JP2965670B2 - Manufacturing method of multilayer thin film capacitor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a multilayer thin film capacitor using an organic thin film dielectric.

2. Description of the Related Art With the recent trend toward miniaturization and weight reduction of electronic devices and the high-density mounting of electronic components using surface mounting technology, there has been a strong demand for electronic components to be made smaller and smaller. Along with this, various efforts have been made for miniaturization of capacitors, one of which is to reduce the thickness of dielectrics, and a multilayer thin film capacitor using organic thin film dielectrics as an applied product. Is being produced.

FIG. 2 shows the internal structure of the organic thin film derivative. In the figure, 1 is an insulating substrate, 2 is an internal electrode, 3 is an organic thin film dielectric, 4 is a protective film, and 5 is an external electrode.

The formation of the element portion of such a multilayer thin film capacitor has conventionally been performed by the steps shown in FIG. In FIG. 3 (A), reference numeral 1 denotes an insulating substrate, and in FIG. 3 (B), an internal electrode 2 is formed on the substrate 1, and in FIG. 3 (C), it extends over the internal electrode 2 and the substrate 1. An organic thin film dielectric 3 is formed on the dielectric 3 and an internal electrode 2 having a polarity different from that of the internal electrode 2 formed on the dielectric 3 in FIG. 4), a dielectric 3 is further formed on the internal electrode 2. The formation of such a laminate is repeated to form the element of the multilayer thin film capacitor. Means for forming the organic thin film include thermal decomposition polymerization, vapor deposition polymerization, plasma polymerization, and the like. The formation of the electrodes is performed by depositing a metal using various heat sources. When forming these organic thin films and electrodes, a plate-shaped mask is used to form them into a predetermined shape.

The element of the multilayer thin film capacitor manufactured as described above is sealed with a protective film in order to enhance environmental resistance, particularly moisture resistance, and external electrodes are provided to complete the multilayer thin film capacitor.

However, when the multilayer thin film capacitor having the above-described configuration is manufactured in the above-described process, when the substrate is transported in this manufacturing process or when the organic material leaks from the gap of the plate-like mask, the capacitor element may be out of the pattern. However, there has been a problem that the monomer component, the incompletely polymerized component, and the dielectric component itself adhere to unnecessary places. In FIG. 3, reference numeral 6 denotes the above-mentioned organic substance attached outside the pattern.

Adhesion of monomer components, incompletely polymerized substances, or dielectric components themselves to places other than the required pattern is particularly noticeable when using thermal decomposition polymerization or vapor deposition polymerization, and occurs when the substrate is transported to the film formation chamber. . This is to form a continuous film,
This is because a structure in which the evaporation source is opened and closed by a shutter is unavoidable, so that the released organic matter exists in the film formation chamber and adheres to the substrate. For pattern formation, it is most effective to use a plate-shaped mask in order to more efficiently form a continuous film. However, in the case of a plate-shaped mask, the above components leak from small gaps between the substrate and the substrate, so that the organic components adhere to places other than the pattern regardless of the film formation method.

The present invention establishes a highly accessible multi-layer thin film capacitor manufacturing method that easily removes monomer components, incompletely polymerized substances, and dielectric components themselves that have adhered to places other than these patterns and significantly improves environmental resistance. The purpose is to do.

Means for Solving the Problems In order to achieve the above object, according to the present invention, the entire surface of the insulating substrate is irradiated with plasma after the organic thin film dielectric is formed.

