JP2001107233A - Magnetron sputtering apparatus and sputtering method - Google Patents

Abstract

(57) [Summary] (Corrected) [Solving Means] A target 13 and a substrate 14 are disposed in a vacuum chamber so as to face each other, and a ring-shaped magnet 15a and a magnet disposed in a hollow portion thereof under the target. A magnetron magnet pair 15 composed of a magnetron 15b and magnetron sputtering for forming a sputtered film by depositing, on the substrate, target atoms struck out of the target by the plasma 16 applied to the magnetic field of the magnet pair. In the apparatus, the substrate 14 is rotatably disposed, and at least three magnetron magnet pairs are disposed under the target so as to be vertically and / or horizontally movable, so that the sputtering intensity can be reduced over the entire surface of the substrate. A magnetron sputtering apparatus characterized in that it can be made uniform. According to the present invention, it is possible to obtain a sputtered film having a high film forming rate, good film quality uniformity, and a uniform thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LSI,
The present invention relates to a magnetron sputtering apparatus and a sputtering method suitably used for forming a sputtered thin film in the production of semiconductor integrated circuits and the like.

[0002]

2. Description of the Related Art In manufacturing a metal thin film or a dielectric thin film of a semiconductor device or the like,
Sputtering is an effective method. Many sputtering apparatuses for mass production employ a magnetron method in which a magnet is incorporated under a target in order to increase a film forming rate. This method is generally used in mass production equipment, and is described in detail in, for example, “Sputtered Thin Film Basic and Applied by Haruhiro Kobayashi Nikkan Kogyo Shimbun”. It is intended to increase the efficiency of confinement and sputtering. Usually, the plasma is confined in a donut shape by a magnet. Sputtering is promoted only in a specific location of the donut shape, and therefore, the in-plane variation of the film to be formed is also strongly affected.

FIG. 1 shows an example of a conventional magnetron sputtering apparatus. In the figure, reference numeral 10 denotes a vacuum chamber provided with a gas introduction pipe 11 and a gas exhaust pipe 12, and the inside thereof is maintained at a required degree of vacuum. A target 13 and a substrate 14 are disposed in the chamber 10 so as to face each other, and a magnet pair 15 for magnetron is disposed below the target 13. The magnet pair 15 is one pair,
As shown in FIG. 2, this consists of a ring-shaped magnet 15a and a magnet 15b arranged at the center of the hollow portion. The ring-shaped magnet 15a has an S-pole on the target side and an N-pole on the opposite side. The magnet 15b has an N pole on the target side,
The opposite side is an S pole.

[0004] Here, a negative potential is applied to the target 13 so that positive ions (usually argon ions) in the introduced plasma gas collide with the target, and the repelled target atoms are deposited on the opposing substrate 14. . In the magnetron method, a magnet pair 15 is arranged under the target 13, and a high-concentration plasma 16 is confined on the target 13 by its magnetic field, thereby increasing the number of positive ions colliding with the target 13.

[0005] However, in this method, the film quality on the substrate is non-uniform between a portion having a high plasma concentration and a portion having a low plasma concentration. In this case, by rotating the substrate, the non-uniformity in the circumferential direction is improved, but the non-uniformity still remains in the radial direction from the rotation center of the substrate.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is possible to improve the in-plane film quality distribution while maintaining the high film forming rate, which is an advantage of the magnetron sputtering apparatus. It is an object of the present invention to provide a magnetron sputtering apparatus capable of forming a sputtered film with little in-plane variation, and a sputtering method using the apparatus.

[0007]

According to the present invention, as a first invention, a target and a substrate are arranged in a vacuum chamber so as to face each other, and a ring-shaped magnet is provided below the target. A magnet pair for a magnetron comprising a magnet disposed in the hollow portion is disposed, and target atoms that are knocked out of the target by the plasma applied to the magnetic field of the magnet pair are deposited on the substrate to form a sputtered film. In the magnetron sputtering apparatus for forming, while the substrate is rotatably disposed, at least three magnetron magnet pairs are disposed under the target so as to be vertically and / or horizontally movable,
Provided is a magnetron sputtering apparatus characterized in that sputtering strength can be made uniform over the entire surface of a substrate.

According to a second aspect of the present invention, a target and a substrate are disposed in a vacuum chamber so as to face each other, and a magnet pair for a magnetron comprising a ring-shaped magnet below the target and a magnet disposed in a hollow portion thereof. And a magnetron sputtering apparatus for depositing target atoms struck from the target by the plasma applied to the magnetic field of the magnet pair on the substrate to form a sputtered film, wherein the substrate is rotatably disposed. And at least three pairs of magnetron magnets are arranged below the target, and a shutter can be moved and / or rotated between the target and the substrate in the horizontal direction corresponding to the pair of magnets. Characterized in that the sputtering strength can be made uniform over the entire surface of the substrate by disposing the magnetron. To provide a Ttaringu apparatus. In this case, it is preferable to dispose the magnet pair so as to be movable in the vertical direction and / or the horizontal direction.

