Semiconductor tunneling diode, rectifier bridge and preparation method thereof

Abstract

The invention provides a semiconductor tunneling diode, and belongs to the technical field of diodes. The semiconductor is selected to be in contact with electrode materials with different work functions, and asymmetric Schottky barriers are respectively formed with the top electrode and the bottom electrode, so that electrons are tunneled in the thin-layer semiconductor to realize rectification. The semiconductor tunneling diodes are used in the rectifier bridge, perfect rectification of sine wave signals is achieved, the rectification performance of the rectifier bridge can be remarkably improved, and an efficient thought is provided for energy detection and collection of ultrahigh frequency bands in the future.

Description

Technical Field

[0001] The present invention relates to the technical field of diodes, and in particular to a semiconductor tunneling diode, a rectifier bridge including the semiconductor tunneling diode, and a preparation method of the rectifier bridge. Background Art

[0002] In 1964, W.C. Brown et al. of Raytheon Company first proposed the concept of a rectenna and took the lead in using Schottky diodes to apply a full-wave rectifier bridge to microwave rectification. As time goes by, people hope to achieve rectification in the terahertz and even visible light bands. An important prerequisite for realizing this idea is to develop a diode with excellent rectification performance and high-frequency response, which undoubtedly makes a tunneling diode with electron tunneling in the femtosecond range a very promising candidate device.

[0003] Tunneling diodes have high responsivity or detectivity and are widely used in signal detection and modulation. The tunneling probability decays rapidly with the increase of the thickness of the insulating layer. When the insulating layer is relatively thick, the on-state current of a metal / insulating layer / metal (MIM) device is low, while when the insulating layer is too thin, both the forward and reverse currents are large, and the rectification ratio of the device is low. Therefore, the rectification characteristics of a conventional MIM-structured tunneling diode are usually inferior to those of an ordinary semiconductor diode. In recent years, people have also studied tunneling diodes with a metal / insulating layer / insulating layer / metal (MIIM) structure and used effects such as resonant tunneling to improve the rectification ratio of the device. However, the design of multiple insulating layers makes the device preparation more complex. Summary of the Invention

[0004] In view of this, to solve the technical problem that it is difficult to significantly improve the rectification performance of tunneling diodes in the prior art, in a first aspect, the present invention provides a semiconductor tunneling diode, which selects a semiconductor to contact electrode materials with different work functions, and forms asymmetric Schottky barriers with a top electrode and a bottom electrode respectively, so that electrons tunnel in a thin-layer semiconductor to achieve rectification. When it is used in a rectifier bridge, perfect rectification of a sine wave signal is achieved, and its rectification performance can be significantly improved, which provides an efficient idea for energy detection and collection in the future ultra-high frequency band.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A semiconductor tunneling diode selects a semiconductor to contact electrode materials with different work functions, and the semiconductor forms asymmetric Schottky barriers with a top electrode and a bottom electrode respectively, so that electrons tunnel in a thin-layer semiconductor to achieve rectification.

[0007] Preferably, the semiconductor is an N-type semiconductor or a P-type semiconductor.

[0008] In a second aspect, the present invention provides a rectifier bridge composed of a plurality of the above-mentioned semiconductor tunneling diodes.

[0009] Preferably, the number of the semiconductor tunneling diodes is four, namely tunneling diode TD1, tunneling diode TD2, tunneling diode TD3, and tunneling diode TD4.

[0010] Preferably, the first output terminal V OUT 1 of the rectifier bridge is connected to the top electrodes of tunneling diode TD1 and tunneling diode TD3, and the second output terminal V OUT 2 is connected to the bottom electrodes of tunneling diode TD2 and tunneling diode TD4. The first input terminal V IN 1 is connected to the bottom electrode of tunneling diode TD1 and the top electrode of tunneling diode TD2, and the second input terminal V IN 2 is connected to the bottom electrode of tunneling diode TD3 and the top electrode of tunneling diode TD4.

