JP2623649B2 - Metal wiring device and metal wiring method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] The present invention relates to a metal wiring apparatus and a metal wiring method, and aims at a metal wiring apparatus and a metal wiring method for forming a fine and high-purity metal pattern. A fixed base 1 having a horizontal upper surface installed in a space, a substrate support base 2 mounted on the fixed base and movable in the horizontal direction, and a lower part of the substrate support base vertically separated from the substrate support base. A needle-shaped negative electrode 4 disposed, a positive electrode 5 disposed in the gas space above the negative electrode with the substrate support separated from the substrate, and a gas space between the positive electrode and the substrate support A first laser 6 that emits a crossing laser beam and decomposes the metal compound gas in the gas space near the crossing to generate a metal gas, and a second laser 6 that ionizes the metal gas to generate metal ions A metal wiring device having a laser 7, and 2] The substrate 3 is mounted on a horizontally movable substrate supporting table 2 mounted on a fixed table 1 having a horizontal upper surface, and is vertically arranged at a lower portion of the substrate supporting table apart from the substrate supporting table. An electric field is generated in the space above the substrate by the needle-shaped negative electrode 4 thus formed and the positive electrode 5 arranged in the gas space above the negative electrode with the substrate support being separated from the gas electrode. The gas is introduced into the space containing the substrate, and the gas of the metal compound is irradiated with a laser beam emitted from the first laser 6 to decompose the gas in an electric field above the substrate to release the metal gas and release the metal gas. The gas is irradiated with a laser beam emitted from the second laser 7 to ionize the metal gas to generate metal ions, and the metal ions are attracted by the electric field on the negative electrode side to adhere and deposit on the substrate. Continuously moving the substrate support on which the substrate is mounted Thereby, the wiring pattern is formed on the substrate in accordance with the movement of the substrate support.

[Industrial applications]

The present invention relates to a metal wiring device and a metal wiring method. 2. Description of the Related Art With the increase in the density of semiconductor devices, it has been required to form fine and high-purity metal wiring patterns.

For this reason, it is necessary to develop a metal wiring device and a metal wiring method that meet such demands.

[Conventional technology]

2. Description of the Related Art Conventionally, as a method for forming fine metal wiring of a semiconductor device, a chemical vapor deposition method (CVD method) using a compound containing the atom as a material has been widely used. For example, for aluminum (Al) wiring, trimethyl aluminum (TMA: Al ₂ (CH ₃ ) ₆ ), triethyl aluminum (TEA: Al (C ₂ H ₅ ) ₃ ), and triisobutyl aluminum (TIBA: Al (i-C
₄ H ₉ ) The chemical vapor deposition method of ₃ ) is used.

In the conventional chemical vapor deposition method, a substrate is heated, a gas of a metal compound reaching the substrate is thermally decomposed, and only the metal is deposited on the substrate. However, the metal compound gas may not be completely thermally decomposed on the substrate, and chemical species other than the metal may remain on the substrate. The most problematic is the carbon (C) atom contained in the material, which mixes with the wiring and deteriorates the characteristics.

[Problems to be solved by the invention]

As the wiring pattern of the semiconductor becomes finer, the carbon atoms mixed therein have a bad influence on the characteristics. For example, the incorporation of carbon atoms into Al wiring is undesirable because it increases the resistance of the wiring. SUMMARY OF THE INVENTION The present invention provides a metal wiring apparatus and a metal wiring method for forming fine wiring while preventing carbon atoms from being mixed.

[Means for solving the problem]

 FIG. 1 shows a metal wiring device of the present invention.

In FIG. 1, 1 is a fixed table, 2 is a substrate support table, 3 is a substrate, 4
Denotes a negative electrode, 5 denotes a positive electrode, 6 denotes a first laser, 7 denotes a second laser, and 8 denotes a chamber.

[1] A fixed base 1 having a horizontal upper surface and installed in a gas space of a metal compound, a substrate supporting base 2 mounted on the fixed base and movable in a horizontal direction, and a substrate mounted under the substrate supporting base. A needle-like negative electrode 4 vertically disposed away from the support, a positive electrode 5 disposed above the negative electrode in the gas space with the substrate support being separated from the substrate, a positive electrode and the substrate support A first laser 6 that emits a crossing laser beam in the gas space between the tables and decomposes the metal compound gas in the gas space near the crossing to generate a metal gas, and ionizes the metal gas. A metal wiring apparatus having a second laser 7 for generating metal ions, and [2] mounting the substrate 3 on a horizontally movable substrate support table 2 mounted on a fixed table 1 having a horizontal upper surface. A needle vertically disposed below the substrate support, away from the substrate support An electric field is generated in a space above the substrate by a negative electrode 4 in a shape of a circle and a positive electrode 5 disposed in the gas space above the negative electrode with the substrate support being separated from the substrate. The substrate is introduced into a space containing the metal compound, and the gas of the metal compound is irradiated with laser light emitted from a first laser to decompose the gas in an electric field above the substrate to liberate the metal gas. The metal gas is ionized by irradiating a laser beam emitted from a laser to generate metal ions, and the metal ions are attracted to the negative electrode side by the electric field and adhere to the substrate.
The above object is solved by a metal wiring method in which a wiring pattern is formed on the substrate according to the movement of the substrate support by continuously moving the substrate support on which the substrate is mounted.