According to the above means, by performing the plasma irradiation, the dielectric itself can be sliced and the monomer component, the incompletely polymerized component and the dielectric component adhering to places other than the required pattern can be removed. In addition, it is possible to prevent the corrosion of the electrode or to improve the sealing property of the protective film, and to improve the environmental resistance, particularly the moisture resistance.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a step of forming a laminated film while performing plasma irradiation. In FIG. 1A, reference numeral 1 denotes an insulating substrate. In FIG. 1B, an internal electrode 2 is formed on the substrate 1, and in FIG. 1C, an organic thin film dielectric 3 is formed so as to extend over the internal electrode 2 and the substrate 1. However, as described above, when the organic thin film dielectric 3 is formed in the step of FIG. 1C, a monomer component, an incompletely polymerized product, or a derivative component itself (hereinafter, simply referred to as an organic material) adheres to the outside of the pattern. The organic matter adhering to portions other than the pattern is indicated by 6 in FIG. In response to this, irradiation of the plasma 7 shown in FIG. 1 (D) is performed. As a result, as shown in (E), the thickness of the organic thin film dielectric 3 is slightly lost, but the organic substance 6 attached to the outside of the pattern is removed. In FIG. 6F, the internal electrodes 2 having a different polarity from the internal electrodes 2 in FIG.
In the same figure (G), the next organic thin film dielectric 3 is formed, and in the same figure (H), the next plasma 7 irradiation is performed, and as shown in the same figure (I), the second organic thin film dielectric 3 is formed. Organic substances attached outside the pattern during formation of the body 3 are completely removed.

The multilayer thin film capacitor is manufactured by repeating the steps shown in FIGS. 1A to 1I, and is completed by sealing with a protective film and attaching external electrodes.

In the following, tests were performed on 11 examples while changing the plasma frequency, power, type and pressure of plasma generating gas, type of dielectric, and processing time, and further, on 6 types of comparative examples by the conventional method. And the characteristics over time were compared to confirm the effect of the example of the present invention.

Hereinafter, 11 examples and 6 comparative examples will be described.

Example 1 An element portion of a multilayer thin film capacitor configured as shown in FIG. 2 was prepared in the steps shown in FIG. The electrode is aluminum
1000Å was formed by EB evaporation (evaporation using an electron beam evaporation source), and 4000Å of dielectric polyurea was formed by evaporation polymerization. The plasma irradiation was performed under the conditions of plasma generating gas nitrogen, a pressure of 100 mTorr, a frequency of 13.56 MHz, a power of 200 W (a distance from the electrode of 70 mm) and a processing time of 2 minutes.

Example 2 An element portion of a multilayer thin film capacitor configured as shown in FIG. 2 was prepared in the steps shown in FIG. Electrode is aluminum 1000
Å was formed by EB vapor deposition, and the dielectric was formed by polyurea 4000 Å by vapor deposition polymerization. Plasma irradiation is plasma generating gas oxygen, its pressure 100mTorr, frequency 13.56MHz, power 200W
(The distance from the electrode was 70 mm) and the processing time was 1 minute.

Example 3 An element portion of a multilayer thin film capacitor configured as shown in FIG. 2 was formed in the steps shown in FIG. Electrode is aluminum 1000
Å was formed by EB vapor deposition, and the dielectric was 4000 Å of polyurea prepared by vapor deposition polymerization. The plasma irradiation was performed under the conditions of a plasma generating gas nitrogen, a pressure of 300 mTorr, a frequency of 400 KHz, a power of 200 W (a distance from the electrode of 70 mm) and a processing time of 2 minutes.

Example 4 An element portion of a multilayer thin film capacitor configured as shown in FIG. 2 was prepared in the process shown in FIG. Electrode is aluminum 1000
Å was formed by EB vapor deposition, and the dielectric was 4000 Å of polyurea prepared by vapor deposition polymerization. Plasma irradiation is plasma generating gas nitrogen, pressure 100mTorr, frequency 2.45MHz, power 100W
(The distance from the electrode was 70 mm) and the processing time was 3 minutes.

Example 5 An element portion of a multilayer thin film capacitor configured as shown in FIG. 2 was prepared in the steps shown in FIG. Electrode is aluminum 1000
Å was formed by EB vapor deposition, and the dielectric was formed by polyurea 4000 Å by vapor deposition polymerization. Plasma irradiation is plasma generation gas argon, its pressure is 100mTorr, frequency is 13.56MHz, power is 10
The test was performed under the conditions of 0 W (distance from the electrode: 70 mm) and a processing time of 1 minute.