[0011] In a third aspect, the present invention provides a method for manufacturing the above rectifier bridge, including the following steps:

[0012] Step (1), cleaning the substrate;

[0013] Step (2), manufacturing the bottom electrode circuit of the rectifier circuit;

[0014] Step (3), manufacturing an insulating layer on the bottom electrode;

[0015] Step (4), removing the insulating layer between the bottom electrode and the pre-connection line of the top electrode of the semiconductor tunneling diode, and digging out a trench to expose the bottom electrode;

[0016] Step (5), manufacturing the connection line of the rectifier circuit and the top electrode circuit perpendicular to the bottom electrode;

[0017] Step (6), removing the insulating layer outside the coverage of the top electrode to expose the bottom electrode;

[0018] Step (7), manufacturing a semiconductor at the step formed by each top electrode, insulating layer, and bottom electrode structure to obtain a rectifier bridge based on semiconductor tunneling diodes.

[0019] Preferably, the electrode material of the bottom electrode is one of a metal electrode, a nitride electrode, and an oxide semiconductor electrode.

[0020] Preferably, the electrode material of the top electrode is one of a metal electrode, a nitride electrode, and an oxide semiconductor electrode.

[0021] Preferably, the insulating material of the insulating layer is one of an organic insulating material, an inorganic insulating material, and a two-dimensional insulating material.

[0022] Preferably, it is characterized in that the thickness of the insulating layer is less than 10 nanometers.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] In tunneling diodes and Schottky diodes, forming an asymmetric barrier is an effective method to improve the rectifying characteristics of the diode. The semiconductor tunneling diode provided by the present invention selects semiconductors to contact electrode materials (bottom electrode and top electrode) with different work functions, and forms asymmetric Schottky barriers with the top electrode and the bottom electrode respectively, which is beneficial to reducing the reverse current and increasing the rectification ratio, enabling electrons to tunnel in the thin-layer semiconductor to achieve the purpose of rectification, and can significantly improve the rectifying characteristics of the diode.

[0025] The present invention also proposes a full-wave rectifier bridge circuit based on a semiconductor tunneling diode and a preparation method thereof. The rectifier bridge of the present invention uses the above-mentioned semiconductor tunneling diode, and uses a semiconductor as the tunneling layer. Compared with insulating materials, it has a smaller resistivity and a larger conduction current density, thereby achieving a higher rectification ratio. In recent years, there have been many reports on rectifier circuits based on Schottky diode rectifier circuits, while the combination of semiconductor tunneling diodes and rectifier bridge circuits has rarely been studied. Due to the limitation of the ultimate response rate (~19.4 A / W) of ordinary Schottky diodes, in the high-frequency application field, the ultra-high-frequency rectifying characteristics of Schottky diodes are not as good as those of tunneling diodes. The present invention proposes to apply a semiconductor tunneling diode with a high forward current density (~22.6 A / cm 2 ), a high rectification ratio (>10 4 )), a high responsivity (~25.3 A / W) and a low turn-on voltage (~100 mV) to an actual rectifier circuit, and for the first time designs and prepares a full-wave rectifier circuit based on a semiconductor tunneling diode, achieving perfect rectification of sine wave signals, which provides an efficient idea for future energy detection and collection in the ultra-high-frequency band. Description of the Drawings

[0026] Figure 1 It is a schematic structural diagram of a semiconductor tunneling diode;

[0027] Figure 2 It is a structural diagram of a semiconductor tunneling diode prepared in Example 1 of the present invention;

[0028] Figure 3 It is a planar structural diagram of a rectifier bridge based on a semiconductor tunneling diode prepared in Example 1 of the present invention;

[0029] Figure 4 It is a normalized rectification result diagram of a rectifier bridge based on a semiconductor tunneling diode prepared in Example 1 of the present invention;

