JPH0765165B2 - Thin film deposition equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a thin film deposition apparatus.

(Prior Art) A wide variety of thin film deposition apparatuses have been proposed and known. Among these various thin film deposition apparatuses, there is known an apparatus capable of forming a thin film having good adhesion to a substrate and using a plastic substrate having no heat resistance as the substrate.

In this thin film vapor deposition apparatus, a grid is provided between the counter electrode holding the vapor deposition substrate and the evaporation source facing the counter electrode. Then, this grit has a positive potential with respect to the counter electrode. Further, a filament for generating thermoelectrons is provided between the grid and the evaporation source.

The vapor deposition material evaporated from the evaporation source is cationized by thermions emitted from the filament. When the cations pass through the grid, they are accelerated by the action of the electric field directed from the grid to the counter electrode and collide with the non-deposited substrate to form a thin film having good adhesion.

The problem with such a thin film deposition apparatus is that cations are mainly generated on the side of the evaporation source rather than the grid, and therefore a large amount of cations cannot pass through the grid due to the positive potential of the grid. This means that the number of cations that contribute to the film is small and the efficiency of thin film formation is not necessarily good.

(Object) The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to improve the above-described thin film deposition apparatus and to provide a novel thin film deposition apparatus capable of efficiently forming a thin film. Is provided.

(Structure) Hereinafter, the present invention will be described.

The thin film vapor deposition apparatus of the present invention includes a vacuum chamber, an evaporation source, a counter electrode, a filament, a grid, a power supply unit, and a conductive unit.

The vacuum chamber is configured so that an active gas or an inert gas, or a mixed gas of an active gas and an inert gas, can be introduced into the internal space of the vacuum chamber, the evaporation source, the counter electrode filament,
The grid is arranged in a vacuum chamber.

The counter electrode and the evaporation source are arranged so as to face each other. The counter electrode is capable of holding the vapor deposition substrate on the side facing the evaporation source. The evaporation source is a means for evaporating the vapor deposition material.

The grid is interposed between the evaporation source and the counter electrode, and is set to a positive potential with respect to the counter electrode by the power supply means. Therefore, during vapor deposition, the electric field generated is directed from the grid to the counter electrode.
Of course, the grid can pass vaporized vapor deposition material.

The filament is for thermionic generation and is arranged between the grid and the counter electrode.

The power supply means is a means for realizing a predetermined electric state in the vacuum chamber, and the power supply means and the inside of the vacuum chamber are electrically connected by the conductive means.

As described above, in the thin film deposition apparatus of the present invention, since the filament is located on the counter electrode side of the grid, the deposition substance and the cation of the introduced gas due to thermoelectrons are mainly generated on the counter electrode side of the grid.

Hereinafter, description will be given with reference to the drawings.

The figure shows an embodiment of the invention.

In the figure, reference numeral 10 is a base plate, reference numeral 12 is a packing, and reference numeral 14 is a bell jar. The bell jar 14 and the base plate 10 are integrated by a packing 12 to form a vacuum chamber, and an active gas and / or an inert gas can be introduced into the internal space by a known appropriate method. The hole 10A formed in the central portion of the base plate 10 is connected to a vacuum system (not shown).

Electrodes 16, 18, 20, 22 that also serve as a support are provided through the base plate 10 while maintaining the airtightness inside the vacuum chamber and the electrical insulation from the base plate 10.

These electrodes 16, 18, 20, 22 electrically connect the inside and the outside of the vacuum chamber, and form a conductive means together with other wiring tools.

Between the pair of electrodes 16 is supported a resistance heating type evaporation source 24 which is made of metal such as tungsten or molybdenum in a coil shape. The evaporation source may have a boat shape instead of the coil shape. Further, instead of the resistance heating type evaporation source, an evaporation source used in a conventional vacuum vapor deposition method such as an electron beam evaporation source can be appropriately used.

A filament 28 for generating thermoelectrons made of tungsten or the like is supported between the pair of electrodes 20. The shape of the filament 28 is determined so as to cover the spread of the particles of the evaporation material evaporated from the evaporation source by arranging a plurality of filaments in parallel or forming a mesh shape.

A grit 26 is supported on the electrode 18. The grit is shaped to allow the evaporated deposition material to pass to the filament 28 side, but in this example, it has a mesh shape.

A counter electrode 30 is supported on the tip of the electrode 22.
The deposition target substrate 100 is held on the surface of 30 facing the evaporation source 24 by an appropriate method.

The electrode 16 supporting the evaporation source 24 is connected to an AC power supply 32 for heating.

