JP2003069185A - Circuit board containing capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit board having a high manufacturing yield in the circuit board containing a thin film capacitor having a low equivalent series resistance and a large capacity density. SOLUTION: The circuit board comprises electrically conductive base boards 1, 5, a first electrically conductive layer 2, a dielectric layer 3 and a second electrically conductive layer 4 sequentially laminated on at least one main surface of each of the boards 1, 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit board having a built-in capacitor, and more particularly to a circuit board having a built-in capacitor suitable for removing high frequency noise and suppressing fluctuations in power supply voltage of integrated circuit elements.

[0002]

2. Description of the Related Art Recently, in semiconductor chips, integrated circuit elements
As the density of (hereinafter referred to as IC) becomes higher, the operating speed is increasing year by year. When the operating speed of the IC increases, there is a problem that switching noise generated inside the semiconductor chip may cause the IC to malfunction. To reduce switching noise, it is effective to install a capacitor having a small equivalent series inductance as a decoupling capacitor between the ground terminal and the power supply terminal.

When the decoupling capacitors are arranged on the wiring board as external parts, the connection distance between these parts and the semiconductor chip becomes long and the wiring inductance becomes large, so that the effect of the decoupling capacitors is insufficient. turn into. Therefore, the decoupling capacitor is required to be as close to the LSI as possible, and it is desirable to directly form the decoupling capacitor on the semiconductor chip. However, in this case, the area of the semiconductor chip increases, the cost increases, and the manufacturing process becomes complicated and long, so that the yield of the semiconductor chip itself decreases due to the defect of the decoupling capacitor. An intermediate substrate (interposer or semiconductor chip carrier) used when mounting a semiconductor chip on a wiring substrate to address these problems.
It has been proposed in JP-A-6-318672, JP-A-8-148595, JP-A-9-213835, etc. to incorporate a decoupling capacitor therein.

Japanese Unexamined Patent Publication (Kokai) No. 8-148595 discloses a structure in which a thick film capacitor is built in a chip carrier made of a glass ceramic substrate. However, it is difficult to make the dielectric layer thin, so that it is equivalent. There was a limit to the reduction of series inductance. JP-A-6-31867
Japanese Unexamined Patent Application Publication No. 2 and Japanese Patent Application Laid-Open No. 9-213835 disclose a structure in which a thin film capacitor capable of reducing an equivalent series inductance is formed on the surface of an insulating base substrate. There is a problem in that the film thickness of the lower electrode cannot be increased and the electric resistance of the lower electrode increases.

Therefore, a refractory metal such as molybdenum (Mo), tantalum (Ta), or tungsten (W) is used as the base substrate, and the metal base substrate is used as a part of the lower electrode of the capacitor. Japanese Patent Application Laid-Open No. 8-88318 proposes a circuit board for reducing the resistance of a part. In Japanese Patent Laid-Open No. 8-88318,
SrTiO ₃ film and Sr _xa B as dielectric film of capacitor
It is disclosed that an a _1-x TiO ₃ film (0 <x <1) is used. These dielectric films need to be annealed after they are formed, but because a base substrate made of a refractory metal is used,
It is possible to anneal the base substrate together.

A circuit board having a built-in capacitor in which an aluminum-based alloy is used as a base substrate, which is anodized to form an alumite coating and which is used as a dielectric is proposed in Japanese Patent Laid-Open No. 11-298104. ing.

[0007]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
A circuit board using a metal substrate as a base and forming a thin film capacitor on the metal substrate as in Japanese Patent No. 318 can reduce the equivalent series resistance and the equivalent series inductance component of the built-in capacitor, and use the base substrate as a ground layer. By using it, there is an advantage that the ground layer can be strengthened. However, since the circuit board of Japanese Patent Laid-Open No. 8-88318 has a dielectric film formed by film formation, the dielectric properties of the dielectric layer are likely to deteriorate due to the generation of pinholes and the inclusion of minute foreign matter, resulting in a manufacturing yield. Was difficult to secure.

The circuit board using the alumite film as the dielectric film disclosed in Japanese Patent Laid-Open No. 11-298104 requires a film thickness of 1 to 10 μm in order to secure the insulating property of the alumite film. The capacitance density of the built-in capacitor was 0.01 to 0.1 pF / mm ² . Therefore, there is a limit to increase the capacity of the built-in capacitor and reduce the equivalent series inductance component, and the applicable range is also limited.

The present invention has been made in view of the above, and provides a circuit board having a low equivalent series resistance and a built-in thin film capacitor having a large capacitance density, which has a high manufacturing yield. With the goal.

[0010]

In order to achieve the above object, according to the present invention, there is provided a circuit board having a built-in capacitor as described below.

That is, an electrically conductive base substrate, a first electrically conductive layer, a dielectric layer, and a second electrically conductive layer, which are sequentially laminated on at least one main surface of the base substrate. And the substrate, the first electrically conductive layer,
The dielectric layer and the second electrically conductive layer use the substrate and the first electrically conductive layer as a first electrode, and the second electrically conductive layer as a second electrode. A capacitor used, wherein the first electrically conductive layer is
A capacitor, which is made of an electrically conductive material containing tantalum, wherein the dielectric layer is made of a dielectric material containing tantalum oxide, which is formed by oxidizing a part of the first electrically conductive layer. A circuit board having a built-in is provided.

In order to achieve the above object, according to the second aspect of the present invention, the following circuit board is provided.

That is, an electrically conductive base substrate, a first electrically conductive layer, a plurality of dielectric layers, and a second electrically conductive layer, which are sequentially laminated on at least one main surface of the base substrate. A conductive layer, the substrate, the first electrically conductive layer, the plurality of dielectric layers, and the second electrically conductive layer include the substrate and the first electrically conductive layer. A capacitor used as a first electrode and using the second electrically conductive layer as a second electrode, wherein the first electrically conductive layer is made of an electrically conductive material containing tantalum,
The layer closest to the first electrically conductive layer among the plurality of dielectric layers is a dielectric material containing tantalum oxide, which is formed by oxidizing a part of the first electrically conductive layer. It is a circuit board having a built-in capacitor.

In the circuit board incorporating the capacitor of the second aspect, at least one of the plurality of dielectric layers can be made of an oxide having a perovskite structure. According to this structure, SrTiO 3
_Since oxides having a perovskite structure, such as ₃ and Sr _x Br _1-x TiO ₃ , have a high dielectric constant, the capacitance of the built-in capacitor can be increased.

The circuit boards of the first and second aspects are
As a base substrate, nickel (Ni), chromium (C
r), cobalt (Co), iron (Fe) -based alloy containing any one of aluminum (Al), iron-based composite material obtained by applying copper (Cu) clad to the iron-based alloy, tungsten (W) , Tantalum (Ta), molybdenum (Mo), nickel (Ni), copper (Cu), or aluminum (Al). According to this structure, the base substrate can be smoothed by surface polishing or the like, so that a thin film capacitor can be formed. Since W, Ta, Mo, Ni, Cu, and Fe-based alloys are refractory metals of 1000 ° C. or higher, it is possible to form a dielectric layer having a high dielectric constant such as a perovskite structure oxide, and a large capacity of a built-in capacitor. Contribute to Further, W, Ta, Mo, and Fe-based alloys have a small difference in coefficient of thermal expansion from Si, and can improve the reliability of bonding with Si semiconductor chips. Cu and Al also have excellent thermal conductivity, and Al also contributes to weight reduction of the circuit board. Further, the Fe-based alloy has excellent through-hole processability, and can provide a circuit board suitable for an interposer having a large number of through vias.

In the circuit boards of the first and second aspects, the base substrate may have a thin film protective layer made of an electrically conductive material on at least a part of the main surface, The thin film protective layer is a platinum group metal material, or an electrically conductive oxide such as indium oxide, tin oxide, a mixture of indium oxide and tin oxide, zinc oxide, ruthenium oxide, rhenium oxide, iridium oxide, osmium oxide, or the like. , High-melting-point metal such as chromium (Cr), titanium (Ti), tungsten (W), molybdenum (Mo), or the like. With this configuration, the adhesion of the first electrically conductive layer forming the first electrode formed on the upper layer to the base substrate is increased, and the base substrate is protected from the manufacturing process of the circuit substrate. It is possible to prevent roughening and corrosion due to the oxidation of.

