JP3421100B2 - Ion beam irradiation equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is for producing a thin film, such as a diamond-like carbon thin film, which is difficult to be prepared by a conventional thermal method such as vacuum deposition, in order to form a thin film of an ionized substance at a low energy of about 500 eV or less. The present invention relates to an ion beam irradiation device for irradiating a substrate with.

[0002]

2. Description of the Related Art A conventional low-energy (about 500 eV or less) ion beam irradiation apparatus is, for example, as shown in FIG. One or more high voltage electrodes b ₁ and b ₂ to which is applied are arranged.

According to this structure, the ion beam is extracted from an ion source (not shown), and is transported at a high energy (about several KeV or more) along the optical axis c in order to suppress the divergence due to the space charge effect. The passed ions are finally decelerated to a predetermined low energy by the electric field created by the high voltage electrode b ₁ provided immediately before the substrate a and the substrate a, and irradiate the substrate a.

[0004]

In the above-mentioned conventional ion beam irradiation apparatus, since the electric field created by the high voltage electrode b ₁ and the substrate a is large, as shown in FIG. When the angle formed by the normal to the substrate a changes significantly, the electric field on the front surface of the substrate a changes, which causes the trajectory d of the beam to largely deviate from the optical axis c. In some cases, the substrate a is irradiated with the ion beam. There was a problem that I could not do it. Further, when a plurality of ion beams are simultaneously applied to the substrate a, there is a problem that the trajectories of the ion beams are changed due to mutual interference of electric fields created by the respective high voltage electrodes and the substrate a. It was

An object of the present invention is to solve the above problems.

[0006]

In order to achieve the above-mentioned object, the present invention slows down an ion beam incident with high energy by an electric field formed by a high voltage electrode opposed to a substrate, thereby reducing the energy consumption. In the apparatus for irradiating the substrate with, a shield electrode is provided which covers at least the substrate side end of the high voltage electrode and extends in the substrate side direction, and the shield electrode has the same potential as the substrate or the potential of the high voltage electrode. It is characterized by a significantly lower potential. An electrode for applying a predetermined voltage is provided on the side of the high-voltage electrode opposite to the substrate, and a predetermined voltage is applied to the electrode to converge the end of the high-voltage electrode and the end of the shield electrode in the middle. Such an ion beam may be incident on the high-voltage electrode, and a control electrode for applying an adjustable voltage is provided on the opposite side of the electrode from the substrate, and the voltage applied to the control electrode is The focus position of the ion beam in the shield electrode may be adjusted by changing the position. A plurality of sets of the ion beam irradiation devices can be arranged so that each ion beam irradiates the same region of the substrate.

[0007]

A high-voltage electrode is provided with a shield electrode which covers at least the end of the high-voltage electrode on the substrate side and extends in the substrate-side direction, and which has the same potential as the substrate or a potential significantly lower than the potential of the high-voltage electrode. All or most of the electric field due to the potential difference between the substrate and the substrate occurs between the high voltage electrode and the shield electrode, and the electric field between the shield electrode and the substrate does not occur or is small. Therefore, the irradiation position on the substrate of the ion beam that is decelerated by the electric field between the high voltage electrode and the shield electrode and irradiates the substrate is
Even if the substrate is tilted, there is little or no influence between the shield electrode and the substrate.

The electric field leaking to the front surface of the substrate can be made small by making the opening of the shield electrode to the substrate small, or even if it is large, by extending the shield electrode sufficiently longer in the direction of the substrate than the high voltage electrode. As is clear from the equipotential surface E formed between the high-voltage electrode 1 and the shield electrode 2 shown in FIG. 1, a strong convex lens action is exerted on the ion beam passing through due to the potential difference between the high-voltage electrode 1 and the shield electrode 2. An ion beam that is generated but is focused between the high voltage electrode 1 and the shield electrode 2 by applying a predetermined voltage to the electrode provided on the opposite side of the high voltage electrode from the substrate is injected into the high voltage electrode 1. By doing so, the influence of this convex lens action on the trajectory of the ion beam can be suppressed to a minimum.

If an applying electrode for applying an adjustable voltage is provided on the side of the high-voltage electrode opposite to the substrate and the voltage applied to the control electrode is changed, the focus position of the ion beam is changed and The size of the area to be irradiated with the ion beam changes at.

The plurality of sets of ion beams of the ion beam irradiation device irradiate the same region of the substrate.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows an embodiment of the present invention. In the figure,
The inner diameter of the high-voltage electrode 1 is D ₀ , the inner diameter of the shield electrode 2 covering the high-voltage electrode 1 is 2D ₀ , and the extension length from the edge of the high-voltage electrode 1 to the edge of the shield electrode 2 is 2D ₀ , The inner diameter of the opening at the edge of the shield electrode 2 is D ₀ , and the distance between the shield electrode 2 and the substrate 3 is 2
It is D ₀ .

By applying a predetermined voltage to an electrode (not shown) provided on the opposite side of the high voltage electrode 1 from the substrate 3, the high voltage electrode 1 is provided between the respective edges of the high voltage electrode 1 and the shield electrode 2. Injecting an ion beam that converges almost in the middle,
When the potential of the shield electrode 2 is the same as that of the substrate 3 and the energy of the ion beam on the substrate 3 is 1/40 of the energy inside the high voltage electrode 1, the trajectory 5 of the ion beam by computer simulation is As shown,
The substrate 3 can be irradiated without diverging the ion beam. As a result of computer simulation, D ₀ = 2
It has been found that when the ion energy is 0 mm and the mass of ions of 40 atomic mass units, that is, the energy of calcium ions on the substrate is 100 ev, the spread of the ion beam can be sufficiently ignored up to an ion current of about 10 μA.

