with respect to the upper surface of the support table. Of the positioning pins, each of which has a surface for positioning the wafer on the upper surface of the support table, and the clamp pins. The toward the upper surface of the support base, characterized in that it comprises a means for pressing by a force greater than the pressing force of the elastic body, the wafer holder.