JP2007149949A - Polishing pad for device wafer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polishing pad for device wafers capable of polishing a conductive layer in a device wafer electrochemically and mechanically by improving flatness and uniformity in a wafer surface and using an electrolytic cell. <P>SOLUTION: The polishing pad 60 is mounted to a polishing apparatus 50, and a polishing member layer 62 is pressed against the conductive layer D1 and is moved relatively, thus mechanically removing an electrochemical protective film (passivated film) formed on the conductive layer D1. The electrolytic cell is formed by the conductive layer D1, a conductive sheet layer 66, and an electrolyte E, thus dissolving and removing the conductive layer D1 electrochemically. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a polishing pad for a device wafer for electrochemically polishing a conductor layer formed on a semiconductor wafer.

In semiconductor devices (semiconductor devices), wirings are stacked with high integration and miniaturization. That is, a process is employed in which a wiring material is patterned on the surface of a semiconductor wafer, this is covered with an insulator such as silicon oxide, the next wiring material is patterned, and this is repeated in sequence.
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 the 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) are proposed in place of CMP. Has been.

(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, 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 in-plane uniformity of the wafer deteriorates. There was a drawback that stable polishing was not possible.

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 electrochemical polishing using a platen / rotary type polishing apparatus or the like.
This electrochemical polishing method uses a platen / rotary type polishing apparatus or the like, and can be freely used for electrochemical polishing by simply attaching a polishing pad to one platen / head of a multi-platen / multi-head. Therefore, multi-step polishing combining electrochemical 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 flatness and wafer in-plane uniformity, it is conceivable to increase the polishing pressure of the polishing pad with respect to the copper wiring material and 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.
Further, in order to increase the relative speed, it is necessary to increase the rotation speed of the platen in the case of a platen rotary type polishing apparatus. 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 within the wafer surface may be deteriorated.
Furthermore, there is a problem that the conductor layer formed in the wiring groove is dissolved and removed at a rate similar to that of the conductor layer on the wafer surface.
JP 2003-193300 A JP-T-2004-531885 Pub. No. US 2004/0214510 A1 JP-A-2005-139480

  SUMMARY OF THE INVENTION An object of the present invention is to provide a polishing pad for a device wafer in which the conductor layer of the device wafer can be polished electrochemically and mechanically using an electrolytic cell by improving flatness and uniformity within the wafer surface. That is.

  In order to solve the above problems, the invention of claim 1 includes a plurality of electrolyte solution storage portions (F) for storing the electrolyte solution (E), and the conductor layer (D1) of the device wafer (D) is an anode. The electrolytic solution (E) is brought into contact with the cathode of the counter electrode of the anode to form an electrolytic cell (C), and a voltage is applied to electrochemically polish the conductor layer (D1). In the polishing pad to be pressed, the mechanical polishing layer (C1) that polishes the conductive layer (D1) electrochemically by pressing the conductive layer (D1) and moving relative to the conductive layer (D1). 62, 362) and a contact conductor (which is disposed in a portion of the mechanical polishing layer (62, 362) other than the electrolysis cell (C) and is in electrical contact with the conductor layer (D1). 61, 261) and below the mechanical polishing layer (62, 362) Power transmission parts (63, 163) that transmit power to the contact conductors (61, 261), and insulating layers (64, 163) that insulate between the power transmission parts (63, 163) and the cathode. 65, 164, 165), and a polishing pad for a device wafer.

