JP2016048779A - Circuit device having three-dimensional wiring, method for forming three-dimensional wiring, and a composition for metal film formation for three-dimensional wiring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit device having three-dimensional wiring with good conductivity, which makes possible to readily manufacture the three-dimensional wiring with a relatively high productivity at a relatively low manufacturing cost.SOLUTION: A silicon through wiring board 1 having three-dimensional wiring arranged so that an upper wiring 12a and a lower wiring 13a are electrically connected to each other by a contact plug 14a is manufactured. The contact plug CP includes a bottom part seed layer BS, a main seed layer MS, and a plug main body PB. The bottom part seed layer BS is formed by a conductor layer formed by vapor deposition. The main seed layer MS is formed by heating a coating film of a composition for metal film formation which includes at least one of a salt of a metal selected from Group X and Group XI of the periodic table and particles thereof.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a circuit device having three-dimensional wiring, a method for forming a three-dimensional wiring, and a metal film forming composition for three-dimensional wiring.

  In integrated circuits and circuit boards, etc., in order to achieve high density mounting of circuit elements, high wiring density, reduction of wiring length, etc., predetermined wirings and circuits are divided into two or more wiring layers and designed. A three-dimensional wiring technique in which the wiring layers are distributed on the upper and lower surfaces of the substrate or laminated on one surface of one substrate is widely used. For example, when two wiring layers are dispersedly arranged on the upper and lower surfaces of the substrate, the wiring layers are electrically connected to a through electrode (hereinafter referred to as a through electrode) that penetrates the substrate from one wiring layer side and reaches the other wiring layer side. , Called contact plug). Further, when a plurality of wiring layers are stacked on one surface of one substrate, the contact plug penetrates the upper wiring layer and reaches the wiring layer positioned below the wiring layer. Non-Patent Document 1, Non-Patent Document 2, and Non-Patent Document 3 describe a technique in which a contact plug is provided on a silicon chip, and wiring on the upper surface side of the silicon chip and an electrode on the lower surface side are electrically connected by the contact plug. Has been.

  As a method for forming a contact plug, a method of filling a conductive paste in a via hole for forming a contact plug is known. For example, Patent Document 1 and Patent Document 2 describe a method of filling a conductive paste with a squeegee in a via hole. Further, as a forming method capable of forming a contact plug having a smaller diameter and higher conductivity than a contact plug using a conductive paste, for example, Patent Document 3, Patent Document 4, and Non-Patent Document 1 include via holes. After forming a seed layer on the inner wall by physical vapor deposition (PVD method), chemical vapor deposition (CVD), atomic layer deposition (ALD), etc., a conductor is deposited by electrolytic plating. A method for filling a via hole is described.

  As a method capable of forming a metal film at a lower cost and in a shorter time than a PVD method, a CVD method, an ALD method, or the like, which is formed in a low-pressure atmosphere or in a vacuum, a metal particle dispersion or metal particle Also known is a method of forming a metal film by applying a heat treatment after coating a composition containing a metal salt or the like as a precursor of the above.

  For example, Patent Document 5 and Patent Document 6 describe that a metal film is formed by applying a dispersion liquid in which metal ultrafine particles are dispersed in a dispersion medium on a base material and then performing heat treatment. Patent Document 7, Patent Document 8, and Patent Document 9 describe that a copper wiring is formed by applying a composition containing copper formate and an amine on a substrate and then heat-treating in an argon atmosphere. Has been.

  Patent Document 10 describes that a copper wiring is formed by applying a composition containing a copper salt and an amine on a substrate and then heat-treating the composition. Patent Document 11 describes that a copper wiring is formed by applying a composition containing copper formate and alkanolamine on a substrate and then heat-treating the composition. Patent Document 12 and Patent Document 13 describe that a copper wiring is formed by applying a composition containing noble metal fine particles, a copper salt, a reducing agent, and a monoamine on a base material, followed by heat treatment. . Patent Document 14 describes that a thermally decomposable metal precursor is coated on a substrate and then thermally decomposed in a reducing atmosphere to form a copper wiring. Patent Document 15 describes a method of forming a conductor on a substrate by coating a conductive precursor containing copper on a substrate and heating.

JP 2002-144523 A JP 2004-39887 A JP 2011-205222 A JP 2000-68651 A JP 2001-35255 A JP 2002-121606 A JP 2008-13466 A JP 2008-31104 A Japanese Patent Laying-Open No. 2005-2471 JP 2004-162110 A JP 2010-242118 A JP 2011-34749 A JP 2011-34750 A US Pat. No. 6,048,790 US Pat. No. 7,629,017

"Through silicon electrode", Tokyo Denki University Press, 2011 "Science & Technology Trends", April 2010, p23-33 “Journal of Japan Institute of Electronics Packaging Vol.12, No.2”, 2009

  From the viewpoint of forming a contact plug with good conductivity, it is desirable to form the contact plug by a plating method. In recent years, however, via holes have become smaller in diameter due to progress in high-density mounting and high wiring density, and the aspect ratio of the via hole (the ratio of the depth to the diameter) has become higher (larger). It has become difficult to form a seed layer under good step coverage in the via hole by either the phase vapor deposition method or the coating method.

  When the seed layer has a low step coverage, when the via hole is filled with metal by plating, the metal deposition on the upper end side of the via hole is larger than the metal deposition on the lower end side, and the via hole is It becomes difficult to deposit a sufficient amount of metal on the lower end side of the metal, and voids are easily generated. In addition, it takes a long time to deposit a sufficient amount of metal on the lower end side of the via hole, and as a result, a metal layer that is thicker than necessary is formed on the upper surface of the substrate, and it takes a long time to remove it. As a result, the productivity is lowered, the manufacturing cost is increased, and the tact time is increased when the excess metal layer is removed by a method such as chemical mechanical polishing (CMP). If a high-performance vapor deposition apparatus is used, it is possible to form a seed layer in a high aspect ratio via hole with good step coverage, but such an apparatus can be used for three-dimensional wiring. This leads to an increase in manufacturing cost and a decrease in productivity.

  An object of the present invention is to provide a three-dimensional wiring having a three-dimensional wiring with good conductivity and capable of easily manufacturing the three-dimensional wiring with a relatively high productivity and a relatively low manufacturing cost. It is providing the circuit device which has these.

  Another object of the present invention is to provide a method for forming a three-dimensional wiring which can form a three-dimensional wiring having good conductivity with relatively high productivity and at a relatively low manufacturing cost. There is.

  Still another object of the present invention is to provide a three-dimensional structure capable of easily forming a metal film with good step coverage in a through hole or a blind via hole having a large aspect ratio even in the through hole or blind via hole. The object is to provide a metal film forming composition for wiring.

The circuit device having the three-dimensional wiring according to the first aspect of the present invention includes an upper wiring formed on the upper surface side of the base material or the electric insulating film, and a lower surface formed on the lower surface side of the base material or the electric insulating film. The side wiring has a three-dimensional wiring electrically connected to each other by a contact plug formed in a through-hole provided in the base material or the electrical insulating film;
The contact plug is formed on the main seed layer, the bottom seed layer constituting the lower end surface side of the contact plug, the main seed layer covering each of the bottom seed layer and the inner wall of the through hole, and the through seed A conductor layer filling the hole,
The bottom seed layer is a conductor layer formed by a sputtering method, and the main seed layer is a metal containing at least one of a metal salt and particles selected from Group 10 and Group 11 of the periodic table. It is a metal film formed by heating the coating film of the film forming composition.

  In the circuit device having the three-dimensional wiring of the first aspect, it is preferable that an average value of the thickness of the main seed layer on the inner wall of the through hole is 10 to 2000 nm.

  In the circuit device having the three-dimensional wiring according to the first aspect, the main seed layer is preferably a sintered film of copper particles.

  In the circuit device having the three-dimensional wiring according to the first aspect, the diameter of the through hole is 1 to 100 μm, the depth is 20 to 200 μm, and the ratio of the depth to the diameter is 1 to 50. preferable.

  In the circuit device having the three-dimensional wiring according to the first aspect, the circuit device further includes a barrier layer that covers at least the inner wall of the through hole as a base layer of the main seed layer. It is preferable to include at least one layer made of a melting point metal alloy or a high melting point metal compound.

In the method for forming a three-dimensional wiring according to the second aspect of the present invention, a contact plug is formed in a through-hole provided in a base material or an electrical insulating film, and is formed on the upper surface side of the base material or the electrical insulating film. The upper wiring and the lower wiring formed on the lower surface side of the base material or the electric insulating film are electrically connected to each other by the contact plug,
A hole forming step of forming a through hole or a blind via hole in the base material or the electrical insulating film;
A bottom seed layer forming step of forming a bottom seed layer by depositing a conductor by vapor deposition on a lower end side of the through hole or on a bottom surface of the blind via hole;
A metal film-forming composition containing at least one of a metal salt and particles selected from Group 10 and Group 11 of the periodic table is applied to the base material or electrical insulating film on which the bottom seed layer is formed. A coating film forming step of forming a coating film covering the upper surface of the base material or the electrical insulating layer, the inner wall of the through-hole or the blind via hole, and the upper surface of the bottom seed layer;
A metal film forming step of heating the coating film to form a metal film;
It is characterized by including.

  In the method for forming a three-dimensional wiring according to the second aspect, the metal film-forming composition preferably has a viscosity of 1 Pa · s or less and a metal concentration of 5 to 50% by mass.

  Moreover, in the formation method of the three-dimensional wiring of a 2nd aspect, it is preferable at the said metal film formation process to heat the said coating film to 100-200 degreeC in the atmosphere or oxygen vacuum of 500 ppm or less of oxygen concentration.

  Further, in the method for forming a three-dimensional wiring according to the second aspect, in the metal film forming step, the metal film having an average thickness on the inner wall of the through hole or the inner wall of the blind via hole is 10 to 2000 nm. Is preferably formed.

  In the second aspect of the method for forming a three-dimensional wiring, the metal film is preferably a sintered film of copper particles.

  In the method for forming a three-dimensional wiring according to the second aspect, the diameter of the through hole or the blind via hole is 1 to 100 μm, the depth is 20 to 200 μm, and the ratio of the depth to the diameter is 1 to 50. Preferably there is.

  Further, in the method for forming a three-dimensional wiring according to the second aspect, prior to the metal film forming step, a high melting point film that forms a high melting point film serving as a base material of the barrier layer on the inner surface of the through hole or the blind via hole. It is preferable to further include a film forming step.

  The method for forming a three-dimensional wiring according to the second aspect further includes a plating step of filling the through hole or the blind via hole by depositing a conductor on the bottom seed layer and the metal film by a plating method. It is preferable.

  Moreover, the method for forming a three-dimensional wiring according to the second aspect preferably further includes a polishing step of removing excess conductor deposited in the plating step by a chemical mechanical polishing method.

  The metal film forming composition for three-dimensional wiring according to the third aspect is characterized by containing at least one of a metal salt and particles selected from Group 10 and Group 11 of the periodic table.

  In the metal film forming composition for three-dimensional wiring according to the third aspect, the metal salt is preferably a carboxylate containing copper or nickel, and the metal particles are preferably copper particles or nickel particles. .

  In the metal film forming composition for three-dimensional wiring according to the third aspect, the metal salt is copper formate or nickel formate, and the metal particles are copper particles having an average particle diameter of 5 to 100 nm. Alternatively, nickel particles are preferable.

  The metal film forming composition for three-dimensional wiring according to the third aspect preferably further contains an amine compound.

  In the composition for forming a metal film for a three-dimensional wiring according to the third aspect, the viscosity is preferably 1 Pa · s or less and the metal concentration is preferably 5 to 50% by mass.

