JP2009215568A - Sputtering apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sputtering apparatus which can keep discharge stable for a long period of time, by preventing a problem that the discharge is not being kept stable because an area ratio of an anode surface to a cathode surface decreases along with a tendency of miniaturizing the apparatus and reducing the cost, furthermore, all the anode surface results in being covered with an insulation film in a shorter period of time due to a higher speed of treatment, and the flow of electrons to the anode surface is obstructed. <P>SOLUTION: The sputtering apparatus is used for forming the insulation film on an object to be film-formed that faces a discharge space surrounded by an anode body 13 and a target 11 and faces to the target 11 with a sputtering technique. In the apparatus, the surface of an inner wall face of the anode body 13 exposed to the discharge space is changed by using a barrier 14. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sputtering apparatus.

In a sputtering apparatus, if a film adheres to a structure in the chamber other than the substrate that is the film formation target, cleaning becomes difficult.Therefore, a removable reflector is provided in the chamber, and the deposit is removed by removing the reflector. The removal is conventionally performed (for example, refer to Patent Document 1).
JP 2004-31493 A

  In general, in a sputtering apparatus, when comparing the areas of a cathode surface (target surface) and an anode surface, the anode surface often has a sufficiently larger area than the cathode surface. Therefore, in sputter deposition of an insulator, even if an insulating film adheres to the anode surface, there are few cases where the insulating film obstructs the path through which electrons enter the anode surface, and the entire anode surface is covered with the insulating film. The period of cleaning the attached insulating film is shorter than the period of time before the film is peeled off and foreign matter adheres to the abnormal discharge. Was not.

  However, with the recent miniaturization of devices and cost reduction, the area ratio of the anode surface to the cathode surface has become smaller, and further, due to the higher processing speed, the insulating film covers the entire anode surface in a short period of time. There is a concern that the flow of electrons to the anode surface is hindered and the discharge cannot be stably maintained.

  The present invention has been made in view of the above problems, and provides a sputtering apparatus that can sustain stable discharge over a long period of time.

  According to one aspect of the present invention, there is provided a sputtering apparatus for sputter-depositing an insulating film on a film-forming target facing a discharge space surrounded by an anode body and a target and facing the target. There is provided a sputtering apparatus characterized in that an exposed surface of the wall surface with respect to the discharge space is changed.

  ADVANTAGE OF THE INVENTION According to this invention, the sputter apparatus which can maintain the stable discharge over a long time is provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a schematic diagram showing a schematic configuration of a sputtering apparatus according to the first embodiment of the present invention.

  This sputtering apparatus is a sputtering apparatus that deposits an insulating film as a film formation target, for example, one sheet at a time on a resin substrate 10 of a disk-shaped recording medium.

  The substrate 10 is supported by a support body (not shown), and at the time of sputtering film formation, the deposition surface faces the discharge space 5 surrounded by the anode body 13 and the target 11 and faces the target 11 (film formation position). Set to

  On the upper part of the discharge space 5, for example, a target 11 formed in a disk shape is held via a backing plate or the like with the surface to be sputtered facing the discharge space 5. A voltage is applied to the target 11 from a power source (not shown). The sputtering apparatus according to this embodiment is, for example, a DC (direct current) sputtering apparatus, the target 11 functions as a cathode, and a negative voltage is applied to the target.

  The anode body 13 is detachably provided separately from the vacuum chamber 12 and is made of a conductive material such as metal and grounded, for example. The anode body 13 is formed in a substantially cylindrical shape as a whole so as to surround the side surface of the target 11, the side surface of the substrate 10, and the periphery of the discharge space 5.

  In the anode body 13, a shielding body 14 is provided in the vicinity of the lower part of the upper inner wall surface 13 a, which is the vicinity of the side surface of the target 11. The shield 14 is formed in a circular ring plate shape as shown in FIG. 2, and its center is made to substantially coincide with the center line C of the discharge space 5 (center line connecting the center of the target 11 and the center of the substrate 10) C. These are arranged so as to surround the side surface of the target 11.

  The shield 14 is connected to a motor provided outside the vacuum chamber 12 via a driving force transmission mechanism or the like (not shown), and can rotate around its center (center line C). As shown in FIG. 2, a plurality of openings 15 are intermittently formed in the shielding body 14 in the rotation direction (circumferential direction).

