JP2007150039A - Polishing fluid supply apparatus, polishing member, and polishing fluid supply apparatus having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polishing fluid supply apparatus capable of improving uniformity in the surface of an object to be polished, and reducing the amount of consumption of polishing fluid, and to provide a polishing member and the polishing fluid supply apparatus having the polishing member. <P>SOLUTION: An electrolyte inlet I is provided in a range nearly at the center of the upper surface of the electrolyte supply apparatus 60, an electrolyte travel path M is provided inside the electrolyte supply apparatus 60, ribs 67c (ribs 67e, 67f in a radial direction and ribs 67g, 67h in a tangential direction) for adjusting the flow of an electrolyte E are provided in the electrolyte travel path M, a through-hole for limiting the inflow of the electrolyte E is provided at the bottom of the electrolyte storage F, and the electrolyte E is injected from the electrolyte inlet I to the electrolyte supply apparatus 60 for supplying from the lower side to the upper side of a polishing member layer 62 via the electrolyte travel path M and the electrolyte storage F. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a polishing liquid supply apparatus that supplies a polishing liquid to a polishing member, a polishing member that polishes a member to be polished using the polishing liquid, and a polishing liquid supply apparatus with a polishing member that supplies the polishing liquid.

In semiconductor devices (semiconductor devices), wirings are stacked with high integration and miniaturization. That is, a process is employed in which wiring is patterned on the surface of a semiconductor wafer, this is covered with an insulator such as silicon oxide, the next wiring is patterned, and this is repeated sequentially.
In the process of patterning the wiring, the hole for the plug and the wiring groove are formed in an insulator such as silicon oxide (hereinafter referred to as an interlayer insulating film) by reactive ion etching or the like, and the copper wiring material is embedded thereon by copper plating. A so-called damascene method is used in which a conductor layer is formed, and excess copper on the surface of the conductor layer is removed by chemical mechanical polishing (CMP) and planarized to form a wiring.

  In recent years, introduction of a low dielectric constant material (so-called low-k material) for an interlayer insulating film has been studied for the purpose of reducing the power consumption and speed of a device. This low dielectric constant material has poor mechanical strength and chemical stability, and the copper wiring material may be peeled off from the interlayer insulating film due to frictional force depending on the rotational speed and polishing pressure in CMP. An ultra-low pressure polishing method in which polishing is performed with extremely reduced pressure has been studied.

  Since this ultra-low pressure CMP has a problem of lowering the polishing rate and deterioration of uniformity in the wafer surface, the following three methods (electrochemical polishing method and electrochemical mechanical polishing method) can be used instead of CMP. Proposed.

(1) An electrochemical polishing method in which an anode electrode is brought into contact with a device wafer, a cathode is curved and confronted in an electrolytic solution, and a conductor layer is dissolved and removed (for example, Patent Document 1).
However, since this method does not mechanically polish the wafer surface, the planarization performance is not sufficient, and it is necessary to perform Cu-CMP after electrochemical polishing in order to form wiring.
(2) A rotating platen having a polishing member is installed in a container (begin) filled with an electrolytic solution, the rotating platen and the cathode installed at the bottom of the container are opposed, and the anode electrode is in contact with the device wafer. This is a method of performing electrochemical mechanical polishing by pressing (pressing) the polishing member (for example, Patent Document 2).
However, generally, a Cu-CMP apparatus is mainly a multi-platen / multi-head type in order to perform Cu-CMP (which may be two steps of rough polishing and final polishing) and barrier metal CMP. Therefore, this method performs removal processing (rough polishing) of an excess conductor layer using an electrolytic polishing apparatus in the first step, and uses a conventional Cu-CMP apparatus in the second step and the third step. Since polishing is performed, there is a problem that the apparatus becomes expensive.
(3) An electrochemical mechanical polishing method using a polishing pad mounted on a platen and having an anode and a cathode (for example, Patent Document 3).
However, in this method, as shown in FIG. 14, since the electrolytic solution is supplied so as to cover the surface of the polishing pad, if the rotation speed of the platen is increased, the electrolytic solution is scattered by the action of centrifugal force, and the polishing speed is increased. However, there is a disadvantage that stable polishing cannot be performed, for example, the uniformity in the wafer surface deteriorates.

In order to solve the problems in the above three methods, one of the inventors of the present invention disclosed in Japanese Patent Application Laid-Open No. H11-228707 as an anode for a copper wiring material of a device wafer and a platen as a cathode for supplying an electrolyte to a plurality of electrolyte containers. A method is disclosed in which an electrolytic cell is formed by filling and electrochemically polished using a platen / rotary polishing apparatus or the like.
This electrochemical polishing method uses a platen / rotary type polishing apparatus or the like, and can be used for electrochemical polishing by simply attaching a polishing pad to one platen of a multi-platen. Multi-step polishing combining mechanical mechanical polishing and barrier metal CMP can be performed using a conventional CMP apparatus. As a result, the cost of the apparatus can be reduced. In addition, the electrolytic cell is formed so as to be relatively movable with respect to the device wafer, and the excess copper wiring material on the surface of the device wafer is electrochemically dissolved and removed. Improvement can be achieved.

When this method is used to further improve the flatness and uniformity of the polishing rate within the wafer surface, it is conceivable to increase the polishing pressure of the polishing pad with respect to the copper wiring material and to increase the relative speed.
However, when the polishing pressure is increased, there is a problem that the copper wiring material is peeled off from the device wafer.
In order to increase the relative speed, in the case of a platen / rotary type polishing apparatus, it is necessary to increase the rotation speed of the platen. However, since the centrifugal force generated in the electrolytic solution of each electrolytic cell varies depending on the difference in the peripheral speed on the platen (the center of the electrolytic cell pad is slow and the outer peripheral portion is fast), there is a difference in the electrolytic solution level between the electrolytic cells. Arise. For this reason, the uniformity of the polishing rate within the wafer surface may be deteriorated.
Furthermore, since this method supplies the electrolytic solution so as to cover the surface of the polishing pad, there is a problem that the above-mentioned problem (3) cannot be solved completely.
JP 2003-193300 A JP-T-2004-531885 Pub. No. US 2004/0214510 A1 JP-A-2005-139480

  An object of the present invention is to provide a polishing liquid supply device, a polishing member, and a polishing liquid supply device with a polishing member capable of improving the in-plane uniformity of the polishing rate of an object to be polished and reducing the consumption of the polishing liquid. It is to be.

  In order to solve the problem, the invention of claim 1 is attached to a rotating surface plate (51) of a platen / rotary type polishing apparatus (50), and polishing members (62, 162, 262, 562) provided on the upper side. In the polishing liquid supply apparatus for supplying the polishing liquid (E) to the inner surface, a polishing liquid injection port (I) for injecting the polishing liquid (E) on the inside, A polishing liquid moving path (M, 2M, 3M, 7M) for moving the polishing liquid (E) is provided, and the polishing liquid (E) is supplied to the polishing liquid inlet (I). ) And supplied from the lower side to the upper side of the polishing member (62, 162, 262, 562) through the polishing liquid movement path (M, 2M, 3M, 7M). A polishing liquid supply device.

