KR101020782B1 - Silicon nanocrystaline structure from amorphous silicon film using focused electron-beam and method for preparing the same - Google Patents

Abstract

The present invention provides a method of depositing an amorphous silicon thin film (a-Al _x Si _{1- x} , 0.025 ≦ _x ≦ 0.10) containing aluminum, and irradiating a focused electron beam to the deposited silicon thin film of step 1 to obtain silicon. Method for producing a silicon nanocrystal structure using a focused electron beam, comprising the step of forming a nanocrystal. According to the manufacturing method of the present invention, when the focused electron beam is irradiated on the amorphous silicon thin film to which aluminum is added, the silicon nanocrystal structure may be formed by precisely adjusting the size and position of the nanocrystals. Therefore, it is possible to develop a single silicon integrated device, a silicon-based optical device, and an optoelectronic device having a nanoscale size by using the method of manufacturing a silicon nanocrystal structure of the present invention.

Silicon nanocrystalline structure, focused electron beam, aluminum

Description

Silicon nanocrystal structure from amorphous silicon film using focused electron-beam and method for preparing the same}

The present invention relates to a method for producing a silicon nanocrystal structure from an amorphous silicon thin film using a focused electron beam and to a silicon nanocrystal structure produced thereby.

Silicon semiconductors do not have luminescent properties in the visible region and are not easy to control optical properties. However, in the case of controlling the silicon particles in the nano-sized structure in the silicon semiconductor, research that not only obtains the light emission characteristics, but also to control the emission wavelength in the visible light region has attracted attention.

Recently, researches for integrating semiconductor lasers, photodetectors, optical waveguides, optical switch devices, and optical amplifiers developed as semiconductor devices into one chip have been conducted. Accordingly, researches are being made to apply silicon memory integration technology, which has been highly advanced, to photoelectric integrated technology.

However, bulk silicon is an indirect transition semiconductor, in which all doped gallium arsenide (GaAs), indium phosphorus (InP), etc., which have been used in the conventional photoelectric integrated technology, are directly transitioned. Unlike electrons being converted to light, since the horizontal transition is included as overheating and vibration, almost no light emission characteristics can be realized at room temperature, and thus, even when integrated using silicon memory integrated technology, there is a problem in that light emission efficiency is lowered.

As a solution to this problem, a study on the fabrication of nanocrystalline silicon and its use in photo-integrated devices has been published by Canham Group [Appl. Phys. Lett., 57, 1046 (1990)]. In this study, nanocrystalline silicon was revealed to emit light at a wavelength of 600-800 nm. This main factor is explained by the quantum confinement effect (QCE).

As bulk silicon is reduced in size to nanocrystalline silicon, the Fermi wavelength (wavelength corresponding to the Fermi level) becomes similar to the actual size of the material. As a result, the electrons in the silicon have spatially limited motion, and low-dimensional characteristics and anisotropy appear to make the wave characteristics of the electrons prominent, and the quantum limiting effect of discontinuous energy levels due to limited motion and boundary. The QCE tends to increase as the size of the nanocrystals becomes smaller, and when the size of the crystals is 2 nm, the energy band gap increases to 2.7 eV or more, and the phototransmittance also increases significantly compared to bulk silicon [Phys. Rev. B, 48, 7 (1993). In addition, the nanocrystals have higher mobility than amorphous silicon because they are crystalline, and high efficiency photoelectric integrated devices can be realized because of low degradation.

As such, the technology for forming nanocrystalline silicon from amorphous silicon is recognized as an important technology in the manufacture of highly integrated circuit semiconductors, information storage media, displays, biochips and optical devices. The thin film of the conventional nanocrystalline silicon optical device has been prepared by a method such as electrochemical oxidation, plasma chemical vapor deposition, sputtering, ion implantation. However, these methods have the disadvantage that it is difficult to precisely control the size and position of the nanocrystals.

