Horizontal structure nanometer air channel transistor based on multilayer thin film

Abstract

This invention discloses a horizontally structured nano-air channel transistor based on multilayer thin films, belonging to the field of transistor technology. It includes an insulating substrate, a multilayer thin film cathode and anode disposed on its front side, with a nano-air channel formed between the cathode and anode. The multilayer thin film cathode is composed of alternating layers of conductive and insulating thin films. The anode is composed of a conductive material, or is composed of alternating layers of conductive and insulating thin films. Conductive sidewalls are also provided on one side of the multilayer thin film cathode and anode for electrical connection between the conductive thin film layers. This invention achieves a large field enhancement factor through the sharp edge structure of the multilayer thin films and effectively increases the field emission current of the transistor by utilizing the tandem emission of the multilayer thin films. Simultaneously, because vertical etching or corrosion processes can easily achieve 90-degree sidewalls, the isomorphism of the emission structure of each layer in the multilayer thin film is maintained, enabling simultaneous electron emission from the multilayer thin films in series to maintain a stable emission current.

Description

Technical Field

[0001] This invention belongs to the field of transistor technology, specifically relating to a horizontally structured nano-air channel transistor based on a multilayer thin film. Background Technology

[0002] Transistors are the cornerstone of modern electronic information technology and the basic unit for realizing large-scale integrated circuits. Based on their working principles, transistors are currently mainly divided into vacuum transistors and semiconductor transistors. Vacuum transistors were the earliest type of transistor; electrons emitted from the cathode undergo unscattered ballistic transport in a vacuum, enabling high-frequency, high-power operation. However, traditional vacuum transistors are limited by the vacuum operating environment, resulting in large size and weight, making large-scale integration difficult. Therefore, they have gradually been replaced by semiconductor transistors in most applications. Semiconductor transistors rely on semiconductor PN junctions, where charge carriers are transported in a semiconductor solid medium, allowing for large-scale integration. However, due to lattice scattering in the solid, their charge carrier transport speed is much lower than in a vacuum. In recent years, nanoscale vacuum transistors have emerged, employing a cathode-cathode spacing (i.e., vacuum channel size) smaller than the mean free path of electrons in air. They can operate in atmospheric environments without vacuum packaging and are therefore also called nanoscale air-channel transistors. Nanoscale air-channel transistors combine the advantages of near-light-speed ballistic transport of electrons in vacuum devices with the high integration and mass production capabilities of semiconductor devices. The femtosecond-level ultrashort transit time brought about by electron ballistic propulsion enables nano-air channel devices to operate in the frequency band above terahertz. At the same time, air channels have higher intrinsic breakdown voltage and lower heat generation, which is expected to break through the frequency, power and power consumption bottlenecks of traditional semiconductor transistors.

[0003] Nanochannel air transistors are generally classified into two structures: horizontal channel and vertical channel. Horizontal nanochannel structures have extremely small capacitance and are more compatible with CMOS planar processes, making them more suitable for high-frequency operation at terahertz (THz) and even petahertz (PHz) and above. Traditional horizontal nanochannel air transistors mostly use nano-tip structures to enhance electron field emission. However, due to the small emission area of ​​the tips, the absolute value of the emission current is usually small, and even a slightly larger emission current can easily affect the tip morphology, leading to instability. To address this, in recent years, a technique has emerged that uses multiple planar nanotip arrays connected in series to increase the emission current. However, it is difficult to ensure the consistency of the size and structure during the fabrication of multiple planar nanotip arrays, and electron emission is very sensitive to the gap size and morphology of the nanochannel. Often, electrons will be mainly emitted from the tip structure closest to the anode, which not only fails to fully utilize the effect of the tip array in increasing the emission current but also results in unstable emission current. Therefore, how to effectively increase the emission current of horizontal nanochannel air transistors through structural design is a major challenge currently faced. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention proposes a horizontal structure nano-air channel transistor based on multilayer thin films, aiming to provide a technical solution for a horizontal structure nano-air channel transistor that can effectively improve the emission current, achieve high yield, and provide stable emission current.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0006] A horizontal structure nano-air channel transistor based on multilayer thin films is characterized by comprising an insulating substrate, a multilayer thin film cathode, and an anode.

