JPH06172995A - Magnetron sputtering device and sputtering gun - Google Patents

Abstract

(57) [Abstract] [Purpose] It is possible to deposit sputtered particles uniformly, and to perform sputtering with the sputtering gas pressure in the entire sputtering process space kept low. To provide a magnetron sputtering device and a sputtering gun that can be implemented. A magnetron includes a vacuum container 10, a sputtering gun 30 for injecting sputtered particles, a support 14 for supporting a wafer in the vacuum container, and a reaction gas supply means 14 for supplying a reaction gas into the vacuum container. Configure a sputtering device. The sputtering gun 30 includes a target 31 having a concave portion 32, a sputtering gas supplying means 18 for supplying a sputtering gas to the concave portion, electric field forming means 34, 45 for forming an electric field in the concave portion, and a perpendicular to the electric field in the concave portion. Magnetic field forming means 38, 3 for forming a magnetic field containing components
Have 9 and.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetron sputtering apparatus and a sputtering gun for depositing a thin film on a semiconductor wafer, for example.

[0002]

2. Description of the Related Art In a magnetron sputtering apparatus, a substrate (for example, a semiconductor wafer) on which a thin film is to be formed and a sputtering gun are provided in a vacuum chamber, and the sputtering gun faces the substrate. It has a target and a sputtering electrode provided.

During sputtering, the inside of the vacuum chamber is maintained in a sputtering gas atmosphere (generally argon gas is used) of the order of mTorr, and the sputtering target is generally provided through a sputtering electrode having a cooling mechanism. Is applied with a negative voltage from a DC power supply. On the other hand, members such as an anode and a shield that are in contact with the sputtering target and the sputtering electrode with a gap of several mm are generally maintained at the ground potential together with the vacuum chamber. A magnetic circuit is provided close to the back surface of the sputtering target, and a parallel magnetic field is applied to the front surface of the sputtering target. Therefore, an orthogonal electromagnetic field is formed on the surface of the sputtering target, which causes cyclones in the electrons in the plasma, and stable sputtering can be performed at a relatively low pressure.

As a target of a conventional sputtering gun, a flat plate type or an inverse cone type sputtering surface having a gentle gradient and having a larger diameter than a wafer is generally used. .

In recent years, as the degree of integration of ICs has increased, the diameter of via holes or contact holes has been reduced to, for example, 0.5 μm, while the thickness of each layer has not changed so much, so that the aspect ratio of via holes or contact holes is large. It is becoming a thing. When a thin film is formed on a wafer having such a high density, the following problems occur when a conventional flat target is used.

That is, as shown in FIG. 10, in the sputtering apparatus having the flat plate-shaped target 2, the sputtered particles ejected from the surface of the target 2 are approximately circles 3 in each part of the target 2. As shown in, it has components in various directions.

A ULSI 1 having a high degree of integration of 4M-DRAM or more used as a substrate has a contact hole (or via hole) 5 having a diameter of 0.5 micron and a depth of 1 micron (that is, an aspect ratio of 2). When the conductive film 4 is formed on such a ULSI 1 by sputtering, not only the sputtered particles from the vertical direction but also the sputtered particles are incident on the contact hole 5 from all angles. The deposition of sputtered particles increases and blocks the entrance of the contact hole 5, and as a result, a conductive film having a sufficient thickness cannot be formed on the inner surface of the contact hole 5. In particular, in a conventional flat plate type sputter gun for a contact hole or via hole of 0.5 μm or less, the step coverage (hereinafter referred to as “step coverage”), especially the amount of deposition on the bottom of the hole (hereinafter referred to as “bottom coverage”). It is pointed out that it will be reduced to 10% or less.

Further, in the conventional magnetron sputtering apparatus, plasma is generated at a sputtering gas pressure of 1 mTor.
If the pressure is higher than r, the pressure will not be stable and the entire processing space must be raised to a stable pressure, so that the amount of collision between the sputtered particles and the sputtered gas particles cannot be ignored. Therefore, the conventional magnetron sputtering apparatus cannot be said to have sufficient sputtering efficiency.

