A diamond power device, a preparation method thereof, and an electronic device

Abstract

Embodiments of the present disclosure provide a diamond power device, a preparation method thereof, and an electronic device. Since field effect transistors are provided on both sides of a single crystal diamond epitaxy, a double-sided structure field effect transistor is formed, effectively reducing costs. Moreover, since the first source electrode and the second source electrode of the double-sided structure field effect transistor are electrically connected, and the first drain electrode and the second drain electrode are electrically connected, compared with a single-sided field effect transistor, the device of the present disclosure can increase the current density while maintaining the same high breakdown voltage level, and a diamond power device with both a large current density and high breakdown voltage performance can be obtained.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor technology, and particularly to a diamond power device, a preparation method thereof, and an electronic device. Background Art

[0002] With the rise of ultra-wide bandgap semiconductor materials, diamond has a series of advantages such as a large bandgap width, a high breakdown field strength, a high thermal conductivity, and a high carrier mobility. It has the title of the ultimate semiconductor material and has great application potential in the fields of high-temperature, high-frequency, and high-power electronic devices. Diamond is a wide bandgap semiconductor material with excellent performance. Different terminals can be formed on its surface after treatment, such as tin terminals, silicon terminals, hydrogen terminals, oxygen terminals, fluorine terminals, etc. Different terminal surfaces have different conductivities. Due to the characteristics of diamond materials, diamond power devices can maintain the stability of the devices in more extreme environments, can withstand higher breakdown voltages, and have better heat dissipation, so they have become a research hotspot in the scientific community.

[0003] However, traditional diamond devices are all of a single structure, with a small current density, a low breakdown voltage, and a high cost. Therefore, more investment in research and development is needed to obtain diamond devices with high breakdown voltages, large current densities, and low costs. Summary of the Invention

[0004] Embodiments of the present disclosure provide a diamond power device, a preparation method thereof, and an electronic device to solve the problems of small current density, low breakdown voltage, and high cost of traditional single diamond power devices.

[0005] The diamond power device, the preparation method thereof, and the electronic device provided by the embodiments of the present disclosure are specifically as follows:

[0006] On the one hand, embodiments of the present disclosure provide a diamond power device, including a double-sided structure field effect transistor. The double-sided structure field effect transistor includes a diamond single crystal epitaxial layer. The diamond single crystal epitaxial layer includes a first side and a second side that are oppositely arranged. The first side includes a first diamond conductive channel region and a first isolation region located outside the first diamond conductive channel region. The second side includes a second diamond conductive channel region and a second isolation region located outside the second diamond conductive channel region;

[0007] A first source electrode and a first drain electrode are provided on a side of the first diamond conductive channel region facing away from the second diamond conductive channel region. A second source electrode and a second drain electrode are provided on a side of the second diamond conductive channel region facing away from the first diamond conductive channel region. The first source electrode and the second source electrode are electrically connected, and / or the first drain electrode and the second drain electrode are electrically connected.

[0008] In some embodiments, in the above-mentioned diamond power device provided by the embodiments of the present disclosure, the first diamond conductive channel region and the second diamond conductive channel region are symmetrically arranged with respect to the diamond single crystal epitaxial layer, and the first isolation region and the second isolation region are symmetrically arranged with respect to the diamond single crystal epitaxial layer;

[0009] The diamond single crystal epitaxial layer has a first through hole and a second through hole penetrating through its thickness at positions corresponding to the first isolation region and the second isolation region. The first through hole is located between the first source electrode and the second source electrode, and the second through hole is located between the first drain electrode and the second drain electrode;

[0010] The first source electrode and the second source electrode are electrically connected by a first connecting metal located in the first through hole, and the first drain electrode and the second drain electrode are electrically connected by a second connecting metal located in the second through hole.

[0011] In some embodiments, in the above-mentioned diamond power device provided by the embodiments of the present disclosure, the cross-sectional width of the first through hole corresponding to the first side is greater than its cross-sectional width corresponding to the second side, and the cross-sectional width of the second through hole corresponding to the first side is greater than its cross-sectional width corresponding to the second side.

[0012] In some embodiments, in the above-mentioned diamond power device provided by the embodiments of the present disclosure, the surface roughness of the side walls of the first through hole and the second through hole is less than 0.1 μm.

[0013] In some embodiments, in the above-mentioned diamond power device provided by the embodiments of the present disclosure, the double-sided structure field effect transistor includes at least a first double-sided structure field effect transistor and a second double-sided structure field effect transistor. The first drain electrode of the first double-sided structure field effect transistor is electrically connected to the first source electrode of the second double-sided structure field effect transistor.

[0014] In some embodiments, in the above-mentioned diamond power device provided by the embodiments of the present disclosure, the double-sided structure field effect transistor includes at least a first double-sided structure field effect transistor and a second double-sided structure field effect transistor. The second source electrode of the first double-sided structure field effect transistor is electrically connected to the first source electrode of the second double-sided structure field effect transistor, and the second drain electrode of the first double-sided structure field effect transistor is electrically connected to the first drain electrode of the second double-sided structure field effect transistor.

[0015] In some embodiments, in the above-mentioned diamond power device provided by the embodiments of the present disclosure, the first diamond conductive channel region and the second diamond conductive channel region are symmetrically arranged with respect to the diamond single crystal epitaxial layer, and the first isolation region and the second isolation region are symmetrically arranged with respect to the diamond single crystal epitaxial layer;

[0016] The first source electrode and the second source electrode on both sides of the diamond single crystal epitaxial layer are electrically connected through a first wire on the periphery, and the first drain electrode and the second drain electrode on both sides of the diamond single crystal epitaxial layer are electrically connected through a second wire on the periphery.

[0017] In some embodiments, in the above-mentioned diamond power device provided by the embodiments of the present disclosure, the double-sided structure field effect transistor at least includes a first double-sided structure field effect transistor and a second double-sided structure field effect transistor, and the second wire of the first double-sided structure field effect transistor is electrically connected to the first wire of the second double-sided structure field effect transistor.

[0018] In some embodiments, in the above-mentioned diamond power device provided by the embodiments of the present disclosure, the double-sided structure field effect transistor at least includes a first double-sided structure field effect transistor and a second double-sided structure field effect transistor, the first wire of the first double-sided structure field effect transistor is electrically connected to the first wire of the second double-sided structure field effect transistor, and the second wire of the first double-sided structure field effect transistor is electrically connected to the second wire of the second double-sided structure field effect transistor.

[0019] In some embodiments, in the above-mentioned diamond power device provided by the embodiments of the present disclosure, the double-sided structure field effect transistor further includes:

[0020] A first gate dielectric layer covering the first source electrode and the first drain electrode and covering the first diamond conductive channel region between the first source electrode and the first drain electrode;

[0021] A first gate electrode located on a side of the first gate dielectric layer away from the diamond single crystal epitaxial layer;

[0022] A second gate dielectric layer covering the second source electrode and the second drain electrode and covering the second diamond conductive channel region between the second source electrode and the second drain electrode;

[0023] A second gate electrode located on a side of the second gate dielectric layer away from the diamond single crystal epitaxial layer.