According to a second aspect of the present invention, in the polishing pad for a device wafer according to the first aspect, the surface (61a, 261a) of the contact conductor (61, 261) is the surface of the mechanical polishing layer (62, 362). (61a, 261a) is provided so as to protrude and is pressed down by contacting the conductor layer (D1), so that the conductor layer (D1) and the mechanical polishing layer (62, 362) are in contact with each other. It is a polishing pad for device wafers which can be displaced until it contacts.
According to a third aspect of the present invention, in the polishing pad for a device wafer according to the second aspect, the displacement of the surface of the contact conductor (261, 361) is caused by elastic deformation of the contact conductor (261, 361) itself. This is a polishing pad for device wafers.
According to a fourth aspect of the present invention, in the polishing pad for a device wafer according to the second aspect, the contact conductors (61, 261) are supported by elastic members (64, 168), and the contact conductors (61, 261). ) Is due to elastic deformation of the elastic member (64, 168), which is a polishing pad for a device wafer.
According to a fifth aspect of the invention, there is provided a polishing pad for device wafer according to the fourth aspect, wherein the insulating layer (64) also serves as the elastic member.
According to a sixth aspect of the present invention, in the polishing pad for a device wafer according to the fourth aspect, the contact conductor (61) is disposed on an upper surface of the power transmission portion (163), and the power transmission portion (163) is The elastic member (168) can be bent following the displacement of the surface of the contact conductor (61), and the elastic member (168) supports the power transmission part (63, 163) from the lower surface side. A polishing pad for a device wafer, characterized in that the surface (61a) of the contact conductor (61) is displaceable.
According to a seventh aspect of the present invention, in the polishing pad for a device wafer according to the first aspect, the insulating layer includes a first layer (64) made of an elastic material, and the first layer (64). A polishing pad for a device wafer, comprising a second layer (65) which is provided in a lower layer and is more rigid than the first layer (64).
According to an eighth aspect of the present invention, in the polishing pad for a device wafer according to the seventh aspect, the first layer (64) is formed of an elastomer material, and the second layer (65) is formed of a synthetic resin. A polishing pad for device wafers.
A ninth aspect of the present invention is the device wafer polishing pad according to the first aspect, wherein the contact conductor (61, 261) is in surface contact with the conductor layer (D1). This is a polishing pad for a wafer.
The invention of claim 10 is the device wafer polishing pad according to claim 1, wherein the contact conductor (61, 261) is formed of gold, platinum, copper, titanium alloy, or stainless steel. A polishing pad for a device wafer.
The invention according to claim 11 is the polishing pad for device wafer according to claim 1, wherein the contact conductor (61, 261) has a mirror surface. .
The invention of claim 12 is the polishing pad for device wafer according to claim 1, wherein the contact conductor (61, 261) is a composite of carbon fiber, graphite fiber, graphite, and synthetic resin whose main component is carbon. A polishing pad for a device wafer, characterized in that it is formed from 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.
A thirteenth aspect of the present invention is the device wafer polishing pad according to the first aspect, further comprising an insulating portion (164d) that insulates between the power transmission portion (163) and the electrolytic solution (E). A polishing pad for a device wafer.
A fourteenth aspect of the present invention is the polishing pad for a device wafer according to the first aspect, wherein the electrolytic cell (C) has a diameter of 10 to 100 mm.
The invention of claim 15 is the polishing pad of the device wafer according to claim 1, wherein the total area of the opening of the electrolyte container (F) is a ratio of 20 to 80% of the total area of the pad, This is a polishing pad for a device wafer.
According to a sixteenth aspect of the present invention, in the polishing pad for a device wafer according to the first aspect, the device is provided so as to connect the electrolyte solution storage portions (F), and the electrolyte solution (E) F) A polishing pad for device wafers, characterized by having a connecting path (165C) for moving between the two.
According to a seventeenth aspect of the present invention, in the device wafer polishing pad according to the first aspect, the contact conductor (61, 261) has a hardness lower than that of the conductor layer (D1). It is a polishing pad for use.
The invention of claim 18 is the polishing pad of the device wafer according to claim 1, wherein the power transmission portion (63, 163) is made of gold, copper, platinum, titanium alloy, stainless steel or carbon. This is a polishing pad for a device wafer.
According to a nineteenth aspect of the present invention, in the polishing pad for a device wafer according to the first aspect, the power transmission portion (63, 163) is made of amorphous carbon, carbon fiber, graphite fiber, graphite, synthetic resin mainly containing carbon. And a composite carbon material with a synthetic resin, or a composite carbon material with a synthetic resin.
According to a twentieth aspect of the invention, there is provided a polishing pad for a device wafer according to the first aspect, wherein the mechanical polishing layer (62, 362) has a groove on a surface thereof. is there.
The invention of claim 21 is the device wafer polishing pad according to claim 1, wherein the mechanical polishing layer (62, 362) is formed of polyurethane or polyurethane foam. It is a polishing pad.
The invention of claim 22 is the device wafer polishing pad according to claim 1, wherein the mechanical polishing layer (62, 362) is formed of a fixed abrasive polishing member to which silicon oxide abrasive grains are fixed. These are polishing pads for device wafers.
The invention of claim 23 is the device wafer polishing pad according to claim 1, wherein the polishing pad is placed on the surface plate (51) of the polishing apparatus (50) and electrically connected to the surface plate (51). A polishing pad for device wafers, comprising a conductive sheet layer (66) forming the cathode.

According to the present invention, the following effects can be obtained.
(1) In the present invention, the mechanical polishing layer presses the conductive layer and moves relative to the conductive layer, thereby polishing the conductive layer electrochemically. The contact conductor is disposed in a portion of the mechanical polishing layer other than the electrolysis cell, and is in contact with the conductor layer to be electrically conductive.
Thereby, excess portions of the conductor layer of the device wafer can be removed by mechanical polishing and electrochemical polishing, that is, by electrochemical mechanical polishing (ECMP).
For this reason, by using an electrolytic solution containing an anticorrosive agent such as BTA (benzotriazole) and an additive such as glycine and a surfactant (hereinafter referred to as a protective film forming agent), the surface of the conductor layer (uneven surface) is Since an electrochemical protective film (passive film) is formed, the polishing pad can remove only the passive film other than the recesses by mechanical polishing. That is, the polishing pad is used to electrochemically dissolve only the convex portions on the surface of the conductor layer in order to mechanically remove the passive film on the convex portions while forming the passive film on the concave portions on the surface of the conductive layer. Since the excess conductor layer can be removed by removal, the flatness can be improved, the conductor layer can be efficiently left in the wiring groove, and the wiring of the device wafer can be formed.
Furthermore, since the power transmission unit is provided below the mechanical polishing layer and transmits power to the contact conductor, the power transmission unit can be prevented from coming into contact with the conductor layer. Power can be supplied well.