  In the circuit device having the three-dimensional wiring according to the first aspect of the present invention, the contact plug has a bottom seed layer, a main seed layer, and a conductor layer formed on the seed layer to fill the through hole, and the bottom portion The seed layer is formed by a vapor deposition method, and the main seed layer is formed by heating the coating film of the metal film forming composition of the third aspect of the present invention, so that the conductivity of the three-dimensional wiring is good. Thus, it is easy to manufacture the three-dimensional wiring with a relatively high productivity and a relatively low manufacturing cost. Moreover, it is easy to ensure high adhesion to the substrate of the main seed layer.

  In the method for forming a three-dimensional wiring according to the second aspect of the present invention, when forming the contact plug, first, the bottom seed layer is formed by vapor deposition, and then the metal film formation according to the third aspect of the present invention is performed. Since the coating film obtained by applying the composition is heated to form a metal film, the plug body of the contact plug can be formed by a plating method using the metal film as a seed layer. For this reason, according to the method of forming the three-dimensional wiring, a three-dimensional wiring having good conductivity can be formed with relatively high productivity and at a relatively low manufacturing cost.

  Since the composition for forming a metal film for a three-dimensional wiring according to the third aspect of the present invention contains at least one of a metal salt and particles selected from Group 10 and Group 11 of the periodic table, the metal film By heating the coating film obtained by coating the forming composition, even if the through-hole or blind via hole has a large aspect ratio, the metal film has a good step coverage in the through-hole or blind via hole. Can be easily formed.

(A) is a top view which shows roughly one Embodiment about the circuit apparatus which has a three-dimensional wiring, (B) is the schematic of the II line cross section shown to FIG. 1 (A). . (A)-(D) is sectional drawing which shows schematically one process at the time of manufacturing the circuit apparatus (silicon through-wiring wiring board) which has the three-dimensional wiring shown in FIG. 1, respectively. (E)-(I) is sectional drawing which shows schematically one process performed after the process shown in FIG.2 (D), respectively. (A) is sectional drawing which shows schematically other embodiment about the circuit apparatus which has three-dimensional wiring, (B) is enclosed by the circle C drawn with the dashed-dotted line in FIG. 4 (A). FIG. (A)-(C) is sectional drawing which shows roughly one process at the time of manufacturing the circuit device (semiconductor device) which has each three-dimensional wiring shown in FIG. (D)-(F) is sectional drawing which shows schematically one process performed after the process shown in FIG.5 (C), respectively.

Embodiment 1 FIG.
<Circuit device having three-dimensional wiring>
FIG. 1A is a plan view schematically showing an embodiment of a circuit device having three-dimensional wiring, and FIG. 1B is a cross-sectional view taken along the line I-I shown in FIG. FIG. The circuit device having a three-dimensional wiring shown in FIGS. 1A and 1B is a through silicon via substrate. Hereinafter, the reference numeral of the through silicon via substrate will be described as “1”.

  The through silicon via substrate 1 is formed on a silicon substrate 10, a plurality of upper wirings formed on the upper surface of the silicon substrate 10 via an upper barrier layer, and on the lower surface of the silicon substrate 10 via a lower barrier layer. A plurality of lower wirings, and a plurality of contact plugs that respectively penetrate the silicon substrate 10 and electrically connect the predetermined upper wiring and the predetermined lower wiring. Each upper barrier layer has the same shape and size as the upper wiring on it in plan view. Similarly, each lower barrier layer has the same shape and size as the lower wiring below it in plan view.

  FIG. 1A shows five upper wirings 12a to 12e, and FIG. 1B shows three upper wirings 12a to 12c and two lower wirings 13a to 13b. 1A shows six contact plugs 14a to 14f, and FIG. 1B shows three contact plugs 14a to 14c. The upper wiring and the lower wiring that are electrically connected to each other by the contact plug constitute one three-dimensional wiring together with the contact plug.

  As shown in FIG. 1B, each of the upper barrier layers 11a1 to 11a3 covers the upper surface of the silicon substrate 10 from the inner wall of the through hole TH provided with the corresponding contact plug 14a, 14b, or 14c. The side barrier layers 11 b 1 and 11 b 2 cover the lower surface of the silicon substrate 10. The upper barrier layers 11a1 to 11a3 and the lower barrier layers 11b1 and 11b2 include at least one layer made of a refractory metal, an alloy of a refractory metal, or a compound of a refractory metal, and each of the upper wirings 12a to 12e, Occurrence of electromigration from the side wirings 13a to 13b and the contact plugs 14a to 14f to the silicon substrate 10 is suppressed.

  Examples of the refractory metal, refractory metal alloy, and refractory metal compound include titanium, titanium nitride, silicon oxide, tantalum, tantalum nitride, tungsten nitride, cobalt, nickel, tungsten, cobalt tungsten, and cobalt. Examples include molybdenum, cobalt nickel, nickel tungsten, nickel molybdenum, and their high melting point metals, alloys of high melting point metals, and compounds of high melting point metals doped with boron and phosphorus. When the upper barrier layers 11a1 to 11a3 or the lower barrier layers 11b1 and 11b2 are formed of a layer made of silicon oxide, the barrier layer can be formed by natural oxidation of the surface of the silicon substrate 10. . In FIG. 1B, the hatching of the upper barrier layers 11a1 to 11a3 is omitted.

  The upper wirings 12a to 12e and the lower wirings 13a to 13b are made of, for example, a metal such as copper, nickel, gold, silver, or aluminum, an alloy containing at least one of these metals, or ITO (indium tin oxide). And the formation method thereof can be selected as appropriate, such as a vapor deposition method.

  Each of the contact plugs 14a to 14c is formed on the bottom seed layer BS constituting the lower end surface side of the corresponding through hole TH, and on the inner wall of the through hole TH via the upper barrier layer 11a1, 11a2 or 11a3, and the bottom seed layer A main seed layer MS that covers each of the BS and the inner wall of the through hole TH, and a plug body PB that is formed on the main seed layer MS and fills the through hole TH. The same applies to other contact plugs.

  Each bottom seed layer BS was formed by depositing copper, nickel, palladium, platinum, gold, silver, or an alloy thereof by a vapor deposition method such as a PVD method such as a sputtering method, a CVD method, or an ALD method. It is a conductor layer. The film thickness of each bottom seed layer BS is preferably selected as appropriate within a range of 200 nm or less, for example, and more preferably selected as appropriate within a range of 5 to 100 nm.

  Each main seed layer MS is formed by heating a coating film of a metal film forming composition containing at least one of a metal salt and particles selected from Group 10 and Group 11 of the periodic table. It is a film and extends from the upper surface of the corresponding bottom seed layer BS to the upper end of the through hole TH. The metal film forming composition used as the material of the main seed layer MS will be described in detail later.

  The thickness of each main seed layer MS is preferably in the range of 10 to 2000 nm, more preferably in the range of 30 to 500 nm, as an average value on the inner wall of the through hole TH. Each main seed layer MS is preferably a sintered film of copper particles. The through hole TH in which the main seed layer MS is formed has a diameter (a diameter at the stage where the upper barrier layers 11a1 to 11a3 have been formed) in the range of 1 to 100 μm, more preferably in the range of 4 to 100 μm. It is preferable that the ratio of the depth to the aperture is in the range of 1-50.

  Each plug body PB is made of a conductor that is deposited on the main seed layer MS by a plating method to fill the through hole TH. Each plug main body PB can be formed of a metal such as copper or nickel or an alloy containing at least one of these metals.

  In the through silicon via substrate 1 having each component described above, the plug body PB of each contact plug 14a to 14f is formed by plating, and the upper wiring 12a to 12e and a predetermined lower wiring are formed by these contact plugs 14a to 14f. Are electrically connected to form a three-dimensional wiring, and therefore, the conductivity of the three-dimensional wiring of the through silicon via substrate 1 is good.

  Further, the coating film of the above-described composition for forming a metal film has good step coverage, and it is relatively easy to form a metal film having a substantially uniform film thickness from the lower end side to the upper end side of the through hole TH. Since the bottom seed layer BS is already formed in the through hole TH prior to the formation of the metal film, it is easier to form a metal film having a substantially uniform film thickness from the lower end side to the upper end side of the through hole TH. For this reason, when the plug body PB is formed by the plating method, the difference between the time required for forming the lower end side of the plug body PB and the time required for forming the upper end side becomes small. As a result, when the plug body PB is formed, the plating film is excessively deposited on the upper surface side of the silicon substrate 10 and it takes a long time to remove it, or the plating film deposited on the upper surface side of the silicon substrate 10 is removed. When removing by a method such as a chemical mechanical polishing (CMP) method, a situation in which the tact time increases is suppressed. Moreover, the generation of voids in the plug body PB is suppressed. Further, it is easy to ensure high adhesion of the main seed layer MS to the silicon substrate 10.

  Therefore, the through silicon via substrate 1 can be easily manufactured with relatively high productivity and at a relatively low manufacturing cost.

  Hereinafter, a manufacturing method of the through silicon via substrate 1 is taken as an example, and referring to FIGS. 2 (A) to 2 (D) and FIGS. 3 (E) to 3 (I), a method for forming a three-dimensional wiring is described. An embodiment will be described.

<Method for forming three-dimensional wiring>
2 (A) to 2 (D) are cross-sectional views schematically showing one step in manufacturing the through silicon via substrate shown in FIG. FIGS. 3E to 3I are cross-sectional views schematically showing one step performed after the step shown in FIG.

  As shown in FIG. 2A, in manufacturing the silicon through wiring substrate 1 shown in FIG. 1A and FIG. 1B, first, the silicon substrate 10 (FIG. 1A and FIG. A mask material layer 21 is formed on the upper surface of the base material 20 finally formed in (B). The material of the mask material layer 21 is appropriately selected depending on whether a blind via hole described later is formed by a wet etching method or a dry etching method. When forming a blind via hole by a wet etching method, an organic positive resist layer or a negative resist layer can be used as the mask material layer 21. Further, when forming the blind via hole by the dry etching method, for example, a silicon nitride film formed by the plasma CVD method can be used as the mask material layer 21.

  Next, the mask material layer 21 is patterned by a lithography method or the like to obtain an etching mask 21a in which openings OP1 are formed at a plurality of predetermined positions, as shown in FIG. 2B. The formation position of each opening OP1 corresponds to the formation position of the through hole TH shown in FIG.

  Next, the base material 20 is etched from, for example, the reactive ion etching method from the upper surface side of the base material 20 to form blind via holes BV at a plurality of locations on the base material 20 as shown in FIG. The diameter of each blind via hole BV is preferably 1 to 100 μm, the depth is 20 to 200 μm, and the aspect ratio (ratio of the depth to the diameter) is preferably 1 to 50. The etching mask 21a is removed after the formation of the blind via hole BV.

  Next, after forming a high melting point film for the upper barrier layer serving as a base material of the upper barrier layer by the PVD method or the CVD method on the upper surface of the base material 20 and the inner surface of each blind via hole BV, The bottom portion is formed on a region located on the bottom surface of the blind via hole BV and on a region located on the upper surface side of the base material 20 by a vapor deposition method such as a PVD method such as a sputtering method, a CVD method, or an ALD method. A seed layer is formed. Thereafter, the above-described composition for forming a metal film is applied by a spin coating method or a printing method to form a coating film, and the coating film is heated to form a metal film.

