JP3264983B2 - Ion implanter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion implantation apparatus.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process, in order to implant ions into a semiconductor wafer, generally, ions extracted from an ion source are passed through a mass analysis magnet or the like and then scanned in the X and Y directions. 2. Description of the Related Art An ion implantation apparatus for implanting a semiconductor wafer in a predetermined pattern is known. A portion for setting a wafer in a vacuum chamber in such an ion implantation apparatus is conventionally configured as shown in FIG. 6, for example. That is, 9 in FIG. 6 is a vacuum chamber, and load lock chambers 9A and 9B are installed on both sides of the vacuum chamber 9, respectively, and a horizontal rotating shaft 91 is installed between both side walls of the vacuum chamber 9. A wafer holding table 93 having a wafer pressing member 92 is attached to the rotating shaft 91,
The wafer holding table 93 is configured to be able to rotate between a horizontal state and an upright state by rotating the rotation shaft 91 by the driving unit 90. Ga ~ in FIG.
Gd is a gate valve. The rotating shaft 91 is supported by bearings 94 and 95 via bearings (not shown). The bearings 94 and 95 are provided on both side walls of the vacuum chamber 9 with O-rings (not shown). Are provided in an airtight manner via the sealing member.

In order to hold a wafer on the wafer holding table 93, the wafer holding table 93 is set to a horizontal state and the load lock chamber 9A is moved by a transfer mechanism (not shown).
The wafer W in (9B) is transferred to the wafer holding table 93, and the wafer W is pressed by the pressing member 92.
3 is erected, and a predetermined ion beam is irradiated on the wafer W to perform ion implantation.

[0004]

In order for the rotating shaft 91 to rotate smoothly, the degree of parallelism between the axis of the rotating shaft and the axis of the bearing must be high, and the shaft supports 94 and 95 and the vacuum chamber must be parallel. In order to enhance the sealing performance between the vacuum chamber 9 and the side wall of the vacuum chamber 9, it is necessary that the orthogonality between the axis of the shaft supports 94 and 95 and the wall surface of the vacuum chamber 9 is high. High precision parallelism between walls is required.

On the other hand, the vacuum chamber 9 is made by welding a plate material having a large thickness, such as aluminum, in order to obtain a large strength.
Since the diameter of the vacuum chamber 9 has been increased to inches, the size of the vacuum chamber 9 has also been increased. Therefore, there has been a problem that it is very difficult to manufacture the vacuum chamber 9 if the parallelism of the side wall of the vacuum chamber 9 is to be increased.

Further, the present inventor has rotated the wafer holding table 93 around an axis orthogonal to the rotation axis 91 to obtain an angle of the wafer surface with respect to the ion beam (ion beam incident angle).
Is being studied, but in this case, there is also the following problem. That is, in order to easily perform the automatic transfer control, the holding table 93 is moved to the load lock chamber 9A,
9B, it is necessary to have a mechanism for sliding the wafer holding table 93 with respect to the rotation shaft 91. However, since the tilt shaft is arranged in the rotation shaft 91, the vacuum Sliding without lowering the airtightness of the chamber 9 also has a problem that the structure becomes very complicated.

The present invention has been made under such circumstances, and an object of the present invention is to provide an ion implantation apparatus in which the vacuum chamber 1 having a rotating shaft can be easily manufactured and has excellent airtightness. It is in.

Another object of the present invention is to provide an ion implantation apparatus in which an object-holding stage can be tilted while the object-holding stage can be slid while maintaining airtightness in a vacuum chamber. It is in.

[0009]

According to a first aspect of the present invention, an object-to-be-processed holding table for mounting and holding an object to be processed is rotated by a rotating shaft disposed in a vacuum chamber. during transfer of the processed and sideways posture mounting surface of the object, in an ion implantation apparatus for the placing surface in the standing posture during ion implantation, the first round of the rotation axis in the longitudinal direction
The rotation shaft is divided into a driving shaft portion and a second rotation shaft portion.
Each end of the part is slidable with each other and pivots together.
And a shaft support at the other end of the second rotating shaft.
Through a bellows body that can expand and contract in the longitudinal direction of the rotation shaft.
And attached to the side wall of the vacuum chamber, and
A processing object holding table is provided, and the processing object holding table is
To rotate the ion beam around the axis
The tilt axis for changing the beam incident angle
Is disposed so as to extend in the axial direction of the rotation shaft.
And the tilt axis is longitudinally aligned with a first tilt axis portion and a second tilt axis portion.
And one end of each tilt shaft
Slidably and integrally pivoted,
Fixing the position of the second rotation shaft with respect to the first rotation shaft
Characterized in that a position fixing means is provided .

