JP2002317264A - Sputtering film deposition system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To deposit a film having high orientation on a substrate by controlling the energy of sputtering particles. SOLUTION: Plasma beams PB from a plasma gun main body 30 are guided to a magnetic field fixed by a steering coil 40 or the like to form high density plasma in a space over a gun anode 51 and a sputtering target 52. The plasma is kept to be in high density by lines of magnetic force and lines of electric force formed in the vicinity of the surface of the sputtering target 52. Almost of the film deposition particles produced by making Ar ion in the plasma incident to the sputtering target 52 are ionized by the plasma in the space over the sputtering target 52 to be made incident to the surface of a work W and then a highly oriented film free from damage is deposited on the work W by controlling the potential of the surface of the work W.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a sputtering film forming apparatus for forming a film by sputtering a target using plasma.

[0002]

2. Description of the Related Art A magnetron sputtering apparatus has been widely used as a sputtering film forming apparatus.

FIG. 6 is a view for explaining the structure of a sputtering target used in a magnetron sputtering apparatus. In this magnetron sputtering apparatus, the permanent magnet PM is arranged concentrically on the back surface of a sputtering target ST opposed to an anode (not shown) that supports a film-forming target, so that the magnetic force lines are reduced.
A magnetic field distribution is formed along the surface in the direction of its center. With such a magnetic field distribution, the electron EL can be confined on the surface of the sputter target ST and a so-called magnetron discharge can be generated.
By impacting the target ST, sputter particles that contribute to film formation are efficiently generated.

[0004]

However, in the above magnetron sputtering apparatus, it was impossible to control the energy of sputter particles deposited on the substrate. That is, in magnetron sputtering, sputtered particles are:
Generally, it is a neutral particle having an energy of about 10 to 30 eV, the energy of the sputtered particle incident on the substrate cannot be adjusted, and the film quality cannot be controlled by the particle energy.

Further, ions of a carrier gas (for example, Ar) for forming plasma may collide with a sputter target and recoil without losing much energy. I know it. Specifically, a large number of defects are generated in a growing film, or a large stress is generated by being buried in the film. In particular, with such defects, it is considered difficult to grow a film having a high orientation, and a film having a high orientation has not been actually obtained by sputtering.

Accordingly, an object of the present invention is to form a highly oriented film on a substrate by adjusting the energy of sputtered particles.

[0007]

In order to solve the above-mentioned problems, a sputter film forming apparatus according to the present invention comprises a plasma gun body for supplying plasma, a gun / anode for guiding the plasma from the plasma gun body, and A sputter target disposed as a cathode near the gun anode. Here, as a technique of the plasma gun, for example, a pressure gradient type plasma gun can be used, and in this case, high-density and stable plasma can be generated from the plasma gun body.

In the above sputtering film forming apparatus, the sputtering
Since the target is disposed near the gun / anode for guiding the plasma from the plasma gun body, the plasma continuously supplied from the plasma gun body covers the sputter target serving as the cathode. As a result, the sputter target is sputtered by the positive ions in the plasma, and the material particles jumping out of the sputter target are ionized with high efficiency by the plasma in the sky. Therefore, by accelerating the ionized material particles by appropriate means, the energy of the material particles incident on the film formation target, that is, the energy of the sputtered particles can be adjusted, and a film with high orientation is formed on the surface of the film formation target. can do.

In a specific aspect of the above-mentioned apparatus, the apparatus further comprises voltage applying means for applying a negative voltage to a film-forming target supported opposite to the sputtering target. In this case, the energy of the sputtered particles incident on the film formation target can be appropriately adjusted and changed by a simple method. When the film formation target is an insulating material, for example, an acceleration electrode can be arranged between the sputtering target and the film formation target to accelerate ionized sputter particles.

[0010] In a specific aspect of the above apparatus, the sputter target is annularly arranged around the gun anode.

[0011] In another specific embodiment of the above device,
The gun anode is annularly disposed around the sputter target.

[0012] In another specific embodiment of the above device,
The gun anode and the sputter target are:
Each is formed annularly and arranged coaxially. In this case, ionized sputtered particles can be made incident from the periphery to the gun / anode and the film formation target arranged at the center of the sputtering, and a film formation target having a three-dimensional shape can be formed.