  By performing this processing, as shown in FIG. 2D, the upper barrier layer high melting point film 22, the bottom seed layer BS, and the metal film 23 are laminated in this order on the bottom surface of each blind via hole BV. The upper barrier layer refractory film layer 22 and the metal film 23 are laminated in this order on the inner wall of each blind via hole BV, and the upper barrier layer refractory film 22 and the upper conductive layer are laminated on the upper surface of the base material 20. The film UM and the metal film 23 are laminated in this order. The upper conductive film UM is formed at the same time as the bottom seed layer BS when the bottom seed layer BS is formed. By forming the upper conductive film UM, the electric resistance value on the upper surface of the base material 20 can be kept lower than when only the main seed layer described later is formed, and productivity in the subsequent plating process Can be high. When the bottom seed layer BS is formed, a discontinuous film or an extremely thin conductor film is formed on the upper barrier layer high-melting point film 22 on the region covering the inner wall of the blind via hole BV using the material for forming the bottom seed layer BS. May be. In FIG. 2 (D) and FIGS. 3 (E) and 3 (F) to be described later, the provision of hatching to the high melting point film 22 for the upper barrier layer is omitted.

  The upper barrier layer refractory film 22 corresponds to the base material of each of the upper barrier layers 11a1 to 11a3 shown in FIG. 1B, and is made of, for example, a refractory metal, a refractory metal alloy, or a refractory metal compound. A high melting point film including at least one layer, specifically, a three-layer laminated film in which a titanium nitride film and a titanium film are laminated in this order on a titanium film, and a titanium nitride film laminated on a titanium film. Layer stack film, silicon oxide film, titanium film, tantalum film, tantalum nitride film, tungsten nitride, cobalt film, nickel film, tungsten film, cobalt tungsten film, cobalt molybdenum film, cobalt nickel film, nickel tungsten film, and Nickel molybdenum films and films with boron and phosphorus added to these films are formed by PVD, CVD, plating, etc. Possible it is.

  The metal film 23 corresponds to the base material of the main seed layer MS shown in FIG. The metal film 23 has good step coverage. In forming the metal film 23, it is preferable that the viscosity at the time of application of the composition for forming a metal film is 1 Pa · s or less, and the metal concentration is 5 to 50% by mass. It is preferable to carry out at 100-200 degreeC in the following atmospheres or a vacuum. Moreover, it is preferable to adjust the coating amount so that the average value of the thickness of the metal film 23 on the inner wall of the blind via hole BV is in the range of 10 to 2000 nm. The metal film 23 is preferably a sintered film of copper particles.

  Next, a conductor such as copper is deposited over the entire outer surface of the metal film 23 by plating to form the conductor layer 24. As shown in FIG. 3E, the conductor layer 24 is formed until each blind via hole BV is filled with the conductor layer 24. The conductor layer 24 serves as a base material for each of the upper wirings 12a to 12c and each plug body PB shown in FIG.

  Next, for each of the metal film 23 and the conductor layer 24, a step of polishing and removing a region formed on the upper surface side of the base material 20 by a chemical mechanical polishing (CMP) method or the like is performed. This polishing is performed until the upper surface of the upper barrier layer high melting point film 22 and the upper surface of the conductor layer 24 are located on substantially the same plane on the upper surface of the base material 20. By performing this step, as shown in FIG. 3F, the region located on the upper surface side of the base material 20 in the metal film 23 is removed, and the metal film 23 becomes the main seed layer MS. At the same time, the plug body PB of each of the contact plugs 14a to 14f shown in FIG.

  Next, the base material 20 is polished from the lower surface side of the base material 20 to reduce its thickness. This polishing is performed until the lower surface of the bottom seed layer BS is completely exposed as shown in FIG. It is also possible to perform a polishing process until the bottom seed layer BS is completely removed. By this polishing, the base material 20 becomes the silicon substrate 10 shown in FIG. Further, by this polishing process, the region located on the bottom surface of the blind via hole BV in the upper barrier layer refractory film 22 and a certain region above it are also removed, and the upper barrier layer refractory film 22 is removed. Becomes the high-melting point film 22a for the upper barrier layer that has been polished. The blind via hole BV becomes the through hole TH shown in FIG. As a result, the contact plugs 14a to 14f shown in FIG. 1A are formed. In FIG. 3G and FIG. 3H described later, the hatching of the polished upper barrier layer high-melting point film 22a is omitted.

  Next, as shown in FIG. 3H, an upper wiring conductor film 25 is formed on the upper surface of the silicon substrate 10, and the lower barrier layer 11b1 shown in FIG. 1B is formed on the lower surface. After forming the high melting point film for the lower barrier layer serving as the base material of ˜11b2, the high melting point film for the lower barrier layer is patterned into a predetermined shape to form the high melting point film 26 for the lower barrier layer. Thereafter, the lower wiring conductor film 27 is formed on the entire lower surface of the silicon substrate 10.

  The upper wiring conductor film 25 is made of a metal such as copper, nickel, gold, silver, or aluminum, an alloy containing at least one of these metals, or a transparent conductive material such as ITO (indium tin oxide). The formation method can be selected as appropriate, such as a vapor deposition method.

  The lower barrier layer high melting point film 26 has an opening OP2 exposing the lower end surfaces of the contact plugs 14a to 14f. The lower barrier layer high-melting point film 26, like the upper barrier layer high-melting point film 22, includes at least one layer made of a refractory metal, a refractory metal alloy, or a refractory metal compound. The film can be formed by depositing the film on the entire lower surface of the silicon substrate 10 by the PVD method, the CVD method or the like and then patterning the high melting point film by a lithography method to provide the opening OP2 at a predetermined position. It is also possible to form the high melting point film 26 for the lower barrier layer by naturally oxidizing the lower surface of the silicon substrate 10.

  Similarly to the upper wiring conductor film 25, the lower wiring conductor film 27 is made of a metal such as copper, nickel, gold, silver, or aluminum, an alloy containing at least one of these metals, or ITO ( Indium tin oxide) can be formed of a transparent conductive material, and the formation method can be selected as appropriate, such as a vapor deposition method. The lower wiring conductor film 27 covers the lower barrier layer refractory film 26 and the lower end surfaces of the individual contact plugs 14a to 14f.

  If a natural oxide film is formed on the upper end surfaces of the contact plugs 14a to 14f between the formation of the contact plugs 14a to 14f and the formation of the upper wiring conductor film 25, It is preferable to form the upper wiring conductor film 25 after removing the natural oxide film by wet etching or the like. The same applies when a natural oxide film is formed on the lower end surfaces of the contact plugs 14a to 14f after the contact plugs 14a to 14f are formed and before the lower wiring conductor film 27 is formed. .

  Next, a resist layer is formed on the upper surface of the upper wiring conductor film 25 by using, for example, an organic resist material, and this resist layer is patterned by, for example, a wet etching method to form openings at a plurality of predetermined locations. An etching mask is obtained. The locations where the openings are formed correspond to locations excluding the locations where the upper wirings 12a to 12e are formed as shown in FIG.

  Next, the upper wiring conductor film 25 and the polished upper barrier layer high-melting point film 22a thereunder are etched from the upper surface side of the upper wiring conductor film 25 by, for example, a wet etching method. At this time, as shown in FIG. 3I, a region of the upper wiring conductor film 25 located below the opening OP3 of the etching mask 28 and the polished upper barrier layer high melting point film 22a. Of these, the region located below the opening OP3 is etched away. By this etching, the upper wirings 12 a to 12 e shown in FIG. 1A are formed, and an upper barrier layer interposed between the individual upper wirings 12 a to 12 e and the silicon substrate 10 is formed. FIG. 3I shows the three upper wirings 12a to 12c and the three upper barrier layers 11a1 to 11a3 shown in FIG.

  Thereafter, the lower wiring conductor film 27 and the lower barrier layer high melting point film 26 are etched in the same manner as the etching of the upper wiring conductor film 25 to obtain a predetermined number of lower wirings and lower barriers. Form a layer. By forming the lower wiring and the lower barrier layer, the through silicon via substrate 1 having the three-dimensional wiring shown in FIGS. 1A and 1B can be obtained.

  When the three-dimensional wiring is formed as described above, as described in the explanation of the through silicon via substrate 1, the three-dimensional wiring having good conductivity can be obtained with relatively high productivity and relatively. It can be formed at a low manufacturing cost.

Embodiment 2. FIG.
<Circuit device having three-dimensional wiring>
FIG. 4A is a cross-sectional view schematically showing another embodiment of a circuit device having three-dimensional wiring, and FIG. 4B is a circle drawn by a one-dot chain line in FIG. 2 is an enlarged view of a region surrounded by C. FIG. The circuit device having a three-dimensional wiring illustrated in FIG. 4A is a semiconductor device. Hereinafter, the reference numeral of the semiconductor device will be described as “100”.

  A semiconductor device 100 shown in FIG. 4A includes a semiconductor substrate 110, a plurality of circuit elements formed on the semiconductor substrate 110, and a multilayer wiring portion formed on the semiconductor substrate 110 so as to cover these circuit elements. 130. In FIG. 4A, two field effect transistors 120 are shown as the circuit elements. Hereinafter, each component of the semiconductor device 100 will be described.

  The semiconductor substrate 110 is a silicon single crystal substrate in which element isolation regions 110a for electrically isolating circuit elements arranged adjacent to each other are formed in a predetermined pattern. Instead of a silicon single crystal substrate, a substrate made of a compound semiconductor such as gallium arsenide or an SOI (Silicon On Insulator) substrate can be used. The plurality of circuit elements formed on the semiconductor substrate 110 constitute an integrated circuit together with the multilayer wiring portion 130 formed on the semiconductor substrate 110, and what kind of circuit elements are formed on the semiconductor substrate 110 and how many. Is appropriately selected according to the function required for the semiconductor device 100, the use of the semiconductor device 100, and the like.

  Each field effect transistor 120 includes a gate electrode 122 disposed on the semiconductor substrate 110 via a gate insulating film 121, a source region 123 and a drain region 124 formed on the semiconductor substrate 110, and a line width direction of the gate electrode 122. And sidewall spacers 125 formed on both side surfaces. In FIG. 4A, the gate insulating film 121 is smudged.

  The multilayer wiring portion 130 has a plurality of wiring layers stacked on the semiconductor substrate 110 via an etching stopper film ES, and a liner layer L interposed between two wiring layers adjacent in the vertical direction. In FIG. 4A, a total of three wiring layers, the first wiring layer 131 to the third wiring layer 133 appear. In FIG. 4A, the application of hatching to the etching stopper film ES and each liner layer L is omitted.

  The etching stopper film ES is formed of, for example, silicon carbonitride or silicon nitride, and is used as an etching stopper when a through hole (contact hole) is provided in the electrical insulating layer serving as a base material of the first wiring layer 131. . Each liner layer L is preferably formed of a material different from the base material of the wiring layer serving as the foundation of the liner layer L. For example, when silicon oxide is used as the base material of the wiring layer, it is preferable to form a liner layer made of, for example, silicon carbonitride on the wiring layer formed from the base material.

  Each of the wiring layers 131 to 133 is exposed from the inner surface of each of the trenches and through holes of a predetermined pattern formed in the electrical insulating layer as a base material by the wet etching method or the dry etching method, and the lower opening of the above through holes. It has a barrier layer B that covers the base layer, and a damascene wiring D that is formed on the barrier layer B and fills each of the trench and the through hole. The electrical insulating layer can be formed of, for example, silicon oxide, silicon nitride, a low dielectric constant dielectric, or the like. The barrier layer B includes at least one layer made of, for example, a refractory metal, a refractory metal alloy, or a refractory metal compound, like the upper barrier layers 11a1 to 11a3 shown in FIG. The barrier layer B includes at least one layer made of, for example, a refractory metal, a refractory metal alloy, or a refractory metal compound, like each of the upper barrier layers 11a1 to 11a3 shown in FIG.

  As shown in FIG. 4B, each damascene wiring D includes a bottom seed layer BS formed on a region covering the base layer exposed from the lower opening of the through hole TH in the barrier layer B, and a trench T. A metal film MT in the trench covering the bottom surface of the trench, and a main seed layer MS covering the upper surface of the bottom seed layer BS and the upper surface of the metal film MT in the trench on the region covering the inner surfaces of the trench T and the through hole TH in the barrier layer B. And a conductor formed on the main seed layer MS and filling the trench T and the through hole TH. A region where the trench T is filled in the conductor becomes the wiring WL, and a region where the through hole TH is filled becomes the plug body PB of the contact plug CP. The plug body PB, the bottom seed layer BS, and the region formed in the through hole TH in the main seed layer MS become the contact plug CP.