Further, according to a third aspect of the present invention, there is provided the first or second aspect.
Provided is a sputtering method characterized by forming a sputtered film having a uniform thickness on a substrate by using the magnetron sputtering apparatus of the present invention.

In the present invention, the above-mentioned vertical direction means a direction approaching / separating from the target, and the left-right direction means a vertical / horizontal direction substantially horizontal to the surface of the target.

According to the present invention, 1) the magnetron sputtering apparatus has a mechanism for rotating the substrate, so that variations in the film thickness in the circumferential direction of the substrate can be reduced. The variation in the radial direction of rotation can be controlled by providing a mechanism that allows the sputter rate to be adjusted at individual positions (that is, a mechanism that moves the magnet pair up and down or left and right or a mechanism that moves or rotates the shutter left and right). Can be improved. 2) The number of magnet pairs provided under the target is usually one, but the present invention includes three or more magnet pairs. Its shape is not defined as a donut shape. The size and strength of each magnet need not necessarily be the same. 3) A plasma corresponding to each individual magnet pair is generated on the target. By providing the above mechanism that can individually adjust the sputter rate from the plasma, it is possible to improve or adjust the variation in the radial direction of rotation. 4) The sputter rate is adjusted by having a mechanism for adjusting the position of each magnet as the sputter rate adjusting mechanism. By adjusting the position of the magnet, the strength of the magnetic field on the target can be changed. By changing the strength of the magnetic field, the concentration of plasma on the target can be changed, and thus the sputter rate can be adjusted. 5) Alternatively, similar effects can be obtained by separately providing shutters whose opening can be adjusted between the target and the substrate. 6) As the sputtering proceeds, the sputter rate fluctuates depending on how much the target is reduced. Even then, by adjusting the sputter rate for each magnet pair,
The optimum condition can always be maintained. 7) In the case of reactive sputtering in which a reactive gas is introduced during sputtering to produce a reacted film (for example, an oxide film),
It becomes difficult to send gas to the center of the plasma,
It is difficult to make the reaction rate (eg, oxidation rate) uniform. This becomes more pronounced as the substrate becomes larger and the target becomes larger. On the other hand, according to the present invention, since the plasma is divided into three or more small plasmas, the gas easily enters the inside and a uniform film can be formed.

[0012]

FIG. 3 shows a first embodiment of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view for explaining an embodiment of the present invention, showing an arrangement of a target and a magnet pair under the target. The other configuration is the same as that of the apparatus shown in FIG.

Here, in this example, the target 1
3 below, three magnet pairs 15 (15X, 15Y, 15Z) each including a ring-shaped magnet 15a and a center magnet 15b.
These magnet pairs 15X, 15
Y and 15Z are provided so as to be movable in the vertical direction (the direction of arrow A in the figure).

In this case, the sputtering rate of the plasma involving the center magnet pair 15Y is, for example, as shown in FIG. Further, the relationship between the sputtering rates of the plasmas involving the left magnet pair 15X in FIG.
FIG. 4C shows the relationship between the sputtering rates of the plasmas involving the right magnet pair 15Z, for example, as shown in FIG. Then, when these sputter rates are superimposed, the result is as shown in FIG. As can be seen from FIG. 4D, the sputter rate near the center of the substrate is slightly higher in this state, so that the central magnet pair 15Y is moved downward (moved in a direction to separate it from the target), and as shown in FIG. As shown, the sputter rate can be made substantially the same level over the entire surface of the substrate, thereby making it possible to form a sputtered film with a uniform thickness.

As described above, by moving the magnet pair away from the target, the magnetic field on the target is weakened, the density of the confined plasma is reduced, and the sputtering rate is also reduced. Then, a uniform sputtering rate is obtained over the entire surface. That is, by making each magnet movable, it is possible to control the sputtering rate of each plasma, and it is possible to form a uniform film.

If necessary, the magnet pair can be further arranged so as to be movable in the left-right direction. In some cases, the magnet pair is arranged so as to be movable only in the left-right direction instead of the up-down direction. In short, as shown in FIG. 5, it is only necessary that each magnet pair can be moved so that the sputtering rate can be controlled to be the same level over the entire surface of the substrate.

FIG. 6 explains an example of the second invention and shows an arrangement of a shutter (mask). Other configurations are the same as those in FIG.

