Gallium oxide Schottky diode, preparation method thereof and electronic equipment

Abstract

The invention provides a gallium oxide Schottky diode, a preparation method thereof and electronic equipment. The gallium oxide Schottky diode comprises a semiconductor layer, a Schottky electrode and an ohmic electrode, the semiconductor layer comprises a gallium oxide thin film, a gallium oxide material in the gallium oxide thin film is amorphous gallium oxide and / or polycrystalline gallium oxide, Schottky contact is formed between the Schottky electrode and the gallium oxide thin film, and the ohmic electrode is arranged between the Schottky electrode and the gallium oxide thin film. Ohmic contact is formed between the ohmic electrode and the gallium oxide thin film, and the on-off ratio of the gallium oxide Schottky diode is more than 108.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a gallium oxide Schottky diode, a preparation method thereof and electronic equipment. Background Art

[0002] Schottky Barrier Diodes (SBD) are commonly used components in circuits. Schottky diodes are also commonly called Schottky barrier diodes. Schottky diodes usually include metals and semiconductors. The interface between the metals and semiconductors can form a barrier, so Schottky diodes have a rectifying effect. Schottky diodes are widely used in amplifiers, logic gates, light detection, and solar cells. High-performance Schottky diodes can also be used in large arrays of resistive random access memory and phase change memory to reduce parasitic currents.

[0003] Gallium oxide (Ga2O3) is a metal oxide semiconductor with a wide band gap of 4.5eV to 4.9eV and a high breakdown strength of 6MV / cm to 8MV / cm. The current preparation cost of gallium oxide Schottky diode devices needs to be further reduced, and the performance needs to be further improved. Summary of the invention

[0004] In view of this, the primary object of the present invention is to provide a gallium oxide Schottky diode, which has a significantly higher switching ratio when using a non-single-crystal gallium oxide material.

[0005] According to some embodiments of the present disclosure, a gallium oxide Schottky diode is provided, which comprises: a semiconductor layer, a Schottky electrode and an ohmic electrode, wherein the semiconductor layer comprises a gallium oxide film, the gallium oxide material in the gallium oxide film is amorphous gallium oxide and / or polycrystalline gallium oxide, a Schottky contact is formed between the Schottky electrode and the gallium oxide film, an ohmic contact is formed between the ohmic electrode and the gallium oxide film, and the switching ratio of the gallium oxide Schottky diode is within 10 8 above.

[0006] In some embodiments of the present disclosure, the thickness of the semiconductor layer is 40 nm to 200 nm.

[0007] In some embodiments of the present disclosure, the ohmic electrode includes an oxygen-absorbing conductive material, the oxygen-absorbing conductive material is in direct contact with the gallium oxide in the semiconductor layer, and the oxygen-absorbing conductive material includes a conductive material that can combine with oxygen atoms in the gallium oxide.

[0008] In some embodiments of the present disclosure, the oxygen-absorbing conductive material includes one or more of indium tin oxide and titanium.

[0009] In some embodiments of the present disclosure, a substrate is further included, wherein the substrate is a flexible substrate, and the semiconductor layer, the Schottky electrode and the ohmic electrode are all arranged on the substrate.

[0010] Furthermore, the present disclosure also provides a method for preparing a gallium oxide Schottky diode as described in any of the above embodiments, comprising the following steps:

[0011] Providing a substrate, and preparing the Schottky electrode, the semiconductor layer and the ohmic electrode on the substrate;

[0012] Among them, the step of preparing the semiconductor layer includes: depositing the gallium oxide film by sputtering, during the sputtering process, the ambient gas in the sputtering chamber includes oxygen, the volume proportion of oxygen in the ambient gas is controlled to be 1 / 20 to 1 / 5, and the thickness of the gallium oxide film is controlled to be 40nm to 200nm.

[0013] In some embodiments of the present disclosure, the step of preparing the Schottky electrode is performed before the step of preparing the semiconductor layer, and the step of preparing the Schottky electrode includes:

[0014] depositing the first electrode material layer on the substrate,

[0015] A first pattern layer is prepared on the first electrode material layer, and the first electrode material layer is etched based on the first pattern layer to form the Schottky electrode.

[0016] In some embodiments of the present disclosure, the gallium oxide film is deposited on the Schottky electrode, and the step of preparing the ohmic electrode is performed after the step of preparing the semiconductor layer. The step of preparing the ohmic electrode includes:

[0017] depositing a second electrode material layer on the semiconductor layer,

[0018] A second pattern layer is prepared on the second electrode material layer, and the second electrode material layer is etched based on the second pattern layer to form the ohmic electrode.

[0019] In some embodiments of the present disclosure, the substrate is a flexible substrate, and in the steps of preparing the Schottky electrode, the semiconductor layer and the ohmic electrode, the temperature of the substrate is controlled not to exceed 200°C.

[0020] Furthermore, the present disclosure also provides an electronic device, which includes a circuit structure, wherein the circuit structure includes the gallium oxide Schottky diode as described in any of the above embodiments.

[0021] The on-off ratio is a key parameter for measuring Schottky diodes. A low on-off ratio will result in a low rectification efficiency of the Schottky diode when used for rectification and energy collection, which will lead to significant energy waste and heat generation. The gallium oxide Schottky diode provided by the present disclosure includes a semiconductor layer, wherein the semiconductor layer includes a gallium oxide film, and the gallium oxide material in the gallium oxide film is amorphous gallium oxide and / or polycrystalline gallium oxide. The on-off ratio of the gallium oxide Schottky diode is 10 8 The gallium oxide Schottky diode can use non-single-crystal gallium oxide material as the gallium oxide film, which significantly simplifies the preparation process and production cost of the gallium oxide Schottky diode. In addition, the gallium oxide Schottky diode has more than 10 8 The above switching ratio is significantly improved compared to the traditional non-single-crystal gallium oxide Schottky diode. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic diagram of the cross-sectional structure of a gallium oxide Schottky diode disclosed in the present invention;

[0023] Figure 2 A schematic diagram of the steps for preparing a gallium oxide Schottky diode;

[0024] Figure 3 This is a current-voltage relationship diagram of the gallium oxide Schottky diode prepared in Example 1;

[0025] The reference numerals and their meanings are as follows:

[0026] 100, substrate; 110, Schottky electrode; 120, semiconductor layer; 130, ohmic electrode; 140, adhesion layer. DETAILED DESCRIPTION

[0027] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items, and "more" used herein includes two or more items.

