News Column

Researchers Submit Patent Application, "Film Deposition Apparatus and Film Deposition Method", for Approval

August 20, 2014



By a News Reporter-Staff News Editor at Electronics Newsweekly -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventors Kato, Hitoshi (Iwate, JP); Honma, Manabu (Iwate, JP); Takeuchi, Yasushi (Iwate, JP), filed on April 3, 2014, was made available online on August 7, 2014.

The patent's assignee is Tokyo Electron Limited.

News editors obtained the following quote from the background information supplied by the inventors: "The present invention relates to a film deposition apparatus and a film deposition method for depositing a film on a substrate by carrying out plural cycles of supplying in turn at least two source gases to the substrate in order to form a layer of a reaction product.

"As a film deposition method in a semiconductor fabrication process, there has been known a so-called Atomic Layer Deposition (ALD) or Molecular Layer Deposition (MLD). In the ALD method, plural cycles are repeated that includes a first reaction gas adsorption step where a first reaction gas is supplied to a vacuum chamber in order to allow the first reaction gas to be adsorbed on a surface of a semiconductor wafer (referred to as a wafer hereinafter), a first purge step where the first reaction gas is purged from the vacuum chamber using a purge gas, a second reaction gas adsorption step where a second reaction gas is supplied to a vacuum chamber in order to allow the second reaction gas to be adsorbed on the surface of the wafer, and a second purge step where the second reaction gas is purged from the vacuum chamber using the purge gas, thereby depositing a film through reaction of the first and the second reaction gases on the surface of the wafer. This method is advantageous in that the film thickness can be controlled at higher accuracy by the number of cycles of alternately supplying the gases, and in that the deposited film can have excellent uniformity over the wafer. Therefore, this deposition method is thought to be promising as a film deposition technique that can address further miniaturization of semiconductor devices.

"As a film deposition apparatus for carrying out such a film deposition method, Patent Document 1 discloses a film evaporation apparatus provided with a rotatable susceptor that has a disk shape and provided in a reaction chamber and a gas supplying portion arranged to oppose the susceptor. The gas supplying portion includes one circular center showerhead arranged in an upper center area of the reaction chamber and ten sector-shaped showerheads arranged to surround the center showerhead. One of the ten showerheads supplies a first source gas; another one of the ten showerheads that is located symmetrically in relation to the showerhead supplying the first source gas with respect to the center circular showerhead supplies a second source gas; and the remaining sector showerheads and the circular center showerhead supply a purge gas. In addition, plural evacuation openings are arranged along an inner surface of the reaction chamber, and thus the gases supplied from the showerheads flow in outward radial directions and are evacuated from the plural evacuation openings. While reducing intermixture of the first source gas and the second source gas in the reaction chamber in such a manner, the source gases are substantially switched by rotating the susceptor, thereby eliminating the need of the purge steps.

"In addition, Patent Document 2 below discloses a film deposition apparatus provided with a substrate supporting platform that is rotatable and vertically movable in a reaction chamber and supports four substrates thereon, and four reaction spaces defined above the substrate supporting platform. In this film deposition apparatus, the substrate supporting platform is rotated until the substrates thereon can be positioned below the corresponding reaction spaces, stopped and moved upward in order to expose the substrates to the corresponding reaction spaces. Then, one reaction gas is supplied in a predetermined period of time (in pulse) to at least one of the reaction spaces, and the other reaction gas is supplied in a predetermined period of time (in pulse) to another one of the reaction spaces. Next, the reaction spaces to which the corresponding reaction gases are supplied are purged with a purge gas. While the purge gas is being supplied, the substrate supporting platform is moved downward and then rotated until the substrates are positioned below the subsequent reaction spaces. In the following, the substrate supporting platform is moved upward and the same operations are repeated. Namely, the reaction gases and the purge gas are supplied in a time-divisional manner, and do not flow at the same time. In addition, when the substrate is exposed to the reaction space to which the reaction gas is supplied, the substrate supporting platform is sealed by a member extending from the ceiling member of the reaction chamber, so that the substrate rather than the substrate supporting platform is exposed to the reaction gas. With this, no film deposition takes place on the substrate supporting platform, thereby reducing particle generation. Patent Document 1: Korean Patent Application Laid-Open Publication No. 10-2009-0012396. Patent Document 2: United States Patent Application Publication No. 2007/0215036."

