JPS5916327A - Manufacture of thin film - Google Patents

Abstract

PURPOSE:To restrain the exfoliation of a thin film by forming the thin film while a substrate is oscillated with ultrasonic waves. CONSTITUTION:The numeral 1 represents a vacuum reaction chamber, and 2 a cathode, which is connected electrically to a high frequency RF power source (not illustrated) in a plasma CVD device. The numeral 3 represents an anode, which serves as a substrate holder, 4 a substrate, which is heated by a substrate heater 5. The numeral 6 represents a gas introducing tube, and 7 a vacuum exhaust tube, which is connected to a vacuum pump (not illustrated). The numeral 8 represents an ultrasonic wave oscillation device, which transmits oscillation to the substrate holder 3 and the substrate 4 by means of an ultrasonic wave oscillation transmitting device 9. The ultrasonic wave oscillation device 8 is so formed as not to transmit the heat from the heater 5, in the presence of a heat shielding plate 10.

Description

[Detailed description of the invention] The present invention relates to a novel method for manufacturing thin films.

Conventionally, the PVD method (Physica
Vapor Deposition - Vacuum evaporation method, ion blating method, sputtering method, etc.) and CVD method (Chemical Vapor Deposition method)
tion - normal pressure CVD method, low pressure CVD method, plasma CVD method, spray method, etc.).

In order to improve the adhesion between the thin film and the substrate, efforts have been made to increase the temperature of the substrate during thin film formation, or to ionize and electrically accelerate evaporated particles to form a thin film. However, because the required properties of thin films vary depending on their material, substrate material, application, etc., the manufacturing methods are naturally limited, and the two-part method is often not effective.

Amorphous silicon is attracting attention as a low-cost thin film semiconductor material for solar cells that utilize clean energy. However, there is a problem in that after the amorphous silicon film is formed, the film peels off from the substrate over time. The amorphous silicon film is manufactured by a so-called plasma CVD method in which silane (SiH4) is decomposed by glow discharge. Amorphous silicon films contain large amounts of hydrogen, which makes amorphous silicon suitable for use in electronic devices such as solar cells.

However, if the substrate temperature is lowered in order to increase the adhesion between the film and the substrate, the amount of hydrogen mixed into the film will decrease and the properties of the film will deteriorate. By forming a thin film while applying ultrasonic vibration, the problem of peeling as described above is solved. The following will be described in detail according to examples.

FIG. 1 is a sectional view showing an example of a plasma CVD apparatus used to carry out the thin film production of the present invention. 1 is a vacuum reaction chamber, and 2 is a cathode which is electrically connected to a radio frequency (RF) power source (not shown). 3 is an anode which also serves as a substrate holder. 4. is a substrate, which is heated by a substrate heating heater 5. 6 is a gas introduction pipe, and 7 is a vacuum exhaust pipe connected to a vacuum pump (not shown). Reference numeral 8 denotes an ultrasonic vibration device that transmits vibrations to the substrate holder 3 and the substrate 4 using an ultrasonic vibration transmission device 9. The ultrasonic vibration device 8 is a heat shield plate IO
This prevents heat from the heater 5 from being transmitted.

Amorphous silicon was manufactured using the plasma CVD apparatus shown in FIG. 1 under the manufacturing conditions described below, and the peeling state one week after film formation was compared with a conventional method in which no ultrasonic vibration was applied to the substrate. Manufacturing conditions are raw material gas: SiH+, gas flow rate: 50S
CCM, gas pressure crab 05Torr, RF electric crab 20W
, Substrate temperature: 250°C1 Ultrasonic vibration frequency: 50kHz
z, ultrasonic vibration frequency: 0.5 μm, substrate material: stainless steel (mirror polished), substrate dimensions: 50×50×0.5 body, thickness of amorphous silicon: 1 pm.

When ultrasonic vibration was not applied in the conventional method, 8 out of 10 substrates peeled off at a portion of the substrate. None of the amorphous silicones produced by this method for producing a sound caused any peeling phenomenon.

As described in detail above, according to the present invention, the phenomenon of thin film peeling can be suppressed. The ultrasonic vibration frequency of the substrate was not very effective at frequencies below 1 kHz. Moreover, the effect was small when the vibration amplitude was 0.01 μm or less.

The above explanation is based on plasma CVD process of amorphous silicon film.
Although the case where the thin film is manufactured by a method has been described, it is clear that the same effect can be obtained even if other thin films are used or other manufacturing methods are used.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of a plasma CVD apparatus used for manufacturing the thin film of the present invention. 1: reaction chamber, 2: cathode, 3: anode, 4: substrate,
5-Heater, 6-Gas introduction pipe, 7: Exhaust pipe, 8: Ultrasonic vibration device, -9-Vibration transmission device, lO: Heat shielding plate Patent applicant Makoto Ishizaka, Director of the Agency of Industrial Science and Technology - 'XJ1 Diagram

Claims (2)

[Claims] (1) A method for producing a thin film, which comprises forming a thin film from orange on a substrate by ultrasonically vibrating the substrate. (2) The method for manufacturing a thin film according to claim 1, wherein the thin film is made of amorphous silicon.