[0007] The multilayer thin film cathode and anode are disposed on the front side of the insulating substrate, and a nano-air channel is formed between the multilayer thin film cathode and anode;

[0008] The multilayer thin-film cathode is composed of alternating layers of conductive and insulating thin films, and both the bottom and top layers of the multilayer thin-film cathode are conductive thin films. A conductive sidewall is provided on the side of the multilayer thin-film cathode facing away from the anode for electrical connection between the conductive thin film layers.

[0009] The anode is made of conductive material, or is a multilayer thin film anode composed of alternating layers of conductive and insulating thin films; the bottom and top films of the multilayer thin film anode are both conductive films, and an anode conductive sidewall is provided on the side facing away from the cathode for electrical connection between the conductive film layers.

[0010] Preferably, in the multilayer thin-film cathode and the multilayer thin-film anode, the thickness of each thin film layer does not exceed 100 μm.

[0011] Preferably, on the side of the multilayer thin-film cathode closest to the anode, each insulating thin-film layer is etched inwards in a portion of its area, creating a partial gap between adjacent conductive thin-film layers.

[0012] Preferably, on the side of the multilayer thin film anode closest to the cathode, each insulating thin film layer is etched inward in a portion of its area, creating a partial gap between adjacent conductive thin film layers.

[0013] Preferably, when the transistor is a triode, it further includes a gate; the gate is located directly below the nano air channel, and an insulating layer is disposed between the gate and the multilayer thin film cathode, anode and nano air channel.

[0014] Preferably, the insulating substrate is made of an insulating material, or is composed of a lower conductive material and an upper insulating material, wherein the lower conductive material is a semiconductor, a metal, or a metalloid.

[0015] Preferably, the insulating substrate is a rigid substrate or a flexible substrate.

[0016] The advantages of this invention are as follows:

[0017] 1. When the thickness of each layer of a multilayer thin film cathode or multilayer thin film anode is in the nanometer range, its edges are very sharp. A large field enhancement factor can be obtained without processing it into a pointed structure. Therefore, a larger area structure can be used to effectively increase the field emission current of the transistor while maintaining a stable emission current.

[0018] 2. When the opposite sides of a multilayer thin film cathode or a multilayer thin film anode are processed into pointed structures, the 90-degree sidewalls can be easily achieved through vertical etching or corrosion processes. Therefore, the pointed structures of each layer can remain the same, enabling simultaneous current emission from multiple pointed structures in series. This avoids the defect of traditional horizontal pointed arrays where the current is mainly emitted from the tip closest to the anode.

[0019] 3. When used as a photodiode, the multilayer thin film structure can form hyperbolic metamaterials and Tamm-state surface plasmon structures, thereby effectively enhancing light absorption and photoelectron emission, and increasing the quantum efficiency and photocurrent of the nano-air channel photodiode. Attached Figure Description

[0020] Figure 1 The diagram shows a horizontal nano-air channel diode structure based on a metal / insulating multilayer thin film cathode proposed in this invention. (a) is a side cross-sectional view, and (b) is a top plan view. Wherein: 11, insulating substrate; 12, metal thin film; 13, insulating thin film; 14, metal anode; 15, nano-air channel; 16, metal conductive sidewall.

[0021] Figure 2 This is a schematic diagram of a horizontal nano-air channel diode structure based on a semiconductor / insulating multilayer gapped thin film cathode proposed in this invention. (a) is a side cross-sectional view, and (b) is a top plan view. Wherein: 21, semiconductor substrate; 22, insulating layer; 23, semiconductor thin film; 24, insulating thin film; 25, metal conductive sidewall; 26, metal anode; 27, nano-air channel.

[0022] Figure 3 This is a schematic diagram of a horizontal nano-air channel diode structure based on a metal / insulating multilayer porous thin-film cathode and an HfN-type metal / insulating multilayer porous thin-film anode proposed in this invention. (a) is a side cross-sectional view, and (b) is a top plan view; wherein: 31, insulating substrate; 32, metal thin film; 33, insulating thin film; 34, HfN-type metal thin film; 35, insulating thin film; 36, nano-air channel; 37, metal conductive sidewall; 38, HfN-type metal conductive sidewall.

[0023] Figure 4This is a schematic diagram of a horizontal nano-air channel photodiode based on a transparent conductive film / semiconductor multilayer thin film cathode and a metal / insulating multilayer porous thin film anode proposed in this invention. (a) is a side cross-sectional view, and (b) is a top plan view; wherein: 41, insulating substrate; 42, transparent conductive film; 43, semiconductor thin film; 44, metal anode; 45, insulating film; 46, nano-air channel; 47, transparent material conductive sidewall; 48, metal conductive sidewall.