On the other hand, in the field of semiconductors, TiN and TiN
A compound film such as an O film is formed by reactive sputtering. Reactive sputtering generally uses an inert gas such as argon gas and nitrogen or a mixed gas of nitrogen and oxygen as a reaction gas, and reacts the sputtered particles with the reaction gas to form a film.

However, in reactive sputtering using such a reaction gas, the following new problems occur. That is, when sputtering is performed using a reaction gas such as nitrogen gas in this way, the sputtering efficiency is reduced to about 1/5 as compared with the case of using an inert gas (argon gas) alone. Further, the film deposited between the electrodes is easily peeled off, which causes abnormal discharge.

The present invention has been made in view of the above circumstances, and it is possible to deposit a sufficient amount of sputtered particles even in the holes of highly integrated wafers, and to reduce the sputter gas pressure in the entire sputtering processing space. It is an object of the present invention to provide a magnetron sputtering apparatus and a sputtering gun that can perform sputtering while maintaining a low temperature and can perform reactive sputtering with high efficiency.

[0012]

SUMMARY OF THE INVENTION The present invention is, firstly, a vacuum container, a sputtering gun disposed therein, for ejecting sputtered particles, and an object to be processed to form a thin film in the vacuum container. The sputtering gun comprises a support for supporting a body and a reaction gas supply means for supplying a reaction gas into the vacuum container, the sputtering gun has a target having a recess, and a sputtering gas supply means for supplying the sputtering gas to the recess. And an electric field forming unit that forms an electric field in the recess to generate plasma of the sputtering gas, and a magnetic field forming unit that forms a magnetic field containing a component orthogonal to the electric field in the recess. Sputtered particles are ejected from the target by the plasma formed inside, and the reaction gas supply means is a region separated from the recess. In this case, a reaction gas is supplied to the sputtered particles, and a reaction product formed by the reaction between the sputtered particles and the reaction gas is deposited on the object to be processed. To do.

Secondly, a target having a concave portion, a sputtering gas supply means for supplying a sputtering gas to the concave portion, an electric field forming means for forming an electric field in the concave portion to generate plasma of the sputtering gas, and the concave portion. A magnetic field forming means for forming a magnetic field containing a component orthogonal to the electric field, and a reactive gas supply means for supplying a reactive gas to the sputtered particles struck from the target by the plasma at a position separated from the plasma. And a reaction product particle formed by a reaction between the sputtered particle and the reaction gas.

[0014]

In the present invention, since the target of the sputtering gun is provided with a concave portion and plasma is formed therein to eject sputtered particles, the sputtered particles are ejected with extremely high directivity. Therefore, it is possible to deposit a sufficient amount of sputtered particles even in the holes of a highly integrated wafer. In addition, when supplying gas to the recess, a pressure gradient of the sputtering gas can be formed from the base end side to the tip end side of the recess, so that sputtering can be performed even when the processing space in the vacuum chamber is maintained at a low pressure. You can Therefore, the chance of the sputtered particles colliding with the gas in the processing space where the sputtered particles move can be reduced, and the sputtering efficiency is extremely high. Furthermore, since the reactive gas is supplied to the sputtered particles at a position separated from the recess where plasma is generated, reactive sputtering can be performed with high efficiency.

[0015]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram showing a magnetron sputtering apparatus according to an embodiment of the present invention. This magnetron sputtering apparatus includes a vacuum chamber 10 in which a film forming process is performed, an assembly 12 of a magnetron sputtering gun 30, and a sputtering gas supply source for supplying a sputtering gas (eg, argon gas) to the sputtering gun 30. 18 and a support 1 for supporting a semiconductor wafer W as an object to be processed
4 and a reaction gas supply means for supplying a reaction gas (for example, nitrogen gas) into the vacuum chamber 10.

The side wall of the vacuum chamber 10 has an exhaust port 10
a is formed, and a vacuum pump 11 is connected to the exhaust port 10a. Then, the inside of the chamber 10 is maintained at a desired degree of vacuum by exhausting the inside of the chamber 10 with the vacuum pump 11.

The support 14 is provided at the bottom of the vacuum chamber 10 and has a heating function. This support 1
An assembly 12 is arranged above the position 4. The sputtering gun 30 incorporated in the assembly 12 includes a target 31 having a recess 32, and the target 31 is sputtered by the plasma of the sputtering gas supplied from the gas supply source 18 described above. Thereby, the sputtered particles are ejected toward the wafer W. The detailed structure of the sputtering gun 30 will be described later.