US Patent Application 2005-0139445 discloses a method of doping a metal ion, which acts as a catalyst for crystallizing amorphous silicon, to crystallized by irradiating a laser. Japanese Patent Laid-Open No. 2000-021773 discloses a method of crystallizing an electron beam by irradiating an SiO ₂ substrate at a temperature of 400 ° C. or higher. The patent discloses a method for crystallizing amorphous silicon, but has the disadvantage of heating to a high temperature to form nanocrystals.

Therefore, the inventors of the present invention have found out that the silicon nanocrystal structure can be formed from the amorphous silicon by irradiating a focused electron beam at a low temperature to the amorphous silicon to which aluminum is added, and thus, the present invention has been developed.

An object of the present invention is to provide a method for producing a silicon nanocrystal structure from an amorphous silicon thin film using a focused electron beam.

Another object of the present invention is to provide a method for producing a silicon nanocrystal structure from an amorphous silicon thin film using a focused electron beam, which can control the structure, size and position of the nanocrystalline silicon using a focused electron beam.

In order to solve the above object, the present invention is a silicon nanocrystal structure formed by depositing an amorphous silicon thin film to which aluminum is added on a silicon wafer and irradiating a focused electron beam to the deposited silicon thin film at a temperature of 200 to 400 ℃ It provides a manufacturing method.

The silicon nanocrystal structure manufactured according to the present invention is manufactured by adjusting the structure, size, and position of nanocrystalline silicon by irradiating a focused electron beam at low temperature, and thus, a single silicon integrated device, a silicon-based optical device, and a nanoscale size. It enables the development of optoelectronic devices and has the effect that can be used in next-generation silicon, such as next-generation semiconductors, displays, and intelligent robots.

The present invention provides a method for producing a nanocrystalline structure from an amorphous silicon thin film using a focused electron beam.

According to the present invention, a method of manufacturing a nanocrystalline structure from an amorphous silicon thin film using a focused electron beam includes depositing an aluminum-doped amorphous silicon thin film (a-Al _x Si _{1 -x} , 0.025 ≦ _x ≦ 0.10) on a silicon wafer. (Step 1) and irradiating a focused electron beam to the deposited silicon thin film of Step 1 to form a silicon nanocrystals (Step 2).

Hereinafter, a method for manufacturing a nanocrystalline structure from an amorphous silicon thin film using the focused electron beam of the present invention will be described in detail step by step.

Step 1 is a step of depositing an amorphous silicon thin film added with aluminum on a silicon wafer. The step of depositing the amorphous silicon thin film to which the aluminum is added onto the silicon wafer may be performed by placing an aluminum chip on the silicon target on the silicon wafer and then sputtering at the same time. The sputtering method is preferably to use the RF magnetron sputtering method.

2.5 to 10% of aluminum is preferably added to the amorphous silicon thin film. The aluminum content added to the amorphous silicon thin film may be controlled by the number of aluminum chips used. By adding aluminum to the amorphous silicon thin film, nanocrystals can be formed by a focused electron beam at low temperatures. When the aluminum content added to the amorphous silicon thin film is added outside the above range, there is a problem that aluminum is mixed in the nanocrystalline silicon formed.

Step 2 is a step of irradiating a focused electron beam on the deposited silicon thin film of step 1 to form a silicon nanocrystal. The current density of the focused electron beam irradiated onto the silicon thin film deposited in step 2 is preferably 15 to 30 pA / cm ² . The current density of the focused electron beam irradiated onto the silicon thin film is 15 pA / cm ² If less than, the crystallization may not occur in the silicon thin film, and the current density of the focused electron beam irradiated to the silicon thin film is 30 pA / cm ^2. Exceeding In this case, the silicon thin film may be in a liquid state before crystallization occurs in the silicon thin film. In the step 2, it is preferable to irradiate the focused electron beam on the silicon thin film using a transmission electron microscope (TEM), a high voltage electron microscope (HVEM), etc. In the case of a device capable of adjusting the density, it can be used in the present invention.