In the circuit boards of the first and second aspects, conductive vias for electrically connecting the two main surfaces of the front and back are provided in the base board, and the conductive vias are electrically connected to the base board. It can be configured to be insulated.
According to this structure, the semiconductor chip is connected to the connection terminal provided on the main surface forming the capacitor, and the wiring board is connected to the connection terminal provided on the main surface on the opposite side of the semiconductor chip. It is possible to provide a circuit board having a built-in capacitor. Here, if the connection terminals are bumps, surface mounting becomes possible and the mounting density can be increased.

At least a part of the conductive via may be made of the same material as the base substrate. With such a configuration, the conductive via can be formed by processing the base substrate around the conductive via, and therefore, the manufacturing process of the circuit substrate having the capacitor built therein can be simplified.

In addition, in the above-described circuit board, it is possible to provide a multi-layer wiring portion including an insulating layer and a wiring layer on at least one of the front and back main surfaces. With this configuration, the first electrode and the second electrode of the built-in capacitor can be used for the power supply layer or the ground layer,
A circuit board having a built-in capacitor that can be used as a mounting board for a semiconductor chip can be provided.

Further, an inductance element and / or a resistance element may be built in the multilayer wiring section. With such a configuration, it is possible to provide a circuit board with a built-in capacitor that also includes a terminating resistor and a filter.

In addition, the various circuit boards described above may be configured such that semiconductor elements are mounted on at least one of the front and back main surfaces. With this configuration, it is possible to provide a semiconductor device that can reduce switching noise by using the built-in capacitor as a decoupling capacitor.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A circuit board 1000 according to a first embodiment of the present invention will be described with reference to FIG.

The circuit board 1000 shown in FIG.
00 is built in. The structure of the circuit board 1000 includes a base substrate 1 made of a conductive member, a thin film protective layer 5 made of an electrically conductive material, and a first thin film layer 2 made of an electrically conductive material, which are stacked on the upper surface of the base substrate 1. . Base substrate 1
Is made of 42 alloy (alloy having iron (Fe) and nickel (Ni) as main components) having a thermal expansion coefficient close to that of Si, and the thin film protective layer 5 is a Cr film having a thickness of 200 nm. The first thin film layer 2 is a tantalum film containing nitrogen having a thickness of 100 nm or more. Base substrate 1, thin film protective layer 5 and first thin film layer 2
Form the lower electrode 41 of the capacitor 400.

An oxide layer 3 formed by oxidizing a part of the first thin film layer 2 is mounted on the upper surface of the first thin film layer 2. Therefore, the oxide layer 3 is a tantalum oxide film containing nitrogen, and its thickness is 200 to 400 nm. The oxide layer 3 is used as a dielectric layer of the capacitor 400.

A second thin film layer 4 made of an electrically conductive material is arranged on the upper surface of the oxide layer 3. The second thin film layer 4 is
It is used as the upper electrode of the capacitor 400. The second thin film layer 4 is a laminated film in which a Cr layer, a Cu layer, and a Cr layer are sequentially laminated. The thickness of the Cr layer is 50 to 200 nm, and the thickness of the Cu layer is 1000 to 5000 nm.

The upper surface of the second thin film layer 4 of the upper electrode and the partially exposed lower electrode 41 of the first thin film layer 2 is covered with an insulating layer 6 of an organic material so as to cover them. The insulating layer 6 includes the second thin film layer of the upper electrode and the lower electrode 41.
A through hole reaching the first thin film layer 2 is formed, and the through hole is filled with the conductor layer 7. Further, an insulating layer 8 made of an organic material is further arranged on the insulating layer 6. Through holes are formed in the insulating layer 8 so as to be in contact with the conductor layers 7 of the through holes in the insulating layer 6,
Connection terminal metallized layers 81, 82, 91, 92 which are in contact with the conductor layer 7 are arranged in the through holes. In this embodiment, the conductor layer 7 is made of copper. The metallized layer 8 is made of a material suitable for a connection method when connecting to an external terminal. For example, when using solder connection, a laminated film of Au layer, Ni layer, Cr layer, NiCu alloy layer, Cr layer. And a NiW alloy layer, a Cr layer, or the like.

Further, a thin film protective layer 501 and an organic insulating layer 601 are laminated on the back surface of the base substrate 1. The thin film protective layer 501 is the thin film protective layer 5 on the upper surface of the base substrate 1.
The same Cr film as

In FIG. 1, the main surface portion of the circuit board is shown in an enlarged manner in order to facilitate understanding of the details of the portion formed by the thin film layer. In particular, the thickness direction is enlarged.

The circuit board 1000 shown in FIG.
Since the lower electrode 41 of No. 00 is configured not only by the first thin film layer 2 but also by the base substrate 1 having low resistance, the equivalent series resistance of the capacitor 400 can be reduced.

The oxide layer 3 which is the dielectric layer of the capacitor 400 is formed by oxidizing a part of the first thin film layer 2. As a method of oxidizing the first thin film layer 2, for example, an anodic oxidation method, a plasma oxidation method, a thermal oxidation method or the like can be used. Since the generation of defects such as pinholes is suppressed in principle by these oxidation methods, it is possible to increase the manufacturing yield of capacitors as compared with the case where they are formed by a high frequency sputtering method, a CVD method, or a sol-gel method. As a result, the circuit board 1000 having the built-in capacitor 400 having a low equivalent series resistance can be manufactured with a high yield.

In this circuit board 1000, semiconductor chips are mounted on the connection terminal metallization layers 82 and 92, the connection terminal metallization layer 81 is used as a power supply layer (or ground layer), and the connection terminal metallization layer 91 is used as a ground layer (or power supply layer). ), The built-in capacitor 400 can act as a decoupling capacitor.

Next, a method of manufacturing the circuit board 1000 of FIG. 1 will be described with reference to FIGS. 2 (A) to (E) and FIGS. 3 (A) to (E).

FIG. 2 (A): Preparation of Base Substrate 1 First, 42 alloy (alloy containing iron (Fe) and nickel (Ni) as main components) is cut into an appropriate size, and the surface is polished as necessary. To make the base substrate 1.
Then, the base substrate 1 is degreased and washed with a neutral detergent or an alkaline detergent to clean the surface.

FIG. 2 (B): Formation of thin film protective layers 5 and 501 A Cr film having a thickness of 200 nm is formed on the upper and lower main surfaces of the base substrate 1 by a sputtering method.
The thin film protective layers 5 and 501 are used. Although Cr is used as the protective film here, the material and film thickness of the thin film protective layers 5 and 501 can be arbitrarily determined according to the process conditions such as the processing temperature and the covering property with respect to the base substrate 1. For example, as the material of the thin film protective layers 5 and 501, a platinum group metal material, indium oxide, tin oxide, a mixture of indium oxide and tin oxide, zinc oxide, ruthenium oxide,
Electrically conductive oxides such as rhenium oxide, iridium oxide and osmium oxide, or chromium (Cr), titanium (Ti), tungsten (W), molybdenum (Mo),
It is possible to use one appropriately selected from refractory metals such as nickel (Ni). Further, the film forming method is not limited to the sputtering method, and may be a vacuum vapor deposition method, a chemical vapor deposition method, a sol-gel method, a MOD (Metal Organic Decompos
ition) method, a plating method, or the like, a method can be selected and used according to the type of material of the thin film protective layers 5 and 501 and the material of the base substrate 1.

FIG. 2C: Formation of first thin film layer 2 On the thin film protective layer 5 on the main surface of the upper surface of the base substrate 1,
A tantalum thin film containing nitrogen is formed as a first thin film layer 2 by a reactive sputtering method. The film thickness may be set in consideration of the film thickness of the oxide layer 3 to be formed in the subsequent process, and can be set to, for example, 200 to 400 nm. Here, the tantalum thin film containing nitrogen is used as the first thin film layer 2, but the present invention is not limited to this, and any material that can form a dense oxide layer by the oxidation treatment can be used, but the oxidation treatment can be used. When anodic oxidation or thermal oxidation is used as the method, pure tantalum or a conductive tantalum-based thin film containing nitrogen and / or oxygen is suitable for obtaining a high-quality layer with few pinholes as the oxide layer 3. .

