JPS62195841A - Ion implanting apparatus - Google Patents

Abstract

PURPOSE:To make an angle correction unnecessary, by composing a deflecting magnet to position the ion beam incident point of the ion beam deflecting magnet on the extension of the side surface at the ion beam radiating side of the deflecting magnet. CONSTITUTION:A deflection scanning electromagnet 8 is composed to position the incident point 7 of the ion beam 3 on the extension of the ion beam radiation side surface 9. The ion beam injected to the deflection scanning magnet 8 reaches to the ion beam radiating end surface 9 when it is deflected at a specific angle and then radiated. Therefore, by converting the magnetic field density of the deflection scanning electromagnet 8, the ion beam 10 to scan in the lateral direction while keeping the constant direction is obtained.When it is combined with the implanting apparatus with a rotary disk 12 on which a semiconductor wafer 11 is furnished, by controlling the ion beam 10 to scan at a scanning speed inversely proportional to the radius position R on the disk 12 where the deflected ion beam 10 is scanned, it is possible to implant the ion beams evenly on the wafer. Therefore, the magnetic field to correct the angle is unnecessary.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Sedentary Application] The present invention relates to an ion implantation device used for manufacturing semiconducting devices, and in particular to an ion implantation device that deflects an ion beam in parallel. , relates to an ion implantation device capable of scanning.

[Conventional technology]

Conventional ion implantation kW1. So, rice 1 permission No. 4, 276
, 477 and No. 4,367,411, in order to deflect the beam with a magnetic field, the first stage is The ion beam is deflected into a fan shape by an electromagnet for one-dimensional scanning, and the deflected ion beam is made to enter the magnetic field of the second stage electromagnet, and at this time, the ion beam is deflected by the first stage electromagnet. Type (
The magnetic field strength of the second stage electromagnet is changed according to the angle),
Accordingly, a method is known in which the trajectory of the ion beam emitted from the latter magnetic field is adjusted to be parallel, and the ion beam is controlled so that it hits all positions on the semiconductor wafer from a perpendicular direction.

As can be seen from the previous explanation, this method requires, in addition to a magnet for deflection and scanning, a second stage magnet for correcting and parallelizing the trajectory of the ion beam.

[Problem that the invention seeks to solve]

In the above conventional technology, the second stage magnet is used to correct the direction (trajectory) of the ion beam in order to align and parallel the exit directions of the ion beam that has been deflected into a fan shape by the first stage deflection magnet. was required separately.

There are 417 types of magnetic fields generated by this correction magnet, and the set value is determined according to the energy. Fine adjustment is performed by actually implanting ions into a semiconductor wafer and determining the bias of the ion beam from the distribution of the implanted amount. The problem was that we had to make guesses.

Furthermore, since it is not possible to monitor deviations in settings due to temperature rises, changes over time, etc., corrections are likely to be delayed.As a result, the amount and profile of ion implantation may not be carried out as designed, resulting in product defects. There was a point.

An object of the present invention is to produce the advantage of deflection scanning of an ion beam using a magnetic field, and to make the ion beam emitted from the magnetic field after deflection scanning essentially parallel, eliminating the need for angle correction of the ion beam. An object of the present invention is to provide an ion implantation device.

[Means for solving problems]

The above object is achieved by configuring the deflection electromagnet so that the beam incidence point of the deflection scanning electromagnet of the ion implantation device is located on an extension of the beam output end face of this electromagnet.

[For production]

The ion beam deflection electromagnet of the present invention allows the ion beam to enter the magnetic field of the magnet, be deflected, and exit from the magnetic field, even if the strength of the magnetic field changes and the radius of gyration of the beam changes. Regardless of this, the ion beam is configured such that when it is deflected by a certain angle, it reaches the output end face of this magnet and is output.

As a result, the beam exiting this deflection electromagnet essentially points in a fixed direction.In other words, the exit direction of the ion beam is fixed and parallelized regardless of the species, energy, or magnetic field strength. So,
There is no need to correct the ion beam angle.

Therefore, by simply controlling the magnetic flux density of the deflecting electromagnet, it is possible to scan the ion beam pointing in a fixed direction onto the semiconductor wafer and implant ions from a fixed direction.