[0013] In another specific embodiment of the above device,
Magnetic field forming means for forming a magnetic field near the sputter target is further provided. In this case, the plasma supplied from the plasma gun main body can be kept around the sputter target by the magnetic field formed by the magnetic field forming means, and the ionization efficiency of the material particles emitted from the sputter target can be increased.

In another specific mode of the above-mentioned device,
Magnetic field forming means for forming magnetic field lines penetrating the gun anode and extending along the surface of the sputter target is further provided. In this case, the plasma can be efficiently held near the sputter target, and the sputter
The ionization efficiency of the material particles emitted from the target can be further increased.

[0015] In another specific embodiment of the above device,
Magnetic field forming means for forming a cusp magnetic field near the center of the annular gun anode and the sputter target is further provided. In this case, the plasma can be efficiently retained near the sputter target, and the ionization efficiency of the material particles emitted from the sputter target can be further increased.

In another specific mode of the above-mentioned device,
The sputter target is divided into a plurality of regions. In this case, it is possible to form a film in which targets are variously arranged.

In another specific mode of the above-mentioned device,
The sputter target is divided into a plurality of regions, each region being formed of a different target material. In this case, not only a material having a single composition but also a material having a composite composition can be easily formed with high orientation.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] FIG. 1 is a view schematically illustrating the overall structure of a sputter film forming apparatus according to a first embodiment. This sputtering film forming apparatus is a vacuum chamber 10 serving as a film forming chamber, a plasma gun body 30 for supplying a plasma beam PB into the vacuum chamber 10, and a plasma beam PB which is disposed at the bottom of the vacuum chamber 10 and receives the plasma beam PB. An electrode member 50 for generating sputtered particles by this and a substrate holding member 60 for holding a work W such as a semiconductor wafer to be formed into a film are provided.

Atmospheric gas supply device 1 is placed in vacuum vessel 10.
4 and the exhaust device 16 are connected. The atmosphere gas supply device 14 supplies an atmosphere gas such as Ar from an atmosphere gas source (not shown) to the vacuum vessel 10 in an appropriate amount at an appropriate timing. The exhaust device 16 is operated by an exhaust pump 16a.
The gas in the vacuum vessel 10 is appropriately exhausted through the vacuum gate 16b to maintain the degree of vacuum of the vacuum vessel 10 at a target value.

The plasma gun body 30 is disclosed in
This is a pressure gradient type plasma gun disclosed in Japanese Patent No. 4232 and the like, and its main body is mounted on a cylindrical portion 12 provided on a side wall of the vacuum vessel 10. The main body is composed of a glass tube 31b one end of which is closed by a cathode 31a. In the glass tube 31b, cylinder 31c formed of molybdenum Mo is arranged concentrically fixed to the cathode 31a, Within the cylindrical 31c, are formed in the disc 31d and tantalum Ta formed of LaB ₆ And a built-in pipe 31e. Between the end of the glass tube 31b opposite to the cathode 31a and the end of the cylindrical portion 12 provided in the vacuum vessel 10, a first and second intermediate electrode 33,
34 are concentrically arranged in series. An annular permanent magnet 35 for converging the plasma beam PB is built in one first intermediate electrode 33. An electromagnet coil 36 for converging the plasma beam PB is also built in the second intermediate electrode 34. In addition, around the cylindrical portion 12, the first and second intermediate electrodes 3 generated on the cathode 31a side are formed.
A steering coil 40 that guides the plasma beam PB extracted to 3, 34 into the vacuum vessel 10 is provided.

The cathode 31a of the plasma gun body 30 is connected to the negative terminal of the power supply 70 and is maintained at an appropriate negative potential. Specifically, a voltage of −30 V is applied to the cathode 31 a and a voltage of +20 to +60 V to the anode 51, and a current of 70 to 100 A is supplied to the grounded vacuum vessel 10. The power supply device 70 is controlled by a gun drive device (not shown), and can turn on and off power supply to the cathode 31a. Further, this gun driving device has a first
The power supply to the second intermediate electrodes 33 and 34, the electromagnet coil 36, and the steering coil 40 can be adjusted. Thereby, the intensity and distribution state of the plasma beam PB supplied into the vacuum vessel 10 can be controlled.

The pipe 31e disposed on the innermost side of the plasma gun body 30 is provided with a carrier gas such as Ar, which is a source of the plasma beam PB, by the plasma gun body 30.
It is intended to be introduced into the vacuum vessel 10, and
It is connected to a carrier gas source not shown.

