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Researchers Submit Patent Application, "Microwave Irradiation Apparatus", for Approval

February 26, 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 YAMAMOTO, Nobuhiko (Yamanashi, JP); Kitagawa, Junichi (Yamanashi, JP); Tanaka, Sumi (Yamanashi, JP); Osada, Yuki (Yamanashi, JP), filed on July 23, 2013, was made available online on February 13, 2014.

The patent's assignee is Tokyo Electron Limited.

News editors obtained the following quote from the background information supplied by the inventors: "In a manufacturing process of a semiconductor device, there is a step of forming an impurity diffusion layer by performing impurity activation annealing after implanting impurities into a semiconductor substrate. Conventionally, in the activation treatment of impurities, heat treatment is performed at a high temperature of 1000.degree. C. or more for a short period of time by lamp annealing. However, in recent years, with the miniaturization of the design rule of the semiconductor device, annealing techniques to suppress the thermal diffusion of impurities have been demanded, and lower temperature annealing techniques have been studied. For annealing at low temperatures, annealing by microwave irradiation has been proposed (see, e.g., Japanese Patent Application Publication No. 2009-516375). Further, a modification process of a gate insulating film by microwave irradiation has also been studied.

"In a microwave irradiation apparatus used for such applications, performing open loop control for defining a process with only the processing time and the set microwave power, or controlling the microwave power by feeding back the temperature is generally performed.

"However, in the open-loop control, there is a stability problem during mass production. On the other hand, when controlling the microwave power by feeding back the temperature, process reproducibility is not sufficient."

As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventors' summary information for this patent application: "In view of the above, the present invention provides a microwave irradiation apparatus capable of performing high stability processing during mass production and high process reproducibility.

"In accordance with an aspect of the present invention, there is provided a microwave irradiation apparatus for performing a predetermined process by irradiating a microwave to a target substrate, the microwave irradiation apparatus including: a processing chamber configured to accommodate the target substrate; a support member configured to support the target substrate in the processing chamber; a microwave introduction mechanism configured to generate microwaves and introduce the microwaves into the processing chamber; one or more microwave introduction ports through which the microwave generated by the microwave introducing mechanism is introduced into the processing chamber; one or more electric field sensors configured to measure an electric field formed by the microwave introduced into the processing chamber; and a control unit configured to control powers of the microwaves introduced into the processing chamber through the microwave introduction ports from the microwave introduction mechanism based on the electric field measured by the electric field sensors.

BRIEF DESCRIPTION OF THE DRAWINGS

"The objects and features of the present invention will become apparent from the following description of embodiments, given in conjunction with the accompanying drawings, in which:

"FIG. 1 is a cross-sectional view showing a schematic configuration of a microwave irradiation apparatus in accordance with an embodiment of the present invention;

"FIG. 2 is a block diagram showing a schematic configuration of a high voltage power supply unit in the microwave irradiation apparatus of FIG. 1;

"FIG. 3 is a diagram for explaining an arrangement example of an electric field sensor in an electric field monitoring unit;

"FIG. 4 is a cross-sectional view showing a configuration of the electric field sensor in the electric field monitoring unit;

"FIG. 5 is a block diagram showing a configuration of a control unit in the microwave irradiation apparatus or FIG. 1;

"FIG. 6 is a diagram for explaining a shape of the microwave introduction port;

"FIGS. 7A and 7B are views schematically showing electromagnetic field vectors of the microwave emitted from the microwave introduction port;

"FIG. 8 is a bottom view of the top wall showing a first arrangement example of the microwave introduction ports;

"FIG. 9 is a bottom view of the top wall showing a second arrangement example of the microwave introduction ports;

"FIG. 10 is a bottom view of the top wall showing a third arrangement example of the microwave introduction ports;

"FIGS. 11A and 11B are diagrams showing the results of obtaining the variation in the resistance of the wafer in the radial direction for a temperature rising region (FIG. 11A) and a saturation region (FIG. 11B) when it is subjected to activation treatment by irradiating the microwave to the wafer to optimize the microwave power in a case where the microwave introduction ports are uniformly arranged and a case where the microwave introduction ports are arranged in two zones; and

"FIGS. 12A and 12B are diagrams showing the results of obtaining the variation in the resistance of the wafer in the radial direction for a temperature rising region (FIG. 12A) and a saturation region (FIG. 12B) when it is subjected to activation treatment by irradiating the microwaves to the wafer while varying the power ratio of the microwave between the inner area and the outer area when the microwave introduction ports are arranged in two zones."

For additional information on this patent application, see: YAMAMOTO, Nobuhiko; Kitagawa, Junichi; Tanaka, Sumi; Osada, Yuki. Microwave Irradiation Apparatus. Filed July 23, 2013 and posted February 13, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=6455&p=130&f=G&l=50&d=PG01&S1=20140206.PD.&OS=PD/20140206&RS=PD/20140206

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

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Source: Electronics Newsweekly


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