Example 6 An element portion of a multilayer thin film capacitor configured as shown in FIG. 2 was prepared in the process shown in FIG. Electrode is aluminum 1000
Å was formed by EB vapor deposition, and the dielectric was formed by polyurea 4000 Å by vapor deposition polymerization. Plasma irradiation is plasma generating gas nitrogen, its pressure is 100mTorr, frequency is 0Hz (DC), power is 20
The test was performed under the conditions of 0 W (distance from the electrode: 70 mm) and a processing time of 1 minute.

Example 7 An element portion of a multilayer thin film capacitor configured as shown in FIG. 2 was prepared in the process shown in FIG. Electrode is aluminum 1000
Å is formed by EB evaporation, and the dielectric is polyparaxylene 4000
Å was formed by vapor deposition. Plasma irradiation was performed under the conditions of plasma-generated nitrogen, a pressure of 100 mTorr, a frequency of 13.56 MHz, a power of 200 W (a distance from the electrode of 70 mm), and a processing time of 2 minutes.

Example 8 An element portion of a multilayer thin film capacitor configured as shown in FIG. 2 was prepared in the steps shown in FIG. Electrode is aluminum 1000
Å is formed by EB evaporation, and the dielectric is fluorocarbon 4000
Å was formed by a plasma polymerization method. The plasma irradiation was performed under the conditions of plasma generating gas nitrogen, a pressure of 100 mTorr, a frequency of 13.56 MHz, a power of 200 W (a distance from the electrode of 70 mm) and a processing time of 2 minutes.

Example 9 An element portion of a multilayer thin film capacitor configured as shown in FIG. 2 was prepared in the process shown in FIG. Electrode is aluminum 1000
Å was formed by EB vapor deposition, and the dielectric was formed by vapor deposition polymerization of 4000 ポ リ ウ レ タ ン polyurethane. Plasma irradiation is plasma generating gas nitrogen, its pressure 100mTorr, frequency 13.56MHz, power 200W
(The distance from the electrode was 70 mm) and the processing time was 2 minutes.

Example 10 An element portion of a multilayer thin film capacitor configured as shown in FIG. 2 was prepared in the steps shown in FIG. Electrode is aluminum 1000
Å was formed by EB vapor deposition, and the dielectric was formed by vapor deposition polymerization of 4000 ポ リ イ ミ ド polyimide. Plasma irradiation is plasma generating gas nitrogen, its pressure 100mTorr, frequency 13.56MHz, power 200W
(The distance from the electrode was 70 mm) and the processing time was 2 minutes.

Example 11 An element portion of a multilayer thin film capacitor configured as shown in FIG. 2 was prepared in the process shown in FIG. Electrode is aluminum 1000
Å was formed by EB vapor deposition, and the dielectric was formed by vapor deposition polymerization of 4000 ポ リ ア ミ ド polyamide. Plasma irradiation is plasma generating gas nitrogen, its pressure 100mTorr, frequency 13.56MHz, power 200W
(The distance from the electrode was 70 mm) and the processing time was 2 minutes.

(Comparative Example 1) An element portion of a multilayer thin film capacitor configured as shown in FIG. 2 was prepared in the process shown in FIG. Electrode is aluminum 1000
Å was formed by EB vapor deposition, and the dielectric was formed by polyurea 4000 Å by vapor deposition polymerization.

(Comparative Example 2) An element portion of a multilayer thin film capacitor configured as shown in FIG. 2 was prepared in the process shown in FIG. Electrode is aluminum 1000
Å was formed by EB vapor deposition, and the dielectric was formed by vapor deposition polymerization of 4000 ポ リ ウ レ タ ン polyurethane.

Comparative Example 3 An element portion of a multilayer thin film capacitor configured as shown in FIG. 2 was prepared in the steps shown in FIG. Electrode is aluminum 1000
Å was formed by EB vapor deposition, and the dielectric was formed by vapor deposition polymerization of 4000 ポ リ イ ミ ド polyimide.

(Comparative Example 4) An element portion of a multilayer thin film capacitor configured as shown in FIG. 2 was prepared in the process shown in FIG. Electrode is aluminum 1000
Å was formed by EB vapor deposition, and the dielectric was formed by vapor deposition polymerization of 4000 ポ リ ア ミ ド polyamide.

