JP3328055B2 - Manufacturing method of multilayer thin film capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multilayer thin film capacitor.

[0002]

2. Description of the Related Art Generally, titanium having a perovskite crystal structure is used.
Barium phosphate (BaTiO_Three ) Has excellent dielectric properties,
Widely used as capacitor material due to its high resistance
I have. This BaTiO_Three Is the ratio in the c-axis direction, which is the polarization axis
The characteristic that the relative permittivity in the a-axis direction is larger than the permittivity
A axis perpendicular to the electrode surface
Direction, that is, preferential orientation in the (100) plane,
It is possible to make a capacitor having good properties. Also, Pero
Strontium titanate (Sr
TiO_Three ) Is cubic at temperatures above about 110K
It is crystalline and paraelectric. SrTiO_Three The main component
Is made of BaTiO with the same crystal structure_Three system
Has a lower relative dielectric constant, but has better temperature characteristics and lower dielectric loss.
It has the feature of being small. In addition, this SrTiO_Three 
To add a shifter such as barium to shift the Curie point.
To obtain a high dielectric constant
Ceramics are obtained. This ceramic is
Widely used as capacitors for waves and high voltages.
Further, Pb (Mg), which is one of the typical relaxation type ferroelectrics, is used.
_1/3 , Nb_2/3 ) O_Three And BaTiO_Three And SrTiO_Three 
Lead titanate having the same perovskite crystal structure (Pb
TiO_Three ) Is a composite material of Pb ｛(Mg_1/3 , Nb
_2/3 )_1-X Ti_X ｝ O_Three Perovskite structural compounds
The thing is BaTiO_ThreeLarge relative dielectric constant compared to ferroelectrics
And have good DC bias characteristics. So this
The compound perovskite structure compound is
It is applied to densa and the like.

On the other hand, in order to cope with miniaturization and high-density mounting of electronic equipment, chip capacitors have been reduced in size and capacity. In order to achieve a large capacity, there is a method of using a dielectric material having a large relative dielectric constant or a method of increasing the number of stacked layers by making the dielectric layer thin. For example, electronic
Ceramic Magazine 103 (1990), pp. 57-6
One page discloses a method for manufacturing a multilayer ceramic capacitor. The method of laminating the dielectric layer and the metal electrode layer in the production of the multilayer ceramic capacitor in this document is as follows. A powder of a dielectric material such as BaTiO ₃ is blended, mixed and dried. This is mixed with a slurry and formed into a thin sheet. An internal electrode paste such as palladium is printed on the sheet, and the sheets are stacked. This operation is repeated a predetermined number of times, and the internal electrodes and sheets are sequentially stacked and laminated. Then cut this to the desired size,
For example, simultaneous firing of ceramic and metal is performed.

[0004]

However, in the above-mentioned laminating method, there is a limit in reducing the thickness of the dielectric layer. That is, since the powder of the dielectric material, which is the starting material of the dielectric layer, has a particle size of about 1 μm, it is mixed with a slurry, formed into a sheet, and fired to reduce the thickness of the dielectric layer to 3 μm or less. Then, problems occurred in the uniformity of the film thickness and the insulation between the electrodes. Therefore, in order to produce a large-capacity chip capacitor, it was necessary to increase the number of layers. However, when trying to increase the number of stacked layers, the size of the chip increases and the number of steps increases, and thus there is a problem in reliability and the like. Furthermore, a firing process is required after the lamination, and the firing temperature is as high as about 1200 ° C. depending on the dielectric material, so that the electrodes are limited to materials such as platinum. for that reason,
It has been required to find a manufacturing method for obtaining a multilayer capacitor having good characteristics at a low temperature.

The present invention solves the above problems,
It is an object of the present invention to provide a method for manufacturing a multilayer thin film capacitor having good characteristics.

[0006]

According to the present invention, a metal electrode thin film layer is first patterned on a substrate by vacuum evaporation or sputtering. On top of this, as a dielectric thin film layer, BaTiO ₃ or SrTiO ₃ preferentially oriented to the (100) plane or (Ba _{1− x} , Sr
_X ) Perovskite oxide thin film of TiO ₃ , Pb
A composite perovskite compound thin film of ｛(Mg _1/3 , Nb _2/3 ) _1-x Ti _x ｝ O ₃ was prepared by plasma activation and CVD.
0.05 to 3 by plasma CVD using reaction
The film is formed with a thickness of μm. By repeating this operation, the metal electrode thin film layer and the dielectric thin film layer are stacked on the substrate. This is cut into a predetermined size, and external electrodes are formed on the cut surface by a vacuum evaporation method, a sputtering method, a plating method, or a coating and baking method. Thus, a multilayer thin film capacitor is manufactured.

