JPS6324061A - Ion implantation device - Google Patents

Abstract

PURPOSE:To uniformly implant an ion into the whole surface of a semiconductor wafer by converting horizontally and vertically deflected ion beams into parallel beams vertical to the wafer, and projecting and implanting the ion into the surface in the title device for implanting an ion into the semiconductor wafer. CONSTITUTION:An ion beam 24 generated in an ion beam generator 23 is accelerated by an accelerator 25, deflected horizontally and vertically in a specified angle range by a deflector 30 having a quadrupole electrostatic lens 26, a vertical deflection electrode 28a, an electron confining magnet 27, and a horizontal deflection electrode 28b, and scans the surface of a semiconductor wafer 36. Since there is a difference in the incidence angle between the central and peripheral parts of the semiconductor wafer 36, the ion cannot be uniformly implanted. In this case, a unipotential electrostatic lens 31 is provided below the deflector 30, the power source 32 for the unipotential electrostatic lens 31 is controlled by a controller 33 in accordance with the impressed voltage of the deflection electrodes 28a and 28b, the resulting parallel ion beams 24 are projected over the whole surface of the semiconductor wafer 36, and the ion can be uniformly implanted into the whole surface of the wafer 36.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an ion implantation apparatus for implanting desired ions into a semiconductor wafer or the like.

(Prior art) Generally, an ion implantation apparatus for implanting ions into a substrate to be ion implanted such as a semiconductor wafer is configured as shown in FIG. Ion beam 4 ejected from beam generator 3 (accelerated by accelerator 5, quadrupole electrostatic lens 6, vertical deflection electrode 7 consisting of opposing electrodes)
A device consisting of a horizontal deflection electrode 7b, a vertical deflection electrode 8a that applies a periodically changing voltage between these electrodes, and a horizontal deflection power source 8b. The ions are irradiated and implanted into a substrate to be ion-implanted, such as a semiconductor wafer 11.

(Problems to be Solved by the Invention) However, in the conventional ion implantation apparatus described above,
For example, the incident angle differs depending on the part of the substrate to be ion-implanted, such as the center and the periphery of the semiconductor wafer that is irradiated with the ion beam, and this causes the problem that ions cannot be uniformly implanted over the entire surface of the substrate to be ion-implanted. Ta.

The present invention has been made in response to such conventional circumstances, and it is an object of the present invention to provide an ion implantation apparatus capable of uniformly implanting ions over the entire surface of a substrate to be implanted.

[Structure of the Invention] (Means for Solving the Problems) That is, the ion implantation device of the present invention applies a periodically changing voltage between an ion beam generator that emits a desired ion beam and an electrode on the moon surface. a deflection means for deflecting the ion beam in the horizontal and vertical directions by applying an applied voltage; and an applied voltage is controlled according to a voltage applied between the electrodes of the deflection means, so that the ion beam deflected in the horizontal and vertical directions is converted into a parallel beam. and collimating means for irradiating the substrate to which ions are implanted.

(Function) In the ion implantation apparatus of the present invention, the ion beam deflected in the horizontal and vertical directions by the deflecting means is converted into a parallel beam and irradiated onto the substrate to be ion implanted. Furthermore, since the voltage applied to the means for collimating the ion beam is controlled according to the voltage applied between the electrodes of the deflection means, all the ion beams deflected in the horizontal and vertical directions by the deflection means are It is possible to form a parallel beam with high accuracy in the area.

(Embodiment) An embodiment of the ion implantation apparatus of the present invention will be described below with reference to the drawings.

FIG. 1 shows an ion implanter according to an embodiment of the present invention, in which an ion generator 21 and a mass spectrometer magnet 2 are shown.
The ion beam 24 ejected from the ion beam generator 23 consisting of 2 is accelerated by an accelerator 25, and is accelerated by an accelerator 25, and then passes through a quadrupole electrostatic lens 26, an electron confinement magnet 27, a vertical deflection electrode 28a consisting of opposing electrodes, and a horizontal deflection electrode. 28b, and a vertical deflection power source 29a and a horizontal deflection power source 29b which apply a voltage between these electrodes. For example, the power supply device 32 is controlled according to the unipotential electrostatic lens 31, the power supply device 32 that applies voltage to the unipotential electrostatic lens 31, the voltage applied between the vertical deflection electrodes 28a, and the voltage applied between the horizontal deflection electrodes 28b. A parallel beam forming device 34 comprising a control device 33 converts the parallel beam into a parallel beam, and temporarily irradiates a substrate to be ion-implanted, such as a semiconductor wafer 36 held on a platen 35 .