  For each contact plug CP, the wiring WL electrically connected to the upper end of the contact plug CP corresponds to the upper wiring, and is electrically connected via the barrier layer B on the lower end side of the contact plug CP. The connected wiring WL or other contact plug CP corresponds to the lower wiring.

  Similarly to the bottom seed layer BS shown in FIG. 1B, the bottom seed layer BS constituting the damascene wiring D is made of copper, by a vapor deposition method such as a PVD method such as a sputtering method, a CVD method, or an ALD method. It is a conductor layer formed by depositing nickel, palladium, platinum, gold, silver, or an alloy thereof. The film thickness of each bottom seed layer BS is preferably selected as appropriate within a range of 200 nm or less, for example, and more preferably selected as appropriate within a range of 5 to 100 nm. The in-trench metal film MT is formed at the same time as the bottom seed layer BS when the bottom seed layer BS is formed. When the bottom seed layer BS is formed, a discontinuous film or a very thin conductor film may be formed on the barrier layer B on the region covering the inner wall of the blind via hole BV depending on the material for forming the bottom seed layer BS. . Similarly, when the bottom seed layer BS is formed, a conductor layer may be formed on the upper surface side of the wiring layer using the same material as that for the bottom seed layer BS.

  The main seed layer MS constituting the damascene wiring D is similar to the main seed layer MS shown in FIG. 1B, and includes at least metal salts and particles selected from Group 10 and Group 11 of the periodic table. It is the metal film formed by heating the coating film of the composition for metal film formation containing one side. The thickness of each main seed layer MS is preferably in the range of 10 to 2000 nm as an average value on the inner wall of the through hole TH. Each main seed layer MS is preferably a sintered film of copper particles. The through hole TH in which the main seed layer MS is formed has a diameter (a diameter at the stage where the barrier layer B has been formed) in a range of 1 to 100 μm, and a depth ratio to the diameter is 1 to 1. It is preferable to be within the range of 50. The conductor constituting the damascene wiring D is deposited on the main seed layer MS by a plating method. As this conductor, for example, copper can be used.

  The contact plug formed in the first wiring layer 131 is electrically connected to the source region 123 or the drain region 124 of the field effect transistor 120 through one region in the barrier layer B formed in the first wiring layer 131. Is done. Similarly, the contact plug formed in each of the second wiring layer 132 and the third wiring layer 133 passes through a region in the barrier layer B formed in the wiring layers 132 and 133, and the first contact plug is formed immediately below. It is electrically connected to the damascene wiring D formed in the wiring layer 131 or the second wiring layer 132. For each contact plug CP, the wiring WL or other contact plug CP electrically connected to the upper end of the contact plug CP via the barrier layer B corresponds to the upper wiring, and the lower end of the contact plug CP. The wiring WL or other contact plug CP electrically connected via the barrier layer B on the side corresponds to the lower wiring. A large number of three-dimensional wirings are formed in the multilayer wiring part 130.

  In the semiconductor device 100 having each component described above, the three-dimensional wiring is formed by the damascene wiring D, and thus the conductivity of the three-dimensional wiring included in the semiconductor device 100 is good. For example, even when a material that can be easily oxidized by oxygen in the atmosphere is used as the barrier layer B, the barrier layer B and the main seed layer MS are connected to each other through the bottom seed layer BS. It is possible to suppress the loss of conductivity. Further, the coating film of the above-described composition for forming a metal film used as a material for the main seed layer MS has a good step coverage and a metal film having a substantially uniform film thickness from the lower end side to the upper end side of the through hole TH. Since the bottom seed layer BS is already formed in the through hole TH prior to the formation of the metal film, the metal having a substantially uniform film thickness from the lower end side to the upper end side of the through hole TH. It is easier to form a film. For this reason, when the plug body PB is formed by plating, the difference between the time required for forming the lower end side of the plug body PB and the time required for forming the upper end side can be easily reduced, and the plug body PB is deposited on the upper surface side of the wiring layer. When the plating film is excessively deposited and it takes a long time to remove it, or when the plating film deposited on the upper surface side of the wiring layer is removed by a method such as a chemical mechanical polishing (CMP) method It can be suppressed that the tact time increases. In addition, the occurrence of voids in the plug body PB is suppressed. Furthermore, it is easy to ensure high adhesion to the wiring layer of the main seed layer MS.

  Therefore, in the semiconductor device 100, it is easy to manufacture the multilayer wiring part 130 with relatively high productivity and relatively low manufacturing cost. As a result, the semiconductor device 100 can be easily manufactured with a relatively high productivity and with a relatively low manufacturing cost.

  Hereinafter, taking a method for manufacturing the semiconductor device 100 as an example, referring to FIGS. 5A to 5C and FIGS. A form is demonstrated.

<Method for forming three-dimensional wiring>
FIG. 5A to FIG. 5C are cross-sectional views schematically showing one step in manufacturing the semiconductor device shown in FIG. FIGS. 6D to 6F are cross-sectional views schematically showing one step performed after the step shown in FIG. 5C.

  As shown in FIG. 5A, in manufacturing the semiconductor device 100 shown in FIGS. 4A and 4B, first, after a desired circuit element such as the field effect transistor 120 is formed. A first etching stopper film ES1 that is a base material of the etching stopper film ES shown in FIG. 4A is formed on the semiconductor substrate 110 by the PVD method or the CVD method. The first etching stopper film ES1 may be formed so as to cover the gate electrode 122 and the side wall spacers 125 of each field effect transistor 120. In FIG. 5A, the hatching of the first etching stopper film ES1 is omitted.

  Next, an electrical insulating layer serving as a base material of the first wiring layer 131 is formed on the semiconductor substrate 110 by a PVD method or a CVD method, an etching mask having a predetermined shape is formed thereon, and then the electrical insulating layer is wet etched. The first wiring layer having a predetermined pattern of trenches and through-holes is obtained by molding by a dry etching method or a dry etching method. Thereafter, the first etching stopper film ES1 is etched using the etching mask as it is to remove a region located below the through-hole provided in the first wiring layer 131, and the first etching stopper film ES1 is formed. The etching stopper film ES shown in FIG.

  FIG. 5B shows the first wiring layer 131 and the etching stopper film ES formed as described above. A predetermined number of trenches T and through holes TH are formed in the first wiring layer 131. In the etching stopper film ES, an opening OP3 is formed in a region located below the through hole TH provided in the first wiring layer 131. In FIG. 5 (B) and FIGS. 5 (C) and 6 (D) to 6 (F) described later, the hatching of the etching stopper film ES is omitted.

  Next, a mask having a predetermined shape for exposing the trench T and each through hole TH of the first wiring layer 131 is provided on the first wiring layer 131, and a high melting point film is formed by, for example, the CVD method. ), The barrier layer high melting point film covering the inner surface of the trench T, the inner surface of the through hole TH, the inner wall of the opening OP3 in the etching stopper film ES, and the surface of the semiconductor substrate 110 exposed from the opening OP3. HB is formed. The barrier layer high melting point film HB can be made of the same material as the upper barrier layers 11a1 to 11a3 shown in FIG. 1B, for example.

  Next, after forming a bottom seed layer by sputtering on the region located on the lower end side of the through hole TH in the barrier layer high melting point film HB, the upper surface of the first wiring layer 131 and the inner surface of the trench T are formed. And coating the metal film forming composition described above on the inner surface of each through-hole TH by a spin coating method, a printing method, or the like to form a coating film, and heating the coating film, FIG. 6 (D) As shown, a metal film MF is formed on the high melting point film HB for the barrier layer.

  When the bottom seed layer BS is formed, a conductor is deposited on the barrier layer refractory film HB also above the bottom surface of the trench T and above the first wiring layer 131 to form a conductive film. Of these conductive films, the one deposited above the bottom surface of the trench T becomes the in-trench metal film MT. A discontinuous film or a very thin conductor film may be formed on the barrier layer high melting point film HB on the region covering the inner wall of the through hole TH, depending on the material for forming the bottom seed layer BS.

  In forming the metal film MF, it is preferable that the viscosity during coating of the composition for forming a metal film is 1 Pa · s or less and the metal concentration is 5 to 50% by mass. It is preferable to carry out at 100-200 degreeC in the following atmospheres or a vacuum. Further, it is preferable to adjust the coating amount so that the average value of the thickness of the metal film MF on the inner wall of the through hole TH is in the range of 10 to 2000 nm. The metal film MF is preferably a sintered film of copper particles. The metal film MF covers the upper surface of the first wiring layer 131, the inner surface of the trench T, the inner wall of each through hole TH, and the bottom seed layer BS under good step coverage.

  Next, a conductor such as copper is deposited on the entire outer surface of the metal film MF by plating to form a conductor layer. As shown in FIG. 6E, the conductor layer CL is formed until the trench T and each through hole TH of the first wiring layer 131 are filled with the conductor layer CL.

  Next, the metal film MF is polished by, for example, a chemical mechanical polishing (CMP) method so that the upper surface of the first wiring layer 131 and the upper surface of the conductor layer CL are located on substantially the same plane. To do. As a result, as shown in FIG. 6F, a contact plug CP having a bottom seed layer BS, a main seed layer MS, and a plug body PB is formed in each through hole TH. A wiring WL having the metal film MT and the conductor layer CL is formed, and a damascene wiring D having a predetermined pattern is formed in the first wiring layer 131. Next, as shown in FIG. 6F, a liner layer L having a predetermined pattern is formed on the first wiring layer 131.

  Thereafter, in the same manner as the formation of the first wiring layer 131 and the damascene wiring D in the first wiring layer 131, a desired number of wiring layers (those formed up to the damascene wiring D) are formed on the first wiring layer 131. Are sequentially laminated through the liner layer L, the semiconductor device 100 shown in FIG. 4A can be obtained. As described in the description of the semiconductor device 100, when the three-dimensional wiring is formed as described above, the three-dimensional wiring having good conductivity is manufactured with relatively high productivity and relatively low production. Can be formed under cost.

Embodiment 3 FIG.
<Formation of metal film forming composition and metal film>
In one embodiment of the metal film-forming composition, the metal film-forming composition contains at least one of a metal salt and metal particles. Hereinafter, this component is called (A) component. Moreover, the composition for metal film formation of this embodiment can contain an amine compound as (B) component. Furthermore, a solvent or a dispersion medium can be contained as an optional component. Hereinafter, this solvent or dispersion medium is referred to as component (C). Furthermore, the composition for forming a metal film of the present embodiment can contain other optional components in addition to the above components.

  The metal film forming composition of this embodiment can form a coating film by various known coating methods, and the coating film can be heated to form a metal film. At this time, the composition for forming a metal film of the present embodiment has the above-described composition, so that it is coated on an appropriate substrate to form a coating film, and then is non-oxidizing in the atmosphere or by nitrogen gas or the like. A metal film can be formed over the substrate in an atmosphere, in an atmosphere having an oxygen concentration of 500 ppm or less, or by heating in a vacuum. And the temperature of a heating can be 250 degrees C or less, and can also be 200 degrees C or less still lower.

  Hereafter, each component of the composition for metal film formation of this embodiment is demonstrated.

[(A) component]
As described above, the composition for forming a metal film of the present embodiment contains at least one of a metal salt and metal particles, which are raw materials for the metal film, as the component (A).

  The component (A) is preferably at least one of a metal salt and particles selected from Group 10 and Group 11 of the periodic table. By including at least one of a metal salt and particles selected from Group 10 and Group 11 as the component (A), a low electrical resistance metal film can be formed.