[0024] Figure 5 The diagram shows a horizontal nano-air channel transistor structure based on a metal / insulating multilayer thin film cathode proposed in this invention. (a) is a side cross-sectional view, (b) is a top plan view, and (c) is a three-dimensional structural diagram. Wherein: 51, insulating substrate; 52, metal gate; 53, insulating layer; 54, metal thin film; 55, insulating thin film; 56, metal-like TaN anode; 57, nano-air channel; 58, metal conductive sidewall. Detailed Implementation

[0025] The technical solutions of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] Example 1

[0027] A horizontally structured nano-air channel diode based on a metal / insulating multilayer thin-film cathode, such as Figure 1 As shown, its structure is as follows: a metal / insulating multilayer thin-film cathode with a triangular apex structure is disposed on the upper left side of the insulating substrate; a conductive metal sidewall is disposed on the left side of the multilayer thin-film cathode to achieve electrical connection between the conductive thin-film layers; a metal anode with a rectangular planar structure is disposed on the upper right side of the insulating substrate; and a nano-air channel is formed between the anode and cathode. The diode provided in this embodiment has the advantage of not requiring semiconductor materials, being able to be fabricated on various insulating substrates including flexible substrates, and the multilayer thin-film cathode with a triangular apex structure can generate a superimposed field enhancement factor to improve the emission current. In addition, due to the extremely asymmetrical configuration of the anode and cathode, a large rectification ratio and ideal unidirectional conduction can be achieved.

[0028] Example 2

[0029] A horizontally structured nano-air channel diode based on a semiconductor / insulator multilayer bandgap thin-film cathode, such as Figure 2As shown, its structure is as follows: an insulating layer is disposed on a semiconductor substrate to form an insulating substrate; a semiconductor / insulating multilayer thin-film cathode with a long strip-shaped planar configuration is disposed on the left side above the insulating layer; a metal conductive sidewall is disposed on the left side of the multilayer thin-film cathode to realize the electrical connection of each semiconductor thin-film layer; at the same time, by selectively removing part of the insulating thin-film layer on the right side of the multilayer thin-film cathode, a partial gap is created between adjacent semiconductor thin-film layers, thereby making the multilayer semiconductor thin film near the nano-air channel in a suspended state; a metal anode with a rectangular planar configuration is disposed on the right side above the insulating layer; a nano-air channel is formed between the anode and cathode. The advantage of the diode provided in this embodiment is that the multilayer semiconductor thin film near the nano-air channel in the multilayer thin-film cathode is in a suspended state, which can generate a large field enhancement factor without the need to process it into a pointed structure.

[0030] Example 3

[0031] A horizontally structured nano-air channel diode based on a metal / insulator multilayer gapped thin-film cathode and an HfN-type metal / insulator multilayer gapped thin-film anode, such as... Figure 3 As shown, its structure is as follows: a metal / insulating multilayer thin-film cathode is disposed on the upper left side of an insulating substrate, and an HfN-type metal / insulating multilayer thin-film anode is disposed on the right side, with a nanoscale air channel formed between the multilayer thin-film cathode and the multilayer thin-film anode. The multilayer thin-film cathode and the multilayer thin-film anode have the same planar configuration, both having a semi-circular arc-shaped elongated structure at their tips. Simultaneously, by selectively removing portions of the insulating thin-film layers on adjacent sides of the multilayer thin-film cathode and the multilayer thin-film anode, gaps are created between adjacent metal thin-film layers and adjacent HfN-type metal thin films, thereby achieving a suspended state for the multilayer semiconductor thin film near the nanoscale air channel. Conductive sidewalls are provided at the other ends of both the multilayer thin-film cathode and the multilayer thin-film anode, enabling electrical connections between the metal thin-film layers of the cathode and the HfN-type metal thin-film layers of the anode. The advantage of the diode provided in this embodiment is that the portions of the metal and metal-like materials in the multilayer thin-film cathode and the multilayer thin-film anode near the nanoscale air channel are suspended, which can generate a large field enhancement factor, and the planar configuration is symmetrical, enabling bidirectional conduction.

