TWI464783B - A semiconductor nanostructure and the forming method thereof - Google Patents

Description

Semiconductor nano structure and manufacturing method thereof

The present invention discloses a semiconductor component, and more particularly to a catalyst intrusion technique to form a one-dimensional semiconductor nanostructure.

The catalysts of nano metal particles and clusters have high activity different from those of bulk materials, and thus are widely used in the fields of physics, chemistry, biology, medicine, and the like. In addition, nanostructured semiconductor materials have extremely high surface area and quantum confinement characteristics, and many studies have been applied to enhance solar cell, field emission display, photodetector or biochemical detection equivalent energy.

Nano metal catalysts have quite good catalytic properties. For many different nano metal particles, such as gold and silver, they are often used to assist in the fabrication of one-dimensional semiconductor nanostructures. At present, the technology for fabricating one-dimensional semiconductor nanostructures includes a bottom-up method, which is mainly composed of a nano-metal catalyst and a gas-liquid-solid (Vapor-Liquid-Solid) which is saturated with a process gas.

The above method can produce homogenous and heterogeneous materials on the substrate, but the preparation method is required to be in a high temperature environment, and the process gas thereof has high risk and toxicity, and the gas thereof is, for example, decane (SiH ₄ ). Another way to make it is the Top-Down method. In this way, the nano metal catalyst on the surface of the substrate is used together with an etching solution, and the catalyst is locally oxidized to etch the substrate to form a one-dimensional nanostructure. This method has the advantages of being simple and can be fabricated at room temperature. However, the structure in which the surface of the nano metal catalyst is easily aggregated and etched is generally 10 to 100 times larger than the catalyst particle size, so that it is difficult to make a grain. The structure size is less than 50 nm.

Therefore, in order to be able to manufacture better semiconductor components, it is extremely necessary to develop a new catalyst intrusion technology, and it is possible to reduce the time and related manufacturing costs of related research and development.

In accordance with the disadvantages of the prior art, the primary object of the present invention is to disclose a catalyst intrusion technique to produce a one-dimensional high density substrate structure of nanometer size to improve component performance.

Another object of the present invention is to provide a simple, low cost, and fast method to form a semiconductor nanostructure that captures light.

It is still another object of the present invention to provide a semiconductor nanostructure that is suitable for light trapping and for use in tantalum solar cells.

It is still another object of the present invention to provide a semiconductor nanostructure that can be used as an ultra-thin microelectronic component for field emission devices.

According to the above object, the present invention discloses a method for fabricating a semiconductor nanostructure, the method comprising: providing a substrate having a native oxide layer; forming a metal film on a substrate having a native oxide layer such that a portion of the metal atoms in the metal film Deposited through the native oxide layer in the substrate and under the surface of the substrate to form a catalyst layer; and stripping the metal film on the substrate.

In an embodiment of the invention, the forming of the metal thin film comprises an evaporation method or a sputtering method.

In an embodiment of the invention, the material of the metal film comprises gold, silver, copper, platinum, iron, cobalt and nickel.

In an embodiment of the invention, the step of stripping the metal film comprises: adhering the adhesive tape on the metal film; and tearing off the tape so that the metal film is simultaneously removed from the substrate having the native oxide layer.

According to the above manufacturing method, the present invention also discloses a semiconductor nanostructure comprising: a substrate having a native oxide layer; and a metal catalyst layer in the substrate and below the surface of the substrate.

In an embodiment of the invention, the material of the substrate comprises a germanium substrate.

In one embodiment of the invention, the thickness of the native oxide layer on the substrate ranges from 1 nanometer (nm) to 2 nanometers.

In an embodiment of the invention, the material of the metal catalyst layer comprises gold, silver, copper, platinum, iron, cobalt and nickel.

In an embodiment of the invention, the metal catalyst layer has a thickness ranging from 1 nm to 5 nm.

The features and implementations of the present invention are described in detail below with reference to the preferred embodiments.

Please refer to FIG. 1 for the present invention. The first figure shows a substrate 10 having a native oxide layer 12. In Fig. 1, the native oxide layer 12 on the substrate 10, generally a ruthenium oxide layer, forms a native oxide layer on the surface of the substrate 10 due to oxidation when the surface of the substrate 10 is exposed to oxygen and water. 12, the substrate 10 thereof is particularly referred to as a germanium substrate. In order to avoid the presence of the native oxide layer 12 prior to the start of the semiconductor process, in the embodiment of the invention, the native oxide layer 12 on the substrate 10 is retained. Generally, the thickness of the native oxide layer 12 on the substrate 10 ranges from 1 nm to 2 nm.