A shutter 17 is provided between the assembly 12 and the wafer W on the support 14.
Pre-sputtering is performed with 7 closed, and the actual sputtering process is performed with shutter 17 open.

A reaction gas supply pipe 15 is connected to the side wall of the vacuum chamber 10 opposite to the exhaust port 10a, and the reaction gas supply source 16 described above is connected to the supply pipe 15. Then, a reaction gas such as nitrogen gas is supplied from the reaction gas supply source 16 through the reaction gas supply pipe 15 into the chamber 10.

The sputtering gun 30 constituting the assembly 12 is constructed, for example, as shown in FIG. That is, the sputtering gun 30 includes the target 31 and the anode 3.
4, target clamp assembly 35, target cooling block 36, insulating material 37, magnet 38, and yoke 39.

The target 31 is made of a film forming material such as aluminum, copper, titanium, titanium nitride or the like, and has a recess 32 which is open on the surface facing the wafer W. The recess 32 has an inverse taper shape whose diameter increases toward the opening end. A gas supply hole 40 is formed at the bottom of the recess 32, and the gas supply source 18 is provided.
From the above, a sputtering gas (plasma gas) such as argon gas is supplied to the recess 32 through the gas supply hole 40.

The magnet 38 is arranged above the target 31, that is, on the rear surface of the target 31, and a pole piece 41 made of a magnetic material is provided on the target 31 side of the magnet 38 so as to define a gas flow path. There is. The yoke 39 is provided so as to define the outside of the sputtering gun 30, and the yoke 39 forms a magnetic closed circuit between the target 31 and the magnet 38 and between the anode 34 and the magnet 38. As a result, target 31
Lines of magnetic force M are formed between the anode 34 and the magnet 38 provided on the opening side of the. That is, a magnetic field is formed in the recess 32.

The anode 34 is made of aluminum, for example, and has an opening equal to or larger than the opening of the target 31. It also serves as a shield ring that shields sputtered particles.

The target cooling block 36 includes the refrigerant passage 4
2 and has a substantially cylindrical shape, and the target 31 is fitted in the space inside thereof. Then, on the opening end side, the target clamp assembly 35 fixes the space between the target 31 and the target 31. The anode 34 is
Notch portion 43 provided on the yoke 39 and itself
Fixed by inserting a pin 44 into the target clamp assembly 35 and the target cooling block 36.
The pin 44 is inserted and fixed in the notch portion 43 provided in the. The target and the anode are electrically insulated by the insulating material 37.

Refrigerant passage 4 of target cooling block 36
Refrigerant is supplied to 2 through the refrigerant supply / drain pipes 42a and 42b, whereby the target 31 is cooled. In addition,
A cooling ring 46 is provided on the outer side of the yoke 39, and a coolant passage 47 in the cooling ring 46 has cooling water supply / discharge pipes 47 a, 4 a.
Refrigerant is supplied via 7b, whereby the yoke 39 is also cooled.

The target 31 is connected to a DC power supply 45, and from this power supply 45, for example, -300 to -800V.
Is applied. Further, the anode 34 is grounded. Therefore, between the anode 34 and the target 31,
That is, an electric field is formed in the concave portion 32, and a component orthogonal to the electric field in the magnetic field formed therein forms an orthogonal electromagnetic field.

In the magnetron sputtering apparatus having such a structure, first, the semiconductor wafer W as the object to be processed is placed on the support 14 and the inside of the vacuum chamber 10 is, for example, 10 ^-9 Torr by the vacuum pump 11. Evacuate the table. Then, the moving mechanism 20 performs the sputtering while the relative movement is caused between the sputtering gun 30 and the semiconductor wafer W as the object to be processed.

At the time of sputtering, a sputtering gas such as Ar gas, that is, a plasma generating gas is supplied from the gas supply source 18 to the concave portion 32 of the target 31 of the sputtering gun 30 through the gas introduction hole 40, and the pressure of 0.05 to 10 mTorr is supplied. Then, a voltage of −300 to −800 V is applied between the target 31 and the anode 34. As a result, plasma of the sputtering gas is generated in the recess 32.