Focused electron beams have the advantage of being energetic particles and at the same time having an electrical charge. Therefore, when the focused electron beam is irradiated to a specific portion of the amorphous silicon thin film to which aluminum is added, nanocrystals may be formed at a specific position (see FIG. 9).

In step 2, a silicon nanocrystal structure in which nanocrystals are formed is formed by irradiating a focused electron beam on the silicon thin film to which aluminum is added in step 1 for 30 to 600 seconds. Nanocrystals start to be irradiated on the silicon thin film to which aluminum is added for 30 seconds or more, and nanocrystal growth does not continuously occur when irradiated for more than 600 seconds.

Nanocrystal formation reaction in the step 2 is preferably carried out at 200 ~ 400 ℃. The size, shape and content of the nanocrystals formed according to the method of manufacturing the silicon nanocrystal structure of the present invention are sensitively changed depending on the temperature as well as the aluminum content. For example, when irradiating a focused electron beam to a silicon thin film at 200 ° C, a silicon nanocrystal having an average particle diameter of 10 nm or less is formed, and when irradiating a focused electron beam at 400 ° C, a three-dimensional rod-shaped silicon nanocrystal is formed. It is formed on the surface of the thin film. In addition, the nanocrystal volume ratio in the thin film may vary between 9.2 to 94.8% when the temperature increases in the range of 100 to 400 ℃.

In addition, the present invention provides a silicon nanocrystal structure prepared by irradiating a focused electron beam on an amorphous silicon thin film according to the method of manufacturing the silicon nanocrystal structure. The average size of the nanocrystals formed on the nanocrystal structure is 5 ~ 15 nm. The nanocrystalline structure may be formed in the form of nanotips.

Hereinafter, the embodiment of the present invention will be described in more detail. However, the following examples are merely to illustrate the invention, but the content of the present invention is not limited by the following examples.

< Example  1> Focus  Fabrication of Silicon Nanocrystal Structures by Electron Beam Irradiation

1) Deposition of Amorphous Silicon Thin Film with Aluminum Added on Silicon Wafer (Step 1)

A cylindrical silicon target having a diameter of 2 inches and a thickness of 5.0 mm and an aluminum chip having a size of 1.0 × 1.0 × 0.5 mm were used, and the aluminum chip was placed on a silicon target to sputter the silicon target and the aluminum chip simultaneously. The aluminum content was adjusted to 2.5 and 5.0% using 4 (m) aluminum chips and 8 (n) aluminum chips. The later using an RF magnetron sputtering technique 2.5% aluminum has a thickness of 100 nm on a silicon wafer doped a-Al _{0 .025} Si _{0 .975} films and aluminum 5.0% by the addition of a-Al _0.05 Si _0.95 Thin Film Was deposited.

2) Formation of Silicon Nanocrystals by Focused Electron Beam Irradiation (Step 2)

The said aluminum 2.5%, is added a-Al _{0 .025} Si _{0 .975} at 200 ℃ temperature for the thin film 30, 60, 120, 300, and 600 seconds using a transmission electron microscope, the current density is 15.7 pA / cm ² of The focused electron beam was irradiated. Crystallization of the amorphous phase was performed using a transmission electron microscope (TEM) equipped with a specimen temperature controller.

< Example  2> Focus  Fabrication of Silicon Nanocrystal Structures by Electron Beam Irradiation

Aluminum 2.5% is added in step a-1 Al Si _{0 .025 0 .975} manufacturing a thin film, and wherein in step 2 a Si-Al _{0 .025 0 .975} at 400 ℃ temperature for the thin film 30, 60, 120 A silicon nanocrystal structure was prepared in the same manner as in Example 1, except that the focused electron beam was irradiated for 300 and 600 seconds.