Please refer to Figure 2 below. In Fig. 2, a metal thin film 14 is formed on the substrate 10 having the native oxide layer 12 by means of a catalyst intrusion technique (INC), which is formed by evaporation or sputtering ( The metal film 14 includes gold (Au), silver (Ag), copper (Cu), platinum (Pt), iron (Fe), cobalt (Co), and nickel (Ni). Since the metal thin film 14 is formed on the substrate 10 having the native oxide layer 12 by vapor deposition or sputtering, a part of the metal atoms 142 in the metal thin film 14 may be subjected to heat and kinetic energy remaining in the process. The intrusion of the native oxide layer 12 into the substrate 10 and deposition under the surface of the substrate 10, in particular, when the material of the substrate 10 is a germanium substrate, the metal atoms 142 enter the germanium lattice of the germanium substrate. A metal catalyst 11 having an atomic-scale is formed inside the substrate 10 as shown in FIG.

Further, a metal catalyst 11 having a thickness of about 1 nm to 5 nm can be uniformly intruded into the substrate 10 and on the surface of the substrate 10 by the transmission electron microscope (TEM) image of FIG. Below. Further, it can also be confirmed by EDS element analysis that the substance under the surface of the substrate 10 is a metal element. In the present invention, the metal invading the lower surface of the substrate 10 depends on the material of the metal thin film 14 formed on the native oxide layer 12 of the substrate 10, and in one embodiment, the native oxide layer 12 formed on the substrate 10. When the material of the upper metal thin film 14 is gold, the metal atoms intruding on the lower surface of the substrate 10 are gold atoms, and the metal catalyst formed in the substrate 10 is a gold catalyst.

Next, please refer to Figure 5. In Fig. 5, a viscous substance (or other viscous substance) 20 such as a tape is attached to the metal thin film 14.

As shown in FIG. 6, since the adhesion property between the native oxide layer 12 and the metal thin film 14 is not good, the metal thin film 14 formed over the substrate 10 can be removed by the tape 20 or by flushing or wiping. .

Thereafter, in the figure shown in Fig. 7, the metal film 14 to be attached to the tape 20 is shown, and the metal film 14 can be separated from the tape 20, and the metal film 14 can be recycled and reused.

As shown in the scanning electron microscope of Fig. 8(a), in the present invention, the metal film 14 above the substrate 10 recovered by stripping the tape 20 is immersed in a mixed etching solution for a time range of 1 ~5 minutes, it can be clearly seen that the stalactite stalactite structure etched by the etching solution has a pore diameter of about 10 nm to 20 nm. Here, the mixed etching solution includes hydrofluoric acid (HF acid), hydrogen peroxide (H ₂ O ₂ ), and pure water in a mixing ratio of 2:1:8 (v/v/v) by volume.

As shown in Fig. 8(b), the structure etched by chemical self-assembled nano metal particle catalyst (SNP) has a size approaching 500 nm and as 8th (c) compared to the prior art. The structure etched by electroless deposition (EMD) as shown in the figure, ranging in size from 100 nm to 200 nm.

Therefore, from the 8th (a), 8th (b), and 8th (c), it is obvious that the catalyst intrusion technology can break through the traditional production of extremely high density but extremely small size. Nano stalactite structure.

As in the side view of Figure 9(a), this sample has excellent anti-reflective properties at a structural height of 250 nm.

In Figure 9(b), the structural height is 1 micron (um), the anti-reflective properties of the chemically self-assembled nano metal particles, and the 9th (c) diagram shows the structural height of 2.5 microns for electroless plating. Anti-reflective properties of the deposition method. Therefore, it is known that the catalyst intrusion technique can be used, and the anti-reflection property can be obtained in a shallow structure.

Further, it can be obtained from the 10th (a) diagram that the catalyst intrusion technique can greatly reduce the reflection of the surface of the substrate 10 in a relatively short etching time range of 3 minutes to 4 minutes.

Figure 10(b) shows the reflection spectrum of the spheroid nanometer stalactite structure integrating sphere spectrometer.

Also in Figure 10(b), there is considerable low reflection in the 300 nm to 1000 full band. At such a shallow height, the structure having the full-band anti-reflection property can be applied to the application of the commercial solar cell anti-reflection layer. In addition, since such a nano stalactite structure has a sharp corner having a relatively small radius of curvature, the electric field is concentrated and enhanced at the sharp corners. This electric field enhancement effect has considerable advantages in the application of field emission elements.