The electrode 18 is connected to the positive electrode side of the DC voltage power supply 36,
The electrode 22 is connected to the negative side of the power supply 36. Therefore, the grid 26 has a positive potential with respect to the counter electrode 30, and the electric field between the grid 26 and the counter electrode 30 goes from the grid 26 to the counter electrode 30.

Further, the pair of electrodes 20 is connected to the power supply 34.

Therefore, in this embodiment, the power supplies 32, 34, 36 form a power supply means. The grounding in the figure is not always necessary.

In practice, the electrical connections include various switches (which form part of the conducting means) and the operation of these switches carries out the deposition process, which switches are not shown.

The thin film deposition according to this installation example will be described below.

The deposition target substrate 100 is held by the counter electrode 30 as shown, and the deposition material is held by the deposition source 24. The vapor deposition material is, of course, determined depending on what kind of thin film is formed. For example, it is a metal such as aluminum or gold, or a metal oxide, fluoride, sulfide, or alloy.

In addition, an active gas, an inert gas, or a mixed gas thereof is previously introduced into the vacuum chamber at a pressure of 10 ^-2 to 10 ^-5 Torr. In the following description, the introduced gas is assumed to be an inert gas such as argon.

When the apparatus is operated in this state, the evaporation material held in the evaporation source 24 is evaporated by the heating by the evaporation source 24. The particles of the vaporized substance, that is, the vapor-deposited substance fly toward the substrate 100 to be vapor-deposited while spreading and pass through the grid 26.

On the other hand, thermoelectrons are emitted from the filament 28, and the generated thermoelectrons fly toward the grid 26 while being accelerated by the electric field between the grid 26 and the counter electrode 30,
When it collides with the vapor deposition material that has passed through 26, the particles are ionized into positive ions.

The ionized vapor deposition material flies while being accelerated by the action of an electric field from the grid 28 toward the counter electrode 30, and collides with the vapor deposition substrate 100 at high speed, thus forming a desired thin film on the vapor deposition substrate 100. . This thin film has excellent adhesion to the substrate and has good crystallinity and orientation. This is due to the ionization of the deposited material.

In the thin film vapor deposition apparatus of the present invention, since the ionization rate of the vaporized vapor deposition material is high, by performing the vapor deposition by independently introducing the active gas into the vacuum chamber or together with the inert gas,
A thin film having desired physical properties can be easily obtained even when the evaporate and the active gas are combined to form a thin film from this compound.

For example, when argon is introduced as the inert gas and oxygen is introduced as the active gas, the pressure is adjusted to 10 ^-3 to 10 ^-4 Torr, and aluminum is selected as the evaporation substance, Al ₂ o is deposited on the substrate to be evaporated.
A thin film of ₃ can be obtained, and if In and Zn are selected as evaporation materials, thin films of In ₂ O ₃ can be obtained.

Moreover, if H ₂ S is selected as the active gas and Cd is selected as the vaporized substance,
A thin film of CdS is obtained. Furthermore, ammonia was used as an active gas together with argon, and Ti and Ta were used as evaporation materials.
By selecting, it is possible to obtain a thin film such as TiN or TaN.

Since thermoelectrons effectively contribute to the ionization of the vaporized substance and the introduced gas, it is possible to perform vapor deposition under a high vacuum of 10 ^-4 Torr or more, and it is extremely possible to incorporate gas molecules into the thin film. Since the amount can be reduced, a high-purity thin film can be obtained. That is, the thin film deposition apparatus of the present invention,
It is suitable for forming semiconductor thin films that make up ICs, LSIs, etc., and high-purity metal thin films as their electrodes.

(Effect) As described above, according to the present invention, a new thin film deposition apparatus can be provided. In this apparatus, the ions involved in the thin film formation are generated on the side of the grid on which the substrate is deposited, so that the generated ions can be effectively participated in the thin film formation, and the thin film formation can be performed efficiently.

[Brief description of drawings]

FIG. 1 is a partial sectional front view showing an embodiment of the present invention. 10 ...... Base plate, 14 ...... Bell jar, 24 ...... Evaporation source, 26 ...... Grid, 28 ...... Filament, 30 ...... Counter electrode, 100 ...... Evaporated substrate

Claims (1)

[Claims] 1. A vacuum chamber into which an active gas and / or an inert gas can be introduced, an evaporation source disposed in the vacuum chamber, and an evaporation source disposed in the vacuum chamber so as to face the evaporation source. A counter electrode for holding a vapor deposition substrate, a filament for generating thermoelectrons arranged between the evaporation source and the counter electrode, and a grit arranged between the filament and the evaporation source and capable of passing a vapor deposition substance. And a power supply means for realizing a predetermined electrical state in the vacuum chamber, and a conductive means for electrically connecting the vacuum chamber and the power source means to each other. Is a positive potential, a thin film vapor deposition apparatus.