In this example, 3
A pair of magnet pairs (15X, 15Y, 15Z) are provided, and a shutter 17X is provided between the target 13 and the substrate 14 (not shown in FIG. 6) corresponding to the magnet pairs 15X, 15Y, 15Z, respectively. , 17Y, and 17Z. In this case, the shutter 17X corresponding to the magnet pair 15X and the shutter 1 corresponding to the magnet pair 15Z
7Z is rotatable in the directions indicated by arrows in the figure,
A shutter 17Y corresponding to the center magnet pair 15Y
Are arranged so as to be reciprocable (movable in the left-right direction) in the direction of the arrow in the figure, and by controlling the operation of the shutters 17X, 17Y, 17Z, plasma generated by the individual magnet pairs 15X, 15Y, 15Z is reduced. The mask is used to adjust the sputter rate to make the sputter rate distribution uniform as shown in FIG.

The movement of the shutters is not limited to the above-described embodiment. Each shutter can be rotated and moved in the left and right directions, that is, each shutter can be controlled so that the sputtering rate is the same over the entire surface of the substrate. Just move it.

Further, as shown in FIG.
It is also preferable to dispose the X, 15Y, and 15Z movably in the vertical and horizontal directions.

The sputtering method of the present invention uses the above-described apparatus, controls the movement of the magnet pair and the shutter, and uniformly adjusts the sputtering rate as shown in FIG. The film thickness is made uniform, and other than that, a known magnetron sputtering method can be adopted, and a reactive sputtering method can also be adopted.

[0022]

According to the present invention, a sputtered film having a high film forming rate, good film quality uniformity, and a uniform thickness can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view of a conventional magnetron sputtering apparatus.

FIG. 2 is a perspective view of a magnetron magnet pair.

3A and 3B show an example of an arrangement of magnet pairs according to the first invention, wherein FIG. 3A is a plan view and FIG. 3B is a cross-sectional view.

4A is a magnet pair 15Y, and FIG. 4B is a magnet pair 15;
X and (C) are graphs showing the relationship between the sputtering rate of plasma involving the magnet pair 15Z and the lateral distance of the substrate;
(D) is a graph of a distribution in which these sputter rates are superimposed.

FIG. 5 is a graph showing a state in which the magnet pair 15Y is moved downward to make the sputter rate the same level in relation to the substrate lateral distance.

FIG. 6 is a plan view showing an example of an arrangement mode of a magnet pair and a shutter according to the second invention.

[Explanation of symbols]

 Reference Signs List 10 vacuum chamber 13 target 14 substrate 15 magnet pair 15a ring-shaped magnet 15b center magnet 17 shutter

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Judge Inazuki 28-1 Nishifukushima, Oku-ku, Nakakushiro-gun, Niigata Prefecture Shin-Etsu Chemical Co., Ltd.Precision Functional Materials Research Laboratories 28-1 Nishifukushima, Kushiro-mura, Kushiro-gun Shin-Etsu Chemical Co., Ltd. Precision Functional Materials Laboratory F-term (reference) 4K029 DA12 DC43 DC46 4M104 DD39 HH20 5F045 AA19 BB02 DP28 EH16 EH19 5F103 AA08 BB14 BB16 BB38 RR10

Claims (4)

[Claims] 1. A target and a substrate are disposed in a vacuum chamber so as to face each other, and a magnetron magnet pair including a ring-shaped magnet and a magnet disposed in a hollow portion thereof is disposed below the target. In a magnetron sputtering apparatus for forming a sputtered film by depositing target atoms knocked out of a target by a plasma applied to a magnetic field of the magnet pair on the substrate, the substrate is rotatably disposed, and A magnetron sputtering apparatus characterized in that at least three pairs of magnetron magnets are disposed under a target so as to be movable vertically and / or horizontally, so that the sputtering intensity can be made uniform over the entire surface of the substrate. 2. A method according to claim 1, further comprising: disposing a target and a substrate in the vacuum chamber so as to face each other, and disposing a magnetron magnet pair including a ring-shaped magnet and a magnet disposed in a hollow portion thereof under the target. In a magnetron sputtering apparatus for forming a sputtered film by depositing target atoms knocked out of a target by a plasma applied to a magnetic field of the magnet pair on the substrate, the substrate is rotatably disposed, and At least three magnetron magnet pairs are provided below the target, and a shutter is provided between the target and the substrate so as to be movable in the left and right direction and / or rotatable in correspondence with the magnet pair. A magnetron sputtering apparatus characterized in that the sputtering strength can be made uniform over the entire surface of the substrate. 3. The magnetron sputtering apparatus according to claim 2, wherein said pair of magnets are arranged so as to be movable in a vertical direction and / or a horizontal direction. 4. A sputtering method comprising forming a sputtered film having a uniform thickness on a substrate by using the magnetron sputtering apparatus according to claim 1, 2 or 3.