< Example  3> Focus  Fabrication of Silicon Nanocrystal Structures by Electron Beam Irradiation

Aluminum 2.5% is added in step _{1 a-Al 0 .025 Si 0} .975 manufacturing a thin film, and the a-Al _{0 .025} Si _{0 .975} for the thin film 30, 60, 120, 300, and 600, in step 2, A silicon nanocrystal structure was prepared in the same manner as in Example 1, except that the focused electron beam was irradiated at 300 ° C. for 2 seconds.

< Example  4> Focus  Fabrication of Silicon Nanocrystal Structures by Electron Beam Irradiation

The aluminum is added _{5.0% a-Al 0 .050 Si} 0 .950 thin films prepared in Step 1 in the step 2, the focused electron beam at 400 ℃ for 600 seconds with respect to the a-Al _{0 .050} Si _{0 .950} thin film A silicon nanocrystal structure was prepared in the same manner as in Example 1 except for the investigation.

< Example  5> Focus  Fabrication of Silicon Nanocrystal Structures by Electron Beam Irradiation

Preparation of aluminum 10% is added to the a-Al _{0 .10} Si _{0 .90} thin film in the step 1, except that in step 2, irradiated with an electron beam focused at 200 ℃ for 600 seconds with respect to the thin film a-Al _0.10 Si _0.90 A silicon nanocrystal structure was prepared in the same manner as in Example 1.

< Example  6> Focus  Fabrication of Silicon Nanocrystal Structures by Electron Beam Irradiation

Preparation of aluminum 10% is added to the a-Al _{0 .10} Si _{0 .90} thin film in the step 1, except that in step 2, irradiated with an electron beam focused at 400 ℃ for 600 seconds with respect to the thin film a-Al _0.10 Si _0.90 A silicon nanocrystal structure was prepared in the same manner as in Example 1.

< Comparative example  1> Focus  Fabrication of Silicon Nanocrystal Structures by Electron Beam Irradiation

Preparing a 5% aluminum is added a-Al _{0 .050} Si _{0 .950} thin film in the step 1, except that in step 2, irradiated with an electron beam focused at 500 ℃ for 300 seconds with respect to the thin film a-Al _0.050 Si _0.950 A silicon nanocrystal structure was prepared in the same manner as in Example 1.

< Comparative example  2> Focus  Fabrication of Silicon Nanocrystal Structures by Electron Beam Irradiation

In the aluminum 15% is added to a-Si Al _{0 .15 0 .85} producing a thin film, and the step 2 in step 1, the focused electron beam at 200 ℃ for 600 seconds with respect to the a-Al _{0 .15} Si _{0 .85} thin film A silicon nanocrystal structure was prepared in the same manner as in Example 1 except for the investigation.

< Comparative example  3> Focus  Fabrication of Silicon Nanocrystal Structures by Electron Beam Irradiation

In the manufacture of aluminum 15% is added to the a-Al _{0 .15} Si _{0 .85} thin film in the step 1, and step 2, the focused electron beam at 400 ℃ for 600 seconds with respect to the a-Al _{0 .15} Si _{0 .85} thin film A silicon nanocrystal structure was prepared in the same manner as in Example 1 except for the investigation.

< Comparative example  4> Focus  Fabrication of Silicon Nanocrystal Structures by Electron Beam Irradiation

Aluminum 2.5% is added in step _{1 a-Al 0 .025 Si 0} .975 manufacturing a thin film, and the a-Al _{0 .025} Si _{0 .975} for the thin film 30, 60, 120, 300, and 600, in step 2, A silicon nanocrystal structure was manufactured in the same manner as in Example 1, except that the focused electron beam was irradiated at 100 ° C. for 2 seconds.

<Analysis> Analysis of Silicon Nanocrystal Structure

1) Analysis of amorphous silicon thin film of step 1

A TEM image of the amorphous silicon thin film to which aluminum was added in Step 1 of Example 1 was measured using a transmission electron microscope is shown in FIG. As shown in FIG. 1A, it can be seen that the silicon thin film before irradiation with the focused electron beam is in an amorphous phase.