The electrons 48 in the plasma region 33 undergo cyclone motion due to the orthogonal electromagnetic field formed by the magnetic field lines M and the electric field applied to the target, and the probability of collision with neutral argon particles is increased, and ionization is promoted. The ionized sputtering gas collides with the wall of the target 31 by the electric field. As a result, the sputtered particles S are ejected from the target 31. The sputtered particles S blown out are ejected from the opening of the target, but the target 31
The sputtered particles that hit the walls of the slag are deposited again on the target. However, the sputtered particles thus deposited are also sputtered again by argon ions and ejected downward from the opening of the target, and as a result, a highly directional flow of sputtered particles S is obtained.

In this case, the gas introduction hole 40 of the target 31 has a small diameter and the diameter increases toward the opening end of the recess 32, so that the introduction gas flows from the gas introduction base end toward the sputtering treatment space 60. A pressure gradient is formed and plasma is stably generated even when the processing space 60 has a low pressure. For example, in the plasma generation region 33, the pressure at which plasma can be stably generated, for example, 1 mTorr order,
In the processing space 60, the pressure that can reduce the chance of the sputtered particles colliding with the gas can be set to, for example, 0.1 mTorr order. Further, it is possible to generate plasma even when the pressure in the recess 32 is 0.1 mTorr order which is one order lower than the conventional pressure, for example, 0.2 mTorr. In this case, the pressure in the processing space 60 can be further reduced.

Thus, the sputtering processing space 60
It is possible to perform sputtering with sputtered particles having high directivity in a state where the pressure is low. Therefore, even when the sputtering process is performed on the wafer in which the contact holes are formed, the thin film can be formed with high efficiency with high step coverage and bottom coverage.

When reactive sputtering is performed, a reactive gas, for example, nitrogen gas, is introduced from the reactive gas supply source 16 into the processing space 60 of the vacuum chamber 10 through the reactive gas supply pipe 15. Since the sputtered particles S from the sputtering gun 30 pass through the processing space 60 toward the wafer W, the reactive gas is supplied toward the sputtered particles. The reactive gas supplied toward the sputtered particles reacts with the sputtered particles, whereby a reaction product is generated and the reaction product is deposited on the wafer W. For example, when the sputtered particles are titanium and the reaction gas is nitrogen gas, TiN is formed on the wafer W. In this case, the reactive gas is supplied to the region separated from the recess 32 where the plasma of the sputtering gas is formed, so that highly efficient reactive sputtering is achieved.

The directivity of the sputtered particles can be adjusted by changing the length of the anode 34 provided on the tip side of the target 31. That is, the anode 34 also functions as a shield ring. For example,
When it is desired to further increase the directivity of sputtered particles, the anode 34 is lengthened.

When such a sputtering process is repeated, the target 31 is gradually consumed due to the generation of sputtered particles, and the sputtered portion 49 becomes larger as shown by the broken line 49a. However, in this case, only the size of the recess 32 is changed, and the above-mentioned function is not deteriorated.

The target 31 is made to have a size slightly smaller than the size of the space so that it can be easily fitted into the space of the target cooling block 36. That is, there is a clearance between the outer peripheral surface of the target 31 and the inner peripheral surface of the cooling device so that the target 31 can be easily attached and detached and the thermal expansion of the target 31 allows the target 31 to adhere to the inner peripheral surface of the target cooling block 36. It is configured like. Therefore, when the consumed target is replaced, the target becomes cold and shrinks, so that there is a gap between the target 31 and the target cooling block 36, and it is extremely easy to remove the target 31 from the target cooling block 36. A new target can be attached. Then, when a voltage is applied to the target electrode, plasma is generated, and the heat generated at that time expands the target 31 and the target cooling block 36, and both are securely fixed. Therefore, the heat of the target 31 is transferred to the target cooling block 36, so that the target 31 does not need to have a cooling means.
Can be cooled. Therefore, the target 31 can have a simple structure in which only the gas supply hole 40 is provided. Further, the cooling water supply / drain pipe to the target cooling block 36 does not need to be attached / detached once fixed, and the cooling water supply / drain mechanism can be simplified.