[0007]

As described above, by using the plasma CVD method for forming the dielectric thin film layer, a dense and excellent dielectric material having a thickness of 0.05 to 3 μm is formed on the metal electrode thin film layer.
(Ba _1-x , Sr _x ) TiO ₃ preferentially oriented to the axis or P
_{b {(Mg 1/3, Nb 2} /3) 1-X Ti X} thin O ₃ is, bulk or baking temperatures, other thin film forming method (a vacuum deposition method, a sputtering method, a thermal CVD method) than Obtained at low temperatures. Further, by using a thin film manufacturing method such as a vacuum evaporation method or a sputtering method for forming the metal electrode thin film layer, a dense metal electrode thin film layer having a thickness of 0.01 to 0.2 μm can be obtained. Therefore, since the thickness can be made thinner than the conventional method of stacking and firing the slurry-like ceramic multilayer capacitors, the capacitance per dielectric thin film layer can be increased. Further, the number of layers can be increased even with the same chip thickness. Therefore, the capacitance per unit volume increases, and a multilayer thin film capacitor corresponding to miniaturization and large capacity can be manufactured.

[0008]

【Example】

(Embodiment 1) FIG. 1 shows a plasma CVD apparatus used for forming a dielectric thin film layer of a multilayer thin film capacitor according to an embodiment of the present invention, and a sputtering apparatus used for forming a metal electrode thin film layer. It is the schematic which shows the manufacturing apparatus which consists of an apparatus.

In FIG. 1, 1 is a base substrate, 2 is a substrate fixing plate, 3 is a preliminary vacuum chamber, 4 is a preliminary heating chamber, 5 is a transfer arm, 6 is a substrate holder, 7 is a lamp heater, and 8 is a lamp heater. Gate, 9 is a sputtering chamber, 10 is a substrate holder, 11 and 12 are metal masks, 13 is a lamp heater, 14 is a mass flow controller, 15 is a target, 16 is a high frequency power supply (13.56 MHz), and 17 is a rotating substrate holder 6 Motor, 18 gate, 1
9 is a plasma CVD chamber, 20 is a substrate holder, 21 is a transfer arm, 22 is a lamp heater, 23 is a motor for rotating the substrate holder 20, 24, 26, 28, and 30 are vaporization containers, 25, 27, 29, and 31 are Raw materials, 32, 3
3, 34, 35 and 36 are mass flow controllers, 3
7 is a nozzle for supplying a source gas and a reaction gas, 38 is a high frequency power supply (13.56 MHz), 39 is an electrode, 40 is a motor for rotating the substrate holder 10, and 41 is a preliminary vacuum chamber.

FIG. 2 is a schematic sectional view showing a multilayer thin film capacitor according to one embodiment of the present invention. In FIG. 2, reference numeral 42 denotes an undersubstrate, 43, 45, and 47 denote metal electrode thin film layers,
6 and 48 are dielectric thin film layers, and 49 and 50 are external electrodes.

FIG. 3 is a schematic sectional view showing a thin film capacitor according to one embodiment of the present invention. In FIG. 3, reference numeral 51 denotes a base substrate, 52 and 54 denote metal electrode thin film layers, and 53 denotes a dielectric thin film layer.

A method for manufacturing the multilayer thin film capacitor will be described below. As shown in FIG. 1, a substrate fixing plate 2 on which a base substrate 1 (size: 50 mm × 50 mm × 0.3 mm) made of alumina is carried from a pre-vacuum chamber 3 into a pre-heating chamber 4 evacuated to a vacuum. . Next, the board fixing plate 2
Is transferred onto the substrate holder 6 by the transfer arm 5, and the substrate holder 6 is
Heat to ° C. After the heating, the gate 8 is opened, and the substrate fixing plate 2 is transferred by the transfer arm 5 onto the substrate holder 10 in the sputtering chamber 9. Two kinds of metal masks 11 and 12 are attached to the substrate holder 10, and by using them alternately, metal electrode thin films 43, 45 and 47 can be formed alternately as shown in FIG. The size of the metal electrode patterns of the metal masks 11 and 12 is 6.0 mm × 1.2 mm. First of all,
The substrate fixing plate 2 is placed on the metal mask 11 and the underlying substrate 1
And the metal mask 11 are completely adhered. Note that the substrate holder 10 is preliminarily 6
Heated to 50 ° C.