(2) In the present invention, the surface of the contact conductor is provided so as to protrude with respect to the surface of the mechanical polishing layer, and is pressed down by contacting the conductor layer. Therefore, the contact conductor and the conductor layer can be electrically and stably conducted.

(3) In the present invention, since the surface of the contact conductor is displaced by elastic deformation of the contact conductor itself, the conductor layer is made to be a mechanical polishing layer while maintaining conduction between the conductor layer and the contact conductor. Can be brought into contact with each other.

(4) In the present invention, since the contact conductor is supported by the elastic member, and the surface of the contact conductor is displaced by the elastic deformation of the elastic member, the same effect as in (3) can be obtained. Further, by changing the elastic member and changing the elastic coefficient, the degree of conduction between the conductor layer and the contact conductor can be easily adjusted.

(5) In the present invention, the insulating layer also serves as an elastic member. That is, the structure of the polishing pad can be simplified by combining the structure in which the insulating layer can displace the surface of the contact conductor.

(6) In the present invention, the contact conductor is disposed on the upper surface of the power transmission unit, and the power transmission unit can bend following the displacement of the surface of the contact conductor. The elastic member supports the contact conductor so that the surface thereof can be displaced via the power transmission unit by supporting the power transmission unit from the lower surface side.
Thereby, the effect similar to (4) can be acquired.

(7) The present invention has a plurality of electrolytic solution storage portions for storing an electrolytic solution, and a connection path is provided between the electrolytic solution storage portions for moving the electrolytic solution, so that an electrolytic cell is formed. Even when the conductor layer closes the opening of the electrolytic solution housing portion, the electrolytic solution can flow. That is, since the electrolytic cell is connected by the connecting path, the electrolytic solution can be moved efficiently.

(8) In the present invention, the insulating layer includes a first layer formed of an elastic material, and a second layer that is provided below the first layer and is more rigid than the first layer. Yes. Thereby, while supporting a contact conductor so that a movement to an up-down direction is possible, the rigidity of the whole polishing pad can be improved.

(9) In the present invention, as the contact conductor, any of carbon fiber, graphite fiber, graphite, composite carbon material with a synthetic resin, composite carbon material with an elastomer material, and composite graphite with a synthetic resin is used as a contact conductor. It is possible to prevent the polishing surface from being damaged by forming one or a combination thereof. Carbon fiber, graphite fiber, and graphite are characterized by low electrical resistance. Graphite is most effective in suppressing damage to the polished surface among these. A composite carbon material with a synthetic resin, a composite carbon material with an elastomer material, and a composite graphite with a synthetic resin have higher electrical resistance than the former, but have the same effect of preventing damage to the polished surface. Or it becomes possible to reduce the contact resistance in an electrode by using gold | metal | money, copper, platinum, a titanium alloy, or stainless steel as a contact conductor.

(10) In the present invention, since the contact conductor makes surface contact with the conductor layer, the current density of the contact surface can be made appropriate, and damage (damage) of the conductor layer can be prevented. it can.

(11) In the present invention, since the surface of the contact conductor is a mirror surface, damage to the conductor layer can be prevented.

(12) Since the present invention includes an insulating portion that insulates between the power transmission portion and the electrolytic solution, the supplied power can be efficiently transmitted to the conductor layer. In addition, since the electrolysis of the electrolytic solution due to the contact between the power transmission unit and the electrolytic solution can be prevented, the supplied power can be efficiently used for electrochemical polishing of the conductor layer.

(13) In the present invention, since the contact conductor has a lower hardness than the conductor layer, damage (damage) of the conductor layer can be prevented.

(14) In the present invention, since the mechanical polishing layer has grooves on the surface, the planarization performance can be improved and the efficiency of mechanical polishing can be improved. In addition, the electrolytic solution can be efficiently supplied and discharged using this groove.

  An object of the present invention is to provide a polishing pad for a device wafer in which the conductive layer of a device wafer can be polished electrochemically and mechanically using an electrolytic cell by improving the flatness and uniformity within the wafer surface. An electrolytic cell is formed from the conductive layer of the polishing pad, the conductive sheet layer and the electrolytic solution, and the conductive layer is dissolved and removed electrochemically, and the polishing member layer and the conductive member can be polished. This was realized by making it possible to mechanically remove the electrochemical protective film G (passive film) by moving the layer while making contact with the layer.

Next, embodiments of the polishing pad according to the present invention will be described with reference to the drawings.
First, an outline of the polishing apparatus 50 to which the polishing pad 60 of this embodiment is attached will be described.
FIG. 1 is a perspective view showing the polishing apparatus 50.
The polishing apparatus 50 is a polishing apparatus that performs platen rotary type chemical mechanical polishing (CMP). The polishing apparatus 50 includes a platen 51 (a surface plate), a polishing head 52, a power source 53, an apparatus-side electrode 55, and a nozzle 56.

The platen 51 is a disk-shaped member that mounts the polishing pad 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 supply 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 polishing pad 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 comes into contact with a conductive member layer 63 (described later) of the polishing pad 60, whereby the conductive member layer 63. Is electrically conducted. 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 a member that is disposed above the polishing pad 60 and supplies the electrolytic solution E. The electrolytic solution E can contain a protective film forming agent, abrasive grains, an oxidizing agent, and the like.

