JPS6154112B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to forming a layer of two or more substances on the surface of a substrate using a magnetron sputtering device for depositing a thin film onto a substrate. The present invention relates to a method of depositing the above substances as an alloy having an arbitrary composition.

Prior Art As shown in FIG. 1, a conventional magnetron sputter device includes a pair of anodes 1 and 2, and a magnet 3 that is placed below the cathode 2 and generates a magnetic field approximately perpendicular to the electric field. There is a known device in which a substrate 4 is installed on the anode 1 and a sputtering substance 5 is placed on the cathode 2 to confine high-speed secondary electrons emitted by the action of a magnetic field. . A method has been adopted in which a substance is deposited as a layer on a substrate using this apparatus.

Problems to be Solved by the Invention However, such conventional sputtering methods have a number of advantages, such as a uniform film deposited by sputtering, no rise in temperature of the substrate, and a fast film formation rate. However, it is not suitable for depositing layers of a plurality of substances on a substrate, or for depositing two or more substances as an alloy in an arbitrary composition ratio.

In addition, in magnetron sputtering equipment, a specific ring-shaped eroded area is formed on the cathode, but the cause of this is not necessarily understood accurately, so it is difficult to sputter two or more different materials at the same time. There wasn't much to do.

Therefore, the present inventors first conducted the following experiment in order to find out the factors that affect the shape of the eroded area.
A conventional magnetron sputtering device was used with a copper disc as the cathode in a mixed gas of 90% argon and 10% oxygen, and the discharge power, gas pressure, and magnetic field distribution, which are considered to be the factors that determine the shape of the eroded area, were varied. I sputtered. As a result, the eroded area takes on a shiny copper color, and the area outside the eroded area turns black with clear contrast and can be easily identified with the naked eye. This is because the spattered material is backscattered by collision with gaseous molecules, depositing copper oxide (CuO) on the cathode and blackening it, but in the eroded area, the erosion rate is faster than the deposition rate. This is because it remains copper-colored because it is much faster. As a result of this experiment, it was found that the factors that determine the shape of the eroded area are discharge power, gas pressure, and magnetic field distribution. Furthermore, regarding the magnetic field, we investigated the absolute value of the magnetic field strength, the components parallel to the electric field, and the components perpendicular to the electric field, and it was found that the magnetic field component Hh parallel to the electric field has a large influence on the eroded area.

For example, discharge power is 50 [W], gas pressure is 1.0×
When set to 10 ^-2 [Torr], it was observed that the eroded region corresponds to the region where the magnetic field component Hh parallel to the electric field is 40 [G] or less. Therefore, when the discharge power and gas pressure are constant, the magnetic field component parallel to the electric field
It was confirmed that the eroded area can be changed freely by changing Hh.

Based on the above-mentioned new knowledge, the present inventors have invented a sputtering method in which a plurality of films are deposited in layers on a substrate, or two or more materials are deposited as an alloy in an arbitrary composition ratio.

Means for Solving the Problem That is, the present invention has a basic configuration of a pair of anode and cathode, and a magnet that generates a magnetic field that is approximately perpendicular to the electric field between the anode and cathode, and that is placed near the cathode by a control device to generate a magnetic field that is approximately parallel to the electric field. In a magnetron sputtering device in which the eroded region is moved inward and outward on the cathode by changing the magnetic field of different components, there is a process of arranging a plurality of different materials concentrically inside and outside the target of the cathode, and After arranging the plurality of materials, a plurality of materials are formed on the multilayer by a sputtering method comprising a step of changing a magnetic field having a component parallel to the electric field via a control device to move an eroded region onto the plurality of materials.

Furthermore, the basic configuration includes a pair of anode and cathode, and a magnet that generates a magnetic field that is substantially orthogonal to the electric field between the anode and cathode, and a control device changes the magnetic field with a component that is substantially parallel to the electric field near the cathode to form an eroded area. In a magnetron sputtering device that moves inward and outward on a cathode, a step of arranging a plurality of different substances on the target of the cathode in a concentric shape and such that the inside and/or outside of the target is radial; After arranging the target, two or more substances are sputtered using a sputtering method, which consists of the step of changing the magnetic field with a component parallel to the electric field via a control device and moving the eroded area alternately inside and outside at predetermined time intervals. It is deposited as an alloy in any composition ratio.

