JP3994513B2 - Sputtering equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sputtering apparatus, and more particularly to a shutter structure.
[0002]
[Prior art]
Conventionally, sputtering apparatuses have been widely used as thin film forming apparatuses. In this sputtering apparatus, a target and a sample (substrate) are disposed facing each other in a sputtering chamber, and a high voltage is applied between them to knock out particles from the target and form a thin film on the surface of the sample.
[0003]
By the way, a contamination layer such as an oxide layer may be formed on the surface of the target after initial replacement of the target or after storage with the target attached to the sputtering apparatus. When the main sputtering is started in this state, the contamination layer is sputtered together with the target material, and the film formed on the sample contains impurities.
[0004]
Therefore, pre-sputtering is performed to remove the contamination layer on the target surface. In order to prevent the particles during the pre-sputtering from adhering to the sample, as shown in FIG. 1, a shutter 3 that shields between the target 1 and the sample 2 is provided so as to be openable and closable, and the shutter 3 is closed. There is known a sputtering apparatus that performs pre-sputtering and opens the shutter 3 after pre-sputtering to perform main sputtering. The shutter 3 is attached to a rotating shaft 4 parallel to the facing direction of the target 1 and the sample 2, and the shutter 3 is moved between the target 1 and the sample 2 by rotating the rotating shaft 4. It has become.
[0005]
[Problems to be solved by the invention]
However, when the rotating shaft 4 is disposed in parallel with the facing direction of the target 1 and the sample 2 as described above, a space 6 for retracting the shutter 3 when the shutter 3 is opened needs to be provided in the side portion of the sputtering chamber 5. As a result, the volume of the sputtering chamber 5 becomes large. The sputter chamber 5 is depressurized to a predetermined degree of vacuum for the sputter process. However, as the sputter chamber 5 becomes large as described above, there is a disadvantage that the depressurization process requires much time. Further, since the sputter chamber 5 has a complicated shape due to the retreat space 6, there is also a drawback that the manufacturing cost is increased.
[0006]
Accordingly, an object of the present invention is to provide a sputtering apparatus capable of making the sputtering chamber small and simple while preventing interference between the shutter and the sputtering chamber.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a first aspect of the present invention is a sputtering apparatus in which a target and a sample are arranged opposite to each other in a sputtering chamber and a shutter that shields between the target and the sample can be opened and closed. The shutter is arranged so as to be rotatable about a rotation axis extending in a direction orthogonal to the opposite direction to the direction opposite to the sample. Provided is a sputtering apparatus characterized by being positioned .
[0008]
In the sputtering apparatus of the present invention, the shutter rotates about a rotation axis extending in a direction orthogonal to the facing direction of the target and the sample. Therefore, when the shutter is opened, the shutter rotates to the side of the sample or the target. become. Therefore, it is not necessary to provide a retracting space for the shutter in the side portion of the sputtering chamber, the volume of the sputtering chamber can be reduced as compared with the conventional case, and the shape of the sputtering chamber can be simplified. In addition, the space behind the sample can be used effectively by placing the shutter rotation shaft on the side opposite to the sample so that it retracts to the side of the sample when the shutter is open. it can.
[0009]
When the shutter is constituted by a plurality of shutter members each supported by a separate rotating shaft, the shielding area when the shutter is closed is larger than when the shutter is constituted by a single shutter. On the contrary, since the retreat space when opened is small, there is an advantage that the space efficiency is improved.
[0011]
Further, when the shutter is formed in a hemispherical shell shape surrounding the sample as in claim 3 , the shutter has a high shielding effect, and not only the particles during pre-sputtering are difficult to adhere to the sample, but also the shutter has a sputtering chamber. It is hard to interfere with the inner wall of the instrument and the sample holder.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
2 to 5 show an example of a sputtering apparatus according to the present invention.
Reference numeral 10 denotes a box-shaped chamber in which a sputtering chamber 11 is formed. The chamber 10 may have any shape such as a rectangular parallelepiped, a cube, or a cylinder. Further, the sputtering chamber 11 of this embodiment is cylindrical, but may be rectangular. The lower surface side of the chamber 10 is open, and the opening 10 a is closed by a plate-like target 13 via a ring-shaped insulating material 12. A backing plate 14 is disposed on the back surface of the target 13, and the backing plate 14 and the target 13 are fastened to the chamber 10 by screws 15. As the material of the insulating material 12, ceramic or resin having excellent heat resistance is used. The insulating material 12 and the chamber 10 and the target 13 are sealed with a sealing material (not shown) such as an O-ring.
[0013]
A sample holder 16 is provided on the ceiling of the sputtering chamber 11 facing the target 13, and a sample 17 such as a substrate is detachably held on the lower surface of the sample holder 16. The sample holder 16 has a shaft portion 16a that hangs downward from the ceiling portion of the sputtering chamber 11, and a holding portion 16b that holds the sample 17 fixed to the lower end of the shaft portion 16a.
[0014]
The inside of the sputtering chamber 11 is evacuated by a decompression pump (not shown), and is maintained at a degree of vacuum of about 10 −4 to 10 −3 Pa, for example. Then, an inert gas such as argon gas is introduced into the sputtering chamber 11 and is set to a pressure of about 0.5 to 2 Pa, for example. A high voltage power source 18 is connected between the sample holder 16 and the backing plate 14 with the cathode side facing the backing plate 14 side. The chamber 10 itself is connected to ground. When the power source 18 is turned on, as is well known, ions in the plasma collide with the target 13 which is a cathode, the atoms of the target 13 are knocked out, and the sputtered atoms adhere to the sample 17 to form a film.
[0015]
