JPH0428863A - Method and device for forming film - Google Patents

Abstract

PURPOSE:To easily form a multilayer film consisting of plural materials in a short time by providing a mechanism for deflecting plasma from its source with a magnetic field, generated from its source, and successively irradiating plural targets with the plasma. CONSTITUTION:A magnetic field is generated by a magnet coil 5A so that the magnetic poles of the coils 5A and magnet coil 1C close to each other are different, and hence the line of magnetic force generated from the coil 1C of an ECR plasma source is deflected toward a target 4A, and the plasma produced from the source 1 is sent to the target 4A as the plasma current 8A along the line of magnetic force. A voltage is then impressed on the plasma source 1 and/or the target 4A to accelerate the ion in the plasma current 8A, then the target 4A is irradiated with the ion to carry out the sputtering, thereby a film is formed on a substrate 3. When the sputtering of the target 4A is finished, a target 4B is sputtered in the same way, and a film is formed on the substrate 3. Consequently, the process is changed in a short time, and plural films are easily laminated on the substrate 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application J] The present invention relates to an apparatus for forming a film on a substrate by alternately supplying film materials from sputter targets made of a plurality of different materials.

[Prior Art] In order to manufacture a loser reflecting mirror or form an anti-reflection film on a lens, it is necessary to form layers of a plurality of substances having different optical properties.

An example of the configuration of such a conventional layered film forming apparatus is shown in FIG.

This device consists of a first
an ion source 21, and sputter targets 22A and 22B that rotate to select target materials and irradiate ions from the ion source 21 to supply film forming substances.
, a substrate 3, and a second ion source 23 that activates the substrate surface by irradiating the substrate surface with ions. In the ion beam sputtering method, 10-' to 10-'T
Since the film can be formed in a high vacuum on an ORR stage, it has the advantage of having strong film adhesion and being able to form a highly pure film. Furthermore, the ion beam irradiation from the second ion source 23 can clean the surface of the substrate 3 and activate the surface during film formation, which has the advantage that a dense film with good adhesion can be formed. be.

[Problem to be Solved by the Invention 1] However, as mentioned above, in such conventional technology,
There is a problem in that it is necessary to use two ion sources 21 and 23, which complicates the control and structure.

In addition, in the conventional example, two types of targets 22A and 22
B are provided on opposite sides, and the target to be sputtered is switched by rotating the target holder 22. However, targets 22A and 2 that require cooling with water etc.
2B and 2B, the mechanism and control are very complicated and also time consuming. Furthermore, in order to increase the number of targets, it is necessary to add more target support rotating surfaces, which causes the problem that the device becomes larger and the device structure and control become dramatically more complicated. That is, the conventional technology has the following problems.

■It is necessary to install two ion sources.

■It takes time to switch targets.

■Increasing the number of target types makes the structure and control extremely complex.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a film forming apparatus and method that can easily switch the supply of film materials from a plurality of targets in a short time.

Another object of the present invention is to provide a film forming apparatus and method in which cleaning and activation of a substrate by plasma can be performed using the same plasma generation source as for film formation.

[Means for Solving the Problems 1] In order to achieve such an object, the apparatus of the present invention includes a member that holds a substrate, a plasma generation source that generates plasma, and a plasma extractor for the substrate and the plasma generation source. a target part that is installed at a position away from the direction connecting the opening and has a target that supplies film-forming elements; and a magnetic field generation source that generates a magnetic field that bends and transports the plasma from the plasma generation source to the target. It is characterized by having the following.

Here, the target section may include at least one target arranged in a direction intersecting the direction.

The magnetic field generation source can generate a magnetic field having a component in a direction perpendicular to a target surface of the target section.

Furthermore, it is also possible to include a second magnetic field generation source that generates a magnetic field that bends and transports the plasma from the plasma generation source to the member that holds the substrate.

The plasma generation source can also be an ECR plasma source.

In the method of the present invention, when forming a multilayer film on a substrate, plasma from a plasma generation source is bent by a magnetic field and placed at a position away from a direction connecting the substrate and a plasma extraction opening of the plasma generation source, a step of transporting film-forming elements to a target portion having a target for supplying the film-forming elements; and a step of controlling the transport of the target of the plasma by controlling the generation of the magnetic field according to the film material of each layer constituting the multilayer film. It is characterized by having the following.