Effect In the method according to the present invention, since the cathode target has a plurality of different materials arranged concentrically on the inside and outside, when the magnetic field of the parallel component to the electric field is changed via the control device, for example, the inside center The material on the substrate is first sputtered to deposit the material on the substrate. In this case, the material on the outside is not spattered, since the erosion area is controlled by the control device. When the material in the center finishes sputtering, the control device operates and changes the magnetic field with a component parallel to the electric field.
Move the eroded area to the outer material side. The material on the outside is then sputtered and adheres to the substrate. Therefore, a thin layer of different materials can be formed on the substrate.

Note that the case where the way the magnetic field of the control device is changed from outside to inside is also the same as described above.

Next, the target of the cathode is arranged concentrically with multiple materials, and the inner part is arranged radially at a specific ratio, and the magnetic field whose component is parallel to the electric field is changed via the control device to control the eroded area to a predetermined area. When moving inside and outside alternately at time intervals, 2 on the inside
More than one species is sputtered at the same time, and the material is sputtered on the outside. Since this sputtering is performed alternately on the inside and outside, the alloy consisting of a specific ratio is gradually deposited on the substrate.

Embodiments The present invention will be described in detail below with reference to embodiments shown in the drawings.

FIG. 2 shows a magnetron sputtering device used in the practice of the present invention. In the figure, reference numerals 11 and 12 denote circular base plates, and a sputtering chamber 14 is formed by sealing a glass cylinder 13 with the plates 11 and 12. An anode 15 connected to a power source (not shown) is fixed to a base plate 11, which is the upper plate of the sputtering chamber 14, via an insulator 16. The center of the base plate 11, insulator 16 and anode 15 is
A hole is hollowed out, and a monitoring device 17 for analyzing elemental components or composition ratios is fitted into the hole. Examples of the monitoring device include a quadrupole mass spectrometer, an ion gauge, or a detection device using atomic absorption spectroscopy. Further, an exhaust hole 19 and a gas introduction hole 20 are perforated in the peripheral portion of the base plate 12, which is a bottom plate, and an exhaust pipe 21 and a gas introduction pipe 22 are connected thereto, respectively. A hole is inserted in the center, and a cathode 23 having a T-shaped cross section and connected to a power supply (not shown) is fixed to the hole through an insulator 24, and a magnetic field orthogonal to the electric field is generated below the cathode 23. The permanent magnets 25 are arranged so as to.
A circular coil 26 is arranged around the glass cylinder 13 and receives current from the control device 18 so that a magnetic field is generated near the cathode 23 in parallel to the electric field. 27 is a substrate to which a film is to be attached;
Reference numeral 28 indicates a target which is the material of the film, 29 indicates a shield plate, E indicates an electric field, Hv indicates lines of magnetic force of the permanent magnet, and Hh indicates lines of magnetic force of the coil 26. Although a flat plate type magnetron sputtering device was adopted as the magnetron sputtering device used in this example, it is a cylindrical type coaxially arranged as shown in Fig. 4, and a plurality of different materials are connected to the N pole of a permanent magnet or Naturally, this method can also be applied to cases in which targets are arranged concentrically in the vertical direction with the S pole as the center, and also to cases in which a permanent magnet is surrounded by circular coils in a square manner.

To explain the operation of the device having the above configuration, the substrate 27 is placed on the surface of the anode 15, and the cathode 2 is placed on the surface of the anode 15.
After placing the target 28 on the surface of the sputtering chamber 14, the sputtering chamber 14 is evacuated and gas is introduced so that the inside of the sputtering chamber 14 reaches a predetermined gas pressure. Thereafter, when a predetermined electric power is applied between the electrodes 15 and 23, the combined magnetic field generated by the permanent magnet 25 and the coil 26 acts on the electrons, causing the electrons to move a predetermined distance from the center of the cathode 23 and perform cycloidal motion. This movement of electrons promotes ionization of the target 28, so that the sputtered material adheres to the substrate 27. In this case, the eroded area in the target 28 on the cathode 23 to be sputtered is such that the magnetic field H parallel to the electric field
It is formed into a ring shape in the range where . Then, the sputtering state and the sputtering state when the control device 18 is activated and the eroded area moves are transmitted to the control device 18, and the control device 18 adjusts the amount of current. It can be sputtering.

If the magnetic field of the coil 26 is initially H=0, then H=
When the magnetic field is changed to Hh, the resultant magnetic field changes from H ₁ to H ₂ as shown in Figure 5, and the eroded area moves from A to B as shown in Figure 6. I started doing spatuta.

