JP3088179B2 - 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 using an organic dielectric thin film.

[0002]

2. Description of the Related Art In recent years, as electronic devices have become smaller and lighter,
2. Description of the Related Art There has been remarkable progress in mounting electronic components on the surface at high density, and there has been a strong demand for electronic components to be formed into chips and miniaturized. Among them, various approaches to miniaturization of capacitors have been made, and as one of them, a multilayer thin film capacitor using an organic dielectric thin film has been studied.

FIG. 3 shows the internal structure of a multilayer thin film capacitor. In the figure, reference numeral 11 denotes a substrate, on which thin film electrodes 12 and organic dielectric thin films 13 are alternately formed, one surface of which is protected by a protective film 14, and external electrodes 15 on both sides.
Is provided.

The element portion of such a multilayer thin film capacitor is formed by forming a thin film electrode 12 and an organic dielectric thin film 13 in a vacuum chamber.
Are alternately laminated. An element structure shown in FIG. 3 is obtained by using a plate-shaped fixing mask for pattern formation. Means for forming an organic thin film include vapor deposition and the like, and formation of an electrode is performed by vapor deposition of a metal using an electron beam method, sputtering, or the like. The element of the multilayer thin film capacitor manufactured in this manner is provided with a protective film 14 for improving environmental resistance, particularly, moisture resistance.
And the external electrodes 15 are provided to complete the multilayer thin film capacitor.

Hereinafter, a method for manufacturing a conventional multilayer thin film capacitor will be described. FIG. 4 is a schematic view of a conventional device for forming an element portion of a multilayer thin film capacitor. In FIG. 4, reference numeral 16 denotes a thin-film electrode forming chamber, and 17 denotes a dielectric thin-film forming chamber. These forming chambers 16 and 17 are evacuated by a vacuum pump 18. Thin-film electrode formation chamber 1
6 and a plate-shaped fixing mask 19 on the upper part of the dielectric thin film forming chamber 17.
A substrate transport table 20 is provided above the plate-shaped fixed mask 19 so that the substrate 11 is transported. In addition, 21 is a shutter, and 22 is a partition plate.

When a multilayer thin film capacitor is manufactured using the above forming apparatus, the forming chambers 16 and 17 are
The gas is exhausted by the vacuum pump 18. This forming chamber 16, 1
The substrate 11 introduced in 7 is conveyed with the element forming surface attached to the substrate conveying table 20 facing downward. The element is formed by forming the thin-film electrode 12 in a predetermined pattern using a plate-shaped fixing mask 19, and then carrying the thin-film electrode 12 into an organic dielectric thin-film forming chamber 17 partitioned by a partition plate 22, and disposing the dielectric thin film 13 in the same manner. A predetermined pattern is formed by the shape fixing mask 19. The thickness is controlled to a predetermined thickness by opening and closing the shutter 21. The above steps are repeated a predetermined number of times to complete the element portion.

[0007]

However, when manufacturing the laminated thin-film capacitor having the above-mentioned structure in the above-mentioned steps, there have been serious problems in both characteristics and productivity.

First, regarding a characteristic surface, a monomer component, an incompletely polymerized component, or a dielectric component itself adheres to unnecessary places outside the pattern of the capacitor element due to leakage of the organic material from the gap of the plate-shaped fixed mask 19. However, there has been a problem that the adhesion of the protective film is reduced and the sealing property is deteriorated.

The adhesion of the monomer component, the incompletely polymerized product, or the dielectric component itself to places other than the required pattern appears remarkably especially when thermal decomposition polymerization or vapor deposition polymerization is used. , 17 are conveyed. This is because a structure in which the evaporation source is opened and closed by the shutter 21 is inevitable for performing the continuous film formation, so that the released organic substances are present in the formation chambers 16 and 17 and adhere to the substrate 11. In order to more efficiently form a continuous film, it is most effective to use the plate-shaped fixed mask 19, but in the plate-shaped fixed mask 19, the above components leak from a minute gap with the substrate 11. Therefore, no matter which film formation method is used, the above-mentioned components adhere to places other than the pattern.

[0010] With respect to such a problem on characteristics, as described in Japanese Patent Application No. 2-307453, deterioration of characteristics can be prevented by performing plasma irradiation on the entire surface of the substrate after patterning an organic dielectric thin film. It became so.

On the other hand, regarding the problem of productivity, since a new step of plasma irradiation is added as described above, when the laminated thin film capacitor element portion is formed using the plate-shaped fixed mask 19, the thin film electrode 12 is formed. , The step of forming the organic dielectric thin film 13, and the step of irradiating plasma must be repeated as a series of steps to the required number of layers. As the number of layers increases, the productivity increases. A new major problem of lowering has arisen.

[0012] In a continuous film deposition machine or the like, it is conventionally known that two steps of a vapor deposition step and a glow discharge treatment step are incorporated in the same vacuum chamber, but the above three steps are repeated up to a predetermined number of times. No method of repeating lamination has been considered.

An object of the present invention is to provide a method for improving the processing capability of a series of steps for forming a multilayer thin film capacitor element portion.

[0014]

In order to achieve the above object, a method of manufacturing a multilayer thin film capacitor according to the present invention comprises a step of forming a pattern of a thin film electrode, a step of forming a pattern of an organic dielectric thin film, and the steps of: And a step of irradiating the plasma with the same pressure in the same vacuum chamber, and these steps are repeated.

In particular, microwave plasma is used as a plasma irradiation method.

