JPH03252037A - Charged particle beam device - Google Patents

Abstract

PURPOSE:To irradiate the charged particle beams of energy energized by the voltage of a target power supply to a target by interposing the target power supply which determines the incident energy of charged particle beams, between an emitter and the target in such a way as to float in the accelerating potential of an accelerating voltage power supply. CONSTITUTION:A voltage power supply 13 which generates voltage corresponding to the difference (VA-BB), is interposed between an ion emitter 1 and a target 10 in such a way as to float in the accelerating potential of an accelerating voltage power supply 4 wherein VA represents accelerating voltage from an accelerating voltage power supply 4 to accelerate ion beams from the emitter 1, and VB represents decelerating voltage from a decelerating voltage power supply to be supplied between the target 10 and the outside electrode 6 of grounding potential of an objective lens 5. In this case, since no decelerating voltage power supply is now required, it is not actually provided. By this constitution, acceleration is provided by voltage corresponding to ions VA from the ion emitter 1, ion beams energized by voltage from the power supply which generates voltage corresponding to the difference (VA-VB), are however, irradiated to the target.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a charged particle beam device suitable for irradiating a target with a focused charged particle beam of low energy.

(Prior Art) Devices using focused ion beams are used, for example, in ion implantation and ion beam writing. In such a focused ion beam device, a target is normally irradiated with a high-energy ion beam accelerated by a high accelerating voltage of several tens of kilovolts or hundreds of kilovolts, but at that time, the surface of the target may be etched. It will be done. Recently, in order to prevent such unspecified etching, the ion beam generated from the ion gun is accelerated with a high acceleration voltage, or the accelerated ion beam is decelerated with a deceleration voltage to reduce the energy. The method used is to irradiate a target with an ion beam.

Note that the method of irradiating a target with a low-energy ion beam by lowering the acceleration voltage itself that accelerates the ion beam extracted from the ion emitter has many problems and cannot be adopted (Japanese Patent Applications No. 62-49326 and No. 63) -16
9625).

FIG. 2 is a schematic diagram of a focused ion beam apparatus that implements the method. In the figure, 1 is an ion emitter, 2 is an extraction electrode, and 3 is an acceleration electrode at ground potential.
An acceleration voltage is applied from an acceleration voltage power source 4 to the electrode 2, and an extraction voltage is applied to the extraction electrode 2 from an extraction voltage power source (not shown). Reference numeral 5 denotes an objective lens, which is an Einzel type electrostatic lens, and has an outer electrode 6 at ground potential.
and a center electrode 8 to which a lens voltage is applied from a lens power supply 7. Reference numeral 9 represents a deflection electrode that controls the irradiation position of the ion beam, and 10 represents a target that is irradiated with the ion beam. A deceleration voltage for decelerating the ion beam is applied to the target 10 from a power source 11. Note that 12 is an insulator.

In the above configuration, ions of a specific substance are extracted from the ion emitter 1 by the extraction electrode 2.

Since an accelerating voltage of, for example, +30 kV is applied to the emitter from the accelerating power source 4, the ion beam is accelerated by the accelerating electrode 3, and is delivered to the objective lens 5 with high energy.
and is focused onto the target 10 by the objective lens 5. The target is connected to a power source 11, for example +
Since a deceleration voltage of 29 kV is applied, an ion beam deceleration electric field is formed between the target lens 1-10 and the outer electrode 6 of the objective lens 5, which is at ground potential. Therefore, the focused ion beam is decelerated by the deceleration electric field,
As a result, several ion beams have lower energy and are irradiated onto the target 10. In this case, if the accelerating voltage from the accelerating voltage power source 4 is VA (e.g. 30 kv) and the deceleration voltage from the power source 11 for deceleration is Va (e.g. 29 kv), the target 10 has a difference (VA). -VB)
An ion beam energized by a voltage corresponding to (for example, 1 kV) is irradiated.

(Problem to be Solved by the Invention) Now, the acceleration voltage power source 4 and the deceleration power source 11
each has a precision error of about 3%.