[0030] Figure 5Calculation results of the responsivity of the TiN / ZnO / Pt / tunneling diode prepared in Example 1 of the present invention;

[0031] Figure 6 Fitting results of the turn-on voltage of the TiN / ZnO / Pt / tunneling diode prepared in Example 1 of the present invention;

[0032] In the figure, 1, substrate layer; 2, bottom electrode; 3, insulating layer; 4, top electrode; 5, semiconductor. Detailed implementation manners

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention; obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "top / bottom end", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0035] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "provided with", "sheathed / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0036] As Figure 1-2 shown, the present invention provides a semiconductor tunneling diode. The semiconductor 5 is selected to be in contact with electrode materials with different work functions, and asymmetric Schottky barriers are respectively formed with the top electrode 4 and the bottom electrode 2, so that electrons tunnel in the thin-layer semiconductor to achieve rectification.

[0037] In the present invention, the semiconductor 5 is preferably an N-type semiconductor or a P-type semiconductor, more preferably an organic semiconductor or an inorganic semiconductor, such as titanium dioxide (TiO2), zinc oxide (ZnO), etc., and can also be a two-dimensional semiconductor material such as molybdenum disulfide (MoS2), etc.

[0038] The semiconductor tunneling diode rectifier bridge developed by the present invention using a semiconductor layer below 10 nm to replace the insulating layer has outstanding rectifying characteristics and excellent thermal stability, which helps to improve the stability of device operation.

[0039] The insulating layer separates the top electrode 4 and the bottom electrode 2. The structure with the semiconductor 5 deposited on the sidewalls enables the tunneling diode to meet a wide range of semiconductor materials and causes little damage to the semiconductor materials.

[0040] In the present invention, the semiconductor 5 is prepared at the step formed by the structures of the top electrode 4, the insulating layer 3 and the bottom electrode 2, so as to form a tunneling diode of the top electrode 4, the semiconductor 5 and the bottom electrode 2 on the sidewalls.

[0041] In the above-mentioned semiconductor tunneling diode provided by the present invention, the electrode materials of the top electrode 4 and the bottom electrode 2 can be metal electrodes, such as metals like gold (Au), platinum (Pt), titanium (Ti), etc., or nitride electrodes, such as titanium nitride (TiN), etc., or oxide semiconductor electrodes, such as indium tin oxide (ITO), etc.

[0042] Such as Figure 3 As shown, in the second aspect, the present invention provides a rectifier bridge composed of several of the above-mentioned semiconductor tunneling diodes.

[0043] In the present invention, the number of the semiconductor tunneling diodes is four, namely tunneling diode TD1, tunneling diode TD2, tunneling diode TD3 and tunneling diode TD4.

[0044] Preferably, the first output terminal V OUT 1 is connected to the top electrodes of the tunneling diode TD1 and the tunneling diode TD3, the second output terminal V OUT 2 is connected to the bottom electrodes of the tunneling diode TD2 and the tunneling diode TD4, the first input terminal V IN 1 is connected to the bottom electrode of the tunneling diode TD1 and the top electrode of the tunneling diode TD2, and the second input terminal V IN 2 is connected to the bottom electrode of the tunneling diode TD3 and the top electrode of the tunneling diode TD4.

[0045] In the third aspect, the present invention provides a preparation method of the above rectifier bridge, including the following steps:

[0046] Step (1), cleaning the substrate;

[0047] Step (2), preparing the bottom electrode 2 circuit of the rectifier circuit, wherein the bottom electrode 2 circuit is preferably a strip-shaped bottom electrode circuit;

[0048] Step (3), preparing the insulating layer 3 on the bottom electrode;

[0049] Step (4): Remove the insulating layer 3 between the pre-connection lines of the bottom electrode 2 and the top electrode 4 of the semiconductor tunneling diode, and make a groove to expose the bottom electrode. Preferably, remove the insulating layer between the pre-connection lines by ion etching technology.

