JPH04176862A - Method for vapor depositing ion beam - Google Patents

Abstract

PURPOSE:To form a vapor deposited film due to a plurality of elements at the excellent productivity by introducing a gaseous raw material into an ionization chamber and simultaneously generating the ions of a plurality of kinds of elements in the case of vapor-depositing the ion beams of the same on a base plate. CONSTITUTION:Gaseous WF6, gaseous CO2 and gaseous SiC4 are introduced into an ionization chamber 4 via valves 2 from a plurality of cylinders 1a-1c thereof. The ions of a plurality of kinds of elements are generated and accelerated by an acceleration electrode 5a in an acceleration chamber 5 and introduced into the circular arclike conduit 8 of a mass separator 7 as the ion beams. Magnitude of current allowed to flow to the coil 9a of an electromagnet 9 of the mass separator 7 is automatically changed over to change over the intensity of the magnetic field due to the electromagnet. The ion of one kind of element correspondent thereto is selected and introduced into a vapor deposition chamber 15. The successively introduced ions of W, C and Si are decelerated and vapor-deposited on a base plate 17.

Description

[Detailed Description of the Invention] "Industrial Application Field" This invention relates to an ion beam evaporation method for producing a thin film by depositing ion beams of multiple types of elements onto a substrate.
In particular, productivity has been improved.

"Prior art" The fourth example uses a case where a tungsten (W) film, a carbon (C) film, and a silicon (Si) film are sequentially deposited on a sample substrate.
The conventional ion beam evaporation method will be explained with reference to the drawings. When raw material gas of tungsten hexafluoride (hp*) is injected into the ionization chamber 4 from the cylinder 1a via the valve 2 and the flow tube 3 and ionized, tungsten ions and fluorine ions are generated.

The acceleration chamber 5 is connected to the ionization chamber 4, and the center hole of the disk-shaped acceleration electrode 5a is closely opposed to the outlet of the ionization chamber 4.
A high voltage v1 is applied to the accelerating electrode 5a to attract and accelerate tungsten ions and fluorine ions from the ionization chamber 4, and the tungsten ions and fluorine ions are transferred from the outlet of the acceleration chamber 5 to the arcuate conduit 8 of the mass separator 7 via the electromagnetic valve 6. Inject into the inlet.

The mass separator 7 includes an arc-shaped conduit 8 and a tM that is arranged near the conduit and generates a magnetic field in a direction perpendicular to the plane surrounded by the arc-shaped conduit 8, that is, in a direction perpendicular to the plane of the paper.
! t supplying current to the L stone 9 and the coil 9a of the electromagnet 9
It is constituted by a deep part 10. Each ion has a charge e, a velocity V, and a magnetic field strength H, which are proportional to the velocity V and the magnetic field H.
A constant force F (electromagnetic force) expressed by the following equation acts in a direction perpendicular to the direction of .

F=kevH(1) In the above formula, k is a constant of proportionality. The trajectory of the ion becomes an arc, and a centrifugal force F1 F,=mv''/r (2) acts on the ion.In the above equation, m is the mass of the ion and r is the radius of curvature of the orbit.The above electromagnetic force F and the centrifugal force Since the force F1 is balanced, the radius of curvature r of the orbit and the strength H of the magnetic field have the relationship eH.Therefore, only tungsten ions are extracted from the mixed gas of tungsten ions and fluorine ions injected into the mass separator 7. Therefore, the radius of curvature of the circular orbit of the tungsten ion is equal to the radius of curvature r of the center line of the arc-shaped conduit 8.
Adjust the magnetic field strength H so that it is equal to 0. The adjustment is performed, for example, by manually adjusting the coil current I using the variable resistor 10a of the power supply section 10. In this way, tungsten ions are guided along the centerline of the arcuate conduit 8 to its outlet. However, since fluorine ions have a smaller mass than tungsten ions, the radius of curvature of their circular orbit becomes smaller than the radius of curvature of the center line of the arc-shaped conduit, so they collide with the inner wall of the conduit 8 and cannot reach the outlet of the conduit. In this way, only tungsten ions are separated by the mass separator 7 and injected into the vapor deposition chamber (also referred to as sample chamber) 15 through the tm valve 11, bellows 13, etc. in this order.

In the deposition chamber 15, the implanted tungsten ions are passed through a ring-shaped deceleration electrode 16 to be decelerated, and then the sample substrate 1 is decelerated.
7 and deposited.

Acceleration chamber 5, electromagnetic Halpro, located in the path of ion flight.
11. The arcuate conduit 8, bellows 13, and vapor deposition chamber 15 are made of metal such as stainless steel, and their interiors are kept in a vacuum to prevent scattering of ions. In addition, except for the vapor deposition chamber 15 which is grounded, high voltage ■2 (voltage V1 of accelerating tube 5a
) is applied. A voltage (2), which is lower than the voltage v2, is applied to the deceleration electrode 16.

After evaporating tungsten ions onto the substrate 17 for a predetermined period of time (for example, several minutes to several hours), ii. Raw material gas for carbon to be removed once and then deposited again, e.g. carbon dioxide (Cow)
Attach the cylinder, and as in the case of tungsten hexafluoride gas, adjust the variable resistor 10a of the power supply section 10 of the mass separator 7 to set the coil current l, and separate only carbon ions for a predetermined period of time. , is deposited on the tungsten film of the substrate 17.