  With the configuration as described above, the polishing apparatus 50 contacts the device wafer D and the polishing pad 60 while supplying the electrolytic solution E, and moves them relative to each other to move the surface layer of the conductor layer D1 of the device wafer D. At the same time as forming an electrochemical protective film, the protective film is mechanically removed, and the conductor layer D1 is dissolved and removed electrochemically. That is, the polishing apparatus 50 can perform the electrochemical mechanical polishing (ECMP) of the conductor layer D1 by attaching the polishing pad 60.

Next, the configuration and the like of the polishing pad 60 will be described.
FIG. 2 is a perspective view showing the polishing pad 60. 3 is an enlarged view of a part of the polishing pad 60. 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 section. It is a figure (BB section arrow directional cross-sectional view shown to Fig.3 (a)). In each drawing, the thickness is emphasized for easy understanding of the configuration of each layer of the polishing pad 60.
As shown in FIGS. 2 and 3, the polishing pad 60 is a disk-shaped pad provided with a plurality of electrolyte solution storage portions F for storing the electrolyte solution E. The polishing pad 60 is provided with four contact conductors 61, a polishing member layer 62 (mechanical polishing layer), a conductive member layer 63 (power transmission portion), a first insulating layer 64, and a second insulating layer 64. The insulating layer 65, the conductive sheet layer 66, and the conductive adhesive tape 67 are laminated in this order from the upper side.

  The contact conductor 61 is a member that is electrically connected by contacting the conductor layer D1 of the device wafer D and forms an anode in the conductor layer D1 (see FIG. 3B). The contact conductor 61 is made of a material having a hardness lower than that of the copper forming the conductor layer D1 so that the conductor layer D1 is not damaged when contacting the conductor layer D1. 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 62a which forms an electrolytic cell. The contact conductor 61 is provided such that its surface 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 a conductive member layer 63 described later. . As will be described later, the contact conductor 61 is supported by a first insulating layer 64 made 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.

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 (mechanical polishing layer) mechanically moves 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 removing. 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 as shown in FIG. 3, a through hole 62 a for providing the contact conductor 61 and a through hole 62 b for forming the electrolyte container F are provided. ing.

The polishing member layer 62 is a non-metallic and insulating urethane-based material (such as a polyurethane material having a foam structure, a polyurethane material having a grooved foam structure, a polyurethane material having a foam structure having a cushion layer), or the polishing member is silica. (Silicon oxide) It is formed from a fixed abrasive polishing member 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 the abrasive grains, 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 supplied and 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 formed in a disk shape. It is laminated below the polishing member layer 62. As shown in FIG. 3, the conductive member layer 63 has a planar outer shape 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. Is transmitted to the contact conductor 61. Further, the conductive member layer 63 is arranged such that the upper surface thereof 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 the electrolytic solution housing portion F.

  The conductive member layer 63 is made of a low resistance material such as metal (gold, copper, platinum, titanium alloy, stainless steel, carbon, etc.) or a carbon material (amorphous carbon containing carbon as a main component, carbon fiber, graphite fiber, graphite). , Composite carbon material with synthetic resin, composite carbon material with synthetic resin, and the like.

The insulating layer composed of the first insulating layer 64 and the second insulating layer 65 is a member for electrically insulating the contact conductor 61, the conductive member layer 63, and a conductive sheet layer 66 described later. , Formed in a disk shape and laminated below the conductive member layer 63. The total thickness of the first insulating layer 64 and the second insulating layer 65 is about 0.5 to 5 mm. The first insulating layer 64 and the second insulating layer 65 are provided with through holes 64b and 65b for forming the electrolyte container F.
The first 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 structure of the polishing pad 60 can be simplified by using the first insulating layer 64 also as an elastic member for allowing the surface 61a of the contact conductor 61 to be displaced.
The second insulating layer 65 is made of a synthetic resin or the like (for example, polycarbonate or the like) that has electrical insulation and is more rigid than the first insulating layer 64.
The first insulating layer 64 and the second insulating layer 65 may be integrally formed from an elastic material. However, the above configuration is preferable because the rigidity of the entire polishing pad 60 can be improved.

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 polishing pressure is used in the range of 6.9 × 10 ⁻⁴ to 6.9 × 10 ⁻³ N / m ² (7 to 70 gf / cm ² , 0.1 to 1 psi). The insulating layer immediately below the conductor 61 is compressed, the contact conductor 61 moves in the vertical direction, and the conductor layer D1 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 set to 4.9 × 10 ^{−3 to} 6.9 × 10 ^{−. It} is preferable to set to about ³ N / m ² (50 to 70 gf / cm ² ).