[0029] In the present invention, unless otherwise stated, the sum of the parts of each component in the composition can be 100 parts by weight. Unless otherwise specified, the basis of the percentages (including weight percentages) of the present invention is the total weight of the composition. In addition, "wt%" herein means mass percentage, and "at%" means atomic percentage.

[0030] In this article, unless otherwise stated, each reaction step may be carried out in the order described herein or may not be carried out in the order described herein. For example, other steps may be included between each reaction step, and the order of the reaction steps may also be appropriately swapped. This can be determined by the technician based on common knowledge and experience. Preferably, the reaction method herein is carried out sequentially.

[0031] The present invention discloses a gallium oxide Schottky diode, which comprises: a semiconductor layer, a Schottky electrode and an ohmic electrode, wherein the semiconductor layer comprises a gallium oxide film, the gallium oxide material in the gallium oxide film is amorphous gallium oxide and / or polycrystalline gallium oxide, a Schottky contact is formed between the Schottky electrode and the gallium oxide film, an ohmic contact is formed between the ohmic electrode and the gallium oxide film, and the switching ratio of the gallium oxide Schottky diode is within 10 8 above.

[0032] The gallium oxide Schottky diode provided by the present invention comprises a semiconductor layer, wherein the semiconductor layer comprises a gallium oxide film, wherein the gallium oxide material in the gallium oxide film is amorphous gallium oxide and / or polycrystalline gallium oxide, and the switching ratio of the gallium oxide Schottky diode is within 10 8 The gallium oxide Schottky diode can use non-single-crystal gallium oxide material as the gallium oxide film, which significantly simplifies the preparation process and production cost of the gallium oxide Schottky diode. In addition, the gallium oxide Schottky diode has more than 10 8 The above switching ratio is significantly improved compared to the traditional non-single-crystal gallium oxide Schottky diode.

[0033] In order to facilitate understanding of the structure of the gallium oxide Schottky diode disclosed in the present invention, Figure 1 A schematic diagram of the cross-sectional structure of a gallium oxide Schottky diode is provided. Figure 1 As shown, the present disclosure provides a gallium oxide Schottky diode, which has a semiconductor layer 120, a Schottky electrode 110 and an ohmic electrode 130. The semiconductor layer 120 includes a gallium oxide film. The gallium oxide material in the gallium oxide film is amorphous gallium oxide and / or polycrystalline gallium oxide. A Schottky contact is formed between the Schottky electrode 110 and the gallium oxide film. An ohmic contact is formed between the ohmic electrode 130 and the gallium oxide film. The switching ratio of the gallium oxide Schottky diode is within 10 8 above.

[0034] It can be understood that in the gallium oxide Schottky diode, Schottky contact means that when the Schottky electrode 110 contacts the gallium oxide film, the energy band of the gallium oxide film is bent at the contact interface and a Schottky barrier is formed, which will lead to a larger interface resistance. The gallium oxide film can be in direct contact with the Schottky electrode 110 so that a Schottky contact is formed between the gallium oxide film and the Schottky electrode 110. The ohmic contact is opposite to the Schottky contact, which means that when the ohmic electrode 130 contacts the gallium oxide film, the barrier at the contact interface is small or does not exist.

[0035] The switching ratio of Schottky diodes using amorphous gallium oxide or polycrystalline gallium oxide is usually significantly lower, which is difficult to meet actual needs. In order to ensure that the switching ratio of gallium oxide Schottky diodes is relatively high, single crystal gallium oxide is usually used as the semiconductor layer in traditional technology. However, single crystal gallium oxide materials usually need to be prepared by a melting method, which leads to significantly higher preparation costs of single crystal gallium oxide materials, thereby limiting the manufacturing cost and production efficiency of gallium oxide Schottky diodes. In addition, the size of single crystal gallium oxide is also usually large, which also limits the application field of the device. The gallium oxide Schottky diode provided by the present invention uses polycrystalline gallium oxide and / or amorphous gallium oxide as the gallium oxide film, and has a switching ratio of 10 8 The above switch ratio.

[0036] Among them, the requirements for the preparation process conditions of polycrystalline gallium oxide and / or amorphous gallium oxide are much lower than those of single crystal gallium oxide. In some examples of this embodiment, the gallium oxide film can be prepared by physical vapor deposition or chemical vapor deposition. For example, the gallium oxide film can be prepared by sputtering. Further, the sputtering can be radio frequency magnetron sputtering.

[0037] Reference Figure 1 As shown, in some examples of this embodiment, in the gallium oxide Schottky diode, the Schottky electrode 110 and the ohmic electrode 130 can be respectively arranged on both sides of the semiconductor layer 120. Further, the gallium oxide Schottky diode can also include a substrate 100, and the Schottky electrode 110, the semiconductor layer 120 and the ohmic electrode 130 are all arranged on the substrate 100. Further, the Schottky electrode 110, the semiconductor layer 120 and the ohmic electrode 130 can be stacked on the substrate 100 in sequence. In other embodiments, the ohmic electrode 130, the semiconductor layer 120 and the Schottky electrode 110 can also be stacked on the substrate 100 in sequence. It can be understood that this will not have a significant impact on the performance of the device itself.

