JPH0448068A - Formation of thin organic high polymer film - Google Patents

Abstract

PURPOSE:To form a high quality thin organic high polymer film with superior adhesive strength by sputtering a 'Teflon(R)' type amorphous fluororesin target and depositing a thin film of the above resin onto a substrate disposed in a manner to be opposed to the above target. CONSTITUTION:A target material 1 composed of 'Teflon(R)' type amorphous fluororesin is placed in a vacuum tank 6, and this target material 1 is irradiated with inert gas ions 9. When the surface of the target material 1 is sputtered by means of these inert gas ions 9 and the resulting sputtered matter 10 is emitted into the space with inert gas atmosphere 12 under reduced pressure, this emitted sputtered matter 10 is allowed to adhere to a substrate 4 disposed in a manner to be opposed to the target material 1 and a thin film 5 of 'Teflon(R)' type amorphous fluororesin is deposited. By this method, the thin organic high polymer film of 'Teflon(R)' type amorphous fluororesin having uniform film thickness, reduced in contamination with impurities, and having superior adhesive strength and high quality can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention is an organic film used for dielectric thin films with low dielectric constant, low refractive index, and good chemical resistance, passivation thin films, etc. used in the electronics field and optoelectronics field. The present invention relates to a method for forming a polymer thin film.

[Prior Art] Teflon-based fluororesin has excellent properties such as heat resistance, chemical resistance, and electrical properties. However, when Teflon is heated above its melting point of 327°C, it becomes a transparent gel, but since it hardly flows, it has difficulties in molding processability, and it is also difficult to form a thin film. Are known.

Among Teflon-based fluororesins, non-quality fluororesin (Teflon: Nikkei New Materials, pp. 8-7.17 (198
9)) is the glass transition temperature.
It is a thermoplastic resin that melts at a high temperature of 350-400°C, about 0°C higher, and has a viscosity of 10° to 10° poise, which is the lowest viscosity among Teflon-based fluororesins, so it can be molded. It can be processed by high temperature/pressure press molding method. In addition, non-grade fluororesin can only be dissolved in a limited amount in special fluorine-based solvents, so to form a thin film of non-grade fluororesin, melted resin must be applied by spin coating or spraying. It is then dried and formed.

[Problems to be Solved by the Invention] As described above, even non-grade fluororesin, which is the easiest to process among Teflon-based fluororesins, has a high viscosity at high temperatures, so it is molded by high-temperature press processing. Therefore, in order to form a thin film of Teflon-based amorphous fluororesin on the surface of a substrate, the substrate is subjected to high temperatures and high pressures, causing deterioration and damage to the substrate, and making it impossible to form a thin film.

On the other hand, even when forming a thin film by spin coating or spraying using a resin solution in a special solvent, impurities or air bubbles may enter the resin film, the film cannot be thinned, the film thickness is uneven, or There were problems such as poor adhesion to the substrate.

[Means for Solving the Problems] In order to solve the above problems, the present invention forms a thin film of Teflon-based amorphous fluororesin by a deposition method using sputtering. That is, the present invention is a method for forming a Teflon-based amorphous fluororesin thin film, in which the processed resin is used as a target, and the resin thin film is deposited on a substrate facing the target by sputtering.

[Function] The present invention uses the sputtering method to remove impurities, bubbles, uneven film thickness, etc. in the formed thin film, which were problems when using the spin coating method and the spray method, and also reduces the Since a thin film can be formed depending on the processing temperature, Teflon-based amorphous fluororesin can be formed with good reproducibility even on substrates with poor heat resistance or pressure resistance. Also,
By controlling the conditions of inert gas ion irradiation for sputtering the target material surface, it is possible to control the amount and energy of the Teflon-based amorphous fluororesin sputtered material sputtered from the target material surface, allowing it to be deposited on the substrate. The thickness of the Teflon-based amorphous fluororesin thin film can be strictly controlled, and the adhesion to the substrate can also be improved.