FIG. 2D: Oxidation of the first thin film layer 2 (formation of the oxide layer 3 to be a dielectric layer) On the first thin film layer 2 on the main surface on the upper surface side of the base substrate 1,
A resist pattern having an opening is formed by a well-known photolithography method. The opening is formed in a portion where the oxide layer 3 which is a dielectric layer is to be formed. Next, the base substrate 1 is placed in the electrolytic solution, and the first thin film layer 2 exposed through the resist pattern opening is oxidized by the anodic oxidation method using the base substrate 1 as an anode. This gives a thickness of 20
An oxide layer 3 having a thickness of 0 to 400 nm is formed. After removing the resist, heat treatment is performed at a temperature of 200 to 300 ° C. Thereby, the dense oxide layer 3 with few pinholes can be formed, and the capacitor 400 having a capacitance density of 0.5 to 1 nF / mm ² can be obtained. In this embodiment, the first thin film layer 2 (that is, the tantalum film containing nitrogen) having a thickness of 100 nm or more is left below the oxide layer 3.

FIG. 2 (E): Formation of second thin film layer 4 Next, on the entire main surface on the upper surface side of the base substrate 1, Cu is sandwiched by Cr using a method such as a sputtering method.
/ Cu / Cr laminated film is formed (however, A / B indicates that A is laminated on B). Then, by using well-known photo etching or the like, Cr / Cu /
Pattern separation is performed so that the Cr laminated film is left only above the oxide layer 3, and the second thin film layer 4 serving as the upper electrode is formed. The film thickness of Cr and Cu is determined in consideration of the adhesion strength between the second thin film layer 4 and the oxide layer 3 which is a dielectric layer, and the resistance of the second thin film layer 4 as an electrode. For example, the Cr film thickness is 5
0-200 nm, Cu film thickness is 1000-5000
can be nm. Thereby, the second thin film layer 4
Sheet resistance can be made as low as 20 mΩ / □ or less. The material forming the second thin film layer 4 can be selected and used according to the material of the oxide layer 3 used as the dielectric layer.

Next, description will be made with reference to FIGS. FIG. 3 (A): Formation of front and back insulating layers 6 and 601 An organic insulating sheet such as a prepreg is attached to the upper and lower main surfaces of the base substrate 1 by using a method such as a vacuum hot pressing method, and the first main The insulating layer 6 on the front surface side and the insulating layer 601 on the second main surface side are formed. Then, a through hole 610 is formed in the insulating layer 6 on the upper surface side by using a known method such as a laser processing method. Note that the organic insulating material is not limited to prepreg, and other materials can be used. For example, a liquid or paste insulating material can be used by another method such as dipping method, printing method, spray coating, transfer method, or the like. A film can be formed by a method to form the insulating layers 6 and 601. Also, as a method of forming the through hole 6, a photo-etching method (wet etching, dry etching, etc.) can be applied depending on the insulating material. When a photosensitive material is used as the insulating material, a well-known photo etching method can be used. The insulating layer 6 is formed by the lithography method.
And the through hole 610 can be formed at the same time.

FIG. 3B: Formation of Conductor Layer 7 Next, the conductor layer 7 is formed on the insulating layer 6 by a well-known method such as a sputtering method, a vacuum vapor deposition method, a chemical vapor deposition method or a plating method. Is formed and the through hole 610 is filled. Then, the conductor layer 7 is processed by a well-known method such as photoetching, the conductor layer 7 is left only in the portion where the through holes 610 are filled, and the surrounding conductor layer 7 is removed. As the conductor layer 7, a metal having low resistance, here Cu is used.

FIG. 3C: Formation of surface insulating layer 8 On the insulating layer 6, an organic insulating resin is applied by a well-known method such as a spin coating method, dried and cured to form the insulating layer 8.
To form a film. Then, a through hole 810 is formed by using a known method such as photo etching. A photosensitive material is used as the organic insulating resin, and coating, drying, exposure,
It can also be formed by each step of development and curing. In this case, the etching process for forming the through hole 810 can be omitted. It is also possible to use an insulating sheet such as prepreg as the organic insulating resin, attach the insulating sheet on the insulating layer 6 by a vacuum hot pressing method, etc., and form the through hole 810 by laser processing or the like.

FIG. 3D: connection terminal metallized layer 81,
Formation of 82, 91, 92 Insulating a material suitable for a connection method used for connection with an electronic component such as a semiconductor element mounted on the circuit board 1000 by a known film forming method such as a sputtering method, a vacuum vapor deposition method, or a plating method. A film is formed on the layer 8 and pattern separation is performed into the shape of the connection terminal by a well-known method such as a photoetching method, and the connection terminal metallization layers 81, 91, 82, 92 are formed on the first main surface side of the circuit board 1000. Form. For example, as the metallized layers 81, 82, 91, 92 suitable for solder connection, an Au / Ni / Cr laminated film, a Ni—Cu / Cr laminated film, a Ni—W / Cr laminated film, or the like can be used.

Through the above steps, the circuit board 1000 shown in FIG. 1 can be manufactured. The characteristic point of the manufacturing method of the circuit board 1000 of the present embodiment is that the base board 1
A thin film protective layer 5 made of Cr or the like is provided on top of which a first
As a thin film layer 2 of, a tantalum-based thin film (here, a tantalum thin film containing nitrogen) is formed, and a part of the tantalum-based thin film is oxidized by an anodic oxidation method to obtain tantalum oxide containing nitrogen, thereby forming a dielectric layer. (Oxide layer 3) is formed. When the dielectric layer (oxide layer 3) is formed by this anodic oxidation, since the base substrate 1 is a metal in the present embodiment, a current can be passed using the base metal 1 as an anode. Therefore, there is no need for a complicated process such as separately providing a wiring pattern for power supply on the circuit board. Further, since the oxide layer 3 formed by anodic oxidation is characterized by having few defects such as pinholes, the oxide layer 3 having few defects can be easily formed. Further, since the anodic oxidation method does not require high temperature, the dielectric layer (oxide layer 3) made of a tantalum oxide film containing nitrogen can be formed at low temperature.
As a result, since the underlying base substrate 1 is not exposed to high temperature, damage such as roughening of the surface of the base substrate 1 is small, and defects are unlikely to occur in the dielectric layer (oxide layer 3). Therefore, a capacitor having an excellent breakdown voltage can be formed on the conductive base substrate.

Further, since the oxide layer 3 formed by the anodizing method of the tantalum thin film 2 can obtain a capacitance density of 0.5 to 1 nF / mm ² , an aluminum base substrate is anodized (as in the conventional case). Compared with the structure of 0.01 to 0.1 pF / mm ² in which the dielectric layer is formed by anodic oxidation) (see Japanese Patent Laid-Open No. 11-298104), a much larger capacitance density can be obtained.

In this embodiment, the coefficient of thermal expansion is S
Although 42 alloy close to i was used as the base substrate 1, the present invention is not limited to this. That is, an iron-based alloy other than 42 alloy, an iron-based composite material obtained by subjecting the iron-based alloy to copper (Cu) cladding, tungsten (W), tantalum (Ta), molybdenum (Mo), nickel (Ni), copper. (Cu), aluminum (Al), or the like can be used.

As described above, according to this embodiment, it is possible to provide a circuit board in which thin film capacitors having a low equivalent series resistance and a large capacitance density are integrated with a high yield. Further, by using this thin film capacitor as a decoupling capacitor, it is possible to provide a semiconductor device capable of reducing switching noise.

In the circuit board 1000, the insulating layer 8 is formed, and the connection terminal metallization layers 81 and 91 are provided through the through holes in the insulating layer 8. However, the insulating layer 8 is not essential, and stress relaxation and conductivity can be achieved. It may be provided as necessary for protection of body layers.

(Second Embodiment) A circuit board 2000 according to a second embodiment of the present invention will be described with reference to FIG.