A second aspect of the present invention is the polishing liquid supply apparatus according to the first aspect, wherein the polishing liquid supply device is provided above the polishing liquid movement path (M, 2M, 3M, 7M), and the polishing member (62, 162, 262) is provided. 562) has a plurality of polishing liquid storage portions (F, 2F, 3F, 4F) forming at least a part of the polishing liquid storage portion (F, 2F, 3F, 4F). ) To the upper opening of the polishing liquid container (F, 2F, 3F, 4F).
According to a third aspect of the present invention, in the polishing liquid supply apparatus according to the second aspect, the polishing liquid (E) is an electrolytic solution (E), and the object to be polished is a conductor layer ( D1), and when the conductive layer (D1) comes into contact with the electrolytic solution (E) stored in the polishing liquid storage portion (F, 2F, 3F, 4F), the conductive layer (D1) ) Is an anode, and an electrolytic cell (C, 2C) is formed by bringing the electrolytic solution (E) into contact between the anode and a cathode which is a counter electrode with respect to the anode, and applying a voltage. The polishing liquid supply apparatus is characterized in that the polishing member (62, 162, 262, 562) polishes the conductor layer (D1) electrochemically and mechanically.
A fourth aspect of the present invention is the polishing liquid supply apparatus according to the third aspect, wherein the cathode is formed at the bottom of the polishing liquid container (F).
According to a fifth aspect of the present invention, in the polishing liquid supply apparatus according to the first aspect, the polishing liquid moving path (M, 2M, 3M, 7M) is a flow adjusting unit (for adjusting the flow of the polishing liquid (E)). 67c, 67e, 67f, 67g, 67h, 367a, 367b, 367c, 7M).
According to a sixth aspect of the present invention, in the polishing liquid supply apparatus according to the fifth aspect, the flow adjusting portions (67c, 67e, 67f, 67g, 67h, 367a, 367b, 367c, 7M) ) Is provided so as to resist the centrifugal force acting on the polishing liquid (E) in the polishing liquid movement path (M, 2M, 3M, 7M). A polishing liquid supply device.
According to a seventh aspect of the present invention, in the polishing liquid supply apparatus according to the sixth aspect, the flow adjusting portions (67c, 67e, 67f, 67g, 67h, 367a, 367b, 367c, 7M) The polishing liquid supply apparatus is characterized by changing from the center toward the outside according to the position in the radial direction so as to correspond to the magnitude of the centrifugal force.
An eighth aspect of the present invention is the polishing liquid supply apparatus according to the fifth aspect, wherein the flow adjusting section (67g, 67h, 367a, 367b, 367c) is substantially in the flow direction of the polishing liquid (E). The polishing liquid supply apparatus is characterized by being provided in a rib shape in a vertical direction.
A ninth aspect of the present invention is the polishing liquid supply apparatus according to the fifth aspect, wherein a plurality of polishing liquid storage portions (F, 2F) provided above the polishing liquid movement path (M, 2M, 3M, 7M). , 3F, 4F) and the bottom of the polishing liquid container (F, 2F, 3F, 4F), and the polishing liquid (F, 2F, 3F, 4F) to the polishing liquid container (F, 2F, 3F, 4F) E) A polishing liquid supply apparatus having a polishing liquid inflow restricting through hole (66a, 67d, 164b, 262b) for restricting inflow of E).
The invention of claim 10 is the polishing liquid supply apparatus according to claim 2, wherein the polishing liquid container (4F) is filled and the polishing liquid (E) in the polishing liquid container (4F) is held. A polishing liquid supply apparatus comprising a polishing liquid holding material (580).
The invention of claim 11 is the polishing liquid supply apparatus according to claim 10, wherein the polishing liquid holding material (580) is formed of a continuous foamed body, a nonwoven fabric, a woven cloth or a felt. This is a liquid supply device.
A twelfth aspect of the present invention is the polishing liquid supply apparatus according to the first aspect, wherein the polishing liquid injection port (I) is a rotary joint capable of injecting the polishing liquid (E) while the apparatus is rotating. (69) It is provided with the polishing liquid supply apparatus characterized by the above-mentioned.
According to a thirteenth aspect of the present invention, in the polishing liquid supply apparatus according to the first aspect of the present invention, the upper surface of the polishing member (62, 162, 262, 562) covers a range where the object to be polished (D, D1) does not contact. And a polishing liquid supply suppressing member (470) that suppresses the supply of the polishing liquid (E) in the above range.
A fourteenth aspect of the present invention is the polishing liquid supply apparatus according to the third aspect, further comprising a contact conductor (61) that is in contact with the conductor layer (D1) and is electrically conductive. A polishing liquid supply device.
The invention of claim 15 is the polishing liquid supply apparatus according to claim 14, wherein the contact conductor (61) is provided so as to protrude from the surface of the polishing member (62, 162, 262, 562), The conductor layer (D1) is pushed down by contacting and can be displaced until the conductor layer (D1) and the polishing member (62, 162, 262, 562) contact each other. This is a polishing liquid supply device.
A sixteenth aspect of the present invention is the polishing liquid supply apparatus according to the fourteenth aspect, wherein the contact conductor (61) has a mirror surface.
The invention according to claim 17 is the polishing liquid supply apparatus according to claim 12, wherein the contact conductor (61) is made of gold, platinum, titanium alloy, copper or stainless steel. This is a liquid supply device.
The invention according to claim 18 is the polishing liquid supply apparatus according to claim 14, wherein the contact conductor (61) is a composite of carbon fiber, graphite fiber, graphite, amorphous carbon, and synthetic resin whose main component is carbon. The polishing liquid supply apparatus is formed of any one of a carbon material, a composite carbon material with an elastomer material, a composite graphite with a synthetic resin, or a combination thereof.
According to a nineteenth aspect of the present invention, in the polishing liquid supply apparatus according to the fourteenth aspect, the polishing liquid supply device is provided below the polishing member (62, 162, 262, 562) and transmits electric power to the contact conductor (61). The polishing liquid supply apparatus includes a power transmission unit (63, 163, 263).
According to a twentieth aspect of the present invention, in the polishing liquid supply apparatus according to the nineteenth aspect, the polishing power transmission unit (63, 163, 263) is formed of gold, copper, platinum, titanium alloy stainless steel, or carbon. This is a polishing liquid supply apparatus.
According to a twenty-first aspect of the present invention, in the polishing liquid supply apparatus according to the nineteenth aspect, the polishing power transmission unit (63, 163, 263) includes amorphous carbon, carbon fiber, graphite fiber, graphite, The polishing liquid supply apparatus is characterized by being formed from a composite carbon material with a synthetic resin or a composite carbon material with a synthetic resin.
The invention of claim 22 is the polishing liquid supply apparatus according to claim 1, wherein the polishing liquid (E) is a chemical mechanical polishing liquid, and the polishing members (62, 162, 262, 562) are: A polishing liquid supply apparatus which is formed from polyurethane or foamed polyurethane and is chemically and mechanically polished by moving relative to the object to be polished while being pressed.
The invention according to claim 23 is the polishing liquid supply apparatus according to claim 1, wherein the polishing member is formed of a fixed abrasive polishing member to which silicon oxide abrasive grains are fixed, and presses against the object to be polished. The polishing liquid supply apparatus is characterized by performing chemical mechanical polishing by relatively moving while moving.

  The invention of claim 24 is attached to the polishing liquid supply apparatus (60, 160, 260, 360, 460, 560, 660) according to any one of claims 1 to 23, and the polishing liquid is A polishing member supplied from below and polishing the object to be polished.

  The invention of claim 25 is the polishing liquid supply apparatus (60, 160, 260, 360, 460, 560, 660) according to any one of claims 1 to 23, and A polishing liquid supply apparatus with a polishing member, comprising a polishing member (62, 162, 262, 562).

According to the present invention, the following effects can be obtained.
(1) The present invention is provided in a substantially central range of the upper surface of the apparatus, and is provided with a polishing liquid injection port for injecting the polishing liquid inside the apparatus, and in a hollow shape inside the apparatus for moving the polishing liquid. And a polishing liquid moving path. The polishing liquid is injected from the polishing liquid inlet, and is supplied from the lower side to the upper side of the polishing member via the polishing liquid moving path. That is, the electrolytic solution is not supplied so as to cover the surface of the polishing member.
Accordingly, since the polishing liquid can be prevented from scattering from the surface of the polishing member, the rotation speed of the polishing member can be increased, and therefore the in-plane uniformity of the polishing speed of the object to be polished can be improved. Further, since the polishing liquid can be supplied stably and efficiently, the consumption of the polishing liquid can be reduced.

(2) The present invention is provided above the polishing liquid moving path, and the polishing member has a plurality of polishing liquid storage portions forming at least a part thereof, and the polishing liquid is polished from the bottom of the polishing liquid storage portion. It is supplied to the upper opening of the liquid container. Thus, a sufficient polishing liquid can be supplied to the polishing member from the upper opening having a certain opening area.

(3) In the present invention, the polishing liquid is an electrolytic solution, and the object to be polished is a conductor layer of a device wafer. The conductor layer is made an anode by contacting the electrolytic solution accommodated in the polishing liquid accommodating portion. Moreover, an electrolytic cell is formed by applying an electric voltage by bringing an electrolytic solution into contact between the anode and the cathode. Thereby, the polishing member can electrochemically and mechanically polish the conductor layer. In addition, due to the effect of (1), the electrolytic solution storage portion can stably flow in the electrolytic solution and be filled uniformly, and can stably contact the electrolytic solution and the conductor layer of the device wafer. Further, it is possible to perform polishing with improved in-plane uniformity of the polishing rate of the conductor layer.

(4) In the present invention, since the cathode is formed at the bottom of the polishing liquid container, an electrolysis cell using the conductor layer as an anode can be configured.

(5) In the present invention, since the polishing liquid moving path has a flow adjusting unit that adjusts the flow of the polishing liquid, the supply amount of the polishing liquid can be adjusted, so that the polishing liquid can be supplied stably.

(6) In the present invention, the flow adjusting unit is provided so as to resist the centrifugal force acting on the polishing liquid in the polishing liquid movement path by the rotational movement of the rotary platen. Since the influence of the centrifugal force acting on the polishing liquid can be reduced, the polishing liquid can be supplied stably.

(7) In the present invention, since the degree of resistance to the centrifugal force changes according to the magnitude of the centrifugal force, the magnitude of the centrifugal force depends on the position (inner circumference, outer circumference of the outer circumference). Even if it changes according to the position), it can be adjusted so that the force acting on the polishing liquid in the polishing liquid movement path is uniform. Thereby, since the speed at which the polishing liquid in the polishing liquid moving path moves can be adjusted to be uniform, the polishing liquid can be stably supplied.

(8) In the present invention, since the flow adjusting portion is provided in a rib shape in a direction substantially perpendicular to the flow direction of the polishing liquid, it can resist the centrifugal force acting on the polishing liquid. Moreover, since it is a rib structure, the degree of resistance can be easily adjusted by adjusting the height and the like, and the structure can be simplified.

(9) In the present invention, since the polishing liquid inflow restricting through-hole is provided at the bottom of the polishing liquid container and restricts the inflow of the polishing liquid into the polishing liquid container, the polishing liquid flowing into the polishing liquid container is Can be adjusted directly.

(10) Since the present invention includes the polishing liquid holding material that is filled in the polishing liquid container and holds the polishing liquid in the polishing liquid container, the polishing liquid in the polishing liquid container is prevented from being scattered by centrifugal force. be able to.

(11) In the present invention, since the polishing liquid inlet includes a rotary joint that can inject the polishing liquid in a state where the apparatus is rotating, the polishing liquid is supplied to the rotating polishing liquid supply device. The structure can be simplified. Moreover, cost can be suppressed by using a general-purpose component (rotary joint).