The conductive sheet layer 66 is a sheet member for forming the cathode of the electrolysis cell, is formed in a disk shape, and is laminated below the second insulating layer 65. As shown in FIG. 3B, the conductive sheet layer 66 closes the through hole 65b of the second insulating layer 65 from the lower side so that the bottom of the electrolytic solution storage portion F for storing the electrolytic solution E is covered. Form. The conductive sheet layer 66 is electrically connected to a DC power source 53 (see FIG. 1) via a conductive adhesive tape 67 and a platen 51 which will be described later. With the above configuration, the conductive sheet layer 66 forms a cathode on the counter electrode of the conductor layer D1 of the device wafer D when the electrolytic solution is stored in the electrolytic solution storage portion F.
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 conductive adhesive tape 67 is an adhesive tape for attaching the polishing pad 60 to the platen 51, and has conductivity in order to make the polishing pad 60 and the platen 51 conductive. However, when the platen is formed of a non-conductive material such as alumina ceramic, it can be omitted.

FIG. 4 is an enlarged longitudinal sectional view showing a state in which the polishing pad 60 and the device wafer D form the electrolytic cell C during polishing.
In the state of FIG. 4, the surface 61 a of the contact conductor 61 is pushed down by being brought into contact with the conductor layer D <b> 1 of the device wafer D, and is displaced until the conductor layer D <b> 1 and the polishing member layer 62 are in contact with each other. This is because the first insulating layer 64 is compressed and elastically deformed.
In addition, since the conductive member layer 63 is provided below the polishing member layer 62, it does not contact the conductor layer D 1, so that power can be efficiently supplied to the contact conductor 61.

During polishing, the electrolytic solution storage portion F of the polishing pad 60 is filled with the electrolytic solution E, and the opening is covered with the conductor layer D1 of the device wafer D. 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 source 53 via the platen 51 and the conductive adhesive tape 67.
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 container increases with respect to the diameter, so that the electrolytic solution E can be stably brought into contact with the conductor layer D1. This is to prevent this because it becomes difficult.
Further, the ratio of the total area of the opening of the electrolytic solution storage part 14 to the total area of the polishing pad 60 (the area of the upper surface of the polishing member layer 62 (including the opening of the electrolytic solution storage part F)) is 20 to 80%. Is preferred. 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 polishing pad 60, and the cross section is not limited circularly, 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.

FIG. 5 is a longitudinal sectional view showing a polishing process of the device wafer D by the polishing pad 60. 5A shows a state before polishing, FIGS. 5B to 5E show a state during polishing, and FIG. 5F 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. 5A, 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. 5F), whereby 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 polishing pad 60 of this 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. 5A, the conductive layer D1 of the device wafer D and the conductive sheet layer 66 of the polishing pad 60 come into contact with each other, and the bottom surface of the conductive layer D1 is formed by the electrolytic cell C (see FIG. 4). The surface layer is dissolved and removed. When dissolution and removal of the conductor layer D1 proceed, as shown in FIG. 5B, the surface of the conductor layer D1 is formed on the lower surface of the conductor layer D1 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. 4) of the polishing pad 60 is moved relative to the device wafer D by the polishing apparatus 50 (see FIG. 1), the protective film G is mechanically removed. At this time, since the protective film G formed in the concave portion D1a does not contact the polishing pad 60, 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. 5C, 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 above process is repeated instantaneously, and the polishing pad 60 can electrochemically and mechanically polish the conductor layer D1, and can remove the convex portions D1c and D1d faster than the concave portion D1a. And the polishing pad 60 can make the surface of the conductor layer D1 flat as shown in FIG.5 (d).

  In the state of FIG. 5D, 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. 5D) 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. 5E, 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. 5F), and an interlayer insulating film is further deposited thereon. For this reason, it is necessary to simultaneously remove the surface layer of the conductor layer D1 and 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. 5E) to the surface of the interlayer insulating film D3. 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 FIG. 5A to the state shown in FIG. 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 polishing pad 60 of this embodiment is attached to the platen rotary type polishing apparatus 50. Then, the polishing member layer 62 (mechanical polishing layer) is relatively moved in a state where the conductor layer D1 is pressed, and the contact conductor 61 is disposed in a portion other than the electrolytic cell C of the polishing member layer 62, It is provided so as to protrude from the surface of the polishing member layer 62, and comes into contact with the conductor layer D1 to be electrically conductive. As a result, the conductor layer D1 is passivated by an electrochemical action, and at the same time, the protrusions D1c and D1d of the conductor layer D1 can be selectively mechanically removed and further electrochemically removed. That is, it is possible to achieve a high level of flatness by performing a good balance between mechanical removal and electrochemical removal of the excess portion of the conductor layer D1 of the device wafer D.

Next, a second embodiment of the polishing pad to which the present invention is applied will be described.
The polishing pad of Example 2 is obtained by changing the method of holding the contact conductor 61 of Example 1 and providing a connecting path between the electrolyte solution storage portions. In addition, the description which overlaps with the part which fulfills the same function as Example 1 mentioned above is abbreviate | omitted suitably, and mainly demonstrates a changed part.
6 to 8 are diagrams illustrating the polishing pad 160 of the second embodiment. 6 (b) is a longitudinal sectional view, FIG. 6 (a) is a transverse sectional view (sectional view taken along the line II of FIG. 6 (b)), and FIG. 7 shows a state during polishing. FIG. 8 is a perspective view showing a support structure of a contact conductor.
As shown in FIG. 6, the polishing pad 160 includes a conductive member layer 163, a first insulating layer 164, a second insulating layer 165, and an elastic member 168.