〔Example〕

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

In FIG. 1, an ion beam 3 emitted from a discharge box 1 by an ion extraction electrode 2 is connected to a mass separation electromagnet 4,
The mass is separated by the mass separation slit 6, deflected by the deflection scanning electromagnet 8, and driven into the wafer 11 as a target.

The IT electromagnet for deflection scanning is arranged so that the incident point 7 of the ion beam 3 is located on the extension of the ion beam exit end face 9.
In this example, the ion beam 3 is shown to be incident perpendicularly to the incident end face of the magnet at the beam incidence point 7, but this is not necessarily the case!
It's not a condition.

According to this embodiment, the ion beam incident on the deflection scanning electromagnet 8 is fixed at a fixed angle (for example, 90
°) When the ion beam is deflected, it reaches the ion beam exit end face 9 and is emitted.

This is because even if the radius of the ion beam changes due to changes in the strength of the electromagnet (8g) magnetic field, the ion beam entrance point 7 and its exit point are always the same as the edge of the ion beam exit end face 9. The ion beam, on the other hand, follows a circular orbit in the magnetic field, resulting in the above-mentioned direct
is a common chord in each orbit.

Therefore, by changing the magnetic field strength of the deflection scanning electromagnet 8, it is possible to obtain an ion beam 10 that scans in the left-right direction in FIG. 1 while maintaining a constant direction.

As shown in FIG. 1, when combined with an implantation device in which a semiconductor wafer 11 is mounted on a rotating disk 12, scanning is inversely proportional to the radial position R on the disk 12 to which the deflected ion beam 10 is irradiated. By controlling the beam 10 to scan at a certain speed, the ion beam can be uniformly implanted into the wafer.

The radial position R on the disk 12 into which the ion beam 10 is implanted is determined by the mass and energy of the ions and the VL flow flowing through the deflection and scanning magnet.

Therefore, as shown in FIG. 2, the current Is to be passed through the deflection scanning magnet 8 is calculated by the CPU 14 based on the ion current IB, the implantation amount D1, the ion energy E, the radial position R, and the like. Based on the calculation result, the CPU 14 controls the electric power fiI to be supplied to the coil 15 of the deflection scanning electromagnet 8.
A control signal is sent to the deflection magnet power supply 16 to control the deflection magnet power supply 16.

FIG. 3 is a schematic diagram of another embodiment of the ion implantation apparatus in which the beam can be deflected in two directions by the deflection scanning electromagnet 20 and has two implantation chambers.

In the figure, the same reference numerals as in FIG. 1 represent the same or equivalent parts. As is clear from the explanation regarding FIG. 1, by reversing the magnetic field polarity of the deflecting electromagnet 20, the respective driving chamber hey-on beams 10 can be switched.

〔Effect of the invention〕

According to the present invention, since the ion beam can be scanned in parallel with a single deflection scanning electromagnet, a magnetic field for angle correction is not required, and the configuration can be simplified and the number of adjustment points can be reduced.

[Brief explanation of drawings]

FIG. 181 shows an ion implantation apparatus according to an embodiment of the present invention. Figure 2 shows the deflection magnet power supply and CPU for controlling the strength and polarity of the magnetic field produced by the deflection electromagnet.
FIG. FIG. 3 shows another embodiment of the present invention in which there are two driving chambers.

Claims (3)

[Claims] (1) An ion source, a magnet for mass-separating the ion beam generated by the ion source, and a deflection magnet for receiving the mass-separated ion beam and deflecting it toward the target. In the ion implantation apparatus configured, the deflection magnet is configured such that the ion beam incident point of the deflection magnet is located on an extension of the beam exit end face of the ion beam deflection magnet. Features of ion implantation equipment. (2) The ion implantation apparatus according to claim 1, wherein the deflection magnet is an electromagnet, generates a substantially uniform magnetic field, and the strength of the magnetic field is controllable. (3) The ion implantation apparatus according to claim 1, wherein the ion beam is incident perpendicularly to the incident side end face of the ion beam deflection magnet at its incident point.