JPS61272376A - End station for ion implantation device - Google Patents

Abstract

PURPOSE:To treat a large bore wafer, to use at a large electric current and to improve the production efficiency by providing a wafer holder, an ion beam source and a shielding plate which are made relatively movable in the radial direction of the wafer an furnishing a sectorial slit for transmitting ion beams to the shielding plate. CONSTITUTION:A wafer 1 is fixed to a wafer holder 2 and rotated at a specified high speed. An ion beam 3a from an ion beam source 3 is passed through a sectorial slit 4a having width smaller than the diameter of the beam, moved in the radial direction of the wafer 1 by an electrical means and the radial direction of the wafer 1 by an electrical means and irradiated. Or the beam 3a is not moved, the holder 2 and the shielding plate 4 are moved in the radial direction of the wafer 1, ions are implanted and implantation is continued while controlling the difference in the irradiation time of the beam 3a due to the difference in the velocity between the outer peripheral part and the central part of the wafer 1 by the opening degree of the slit 4a. By such a constitution, the sheet-fed treatment by mechanical or semimechanical scanning is made possible and the productivity can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an end station that is a wafer processing section that handles and implants wafers in an ion implantation apparatus used in one process of manufacturing semiconductor integrated circuits.

[Conventional technology]

In an ion implantation apparatus, it is most important to uniformly implant ions into a wafer, so various measures have been taken in the past. Normally, the diameter of the ion beam obtained with an ion implanter is much smaller than the size of the wafer, so during implantation, the wafer and the ion beam must be moved relatively to each other by some means to spread the ion beam uniformly over the wafer surface. It is necessary to irradiate it with an ion beam. Means for performing relative movement include electrical means for moving and scanning the ion beam electrostatically or electromagnetically, and mechanical means for mechanically moving the wafer, as well as a combination of the above two methods. There are three types of semi-mechanical methods that are used in combination.

[Problem that the invention seeks to solve]

Conventional methods of electrically scanning an ion beam do not move the wafer, which simplifies the structure of the end station, and single-wafer systems that process wafers continuously are generally used. ing. This method is easy to automate and has the advantage of being able to transfer the wafer into a vacuum with high efficiency. However, when used with a large ion beam current, electrical scanning becomes difficult and the wafer diameter is large. When the diameter becomes large, it becomes difficult to perform multiple scans, and at the same time, it becomes difficult to correct the difference in implantation amount between the outer periphery and the center of the wafer.

On the other hand, a method that moves the wafer mechanically or a semi-mechanical method that combines both methods can use a large ion beam, and are therefore generally popular for use with large beam currents. However, conventional end stations of this type have a method in which several wafers are mounted on a jig in the implantation chamber, and the jig is rotated or moved in parallel to uniformly irradiate the ion beam onto the wafer surface. It became. Since this is a batch process, it takes time to vacuum, which has the drawback of poor production efficiency. This becomes more significant as the diameter of the wafers increases, as the number of wafers that can be mounted on a jig per batch decreases.

The present invention provides an apparatus that solves the above problems.

[Failure to solve the problem]

The present invention includes a wafer holder that holds and rotates one wafer to be processed, an ion beam source located in front of the wafer on the wafer holder, and a shielding plate located between the wafer holder and the ion beam source. and has
A wafer holder, an ion beam source, and a shielding plate are installed so as to be movable relative to each other in the diametrical direction of the wafer, and the shielding plate is provided with a fan-shaped slit for transmitting the ion beam that expands in a radial direction from the center of the wafer. This is an end station for an ion implanter characterized by the following.

〔Example〕

Next, one embodiment of the present invention will be explained with reference to the drawings.

FIG. 1 is a diagram explaining the principle of the present invention. In the figure, 2 is a wafer holder that holds one wafer 1 and rotates it. An ion beam source 3 is installed in front of the wafer holder 2, and a shielding plate 4 is placed between them. Further, the wafer holder 2 and the ion beam source 3 are disposed so as to be relatively movable in the diametrical direction of the wafer 1, and the shielding plate 4 is provided with a fan-shaped slit 4a that widens in the radial direction from the center of the wafer 1.

In the embodiment, a wafer 1 transferred from an external wafer handling section is fixed to a wafer holder 2 by mechanical means and rotated at high speed.

When the rotation reaches a constant speed, the ion beam 3a from the ion beam source 3 is passed through a fan-shaped slit (4a) having a width smaller than the diameter of the ion beam 3a, and is transferred to the wafer 1 by electrical means.
Implantation is performed by moving irradiation in the diametrical direction of the wafer 1, or by moving the wafer holder 2 and fan-shaped slit 4 in the diametrical direction of the wafer 1 without moving the ion beam 3.

In any of the above means, the ion beam 3a crosses the surface of the Weno S-1 through the fan-shaped slit 4a. This means that the difference in ion beam irradiation time due to the speed difference between the outer periphery and the center of the wafer 1 caused by the rotation of the wafer 1 can be implanted while being corrected by the opening degree of the slit. Even in this case, the speed at which the ion beam 3a moves across the surface of the wafer in the diametrical direction of the wafer may be constant. Since it is easier to control a constant speed than to control a variable speed, the device is simplified.

〔Effect of the invention〕

As described above, the ion implantation apparatus equipped with the end station of the present invention is capable of single-wafer processing using mechanical scanning or semi-mechanical scanning, so it is highly productive and can be used with large currents. This has the effect of easily achieving large-diameter wafer processing.

In addition, as a side effect, even if the wafer diameter becomes larger,
The equipment can be made smaller compared to conventional batch mechanical or semi-mechanical scanning end stations.
Another advantage is that the dedicated area is small.

[Brief explanation of the drawing]

FIG. 1 is a diagram explaining the principle of an embodiment of the present invention. '1...Wafer, 2...Wafer holder,
3...Ion beam source, 3a...Ion beam, 4
...shielding plate, 4 &... fan-shaped slit. Figure 1

Claims (1)

[Claims] (1) A wafer holder that holds and rotates one wafer to be processed, an ion beam source located in front of the wafer on the wafer holder, and a shielding plate located between the wafer holder and the ion beam source. The wafer holder, the ion beam source, and the shielding plate are installed so as to be movable relative to each other in the diametrical direction of the wafer, and the shielding plate includes:
An end station for an ion implanter characterized by having a fan-shaped slit for transmitting an ion beam that expands radially from the center of the wafer.