The circuit board 200 of FIG. 4 according to the second embodiment.
0 is basically the circuit board 100 of the first embodiment.
0 has the same structure as the above, but as the dielectric layer 40 constituting the capacitor 400, an oxide layer 3 formed by oxidizing a part of the first thin film layer 2 and a second dielectric layer laminated thereon. 1
It has a two-layer structure of 0. As a result, the dielectric layer 40 forming the capacitor 400 has a two-layer structure, so that the breakdown voltage of the capacitor is improved and the manufacturing yield can be increased. In addition, as the second dielectric layer 10, SrT
iO ₃ and _{(Ba, Sr) TiO 3,} Pb (Zr, Ti) O
₃ , Pb (Mg _1/3 Nb _2/3 ) O ₃ or the like is used to form the capacitor 4 by using a perovskite structure oxide having a high dielectric constant.
00 capacity can be significantly increased.

Further, in the circuit board 2000 of FIG.
The thin film layer 2 is patterned, and the first thin film layer 2 is provided only in the portion where the oxide layer 3 is arranged.

In the circuit board 2000 of FIG. 4,
The same components as those of the circuit board 1000 of FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. Also in the case of FIG. 4, in order to make the details of the portion formed by the thin film layer easy to understand, the portion of the main surface of the circuit board 2000 on which the capacitor 400 is formed is enlarged and shown. In particular, the film thickness direction is shown enlarged.

Further, the circuit board 200 according to the second embodiment.
0 is the same as the circuit board 1000 of the first embodiment,
Since the base substrate 1 made of a conductive member acts as the lower electrode of the capacitor 400, the equivalent series resistance of the capacitor 400 can be reduced. Also in the case of the circuit board 2000 of this embodiment, a semiconductor chip (not shown) is formed on the connection terminal metallization layers 82 and 92 as in the first embodiment.
And connecting the connection terminal metallization layer 81 to the power supply layer (or the ground layer) and the connection terminal metallization layer 91 to the ground layer (or the power supply layer), the built-in capacitor 400 can be used as a decoupling capacitor. it can.

Next, an example of a method of manufacturing the circuit board 2000 of FIG. 4 of the second embodiment will be briefly described. First, as in the steps of FIGS. 2A to 2B of the first embodiment,
A base substrate 1 made of a conductive material such as 42 alloy is prepared, and thin film protective layers 5 and 501 are formed on the surface thereof. A tantalum film containing nitrogen is formed on the thin film protective layer 5 by a reactive sputtering method to a film thickness of 150 to 200 nm,
This is the first thin film layer 2. Then, the second thin film layer 2 is processed into a pattern of the lower electrode by using a well-known method such as a photo etching method (including wet etching and dry etching).

Next, a resist pattern having an opening is formed on the first thin film layer 2 by a well-known photolithography method, and the first thin film layer 2 exposed from the opening of the resist pattern is oxidized by an anodic oxidation method. To do. As a result, the oxide layer 3 forming a part of the dielectric 40 is formed in a thickness of 100 to 200 n
It is formed with a film thickness of m. The resist is then removed, 20
Heat treatment is performed at 0 to 300 ° C. In this example, 100
The first thin film layer 2 (that is, a tantalum film containing nitrogen) having a thickness of nm or more is left below the oxide layer 3.

Although the first thin film layer 2 is oxidized by the combination of the photolithography method and the anodic oxidation here, the photolithography method is not used.
It is also possible to oxidize the first thin film layer 2 by thermal oxidation at 0 ° C. to form the oxide layer 3.

Next, the second dielectric layer 10 is formed on the oxide layer 3 by a well-known film forming method such as a sputtering method, a vacuum evaporation method, a chemical vapor deposition method, a sol-gel method and a MOD method.
It is formed with a film thickness of up to 200 nm. In order to increase the capacitance of the capacitor, SrT is used as the material of the second dielectric layer 10.
A perovskite structure oxide such as iO ₃ or (Br, Sr) TiO ₃ can be used. After improving the crystallinity by performing a heat treatment at 600 to 800 ° C. on the second dielectric layer 10, the well-known photo-etching method is used to leave the second dielectric layer 10 only above the oxide layer 3, Remove the extra part around it.

Then, the second thin film layer 4, the insulating layers 6, 8, and 601 and the conductor layer are processed by the process of FIG. 2E and the process of FIGS. 3A to 3D of the first embodiment. 7. By forming the connection terminal metallized layers 81, 91, 82, 92, the circuit board 2000 shown in FIG. 4 can be manufactured.

In the second embodiment, the film thickness of the oxide layer 3 (dielectric layer) obtained by oxidizing the first thin film layer 2 is reduced, and the second dielectric layer made of a perovskite structure oxide having a high dielectric constant is used. The body layers 10 are laminated to form a dielectric layer 40 having a multilayer structure. Therefore, as compared with the case of the first embodiment, the capacity of the built-in capacitor 400 can be increased, and 1.5
A capacity of nF / mm ² or more is also possible.

In this embodiment, the coefficient of thermal expansion is S
Although 42 alloy close to i was used as the base substrate, the present invention is not limited to this. That is, any refractory metal that is resistant to the formation temperature of the perovskite structure oxide and the thermal oxidation temperature can be used. For example, an iron-based alloy other than 42 alloy or a copper (Cu) clad to the iron-based alloy can be used. The applied iron-based composite material, tungsten (W), tantalum (Ta), molybdenum (Mo), nickel (Ni), copper (Cu), or the like can be used.

As described above, according to the present embodiment, it is possible to provide a circuit board in which thin film capacitors having a low equivalent series resistance and a large capacitance density are integrated with a high yield. Further, by using this thin film capacitor as a decoupling capacitor, it is possible to provide a semiconductor device capable of reducing switching noise.

(Third Embodiment) A circuit board 3000 according to a third embodiment of the present invention will be described with reference to FIG.

The circuit board 3000 shown in FIG. 5 has a structure similar to that of the circuit board 1000 shown in FIG. 1 according to the first embodiment, but the connection terminal metallization 8101 is formed on the back surface side of the base board 1.
9101 and a conductor layer 701 are provided. Further, the base substrate 1 is provided with through holes penetrating the base substrate 1 and filled with the insulating layer 11. As a result, the conductive via 12 surrounded by the insulating layer 11 is formed in the base substrate 1. The conductive via 12 electrically connects the upper surface side and the back surface side of the circuit board 3000. Thereby, the connection terminal metallization 8101 on the back surface side
Is electrically connected to the second thin film layer 4 of the upper electrode of the capacitor 400, the conductor layer 7 on the upper surface side, and the connection terminal metallization 81 through the conductor layer 701 on the back surface side and the conductive vias 12. There is. Connection terminal metallized layers 91, 9
Reference numeral 101 is connected to the base substrate 1.

Other reference numerals of the circuit board 3000 of FIG.
~ It is the same as the case of FIG. Also in the case of FIG. 5, the main surface portion of the circuit board 3000 is enlarged in order to facilitate understanding of the details of the portion formed by the thin film layer. In particular, the thickness direction was enlarged.

According to the configuration of the circuit board 3000 shown in FIG.
By connecting the base substrate 1 to the ground electrode and the conductive via 12 connected to the upper electrode (the second thin film layer 4) of the capacitor 400 to the power supply electrode, the capacitor 400 can act as a decoupling capacitor. .
Further, in the circuit board 3000, a semiconductor chip (not shown) is connected to the connection terminal metallization layers 81 and 91 on the upper surface, and the connection terminal metallization layer 810 provided on the back surface.
Since a wiring board (motherboard or module board, not shown) can be connected to 1 and 9101, the circuit board 3000 of FIG. 5 can provide a circuit board having a built-in decoupling capacitor and suitable as an interposer.

In the case of the circuit board 3000 shown in FIG. 5, the lower electrode 41 of the capacitor 400 is also the first thin film layer 2.
In addition to the base substrate 1 having a low resistance, the dielectric layer is an oxide layer 3 made of a tantalum-based thin film.
Since it is formed by, the same effect as that of the first embodiment can be obtained. That is, it is possible to provide a circuit board in which thin film capacitors having a low equivalent series resistance and a large capacitance density are integrated with a high yield.

In the circuit board 3000, the insulating layer 8,
801 is formed, and the connection terminal metallized layers 81, 91, 8101, 9101 are provided through the through holes therein, but the insulating layers 8, 801 are not essential conditions, but stress relaxation, protection of the conductor layer, etc. , May be provided if necessary.

Next, a method of manufacturing the circuit board 3000 of FIG. 5 of the third embodiment will be described with reference to FIGS. 6 (A) to 6 (E) and FIG. 7 (A).
This will be described with reference to (E).

