JP2007186772A - Film-forming method by gas-flow sputtering - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film-forming method by gas-flow sputtering, which can form a metallic compound film having an adequate crystallinity, and to provide an apparatus therefor. <P>SOLUTION: This film-forming method includes the steps of: introducing an inert gas such as argon gas from an inlet 11 for a sputtering gas into a chamber 20; producing sputtered particles by electric discharge generated between an anode 13 and a cathode 15; transporting the sputtered particles to a substrate 16 by a forced flow of the inert gas such as argon; and depositing them on the substrate 16. A voltage of a DC-RF superimposing power source 12 is preferably lower than 500 V. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a gas flow sputtering film forming method for forming a metal compound film on a substrate by a gas flow sputtering method.

  Sputtering is well known as a method for forming a metal compound film, but a normal sputtering method such as a planar magnetron sputtering method allows uniform film formation, but the film formation speed is slow and the inside of the vacuum chamber is highly vacuumed. Since a large exhaust device is indispensable for exhausting to a state, there is a disadvantage that expensive equipment is required.

  On the other hand, the gas flow sputtering method is known, and the applicant of the present invention first performs the gas flow sputtering method using a catalyst layer of a polymer electrolyte fuel cell electrode or a semiconductor electrode for a dye-sensitized solar cell. The technique applied to formation of a layer is proposed (patent documents 1-3).

The gas flow sputtering method is a method in which sputtering is performed under a relatively high pressure, and sputtered particles are transported to a deposition target substrate by a forced flow of gas and deposited. Since this gas flow sputtering method does not require high vacuum evacuation, it is possible to form a film by mechanical pump evacuation without using a large evacuation device as in the conventional normal sputtering method. It can be implemented with inexpensive equipment. Moreover, the gas flow sputtering method can form a film 10 to 1000 times faster than the usual sputtering method. Therefore, according to the gas flow sputtering method, the film formation cost can be reduced by reducing the equipment cost and the film formation time.
Japanese Patent Application No. 2004-319592 Japanese Patent Application No. 2004-319548 Japanese Patent Application No. 2004-319598

  In the conventional gas flow sputtering method, it is not easy to form a metal compound with good crystallinity, particularly a metal oxide thin film.

  An object of the present invention is to solve the above-mentioned conventional problems and to provide a gas flow sputtering film forming method and apparatus capable of forming a metal compound thin film having good crystallinity.

  The gas flow sputtering film forming method according to claim 1, wherein the metal flow film is formed on a substrate by a gas flow sputtering apparatus, the discharge voltage of the gas flow sputtering apparatus is less than 500 V, and the gas flow sputtering apparatus A high-frequency voltage is simultaneously applied to the cathode in addition to a DC voltage, and a bias voltage is applied to the substrate.

  A gas flow sputtering film forming method according to claim 2 is characterized in that, in claim 1, the voltage applied to the substrate is a high-frequency voltage.

  A gas flow sputtering film forming method according to a third aspect is the method according to the first or second aspect, wherein the frequency of the high frequency is 1 MHz to 50 MHz.

  The gas flow sputtering film forming method of claim 4 is characterized in that, in claim 3, the direct current component bias to the substrate by the high frequency voltage is -150 to 0V.

  A gas flow sputtering film forming method according to claim 5 is characterized in that, in claim 1, the bias voltage is a DC voltage.

  A gas flow sputtering film forming method according to a sixth aspect is characterized in that, in the fifth aspect, the DC bias voltage is -150 to 0V.

  A gas flow sputtering film forming method according to a seventh aspect is characterized in that, in any one of the first to sixth aspects, the metal compound contains a metal oxide as a main component.

  An eighth aspect of the gas flow sputtering film forming method according to any one of the first to sixth aspects is characterized in that the base material is a polymer base material.

  A gas flow sputtering film forming method according to a ninth aspect is characterized in that, in any one of the first to eighth aspects, the discharge voltage is less than 500V.

  In the present invention, the plasma density is increased by performing DC-RF superposition sputtering in which DC (direct current voltage) and RF (high frequency radio wave) are simultaneously applied to the cathode in the gas flow sputtering apparatus, and the discharge voltage is suppressed. Since a bias voltage is applied to the substrate, the incidence of ions on the base material is promoted, and a metal compound thin film with good crystallinity, particularly a metal oxide thin film can be formed.

  The gas flow sputtering method has the following advantages and is extremely useful industrially.

  (1) Since high vacuum evacuation is not required, it is possible to form a film by mechanical pump evacuation without using a large evacuation device such as a conventional normal sputtering method. Can be implemented.

  (2) High-speed film formation can be performed 10 to 1000 times faster than normal sputtering.

  (3) The deposition cost can be reduced by reducing the equipment cost and shortening the deposition time from (1) and (2).

  (4) A film having good adhesion to the substrate can be formed.

  Hereinafter, embodiments of the present invention will be described in detail.

  With reference to FIG. 1, the film-forming method by the gas flow sputtering method which concerns on embodiment is demonstrated.

  FIG. 1A is a schematic diagram showing a schematic configuration of a gas flow sputtering apparatus suitable for carrying out the present invention, and FIG. 1B shows a target and back plate configuration of FIG. 1A. It is a perspective view.