  Therefore, the shield 14 does not completely shield the upper inner wall surface 13a of the anode body 13 from the discharge space 5, but partially shields it. In other words, only the portion of the upper inner wall surface 13 a of the anode body 13 that faces the opening 15 of the shield 14 is exposed to the discharge space 5 through the opening 15. The shape of the opening 15 is not limited to a circular shape, and may be a square shape, an oval shape, a long hole shape, or the like. Further, the number and area of the openings 15 are not limited to the illustrated form, and can be appropriately designed.

  Next, a sputtering film forming process using the sputtering apparatus according to this embodiment described above will be described.

  For example, argon gas, nitrogen gas, oxygen gas or the like is introduced into the discharge space 5 through a gas introduction mechanism (not shown), and a predetermined reduced pressure atmosphere is provided by a vacuum exhaust system (not shown).

  When the substrate 10 is set at the film formation position shown in FIG. 1 and a voltage is applied to the target 11, a discharge is generated in the discharge space 5, and the introduced gas is ionized to generate plasma in the discharge space 5. The target 11 is sputtered by the accelerated ions.

  In this embodiment, reactive sputter film formation is performed, and target constituent atoms knocked out from the target 11 react with a gas introduced into the discharge space 5 to form a film on the substrate 10 as an insulating film. A film is formed on the surface. For example, when a silicon target is used, a silicon nitride film is formed on the substrate 10 when nitrogen gas is introduced, and a silicon oxide film is formed on the substrate 10 when oxygen gas is introduced.

  When such sputter film formation is repeated one by one on the plurality of substrates 10 one after another, an insulating film adheres to and deposits on the inner wall surface of the anode body 13 other than the substrate 10. Since electrons in the discharge space 5 jump into the grounded anode body 13, a current flows between the discharge space 5 and the ground via the anode body 13, and the discharge continues, so that the inner wall surface ( If the anode surface) is covered with the insulating film, electrons do not enter the anode body in the discharge space 5 to cause abnormal discharge or discharge stop.

  Therefore, in the present embodiment, the shielding body 14 in which the opening 15 is selectively formed is rotated to change the exposed surface of the upper inner wall surface 13a of the anode body 13 with respect to the discharge space 5, thereby covering the insulating film. The anode surface that enables the entry of electrons is secured. The “change in the exposed surface” here means a change (position) in the exposed portion or a change in the exposed area.

  In the upper inner wall surface 13a of the anode body 13 facing the shield body 14, only the portion facing the opening 15 of the shield body 14 is exposed to the discharge space 5, and only that portion functions as an anode surface into which electrons jump. The exposure to the discharge space 5 means that the molecules constituting the insulating film also fly, and when the sputter film forming process is repeated, the insulating film adheres to the exposed surface and inhibits the entry of electrons.

  However, since the insulating film is not attached to the portion of the upper inner wall surface 13a of the anode body 13 covered with the shielding body 14, the opening 15 is moved in the rotation direction (circumferential direction) by rotating the shielding body 14. Thus, the portion previously covered by the shield 14 can be exposed to the discharge space 5 from the opening 15, and a new anode surface not covered with the insulating film can appear.

  If sputter film formation is performed with the new anode surface exposed to the discharge space 5, even if other portions such as the side surface portion 13b of the anode body 13 are covered with an insulating film, the anode of electrons The entry path to the body 13 can be secured, and the discharge can be continued. Then, even if the anode surface is covered with the insulating film due to further continuation of the sputter film formation, a new anode surface not covered with the insulating film can appear by rotating the shield 14 again.

  By such rotation of the shield 14 (movement of the opening 15), new anode surfaces appear one after another, so that the flow of electrons between the discharge space 5 and the ground can be secured over a long period of time. The discharge can be sustained.

  Further, by forming the opening 15 symmetrically around the center line C of the discharge space 5, the anode surface exposed from the opening 15 can be positioned symmetrically around the center line C, and electrons are The path that jumps into the anode body 13 is not biased in the discharge space 5, and the discharge is uniformly generated around the center line C. As a result, variation in the in-plane film thickness distribution of the insulating film formed on the substrate 10 can be suppressed. .