[0024] In some embodiments, in the above-mentioned diamond power device provided by the embodiments of the present disclosure, the first diamond conductive channel region includes at least a first sub-channel region and a second sub-channel region arranged at intervals. The first source electrode is disposed in the first sub-channel region and close to the side surface of the diamond single crystal epitaxial layer, and the first drain electrode is disposed in the second sub-channel region and close to the side surface of the diamond single crystal epitaxial layer;

[0025] A third drain electrode is further disposed on one side of the first sub-channel region, and a third source electrode is further disposed on one side of the second sub-channel region. The third drain electrode and the third source electrode are adjacent and electrically connected through a third conductive wire;

[0026] The second diamond conductive channel region includes at least a third sub-channel region and a fourth sub-channel region arranged at intervals. The second source electrode is disposed in the third sub-channel region and close to the side surface of the diamond single crystal epitaxial layer, and the second drain electrode is disposed in the fourth sub-channel region and close to the side surface of the diamond single crystal epitaxial layer;

[0027] A fourth drain electrode is further disposed on one side of the third sub-channel region, and a fourth source electrode is further disposed on one side of the fourth sub-channel region. The fourth drain electrode and the fourth source electrode are adjacent and electrically connected through a fourth conductive wire.

[0028] In some embodiments, in the above-mentioned diamond power device provided by the embodiments of the present disclosure, the double-sided structure field effect transistor further includes:

[0029] A first gate dielectric layer covering the first source electrode and the third drain electrode and covering the first sub-channel region between the first source electrode and the third drain electrode;

[0030] A first gate electrode located on a side of the first gate dielectric layer away from the diamond single crystal epitaxial layer;

[0031] A second gate dielectric layer covering the second source electrode and the fourth drain electrode and covering the third sub-channel region between the second source electrode and the fourth drain electrode;

[0032] A second gate electrode located on a side of the second gate dielectric layer away from the diamond single crystal epitaxial layer;

[0033] A third gate dielectric layer covering the third source electrode and the first drain electrode and covering the second sub-channel region between the third source electrode and the first drain electrode;

[0034] A third gate electrode located on a side of the third gate dielectric layer away from the diamond single crystal epitaxial layer;

[0035] A fourth gate dielectric layer, covering the fourth source electrode and the second drain electrode and covering the fourth sub-channel region between the fourth source electrode and the second drain electrode;

[0036] A fourth gate electrode, located on a side of the fourth gate dielectric layer away from the diamond single crystal epitaxial layer.

[0037] In some embodiments, in the above-mentioned diamond power device provided by the embodiments of the present disclosure, the first diamond conductive channel region is a single conductive terminal or a composite conductive terminal, and the second diamond conductive channel region is a single conductive terminal or a composite conductive terminal.

[0038] In some embodiments, in the above-mentioned diamond power device provided by the embodiments of the present disclosure, the conductive terminal includes a hydrogen terminal, a tin terminal or a silicon terminal.

[0039] On the other hand, the embodiments of the present disclosure also provide a method for manufacturing a diamond power device for manufacturing the above-mentioned diamond power device provided by the embodiments of the present disclosure, and the manufacturing method includes:

[0040] Forming a first diamond conductive channel region and a first isolation region located outside the first diamond conductive channel region on a first side of the diamond single crystal epitaxial layer;

[0041] Forming a second diamond conductive channel region and a second isolation region located outside the second diamond conductive channel region on a second side of the diamond single crystal epitaxial layer; the first side and the second side are oppositely arranged;

[0042] Preparing a first source electrode and a first drain electrode on both sides in the first diamond conductive channel region;

[0043] Preparing a second source electrode and a second drain electrode on both sides in the second diamond conductive channel region, the first source electrode and the second source electrode are electrically connected, and the first drain electrode and the second drain electrode are electrically connected.

[0044] In some embodiments, in the above-mentioned manufacturing method provided by the embodiments of the present disclosure, after preparing the first source electrode and the first drain electrode on both sides in the first diamond conductive channel region and before preparing the second source electrode and the second drain electrode on both sides in the second diamond conductive channel region, it further includes: successively adopting a laser drilling process and a reactive ion etching process on the diamond single crystal epitaxial layer at the positions of the first isolation region and the second isolation region to form a first through hole and a second through hole, the first through hole overlaps with the first source electrode, and the second through hole overlaps with the first drain electrode;

[0045] When preparing the second source electrode and the second drain electrode on both sides within the second diamond conductive channel region, a first connection metal filled in the first through hole and a second connection metal filled in the second through hole are simultaneously formed.

[0046] In some embodiments, in the above preparation method provided by the embodiments of the present disclosure, the femtosecond laser used in the laser drilling process has a pulse repetition frequency of 2 kHz, a pulse width of 120 fs, and a power of 0.35 W;

[0047] The reactive ion etching process is carried out in a microwave chemical vapor deposition system, where the reaction gas is H2 / Ar, the flow rate of the H2 gas is 20 - 40 sccm, the flow rate of the Ar gas is 10 - 30 sccm, the microwave input power is 800 - 1200 W, the reaction pressure is 0.8 - 2 kPa, the bias voltage applied to the diamond single crystal epitaxial layer is -400 - -200 V, and the etching time is 1 - 2 h.

[0048] On the other hand, the embodiments of the present disclosure also provide an electronic device, including the above diamond power device provided by the embodiments of the present disclosure.

[0049] The beneficial effects of the present disclosure are as follows:

[0050] For a diamond power device, its preparation method, and an electronic device provided by the embodiments of the present disclosure, since field effect transistors are provided on both sides of a single diamond single crystal epitaxy, a double-sided structure field effect transistor is formed, effectively reducing the cost; and, since the first source electrode and the second source electrode of the double-sided structure field effect transistor are electrically connected, and the first drain electrode and the second drain electrode are electrically connected, compared with a single-sided field effect transistor, the device of the present disclosure can increase the current density while maintaining the same high breakdown voltage level, and a diamond power device with both a large current density and high breakdown voltage performance can be obtained. Description of the Drawings

[0051] Figure 1 It is a schematic structural diagram of a diamond power device provided by the embodiments of the present disclosure;

[0052] Figure 2 It is a schematic diagram of only using the laser drilling process in the prior art to form a through hole on a diamond single crystal epitaxial layer;

[0053] Figure 3 For the present disclosure, it is shown separately Figure 1 A schematic diagram of the first through hole and the second through hole;

[0054] Figure 4 It is another schematic structural diagram of a diamond power device provided by the embodiments of the present disclosure;

[0055] Figure 5Another schematic structural diagram of the diamond power device provided by the embodiments of the present disclosure;

[0056] Figure 6 Another schematic structural diagram of the diamond power device provided by the embodiments of the present disclosure;