[Operation] In the present invention, first, the gas in the metal compound is introduced into the chamber 8 of the chemical vapor deposition furnace. Next, a laser beam from the first laser 6 is applied to the space above the substrate to decompose the metal compound gas in the space above the substrate and release the metal gas. An excimer laser that can provide a large output in the ultraviolet region is used for decomposing a metal compound gas. The metal compound gas continuously absorbs the laser light within the pulse time of the excimer laser light, and decomposes the metal compound gas into metal atoms. For example, the decomposition process of trimethylaluminum is as follows.

At the stage of decomposition into metal atoms, a laser beam of a specific wavelength by the second laser 7 is irradiated to the space above the substrate so as to cross the laser beam by the first laser 6, and the liberated metal gas is subjected to a multiphoton resonance ionization process. Ionize. The wavelength of the laser light that causes the multiphoton resonance ionization process differs depending on the metal atom, and there are several laser beams for each metal atom. 457 nm in the case of Al and 408 nm in the case of Ga efficiently cause ionization by the multiphoton resonance ionization process. A metal atom absorbs three or four such photons of the visible light wavelength and ionizes them. For example, Al atoms absorb three photons of 457 nm and become Al ⁺ ions.

When a specific metal atom is ionized by a multiphoton resonance ionization process, other non-resonant metal atoms are not ionized. Also, other chemical species such as M (CH ₃ ), CH ₃
Are extremely small. Therefore, only specific metal atoms can be ionized.

A tunable dye laser is used as a laser to cause this multiphoton resonance ionization process. In dye lasers, the wavelength of the laser light is changed by changing the dye.
It can be varied in the range of 200 to 900 nm.

In this way, metal ions can be selectively generated in a minute area of about the diameter of the laser beam in the space above the substrate.

The metal ions in the minute region are attracted to the negative electrode provided below the substrate by the action of the electric field. Since the negative electrode is formed in a needle shape and converges the flow of metal ions, extremely fine metal ions are deposited on the substrate.
In addition, since only a specific metal ion adheres to the substrate, it is possible to obtain a high-purity metal deposition without the incorporation of carbon atoms.

By operating the first laser 6 and the second laser 7 continuously and further moving the substrate support on which the substrate is mounted in a horizontal direction according to a desired pattern, a fine metal wiring pattern can be formed on the substrate. .

〔Example〕

Hereinafter, embodiments of the present invention will be described. An Al metal wiring device and a metal wiring method will be described with reference to FIGS. Trimethyl aluminum (TMA: Al ₂ (CH ₃ ) ₆ ) is used as a material for the Al wiring.

Trimethylaluminum is liquid at room temperature but has some vapor pressure. This vapor is introduced into the chamber 8 of the chemical vapor deposition furnace. The pressure in the chamber is 0.1T
orr.

A fixed table 1 having a horizontal upper surface is set in the chamber.

The substrate support 2 is placed on the fixed base. The substrate support can be moved in the horizontal direction by an X-direction drive mechanism and a Y-direction drive mechanism as indicated by arrows in FIG.

The substrate 3 is set on the substrate support. The substrate is not heated.

A needle-like negative electrode 4 that is vertically set apart from the support stand is arranged below the support stand.

The disk-shaped positive electrode 5 is arranged in the space above the negative electrode with the substrate support being separated, so that the center of the disk is directly above the needle-shaped negative electrode.

 The negative electrode and the positive electrode are fixed to the chamber 8.