Various shapes can be adopted as the shape of the concave portion 32 of the target 31. For example, the structure shown in FIGS. 3A and 3B can be adopted.
In (a), the tip of the recess 32 is cylindrical and the bottom is funnel-shaped, and the gas supply hole 40 is formed in the center of the bottom. In (b), the tip of the recess 32 is conical and the bottom is hemispherical, and the gas supply hole 40 is opened in the center of the bottom as in the example of (a). In (c),
The recess 32 has a conical shape (a pyramid may be used) in which the top is cut, and the gas supply hole 40 is also formed at the center of the bottom. Next, a case where an assembly having a plurality of sputtering guns is used will be described.

As the size of the object to be processed becomes larger than the 8-inch wafer, a plurality of sputtering guns are required to form a thin film on all areas of the object to be processed in a short time. The apparatus configuration in this case is shown in FIG. The apparatus of FIG. 4 is different from the apparatus of FIG. 1 in that an assembly 12a having a plurality of sputtering guns 30 is provided instead of the assembly 12, and a moving mechanism 20 for moving the support 14 is provided. However, the other points are substantially the same.

The moving mechanism 20 is provided below the support body 14 and is connected to the support body 14 by a drive shaft 14a. The moving mechanism 20 includes a first moving unit 21 that vertically moves (Z direction) and rotationally moves (θ direction) the support body 14,
In addition, a second moving unit 22 that horizontally moves is provided.

The first moving section 21 converts the rotation of the motor into a linear driving force by a ball screw mechanism or the like, moves the mounting table 14 connected to the driving shaft 14a up and down, and rotates the motor. It is possible to rotate the support 14.

The second moving unit 22 has X tables 23, X
A table rail 24, a Y table 25, a Y table rail 26, and a base 27 are provided. X table 23
Is movable on the rail 24 in the X direction together with the first drive unit 21. In addition, the Y table 25 has a base 27.
On the Y table rail 26 provided above, it is movable in the Y direction (direction orthogonal to the X direction) together with the first moving unit 21 and the X table 23.

As described above, the first moving unit 21,
Since the X table 23 and the Y table 25 can be independently moved, the mounting table 14 connected to the drive shaft 14a can be independently moved in the X, Y, Z, and θ directions.

Since the moving mechanism 20 is provided outside the vacuum chamber 10, it is possible to prevent heat and dust generated from the driving mechanism from adversely affecting the vacuum state in the vacuum chamber 10.

The bottom of the support 14 and the vacuum chamber 10
A bellows 28 is provided between the bottom and the bottom. The bellows 28 expands and contracts when the support 14 moves in the Z direction, and deforms in a direction inclined with respect to the vertical axis when the support 14 moves in the X and Y directions. Therefore, even if the support 14 is moved by the moving mechanism 50 along the X, Y, and Z directions, the vacuum state in the vacuum chamber can be maintained.

The assembly 12a is composed of, for example, seven sputtering guns 30, and their targets are arranged as shown in FIG. In FIG. 5, seven targets 31 are arranged at the center A of the sputter gun assembly 12a and at each vertex of a regular hexagon having the center A as the center of gravity. According to this arrangement, it is possible to arrange the sputtering guns 30 in the closest arrangement. Therefore, the sputtering gun assembly 1 using the sputtering gun 30 having a certain size is used.
2a can be minimized, which is advantageous in terms of space efficiency. However, the arrangement of the sputtering guns 30 is not limited to this arrangement, and can be appropriately determined according to various conditions such as the size of the wafer W and the size of the openings of the sputtering gun 30. In this way multiple sputtering guns 3
When the assembly 12a having 0 is provided, the moving mechanism 20
The reason why is required is explained below.

Target 31 of sputtering gun 30
Since the concave portion 32 is formed in the
The sputtered particles S are emitted with high directivity. Therefore, a large number of sputtered particles S flying substantially vertically are provided for film formation in the holes existing at the positions facing the range of the diameter of the target 31. However, if the wafer W is fixed, the sputtered particles toward the wafer position facing the intermediate position between the two adjacent targets 31 are reduced. Also, the vertical component of sputtered particles is reduced. That is, when the wafer W is fixed, the amount of sputtered particles deposited on the surface of the wafer W and the incident angle vary. Therefore, in order to avoid such an inconvenience, the moving mechanism 20 causes relative movement between the sputtering gun 30 and the wafer W. An example of such relative movement will be described with reference to FIGS.