The electrode member 50 disposed at the lower part in the vacuum vessel 10 includes a gun anode 51 for guiding the plasma beam PB downward, a sputter target 52 disposed around the gun anode 51 as a cathode, and a sputter target 52.・
A magnetic field forming member 53 that forms lines of magnetic force extending along the surface of the target 52. Note that the gun anode 5
1 and the sputter target 52 are insulated from each other, and are supported by a grounded vacuum vessel 10 via an insulator (not shown).

FIG. 2A is a plan view of the electrode member 50, and FIG. 2B is a side sectional view of the electrode member 50.

The gun anode 51 is a disc made of a water-cooled conductive material such as copper, and is disposed at the center of the electrode member 50. The sputter target 52 is a ring plate made of a film-forming material, and is arranged concentrically around the gun anode 51 and in the same plane. Magnetic field forming member 53
Are a yoke 54 formed of a circular magnetic material and a yoke 5
Annular coil 55 for applying magnetic force to 4 to form magnetic lines of force
And Here, the yoke 54 is connected to the gun anode 5
On the lower surface of the target 1, a first magnetic pole portion 54 a having a columnar shape extending in the vertical direction and a second magnetic pole portion 54 b having a cylindrical shape surrounding the outer periphery of the sputter target 52 are provided. The first magnetic pole portion 54a is surrounded by a coil 55 disposed below the sputter target 52. Note that a magnet can be embedded in the yoke 54 instead of or together with the coil 55.

The gun anode 51 is connected to the positive terminal of the above-described constant current power supply 70 (see FIG. 1) and is balanced at a positive potential so as to maintain a predetermined discharge current. Specifically, the gun / anode 51 is +3 with respect to the grounded vacuum vessel 10.
The voltage is 0 to + 60V. As a result, the plasma beam PB emitted from the plasma gun body 30 is attracted to the gun / anode 51 side, and the electrons in the plasma beam PB enter here. On the other hand, the sputter target 52 is connected to the negative terminal of another power supply 72 and is maintained at an appropriate negative potential. As a result, near the surface of the sputter target 52, an electric field EF extending in the normal direction is formed, and Ar ions in the plasma beam PB enter.
Further, when the coil 55 is energized, the first magnetic pole 5
Radial lines of magnetic force BL are formed from the upper end of 4a to the upper end of the second magnetic pole portion 54b, and near the surface of the sputter target 52, the lines of magnetic force BL extend substantially parallel to the surface.

In the above state, the sputtering target 5
2 is covered with high-density plasma, and a large amount of Ar ions are incident on the sputter target 52, and sputter particles, that is, film-forming particles are generated with high efficiency. Further, the lines of magnetic force BL and the electric field EF intersect near the surface of the sputter target 52, and a state similar to that of the magnetron discharge occurs, and electrons are confined near the surface of the sputter target 52. For this reason, the plasma density above the sputter target 52 further increases, and almost all of the film-forming particles generated by the Ar ions incident on the sputter target 52 are ionized by the plasma above the sputter target 52, and the work W Incident on the surface.

Returning to FIG. 1, the substrate holding member 60 disposed on the upper portion in the vacuum vessel 10 holds the workpiece W above the electrode member 50 with the film forming surface on the lower side. The substrate holding member 60 is supported by the vacuum vessel 10 via an insulator (not shown), and receives a supply of cooling water or the like from a temperature controller (not shown) provided outside the vacuum vessel 10 to work the substrate. The temperature of W is adjusted from the back side. The work W fixed on the substrate holding member 60 is applied with an appropriate zero or negative voltage with respect to the grounded vacuum vessel 10 by the power supply device 76. The sputtered material particles (sputtered particles) enter with appropriate energy. At this time, the energy at which Ar ions enter the work W can be made similar to that of the material particle ions, so that a highly oriented film that is not damaged on the work W can be formed. If the voltage applied to the work W is less than -100 V, the incident energy of the material particle ions or Ar ions increases, and the surface of the work W and the film on the surface of the work W are easily damaged.

Hereinafter, the operation of the sputtering film forming apparatus shown in FIG. 1 will be described. At the time of film formation by this sputtering film forming apparatus, the cathode 31a of the plasma gun body 30 and the vacuum vessel 1
A discharge is generated between the gun and the anode 51 in the zero, thereby generating a plasma beam PB. This plasma beam PB is guided by a magnetic field determined by the steering coil 40 and the like to form a high-density plasma above the gun anode 51 and the sputter target 52.
This plasma is maintained at a high density by the lines of magnetic force and the lines of electric force formed near the surface of the sputter target 52. Ar ions in such plasma are sputtered.
Most of the material particles generated by being incident on the target 52 are ionized by the plasma above the sputter target 52 and are incident on the surface of the work W. A highly oriented film without damage can be formed.