Here, the step of bending the plasma by a second magnetic field and transporting it toward the substrate, and the step of controlling to generate the second magnetic field in the cleaning step and the activation step of the substrate, It can also be equipped.

[Function 1] According to the present invention, the direction in which plasma is transported from the plasma generation source can be controlled in a short time and with good controllability by electrically controlling the magnetic field generation source.
Since the film material to be supplied can be changed or plasma can be directed toward the substrate to clean or activate the substrate, multilayer films with complex configurations can be easily formed. In particular, the present invention aims at rapid switching of supplied materials to form a film of a material having a crystalline structure in which four or more elements are arranged in layers, such as an oxide high-temperature superconductor, in atomic layer units. This is very effective for speeding up film formation methods that require

[Example 1 The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. In Figure 1, 1
is an ECR (electron cyclotron resonance) plasma source, which includes a plasma chamber IA, a microwave introduction window IB that seals the vacuum of the plasma chamber IA and introduces microwaves into the plasma chamber IA, and the intensity required for ECR discharge. It consists of a magnet coil IC that generates a magnetic field in the plasma chamber IA. , 2 is a ring-shaped insulator for insulating and grounding the ECR plasma source 1 from the vacuum chamber 7 so that a voltage can be applied to the ECR plasma source 1. 3
are the substrates fixed to the substrate holder 6, 4A, 4B
are sputter targets, respectively. 5A, 5B
is a magnetic coil. 8A, 8B, 8G are
Each shows a plasma flow generated by the ECR plasma source 1 and transported by magnetic lines of force, and is designated by symbols 8A, 8B, and 8B depending on the operation mode of the magnet coils 5A and 5B.
It is transported as shown in 8C.

In this embodiment, the plasma flow generated by the ECR plasma source 1 is irradiated onto the target 4A or 4B by magnetic lines of force generated by the magnet coils 5A and/or 5B, and a negative voltage is applied to the irradiated target. The ions are accelerated and made incident on the target, and the target material is sputtered to form a film on the substrate 3.

The operation of this embodiment will be explained. First, the operation for cleaning the substrate and activating the substrate surface will be explained. Ar is applied to the ECR plasma source 1 as a sputtering gas at a gas pressure of 1 to 5.
xlO-' Torr, and the magnet coil IC generates a current of 875 to 100 Torr in the axial direction of the plasma chamber IA near the microwave introduction window IB in the plasma chamber IA.
Generates a magnetic field of approximately 0 Gauss.

When a 2.45 GHz microwave is introduced into the plasma chamber IA through the introduction window IB, plasma is generated by ECR discharge. The generated plasma is transferred to a magnetic coil IC.
It is transported to the substrate 3 like a plasma flow 8C by the lines of magnetic force generated by the magnetic field, and is used for cleaning and activating the substrate surface. At this time, a voltage may be applied to the substrate 3 and/or the ECR plasma source 1 to accelerate the ions in the incident plasma flow 8C to increase the ion incident energy to the substrate 3 and strengthen the ion bombardment effect. can.

Next, the operation when supplying a film material from a sputter target will be explained. Coil 5 by magnet coil 5A
If a magnetic field is generated so that the magnetic poles of A and coil IC that are closer to each other are different, the lines of magnetic force generated by coil IC of ECR plasma source 1 will be bent toward target 4A.
The plasma generated in the ECR plasma source 1 is transported along its magnetic field lines and reaches the target 4A like a plasma flow 8A.

In addition, as a means to bend the lines of magnetic force toward the target 4A, the magnetic coil 5B connects the coil 5B and the coil I.
The magnetic field may be generated so that the magnetic poles of C that are closer to each other are equal.

Alternatively, both coils 5A and 5B may be used simultaneously.

Next, ECR plasma source 1 and/or target 4
By applying a voltage to A, ions in the plasma flow 8A are accelerated and irradiated onto the target 4A, the target 4A is sputtered by these ions, and the obtained film-forming substance is supplied to the substrate 3.

Next, cut off the applied voltage, stop the operation of the coil 5A,
The plasma flow is transported to the target 4B as shown by reference numeral 8B by the same operation as above, such as generating a magnetic field by the coil 5B so that the magnetic poles of the coil 5B and the coil IC of the ECR plasma source 1 nearer to each other are different. . A voltage is applied to the target 4B and/or the ECR plasma source 1 to accelerate the ions in the plasma stream to generate the target 4B.
By irradiating the target 4B with sputtering, the film material is supplied to the substrate 3 by sputtering the target 4B. By repeating such operations, multilayer films made of different compositions or substances can be laminated on the substrate 3.