  From the viewpoint of simply forming a metal film having low electrical resistance, the composition for forming a metal film of the present embodiment includes a transition metal (palladium) of Group 10 and Group 11 of the periodic table as component (A). Containing at least one of a metal salt containing a metal selected from the group consisting of (Pd), platinum (Pt), copper (Cu), silver (Ag), nickel (Ni) and gold (Au)) and metal particles. Is more preferable. Further, from the viewpoint of forming a metal film with low electrical resistance at a lower production cost, the metal film forming composition of this embodiment is selected from the group consisting of copper, silver and nickel as the component (A). It is particularly preferable to contain at least one of a metal salt containing metal and metal particles.

  The metal salt that can be used as the component (A) is not particularly limited as long as it is a compound containing a metal ion. As this metal salt, for example, a metal salt composed of a metal ion and at least one of an inorganic anion species and an organic anion species can be used.

  As described above, the metal film-forming composition of this embodiment particularly preferably uses a metal salt containing a metal selected from the group consisting of copper, silver and nickel as the component (A). (A) When using a metal salt containing copper as a component, that is, a copper salt, from the viewpoint of solubility, one or more selected from the group consisting of a copper carboxylate and a complex salt of copper and an acetylacetone derivative Is preferably used.

  For example, as copper carboxylate, copper acetate, copper trifluoroacetate, copper propionate, copper butyrate, copper isobutyrate, copper 2-methylbutyrate, copper 2-ethylbutyrate, copper valerate, copper isovalerate , Copper pivalate, copper hexanoate, copper heptanoate, copper octoate, copper 2-ethylhexanoate, copper nonanoate, etc., copper salt of malonic acid, copper malonate, copper succinate, copper maleate, etc. Copper salt of dicarboxylic acid, copper salt of aromatic carboxylic acid such as copper benzoate, copper salicylate, copper formate, copper hydroxyacetate, copper glyoxylate, copper lactate, copper oxalate, copper tartrate, copper malate, copper citrate Suitable examples include copper salts of carboxylic acids having a reducing power such as the above, and hydrates of the copper salts.

  Examples of complex salts of copper and acetylacetone derivatives include those in which acetylacetone derivatives or acetoacetate derivatives are complexed at a ratio of 1 to 2 molecules per copper atom. Specific examples thereof include acetylacetonate copper, acetoacetate Ethyl copper acetate, 1,1,1-trimethylacetylacetonatocopper, 1,1,1,5,5,5-hexamethylacetylacetonatocopper, 1,1,1-trifluoroacetylacetonatocopper, and Preferred examples include 1,1,1,5,5,5-hexafluoroacetylacetonato copper.

  Among these, from the viewpoint of forming a soluble and low electrical resistance metal film (copper film), copper acetate, copper trifluoroacetate, copper propionate, copper butyrate, copper isobutyrate, copper 2-methylbutyrate, Copper pivalate, copper formate, copper hydroxyacetate, copper glyoxylate, copper oxalate, copper acetylacetonate, ethyl copper acetoacetate, 1,1,1-trifluoroacetylacetonato copper and 1,1,1,5 5,5-Hexafluoroacetylacetonato copper and hydrates thereof are mentioned as more preferable copper salts. Furthermore, copper formate and copper formate hydrate can be mentioned as particularly preferred copper salts.

  Further, when using a metal salt containing silver as the component (A), that is, a silver salt, as described above, there is no particular limitation as long as it is a silver salt. When a silver salt is used as the component (A), for example, silver nitrate, silver acetate, silver formate, silver oxalate, silver oxide, silver acetylacetone, ethyl acetoacetate, silver benzoate, silver bromate, silver bromide, silver carbonate Silver chloride, silver citrate, silver fluoride, silver iodate, silver iodide, silver lactate, silver nitrite, silver perchlorate, silver phosphate, silver sulfate, silver sulfide, and silver trifluoroacetate are suitable. Can be cited as a thing.

  Among these silver salts, from the viewpoint of forming a low electric resistance metal film (silver film), it is more preferable to use a silver carboxylate, and silver acetate, silver formate, silver oxalate and the like are more preferable silver salts. As an example. And silver formate can be mentioned as a particularly preferable silver salt.

  Further, when a metal salt containing nickel as the component (A), that is, a nickel salt is used, there is no particular limitation as long as it is a nickel salt as described above. From the viewpoint of forming a low electric resistance metal film (nickel film), nickel carboxylate is preferably used, and nickel acetate, nickel formate, nickel oxalate, and the like can be cited as examples of more preferable nickel salts. . And nickel formate can be mentioned as a particularly preferable nickel salt.

  The metal salt as component (A) may be commercially available or synthesized by a known method, and further, a compound containing a metal ion and at least one of an inorganic anion species and an organic anion species are mixed. By doing so, even those formed in the reaction system can be used without any limitation, and are not particularly limited.

  In addition, when a metal salt with a carboxylic acid having a reducing power as the metal salt of the component (A), that is, a metal carboxylate, a carboxylic acid having a reducing power as a counter anion acts as a reducing agent. There is no need to add a reducing agent.

  The purity of the metal salt as the component (A) is not particularly limited. However, if the metal salt is too low, the conductivity (electric resistance characteristics) may be adversely affected when the metal film is formed. Therefore, the purity of the metal salt of the component (A) is preferably 90% or more, and more preferably 95% or more.

  When metal particles are used as the component (A), the metal particles are not particularly limited as long as they are particles made of metal. From the viewpoint of easily forming a metal film with low electrical resistance, the metal particles of the component (A) include group 10 and group 11 transition metals (palladium, platinum, copper, silver, nickel) of the periodic table. It is more preferable to use metal particles containing at least one metal selected from the group consisting of and gold. These metal species may be simple substances or alloys with other metals. When these metal species are a simple substance, preferable metal particles include at least one or a combination of two or more selected from the group consisting of palladium particles, platinum particles, copper particles, silver particles, nickel particles, and gold particles. Become.

  Among these, from the viewpoint of cost, availability, and formation of a metal film with lower electrical resistance, it contains one or more metal species selected from the group consisting of silver, copper and nickel. It is preferable. Although metal particles other than these may be used, for example, when used in combination with a copper salt that is a metal salt, the metal particles may be oxidized by copper ions. More preferred.

  (A) It is preferable that the average particle diameter of the metal particle used as a component is the range of 5-100 nm. When the particle diameter of the metal particles used as the component (A) is less than 5 nm, the activity of the metal surface becomes very high, which may cause an oxidation reaction or dissolution, and also forms aggregates between the particles and preserves them. May settle in. Moreover, when it exceeds 100 nm, when it preserve | saves for a long time, a metal particle may settle. Therefore, the average particle diameter of the metal particles used as the component (A) is preferably within the above range.

  (A) As a measuring method of the particle diameter of the metal particle used as a component, the measuring method applied to a general fine particle can be used. For example, a transmission electron microscope (TEM), a field emission transmission electron microscope (FE-TEM), a field emission scanning electron microscope (FE-SEM), or the like can be used as appropriate. The average particle size value is observed using the above-mentioned microscope, and three locations where the particle sizes are relatively uniform are selected from the observed field of view and photographed at a magnification most suitable for particle size measurement. . From each of the obtained photos, select the 100 most likely particles, measure the diameter with a measuring machine such as a ruler, and divide by the measurement magnification to calculate the particle size. Can be obtained by arithmetic averaging. Further, the standard deviation can be obtained from the particle diameter and number of individual metal particles at the time of the above observation. The coefficient of variation can be calculated by the following equation based on the above average particle diameter and its standard deviation.

  The metal particles used as the component (A) may be commercially available or synthesized by a known method, and are not particularly limited. As a known synthesis method, for example, a gas phase method (dry method) in which a synthesis reaction is performed by a physical method such as a sputtering method or a gas evaporation method, or a metal compound solution is reduced in the presence of a surface protective agent. A liquid phase method (wet method) or the like for depositing metal particles is generally known.

  The purity of the metal particles used as the component (A) is not particularly limited, but is preferably 95% or more because it may adversely affect the conductivity of the formed metal film if the purity is low. The above is more preferable.

  As content of (A) component in the composition for metal film formation of this embodiment, when the total mass of all the components which the composition for metal film formation of this embodiment contains is 100 mass%, it is 1 % By mass to 70% by mass is preferable, and 5% by mass to 50% by mass is more preferable. The metal film which has the outstanding electroconductivity can be formed by making content of (A) component into 1 mass%-70 mass%. By setting the content of the component (A) to 5% by mass to 50% by mass, a metal film having a lower electrical resistance value can be formed.

[Component (B)]
In the composition for forming a metal film of the present embodiment, an amine compound can be contained as the component (B) in addition to the component (A) described above.

  As the amine compound of the component (B), an amine compound represented by at least one general formula of the following general formula (1), the following general formula (2), and the following general formula (3) can be used.

In the general formula (1), R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or an alicyclic hydrocarbon group having 3 to 18 carbon atoms. R ³ represents a single bond, a methylene group, an alkylene group having 2 to 12 carbon atoms, or a phenylene group. R ⁴ represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an amino group, a dimethylamino group, or a diethylamino group.

In the general formula ^{(2), R 5, R} 6 are each independently a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or an alicyclic hydrocarbon group having 3 to 18 carbon atoms. R ⁷ represents a methylene group, an alkylene group having 2 to 12 carbon atoms, or a phenylene group. R ⁸ represents an alkyl group having 1 to 18 carbon atoms or an alicyclic hydrocarbon group having 3 to 18 carbon atoms. However, when R ⁵ and R ⁶ are hydrogen atoms, R ⁸ represents a group other than a methyl group and an ethyl group.

In the general formula (3), R ⁹ and R ¹⁰ each independently represent a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or an alicyclic hydrocarbon group having 3 to 18 carbon atoms. R ¹¹ represents a methylene group, an alkylene group having 2 to 12 carbon atoms, or a phenylene group. R ¹² and R ¹³ each independently represent an alkyl group having 1 to 18 carbon atoms or an alicyclic hydrocarbon group having 3 to 18 carbon atoms.

Examples of the groups R ¹ and R ² included in the amine compound represented by the general formula (1) include a hydrogen atom, a linear alkyl group, a methyl group, an ethyl group, a propyl group, a butyl group, Examples include a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a stearyl group, and the branched ones include an isopropyl group, a sec-butyl group, an isobutyl group, and a tert-butyl group. Group, isopentyl group, neopentyl group, tert-pentyl group, 1-ethylpropyl group, 1,1-dimethylpropyl group, 1,2-dimethylpropyl group, 1,1,2-trimethylpropyl group, 1,2,2 -Trimethylpropyl group, 1,3-dimethylbutyl group, 1,5-dimethylhexyl group, 2-ethylhexyl group, 4-heptyl group, 2-heptyl group Group. Examples of the alicyclic hydrocarbon group, a cyclohexyl group, a cyclopentyl group.

Examples of the group R ⁴ contained in the amine compound represented by the general formula (1) include a hydrogen atom, an amino group, a dimethylamino group, and a diethylamino group, as a linear alkyl group, a methyl group, Examples include an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, and a stearyl group. Butyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, tert-pentyl group, 1-ethylpropyl group, 1,1-dimethylpropyl group, 1,2-dimethylpropyl group, 1,1,2- Trimethylpropyl group, 1,2,2-trimethylpropyl group, 1,3-dimethylbutyl group, 1,5-dimethylhexyl group, 2 -An ethylhexyl group, 4-heptyl group, 2-heptyl group, etc. are mentioned, As an alicyclic hydrocarbon group, a cyclohexyl group and a cyclopentyl group are mentioned.

