CN104867868A - Method of transversely growing nanonet circuit without catalyst - Google Patents

Abstract

The invention provides a catalyst-free method for laterally growing nanowire network circuits, which is applied in the field of semiconductors. The method includes: 1) providing a silicon substrate with periodic nano-silicon pillars prepared on the surface and a container for containing chemical reactants 2) Place the side of the silicon substrate prepared with periodic nano-silicon pillars facing the boat containing the chemical reactants; 3) Use high-temperature chemical vapor deposition to prepare lateral growth at the corners of the sides of each nano-silicon pillar. ZnO nanowire network. In the present invention, the growth surface of the silicon electrode substrate with periodic nanopillars prepared on the surface is placed downward on a boat filled with chemical reactants, and then the laterally grown nanowire network can be controlled to form a nanonet bridging circuit without the need for a gold-plated film as a catalyst. Save process and reduce cost.

Description

Catalyst-free method for laterally growing nanowire mesh circuits

technical field

The invention relates to a method, in particular to a catalyst-free method for laterally growing nanowire network circuits.

Background technique

Scientific research shows that nanowire nets can improve the specific surface area and electrical properties of semiconductor materials, so the research on how to prepare nanowire nets is also constantly being studied. There are two main types of existing technologies for preparing nanowire networks:

First, in the published document 1 (see the end of the article for details), a method for preparing a horizontal single-arm carbon nanotube network (Carbon nanotube nanonets) circuit using a post-processing method is disclosed, as can be seen in Figure 1. The method is Distribute the nanotubes on the surface of the silicon substrate of silicon dioxide, and then use the method of ultraviolet exposure photolithography to coat the metal film as the technical method of the grid, drain and gate electrodes to prepare the triode electronic device based on the carbon nanotube network.

Although the above method can be used to prepare nanowire nets, it has certain defects. The disadvantage of the above-mentioned prior art 1 is that in the preparation process, photolithography processes such as glue removal and ultraviolet exposure on the surface of the nanowires are required. The density of the wires is difficult to control, and the uniformity of the nano-net wires contained in each prepared nano-net electronic device cannot be guaranteed.

Second, in the published related technical literature (2), it is disclosed that a soap-like polyacrylic acid nano-nets (polyacrylic acid nano-nets) prepared by electrospinning (electro-netting) is used. Has a huge specific surface area.

Although the nanowire network prepared in the above method 2 has a large specific surface area, various additives need to be added in the preparation process, and various acid-base chemical environments are also required, which is not conducive to the development of silicon-based nanoelectronic devices. Applications.

To sum up, the nanowire network prepared by the existing technology is not only complicated in the preparation process, but also requires various additives, and the density and final uniformity of the nanowire network are not good during the production process. control. Therefore, it is necessary to improve this.

Attachment: Existing public documents:

Document 1, [Ninad Pimparkar and Muhammad Ashraful Alam, IEEE ELECTRON DEVICELETTERS, VOL.29, NO.9, 1036-1039, 2008];

Literature 2, [Shangbin Yang et al, Nanoscale, 2011, 3, 564–568].

Contents of the invention

In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a method for laterally growing nanowire network circuits without a catalyst, which is used to solve the problem that the nanowire network prepared in the prior art is not only complicated in the preparation process, but also There are many steps, various additives are required, and it is difficult to control the density and final uniformity of the nanowires during the production process.

In order to achieve the above object and other related objects, the present invention provides the following solutions:

A method for laterally growing nanowire network circuits without a catalyst, the method comprising: 1) providing a silicon substrate with periodic nano-silicon pillars on the surface and a boat for containing chemical reactants; 2) placing the silicon The side of the substrate prepared with periodic nano-silicon pillars is placed facing the boat containing the chemical reactants; 3) using a high-temperature chemical vapor deposition method to prepare laterally grown zinc oxide nanowire networks at the corners of the sides of each nano-silicon pillar.

As a preferred mode of the above-mentioned method for laterally growing nanowire network circuits without a catalyst, step 3) in the method specifically includes: 3-1) placing the boat containing the chemical reactants and the silicon substrate placed thereon together 3-2) maintain the high temperature tube vacuum furnace as a vacuum and heat the vacuum tube therein to 900-1000°C; 3-3) feed 100-150sccm inert carrier gas and 1 -2sccm oxygen, and control the pressure to 300mbar; 3-4) keep the growth time for 30-35 minutes, then let the high-temperature tubular vacuum furnace cool down naturally, to prepare lateral growth at the corners of the nano-column side of the silicon substrate ZnO nanowire network.

As a further optimization of the preferred solution, the inert carrier gas is nitrogen or argon.

As a further optimization of the preferred solution, the volume flow ratio of the inert carrier gas and oxygen is 100:1.5.

As a further optimization of the above catalyst-free method for laterally growing nanowire network circuits and its preferred solution, the chemical reactants are zinc oxide powder and graphite powder.