The gate 8 is closed and the inside of the sputtering chamber 9 is 1 × 1
After exhausting to 0 ^-4 Pa, the mass flow controller 1
Ar whose flow rate is controlled by 4 is supplied into the sputtering chamber 9. The degree of vacuum in the sputtering chamber 9 was maintained at 1 Pa, and a high frequency power supply (13.56 MHz) was placed on the Ni target 15.
A plasma (electric power: 0.8 W / cm ² ) is generated by 16 to form a patterned Ni metal electrode thin film layer 43 on the underlying substrate 1. Ni by this sputtering
Is about 0.01 μm / min. So, 5
By performing film formation for a minute, a metal electrode thin film layer 43 of about 0.05 μm is obtained.

After the film formation, the supply of Ar is stopped and the gate 8
Is opened, and the substrate fixing plate 2 is transported by the transport arm 5 onto the substrate holder 6 again. Mount the substrate holder 6 on the motor 1
7, the substrate fixing plate 2 is moved to the gate 18 side.

After the movement, the gate 18 is opened and the plasma CV
The substrate fixing plate 2 is carried on the substrate holder 20 in the D chamber 19.
The sheet is conveyed by the transfer arm 21. In addition, the substrate holder 2
0 is set to 650 ° C by the lamp heater 22 in advance.
Heating. After the transfer, close the gate 18 and
The inside of the CVD chamber 19 is evacuated to 1 Pa, and the substrate holder 2 is evacuated.
0 is rotated at a speed of 120 revolutions per minute by the motor 23
Let it. In advance, the raw material 25
Lium dipivaloylmethane [Ba (C₁₁H₁₉O _Two )_Two ]
Is placed in a vaporization vessel 26 as a raw material 27, isopropoxy tita.
[Ti (C_ThreeH₇ O)_Four ] In the vaporization vessel 28
Strontium dipivaloylmethane [Sr (C
₁₁H₁₉O_Two )_Two ], 230 ° C, 50 ° C,
Heat to 240 ° C. and hold. Vaporized Ba (C₁₁H
₁₉O_Two )_Two Steam with the mass flow controller 32
Flow rate 50cm / min^Three Vaporized carrier gas Ar
Flowed into the container 24 and further vaporized Ti (C_Three H₇ O)
_Four Of the steam, and the mass flow controller 33
Min 30cm^Three Of the carrier gas Ar controlled in the vaporizing vessel 26
Sr (C)₁₁H₁₉O_Two )_Two Steaming
The mass flow controller 34 sets the flow rate to 40
cm^Three The carrier gas Ar controlled in
By doing so, both are supplied into the plasma CVD chamber 19.
I do. Further, the mass flow controller 36 controls the flow rate.
50cm per minute^Three Controlled reaction gas O_TwoThe plasma CVD
It is supplied into the chamber 19. Note that these source gases and
The reaction gas is supplied onto the base substrate 2 by the nozzle 37.
You. The degree of vacuum in the plasma CVD chamber 19 became constant
Then, the electrode 3 is supplied by a high frequency power source (13.56 MHz) 38.
9 between the substrate 9 and the substrate holder 20 (power 1.4 W /
cm^Two ) Is generated and the underlayer with the metal electrode thin film layer 43 is formed.
A dielectric thin film layer 44 is formed on the entire surface of the substrate 1. this
By plasma CVD (Ba_1-X , Sr_X ) TiO_Three Thin
The deposition rate of the film is about 0.18 μm / min. So that
By forming a film for 5 minutes, a dielectric material of about 0.9 μm
A thin film layer 44 is obtained.

After the film formation, the supply of the source gas and the reaction gas is stopped, the gate 18 is opened, and the substrate fixing plate 2 is transferred onto the substrate holder 6 by the transfer arm 21. The substrate holder 6 is rotated by a motor 17 by a half turn, and the substrate fixing plate 2
Is moved to the gate 8 side. After moving, open gate 8,
The substrate fixing plate 2 is placed on the substrate holder 10 in the sputtering chamber 9.
Is transported by the transport arm 5. At this time, the substrate holder 10 is rotated in advance by the motor 40 by a half turn, and then the substrate fixing plate 2 is placed on the metal mask 12 so that the underlying substrate 1 and the metal mask 12 are completely adhered.

The gate 8 is closed, and the inside of the sputtering chamber 9 is 1 × 1
After exhausting to 0 ^-4 Pa, the mass flow controller 1
Ar whose flow rate is controlled by 4 is supplied into the sputtering chamber 9. The degree of vacuum in the sputtering chamber 9 was maintained at 1 Pa, and a high frequency power supply (13.56 MHz) was placed on the Ni target 15.
A plasma (electric power: 0.8 W / cm ² ) is generated by 16, and a patterned Ni metal electrode thin film layer 45 is formed on the dielectric thin film layer 44 while being shifted from the first patterned metal electrode thin film layer 43. . These operations are repeated 14 times to alternately form the metal electrode thin film layers and the dielectric thin film layers, and to stack 13 dielectric thin film layers.