As an example, the wafer W is raster-scanned in the X and Y directions which are parallel to the main surface of the wafer W shown in FIG. The raster scan in this case is, for example, as shown in FIG. 5, within the range of 1/2 of the distance L1 between the center positions A and B of two adjacent targets 31 and the distance L2 between C and C ' Raster scan along. As a result, a sufficient amount of sputtered particles can be uniformly deposited on the wafer W under almost the same conditions.

Next, the case where the wafer W is moved in the Z direction in FIG. 6 will be described. In this case, when the sputter gun assembly 12 is brought closer to the wafer W, the angle of view of the target 18 with respect to the contact hole is increased, and more sputter particles are deposited on the shoulder portion of the contact hole. On the contrary, when the sputter gun assembly 12 is moved away, the angle of view is reduced and more sputter particles are deposited in the contact hole. Therefore, Z
By moving the wafer W in the direction, the shape of the film can be controlled.

The range of movement in the Z direction in this case is
For example, it is 100 mm to 250 mm, and within this range, movement in the Z direction is possible without changing the volume of the vacuum chamber 10.

It should be noted that the movements in the X, Y and Z directions can be independently made as described above, and only one of them may be moved or a combination of these movement directions may be used as required. By combining these, it becomes possible to form a more uniform film.

In addition to such movements in the X, Y and Z directions, the wafer W may be rotationally moved about the center of rotation. By this rotational movement, it becomes possible to improve the uniformity of film formation on the circumference connecting the centers of the targets 18. The rotational movement of the wafer W is X,
It may be performed in combination with any one or more of the movements in the Y and Z axis directions, or only the rotational movement may be performed independently.

Further, eccentric rotation movement about the eccentric axis offset from the center of the wafer W may be performed.
When the wafer W is rotationally moved around the rotation axis as described above, in order to improve the uniformity of the film formation in the radial direction, the distances from the centers of the peripheral targets are different. Need to be. In this case, it is difficult to make the arrangement of the targets 31 in the sputter gun assembly a close-packed structure, and the device structure must be complicated. However, if the eccentric rotation movement is performed in this manner, the uniformity of the film formation in the radial direction as well as in the circumferential direction can be achieved without complicating the apparatus structure while keeping the arrangement of the targets 31 in the close-packed structure shown in FIG. It becomes possible to improve. Also in this case, the rotational movement of the wafer W may be performed in combination with any one or more movements in the X-, Y-, and Z-axis directions, or only the rotational movement may be performed independently.

Further, the position of the central axis of the assembly 12a and the position of the central axis of the wafer W may be shifted so that both of them are rotated. By causing such a rotational movement, it becomes possible to improve the uniformity of film formation on a wide two-dimensional plane. When performing the rotational movement as described above, a magnetic seal, an O-ring, or other airtight seal that allows rotation can be used as the airtight seal.

The relative movement between the sputtering gun and the wafer W is not limited to the above-mentioned mode, but X, Y,
Various combinations of Z direction, circular movement, eccentric movement, and rotation movement can be performed. Further, such relative movement may be performed intermittently using a step motor,
It may be a continuous movement.

Next, a modification of the sputtering gun will be described. The sputtering gun used in the present invention is not limited to the structure shown in FIG.
A structure as shown in can be adopted.

FIG. 7 shows a case where a plurality of magnets are used without using a yoke, and FIG. 8 shows a case where an electromagnet is used as a magnetic field forming means. 7 and 8, those substantially the same as those in FIG. 2 are designated by the same reference numerals and the description thereof will be omitted.

