JP4016105B2 - Manufacturing method of silicon nanowires - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The invention of this application relates to a method for producing a silicon wire useful as an information communication device such as a semiconductor or a member for a nanomachine. More specifically, the invention of this application, cutting, those assembled easily the next generation three-dimensional semiconductor materials, nanomachines for shaft, a method for manufacturing a nanowire suitable silicone on to nano tweezers.
[0002]
[Prior art and its problems]
Conventionally, it is known that silicon nanowires are manufactured by a melting method or the like (Reference 1).
[0003]
However, it is difficult to control the temperature with high accuracy, which is indispensable for obtaining nanowires having a uniform crystal orientation and length in this melting method.
[0004]
Moreover, manufacturing by heating with an electric furnace has also been reported (Reference 2).
[0005]
However, even with this method, the temperature is not uniform and high-precision temperature control is difficult, and it is necessary to add an oxide such as SiO ₂ in addition to silicon in the manufacturing process. Only silicon nanowires can be obtained.
[0006]
[Literature]
Literature 1: Japanese Patent Application No. 2001-333257 Literature 2: ZWPan, ZRDai, L.Xu, STLee, ZLWang, J.Phys.Chem., B2001,105, p2507-2514
[0007]
Therefore, the invention of the present application solves the problems of the prior art as described above, is simple, has a uniform crystal orientation, a constant size, and a nanowire of silicon nanowire or silicon alloy having a linear portion of several millimeters. It is an object to provide a new method capable of manufacturing a wire.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the invention of this application firstly, under the circulation of the carrier gas, silicon or silicon-germanium alloy is evaporated at a temperature lower than its melting point, and the downstream region of the carrier gas circulation to provide a method of manufacturing silicon nanowires, wherein the growing the nanowires silicon emissions at a temperature range of 900 ° C. or higher 1300 ° C. in the following soaking section.
[0009]
The second, in the above method, a method of manufacturing silicon nanowires, characterized in that evaporating the silicon down at exceed 1300 ° C. 1400 ° C. or less of the temperature, the third, the soaking unit The temperature is stabilized with a temperature fluctuation range of 100 ° C. or less as a temperature in the process of lowering the evaporation temperature. Fourth, the carrier gas is an argon gas. the method of manufacturing silicon nanowires, which is a hydrogen gas or a gas mixture, the fifth, the flow rate of the carrier gas is a ^{1cm 3} / ^min~1000cm 3 / min, partitioned soaking section Provided is a method for producing silicon nanowires having a length of 5 cm or more.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The invention of this application has the features as described above, and an embodiment thereof will be described below.
[0011]
In the method of the invention of this application, as described above, in the distribution of a carrier gas, evaporated silicon down at a temperature lower than its melting point, the flow downstream region of the carrier gas in the soaking section 900 ° C. 1300 ° C. of less than by growing the nanowires silicon down temperature range, it is made possible to control the growth rate of these nanowires with high accuracy. Unlike conventional methods, it is not necessary to add foreign substances such as oxides during the reaction process, and a uniform temperature distribution zone is formed, and nanowires are generated at the soaking part as a long nanowire generation region. Therefore, silicon nanowire over the aligned its crystal orientation, size is constant, and the one with a linear shape having a length up to several mm.
[0012]
In the invention of this application, although producing a silicon nanowire over, in the evaporation, the powder or its green compact silicon down, it further of interest also evaporated intended any form of sintered bodies were calcined Can do. This for the evaporation of the case is carried out at a temperature lower than the melting point, in practice, it is preferable to evaporate the silicon down at exceed 1300 ° C. 1400 ° C. or lower.
[0013]
And it is considered that the temperature of the soaking part is stabilized within a temperature fluctuation range of 150 ° C. or less, more preferably 100 ° C. or less, as the temperature in the process of lowering the evaporation temperature.
[0014]
As the carrier gas, a rare gas or a hydrogen gas is considered, but in practice, an argon gas, a hydrogen gas, or a mixed gas thereof is preferable.