[0010]

[0011]

When the rotating shaft is installed between the side walls of the vacuum chamber, even if the parallelism of the side walls is poor, the deviation of the parallelism is absorbed by the inclination of the bellows body.
The airtightness between the shaft support of the rotating shaft and the side wall of the vacuum chamber can be increased while the rotating shaft and the side wall of the vacuum chamber are not orthogonal to each other.

The movement of the second rotating shaft with respect to the first rotating shaft and the first tilt can be absorbed by the expansion and contraction of the bellows body. The left and right positions of the workpiece holding table can be adjusted by sliding with respect to the moving shaft portion.

[0013]

FIG. 1 is a view showing the external appearance of a portion for carrying a semiconductor wafer as an object to be processed into and out of an apparatus main body in an ion implantation apparatus according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a vacuum chamber, and a front side (a front side in FIG. 1) of the vacuum chamber 1 is configured as a processing chamber 11 for transferring a wafer to a platen section described later and implanting ions into the wafer. . Load lock chambers 2A, 2A,
B is continuously provided, and on the rear side of the processing chamber 11,
A beam passage chamber 12 through which an ion beam IB from an ion source (not shown) passes is continuously provided, for example, at a predetermined angle θ in the horizontal direction with respect to the side wall surface of the processing chamber 11.

As shown in the schematic view of FIG. 2, a rotating shaft 3 extending horizontally between both side walls of the processing chamber 11 is provided in the processing chamber 11. A platen unit 4, which is a workpiece holding table for mounting and holding a wafer, is attached. The platen unit 4 is attached to the rotation shaft 3 via an attachment unit 41 so that the mounting surface of the wafer can be rotated between a horizontal state, for example, a horizontal state, and a vertical state, for example. ing.

The rotating shaft 3 is formed of a cylindrical body, and a tilt shaft 5 for setting the wafer at a predetermined angle with respect to the ion beam as described later in detail.
Is supported inside. And the platen part 4
When it is in a horizontal state (the state shown by a chain line in FIG. 2), it is located on the wafer transfer path formed between the load lock chambers 2A and 2B and is load locked by a transfer machine such as a clamp mechanism (not shown). Mounting table 21 of room 2A (2B)
The upper wafer W is received and pressed against the platen unit 4 by a pressing member (not shown in FIG. 2), and the processed wafer W on the platen unit 4 is loaded by the transfer mechanism into the load lock chamber 2A.
It is transported onto the mounting table 21 of (2B).

Here, the structure of the rotating shaft 3 will be described in more detail with reference to FIG. 3. FIG. 3 is a view of the rotating shaft 3 and the platen section 4 from the direction of ion beam irradiation. Has a hollow inside and the first in the length direction.
Are divided into a rotating shaft portion 31 and a second rotating shaft portion 32. The first rotation shaft 31 is supported by a cylindrical support 33 via a bearing 34.
Is hermetically fixed to one side wall 13 of the processing chamber 11 (vacuum chamber 1) by an O-ring (not shown) or the like.

The tilt shaft 5 is also divided into a first tilt shaft portion 51 and a second tilt shaft portion 52 in the longitudinal direction. A tilt shaft 51 is coaxially supported via a bearing 50. Magnetic seals 35 and 53 are used to hermetically seal the space between the shaft support 33 and the first rotation shaft 31 and the space between the first rotation shaft 31 and the first tilt shaft 51, respectively. ing.

The second end of the first rotating shaft 31 is provided with a second
One end side of the rotation shaft portion 32 is slidably fitted to the outside, and the rotation shaft portions 31 and 32 are integrated between the rotation shaft portions 31 and 32 without sliding in the circumferential direction. An anti-slip member 6 is interposed so as to pivotally rotate.

The second tilt shaft 52 is supported in the second rotation shaft 32 via bearings 61 and 62, and has a spline structure at one end as shown in FIG. A plurality of ridges 54 each extending in the longitudinal direction are formed in the circumferential direction, and one end of the first tilt shaft 51 is engaged with one end of the second tilt shaft 52 to slide in the longitudinal direction. It is configured to move and rotate integrally.