As shown in FIG. 6A, the conductive member layer 163 has an annular portion 163a, an arm portion 163b, and an electrode support portion 163c.
The annular portion 163 a is an outer portion of the conductive member layer 163. The arm portion 163b is an arm-shaped portion that connects the annular portion 163a and the electrode support portion 163c, bends with the annular portion 163a side as a fulcrum, and can move the electrode support portion 163c in the vertical direction. The electrode support portion 163c is a member having a planar shape substantially the same as that of the contact conductor 61. The contact conductor 61 is disposed on the upper side of the electrode support portion 163c and transmits electric power to the contact conductor 61.

  The insulating layer made up of the first insulating layer 164 and the second insulating layer 165 is a member for electrically insulating the conductive member layer 163 and the conductive sheet layer 66, and is a highly rigid resin or the like ( For example, polycarbonate is used. The first insulating layer 164 and the second insulating layer 165 are provided with through holes 164a and 165a communicating with the through holes 62a of the polishing member layer 62 in order to accommodate the electrode support portion 163c and an elastic member 168 (described later). It has been.

  The first insulating layer 164 is provided with a groove 164c for accommodating the conductive member layer 163 so as to insulate between the electrolytic solution E accommodated in the electrolyte accommodating portion F and the conductive member layer 163. . That is, the portion 164 d (insulating portion) of the first insulating layer 164 prevents the conductive member layer 163 from being exposed to the electrolyte solution containing portion F. As shown in FIG. 7, the first insulating layer 164 isolates the electrolytic solution E and the conductive member layer 163 when the conductive layer D1 of the device wafer D is electrolyzed and dissolved. It is possible to prevent the flow of current consumed for water electrolysis (see arrow J shown in FIG. 7). Thereby, the polishing pad 160 can efficiently use the supplied power for electrolysis and dissolution of the conductor layer D1.

As shown in FIG. 6, the second insulating layer 165 is provided with an opening 165 c and forms a connection path (through hole) that connects between the electrolyte solution containing portions F that form the electrolytic cell C (see FIG. 4). To do. For this reason, the electrolytic solution E can move between the electrolytic solution storage parts F. That is, the electrolyte E entering from the upper opening of the electrolyte container F can prevent the electrolyte solution from deteriorating by preventing the electrolyte container F from staying through this connection path. Further, since the polishing pad 160 can discharge the electrolytic solution E from other than the upper opening by providing a discharge port (not shown) in the electrolytic solution storage portion F, the electrolytic solution E is kept in a newer state. be able to.
In addition, although the 1st insulating layer 164 and the 2nd insulating layer 165 may be integrally formed in order to simplify a structure, when forming the connection path between the electrolyte solution accommodating parts F, the direction used as another member However, workability is good.

The elastic member 168 is a member for supporting the contact conductor 61 so as to be movable up and down. The elastic member 168 is, for example, a columnar member formed of a fluorine-based rubber material or an elastomer resin, or a coil spring, a leaf spring, or the like formed of stainless steel or the like. When a rubber material is used for the elastic member 168, for example, the amount of deformation can be increased by setting the rubber hardness to JIS A hardness 10 or less and making the inside of the cylinder hollow. As shown in FIG. 8, the elastic member 168 supports the contact conductor 61 via the electrode support portion 163 c of the conductive member layer 163. The elastic member 168 is accommodated in the through holes 164 a and 165 a of the first insulating layer 164 and the second insulating layer 165. The elastic member 168 has a spring constant of 9.8 × 10 ^{2 to} 6.9 × 10 ³ N / m in order to bring the contact conductor 61 and the device wafer D into stable contact with each other and make them electrically conductive. It is preferable to set it to about (1-7 kgf / cm). The spring constant can be easily adjusted by replacing the elastic member 168. Therefore, the contact pressure between the conductor layer D1 and the contact conductor 61 is adjusted to increase the degree of electrical conduction. It can be adjusted easily.

An operation in which the elastic member 168 supports the contact conductor 61 will be described.
At the time of polishing, the contact conductor 61 is pressed downward in the vertical direction (arrow Z3 direction) by the device wafer D, as shown in FIG. At this time, as shown in FIG. 8, since the electrode support portion 163c can be moved in the vertical direction (arrow θ3 direction) by the arm portion 163b, the electrode support portion 163c moves downward in the vertical direction while being in contact with the contact conductor 61. To do. The elastic member 168 can support the contact conductor 61 by compressing in the vertical direction (arrow Z4 direction) according to the movement of the contact conductor 61 and the electrode support portion 163c. Thereby, the surface 61a of the contact conductor 61 can be displaced in the vertical direction.

  As described above, in the polishing pad 160 of the present embodiment, the first insulating layer 164 includes the portion 164d (insulating portion) that insulates the conductive member layer 163 (power transmission portion) and the electrolytic solution E from each other. Therefore, the supplied electric power can be efficiently transmitted to the conductor layer. In addition, since electrolysis due to contact between the conductive member layer 163 and the electrolytic solution E can be prevented, the supplied power can be efficiently used for electrochemical polishing of the conductor layer.