FIG. 6A: Formation of Capacitor 400 Similar to the first embodiment, the base substrate 1 made of a conductive material such as 42 alloy is formed by the steps shown in FIGS. 2A to 2E. On the upper surface, a thin film protective layer 5 made of Cr or the like, a first thin film layer 2 made of a tantalum-based thin film, an oxide layer 3 of the first thin film layer 2, and a second thin film layer made of a Cr / Cu / Cr laminated film. To form. As a result, the thin film capacitor 400 is formed on the upper surface of the base substrate 1. Further, a thin film protective layer 501 made of Cr or the like is formed on the back surface of the substrate 1.

FIG. 6B: Formation of conductive via 12 Using a well-known method such as a photoetching method or a laser processing method, the periphery of the region where the conductive via 12 is to be formed is formed from the upper surface side of the base substrate 1. Then, a ring-shaped groove 1110 is formed so as to surround the conductive via 12.

FIG. 6C: Formation of insulating layer 6 An organic insulating sheet such as a prepreg is attached to the upper surface of the base substrate 1 by using a method such as a vacuum hot pressing method, and the ring-shaped groove 1110 is formed from the organic insulating film. The insulating layer 6 is formed and the insulating layer 6 is formed. The organic insulating material is not limited to the prepreg, other materials may be used, and liquid (or paste) may be used.
The insulating layer 11 and the insulating layer 6 can be formed by another method such as a dipping method, a printing method, a spray coating method, or a transfer method.

FIG. 6D: While protecting the upper surface side of the base substrate 1 on which the etching capacitor 400 of the base substrate 1 is formed, the back surface of the base substrate 1 is previously formed by a known method such as etching or polishing. Remove only the specified thickness,
The insulating layer 11 is exposed. Next, smoothing and cleaning are performed to clean the new back surface of the base substrate 1.

FIG. 6 (E): Formation of insulating layer 601 on the back surface of the base substrate 1. Similar to FIG. 6 (C), an organic insulating sheet such as a prepreg is formed on the base substrate by using a method such as a vacuum hot pressing method. 1. An insulating layer 6 made of an organic insulating film attached to the second main surface side of 1.
01 is formed. Also in this case, the organic insulating material is not limited to the prepreg, and other materials may be used, and a liquid (or paste) insulating material may be used for the dipping method, the printing method, the spray coating, the transfer method, etc. The insulating layer 601 can be formed using another method.

Description will be given below with reference to FIGS. 7 (A) to 7 (D).

FIG. 7A: Through hole formation in the insulating layers 6 and 601 The insulating layer 6 on the upper surface side and the insulating layer 601 on the rear surface side are formed by a well-known method such as a photoetching method or a laser processing method. Through holes 610 and 6010 are formed, respectively. In this case, when a photosensitive resin is used as the insulating layers 6 and 601, it can be formed by each step of coating, drying, exposing, developing and curing, and the through hole forming step can be simplified.

FIG. 7B: Formation of conductor layers 7, 701 Physical method such as sputtering method, chemical vapor deposition method, sol-
A conductive thin film layer is formed on the upper surface and the back surface of the base substrate 1 by using a known method such as a gel method and a plating method, and then patterning is performed by using a known method such as a photoetching method. Thereby, the conductor layers 7 and 701 are formed. As a material for the conductor layers 7 and 701, a low resistance material such as Cu or Al can be used.

FIG. 7C: Formation of insulating layers 8 and 801 An organic insulating resin is applied to the upper surface and the back surface of the base substrate 1 by a well-known method such as a spin coating method or a printing method, and then dried and cured. Then, the insulating layers 8 and 801 are formed. Then, through holes 81 are formed in the insulating layers 8 and 801 by a well-known method such as a photoetching method or a laser processing method.
0, 8010 is formed. In this case, as in the case of FIG. 6C, an organic insulating sheet such as a prepreg may be attached by using a method such as a vacuum hot pressing method, or a photosensitive material may be used as the organic insulating resin, and coating and drying may be performed. , Exposure, development,
It can also be formed by each step of curing.

FIG. 7D: connection terminal metallization layer 81,
81, 8101, 9101 are formed on the upper surface and the back surface of the base substrate 1 by a well-known film forming method such as a sputtering method, a vacuum evaporation method, a plating method, etc. Then, patterning is performed by a well-known method such as a photo etching method, and the connection terminal metallized layers 81, 91, 8101, 91 are formed.
01 is formed. If solder connection is assumed, A
u / Ni / Cr laminated film, Ni-Cu / Cr laminated film, Ni
A -W / Cr laminated film or the like may be used. Here, A / B indicates that A is stacked on B.

With the above, the circuit board 3000 is completed.

The features of the manufacturing method described here are as follows. (1) After forming the capacitor 400 on the base substrate 1, the conductive vias 12 are formed in the base substrate 1.
As a result, the capacitor 400 can be formed on the flat substrate even though the circuit board is provided with the conductive vias 12 penetrating the base substrate 1. Therefore, the capacitor forming process is easy. (2) It is made of the same material as the base substrate 1 by leaving a region for forming the conductive via 12 core portion on the upper surface of the conductive base substrate 1 and forming an annular groove of a predetermined depth at the outer peripheral portion of this region. The conductive via 12 is formed. Thereby, the conductive via 12 having excellent mechanical strength can be obtained by the simplified process.

The conductive via 12 does not necessarily have to be formed of the same material as the base substrate, but may be formed by filling a through hole provided in the insulating layer 11 with a conductive material different from that of the base substrate 1. It doesn't matter. In addition, in this embodiment, the insulating layer 11 filling the annular groove 1110 is used.
And the insulating layer 6 on the first main surface are made of the same material, and are simultaneously formed using a vacuum pressing method or the like. However, the present invention is not limited to this, and using different insulating materials,
They may be formed by separate steps.

Next, another circuit board 4000, 5000, 6000, 7000, 80 according to the third embodiment.
00 is shown in FIGS. 8 to 12,
The same reference numerals as those in FIGS. 1 to 7 indicate the same configurations as those in FIGS.

The circuit board 4000 shown in FIG. 8 is similar to the second embodiment shown in FIG. 4 in that the first thin film layer 2 made of a tantalum-based thin film is similar to the second thin film layer 4 of the upper electrode. The dielectric layer 3 is formed by preliminarily pattern-separating into the above shape and oxidizing the surface portion.

The circuit board 5000 shown in FIG. 9 has connection terminal metallization layers 81 and 91 on the upper surface side of the base substrate 1 and connection terminal metallization layers 8101 and 91 on the back surface side.
01 are arranged adjacent to each other, and the electric currents flowing through the lower electrode 41 and the second thin film layer 4 of the upper electrode of the capacitor 400 are made opposite to each other, so that the capacitor 40
This is an attempt to reduce the inductance component of 0.

The circuit board 6000 shown in FIG. 10 and FIG.
The circuit board 7000 shown in FIG.
It has a multi-layered structure including a thin film layer 21 made of a conductive material such as the above and a thin film layer 22 made of a tantalum-based thin film. In the case of the circuit board 6000, the dielectric layer 3 is formed by partially oxidizing the surface of the thin film layer 22 of the upper tantalum-based thin film, and in the case of the circuit board 7000, the thin film of the tantalum-based thin film. The dielectric layer 3 is formed by oxidizing the entire layer 22. The structure of the circuit board 7000 is suitable when the thin film layer 22 made of a tantalum-based thin film is oxidized by thermal oxidation.

The circuit board 8000 shown in FIG. 12 has a multilayer structure in which the dielectric layer 40 of the capacitor 400 comprises the oxide layer 3 of the first thin film layer 2 made of a tantalum-based thin film and the insulating layer 10 made of perovskite structure oxide. The above is an example, and it is effective when increasing the capacity of a built-in capacitor.

As is apparent from FIGS. 8 to 12 described above, the circuit boards 4000, 5000, 6000, 700.
In any case of 0 and 8000, the same effect as the circuit board 3000 shown in FIG. 5 can be obtained by applying the present invention.

(Fourth Embodiment) FIG. 13 shows a circuit board 9000, 10000 according to a fourth embodiment of the present invention.
A description will be given using (A) and (B).