Therefore, for example, the acceleration voltage is set to 30kv by the acceleration voltage power supply 4.
Even if it is set to Ion beam cannot be irradiated.

Also, although it is possible to create a high-voltage power source with high absolute accuracy, it is expensive, so for boat fishing, power sources such as those for scanning electron microscopes, which do not have very good absolute accuracy, are used. There are many things.

In particular, in applications such as direct deposition, the number 10
It is necessary to irradiate ions with an energy of eV, and the above-mentioned problems become noticeable with a general power source.

The present invention is aimed at solving such problems.

(Means for Solving the Problem) For this purpose, the charged particle beam device of the present invention includes a charged particle beam generation source, an accelerating voltage source for applying an accelerating voltage between the generation source and an accelerating electrode, and a charged particle beam generating source for applying an accelerating voltage between the source and the accelerating electrode. A lens for focusing the beam on a target placed insulated from the ground, and a voltage between the charged particle beam generation source and the target to energize the charged particle beam to be irradiated to the target. Equipped with a voltage source to generate the voltage.

(Function) The present invention uses an accelerating voltage vA from an accelerating voltage power source for accelerating the ion beam from an ion emitter, and a decelerating voltage from a decelerating voltage power source applied between the target and the outer electrode of the objective lens at a ground potential. Difference with VB (VA VB)
A voltage power source that generates a voltage corresponding to the ion emitter and the target is provided between the ion emitter and the target so that it floats on the acceleration potential of the acceleration voltage power source. Note that the deceleration voltage power source is not provided because it is unnecessary. If this is done, the ions from the ion emitter will be accelerated with a voltage corresponding to vA, but the ion beam energized by the voltage from the power supply that generates the voltage corresponding to (VA VB) will irradiate the target. be done.

(Embodiment) FIG. 1 is a schematic diagram of a focused ion beam apparatus showing an embodiment of the present invention. In the figure, the same components as in FIG. 2 are denoted by the same numbers. Also, in Figure 1, the second
The difference from the configuration shown in the figure is that a power source 13 is installed between the ion emitter 1 and the target 10, without providing a deceleration voltage power source between the target 10 and the ground.

First, in the configuration shown in FIG. 1, an accelerating voltage of, for example, +30 kV is applied to the ion emitter 1 from the accelerating voltage power source 4, so that the ion beam enters the objective lens 5 with high energy, and the objective lens directs the target 10. narrowly focused at the top.

At this time, for example, a voltage of +lkv is applied from the power supply 13 at the same time. Therefore, the ion beam is energized by the voltage (+1 kv) from the power source 13 and irradiates the target with low energy.

At this time, even if the power source 13 has an error of, for example, about 3%, the error is about 30V, and the ion beam can be irradiated with an approximately predetermined low-energy ion beam.

Note that the present invention is also applicable to devices using electron beams, such as electron microscopes.

(Effects of the Invention) In the present invention, the target power source that determines the incident energy of the charged particle beam to the target is provided between the source and the target so that it floats on the accelerating potential of the accelerating voltage power source. A charged particle beam energized by the voltage of the target power source is irradiated onto the target.

Therefore, only the accuracy error of the target power source that affects the energy of the charged particles irradiated onto the target is extremely small, and therefore the target can be irradiated with a charged particle beam having approximately a predetermined energy.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a focused ion beam device showing an embodiment of the present invention, and FIG. 2 is a schematic diagram of a conventional focused ion beam device. 1...Ion emitter 2...Extraction electrode 3...
・Accelerating electrode 4... Accelerating voltage power source 5... Objective lens 6... Outer electrode 7... Lens power source
8... Center electrode 9... Deflection electrode 10...
Target 11...Deceleration voltage power supply 12...Insulator 13...Deceleration voltage power supply

Claims (1)

[Claims] A charged particle beam generation source, an accelerating voltage source for applying an accelerating voltage between the generation source and an accelerating electrode, a lens for focusing the charged particle beam on a target placed insulated from the ground; A charged particle beam device further comprising a voltage source between the charged particle beam generation source and the target that generates a voltage for energizing the charged particle beam irradiated onto the target.