[0057] Figure 7 Another schematic structural diagram of the diamond power device provided by the embodiments of the present disclosure;

[0058] Figure 8 Another schematic structural diagram of the diamond power device provided by the embodiments of the present disclosure;

[0059] Figure 9 Another schematic structural diagram of the diamond power device provided by the embodiments of the present disclosure;

[0060] Figure 10 Schematic flow diagram of a preparation method of a diamond power device provided by the embodiments of the present disclosure;

[0061] Figure 11A - Figure 11Q Respectively for preparing Figure 1 The corresponding schematic structural diagrams of the diamond power device shown in each step during execution;

[0062] Figure 12 For preparing Figure 6 The corresponding schematic structural diagrams of the diamond power device shown during the execution process;

[0063] Figure 13 For preparing Figure 9 The corresponding schematic structural diagrams of the diamond power device shown during the execution process. Detailed implementation manners

[0064] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure clearer, the following will clearly and completely describe the technical solutions of the embodiments of the present disclosure with reference to the accompanying drawings of the embodiments of the present disclosure. It should be noted that in the drawings, for clarity, the thicknesses of layers, films, panels, regions, etc. are enlarged. In the present disclosure, exemplary embodiments are described with reference to cross-sectional views that are schematic diagrams of idealized embodiments. Thus, deviations from the shapes of the figures are to be expected as a result of, for example, manufacturing techniques and / or tolerances. Therefore, the embodiments described in the present disclosure should not be construed as being limited to the specific shapes of the regions shown in the present disclosure, but include deviations in shape caused by, for example, manufacturing. For example, a region illustrated or described as flat may typically have rough and / or non-linear features; the sharp corners illustrated may be rounded, etc. Thus, the regions shown in the figures are schematic in nature, and their dimensions and shapes are not intended to illustrate the exact shape of the regions, do not reflect true proportions, and are only intended to schematically illustrate the content of the present disclosure. Also, the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. To keep the following description of the embodiments of the present disclosure clear and concise, detailed descriptions of known functions and known components are omitted from the present disclosure.

[0065] Unless otherwise defined, the technical terms or scientific terms used herein shall have the ordinary meanings as understood by those of ordinary skill in the art to which the present disclosure pertains. The terms "first", "second", and similar terms used in the specification and claims of the present disclosure do not denote any order, quantity, or importance, but are only used to distinguish different components. The terms "comprising", "including", or similar terms mean that the elements or items appearing before the term cover the elements or items listed after the term and their equivalents, without excluding other elements or items. The terms "connected" or "coupled" or similar terms are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms "inner", "outer", "upper", "lower", etc. are only used to indicate relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0066] In the following description, when an element or layer is referred to as being "on" or "connected to" another element or layer, the element or layer can be directly on the other element or layer, directly connected to the other element or layer, or there may be intervening elements or layers. When an element or layer is referred to as being "disposed on one side of" another element or layer, the element or layer can be directly on one side of the other element or layer, directly connected to the other element or layer, or there may be intervening elements or layers. However, when an element or layer is referred to as being "directly on" or "directly connected to" another element or layer, there are no intervening elements or layers. The term "and / or" includes any and all combinations of one or more of the associated listed items.

[0067] A diamond power device provided by an embodiment of the present disclosure, such as Figure 1 , Figures 4 - 9 shown, includes a double-sided structure field effect transistor. The double-sided structure field effect transistor includes a diamond single crystal epitaxial layer 1. The diamond single crystal epitaxial layer 1 includes a first side A1 and a second side A2 which are oppositely arranged. The first side A1 includes a first diamond conductive channel region 11 and a first isolation region 12 located outside the first diamond conductive channel region 11. The second side A2 includes a second diamond conductive channel region 13 and a second isolation region 14 located outside the second diamond conductive channel region 13.

[0068] A first source electrode S1 and a first drain electrode D1 are disposed on a side of the first diamond conductive channel region 11 facing away from the second diamond conductive channel region 13. A second source electrode S2 and a second drain electrode D2 are disposed on a side of the second diamond conductive channel region 13 facing away from the first diamond conductive channel region 11. The first source electrode S1 and the second source electrode S2 are electrically connected, and / or the first drain electrode D1 and the second drain electrode D2 are electrically connected.

[0069] For the above diamond power device provided by the embodiment of the present disclosure, since both sides of a piece of diamond single crystal epitaxy have field effect transistors, a double-sided structure field effect transistor is formed, effectively reducing the cost. Moreover, since the first source electrode and the second source electrode of the double-sided structure field effect transistor are electrically connected, and / or the first drain electrode and the second drain electrode are electrically connected, compared with a single-sided field effect transistor, the device of the present disclosure can increase the current density while maintaining the same high breakdown voltage level, and a diamond power device with both a large current density and high breakdown voltage performance is obtained.

[0070] In some embodiments, in the above diamond power device provided by the embodiment of the present disclosure, such as Figure 1As shown, the first diamond conductive channel region 11 and the second diamond conductive channel region 13 are symmetrically arranged with respect to the diamond single crystal epitaxial layer 1, and the first isolation region 12 and the second isolation region 14 are symmetrically arranged with respect to the diamond single crystal epitaxial layer 1; this is conducive to the electrical connection of the source electrodes on both sides of the diamond single crystal epitaxial layer 1 and the electrical connection of the drain electrodes on both sides;

[0071] The diamond single crystal epitaxial layer 1 has a first through hole V1 and a second through hole V2 penetrating through its thickness at positions corresponding to the first isolation region 12 and the second isolation region 13. The first through hole V1 is located between the first source electrode S1 and the second source electrode S2, and the second through hole V2 is located between the first drain electrode D1 and the second drain electrode D2; by arranging the first through hole V1 and the second through hole V2 in the isolation regions on both sides of the diamond single crystal epitaxial layer 1, the short - circuit of the diamond conductive channel regions on both sides of the diamond single crystal epitaxial layer 1 is avoided;

[0072] The first source electrode S1 and the second source electrode S2 are electrically connected through a first connecting metal 21 located in the first through hole V1, and the first drain electrode D1 and the second drain electrode D2 are electrically connected through a second connecting metal 22 located in the second through hole V2. In this way Figure 1 the field - effect transistors on both sides of the diamond single crystal epitaxial layer 1 form a parallel - integrated device. Compared with the single - sided field - effect transistor, the double - sided structure field - effect transistor of the present disclosure can increase the current density to 2 times while maintaining the same high breakdown voltage level, and a double - sided structure field - effect transistor with both high current density and high breakdown voltage performance is obtained.

[0073] As Figure 2 shown, Figure 2 is a schematic diagram of the prior art that only uses a laser drilling process to form a through hole H on the diamond single crystal epitaxial layer 1. It can be seen that non - diamond impurities NG (such as graphite) are formed on the side wall surface of the through hole H due to the laser process, and at the same time, the side wall surface of the through hole H is not smooth, and the roughness reaches 2μm, that is, there are hole - like morphology defects on the side wall surface of the through hole H, resulting in a reduction in the reliability and transmission efficiency of metal filling interconnection.