As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventors' summary information for this patent application: "In the film deposition apparatus disclosed in Patent Document 1, even if the reaction gases are made to flow in outward radial directions by providing plural evacuation openings along the inner circumferential wall of the reaction chamber, because the gases are likely to flow in a rotation direction of the susceptor when the susceptor is rotated, especially at higher speeds, the intermixture of the first source gas and the second source gas is not sufficiently suppressed. When the intermixture takes place, an appropriate ALD cannot be realized. Because of such a circumstance, a rotation speed of 3 revolutions per minute (rpm) through 10 rpm is exemplified in Patent Document 1. Such a low rotation speed is not acceptable from a viewpoint of production throughput.

"In addition, in the film deposition method disclosed in Patent Document 2, it takes a relatively long time to purge the reaction space. Moreover, because cycles of the substrate supporting platform being rotated, stopped, moved upward, and moved downward are repeated and the reaction gases are intermittently supplied, it is difficult to increase production throughput.

"The present invention has been made in view of the above, and provides a film deposition apparatus and a film deposition method that are capable of impeding intermixture of a first reaction gas and a second reaction gas even when a rotation speed of a turntable is increased, thereby improving throughput.

"According to a first aspect of the present invention, there is provided a film deposition apparatus for depositing a film on a substrate by performing plural cycles of alternately supplying at least two kinds of reaction gases that react with each other on the substrate to produce a layer of a reaction product in a chamber. The film deposition apparatus includes a turntable that is rotatably provided in a chamber and includes a substrate receiving area in which a substrate is placed; a separation member that extends to cover a rotation center of the turntable and two different points on a circumference of the turntable above the turntable, thereby separating the inside of the chamber into a first area and a second area, wherein a pressure in a space between the turntable and the separation member may be maintained higher than pressures of the first area and the second area by use of a first separation gas supplied to the space; a pressure control portion that maintains along with the separation member the pressure in the space between the turntable and the separation member higher than the pressures in the first area and the second area; a first reaction gas supplying portion that is provided in the first area and supplies a first reaction gas toward the turntable; a second reaction gas supplying portion that is provided in the second area and supplies a second reaction gas toward the turntable; a first evacuation port that evacuates therefrom the first reaction gas supplied in the first area and the first separation gas supplied to the space between the separation member and the turntable by way of the first area, after the first reaction gas and the first separation gas converge with each other in the first area; and a second evacuation port that evacuates therefrom the second reaction gas supplied in the second area and the first separation gas supplied to the space between the separation member and the turntable by way of the second area, after the second reaction gas and the first separation gas converge with each other in the second area.

"According to a second aspect of the present invention, there is provided a film deposition method for depositing a film on a substrate by carrying out plural cycles of alternately supplying at least two kinds of reaction gases that react with each other on the substrate to produce a layer of a reaction product in a chamber. The film deposition method includes steps of placing a substrate in a substrate receiving area of a turntable that is rotatably provided in the chamber; supplying a first separation gas to a space between the turntable and a separation member that extends to cover a rotation center of the turntable and two different points on a circumference of the turntable above the turntable, thereby separating the inside of the chamber into a first area and a second area, so that a pressure in the space is greater than pressures of the first area and the second area; supplying a first reaction gas from a first gas supplying portion arranged in the first area toward the turntable; supplying a second reaction gas from a second gas supplying portion arranged in the second area toward the turntable; evacuating the first reaction gas supplied to the first area and the first separation gas from the space between the turntable and the separation member by way of the first area, after the first reaction gas and the first separation gas converge in the first area; and evacuating the second reaction gas supplied to the second area and the first separation gas from the space between the turntable and the separation member by way of the second area, after the second reaction gas and the first separation gas converge in the second area.