[Second Embodiment] Hereinafter, a sputtering film forming apparatus according to a second embodiment will be described. Note that the sputter deposition apparatus of the second embodiment is a modification of the electrode member 50 of the apparatus of the first embodiment, and only the changed portions will be described here.

FIG. 3A is a plan view of an electrode member 150 constituting a sputtering film forming apparatus according to the second embodiment.
FIG. 3B is a side sectional view of the electrode member 150.

In this case, the sputter target 152 is disposed at the center of the electrode member 150, and the gun anode 151 is disposed concentrically and in the same plane around the sputter target 152. In addition, the gun anode 15
An annular auxiliary anode 156 is arranged around the periphery of the first auxiliary anode 156. The coil 153, which is a magnetic field forming member, is annularly arranged below the auxiliary anode 156. As a result, near the surface of the sputter target 152, an electric field EF extending in the normal direction is formed, and Ar ions in the plasma beam PB enter. Furthermore, when the coil 153 is energized, magnetic force lines BL extending in the normal direction are formed near the surface of the sputter target 152.

In the above state, the sputtering target 1
52 is covered with high-density plasma, and a large amount of Ar ions are incident on the sputter target 152, and sputter particles, that is, film-forming particles are generated with high efficiency. Further, the plasma density over the sputter target 152 is maintained, and the Ar
Sputter particles generated by the incidence of ions,
The ions are efficiently ionized by the plasma above the sputtering target 152 and enter the surface of the work W.

The auxiliary anode 156 is made of a conductive material, and the electric field above the gun anode 151 can be complementarily controlled by changing the voltage applied thereto. That is, when the potential of the auxiliary anode 156 is set to be the same as that of the gun anode 151, the plasma beam PB is also attracted to this, and the supply of the plasma beam PB to the gun anode 151 and the sputtering target 152 is reduced. On the other hand, when the potential of the auxiliary anode 156 is lowered to the same level as that of the vacuum vessel 10, the plasma beam PB is drawn to the gun anode 151 and the like, and the sputter target 152
Ar ions are incident on the substrate to form sputtered particles.

[Third Embodiment] Hereinafter, a sputtering film forming apparatus according to a third embodiment will be described. The sputtering apparatus according to the third embodiment is also the same as the electrode member 5 of the apparatus according to the first embodiment.
0, etc., and only the changed portions will be described here.

FIG. 4 is a block diagram conceptually illustrating the structure of a sputtering film forming apparatus according to the third embodiment. In this case, the electrode member 250 has a double cylindrical structure with the gun anode 251 outside and the sputter target 252 inside. That is, the gun anode 251 and the sputter target 252 are each formed in an annular shape and are arranged concentrically and coaxially. The coil 253 disposed below the electrode member 250 and the steering coil 40 disposed above the electrode member 250 and directly below the plasma gun main body 30 serve as a magnetic field forming member, and serve as a space inside the electrode member 250. To form a cusp magnetic field. For reference, the line of magnetic force B formed by the coils 40 and 253
L is illustrated.

The substrate holding member 260 disposed immediately below the electrode member 250 holds the three-dimensional work W on the stage 262 provided thereon. Thereby, the electrode member 25
The work W is supported in the center space of zero. Substrate holding member 6
An appropriate zero or negative voltage is applied to the workpiece W on the ground 0 by the power supply device 76 with respect to the grounded vacuum vessel 10, and sputtered particles emitted from the sputter target 252 and ionized are appropriately applied. Incident with energy.

Hereinafter, the operation of the sputtering film forming apparatus shown in FIG. 4 will be described. During film formation by this sputtering film forming apparatus, the plasma beam P
Generate B. The plasma beam PB is guided to the central space of the electrode member 250 by a cusp magnetic field formed by the pair of coils 40 and 253, and is confined therein to form high-density plasma. Most of the sputtered particles, or film-forming particles, generated by the Ar ions in the plasma incident on the sputter target 252 are ionized by the plasma around the sputter target 252, and from around the work W to the surface of the work W. Incident on. Therefore, by adjusting the potential of the surface of the work W, it is possible to uniformly form a highly oriented film on the three-dimensional work W without damage.