In the sputtering gun of FIG. 7, a columnar magnet 61 is arranged above the target 31, that is, on the back side, and an annular magnet 62 is arranged on the tip side of the target 31. To the target 31 side of the magnet 61, a pole piece 63 made of a magnetic material is connected so as to define a gas flow path. The tip portion 63a of the pole piece 63 is formed with a screw and is fixed to the body of the pole piece with a screw so that only the tip portion 63a can be replaced. Magnet 61
Lines of magnetic force are formed on the magnet 62 from the pole piece 63 through the pole piece 63, and as a result, similar to the sputtering gun of FIG.
A magnetic field is formed in the recess 32. The target cooling block 36 is provided with a spiral refrigerant passage 68 a, and the refrigerant is supplied through the refrigerant supply / drain pipe 68. Further, around the pole piece 63, a cooling ring 6 for the pole piece is provided.
6, a cooling medium passage 67a is formed in the cooling ring 66, and the cooling medium is supplied through the cooling medium supply / drain pipe 67. Further, an anode cooling ring 69 is provided around the anode 34, and the refrigerant passage 6 is provided therein.
9a is formed. The outer circumference of this sputtering gun is surrounded by a stainless steel member 71, and the stainless steel member 71 and the target cooling block 36
An insulating member 72 insulates between and. Reference numeral 65 is a spacer interposed between the target 31 and the cooling block 36, 64 is an insulating member, and 70 is a clamp member.

The sputtering gun of FIG. 8 has basically the same structure as that of FIG. 3 except that the permanent magnet 38 in FIG. 2 is replaced with an electromagnet 80. By using the electromagnet 80 in this manner, it is possible to change the current and the magnitude of the magnetic field according to the consumption of the target.

Next, another aspect of the present invention will be described. In the above embodiment, the reaction gas such as nitrogen is introduced from the chamber 10 into the processing space 60. Here, an example in which the reaction gas supply means is provided in the sputtering gun itself will be described.

FIG. 9 is a sectional view showing a sputtering gun equipped with a reaction gas supply means. The basic structure of the sputtering gun of FIG. 9 is the same as that of FIG. 7, and the same parts as those of FIG. 7 are designated by the same reference numerals. In FIG. 9, reference numeral 93
Is a reaction gas supply source for supplying a reaction gas such as nitrogen gas. The reaction gas from this reaction gas supply source 93 is
It is introduced into the hollow portion of the anode 34 through the reaction gas supply hole 94 formed in the sputter gun.

On the other hand, the argon gas as the sputtering gas is supplied to the recess 32 through the gas supply introduction hole 40. In this case, since the argon gas passes through the plasma region, the ionization efficiency is high and the sputtering efficiency is high. The sputtered particles blown out by the plasma generated in the recess 32 fly into the processing space 60 from the recess 32 through the hollow portion of the anode 34. Then, the reactive gas is supplied to the sputtered particles in the hollow portion of the anode 34, and these are supplied from the recess 32 to the anode 34.
The reaction product particles are formed by reaction due to the action of the electrons directed toward, and the reaction product particles are deposited on the wafer to realize the reactive sputtering. For example, TiN can be deposited when the sputtered particles are Ti and the reaction gas is N ₂ . Also in this mode, the reaction gas is the recess 32 where plasma of the sputtering gas is formed.
Since it is supplied to a region spaced apart from the above, highly efficient reactive sputtering is achieved.

Another advantage of this example is that since the reaction gas is introduced through the gap between the target and the anode, it is possible to prevent the sputtered particles from flowing around between the electrodes. Further, since the pressure in the processing space 60 is low, the scattering of sputtered particles by the introduced gas is eliminated and the wraparound is reduced, so that the shield plate around the processing space can be made smaller.

Furthermore, the conductance of the sputtering gas can be made large, and the exhaust capacity can be increased by one digit without increasing the size of the exhaust device.
The background pressure is improved by two orders of magnitude due to the synergistic effect with the decrease of the discharge pressure, which greatly contributes to the improvement of the film quality.

Although an example in which the reactive gas supply means is basically provided in the sputtering gun of FIG. 7 is shown here, the similar reactive gas supply means can also be provided in the sputtering guns of FIGS. 2 and 8. Needless to say.

The film forming rate in the case of performing the sputtering with only the nitrogen gas is about 1/5 of that in the case of performing the sputtering with only the argon gas, but as described above, the nitrogen gas is applied to the region where the sputtered particles fly. When supplied, the film formation rate is three times or more as high as the sputtering rate using only nitrogen gas.

From the viewpoint of film quality, it is preferable to apply a negative DC bias or a negative AC bias, or both of them, to the object to be processed, as is done in normal sputtering. As a result, the formed film becomes dense and the film quality is further improved. The film to be formed is TiN
In this case, this can reduce the resistance of the film.