[0050] Step (5): Prepare the rectifier circuit connection line and the top electrode 4 circuit perpendicular to the bottom electrode 2.

[0051] Step (6): Remove the insulating layer outside the coverage of the top electrode to expose the bottom electrode 2. Preferably, remove the insulating layer outside the coverage of the top electrode by ion etching technology.

[0052] Step (7): Prepare the semiconductor 5 at the step formed by each top electrode 4, insulating layer 3, and bottom electrode 2 structure to obtain a rectifier bridge based on the semiconductor tunneling diode.

[0053] In the preparation method of the rectifier bridge provided by the present invention, the electrode material of the bottom electrode 2 is one of a metal electrode, a nitride electrode, and an oxide semiconductor electrode.

[0054] In the preparation method of the rectifier bridge provided by the present invention, the electrode material of the top electrode 4 is one of a metal electrode, a nitride electrode, and an oxide semiconductor electrode.

[0055] In the preparation method of the rectifier bridge provided by the present invention, the insulating material of the insulating layer 3 can be an organic insulating material (such as polymethyl methacrylate, poly(vinylidene fluoride-trifluoroethylene), etc.), an inorganic insulating material (such as zirconia, hafnium dioxide, silicon dioxide, aluminum oxide, etc.), or a two-dimensional insulating material such as hexagonal boron nitride (h-BN), etc.

[0056] In the preparation method of the rectifier bridge provided by the present invention, it is characterized in that the thickness of the insulating layer is less than 10 nanometers.

[0057] Example 1

[0058] Preparation of the rectifier bridge

[0059] This example is illustrated by the preparation of (TiN / ZnO / Pt / tunneling diode full-wave rectifier bridge). The specific preparation steps are as follows:

[0060] (1) Put the substrate layer 1 (Si / SiO2) into acetone and ultrasonicate for 5 - 10 minutes, then put it into absolute ethanol and ultrasonicate for 5 - 10 minutes, then put it into deionized water and ultrasonicate for 5 - 10 minutes, and finally dry the substrate with a nitrogen gun.

[0061] (2) A 50-nanometer TiN layer is sputtered on the cleaned SiO2 / Si surface by radio frequency magnetron sputtering as the strip-shaped bottom electrode 2 circuit of the rectifier circuit. The power is 120 watts, the time is 10 minutes, and the chamber pressure is 0.3 Pa.

[0062] (3) A 10-nanometer aluminum oxide layer is deposited by ALD at 150 °C on the prepared TiN strip-shaped bottom electrode circuit as the insulating layer 3.

[0063] (4) Using a mask, the cross-connections of the bottom and top electrodes of TD1 with TD2 and TD3 with TD4 are etched away by ion etching technology to create trenches, ensuring conduction between TD1 and TD2 and between TD3 and TD4 respectively. Among them, the connection methods of TD1 with TD2 and TD3 with TD4 are as follows:

[0064] The first output terminal V OUT 1 of the rectifier bridge is connected to the top electrodes of tunneling diode TD1 and tunneling diode TD3, and the second output terminal V OUT 2 is connected to the bottom electrode of tunneling diode TD2 and the bottom electrode of tunneling diode TD4. The first input terminal V IN 1 is connected to the bottom electrode of tunneling diode TD1 and the top electrode of tunneling diode TD2, and the second input terminal V IN 2 is connected to the bottom electrode of tunneling diode TD3 and the top electrode of tunneling diode TD4.

[0065] (5) By magnetron sputtering technology, a 50-nanometer metal (Pt) layer is deposited on the 10-nanometer-thick insulating aluminum oxide layer as the connection wire of the rectifier circuit and the circuit of the top electrode 4 perpendicular to the bottom electrode 2. The power is 120 watts, the time is 3 minutes, and the chamber pressure is 0.3 Pa.