(12) In the present invention, the polishing liquid supply suppressing member is provided so as to cover a range where the polishing member on the upper surface of the object to be polished is not polished, and suppresses the supply of the polishing liquid in this range. That is, since the supply of the polishing liquid that is not used for polishing and discharged is suppressed, the consumption of the polishing liquid can be reduced and the polishing cost can be suppressed.

(13) Since the present invention includes the contact conductor that is in contact with the conductor layer and can be electrically conducted, the positive charge can be applied to the conductor layer to form the anode.

(14) In the present invention, the contact conductor is provided so as to protrude from the surface of the polishing member, and is pressed down by contacting the conductor layer, and can be displaced until the conductor layer and the contact conductor contact each other. It is. Accordingly, when the conductor layer is mechanically polished, the contact conductor and the conductor layer can be reliably brought into contact with each other, and power can be stably supplied to the conductor layer.

(15) According to the present invention, since the surface of the contact conductor is a mirror surface, damage (damage) of the conductor layer due to the contact conductor contacting the conductor layer can be prevented.

(16) In the present invention, since the power transmission portion is provided below the polishing member and transmits power to the contact conductor, current can be prevented from flowing through the object to be polished, so that power can be transmitted efficiently. can do.

(17) In the present invention, the polishing member is formed of polyurethane or foamed polyurethane, the polishing liquid is a chemical mechanical polishing liquid, and the polishing member moves relative to the object to be polished while being pressed against the object to be polished. Polish mechanically. Thus, chemical mechanical polishing having the effect (1) can be performed, and sufficient polishing liquid is supplied to the upper surface (polishing surface) of the polishing member from the upper opening of the polishing liquid container. be able to.

(18) In the present invention, the polishing member is formed of a fixed abrasive polishing member to which silicon oxide abrasive grains are fixed, and moves relative to the object to be polished while being pressed. Polishing can be performed.

  The present invention provides a polishing liquid supply device, a polishing member, and a polishing liquid supply device with a polishing member that can improve the uniformity of the polishing speed of an object to be polished in the wafer surface and reduce the consumption of the polishing liquid. For this purpose, an electrolyte injection port is provided in a substantially central range on the upper surface of the electrolyte supply device, an electrolyte movement path is provided inside the electrolyte supply device, and a rib for adjusting the flow of the electrolyte is provided in the electrolyte movement path. Providing a through hole for restricting the inflow of the electrolyte at the bottom of the electrolyte container, and injecting the electrolyte into the electrolyte supply device from the electrolyte inlet, and providing the electrolyte movement path and the electrolyte container It was realized by supplying from the lower side to the upper side of the polishing member layer.

Next, Embodiment 1 of the electrolytic solution supply apparatus (polishing liquid supply apparatus) according to the present invention will be described with reference to the drawings.
First, the outline of the polishing apparatus 50 to which the electrolytic solution supply apparatus 60 of the present embodiment is attached will be described.
The polishing apparatus 50 is a Cu-CMP apparatus used for chemical mechanical polishing (CMP) of a platen rotary type having a multi-platen / multi-head. FIG. 1 is a perspective view showing the pair of platens / heads.
As shown in FIG. 1, the polishing apparatus 50 includes a platen 51 (rotating surface plate), a polishing head 52, a power supply 53, an apparatus-side electrode 55, and a nozzle 56.

The platen 51 is a disk-shaped member that mounts the electrolytic solution supply device 60 and rotates around the vertical axis Z1 (in the direction of the arrow θ1).
The polishing head 52 is a disk-shaped member that has the device wafer D mounted on its lower surface and rotates around the vertical axis Z2 (in the direction of the arrow θ2). The device wafer D is mounted on the polishing head 52 so that the conductor layer D1 is on the lower side.

The power source 53 is a device that supplies electric power for forming an electrolytic cell that performs electrochemical polishing (ECP). As will be described later, the power source 53 forms an anode on the conductor layer D1 of the device wafer D, and forms a cathode on a conductive sheet layer 66 (described later) of the electrolytic solution supply apparatus 60. The power to be supplied is generally DC power, but the power waveform may be pulsed or AC power that fluctuates positively and negatively if there is a DC component.
The device-side electrode 55 is a member for transmitting electric power to the conductive member layer 63. The device-side electrode 55 is electrically connected to the positive terminal of the power supply 53 via a wiring, and is brought into contact with a conductive member layer 63 (described later) of the electrolytic solution supply device 60 to thereby form a conductive member. Electrical conduction is made to layer 63. The device-side electrode 55 is preferably made of the same material as that of the conductive member layer 63 in contact with the conductive member layer 63, but is stable with respect to the rotating conductive member layer 63. In order to make electrical contact, it is desirable to have wear resistance.
The nozzle 56 is disposed above the electrolytic solution supply device 60, is connected to the electrolytic solution supply device 60 by a rotary joint 69 (described later), and injects the electrolytic solution E into the electrolytic solution supply device 60.
The electrolytic solution E can be an aqueous solution mainly composed of an organic acid such as citric acid, an inorganic acid such as phosphoric acid, or a salt such as copper sulfate, and contains a protective film forming agent, abrasive grains, an oxidizing agent, or the like. be able to.

  With the above-described configuration, the polishing apparatus 50 contacts the device wafer D and the polishing member layer 62 of the electrolytic solution supply apparatus 60 while supplying the electrolytic solution E, and relatively moves them. Thereby, the surface of the conductor layer D1 of the device wafer D is formed with an electrochemical protective film, and at the same time, the protective film is mechanically removed and dissolved and removed electrochemically (dissolution removal step). Will be described later). That is, the polishing apparatus 50 can perform the electrochemical mechanical polishing (ECMP) of the conductor layer D1 by attaching the electrolytic solution supply apparatus 60.

Next, the configuration and the like of the electrolytic solution supply device 60 will be described.
2 to 5 are diagrams showing an electrolytic solution supply device 60. FIG.
2 is a perspective view, FIG. 3 (a) is a plan view (shown from the direction of arrow A shown in FIG. 2), and FIG. 3 (b) is a longitudinal sectional view (B shown in FIG. 3 (a)). -B section arrow sectional view). 4A is a partially enlarged view of FIG. 3 (within the two-dot chain line shown in FIG. 3B), and FIG. 4B is a diagram showing an example in which a part of the structure is changed. 5 is a cross-sectional view (a cross-sectional view taken along the line KK in FIG. 3B).
Each drawing emphasizes the thickness in order to make the configuration of each layer of the electrolytic solution supply device 60 easier to understand.
As shown in FIGS. 2 and 3, the electrolytic solution supply device 60 is a disk-shaped device provided with a plurality of electrolytic solution storage portions F (polishing liquid storage portions) for storing the electrolytic solution E. The electrolyte solution supply device 60 is provided in the center range of the upper surface, and is provided with an electrolyte solution injection port I (polishing solution injection port) for injecting the electrolyte solution E on the inside and a hollow shape on the inside. It has an electrolytic solution movement path M (polishing liquid movement path) for moving the electrolytic solution E. The injected electrolytic solution E is supplied from the lower side to the upper side of the polishing member layer 62 (described later) through the electrolytic solution movement path M and the electrolytic solution storage part F.
The electrolyte supply device 60 is provided with four contact conductors 61, and includes a polishing member layer 62 (polishing member), a conductive member layer 63 (power transmission unit), an insulating layer 64, and a conductive sheet layer 66. The base layer 67 and the adhesive tape 68 are laminated in this order from the upper side, and the rotary joint 69 is attached.

  The contact conductor 61 is a member for electrically conducting by contacting the conductor layer D1 of the device wafer D and forming an anode in the conductor layer D1 (see FIG. 4A). The contact conductor 61 is a material having a lower hardness than copper forming the conductor layer D1 (for example, a composite of carbon and an elastomer material) so that the conductor layer D1 is not damaged when contacting the conductor layer D1. Formed body, graphite and the like). In the present embodiment, the four contact conductors 61 are positioned at substantially equal angles (90 degrees in the present embodiment) at positions approximately equidistant from the center of the polishing pad surface of the polishing member layer 62 in the plan view. An example of arrangement is shown below. Moreover, the contact conductor 61 is arrange | positioned in parts other than the through-hole 62b which forms an electrolysis cell. The contact conductor 61 is provided such that its surface 61a protrudes a predetermined amount (for example, 0.5 mm or less) from the surface of the polishing member layer 62, and its lower surface is in contact with the conductive member layer 63 described later. Yes. As will be described later, the contact conductor 61 is supported by an insulating layer 64 formed of an elastic material so as to be movable in the vertical direction (direction in contact with the conductor layer D1). Thereby, the surface 61a of the contact conductor 61 can be displaced in this direction when contacting the conductor layer D1. (This displacement may be caused by elastic deformation of the contact conductor 61 itself).

Examples of the material of the contact conductor 61 include metals (gold, platinum, titanium alloys, copper, stainless steel, etc.) and carbon materials (carbon fibers mainly composed of carbon, graphite fibers, graphite, amorphous carbon, and synthetic resins). A composite carbon material, a composite carbon material with an elastomer material, composite graphite with a synthetic resin, or a combination thereof).
Contact between the contact conductor 61 and the conductor layer D1 may be any of point contact, line contact, and surface contact. However, the continuity by point contact or line contact causes the current density at the contact portion to be excessive because the total contact area is small even if the number of contact points is increased. As a result, there are problems such as heat generation and voltage drop, as well as problems such as damage to the conductor layer D1 due to pressure concentration due to the small contact area. For this reason, the contact method by surface contact (a diameter is about 5-20 mm) is suitable for the contact conductor 61. FIG. Further, when the contact conductor 61 is made of a material having a higher hardness than the conductor layer D1, such as metal or carbon, the surface of the contact conductor needs to be a mirror surface in order not to damage the conductor layer D1. . In the case of a material having a hardness lower than that of the conductor layer D1, natural graphite, a composite carbon material with a synthetic resin or an elastomer material is suitable as a material that does not damage, and natural graphite has a relatively large conductivity, It is most suitable as a material that does not damage the conductor layer D1.