[0074] In some embodiments, in the above - mentioned diamond power device provided by the embodiments of the present disclosure, as Figure 3 shown, Figure 3 is a schematic diagram separately shown in the present disclosure Figure 1Schematic diagram of the first through-hole V1 and the second through-hole V2. The first through-hole V1 and the second through-hole V2 in the present disclosure can be formed by using a laser drilling process and a reactive ion etching process in sequence. For example, in the embodiments of the present disclosure, the second source electrode S2 and the second drain electrode D2 are first formed on the second side A2, and then the first through-hole V1 and the second through-hole V2 are formed on the first side A1 by using a laser drilling process and a reactive ion etching process in sequence. In this way, the cross-sectional width of the first through-hole V1 corresponding to the first side A1 is greater than its cross-sectional width corresponding to the second side A2, and the cross-sectional width of the second through-hole V2 corresponding to the first side A1 is greater than its cross-sectional width corresponding to the second side A2. The surface roughness of the side walls of the first through-hole V1 and the second through-hole V2 is less than 0.1 μm. Therefore, compared with using only reactive ion etching and focused ion beam etching for drilling, using laser drilling in the present disclosure can improve the diamond drilling efficiency. After laser drilling and then through the reactive ion etching process, non-diamond impurities (such as graphite) formed on the side walls of the through-holes due to the laser process can be effectively removed. At the same time, after reactive ion etching, the surface of the through-holes can be made smooth, the hole morphology defects can be removed, and the reliability and transmission efficiency of metal filling interconnection can be improved.

[0075] It should be noted that the first side A1 and the second side A2 of the diamond single crystal epitaxial layer 1 in the embodiments of the present disclosure can be interchanged. For example, Figure 1 the upper side of the diamond single crystal epitaxial layer 1 is taken as the first side A1, and the lower side is taken as the second side A2; of course, it can also be that the lower side of the diamond single crystal epitaxial layer 1 is taken as the first side A1, and the upper side is taken as the second side A2.

[0076] Specifically, a femtosecond laser with a pulse repetition frequency of 2 kHz, a pulse width of 120 fs, and a power of 0.35 W can be used to drill holes in the isolation region of the diamond single crystal epitaxial layer 1 to form the first through-hole and the second through-hole. Then, reactive ion etching is used to further optimize the etching of the first through-hole and the second through-hole, including: the reactive ion etching process is carried out in a microwave chemical vapor deposition system, where the reaction gas is H2 / Ar, the flow rate of the H2 gas is 20 - 40 sccm, the flow rate of the Ar gas is 10 - 30 sccm, the microwave input power is 800 - 1200 W, the reaction gas pressure is 0.8 - 2 kPa, the bias voltage applied to the diamond single crystal epitaxial layer is -400 - -200 V, and the etching time is 1 - 2 h.

[0077] Optionally, the materials of the first source electrode S1, the second source electrode S2, the first drain electrode D1, and the second drain electrode D2 can be Ti / Au, but are not limited thereto.

[0078] In some embodiments, in the above-mentioned diamond power device provided by the embodiments of the present disclosure, as Figure 1 shown, the double-sided structure field effect transistor further includes:

[0079] A first gate dielectric layer 41 covers the first source electrode S1 and the first drain electrode D1, and covers the first diamond conductive channel region 11 between the first source electrode S1 and the first drain electrode D1. Specifically, the first gate dielectric layer 41 contacts the first source electrode S1 and the first drain electrode D1, which can reduce the electric field and increase the breakdown voltage. The material of the first gate dielectric layer 41 can be SiO2, but is certainly not limited thereto.

[0080] The first gate electrode G1 is located on the side of the first gate dielectric layer 41 away from the diamond single crystal epitaxial layer 1; optionally, the material of the first gate electrode G1 can be Ti / Au, but is certainly not limited thereto;

[0081] A second gate dielectric layer 42 covers the second source electrode S2 and the second drain electrode D2 and covers the second diamond conductive channel region 13 between the second source electrode S2 and the second drain electrode D2. Specifically, the second gate dielectric layer 42 contacts the second source electrode S2 and the second drain electrode D2 to reduce the electric field and increase the breakdown voltage. The material of the first gate dielectric layer 41 may be SiO2, but is certainly not limited thereto.

[0082] The second gate electrode G2 is located on a side of the second gate dielectric layer 42 away from the diamond single crystal epitaxial layer 1 . Optionally, the material of the first gate electrode G1 may be Ti / Au, but is certainly not limited thereto.

[0083] In some embodiments, in the above-mentioned diamond power device provided in the embodiments of the present disclosure, if Figure 1 As shown, the first diamond conductive channel region 11 and the second diamond conductive channel region 13 can each have a single conductive terminal, and the first diamond conductive channel region 11 and the second diamond conductive channel region 13 can have the same conductive terminal or different conductive terminals. Optionally, the first diamond conductive channel region 11 is a hydrogen terminal, a tin terminal, or a silicon terminal, and the second diamond conductive channel region 13 is a hydrogen terminal, a tin terminal, or a silicon terminal.

[0084] In some embodiments, in the above-mentioned diamond power device provided in the embodiments of the present disclosure, if Figure 1 As shown, the first diamond conductive channel region 11 and the second diamond conductive channel region 13 can also be composite conductive terminals. For example, the first diamond conductive channel region 11 can be a composite structure of at least two conductive terminals among hydrogen terminals, tin terminals or silicon terminals, and the second diamond conductive channel region 13 can also be a composite structure of at least two conductive terminals among hydrogen terminals, tin terminals or silicon terminals.

[0085] Specifically, the embodiment of the present disclosure takes the case where both the first diamond conductive channel region 11 and the second diamond conductive channel region 13 are tin terminals as an example.

[0086] In some embodiments, the materials of the first connecting metal 21 and the second connecting metal 22 may be the same as those of the first source electrode S1 and the first drain electrode D1, that is, the first connecting metal 21 and the second connecting metal 22 and the first source electrode S1 and the first drain electrode D1 may be formed by a single deposition process.

[0087] In some embodiments, in the above-mentioned diamond power device provided by the embodiments of the present disclosure, as Figure 4 shown, the double-sided structure field effect transistor at least includes a first double-sided structure field effect transistor M1 and a second double-sided structure field effect transistor M2, and the first drain electrode D1 of the first double-sided structure field effect transistor M1 is electrically connected to the first source electrode S1 of the second double-sided structure field effect transistor M2. Specifically, the first drain electrode D1 of the first double-sided structure field effect transistor M1 and the first source electrode S1 of the second double-sided structure field effect transistor M2 may be electrically connected by a fifth conductive wire 100, that is, the structure shown in the embodiments of the present disclosure Figure 4 is to connect two Figure 1 shown single double-sided structure field effect transistors in series with a wire to form a series integrated device. Therefore, Figure 4 the two double-sided structure field effect transistor series integrated devices shown and Figure 1 the single double-sided structure field effect transistor shown, Figure 4 compared with the single double-sided structure field effect transistor shown, the breakdown voltage of the series integrated device shown can be increased to 2 times, and the current density can be increased to 2 times, obtaining a diamond power device with high breakdown voltage, large current density and good heat dissipation at the same time.

