JPH0313571A - Vapor deposition device, vaporization source and formation of thin film - Google Patents

Abstract

PURPOSE:To effectively utilize sputtered particles to form a thin film by irradiating a target material with an energy beam while moving the irradiation position. CONSTITUTION:The ions of Ar, etc., are drawn out by a focusing electrode 6, focused by an Einzel lens formed along with an ion beam deflecting electrode 4 and a source gas supply plate 8 and introduced to a sputtering region. A periodical voltage is impressed on the electrode 4, and the beam is deflected, rotated and scanned. Furthermore, the beam is modulated in a serrated form with a slow cycle, and the focused point of the beam is scanned over the whole region of a condensed source 13 in its axial direction. The inner surface of a condensed target 1 is irradiated with the focused beam which is moved in its axial direction and draws a circle, and the condensed source 13 is also irradiated. The sputtered surface is cooled until the beam comes next time, and a fresh source gas is condensed. The sputtered particles are deposited on a sample substrate 10 to form a thin film.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a vapor deposition apparatus, an evaporation source, and a thin film forming method using these, and particularly to a vapor deposition apparatus, an evaporation source, and a method using these suitable for forming a thin film. This invention relates to a thin film forming method.

[Conventional technology]

Conventionally, it has been known to use a sputtering method to create thin films of metals, dielectric materials, and the like.

Sputtering methods include DC bipolar sputtering and bias sputtering, as described in "Thin Film Handbook, edited by the 131st Committee of the Japan Society for the Promotion of Science, pp. 171-195 (Ohmsha, December 1981)." ,
High frequency sputtering, magnetron sputtering,
Ion beam sputtering and the like are known.

All of these methods utilize the phenomenon of sputtering substances that are in a solid state at room temperature with an ion beam or ions in plasma. Therefore, the film formation rate is limited by the sputtering rate of the solid state material.

On the other hand, - to cool gases such as carbon oxide and methane,
The process of sputtering the solidified material by ion irradiation by combining these molecules with each other using DeWalska is known as ``desorption infusion by electronic transition DIET''.
II (Desorption Induced by
Electronic Transition DIE
T U ) W, Brenig, D, Menzel
[, Springer Publishing, pp. 170-176 (198
5 years)”.

In this case, the number of atoms and molecules decomposed by sputtering of a substance in which gases such as carbon oxide and methane are assimilated per irradiated ion, the so-called sputtering rate, is approximately 100 to 1000. Are known.

In addition, a method of irradiating gases and solidified substances with focused laser light to rapidly give energy to these substances, turning them into a plasma state, and forming a thin film using the particles generated in the plasma was developed in Japanese Patent Application Laid-Open No. 63-177414.

[Problem to be solved by the invention]

Among the conventional techniques mentioned above, all sputtering methods using ions or plasma use substances that are solid at room temperature as the sputtering target material, and the target material is decomposed by the sputtering mechanism shown in the "Thin Film Handbook" mentioned above.・This method involves scattering and forming a film using the scattered sputtered particles. In this case, the sputtering rate of the target per ion incident on the sputtering target has a value of 1 to 10, resulting in a problem that the film forming rate is as slow as 0.1 to lnm/sec.

In addition, in the sputtering method in which gas is condensed into a solidified substance and the material in this state is sputtered, the surface temperature of the cooling substrate on which the gas is condensed increases due to irradiation with an ion beam or laser beam, so the condensation of the raw material gas is difficult. There was a problem that it was not always carried out effectively.

An object of the present invention is to provide a vapor deposition apparatus that effectively utilizes sputtered particles to form a thin film, and further includes:
The object of the present invention is to provide an evaporation source that can effectively utilize sputtered particles, and furthermore, to provide a thin film forming method that effectively utilizes sputtered particles to form a thin film. The object of the present invention is to provide an evaporation device that can effectively condense a target substance to form a thin film; It is an object of the present invention to provide a method for forming a thin film in which a target substance is favorably condensed to form a thin film.

[Means to solve the problem]

The above objects include (1) an energy beam source that emits an energy beam, a focusing means that focuses the energy beam, a target holding means that holds the target sputtered by the irradiation of the energy beam, and a particle of the sputtered target. A vapor deposition apparatus having at least a sample holding means for holding a sample for vapor deposition on the sample, characterized in that the vapor deposition apparatus includes a moving means for moving the irradiation position of the energy beam on the target during irradiation. (2) The vapor deposition apparatus according to (1) above, wherein the target holding means has a structure in which the held target is held axially symmetrically and facing the direction of the axis.