(Comparative Example 5) An element portion of a multilayer thin film capacitor configured as shown in FIG. 2 was prepared in the process shown in FIG. Electrode is aluminum 1000
Å is formed by EB evaporation, and the dielectric is polyparaxylene 4000
Å was formed by vapor deposition.

(Comparative Example 6) An element portion of a multilayer thin film capacitor configured as shown in FIG. 2 was formed in the process shown in FIG. Electrode is aluminum 1000
Å is formed by EB evaporation, and the dielectric is fluorocarbon 4000
Å was formed by a plasma polymerization method.

About the test sample of the multilayer thin film capacitor manufactured by the method of the above 11 kinds of examples and the comparative example 6 kinds,
A comparative test of the change over time in the capacitance under the environment of 50 ° C., 95% RH, and 50 VDC was performed. The results are shown in the following table.

As shown in the above table, with respect to the six types of Comparative Examples, the sealing of the protective film was incomplete and poor in moisture resistance due to the adhesion of organic substances other than the pattern inside the capacitor, and the corrosion of the aluminum electrode was less than 100 hours. Causes a large change in capacity, 1000
After the lapse of time, four out of six pieces were damaged due to the progress of corrosion. On the other hand, in the eleventh embodiment, there was no breakage even after the elapse of 1000 hours, and all the capacity changes were ± 1% or less. Although not shown in the table, the dielectric loss tangent and the insulation resistance were unchanged, indicating that the environment resistance was extremely excellent.

In this embodiment, the plasma generating gas is nitrogen or oxygen, but may be a dischargeable gas such as argon or helium. The same effect can be obtained even if the discharge frequency of the laser is other than the frequency shown in the embodiment.

Effect of the Invention As is clear from the above description, in the multilayer thin film capacitor, every time an organic thin film dielectric is formed as in the present invention, by performing plasma irradiation, organic substances adhering other than the pattern in the capacitor are removed. It is possible to establish a highly reliable method of manufacturing a multilayer thin film capacitor which is removed, has excellent environmental resistance, particularly excellent moisture resistance.

[Brief description of the drawings]

1 (A) to 1 (I) are process diagrams showing one embodiment of a method for manufacturing a multilayer thin film capacitor of the present invention, FIG. 2 is a sectional view showing the internal structure of the multilayer thin film capacitor, and FIG. 3 (A). ~ (E)
FIG. 2 is a process chart showing an example of a conventional method for manufacturing a multilayer thin film capacitor. 1 ... insulating substrate, 2 ... internal electrode (electrode), 3 ... organic thin film dielectric, 7 ... plasma.

Continued on the front page (72) Inventor Mikio Haga 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. Inventor Yoshikazu Takahashi 2500 Hagizono, Chigasaki-shi, Kanagawa Japan Nippon Vacuum Engineering Co., Ltd. (56) References JP-A-2-121313 (JP, A) JP-A-2-271606 (JP, A) -170229 (JP, A) JP-A-59-188110 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01G 4/00-4/40

Claims (5)

(57) [Claims] In a method of manufacturing a multilayer thin film capacitor in which an organic thin film dielectric and an electrode are formed on an insulating substrate by a dry process, and are patterned and stacked alternately, after forming the organic thin film dielectric, each time, A method of manufacturing a multilayer thin film capacitor, comprising: performing plasma irradiation on an entire surface of an insulating substrate to remove organic substances attached to the insulating substrate or electrodes when forming an organic thin film dielectric. 2. The method for manufacturing a multilayer thin film capacitor according to claim 1, wherein the pattern formation of the organic thin film dielectric and the electrode is performed using a plate-like mask. 3. The method according to claim 1, wherein the plasma is generated by high-frequency discharge. 4. The method according to claim 1, wherein the plasma is generated by a DC discharge. 5. The method for manufacturing a multilayer thin film capacitor according to claim 1, wherein a vapor deposition polymerization method is used for forming the organic thin film dielectric.