  The polishing member layer 62 (polishing member) mechanically removes a protective film (described later) formed on the surface of the conductor layer D1 by moving relative to the conductor layer D1 of the device wafer D while being pressed. It is a member for doing. The polishing member layer 62 can move relative to the device wafer D when the platen 51 and the polishing head 52 (see FIG. 1) of the polishing apparatus 50 rotate. The polishing member layer 62 is a disk-shaped member, and is provided with a through hole 62b for forming a part of the electrolytic solution housing part F.

The polishing member layer 62 is a non-metallic and insulating urethane-based material (a foamed polyurethane material, a grooved foamed polyurethane material, a foamed polyurethane material having a cushion layer, etc.), or silica (silicon oxide). ) It is formed from a fixed abrasive polishing member or the like to which abrasive grains are fixed. As the material of the polishing member layer 62, a material obtained by impregnating the above-described non-metallic material with a thermosetting resin or an elastomer material may be used. In this case, it is preferable to use a thermosetting resin or an elastomer material in which abrasive grains are dispersed because the surface roughness of the conductor layer D1 can be reduced and polished to a mirror surface.
Further, the polishing member layer 62 may be formed by alternately arranging the above-described nonmetallic material and a sheet containing polishing abrasive grains perpendicular to the polishing surface. As this abrasive grain, silicon oxide, aluminum oxide, iron oxide, zinc oxide, silicon carbide, boron carbide, and synthetic diamond powder can be used alone or in combination.
Further, the polishing member layer 62 may be provided with concentric circular grooves or xy grooves (not shown) provided with a recessed surface. As a result, the contact pressure between the polishing member layer 62 and the conductor layer D1 increases, so that the frictional force with the conductor layer D1 increases, so that the efficiency of mechanical polishing can be improved. The electrolytic solution E can be discharged using the groove.

The conductive member layer 63 (power transmission portion) is a member for conducting power between the device-side electrode 55 (see FIG. 1) of the polishing apparatus 50 and the contact conductor 61, and is shown in FIGS. As shown, it is formed in a disk shape and is laminated below the polishing member layer 62. The conductive member layer 63 has an outer shape in plan view larger than that of the polishing member layer 62, and the exposed portion 63 a on the upper surface comes into contact with the device-side electrode 55, whereby the power of the power source 53 is supplied to the contact conductor 61. introduce. Further, the conductive member layer 63 is arranged so that the upper surface is electrically connected to the contact conductor 61 and supports the contact conductor 61 from the lower surface. The conductive member layer 63 is provided with a through hole 63b for forming a part of the electrolytic solution housing part F (see FIG. 4A).
The conductive member layer 63 is made of a low-resistance material such as metal (gold, copper, platinum, titanium alloy, stainless steel, carbon, or the like) or a carbon material (amorphous carbon mainly composed of carbon, carbon fiber, graphite fiber, graphite). , Composite carbon material with synthetic resin, composite carbon material with synthetic resin, and the like.

  As shown in FIG. 4B, an annular insulating member 70 may be provided in order to prevent a current (see arrow J) flowing from the conductive member layer 63 to the electrolytic solution housing part F. Thereby, the electrolyte supply device 60 can efficiently use the supplied power for electrolysis and dissolution of the conductor layer D1.

  The insulating layer 64 is a member for electrically insulating between the conductive member layer 63 and the conductive sheet layer 66, and is formed in a disk shape as shown in FIGS. The layer 63 is laminated below the layer 63. As shown in FIG. 4A, the insulating layer 64 is provided with a through hole 64 b for forming a part of the electrolytic solution housing part F. The insulating layer 64 is made of an elastic material such as an elastomer material in order to support the contact conductor 61 so as to be movable in the vertical direction. That is, the insulating layer 64 can simplify the configuration of the electrolytic solution supply device 60 by also using an elastic member for allowing the surface 61a of the contact conductor 61 to be displaced.

Since the contact conductor 61 is directly pressurized by the device wafer D, the pressing value of the contact conductor 61 is substantially equal to the polishing pressure. In ultra-low pressure polishing, the contact pressure is 6.9 × 10 ² to 6.9 × 10 ³ N / m ² (7 to 70 gf / cm ² , 0.1 to 1 psi). The insulating layer immediately below 61 is compressed, the contact conductor 61 moves in the vertical direction, and the conductor layer D 1 needs to be pressed against the polishing member layer 62. For example, when the polishing pressure is 6.9 × 10 ² N / m ² (7 gf / cm ² , 0.1 psi) and the contact conductor 61 protrudes 0.3 mm from the surface of the polishing member layer 62, the insulating layer 64 is It is necessary to select one having a longitudinal elastic modulus of 6.9 × 10 ³ N / m ² (70 gf / cm ² ) or less. Further, in order to bring the contact conductor 61 and the conductor layer D1 into stable contact and make them electrically conductive, the longitudinal elastic modulus of the insulating layer 64 is 4.9 × 10 ^{3 to} 6.9 × 10 ³ N. / M ² (50 to 70 gf / cm ² ) is preferable.

The conductive sheet layer 66 is a sheet member for forming a cathode, and is formed in a disk shape and laminated below the insulating layer 64 as shown in FIGS. As shown in FIG. 3B, the conductive sheet layer 66 closes the through hole 64b of the insulating layer 64 from the lower side, thereby forming the bottom of the electrolyte solution storage portion F, and the electrolyte solution storage portion F. A through hole 66a is provided for supplying the electrolyte solution E to the substrate. The conductive sheet layer 66 is electrically connected to a DC power source 53 (see FIG. 1), and when the electrolytic solution E is stored in the electrolytic solution storage part F, the conductive sheet layer 66 of the device wafer D that forms the anode. A cathode is formed on the counter electrode of the conductor layer D1.
The conductive sheet layer 66 can be used regardless of metal or non-metal as long as it is conductive and insoluble in the electrolyte solution E. As such a material, gold, platinum, titanium alloy, and the like can be used, but carbon, graphite, stainless steel, copper, and the like are preferable from an economic viewpoint.

The base layer 67 is a member that constitutes the foundation of the electrolytic solution supply device 60, and is formed in a disk shape and provided below the conductive sheet layer 66 as shown in FIGS. 3 and 4. The base layer 67 is provided with ribs 67c so as to have a gap between the upper plate 67a and the lower plate 67b, and the electrolyte solution movement path M is formed in a hollow shape inside.
As shown in FIG. 4A, the upper plate 67 a has a through hole 67 d that communicates with the through hole 66 a of the conductive sheet layer 66. The through-hole 66a and the above-described through-hole 67d are provided so as to penetrate the bottom of the electrolytic solution housing part F. The through-hole 66a and the through-hole 67d are through-holes that restrict the inflow of the electrolytic solution E from the electrolytic solution movement path M to the plurality of electrolytic solution storage portions F provided above the electrolytic solution moving path M (polishing solution inflow limiting penetration). The size of the opening hole is adjusted. The through hole 66a and the through hole 67d can directly adjust the electrolyte E flowing into the electrolyte container F.
The lower plate 67 b is fixed to the platen 51 using an adhesive tape 68 in order to place the electrolytic solution supply device 60 on the polishing device 50.

The rib 67c is a flow adjusting unit that adjusts the flow of the electrolytic solution E in the electrolytic solution movement path M. The rib 67c is composed of radial ribs 67e and 67f and tangential ribs 67g and 67h, as indicated by broken lines in FIG.
A total of 18 radial ribs 67e and 67f are provided in the radial direction of the electrolyte supply device 60. The tangential ribs 67g and 67h are provided so as to be orthogonal to the radial ribs 67e and 67f in the plan view, that is, in a direction perpendicular to the flow direction of the electrolytic solution E, respectively. The tangential rib 67g is a rib provided so as to contact a circle concentric with the center of the electrolyte supply device 60, and the tangential rib 67h is provided so as to contact a circle further outside the circle. Yes. The width of the tangential rib 67h is larger than the width of the tangential rib 67g. By being provided in such a shape, the tangential ribs 67g and 67h are subjected to a centrifugal force acting on the electrolytic solution E in the electrolytic solution movement path M by the rotational movement of the platen 51 (that is, the electrolytic solution supply device 60). Resist. Further, the degree of this resistance changes in accordance with the position in the radial direction (the radial direction) from the center toward the outside in accordance with the magnitude of the centrifugal force. The operation of the electrolytic solution E moving in the electrolytic solution movement path M will be described later.
Further, the rib 67c allows the base layer 67 and the electrolyte supply device 60 to maintain sufficient strength even if the inside is hollow.

  The rotary joint 69 is provided at the electrolyte injection port I, mechanically connected to the nozzle 56, and a member that can inject the electrolyte E into the electrolyte supply device 60 while the electrolyte supply device 60 is rotating. It is. Since the rotary joint 69 is provided at the center of the upper surface of the electrolytic solution supply device 60, the structure for injecting the electrolytic solution E into the rotating electrolytic solution supply device 60 can be simplified. Since the rotary joint 69 can obtain general-purpose parts inexpensively and stably from the market, the electrolyte supply device 60 can reduce the cost.