(3) The vapor deposition apparatus according to the above item 1, wherein the target holding means has a means for cooling the target; (4) the vapor deposition apparatus includes a supply means for supplying a condensable gas; (5) The vapor deposition apparatus according to item 1, further comprising a cooling means for condensing the supplied condensable gas onto the target holding means to form a target; (6) an energy beam source that emits an energy beam; a focusing means that focuses the energy beam; a target holding means for holding a target to be sputtered by irradiation with the energy beam; a scanning means for the energy beam for rotationally symmetrically moving the irradiation position of the energy beam along the axis of progress; A vapor deposition apparatus comprising a sample holding means for holding a sample in order to vapor-deposit the target particles onto the sample;
(7) The vapor deposition apparatus according to the above item 6, wherein the target holding means has means for cooling the target; (8) The vapor deposition apparatus includes a supply means for supplying a condensable gas; 6. The vapor deposition apparatus as described in 6 above, further comprising a cooling means for condensing the supplied condensable gas onto the target holding means to form a target; 8. The vapor deposition apparatus described in 8 above, characterized in that it has a structure in which the energy beam is supplied to the target from the incident side (10).
) The vapor deposition apparatus according to the above item 8, wherein the supply means has a structure for supplying a plurality of condensable gases, (
11) In an evaporation source having at least an energy beam source that emits an energy beam, a focusing means that focuses the energy beam, and a target holding means that holds a target sputtered by irradiation with the energy beam, the energy beam on the target (12) The target holding means is arranged such that the held target is axially symmetrical and facing the direction of the axis. 1 above, characterized in that the structure is retained;
The evaporation source according to 1.

(13) The evaporation source according to 11 above, wherein the target holding means has a means for cooling the target; (14) the evaporation source includes a supply means for supplying condensable gas; (15) The evaporation source according to the above item 11, further comprising a cooling means for condensing the supplied condensable gas onto the target holding means and making it a target. (16) irradiating the target material bonded by van der Waalska or hydrogen bonding force with the energy beam while moving the irradiation position; (17) A method for forming a thin film, characterized in that the particles generated by the sputtering are deposited on a sample to form a thin film containing at least a part of the target material; (17) the target material is placed in a vacuum; introducing and solidifying the target material on a substrate cooled to below the freezing point of the target material,
Sputtering is performed by irradiating the solidified target material with an energy beam while moving the irradiation position, and evaporating particles generated by the sputtering onto the sample to form a thin film containing at least a portion of the target material. This is achieved by a thin film forming method characterized by the following.

In the present invention, the energy beam is an ion beam,
An electron beam, a particle beam such as plasma, a laser beam, etc. can be used. The ion beam is H, He, Ne, Ar.
, Xs, Kr, or a mixed gas containing at least one of these.

In the present invention, the irradiation position of the energy beam may be moved during irradiation by scanning the energy beam, mechanically moving the target, or a combination of the two.

For example, if the energy beam is an ion beam, the energy beam can be scanned by an ion beam deflector comprising at least two opposing electrodes or opposing magnetic poles.

When a condensable gas is used in the present invention, it is formed as such. In addition to this, silicon tetrachloride.

Titanium tetrachloride, WF, CF, GaH, acetylene, etc. can be used, and from these raw materials Si, Si,
Thin films of Ti, W, carbon, Ge, and polyacetylene can be obtained. Furthermore, as an example of using a plurality of raw materials, a thin film of titanium silicide can be obtained from titanium tetrachloride and silicon tetrachloride, and a thin film of boron nitride can be obtained from ammonia gas and boron trifluoride.

In this way, the condensable gas does not have to be a gas at normal temperature and pressure, but can be used as long as it is a gas under desired conditions.

Further, when condensing a condensable gas, at least the surface of the portion of the target holding means to which the gas adheres can be made of a material containing the same element as the condensable gas.

When using an ion source as an energy beam source, it is preferable to have an axially symmetrical structure from the viewpoint of ion output. The axisymmetric ion beam has a simple focusing means and a simple mechanism for rotational scanning. Furthermore, by making the target also axially symmetrical, it is possible to arrange the target close to the ion source on the same central axis.

As the above-mentioned axially symmetric target, there is one having a hollow cylindrical shape. For example, the target having the above shape can be obtained by configuring the surface of the target holding means on which the condensable gas is condensed into a cylindrical shape and solidifying the condensable gas inside the cylindrical shape.