  The timing for rotating the shield 14 to move the opening 15 (timing for exposing a new anode surface) can be performed, for example, every predetermined number of processing or every elapse of a predetermined processing time. At that time, the openings 15 may be moved so as to be shifted little by little in the rotation direction as shown in FIG. 3A, or at a pitch of one opening 15 as shown in FIG. It may be moved. The number of openings 15 may be one.

[Second Embodiment]
FIG. 4 is a perspective view of the shield 24 in the sputtering apparatus according to the second embodiment of the present invention.

  In the present embodiment, a shield 24 is provided in the vicinity of the inner wall surface 13b of the side surface portion surrounding the discharge space 5 in the anode body 13 shown in FIG. The shield 24 is formed in a circular ring plate shape as shown in FIG. 4, and its center substantially coincides with the center line C of the discharge space 5 (center line connecting the center of the target 11 and the center of the substrate 10) C. It is possible to rotate around the center line C.

  The shield 24 has its peripheral surface opposed to the inner wall surface 13b of the side surface of the anode body 13, and a plurality of openings 25 are selectively formed in the peripheral surface in the rotation direction (circumferential direction).

  Therefore, the shield 24 does not completely shield the inner wall surface 13 b of the side surface of the anode body 13 from the discharge space 5 but partially shields it. In other words, only the part of the side wall inner wall surface 13 b of the anode body 13 that faces the opening 25 of the shield 24 is exposed to the discharge space 5 through the opening 25.

  By rotating the shield 24, the opening 25 is moved in the rotation direction (circumferential direction), and the portion previously covered by the shield 24 is exposed from the opening 25 to the discharge space 5. A new uncovered anode surface can appear. Then, by rotating the shield 24 (moving the opening 25), new anode surfaces appear one after another, thereby ensuring the flow of electrons between the discharge space 5 and the ground over a long period of time. Can be sustained.

  Further, by forming the opening 25 symmetrically around the center line C of the discharge space 5, the anode surface exposed from the opening 25 can be positioned symmetrically around the center line C, and electrons are The path that jumps into the anode body 13 is not biased in the discharge space 5, and the discharge is uniformly generated around the center line C. As a result, variation in the in-plane film thickness distribution of the insulating film formed on the substrate 10 can be suppressed. .

  The timing for rotating the shield 24 to move the opening 25 (timing for exposing a new anode surface) can be performed, for example, for every predetermined number of processed sheets or for every predetermined processing time. At that time, the openings 25 may be moved so as to be shifted little by little in the rotation direction as shown in FIG. 5A, or at a pitch of one opening 25 as shown in FIG. 5B. It may be moved. The number of openings 25 may be one.

[Third Embodiment]
FIG. 6 is a schematic diagram showing a planar arrangement relationship between the target 11, the vacuum chamber 12, and the shield 34 in the sputtering apparatus according to the third embodiment of the present invention.

  In the present embodiment, a plurality of shields 34 are held on the peripheral wall of the vacuum chamber 12. Each shield 34 is formed in a plate shape, for example. The plurality of shields 34 are arranged, for example, at regular intervals along the circumferential direction of the vacuum chamber 12. Since each shield 34 is provided to protrude from the outside of the vacuum chamber 12, that is, from the outside of the discharge space 5 into the discharge space 5, and is provided to be movable in the radial direction while maintaining airtightness, The amount of protrusion into 5 can be changed.

  A portion of the shield 34 protruding into the discharge space 5 faces the upper inner wall surface 13 a of the anode body 13 shown in FIG. 1 and shields the inner wall surface 13 a from the discharge space 5. Therefore, the upper inner wall surface 13 a of the anode body 13 is exposed to the discharge space 5 by changing the amount of projection of each shield 34 into the discharge space 5 by an operation from the atmosphere side outside the discharge space 5. The area of the exposed surface (anode surface) can be controlled.

  That is, by changing (shortening) the amount of projection of the shielding body 34 into the discharge space 5, the portion of the upper inner wall surface 13 a of the anode body 13 that has been covered by the shielding body 34 with respect to the discharge space 5. A new anode surface that is exposed and is not covered with an insulating film can appear. Then, by moving the shield 34 outwardly, new anode surfaces appear one after another, and the flow of electrons between the discharge space 5 and the ground is ensured over a long period of time, so that stable discharge can be sustained. It becomes possible.

