JPH01240656A - Three-electrode magnetron sputtering device - Google Patents

Abstract

PURPOSE:To uniformize the film-thickness distribution of a thin film formed on a substrate by attaching an anode between targets and also providing plural filaments which double as cathodes to the outer ends of the targets. CONSTITUTION:In a three-electrode magnetron sputtering device, targets 2, 3 are attached to a target stand 1. When filaments 5, 5 at both ends of a target stand 1 are connected to the negative pole of a D.C. power source 7 and an anode 8 attached between the targets 2, 3 is connected to the positive pole, electric fields E orthogonal to magnetic fields H generated at magnets 4, 4 are formed on the respective surfaces of the targets 2, 3. When electric currents are applied to the filaments 5, 5 by means of an A.C. power source 6 to heat the filaments 5, 5, electrons are emitted along the electric fields E, by which the electrons emitted from the filaments 5, 5 are allowed to perform cycloidal motions on the targets 2, 3 and increase the ionization of the gases introduced through inert gas-introducing holes 9, 9. As a result, plasma density is increased and sputtering efficiency can be improved.

Description

[Detailed description of the invention] [1! I Summary] Regarding a triode magnetron sputtering device, the purpose is to uniformly form a thin film on a substrate, and the device includes a target disposed facing the wafer, a pair of magnets attached on both sides of the target, The device includes an anode electrode attached on the target, a plurality of filaments serving as cathodes attached to the outer end of the target, and a plurality of inert gas supply ports attached near the filaments.

[Industrial application field]

The present invention relates to a triode magnetron sputtering apparatus.

[Conventional technology]

As a sputtering device, as shown in Fig. 6,
A filament 51 and an anode 5 are installed at both ends of the target 50.
2 are arranged facing each other, and a pair of magnets 5 are placed on both sides thereof.
Generally, a three-pole magnetron sputtering apparatus is used in which a magnetic field and an electrolytic field are made perpendicular to each other on the target 50 by attaching a magnetron 3 to confine plasma generated in a vacuum in a space above the surface of the target 50.

According to this apparatus, since the generation of inert gas ions can be promoted by causing electrons to move in a cycloid on the target 50, it is possible to increase the plasma density and improve the sputtering efficiency.

[Problem to be solved by the invention]

However, in this type of device, metal molecules and atoms flying out from the surface of the target 50 diffuse in a fan shape.
The metal film formed on the group Fi, 54 facing the target 50 is thicker in the center, and moreover,
The distribution of electrons emitted from the anode 51 tends to decrease, and the film thickness becomes thinner as the amount of electrons decreases.

For this reason, as shown in FIG. 7, the metal film formed on the substrate 54 is thick near the center and thinnest at the edge near the anode 51, which reduces the usage efficiency of the substrate. There is a problem of a decrease in

The present invention has been made in view of such problems, and an object of the present invention is to provide a frame for a three-pole magnetron sputtering apparatus that can uniformly form a thin film on a substrate.

[Means to solve the problem]

The above problem consists of a target 2.3 disposed facing the wafer 14, a pair of magnets 4 attached to both sides of the target 2.3, an anode electrode 8 attached between the targets 2.3, and the target 2.3. 2.3 is solved by a three-pole magnetron sputtering device characterized by having a plurality of filaments 5 which also serve as cathodes and which are attached to the outer ends of the filaments 5, and a plurality of inert gas supply ports 9 which are attached near the filaments 5.

[For production]

That is, in the present invention, while the target 2.3 is facing the wafer 14, the negative pole of the DC power source is connected to the plurality of filaments 5.5 attached to the outer end of the target 2.3. Anode electrode 8 attached on 3
When the positive electrode of a DC power source is connected to target 2.
filament 5.5 from the anode electrode 8 attached on 3
Since an electric field E is generated in the outward direction to the target 2.3, this electric field E is perpendicular to the magnetic field H which is exerted by the magnet 4 between the two sides of the target 2.3.

For this reason, a plurality of filaments 5. which also serve as cathodes.
The electrons emitted from the target 2.3 move cycloidally on the target 2.3 and increase the ionization of the inert gas from the inert gas supply port 9, thereby increasing the density of the plasma and improving the sputtering efficiency.

Then, metal molecules and atoms ejected from the Couget 2.3 are deposited on the wafer 14 mounted opposite the Couget 2.3 to form a film.

In this case, the target materials discharged in a fan shape from the parts of the target 2.3 near the anode electrode 8 overlap in the center of the wafer 14 to form a film, so the film in this part is near the anode electrode 8. Target 2
．． Compared to the film formed by ejecting from the center of No. 3, almost the same film thickness can be obtained.

Therefore, the film formed on the wafer 14 has a uniform thickness as shown in FIG. 4.