Next, the operation in which the electrolytic solution supply device 60 supplies the electrolytic solution E will be described.
Hereinafter, a part of the electrolyte solution movement path M shown in FIG. 5 will be described, but the same applies to other parts.
The electrolytic solution E that has passed through the nozzle 56 (see FIGS. 1 and 3) passes from the upper center of the rotating electrolytic solution supply device 60 to the inside through a rotary joint 69 provided in the electrolytic solution injection port I. Injected. As shown in FIG. 5, the injected electrolyte E moves radially outward from the center in the electrolyte movement path M (see arrow M1). At this time, the electrolytic solution E is rectified in the radial direction by the radial ribs 67e and 67f. As the electrolytic solution E moves in the radial direction, a larger centrifugal force is applied by the rotation of the electrolytic solution supply device 60. However, the electrolyte E has a force acting to resist the centrifugal force by the tangential rib 67g, and the portion Ma of the electrolyte moving path M is narrowed. Move inside at a constant speed. Further, the electrolytic solution E moved outward in the radial direction has a larger centrifugal force. However, the electrolytic solution E resists according to the magnitude of the centrifugal force by the tangential rib 67h having a width larger than that of the tangential rib 67g. The portion Mb in which the path M is narrowed moves in the electrolyte movement path M at a constant speed. Thus, the electrolytic solution E can move at a constant speed from the center to the outer periphery in the electrolytic solution movement path M by the action of the rib 67c which is a flow adjusting portion.

As shown in FIG. 4A, the electrolytic solution E that is moving through the electrolytic solution movement path M is transferred to the electrolytic solution storage part F by the polishing solution inflow restricting through hole formed by the through hole 66a and the through hole 67d. Inflow is limited.
The electrolyte E flowing into the electrolyte container F is supplied from the bottom of the electrolyte container F to the upper opening of the electrolyte container F, and then discharged. This discharge is most often performed when the device wafer D is moved from the upper opening by rotation. However, when the polishing member layer 62 is provided with a groove, the upper opening is covered by the device wafer D. Even when it is in the state, it is done efficiently.
As described above, the electrolytic solution supply device 60 can supply the electrolytic solution E almost uniformly to the plurality of electrolytic solution storage portions F, so that the uniformity of the polishing rate within the wafer surface can be improved.
The in-plane uniformity of the polishing rate refers to the uniformity of the polishing rate (polishing rate) within the surface of the conductor layer D1 when polishing the conductor layer D1 (for example, the polishing rate at the inner and outer circumferences). Degree of difference).

  In addition, conventionally, in order to supply the electrolytic solution so as to cover the surface of the polishing member layer, when the rotation speed of the platen is increased, a part of the electrolytic solution is scattered by the action of centrifugal force. The electrolytic solution supply device 60 supplies the electrolytic solution E from the lower side of the electrolytic solution storage part F. For this reason, since the electrolytic solution supply device 60 can prevent the electrolytic solution E from being scattered and supply the electrolytic solution E efficiently, the consumption amount of the electrolytic solution E can be reduced. Further, even when the rotational speed of the polishing member layer 62 is increased, the electrolytic solution E is efficiently supplied, and the electrolytic solution E can be uniformly filled in the plurality of electrolytic solution storage portions F. Thereby, since the electrolyte solution E can be brought into contact with the conductor layer D1 without unevenness, the in-plane uniformity of the polishing rate of the conductor layer D1 can be improved.

Next, formation of the electrolytic cell C at the time of polishing will be described.
In the state of FIG. 4A, the surface 61a of the contact conductor 61 is pushed down by contacting the conductor layer D1 of the device wafer D, and is displaced until the conductor layer D1 and the polishing member layer 62 contact each other. ing. This is because the insulating layer 64 is compressed and elastically deformed. As a result, when the electrolytic solution supply device 60 mechanically polishes the conductive layer D1, the contact conductive member 61 and the conductive layer D1 are reliably brought into contact with each other, and power is stably supplied to the conductive layer D1. can do.
In addition, since the conductive member layer 63 is provided below the polishing member layer 62 (see FIG. 4), the conductive member layer 63 does not come into contact with the conductive layer D1. Can be supplied.

As shown in FIG. 4A, during the polishing, the electrolytic solution container F of the electrolytic solution supply apparatus 60 is filled with the electrolytic solution E, and the upper opening thereof is a conductive member of the device wafer D. It will be in the state covered with the body layer D1. The conductor layer D1 is electrically connected to the positive electrode of the power source 53 (see FIG. 1) via the device-side electrode 55, the conductive member layer 63, and the contact conductor 61 (see FIG. 3). Therefore, it becomes an anode. On the other hand, the conductive sheet layer 66 becomes a cathode because it is electrically connected to the negative electrode of the power supply 53.
By forming the conductor layer D1 as an anode, the copper forming the conductor layer D1 is dissolved and removed by an electrochemical reaction by “Cu → Cu ²⁺ + 2e ⁻ ”.

In addition, it is necessary to form the diameter of the electrolyte container F smaller than the diameter of the device wafer D. When the cross section is circular, the diameter is preferably 10 to 100 mm. Further, it is desirable that the thickness is 15 to 30 mm in order to improve the uniformity of the polished wafer surface. The reason why the diameter is set to this size is that when the diameter is 10 mm or less, the depth of the electrolytic solution containing portion F increases with respect to the diameter, and thus the electrolytic solution E is stably brought into contact with the conductor layer D1. This is to prevent this.
The ratio of the total opening area of the electrolyte container F to the total area of the electrolyte supply device 60 (the area of the upper surface of the polishing member layer 62 (including the opening of the electrolyte container F)) is 20 to 80%. Preferably there is. Furthermore, 40 to 60% is also desirable for improving the uniformity of the polished wafer surface. The reason is that if this ratio is too small, the electrochemical polishing efficiency decreases, and if it is too large, the electrical resistance of the conductive member layer 63 becomes too large, and the mechanical polishing efficiency decreases and the flatness deteriorates. It is. Moreover, the electrolyte solution accommodating part F should just be formed with the some opening in the electrolyte solution supply apparatus 60, and the cross section is not limited to a circle, A polygon may be sufficient. Furthermore, the electrolytic solution storage part F may be formed in a ring-shaped or linear opening, instead of a circular or polygonal hole.

Next, the polishing process for the device wafer D will be described.
FIG. 6 is a longitudinal sectional view showing a polishing process of the device wafer D by the electrolytic solution supply apparatus 60. 6A shows a state before polishing, FIGS. 6B to 6E show a state during polishing, and FIG. 6F shows a state after polishing. In the following description, the polishing surface (lower surface in the figure) is referred to as the lower surface, and the opposite surface is referred to as the upper surface (upper surface in the drawing).
First, the configuration of the device wafer D will be described.
As shown in FIG. 6A, before polishing, the device wafer D is laminated with a conductor layer D1, a barrier metal D2, and an interlayer insulating film D3 from the lower layer side. (In the figure, the transistor portion is omitted.)

  The conductor layer D1 is a layer for configuring the wiring of the device wafer D, and is formed by laminating copper using a technique such as plating. The conductor layer D1 is polished so that the portion laminated in the wiring groove D3a provided by recessing the lower surface of the interlayer insulating film D3 remains (see FIG. 6F), thereby obtaining the device wafer D. Wiring inside. In the conductor layer D1, a depression (concave portion D1a) may be formed in a portion of the interlayer insulating film D3 laminated in the range of the wiring groove D3a. However, even if the recess D1a is formed in the conductor layer D1, the electrolyte supply device 60 of the present embodiment can uniformly polish the conductor layer D1 as described later.

The barrier metal D2 is provided to prevent the metal atoms of the conductor layer D1 from migrating to the interlayer insulating film D3. As this barrier metal D2, a material having a high melting point and conductivity, for example, a metal nitride such as tantalum nitride or titanium nitride can be used.
The interlayer insulating film D3 is an insulating layer (film) for insulating between the layers of the device wafer D.

Next, the polishing process for the device wafer D will be described.
In the state shown in FIG. 6A, the conductive layer D1 of the device wafer D and the conductive sheet layer 66 of the electrolytic solution supply device 60 come into contact with each other, and the electrolytic cell C (see FIG. 4A) The surface layer on the lower surface of the layer D1 is dissolved and removed. When dissolution and removal of the conductor layer D1 proceed, as shown in FIG. 6B, the surface of the lower surface of the conductor layer D1 is formed by the action of the protective film forming agent (anticorrosive and surfactant) of the electrolyte E. An electrochemical protective film G (copper complex layer) is formed, which becomes a passive film, and the dissolution of the conductor layer D1 stops.
Since the polishing member layer 62 (see FIG. 4A) of the electrolytic solution supply apparatus 60 is moved relative to the device wafer D by the polishing apparatus 50 (see FIG. 1), the protective film G is mechanical. Removed. At this time, since the protective film G formed in the concave portion D1a does not contact the polishing member layer 62, only the protective film G formed on the convex portions D1c and D1d of the conductor layer D1 is removed.

Then, as shown in FIG. 6C, if the copper of the convex portions D1c and D1d of the conductor layer D1 is exposed, only the exposed portions are dissolved and removed by the electrolytic cell C and formed again. The protective film G is mechanically removed.
The steps as described above are repeated instantaneously, and the electrolytic solution supply device 60 polishes the conductive layer D1 electrochemically and mechanically so that the removal rate of the convex portions D1c and D1d is faster than that of the concave portion D1a. it can. And the electrolyte solution supply apparatus 60 can make the surface of the conductor layer D1 into a plane as shown in FIG.6 (d).