  In order to drive each shield 34 in the radial direction, a motor, a cylinder device, or the like may be used, or the shield 34 may be manually operated.

  Further, by arranging the shields 34 symmetrically around the center line C of the discharge space 5, the exposed surface (anode surface) of the upper inner wall surface 13 a of the anode body 13 is symmetrical around the center line C. The path through which electrons jump into the anode body 13 is not biased in the discharge space 5, and discharge is uniformly generated around the center line C, resulting in the in-plane film thickness of the insulating film formed on the substrate 10. Variation in distribution can be suppressed.

  Note that the anode surface that is successively exposed by driving the shielding body in each of the above-described embodiments may be an inner wall surface at any location in the anode body 13, but the deposition rate of the film constituent is difficult to fly. It is preferable to expose a portion near the target 11 that is relatively slow so that the portion functions as an anode surface.

  Further, when the substrate 10 is an insulator such as a resin, there is no fear of damage because electrons do not enter the substrate 10, but when the substrate 10 is a conductor such as a metal, electrons enter the substrate 10 and the substrate 10 10 may be damaged. Also from the viewpoint of suppressing the entry of electrons into the substrate 10, the vicinity of the target 11 is preferable for the anode surface exposed by driving the shield.

[Fourth Embodiment]
FIG. 7 is a schematic diagram showing a planar arrangement relationship of the target 11, the vacuum chamber 12, and the movable anode body 44 in the sputtering apparatus according to the fourth embodiment of the present invention.

  In the present embodiment, a plurality of movable anode bodies 44 are held on the peripheral wall of the vacuum chamber 12. Each movable anode body 44 is formed in, for example, a plate shape, a column shape, or a prism shape. The plurality of movable anode bodies 44 are arranged, for example, at regular intervals along the circumferential direction of the vacuum chamber 12. Each movable anode body 44 protrudes from the outside of the vacuum chamber 12, that is, from the discharge space 5 into the discharge space 5, and is provided so as to be movable in the radial direction while maintaining airtightness. The amount of protrusion into the space 5 can be changed.

  The portion of the movable anode body 44 that protrudes into the discharge space 5 is located, for example, in the vicinity of the upper inner wall surface of the vacuum chamber 12 around the target 11. By changing the amount of protrusion of each movable anode body 44 into the discharge space 5 by an operation from the atmosphere side outside the discharge space 5, the area of the anode surface near the periphery of the target 11 can be changed.

  By moving the movable anode body 44 inward in the diameter, new anode surfaces (electron entry surfaces) can appear one after another in the discharge space 5, and between the discharge space 5 and the ground for a long time. The flow of electrons is ensured, and stable discharge can be sustained.

  In order to drive each movable anode body 44 in the radial direction, a motor, a cylinder device or the like can be used, or it can be operated manually.

  Further, by arranging the movable anode bodies 44 symmetrically around the center line C of the discharge space 5, the path for electrons to jump into the movable anode body 44 is not biased in the discharge space 5 and around the center line C. Discharge occurs uniformly, and as a result, variation in the in-plane film thickness distribution of the insulating film formed on the substrate 10 can be suppressed.

[Fifth Embodiment]
The movable anode body is not limited to moving in the radial direction, and may be a rotating body as shown in FIG.

  In the present embodiment, a plurality of movable anode bodies 54 (only one of which is shown in FIG. 8) are held on the peripheral wall of the vacuum chamber 12. The movable anode body 54 is formed, for example, in a columnar shape, and is provided with its axial direction substantially parallel to the axial direction of the vacuum chamber 12. The movable anode body 54 can be rotated around the central axis with its central axis (indicated by a one-dot chain line) positioned on the atmosphere side outside the vacuum chamber 12 and airtight with respect to the vacuum chamber 12. ing. For example, a driving shaft of a motor is connected to a central shaft located on the atmosphere side, and the movable anode body 54 is rotated by receiving the driving force.