[0066] (6) Then, using the 50-nanometer Pt layer as a self-masking plate, the aluminum oxide outside the coverage of the top electrode is removed by ion etching technology, and the aluminum oxide covered by Pt is retained, exposing the strip-shaped bottom electrode circuit.

[0067] (7) By radio frequency magnetron sputtering technology, a 20-nanometer-thick ZnO layer is sputtered as the semiconductor 5 to the step formed by the structure of the top electrode 4 / insulating layer 3 / bottom electrode 2. The power is 80 watts, the time is 10 minutes, and the chamber pressure is 0.8 Pa. Finally, the planar structure diagram of the rectifier bridge of the semiconductor tunneling diode as shown in Figure 3 is obtained.

[0068] The rectification performance of the device prepared in Example 1 was tested, and the normalized results are as shown in Figure 4 It is found that the rectification performance of this rectifier bridge is good.

[0069] The above is only a preferred specific embodiment of the present invention; however, the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and its improved concept of the present invention, making equivalent substitutions or changes, shall be covered by the protection scope of the present invention.

Claims

1. A semiconductor tunneling diode, characterized in that, Select a semiconductor to contact electrode materials with different work functions, and form asymmetric Schottky barriers with the top electrode and the bottom electrode respectively, so that electrons can tunnel through the thin-layer semiconductor to achieve rectification.

2. The semiconductor tunneling diode according to claim 1, wherein The semiconductor is an N-type semiconductor or a P-type semiconductor.

3. A rectifier bridge, characterized in that, It is composed of several semiconductor tunneling diodes described in claim 1 or 2.

4. A rectifier bridge according to claim 3, characterized in that, The number of the semiconductor tunneling diodes is four, namely tunneling diode TD1, tunneling diode TD2, tunneling diode TD3 and tunneling diode TD4.

5. A rectifier bridge according to claim 4, characterized in that, The first output terminal V of the rectifier bridge OUT 1 is connected to the top electrodes of the tunneling diode TD1 and the tunneling diode TD3, and the second output terminal V OUT 2 is connected to the bottom electrodes of the tunneling diode TD2 and the tunneling diode TD4. The first input terminal V IN 1 is connected to the bottom electrode of the tunneling diode TD1 and the top electrode of the tunneling diode TD2, and the second input terminal V IN 2 is connected to the bottom electrode of the tunneling diode TD3 and the top electrode of the tunneling diode TD4.

6. A method for preparing a rectifier bridge according to any one of claims 3-5, characterized in that, It includes the following steps: Step (1): Clean the substrate. Step (2): Prepare the bottom electrode circuit of the rectifier circuit. Step (3): Prepare an insulating layer on the bottom electrode. Step (4): Remove the insulating layer between the bottom electrode and the pre-connection wire of the top electrode of the semiconductor tunneling diode, and dig out a groove to expose the bottom electrode. Step (5): Prepare the connection wire of the rectifier circuit and the top electrode circuit perpendicular to the bottom electrode. Step (6): Remove the insulating layer outside the coverage of the top electrode to expose the bottom electrode. Step (7): Prepare a semiconductor at the step formed by each top electrode, insulating layer and bottom electrode structure to obtain a rectifier bridge based on semiconductor tunneling diodes.

7. The preparation method of a rectifier bridge according to claim 6, characterized in that, The electrode material of the bottom electrode is one of a metal electrode, a nitride electrode and an oxide semiconductor electrode.

8. The manufacturing method of a rectifier bridge according to claim 6, characterized in that, The electrode material of the top electrode is one of a metal electrode, a nitride electrode and an oxide semiconductor electrode.

9. The preparation method of a rectifier bridge according to claim 6, wherein, The insulating material of the insulating layer is one of an organic insulating material, an inorganic insulating material and a two-dimensional insulating material.

10. A method for preparing a rectifier bridge according to any one of claims 6-9, characterized in that, The thickness of the insulating layer is less than 10 nanometers.

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