[Effect]

When a target is irradiated with a focused energy beam, only the irradiated position is sputtered, and a recess is formed at that position. By moving the irradiation position of the energy beam, each part of the target can be averaged and used.

In addition, it is desirable for the energy beam source, especially the ion source, to be axially symmetrical from the viewpoint of ion output, but by configuring the target similarly axially symmetrically, it is possible to place it close to the ion source on the same central axis. The ion beam emitted from the ion source can be introduced into the sputtering region with almost no loss.

Furthermore, by making the target into a hollow cylindrical shape and using its inner surface as the area to be sputtered, the energy beam enters from the negative end, and most of the sputtered particles and reflected ions exit from the other end. As a result, directivity is added to the sputtered particles, and the efficiency as an evaporation source is improved.

Also, when condensing a condensable gas as a target, heat is generated in the area irradiated by the energy beam, which prevents the above condensation, but if the irradiation position is moved during irradiation with the energy beam, the heat Diffusion is effectively performed, and the supplied condensable gas can be effectively cooled and condensed.

Some of the inventors of the present invention have proposed a method in which a gaseous substance at room temperature is kept below its melting point as a target, and the sputtered particles are formed into a thin film on a sample by ion beam sputtering. ing. In this case, there is a problem in that the surface temperature rises due to ion beam irradiation, and the condensation of the substance is not necessarily carried out effectively. In the present invention, the above problem is solved by moving the irradiation position during irradiation with the energy beam. It also solves the problem.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. 1st
The figure is a schematic cross-sectional view of the vapor deposition apparatus of the present invention. The evaporation source is housed in a vacuum container (housing 7), and is connected by a flange to another vacuum container (housing 7') having a sample substrate holder 11 holding a sample substrate 10. Two housings 7. 7' is written in one piece.

The overall structure is larger from the left side, including an ion source 12', a focusing electrode 6, an ion beam deflection electrode 4, and a source gas supply plate 8. It consists of a cooling substrate 9 and has an axially symmetrical structure with respect to the central axis.

The ion source 12' includes a card 51 and an anode housing 12.
, and an intermediate electrode 5. Ar is supplied from the ionized gas supply pipe 15 at a level of 10-3 Torr, and the sAr ions that generate a pinched plasma arc by the magnetic field coil 52 are extracted by the focusing electrode 6, and together with the ion beam deflection electrode 4 and the source gas supply plate 8. The light is focused by an Einzel lens and introduced into the sputtering region. The ion beam deflection electrode 4 has two cylinders 2
It has a four-electrode structure with pairs facing each other. Behind the source gas supply plate 8 is a cylindrical cooling substrate 9, which is composed of a liquid nitrogen jacket 2 and a condensation target 1. In this embodiment, the condensation target 1 is a silicon block processed. The inner surface was cylindrical and the outer surface was conical, and the tube was fitted and fixed into a liquid nitrogen jacket 2 whose inner surface was tapered at the same ratio. This shape is intended to strengthen the contact between the condensation target 1 and the liquid nitrogen jacket 2, to minimize thermal resistance, and to facilitate exchange of the condensation target from the vapor deposition source outlet end.

The source gas supply plate 8 is disk-shaped, but the fumarole holes provided around the center hole open toward the cooling board 9, and the length of the cooling board 9 is approximately twice the inner diameter. Therefore, the probability of the introduced source gas molecules leaving the deposition source without colliding with the inner surface of the condensation target 1 is as small as 7% or less. These source gas molecules that are emitted without collision also have directivity in the ion beam traveling direction, and can be effectively used for the purpose of forming a film on the sample substrate surface. The source gas that collides with the inner surface of the condensation target 1 has an adhesion coefficient close to 1, and most of it is effectively condensed to form a layer of condensed source 13 on the inner surface of the condensation target 1 .

Next, the operation of this vapor deposition apparatus will be explained.

The Ar ion current obtained by introducing Ar is about 2 A, and +2 kV is applied to the cooling substrate 9 from the ion source 12'. The ion beam deflection electrode 4 is provided with ±A I, sin ω in order to deflect and rotate the beam. and ±Aoco
sω. A periodic voltage of t is applied, and in order to further scan the focal point of the ion beam in the axial direction over the entire area of the condensation source 13, Ao is modulated in a sawtooth manner with a slow period ω1 of ω, (ω. Ru.