  As the movable anode body 54 rotates, the exposed surface (circumferential surface) of the movable anode body 54 into the discharge space 5 changes. Therefore, by rotating the movable anode body 54, new anode surfaces (electron entry surfaces) appear one after another in the discharge space 5, and the flow of electrons between the discharge space 5 and the ground is ensured for a long time. Thus, stable discharge can be sustained.

  Further, by arranging the plurality of movable anode bodies 54 symmetrically around the center line C of the discharge space 5 along the circumferential direction, the path for electrons to jump into the movable anode body 54 is not biased in the discharge space 5, Discharge occurs uniformly around the center line C, and as a result, variations in the in-plane film thickness distribution of the insulating film formed on the substrate 10 can be suppressed.

  Further, as shown in FIG. 9A, the rotating shaft O (extending in the direction passing through the paper surface in the illustrated example) is horizontal or inclined with respect to the vertical direction, and the discharge space 5 has a circumferential surface. The movable anode body 55 may be provided so as to be rotatable with the portion facing. Also in this case, the position of the peripheral surface facing the discharge space 5 is changed by the rotation of the movable anode body 55, so that a new anode surface can be exposed to the discharge space 5.

  Further, the movable anode body is not limited to a part protruding into the discharge space 5, and may be provided outside the vacuum chamber 12 like the movable anode body 56 shown in FIG. An opening 50 leading to the discharge space 5 is formed on the side wall of the vacuum chamber 12, and the movable anode body 56 is rotatably provided outside the vacuum chamber 12 with the peripheral surface being in airtight contact with the opening 50. As the movable anode body 56 rotates, the peripheral surface exposed to the discharge space 5 through the opening 50 changes, and a new anode surface is exposed to the discharge space 5. The movable anode body configured as a rotating body is not limited to a cylinder but may be a polygon.

The schematic diagram which shows schematic structure of the sputtering device which concerns on the 1st Embodiment of this invention. The top view of the shielding body in the sputtering device shown in FIG. The schematic diagram which shows an example of how much the opening formed in the shielding body shown in FIG. 2 is moved for every movement. The perspective view of the shield in the sputtering device concerning a 2nd embodiment of the present invention. The schematic diagram which shows an example of how much the opening formed in the shielding body shown in FIG. 4 is moved for every movement. The schematic diagram which shows the planar arrangement | positioning relationship of the principal part structure in the sputtering device which concerns on the 3rd Embodiment of this invention. The schematic diagram which shows the planar arrangement | positioning relationship of the principal part structure in the sputtering device which concerns on the 4th Embodiment of this invention. The schematic perspective view of the principal part in the sputtering device which concerns on the 5th Embodiment of this invention. The schematic diagram which shows the other specific example of the rotatable movable anode body in the sputtering device which concerns on 5th Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Board | substrate, 11 ... Target, 12 ... Vacuum chamber, 13 ... Anode body, 14 ... Shielding body, 15 ... Opening, 24 ... Shielding body, 25 ... Opening, 34 ... Shielding body, 44, 54, 55, 56 ... Movable Anode body

Claims (7)

A sputtering apparatus for sputter-depositing an insulating film on a deposition target facing a target and facing a discharge space surrounded by an anode body and a target,
An exposed surface of the inner wall surface of the anode body with respect to the discharge space changes. A shielding body that partially shields the inner wall surface of the anode body from the discharge space;
The sputtering apparatus according to claim 1, wherein an exposed surface of the inner wall surface of the anode body with respect to the discharge space is changed by the movement of the shielding body.   The sputtering apparatus according to claim 2, wherein the shield is rotatably provided and has an opening that moves in the rotation direction.   The sputtering apparatus according to claim 2, wherein the shield is provided to protrude from the outside of the discharge space into the discharge space, and a protrusion amount into the discharge space can be changed. A movable anode body provided with a part exposed to the discharge space,
The sputtering apparatus according to claim 1, wherein the movable anode body moves to change an exposed surface with respect to the discharge space.   The sputtering apparatus according to claim 5, wherein the movable anode body is rotatably provided.   The sputtering apparatus according to claim 5, wherein the movable anode body is provided so as to protrude from the outside of the discharge space into the discharge space, and the amount of protrusion into the discharge space can be changed.

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