  In the state of FIG. 6D, since the lower surface of the conductor layer D1 is flat, the portion up to the lower surface of the barrier metal D2 (the portion in the range H1 shown in FIG. 6D) is electrically charged at the same polishing rate. It is removed chemically and mechanically and the state shown in FIG.

  In the state of FIG. 6E, the device wafer D is in a state where the conductor layer D1 and the barrier metal D2 are exposed on the lower surface. In the case of multilayer wiring, the interlayer insulating film D3 is exposed (state shown in FIG. 6F), and an interlayer insulating film is further deposited thereon. For this reason, it is necessary to remove the conductor layer D1 and the surface layer of the lower surface of the barrier metal D2 made of a material different from that of the conductor layer D1 (the portion in the range H2 shown in FIG. 6E) to the surface of the interlayer insulating film D3 at the same time. is there. These removals are performed by conventional chemical mechanical polishing (CMP) as the second step using the above-described multi-platen / multi-head type polishing apparatus. Further, when it is necessary to correct the dishing (a state in which the conductor layer D1 is excessively polished and removed), the interlayer insulating film D3 is chemically and mechanically polished as a third step.

  As described above, the electrochemical mechanical polishing is to polish the conductor layer D1 of the device wafer D from the state shown in FIGS. 6A to 6E, and form an electrical protective film. Further, mechanical removal of the protective film and dissolution removal (electrochemical removal) of copper are performed in a well-balanced manner, and planarization can be performed while maintaining a high polishing rate and in-plane uniformity.

  As described above, the electrolytic solution supply device 60 (polishing solution supply device) of this embodiment is attached to a platen / rotary type chemical mechanical polishing (CMP) device having a multi-platen / multi-head. It can be used for electrochemical mechanical polishing of the device wafer D.

Further, the electrolytic solution E is injected into the electrolytic solution supply device 60 from the electrolytic solution injection port I provided in a substantially central range on the upper surface of the electrolytic solution supply device 60, and the polishing member layer is passed through the electrolytic solution movement path M. 62 (abrasive member) is supplied from the lower side to the upper side.
Accordingly, the electrolytic solution supply device 60 can prevent the electrolytic solution E from being scattered from the polishing member layer 62, and can supply the electrolytic solution E more efficiently than supplying the electrolytic solution E so as to cover the surface of the polishing member layer 62. Therefore, the consumption amount of the electrolytic solution E can be reduced. Further, since the rotation speed of the polishing member layer 62 can be increased, the in-plane uniformity of the polishing speed of the conductor layer D1 (object to be polished) can be improved.

Further, the ribs 67c (radial ribs 67e and 67f, tangential ribs 67g and 67h) are flow adjusting portions that adjust the flow of the electrolytic solution E in the electrolytic solution movement path M. That is, the radial ribs 67e and 67f rectify the electrolytic solution E in the electrolytic solution movement path M in the radial direction. Further, the tangential ribs 67g and 67h are provided so as to resist the centrifugal force acting on the electrolyte E, and the degree of resistance is radial from the center toward the outside depending on the magnitude of the centrifugal force. It is provided so as to change according to the position in the radial direction.
Thereby, since the electrolytic solution supply apparatus 60 can reduce the influence of the centrifugal force acting on the electrolytic solution E in the electrolytic solution movement path M, the electrolytic solution E can be moved at a uniform speed.

Furthermore, since the polishing liquid inflow restricting through hole formed by the through hole 66a and the through hole 67d restricts the inflow of the electrolytic solution E into the electrolytic solution storage part F, the electrolytic solution supply device 60 has an electrolytic solution storage. The electrolyte E flowing into the part F can be adjusted to be appropriate directly.
That is, in the electrolytic solution supply device 60, the flow adjusting unit and the polishing liquid inflow restriction through-hole can adjust the flow of the electrolytic solution E and adjust the inflow amount to the electrolytic solution storage unit F for each electrolytic solution storage unit F. it can. For this reason, it can prevent that the level of electrolyte solution becomes non-uniform | heterogenous between the electrolyte solution accommodating parts F, and can fill the electrolyte solution E fully in each electrolyte solution accommodating part F, and can form the electrolytic cell C reliably. . (If there is a bias in the formation location of the electrolysis cell C, the wafer polishing will also be biased). And the in-plane uniformity of a grinding | polishing speed can be improved and the in-plane uniformity of the conductor layer D1 can be improved.

Next, a second embodiment of the electrolytic solution supply apparatus (polishing liquid supply apparatus) to which the present invention is applied will be described.
The electrolyte solution supply device 160 of Example 2 is obtained by changing the shape of the electrolyte solution storage portion F of the electrolyte solution supply device 60 of Example 1 and changing the arrangement of the conductive sheet layer 66.
In the following description, parts having the same functions as those in the above-described first embodiment are given the same names, and redundant descriptions are omitted as appropriate.
7 and 8 are diagrams showing the electrolytic solution supply device 160. FIG.
7A is a plan view, FIG. 7B is a vertical cross-sectional view (a cross-sectional view taken along the line 2B-2B shown in FIG. 7A), and FIG. 8 is a partially enlarged view of FIG. It is a figure (within the dashed-two dotted line shown in FIG.7 (b)).
As shown in FIG. 7, the electrolyte solution storage unit 2F (polishing solution storage unit) of the electrolyte solution supply device 160 is formed so that the size of the opening hole is smaller than that of the electrolyte solution storage unit F of Example 1. (See FIG. 3). As shown in FIG. 8, the electrolyte container 2 </ b> F is formed by through holes 162 b, 163 b, and 164 b provided in the polishing member layer 162, the conductive member layer 163, and the insulating layer 164. The through hole 164b is a polishing liquid inflow restricting through hole that restricts the inflow of the electrolytic solution E from the electrolytic solution moving path 2M (polishing liquid moving path) to the electrolytic solution storage portion 2F, and the size of the opening hole is adjusted. Yes.
The conductive sheet layer 166 is disposed below the electrolyte solution movement path 2M, and is provided so as to also serve as the lower plate 67b of the base layer 67 of the first embodiment.
The base layer 167 is provided with ribs 167c similar to the ribs 67c of the first embodiment (illustration in the plan view is omitted). The rib 167c is a flow adjusting unit that adjusts the flow of the electrolytic solution E in the electrolytic solution movement path 2M.

At the time of polishing, as shown in FIG. 8, the electrolytic solution supply device 160 is formed from the conductive layer D1 as an anode, the conductive sheet layer 166 as a cathode, and the electrolytic solution storage part 2F and the electrolytic solution movement path 2M. The electrolytic cell 2C to be formed is formed.
Even with such a configuration, the electrolytic solution supply device 160 restricts the electrolytic solution E in the electrolytic solution moving path 2M to move at a constant speed and to appropriately flow into the electrolytic solution storage unit 2F. can do. Thereby, the electrolyte solution E can be supplied efficiently, the consumption amount of the electrolyte solution E can be reduced, and the in-plane uniformity of the polishing rate of the conductor layer D1 can be improved.

Next, a third embodiment of the electrolytic solution supply apparatus (polishing liquid supply apparatus) to which the present invention is applied will be described.
The electrolyte solution supply device 260 of Example 3 is obtained by changing the shape of the electrolyte solution storage unit 2F of Example 2.
As shown in FIG. 9, the electrolyte container 3 </ b> F of the electrolyte supply device 260 includes a plurality of conductive holes 263 b and 264 b provided in the conductive member layer 263, the insulating layer 264, and a plurality ( In this embodiment, it is formed of three through holes 262b.
Even with the structure as described above, in the electrolytic solution supply device 260, the through hole 262b functions as a polishing liquid inflow restricting through port that restricts the inflow of the electrolytic solution E into the electrolytic solution storage unit 3F, and is the same as in the second embodiment. An effect can be obtained.

Next, Example 4 of the electrolytic solution supply apparatus (polishing liquid supply apparatus) to which the present invention is applied will be described.
The electrolyte solution supply device 360 according to the fourth embodiment is obtained by changing the shape of the rib 67c of the base layer 67 according to the first embodiment.
FIG. 10 is a longitudinal sectional view showing the electrolytic solution supply device 360. In FIG. 10, the structure above the electrolyte movement path 3M (polishing liquid movement path), that is, the structure from the polishing member layer to the conductive sheet layer is shown in a simplified manner.
As shown in FIG. 10, the tangential ribs 367 a, 367 b, 367 c (flow adjusting portions) of the base layer 367 are provided in a direction perpendicular to the flow direction of the electrolytic solution E. As shown by a two-dot chain line, the tangential ribs 367a, 367b, and 367c have a higher rib height toward the outer side in the radial direction. In other words, the tangential ribs 367a, 367b, and 367c change in accordance with the position in the radial direction (radial direction) from the center toward the outside so that the degree of resistance to the centrifugal force corresponds to the magnitude of the centrifugal force. It is provided to do.
A plurality of the tangential ribs 367a, 367b, and 367c may be provided in a planar shape so as to have a predetermined length in the same manner as the tangential ribs 67g and 67h (see FIGS. 3 and 5) of the first embodiment. Although it is good, you may provide so that it may become a circle which has a predetermined diameter. That is, the tangential rib 367a may be a circle concentric with the center of the electrolyte supply device 360, the tangential rib 367b may be an outer circle, and the tangential rib 367c may be an outermost circle. .
In order to rectify the electrolyte E, the base layer 367 may be appropriately provided with radial ribs (see the radial ribs 67e and 67f shown in FIG. 5) as necessary.