In the ion implantation apparatus of this embodiment having the above configuration, in the deflection device 30, the quadrupole electrostatic lens 26 and, for example, the vertical deflection power source 29a and the horizontal deflection power source 29b are connected to the vertical deflection electrode 28a and the horizontal deflection electrode 28b, respectively. to 1
The ion beam 24 is deflected and scanned in the horizontal and vertical directions within a certain angular range by a multi-exposure electrostatic field formed by applying a voltage with a frequency of approximately KHz. Note that the electron confinement magnet 27 restricts the movement of electrons by forming a weak magnetic field of approximately several hundred Gauss, and the ion beam 2
Improve the deflection characteristics of 4.

The ion beam 24 deflected in the horizontal and vertical directions within a certain angular range is converted into a parallel beam by a controlled parallel beam converter 34 as described below. That is,
The ion beam incident on the wafer 36 is controlled to be approximately parallel to both the center and the periphery.

That is, as shown in FIG. 2, when the absolute value of the deflection angle θ of the ion beam 24 that passes between the opposing flat electrodes 28 and is deflected is large, and the ion beam 24 passes through the periphery of the unipotential electrostatic lens 31. Generally, a deflection error occurs, and the ion beam 24 does not become a parallel beam as shown by the dotted line B, but is excessively deflected as shown by the solid line A and may be deflected toward the optical axis side shown by the dashed-dotted line C. many.

On the other hand, the displacement χ of the ion beam 24 from the optical axis C is proportional to the voltage applied between the opposing flat electrodes 28.

Therefore, as shown by the solid line D in the graph of FIG. 3 in which the vertical axis is the applied voltage and the horizontal axis is time, the change in the voltage applied between the facing plate electrodes 28 (the displacement χ of the ion beam 24 from the optical axis C) . It is possible to suppress excessive deflection at the portion and eliminate deflection errors.

By performing such control in the horizontal and vertical directions, highly accurate parallel beams can be obtained.

Note that, for example, depending on the shape of the electrode of the unipotential electrostatic lens 31, etc., it is necessary to change the lul control of the voltage to eliminate deflection errors.
It is necessary to actually measure the relationship between the applied voltage of 8 and the deflection error of the unipotential electrostatic lens 31 to find the voltage applied to the unipotential electrostatic lens 31 that will produce a parallel beam.

Therefore, in this embodiment, for example, the oscillator outputs of the vertical deflection power source 29a and the horizontal deflection power source 29b are input as reference signals to the control device 33, and the vertical deflection electrode 28a is The voltage applied to the unipotential electrostatic lens 31 is controlled in synchronization with the voltage applied between the unipotential electrostatic lens 31 and the horizontal deflection electrode 28b, and the ion beam 24 is made into a parallel beam with high precision.

Therefore, in the ion implantation apparatus of this embodiment, the entire surface of the substrate to be ion implanted, such as the semiconductor wafer 36, can be irradiated with the ion beam 24 in the form of a parallel beam of 9 Av at a constant incident angle, making it possible to uniformly implant ions. can.

[Effects of the Invention] As described above, the ion implantation apparatus of the present invention can form an ion beam into a parallel beam with high precision, and can irradiate the entire surface of a substrate to be ion implanted, such as a semiconductor wafer, with an ion beam at a constant incident angle. Therefore, ions can be uniformly implanted over the entire surface of the substrate to be ion implanted.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing an ion implanter according to an embodiment of the present invention, Fig. 2 is an explanatory diagram showing the deflection error of the unipotential electrostatic lens of the deflection device shown in Fig. 1, and Fig. 3 is parallel to Fig. 1. FIG. 4 is a graph showing an example of voltage control of a beam forming device, and is a configuration diagram showing a conventional ion implantation device. 23... Ion beam generator, 24...
...Ion beam, 28a...Vertical deflection electrode,
28b...Horizontal deflection electrode, 29a...
Vertical deflection electrode, 29b...Horizontal deflection power supply, 30
... Deflection device, 31 ... Unipotential electrostatic lens, 32 ... Power supply device, 33 ...
... Control device, 36 ... Semiconductor wafer applicant Tokyo Electron Co., Ltd. agent Patent attorney Satoshi Suyama - ゛Figure 1 Figure 2 Time- Figure 4

Claims (1)

[Claims] (1) An ion beam generator that emits a desired ion beam, a deflection means that applies a periodically changing voltage between opposing electrodes to deflect the ion beam in horizontal and vertical directions, and electrodes of the deflection means. ion beam converting means for converting the horizontally and vertically deflected ion beam into a parallel beam and irradiating the ion-implanted substrate with an applied voltage controlled in accordance with a voltage applied between the ions. Injection device.