[0038] In conventional technology, Schottky diodes using single-crystal gallium oxide are limited by the requirements of single crystals, resulting in a relatively limited application range of the device, while polycrystalline gallium oxide and amorphous gallium oxide used in the present disclosure are more resistant to bending. In some examples of this embodiment, the substrate 100 may be a flexible substrate 100. The flexible substrate 100 can be bent while ensuring the normal operation of the gallium oxide Schottky diode, which enables it to be applied to flexible circuits, further broadening the application range of the gallium oxide Schottky diode.

[0039] In some examples of this embodiment, the material of the flexible substrate 100 may include a polymer material. For example, the flexible substrate 100 may be polyethylene naphthalate, polyethylene terephthalate, polyimide, polymethyl methacrylate, polydimethylsiloxane, polyvinyl chloride, polycarbonate, polystyrene, or organic glass.

[0040] On the other hand, polymer materials generally have a low melting point, and the processing of single-crystal gallium oxide usually involves high-temperature treatment, which also makes it difficult to combine single-crystal gallium oxide with the flexible substrate 100. In the present disclosure, polycrystalline gallium oxide and / or amorphous gallium oxide are used to better overcome this problem.

[0041] It can be understood that in some other examples, the substrate 100 may also be a non-flexible substrate 100. For example, the substrate 100 may be a rigid substrate 100, and the material of the rigid substrate 100 may include one of a silicon wafer, sapphire and quartz glass.

[0042] In some examples of this embodiment, the material of the Schottky electrode 110 may include a conductive material. The conductive material may include a metal material or a metal oxide semiconductor material, as long as it can form a Schottky contact with the gallium oxide film. Among them, the metal material may be a metal material with a higher work function, for example, the work function of the metal material is above 4.7 eV. Further, the metal material may be selected from one or more of gold, chromium, copper, iron, nickel, tungsten, platinum and palladium.

[0043] In some examples of this embodiment, the potassium oxide Schottky diode may further include an adhesion layer 140, which may be disposed on the substrate 100 and between the substrate 100 and the semiconductor layer 120. The adhesion layer 140 may be used to enhance the adhesion between the substrate 100 and the Schottky electrode 110.

[0044] In some examples of this embodiment, the ohmic electrode 130 includes an oxygen-absorbing conductive material, which is in direct contact with the gallium oxide film in the semiconductor layer 120, and the oxygen-absorbing conductive material includes a conductive material that can be combined with oxygen atoms in the gallium oxide film. The oxygen-absorbing conductive material can be combined with oxygen atoms in the gallium oxide film, which can increase oxygen vacancy defects at the interface between the gallium oxide film and the oxygen-absorbing conductive material, thereby significantly improving the on-state current of the gallium oxide Schottky diode.

[0045] Furthermore, in some examples of this embodiment, the ohmic electrode 130 includes one or more of indium tin oxide and titanium. Indium tin oxide has a strong ability to bind oxygen atoms. When indium tin oxide contacts the gallium oxide film, it can capture oxygen atoms in the gallium oxide film, so that more oxygen vacancy defects are generated at the interface of the gallium oxide film, which can effectively improve the on-state current of the gallium oxide Schottky diode.

[0046] In some examples of this embodiment, in the gallium oxide Schottky diode, the thickness of the gallium oxide film can be 40nm to 200nm. Among them, controlling the thickness of the gallium oxide film to be above 40nm can make the off-state current of the gallium oxide Schottky diode lower, and controlling the thickness of the gallium oxide film to be below 200nm can make the on-state current of the gallium oxide Schottky diode higher, and further make the gallium oxide Schottky diode have a higher switching ratio. In addition, polycrystalline gallium oxide and / or amorphous gallium oxide can also be prepared with a thinner thickness, which can further reduce the overall size of the gallium oxide Schottky diode device, making it suitable for some scenes such as integrated circuits that have high requirements on device size.

[0047] In some examples of this embodiment, the thickness of the gallium oxide film may be 40 nm, 60 nm, 90 nm, 120 nm, 150 nm or 200 nm. Further, the thickness of the gallium oxide film may also be in a range between any two of the above thicknesses.

[0048] In some examples of this embodiment, the Schottky electrode 110 may also have a thinner thickness to further reduce the overall device size of the gallium oxide Schottky diode. For example, the thickness of the Schottky electrode 110 may be 20nm to 100nm. Further, the thickness of the Schottky electrode 110 may be 20nm, 30nm, 50nm, 60nm, 80nm or 100nm. Furthermore, the thickness of the Schottky electrode 110 may also be a range between any two of the above thicknesses.

[0049] In some examples of this embodiment, the ohmic electrode 130 may also have a thinner thickness to further reduce the overall device size of the gallium oxide Schottky diode. For example, the thickness of the ohmic electrode 130 may be 10nm to 100nm. Further, the thickness of the ohmic electrode 130 may be 10nm, 20nm, 40nm, 60nm, 80nm or 100nm. Furthermore, the thickness of the ohmic electrode 130 may also be a range between any two of the above thicknesses.

[0050] Furthermore, the present disclosure also provides a method for preparing the gallium oxide Schottky diode in the above embodiment, Figure 2 The schematic diagram of the steps of the preparation method is shown. Figure 2 As shown, the method for preparing the gallium oxide Schottky diode includes steps S1 to S4.

[0051] Step S1, providing a substrate.

[0052] In some examples of this embodiment, quartz glass may be used as the substrate 100. It is understood that the use of quartz glass here is only an example, and in other embodiments, the substrate 100 may also be designed as a flexible substrate 100. For example, the substrate 100 may include a polymer material.

[0053] In some examples of this embodiment, a step of cleaning the substrate 100 may also be included. For example, the substrate 100 may be cleaned by ultrasonic cleaning. Ultrasonic cleaning can effectively remove impurities remaining on the surface of the substrate 100. Further, the cleaning solution used to clean the substrate 100 may include one or more of acetone, ethanol and deionized water.