[0015]
Which varies also depending on the size and shape of the reactor, in the invention of this application, for example, the flow rate of the carrier gas was 1cm ³ / min~1000cm ³ / min, the classification length of the soaking part and more 5cm that Is considered as a general guide.
[0016]
For example, FIG. 1 is a configuration diagram showing an example of a reaction apparatus for carrying out the method of the invention of this application. Referring to FIG. 1, the reaction tube (1) under the flow of the carrier gas (5) has an evaporation part (A) and a soaking part (B-C), The reaction tube (1) is charged in the heating furnace (2).
[0017]
In the evaporation part (A), for example, silicon (4) is heated and evaporated, and mainly heated in a temperature range of 900 ° C. or more and 1300 ° C. or less in the soaking part (B-C). 3) will grow.
[0018]
FIG. 2 is a diagram illustrating the distance of positions (A), (B), and (C) and the temperature distribution in this reactor. In this example, in the evaporation part (A), silicon (4) is evaporated at a temperature (1340 ° C.) lower than the melting point (mp 1420 ° C.) of silicon (4). The positions (B) and (C) are maintained at 1270 ° C. and 1290 ° C., respectively, and the positions (B) and (C) constitute a soaking part.
[0019]
Therefore, in the following, the embodiment shown in the temperature distribution of FIG. Of course, the invention is not limited by the following examples.
[0020]
【Example】
Finely pulverize silicon powder with a purity of 99.999% in a mortar to 300 mesh (about 50 μm particle size). The obtained fine powder silicon is pre-sintered at 1170 ° C. for 2 hours while maintaining a reduced pressure of 10 ⁻⁶ Torr. The pre-sintered silicon is put in an alumina boat in the reaction tube (1) of the reactor illustrated in FIG. Further, the nanowire growth substrate is set on the downstream side in the reaction tube (1).
[0021]
Silicon (4) is evaporated at an atmospheric pressure of 1340 ° C. under an argon gas flow rate of 20 cm ³ / min.
[0022]
The temperature profile as shown in FIG. 2 was obtained by setting the temperature soaking section from the point (B) 10 cm downstream from the evaporation part (A) to the point (C) further 10 cm downstream.
[0023]
3 and 4 show scanning electron microscope (SEM) images of the silicon nanowires generated and generated in the soaking part.
[0024]
The generated silicon nanowire has a linear shape of several mm as is apparent from FIGS. Further, when observed with a transmission electron microscope, as shown in FIG. 5, the silicon nanowires are linear and crystalline as shown in FIG. It is confirmed that the diameter is several 50 nm to 100 nm and the length is several mm.
[0025]
【The invention's effect】
As described above in detail, the invention of this application, a simple method, cutting, etc. is easy assembly, manufacture next generation three-dimensional semiconductor materials, nanomachines for shaft, a suitable silicon nanowires over a member, such as a nanotweezers can do.
[Brief description of the drawings]
FIG. 1 is a configuration diagram illustrating a reaction apparatus.
FIG. 2 is a diagram illustrating a position and a temperature profile in the apparatus of FIG. 1;
FIG. 3 is a scanning electron micrograph of silicon nanowires.
FIG. 4 is an enlarged scanning electron micrograph.
FIG. 5 is a view showing a transmission electron micrograph and electron diffraction results of silicon nanowires.
[Explanation of symbols]
1 reaction tube 2 heating furnace 3 silicon nanowire 4 silicon 5 carrier gas

Claims (5)

In the distribution of a carrier gas, and evaporated at low temperature silicon emissions than its melting point, growing the nanowires silicon emissions at a temperature range of 900 ° C. or higher 1300 ° C. or less at a soaking part of the flow downstream region of the carrier gas A method for producing silicon nanowires. Method for producing a silicon nanowire of claim 1, wherein evaporating the silicon down beyond 1300 ° C. at 1400 ° C. or lower.   The method for producing silicon nanowires according to claim 1 or 2, wherein the temperature of the soaking part is stabilized within a temperature fluctuation range of 100 ° C or less as a temperature in the process of lowering the evaporation temperature.   The method for producing silicon nanowires according to any one of claims 1 to 3, wherein the carrier gas is argon gas, hydrogen gas, or a mixed gas thereof. The flow rate of the carrier gas is a 1cm ³ / min~1000cm ³ / min at atmospheric pressure, either silicon nano of claims 1, wherein the segment length of the soaking part is 5cm above 4 Manufacturing method of wire.

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