In the sputtering chamber 11, a shutter 20 that shields between the target 13 and the sample 17 is provided to be openable and closable. The shutter 20 includes a pair of left and right shutter members 21 and 22. Each of the shutter members 21 and 22 includes rotary shafts 21a and 22a that are rotatably attached to the side wall 1b of the chamber 1, and arm portions 21b and 22b that extend in the radial direction at the inner ends of the rotary shafts 21a and 22a. The shielding portions 21c and 22c are fixed by screws 23 or the like (see FIG. 4). An O-ring 24 is attached to the outer periphery of the rotary shafts 21a and 22a, and seals between the chamber 1 and the side wall 1b. The shielding portions 21c and 22c of this embodiment are formed in a semi-cylindrical shape, and rotating shafts 21a and 22a are arranged at the centers of curvature.
[0016]
The rotating shafts 21a and 22a extend in a direction orthogonal to the opposing axial direction connecting the center portions of the target 13 and the sample 17, that is, in the horizontal direction in the example of FIG. In this embodiment, the rotating shafts 21a and 22a are located above the sample 17 (on the opposite target side). Therefore, when the shutter 20 is opened as shown in FIG. 5, the shielding portions 21 c and 22 c wrap around the sample holder 16, and the dead space behind the sample holder 16 can be effectively used as a retracting space for the shutter 20.
[0017]
In the above embodiment, when the shutter is closed (see FIG. 2), the end surfaces of the shielding portions 21c and 22c are made to contact each other. However, if the shielding portions 21c and 22c are distorted or inclined, the end surfaces are not accurately adhered. , Gaps may occur. If there is a gap, particles during pre-sputtering may adhere to the sample 17. Therefore, as shown in FIG. 6, if one shield 22c is configured to overlap the other shield 21c, a gap is not generated when the shutter is closed, and a good shielding effect can be exhibited.
[0018]
In the above embodiment, the shutter members 21 and 22 are provided with the semi-cylindrical shielding portions 21c and 22c, but in this case, both ends in the axial direction of the shielding portions 21c and 22c approach the inner wall of the sputter chamber 11, which is the worst. In some cases, interference may occur (see FIG. 3). In that case, both ends in the axial direction of the shielding portions 21c and 22c may be cut off, but the shielding effect may be reduced.
[0019]
Therefore, the shielding portions 21c and 22c may be hemispherical as shown in FIG. In this case, the shielding portions 21c and 22c are less likely to interfere with the inner wall of the sputtering chamber 11 and the sample holder 16, and the shielding portions 21c and 22c can uniformly surround the entire circumference of the sample 17 when the shutter is closed. The shielding effect is high, and there is an effect that particles at the time of pre-sputtering hardly adhere to the sample 17. In particular, the hemispherical shielding portions 21c and 22c are effective when the sputtering chamber 11 is cylindrical and the sample holder 16 is circular.
[0020]
The present invention is not limited to the above embodiments.
In the embodiment shown in FIG. 2, the target 13 itself closes the opening 10a of the chamber 10, but it goes without saying that a target smaller than the opening 10a may be used as shown in FIG. Therefore, the method for attaching the target 13 and the chamber 10 is not limited to the method in which the target 13 and the backing plate 14 are overlapped and fastened to the chamber 10.
In the above embodiment, two shutters are configured as one set, but it is needless to say that the shutters may be configured with only one shutter. Moreover, the shielding part of the shutter is not limited to a cylindrical shape or a spherical shell shape, and may be a flat plate shape. The shape of the shielding part can be arbitrarily selected according to the shape of the sample holder or the sputtering chamber.
In the above embodiment, the rotation shaft is disposed on the side opposite to the target so that the shutter is retracted to the side of the sample in the open position, but the rotation shaft is disposed so that the shutter is retracted to the side of the target in the open position. May be placed behind the target. In this case, it is necessary to provide a retreat space on the side of the target.
[0021]
【The invention's effect】
As is apparent from the above description, according to the sputtering apparatus of the present invention, the shutter rotates around the rotation axis extending in the direction orthogonal to the facing direction of the target and the sample. Is retracted to the side of the sample or target, and there is no need to provide a retracting space for the shutter on the side of the sputtering chamber. Therefore, the volume of the sputtering chamber can be reduced as compared with the conventional case, the pressure reduction process can be shortened, and the shape of the sputtering chamber can be simplified, so that the chamber can be manufactured at low cost.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a conventional sputtering apparatus.
FIG. 2 is a longitudinal sectional view of a first embodiment of a sputtering apparatus according to the present invention.
3 is a cross-sectional view of the sputtering apparatus shown in FIG.
FIG. 4 is an enlarged view of a shutter mounting portion.
FIG. 5 is a schematic cross-sectional view of the sputtering apparatus shown in FIG. 2 when the shutter is opened.
FIG. 6 is a schematic cross-sectional view of a second embodiment of the sputtering apparatus according to the present invention.
FIG. 7 is a perspective view of another example of the shutter.
[Explanation of symbols]
10 Chamber 11 Sputtering chamber 13 Target 16 Sample holder 17 Sample 20 Shutters 21 and 22 Shutter members 21a and 22a Rotating shafts 21c and 22c Shielding portion

Claims (3)

In a sputtering apparatus in which a target and a sample are arranged opposite to each other in a sputtering chamber, and a shutter that shields between the opening and closing is provided,
The shutter is disposed so as to be rotatable about a rotation axis extending in a direction orthogonal to the facing direction of the target and the sample ,
The sputtering apparatus according to claim 1, wherein a rotation axis of the shutter is positioned on the side opposite to the target so as to retract to the side of the sample in the open position . The sputtering apparatus according to claim 1, wherein the shutter includes a plurality of shutter members supported by different rotating shafts. The shutter is sputtering apparatus according to claim 1 or 2, characterized in that it is formed in a hemispherical surrounding the sample.

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