The circuit boards 9000 and 10000 have a structure in which the capacitor 40001 is also built in on the back surface side of the base board 1. The capacitor 40001 includes a thin film protective layer 501 disposed on the back surface side of the base substrate 1 and a first thin film layer 20.
1, an oxide layer 301 obtained by oxidizing the first thin film layer 201, and a second thin film layer 401. First thin film layer 201, oxide layer 301, and second thin film layer 4
The structure and material of 01 are the same as those of the first thin film layer 2, the oxide layer 3 and the second thin film layer 4 described in the first embodiment and the like. Base substrate 1, thin film protection layer 501, first thin film layer 20
1 constitutes the lower electrode 4101. Other symbols are shown in FIGS.
This is the same as the case of FIG.

In the circuit boards 9000 and 10000, the capacitors 400 and 400 are provided on the upper surface and the back surface of the base substrate 1.
No. 01 is arranged respectively, the second thin film layer 4 serving as the upper electrode of the capacitor 400 on the upper surface side and the capacitor 4 on the rear surface side.
The second thin film layer 401, which serves as the upper electrode of 0001, is connected by the conductive via 12. This point is the first to third
Different from the embodiment. With such a configuration, the capacitors 400 and 40001 formed on the upper surface side and the rear surface side are connected in parallel, and the capacitance of the capacitor incorporated in the circuit board is increased as compared with the first to third embodiments. You can

The circuit board 90 shown in FIG.
00, the connection terminal metallization layers 81, 91, 810
1, 9101 are arranged on the upper surface side and the rear surface side. The connection terminal metallization layers 81 and 8101 are conductive vias 12.
Further, the connection terminal metallized layers 91 and 9101 are connected to the base substrate 1, respectively. On the other hand, in the circuit board 10000 shown in FIG. 13B, the connection terminal metallized layers 81, 82, 91, 92 are all arranged on the upper surface side. The connection terminal metallization layers 81 and 82 are the capacitors 4
The second thin film layer 4 serving as the upper electrode of the capacitor 00001 is connected to the second thin film layer 4 serving as the upper electrode of the capacitor 40001 through the conductive via 12. The connection terminal metallized layers 91 and 92 are connected to the base substrate 1.

In the circuit boards 9000 and 10000, the base board 1 is connected to the ground electrode and the second electrodes (second thin film layers 4 and 401) of the capacitors 400 and 40001 formed on the two main surfaces of the front and back. By connecting the conductive via 12 to the power supply electrode, the capacitors 400 and 40001 formed on the two main surfaces of the front and back can act as decoupling capacitors.

Further, in the case of the circuit board 9000, semiconductor chips (not shown) are provided on the connection terminal metallization layers 81 and 91 on the upper surface side, and the connection terminal metallization layers 8101 and 9 on the back surface side.
Since a wiring board (motherboard or module board, not shown) can be connected to 101, the circuit board 9000 shown in this embodiment can provide a circuit board having a built-in decoupling capacitor and suitable as an interposer. .

Further, the circuit board 9000 and the circuit board 100
In any case of 00, capacitors 400, 4000
One of the lower electrodes 41, 4101 is the first thin film layer 2, 201
Not only the base substrate 1 having a low resistance but also the oxide layers 3 and 301 of the dielectric layer are formed by oxidizing a part of the first thin film layer 2 formed of a tantalum-based thin film. Therefore, by applying the present invention, the same effects as those of the first to third embodiments can be obtained. That is, it is possible to provide a circuit board in which thin film capacitors having a low equivalent series resistance and a large capacitance density are integrated with a high yield. In this embodiment, the insulating layers 8 and 801 are formed,
Connection terminal metallization layer 8 through the through hole in it
1, 91, 8101, 9101 or metallized layer 8
1, 82, 91, 92 are provided, but insulating layers 8, 80
1 is not essential, and may be provided as necessary for stress relaxation, protection of the circuit board, and the like.

The circuit boards 9000 and 10000 can be formed by almost the same manufacturing process. Here, the manufacturing method of the circuit board 9000 will be described with reference to FIG.
(E), FIGS. 15 (A) to (D), and FIGS. 16 (A) to (C).
Will be explained. First, the manufacturing process of the circuit board 9000 will be described with reference to FIGS.

FIG. 14 (A): Preparation of Base Substrate 1 For example, a conductive member such as 42 alloy is cut into an appropriate size and, if necessary, surface-polished or the like to make the base substrate 1 smooth. Next, degreasing treatment of the base substrate 1,
Clean the surface by washing with neutral detergent or alkaline detergent.

FIG. 14B: Formation of thin film protective layers 5, 501 A Cr film having a thickness of 200 nm is formed on the upper surface and the back surface of the base substrate 1 by a method such as a sputtering method, and the thin film protective layers 5, 501 are formed. And Although Cr is used as the thin film protective layer here, the type and film thickness of the thin film protective layer may be determined by the process conditions such as the processing temperature and the coverage with the base substrate. For example, a platinum group metal material, an electrically conductive oxide such as indium oxide, tin oxide, a mixture of indium oxide and tin oxide, zinc oxide, ruthenium oxide, rhenium oxide, iridium oxide, osmium oxide, or chromium (Cr ), Titanium (Ti), tungsten (W), molybdenum (Mo), nickel (Ni), or any other refractory metal. Also,
The film forming method is not limited to the sputtering method, and may be a vacuum vapor deposition method, a chemical vapor deposition method, or a MOD (Metal Organic) method.
Decomposition method, sol-gel method, plating method and the like can be selected and used according to the type of the thin film protective layer and the material of the base substrate.

FIG. 14C: Formation of first thin film layers 2 and 201. A tantalum thin film containing nitrogen is formed on the upper surface and the back surface of the base substrate 1 by the reactive sputtering method, and the first thin film layers 2 and 201 are formed. And The film thickness may be set in consideration of the film thickness of the oxide layers 3 and 301 formed in the next step.
A typical range is 00 to 400 nm. Although the tantalum containing nitrogen is used as the first thin film layers 2 and 201 here, the material is not limited to this, and any material can be used as long as a dense oxide layer is formed by the oxidation treatment. However, considering the quality of the oxide layer when forming the dielectric layer by anodic oxidation or thermal oxidation, pure tantalum or a conductive tantalum-based thin film containing nitrogen and / or oxygen is suitable.

FIG. 14D: Oxidation of the first thin film layers 2 and 201 (formation of oxide layers 3 and 301 to be dielectric layers) The first thin film layers 2 and 201 are oxidized by a well-known photolithography method. A resist pattern having an open area is formed. Then, the regions exposed from the resist pattern openings of the first thin film layers 2 and 201 are oxidized using an anodic oxidation method to form oxide layers 3 and 301 to be dielectric layers with a thickness of 200 to 400 nm. . After removing the resist, heat treatment is performed at a temperature of 200 to 300 ° C. This makes it possible to obtain a capacitor having a capacitance density of 0.5 to 1 nF / mm ² . In addition, in this embodiment,
The first thin film layers 2 and 201 having a thickness of 100 nm or more (that is, the tantalum film containing nitrogen) are left under the oxide layers 3 and 301.

FIG. 14E: Formation of second thin film layers 4 and 401 Cr / Cu / C in which a Cu film is sandwiched between Cr films on the upper surface and the back surface of the base substrate 1 by a method such as a sputtering method.
r A laminated film is formed. Then, pattern separation of the Cr / Cu / Cr laminated film is performed by a well-known method such as photoetching to form the second thin film layers 4 and 401 to be the upper electrodes of the capacitors 400 and 40001. The film thicknesses of Cr and Cu can be determined in consideration of the adhesion strength of the second thin film layers 4 and 401 to the dielectric layer and the resistance of the electrode portion. For example, the Cr film thickness is 50 to 200 nm, and the Cu film thickness is Cu. The film thickness can be 1000 to 5000 nm. As a result, the sheet resistance of the second thin film layers 4 and 401 is 20 mΩ.
/ Can be less than or equal to Here, the Cr / Cu / Cr laminated film formed by the sputtering method is used as the second thin film layer 4,
Although it is set to 401, it is not limited to this. It may be selected according to the oxide layers 3 and 301 used as the dielectric layer.

Description will be made below with reference to FIGS. 15 (A) to 15 (D).