With the structure as described above, the tangential ribs 367a, 367b, and 367c (flow adjusting portions) have the electrolytic solution in the electrolytic solution moving path 3M even if the centrifugal force varies depending on the positions of the inner and outer circumferences. The force acting on E and the moving speed of the electrolytic solution E can be adjusted to be uniform. Thereby, the electrolyte solution supply device 360 can stably supply the electrolyte solution E.
Further, since the tangential ribs 367a, 367b, and 367c have a rib structure, the degree of resistance to centrifugal force can be easily adjusted by adjusting the height and the like, and the structure can be simplified. Can do.

Next, a fifth embodiment of the electrolytic solution supply apparatus (polishing liquid supply apparatus) to which the present invention is applied will be described.
The electrolytic solution supply device 460 of the fifth embodiment is obtained by providing the electrolytic solution supply device 60 of the first embodiment with an electrolytic solution supply suppressing member 470 (polishing liquid supply suppressing member).
FIG. 11 is a perspective view showing the electrolytic solution supply device 460 and the like.
The electrolytic solution supply suppressing member 470 is provided so as to cover the area of the upper surface of the polishing member layer 62 where the conductor layer D1 (object to be polished) of the device wafer D is not in contact. The electrolytic solution supply suppressing member 470 suppresses the supply of the electrolytic solution E to this range by closing the upper opening of the electrolytic solution storage unit in this range.
Thereby, the electrolyte solution supply suppressing member 470 can reduce the consumption of the electrolyte solution E that is discharged without being used for polishing, and can suppress the polishing cost.

Next, a sixth embodiment of the electrolytic solution supply apparatus (polishing liquid supply apparatus) to which the present invention is applied will be described.
The electrolyte solution supply device 560 of Example 6 is obtained by providing the electrolyte solution supply device 60 of Example 1 with an electrolyte solution holding material 580 (polishing solution holding material).
FIG. 12 is a longitudinal sectional view of the electrolytic solution supply device 460.
As shown in FIG. 12, in the electrolytic solution storage portion 4F (polishing liquid storage portion), the diameter of the through hole 564b of the insulating layer 564 is larger than the diameters of the through holes 562b and 563b of the polishing member layer 562 and the conductive member layer 563. Is also formed large. That is, the electrolytic solution storage part 4F is formed in an undercut shape.
The electrolyte solution holding material 580 is formed in a stepped cylindrical shape with a large lower diameter, and is filled in the electrolyte solution storage portion 4F. The electrolyte solution holding material 580 is formed to be slightly larger than the inner diameter of the electrolyte solution storage portion 4F and is press-fitted into the electrolyte solution storage portion 4F. The electrolyte solution holding member 580 has a through hole 580a coaxial with the central axis of the through hole 66a and the through hole 67d of the conductive sheet layer 66 and the base layer 67.
Electrolyte holding material 580 is made of continuous foam (urethane foam (sponge), etc.), non-woven cloth, felt or other fibrous body (PET (polyethylene terephthalate)) to ensure ionic conductivity between the anode and cathode. PE (polyethylene), PP (polypropylene), nylon (polyamide), and cellulose (including cotton)) are preferable.

The flow of the electrolytic solution E will be described. The electrolytic solution E that has passed through the electrolytic solution movement path M flows into the electrolytic solution storage part 4F through the through hole 66a and the through hole 67d, and a part of the electrolytic solution E is retained. The material 580 is held in the electrolyte solution storage portion 4F by the capillary phenomenon. Thereby, the electrolytic solution holding material 580 can prevent the polishing liquid E in the electrolytic solution storage part 4F from being blown off by centrifugal force.
Further, when the electrolytic solution E flows into the electrolytic solution storage part 4F, the electrolytic solution holding member 580 has a through hole 580a, and therefore can smoothly flow in the electrolytic solution E. Can relieve the force. Furthermore, since the electrolytic solution holding material 580 is press-fitted into the electrolytic solution storage portion 4F formed in an undercut shape, the electrolytic solution holding material 580 can remain stably in the electrolytic solution storage portion 4F.

By the way, the electrolytic solution supply device 560 is, for example, the level of the level of the polishing liquid E (electrolytic solution) in each electrolytic solution storage unit 4F when changing the rotation speed of the platen or changing the viscosity of the polishing liquid. Adjustment may be necessary. It is difficult to adjust the level of the electrolytic solution E by changing the shape or the like of the polishing liquid supply device every time the rotation speed of the platen is changed.
The electrolyte supply device 560 can perform this adjustment by selectively filling a part of the plurality of electrolyte storage units 4F with the polishing liquid holder 580. Filling the electrolytic solution holding part 4F with the electrolytic solution holding member 580 can be easily performed because the electrolytic solution supply device 560 can be attached to the platen from the outside of the device. In the present embodiment, the electrolyte solution holding material 580 is filled in the outer three electrolyte solution storage portions 4F having a large centrifugal force, and the level of the polishing liquid E in each electrolyte solution storage portion 4F on the inner and outer periphery. Adjustments are made so that the level is uniform. Thereby, since the electrolytic solution supply apparatus 560 can reliably form the electrolytic cell C in each electrolytic solution storage portion 4F, the in-plane uniformity of the polishing rate can be improved.

  Furthermore, in electrochemical mechanical polishing, the Cu film attached to the cathode due to electrochemical action may peel off and damage the conductor layer D1. Since the Cu film peeled off by 580 can be prevented from floating in the electrolyte solution storage portion 4F, this damage can be prevented.

Next, a seventh embodiment of the electrolytic solution supply apparatus (polishing liquid supply apparatus) to which the present invention is applied will be described.
The electrolyte solution supply device 660 of Example 7 is obtained by changing the shape of the electrolyte solution movement path M of the electrolyte solution supply device 60 of Example 1.
13A and 13B are diagrams showing an electrolytic solution supply apparatus according to Example 7. FIG. 13A is a plan view showing a part thereof, and FIG. 13B is a longitudinal sectional view (L in FIG. 13A). -L section arrow sectional view). FIG. 13B shows a simplified layer structure of the electrolytic solution supply apparatus.
As shown in FIG. 13 (a), the electrolyte supply device 660 has a plurality (eight in the present embodiment) of electrolyte movement paths 7M (polishing liquid movement paths) centered on the electrolyte injection port I. They are arranged radially. The electrolyte solution movement path 7M has a tubular shape with a narrower width toward the outer periphery and a shallow bottom portion 7Ma (see FIG. 13B). That is, since the electrolyte movement path 7M is formed so as to narrow toward the outer periphery, the degree of resistance to centrifugal force is the magnitude of the centrifugal force acting on the polishing liquid E in the electrolyte movement path 7M. Accordingly, it changes in accordance with the position in the radial direction (the radial direction) from the center toward the outside. For this reason, the electrolytic solution moving path 7M can adjust the amount of the polishing liquid E flowing into the polishing liquid container F depending on the position in the radial direction, and the level of the polishing liquid E between the polishing liquid containers F. (That is, the electrolyte movement path 7M itself is a flow adjusting unit that adjusts the flow of the polishing liquid E). Thereby, since the electrolytic solution holding material 580 can reliably form the electrolytic cell C in each electrolytic solution storage portion F, the in-plane uniformity of the polishing rate can be improved.

By the way, the electrolytic solution supply apparatus 560 needs to periodically clean the polished surface with water or the like. At this time, since the cleaning water enters the polishing liquid storage portion F, it is necessary to rotate the platen at a high speed to discharge the cleaning water in the polishing liquid storage portion F. In this case, the polishing liquid E is added together. It will be discharged.
In this cleaning process, the electrolytic solution movement path M of Example 1 is formed in a hollow shape and has a large volume, so that a large amount of the polishing solution E is discharged, so that the consumption amount of the polishing solution E increases. In comparison, since the electrolyte solution movement path 7M of the present embodiment is formed in a tubular shape and has a small volume, the amount of the polishing liquid E to be discharged can be reduced and the consumption amount of the polishing liquid E can be reduced. Can be further reduced.

  As described above, the electrolytic solution supply apparatus 560 of the present embodiment can improve the in-plane uniformity of the polishing rate, and can reduce the consumption of the polishing solution E and further reduce the polishing cost. it can.

(Modification)
The present invention is not limited to the embodiments described above, and various modifications and changes are possible, and these are also within the equivalent scope of the present invention.
(1) In each embodiment, the electrolytic solution supply apparatus (polishing liquid supply apparatus) is an example in which the polishing liquid is an electrolytic solution and is used for electrochemically polishing a device wafer. It is not limited to. For example, in this apparatus (polishing liquid supply apparatus), the polishing member layer (polishing member) is made of polyurethane or foamed polyurethane, the polishing liquid is a chemical mechanical polishing liquid, and the polishing member layer is against the object to be polished. You may use for the chemical mechanical polishing apparatus which moves relatively, pressing. This also makes it possible for the polishing liquid supply device to efficiently supply the polishing liquid, reduce the consumption of the polishing liquid, reduce the polishing cost, and to open the upper opening of the polishing liquid container having a certain opening area. From the portion, a sufficient polishing liquid can be supplied to the polishing surface of the polishing member layer.
Further, this apparatus (polishing liquid supply apparatus) includes a polishing member layer formed of a fixed abrasive polishing member in which silicon oxide abrasive grains are fixed, the polishing liquid is, for example, a weak alkaline aqueous solution, and the polishing member layer is Even when used in a chemical mechanical polishing apparatus that moves relative to the object to be polished, sufficient polishing liquid (weak alkaline aqueous solution) can be supplied to the polishing surface of the polishing member layer.
Further, this polishing liquid supply apparatus can obtain the same effect even when used for mechanical polishing in which the polishing liquid is a mechanical polishing liquid and the polishing member layer moves relative to the object to be polished while pressing. It is done.