  In the gas flow sputtering apparatus, a rare gas such as argon is introduced into the chamber 20 from the sputtering gas inlet 11 and is generated by discharge between the anode 13 connected to the DC-RF superimposed power source 12 and the target 15 serving as the cathode. The target 15 is sputtered by the generated plasma, and the sputtered particles that have been blown off are transported to the substrate 16 and deposited by a forced flow of a rare gas such as argon. Reference numeral 14 denotes a backing plate. In the illustrated example, the base material 16 is supported by a holder 17, and a reactive gas inlet 18 is disposed in the vicinity of the base material 16 so that reactive sputtering can be performed. .

  A bias power source 21 is provided so as to apply a bias voltage to the substrate 16.

  In the present invention, a metal compound film is formed using such a gas flow sputtering apparatus.

  The DC component voltage of the DC-RF superimposed power supply 12 is preferably less than 500V.

  The bias power source 21 is preferably a direct current power source or a high frequency power source having a frequency of about 1 MHz to 50 MHz, particularly about 5 to 20 MHz.

  Thus, by forming the film by applying the bias voltage by the bias power source 21 with the discharge voltage from the DC-RF superimposed power source 12 being lowered to less than 500 V, a thin film of a metal compound with good crystallinity, particularly a metal oxide, is formed. A film can be formed.

Examples of such metal oxides include, but are not limited to, ITO, ZnO, AZO, GNO, In ₂ O ₃ , SnO ₂ , ZnO, TiO _{2 and the} like.

  In addition, when forming an ITO film as a metal oxide film by a gas flow sputtering method, an ITO target can be used as a target, and conditions other than the discharge voltage and the bias voltage can be formed under the following conditions.

Sputtering pressure: 10-100 Pa
Sputtering power: 1 to 25 W / cm ²
Forced flow Gas type: Argon
Flow rate: 0.5-30 SLM
Reactive gas Gas type: Oxygen
Flow rate: 0-50sccm
Substrate temperature: room temperature Substrate moving speed: 0.1 to 10 m / min

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.

Examples 1 and 2 and Comparative Examples 1 to 3
Using a gas flow sputtering apparatus shown in FIG. 1 (target ITO), into the chamber, and sets the PET film as a substrate, was evacuated to 1 × 10 -1 ^Pa by roughing pump (rotary pump + mechanical booster pump) A crystalline transparent conductive film made of ITO was formed. In addition, in order to obtain the target film thickness, the base material moving speed was adjusted.

Conditions other than those in Table 1
・ Target dimensions: 80mm x 160mm x 5mmt
・ Cathode shape: Parallel plate facing type (using two of the above targets, distance 30 mm)
・ Substrate movement frequency: 1 time ・ Substrate position: Distance between cathode end and substrate 50 mm
It was.

Examples 3, 4 and Comparative Examples 4, 5, 6
The target was Ti, the conditions were as shown in Table 2, and a TiO ₂ thin film was formed in the same manner as described above. The number of substrate movements is one. The results are shown in Table 2.

Examples 5, 6 and Comparative Examples 7, 8, 9
The target was Si, the conditions were as shown in Table 3, and a SiO ₂ thin film was formed in the same manner as described above. The number of substrate movements is one. The results are shown in Table 3.

  As shown in Tables 1 to 3, when the discharge voltage is high as in Comparative Examples 1, 4, and 7, crystallization is not performed. On the other hand, even if the voltage is low, crystallization does not occur unless a bias is applied. As in Examples 1 to 4, crystallization is promoted when a voltage is low and a bias is applied, and a film having good crystallinity can be formed on a resin such as a PET film at a low temperature.

FIG. 1A is a schematic diagram showing a schematic configuration of a gas flow sputtering apparatus suitable for carrying out the present invention, and FIG. 1B shows a target and back plate configuration of FIG. 1A. It is a perspective view.

Explanation of symbols

12 DC-RF superimposed power supply 13 Anode 14 Cathode 15 Target 16 Base material 21 Bias power supply

Claims (9)

In a method of forming a film of a metal compound on a substrate with a gas flow sputtering apparatus,
A gas flow sputtering characterized in that a discharge voltage of the gas flow sputtering apparatus is less than 500 V, a high frequency voltage is simultaneously applied to a cathode of the gas flow sputtering apparatus in addition to a DC voltage, and a bias voltage is applied to a substrate. Film forming method.   2. The gas flow sputtering film forming method according to claim 1, wherein the voltage applied to the substrate is a high frequency voltage.   3. The gas flow sputtering film forming method according to claim 1, wherein the high frequency frequency is 1 MHz to 50 MHz.   4. The gas flow sputtering film forming method according to claim 3, wherein a direct current component bias to the substrate by a high frequency voltage is −150 to 0V.   2. The gas flow sputtering film forming method according to claim 1, wherein the bias voltage is a DC voltage.   6. The gas flow sputtering film forming method according to claim 5, wherein the DC bias voltage is −150 to 0V.   7. The gas flow sputtering film forming method according to claim 1, wherein the metal compound contains a metal oxide as a main component.   7. The gas flow sputtering film forming method according to claim 1, wherein the base material is a polymer base material.   9. The gas flow sputtering film forming method according to claim 1, wherein the discharge voltage is less than 500V.

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