JPH0793122B2 - Ion processing device - Google Patents

Description

TECHNICAL FIELD The present invention relates to an ion processing apparatus, such as an ion implantation apparatus, which irradiates a wafer with an ion beam in a vacuum container to process the wafer, and more particularly, to an ion processing apparatus. The present invention relates to an ion processing apparatus in which a wafer moves in a so-called pestle motion (also referred to as miso-saw motion).

[Conventional technology and its problems]

In recent years, along with the miniaturization of semiconductor devices, for example, as shown in FIG. 5, not only the bottom surface 4a of the recess 4 such as a hole or groove formed in the surface of the wafer 2 but also the side wall (side surface) 4b of the recess 4a. There is an increasing demand for an apparatus that can irradiate the beam 6 to perform ion implantation and the like.

However, in the conventional ion implanter or the like, the incident direction of the ion beam 6 with respect to the surface of the wafer 2 is fixed, so that it is impossible to meet the above demand.

Therefore, an object of the present invention is to provide an ion processing apparatus capable of meeting the above demands.

[Means for solving problems]

The ion processing apparatus of the present invention includes a holder that is housed in a vacuum container and holds a wafer, and a support mechanism that rotatably supports the holder around two orthogonal axes that pass through the center point of the wafer surface held by the holder. And a connecting member engaged substantially perpendicularly to the substantially central portion of the surface of the holder opposite to the wafer holding surface, and a drive mechanism for circularly moving the end of the connecting member opposite to the holder. Moreover, the drive mechanism is provided behind the holder, and the center line passes through the center point of the wafer surface held by the holder, the rotary drive source for rotating the drive shaft, and the drive shaft. A first connecting mechanism that connects between the end portion of the connecting member and causes the end portion to move circularly around the center line of the drive shaft by rotation of the drive shaft; With the angle adjustment axis stored in And connecting the degree adjusting shaft and the end portion of the connecting member, by movement of the angle adjustment shaft, characterized in that it comprises a second connecting mechanism for changing the radius of the circular motion of the end portion.

[Action]

Since the holder is rotatably supported about the two orthogonal axes by the support mechanism, when the end of the connecting member opposite to the holder is circularly moved by the drive mechanism, the connecting member makes a so-called scouring motion, The holder engaged with it, and thus the wafer held by it, also makes a pestle movement.
From a different point of view, even if the ion beam is fixed, the ion beam is irradiated so as to make a rubbed motion with respect to the wafer surface. Therefore, it becomes possible to irradiate the side walls of the recesses such as holes and grooves provided on the wafer surface with the ion beam.

〔Example〕

FIG. 1 is a cross sectional view showing an ion treatment apparatus according to an embodiment of the present invention. For example, an ion beam 6 from an ion source (not shown) or the like is introduced into a vacuum container 8 which is composed of a container body 8a and a container lid 8b and which can be opened and closed by a hinge 9, for example. 10 is a gate valve. Then, in the vacuum container 8, the wafer 2 is provided on one side.
A holder 12 capable of mounting and holding is stored.

Specifically, the holder 12 is supported by a support mechanism 16 that rotatably supports the holder 12 around two orthogonal axes. The support mechanism 16 is a so-called gimbal mechanism, and for example, as shown in FIG. 2, a frame (so-called so-called gimbal mechanism) attached to shafts 14a and 14b rotatably supported by the vacuum container 8 as shown by an arrow C. The holder 12 is provided in a cardan frame 14 and is rotatably supported by the shafts 12a and 12b with respect to the frame 14 as shown by an arrow D. As a result, the holder 12 is supported so as to be freely tilted in all directions around the center point O of the surface of the wafer 2 so that the holder 12 can be rubbed, that is, can be rotated about two orthogonal axes passing through the center point O. ing.

A connecting member 18 is engaged substantially perpendicularly to the substantially central portion of the surface of the holder 12 opposite to the wafer holding surface, and is fixed in this example, and the end of the connecting member 18 on the opposite side of the holder 12 is provided. A shaft 20 is fixed to the part in this example.

The shaft 20 is rotatably supported by a variable spherical crank 22, and the variable spherical crank 22 has a crankshaft 24.
Is rotatably supported by the crank 29. The crank 29 is attached to one end of a drive shaft 32 which is rotatably supported by a bearing 33 provided in the vacuum container 8, and an angle adjusting shaft 30 rotates in the drive shaft 32. It has been passed through. The crankshaft 24 and the angle adjusting shaft 30 are connected by a pair of bevel gears 26 and 28. That is, in this embodiment, the connecting member is rotated by the rotation of the drive shaft 32 by the variable spherical crank 22 and the crank 29.
A first connecting mechanism that makes a circular motion of the ends of 18 around the center line J of the drive shaft 32 is configured. Further, by rotating the angle adjusting shaft 30 by the variable spherical crank 22, the bevel gears 26, 28, etc., the radius R of the circular motion of the end of the connecting member 18
A second connecting mechanism that changes (see FIGS. 3 and 4) is configured.