〔Example〕

1 to 4 show an embodiment of the present invention,
In the figure, reference numeral l denotes a target mounting table on which two plate-shaped targets 2.3 are placed on the same plane in a non-contact or in contact state, and is attached to the bottom of the Pelger 1o. A magnet 4 is attached, and the structure is such that a magnetic field H in the width direction is generated on the surfaces of the two cugets 2 and 3.

Reference numeral 5 denotes filaments attached to both ends of the target mounting table l.The two filaments 5.5 are connected to an AC power source 6 and generate heat, while they are connected to the negative pole of a DC power source 7 and have the function of a cathode. The anode electrode 8 is connected to the positive electrode of the DC power source 7 and is configured to emit electrons to an anode electrode 8, which will be described later.

The above-mentioned anode electrode 8 is placed on the target mounting table ■! !
It is installed above between the two targets 2.3 placed on the ground, and receives the electrons emitted from the filament 5.5 at both ends. It is configured to generate an electric field E between it and the filament 5.

9 is an inert gas supply port attached to both ends of the target mounting member 1, and this inert gas inlet 9 releases inert gas such as argon gas along the electric field E above the target 2.3. It is configured as follows.

Note that 11 indicates the target mounting member 1 and the filament 6.
．． A casing for storing 7 etc., 12 is a casing 11
The gas diffusion port 13 formed at the top of the target 8M
A wafer support member 15, which attaches the wafer 14 facing the table 1, is connected to the target 2.3 and represents a DC power source that generates an electric field for sputtering between the wafer 14 and the wafer 14.

Next, the operation of the present invention will be explained.

Attach the two targets 2.3 to the target mounting table 1, connect the filament 5.5 at both ends to the negative pole of the DC power supply 7, and attach the two targets 2.3 to the target mounting table.
When the anode electrode 8 attached therebetween is connected to the positive electrode, an electric field E is generated on the surface of the target 2.3, which is perpendicular to the magnetic field H generated by the magnet 4.4.

Further, when the filament 5.5 is heated by applying an AC power source 6, electrons are emitted from the filament 5 along the electric field path.

Therefore, the electrons emitted from the filament 5.5, which also serves as a cathode, move cycloidally on the target 2.3 and increase the ionization of the active gas emitted from the two gas discharge ports 9.9. The density becomes high (which improves sputtering efficiency).

Then, on the wafer 14 mounted opposite to the target 2.3, metal molecules flying out from the target 2.3,
Atoms are deposited to form a film.

In this case, the molecules and atoms released in a fan shape from the parts of the two targets 2.3 closer to the anode electrode 8 are as follows:
Since the film is formed by overlapping in the center of the wafer 14, the film in this part is almost the same as the film formed by the gas released from the center part of the target 2.3, even though it is near the anode electrode 8. ffff can be obtained.

Therefore, the film formed on the wafer 14 has a highly uniform thickness, as shown in FIG.

The above-mentioned embodiment uses two targets 2.3, but as shown in FIG. 5, a target 23 formed integrally with these targets 2.
It is also possible to arrange an anode electrode 8 on, for example, the center of 3 to generate an electric field E outward from the center.

〔Effect of the invention〕

As described above, according to the present invention, the anode is attached to the target lined up facing the wafer, and a plurality of filaments that also serve as cathodes are provided at the outer end. The amount of target molecules that reach the target in the longitudinal direction can be made uniform), and the film thickness distribution in the longitudinal direction of the target formed on the wafer can be made uniform.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the main parts of a device that is an embodiment of the present invention, FIG. 2 is a sectional view showing the main parts of a device that is an embodiment of the invention, and FIG. FIG. 4 is a schematic diagram of an apparatus showing an embodiment of the invention. FIG. 4 is a distribution diagram showing the thickness of a film formed according to the invention. FIG. 5 is a cross-section of a main part of an apparatus showing another embodiment of the invention. FIG. 6 is a plan view and a cross-sectional view of an example of a conventional device, and FIG. 7 is a distribution diagram showing the ff'2F\ distribution and electron amount distribution of a film formed by the conventional device. (Explanation of symbols) 1... Target mounting table, 2.3.23... Target, 4... Magnet, 5... Filament, 6... AC power supply, 7... DC power supply, 8 ... Anode electrode, 9... Inert gas supply port, 10... Pelger. Chishudan's hit persimmon sound 1j begging rJj fold,! Figure 1 Figure 3 Figure 3 shows the inversion! 2 vessels, +Fi sa! Reference≧Meikaku Se no Mi〕Se Messenger” 2 Hosu Device’s Chopsticks N Loaf Side Diagram No. 5
figure

Claims (1)

[Claims] A target (2,
3) and a pair of magnets (
4) and an anode electrode (
8), a plurality of cathode-duty filaments (5) attached to the outer ends of the targets (2, 3), and the filaments (5).
) A three-pole magnetron sputtering device characterized by comprising an inert gas supply port (9) installed near the