[0088] In some embodiments, three or even more Figure 1 shown single double-sided structure field effect transistors can be connected in series to obtain a large current diamond power device with multiple times higher breakdown voltage.

[0089] In some embodiments, in the above-mentioned diamond power device provided by the embodiments of the present disclosure, as Figure 5 shown, the double-sided structure field effect transistor may at least include a first double-sided structure field effect transistor M1 and a second double-sided structure field effect transistor M2, the second source electrode S2 of the first double-sided structure field effect transistor M1 is electrically connected to the first source electrode S1 of the second double-sided structure field effect transistor M2, and the second drain electrode D2 of the first double-sided structure field effect transistor M1 is electrically connected to the first drain electrode D1 of the second double-sided structure field effect transistor M2. Specifically, the second source electrode S2 of the first double-sided structure field effect transistor M1 and the first source electrode S1 of the second double-sided structure field effect transistor M2 may be electrically connected by a sixth conductive wire 200, and the second drain electrode D2 of the first double-sided structure field effect transistor M1 and the first drain electrode D1 of the second double-sided structure field effect transistor M2 may be electrically connected by a seventh conductive wire 300, that is, the embodiments of the present disclosure Figure 5The structure shown is to connect two Figure 1 shown single-sided double-sided structure field-effect transistors in parallel with wires to form a parallel integrated device. Therefore, Figure 5 compared with a single-sided structure field-effect transistor, the two double-sided structure field-effect transistor parallel integrated devices shown Figure 5 the parallel integrated device shown can increase the current density to 4 times, obtaining a diamond power device with large current density, high breakdown voltage, and good heat dissipation performance.

[0090] In some embodiments, three or even more Figure 1 shown single-sided double-sided structure field-effect transistors can be connected in parallel, thereby obtaining a diamond power device with several times greater current.

[0091] In some embodiments, in the above diamond power device provided by the embodiments of the present disclosure, as Figure 6 shown, Figure 6 the structure shown is basically the same as Figure 1 the structure shown, the difference is that Figure 6 the first source electrode S1 and the second source electrode S2 on both sides of the diamond single crystal epitaxial layer 1 in Figure 6 can be electrically connected through the first peripheral wire 31, and the first drain electrode D1 and the second drain electrode D2 on both sides of the diamond single crystal epitaxial layer 1 can be electrically connected through the second peripheral wire 32. In this way, the field-effect transistors on both sides of the diamond single crystal epitaxial layer 1 form a parallel integrated device. Compared with a single-sided field-effect transistor, the structure shown in the present disclosure

[0092] In some embodiments, in the above diamond power device provided by the embodiments of the present disclosure, as Figure 7 shown, the double-sided structure field-effect transistor includes at least a first double-sided structure field-effect transistor M1 and a second double-sided structure field-effect transistor M2, and the second wire 32 of the first double-sided structure field-effect transistor M1 is electrically connected to the first wire 31 of the second double-sided structure field-effect transistor M1. That is, the structure shown in the embodiments of the present disclosure Figure 7 is to connect two Figure 6 shown single parallel double-sided structure field-effect transistors in series to form a series integrated device. Therefore, Figure 7 compared with a single parallel double-sided structure field-effect transistor shown in Figure 6 the two double-sided structure field-effect transistor series integrated devices shown Figure 7 the series integrated device shown can increase the breakdown voltage to 2 times and the current density to 2 times, obtaining a diamond power device with high breakdown voltage, large current density, and good heat dissipation performance.

[0093] In some embodiments, three or even more Figure 6 of the single parallel double-sided structure field effect transistors shown are connected in series, so as to obtain a high-current diamond power device with multiple times higher breakdown voltage.

[0094] In some embodiments, in the above-mentioned diamond power device provided by the embodiments of the present disclosure, as Figure 8 shown, the double-sided structure field effect transistor includes at least a first double-sided structure field effect transistor M1 and a second double-sided structure field effect transistor M2. The first conducting wire 31 of the first double-sided structure field effect transistor M1 is electrically connected to the first conducting wire 31 of the second double-sided structure field effect transistor M2, and the second conducting wire 32 of the first double-sided structure field effect transistor M1 is electrically connected to the second conducting wire 32 of the second double-sided structure field effect transistor M2. That is, the structure shown in the embodiments of the present disclosure Figure 8 is that two Figure 6 of the single parallel double-sided structure field effect transistors shown are connected in parallel to form a parallel integrated device. Therefore, Figure 8 compared with the single-sided structure field effect transistor, the two double-sided structure field effect transistor parallel integrated devices shown Figure 8 can increase the current density of the parallel integrated device shown to 4 times, and a diamond power device with high current density, high breakdown voltage and good heat dissipation can be obtained.

[0095] In some embodiments, three or even more Figure 6 of the single parallel double-sided structure field effect transistors shown are connected in parallel, so as to obtain a diamond power device with multiple times larger current.

[0096] In some embodiments, in the above-mentioned diamond power device provided by the embodiments of the present disclosure, as Figure 9 shown, the first diamond conductive channel region 11 includes at least a first sub-channel region 111 and a second sub-channel region 112 which are arranged at intervals. The first source electrode S1 is arranged in the first sub-channel region 111 and close to the side surface of the diamond single crystal epitaxial layer 1, and the first drain electrode D1 is arranged in the second sub-channel region 112 and close to the side surface of the diamond single crystal epitaxial layer 1;

[0097] A third drain electrode D3 is further arranged on one side of the first sub-channel region 111, and a third source electrode S3 is further arranged on one side of the second sub-channel region 112. The third drain electrode D3 and the third source electrode S3 are adjacent and electrically connected through a third conducting wire 33;

[0098] The second diamond conductive channel region 13 includes at least a third sub-channel region 131 and a fourth sub-channel region 132 that are spaced apart. The second source electrode S2 is disposed in the third sub-channel region 131 and is close to the side surface of the diamond single crystal epitaxial layer 1. The second drain electrode D2 is disposed in the fourth sub-channel region 132 and is close to the side surface of the diamond single crystal epitaxial layer 1;

[0099] On one side of the third sub-channel region 131, a fourth drain electrode D4 is further disposed. On one side of the fourth sub-channel region 132, a fourth source electrode S4 is further disposed. The fourth drain electrode D4 and the fourth source electrode S4 are adjacent and are electrically connected through a fourth conductive wire 34.