As described above, in the present invention, switching of the membrane material supply source is performed by electrical operation of energizing the selected target and coil, and therefore, such switching can be performed instantaneously and without a complicated mechanism. Further, the substrate 3 can be irradiated with ions by the plasma flow 8C, and there is an advantage that two ion sources for cleaning the substrate and activating the substrate surface are not required.

Furthermore, since the ECR plasma source 1 operates at a gas pressure on the order of 10-'Torr and can easily generate high-density plasma at a gas pressure on the order of 10-'Torr, the generated plasma can be transported to the targets 4A and 4B. The present invention utilized for sputtering has the advantage of being able to form a film stably and at high speed at such a low gas pressure. Moreover, since the density of the plasma flow can be easily changed by changing the microwave power input to the ECR plasma source 1, etc., the voltage applied to the targets 4A and 4B can be kept constant.
It has the advantage of excellent controllability, such as being able to change the ion current incident on the targets 4A and 4B.

In this example, in order to easily explain the operation, an example was shown in which two targets 4A and 4B were used, but the By arranging three or more targets, the film material can be supplied to the substrate 3 from four or more targets in any desired order by the same operation as described above.

In addition, in the embodiment shown in FIG. 1, the main surfaces of the targets 4A and 4B are arranged perpendicular to the main surface of the substrate 3, but the plasma flows 8A and 8B are bent by magnetic lines of force to reach the targets 4A and 4B. Although the targets 4A and 4B are being transported, the main surfaces of the targets 4A and 4B can also be set at an angle to the main surface of the substrate 3, as shown in FIG. By directing the target surface toward the substrate 3, the film formation rate can be improved.

Furthermore, when it is necessary to promote oxidation or nitridation during film formation, such as when forming an oxide or nitride film, the plasma a1 and the opening 2 from which the plasma flow exits are connected to the substrate 3.
It is best to place it facing towards.

If arranged in this way, the plasma flow will be 8A, 8B.
Even when sputtering is carried out by bending and transporting to the targets 4A and 4B as shown in , the highly reactive neutral radicals of enzymes and nitrogen go straight and enter the substrate 3, so the film material is not transferred to the substrate 3. Oxidation and nitridation can be promoted at the same time as supply.

The plasma source 1 can also be arranged in a direction that avoids straight radicals and the like from entering the substrate 3.

In addition, in the embodiment shown in the first figure, targets 4A and 4B
We explained an example in which a shutter is not installed in the target, but material from one target adheres to the surface of the other target,
In order to prevent the composition of the formed film from being disturbed when the target is switched, a shutter may be installed near the target surface.

This shutter may have a simple structure as long as it has a function of preventing particles from adhering to the target surface, and the addition of the shutter does not substantially complicate the mechanism or control of the apparatus.

Another way to achieve a similar effect is to arrange the targets side by side so that the angle at which one target looks into the other target is reduced. If the targets are arranged in this way, the adhesion of substances from one target to the other can be ignored even without providing a shutter.

FIGS. 3A and 3B are a front view and a side view, respectively, of the embodiment of the present invention showing an example of target arrangement in this case. Here, the sputter targets 4A and 4B are arranged in parallel in the lateral direction with respect to the direction connecting the ECR plasma source 1 and the substrate 3, as shown in FIG. 3(B). In this case, since the angle at which targets 4A and 4B look at each other is small, there is almost no possibility that substances from one target will adhere to the other target.

FIGS. 4A and 4B are a front view and a side view, respectively, showing still another embodiment of the present invention. In this embodiment, sputter targets 4A and 4B are arranged so that their main surfaces are at an angle to each other. In this case, since the angle at which targets 4A and 4B look at each other becomes large, the baffle plate 9 is disposed between both targets 4A and 4B, thereby allowing one target to look at the other. Try to prevent film substances from adhering to the target. In this way, the baffle plate 9 prevents particles from adhering from one tarp to the other target, so that a film with high purity in each layer can be formed.