A wheel 34 is attached to the other end of the drive shaft 32, which is a wheel 38 of the motor 40 and a timing belt.
They are connected by 36, and the drive shaft 32 and the like are rotated by the motor 40 as shown by arrow A, for example.

A handle 42 is provided at the tip of the angle adjusting shaft 30, so that the angle adjusting shaft 30 can be manually moved by, for example, the arrow B.
It can be rotated left and right like.

Incidentally, 44 in FIG. 1 is a packing such as an O-ring for vacuum sealing.

The angle adjusting shaft 30 is arranged so that its center line J (which is also the center line of the drive shaft 32) passes through the center point O of the surface of the wafer 2 held by the holder 12, and the normal line of the center point O. The angle α formed between H and the center line J is determined by the handle 42 as described later.
In this example, by turning, it is variable in the range of 0 to 45 degrees. Incidentally, this angle α corresponds to the incident angle θ of the ion beam 6 with respect to the surface of the wafer 2. The center line K of the crankshaft 24 also passes through the center line O, and the angle β between the center lines J and K is half the maximum value of the angle α, that is, 22.5 degrees in this example. ing.

In the above apparatus, when the motor 40 is driven with the angle α set to a predetermined value, the drive shaft 32, the crank 29, the variable spherical crank 22 and the like are integrated into one as shown by an arrow A about the center line J. Rotate to move the part of shaft 20 in a circular motion. By the way, in this case, the angle adjusting shaft 30 rotates together with the drive shaft 32 and does not rotate (rotate) by itself, so that the angle α does not change.

This will be described with reference to FIG. 3. One end of the connecting member 18 is fixed to the center point O and the other end is pivotally supported by a shaft 20 portion, and the shaft 20 portion is centered on a center line J. Circle E with radius R
It makes a circular motion as shown by arrow A above. As a result, the connecting portion 18 is caused to perform a so-called pestle movement (rubbing movement), and the wafer 2 is also rubbed around the center point O. That is, the normal line H to the center point O of the wafer 2 makes a rubbing motion around the center line J while maintaining a predetermined angle α. Needless to say, in this case, the holder 12 and the wafer 2 do not rotate (rotate).

From a different point of view from the above point of view, even if the ion beam 6 is fixed, the ion beam 6 moves in a pestle motion while maintaining a predetermined incident angle θ (θ = α in this example) with respect to the surface of the wafer 2. It will be irradiated. Therefore, when the surface of the wafer 2 is provided with a recess 4 such as a hole or groove as shown in FIG. 5, the ion beam 6 is evenly applied not only to the bottom surface 4a but also to the side wall 4b thereof. Processing such as injection can be performed.

Moreover, in this embodiment, as described above,
By rotating 42, the angle α can be adjusted within the range of 0 to 45 degrees, for example.

This will be described with reference to both FIG. 1 and FIG. 4. When the handle 42 is rotated, for example, by 0 to 180 degrees as indicated by an arrow B while the motor 40 is stopped, the angle adjustment shaft 30, the bevel gear 2 are shown.
6, 28, the crankshaft 24, and the variable spherical crank 22 rotate, so that the center of the shaft 20 moves on the semicircle F of FIG. It can also coincide with the center line J.

The shaft 20 is 180 degrees from the center line J of the angle adjusting shaft 30 as shown in FIG.
When they are separated from each other, the radius R of rotation of the shaft 20 becomes maximum, and the tilt angle α during the rubbing movement of the wafer 2, that is, the incident angle θ of the ion beam 6 becomes maximum 45 °. On the other hand, when the shaft 20 is aligned with the center line J of the angle adjusting shaft 30, the radius R of rotation of the shaft 20 becomes zero, the wafer 2 remains stationary without performing the rubbing movement, and the ion beam 6 is incident. The angle θ is 0 degree.

Therefore, if the angle α can be adjusted as in this embodiment, the recesses 4 such as holes and grooves of the wafer 2 as shown in FIG.
It can be said that it is more preferable because an appropriate incident angle θ can be selected according to the size, shape, etc.