[0100] In some embodiments, in the above-mentioned diamond power device provided by the embodiments of the present disclosure, as Figure 9 shown, the double-sided structure field effect transistor further includes:

[0101] A first gate dielectric layer 41 covers the first source electrode S1 and the third drain electrode D3 and covers the first sub-channel region 111 between the first source electrode S1 and the third drain electrode D3; specifically, the first gate dielectric layer 41 is in contact with the first source electrode S1 and the third drain electrode D3, which can reduce the electric field and increase the breakdown voltage. The material of the first gate dielectric layer 41 can be SiO2, but is not limited thereto;

[0102] A first gate electrode G1 is located on the side of the first gate dielectric layer 41 away from the diamond single crystal epitaxial layer 1; optionally, the material of the first gate electrode G1 can be Ti / Au, but is not limited thereto;

[0103] A second gate dielectric layer 42 covers the second source electrode S2 and the fourth drain electrode D4 and covers the third sub-channel region 131 between the second source electrode S2 and the fourth drain electrode D4; specifically, the second gate dielectric layer 42 is in contact with the second source electrode S2 and the fourth drain electrode D4, which can reduce the electric field and increase the breakdown voltage. The material of the second gate dielectric layer 42 can be SiO2, but is not limited thereto;

[0104] A second gate electrode G2 is located on the side of the second gate dielectric layer 42 away from the diamond single crystal epitaxial layer 1; optionally, the material of the second gate electrode G2 can be Ti / Au, but is not limited thereto;

[0105] A third gate dielectric layer 43 covers the third source electrode S3 and the first drain electrode D1 and covers the second sub-channel region 112 between the third source electrode S3 and the first drain electrode D1; specifically, the third gate dielectric layer 43 is in contact with the third source electrode S3 and the first drain electrode D1, which can reduce the electric field and increase the breakdown voltage. The material of the third gate dielectric layer 43 can be SiO2, but is not limited thereto;

[0106] The third gate electrode G3 is located on the side of the third gate dielectric layer 43 away from the diamond single crystal epitaxial layer 1; optionally, the material of the third gate electrode G32 can be Ti / Au, but of course it is not limited to this;

[0107] The fourth gate dielectric layer 44 covers the fourth source electrode S4 and the second drain electrode D2 and the fourth sub-channel region 132 between the fourth source electrode S4 and the second drain electrode D2; specifically, the fourth gate dielectric layer 44 is in contact with the fourth source electrode S4 and the second drain electrode D2, which can reduce the electric field and increase the breakdown voltage. The material of the fourth gate dielectric layer 44 can be SiO2, but of course it is not limited to this;

[0108] The fourth gate electrode G4 is located on the side of the fourth gate dielectric layer 44 away from the diamond single crystal epitaxial layer 1; optionally, the material of the fourth gate electrode G4 can be Ti / Au, but of course it is not limited to this.

[0109] Specifically, Figure 9 The structure shown forms at least two spaced-apart field-effect transistors on both sides of the diamond single crystal epitaxial layer 1, and each field-effect transistor on each side is connected in series in pairs through the corresponding third conductive wire 33 or fourth conductive wire 34. And the outermost first source electrode S1 and second source electrode S2 are electrically connected through the peripheral first conductive wire 31, and the outermost first drain electrode D1 and second drain electrode D2 are electrically connected through the peripheral second conductive wire 32 to form a series integrated device. In this way, compared with a single double-sided field-effect transistor, Figure 9 The breakdown voltage of the series integrated device shown can be increased to at least 2 times, and the current density can be increased to at least 2 times, obtaining a diamond power device with high breakdown voltage, large current density and good heat dissipation.

[0110] It should be noted that, Figure 9 Taking the series connection of two spaced-apart field-effect transistors formed on both sides of the diamond single crystal epitaxial layer 1 as an example, of course, three or more spaced-apart field-effect transistors can also be formed in series on both sides of the diamond single crystal epitaxial layer 1, so as to obtain a large-current diamond power device with multiple times higher breakdown voltage.

[0111] Based on the same inventive concept, the embodiments of the present disclosure provide a preparation method of the above diamond power device. Since the principle of solving problems by this preparation method is similar to that of the above diamond power device, therefore, the implementation of this preparation method provided by the embodiments of the present disclosure can refer to the implementation of the above diamond power device provided by the embodiments of the present disclosure, and the repeated parts will not be described again.

[0112] In some embodiments, the preparation method of the above diamond power device provided by the embodiments of the present disclosure, as Figure 10 shown, may include:

[0113] S1001. Form a first diamond conductive channel region and a first isolation region located outside the first diamond conductive channel region on the first side of the single-crystal diamond epitaxial layer;

[0114] S1002. Form a second diamond conductive channel region and a second isolation region located outside the second diamond conductive channel region on the second side of the single-crystal diamond epitaxial layer; the first side and the second side are oppositely arranged;

[0115] S1003. Prepare a first source electrode and a first drain electrode on both sides within the first diamond conductive channel region;

[0116] S1004. Prepare a second source electrode and a second drain electrode on both sides within the second diamond conductive channel region, the first source electrode and the second source electrode are electrically connected, and the first drain electrode and the second drain electrode are electrically connected.

[0117] In some embodiments, in the above preparation method provided by the embodiments of the present disclosure, after performing step S1003 to prepare the first source electrode and the first drain electrode on both sides within the first diamond conductive channel region, and before performing step 1004 to prepare the second source electrode and the second drain electrode on both sides within the second diamond conductive channel region, it further includes: successively adopting a laser drilling process and a reactive ion etching process on the single-crystal diamond epitaxial layer at the positions of the first isolation region and the second isolation region to form a first through hole and a second through hole, the first through hole overlaps with the first source electrode, and the second through hole overlaps with the first drain electrode;

[0118] When performing step S1004 to prepare the second source electrode and the second drain electrode on both sides within the second diamond conductive channel region, a first connection metal filled in the first through hole and a second connection metal filled in the second through hole are simultaneously formed.

[0119] In some embodiments, in the above preparation method provided by the embodiments of the present disclosure, the laser drilling process uses a femtosecond laser with a pulse repetition frequency of 2 kHz, a pulse width of 120 fs, and a power of 0.35 W;

[0120] The reactive ion etching process is carried out in a microwave chemical vapor deposition system, where the reactive gas is H2 / Ar, the flow rate of H2 gas is 20 - 40 sccm, the flow rate of Ar gas is 10 - 30 sccm, the microwave input power is 800 - 1200 W, the reaction pressure is 0.8 - 2 kPa, the bias voltage applied to the diamond single crystal epitaxial layer is -400 - -200 V, and the etching time is 1 - 2 h. In this way, laser drilling can improve the diamond drilling efficiency. After laser drilling and then through the reactive ion etching process, non-diamond impurities (such as graphite) formed on the sidewalls of the through holes due to the laser process can be effectively removed. At the same time, the surface of the through holes can be smoothed after reactive ion etching, the hole morphology defects can be removed, and the reliability and transmission efficiency of metal-filled interconnections can be improved.

