JPH06184749A - Production of thin film using organometallic complex - Google Patents

Abstract

PURPOSE:To provide a method for easily producing a uniform thin film having excellent electrical characteristics with good reproducibility by using organometallic complexes. CONSTITUTION:A material container 2 (made of SUS 316 and kept at 100 deg.C) is filled with 1g of copper t-butoxycarbonyl 1 as the raw material in a thermostatic bath 3. A carrier inert gas 4 (gaseous argon) is introduced into the container through a flowmeter 5 at a flow rate of 100ml/min, and the copper t- butoxycarbonyl 1 is entrained by the gas 4 and sublimated. The mixture is introduced into a quartz reaction tube 7 (kept at 500 deg.C by a heater 8) provided in a pyrolytic furnace 6 and contg. a substrate 9, and a thin copper film is formed on the substrate 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a thin film by a vapor phase growth method, and more specifically, it is possible to produce a copper thin film or a copper oxide thin film useful as a thin film wiring material for LSI and a superconducting material. The present invention relates to a method for producing a thin film using tertiary butoxycarbonyl copper.

[0002]

2. Description of the Related Art Conventionally, as a method for forming a copper thin film or a copper oxide thin film by using a single crystal or a polycrystal, a dry process is often used at present.

The dry process includes a physical film forming method such as a vacuum vapor deposition method, an ion plating method and a sputtering method, and a chemical film forming method such as a chemical vapor deposition method (CVD method). Among them, the CVD method is suitable for mass production because it is easy to control the film formation rate, does not need to be formed under high vacuum, and is capable of high speed film formation.

In such a CVD method, when the metal thin film is formed by decomposing the vapor of the organometallic complex, heat C
The VD method, the photo CVD method, the plasma CVD method, or the like is adopted, and an organometallic complex is used as one of the raw material compounds, and acetylacetone, dipivaloylmethane, and hexafluoroacetylacetone are used as the organic moiety (ligand). Alternatively, diisobutyrylmethine and the like are known.

However, if a thin film is produced by a vapor phase growth method (such as a thermal CVD method) using an organocopper complex composed of the above-mentioned ligand, a satisfactory thin film formation rate cannot be obtained, and mass production is performed. There is a problem that the base thin film cannot be formed. In addition, the results also differ depending on the ligand of the above organometallic complex. For example, when the ligand is acetylacetone, it decomposes before a satisfactory thin film is formed, and in the case of dipivaloylmethane. However, since it has low sublimation property, it is difficult to control film formation and it is extremely difficult to form a uniform thin film with good reproducibility.

On the other hand, in order to improve the above-mentioned low sublimation property, a method for producing a thin film using an organometallic complex in which hydrogen of an organic portion (ligand) is replaced with a fluoride such as hexafluoroacetone as a raw material compound is proposed. Although being developed, the use of an organometallic complex in which hydrogen in the organic moiety (ligand) is replaced with fluoride causes the contamination of fluoride during film formation, resulting in deterioration of the electrical properties of the thin film. There was a point.

[0007]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art and facilitates high speed film formation of a uniform thin film having excellent electrical characteristics and good reproducibility. It is an object of the present invention to provide a method for producing a thin film using a possible organometallic complex.

[0008]

Means for Solving the Problems As a result of intensive studies for solving the above-mentioned problems, the present inventors have found that tertiary butoxycarbonyl copper shows a considerable vapor pressure even at 50 ° C. and has an evaporation temperature (sublimation temperature). It was found that the decomposition temperature is clearly separated from each other, and that the amount of the copper compound entrained in the inert gas is large, and the present invention can be provided.

That is, the present invention provides a method for producing a thin film by vapor phase epitaxy, which is characterized in that tert-butoxycarbonyl copper is used as a raw material compound, and a method for producing a thin film using an organometallic complex. Is.

[0010]

The method for producing a thin film using the organometallic complex of the present invention will be described below with reference to FIG. 1 by taking the case of utilizing the thermal CVD method as an example. Note that FIG. 1 is a diagram schematically showing the outline of the thermal CVD method.

First, in a raw material container 2 (maintained at a constant temperature of 50 to 100 ° C.) filled with the synthesized tertiary butoxycarbonyl copper 1 in a constant temperature tank 3, an inert carrier gas 4 and a flow meter 5 are placed. Flow rate of 5 to 500 ml / min
The gas 4 is accompanied and sublimated with the tertiary butoxycarbonyl copper 1 and introduced into the quartz reaction tube 7 provided in the thermal decomposition furnace 6. The quartz reaction tube 7
Is heated and held at a predetermined temperature (250 to 750 ° C.) by a heater 8, and a substrate 9 is placed inside it.