Furthermore, the ion beam deflection electrode 4 is constructed with a focusing electrode 6 and a source gas supply plate 8 (both of which are normally at ground potential).
A focusing voltage A2 of the Einzel lens is applied, which is also modulated in a sawtooth pattern in synchronization with ω so that it changes in the axial direction as the focusing point moves.

With the above configuration, the Ar ion beam irradiates the inner surface of the condensation target 1 in a circular manner while moving in the axial direction while maintaining a focused state, and sputters the condensation source 13 formed by condensation of the source gas. The same region is sputtered at the period of the sawtooth modulated wave, and the surface sputtered by the -degree beam is cooled until the next beam arrives, and new source gas is condensed.

In this example, 100% 5i2H was used as the source gas to form an amorphous SiH thin film. This gas is 1
The melting point at atmospheric pressure is -132.5°C, the boiling point is -115°C, and when liquid nitrogen is used as the cooling refrigerant and no sputtering is performed, it condenses as a solid on the condensation target 1.The condition of the condensation target surface during sputtering is Although it is unknown whether it is a solid or not, a sputtered particle flux equivalent to approximately IA of ion current was obtained for the introduction of 15 can, and it seems that it is effectively condensed. Using this evaporation apparatus, amorphous SiH was deposited at a rate of 15 people/sec on a substrate 20 cm away from the evaporation source. The sample substrate is approximately 20
Although it is heated to 0° C., since there is no film formation from the gas phase at this temperature, directional sputtering and primary ion irradiation contribute to film formation. This is another effect of this directional vapor deposition apparatus.

Although an inorganic material was used as the source gas in this embodiment, the present invention is also suitable for sputter deposition of organic materials and composite materials. Further, in the embodiment, a material that is gaseous at room temperature is used, but the present invention can be applied as long as the material is supplied at least from the gas supply plate in a gaseous state. In that case, use a gas supply system with a heating device, etc.

In addition, although a single type of gas was used in the embodiment, the configuration of the present invention allows the formation of a mixed thin film by simultaneously supplying multiple types of gas, and by switching and supplying multiple gases, it is possible to form a mixed thin film. It is also possible to form a film, a superlattice structure film, a gradient composition film, and the like.

In addition, in this example, only the reducing action of the source gas was targeted, but by simultaneously supplying an oxidizing or reactive gas,
Formation of reaction product films is also possible.

Next, another embodiment will be explained with reference to FIG. In this embodiment, the beam extraction hole of the ion source 12' is shaped like a long slit in the direction perpendicular to the plane of the paper, and the ion beam deflection electrode 4, cooling substrate 9, etc. are also made long in the direction perpendicular to the plane of the paper. 0 The ion beam deflection electrode 4 in this embodiment consists of two pieces, upper and lower, and is designed to scan the ion beam vertically.

The present invention is characterized in that it is particularly efficient when processing large-area samples.

Next, still another embodiment of the present invention will be described with reference to FIG. FIG. 3 shows the cooling substrate 9 of the vapor deposition apparatus shown in FIG. 1 rotated in the form of a roll.

At this time, the gas supply port of the source gas supply plate 8 is opened toward the side 180° opposite to the beam irradiation side of the cooling substrate 9. By doing so, sputtering can be performed without deteriorating the degree of vacuum on the beam irradiation side. By suppressing deterioration of the degree of vacuum during beam irradiation, the charge conversion effect of the ion beam 16 can be suppressed, and the energy width of the sputtered particles is also suppressed from expanding, resulting in a sputtered particle beam with good monochromaticity.

Next, another embodiment of the present invention will be described with reference to FIG. This embodiment has a configuration in which the rotation axis of the roll-shaped cooling substrate 9 in the embodiment shown in FIG. 3 is parallel to the traveling direction of the ion beam 16.

With this configuration, a plurality of cooling boards 9 can be provided.Although only two cooling boards 9 are shown in Figure 0, for example, similar cooling boards 9 can be installed at the back and front of the paper in Figure 1. can be provided. Therefore, by condensing several different source gases onto each cooling substrate 9, it becomes possible to easily form a multilayer film or a composite film on the sample substrate.In this embodiment, a plurality of source gases are condensed. It is particularly effective when sputtering.

〔Effect of the invention〕

According to the present invention, by moving the irradiation position of the energy beam, each part of the target can be used on average.

Furthermore, the energy beam emitted from the energy beam source can be introduced into the sputtered region with almost no loss, and the sputtered particles can be used effectively.