[0054] In this embodiment, the substrate 100 may be placed in acetone, ethanol and deionized water in sequence for ultrasonic cleaning.

[0055] Step S2, preparing a Schottky electrode on the substrate.

[0056] In some examples of this embodiment, the step of preparing the Schottky electrode 110 on the substrate 100 includes: depositing a first electrode material layer on the substrate 100, and preparing a first pattern layer on the first electrode material layer, and etching the first electrode material layer based on the first pattern layer to form the Schottky electrode 110.

[0057] It can be understood that the Schottky electrode 110 is prepared by etching the first electrode material layer, so the material of the first electrode material layer should be the same as that of the Schottky electrode 110 .

[0058] In some examples of this embodiment, the material of the first electrode material layer may include a conductive material. Further, the conductive material may include a metal material or a metal oxide semiconductor material, as long as it can form a Schottky contact with the gallium oxide film. Among them, the metal material may be a metal material with a higher work function, for example, the work function of the metal material is above 4.7 eV. In this embodiment, the material of the first electrode material layer may be gold.

[0059] In some examples of this embodiment, the first electrode material layer may be deposited by physical vapor deposition, for example, the first electrode material layer may be deposited by sputtering.

[0060] In some examples of this embodiment, before depositing the first electrode material layer, a step of preparing an adhesion layer 140 on the substrate 100 may be further included. The adhesion layer 140 may also include a metal material, for example, the material of the adhesion layer 140 may include but is not limited to one or more of chromium and titanium.

[0061] In some examples of this embodiment, the adhesion layer 140 may be prepared by physical vapor deposition, for example, the adhesion layer 140 may be prepared by sputtering.

[0062] In some examples of this embodiment, the thickness of the deposited first electrode material layer can be controlled to be 20nm to 100nm. Further, the thickness of the deposited first electrode material layer can be controlled to be 20nm, 30nm, 50nm, 60nm, 80nm or 100nm. Furthermore, the thickness of the first electrode material layer can also be a range between any two thicknesses mentioned above. It can be understood that the thickness of the first electrode material layer can be more accurately controlled by controlling the deposition time.

[0063] In some examples of this embodiment, the thickness of the adhesion layer 140 can be controlled to be 5 nm to 30 nm. For example, the thickness of the adhesion layer 140 can be controlled to be 5 nm, 10 nm, 15 nm, 20 nm, 25 nm or 30 nm. Further, the thickness of the adhesion layer 140 can also be a range between any two of the above thicknesses.

[0064] In some examples of this embodiment, the material of the first pattern layer may include a patterned photoresist. The step of preparing the first pattern layer may include: coating the photoresist on the first electrode material layer, exposing and developing the photoresist to form the first pattern layer. It is understood that after the etching of the first electrode material layer is completed, the first pattern layer may be removed, and the method of removing the first pattern layer may include dissolving the photoresist with a stripping solution.

[0065] In addition, in conventional technology, a patterned photoresist is usually prepared first, and then a Schottky electrode 110 is deposited on the patterned photoresist and then the patterned photoresist is removed, i.e., a lift-off process. However, this will contaminate the interface between the Schottky electrode 110 and the subsequently prepared semiconductor layer 120, resulting in poor performance of the Schottky contact. In this embodiment, a first electrode material layer is prepared first, and then the Schottky electrode 110 is formed through an etching process, which can protect the Schottky contact and make it have better performance, which helps to optimize the Schottky contact and increase the on-state current.

[0066] It can be understood that etching the first electrode material layer can form a Schottky electrode 110 with a specific shape and size on the substrate 100. In addition, multiple Schottky electrodes 110 arranged at intervals can be simultaneously prepared on the substrate 100 by etching.

[0067] In some examples of this embodiment, in the step of preparing the Schottky electrode 110, the temperature of the substrate 100 may be controlled not to exceed 200°C. For example, the first electrode material layer may be deposited on the substrate 100 when the substrate 100 is at room temperature or 20°C to 50°C. In the step of preparing the first pattern layer, the temperature of the substrate 100 may also be controlled not to exceed 200°C. Controlling the preparation temperature to be low can, on the one hand, reduce the process difficulty and corresponding steps in the production and preparation process, and on the other hand, when the substrate 100 is a flexible substrate 100, it can also avoid the thermal deformation of the flexible substrate 100.

[0068] Step S3, preparing a semiconductor layer on the Schottky electrode.

[0069] The semiconductor layer 120 may include a gallium oxide film, which may be prepared by sputtering. Specifically, the step of preparing the semiconductor layer 120 includes: depositing the gallium oxide film by sputtering, wherein the ambient gas in the sputtering chamber includes oxygen during the sputtering process, the volume ratio of oxygen in the ambient gas is controlled to be 1 / 20 to 1 / 5, and the thickness of the gallium oxide film is controlled to be 40 nm to 200 nm.

[0070] By controlling the volume ratio of oxygen in the ambient gas to 1 / 20 to 1 / 5, the gallium oxide film can have more suitable oxygen vacancy defects, thereby optimizing the Schottky contact between the gallium oxide film and the Schottky electrode 110. By controlling the thickness of the gallium oxide film to 40nm to 200nm, the gallium oxide Schottky diode can have a higher on-state current and a lower off-state current. Experiments have shown that by controlling the volume ratio of oxygen and the thickness of the gallium oxide film, the on-off ratio of the prepared gallium oxide Schottky diode can reach 10 8Furthermore, in some embodiments, this can also make the off-state current of the prepared gallium oxide Schottky diode lower, at 10 -10 A / cm 2 the following.

