JPS6343466B2 - - Google Patents

Description

Detailed Description of the Invention (Technical Field) The present invention involves scattering particles of a metal material or a semiconductor material from a target in a gas atmosphere under the application of an electric field and a magnetic field, and depositing the particles on substrates arranged opposite to each other. Regarding the magnetron sputtering source used as a source of emitting material particles when forming thin films of these materials, in particular, it is possible to compress the lines of magnetic force of the applied magnetic field parallel to the target surface, and to direct the power lines of the applied electric field to the target surface. The magnetic field crimping effect of the electromagnetic crimping type magnetron sputter source is designed to greatly increase the magnetic field crimping effect of the electromagnetic field crimping type magnetron sputter source, which promotes the release of material particles from the target surface by gas ion bombardment.

(Prior Art) As a conventional magnetic field compression type magnetron sputter source of this type, there is one described in Japanese Patent Application Laid-Open No. 1983-31142, which was proposed and filed by the present inventor. The conventional device described in this publication is constructed as shown in FIG. In the configuration shown in the figure, a magnet 2 is attached to the back surface of a disk-shaped target 1, with one end, for example, the north end being centered, and the other end, for example, the south end being annular. Further, a solenoid coil 3 is coaxially arranged on the front outside thereof, and a part 5a of the magnetic field component 5 of the magnet 2 is targeted by a magnetic field component 6 having the same polarity as the magnetic field component 5 from the central magnetic pole N of the magnet 2. It is pressed onto the surface of 1 and made parallel. That is,
As shown in the figure, a magnet 2 is attached to the back surface of the target 1, and the magnet 2 traps electrons with a magnetic field component 5a parallel to the surface of the target 1 of the leakage magnetic field 5 appearing on the surface of the target 1, thereby creating magnetic lines of force 5a. The target 1 is struck by the impact of the gas ions generated by the collision with the electrons.
The sputtering efficiency is increased by promoting the release of material particles from the surface of the sputtering device.

However, in the conventional magnetic field compression type magnetron sputter source with such a configuration, the magnetic field component 5a parallel to the surface of the target 1, which effectively acts to trap electrons, is still only a part of the leakage magnetic field 5, and the leakage magnetic field 5 enters and leaves the target 1 perpendicularly to its surface in the center and periphery. Therefore, the surface of the target 1 is not eroded in those parts, and the effective utilization rate of the target 1 remains at about 30%, which is the biggest drawback of the conventional apparatus. As a result, the erosion groove carved into target 1 during thin film fabrication gradually becomes deeper as thin film fabrication progresses, and the optimal thin film fabrication conditions change over time.
It becomes difficult to continue producing thin films for a long time under certain optimal conditions. Furthermore, in this conventional apparatus, since the plasma made of gas ions extends along the lines of magnetic force of the leakage magnetic field 5, polymer In order to prevent the substrate (not shown) from coming into contact with the plasma, the distance between the substrate and the target is at least 4 to 5 cm, which increases the thickness distribution of the thin film deposited on the substrate. Another drawback was that control had to be performed by mechanically adjusting the distance between the substrate and the target. Furthermore, in this conventional apparatus, when a ferromagnetic target is used in the production of magnetic thin films for high-density magnetic recording, target 1 short-circuits the magnetic path of magnet 2. Another drawback was that it was extremely difficult to produce magnetic thin films at high speed.

In addition, in conventional sputtering technology,
Generally, relatively heavy argon is used as a sputtering gas, so when manufacturing thin films of lightweight materials such as silicon, which are often used in semiconductor devices, heavy argon gas particles enter the thin film and deteriorate its homogeneity. The drawback was that it was not possible to produce a high-quality thin film because of this.

(Summary of the Invention) The purpose of the present invention is to eliminate the above-mentioned conventional drawbacks at once, improve target utilization efficiency, stabilize film formation conditions, and enable the production of magnetic thin films. The object of the present invention is to provide an electromagnetic field compression type magnetron sputtering source that enables low-temperature and ultra-high-speed production.

Another object of the invention is the semiconductor industry, or
The object of the present invention is to provide a sputtering source that enables the realization of sputtering technology that can replace all existing thin film production techniques, such as the production of magnetic material thin films for storage in electronic devices, computers, etc., and surface treatment techniques.

Still another object of the present invention is to realize a sputtering technique that is much faster than conventional sputtering, thereby making it possible to use helium gas, a light element, as a sputtering gas, which is difficult to manufacture using conventional sputtering techniques. An object of the present invention is to provide a sputtering source that can produce high-quality silicon thin films.