A first laser 6 and a second laser 7 are arranged outside the chamber 8, emit laser light in a horizontal direction, are guided into the chamber through a window provided on an outer wall of the chamber, and are connected to the center of the positive electrode and the center of the positive electrode. The laser light is crossed in a space above the substrate support that connects the tips of the negative electrodes. Wavelength as the first laser 6
A 258 nm KrF excimer laser is used. A dye laser is used as the second laser 7, and the wavelength of the laser light is 457 nm.
Choose FIG. 2 shows an enlarged view of the laser beam. First laser 6
The cross section of the laser light from the laser beam is a rectangle having a length of about 50 mm and a width of about 15 mm. The laser light is stopped down by the first lens system 9 disposed outside the chamber 8, and the center of the positive electrode and the tip of the negative electrode are connected. They are gathered in the space above the substrate support to be tied.
As a result, trimethylaluminum in the range of 1 to 100 μm in the space above the substrate support is decomposed into Al atoms to form Al metal gas. The cross section of the laser beam emitted from the second laser 7 is circular with a diameter of about 3 mm,
The laser light is squeezed by a second lens system 10 disposed outside the chamber 8 and collected in a space above the substrate supporting base connecting the center of the positive electrode and the tip of the negative electrode, and is irradiated with the laser light of the first laser. Irradiate Al metal gas generated by 1 to 10μm
Al metal ions are ionized over the length of the to produce Al ⁺ ions.

The cross angle between the laser light from the first laser and the laser light from the second laser does not necessarily have to be a right angle.

The distance between the tip of the negative electrode 4 and the center of the positive electrode 5 is 5 mm,
Apply a voltage of 300V. Thus, the Al ⁺ ions are attracted to the needle-like negative electrode by the action of the electric field and collide with the substrate, forming an Al deposit having a diameter of 1 to 10 μm there.

The firing frequency from the first laser 6 and the second laser 7 is 1 second
About 10 times, the laser beam emitted from the first laser decomposes the trimethylaluminum, and the Al metal gas is emitted by emitting the laser beam from the second laser at the time when the Al metal gas is generated. Ionize. By moving the substrate support 2 on which the substrate 3 is mounted in the horizontal direction continuously at a speed of 0.01 mm / s to 0.1 mm / s, an Al wiring pattern having a width of 1 μm to 10 μm can be formed on the substrate.

The shape of the negative electrode 4 is preferably needle-like because it converges the electric field.
The shape of the positive electrode 5 can be formed in various shapes so as to form a desired electric field distribution. FIG. 3 shows an example.

FIG. 3 (a) shows a disk-shaped positive electrode, and FIG. 3 (b)
Is an example in which a hollow cylindrical positive electrode is arranged around and above a negative electrode.

〔The invention's effect〕

As described above, according to the present invention, it is possible to form a high-purity fine metal wiring that does not contain carbon on a substrate. This can contribute to higher density and higher frequency of the semiconductor device.

[Brief description of the drawings]

 FIG. 1 is a metal wiring device, FIG. 2 is an enlarged view of a laser beam, and FIG. 3 is a shape of an electrode. In the figure, 1 is a fixed table, 2 is a substrate support table, 3 is a substrate, 4 is a negative electrode, 5 is a positive electrode, 6 is a first laser beam, 7 is a second laser beam, 8 is a chamber, and 9 is a first laser beam. The lens system, 10 represents the second lens system.

Claims (2)

(57) [Claims] 1. A fixed base (1) having a horizontal upper surface provided in a gas space of a metal compound; a substrate support (2) mounted on the fixed base and movable in a horizontal direction; A needle-like negative electrode (4) vertically arranged at a lower portion of the table away from the substrate support, and a positive electrode (5) arranged in the gas space above the negative electrode with the substrate support separated from the negative electrode. A) emitting laser light that intersects in the gas space between the positive electrode and the substrate support, and decomposes the gas of the metal compound in the gas space near the intersection to generate a metal gas. A metal wiring device comprising: a laser (6); and a second laser (7) for ionizing the metal gas to generate metal ions. 2. A substrate (3) is mounted on a substrate support (2) mounted on a fixed base (1) having a horizontal upper surface and movable in a horizontal direction. A needle-shaped negative electrode (4) vertically arranged away from the substrate support and a positive electrode (5) arranged in the gas space above the negative electrode with the substrate support separated from the substrate support. An electric field is generated in the space, and a gas of the metal compound is introduced into the space including the substrate. The gas of the metal compound is irradiated with a laser beam emitted from a first laser (6) to generate an electric field in the electric field above the substrate. The metal gas is decomposed to release a metal gas, and the metal gas is irradiated with a laser beam emitted from a second laser (7) to ionize the metal gas to generate metal ions. Attracted on the negative electrode side by the electric field,
A metal that is attached to and deposited on the substrate, and a wiring pattern is formed on the substrate according to the movement of the substrate support by continuously moving the substrate support on which the substrate is mounted. Wiring method.