In order to further deposit silicon on the carbon film laminated on the substrate 17 in this way, the gas in the ionization chamber is removed again, and silicon tetrachloride (SiCI), which is a raw material gas, is removed again.
! , n) Set the gas cylinder and perform the same process as above.

``Problems to be Solved by the Invention'' When forming a multilayer film on a substrate by a conventional ion beam deposition method, the ionization chamber 4 is used each time each layer is deposited.
The previous raw material gas remaining in the ionization chamber 4 must be removed, and a new raw material gas must be introduced into the ionization chamber 4. Further, the variable resistor 10a of the power supply unit 10 of the mass separator 7 must be adjusted to set the coil flow for each source gas corresponding to each layer. These operations take a considerable amount of time and cause a decrease in productivity.

An object of the present invention is to solve these conventional difficulties and provide an ion beam deposition method with good productivity.

"Means for Solving the Problems" In the ion beam evaporation method of the present invention, a source gas is injected into an ionization chamber to simultaneously generate ions of multiple types of elements. The ions are then injected into an ion acceleration chamber, accelerated, and injected into the arcuate conduit of the mass separator.

The mass separator consists of the arc-shaped conduit, an electromagnet placed near the arc-shaped conduit that generates a magnetic field in a direction perpendicular to the plane surrounded by the arc-shaped conduit, and a current flowing through the coil of the electromagnet. Use a device consisting of a power supply unit that supplies

The strength of the magnetic field is changed by automatically switching the magnitude of the current supplied from the power supply at a predetermined timing, and ions of one type of element corresponding to each magnetic field strength are selected and sampled. The ions are injected into the chamber, and the sequentially injected ions are slowed down and sequentially deposited onto the sample substrate.

"Embodiment" An embodiment of the present invention is shown in FIG. 1, and parts corresponding to those in FIG. 4 are given the same reference numerals, and repeated explanation will be omitted.

In this invention, the gas cylinders 1a to 1n containing different raw material gases are respectively connected to the multi-input flow tube 21 via the valve 2, and these raw material gases are injected into the ionization chamber 4, thereby simultaneously producing multiple types of gases. Generates ions of elements. Taking as an example the case of forming a multilayer film of tungsten, carbon, and silicon as described in the conventional example, each of the cylinders contains tungsten hexafluoride gas, carbon dioxide gas, and silicon tetrachloride gas, respectively.

In addition, in the power supply section 10 of the mass separator 7, in order to sequentially and selectively separate one type of ion from a plurality of types of ions by switching the strength of the magnetic field, resistors R, , .
R, . . . , R, , are selectively switched by the switch 10c. The control unit 22 controls the switch 10c and automatically switches the switch 10c at a predetermined timing.

When the raw material cylinder of the above specific example is set, the coil current 1 is set to 1. ．． 1. ,L.

By switching to 1, T, , I, and IC, a multilayer film consisting of tungsten 11a, carbon film and silicon film C can be formed as shown in FIG.

The ion beam evaporation method of the present invention can be applied not only to forming a multilayer film on a substrate but also to forming a thin film of a compound consisting of a plurality of elements. In that case, the deposition time of each type of ion is shortened, for example, from several mS to several seconds, and
Each deposited film has one to several atomic layers, which are deposited on top of previously deposited atomic layers and chemically bonded to form a compound.

In the explanation so far, a plurality of types of raw material gases are injected into the ionization chamber 4, but it is clear that the present invention can also be applied to the case where one type of raw material gas is injected to ionize a plurality of types of elements.

Effects of the invention j According to the present invention, one or more types of raw material gas necessary for forming a multilayer film are injected into the ionization chamber, multiple types of elements are simultaneously ionized, and these ions are transferred to the mass separator 7. At the same time, by automatically switching the magnitude of the current I of the magnet coil at a predetermined timing, the strength of the magnetic field can be switched, and ion species can be selected and sequentially deposited on the substrate. Therefore, it is no longer necessary to vent gas in the ionization chamber 4 for each raw material gas or manually adjust the variable resistor 10a to set the coil current, as in the past, and it is possible to provide an extremely productive ion beam evaporation method. .

[Brief explanation of the drawing]

Fig. 1 is a basic configuration diagram of an ion beam evaporation apparatus for explaining the present invention in detail, Fig. 2 is a waveform diagram of the coil current I in Fig. 1 when forming a multilayer film, and Fig. 3 is a diagram showing the waveform of the coil current I in Fig. 1. Figure 2 is a cross-sectional view showing an example of a multilayer film formed on a substrate in response to switching of the coil current, Figure 4 is a basic configuration diagram of a conventional ion beam evaporation apparatus, and Figure 5 is FIG. 3 is a cross-sectional view showing an example of a multilayer film deposited on the substrate.

Claims (1)

[Claims] (1) Injecting raw material gas into an ionization chamber to generate ions of multiple types of elements simultaneously, injecting those ions into an ion acceleration chamber, accelerating them, and injecting them into an arcuate conduit of a mass separator; The mass separator consists of the arc-shaped conduit, an electromagnet placed near the arc-shaped conduit that generates a magnetic field in a direction perpendicular to the plane surrounded by the arc-shaped conduit, and a current flowing through the coil of the electromagnet. The strength of each magnetic field can be changed by automatically switching the magnitude of the current supplied from the power supply at a predetermined timing. An ion beam deposition method in which ions of one type of element corresponding to each sample are selected and injected into a sample chamber, and the sequentially injected ions are decelerated and sequentially deposited onto a sample substrate.