Figure 11 is a schematic diagram showing the comparison of the field emission characteristics of the structure etched by the catalyst intrusion technique and the electroless deposition method disclosed in the present invention. In Fig. 11, it can be seen that the turn-on voltage of the very fine structure etched by the catalyst intrusion technique is much smaller than the turn-on voltage of the structure etched by the electroless deposition method, so by touch The structure formed by the media intrusion technique has better field emission characteristics.

Therefore, in summary, the nanostructure formed by the catalyst intrusion technique has a simple process and a relatively fast technique, and has a full-band anti-reflection characteristic in a shallow structure and has a low turn-on voltage characteristic. It can be widely used in anti-reflection layers or field emission elements in photovoltaic elements.

10. . . Substrate

11. . . Metal catalyst

12. . . Primary oxide layer

14. . . Metal film

142. . . Metal atom

20. . . tape

1 is a schematic cross-sectional view showing a substrate having a native oxide layer in accordance with the teachings of the present invention;

2 is a schematic cross-sectional view showing a metal film formed on a substrate having a native oxide layer by a catalyst intrusion technique (INC) according to the technique disclosed in the present invention;

3 is a schematic cross-sectional view showing a metal catalyst in a substrate and under the surface of the substrate according to the disclosed technology;

Figure 4 is a schematic view showing a transmission electron microscope (TEM) having a metal catalyst in a substrate according to the technology disclosed in the present invention;

Figure 5 is a schematic cross-sectional view showing the tape attached to a metal film according to the technology disclosed in the present invention;

Figure 6 is a schematic cross-sectional view showing the removal of a metal film when stripping the tape according to the technique disclosed in the present invention;

Figure 7 is a schematic view showing the separation of the metal film from the tape and the metal film can be recycled for continued use according to the technology disclosed in the present invention;

Figure 8(a) is a SEM image showing the structure of a stalactite stalactite structure after etching through a etching solution of a sample formed by a catalyst intrusion technique in accordance with the teachings of the present invention;

Figure 8(b) is a SEM image showing the structure of the ruthenium nanostructure after etching through the etching solution of the sample formed by the chemical self-assembled nano metal particle catalyst;

Figure 8(c) is a SEM image showing the structure of the ruthenium nanostructure after etching through the etching solution of the sample formed by the electroless deposition method;

Figure 9(a) is a SEM image of the sample having excellent anti-reflection properties at a structural height of 250 nm after exposure to the technique via the catalyst according to the present invention;

Figure 9(b) shows an SEM image of the anti-reflection properties of chemically self-assembled nano metal particles having a structure height of 1 μm;

Figure 9(c) shows an SEM image of the anti-reflection properties of the electroless deposition method with a structure height of 2.5 μm;

Figure 10(a) is a technique according to the present invention, which shows that the catalyst intrusion technique can greatly reduce the reflection of the surface of the substrate during a relatively short etching time;

10(b) is a view showing a reflection spectrum of an etched out nano stalactite structure integrating sphere spectrometer according to the technique disclosed in the present invention;

Figure 11 is a schematic diagram showing the comparison of the field emission characteristics of the structure etched by the catalyst intrusion technique and the electroless deposition method in accordance with the technique disclosed in the present invention.

10. . . Substrate

11. . . Metal catalyst

12. . . Primary oxide layer

14. . . Metal film

142. . . Metal atom

Claims (4)

A method for fabricating a catalyst intrusion technique for capturing a semiconductor nanostructure of light, the method comprising: providing a substrate having a native oxide layer; forming a metal film on the substrate having the native oxide layer, such that the metal film a portion of the metal atoms pass through the native oxide layer, are deposited in the substrate, and are located under one surface of the substrate to form a metal catalyst layer, wherein the metal thin film is formed by evaporation and sputtering. Selecting from the group; and stripping the metal film on the substrate, comprising the steps of: attaching a viscous substance on the metal film; and tearing off the viscous material so that the metal film simultaneously has the Removed from the substrate. The method of claim 1, wherein the material of the metal film is selected from the group consisting of gold, silver, copper, platinum, iron, cobalt and nickel. A trappable semiconductor nanostructure formed by a catalyst intrusion technique, comprising: a substrate having a native oxide layer, wherein the native oxide layer has a thickness ranging from 1 nm to 2 nm; and a metal touch The dielectric layer is in the substrate and below a surface of the substrate, wherein the metal catalyst layer has a thickness ranging from 1 nm to 5 nm, and the material of the metal catalyst layer comprises gold. The semiconductor nanostructure of claim 3, wherein the material of the substrate comprises a germanium substrate.