That is, the electromagnetic field compression type magnetron sputter source of the present invention is made of a ferromagnetic material having electrical conductivity,
The one end of the magnet has a magnetically conductive electrical insulator interposed between the magnetic poles, and the other end is approximately annular with one end at the center. The magnet is placed in contact with the center of the back surface of the sputtering target, and the other end portion, which is substantially annular, is placed in front of the outer periphery of the target and spaced apart from it, and the magnet is placed between the other end portion of the magnet and the target. Applying a direct current or high frequency electric field substantially parallel to the surface of the target, and coaxially disposing a substantially cylindrical solenoid in front of the target so that the leakage magnetic field of the solenoid engages the leakage magnetic field of the magnet. This is characterized in that the leakage magnetic field of the magnet can be pressed substantially parallel to the surface of the target.

(Example) The present invention will be described in detail below with reference to the drawings.

FIG. 2 shows an example of the configuration of the electromagnetic field compression type magnetron sputtering source of the present invention, which has been improved so as to eliminate all of the above-mentioned conventional drawbacks. The sputtering source of the present invention having the configuration shown in the figure is completely different from the conventional device shown in the first figure described above, especially in the structure of the magnet 2 that applies a leakage magnetic field to the sputtering area.
The central magnetic pole part, for example, the N-pole part 2
a is almost the same as in the conventional device shown in the first figure, but the annular other end part, for example, the S end part 2b, is not attached to the back surface of the target 1 but is properly attached to the front of the outer periphery of the target 1, as shown in the figure. The lines of magnetic force from the center magnetic pole N are not terminated on the surface of the target 1 as in the conventional case, but are directly terminated at the annular magnetic pole S while extending approximately parallel to the surface of the target 1. There is. Furthermore, in order to make such leakage as completely parallel to the surface of the target 1 as possible, a solenoid coil 4 is coaxially arranged slightly forward and outward of the target 1 and the annular magnetic pole N, as in the past, and a direct current is passed therethrough. , a leakage magnetic field having the same polarity as the leakage magnetic field from the center magnetic pole N is applied toward the target 1.

That is, the annular magnetic pole S of the magnet 2 is located apart from the outer circumference of the target 1 in front of the target 1.
The magnetic field lines 5 of the leakage magnetic field from the center of the target 1 are pressed against the surface of the target 1 by the magnetic field lines 6 of the same polarity induced by the solenoid coil 4. The parallel magnetic field component 5a increases significantly. moreover,
As in the past, a part 7 of the magnetic path of the conductive ferromagnetic material 2 is made of a ceramic magnet material such as ferrite or an extremely thin electrical insulating material, without being magnetically insulated. It is electrically insulated only, and the outer conductive magnetic pole part 2b is used in place of the anode ring 3 conventionally provided for applying an electric field, as shown in FIG. 1, so that the anode ring 3 is not required. Use as magnetron sputter source.

As mentioned above, a part of the magnetic path of the magnet 2 made of a conductive ferromagnetic material is insulated electrically but not magnetically by a ceramic magnet or a thin electrically insulating material. Acting as a magnet, one magnetic pole, for example, the N pole, is adhered to the center of the back surface of the target 1, and the other annular conductive magnetic pole, for example, the S pole, is positioned in front of the outer periphery of the target 1 without contacting the peripheral edge of the target 1. Preferably, the positive electrode is water-cooled, and the target 1 or its conductive holder is used as the negative electrode. Both electrodes are connected to a DC or high frequency power source to apply an electric field approximately parallel to the surface of the target 1.

Note that a direct current electric field is normally applied to the sputter region, but if the target material has a high resistivity, charge will accumulate on the target and the function will deteriorate, so a high frequency electric field is applied to the sputter area. Avoid the occurrence of degradation.

Generally, in the magnetron sputtering technique, it is necessary to arrange the anode ring 3, which serves as a positive electrode for glow discharge to generate gas ions in the sputtering gas, to face the target 1, which serves as a negative electrode. If the inventive magnetron sputtering source is used, the annular conductive magnetic pole portion 2b can also be used as the anode as described above, so there is no need to separately provide the anode ring 3, and the configuration of the sputtering apparatus is significantly simplified.