[0071] In some examples of this embodiment, during the sputtering process, the volume proportion of oxygen in the ambient gas can be controlled to be 1 / 20, 1 / 15, 1 / 10, or 1 / 5. Further, the volume proportion of oxygen in the ambient gas can be controlled to be within a range between any two of the above proportions.

[0072] It is understood that the ambient gas may also include other gases, which may be protective gases. For example, the ambient gas may also include argon. Further, the ambient gas may be composed of oxygen and protective gas. It is understood that when the volume ratio of oxygen in the ambient gas is 1 / 20, the volume ratio of oxygen to argon may be 1:19.

[0073] It is understood that the thickness of the gallium oxide film can be controlled by controlling the duration of sputtering. In some examples of this embodiment, the thickness of the gallium oxide film can be 40nm, 60nm, 90nm, 120nm, 150nm or 200nm. Further, the thickness of the gallium oxide film can also be a range between any two of the above thicknesses.

[0074] In some examples of this embodiment, in the step of preparing the semiconductor layer 120, the temperature of the substrate 100 may be controlled not to exceed 200° C. For example, a gallium oxide thin film may be deposited on the substrate 100 when the substrate 100 is at room temperature or 20° C. to 50° C.

[0075] It can be understood that in the preparation method of this embodiment, the gallium oxide film prepared by sputtering is in an amorphous state and / or a polycrystalline state, so the gallium oxide film includes amorphous gallium oxide and / or polycrystalline gallium oxide. By controlling the ambient gas used in the sputtering process and the thickness of the gallium oxide film, an on / off ratio of 10 can be achieved. 8 In some other embodiments, other preparation processes or materials used can be further controlled, which can also achieve a switching ratio of 10 while widening the process window. 8 For example, the preparation process of the Schottky electrode 110 can be optimized to improve the performance of the Schottky contact, and the material and preparation process of the ohmic electrode 130 can be optimized to improve the performance of the ohmic contact.

[0076] Step S4, preparing an ohmic electrode on the gallium oxide film.

[0077] The step of preparing the ohmic electrode 130 on the gallium oxide film may include: depositing a second electrode material layer on the semiconductor layer 120 , preparing a second pattern layer on the second electrode material layer, and etching the second electrode material layer based on the second pattern layer to form the ohmic electrode 130 .

[0078] It can be understood that the ohmic electrode 130 is prepared by etching the second electrode material layer, so the material of the second electrode material layer should be the same as that of the ohmic electrode 130 .

[0079] In some examples of this embodiment, the material of the second electrode material layer may include a conductive material. Further, the material of the second electrode material layer includes an oxygen-absorbing conductive material, the oxygen-absorbing conductive material is in direct contact with the gallium oxide film, and the oxygen-absorbing conductive material includes a conductive material that can bind to oxygen atoms in the gallium oxide film. Further, the oxygen-absorbing conductive material includes one or more of indium tin oxide and titanium. Among them, indium tin oxide has a strong ability to bind oxygen atoms. When indium tin oxide contacts the gallium oxide film, it can capture oxygen atoms in the gallium oxide film, so that more oxygen vacancy defects are generated at the interface of the gallium oxide film, which can effectively improve the on-state current of the gallium oxide Schottky diode.

[0080] In some examples of this embodiment, the second electrode material layer may be deposited by physical vapor deposition, for example, the second electrode material layer may be deposited by sputtering.

[0081] In some examples of this embodiment, the thickness of the second electrode material layer can be controlled to be 10nm to 100nm. Further, the thickness of the second electrode material layer can be controlled to be 10nm, 20nm, 40nm, 60nm, 80nm or 100nm. Furthermore, the thickness of the second electrode material layer can also be a range between any two of the above thicknesses.

[0082] In some examples of this embodiment, the material of the second pattern layer may include a patterned photoresist. The step of preparing the second pattern layer may include: coating the photoresist on the second electrode material layer, exposing and developing the photoresist to form the second pattern layer. It is understood that after the etching of the second electrode material layer is completed, the second pattern layer may also be removed, and the method of removing the second pattern layer may include dissolving the photoresist with a stripping solution.

[0083] In some examples of this embodiment, the step of etching the second electrode material layer based on the second pattern layer may further include: etching a gallium oxide film based on the second pattern layer to form the semiconductor layer 120 .

[0084] In some examples of this embodiment, in the step of preparing the ohmic electrode 130, the temperature of the substrate 100 may be controlled not to exceed 200° C. For example, the second electrode material layer may be deposited on the substrate 100 when the substrate 100 is at room temperature or 20° C. to 50° C. In the step of preparing the second pattern layer, the temperature of the substrate 100 may also be controlled not to exceed 200° C.

[0085] It can be understood that through steps S1 to S4, the following can be prepared: Figure 1 The gallium oxide Schottky diode shown in FIG. has a 8 The above switch ratio.

[0086] Furthermore, the present disclosure also provides an electronic device, which includes a circuit structure, wherein the circuit structure includes a gallium oxide Schottky diode as in the above embodiment.

[0087] In some examples of this embodiment, the circuit structure may be a flexible printed circuit board or an integrated circuit.

[0088] In order to make it easier to understand and implement the present invention, the following more specific and detailed embodiments and comparative examples are provided as references. Through the description and performance results of the following specific embodiments and comparative examples, the embodiments of the present invention and their advantages will also be apparent. In the following test examples and comparative examples, unless otherwise specified, the raw materials used in the following embodiments and comparative examples can all be purchased conventionally on the market.

[0089] Example 1

[0090] The quartz glass was ultrasonically cleaned in acetone, ethanol and deionized water for 10 min each, and then taken out and blown dry;

[0091] The quartz glass is placed in a sputtering chamber of a magnetron sputtering device, the temperature of the sputtering chamber and the substrate is controlled to be room temperature (25° C.), a chromium film with a thickness of 10 nm and a gold film with a thickness of 30 nm are sputtered in sequence, a photoresist is spin-coated on the gold film, and exposure and development are performed in sequence to form a pattern layer with an opening, the gold film and the chromium film are etched based on the pattern layer to form a Schottky electrode, and then the pattern layer is removed by dissolving with a degumming solution;

[0092] A 60 nm thick gallium oxide film was sputtered on the gold film. The ambient gas in the sputtering chamber was a mixture of oxygen and argon, wherein the volume ratio of oxygen to argon was 1:9, and the sputtering power was 60 W.