After the lamination, the substrate fixing plate 2 with the base substrate 1 is removed from the substrate holder 6 by the transfer arm 21.
It is transported to the preliminary vacuum chamber 41. It is cooled to room temperature in the preliminary vacuum chamber 41 and carried out of the apparatus. As shown in FIG. 2, the substrate is cut into 3.2 mm × 1.6 mm so that every other metal electrode thin film layer faces alternate side walls. At this time, the area of the metal electrode thin film was 3.0 mm × 1.
4 mm. On the cut surface where this metal electrode thin film is exposed,
Silver external electrodes 49 and 50 are applied and baked to establish conduction between the internal metal electrode thin film layer and the external electrodes. The capacitance of the multilayer thin film capacitor manufactured as described above was measured.
μF.

As shown in FIG. 3, a Ni film is formed on an alumina substrate, and (Ba ₁ -x, Sr _x ) TiO _{3 is formed} thereon.
A sample in which only one thin film was formed and Ni was further formed thereon as an upper electrode was prepared. Electric characteristics were measured between the electrodes 52 and 54 of the thin film capacitor. The dielectric properties were measured at 1 kHz and room temperature with an LCR meter. The relative dielectric constant was 4500, the dielectric loss was 0.7%, and the insulation resistance was 10 ⁹ Ω · cm or more. In this sample, X
Analysis by X-ray diffraction and reflection high-energy electron diffraction (RHEED) revealed that the crystal had a perovskite crystal structure preferentially oriented to the (100) plane. BaTi
In O ₃ , the relative dielectric constant of the a-axis is larger than that of the c-axis, and therefore, it is considered that the relative dielectric constant of (Ba ₁ -x, Sr _x ) TiO ₃ was increased. Further, as a result of analyzing the film composition by an X-ray microanalyzer, the film composition was (Ba _0.5 Sr _0.5 ) TiO ₃ .

In the above steps, the vaporization temperature of each raw material,
By changing the substrate temperature, multilayer thin film capacitors having various compositions were produced. Table 1 shows the composition and electrical characteristics of these multilayer thin film capacitors.

[0021]

[Table 1]

From these results, it can be seen that the composition ratio of Ba and Sr can be changed by changing the vaporization temperature of each raw material. Therefore, a multilayer thin film capacitor having desired dielectric properties can be manufactured by controlling the composition of the thin film. When the substrate temperature is changed, 5
In the range of 50 ° C. to 750 ° C., a multilayer thin film capacitor having good dielectric properties was obtained.
When the temperature exceeded 50 ° C., the dielectric properties deteriorated. Therefore, a preferable film forming temperature range of the multilayer thin film capacitor using (Ba _1-x , Sr _x ) TiO ₃ for the dielectric thin film layer is 550 ° C. to 750 ° C. Further, when comparing the multilayer thin film capacitor with the multilayer sintered capacitor manufactured by the conventional method, a capacitor having the same capacity can be obtained with a smaller number of layers. With the same number of layers, a capacitor with a larger capacity can be obtained. This is the plasma C
This is because by forming the dielectric thin film layer by the VD method, a thinner and denser film can be obtained than by forming the dielectric thin film layer by the conventional sintering method.

Next, using the raw materials of the above embodiments, the film forming time of the dielectric thin film layer and the metal electrode thin film layer was changed to change the thickness of each thin film layer, or to change the number of stacked thin film layers. A capacitor was manufactured and its electrical characteristics were measured. Table 2 shows the thickness, the number of laminated layers, and the electrical characteristics of these multilayer thin film capacitors.

[0024]

[Table 2]

From these results, it is found that the dielectric thin film layer has a thickness of 0.05 μm.
It can be seen that if the thickness is smaller than m, a sufficient capacity cannot be obtained. When the thickness is more than 3 μm, the characteristics can be obtained, but the superiority as a thin film capacitor is lost. Therefore, the preferable range of the thickness of the dielectric thin film layer is 0.05
μm to 3 μm. The metal electrode thin film layer has a thickness of 0.01
When the thickness was smaller than μm, there was a problem in conductivity, and a predetermined capacity could not be obtained. On the other hand, when the thickness was more than 0.2 μm, as the number of stacked layers increased, the step between the center and the end became large, cracks occurred, and the conductivity was also impaired. Therefore, a preferable range of the thickness of the metal electrode thin film layer is 0.01 μm to 0.2 μm.