In addition, when producing a thin film by sputtering, depending on the type of thin film material, it is possible to produce a thin film of better quality if the particles of the material released from the target are ionized, or if they are released as neutral particles. In some cases, a thin film of good quality is formed. Therefore, if the sputtering source of the present invention is used, by appropriately setting the length of the solenoid coil 4 in the axial direction and making the solenoid coil 4 longer, the ionized material particles will be directed directly to the substrate. The ionized particles travel in a spiral along the lines of magnetic force and are efficiently transported to the substrate.If the solenoid coil 4 is shortened, the lines of magnetic force of the solenoid coil 4 become difficult to reach the substrate, and the ionized particles come off the substrate along the lines of magnetic force, reducing the influence of the magnetic field. Only the unaffected neutral particles travel straight and reach the substrate, where they adhere and accumulate. moreover,
The thickness distribution of the thin film deposited on the substrate can be controlled not only by mechanically adjusting the distance between the substrate and the target, but also by keeping it mechanically fixed.
Control can also be achieved by adjusting the current in the solenoid coil 4. Therefore, the solenoid coil 4 used in the sputtering source of the present invention can not only compress the leakage magnetic field appearing from the back side of the target 1 to the front side in parallel to the target surface;
As mentioned above, there are three ways to control the leakage magnetic field distribution by adjusting the coil shape and excitation current, control the electrical properties of target material particles deposited on the substrate, and control the thickness distribution of the thin film deposited on the substrate. It has the effect of

(Effects) As is clear from the above explanation, according to the present invention, in a magnetic field compression type magnetron sputtering source, a magnetically conductive electrically insulating member is interposed in the magnetic path of the magnet disposed close to the back surface of the target. The free conductive annular magnetic pole tip is separated from the target and pulled out to the front of its outer periphery, causing the leakage magnetic field to extend almost parallel to the target surface, and the magnetic field of the same polarity from the solenoid coil is applied to almost the entire surface of the target. Since the sputter gas ions can be compressed in parallel over the target surface, almost the entire surface of the target is uniformly eroded by the sputtering gas ions, and the effective utilization rate can be greatly improved to 87%. Furthermore, like the leakage magnetic field, the plasma made up of charged gas particles formed near the target surface is compressed to the target surface to form a flat disk or donut shape. It can be shortened and a homogeneous sputtered thin film can be easily produced. Furthermore, even if a ferromagnetic target is used, there is no risk of shorting the magnetic path of the magnet for applying a magnetic field, so high-speed sputtering of ferromagnetic materials is possible, and the effective utilization rate of the ferromagnetic target is over 70%. It can be made good.

Furthermore, the sputtering source of the present invention can be used as an ion generation source as it is, and the sputtering source of the present invention has extremely remarkable effects.
It can be used in an extremely wide range of applications, including low-temperature and high-speed production of thin films of metals and dielectrics, and dry plating of metals.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the structure of a conventional magnetic field crimping type magnetron sputter source, and FIG. 2 is a sectional view showing an example of the structure of the electromagnetic field crimping type magnetron sputter source of the present invention. 1...Target, 2, 2a, 2b...Magnet, 3...
Anode ring, 4... Solenoid coil, 5, 5
a, 6, 6a...Magnetic field component, lines of magnetic force, 7...Ceramic magnet, magnetically conductive electrical insulating member.

Claims (1)

[Scope of Claims] 1. A magnet made of a conductive ferromagnetic material, with a magnetically conductive electrical insulator interposed between both magnetic poles, each of which has one end formed into a substantially annular shape, with the one end of the magnet having at least the base. The sputtering target is disposed in contact with the center of the back surface of a sputtering target having a substantially disc-shaped part that is magnetically conductive, and the other end, which is substantially annular, is disposed close to and spaced from the outer circumferential front of the target. A direct current or high frequency electric field approximately parallel to the surface of the target is applied between the other end and the target, and a nearly cylindrical solenoid is coaxially arranged in front of the target to prevent leakage magnetic field from the solenoid. An electromagnetic field compression type magnetron sputter source, characterized in that the leakage magnetic field of the magnet can be pressed substantially parallel to the surface of the target by engaging the leakage magnetic field of the magnet. 2. The sputter source according to claim 1, wherein the electrical properties of the sputter particles emitted from the target can be selectively controlled depending on the length of the substantially cylindrical solenoid. Features an electromagnetic field crimping type magnetron sputter source. 3. The sputter source according to claim 1 or 2, wherein the electromagnetic field is characterized in that the uniformity of sputter particles emitted from the target can be controlled in accordance with the current of the solenoid. Crimp type magnetron sputter source. 4. Claims: In the sputtering source according to any one of the preceding claims, an electromagnetic pressure bonding type magnetron sputtering device is characterized in that the sputtering source is operated in a sputtering gas made of a gas having an atomic weight lighter than the sputtering particles emitted from the target. source.