A screw portion 30 (see FIG. 4) is provided on the outer peripheral surface at one end side (left end side in FIG. 3) of the second rotating shaft portion 32.
A nut 60 serving as a position fixing means for adjusting and fixing the position of the rotating shaft portion 32 to the second rotating shaft portion 32 so as to screw with the screw portion 30 is formed. Installed.

One end of the first rotating shaft portion 31 is formed by bending the peripheral edge so that the vertical cross-sectional shape becomes a U-shape, and a flange portion 60a is formed on one end of the nut 60. The flange portion 60a is inserted into the U-shaped space of the first rotating shaft portion 31, and the movement in the axial direction is prevented by the U-shaped peripheral portion. Therefore, when the nut 60 is turned, the second turning shaft 32 is turned into the first turning shaft 31.
In the length direction.

A worm gear 55 is formed on the second tilt shaft portion 52, while a worm gear 55 is provided in the mounting portion 41.
A platen shaft 42 is provided so as to be orthogonal to the rotation shaft 3, and a worm wheel 56 meshed with the worm gear 55 is provided at a lower end of the platen shaft 42. The platen portion 4 is attached to the upper end of the platen shaft 42, so that the tilt shaft 5 rotates, so that the platen portion 4 rotates around an axis orthogonal to the rotation shaft 3.

The platen section 4 is provided so that a wafer pressing member 43 is rotated by an air mechanism (not shown) so as to come into contact with and separate from a wafer mounting surface by an air mechanism. In FIG. 3, reference numerals 63 and 64 denote connection portions to which air pipes in the air mechanism are connected.

The other end (the right end in FIG. 3) of the second rotating shaft 32 is supported by a shaft support 7 via bearings 65 and 66, and the outer end of the shaft support 7 is not shown. The flange 71 is hermetically attached via an O-ring.
Between the inner surface of the flange 71 and the side wall 14 of the vacuum chamber 1, for example, a bellows body 72 (see FIGS. 1 and 3) made by welding an aluminum material is interposed. The guide rod 73 extending from the side wall 14 is loosely penetrated, so that the shaft support 7 can be separated from or slightly inclined with respect to the side wall 14 by expansion and contraction or bending of the bellows body 72.

The shaft support 7 is provided with an air pipe connection 74 for taking in the air used in the air mechanism, and the inside thereof communicates with the connection 64 via the second rotation shaft 32. It is configured to be. Further, the shaft support 7 is provided with a decompression pipe connecting portion 75 whose interior communicates with the space so as to reduce the pressure between the rotating shaft 3 and the tilt shaft 5 to, for example, about 10 ⁻³ Torr. . By reducing the pressure in the space, the pressure difference between the space and the inside of the vacuum chamber 1 is reduced, and the sealing property is improved. However, in the present invention, the pressure may be set to the atmospheric pressure without reducing the pressure.

The other end of the first rotating shaft 31 is hung on a drive belt 15 as a drive source for rotating the first rotating shaft 31. The other end of the first tilt shaft 51 is connected to the other end of the first rotating shaft 31. , And is connected to a motor (not shown) attached to the first rotating shaft 31.

In this embodiment, as shown in FIG. 1, the front side of the processing chamber 11 and the load lock chambers 2A and 2B are constituted by a removable common panel 81.
By doing so, the platen unit and the load lock chamber 2
When performing maintenance such as a transfer mechanism for transferring a wafer between A and 2B, it is convenient because the panel 81 can be removed.

Further, air chambers 82 and 83 for operating the gate valves of the load lock chambers 2A and 2B and an air tank 84 for supplying air to the air mechanism for the wafer holding member described above are provided in the vacuum chamber 1. In this case, the space is reduced as compared with the configuration in which the air tank 84 is separately provided, and the space in the vacuum chamber 1 is reduced by the amount of the air tank 84, so that the time required for evacuation is shortened.

Next, the operation of the above embodiment will be described. For example, a wafer is carried into the load lock chamber 2A from the outside by a transfer means (not shown), and the wafer is further conveyed onto the platen portion 4 which is horizontally lying down by a transfer means (not shown). After the rotation axis 3
Is rotated to raise the platen portion 4 vertically. Then, the tilt shaft 5 is rotated to rotate the platen unit 4 about an axis orthogonal to the rotation shaft 3, thereby setting the angle of incidence of the ion beam on the surface of the wafer to a predetermined angle. Then, the surface of the wafer is irradiated with an ion beam of a predetermined impurity from an ion source (not shown) to inject the ions of the impurity into the wafer. 2B,
It is further carried out.