  Specific examples of the amine compound represented by the general formula (1) include, for example, methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecyl. Amine, dodecylamine, stearylamine, isopropylamine, sec-butylamine, isobutylamine, tert-butylamine, isopentylamine, neopentylamine, tert-pentylamine, 1-ethylpropylamine, 1,1-dimethylpropylamine, 1 , 2-dimethylpropylamine, 1,1,2-trimethylpropylamine, 1,2,2-trimethylpropylamine, 1,3-dimethylbutylamine, 1,5-dimethylhexylamine, 2-ethylhexyl Min, 4-heptylamine, 2-heptylamine, cyclohexylamine, cyclopentylamine, ethylenediamine, N-methylethylenediamine, N, N′-dimethylethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, N-ethyl Ethylenediamine, N, N′-diethylethylenediamine, 1,3-propanediamine, N, N′-dimethyl-1,3-propanediamine, 1,4-butanediamine, N, N′-dimethyl-1,4-butane Examples include diamine, 1,5-pentanediamine, N, N′-dimethyl-1,5-pentanediamine, 1,6-hexanediamine, N, N′-dimethyl-1,6-hexanediamine, and the like.

Examples of the groups R ⁵ and R ⁶ included in the amine compound represented by the general formula (2) include a hydrogen atom, a linear alkyl group, a methyl group, an ethyl group, a propyl group, a butyl group, Examples include a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a stearyl group, and the branched ones include an isopropyl group, a sec-butyl group, an isobutyl group, and a tert-butyl group. Group, isopentyl group, neopentyl group, tert-pentyl group, 1-ethylpropyl group, 1,1-dimethylpropyl group, 1,2-dimethylpropyl group, 1,1,2-trimethylpropyl group, 1,2,2 -Trimethylpropyl group, 1,3-dimethylbutyl group, 1,5-dimethylhexyl group, 2-ethylhexyl group, 4-heptyl group, 2-heptyl group Group. Examples of the alicyclic hydrocarbon group, a cyclohexyl group, a cyclopentyl group.

Examples of the group R ⁸ contained in the amine compound represented by the general formula (2) include a linear alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, Examples include heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, stearyl group, etc., and isopropyl group, sec-butyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group as branched ones Group, tert-pentyl group, 1-ethylpropyl group, 1,1-dimethylpropyl group, 1,2-dimethylpropyl group, 1,1,2-trimethylpropyl group, 1,2,2-trimethylpropyl group, 1 , 3-dimethylbutyl group, 1,5-dimethylhexyl group, 2-ethylhexyl group, 4-heptyl group, 2-heptyl group, etc. Examples of the alicyclic hydrocarbon group include a cyclohexyl group and a cyclopentyl group. However, when R ⁵ and R ⁶ are both hydrogen atoms, R ⁸ is other than a methyl group or an ethyl group.

  Specific examples of the amine compound represented by the general formula (2) include, for example, methoxy (methyl) amine, 2-methoxyethylamine, 3-methoxypropylamine, 4-methoxybutylamine, ethoxy (methyl) amine, 2-ethoxyethylamine, 3-ethoxypropylamine, 4-ethoxybutylamine, propoxymethylamine, 2-propoxyethylamine, 2-isopropoxypropylamine, 3-isopropoxypropylamine, 2-propoxypropylamine, 3-propoxypropylamine 4-propoxybutylamine, butoxymethylamine, butoxyethylamine, 2-butoxypropylamine, 3-butoxypropylamine, 3- (2-ethylhexyloxy) propylamine, 3-isobutoxypropylamine 4-butoxy-butyl amine, oxybis (ethylamine) and the like.

Examples of the groups R ⁹ and R ¹⁰ contained in the amine compound represented by the general formula (3) include a hydrogen atom, a linear alkyl group, a methyl group, an ethyl group, a propyl group, a butyl group, Examples include a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a stearyl group, and the branched ones include an isopropyl group, a sec-butyl group, an isobutyl group, and a tert-butyl group. Group, isopentyl group, neopentyl group, tert-pentyl group, 1-ethylpropyl group, 1,1-dimethylpropyl group, 1,2-dimethylpropyl group, 1,1,2-trimethylpropyl group, 1,2,2 -Trimethylpropyl group, 1,3-dimethylbutyl group, 1,5-dimethylhexyl group, 2-ethylhexyl group, 4-heptyl group, 2-heptyl group Le group. Examples of the alicyclic hydrocarbon group, a cyclohexyl group, a cyclopentyl group.

Then, as examples of groups R ¹² and R ¹³ amine compound represented by the general formula (3) contains, as a linear alkyl group, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, Hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, stearyl group, etc. are mentioned, and isopropyl group, sec-butyl group, isobutyl group, tert-butyl group, isopentyl as branched ones Group, neopentyl group, tert-pentyl group, 1-ethylpropyl group, 1,1-dimethylpropyl group, 1,2-dimethylpropyl group, 1,1,2-trimethylpropyl group, 1,2,2-trimethylpropyl group Group, 1,3-dimethylbutyl group, 1,5-dimethylhexyl group, 2-ethylhexyl group, 4-heptyl group, 2-heptyl group Etc., and examples of the alicyclic hydrocarbon group, a cyclohexyl group, a cyclopentyl group.

  Specific examples of the amine compound represented by the general formula (3) include aminoacetaldehyde diethyl acetal.

  The metal film forming composition of the present embodiment is selected from the group consisting of amine compounds represented by at least one general formula of the general formula (1), the general formula (2), and the general formula (3). One or a combination of two or more compatible with each other is preferably used as the component (B). As the component (B), a commercially available product can be used, and the obtaining method and the like are not particularly limited.

  Although the purity of the component (B) is not particularly limited, it is possible to reduce the impure content in the metal film in consideration that the metal film forming composition is used in the field of electronic materials. In addition, 95% or more is preferable, and 99% or more is more preferable.

  (B) As content of a component, when the total mass of all the components which the composition for metal film formation of this embodiment contains is 100 mass%, it can be 99 mass% or less, 0.1 % By mass to 99% by mass is preferable, 1% by mass to 90% by mass is more preferable, and 2% by mass to 80% by mass is still more preferable. (B) By making content of a component into 0.1 mass%-99 mass%, the metal film which has the outstanding electroconductivity can be formed. By setting the content of the component (B) to 1% by mass to 90% by mass, a metal film having a lower electric resistance value can be formed by heating at a lower temperature. By setting it as 2 mass%-80 mass%, while being able to achieve metal film formation of a low electrical resistance value, the composition for metal film formation excellent in productivity can be prepared.

[Component (C)]
As described above, the composition for forming a metal film of the present embodiment includes a solvent or a dispersion medium (hereinafter collectively referred to as a solvent) as an optional component (C) component in addition to the component (A) and the component (B). Can be included. By including a solvent in the metal film forming composition, it is easy to adjust the viscosity of the metal film forming composition corresponding to the coating method, and it is possible to form a metal film having stable and uniform physical properties. It becomes.

  A solvent will not be specifically limited if each component in the composition for metal film formation can be melt | dissolved or disperse | distributed. Examples thereof include one liquid selected from water, alcohols, ethers, esters, aliphatic hydrocarbons and aromatic hydrocarbons, or two or more compatible liquids.

  Specific examples of alcohols that can be used as the solvent include, for example, methanol, ethanol, n-propyl alcohol (1-propanol), i-propyl alcohol, n-butyl alcohol (1-butanol), i-butyl alcohol, Examples include sec-butyl alcohol, pentanol, hexanol, heptanol, octanol, nonyl alcohol, decanol, cyclohexanol, benzyl alcohol, terpineol, dihydroterpineol and the like.

  Examples of ethers include hexyl methyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n. -Propyl ether, propylene glycol mono-n-butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol monomethyl ether, Tripropylene Monoethyl ether, tripropylene glycol dimethyl ether, (poly) alkylene glycol alkyl ethers such as tripropylene glycol diethyl ether, tetrahydrofuran, tetrahydropyran, 1,4-dioxane.

  Examples of esters include methyl formate, ethyl formate, butyl formate, methyl acetate, ethyl acetate, butyl acetate, methyl propionate, ethyl propionate, butyl propionate, γ-butyrolactone, propylene glycol methyl ether acetate, propylene glycol ethyl Examples include ether acetate and dipropylene glycol methyl ether acetate.

  Examples of the aliphatic hydrocarbons include n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, n-undecane, n-dodecane, tetradecane, cyclohexane, decalin and the like. It is done.

  Examples of aromatic hydrocarbons include benzene, toluene, xylene, ethylbenzene, n-propylbenzene, i-propylbenzene, n-butylbenzene, mesitylene, tetralin, chlorobenzene, dichlorobenzene, and the like.

  Of these solvents, ethers are particularly preferable from the viewpoint of easy adjustment of the viscosity of the metal film-forming composition.

  (C) Content of the solvent which is a component is the range of 0 mass%-95 mass% when the total mass of all the components of the composition for metal film formation of this embodiment is 100 mass%, 0 The range is preferably from mass% to 70 mass%, more preferably from 0 mass% to 50 mass%.

[Other optional ingredients]
The composition for forming a metal film of the present embodiment can contain other optional components as long as the effects of the present invention are not impaired in addition to the component (A) described above. As other optional components, it can contain at least one of formic acid and ammonium formate, and in addition, a dispersant, an antioxidant, a concentration adjusting agent, a surface tension adjusting agent, a viscosity adjusting agent, a coating film forming auxiliary agent, It is possible to contain adhesion assistants and the like.

  The other optional components, formic acid and ammonium formate, have the effect of promoting a reduction reaction when forming a metal film from the metal film forming composition of the present embodiment, and form a metal film with desired electrical resistance characteristics. Can be promoted.

  As formic acid and ammonium formate that can be contained in the metal film forming composition of the present embodiment, commercially available products can be used, and the obtaining method and the like are not particularly limited.

  The purity of formic acid and ammonium formate is not particularly limited. However, if the purity is low, there is a concern that the conductivity of the metal film is lowered when the metal film is formed. Therefore, the purity of formic acid and ammonium formate is preferably 95% or more, and more preferably 99% or more.

  The total content of formic acid and ammonium formate in the metal film forming composition of the present embodiment is not particularly limited, but the total mass of all components contained in the metal film forming composition of the present embodiment is 100% by mass. Sometimes, it is preferably in the range of 0% by mass to 50% by mass, and more preferably in the range of 0% by mass to 20% by mass. Even when the total content of formic acid and ammonium formate exceeds 50% by mass, an effect corresponding to the content cannot be obtained. Furthermore, the amount of metal formation per unit mass of the composition for forming a metal film may be reduced, and a metal film having desired characteristics may not be formed with high production efficiency.

  Moreover, the composition for metal film formation of this embodiment can also contain components other than the formic acid etc. mentioned above as other arbitrary components, unless the effect of this invention is impaired. Other optional components other than formic acid and the like that can be contained in the metal film forming composition of the present embodiment are those that have desired characteristics and that do not inhibit the metal film formation reaction by component (A). There is no particular limitation. For example, it is possible to select from organic solvents in which the above-described components are dissolved and do not react and to be contained as other optional components. By adding the organic solvent, the composition for forming a metal film can be prepared so as to have a desired concentration, surface tension, and viscosity, or the adhesion with a barrier layer or the like can be improved.

  In the composition for forming a metal film of the present embodiment, the content of other optional components other than formic acid and ammonium formate is not particularly limited, but the total mass of all the components contained in the composition for forming a metal film of the present embodiment is calculated. When the content is 100% by mass, the range is preferably 0% by mass to 50% by mass, and more preferably 0% by mass to 20% by mass. Even if it is added so that the content of other optional components exceeds 50% by mass, the effect of other optional components corresponding to the content cannot be obtained. Furthermore, the amount of metal formation per unit mass of the composition for forming a metal film may be reduced, and a metal film having desired characteristics may not be formed with high production efficiency.