In the above embodiment, Ba, Ti, Sr
Ba (C₁₁H₁₉O_Two ) _Two , Ti (C_Three H₇ 
O)_Four , Sr (C₁₁H₁₉O_Two )_Two Used in the present invention.
The production method is not limited to this raw material,
Using a β-diketone metal complex or metal alkoxide
Then, the perovskite type preferentially oriented to the (100) plane
Crystal structure of (Ba_1-X , Sr_X ) TiO_Three Get a thin film of
be able to. Further, in the above embodiment, the reaction gas is
O_Two Was used in the production method of the present invention.
The reaction gas is not limited to_Two O or H_Two O
In the case where is used, similarly, preferentially oriented to the (100) plane
(Ba of perovskite type crystal structure_1-X, Sr_X ) Ti
O_Three Can be obtained. Therefore, the raw material Ba
(C₁₁H₁₉O_Two )_Two , Sr (C₁₁H₁₉O_Two )_Two , Ti
(C_Three H₇ O)_Four , Ti (C₁₁H₁₉O _Two )_Two (C_Three H₇ 
O)_Two , Ti (C_Five H₇ O_Two )_Four To the reaction gas_Two ,
N_Two O, H_Two O and the same plasma CVD equipment
Conditions and conditions for multilayer thin film capacitors
Table 3 shows the electrical characteristics.

[0027]

[Table 3]

From these results, it was found that a β-diketone metal complex or metal alkoxide was used as a raw material, and O ₂ ,
It was confirmed that when N ₂ O and H ₂ O were used, a dielectric thin film layer having the same dielectric characteristics and preferentially oriented to the (100) plane could be obtained.

In the above embodiment, Ni formed by sputtering is used for the metal electrode thin film layer. However, the manufacturing method of the present invention is not limited to this film forming method and metal electrode thin film layer. When a vacuum deposition method is used as a film method, or a metal other than Ni, for example, palladium,
It was confirmed that even when palladium / silver alloy, platinum, copper, or the like was used, it was possible to manufacture a multilayer thin film capacitor having equivalent characteristics.

Further, in the above embodiment, the external electrode is made of silver and the coating and baking method is used as the forming method. However, the manufacturing method of the present invention is not limited to this external electrode and its forming method. Even if a metal other than silver is used for forming the electrodes, or if a vacuum evaporation method, a sputtering method, or a plating method is used in addition to the coating and baking method, it is possible to manufacture a multilayer thin film capacitor having equivalent characteristics. confirmed. (Embodiment 2) Since the configuration of the manufacturing apparatus and the configuration of the multilayer thin film capacitor of this embodiment are exactly the same as those of Embodiment 1, the drawings are shared and the description of the configuration is omitted. A method for manufacturing this multilayer thin film capacitor will be described below.

The type of the substrate, the method of transport, the method of forming and laminating the metal electrode thin film layer, the method of manufacturing the external electrode after lamination, and the like are exactly the same as those in the first embodiment, and therefore will not be described. The method of forming the dielectric thin film layer 44 after forming the metal electrode thin film layer 43 will be described below.