Here, the platen section 4 is provided, for example, from the load lock chambers 2A, 2B to facilitate control of a transfer mechanism for transferring a wafer between the platen section 4 and the load lock chambers 2A, 2B. It is advantageous to be at a distance, so in this embodiment the nut 60 shown in FIG. 3 is pivoted to move the second pivot shaft 32 as shown in FIG. The platen unit 4 is slid with respect to the shaft 31 to set the platen unit 4 at a position equidistant from the load lock chambers 2A and 2B. By the way, when the tilt shaft 5 is not arranged in the rotation shaft 3, it is easy to move the platen unit 4 to the left and right. However, when the tilt shaft 5 is provided, The structure for moving the part 4 is expected to be extremely complicated. On the other hand, if the bellows body 72 is provided as in this embodiment, the movement of the second rotary shaft 32 in the longitudinal direction is absorbed by the expansion and contraction of the bellows body 72, so that the vacuum chamber 1 is airtight. This is very effective in that the platen section 4 can be moved by a simple structure while maintaining the properties.

By providing the bellows body 72, even if the parallelism between the side walls 13, 14 of the vacuum chamber 1 is poor,
The difference in the parallelism is absorbed by the bellows body 72,
The shaft support 7 is in close contact with the flange 71 and the bellows body 72
Of the vacuum chamber 1 is also in close contact with the side wall 14 of the vacuum chamber 1 so that there is no danger that the airtightness will decrease. Further, since the bearing and the rotating shaft 3 can be arranged coaxially, the rotating shaft 3 can be smoothly rotated. I do.

[0032]

[0033]

According to the first aspect of the present invention, since the shaft supporting portion for supporting one end of the rotating shaft is attached to the side wall of the vacuum chamber via the bellows body, the parallelism of both side walls of the vacuum chamber is reduced. At worst, there is no danger of lowering the airtightness between the shaft support of the rotating shaft and the side wall of the vacuum chamber, and since the shaft support and the rotating shaft can be arranged coaxially, the rotating shaft can rotate smoothly. Move.

Further it is possible to perform the tilt axis position adjustment of the right and left of the object holder with a simple structure when Ru provided in the rotating shaft for tilting the holder workpiece.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an appearance of a part of an apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic perspective view illustrating the operation of a platen unit serving as a workpiece holding table.

FIG. 3 is a partially cutaway sectional view showing a main part of the embodiment of the present invention.

FIG. 4 is a perspective view showing a main part of the embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a state of adjustment of the left and right of a platen unit.

FIG. 6 is a plan view showing a conventional ion implantation apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum chamber 2A, 2B Load lock chamber 3 Rotation axis 31 1st rotation axis part 32 2nd rotation axis part 4 Platen part 5 Tilt axis 51 1st tilt axis part 52 2nd tilt axis part 60 Position adjustment nut 72 Bellows body

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-278643 (JP, A) JP-A-5-25629 (JP, A) JP-A-61-263038 (JP, A) 20953 (JP, U) Japanese Patent Application No. 2-99983 (Japanese Utility Model Application No. 4-56330) Microfilm (JP, U) (58) Photograph of the contents of the specification and drawings attached to the application Int.Cl. ⁷ , DB name) H01J 37/317

Claims (1)

(57) [Claims] An object holding table for mounting and holding an object to be processed is rotated by a rotation shaft arranged in a vacuum chamber, so that the object to be processed is placed when the object is transferred. In the ion implantation apparatus, the surface is set to a sideways posture and the mounting surface is set to an upright posture at the time of ion implantation, wherein the rotation axis is a first rotation axis portion and a second rotation axis in a longitudinal direction.
And one end of each of these rotating shafts is
While slidably and integrally connected to rotate,
The other end of the second rotating shaft is supported in the longitudinal direction of the rotating shaft.
To the side wall of the vacuum chamber via a bellows body
A workpiece holder is provided on the second rotation shaft, and the workpiece holder is mounted around an axis orthogonal to the rotation axis.
To change the angle of incidence of the ion beam on the workpiece.
A tilt axis for rotating the axis of the
The tilt shaft is disposed so as to extend in the direction of the first axis and the first axis is tilted in the longitudinal direction.
And one end of each tilt shaft.
Slidably and integrally connected so that the position of the second rotating shaft with respect to the first rotating shaft is fixed.
An ion implantation apparatus provided with a position fixing means for fixing .