  Next, a method for preparing the metal film-forming composition of the present embodiment containing the above-described components will be described.

[Preparation of composition for forming metal film]
The composition for forming a metal film of the present embodiment is easily prepared and manufactured by mixing the component (B) and other optional components as necessary in addition to the component (A) described above. Can do. Moreover, also when the composition for metal film formation of this embodiment contains the solvent which is (C) component, (A) component and (C) component, and (B) component and other arbitrary components as needed Can be easily prepared and manufactured.

  In the preparation of the metal film forming composition of the present embodiment, when the amine compound as the component (B) and the solvent as the component (C) are added, the addition of the component (C) is the component (A) described above. And (B) component can be mixed and mixed. The solvent to be added is not particularly limited as long as it dissolves or disperses the component (A) and the component (B) as described above. And what melt | dissolves or disperse | distributes (B) component is preferable.

  In the preparation of the composition for forming a metal film of the present embodiment, as other optional components, formic acid and the like described above, a dispersant, an antioxidant, a concentration adjusting agent, a surface tension adjusting agent, a viscosity adjusting agent, etc. The other optional components can be added, for example, after mixing the (A) component and the (B) component, or after mixing the (A) component, the (B) component, and the (C) component. And optional components such as a dispersant, an antioxidant, a concentration adjusting agent, a surface tension adjusting agent, a viscosity adjusting agent, and an adhesion assistant are component concentrations, surface tension, viscosity, etc. of the metal film forming composition of the present embodiment. Or improve adhesion with a barrier layer or the like.

  The mixing method at the time of preparation of the metal film forming composition of the present embodiment is not particularly limited. For example, stirring with a stirring blade, stirring with a stirrer and a stirring bar, stirring with a boiler, ultrasonic homogenizer , A method using a dissolver, a bead mill, a paint shaker, a stirring deaerator, or the like. As mixing conditions, for example, in the case of stirring with a stirring blade, the rotation speed of the stirring blade is usually in the range of 1 rpm to 4000 rpm, preferably in the range of 10 rpm to 2000 rpm.

  Next, formation of a metal film using the metal film forming composition of the present embodiment and the formed metal film will be described.

[Formation of metal film]
In forming a metal film using the metal film-forming composition of the present embodiment, first, the metal film-forming composition is applied onto a desired appropriate substrate to form a coating film. . Next, this coating film is heated to form a metal film on the substrate.

  The coating is heated in the air, in a non-oxidizing atmosphere using an inert gas such as nitrogen gas, helium gas and argon gas, in an atmosphere having an oxygen concentration of 500 ppm or less, or in a vacuum. Can do. The composition for forming a metal film of the above-described embodiment can form a metal film by simply performing heating for forming the metal film. When the metal film-forming composition contains a metal salt as the component (A), the metal ion of the metal salt undergoes a reduction reaction to produce metal particles, and therefore a reducing atmosphere using a reducing gas such as hydrogen gas. There is no need to heat under.

  As a base material which forms the coating film of the composition for metal film formation, a well-known thing can be used and it does not specifically limit.

  As this base material, for example, an organic base material such as a resin, an inorganic base material such as a metal, a metal alloy, a nonmetal, a ceramic, and a glass, more specifically, an epoxy resin, a polyimide resin, an acrylic resin, Styrene resin, vinyl chloride resin, polyester resin (polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate), polyacetal resin, resin base materials such as cellulose derivatives, copper, iron, silver, gold Metal substrates such as platinum, aluminum, nickel, titanium, tantalum, cobalt, tungsten, ruthenium, lead, metal alloy substrates such as duralumin and stainless steel, non-metal substrates such as carbon, silicon, gallium, alumina, titania , Tin oxide, yttrium oxide, barium titanate Ceramic substrates such as strontium titanate, sapphire, zirconia, gallium nitride, silicon nitride, titanium nitride, tantalum nitride, polysilicon, glass substrates such as soda glass, borosilicate glass, silica glass, quartz glass, and chalcogen glass, Examples thereof include organic-inorganic composite base materials such as glass epoxy.

  As a coating method of the composition for forming a metal film of the present embodiment, inkjet printing, gravure printing, gravure offset printing method, reverse offset printing method, flexographic printing, (silk) screen printing, letterpress printing, and other printing methods, Examples of the coating method include spin coating, spray coating, bar coating, casting, dip coating, and roll coater.

  When the printing method is used, a desired pattern can be directly drawn. As a result, it is possible to form a conductive layer applied to the plating method using a metal film formed by heating a coating film formed on an appropriate substrate. When a spin coat method is used, a uniform solid coating film is formed on the substrate. By heating this coating film, a uniform solid metal film can be formed. become. In addition, when a spin coating method or the like is used, even if through holes or blind via holes are formed in the base material, they are substantially uniform on the inner surfaces of the through holes and blind via holes and on the upper surface of the base material. Therefore, it is possible to form a substantially conformal metal film by heating the coating film.

  The coating amount of the metal film forming composition can be appropriately adjusted according to the desired film thickness of the metal film. Moreover, it is preferable to adjust the viscosity of the composition for forming a metal film according to the coating method, the wettability with the substrate (the surface energy of the substrate), and the like. The viscosity of the metal film-forming composition can be adjusted by appropriately selecting the type and content of the component (C) when the solvent as the component (C) is contained. When the amine compound as the component (B) is contained in the metal film forming composition, the viscosity of the metal film forming composition is also adjusted by appropriately selecting the type and content of the component (B). It is possible.

  The temperature at which the coating film obtained by applying the metal film forming composition of the present embodiment is heated depends on whether the metal salt is contained as the component (A) or the metal fine particles are contained. It can be set as appropriate. The heating temperature when the metal film-forming composition contains a metal salt as the component (A) may be any temperature at which the metal salt of the component (A) is reduced and unnecessary organic substances are decomposed and volatilized. It is preferable to select in the range of from ° C to 300 ° C, more preferably in the range of 50 ° C to 250 ° C, and still more preferably in the range of 50 ° C to 200 ° C. If the heating temperature is less than 50 ° C., the reduction reaction of the metal salt does not proceed completely, and unnecessary organic matter may remain significantly. If the heating temperature exceeds 300 ° C., a substrate made of an organic material cannot be used. Or, there is a risk of damaging an already formed circuit portion. If it is 250 degrees C or less, it will become possible to select and use the board | substrate which consists of organic materials. Moreover, if it is 200 degrees C or less, a desired board | substrate can be selected and used from the group of the more various board | substrates including the board | substrate which consists of organic materials.

  On the other hand, the heating temperature in the case of containing metal particles as the component (A) is preferably a temperature at which the metal particles of the component (A) are sintered or fused. When the average particle diameter of the metal fine particles is about several nanometers to several tens of nanometers, the melting point is lower than that of the bulk metal, and the particles are sintered or fused by heating at a relatively low temperature of about 300 ° C. Even when the average particle diameter of the metal fine particles is about 100 nm, the particles are sintered or fused by heating at a relatively low temperature.

  In addition, the heating time is the type of each component such as the component (A) in the composition for forming a metal film, the component (B), the component (C), and other optional components added as necessary, and the like. What is necessary is just to select suitably considering the electroconductivity (electrical resistance value) of a metal film, and it does not specifically limit. When a relatively low heating temperature of about 200 ° C. or lower is selected, the heating time is preferably about 5 to 100 minutes.

  When the metal film obtained by heating the coating film of the metal film forming composition is used as a seed layer for plating treatment for forming a contact plug, as described in the first and second embodiments. The viscosity of the metal film forming composition is preferably 1 Pa · s or less, and the metal concentration is preferably 5 to 50% by mass. Here, the metal concentration of the composition for forming a metal film means the ratio of the component (A) in the composition for forming a metal film. In this case, the metal film is preferably formed by heating the coating film of the composition for forming a metal film to 100 to 200 ° C. in an atmosphere having an oxygen concentration of 500 ppm or less or in a vacuum.

  The film thickness and step coverage of the metal film obtained by heating the coating film of the metal film forming composition are the composition of the metal film forming composition, the coating amount of the metal film forming composition, and the metal film forming It varies depending on the viscosity of the composition, the metal concentration of the metal film forming composition, the wettability between the metal film forming composition and the substrate, the coating conditions, and the like. In order to form a metal film with a desired film thickness having good step coverage, the composition, viscosity and metal concentration of these metal film-forming compositions, and coating conditions are taken into account in consideration of wettability with the substrate. It is desirable to obtain a preferable range in advance through experiments.

  For example, when a metal film forming composition is applied onto a silicon wafer on which blind via holes are formed by spin coating to obtain a coating film, and the coating film is heated to form a metal film, the metal film forming composition By adjusting the composition of the product, the coating amount of the metal film forming composition, the viscosity of the metal film forming composition, the metal concentration of the metal film forming composition, etc. A simple metal film can be formed. That is, a conformal metal film can be formed.

  As described above, by using the metal film forming composition of the present embodiment, it is possible to easily form a metal film having good electric resistance characteristics and to form a metal with good step coverage. It becomes easy to form a film. Even in the case of a through hole or blind via hole having a large aspect ratio, a metal film can be easily formed in the through hole or blind via hole with good step coverage.

  Hereinafter, embodiments of the present invention will be described more specifically based on examples. However, the present invention is not limited to these examples. In the examples, the viscosity was measured with an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.).

Example 1
A glass reactor equipped with a cooling jacket and a stirrer was charged with 33 parts by weight of copper formate tetrahydrate and 67 parts by weight of n-octylamine. Next, while controlling the liquid temperature at 30 ° C., mixing was performed at 300 rpm for 20 hours to prepare a metal film forming composition 1 having a copper concentration in terms of atoms of 9.3 mass%. The viscosity of the metal film forming composition 1 was 390 mPa · s.

Example 2
In the same manner as in Example 1, except that copper formate tetrahydrate was replaced by 22 parts by weight of anhydrous copper formate and 2-ethylhexylamine was replaced by 78 parts by weight instead of n-octylamine. A metal film forming composition 2 having a copper concentration of 9.1% by mass was prepared. The viscosity of the metal film forming composition 2 was 100 mPa · s.

Example 3
The copper concentration in terms of atoms was 9.0 mass in the same manner as in Example 1 except that 23 parts by weight of nickel formate was used instead of copper formate tetrahydrate and 77 parts by weight of n-octylamine was used. % Of a metal film-forming composition 3 was prepared. The viscosity of the metal film forming composition 3 was 150 mPa · s.

Example 4
A metal film was prepared in the same manner as in Example 1 except that 7 parts by weight of nickel formate, 15 parts by weight of anhydrous copper formate, 58 parts by weight of n-octylamine, and 20 parts by weight of 3-ethoxypropylamine were used. A forming composition 4 was prepared. The viscosity of the metal film forming composition 4 was 320 mPa · s.

Example 5
22 parts by weight of anhydrous copper formate, 55 parts by weight of n-octylamine, 23 parts by weight of diethylene glycol dimethyl ether, and 0.5 parts by weight of BYK370 (BIC Chemie, solid content concentration 25% by mass) as a surface conditioner A metal film-forming composition 5 was prepared in the same manner as in Example 1 except that. The viscosity of the metal film forming composition 5 was 90 mPa · s.