[0121] Next, taking the preparation of Figure 1 the diamond power device shown as an example, the above preparation method provided by the embodiments of the present disclosure will be described in detail. Among them, both the first diamond conductive channel region 11 and the second diamond conductive channel region 13 are tin terminals.

[0122] The preparation of Figure 1 the diamond power device shown specifically includes the following steps:

[0123] (1) Polish and clean the surface of the diamond single crystal to obtain the treated diamond single crystal 10; specifically, first, cut and polish the diamond single crystal so that the surface roughness reaches 0 - 10 nm; second, perform inorganic cleaning and organic cleaning on the polished diamond single crystal, and rinse it in flowing deionized water and then dry it with a nitrogen gun. Optionally, the inorganic cleaning may include: cleaning the polished diamond single crystal with a mixed solution of heated sulfuric acid and nitric acid; the organic cleaning may include: ultrasonically cleaning with acetone, ethanol or isopropanol and deionized water for 0 - 30 minutes respectively.

[0124] (2) As Figure 11A shown, deposit the first SnO2 thin film 20 on the surface of the treated diamond single crystal 10 by means of electron beam evaporation, thermal evaporation, magnetron sputtering, atomic layer deposition or chemical vapor deposition; the thickness of the first SnO2 thin film 20 can be 0 - 600 nm, such as 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, etc.

[0125] It should be noted that in step (2) of the embodiments of the present disclosure, depositing an SnO2 thin film is taken as an example. Of course, an SnO thin film can also be deposited.

[0126] (3) As Figure 11B shown, form a first photoresist layer 30 on the side of the first SnO2 thin film 20 away from the diamond single crystal 10, and the thickness of the first photoresist layer 30 can be 1 - 10 μm.

[0127] (4) As Figure 11C shown, the first photoresist layer 30 is exposed and developed to form a first photoresist pattern 30' including a first photoresist completely retained region 301 and a first photoresist completely removed region 302.

[0128] (5) As Figure 11D shown, using the first photoresist pattern 30' as a mask, the first SnO2 thin film 20 is etched by reactive ion etching (RIE) to form a patterned first SnO2 layer 20', and the first SnO2 layer 20' includes a first SnO2 retained region 201 and a first SnO2 removed region 202; specifically, the reaction gas introduced into the reactive ion etching equipment can be a gas mixture of HBr / Ar (hydrogen bromide / argon), the percentage of Ar in the gas mixture can be 0%-100% (and not 100%), the input power can be 400-700W, and the air pressure can be 4-10mTorr.

[0129] (6) As Figure 11E shown, the first photoresist pattern 30' is removed, that is, a first SnO2 layer 20' including a first SnO2 retained region 201 and a first SnO2 removed region 202 is formed.

[0130] (7) As Figure 11FAs shown in the figure, a diamond single crystal epitaxial layer 1 is epitaxially grown on the surface of the first SnO₂ layer 20 by using a microwave plasma chemical vapor deposition (MPCVD) device. The temperature inside the MPCVD is set to 800 °C - 1200 °C, and the pressure is set to 100 - 200 mbar. A mixed gas of H₂, CH₄, and N₂ is introduced into the MPCVD, where the flow rate of H₂ is 200 - 600 sccm, the flow rate of CH₄ is 0 - 100 sccm, and the flow rate of N₂ is 0.01 - 1 sccm. In this way, a diamond single crystal epitaxial layer 1 can be laterally heteroepitaxially grown on the diamond single crystal 10 formed with the first SnO₂ layer 20'. The thickness of the diamond single crystal epitaxial layer 1 can be 300 μm - 1000 μm, such as 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, 1000 μm, etc. Due to the high temperature inside the MPCVD, Sn in the first SnO₂ layer 20' undergoes thermal diffusion to displace C in the diamond single crystal epitaxial layer 1 to form a carbon-tin bond. Thus, on the first side A1 of the diamond single crystal epitaxial layer 1 facing the diamond single crystal 10, a first diamond conductive channel region 11 (i.e., tin terminal) corresponding to the first SnO₂ retention region 201 and a first isolation region 12 (i.e., non-tin terminal) corresponding to the first SnO₂ removal region 202 can be formed. After that, the inside of the microwave plasma chemical vapor deposition device is cooled down, and the grown diamond single crystal epitaxial layer 1 will have uneven stress to achieve self-peeling, so that the diamond single crystal epitaxial layer 1 formed with the first diamond conductive channel region 11 and the first isolation region 12 peels off from the first SnO₂ layer 20'.

[0131] (8) As shown in Figure 11G the figure, Figure 11G Figure Figure 11F is a plan view of the first side A1 of the peeled diamond single crystal epitaxial layer 1 in

[0132] (9) As shown in Figure 11H the figure, a second SnO₂ thin film 50 is deposited on the second side A2 of the diamond single crystal epitaxial layer 1 by using electron beam evaporation, thermal evaporation, magnetron sputtering, atomic layer deposition, or chemical vapor deposition methods. The second side A2 and the first side A1 are oppositely arranged; optionally, the thickness of the second SnO₂ thin film 50 can be 0 - 600 nm, such as 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, etc.

[0133] (10) As shown in Figure 11IAs shown, the second SnO₂ film 50 is patterned to form a second SnO₂ layer 50' including a second SnO₂ retention region 501 and a second SnO₂ removal region 502. Specifically, for the specific steps of forming the second SnO₂ layer 50', reference can be made to Figures 11B - 11E the steps, which will not be elaborated here.

[0134] (11) As Figure 11J shown, the diamond single-crystal epitaxial layer 1 with the second SnO₂ layer 50' formed thereon is subjected to plasma hydrogenation treatment using a microwave plasma chemical vapor deposition system. The temperature of the plasma hydrogenation treatment is 900 - 1200 °C, the hydrogen flow rate is 400 - 600 sccm, the gas pressure is 110 - 130 Torr, and the treatment time is 10 - 30 min. In this way, the second side A2 of the diamond single-crystal epitaxial layer 1 corresponding to the second SnO₂ retention region 501 is converted into a second diamond conductive channel region 13 (i.e., tin terminal) by the strong reduction and thermal environment of the hydrogen plasma, and the region corresponding to the second SnO₂ removal region 502 is converted into a second isolation region 14 (at this time, the second isolation region 14 is a hydrogen terminal), that is, a second diamond conductive channel region 13 and a second isolation region 14 are formed on the second side A2 of the diamond single-crystal epitaxial layer 1.

[0135] (12) As Figure 11K shown, the second SnO₂ layer 50' on the second side A2 of the diamond single-crystal epitaxial layer 1 is removed by pickling to obtain a double-sided tin-terminal diamond with better conductivity. Optionally, the pickling solution can be dilute hydrochloric acid with a concentration of 2 mol / L, and the cleaning time can be about 20 minutes.