The tertiary butoxycarbonyl copper entrained gas introduced into the quartz reaction tube 7 as described above thermally decomposes the organometallic complex on the substrate 9 to form a copper thin film. The pipe from the raw material container 2 to the pyrolysis furnace 6 is kept warm at 50 to 150 ° C. by the heat retaining layer 10 or the heat retaining means in order to prevent condensation. Also, in the figure, 11
Is a cooling trap, 12 is a valve, 13 is a rotary pump, and the arrows show the direction in which sublimated tertiary-butoxycarbonyl copper is transferred or the decomposition gas discharge direction.

The tertiary butoxycarbonyl copper used as a raw material compound in the method of the present invention has excellent stability and high sublimability, and since the sublimation temperature and the decomposition temperature are considerably separated from each other, they are accompanied by an inert gas. The amount of complex formed is larger than that of conventional products. Therefore, a homogeneous film free from impurities can be obtained at a high film formation rate.

Further, the above-mentioned tertiary butoxycarbonyl copper does not have a substitution portion with a fluoride, unlike an organometallic complex used as a raw material compound in a conventional method for producing a thin film, and therefore has electrical characteristics. It does not deteriorate.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited by the following examples.

[0016]

EXAMPLES As one example of the method of the present invention, a method for producing a thin film by the thermal CVD method will be described below. Note that FIG. 1 shows thermal CVD.
It is the figure which showed the outline of the method typically.

First, a raw material container 2 in a constant temperature bath 3 filled with 1 g of tertiary butoxycarbonyl copper 1
Inert carrier gas 4 (argon gas) was introduced into (made of SUS316, kept at a constant temperature of 70 ° C.) through a flow meter 5 at a flow rate of 100 ml / min and introduced into the gas 4. Copper 1 was entrained and sublimed. Next, this gas is introduced into the quartz reaction tube 7 (heated and held at 500 ° C. by the heater 8) provided in the thermal decomposition furnace 6 and in which the silicon substrate 9 is placed, and copper on the substrate 9 is introduced. A thin film was formed (FIG. 1).

The pressure inside the reaction vessel was maintained at 20 torr. In addition, the piping from the raw material container 2 to the thermal decomposition furnace 6 is provided with a heat insulation layer 10 or a heat insulation means to prevent condensation.
It is kept warm at 50 ℃. Further, in the figure, 11 is a cooling trap, 12 is a valve, 13 is a rotary pump, and the arrows show the direction in which the sublimed organometallic complex is transferred or the direction in which decomposed gas is discharged.

Film formation was performed for 1 hour as described above, and a uniform thin copper film having a thickness of 2500 Å and good reproducibility was obtained on the substrate 9.

[0020]

Comparative Example A thin film was formed in the same manner as in Example except that the conventionally used copper dipivaloylmethanite was used in place of the tertiary butoxycarbonyl copper. Only a 200 Å thick copper film was obtained.

[0021]

The tertiary butoxycarbonyl copper used as a raw material compound in the method of the present invention has a high vapor pressure, and the sublimation temperature and the decomposition temperature are clearly separated from each other. Thus, it is possible to obtain a copper thin film that is homogeneous and has excellent reproducibility. Further, according to the method of the present invention, since the fluoride is not generated during the film formation, the electrical characteristics of the thin film are not deteriorated.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing an outline of a thermal CVD method.

[Explanation of symbols]

 1 ... Tertiary butoxycarbonyl copper 2 ... Raw material container 3 ... Constant temperature bath 4 ... Inert carrier gas 5 ... Flow meter 6 ... Pyrolysis furnace 7 ... Quartz reaction tube 8 ‥‥ Heater 9 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥

Front page continuation (72) Shinya Yamada 1-8-2 Marunouchi, Chiyoda-ku, Tokyo Dowa Mining Co., Ltd. (72) Inventor Ryo Sakamoto 1-2-8 Marunouchi, Chiyoda-ku, Tokyo Dowa Mining Co., Ltd. In the company

Claims (1)

[Claims] 1. A method for producing a thin film by a vapor phase growth method, wherein tert-butoxycarbonyl copper is used as a raw material compound, and a method for producing a thin film using an organometallic complex.