FIG. 2 shows X-ray optoelectronics for amorphous silicon thin films added with aluminum by increasing the number of aluminum chips to 4 (m) and 8 (n) in step 1 of Example 1 to adjust aluminum content by 2.5 and 5.0%. XPS spectral graph measured using spectroscopy (XPS). XPS data were measured using PHI 5700 electron spectroscopy for chemical analysis (ESCA) analysis using non-monochromatic MgKα radiation (300 W, 15 kV, hv = 1253.6 eV) as the excitation source. The XPS spectrum in FIG. 2 represents the binding energy of Si 2p and Al 2p in the amorphous silicon thin film. In FIG. 2A, the maximum peak appeared at 99.9 eV. The peak is due to the presence of silicon. As shown in FIG. 2B, the Al 2p peak observed at 72.9 eV indicates the presence of aluminum in the thin film. In addition, it can be seen that when the number of used aluminum chips is increased to 4 (m) and 8 (n), the aluminum content increases to 2.5 and 5.0%.

Example 2 of the step shown in the _{1 a-Al 0 .025 Si 0} .975 of a TEM image measurement with a transmission electron microscope on the thin film Fig 4 (a). As shown in (a) of FIG. 4, the electron diffraction pattern (SAED) of the selected portion is composed of a diffused ring having an amorphous phase.

2) Analysis of silicon nanocrystal structure after focused electron beam irradiation in step 2

High-Resolution TEM (HRTEM) images of silicon nanocrystal structures formed at 30, 60, 120, 300, and 600 seconds after irradiation with the focused electron beam in Example 1 were respectively shown in FIGS. 1B, 1C, and 3D. ), (e) and (f). As shown in the figure, after irradiation with the focused electron beam, it can be seen that silicon nanocrystals having a size of less than 10 nm were formed in the amorphous portion. Latice fringes appeared on the crystal parts. Also, as the electron beam irradiation time increased, the content of nanocrystals increased. In FIG. 1 (f), a substantial portion of the amorphous phase is changed into a nanocrystalline phase having a size of 10 nm.

Figure 3 Example 1 2.5% Aluminum is added in the a-Al _{0 .025} Si _{0 .975} irradiating an electron beam focused on a thin film before and after ((a) in Fig. 3) ((b) in Fig. 3) A graph showing each electron energy loss spectrum (EELS). It can be seen that at 99.9 eV indicated by the arrow, the intensity of the peak increased after the focused electron beam irradiation. These results show a change in the chemical bonding characteristics of the film during irradiation of the focused electron beam.

High-Resolution TEM (HRTEM) photographs of silicon nanocrystal structures formed at 30, 60, 120, 300, and 600 seconds after irradiation with the focused electron beam in Example 2 are respectively shown in FIGS. 4B, 4C, and 4D. ), (e) and (f). The circled portion of FIG. 4B indicates that crystals are formed by irradiating the focused electron beam for 30 seconds. It can be seen from the figure that polycrystals are formed on the thin film after irradiating the focused electron beam.

5 is a TEM image of a nano-crystal a-Al _{0 .050} Si _{0 .950} thin film produced by irradiating a focused electron beam for 600 seconds in Example 4. Figure 5 (a) shows a variety of three-dimensional nano-crystal silicon structure formed on a-Al _{0 .050} Si _{0 .950} thin film. FIG. 5B is a magnified photograph of the rod-shaped silicon nanocrystal structure shown in section 1 of FIG. FIG. 5C is an HRTEM photograph showing a section P in FIG. 5B. The crystal plane is formed so that the surface of the thin film is composed of {111} and {011}. FIG. 5D illustrates an interface (section Q of FIG. 5B) between the rod-shaped silicon nanocrystal structure and the surface of the thin film. It shows the growth of the rod-shaped silicon nanocrystal structure (N) at the portion indicated by M. This is indicative of the crystallized portion, which indicates that the crystallized portion is expanded to the silicon nanocrystal structure (N). On the other hand, the surface of the thin film denoted by L represents an amorphous phase in which no crystallization occurs. The lattice plane of the silicon nanocrystal structure (silicon rod form) (N) was observed to be continuous with the lattice plane of the crystallization section (M). The rod-shaped silicon nanocrystal structure N of FIG. 5E was grown by focused electron beam irradiation in the section M. FIG.