As a preferred method of the catalyst-free method for laterally growing nanowire network circuits, the periodic nano-silicon pillars are a plurality of polygonal silicon pillars etched and formed on the silicon substrate.

As a further optimization of the preferred solution, the height of each of the polygonal silicon pillars is 500-800 μm, and the distance between the plurality of polygonal silicon pillars is in the range of 50-200 μm.

As mentioned above, the present invention has the following beneficial effects: the present invention places the growth surface of the silicon electrode substrate with periodic nanocolumns on the boat containing the chemical reactant downwards, and then can control the formation of lateral growth nanowire network The nano-network bridging circuit does not require a gold-plated film as a catalyst, which saves the process and reduces the cost.

Description of drawings

Figure 1 shows the effect diagram of the horizontal single-arm carbon nanotube network circuit prepared by the post-processing method.

Fig. 2 is a flow chart showing a method for laterally growing a nanowire network circuit without a catalyst provided by the present invention.

FIG. 3 is a flow chart of a specific embodiment of step S50 in FIG. 1 above.

Explanation of reference numbers

S10-S50 method steps

S501-S507 Method steps

Detailed ways

Embodiments of the present invention are described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes, and various modifications or changes can be made to the details in this specification based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, in the case of no conflict, the following embodiments and features in the embodiments can be combined with each other.

It should be noted that the diagrams provided in the following embodiments are only schematically illustrating the basic ideas of the present invention, and only the components related to the present invention are shown in the diagrams rather than the number, shape and shape of the components in actual implementation. Dimensional drawing, the type, quantity and proportion of each component can be changed arbitrarily during actual implementation, and the component layout type may also be more complicated.

Before specifically providing the catalyst-free method for laterally growing nanowire network circuits provided by the present invention, the inventor also provides a method for positioning and laterally growing zinc oxide nanowires on silicon electrodes (see CN103966662A), which discloses A method for independently producing zinc oxide nanowires grown laterally on a silicon electrode was developed. On the basis of the method, the inventors again proposed a method for laterally growing nanowire network circuits without catalysts through experiments and research. Please refer to the following examples for the detailed scheme.

Example 1

Please refer to FIG. 2, a method for laterally growing a nanowire network circuit without a catalyst provided by the present invention, the method at least includes the following steps:

Step S10, providing a silicon substrate with periodic nano-silicon columns prepared on the surface and a boat for containing chemical reactants;

Step S30, placing the side of the silicon substrate prepared with periodic nano-silicon columns facing the boat containing the chemical reactants;

Step S50 , using a high-temperature chemical vapor deposition method to prepare laterally grown zinc oxide nanowire networks at the corners of the sides of each nano-silicon pillar.

Specifically, in the above step S10, periodic nano-silicon pillars are prepared on a surface of the provided silicon substrate, and the periodic nano-silicon pillars are specifically a plurality of polygonal silicon pillars etched on the silicon substrate , the polygonal silicon pillars can be regular square pillars or rectangular pillars, or irregular polygonal pillars, such as trapezoidal pillars, triangular pillars and the like. Moreover, the end face of the same silicon substrate may also include multiple different polygonal silicon pillars, or only include multiple polygonal silicon pillars. That is, as long as the periodic nanopillars have edges and corners, the specific shape thereof is not important.

In more detail, although there are various options for the shape of the periodic nanopillars, the range of spacing between each polygonal silicon pillar in the periodic nanopillars is limited, and the anti-counterfeiting design of the spacing is generally 50 -200μm is all good. If the spacing is too narrow, the effect of the prepared nanowires is not ideal, and more stringent or better reaction conditions are required, which is not conducive to the conditions for simple preparation; and if the spacing is too large, it may be The unobtainable nanometer network wire, and the preparation time will increase accordingly.

Also, the height of each of the polygonal silicon pillars is generally 500-800 μm. If the height is too high, the reaction gas cannot effectively contact and reflect with the periodic nano-pillars, resulting in the inability to make nano-network wires; and if it is If the height is too low, it is not conducive to the smooth passage of the reaction gas, so that it is impossible to produce longer horizontal nanowires.

Further, in the above step S30, the growth side of the silicon electrode substrate prepared with periodic nanocolumns on the surface is placed downward on the boat containing the chemical reactants, which can control the lateral growth of the nanowire network to form a nanonet bridging circuit. A gold-plated film is required as a catalyst, which saves the process and reduces the cost.

Further, please refer to Fig. 3., in said step S50, utilize the high temperature chemical vapor deposition method to prepare the specific method of zinc oxide nanowire network as follows:

Step S501, putting the boat containing the chemical reactants and the silicon substrate placed on it together into a high-temperature tube vacuum furnace;

Step S503, maintaining the vacuum of the high-temperature tube-type vacuum furnace and heating the vacuum tube therein to 900-1000°C, generally, heating to about 950°C is better;

Step S505, injecting 100-150 sccm inert carrier gas and 1-2 sccm oxygen, and controlling the pressure to 300 mbar, generally, inert gas such as nitrogen or argon can be used as the carrier gas;

In step S507, keep the growth time for 30-35 minutes, and then let the high-temperature tubular vacuum furnace cool down naturally, so as to prepare laterally grown zinc oxide nanowire network at the corners of the nanopillar sides of the silicon substrate.