The substrate holder 2 in the plasma CVD chamber 19
0, the substrate fixing plate 2 is transferred by the transfer arm 21.
You. Note that the substrate holder 20 is
Heated to 680 ° C. by the heater 22. After transport,
The gate 18 is closed and the inside of the plasma CVD chamber 19 is reduced to 1 Pa.
And exhaust the substrate holder 20 by the motor 23 every time.
Rotate at a speed of 120 revolutions per minute. In advance, vaporization volume
The raw material 25, lead dipivaloyl methane [Pb
(C₁₁H₁₉O_Two )_Two ] In the vaporization vessel 26
Isopropoxy titanium [Ti (C_Three H₇ O)_Four ]
The raw material 29 of magnesium acetyl acetate
Settonate [Mg (C_Five H₇ O_Two )_Two ・ H _Two O]
Pentaethoxy niobium [N
b (OC_TwoH_Five )_Five 145 ° C, 50
C., 220.degree. C. and 60.degree. Vaporized
Pb (C₁₁H₁₉O_Two )_Two The steam from the mass flow control
35cm per minute with the roller 32^Three Carrier gas
By flowing the gas Ar into the vaporization container 24,
Ti (C_Three H₇ O)_Four The steam of the mass flow con
The flow rate is 20 cm per minute with the trawler 33^Three Carry controlled to
By flowing the Agas Ar into the vaporization vessel 26,
Mg (C_Five H₇ O_Two )_Two ・ H_Two O vapor
30cm / min flow rate with mass flow controller 34^Three To
Flowing the controlled carrier gas Ar into the vaporization vessel 28
Further evaporates Nb (OC_TwoH_Five )_Five Steam
The flow rate is 15 cm / min with the mass flow controller 35
^Three Of the carrier gas Ar controlled to a predetermined value into the vaporization vessel 30
As a result, both are supplied into the plasma CVD chamber 19.
You. Further, the mass flow controller 36 controls the flow rate every time.
Min 100cm^Three Controlled reaction gas O_Two The plasma CVD
It is supplied into the chamber 19. Note that these source gases and
The reaction gas is supplied onto the base substrate 2 by the nozzle 37.
You. The degree of vacuum in the plasma CVD chamber 19 became constant
Then, the electrode 3 is supplied by a high frequency power source (13.56 MHz) 38.
9 between the substrate 9 and the substrate holder 20 (power 1.4 W /
cm^Two ) Is generated and the underlayer with the metal electrode thin film layer 43 is formed.
A dielectric thin film layer 44 is formed on the entire surface of the substrate 1. this
Pb ｛(Mg_1/3, Nb_2/3 )_1-X
 Ti_X ｝ O_Three Is about 0.15 μm / min.
Therefore, by performing film formation for 4 minutes, about 0.6
A μm dielectric thin film layer 44 was obtained. Below, the actual
In the same manner as in Example 1, 14 dielectric thin film layers were stacked,
A multilayer thin film capacitor was manufactured. Work as above
The capacitance of the manufactured multilayer thin film capacitor was measured to be 7 μF
Met.

For analysis of the dielectric thin film layer, as shown in FIG. 3, a Ni film was formed on an alumina substrate, and Pb was formed thereon.
A sample was prepared in which a _{single layer of} ｛(Mg _1/3 , Nb _2/3 ) _1-x Ti _x ｝ O ₃ was formed, and Ni was formed thereon as an upper electrode. Electrode 5 of this thin film capacitor
Electric characteristics were measured between 2, 54. Dielectric properties are LCR
When measured with a meter at 1 kHz and room temperature, the relative dielectric constant was 9,800 and the dielectric loss was 0.8%. The insulation resistance was 10 ⁹ Ω · cm or more. Further, analysis of the sample by X-ray diffraction revealed that the sample had a perovskite crystal structure. Further, as a result of analyzing the film composition with an X-ray microanalyzer, the film composition was found to be Pb ｛(M
g _1/3 Nb _2/3 ) _0.7 Ti _0.3 ｝ O ₃ .

In the above steps, the vaporization temperature of each raw material,
By changing the substrate temperature, multilayer thin film capacitors having various compositions were produced. Table 4 shows the composition and electrical characteristics of these multilayer thin film capacitors.

[0035]

[Table 4]

From these results, it is understood that the composition ratio of Pb, Mg, Nb, and Ti can be changed by changing the vaporization temperature of each raw material. Therefore, a multilayer thin film capacitor having desired dielectric properties can be manufactured by controlling the composition of the thin film. When the substrate temperature was changed, a multilayer thin film capacitor having good dielectric properties was obtained in the range of 450 ° C. to 750 ° C.
Below 750 ° C., the dielectric properties deteriorated. Therefore, the _{Pb {(Mg 1/3, Nb 2} /3)
A preferable film forming temperature range of the multilayer thin film capacitor using _1-X Ti _X ｝ O ₃ for the dielectric thin film layer is 450 ° C. to 750 ° C. Further, when comparing the multilayer thin film capacitor with the multilayer sintered capacitor manufactured by the conventional method, a capacitor having the same capacity can be obtained with a smaller number of layers. With the same number of layers, a capacitor with a larger capacity can be obtained. This is because a thinner and more dense film can be obtained by producing a dielectric thin film layer by a plasma CVD method than by producing a dielectric thin film layer by a conventional sintering method.

Next, using the raw materials of the above embodiments, the film formation time of the dielectric thin film layer and the metal electrode thin film layer was changed to change the thickness of each thin film layer, or to change the number of stacked thin film layers. A capacitor was manufactured and its electrical characteristics were measured. Table 5 shows the thin film layer thickness, the number of stacked layers, and the electrical characteristics of these multilayer thin film capacitors.