FIG. 6 is a graph showing electron energy loss values of the sections irradiated with the focused electron beams and the electron energy loss values of the sections not irradiated with the focused electron beams according to the fourth embodiment. Spectra (a) and (b) of FIG. 6 respectively show electron energy loss values in the section where the focused electron beam is irradiated and electron energy loss values in the section where the focused electron beam is not irradiated. Spectrum (c) of FIG. 6 is a value measured from the thin film surface (similar to the section L of FIG. 5E) near the rod-shaped silicon nanocrystal structure. In the case of irradiating a focused electron beam on a silicon thin film, a peak is observed at 99.9 eV. However, the electron energy loss spectrum of the section not irradiated with the focused electron beam showed a peak at 73.5 eV, indicating that aluminum is present. 6 shows that when the focused electron beam is irradiated onto the silicon thin film, the aluminum content decreases rapidly at the nucleation site. The process of generating such nanocrystals can be more simply understood through FIG. FIG. 9 is a view schematically illustrating a process of forming nanocrystals in an Al / a-Si thin film by focused electron beam irradiation. As shown in FIG. 9, the focused electron beam is irradiated onto the Al / a-Si thin film (FIG. 9 (a)), and aluminum atoms are removed in the section where the focused electron beam is irradiated, and the atoms are rearranged to generate crystal nuclei. (FIG. 9B), the crystal grows from the surface to the vacuum portion (FIG. 9C).

7 and 8 are HRTEM photographs of the silicon nanocrystal structures prepared in Examples 5 and 6. FIG. As shown in Figures 7 and 8, it can be seen that the nanotip is grown when the focused electron beam for 600 seconds at 200 to 400 ℃.

However, as shown in FIG. 11, the amorphous phase was observed in the silicon nanocrystal structure prepared by irradiating a focused electron beam at 500 ° C. in Comparative Example 1. As such, when the focused electron beam is irradiated in a state exceeding 400 ° C., an amorphous phase may be mixed in the silicon nanocrystal structure. In addition, in Comparative Examples 2 and 3 in which the aluminum content was added to the amorphous silicon thin film in excess of 10%, crystalline aluminum / silicon alloy nanotips were produced or amorphous nanotips were produced.

< Experimental Example > Focus  When the temperature is different during electron beam irradiation Amorphous  Silicon nanocrystals formed on silicon thin film Volume ratio  Measure

For each of Example 1, Example 2, Example 3 and Comparative Example 4, the crystal volume ratio generated while increasing the irradiation time was measured using an auto-correlation function, and the results are shown in FIG. Indicated. As shown in FIG. 10, when the focused electron beam was irradiated at 400 ° C. for 120 seconds, the total volume converted from the amorphous phase to the crystalline phase was about 77.5%, and when the focused electron beam was irradiated at 200 ° C. for 120 seconds, the total volume converted to the crystal phase. Was about 22.5%. As such, it can be seen that the irradiation of the focused electron beam at 400 ° C. results in more nanocrystals than the irradiation of the focused electron beam at 200 ° C. FIG.

As shown in the Figure 10, a Si-Al _{0 .025 0 .975} increases with the nanocrystalline growth time when irradiated with an electron beam focused on the 200 and 400 ℃ for the thin film compared to a single research focusing the electron beam at 100 ℃ Example 4 In this case, it can be seen that the growth rate of nanocrystals does not change continuously with the focused electron beam irradiation time.