The present invention is not limited to the above embodiment, but can be variously modified. For example, although the above-mentioned embodiment shows an example in which a semiconductor wafer is used as the processing target,
The present invention is not limited to this, and is applicable to, for example, LCD substrates, magnetic disks, magnetic tapes, and the like. Also,
Although the support is moved by the moving mechanism, the sputtering gun may be moved as long as the relative movement between the object to be processed and the sputtering gun occurs.

[0068]

According to the present invention, a sufficient amount of sputtered particles can be deposited even in the holes of a highly integrated wafer, and sputtering is performed with the sputtering gas pressure in the entire sputtering processing space kept low. It is possible to provide a magnetron sputtering apparatus and a sputtering gun capable of performing reactive sputtering with high efficiency.

[Brief description of drawings]

FIG. 1 is a sectional view showing a magnetron sputtering apparatus according to an embodiment of the present invention.

2 is a cross-sectional view showing one embodiment of a sputtering gun used in the apparatus of FIG.

FIG. 3 is a cross-sectional view showing an example of the shape of a target.

FIG. 4 is a sectional view showing a magnetron sputtering apparatus according to another embodiment of the present invention.

5 is a diagram schematically showing the arrangement of targets in the assembly of the apparatus shown in FIG.

6 is a schematic diagram for explaining relative movement between a wafer and a sputtering gun in the apparatus of FIG.

FIG. 7 is a diagram showing another example of a sputtering gun used in the magnetron sputtering apparatus of the present invention.

FIG. 8 is a view showing still another example of the sputtering gun used in the magnetron sputtering apparatus of the present invention.

FIG. 9 is a sectional view showing a sputtering gun according to an embodiment of the present invention.

FIG. 10 is a view showing a state in which a thin film is formed in a contact hole using a conventional flat plate-shaped sputtering gun.

[Explanation of symbols]

10 ... Vacuum chamber, 12, 12a ... Assembly, 1
4 ... Support, 15 ... Reactive gas supply pipe, 16, 93
... Reaction gas supply source, 18 ... Sputtering gas supply source, 30 ... Sputtering gun, 31 ... Target, 32 ... Recessed portion, 34 ... Anode, 38 ...
Magnet, 39 ... Yoke, 40 ... Sputtering gas supply hole, 45 ... Power supply, 94 ... Reaction gas supply hole,
S ... Sputtered particles W ... Wafer

Claims (5)

[Claims] 1. A vacuum container, a sputtering gun which is disposed therein for ejecting sputtered particles, a support for supporting an object to be formed a thin film in the vacuum container, and the inside of the vacuum container And a reactive gas supply means for supplying a reactive gas to the sputtering gun, wherein the sputtering gun includes a target having a recess, a sputtering gas supply means for supplying a sputtering gas to the recess, and an electric field formed in the recess to form the sputtering gas. Sputtered particles from the target by electric field forming means for generating plasma of gas and magnetic field forming means for forming a magnetic field containing a component orthogonal to the electric field in the concave portion by the plasma formed in the concave portion. Is sputtered out, and the reaction gas supply means supplies the reaction gas to the sputtered particles in a region separated from the recess. A magnetron sputtering apparatus, characterized in that a reaction product, which is supplied and formed by the reaction between the sputtered particles and the reaction gas, is deposited on the object to be processed. 2. A target having a recess, a sputtering gas supply means for supplying a sputtering gas to the recess, an electric field forming means for forming an electric field in the recess to generate plasma of the sputtering gas, and the recess in the recess. A magnetic field forming means for forming a magnetic field including a component orthogonal to the electric field, and a reactive gas supply means for supplying a reactive gas to the sputtered particles knocked out of the target by the plasma at a position separated from the plasma are provided. A sputtering gun, which ejects reaction product particles formed by a reaction between the sputtered particles and the reaction gas. 3. The magnetron sputtering apparatus according to claim 1, further comprising means for introducing a negative DC bias to the object to be processed. 4. The magnetron sputtering apparatus according to claim 1, further comprising means for introducing a negative AC bias to the object to be processed. 5. The magnetron sputtering apparatus according to claim 1, further comprising means for introducing a negative DC and AC bias to the object to be processed.