Therefore, as shown in FIG. 7, a target in which substances A and B are arranged concentrically on the inner and outer sides of a disc is installed at the cathode. Afterwards, the air in the sputtering chamber 14 is exhausted, and gas is injected to a predetermined gas pressure. Then, if a predetermined power is applied between both electrodes and the coil current is adjusted so that the eroded area first comes to the material B side and then the eroded region comes to the material A side, the sputtering is performed separately for each electrode. Therefore, a thin film consisting of two layers of substance B and substance A is formed on the substrate 27.

Yet another method is to arrange targets radially outside the concentric circle of material A and radially inside the concentric circle with materials B and C, as shown in FIG.

Specifically, lead (Pb) is selected for A, zirconium (Zr) for B, and (Ti) for C.

Next, to check the amount of each attached, Pb,
Zr, Ti with argon (Ar) 90%, oxygen (O ₂ ) 10%
According to experiments, the rate of deposition on the substrate when sputtering is performed under the same conditions in an atmosphere of
It was 15.4:1.28:1.0.

Therefore, we set the area ratio of Zr and Ti to 47.3:52.7, set the sputtering time on the Pb side, Zr, and Ti side to 1:13.6, and applied a waveform current as shown in Figure 9 to move the eroded area. . Then, layers _of PbO-(Zr _{0.54 ·} Ti _0.46 )O ₂ are formed on the surface of the substrate.

In this case, if sputtering is repeated so that each layer becomes _a monoatomic layer, Pb(Zr _0.54・_{Ti 0.46 )
Zirconate} /lead titanate (Lead
zirconate titanate) can be grown in the (001) direction.

In addition, in the sputtering method according to the present invention, the characteristics of the eroded area of the magnetron sputtering device are grasped in advance, and the characteristics of the eroded area (inside and outside of the cathode) when the coil current is applied and when it is not applied are determined in advance. Preferably, the materials are arranged in a concentric configuration.

Effects As explained above, the sputtering method according to the present invention allows the eroded area to be moved via the control device compared to the conventional method, so that it is possible to deposit layers of multiple substances on the substrate. be able to.

Furthermore, it is possible to deposit an alloy film of any composition depending on the arrangement of the target substance, so its utility value is extremely high compared to conventional methods.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing a conventional magnetron sputtering device, Fig. 2 is an end view showing a magnetron sputtering device used for carrying out the present invention, and Fig. 3 is a state of the magnetic field of the cathode part of the magnetron sputtering device. FIG. 4 is a partial cross-sectional view of another magnetron sputtering device used for carrying out the present invention.
Fig. 5 is a graph showing the relationship between changes in magnetic field and the eroded area, Fig. 6 is a partial plan view showing the state of the eroded area of the target, and Figs. 7 and 8 are plan views showing examples of the target. , FIG. 9 is a waveform diagram showing one aspect of the waveform current flowing through the coil. 1... Anode, 2... Cathode, 3... Magnet, 4...
Substrate, 11, 12... Base plate, 13...
Cylinder, 14... Spatuta chamber, 15... Anode, 16
... Insulator, 17 ... Monitoring device, 18 ... Control device, 19 ... Exhaust hole, 20 ... Gas introduction hole, 21
...Exhaust pipe, 22...Gas introduction pipe, 23
... cathode, 24 ... insulator, 25 ... permanent magnet,
26...Circular coil, 27...Substrate.

Claims (1)

[Scope of Claims] 1. The basic structure includes a pair of anode and cathode, and a magnet that generates a magnetic field substantially perpendicular to the electric field between the anode and cathode, and a magnetic field with a component substantially parallel to the electric field is generated near the cathode by a control device. In a magnetron sputtering device in which the eroded area is moved inward and outward on the cathode, the steps include arranging a plurality of different materials concentrically inside and outside the target of the cathode, and after arranging the target. A sputtering method comprising the step of moving an eroded region onto the plurality of substances by changing a magnetic field having a component parallel to the electric field via a control device. 2 The basic structure consists of a pair of anode and cathode, and a magnet that generates a magnetic field that is substantially perpendicular to the electric field between them, and a control device changes the magnetic field with a component that is substantially parallel to the electric field near the cathode to form an eroded area. In a magnetron sputtering device that moves inward and outward on a cathode, a step of arranging a plurality of different substances on the target of the cathode in a concentric shape and with the inside and/or outside of the target radial. A sputtering method comprising the steps of, after placing a target, changing a magnetic field with a component parallel to the electric field via a control device to move the eroded area alternately inward and outward at predetermined time intervals.