As described in the Examples and Experimental Examples, the focused electron beam in the range of 200 to 400 ℃ temperature in the aluminum-added amorphous silicon thin film according to the method for producing a nanocrystalline silicon thin film to which aluminum is added using the focused electron beam according to the present invention In the case of irradiation, the silicon thin film in which the nanocrystals are formed may be manufactured by controlling the structure, position, and content of the nanocrystals.

Figure 1 (a) is a TEM image measured using a transmission electron microscope for the amorphous silicon thin film to which the aluminum content of 2.5% in step 1 of Example 1 added.

(B), (c), (d), (e) and (f) of FIG. 1 are for the silicon nanocrystal structures formed at 30, 60, 120, 300 and 600 seconds after irradiation with the focused electron beam in Example 1; High-Resolution TEM (HRTEM)

FIG. 2 is an XPS spectral graph showing binding energy of Si2p and Al2p of amorphous silicon thin films added by adjusting aluminum content to 2.5% and 5.0% in Step 1 of Example 1. FIG.

FIG. 3 is a graph showing electron energy loss spectra (EELS) before and after irradiating an electron beam in Example 1 (FIG. 3A) and after FIG. 3B.

Of Figure 4 (a) is a TEM image measured by transmission electron microscopy for the a-Al _{0 .025} Si _{0 .975} thin film in the step of Example 21.

4 (b), (c), (d), (e) and (f) of the silicon nanocrystal structure formed at 30, 60, 120, 300 and 600 seconds after irradiating the focused electron beam in Example 2 High-Resolution TEM (HRTEM)

Figure 5 (a) of Example 4 in a-Si Al _{0 .050 0 .950} of a TEM photo of the three-dimensional structure of silicon nanocrystals grown on the thin film, FIG. 5 (b) of Figure 5 (a) TEM image of the rod-shaped silicon nanocrystal structure shown in section 1.

FIG. 6 is an electron energy loss spectrum (EELS) graph showing an electron energy loss value of each of sections in which the electron beam is irradiated and an electron energy loss value of each section in which the electron beam is not irradiated.

Fig. (A) of 7 in Example _{5 a-Al 0 .10 Si 0} .90 is a TEM photograph of a silicon thin film to grow nano-tip, (b) of Figure 7 In Example 5 a-Al _0. a TEM photograph of the nano-crystals formed at the surface of the silicon nano-tip growing on the ₁₀ Si _{0 .90} thin film.

8 is a TEM image of Example 6 in the crystalline silicon nano-tip growth on a-Al _{0 .10} Si _{0 .90} thin film, {111} and {011} represents the crystal plane on the surface of the silicon nano-tips.

FIG. 9 is a view schematically illustrating a process of forming a silicon nanocrystal structure in an Al / a-Si thin film by electron beam irradiation.

10 is a graph showing a volume ratio of the nanocrystals generated increases the exposure time at 100, 200, 300, 400 ℃ respectively for the 2.5% aluminum is added a-Al _{0 .025} Si _{0 .975} thin film.

11 is a TEM image of a silicon nanocrystal structure grown on a 5% aluminum is added a-Al _{0 .050} Si _{0 .950} thin film in Comparative Example 1. Fig.

Claims (7)

Depositing an aluminum-doped amorphous silicon thin film (a-Al _x Si _1-x , 0.025 ≦ _x ≦ 0.10) on a silicon wafer (step 1); And Irradiating a focused electron beam having a current density of 15 to 30 pA / cm ² to the deposited silicon thin film of step 1 at 200 to 400 ° C. for 30 to 600 seconds to form silicon nanocrystals (step 2) Method of manufacturing a nanocrystalline structure from an amorphous silicon thin film using a focused electron beam comprising a. delete delete delete A silicon nanocrystal structure manufactured by irradiating a focused electron beam to an amorphous silicon thin film by the method of claim 1. The silicon nanocrystal structure of claim 5, wherein the average size of the nanocrystals is 5 to 15 nm. The silicon nanocrystal structure of claim 5, wherein the nanocrystal structure is a silicon nanotip.

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