  The second insulating layer 165 forms a connection path (through hole) for circulating the electrolytic solution E. Thereby, in order to form the electrolytic cell C, the electrolytic solution E can be moved even when the conductor layer D1 closes the upper opening of the electrolytic solution storage portion F (concave portion). In particular, the orbital type polishing apparatus has a great effect of using the polishing pad 160 because the upper opening of the electrolyte solution containing portion F (concave portion) is always closed. In the orbital type polishing apparatus, it is desirable to supply the electrolytic solution from below the electrolytic polishing pad.

  Further, the contact conductor 61 is supported by the elastic member 168, and the surface 61 a can be displaced by elastic deformation of the elastic member 168. Thereby, the polishing pad 160 can contact the conductor layer D1 and the polishing member layer 62 (mechanical polishing layer) while maintaining the electrical connection between the conductor layer D1 and the contact conductor 61. Further, since the contact pressure between the conductor layer D1 and the contact conductor 61 can be easily adjusted by adjusting the spring constant of the elastic member 168, the electrical connection between the conductor layer D1 and the contact conductor 61 is achieved. The degree of proper conduction can be easily adjusted.

Next, a third embodiment of the polishing pad to which the present invention is applied will be described.
As shown in FIG. 9A, the polishing pad 260 of Example 3 is obtained by replacing the contact conductor 61 of Example 1 with the contact conductor 261 having low rigidity, and the first insulating layer 64 of Example 1. The second insulating layer 65 is changed to an insulating layer 264 formed integrally.
As shown in FIG. 9B, the surface of the contact conductor 261 is displaced downward in the vertical direction (arrow Z5 direction) due to elastic deformation of the contact conductor 261 itself when contacting the polishing pad 260.

Even with the above-described configuration, as in the first embodiment, the polishing pad 260 maintains the electrical connection between the conductive layer D1 and the contact conductor 261, and the conductive layer D1 and the polishing member layer 62 (mechanical layer). A polishing layer), and electrochemical mechanical polishing is possible. In addition, the polishing pad 260 can have a simpler configuration.
Note that the above-described effects can be similarly obtained by forming the contact conductor 261 from a highly rigid material and forming the conductive member layer 63 from an elastically deformable material. That is, the polishing pad 260 may be configured such that when the contact conductor 261 is pressed by the device wafer D, the conductive member layer 63 is elastically deformed to support the contact conductor 261.

Next, Example 4 of the polishing pad to which the present invention is applied will be described.
As illustrated in FIG. 10, the polishing pad 360 of Example 4 includes a contact conductor 361, a polishing member layer 362, and a harness 368.
The contact conductor 361 is accommodated in a recess 362 c provided by denting the surface of the polishing member layer 362. The polishing member layer 362 is formed of an insulating material and is laminated directly on the conductive sheet layer 66. The harness 368 is a wiring that electrically connects the DC power supply 53 of the polishing apparatus 50 and the contact conductor 361.

At the time of polishing, when the surface 361a of the contact conductor 361 is pressed against the conductor layer D1 of the device wafer D, the contact conductor 361 itself is elastically deformed or the polishing member layer 362 is elastically deformed in the vertical direction. Displace.
Even with the above configuration, the polishing pad 360 can contact the conductor layer D1 and the polishing member layer 62 in a state where the conductor layer D1 and the contact conductor 361 are in contact with each other. Electrochemical mechanical polishing of D1 is possible. Further, the polishing pad 360 can be further simplified.

(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 Example 2, although the example which provided the groove | channel in the 1st insulating layer 164 was shown in order to insulate between the electrolyte solution E and the electroconductive member layer 163, it is not limited to this. Since it is only necessary to insulate between the electrolytic solution E and the conductive member layer 163, for example, an insulating member formed in an annular shape may be provided along the inner wall of the electrolytic solution storage portion F.

1 is a perspective view of a polishing apparatus to which Example 1 of a polishing pad to which the present invention is applied is attached. 1 is a perspective view showing a polishing pad of Example 1. FIG. 2 is an enlarged plan view and a longitudinal sectional view showing a part of the polishing pad of Example 1. FIG. 2 is a longitudinal sectional view showing a state of the polishing pad of Example 1 during polishing. FIG. 3 is a longitudinal sectional view showing a polishing process of the polishing pad of Example 1. FIG. It is the longitudinal cross-sectional view which shows Example 2 of the polishing pad to which this invention is applied, and a cross-sectional view. It is a longitudinal cross-sectional view which shows the state at the time of grinding | polishing of the polishing pad of Example 2. FIG. It is a perspective view which shows the support structure of the contact conductor of Example 2. FIG. It is a longitudinal cross-sectional view which shows Example 3 of the polishing pad to which this invention is applied. It is a longitudinal cross-sectional view which shows Example 4 of the polishing pad to which this invention is applied.

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 Polishing pad 61,261 Contact conductor 62,362 Polishing member layer 63,163 Conductive member layer 64,164 1st insulation Layers 65 and 165 Second insulating layer 66 Conductive sheet layer 67 Conductive adhesive tape 163c Electrode support 168 Elastic member 264 Insulating layer C Electrolytic cell D Device wafer D1 Conductor layer D2 Barrier metal D3 Interlayer insulating film E Electrolyte F Electrolysis Liquid container

Claims (23)

It has a plurality of electrolytic solution storage portions for storing the electrolytic solution, the conductive layer of the device wafer is an anode, the electrolytic solution is contacted with the cathode of the counter electrode of the anode to form an electrolytic cell, and a voltage is applied. In the polishing pad for electrochemically polishing the conductor layer by applying,
A mechanical polishing layer for electrochemically and mechanically polishing the conductive layer by pressing the conductive layer and moving relative to the conductive layer;
A contact conductor disposed on a portion of the mechanical polishing layer other than the electrolysis cell, and in contact with the conductor layer and electrically conductive;
A power transmission unit provided below the mechanical polishing layer and transmitting power to the contact conductor;
An insulating layer that insulates between the power transmission unit and the cathode;
A polishing pad for device wafers. In the polishing pad of the device wafer according to claim 1,
The surface of the contact conductor is provided so as to protrude with respect to the surface of the mechanical polishing layer, and is pressed down by contacting the conductor layer so that the conductor layer and the mechanical polishing layer are Be displaceable until it abuts,
A polishing pad for device wafers. In the polishing pad of the device wafer according to claim 2,
The displacement of the surface of the contact conductor is due to elastic deformation of the contact conductor itself;
A polishing pad for device wafers. In the polishing pad of the device wafer according to claim 2,
The contact conductor is supported by an elastic member,
The displacement of the contact conductor is due to elastic deformation of the elastic member;
A polishing pad for device wafers. In the polishing pad of the device wafer according to claim 4,
The insulating layer also serves as the elastic member;
A polishing pad for device wafers. In the polishing pad of the device wafer according to claim 4,
The contact conductor is disposed on an upper surface of the power transmission unit,
The power transmission portion can be bent following the displacement of the surface of the contact conductor,
The elastic member is configured to displace the surface of the contact conductor by supporting the power transmission unit from the lower surface side.
A polishing pad for device wafers. In the polishing pad of the device wafer according to claim 1,
The insulating layer is
A first layer formed from an elastic material;
A second layer which is provided below the first layer and is more rigid than the first layer;
A polishing pad for device wafers, comprising: The device wafer polishing pad according to claim 7,
The first layer is formed of an elastomer material;
The second layer is formed of a synthetic resin;
A polishing pad for device wafers. In the polishing pad of the device wafer according to claim 1,
The contact conductor is in surface contact with the conductor layer;
A polishing pad for device wafers. In the polishing pad of the device wafer according to claim 1,
The contact conductor is made of gold, platinum, copper, titanium alloy, or stainless steel;
A polishing pad for device wafers. In the polishing pad of the device wafer according to claim 1,
The contact conductor has a mirror surface.
A polishing pad for device wafers. In the polishing pad of the device wafer according to claim 1,
The contact conductor may be any one of carbon fiber containing carbon as a main component, graphite fiber, graphite, composite carbon material with synthetic resin, composite carbon material with elastomer material, composite graphite with synthetic resin, or Being formed from a combination of them,
A polishing pad for device wafers. In the polishing pad of the device wafer according to claim 1,
Comprising an insulating part that insulates between the power transmission part and the electrolyte;
A polishing pad for device wafers. In the polishing pad of the device wafer according to claim 1,
The electrolytic cell has a diameter of 10 to 100 mm.
A polishing pad for device wafers. In the polishing pad of the device wafer according to claim 1,
The total area of the openings of the electrolytic housing is 20 to 80% of the total pad area;
A polishing pad for device wafers. In the polishing pad of the device wafer according to claim 1,
Provided so as to connect between the electrolytic solution storage portions, the electrolytic solution has a connection path for moving between the electrolytic solution storage portions;
A polishing pad for device wafers. In the polishing pad of the device wafer according to claim 1,
The contact conductor has a lower hardness than the conductor layer;
A polishing pad for device wafers. In the polishing pad of the device wafer according to claim 1,
The power transmission part is made of gold, copper, platinum, titanium alloy, stainless steel or carbon;
A polishing pad for device wafers. In the polishing pad of the device wafer according to claim 1,
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 pad for device wafers. In the polishing pad of the device wafer according to claim 1,
The mechanical polishing layer has a groove on its surface;
A polishing pad for device wafers. In the polishing pad of the device wafer according to claim 1,
The mechanical polishing layer is formed of polyurethane or polyurethane foam;
A polishing pad for device wafers. In the polishing pad of the device wafer according to claim 1,
The mechanical polishing layer is formed of a fixed abrasive polishing member to which silicon oxide abrasive is fixed;
A polishing pad for device wafers. In the polishing pad of the device wafer according to claim 1,
A conductive sheet layer mounted on a surface plate of a polishing apparatus, electrically connected to the surface plate, and forming the cathode;
A polishing pad for device wafers.

Images