FIG. 15A: Formation of the upper surface side portion 1201 of the conductive via 12 Using the well-known method such as the photo etching method or the laser processing method, the conductive via 12 forming region is formed from the upper surface side of the base substrate 1. The annular groove 1110 is formed so as to surround the periphery of the above, and the upper surface side portion 1201 of the conductive via 12 is formed.

FIG. 15B: Upper surface side portion 1 of the insulating layer 11
Formation of 101 An organic insulating sheet such as a prepreg is attached to the upper surface side of the base substrate 1 by using a method such as a vacuum hot pressing method, the annular groove 1110 is filled with an insulating layer 1101 made of an organic insulating material, and at the same time, on the upper surface. Then, the insulating layer 6 is formed. The organic insulating material is not limited to the prepreg, and other materials can be used. For example, liquid (or paste) insulating material can be used for dipping or printing,
It can be formed by another method such as spray coating or transfer method.

FIG. 15C: Completion of conductive via 12 By repeating the steps shown in FIGS. 15A and 15B from the back surface side of base substrate 1, base substrate 1 is formed.
The back side portion of the conductive via 12 is formed on the back side, and the insulating groove is filled in the annular groove on the back side. As a result, the conductive via 12 separated from the base substrate 1 by the insulating layer 11 is completed, and at the same time, the insulating layer 601 is formed on the back surface.
Is formed.

FIG. 15D: Formation of through holes in insulating layers 6 and 604. Through holes 610 are formed in the insulating layers 6 and 601 on the upper and lower surfaces by using a well-known method such as a laser processing method or a photoetching method. 6010 is formed.

Hereinafter, description will be made with reference to FIGS. 16 (A) to 16 (C).

FIG. 16A: Formation of the conductor layers 7 and 701. The conductor layers 7 and 701 are formed on the insulating layers 6 and 601 by a well-known method such as a sputtering method, a vacuum deposition method, a chemical vapor deposition method or a plating method. 701 is formed into a film. Then, the conductor layers 7 and 701 are processed using a well-known method such as photoetching,
The conductor layers 7 and 701 are left so as to fill the through holes 610 and 6010. As a material for the conductor layers 7 and 701, a conductor having a low resistance, here Cu is used.

FIG. 16B: Formation of surface insulating layers 8 and 801 An organic insulating resin is applied by a known method such as a spin coating method, dried and cured to insulate the upper surface and the back surface of the base substrate 1. The layers 8 and 801 are formed. Then, through holes 810 and 8010 are formed by using a known method such as photo etching. In this case, a photosensitive material may be selected as the organic insulating resin, and the organic insulating resin may be formed by the steps of coating, drying, exposing, developing and curing. In this case, the step of processing (etching) the organic insulating resin can be omitted. Alternatively, an insulating sheet such as a prepreg may be attached to both surfaces of the substrate by a vacuum hot pressing method or the like, and the through holes 810 and 8010 may be formed by laser processing or the like.

FIG. 16C: Connection terminal metallization layer 8
1, 91, 8101, 9101 are formed by a known film forming method such as a sputtering method, a vacuum vapor deposition method, a plating method, or the like, and a known material such as a photo etching method. The patterns are separated, and the connection terminal metallization layers 81 and 91 are formed on the upper surface side of the circuit board 9000, and the connection terminal metallization layers 8101 and 9101 are formed on the back surface side. The material used for the connection terminal metallized layers 81, 91, 8101, 9101 will be selected depending on the connection method. However, when solder connection is assumed, an Au / Ni / Cr laminated film or N
An i-Cu / Cr laminated film, a Ni-W / Cr laminated film, or the like may be used. However, A / B indicates that A is laminated on B. Through the above steps, the circuit board 9000 shown in FIG. 13A is completed.

The method of manufacturing the circuit board 9000 described here has the following characteristics, and has a low equivalent series resistance,
It is possible to provide a circuit board with a conductive via in which a large-capacity capacitor is built-in with a high yield. (1) A thin film protective layer 5 made of Cr or the like is provided on the upper surface and the back surface of the base substrate 1, a tantalum thin film is formed as a first thin film layer 2 on the thin film protective layer 5, and the tantalum-based thin film is formed using an anodizing method. Dielectric layers 3, 3 by oxidizing a part of the thin film
Forming 01. When the dielectric layer is formed by this anodic oxidation, the base substrate 1 may be used as an anode and an electric current may be passed therethrough, and it is not necessary to separately prepare a power supply wiring pattern or the like. According to this manufacturing method, since the dielectric layer made of a tantalum oxide film with few defects such as pinholes is formed at a low temperature, damage to the underlying base substrate 1 is small,
A capacitor having an excellent withstand voltage can be formed on the conductive base substrate. (2) Capacitor 4 is formed on the upper surface and the back surface of base substrate 1.
00, 40001 are formed, and then the conductive via 12 is formed in the base substrate 1. As a result, even in the circuit board having the conductive vias 12 penetrating the base board 1, the capacitors 400 and 40001 can be formed on the flat board, and the capacitor forming process is facilitated. (3) Same as the base substrate 1 by leaving a region for forming the conductive via 12 core portion on the upper surface and the back surface of the conductive base substrate 1 and forming an annular groove of a predetermined depth on the outer peripheral portion of this region. A conductive via 12 made of a material is formed. Thereby, the conductive via 12 having excellent mechanical strength can be obtained.

In the case of this embodiment, as the base substrate 1, nickel (Ni), chromium (Cr), cobalt (C
o), an iron (Fe) -based alloy containing any one of aluminum (Al), an iron-based composite material obtained by applying a copper (Cu) clad to the iron-based alloy, tungsten (W), tantalum (T).
a), molybdenum (Mo), nickel (Ni), copper (C
u) or aluminum (Al) can be used, but in view of the workability of the base substrate 1, etc., 42
Iron (Fe) alloys such as alloys are preferable.

In the present embodiment, the first thin film layers 2 and 201 are single layers of tantalum-based thin film, but P
It may be a multilayer film with another conductive thin film such as t. The dielectric layer is also composed of the oxide layers 3 and 301 formed by oxidizing the thin film layers 2 and 201 made of a tantalum-based thin film, but it may be a multilayer film with another insulating layer such as a perovskite structure oxide. .

Although the conductive via 12 is made of the same material as the base substrate 1, it may be made of a material different from that of the base substrate 1. Further, in the present embodiment, the insulating layer 11 filling the annular groove around the conductive via 12 is formed.
The insulating layers 6 and 601 on the two main surfaces of the front and back are made of the same material, and are simultaneously formed using a vacuum pressing method or the like.
However, it is not necessary to be limited to this, and different insulating materials may be used and they may be formed in separate steps.

(Fifth Embodiment) FIG. 17 shows circuit boards 11000 and 12000 according to a fifth embodiment of the present invention.
A description will be given using (A) and (B).

The circuit boards 11000 and 12000 have a thin film multilayer wiring section 13 in which conductor layers and insulating layers are alternately laminated. Other reference numerals that are the same as those in FIGS. 1 to 16 indicate the same configurations. In order to make the details of the portion formed by the thin film layers easy to understand, the circuit boards 11000, 120
The main surface portion of 00 was enlarged. In particular, the thickness direction is enlarged.

The feature of this embodiment is that the capacitor 40
The thin film multilayer wiring portion 13 is disposed between the insulating layer 6 and the insulating layer 8 on the upper surface side where 0 is formed. In the circuit board 11000, the circuit board 1000 shown in FIG.
Top insulating layer 6 on which the capacitor 400 of FIG.
The thin-film multilayer wiring portion 13 is formed between the insulating layer 8 and the insulating layer 8. In the circuit board 12000, the circuit board 3 shown in FIG.
Thin film multilayer wiring portion 13 is formed between the insulating layer 6 and the insulating layer 8 on the upper surface side where the capacitor 400 of No. The circuit board 11000 has a typical configuration in which the thin film multilayer wiring section 13 is arranged in the circuit board of each of the above-described embodiments in which the connection terminals are provided only on the upper surface side. The circuit board 12000 is
It shows a configuration in which a thin film multilayer wiring section is arranged in a circuit board having connection terminals provided on the upper surface and the back surface. In the case of the circuit board 12000, the thin film multilayer wiring portion can be arranged between the insulating layer 601 and the insulating layer 801 on the back surface side where no capacitor is provided.