[Fourth Embodiment] Hereinafter, a sputter film forming apparatus according to a fourth embodiment will be described. The sputter film forming apparatus of the fourth embodiment is also the same as the electrode member 5 of the apparatus of the first embodiment.
0, etc., and only the changed portions will be described here.

FIG. 5 is a plan view of an electrode member 350 constituting the sputter film forming apparatus according to the fourth embodiment. In this case, the sputter target 352 has four portions 352
a to 352d. Each part 352a to 352d is
All can be formed from different film forming materials. Or,
The pair of portions 352a and 352c can be a first film forming material, and the other portions 352b and 352d can be a different film forming material. By making the plasma beam PB incident on such a sputter target 352, each portion 35
2a to 352d can be sputtered at the same time, so that two or more materials (for example, a trace (0.5
%) Containing Si, about 3% N in Al
d) can be formed on the work W. Note that the portions 352a to 352d are not limited to four divisions, but may be two divisions, three divisions, or five divisions or more. Further, the division ratio does not need to be the same, and can be appropriately set according to the composition ratio.

[0041]

As is apparent from the above description, according to the sputter film forming apparatus according to the present invention, the sputter target is formed as a sputter target in the vicinity of the gun anode for guiding the plasma from the plasma gun body. Since it is arranged, the plasma continuously supplied from the plasma gun body covers the sputter target. As a result, the material particles sputtered by the positive ions in the plasma and jumping out of the sputter target are ionized with high efficiency by the plasma in the sky. Therefore, by accelerating the ionized material particles by appropriate means, the energy of the sputtered particles incident on the film formation target can be adjusted, and a highly oriented film can be formed on the surface of the film formation target. it can.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a structure of a sputtering film forming apparatus according to a first embodiment.

2A is a plan view illustrating a main structure of the sputtering film forming apparatus of FIG. 1, and FIG. 2B is a side sectional view thereof.

FIG. 3A is a plan view illustrating a main structure of a sputtering film forming apparatus according to a second embodiment, and FIG. 3B is a side sectional view thereof.

FIG. 4 is a diagram illustrating a structure of a sputtering film forming apparatus according to a third embodiment.

FIG. 5 is a plan view illustrating a main structure of a sputtering film forming apparatus according to a fourth embodiment.

FIG. 6 is a diagram illustrating a main structure of a conventional sputtering apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Vacuum container 14 Atmospheric gas supply device 16 Exhaust device 30 Plasma gun main body 31a Cathode 31b Glass tube 31c Cylindrical 31d Disk 31e Pipe 40 Steering coil 50 Electrode member 51 Gun / anode 52 Sputter target 53 Magnetic field forming member 54 Yoke 55 Coil 60 Substrate Holding member 70, 72, 76 Power supply device PB Plasma beam W Work

Claims (10)

[Claims] A plasma gun body for supplying plasma; and a gun for guiding the plasma from the plasma gun body.
A sputter deposition apparatus comprising: an anode; and a sputter target disposed as a cathode near the gun / anode. 2. The sputter film forming apparatus according to claim 1, further comprising a voltage applying means for applying a negative voltage to a substrate supported opposite to said sputter target. 3. The sputter film forming apparatus according to claim 1, wherein said sputter target is arranged annularly around said gun / anode. 4. The method according to claim 1, wherein the gun anode is connected to the sputtering anode.
The sputter film forming apparatus according to claim 1, wherein the sputter film forming apparatus is arranged annularly around the target. 5. The gun anode and the sputter
3. The sputtering film forming apparatus according to claim 1, wherein the targets are formed in a ring shape and are arranged coaxially. 6. The sputter film forming apparatus according to claim 1, further comprising a magnetic field forming means for forming a magnetic field near the sputter target. 7. The sputter film forming apparatus according to claim 3, further comprising magnetic field forming means for forming a magnetic field line penetrating the gun anode and extending along the surface of the sputter target. 8. The sputter film forming apparatus according to claim 5, further comprising a magnetic field forming means for forming a cusp magnetic field near the center of said annular gun anode and said sputter target. 9. The apparatus according to claim 1, wherein the sputter target is divided into a plurality of regions. 10. The sputter according to claim 1, wherein the sputter target is divided into a plurality of regions, and each region is formed of a different target material. Film forming equipment.