The method in the above-mentioned embodiment 1 provided by the present invention is realized at the side corners of the silicon substrate nano-pillars by facing the silicon substrate of the periodic silicon nano-columns without the metal-plated catalyst on the boat of the chemical reactants. The purpose of growing nanowire network laterally, this method can use nanowire network to bridge multiple silicon electrodes to prepare nano-circuits in the true sense, and prepare nano-network circuits on etched silicon micro-electrodes. The nanomesh circuits and nanoelectronic devices provide a concise approach.

As can be known from the foregoing embodiments, the key point of the present invention is to directly place the silicon electrode growth surface, which is not plated with a metal film and has periodically distributed nanopillars, facing the chemical reactants on a boat containing the reactants, and conducts the chemical reaction. reaction.

Example 2

Further, in this embodiment, according to the method of the above-mentioned embodiment 1, a laterally grown zinc oxide nanowire network is prepared at the corners of the sides of each nano-silicon pillar. To make the zinc oxide nanowire network, the chemical reactants contained in the boat are zinc oxide powder and graphite powder, and nitrogen is used as the inert carrier gas, and then according to the preparation steps provided in the above-mentioned embodiment 1, Zinc oxide nanowire network can be prepared.

Preferably, in this embodiment, the volume flow ratio of the inert carrier gas and oxygen is set to 100:1.5, and the pressure of the nitrogen and oxygen atmosphere in the tube is kept at 300mbar, so that the zinc oxide nanowire network can be obtained quickly .

In summary, the principle of the present invention is that, according to the principle of crystal growth, due to the low binding energy at the edges and corners of the electrodes, the silicon electrode growth surface engraved with periodic nano-columns on the surface is placed facing the chemical reaction raw materials, and by controlling the gas flow distribution In this way, the nano-network bridging electrode is only grown laterally on the edge of the nano-column electrode, and the result is not grown on the surface, which reduces unnecessary zinc oxide nanowires grown on the surface of the electrode by using a traditional growth method. The innovative point of the present invention is: place the growth side of the silicon electrode substrate with periodic nano-columns on the surface downwards on a boat filled with chemical reactants, and then control the lateral growth of nano-wire network to form a nano-network bridge circuit, without The gold-plated film is used as a catalyst, which saves the process and reduces the cost. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial application value.

The above-mentioned embodiments only illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Anyone skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical ideas disclosed in the present invention should still be covered by the claims of the present invention.

Claims (7)

1. A method for catalyst-free lateral growth of nanowire network circuits, characterized in that the method comprises: 1) providing a surface with a silicon substrate prepared with periodic nano-silicon pillars and a boat for holding chemical reactants; 2) The side of the silicon substrate prepared with periodic nano-silicon pillars is placed towards the boat containing the chemical reactant; 3) A high-temperature chemical vapor deposition method is used to prepare laterally grown zinc oxide nanowire networks at the corners of the side surfaces of each nano-silicon pillar. 2. the method for catalyst-free lateral growth nanowire network circuit according to claim 1, is characterized in that: step 3) in the described method specifically comprises: 3-1) Put the boat containing the chemical reactants and the silicon substrate placed on it into a high-temperature tube vacuum furnace; 3-2) maintaining the high temperature tube vacuum furnace in vacuum and heating the vacuum tube therein to 900-1000°C; 3-3) Inject 100-150sccm inert carrier gas and 1-2sccm oxygen, and control the pressure to 300mbar; 3-4) Keep the growth time for 30-35 minutes, and then allow the high-temperature tubular vacuum furnace to cool down naturally, so as to prepare laterally grown zinc oxide nanowire networks at the corners of the nanopillar sides of the silicon substrate. 3 . The method for laterally growing nanowire network circuits without catalysts according to claim 2 , wherein the inert carrier gas is nitrogen or argon. 4 . 4 . The method for laterally growing nanowire network circuits without catalysts according to claim 2 , wherein the volume flow ratio of the inert carrier gas and oxygen is 100:1.5. 5 . The method for laterally growing nanowire network circuits without a catalyst according to claim 1 , wherein the chemical reactants are zinc oxide powder and graphite powder. 6 . 6 . The method for laterally growing nanowire network circuits without catalysts according to claim 1 , wherein the periodic nano-silicon pillars are a plurality of polygonal silicon pillars etched and formed on the silicon substrate. 7 . 7. The method for catalyst-free lateral growth of nanowire network circuits according to claim 5, characterized in that: the height of each of the polygonal silicon pillars is 500-800 μm, and the distance between the plurality of polygonal silicon pillars is The range is 50-200 μm.