(2) In each example, the flow adjusting part such as the tangential rib, the through hole (polishing liquid inflow restricting through hole) at the bottom of the electrolyte container, the polishing liquid holding material, etc., according to the position in the radial direction, Although an example of changing the shape has been shown, the present invention is not limited to this. For example, you may increase / decrease the number of the grinding | polishing liquid holding | maintenance materials with which it fills according to the rotational speed (centrifugal force) at the time of grinding | polishing.

It is a perspective view which shows the grinding | polishing apparatus to which the electrolyte solution supply apparatus of Example 1 is attached. 1 is a perspective view showing an electrolytic solution supply apparatus of Example 1. FIG. It is the top view and longitudinal cross-sectional view which show the electrolyte solution supply apparatus of Example 1. FIG. 1 is a partially enlarged view showing an electrolytic solution supply apparatus of Example 1. FIG. 1 is a transverse cross-sectional view showing an electrolytic solution supply apparatus of Example 1. FIG. FIG. 4 is a longitudinal sectional view showing a polishing step by the electrolytic solution supply apparatus of Example 1. It is the top view which shows the electrolyte solution supply apparatus of Example 2, and a longitudinal cross-sectional view. 6 is a partially enlarged view showing an electrolytic solution supply apparatus of Example 2. FIG. 6 is a longitudinal sectional view showing an electrolytic solution supply apparatus of Example 3. FIG. 6 is a longitudinal sectional view showing an electrolytic solution supply apparatus according to Example 4. FIG. 10 is a perspective view showing an electrolytic solution supply apparatus according to Embodiment 5. FIG. 6 is a longitudinal sectional view showing an electrolytic solution supply apparatus according to Embodiment 6. FIG. It is the top view which shows the electrolyte solution supply apparatus of Example 7, and a longitudinal cross-sectional view. It is a figure which shows the supply method of the electrolyte solution by a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 50 Polishing apparatus 51 Platen 52 Polishing head 53 Power supply 55 Apparatus side electrode 56 Nozzle 60,160,260,360,460,560,660 Electrolyte supply apparatus 61 Contact conductor 62,162,262,562 Polishing member layer 63,163 , 263, 563 Conductive member layer 64, 164, 264, 564 Insulating layer 66, 166 Conductive sheet layer 67, 367 Base layer 67c Rib 67e, 67f Radial rib 67g, 67h Tangential rib 69 Rotary joint 367a, 367b, 367c Tangential rib 470 Electrolyte supply suppression member 580 Electrolyte holding material C Electrolytic cell D Device wafer D1 Conductor layer D2 Barrier metal D3 Interlayer insulating film E Electrolyte F, 2F, 3F, 4F Electrolyte container I Electrolyte inlet M, 2M, 3M, 7M Electrolyte moving path

Claims (25)

In a polishing liquid supply apparatus that is attached to a rotating platen of a platen / rotary type polishing apparatus and supplies a polishing liquid to a polishing member provided on the upper side,
A polishing liquid inlet for injecting the polishing liquid on the inside, provided in a substantially central range of the upper surface;
It is provided in a hollow shape inside, and has a polishing liquid moving path for moving the polishing liquid,
The polishing liquid is injected from the polishing liquid injection port, and is supplied from the lower side to the upper side of the polishing member via the polishing liquid moving path;
A polishing liquid supply apparatus. In the polishing liquid supply apparatus according to claim 1,
Provided above the polishing liquid movement path, the polishing member has a plurality of polishing liquid storage portions forming at least a part thereof,
The polishing liquid is supplied from the bottom of the polishing liquid container to the upper opening of the polishing liquid container;
A polishing liquid supply apparatus. In the polishing liquid supply apparatus according to claim 2,
The polishing liquid is an electrolytic solution,
The object to be polished is a conductor layer of a device wafer,
The conductive layer is brought into contact with the electrolytic solution accommodated in the polishing liquid accommodating portion, whereby the conductive layer becomes an anode, and the anode and the cathode that is a counter electrode with respect to the anode An electrolytic cell is formed by contacting the electrolytic solution and applying a voltage, and the polishing member polishes the conductor layer electrochemically and mechanically;
A polishing liquid supply apparatus. In the polishing liquid supply apparatus according to claim 3,
The cathode is formed at the bottom of the polishing liquid container;
A polishing liquid supply apparatus. In the polishing liquid supply apparatus according to claim 1,
The polishing liquid moving path has a flow adjusting section for adjusting the flow of the polishing liquid;
A polishing liquid supply apparatus. In the polishing liquid supply apparatus according to claim 5,
The flow adjusting unit is provided so as to resist the centrifugal force acting on the polishing liquid in the polishing liquid moving path by the rotational movement of the rotary platen;
A polishing liquid supply apparatus. In the polishing liquid supply apparatus according to claim 6,
The flow adjusting unit is changing in accordance with the position in the radial direction from the center toward the outside so that the degree of resistance corresponds to the magnitude of the centrifugal force;
A polishing liquid supply apparatus. In the polishing liquid supply apparatus according to claim 5,
The flow adjusting portion is provided in a rib shape in a direction substantially perpendicular to the flow direction of the polishing liquid;
A polishing liquid supply apparatus. In the polishing liquid supply apparatus according to claim 5,
A plurality of polishing liquid containers provided above the polishing liquid movement path;
A polishing liquid inflow restricting through-hole that is provided through the bottom of the polishing liquid container and restricts the inflow of the polishing liquid into the polishing liquid container;
A polishing liquid supply apparatus. In the polishing liquid supply apparatus according to claim 3,
A polishing liquid holding material that is filled in the polishing liquid container and holds the polishing liquid in the polishing liquid container;
A polishing liquid supply apparatus. In the polishing liquid supply apparatus according to claim 10,
The polishing liquid holding material is formed from a continuous foam, a nonwoven fabric, a woven fabric or a felt,
A polishing liquid supply apparatus. In the polishing liquid supply apparatus according to claim 1,
The polishing liquid inlet has a rotary joint capable of injecting the polishing liquid in a state where the apparatus is rotating;
A polishing liquid supply apparatus. In the polishing liquid supply apparatus according to claim 1,
A polishing liquid supply suppressing member that is provided so as to cover a range of the upper surface of the polishing member that is not in contact with the object to be polished, and that suppresses the supply of the polishing liquid in the range;
A polishing liquid supply apparatus. In the polishing liquid supply apparatus according to claim 3,
A contact conductor that is in contact with the conductor layer and is electrically conductive;
A polishing liquid supply apparatus. In the polishing liquid supply apparatus according to claim 14,
The contact conductor is provided so as to protrude from the surface of the polishing member, is pressed down by contacting the conductor layer, and can be displaced until the conductor layer and the polishing member are in contact with each other. ,
A polishing liquid supply apparatus. In the polishing liquid supply apparatus according to claim 14,
The contact conductor has a mirror surface.
A polishing liquid supply apparatus. In the polishing liquid supply apparatus according to claim 14,
The contact conductor is made of gold, platinum, titanium alloy, copper or stainless steel;
A polishing liquid supply apparatus. In the polishing liquid supply apparatus according to claim 14,
The contact conductor is any one of carbon fiber containing carbon as a main component, graphite fiber, graphite, amorphous carbon, composite carbon material with synthetic resin, composite carbon material with elastomer material, and composite graphite with synthetic resin. One or a combination thereof,
A polishing liquid supply apparatus. In the polishing liquid supply apparatus according to claim 14,
A power transmission unit that is provided below the contact conductor and transmits power to the contact conductor;
A polishing liquid supply apparatus. In the polishing liquid supply apparatus according to claim 19,
The power transmission part is made of gold, copper, platinum, titanium alloy, stainless steel or carbon;
A polishing liquid supply apparatus. In the polishing liquid supply apparatus according to claim 19,
The power transmission part is formed of amorphous carbon mainly composed of carbon, carbon fiber, graphite fiber, graphite, composite carbon material with synthetic resin, or composite carbon material with synthetic resin,
A polishing liquid supply apparatus. In the polishing liquid supply apparatus according to claim 1,
The polishing liquid is a chemical mechanical polishing liquid,
The polishing member is formed of polyurethane or foamed polyurethane, and is chemically and mechanically polished by moving relative to the object to be polished while being pressed.
A polishing liquid supply apparatus. In the polishing liquid supply apparatus according to claim 1,
The polishing member is formed from a fixed abrasive polishing member to which silicon oxide abrasive grains are fixed, and is subjected to chemical mechanical polishing by moving relatively while pressing against the object to be polished.
A polishing liquid supply apparatus. It is attached to the polishing liquid supply apparatus according to any one of claims 1 to 23,
The polishing liquid is supplied from below and polishing the object to be polished;
A polishing member characterized by the above. A polishing liquid supply device according to any one of claims 1 to 23 and a polishing member according to claim 24,
A polishing liquid supply apparatus with a polishing member.

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