[0016]

In order to solve the conventional problems, in a method of forming a multilayer thin film capacitor, independent vacuum chambers are provided in each of three steps of a plasma processing step in addition to a step of forming a thin film electrode and a step of forming a dielectric thin film. I was Therefore, when the degree of vacuum is different between the tanks, a partition plate for maintaining the degree of vacuum is provided, and the movement of the element requires opening and closing of the partition plate and pressure adjustment. In other words, in such a device forming method, for example, in a process having a high processing pressure compared to other processes, the process is performed by lowering the pressure once and then charging the device, then performing the process by increasing the pressure, and lowering the pressure in the vacuum chamber again. It is necessary to take out the element after processing. When such a forming method is used, the time required for one layer is long, and in the case of multi-layering, productivity is significantly reduced. However, in the present invention, since the operating pressures between the processes are equal, not only is the opening and closing of the partition plate between the vacuum tanks and the adjustment of the pressure by a valve or the like unnecessary when moving the element between the processes, but also in the same vacuum tank. Can be continuously processed, and productivity is greatly improved. Further, microwave plasma irradiation using a coaxial tube is effective for these forming methods because the operating pressure is low and the pressure difference from low pressure steps such as electron beam method and vapor deposition polymerization method is small.

[0017]

【Example】

(Embodiment) An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a schematic sectional view of an apparatus in which the three steps of the present invention are incorporated in the same vacuum chamber. In FIG. 1, 1
Is a thin-film electrode forming chamber in which an Al thin-film electrode using an electron beam evaporation method is patterned using the plate-shaped fixed mask 2. Reference numeral 3 denotes a dielectric thin film forming chamber in which an aromatic polyurea dielectric thin film formed by vapor deposition polymerization is patterned by the plate-shaped fixed mask 2. Reference numeral 4 denotes a plasma processing chamber using a coaxial tube type microwave discharge.
These chambers were pressured 5 × 10 by three vacuum pumps 5
It is exhausted to ^-2 Pa.

The substrate 6 introduced into the vacuum chamber is mounted on the substrate transport table 7 with the element forming surface facing downward. The device is formed by first forming an aluminum vapor-deposited film of 500 .mu.m by an electron beam method, and then forming an aromatic polyurea thin film of 2000 .ANG. By a vapor-deposition polymerization method.
The film thickness is controlled to a predetermined film thickness by opening and closing the shutter 8. Thereafter, the substrate 7 is successively carried into the plasma processing chamber 4, and the entire surface of the substrate 7 is irradiated with microwaves by microwave plasma for one minute to remove extraneous deposits. By repeating the above steps, an element having 50 layers (capacity: 5 nF) is completed. According to this method, the processing time per layer was about 4 minutes in total.

Comparative Example Hereinafter, a comparative example of the present invention will be described with reference to FIG. FIG. 2 is a schematic sectional view of the apparatus when RF plasma is used as a plasma processing method. Note that the same reference numerals are used for the same members as in the above embodiment. This comparative example differs from the configuration of the above-described embodiment of FIG. 1 in that RF plasma is used for plasma processing, and that each vacuum chamber is independent and separated by a partition plate 9.

In the case of performing the RF plasma processing, the processing pressure is 1 to 10 Pa, and the pressure is higher than the other steps, so that a partition plate 9 for separating from the other steps is required.
Therefore, when performing the RF plasma treatment, it is necessary to open and close the partition plate 9 and adjust the pressure when the element is moved. Therefore, when an element similar to that of the example was formed, the processing time per layer was about 6 minutes.

As is apparent from the results, when the device forming method shown in this embodiment is performed, the time can be reduced by about 2 minutes per layer, and the processing capacity is increased 1.5 times. As described above, according to the present embodiment, the three steps of forming the thin film electrode, forming the organic dielectric thin film, and irradiating the entire surface of the substrate 6 with plasma are performed at the same pressure, whereby each step is performed. It is possible to eliminate the differential pressure in each room, and at the same time, improve productivity by incorporating three processes in the same vacuum chamber. In particular, the use of a microwave plasma processing method with a low operating pressure is very effective in combination with a thin film forming method capable of high-speed film formation such as an electron beam method and a vapor deposition polymerization method.

[0023]

According to the present invention, as is apparent from the above embodiment, the formation of the thin film electrode, the formation of the dielectric thin film, and the plasma treatment on the substrate are performed in the same vacuum chamber at the same pressure. By repeating and laminating, a method of manufacturing a multilayer thin film capacitor with good productivity can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an apparatus for forming a multilayer thin film capacitor according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view of an apparatus for forming a multilayer thin film capacitor in a comparative example of the present invention.

FIG. 3 is a schematic sectional view of a multilayer thin film capacitor.

FIG. 4 is a schematic sectional view of a conventional apparatus for forming a multilayer thin film capacitor.

[Explanation of symbols]

 Reference Signs List 1 thin-film electrode formation chamber (electron beam method) 2 plate-shaped fixed mask 3 dielectric thin-film formation chamber (vapor deposition polymerization method) 4 plasma processing tank (microwave or RF) 5 vacuum pump 6 substrate 7 substrate transfer table 8 shutter −

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hatsuhiko Shibasaki 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Mikio Haga 1006 Kadoma, Kazuma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-3-209805 (JP, A) JP-A-62-24507 (JP, A) JP-A-59-188110 (JP, A) JP-A-2-121313 (JP, A) Patent 2965670 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01G 4/00- 4/40 H01G 13/00-13/06

Claims (2)

(57) [Claims] 1. A step of patterning a thin film electrode, a step of patterning an organic dielectric thin film, and a step of irradiating plasma on the entire surface of the substrate under the same pressure and in the same vacuum chamber. A method for manufacturing a multilayer thin film capacitor in which a process is repeated and stacked. 2. The method according to claim 1, wherein the plasma irradiation is microwave plasma.