Furthermore, when condensing a condensable gas as a target, by moving the irradiation position during irradiation with the energy beam, it is possible to effectively diffuse the heat caused by the irradiation of the energy beam, and the supplied condensation It can effectively condense gases.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of an embodiment of the vapor deposition apparatus of the present invention;
FIG. 2, FIG. 3, and FIG. 4 are schematic cross-sectional views of an evaporation source of a vapor deposition apparatus according to another embodiment of the present invention. 1... Condensation target 2... Liquid nitrogen jacket 3... Coolant supply pipe 4... Ion beam deflection electrode 5... Intermediate electrode 6... Focusing electrode 7.7'
...Housing (vacuum container) 8...Source gas supply plate 9...Cooling substrate 10...Sample substrate 11.
...Sample substrate holder 12...Anode housing 12'...Ion source 13...Condensation source 14...Heater 15...Ionized gas supply pipe 16...Ion beam 51...Cathode 52...・Magnetic field coil

Claims (17)

[Claims] 1. an energy beam source that emits an energy beam;
A focusing means for focusing the energy beam, a target holding means for holding a target to be sputtered by irradiation with the energy beam, and a sample holding means for holding the sample in order to deposit particles of the sputtered target onto the sample. A vapor deposition apparatus comprising at least a moving means for moving the irradiation position of the energy beam on the target during irradiation. 2. 2. The vapor deposition apparatus according to claim 1, wherein the target holding means has a structure in which the held target is held axially symmetrically and facing the direction of the axis. 3. 2. The vapor deposition apparatus according to claim 1, wherein the target holding means includes means for cooling the target. 4. A claim characterized in that the vapor deposition apparatus has a supply means for supplying a condensable gas, and a cooling means for condensing the condensable gas supplied from the supply means on the target holding means to form a target. Item 1. Vapor deposition apparatus according to item 1. 5. 5. The vapor deposition apparatus according to claim 4, wherein the supply means has a structure for supplying a plurality of condensable gases. 6. an energy beam source that emits an energy beam;
a focusing means for focusing the energy beam; a target holding means disposed axially symmetrically along the traveling axis of the energy beam; and a target holding means for holding a target to be sputtered by irradiation with the energy beam; A vapor deposition apparatus comprising a scanning means for moving the energy beam rotationally symmetrically along an axis, and a sample holding means for holding a sample in order to vapor deposit sputtered particles of the target onto the sample. 7. 7. The vapor deposition apparatus according to claim 6, wherein the target holding means includes means for cooling the target. 8. A claim characterized in that the vapor deposition apparatus has a supply means for supplying a condensable gas, and a cooling means for condensing the condensable gas supplied from the supply means on the target holding means to form a target. Item 6. Vapor deposition apparatus according to item 6. 9. 9. The vapor deposition apparatus according to claim 8, wherein the supply means has a structure for supplying the condensable gas to the target from the incident side of the energy beam. 10. 9. The vapor deposition apparatus according to claim 8, wherein the supply means has a structure for supplying a plurality of condensable gases. 11. Irradiation of the energy beam on the target in an evaporation source having at least an energy beam source that emits an energy beam, a focusing device that focuses the energy beam, and a target holding device that holds a target that is sputtered by irradiation with the energy beam. An evaporation source characterized by having a moving means for moving the position during irradiation. 12. The evaporation source according to claim 11, wherein the target holding means has a structure in which the held target is held axially symmetrically and facing the direction of the axis. 13. The evaporation source according to claim 11, wherein the target holding means includes means for cooling the target. 14. The evaporation source is characterized by having a supply means for supplying a condensable gas, and a cooling means for condensing the condensable gas supplied from the connecting means on the target holding means and making it a target. The evaporation source according to claim 11. 15. The evaporation source according to claim 14, wherein the supply means has a structure for supplying a plurality of condensable gases. 16. A target material bonded by van der Waalska or hydrogen bonding force is irradiated with an energy beam while moving its irradiation position to perform sputtering, particles generated by the sputtering are deposited on a sample, and at least one part of the target material is sputtered. 1. A method for forming a thin film, the method comprising forming a thin film having a component comprising: 17. A target material is introduced into a vacuum, the target material is solidified on a substrate cooled below the freezing point of the target material, and an energy beam is irradiated onto the solidified target material while moving the irradiation position to perform sputtering. A method for forming a thin film, comprising: depositing particles generated by sputtering on a sample to form a thin film having at least a part of the target material as a constituent element.