[0032] Example 4

[0033] A horizontally structured nanochannel photodiode based on a transparent conductive thin film / semiconductor multilayer thin film cathode and a metal / insulating multilayer porous thin film anode, such as... Figure 4As shown, its structure is as follows: a transparent conductive thin film / semiconductor multilayer thin film cathode is disposed on the upper left side of an insulating substrate, and a metal / insulating multilayer thin film anode is disposed on the right side, forming a nano-air channel between the multilayer thin film cathode and the multilayer thin film anode. The multilayer thin film cathode has a rectangular planar configuration, with a transparent conductive sidewall disposed on the left side to achieve electrical connection between the semiconductor thin film layers. The multilayer thin film anode has a bullet-shaped elongated structure with a larger anode tip size than the cathode tip size; simultaneously, by selectively removing part of the insulating thin film layer at the tip of the multilayer thin film anode, a partial gap is created between adjacent metal thin film layers, thereby achieving a suspended state of the multilayer metal thin film near the nano-air channel; a conductive metal sidewall is disposed on the right side of the multilayer thin film anode to achieve electrical connection between the metal thin film layers. The advantages of the photodiode provided in this embodiment are that the transparent conductive thin film / semiconductor multilayer thin film cathode also forms a hyperbolic metamaterial and a Tamm state surface plasmon structure, which can effectively enhance light absorption and photoelectron emission, and increase the quantum efficiency and photocurrent of the nano-air channel photodiode; and the structure of the cathode with a stronger enhancement factor lower than that of the anode (the cathode tip size is larger than that of the anode tip size) can effectively suppress the dark current emitted by the cathode.

[0034] Example 5

[0035] A horizontally structured nano-air channel transistor based on a metal / insulating multilayer thin-film cathode, such as Figure 5 As shown, its structure is as follows: a long strip-shaped metal gate is disposed on an insulating substrate, an insulating layer is disposed on the metal gate, and a portion of the metal gate is exposed; a metal / insulator multilayer porous thin film cathode is disposed on the upper left side of the insulating layer, and its planar configuration is a long strip structure with a semi-circular tip; a metal-like TaN anode is disposed on the right side of the insulating layer, and its planar configuration is a rectangular structure with a circular depression at the tip; a nano-air channel is formed between the anode and cathode, and the nano-air channel is located directly above the metal gate.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications, combinations or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A horizontally structured nano-air channel transistor based on multilayer thin films, characterized in that: Includes an insulating substrate, a multilayer thin-film cathode, and an anode; The multilayer thin film cathode and anode are disposed on the front side of the insulating substrate, and a nano-air channel is formed between the multilayer thin film cathode and anode; The multilayer thin-film cathode is composed of alternating layers of conductive and insulating thin films, and both the bottom and top layers of the multilayer thin-film cathode are conductive thin films; a conductive sidewall is provided on the side of the multilayer thin-film cathode facing away from the anode for electrical connection between the conductive thin film layers. The anode is made of conductive material, or is a multilayer thin film anode composed of alternating layers of conductive and insulating thin films; the bottom and top films of the multilayer thin film anode are both conductive films, and an anode conductive sidewall is provided on the side facing away from the cathode for electrical connection between the conductive film layers.

2. The horizontal structure nano-air channel transistor based on a multilayer thin film as described in claim 1, characterized in that: In the multilayer thin-film cathode and the multilayer thin-film anode, the thickness of each thin film layer does not exceed 100 μm.

3. A horizontally structured nano-air channel transistor based on a multilayer thin film as described in claim 1 or 2, characterized in that: On the side of the multilayer thin-film cathode closest to the anode, each insulating thin-film layer is etched inwards in a portion of its area, creating gaps between adjacent conductive thin-film layers.

4. The horizontal structure nano-air channel transistor based on a multilayer thin film as described in claim 3, characterized in that: On the side of the multilayer thin film anode closest to the cathode, each insulating thin film layer is etched inwards in a portion of its area, creating gaps between adjacent conductive thin film layers.

5. A horizontally structured nano-air channel transistor based on a multilayer thin film as described in claim 4, characterized in that: When the transistor is a triode, it also includes a gate; the gate is located directly below the nano air channel, and an insulating layer is disposed between the gate and the multilayer thin film cathode, anode and nano air channel.

6. The horizontal structure nano-air channel transistor based on a multilayer thin film as described in claim 5, characterized in that: The insulating substrate is made of insulating material, or is composed of a lower conductive material and an upper insulating material, wherein the lower conductive material is a semiconductor, a metal, or a metalloid.

7. A horizontally structured nano-air channel transistor based on a multilayer thin film as described in claim 6, characterized in that: The insulating substrate can be a rigid substrate or a flexible substrate.

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