FIGS. 5A and 5B are a front view and a side view, respectively, showing the configuration of another embodiment of the present invention. In this embodiment, a magnet coil 10 is arranged around the substrate holder 6 as a magnetic field generation source.

The remaining configuration is the same as the embodiment shown in FIGS. 3(A) and CB). Here, the plasma from the plasma generation source 1 is bent and transported to the substrate 3 by the magnetic field generated by the magnetic field generation source 10, and the substrate 3 is irradiated with plasma.

Switching of plasma irradiation to the targets 4A, 4B and the substrate 3 is performed by switching the magnet coil 5 as in the first embodiment.
This is done by switching the energization state between A, 5B and the magnet coil 10, thereby switching the generation of the magnetic field. By arranging the targets 4A, 4B and the substrate 3 in this way, the angle of view of the targets 4A, 4B with respect to the substrate 3 can be increased, so that the film formation rate can be improved.

In this case as well, baffle plates can be provided for the targets 4A and 4B, similar to the embodiments of FIGS. 4FA) and 4B in which baffle plates 9 are provided for the targets 4A and 4B.

In the above description of the embodiments of the present invention, the case where a plurality of target parts are provided has been shown, but even in film formation using a single target, if the present invention is used, a single plasma source can be used to form a film on the substrate. It has the advantage that the surface can be cleaned, activated, and sputtered film can be formed, and the device configuration can be greatly simplified.

[Effects of the Invention] As explained above, according to the present invention, the direction in which plasma is transported from the plasma generation source can be controlled in a short time and with good controllability by electrically controlling the magnetic field generation source. For this purpose, the membrane material to be supplied may be changed,
Alternatively, since the substrate can be cleaned or activated by directing plasma toward the substrate, a multilayer film with a complicated structure can be easily formed. In particular, the present invention aims at rapid switching of supplied materials to form a film of a material having a crystalline structure in which four or more elements are arranged in layers, such as an oxide high-temperature superconductor, in atomic layer units. This is very effective for speeding up film formation methods that require

[Brief explanation of the drawing]

1 to 5 are schematic diagrams of embodiments of the present invention, and FIG. 6 is a schematic diagram of a conventional film forming apparatus. 1... ECR (Electron Cyclotron Resonance) source, IA... Plasma chamber, 1B... Microwave introduction window, IC... Magnet coil, 2... Ring-shaped insulator, Bladder 3... Substrate, 4A... Target, 4B... Target, 5A... Magnet coil, 5B... Magnet coil, 6... Substrate holder, 8A... Plasma flow, 8B... Plasma flow, 8C ... Plasma flow, 9... Baffle plate, lO... Magnet coil, 21... First ion source, 22... Holder, 22A, 22B... Sputter target, 23...
Second ion source.

Claims (1)

[Scope of Claims] 1) A member that holds a substrate, a plasma generation source that generates plasma, and a member that is installed at a position away from a direction connecting the substrate and a plasma extraction opening of the plasma generation source, and that includes a film forming element. What is claimed is: 1. A film forming apparatus comprising: a target section having a target that supplies a target; and a magnetic field generation source that generates a magnetic field that bends and transports the plasma from the plasma generation source to the target. 2) The film forming apparatus according to claim 1, wherein the target section has at least one target arranged in a direction intersecting the direction. 3) The film forming apparatus according to claim 1 or 2, wherein the magnetic field generation source generates a magnetic field having a component in a direction perpendicular to a target surface of the target section. 4) The method according to any one of claims 1 to 3, further comprising a second magnetic field generation source that generates a magnetic field that bends and transports plasma from the plasma generation source to a member that holds the substrate. film forming equipment. 5) The film forming apparatus according to any one of claims 1 to 4, wherein the plasma generation source is an ECR plasma source. 6) When forming a multilayer film on a substrate, the plasma from the plasma generation source is bent by a magnetic field.
a step of transporting the film material of each layer constituting the multilayer film to a target section having a target arranged at a position away from the direction connecting the substrate and the plasma extraction opening of the plasma generation source and supplying film forming elements; A method for forming a film, comprising the step of controlling generation of the magnetic field in accordance with the above to control transport of the target in the plasma. 7) The method further comprises: bending the plasma by a second magnetic field and transporting it toward the substrate; and controlling the generation of the second magnetic field in the substrate cleaning step and the activation step. A film forming method characterized by: