JP2006274369A - Method and apparatus for forming substrate wiring, and plating suppressing substance transfer stamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for forming substrate wiring capable of suppressing the occurrence of a failure, such as disconnection, controlling the time required for a CMP process to an appropriate range, performing sufficient planarization at the end time point of a plating process and in the CMP process, completely removing the excess metals, and forming substrate wiring by forming such metallic plating film which does give rise to peeling among a seed layer, barrier layer, insulation layer, etc., and does not give rise to dishing and erosion by an electrolytic plating on a substrate., and a transfer stamp for a plating suppressing substance. <P>SOLUTION: The substrate wiring forming method of forming the wiring by embedding recessed parts 11, such as wiring grooves, and contact holes, formed on a substrate 10 with copper 13 by electroplating is equipped with a process of sticking the plating suppressing substance (ink 4) to the extreme surface of the substrate 10 exclusive of the inner surface of the recessed parts 11 of the substrate, a process for performing the electrolytic plating, a process of desorbing the plating suppressing substance (ink 4) and a process of performing the electroplating. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a substrate wiring forming method, a substrate wiring forming apparatus, and a method for forming a wiring of a semiconductor device (semiconductor integrated circuit) by filling a concave portion such as a wiring groove or a contact hole formed on a surface of a semiconductor substrate with a metal by electrolytic plating. The present invention also relates to a plating suppression material transfer stamp for transferring a plating suppression material to the surface of the substrate excluding the concave inner surface.

  Conventionally, aluminum or an aluminum alloy has been used as a metal material for internal wiring of a semiconductor integrated circuit. Recently, however, copper having low electrical resistance and electromigration resistance has been used. In order to form wiring with copper, as shown in FIG. 1A, copper (copper plating film 102) is placed in a contact hole or wiring groove (hereinafter also referred to as “trench”) 101 provided in the insulating layer 100 of the substrate. The plating process is completed by embedding and depositing on the entire surface of the substrate where contact holes and wiring grooves 101 are processed, and then the excess copper and copper diffusion preventing barrier layer 103 is formed by CMP (Chemical Mechanical Polishing) A damascene method is used which is removed and planarized by polishing. This copper embedding is usually performed by electrolytic copper plating, but a copper layer (not shown) called a seed layer for energization is formed in advance on the barrier layer 103 by sputtering or the like.

  When the surface of the substrate on which the copper plating film 102 is formed by the CMP process is planarized, a part of the wiring portion 102a of the copper plating film 102 that should be left as shown in FIG. Since the dishing 104 and the erosion 105 are generated, in order to avoid these, the thickness of the copper plating film 102 is previously increased as shown in FIG. That is, a method of flattening the entire plating surface by increasing the deposition thickness of the copper plating film 102 deposited on the entire wiring forming surface of the substrate is employed. However, if the thickness of the copper plating film 102 is increased, a longer time is required for the CMP process. On the other hand, as the copper plating film 102 is thinner, the surface shape after the plating finishes the irregularities such as contact holes and trenches of the semiconductor substrate as they are, and the irregularities (see FIG. 1 (a) 102b) remain on the substrate surface. .

  If CMP is performed in this state, it becomes difficult not only to remove the excessive copper plating film 102 on the substrate surface and to flatten the substrate surface, but also to generate a dishing 104 and an erosion 105 in the wiring portion of the substrate. . That is, if the thickness of the copper plating film 102 is increased, a long time is required for the CMP process. On the other hand, if the thickness is reduced, it is difficult to remove the excessive copper plating film 102 and planarize the substrate, Or erosion 105 occurs.

  Therefore, various additives are conventionally added to the plating solution in order to flatten the surface at the end of plating. In order to bury copper in trenches (trench and via holes) that become fine wiring patterns by electrolytic copper plating using a copper sulfate plating solution as the plating solution, a uniform electrodeposition (thickness plating bath) This is because it is necessary to realize a plating process having a high leveling ability and a leveling property (the ability of the electroplating bath to smooth the microscopic unevenness of the substrate and the polishing conditions). Therefore, conventionally, as a technique for performing flat plating, a compound called an additive as shown in the following (1) to (3) is generally added to a plating solution. The concave portions formed on the surface of the semiconductor substrate in order to form fine wiring by embedding copper by plating can be used to form concave portions such as contact holes, via holes, wiring grooves, trenches, and grooves as described above. There are several ways to call them. However, in the present invention, it is not necessary to distinguish these recesses. Therefore, when it is necessary to clarify the meaning of the wording by this name, they are collectively referred to as a recess or a wiring groove. And so on.

(1) Sulfur compounds called carriers that generate crystal nuclei at many locations on the plating surface and promote the refinement of the precipitated particles. (2) Polymers that increase the overpotential of copper deposition and improve the throwing power. (3) Plating that is easy to grow plating (in the substrate, the portion where the recess such as the wiring groove is not formed, that is, corresponding to the outermost surface of the substrate) is adsorbed to increase the overvoltage to deposit on the protruding portion, that is, the outermost surface. Nitrogen compound called leveler that enables flat plating by delaying (2) In the substrate, as described above, (a) a portion in which a recess such as a wiring groove is processed and (b) a wiring groove or the like There are portions that are not processed and formed, for example, as representatively illustrated in FIG. In the present invention, when it is necessary to clarify the meaning of the word by referring to these, the part (a), that is, the surface in the recess is called the inner surface of the recess or the inner surface of the recess. Is called the outermost surface of the substrate or the substrate protrusion. 2 and 3, 51 indicates the outermost surface of the substrate, and 52 indicates the inner surface of the recess.

  However, when the above compounds (1) to (3) are added as additives to the plating solution, these compounds are taken in as impurities in the plated copper plating film 102, which may adversely affect the electrical conductivity. There is sex.

  As a method for realizing flat electrolytic copper plating, an electrochemical mechanical deposition (ECMD) technique is disclosed in Patent Document 1 below as “Method and Apparatus for Electrochemical Mechanical Deposition”. According to this method, when the copper is deposited, the field region in which the copper wiring portion is not formed is polished with the pad, thereby minimizing the copper deposition on the field region and into the trench on the substrate surface. The preferential deposition of copper is achieved, which ultimately produces a generally flat copper deposit on the substrate surface on which the copper is deposited.

  Non-patent document 1 below discloses a paper using so-called microcontact printing in which an alkanethiol coated on a silicone resin is contact-transferred to a substrate. In this method, alkanethiol, which is a plating inhibitory material, is transferred in advance to the outermost surface (substrate convex portion) on the side where the copper wiring of the substrate is embedded using copper contact printing to suppress copper plating in that portion, and to the concave portion. Only a method of depositing copper has been proposed as a new process.

  If this method is used, the removal of excess copper and the planarization of the substrate can be more preferably performed in the CMP process, and the occurrence of the dishing 104 and the erosion 105 (see FIG. 1B) can be suppressed. However, in this method, since the damascene copper plating is completely suppressed at the substrate convex portion (the outermost surface of the substrate), only the inside of the wiring groove or the like that becomes the wiring portion, that is, the inside of the trench or the contact hole is buried. In the case where the width is smaller than the size of the crystal grains, the effects of copper recrystallization and strain relaxation, which are the purposes, may be reduced in the heat treatment step performed after the plating step.

In addition, since the shape of the upper part of the copper embedding (upper part of the copper plating film 102) in the trench 101 at the end of the plating process is a convex shape 102c as shown in FIG. In this case, a shearing force is locally applied to the film, and peeling may occur between the copper layer and the underlying barrier layer (film) 103, or between the barrier film and the insulating layer 100 such as a low-k material, or both. That is, problems such as stress migration and electromigration due to insufficient effects of recrystallization and strain relaxation of the copper plating film (layer) 102 are likely to occur.
US Pat. No. 6,176,992 Electrochemical and Solid-State Letters September 2004 C101-C103

  When copper is embedded by electrolytic plating inside contact holes, trenches, etc. (wiring grooves, etc.) using electrolytic plating with a plating solution that has improved electrodeposition and leveling properties by adjusting additives, A copper film is formed on the entire surface including the portion where contact holes, trenches and the like are formed on the substrate surface, and the film thickness thereof is a dense portion such as wiring, that is, trench 101 as shown in FIG. In the dense portion, the film thickness becomes thicker than the film thickness of the non-wiring portion, while in the portion where the wide wiring is formed, the phenomenon becomes thinner than the film thickness of the non-wiring portion. When the film thickness varies in this way, the copper embedding itself in the wiring part does not cause a problem, but flattening in the CMP process, which is a subsequent process of plating, becomes extremely difficult.

  That is, as described above, if a thin film is formed to shorten the time required for the CMP process, the plating is completed as described above even if a plating solution having high uniform electrodeposition and leveling properties is used. Since unevenness is present on the plating surface due to subsequent variations in film thickness, removal of excess copper film and flattening of the substrate surface are not performed sufficiently, or the dishing 104 and erosion 105 (see FIG. 1B) are used. The problem that it occurs will occur. In addition, when a thick copper plating film 102 is applied as shown in FIG. 3 in order to suppress such defects due to variations in the plating film thickness, the processing time in the CMP process may become long.

  Further, the substrate surface other than the inner surface of the recess formed on the substrate, such as the contact hole or the trench 101 or the like (wiring groove or the like) or the bottom surface of the substrate (that is, the outermost surface of the substrate, the substrate surface When the electroplating is carried out after completely covering the substrate with a plating inhibitor (plating inhibitor), as shown in FIG. 2, only the wiring portion in which the concave portion such as the contact hole or the trench 101 is formed is provided with the copper plating film 102. A convex plating film 102 having a plating surface higher than the outermost surface (substrate convex portion) of the substrate in the non-wiring portion is formed.

  In this case, the following occurs during the heat treatment or CMP process, which is a subsequent process. That is, since the copper plating film 102 is deposited only on the wiring portion, the volume of the copper itself is limited, and the effects of recrystallization of plated copper, relaxation of strain, and the like may be reduced during the heat treatment process. Further, as described above, since the surface shape of the copper embedded portion in the contact hole, the trench 101 or the like is the convex shape 102c, a shearing force is locally applied during the CMP process, and the copper layer and the underlying barrier layer 103, Alternatively, separation occurs between the barrier layer 103 and the insulating layer 100 such as a low-k material, or both.

  The present invention has been made in view of the above points, and can sufficiently recrystallize plated copper and relax strain in a heat treatment process performed after the plating process, and can reduce the time required for the process in the CMP process. , Removal of excess copper film and flattening of the substrate surface can be sufficiently performed, and defects such as peeling between copper layers, barrier layers and insulating layers can be achieved without causing problems such as dishing and erosion. It is strongly desired to obtain a plating film that does not cause the occurrence of plating at the end of the plating process. Therefore, in the present invention, the plating film at the end of the plating step is formed over the entire surface of the substrate on which the wiring grooves and the like are formed, that is, the surface of the substrate to be plated, and the plating film. A substrate wiring forming method by electrolytic plating, a substrate wiring forming apparatus, and plating suppression, which can be formed flat on the surface of the substrate and further reduce the plating film thickness, that is, the thickness of the plating layer deposited on the outermost surface of the substrate. The object is to provide a mass transfer stamp.

  The invention according to claim 1, which solves the above problem, is a substrate wiring forming method in which a recessed portion such as a wiring groove formed on a substrate is filled with metal by electrolytic plating to remove the inner surface of the recessed portion of the substrate. It is characterized by comprising a plating inhibiting substance attaching step for attaching a plating inhibiting substance that suppresses plating to the surface of the substrate, that is, the outermost surface of the substrate, and an electrolytic plating (electroplating) step for performing electrolytic plating thereafter.

  The invention according to claim 2 is the substrate wiring forming method according to claim 1, further comprising a plating inhibitor release process for releasing the plating inhibitor from the surface of the substrate after the electrolytic plating process. And

  According to a third aspect of the present invention, in the substrate wiring forming method according to the second aspect of the present invention, an electrolytic plating step of performing electrolytic plating is provided after the plating suppression substance removing step.

  According to a fourth aspect of the present invention, in the method for forming a substrate wiring according to the second or third aspect, in the plating inhibiting substance removing step, electrolysis is performed in the opposite direction to the electrolytic plating direction (electrolysis in which the positive and negative of the power source are reversed). It is characterized by performing by plating.

  According to a fifth aspect of the present invention, in the method for forming a substrate wiring according to the fourth aspect, when the electrolysis is applied in the direction opposite to the electroplating direction of the plating inhibitor releasing step, the concave portion of the substrate is formed by the electrolytic plating step. When the surface of the metal embedded in the substrate and the surface of the substrate on which the plating inhibitor is adhered (the outermost surface of the substrate) are flush with each other, that is, as a result of the recesses in the substrate being embedded with metal, these It is characterized in that both surfaces are at the same height.

  According to a sixth aspect of the present invention, in the substrate wiring forming method according to any one of the first to fifth aspects, the plating suppression substance attaching step includes supporting the plating suppression substance on a stamp in advance, The plating inhibitor is transferred to the surface of the substrate by pressing the stamp against the surface of the substrate (the outermost surface of the substrate).

  The invention according to claim 7 is the substrate wiring forming method according to any one of claims 1 to 6, wherein the metal embedded in the concave portion of the substrate in the electrolytic plating step is copper, a copper alloy, or It is characterized by being silver.

  The invention according to claim 8 is the method for forming a substrate wiring according to any one of claims 1 to 7, wherein the plating inhibiting substance attached to the surface of the substrate in the plating inhibiting substance attaching step has a thickness of It is characterized by a uniform film state.

  A ninth aspect of the present invention is the method for forming a substrate wiring according to any one of the sixth to eighth aspects, wherein the plating suppression material-carrying portion that carries the plating suppression material as the stamp is a silicone resin or a fluororesin. A stamp having at least one of the above is used.

  According to a tenth aspect of the present invention, in the substrate wiring forming method according to the ninth aspect of the present invention, the stamp is a stamp in which a plating-suppressing substance carrying portion is supported by a support.

  According to an eleventh aspect of the present invention, in the substrate wiring forming method according to the ninth or tenth aspect of the present invention, as the stamp, a stamp in which at least the outer surface of the plating suppression substance-carrying part is configured in a flat plate shape or a cylindrical shape is used. It is characterized by.

  The invention according to claim 12 includes a plating solution tank for containing a plating solution, and a substrate on which a recess such as a wiring groove is formed in the plating solution in the plating solution tank and an anode electrode, In a substrate wiring forming apparatus in which a predetermined plating voltage is applied between an anode electrode and the substrate, and a wiring is formed by embedding the concave portion of the substrate with metal by electrolytic plating, the substrate is formed on the substrate except for the inner surface of the concave portion. The substrate is characterized in that a plating inhibitory substance that suppresses plating is attached to the surface, that is, the outermost surface of the substrate.

  The invention according to claim 13 is the substrate wiring forming apparatus according to claim 12, wherein the polarity of the polarity of the voltage applied between the anode electrode and the substrate is determined at a predetermined timing during the electrolytic plating. It is characterized by comprising polarity switching means for switching and applying the polarity so that the polarity is reversed.

  In the invention described in claim 14, when the wiring is formed on the substrate by embedding a recess such as a wiring groove formed on the substrate with metal by electrolytic plating, the surface of the substrate excluding the inner surface of the recess of the substrate That is, a plating suppression material transfer stamp used to transfer a plating suppression material that suppresses plating to the outermost surface of the substrate and having a plating suppression material supporting portion, and at least the plating suppression material supporting portion of the stamp is made of silicone resin or fluorine It has at least one of resin, It is characterized by the above-mentioned.

  According to a fifteenth aspect of the present invention, in the plating suppression material transfer stamp according to the fourteenth aspect, the stamp has a configuration in which at least a plating suppression material carrying portion is supported by a support.

  The invention described in claim 16 is the plating inhibitor transfer stamp according to claim 14 or 15, characterized in that the stamp has at least an outer surface of the plating inhibitor carrying part having a flat plate shape or a cylindrical shape.

  According to the present invention, a substrate other than the inner surface of a recess such as a wiring groove, that is, the side wall surface or the bottom surface of a recess such as a trench or a contact hole, on which copper for wiring is to be deposited in contact with these surfaces After covering the surface (that is, the outermost surface of the substrate, also referred to as the convex portion of the substrate) with a plating inhibitor (plating inhibitor), electrolytic plating is performed, and then electrolysis is performed opposite to the electrolytic direction of electrolytic plating. By removing the plating inhibitor (plating inhibitor) from the outermost surface of the substrate, and then restarting the electrolytic plating and performing it for an appropriate time, a plating film that is thin at the end of the plating process and has a high flatness on the plating surface, Since the film can be formed over the entire surface on the wiring embedding side of the substrate, the above-described problems can be solved.

  That is, the substrate wiring forming method according to the present invention is a method of forming a wiring by embedding a metal by electrolytic plating in a concave portion of a substrate on which a concave portion such as a trench or a contact hole is processed and formed. The method further includes a suppressive substance attaching step for attaching a substance that suppresses plating to a surface excluding the inner surface of the recess, such as a wall surface and a bottom surface, and an electrolytic plating step for performing subsequent electrolytic plating.

  Further, in the present invention, the plating suppression substance detachment that causes the substance that suppresses the plating to be released from the outermost surface of the substrate by performing electrolysis in a direction opposite to the electrolysis direction of the plating further after the above-described suppression substance attaching step and the electrolytic plating step. It is preferable to perform the process, and in addition, it is more preferable to perform the electrolytic plating process again as a subsequent process of the above-mentioned various processes.

  In addition to the plating suppression substance removing step of performing electrolysis in the direction opposite to the electrolysis direction of the plating, there are the following methods for releasing the substance that suppresses plating from the outermost surface of the substrate.

  A method in which a substance that suppresses plating is removed from the outermost surface of the substrate in or outside the plating solution by an elastic body having physical properties that do not damage the substrate.

  A method of detaching a substance that suppresses plating from the outermost surface of the substrate by immersing the substrate outside a plating solution in a solution that dissolves the substance that suppresses plating.

  A method in which a substance that suppresses plating is detached from the outermost surface of the substrate by vibrating the outermost surface of the substrate with ultrasonic waves in or outside the plating solution.

A method in which a water pressure is applied to the outermost surface of the substrate in a plating solution or outside the plating solution by a nozzle or the like to release a substance that suppresses plating from the outermost surface of the substrate.
As described above, several methods for releasing the material for suppressing plating from the outermost surface of the substrate have been shown.

  As described above, a substance that suppresses plating is attached only to the outermost surface (substrate convex part) of the substrate, and a substance that suppresses plating is not attached to the inner surface of a recess such as a wiring groove, that is, a trench or a contact hole. When the electrolytic plating is performed, the copper layer is formed so as to fill the recess.

  As described above, the concave portion of the substrate is filled with copper, and when the surface of the copper reaches the same surface as the outermost surface of the substrate to which a substance that suppresses plating is attached, electrolysis is performed in the opposite electrolysis direction to plating. The material that suppresses plating is released from the outermost surface of the substrate. Needless to say, “the same surface as the outermost surface of the substrate” is the same surface as the surface formed by the seed layer and the barrier layer formed on the outermost surface of the substrate, and is attached to the outermost surface of the substrate. It is not the same surface as the surface on which the plating inhibitor is formed. This also has the same meaning throughout the present invention (specification).

  Next, when electrolytic plating is performed again, in addition to the surface of the copper layer (the portion that becomes the wiring of the semiconductor integrated circuit) embedded in the recess such as the wiring groove, the most of the substrate from which the substance that suppresses the plating has separated is removed. On the surface (substrate convex portion), electrolytic plating proceeds simultaneously, and a copper film is deposited with a uniform thickness on the entire surface of one side of the substrate (that is, the entire surface where the concave portions such as the wiring grooves are processed and formed). Therefore, if the electroplating is completed when the thickness of the copper film deposited on the outermost surface of the substrate reaches a desired value, a substrate having a copper plating surface with high flatness over the entire surface can be obtained. .

Since the above substrate can be obtained, the following advantages are obtained.
(1) In the heat treatment step performed after the plating step, the deposited copper metal is controlled at a uniform temperature over the entire substrate, so that an ideal heat treatment effect can be obtained, so recrystallization and strain relief. Is made enough. Therefore, for example, it is possible to suppress the occurrence of problems such as disconnection of a semiconductor chip formed on the substrate.

  (2) Further, the plating film thickness can be suppressed to a small value as long as the copper film on the entire substrate has a thickness that can be heat-treated at a uniform temperature including the thickness direction. Time can be shortened.

  (3) Further, for example, if the time of electrolysis opposite to the electrolysis direction of electroplating and the conditions (current density, applied voltage, treatment time for electrolysis opposite to electrolysis direction of electroplating, etc.) are appropriately selected, Since the plating surface can be made sufficiently flat when the plating process is completed, the following advantages can be obtained in the subsequent CMP process.

-It can be sufficiently flattened and removed without excess copper.
-An abrasive such as a grindstone does not apply an excessive shearing force to the copper wiring or the like of the substrate, so that the above-described peeling does not occur between the copper layer, the barrier layer, the insulating material and the like.
In addition, since the flatness is high from the beginning of the CMP process, dishing and erosion do not occur.

  Furthermore, in the present invention, when a substance that suppresses plating is attached to the outermost surface (substrate convex portion) of the substrate, a substance that suppresses plating is attached to the stamp in advance, and then the stamp is pressed against the outermost surface of the substrate. By adopting the transfer method, the plating inhibiting substance can be adhered to the outermost surface of the substrate with a uniform thickness, so that an advantageous result that a flat plating film can be obtained can be obtained.

  In the substrate wiring forming method according to the present invention, copper, a copper alloy, or silver is used as the plating metal. Thereby, a highly practical substrate wiring can be obtained.

  Furthermore, in the substrate wiring forming method according to the present invention, a substance that suppresses plating is attached to the outermost surface of the substrate so that the thickness thereof is uniform, for example, the entire outermost surface (substrate convex portion) of the substrate. When the electrolysis is applied in the direction opposite to the electrolysis direction of the electroplating, the substance that suppresses the plating can be uniformly detached from the outermost surface of the substrate. Therefore, it contributes to the flattening of the plating surface at the end of the electrolytic plating process.

  Furthermore, as described above, the stamp used in the substrate wiring forming method according to the present invention attaches a substance that suppresses plating to the surface other than the inner surface of the recess, such as a wiring groove of the substrate, such as a trench or a contact hole, that is, the outermost surface of the substrate. The plating suppression substance carrying part is manufactured using at least one of silicone resin or fluororesin. In addition, you may manufacture together with materials other than these resin as needed. In addition, when there is a situation such as the mechanical strength of the plating suppression substance carrying part itself being small, it is preferable that the stamp is formed by providing a support on the plating suppression substance carrying part.

  Since the stamp is manufactured using the above-mentioned material as the material for the plating suppression substance supporting portion, an advantageous effect that the ink releasability is good can be obtained. Further, in the stamp according to the present invention, at least the outer surface of the plating suppression substance supporting portion is formed in a flat plate shape or a cylindrical shape. A stamp having a plate-like surface shape of the plating-suppressing substance-carrying portion is versatile because it can be used by processing its outer shape into, for example, a rectangle or a circle. A cylindrically formed stamp can be rotated around its axis.

  According to the first aspect of the present invention, since the plating suppression substance attaching step and the electrolytic plating step are provided, it is effective only on the inner surface of the recess such as a wiring groove without forming a plating film on the outermost surface of the substrate. A substrate having a metal plating film formed thereon is obtained.

  According to the second aspect of the present invention, since the plating suppression substance removal step is provided after the electrolytic plating step, the plating suppression material on the outermost surface of the substrate is removed. A substrate having a configuration in which a metal plating film can be formed on the entire surface on the side where the recesses are formed is obtained.

  In the inventions according to claims 3 to 11, since the electrolytic plating step is provided after the plating inhibitor releasing step, a substrate in which a metal plating film is formed on the entire surface of the substrate on which the recesses such as wiring grooves are formed is obtained. Therefore, the following excellent effects can be obtained.

(1) Since the metal plating film is formed on the entire surface of the substrate where the recesses such as wiring grooves and contact holes are formed, recrystallization and distortion can be sufficiently relaxed in the heat treatment step after the electrolytic plating step. Therefore, it is possible to suppress the occurrence of problems such as disconnection of the wiring of the semiconductor chip formed in the substrate, for example.
(2) Since the plating film thickness, for example, the thickness of the plating film deposited so as to cover the outermost surface of the substrate can be controlled to an appropriate value, the time required for the CMP process can be suppressed to an appropriate value.
(3) Further, in the CMP (Chemical Mechanical Polishing) step, the entire substrate can be flattened, the excess copper film can be removed, and dishing and erosion are less likely to occur, so that excellent CMP processing can be performed. .

  According to invention of Claim 12 and 13, the board | substrate wiring formation apparatus which has the effect of said (1) thru | or (3) can be provided.

  According to the fourteenth to sixteenth aspects of the present invention, it is possible to provide a plating-inhibiting substance transfer stamp capable of adhering a substance that suppresses plating to the outermost surface of the substrate so that the thickness thereof is uniform.

  Hereinafter, embodiments of the present invention will be described. In the substrate wiring forming method according to the present invention, as a process performed before so-called damascene plating in which a wiring groove or the like formed on the substrate, that is, a recess such as a wiring groove or a contact hole is filled with metal by electrolytic plating, After damascene plating, an ink (plating inhibitor) that selectively suppresses plating is usually applied onto the barrier layer covering the insulating material and the seed layer on the insulating layer by transfer or the like. A plating-inhibiting substance adhering step for controlling the film thickness of the copper layer removed in this step. Here, “ink” is a substance that should be finally attached to the adherend surface, for example, the copper layer or barrier layer on the outermost surface of the substrate, and is usually dissolved in an appropriate solvent as a solute. In the state of the solution thus applied, it is applied to the plating-suppressing substance carrying portion of the stamp or adhered (transferred) to the adherend surface (transfer surface).

  The ink deposition method is an excess copper seed layer excluding semiconductor device wiring that is removed in the post-damascene plating process (fine wiring formed as recesses such as trenches and contact holes formed on the substrate) In order to embed copper in the pattern by electroplating, it is necessary to prevent the metal species from diffusing in the interlayer insulating film or barrier layer (layer formed by sputtering or CVD in advance to provide electrical conductivity to the entire substrate). This is a method of selectively depositing ink on a layer formed for the purpose of prevention, and is a step performed before damascene plating, and is performed to suppress plating in damascene plating, which is electrolytic plating. Is called.

  The electrolytic plating method is a side surface in which concave portions such as trenches and contact holes for embedding metal in a substrate are processed and formed, and the surface of the substrate excluding the inner surface of the concave portion such as the wall surface and bottom surface of the concave portion (the outermost surface of the substrate, that is, the substrate It is a plating method including a step of attaching a substance that suppresses plating to the projections) and a step of performing subsequent electrolytic plating.

  After the step of attaching the substance that suppresses plating and the step of performing electrolytic plating, the step of separating the substance that suppresses plating from the outermost surface of the substrate by performing electrolysis in the direction opposite to the electrolytic direction of plating is performed. In addition, it is more preferable to perform the electroplating step again as a subsequent step of the above steps.

The method for releasing the substance that suppresses plating from the substrate surface includes the following (a) to (a) in addition to releasing the substance that suppresses plating from the substrate surface by performing electrolysis in a direction opposite to the electrolytic direction of the plating. There is a method d).
(A) A method in which a substance that suppresses plating is separated from the outermost surface of the substrate in or outside the plating solution by an elastic body having physical properties that do not damage the substrate surface.
(B) A method of immersing in a solution that dissolves a substance that suppresses plating outside the plating solution and releasing it.
(C) A method in which a substance that suppresses plating is detached from the outermost surface of the substrate by vibrating the outermost surface of the substrate with ultrasonic waves in or outside the plating solution.
(D) A method of applying a water pressure to the outermost surface of the substrate with a nozzle or the like in the plating solution or outside the plating solution to release the substance that suppresses plating from the outermost surface of the substrate.

  When transfer is performed as a method for attaching a plating inhibitor, a stamp and ink dissolved in a solvent are used. In the transfer method, a stamp is first manufactured, ink dissolved in a solvent is applied to the stamp, and then the surface of the stamp where the ink is applied is brought into contact with the transfer surface of the substrate. Transfer to the transfer surface. 4 and 5 are diagrams showing an outline of the ink transfer method. FIG. 4 shows a transfer method using a flat stamp, and FIG. 5 shows a transfer method using a roller-shaped (columnar) stamp.

  As shown in FIG. 4 (a), the transfer method shown in FIG. 4 includes a plating inhibitor carrying part 1 made of a silicone resin material or a fluororesin material for carrying the ink 4, and the plating inhibitor carrying part 1 A stamp 3 having a support 2 to be supported is prepared, and an ink 4 is applied to a plating inhibitor carrying part 1 having a flat outer surface as shown in the figure. The ink is usually dissolved in an appropriate solvent to be in a solution state. Next, as shown in FIG. 4B, among the seed layer and the barrier layer 12 formed on the surface including the inner surface of the recess 11 of the substrate 10 in which the recess 11 such as a trench and a contact hole is formed. As shown in FIG. 4C, the inner surface of the concave portion 11 of the substrate 10 is removed by bringing the stamp 3 coated with the ink 4 into contact with the plating suppression substance carrying portion 1 against the outermost surface of the substrate. The ink 4 is transferred to the surface of the seed layer and the barrier layer 12.

  In the transfer method shown in FIG. 5, a stamp 6 having a structure in which a plating suppression substance supporting portion 5 having an outer surface of a roller (columnar) is provided on the outer periphery of a support 7 is prepared, and the outer periphery of the plating suppression substance supporting portion 5 is prepared. Ink 4 is applied to the surface. The plating-suppressing substance supporting portion 5 coated with the ink 4 is rotated in contact with the outermost surface of the substrate among the seed layer and the barrier layer 12 on the side where the recesses 11 such as trenches and contact holes of the substrate 10 are processed and formed. As a result, the ink 4 is transferred to the surface of the seed layer and the barrier layer 12 excluding the inner surface of the recess 11 of the substrate 10.

[Stamp plating inhibitor carrying part]
[Material for plating inhibitor carrying part]
Silicone resin is used as the material of the plating inhibiting substance supporting portion 1 of the stamp 3. Polydimethylsiloxane (PDMS), PDMS-methyl H siloxane copolymer, H-terminal polydimethyl siloxane and the like can be preferably used. These are resins usually used in existing microcontact printing technology. Silicone resin is not a rubber having a normal carbon skeleton C—C bond (the ionic bond is approximately 0%) but has a Si—O bond in the main chain, and this Si—O bond has a large ionic bond of approximately 50%. For this reason, the thermal mobility of the side chain bonded to Si is increased, and other adjacent substances are hardly approached, so that the releasability of ink or the like is improved.

  Moreover, as long as the plating suppression substance carrying | support part 1 is a thing with high flatness, inorganic compounds, such as resin other than the said silicone resin, a metal, glass, a ceramic, may be sufficient. The flatness is preferably higher than the surface roughness and waviness of the outermost surface of the substrate that is the transfer object. In addition, it is desirable that the material is such that when the ink 4 is applied, the plating-suppressing substance-carrying portion 1 does not swell and impair the flatness.

  In addition, the hardness of the material of the plating inhibitor carrying part 1 is such that when there is unevenness intentionally formed on the surface of the transfer object, for example, a portion where ink is not transferred, such as a semiconductor wafer, that is, a recess such as a trench or a contact hole Is processed and formed, it is not desirable that the stamp 1 is so soft that the stamp 1 enters the recess.

  In addition, when the plating inhibitor supporting part 1 is non-conductive or non-magnetic, conductive materials {metals (metal particles, metal fibers, metal flakes), carbons (carbon nanotubes, carbon wires, carbon coils, carbon particles) ), An organic conductive substance} or a magnetic material can be mixed in the material of the plating inhibitor carrying part 1 to control the transfer process using an electric field / magnetic field. Further, in the case of non-conductivity, the transfer process can be electrostatically controlled by positively utilizing the non-conductivity.

[Manufacturing Method of Stamping Plating Suppressing Substance Carrier]
The method for producing the plating inhibitor carrying part 1 is a surface having a higher degree of flatness than the surface roughness of the transfer object, that is, the surface roughness or waviness of the transfer surface such as the surface of the copper seed layer and the barrier layer 12 (normally The material of the plating inhibitor supporting part 1, for example, PDMS, is applied in a liquid state to a mold for forming a plating inhibitor supporting part having a mirror surface (which corresponds to a mold if the plating inhibitor supporting part 1 is a casting). . Next, it is cured using a curing agent at a greenhouse or at a high temperature or if necessary, to release the mirror surface, so that the plating-suppressing substance-carrying part 1 has a mirror surface state.

  In addition, after the material of the plating inhibitor carrying part 1 such as a silicone resin is once cured, the surface can be finished to a mirror surface by polishing or the like. When the plating inhibitor carrying part 1 is soft and the mechanical strength is not sufficient when performing the transfer operation, it is preferable to provide a support 2 for reinforcement on the base of the plating inhibitor carrying part 1. At this time, the primer is applied to the support 2 and then brought into contact with the material of the plating inhibitor carrying part 1 in a liquid state, and then the material of the plating inhibitor carrying part 1 is cured. As a result, the support 2 and, for example, a silicone resin, which is the plating-suppressing substance-carrying part 1, can be preferably used as the stamp 3 by firmly bonding.

  In addition, although the above demonstrated the structural material, manufacturing method, etc. of the flat plating inhibitory substance support part 1, it is substantially the same also in the case of the roller-shaped (columnar-shaped) plating inhibitory substance support part 5 shown in FIG.

〔ink〕
As a method for adhering the ink 4 to the seed layer and the barrier layer 12 formed on the substrate 10, adsorption (chemical adsorption, physical adsorption, etc.), chemical bonding, anchoring effect utilizing surface irregularities, fusion, static There are electroadsorption. As described above, the ink 4 needs to have a proper adhesion to the seed layer and the barrier layer 12 because it is necessary to form a film, particularly a film that performs a plating suppression function. The adhesive strength must be such that it can be completely removed in the process of electrolysis in the direction opposite to the electrolysis direction of the plating. In addition, the thickness of the ink 4 transferred to the seed layer and the barrier layer 12 as the transfer target is preferably such that the aspect ratio of the wiring groove or the like of the wiring portion is suppressed to a value of 2 times or less. That is, it is preferable to suppress the thickness of the ink 4 to a value equal to or less than the depth of the wiring groove before transferring the ink 4 (distance from the top surface of the substrate to the bottom surface of the wiring groove). The thickness is about 10 to 1 μm.

  When the ink 4 is adsorbed and chemically bonded, the adhesion force between the seed layer and the barrier layer 12 that is the transferred object of the ink is a metal that is an acid that accepts electrons or a negative ion that is a base that donates electrons and cations. Since it can be known by the HSAB (Hard and Soft Acids and Bases) rule for determining the stability of the bond with ions and molecules, an appropriate substance can be selected as the ink 4.

When the material of the seed layer and the barrier layer 12 of the substrate 10 to be transferred is copper, copper alloy, titanium, titanium alloy, tantalum, tantalum alloy, ruthenium, ruthenium alloy, RSH, R2S, RS ⁻ , I ⁻ , SCN ⁻ , S ₂ o ₃ ²⁻ , R ₃ P, R ₃ As, (RO) ₃ P, CN ⁻ , RCN ⁻ , CO, C ₂ H ₄ , C ₆ H _{6 and the} like (R is an alkali group or an aryl group The following are examples of substances suitable for the ink 4.

  Alkanethiol, benzotriazole, casein, dextrin, dimethylamino derivative, 1,8-disulfonic acid, ethylene oxide, gelatin, mulberry, lactose benzoyl hydrazone, molasses, petroleum sulfonic acid, o-phenanthroline, polyethoxy Ether (polyethylene glycol), polyethyleneimine, poly N, N'-diethylsafranine, polypropylene ether, propylene oxide, sugar, thiourea, polyalkylene glycol, animal mulberry, polymers containing ether groups, high protein polymers of amino acids, poly Alkylene glycol, polyethylene oxide, hydroquinone or ethoxylated alkylphenol, polyethylene oxide, glycol, amine, alkoxylated lactam , Disubstituted ethanesulfonic acid, urea and glycerin, urea, sodium lauryl sulfonate, tosyl or mesyl sulfonic acid, phenazine dye, polyether surfactant + benzene sulfonic acid + grain improver, polyether + mercaptoimidazole + benzene sulfonic acid , Polyether + organic divalent sulfur compound + tertiary alkylamine + polyepichlorohydrin, sulfamic acid, alkylated polyalkyleneimine, ω-sulfo-n-propyl-N, N-diethyldithiocarbamate + polyethylene glycol + Crystal violet, phthalocyanine + tertiary alkylamine + polyepichlorohydrin + benzene sulfonic acid, polyether + mercaptoimindazole + benzene sulfonic acid, phenolphthalein, substituted phthalocyanine radicals, Regular coffee, alkylated polyalkyleneimine, disulfide, sulfonic acid, aliphatic aldehyde, di- or triaminotriphenylmethane dye and sulfoalkyl sulfide, urea, polyether, polysulfide, heterocyclic sulfur and polyether compounds, polyethyleneimine , Polyethylene glycol, formaldehyde and thiourea, ethylene oxide product and 2-mercaptopyridine, polysulfide, thiourea and polyether, polyethers, phenazonium polymer, tannin (acid), various complexing agents that coordinate with copper .

  The ink 4 may be used as it is when these solutes are liquid, but is generally used after being dissolved in a solvent, including the case where it is solid. In consideration of solubility parameters and mixing properties, the concentration is adjusted by dissolving in a solvent that can be dissolved (solvent).

  When the material of the transfer surface, that is, the material of the outermost surface of the substrate 10 is copper, copper alloy, titanium, titanium alloy, tantalum, tantalum alloy, ruthenium, or ruthenium alloy, the ink 4 is adhered to the substrate 10 by the throwing effect. Can use an existing high molecular compound such as a photoresist as the ink 4.

  Similarly, a low-melting-point metal can be used in place of the ink 4 and its solvent for adhesion by fusing.

  In the case of adhesion by electrostatic adsorption, a solution containing a solvent having a different complex dielectric constant and fine particles functioning as the ink 4 can be used. This is because direct current or alternating current is present between the plating suppression substance supporting part 1 (or the plating suppression substance supporting part 5) of the stamp 3 (or stamp 6) and the transfer target (seed layer and barrier layer 12) in a state where the solvent is not evaporated. Electrophoresis or dielectrophoresis generated by applying the above voltage is used to fix the fine particles as ink 4 on the transfer object. As the fine particles, metal or non-metallic oxide particles or polymer compound fine particles can be used.

[Method of applying ink to stamping plating inhibitor carrying part]
The various inks 4 are normally applied to the stamp 3 (or the stamp 6) in a state where the ink 4 is dissolved in a solvent. Various coating devices can be used for coating on the stamp. For example, forward rotation roll coater, reverse roll coater, gravure coater, knife coater, blade coater, rod coater, air doctor coater, curtain coater, fountain coater, kiss coater, spin coater, spray coater, impregnation machine, extrusion coater, dip coating Machine, screen printing machine, cast coating machine, vacuum coating machine, coating machine using LB method, and the like.

[Method of transferring and adhering (fixing) the stamp from the plating-suppressing substance-bearing part to the transfer object]
Here, the situation in which the ink 4 is transferred from the plating suppression substance carrying portion 1 (or the plating inhibition substance carrying portion 5) to the transfer target (transfer target surface) and the situation in which the ink 4 is fixed (adhered) to the transfer target surface. explain. In general, the ink 4 applied to the plating inhibiting substance carrying part 1 (or the plating inhibiting substance carrying part 5) of the stamp 3 (or stamp 6) in the state of a solution dissolved in a solvent is generally applied to the surface to be transferred. By being pressed against the plating inhibiting substance carrying part 1 (or the plating inhibiting substance carrying part 5), it is transferred to the transfer surface side. At this time, a pressing force is applied to the stamp 3 (or the stamp 6) by, for example, a press mechanism. This pressing force is preferably controlled so that the pressure acting between the transferred surface and the plating suppression substance carrying part 1 (or the plating suppression substance carrying part 5) becomes an appropriate value. The pressing time is preferably an appropriate time.

  Next, the situation where the ink 4 adheres to the transfer surface will be described. Generally, ink is used as a solute as described above, and a solvent (solvent) in which the solute is dissolved is transferred onto the transfer surface as a medium. After the transfer, the ink adheres to the transfer object by volatilization of the solvent (solvent). Therefore, the ink is transferred to the surface of the copper seed layer and the barrier layer 12 on the outermost surface of the substrate as the transfer surface. At the time, since the solvent is still present, it is necessary to adjust the temperature / humidity of the adhesion (transfer) site environment so that the solvent is volatilized and evaporated.

[Plating inhibitor removal method]
In order to remove (separate) the ink 4 adhered to the outermost surface of the substrate 10 on which the concave portion 11 is formed, there are methods shown in the following (1) to (5).

  (1) When the upper surface of the copper embedded in the recess 11 by electrolytic plating reaches the same surface as the outermost surface of the substrate to which a substance that suppresses plating is applied, an electric field is applied in the opposite direction to the electrolytic plating, and plating is performed. A method in which the substance to be suppressed is released from the outermost surface of the substrate. (It should be noted that the “outermost surface of the substrate on which a substance that suppresses plating is attached” refers to the surface on which the seed layer and the barrier layer 12 formed on the outermost surface of the substrate are formed. (This is not the surface formed by the plating-suppressing substance attached to the outermost surface, which is the same for the entire present invention (the entire present specification).)

  (2) An elastic body having physical properties that does not damage the substrate when the upper surface of the copper embedded in the recess 11 by electrolytic plating reaches the same surface as the outermost surface of the substrate on which a substance that suppresses plating is adhered; For example, a non-woven fabric such as rubber, polyurethane, acrylic resin, or the like, and a method of releasing a substance that suppresses plating with a pad from the outermost surface of the substrate in or outside the plating solution.

  (3) An organic solvent or acid that dissolves the substance that suppresses plating when the upper surface of the copper embedded in the recess 11 by electrolytic plating reaches the same surface as the outermost surface of the substrate to which the substance that suppresses plating is attached. A method of detaching by immersing outside the plating solution with an aqueous solution of alkali or the like.

  (4) When the upper surface of the copper embedded in the recess 11 by electrolytic plating reaches the same surface as the outermost surface of the substrate to which a substance that suppresses plating is adhered, the outermost surface of the substrate is exposed in the plating solution or outside the plating solution. A method of detaching substances that suppress plating by vibrating the liquid using an ultrasonic vibrator.

  (5) When the upper surface of the copper embedded in the recess 11 by electrolytic plating reaches the same surface as the outermost surface of the substrate to which a substance that suppresses plating is adhered, the uppermost surface of the substrate in the plating solution or outside the plating solution A method of removing a substance that suppresses plating by applying water pressure with a nozzle or the like.

  First, an embodiment of the present invention for forming a substrate wiring will be described with a focus on an electrolytic copper plating process. FIG. 6 is a diagram showing a configuration example of the substrate wiring forming apparatus according to the present invention. This board | substrate wiring formation apparatus 20 is an electroplating apparatus, and comprises the plating tank 21 in which the plating solution (copper sulfate plating) Q is accommodated. In the plating tank 21, the substrate 10 held by the substrate holder 22 and the anode 24 held by the anode holder 23 are arranged to face each other. An overflow tank 26 is disposed outside the plating tank 21, and the plating solution overflowing the overflow weir 25 of the plating tank 21 flows into the overflow tank 26.

  The plating solution Q flowing into the overflow tank 26 is supplied by the pump 28 through the constant temperature unit 29 and the filter 30 provided in the circulation pipe 27 into the plating tank 21 and circulates. That is, the temperature of the plating solution Q in the overflow tank 26 is adjusted to a predetermined temperature by the constant temperature unit 29, contaminants are removed by the filter 30, and supplied to the plating tank 21. Reference numeral 32 denotes a switching means (a changeover switch or the like). When the switching means 32 is in contact with the contacts a and a, the cathode of the plating power supply (DC power supply) 31 is connected to the substrate 10 and the anode is connected to the anode 24. The cathode is applied to the anode, and the anode is applied to the anode 24. When the switching means 32 is in contact with the contacts b and b, the anode of the plating power source 31 is connected to the substrate 10 and the cathode is connected to the anode 24, and the anode is applied to the substrate 10 and the cathode is applied to the anode 24. ing.

  An example of a substrate wiring forming method according to the present invention used in the substrate wiring forming apparatus 20 having the above configuration will be described with reference to FIG. FIG. 7 mainly shows the progress of the plating of the substrate in the plating process according to the present invention. As shown in FIG. 7A, the surface of the substrate 10, that is, the surface of the substrate 10 excluding the seed layer on the side where the recesses 11 such as the trenches and contact holes of the substrate 10 are processed and the inner surface of the recesses 11 of the barrier layer 12 is formed. The substrate 10 with the ink 4 attached to the outermost surface is held by the substrate holder 22 so that the surface with the ink 4 attached faces the anode 24. Thereafter, when the switching means 32 is brought into contact with the contacts a and a, the cathode is applied to the substrate 10 and the anode is applied to the anode 24 from the plating power source 31, and the electrolytic plating is started. As a result, copper 13 is deposited in the recess 11 of the substrate 10. When the upper surface 13a of the copper 13 deposited in the recess 11 coincides with the seed layer to which the ink 4 is adhered and the upper surface 12a of the barrier layer 12 as shown in FIG. The electroplating is stopped after separating from a.

  Thereafter, the switching means 32 is brought into contact at the contacts b and b, an anode is applied to the substrate 10 from the plating power source 31 and a cathode is applied to the anode 24, and electrolysis in the direction opposite to that during electrolytic plating is applied for a predetermined time. As a result, the ink 4 attached to the seed layer and the barrier layer 12 is removed as shown in FIG. 7C, and the upper surface 13a of the copper 13 and the upper surface 12a of the seed layer and the barrier layer 12 appear to coincide with each other. . Next, in this state, the switching means 32 is brought into contact with the contacts a and a and electrolytic plating is performed for a predetermined time, whereby a flat deposited layer of copper 13 is formed on the entire surface of the substrate 10 on the side where the recess 11 is formed. It is formed (see FIG. 7D). In FIG. 7, 51 indicates the outermost surface of the substrate 10, 52 indicates the inner surface of the recess, and 53 indicates the flat plating surface obtained at the end of the plating process according to the present invention, that is, the surface at the end of the plating process.

  As described above, the substrate 10 on which the flat deposited layer of copper 13 is formed on the entire surface on which the concave portion 11 is formed is heat-treated in a subsequent step of the plating step, thereby reducing recrystallization and strain. Since it can be performed sufficiently, it is possible to suppress the occurrence of problems such as disconnection of wiring. Further, by controlling the thickness of the deposited layer of copper 13 to an appropriate value, the time required for the CMP process can be suppressed to an appropriate value. Thus, planarization of the entire substrate 10 can be realized, and an excess deposited layer of the copper 13 can be removed, and the dishing 104, the erosion 105 (see FIG. 1B), and the peeling between the copper layer, the barrier layer, and the insulating layer can be performed. Therefore, CMP can be suitably performed.

  Next, an embodiment in which a copper plating film is formed on a semiconductor wafer by electrolytic copper plating using a substrate wiring forming method or a plating inhibitor transfer stamp according to the present invention will be described. For the stamp, a two-component room temperature curing type silicone rubber (trade name; Sylpot 184W / C) manufactured by Dow Corning is used as the silicone rubber.

  For the support 2 of the stamp 1, an 8-inch Si wafer (first wafer) with a SiO2 oxide film is used. This wafer is cleaned by UV ozone cleaning, and a primer (FSXA-2869; Dow Corning) is applied to the mirror surface side. Subsequently, the above-mentioned sylpot 184 W / C is mixed and degassed under reduced pressure, and dropped onto the above-described first wafer. An 8-inch wafer (second wafer) with a separate oxide film is placed on this so that the mirror side is in contact with the silicone rubber (Sylpot 184W / C) without using a primer, and is kept for about one day at room temperature or a constant temperature bath. The silicone rubber is cured by allowing it to stand for a certain time (for example, about 1 hour at 150 ° C).

  After the curing, the separate 8-inch wafer with oxide film (second wafer) without the primer is peeled off from the silicone rubber, and the wafer with the silicon rubber having a certain thickness (first wafer) is removed. Used as a stamp.

  The plating-suppressing substance-carrying portion of the stamp, that is, the silicone rubber surface is appropriately cleaned using the same solvent as the solvent used for the ink, but when used in the initial state, only UV ozone cleaning is required.

As a plating inhibitor, that is, a solution in which octadecyltrichlorosilane is mixed with hexane or toluene as a solvent as an ink (solute) in an amount of about 0.1 to 50 mmol / l (mole per liter), or an alkanethiol C _n H _{2n + 1} as an ink. Using SH (n = 8, n = 10) mixed with alcohol (ethyl alcohol, isopropyl alcohol, butyl alcohol) as a solvent in an amount of about 0.1 to 50 mmol / l (mmole per liter) Transfer to the surface. Alkanethiol adsorbs on the metal surface as the number of n increases, and then the alkanethiol alkyl chains tend to adsorb at high density in a stable energy state in which the attractive force and repulsive force are balanced by van der Waals forces. Therefore, it is preferable as an ink. However, when the number of n is large, the solubility in a solvent is lowered, and therefore the number of n is preferably 8-10.

  The solution containing the ink is applied to the silicone rubber, which is a plating inhibitor supporting part on the stamp surface, using a spin coater.

A concave portion such as a wiring groove is formed on the surface of the silicone rubber of the stamp, and the semiconductor wafer on which the copper seed layer is formed is pressed against the surface to be transferred to transfer the solution in which the ink is dissolved. When transferring, the contact time is appropriately changed within a range of 3 seconds to 2 minutes. Usually, the electrolytic copper plating is started by dipping in a copper sulfate plating solution within about 1 minute. An example of the solution composition of copper sulfate plating is shown below.
CuSO ₄ · H ₂ O 225 g / l
H ₂ SO ₄ 55 g / l
Cl-60 ppm
Plating is performed at a current density of −5 to −50 mA / cm ² on the substrate until filling of the recesses of the substrate is completed.

Reverse electrolysis is performed after the trench is filled with metal by plating. That is, the current density in the substrate is set to +5 to +50 mA / cm ² on the positive electrode side, and the time is applied for 10 to 5 seconds to desorb the ink from the substrate to be transferred into the plating solution.

  Thereafter, electrolytic plating is again performed under the above-described conditions. As a result of the above series of steps, a thin copper film having a thickness of several tens of nanometers on the outermost surface of the substrate is spread over the entire surface to be plated (that is, the surface on the side where the recesses such as the wiring grooves are formed). It was possible to form a flat film.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Is possible.

It is a figure which shows the state of the board | substrate in the middle of the board | substrate wiring formation process by the conventional damascene method. It is a figure which shows the state of the board | substrate in one process in the board | substrate wiring formation process by the conventional damascene method. It is a figure which shows the state of the board | substrate in one process in the board | substrate wiring formation process by the conventional damascene method. It is a figure which shows the ink transfer process of the board | substrate wiring formation process which concerns on this invention. It is a figure which shows the ink transfer process of the board | substrate wiring formation process which concerns on this invention. It is a figure which shows the structural example of the board | substrate wiring formation apparatus which concerns on this invention. It is a figure which shows the board | substrate wiring formation process which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plating suppression substance carrying part 2 Support body 3 Stamp 4 Ink 5 Plating suppression substance carrying part 6 Stamp 7 Support body 10 Substrate 11 Recess 12 Seed layer and barrier layer 13 Copper 20 Substrate wiring formation device 21 Plating tank 22 Substrate holder 23 Anode holder 24 Anode 25 Overflow weir 26 Overflow tank 27 Circulating piping 28 Pump 29 Constant temperature unit 30 Filter 31 Plating power source 32 Switching means 51 Substrate outer surface 52 Recessed inner surface 53 Surface at end of plating process

Claims (16)

In a substrate wiring forming method for forming a wiring by embedding a recess such as a wiring groove formed on a substrate with a metal by electrolytic plating,
A substrate wiring comprising: a plating suppressing substance attaching step for attaching a plating suppressing substance for suppressing plating to the surface of the substrate excluding the inner surface of the concave portion of the substrate; and an electrolytic plating step for performing electrolytic plating thereafter. Forming method. In the board | substrate wiring formation method of Claim 1,
A substrate wiring forming method, comprising: a plating suppression substance detachment step of detaching the plating suppression substance from the surface of the substrate after the electrolytic plating step. In the substrate wiring formation method of Claim 2,
A substrate wiring forming method comprising an electroplating step of performing electroplating after the plating inhibitor releasing step. In the board | substrate wiring formation method of Claim 2 or 3,
The method for forming a substrate wiring according to claim 1, wherein the plating inhibiting substance removing step is performed by applying electrolysis in the direction opposite to the electrolytic plating direction. In the substrate wiring formation method of Claim 4,
The time of applying electrolysis in the direction opposite to the electroplating direction of the plating inhibitor release process is the surface of the substrate embedded in the recess of the substrate by the electrolytic plating process and the surface of the substrate on which the plating inhibitor is adhered. A method for forming a substrate wiring, characterized in that the two are on the same plane. In the board | substrate wiring formation method of any one of Claims 1 thru | or 5,
The plating inhibiting substance adhering step is characterized in that after the plating inhibiting substance is previously supported on a stamp, the plating inhibiting substance is transferred to the surface of the substrate by pressing the stamp against the surface of the substrate. Substrate wiring forming method. In the board | substrate wiring formation method of any one of Claims 1 thru | or 6,
The method of forming a substrate wiring according to claim 1, wherein the metal embedded in the concave portion of the substrate in the electrolytic plating step is copper, a copper alloy, or silver. In the board | substrate wiring formation method of any one of Claims 1 thru | or 7,
The method of forming a substrate wiring according to claim 1, wherein the plating inhibitor substance adhered to the surface of the substrate in the plating inhibitor substance attaching step is in a film state having a uniform thickness. In the board | substrate wiring formation method of any one of Claim 6 thru | or 8,
A method for forming a substrate wiring according to claim 1, wherein the stamping material carrying part carrying the plating inhibiting material as the stamp uses a stamp having at least one of silicone resin or fluororesin. In the board | substrate wiring formation method of Claim 9,
A substrate wiring forming method, wherein the stamp is a stamp in which a plating suppressing substance supporting portion is supported by a support. In the board | substrate wiring formation method of Claim 9 or 10,
A method for forming a substrate wiring according to claim 1, wherein at least the outer surface of the plating-suppressing substance-carrying part is formed in a flat plate shape or a cylindrical shape as the stamp. A plating solution tank containing a plating solution is provided, and a substrate and an anode electrode having a recess such as a wiring groove formed in the plating solution in the plating solution tank are disposed between the anode electrode and the substrate from a plating power source. In a substrate wiring forming apparatus in which a predetermined plating voltage is applied and a recess is formed with metal by electrolytic plating to form a wiring, the substrate is provided with a plating inhibitor that suppresses plating on the surface of the substrate except the inner surface of the recess. A substrate wiring forming apparatus, which is an attached substrate. The board | substrate wiring formation apparatus of Claim 12 WHEREIN:
Polarity switching means for switching the polarity of the voltage applied between the anode electrode and the substrate at a predetermined timing during the electrolytic plating so that the polarity of the polarity is opposite to that during the electrolytic plating. A substrate wiring forming apparatus comprising: When forming a wiring on the substrate by embedding a recess such as a wiring groove formed on the substrate with metal by electrolytic plating,
A plating inhibitor transfer stamp used to transfer a plating inhibitor that suppresses plating to the surface of the substrate excluding the concave inner surface of the substrate,
The plating inhibitor transfer stamp, wherein at least the plating inhibitor carrying part of the stamp comprises at least one of silicone resin or fluororesin. The plating-inhibiting substance transfer stamp according to claim 14,
The stamping material transfer stamp is characterized in that the stamp has a structure in which at least a plating restraining material carrier is supported by a support. The plating inhibitor transfer stamp according to claim 14 or 15,
The stamping material transfer stamp characterized in that the stamp has at least an outer surface of the plating restraining material carrying part being flat or cylindrical.

Images