BRIEF DESCRIPTION OF THE DRAWINGS

"FIG. 1 is a cross-sectional view of a film deposition apparatus according to an embodiment of the present invention;

"FIG. 2 is a perspective view schematically illustrating the inside of a vacuum chamber of the film deposition apparatus of FIG. 1;

"FIG. 3 is a plan view of the vacuum chamber of the film deposition apparatus of FIG. 1;

"FIG. 4 has cross-sectional views illustrating an example of a separation area, a first area, and a second area in the vacuum chamber of the film deposition apparatus of FIG. 1;

"FIG. 5 is another cross-sectional view of the vacuum chamber of the film deposition apparatus of FIG. 1;

"FIG. 6 has explanatory views for explaining a size of a separation area in the vacuum chamber of the film deposition apparatus of FIG. 1;

"FIG. 7 illustrates results of computer simulation carried out on the pressure in the separation area in the vacuum chamber of the film deposition apparatus of FIG. 1;

"FIG. 8 is a schematic view of a pressure distribution in the separation area in the vacuum chamber of the film deposition apparatus of FIG. 1;

"FIG. 9 is another cross-sectional view of the vacuum chamber of the film deposition apparatus of FIG. 1;

"FIG. 10 is a partial broken perspective view illustrating the vacuum chamber of the film deposition apparatus of FIG. 1;

"FIG. 11 is a schematic view of a reaction gas nozzle and a nozzle cover attached to the reaction gas nozzle in the vacuum chamber of the film deposition apparatus of FIG. 1;

"FIG. 12 is an explanatory view of the reaction gas nozzle with the nozzle cover of FIG. 11;

"FIG. 13 is an explanatory view illustrating a gas flow pattern in the vacuum chamber of the film deposition apparatus of FIG. 1;

"FIG. 14 is another cross-sectional view of the vacuum chamber of the film deposition apparatus of FIG. 1;

"FIG. 15 is yet another cross-sectional view of the vacuum chamber of the film deposition apparatus of FIG. 1;

"FIG. 16 is a plan view illustrating a flow regulatory plate to be used in the vacuum chamber of the film deposition apparatus of FIG. 1;

"FIG. 17 is a cross-sectional view of the flow regulatory plate of FIG. 16;

"FIG. 18 illustrates results of computer simulations carried out on the pressure in the separation area in the vacuum chamber of the film deposition apparatus of FIG. 1, comparing pressure differences according to evacuation ports;

"FIG. 19 illustrates a modified example of the reaction gas nozzle and a separation gas nozzle in the vacuum chamber of the film deposition apparatus of FIG. 1;

"FIG. 20 illustrates another modified example of the reaction gas nozzle and a separation gas nozzle in the vacuum chamber of the film deposition apparatus of FIG. 1;

"FIG. 21A illustrates a modified example of the separation area in modified example of the reaction gas nozzle and a separation gas nozzle in the vacuum chamber of the film deposition apparatus of FIG. 1;

"FIG. 21B is a cross-sectional view taken along an E-E line in FIG. 21A;

"FIG. 22 illustrates another modified example of the separation area;

"FIG. 23 illustrates another modified example of the separation area;

"FIG. 24 illustrates another modified example of the separation area;

"FIG. 25 illustrates another modified example of the separation area;

"FIG. 26 illustrates another modified example of the separation area;

"FIG. 27 illustrates another modified example of the separation area;

"FIG. 28 illustrates a modified example of the nozzle cover of FIG. 11;

"FIG. 29 illustrates another modified example of the nozzle cover;

"FIG. 30 illustrates another modified example of the nozzle cover;

"FIG. 31 is a cross-sectional view of a film deposition apparatus according to another embodiment of the present invention; and

"FIG. 32 is a schematic view of a wafer processing apparatus including a film deposition apparatus according to an embodiment of the present invention."

For additional information on this patent application, see: Kato, Hitoshi; Honma, Manabu; Takeuchi, Yasushi. Film Deposition Apparatus and Film Deposition Method. Filed April 3, 2014 and posted August 7, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=2605&p=53&f=G&l=50&d=PG01&S1=20140731.PD.&OS=PD/20140731&RS=PD/20140731

Keywords for this news article include: Electronics, Semiconductor, Tokyo Electron Limited.

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Source: Electronics Newsweekly


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