[0093] An indium tin oxide film with a thickness of 20 nm is sputtered on the gallium oxide film, and a photoresist is spin-coated on the indium tin oxide film, and exposure and development are performed in sequence to form a pattern layer with an opening. The indium tin oxide film and the gallium oxide film are etched based on the pattern layer to form an ohmic electrode and a semiconductor layer, respectively, and then the pattern layer is removed by dissolving with a degumming solution.

[0094] Example 2

[0095] The quartz glass was ultrasonically cleaned in acetone, ethanol and deionized water for 10 min each, and then taken out and blown dry;

[0096] The quartz glass is placed in a sputtering chamber of a magnetron sputtering device, the temperature of the sputtering chamber and the substrate is controlled to be room temperature (25° C.), a chromium film with a thickness of 10 nm and a gold film with a thickness of 30 nm are sputtered in sequence, a photoresist is spin-coated on the gold film, and exposure and development are performed in sequence to form a pattern layer with an opening, the gold film and the chromium film are etched based on the pattern layer to form a Schottky electrode, and then the pattern layer is removed by dissolving with a degumming solution;

[0097] A 150 nm thick gallium oxide film was sputtered on the gold film. The ambient gas in the sputtering chamber was a mixture of oxygen and argon, wherein the volume ratio of oxygen to argon was 1:9, and the sputtering power was 60 W.

[0098] An indium tin oxide film with a thickness of 20 nm is sputtered on the gallium oxide film, and a photoresist is spin-coated on the indium tin oxide film, and exposure and development are performed in sequence to form a pattern layer with an opening. The indium tin oxide film and the gallium oxide film are etched based on the pattern layer to form an ohmic electrode and a semiconductor layer, respectively, and then the pattern layer is removed by dissolving with a degumming solution.

[0099] Example 3

[0100] The quartz glass was ultrasonically cleaned in acetone, ethanol and deionized water for 10 min each, and then taken out and blown dry;

[0101] The quartz glass is placed in a sputtering chamber of a magnetron sputtering device, the temperature of the sputtering chamber and the substrate is controlled to be room temperature (25° C.), a chromium film with a thickness of 10 nm and a gold film with a thickness of 30 nm are sputtered in sequence, a photoresist is spin-coated on the gold film, and exposure and development are performed in sequence to form a pattern layer with an opening, the gold film and the chromium film are etched based on the pattern layer to form a Schottky electrode, and then the pattern layer is removed by dissolving with a degumming solution;

[0102] A 60 nm thick gallium oxide film was sputtered on the gold film. The ambient gas in the sputtering chamber was a mixture of oxygen and argon, wherein the volume ratio of oxygen to argon was 1:6, and the sputtering power was 60 W.

[0103] An indium tin oxide film with a thickness of 20 nm is sputtered on the gallium oxide film, and a photoresist is spin-coated on the indium tin oxide film, and exposure and development are performed in sequence to form a pattern layer with an opening. The indium tin oxide film and the gallium oxide film are etched based on the pattern layer to form an ohmic electrode and a semiconductor layer, respectively, and then the pattern layer is removed by dissolving with a degumming solution.

[0104] Example 4

[0105] The quartz glass was ultrasonically cleaned in acetone, ethanol and deionized water for 10 min each, and then taken out and blown dry;

[0106] Spin-coating photoresist on quartz glass, and sequentially performing exposure and development to form a pattern layer with an opening, placing the quartz glass in a sputtering chamber of a magnetron sputtering device, controlling the temperature of the sputtering chamber and the substrate to be room temperature (25° C.), sequentially sputtering a chromium film with a thickness of 10 nm and a gold film with a thickness of 30 nm, and then removing the pattern layer by dissolving with a degumming liquid to form a Schottky electrode;

[0107] A 60 nm thick gallium oxide film was sputtered on the gold film. The ambient gas in the sputtering chamber was a mixture of oxygen and argon, wherein the volume ratio of oxygen to argon was 1:9, and the sputtering power was 60 W.

[0108] An indium tin oxide film with a thickness of 20 nm is sputtered on the gallium oxide film, and a photoresist is spin-coated on the indium tin oxide film, and exposure and development are performed in sequence to form a pattern layer with an opening. The indium tin oxide film and the gallium oxide film are etched based on the pattern layer to form an ohmic electrode and a semiconductor layer, respectively, and then the pattern layer is removed by dissolving with a degumming solution.

[0109] Example 5

[0110] The quartz glass was ultrasonically cleaned in acetone, ethanol and deionized water for 10 min each, and then taken out and blown dry;

[0111] The quartz glass is placed in a sputtering chamber of a magnetron sputtering device, the temperature of the sputtering chamber and the substrate is controlled to be room temperature (25° C.), a chromium film with a thickness of 10 nm and a gold film with a thickness of 30 nm are sputtered in sequence, a photoresist is spin-coated on the gold film, and exposure and development are performed in sequence to form a pattern layer with an opening, the gold film and the chromium film are etched based on the pattern layer to form a Schottky electrode, and then the pattern layer is removed by dissolving with a degumming solution;

[0112] A 60 nm thick gallium oxide film was sputtered on the gold film. The ambient gas in the sputtering chamber was a mixture of oxygen and argon, wherein the volume ratio of oxygen to argon was 1:9, and the sputtering power was 60 W.