Example 6
To a glass reactor equipped with a glass reflux condenser and a stirrer, 32.3 parts by weight of 1-butanol, 46.2 parts by weight of 2-ethylhexylamine, 3.2 parts by weight of oleic acid, and 18.3 parts by weight of anhydrous copper formate Then, the mixture was stirred until it was uniformly dissolved under a nitrogen stream, and then heated to 100 ° C. in an oil bath and stirred for 60 minutes to obtain a black copper fine particle dispersion. The copper fine particle dispersion was allowed to cool to room temperature, 100 parts by weight of methanol was added, and the supernatant was separated and removed by centrifugation to obtain 10.2 parts by weight of a solid mainly composed of copper nanoparticles. In the analysis with a transmission electron microscope (TEM), the average particle diameter of the copper nanoparticles was 54 nm. To 4.0 parts by weight of the solid matter mainly composed of the obtained copper nanoparticles, 0.4 parts by weight of oleic acid, 0.3 parts by weight of octylamine, 3.5 parts by weight of n-octane, 3.5 parts of butanol Part by weight and 0.1 part by weight of Solsperse 24000 (manufactured by Lubrizol) were mixed with a planetary defoaming stirring mixer to obtain a metal film forming composition 6 having a copper concentration of 33% by mass in terms of atoms. . The viscosity of the metal film forming composition 6 was 75 mPa · s.

Example 7
In place of the copper formate tetrahydrate of Example 1, 10.5 parts by weight of anhydrous copper formate and 67 parts by weight of n-octylamine were replaced by 89 parts by weight, and BYK370 (manufactured by BYK Chemie, solid concentration 25 mass) %) A metal film-forming composition 7 having a copper concentration of 4.4 wt% in terms of atoms was prepared in the same manner as in Example 1 except that 0.5 part by weight was added. The viscosity of the metal film forming composition 7 was 80 mPa · s.

Examples 8-14
(Creation of through silicon via substrate)
A substrate having the structure shown in FIG. 1 was prepared according to the steps shown in FIGS. First, a silicon nitride film was formed on the upper surface of the silicon wafer substrate by plasma CVD. A resist was patterned thereon by photolithography, and a mask material layer having a blind via hole shape was formed by subsequent wet etching. Next, a blind via hole having a diameter of 10 μm and a depth of 100 μm was formed on the silicon wafer substrate by reactive ion etching from the mask material layer forming surface. Thereafter, the silicon nitride film as the mask material layer was removed by wet etching.

  Next, a silicon oxide film was formed on the upper surface of the silicon wafer substrate and the inner surface of the blind via hole by plasma CVD. Further, a titanium film as a barrier layer is formed by the PVD method, and then copper is deposited by the PVD method to form the bottom seed layer BS and the upper conductive film UM (see FIGS. 2 and 3) at the same time. A blind via hole substrate having a BS and an upper conductive film UM was prepared. In the substrate, the thickness of the copper film was adjusted so that the bottom seed layer BS was 10 nm and the upper conductive film UM was 30 nm, and the presence of the copper film was not observed on the inner wall portion of the via.

The above-described blind via-hole substrate having the bottom seed layer BS is spin-coated with the metal film-forming compositions 1 to 7 of Examples 1 to 7, and baked at a predetermined temperature for 30 minutes in a hot air plate under a nitrogen stream. A sintered film of copper particles was formed as a metal film 23 (see FIG. 2) serving as a base material of the main seed layer MS on the upper surface of the via hole forming surface and the inner surface of the blind via hole. Conditions were adjusted so that the average thickness of the main seed layer MS was 250 nm on the upper surface and 60 nm on the inner wall. The surface resistance value of the upper surface of the obtained blind via-hole substrate with a metal film was measured using a four-point probe resistance measuring machine (trade name: Model sigma-5, NPS). Further, the adhesion test was conducted in accordance with the tape test method described in JIS-H-8504. Evaluation was performed in the following three stages A to C.
A: When the metal film does not adhere to the adhesive surface of the tape B: When the metal film partially adheres to the adhesive surface of the tape C: When the entire metal film adheres to the adhesive surface of the tape Table 1 shows the evaluation results.

  Next, under the conditions described in Example 2 of Japanese Patent No. 3964263, the surface of the blind via hole is subjected to electrolytic copper plating, and after filling the blind via hole with copper, the method described in Example 1 of Japanese Patent No. 3837277 is described. The copper film on the upper surface of the blind via hole was flattened by polishing the electrolytic copper plating layer by a chemical mechanical polishing (CMP) method under the conditions. Next, the surface opposite to the blind via hole forming surface (the lower surface of the silicon wafer substrate) is polished by CMP until the lower surface of the barrier layer is completely exposed, and then a silicon oxide film is formed by plasma CVD, After removing the silicon oxide film in a position overlapping the electrolytic copper plating layer in the blind via hole in plan view by wet etching, an aluminum layer was formed as a lower common electrode by the PVD method.

  Next, the upper side wiring was formed by removing the copper electroplating layer / upper conductive film / barrier layer other than the region to be left as the upper wiring by wet etching to obtain a through silicon via substrate. By measuring the electrical resistance value between the lower common electrode and the upper wiring of the through silicon via substrate, the conductivity of the formed 20 contact plugs was confirmed. The resistance value from the measurement terminal of the upper wiring to the contact plug was corrected, and the resistance value between the upper and lower sides of the contact plug was calculated. The results summarized for each resistance value range are shown in Table 2.

Further, the contact plug portion of each substrate was cross-sectional processed by focused ion beam processing (FIB), and observed by a high-resolution scanning electron microscope (SEM) to evaluate the filling property, that is, the state of void generation. Evaluation was performed in the following two stages.
○: Void is not seen and connected well Δ: There is a portion where void is generated Table 2 shows the evaluation results.

Example 15
In the production of the through silicon via substrate of Example 8, sample preparation and evaluation similar to Example 8 were carried out except that palladium was deposited instead of depositing copper by the PVD method.
The firing temperature conditions and the evaluation results are shown in Tables 1 and 2.

  The present invention has been described with reference to the examples. However, the present invention is not limited to the above-described embodiments and examples. Various changes, improvements, combinations, and the like are possible for the present invention. For example, the lower end of the contact plug constituting the three-dimensional wiring and the lower wiring may be directly connected without any barrier layer as described in the first embodiment. As described in 8 to 15, they may be connected via a barrier layer. Even when the contact plug and the lower wiring are connected via the barrier layer, the surface of the barrier layer is passivated by oxidation, nitridation, etc., between the formation of the barrier layer and the formation of the bottom seed layer. If this is prevented, the contact resistance value between the contact plug and the lower wiring can be made relatively low. The passivation of the barrier layer surface can be prevented, for example, by performing the formation of the barrier layer and the bottom seed layer in a series of vacuum environments.

  The circuit device having the three-dimensional wiring of the present invention may be a wiring board, a circuit board, or a mounting board having a multilayer wiring structure such as a build-up wiring board. The method for forming a three-dimensional wiring of the present invention can be suitably applied to the formation of a three-dimensional wiring composed of a plurality of damascene wirings.

DESCRIPTION OF SYMBOLS 1 Silicon through wiring board 10 Silicon substrate 11a1-11a3 Upper barrier layer 11b1, 11b2 Lower barrier layer 12a-12e Upper wiring 13a, 13b Lower wiring 100 Semiconductor device 130 Multilayer wiring part 131 1st wiring layer 132 2nd wiring layer 133 Third wiring layer BS Bottom seed layer MS Main seed layer PB Plug body CP Contact plug D Damascene wiring WL wiring

Claims (19)

An upper wiring formed on the upper surface side of the base material or the electric insulating film and a lower wiring formed on the lower surface side of the base material or the electric insulating film are provided on the base material or the electric insulating film. Having three-dimensional wiring electrically connected to each other by contact plugs formed in the through holes;
The contact plug is formed on the main seed layer, the bottom seed layer constituting the lower end surface side of the contact plug, the main seed layer covering each of the bottom seed layer and the inner wall of the through hole, and the through seed A conductor layer filling the hole,
The bottom seed layer is a conductor layer formed by vapor deposition, and the main seed layer contains at least one of a metal salt and particles selected from Group 10 and Group 11 of the periodic table. A circuit device having a three-dimensional wiring, which is a metal film formed by heating a coating film of a composition for forming a metal film.   2. The circuit device having a three-dimensional wiring according to claim 1, wherein an average value of the thickness of the main seed layer on the inner wall of the through hole is 10 to 2000 nm.   The circuit device having a three-dimensional wiring according to claim 1, wherein the main seed layer is a sintered film of copper particles.   4. The diameter of the through hole is 1 to 100 μm, the depth is 20 to 200 μm, and the ratio of the depth to the diameter is 1 to 50. 5. A circuit device having three-dimensional wiring.   A barrier layer covering at least the inner wall of the through hole is further provided as an underlayer for the main seed layer, and the barrier layer includes at least one layer made of a refractory metal, a refractory metal alloy, or a refractory metal compound. The circuit device having a three-dimensional wiring according to any one of claims 1 to 4, further comprising a layer. A contact plug is formed in a through-hole provided in the base material or the electric insulation film, and an upper wiring formed on the upper surface side of the base material or the electric insulation film, and a lower surface side of the base material or the electric insulation film A lower wiring formed in the three-dimensional wiring is electrically connected to each other by the contact plug,
A hole forming step of forming a through hole or a blind via hole in the base material or the electrical insulating film;
A bottom seed layer forming step of forming a bottom seed layer by depositing a conductor by vapor deposition on a lower end side of the through hole or on a bottom surface of the blind via hole;
A metal film-forming composition containing at least one of a metal salt and particles selected from Group 10 and Group 11 of the periodic table is applied to the base material or electrical insulating film on which the bottom seed layer is formed. A coating film forming step of forming a coating film covering the upper surface of the base material or the electrical insulating layer, the inner wall of the through-hole or the blind via hole, and the upper surface of the bottom seed layer;
A metal film forming step of heating the coating film to form a metal film;
A method for forming a three-dimensional wiring, comprising:   The method for forming a three-dimensional wiring according to claim 6, wherein the composition for forming a metal film has a viscosity of 1 Pa · s or less and a metal concentration of 5 to 50 mass%.   The three-dimensional wiring according to claim 6 or 7, wherein, in the metal film forming step, the coating film is heated to 100 to 200 ° C in an atmosphere having an oxygen concentration of 500 ppm or less or in a vacuum. Method.   9. The metal film having an average thickness of 10 to 2000 nm on the inner wall of the through hole or the inner wall of the blind via hole is formed in the metal film forming step. The method for forming a three-dimensional wiring according to any one of the above.   The method for forming a three-dimensional wiring according to any one of claims 6 to 9, wherein the metal film is a sintered film of copper particles.   11. The diameter of the through hole or the blind via hole is 1 to 100 μm, the depth is 20 to 200 μm, and the ratio of the depth to the diameter is 1 to 50. 11. The method for forming a three-dimensional wiring according to one item.   The high melting point film forming step of forming a high melting point film as a base material of the barrier layer on the inner surface of the through hole or the blind via hole prior to the metal film forming step is further included. Item 12. The method for forming a three-dimensional wiring according to any one of Items 11 to 11.   13. The method according to claim 6, further comprising a plating step of filling the through hole or the blind via hole by depositing a conductor on the bottom seed layer and the metal film by a plating method. The method for forming a three-dimensional wiring according to the item.   The method of forming a three-dimensional wiring according to claim 13, further comprising a polishing step of removing surplus conductor deposited in the plating step by a chemical mechanical polishing method.   A composition for forming a metal film for three-dimensional wiring, comprising at least one of a metal salt and particles selected from Group 10 and Group 11 of the periodic table.   The composition for forming a metal film for a three-dimensional wiring according to claim 15, wherein the metal salt is a carboxylate containing copper or nickel, and the metal particles are copper particles or nickel particles. .   The metal salt is copper formate or nickel formate, and the metal particles are copper particles or nickel particles having an average particle diameter of 5 to 100 nm. A metal film forming composition for dimension wiring.   The composition for forming a metal film for a three-dimensional wiring according to any one of claims 15 to 17, further comprising an amine compound.   The composition for forming a metal film for a three-dimensional wiring according to any one of claims 15 to 18, wherein the viscosity is 1 Pa · s or less and the metal concentration is 5 to 50% by mass.

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