For the diameter D ₀ of the high voltage electrode 1, the shield electrode 2
Diameter was shorter than 2D ₀ the length of the shielding electrode 2 extending from an end of the high voltage electrode 1 is made smaller than 2D ₀ of and if the diameter of the shielding electrode 2 greater than 2D _0, the shielding electrode 2 length By making the length longer than 2D _{0, the} electric field leaking to the front surface of the substrate can be made small as in the above-mentioned embodiment.

The flange of the opening of the shield electrode 2 can be omitted by reducing the diameter of the shield electrode 2.

According to the structure shown in FIG. 2, since the electric field on the front surface of the substrate 3 is small, even if the normal direction of the substrate 3 is tilted 45 degrees with respect to the optical axis 4 as shown in FIG. The deviation of the trajectory 5 of the ion beam from the optical axis 4 due to tilting 3 is slight.

FIG. 4 shows another embodiment of the present invention.

In the figure, 6 is a control electrode for applying an adjustable high voltage, and 7 is a high-voltage electrode having the same potential as the ion beam carrier.

By adjusting the voltage applied to the high-voltage electrode 6 to adjust the potential of the control electrode 6, the focus position of the ion beam is adjusted as shown in the figure, and the electric field on the front surface of the substrate 3 is reduced. The size of the ion beam irradiation region on the substrate can be changed while keeping the same.

FIG. 5 shows an example in which, for example, two sets A and B are arranged so that the ion beams 5A and 5B irradiate the same region of the substrate 3 with the ion beam irradiation apparatus shown in FIG.

According to this configuration, for example, two ion beams 5A, 5 having different energies, ion species, charges, etc.
B can be simultaneously applied to the same region of the substrate 3.

As described above, the ion beam irradiation apparatus shown in FIG. 1 does not substantially change the irradiation position of the ion beam on the substrate 3 and the normal line of the substrate 3 and the optical axis 4 of the ion beam.
The angle formed by and can be greatly changed, and the distance between the shield electrode 2 and the substrate 3 can be made relatively large. Therefore, for the purpose of irradiating the same region of the substrate 3 with the ion beam and the electrically neutral molecular beam at the same time. Can be used.

[0022]

Since the present invention is configured as described above, even if the angle formed by the normal line of the substrate with respect to the optical axis of the ion beam from the ion irradiation device is greatly changed, the ion irradiation of the substrate is performed. The position has an effect that it is slightly deviated from the optical axis of the ion beam, and there is an effect that a plurality of ion beams can be simultaneously irradiated to the same position on the substrate without interfering with each other.

[Brief description of drawings]

FIG. 1 is an explanatory diagram for explaining the principle of the present invention.

FIG. 2 is a cross-sectional view showing a schematic configuration of an embodiment of the invention according to claim 1;

FIG. 3 is a sectional view of the embodiment shown in FIG. 2 when the substrate is tilted.

FIG. 4 is a sectional view showing a schematic configuration of an embodiment of the invention according to claim 3;

FIG. 5 is a cross-sectional view showing a schematic configuration of an embodiment of the invention according to claim 4;

FIG. 6 is a cross-sectional view showing a schematic configuration of a conventional ion beam irradiation apparatus.

7 is a sectional view of the device shown in FIG. 6 when the substrate is tilted.

[Explanation of symbols]

1 High Voltage Electrode 2 Shielding Electrode 3 Substrate 4 Optical Axis 5, 5A, 5B Ion Beam (Orbit) 6 Control Electrode

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-5-121195 (JP, A) JP-A-4-277459 (JP, A) JP-A-4-37024 (JP, A) JP-A-5- 211120 (JP, A) JP-A-4-36948 (JP, A) JP-A-2-44715 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C23C 14 / 00-14 / 58 H01J 37/317

Claims (4)

(57) [Claims] 1. An apparatus for irradiating the substrate with low energy by decelerating an ion beam incident with high energy by an electric field formed by a high voltage electrode opposite to the substrate, and at least the substrate of the high voltage electrode. An ion beam irradiation apparatus comprising a shield electrode which covers a side end portion and extends in the substrate side direction, and the shield electrode has the same potential as the substrate or a potential significantly lower than that of a high voltage electrode. 2. An electrode for applying a predetermined voltage is provided on the opposite side of the high voltage electrode from the substrate, the electrode comprising:
The ion beam according to claim 1, wherein an ion beam that converges to an intermediate portion between an edge of the high voltage electrode and an edge of the shield electrode by applying a predetermined voltage is incident on the high voltage electrode. Beam irradiation device. 3. A control electrode for applying an adjustable voltage is provided on the side of the high voltage electrode opposite to the substrate, and the control electrode controls the ion beam in the shield electrode by adjusting the applied voltage. The ion beam irradiation apparatus according to claim 1, wherein the focus position is adjusted. 4. An ion beam irradiation apparatus, characterized in that a plurality of sets of the ion beam irradiation apparatus according to claim 1, 2 or 3 is arranged so that each ion beam irradiates the same region of a substrate.