[0113] A molybdenum film with a thickness of 20 nm is sputtered on the gallium oxide film, and a photoresist is spin-coated on the indium tin oxide film. The two films are exposed and developed in sequence to form a pattern layer with an opening. The indium tin oxide film and the gallium oxide film are etched based on the pattern layer to form an ohmic electrode and a semiconductor layer, respectively. The pattern layer is then removed by dissolving with a degumming solution.

[0114] Comparative Example 1

[0115] The quartz glass was ultrasonically cleaned in acetone, ethanol and deionized water for 10 min each, and then taken out and blown dry;

[0116] The quartz glass is placed in a sputtering chamber of a magnetron sputtering device, the temperature of the sputtering chamber and the substrate is controlled to be room temperature (25° C.), a chromium film with a thickness of 10 nm and a gold film with a thickness of 30 nm are sputtered in sequence, a photoresist is spin-coated on the gold film, and exposure and development are performed in sequence to form a pattern layer with an opening, the gold film and the chromium film are etched based on the pattern layer to form a Schottky electrode, and then the pattern layer is removed by dissolving with a degumming solution;

[0117] A 300 nm thick gallium oxide film was sputtered on the gold film. The ambient gas in the sputtering chamber was a mixture of oxygen and argon, wherein the volume ratio of oxygen to argon was 1:9, and the sputtering power was 60 W.

[0118] An indium tin oxide film with a thickness of 20 nm is sputtered on the gallium oxide film, and a photoresist is spin-coated on the indium tin oxide film, and exposure and development are performed in sequence to form a pattern layer with an opening. The indium tin oxide film and the gallium oxide film are etched based on the pattern layer to form an ohmic electrode and a semiconductor layer, respectively, and then the pattern layer is removed by dissolving with a degumming solution.

[0119] Comparative Example 2

[0120] The quartz glass was ultrasonically cleaned in acetone, ethanol and deionized water for 10 min each, and then taken out and blown dry;

[0121] The quartz glass is placed in a sputtering chamber of a magnetron sputtering device, the temperature of the sputtering chamber and the substrate is controlled to be room temperature (25° C.), a chromium film with a thickness of 10 nm and a gold film with a thickness of 30 nm are sputtered in sequence, a photoresist is spin-coated on the gold film, and exposure and development are performed in sequence to form a pattern layer with an opening, the gold film and the chromium film are etched based on the pattern layer to form a Schottky electrode, and then the pattern layer is removed by dissolving with a degumming solution;

[0122] A 30 nm thick gallium oxide film was sputtered on the gold film. The ambient gas in the sputtering chamber was a mixture of oxygen and argon, wherein the volume ratio of oxygen to argon was 1:9, and the sputtering power was 60 W.

[0123] An indium tin oxide film with a thickness of 20 nm is sputtered on the gallium oxide film, and a photoresist is spin-coated on the indium tin oxide film, and exposure and development are performed in sequence to form a pattern layer with an opening. The indium tin oxide film and the gallium oxide film are etched based on the pattern layer to form an ohmic electrode and a semiconductor layer, respectively, and then the pattern layer is removed by dissolving with a degumming solution.

[0124] Comparative Example 3

[0125] The quartz glass was ultrasonically cleaned in acetone, ethanol and deionized water for 10 min each, and then taken out and blown dry;

[0126] The quartz glass is placed in a sputtering chamber of a magnetron sputtering device, the temperature of the sputtering chamber and the substrate is controlled to be room temperature (25° C.), a chromium film with a thickness of 10 nm and a gold film with a thickness of 30 nm are sputtered in sequence, a photoresist is spin-coated on the gold film, and exposure and development are performed in sequence to form a pattern layer with an opening, the gold film and the chromium film are etched based on the pattern layer to form a Schottky electrode, and then the pattern layer is removed by dissolving with a degumming solution;

[0127] A 60 nm thick gallium oxide film was sputtered on the gold film. The ambient gas in the sputtering chamber was a mixture of oxygen and argon, wherein the volume ratio of oxygen to argon was 1:3, and the sputtering power was 60 W.

[0128] An indium tin oxide film with a thickness of 20 nm is sputtered on the gallium oxide film, and a photoresist is spin-coated on the indium tin oxide film, and exposure and development are performed in sequence to form a pattern layer with an opening. The indium tin oxide film and the gallium oxide film are etched based on the pattern layer to form an ohmic electrode and a semiconductor layer, respectively, and then the pattern layer is removed by dissolving with a degumming solution.

[0129] Comparative Example 4

[0130] The quartz glass was ultrasonically cleaned in acetone, ethanol and deionized water for 10 min each, and then taken out and blown dry;

[0131] The quartz glass is placed in a sputtering chamber of a magnetron sputtering device, the temperature of the sputtering chamber and the substrate is controlled to be room temperature (25° C.), a chromium film with a thickness of 10 nm and a gold film with a thickness of 30 nm are sputtered in sequence, a photoresist is spin-coated on the gold film, and exposure and development are performed in sequence to form a pattern layer with an opening, the gold film and the chromium film are etched based on the pattern layer to form a Schottky electrode, and then the pattern layer is removed by dissolving with a degumming solution;

[0132] A 60 nm thick gallium oxide film was sputtered on the gold film. The ambient gas in the sputtering chamber was a mixture of oxygen and argon, wherein the volume ratio of oxygen to argon was 1:70, and the sputtering power was 60 W.

[0133] An indium tin oxide film with a thickness of 20 nm is sputtered on the gallium oxide film, and a photoresist is spin-coated on the indium tin oxide film, and exposure and development are performed in sequence to form a pattern layer with an opening. The indium tin oxide film and the gallium oxide film are etched based on the pattern layer to form an ohmic electrode and a semiconductor layer, respectively, and then the pattern layer is removed by dissolving with a degumming solution.

[0134] The size of the devices prepared in each embodiment and comparative example is 20 μm×50 μm.