〔Example〕

FIG. 1 is a diagram showing an example of the configuration of an ion beam sputtering apparatus used in the thin film forming method of the present invention. In the figure, 1 is a Teflon-based amorphous fluororesin target material, 2 is a water-cooled target holder 3 is a substrate holder, 4 is a substrate on which a thin film is to be formed, and 5 is a deposit of Teflon-based amorphous fluororesin. 6 is a vacuum chamber, 7 is an ion beam generation chamber, 8 is an inert gas inlet, 9 is an inert gas ion, 10 is a sputtered material of Teflon-based amorphous fluororesin, 11 is a vacuum exhaust device, 12 is a thin film Shows an inert gas sputtering atmosphere. A target material l of Teflon-based amorphous fluororesin to be made into a thin film is placed in a vacuum chamber 6, and the target material l is irradiated with inert gas ions 9. At this time, the surface of the target material 1 is sputtered by the inert gas ions 9, and the sputtered material is radiated into the reduced pressure space of the inert gas atmosphere 12. Then, most of the emitted sputtered material is blown away in the direction of the sputtered material 10. Therefore, the substrate 4 on which the sputtered material 10 of the Teflon-based amorphous fluororesin is deposited is placed at this position, and the Teflon-based amorphous fluororesin thin film 5 is deposited on the substrate 4.

A specific example based on the above configuration and principle will be described. First, the entire inside of the vacuum chamber 6 is
After evacuating to X 10-' Torr and maintaining the inside of the vacuum chamber 6 in a constant state, ions of argon (Ar) gas are injected from the inert gas inlet 8 so that the pressure is ≦5 X 10-' Torr. Introduced through the generation chamber 7. In this gas atmosphere and pressure state, Ar'' ions 9 taken out from the ion generation chamber (ion beam gun) 7 are irradiated toward the surface of the Teflon-based amorphous fluororesin target material 1. . At this time, the target material 1 generates heat due to the irradiation of the ions 9, so the target material 1 is placed in a water-cooled holder 2.
It is fixed and cooled. The surface of the Teflon-based fluororesin target material 1 is sputtered by the beam of inert gas ions 9, and the sputtered material is emitted into the reduced pressure space 12. Most of this radiated spatter is
Since the sputtered material 1o would proceed in the direction, the substrate 4 was placed so as to face that direction, and the Teflon-based amorphous fluororesin thin film 5 was deposited on the substrate 4. In addition, the board 4
In order to improve the uniformity of the in-plane film thickness, the thin film was deposited while rotating the substrate 4 by rotating the substrate holder 3. As a result, the in-plane variation in film thickness was ±5
A thin film with good uniformity of less than 30% could be formed.

Furthermore, by increasing the ejection energy during sputtering, a Teflon-based fluororesin thin film with good adhesion to the substrate was obtained.

Furthermore, since the deposition method uses ions, a thin film could be formed at a low processing temperature of 100° C. or less.

FIG. 2 is a diagram showing the relationship between deposition time and film thickness of a thin film. The film thickness increases with the deposition time, indicating that it is possible to make the Teflon-based amorphous fluororesin into a thin film.

It can also be seen from the figure that the deposition rate at this time is as fast as about 30 nm/min.

Although the present invention has been specifically explained above based on the above-mentioned embodiments, the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various changes can be made without departing from the gist thereof. For example, the present invention is not limited to the ion beam sputtering method as in the above embodiments, but can use other sputtering methods such as radio frequency (RF) plasma sputtering.

[Effect of the invention 1] As explained above, according to the present invention, it is possible to make a Teflon-based fluororesin, which is difficult to make into a thin film, into a thin film, and the obtained thin film has a uniform thickness and a small thickness. can be strictly controlled. Furthermore, since it is possible to form a thin film in a highly clean atmosphere, there is less contamination of impurities. Furthermore, 10
Thin films can be formed at low processing temperatures below 0°C, so
It is possible to form high-quality Teflon-based amorphous fluororesin organic polymer thin films, making it possible to realize high-performance optical and electronic devices.

[Brief explanation of drawings]

FIG. 1 shows an example of the configuration of an ion beam sputtering apparatus used in the thin film forming method of the present invention. FIG. FIG. 1... Teflon-based amorphous fluororesin target material 2... Water-cooled target holder 3... Substrate holder... Substrate Teflon-based fluororesin deposition source Hri... Vacuum chamber/ion beam generation chamber Inert gas inlet: Irradiation direction of inert gas ions: Sputtered Teflon-based amorphous fluororesin Vacuum pumping device Inert gas sputtering atmosphere Patent applicant: Nippon Telegraph and Telephone Corporation Representative Patent Attorney Junnosuke Nakamura No. Figure 1

Claims (1)

[Claims] 1. A method for forming a Teflon-based amorphous fluororesin thin film, an organic polymer characterized by using the formed resin as a target and depositing the resin thin film on a substrate facing the target by sputtering. Method of forming thin films.