[0038]

[Table 5]

From this result, it is found that the dielectric thin film layer has a thickness of 0.05 μm.
It can be seen that if the thickness is smaller than m, a sufficient capacity cannot be obtained. When the thickness is more than 3 μm, the characteristics can be obtained, but the superiority as a thin film capacitor is lost. Therefore, the preferable range of the thickness of the dielectric thin film layer is 0.05
μm to 3 μm. The metal electrode thin film layer has a thickness of 0.01
When the thickness was smaller than μm, there was a problem in conductivity, and a predetermined capacity could not be obtained. On the other hand, when the thickness was more than 0.2 μm, as the number of stacked layers increased, the step between the center and the end became large, cracks occurred, and the conductivity was also impaired. Therefore, a preferable range of the thickness of the metal electrode thin film layer is 0.01 μm to 0.2 μm.

In the above embodiment, Pb, Ti, M
g and Nb as Pb (C₁₁H₁₉O_Two )_Two , Ti
(C_Three H₇ O)_Four , Mg (C_Five H₇ O_Two )_Two ・ H_Two O,
Nb (OC_Two H_Five )_Five Was used in the production method of the present invention.
Is not limited to this raw material, but β-dike
When metal complexes or metal alkoxides are used,
Pb ｛(Mg_1/3 , Nb_2/3 )
_1-X Ti_X ｝ O_Three Can be obtained. further,
In the above embodiment, O was used as the reaction gas._Two Was used.
In the production method of Ming, without being limited to this reaction gas,
N as reaction gas_TwoO or H_Two Even if O is used,
Pb ｛(Mg_1/3 , Nb_2/3 )
_1-X Ti_X ｝ O_Three Can be obtained. Therefore,
Pb (C₁₁H₁₉O_Two )_Two , Pb (C_Two O_Five )_Four ,
Ti (C_Three H₇ O)_Four , Ti (C₁₁H ₁₉O_Two )_Two (C_Three 
H₇ O)_Two , Mg (C_Five H₇ O_Two )_Two ・ H_Two O, Mg
(C₇ H _FifteenCOO)_Two , Nb (OC_Two H_Five )_Five , Nb
(C₁₁H₁₉O_Two )_Two ・ Cl_Three To the reaction gas_Two , N_Two 
O, H_Two Using O, the same plasma CVD equipment
The film formation conditions and the
Table 6 shows the electrical characteristics.

[0041]

[Table 6]

From these results, it was found that a β-diketone metal complex or metal alkoxide was used as a raw material, and O ₂ ,
It was confirmed that equivalent dielectric properties could be obtained by using N ₂ O and H ₂ O.

In the above embodiment, Ni formed by sputtering is used for the metal electrode thin film layer. However, the manufacturing method of the present invention is not limited to this film forming method and metal electrode thin film layer. Production of multilayer thin film capacitors having the same characteristics even when using a vacuum deposition method as the film method or when using a metal other than Ni, for example, palladium, palladium / silver alloy, platinum, copper, etc. for the metal electrode thin film layer. Confirmed that it is possible.

In the above embodiment, silver was used for the external electrode, and the coating and baking method was used for forming the external electrode. However, the manufacturing method of the present invention is not limited to this external electrode and its forming method. Even if a metal other than silver is used for forming the external electrodes, or if a vacuum evaporation method, a sputtering method, or a plating method is used in addition to the coating and baking method, it is possible to manufacture multilayer thin film capacitors having equivalent characteristics. confirmed.

[0045]

As described above, according to the present invention,
By using a plasma CVD method for forming the dielectric thin film layer, a dense and favorable dielectric property having a thickness of 0.05 to 3 μm and preferentially oriented in the a-axis on the metal electrode thin film layer (Ba).
_1-X , Sr _x ) TiO ₃ , Pb ｛(Mg _1/3 , Nb
_2/3 ) A thin film of _1-x Ti _x薄膜 O ₃ can be obtained at a temperature lower than the bulk baking temperature or other thin film forming methods (vacuum deposition, sputtering, thermal CVD). Further, by using a thin film manufacturing method such as a vacuum evaporation method or a sputtering method to form the metal electrode thin film layer,
A dense metal electrode thin film layer having a thickness of about 0.2 μm is obtained. Therefore, since the thickness can be made thinner than the conventional method of stacking and firing the slurry-like ceramic multilayer capacitors, the capacitance per dielectric thin film layer can be increased. Further, the number of layers can be increased even with the same chip thickness. Therefore, the capacitance per unit volume increases, and a multilayer thin film capacitor corresponding to miniaturization and large capacity can be manufactured.