By arranging the thin film multilayer wiring portion 13 like the circuit boards 11000 and 12000, the connection terminal metallized layers 71, 72, 91 and 92 and the metallized layers 81 and 91 can have desired terminal pitches (terminal intervals). Can be on pitch. That is, the thin-film multilayer wiring section 13
Thus, the terminal pitch can be converted. As a result, it is possible to match the terminal pitch of the mounted semiconductor chips, diodes, and passive elements (capacitors, coils, resistors, etc.), and thus provide a circuit board with a built-in capacitor that can be used as a mounting board for semiconductor chips and electronic components. it can. Then, the lower electrode 41 of the built-in capacitor,
By using the second thin film layer 4 as the upper electrode for the power supply layer or the ground layer, it is possible to provide a semiconductor device capable of reducing switching noise.

Further, by utilizing the thin film multilayer wiring section 13,
It becomes possible to form an inspection pad for a semiconductor chip and perform repairs, which can contribute to an improvement in the manufacturing yield of semiconductor devices.

Furthermore, the circuit board 1100 of this embodiment
In the case of 0, 12000, it is possible to incorporate an inductance element or a resistance element in the thin film multilayer wiring portion 13, and it is possible to provide a circuit board with a built-in capacitor in which a termination resistor or a filter is incorporated.

[0118]

As described above, according to the present invention,
It is possible to provide a circuit board having a low equivalent series resistance and a built-in thin film capacitor having a large capacitance density and a high manufacturing yield.

[Brief description of drawings]

FIG. 1 is a circuit board 1000 according to a first embodiment of the present invention.
FIG. 3 is a cross-sectional view of an essential part showing the configuration of FIG.

2A to 2E are cross-sectional views of relevant parts for explaining the flow of the manufacturing process of the circuit board 1000 in FIG.

3A to 3D are cross-sectional views of main parts for explaining the flow of the manufacturing process of the circuit board 1000 of FIG. 1, following FIG. 2E.

FIG. 4 is a circuit board 2000 according to a second embodiment of the present invention.
FIG. 3 is a cross-sectional view of an essential part showing the configuration of FIG.

FIG. 5 is a circuit board 3000 according to a third embodiment of the present invention.
FIG. 3 is a cross-sectional view of an essential part showing the configuration of FIG.

6A to 6E are cross-sectional views of relevant parts for explaining the flow of the manufacturing process of the circuit board 3000 of FIG.

7A to 7D are cross-sectional views of main parts for explaining the flow of the manufacturing process of the circuit board 3000 of FIG. 5, following FIG. 6E.

FIG. 8 is a main-portion cross-sectional view showing a circuit board 4000 which is different from that in FIG. 5 in the third embodiment of the present invention.

FIG. 9 is a cross-sectional view of essential parts showing a circuit board 5000, which is different from those of FIGS. 5 and 8 according to the third embodiment of the present invention.

FIG. 10 is a cross-sectional view of essential parts showing a circuit board 6000 different from those of FIGS. 5, 8 and 9 according to the third embodiment of the present invention.

FIG. 11 is a cross-sectional view of essential parts showing a circuit board 7000 different from those of FIGS. 5 and 8 to 10 of the third embodiment of the present invention.

FIG. 12 is a cross-sectional view of essential parts showing a circuit board 8000 different from those of FIGS. 5 and 8 to 11 of the third embodiment of the present invention.

FIG. 13 (A) is a sectional view of a key portion showing a circuit board 9000 according to a fourth embodiment of the present invention. (B) Fourth aspect of the present invention
3 is a cross-sectional view of essential parts showing a circuit board 10000 of the embodiment of FIG.

14 (A) to (E) FIG. 13 (A) circuit board 900
It is a principal part sectional view explaining the flow of the manufacturing process of 0.

15A to 15D are cross-sectional views of main parts for explaining the flow of the manufacturing process of the circuit board 9000 following FIG. 14E.

16A to 16C are main-portion cross-sectional views illustrating the flow of the manufacturing process of the circuit board 9000, which is subsequent to FIG. 15D.

FIG. 17 (A) is a sectional view of a key portion showing a circuit board 11000 according to a fifth embodiment of the present invention. (B) It is an essential part sectional view showing circuit board 12000 of a 5th embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Base substrate, 2 ... 1st thin film layer, 3 ... Oxidized layer of 1st thin film layer, 4 ... 2nd thin film layer, 5, 501 ... Thin film protective layer, 6,
8, 11, 601, 801 ... Insulating layer, 7,701 ... Conductor layer, 10 ... Second dielectric layer, 12 ... Conductive via, 13 ...
Thin film multilayer wiring part, 81, 82, 91, 92, 8101,
9101 ... Connection terminal metallized layer, 40 ... Capacitor dielectric layer, 41 ... Capacitor first electrode, 400 ... Capacitor, 610, 810, 8010 ... Through hole,
1110 ... Annular groove, 1000, 2000, 3000, 4
000, 5000, 6000, 7000, 8000, 9
000, 10000 ... Circuit board.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05K 3/46 H01L 23/12 N (72) Inventor Naoki Matsushima 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa F-Term (Reference) 4H351 AA14 AA18 BB04 BB24 BB32 BB33 CC03 CC06 CC29 DD02 DD04 DD05 DD10 DD17 DD19 DD21 DD32 DD34 DD35 DD42 GG06 5E315 AA05 BB02 BB03 BB05 BB07 BB14 CC01GG17 DD25 A346 A AA15 AA33 AA35 BB01 BB16 BB20 CC16 CC31 CC32 DD01 DD02 DD05 DD07 DD11 DD32 EE33 FF01 FF45 GG17 GG22 GG40 HH01 HH33

Claims (5)

[Claims] 1. An electrically conductive base substrate, a first electrically conductive layer, a dielectric layer, and a second electrically conductive layer, which are sequentially laminated on at least one main surface of the base substrate. And a base substrate, the first electrically conductive layer, the dielectric layer, and the second electrically conductive layer, the base substrate and the first electrically conductive layer To form a capacitor using the second electrically conductive layer as a second electrode, wherein the first electrically conductive layer is made of an electrically conductive material containing tantalum, and the dielectric layer is A circuit board having a built-in capacitor, which is formed by oxidizing a part of the first electrically conductive layer and is made of a dielectric material containing tantalum oxide. 2. An electrically conductive base substrate, a first electrically conductive layer, a plurality of dielectric layers, and a second electrically conductive layer, which are sequentially laminated on at least one main surface of the base substrate. A conductive layer, the base substrate, the first electrically conductive layer, the plurality of dielectric layers, and the second electrically conductive layer, the base substrate and the first electrically conductive layer. A capacitor using the layer as a first electrode and the second electrically conductive layer as a second electrode, wherein the first electrically conductive layer is made of an electrically conductive material containing tantalum, The layer closest to the first electrically conductive layer among the plurality of dielectric layers is made of a dielectric material containing tantalum oxide, which is formed by oxidizing a part of the first electrically conductive layer. A circuit board with a built-in capacitor. 3. A circuit board having a built-in capacitor according to claim 2, wherein at least one of the plurality of dielectric layers is made of an oxide having a perovskite structure. Built-in circuit board. 4. A circuit board having a built-in capacitor according to claim 1, 2 or 3, wherein the base substrate is one of nickel (Ni), chromium (Cr), cobalt (Co) and aluminum (Al). Iron (Fe) -based alloy containing at least one, iron-based composite material obtained by applying copper (Cu) clad to the iron-based alloy, tungsten (W), tantalum (T
a), molybdenum (Mo), nickel (Ni), copper (C
A circuit board having a built-in capacitor, which has a member made of any one of u) and aluminum (Al). 5. A circuit board having a built-in capacitor according to claim 1, 2, 3 or 4, wherein the base substrate is
At least a part of the main surface has a thin film protective layer made of an electrically conductive material, and the thin film protective layer comprises a platinum group metal material, indium oxide, tin oxide, a mixture of indium tin oxide and zinc oxide,
A capacitor formed of any one of ruthenium oxide, rhenium oxide, iridium oxide, osmium oxide, chromium (Cr), titanium (Ti), tungsten (W), and molybdenum (Mo). Built-in circuit board.