Further, in the above-mentioned apparatus, if the motor 40 is stopped at a predetermined position, it is possible to irradiate only a predetermined side wall of the recess 4 of the wafer 2 with the ion beam 6 to perform ion implantation or the like.

Unlike the above embodiment, the connecting member 18 has one end rotatably supported on the back surface of the holder 12 and the other end fixed to the variable spherical crank 22 to obtain the same operation as above. To be

Further, when the angle α is adjustable as in this embodiment, the adjustment range is not necessarily limited to the above-mentioned 0 to 45 degrees, and may be another angle range.

Furthermore, instead of the handle 42, a motor (for example, a pulse motor) or the like may be attached to the wheel 34, and the angle adjusting shaft 30 may be rotated thereby to remotely control the angle α.

〔The invention's effect〕

Since the present invention is configured as described above, it has the following effects.

By rotating the drive shaft of the drive mechanism, the wafer can be so-called rubbed, which means that the ion beam rubs against the wafer surface even if it is fixed. Since the irradiation is performed as described above, it is possible to irradiate the ion beam also to the side walls of the recesses such as holes and grooves provided on the surface of the wafer to perform a process such as ion implantation.

The wafer can be rubbed by a simple operation of rotating one drive shaft in one direction.

In the drive mechanism, the support mechanism supports the holder rotatably around two orthogonal axes passing through the center point of the wafer surface held by the holder, and the center line of the drive shaft is held by the holder. Since the first connecting mechanism is arranged so as to pass through the center point of the wafer surface, and the end portion of the connecting member is moved circularly about the center line of the drive shaft, Is rubbed around the center of its surface, while the center of the wafer does not move. If the center of the wafer moves during the rubbing movement, the irradiation area of the ion beam must be enlarged by taking into account the amount of movement as well, and the entire wafer is irradiated with the ion beam during the rubbing movement. Since the beam utilization efficiency determined by the irradiation area of the ion beam and the area of the wafer is lowered because it is impossible to do so, in the present invention, the center of the wafer does not move during the plucking motion, so that the beam utilization efficiency is reduced. Can be prevented.

For the same reason as above, if the ion beam irradiation area is enlarged, the non-uniformity of the beam current density of the ion beam between the central part and the peripheral part of the irradiation area becomes large regardless of whether or not the ion beam is scanned. However, since the center of the wafer does not move during the rubbing movement, it is possible to prevent the uniformity of processing in the wafer surface from decreasing. it can.

In the drive mechanism, since the angle of the rubbing movement of the wafer can be adjusted by the angle adjusting shaft and the second connecting mechanism, it is possible to adjust the rubbing movement according to the size and shape of the recess of the wafer. The angle of incidence of the ion beam can be selected to be appropriate, which enables more appropriate wafer processing.

[Brief description of drawings]

FIG. 1 is a cross sectional view showing an ion treatment apparatus according to an embodiment of the present invention. FIG. 2 is a front view showing the support mechanism of FIG. FIG. 3 is a diagram for explaining the grooving movement of the connecting member of FIG. FIG. 4 is a schematic view showing the bevel gear portion of FIG. 1 in the direction of arrow P. Fifth
The figure is a partial cross-sectional view showing an example of a wafer. 2 ... Wafer, 6 ... Ion beam, 8 ... Vacuum container,
12 ... Holder, 16 ... Support mechanism, 18 ... Connecting member, 22 ...
… Variable spherical crank, 30 …… Angle adjusting axis, 32 …… Drive axis, 40 …… Motor

Claims (1)

[Claims] 1. An ion processing apparatus for irradiating a wafer with an ion beam in a vacuum container to process the wafer, and a holder housed in the vacuum container for holding the wafer.
A support mechanism for rotatably supporting the holder rotatably around two orthogonal axes passing through the center point of the wafer surface held by the holder, and substantially perpendicularly engaged with the substantially central portion of the surface of the holder opposite to the wafer holding surface. And a drive mechanism for circularly moving the end of the connection member opposite to the holder, and the drive mechanism is provided at the rear of the holder and the center line is held by the holder. The drive shaft that passes through the center point of the wafer surface, the rotary drive source that rotates the drive shaft, and the drive shaft and the end portion of the connecting member are connected to each other, and the end portion is rotated by the rotation of the drive shaft. A first connecting mechanism that makes a circular motion about the center line of the drive shaft, an angle adjusting shaft housed in the drive shaft coaxially therewith, and the angle adjusting shaft and the end portion of the connecting member. Connect the two and connect the ends by the movement of the angle adjustment shaft. Ion processing apparatus, characterized in that it comprises a second connecting mechanism for changing the radius of the circular motion.