[Brief description of the drawings]

FIG. 1 is a manufacturing apparatus including a plasma CVD apparatus used for forming a dielectric thin film layer of a multilayer thin film capacitor according to an embodiment of the present invention and a sputtering apparatus used for forming a metal electrode thin film layer. Schematic diagram of

FIG. 2 is a schematic cross-sectional view of a multilayer thin film capacitor according to one embodiment of the present invention.

FIG. 3 is a schematic sectional view showing a thin film capacitor according to one embodiment of the present invention.

[Explanation of symbols]

 42 base substrate 43 metal electrode thin film layer 44 dielectric thin film layer 45 metal electrode thin film layer 46 dielectric thin film layer 47 metal electrode thin film layer 48 dielectric thin film layer 49 external electrode 50 external electrode

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Eiji Fujii 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Hideo Torii 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Masuzi Hattori 1006 Oji Kadoma, Kadoma City, Osaka Pref. Document JP-A-2-121313 (JP, A) JP-A-4-51407 (JP, A) JP-A-3-80562 (JP, A) JP-A-2-197108 (JP, A) JP-A-2- 157123 (JP, A) JP-A-61-136995 (JP, A) JP-A-4-282810 (JP, A) JP-A-5-258988 (JP, A)

Claims (9)

(57) [Claims] 1. A metal electrode thin film layer is formed on a substrate by patterning by vacuum evaporation or sputtering.
(100) perpendicular to the surface of the metal electrode thin film layer
(Ba) of a tetragonal perovskite structure preferentially oriented on the plane
_1-X, Sr _X) a dielectric thin film layer of TiO ₃ (X = 0~1.0), using a mixed gas of a reactive gas and β- diketone metal complex or metal alkoxide of the metal compound precursor vapor plasma The metal electrode thin film layer and the dielectric thin film layer are laminated by alternately repeating the production of the metal electrode thin film layer and the production of the dielectric thin film layer by the CVD method, and the patterned metal electrode thin film layer has one layer. A method for manufacturing a multilayer thin film capacitor, characterized in that after cutting so as to face alternate sidewalls, external electrodes are formed on the cut surface by vacuum evaporation, sputtering, plating, or coating and baking. 2. (Ba ₁ -x, Sr _x ) TiO ₃ (X = 0 to 2)
2. The method for manufacturing a multilayer thin film capacitor according to claim 1, wherein the temperature range of the substrate used for manufacturing the substrate (1.0) by the plasma CVD method is 550 ° C. to 750 ° C. 3. (Ba ₁ -x, Sr _x ) TiO ₃ (X = 0 to ₃ )
2. The method according to claim 1, wherein the thickness of (1.0) is 0.05 μm to 3 μm. 4. A metal electrode thin film layer patterned on a substrate by a vacuum deposition method or a sputtering method, and
On the metal electrode thin film layer, a composite perovskite-type compound Pb ｛(Mg _1/3 , Nb _2/3 ) _1-x Ti _x ｝ O ₃ (X = 0 to
1.0) is produced by a plasma CVD method using a mixed gas of a vapor of a metal compound raw material of a β-diketone metal complex or a metal alkoxide and a reaction gas,
By alternately repeating the production of the metal electrode thin film layer and the production of the dielectric thin film layer, the metal electrode thin film layer and the dielectric thin film layer are laminated, and the patterned metal electrode thin film layers are alternately formed on alternate side walls. A method for manufacturing a multilayer thin film capacitor, comprising cutting an external electrode on the cut surface by vacuum evaporation, sputtering, plating, or coating and baking. 5. Pb {(Mg _1/3 , Nb _2/3 ) _1-x Ti _x }
O ₃ (X = 0~1.0) multilayer thin film of claim 4, wherein the temperature range of the substrate using a composite perovskite compound to produce the plasma CVD method is characterized in that it is a 450 ° C. to 750 ° C. of Manufacturing method of capacitor. 6. Pb {(Mg _1/3 , Nb _2/3 ) _1-X Ti _X }
O ₃ film thickness of the composite perovskite (X = 0 to 1.0) The method for producing a laminated thin film capacitor according to claim 4, characterized in that the 0.05Myuemu～3myuemu. 7. The method according to claim 1, wherein oxygen, N ₂ O, or H ₂ O is used as a reaction gas used for forming the dielectric thin film layer. 8. The method according to claim 1, wherein a metal mask is used to form a pattern of the metal electrode thin film layer, and the metal mask is shifted for each layer so that the metal electrode thin film layers are formed alternately at alternate positions. A method for manufacturing a multilayer thin film capacitor according to claim 1. 9. The metal electrode thin film layer having a thickness of 0.01 μm or less.
The method for manufacturing a multilayer thin film capacitor according to claim 1, wherein the thickness is 0.2 μm.