[0135] Experiment: The on-state current, off-state current and switch ratio of the gallium oxide Schottky diodes prepared in the above-mentioned embodiments and comparative examples were tested. The results can be seen in Table 1, wherein the current-voltage test diagram of the gallium oxide Schottky diode of Example 1 can be seen in Figure 3 .

[0136] Table 1

[0137] Off-state current / (A) On-state current / (A) On / Off Ratio Example 1 <![CDATA[5×10 -14 ]]> <![CDATA[1×10 -5 ]]> <![CDATA[>10 8 ]]> Example 2 <![CDATA[2×10 -14 ]]> <![CDATA[4×10 -6 ]]> <![CDATA[>10 8 ]]> Example 3 <![CDATA[4×10 -14 ]]> <![CDATA[8×10 -6 ]]> <![CDATA[>10 8 ]]> Example 4 <![CDATA[7×10 -14 ]]> <![CDATA[1×10 -5 ]]> <![CDATA[>10 8 ]]> Example 5 <![CDATA[5×10 -14 ]]> <![CDATA[5×10 -6 ]]> <![CDATA[10 8 ]]> Comparative Example 1 <![CDATA[1×10 -14 ]]> <![CDATA[1×10 -9 ]]> <![CDATA[10 5 ]]> Comparative Example 2 <![CDATA[2×10 -10 ]]> <![CDATA[3×10 -5 ]]> <![CDATA[~10 5 ]]> Comparative Example 3 <![CDATA[3×10 -14 ]]> <![CDATA[3×10 -8 ]]> <![CDATA[10 6 ]]> Comparative Example 4 <![CDATA[1×10 -9 ]]> <![CDATA[1×10 -4 ]]> <![CDATA[10 5 ]]>

[0138] As shown in Table 1, in the process of preparing the gallium oxide film in Examples 1 to 5, amorphous gallium oxide and / or polycrystalline gallium oxide material is prepared as the gallium oxide film by magnetron sputtering, the volume proportion of oxygen is controlled to be 1 / 20 to 1 / 5, and the thickness of the prepared gallium oxide film is controlled to be 40nm to 200nm, and the switching ratio of the prepared devices can reach 10 8 The switching ratio of the devices prepared in Comparative Examples 1 to 4 can only reach 10 5 ~10 6 Compared with Comparative Examples 1 to 4, the GaO Schottky diodes of Examples 1 to 5 have significantly improved switching performance.

[0139] In addition, there is no need to introduce a high-temperature annealing step during the preparation process of Examples 1 to 5, which enables the gallium oxide Schottky diode to be prepared on a flexible film made of polymer material, helping to further broaden the application range of the gallium oxide Schottky diode.

[0140] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0141] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A gallium oxide Schottky diode, characterized in that: include: A semiconductor layer, a Schottky electrode and an ohmic electrode, wherein the semiconductor layer includes a gallium oxide film, the gallium oxide material in the gallium oxide film is amorphous gallium oxide and / or polycrystalline gallium oxide, a Schottky contact is formed between the Schottky electrode and the gallium oxide film, an ohmic contact is formed between the ohmic electrode and the gallium oxide film, and the switching ratio of the gallium oxide Schottky diode is within 10 8 above.

2. The gallium oxide Schottky diode according to claim 1, characterized in that: The thickness of the gallium oxide film is 40nm-200nm.

3. The gallium oxide Schottky diode according to any one of claims 1 to 2, characterized in that: The ohmic electrode includes an oxygen absorbing conductive material, the oxygen absorbing conductive material is in direct contact with the gallium oxide in the semiconductor layer, and the oxygen absorbing conductive material includes a conductive material that can be combined with oxygen atoms in the gallium oxide.

4. The gallium oxide Schottky diode according to claim 3, characterized in that: The oxygen absorbing conductive material includes one or more of indium tin oxide and titanium.

5. The gallium oxide Schottky diode according to any one of claims 1 to 2 and 4, characterized in that: It also includes a substrate, which is a flexible substrate, and the semiconductor layer, the Schottky electrode and the ohmic electrode are all arranged on the substrate.

6. A method for preparing a gallium oxide Schottky diode according to any one of claims 1 to 5, characterized in that: The steps include: Providing a substrate, and preparing the Schottky electrode, the semiconductor layer and the ohmic electrode on the substrate; Among them, the step of preparing the semiconductor layer includes: depositing the gallium oxide film by sputtering, during the sputtering process, the ambient gas in the sputtering chamber includes oxygen, the volume proportion of oxygen in the ambient gas is controlled to be 1 / 20 to 1 / 5, and the thickness of the gallium oxide film is controlled to be 40nm to 200nm.

7. The method for preparing a gallium oxide Schottky diode according to claim 6, characterized in that: The steps of preparing the Schottky electrode include: depositing a first electrode material layer on the substrate, A first pattern layer is prepared on the first electrode material layer, and the first electrode material layer is etched based on the first pattern layer to form the Schottky electrode.

8. The method for preparing a gallium oxide Schottky diode according to claim 7, characterized in that: The Schottky electrode, the semiconductor layer and the ohmic electrode are sequentially prepared on the substrate, and the steps of preparing the ohmic electrode include: depositing a second electrode material layer on the gallium oxide film, A second pattern layer is prepared on the second electrode material layer, and the second electrode material layer is etched based on the second pattern layer to form the ohmic electrode.

9. The method for preparing a gallium oxide Schottky diode according to any one of claims 6 to 8, characterized in that: The substrate is a flexible substrate, and in the step of preparing the Schottky electrode, the semiconductor layer and the ohmic electrode, the temperature of the substrate is controlled not to exceed 200°C.

10. An electronic device, characterized in that: The invention comprises a circuit structure, wherein the circuit structure comprises the gallium oxide Schottky diode according to any one of claims 1 to 5.

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