[0136] (13) As Figure 11L shown, first source electrodes S1 and first drain electrodes D1 are prepared on both sides within each first diamond conductive channel region 11 on the first side A1 of the diamond single-crystal epitaxial layer 1. Specifically, first, a layer of photoresist is coated on the first side A1, and the photoresist is exposed and developed to expose the regions of the first source electrodes S1 and the first drain electrodes D1. Then, a layer of metal material (such as Ti / Au) with a thickness of 0 - 100 nm is deposited by electron beam evaporation. Subsequently, the remaining photoresist is washed away, and after annealing for 30 minutes, the first source electrodes S1 and the first drain electrodes D1 that are in ohmic contact with the tin terminal are formed.

[0137] (14) As Figure 11MAs shown, a first gate dielectric layer 41 (the material may be SiO2) is formed on the side of the first source electrode S1 and the first drain electrode D1 away from the diamond single crystal epitaxial layer 1; specifically, a layer of photoresist is first coated on the surface of the first source electrode S1 and the first drain electrode D1, and the photoresist is exposed and developed to expose the middle area of the first diamond conductive channel region 11 and a portion of the first source electrode S1 and a portion of the first drain electrode D1, and then SiO2 is deposited, and the remaining photoresist is subsequently washed away, thereby forming a first gate dielectric layer 41 covering the corresponding middle area of the first diamond conductive channel region 11 and covering a portion of the first source electrode S1 and a portion of the first drain electrode D1. The first gate dielectric layer 41 covers a portion of the first source electrode S1 and a portion of the first drain electrode D1, which can reduce the electric field and increase the breakdown voltage.

[0138] (15) Figure 11N As shown, a layer of photoresist is first coated on the surface of the first gate dielectric layer 41, and the photoresist is exposed and developed to expose the middle area of the first gate dielectric layer 41. Then, an electron beam evaporation device is used to deposit a metal material (such as Ti / Au) on the side of the first gate dielectric layer 41 away from the diamond single crystal epitaxial layer 1. The remaining photoresist is then washed away to form a first gate electrode G1 covering the middle area of the first gate dielectric layer 41 and a Schottky contact. In this way, a single-sided field effect transistor is formed on the first side A1 of the diamond single crystal epitaxial layer 1.

[0139] like Figure 11O As shown, Figure 11O for Figure 11N Schematic diagram of the cross section along the AA' direction.

[0140] (16) Figure 11P As shown, the diamond single crystal epitaxial layer 1 is punched at the first isolation region 12 and the second isolation region 14 to form a first through hole V1 and a second through hole V2, the first through hole V1 overlaps with the first source electrode S1, and the second through hole V2 overlaps with the first drain electrode D1.

[0141] (17) Figure 11QAs shown, second source electrodes S2 and second drain electrodes D2 are fabricated on both sides within each second diamond conductive channel region 13 on the second side A2 of the single-crystal diamond epitaxial layer 1. Meanwhile, a first connecting metal 21 filled in the first through-hole V1 and a second connecting metal 22 filled in the second through-hole V2 are formed. Since the second isolation region 14 is hydrogen-terminated at this time and hydrogen-terminated regions conduct electricity, in order to prevent the formed device from leaking electricity, it is necessary to convert the hydrogen-terminated region into an insulating region. Therefore, a second photoresist layer can be formed on the side of the second source electrode and the second drain electrode facing away from the tin-terminated diamond, and the second photoresist layer is exposed and developed to form a second photoresist pattern including a second photoresist completely retained region and a second photoresist completely removed region; wherein, the second photoresist completely retained region corresponds to the second diamond conductive channel region, the second source electrode S2, and the second drain electrode D2, and the second photoresist completely removed region corresponds to the remaining hydrogen-terminated regions; using the second photoresist pattern as a mask, the hydrogen-terminated regions are subjected to oxygen plasma treatment to convert the hydrogen-terminated regions into oxygen-terminated regions; the second photoresist pattern is removed. In this way, oxygen plasma removal is performed on the hydrogen-terminated regions to form a second isolation region that is oxygen-terminated, preventing device leakage.

[0142] Specifically, the above oxygen plasma treatment process may specifically include: using ultraviolet / ozone and oxygen plasma to treat the hydrogen-terminated regions, where the gas flow rate of oxygen or ozone is 1 - 100 sccm, the power of the plasma is 100 - 300 W, and the treatment time is 1 - 60 min.

[0143] (18) As Figure 1 shown, a second gate dielectric layer 41 is formed on the side of the second source electrode S2 and the second drain electrode D2 away from the single-crystal diamond epitaxial layer 1. The second gate dielectric layer 41 covers the middle region of the corresponding second diamond conductive channel region 13 and covers part of the second source electrode S2 and part of the second drain electrode D2; a second gate electrode G2 is formed on the side of the second gate dielectric layer 42 away from the single-crystal diamond epitaxial layer 1. The second gate electrode G2 covers the middle region of the second gate dielectric layer 42. In this way, a field-effect transistor is formed on the second side A2 of the single-crystal diamond epitaxial layer 1, that is, a double-sided field-effect transistor with top and bottom field-effect transistors connected in parallel as Figure 1 shown.

[0144] It should be noted that the methods for fabricating the second source electrode, the second drain electrode, the second gate dielectric layer, and the second gate electrode can refer to the methods for fabricating the first source electrode, the first drain electrode, the first gate dielectric layer, and the first gate electrode described above, and will not be elaborated here.

[0145] It should be noted that, Figure 1Only a group of double-sided parallel field-effect transistors in the double-sided field-effect transistor is schematically shown. Both the first side A1 and the second side A2 of the diamond single-crystal epitaxial layer 1 actually fabricated in step (18) include multiple field-effect transistors, that is, both the first side A1 and the second side A2 form a field-effect transistor array. The planar schematic diagrams of the multiple field-effect transistors on the first side A1 and the second side A2 can both be as shown in Figure 11N shown. The first source electrode S1 and the second source electrode S2 of two field-effect transistors at the same position on the first side A1 and the second side A2 are electrically connected through the first connecting metal 21, and the first drain electrode D1 and the second drain electrode D2 are electrically connected through the second connecting metal 22.

[0146] (19) Slice the double-sided field-effect transistor array prepared in step (18). The slicing can adopt the method of laser cutting. Use a pulsed laser operating at 532 nm or 1064 nm to longitudinally slice the isolation region of the diamond single-crystal epitaxial layer through an electric control machine tool to obtain Figure 1 the single parallel double-sided field-effect transistor with one field-effect transistor included on each side as shown.

[0147] In this way, through the above steps (1)-(19), the diamond power device as shown in Figure 1 can be formed.

[0148] Specifically, connect two Figure 1 shown double-sided parallel field-effect transistors in series with wires, and a series integrated device as shown in Figure 4 can be formed.

[0149] Specifically, connect two Figure 1 shown double-sided parallel field-effect transistors in parallel with wires, and a parallel integrated device as shown in Figure 5 can be formed.

[0150] Next, taking the preparation of the diamond power device as shown in Figure 6 as an example, the above preparation method provided by the embodiments of the present disclosure will be described in detail. Among them, both the first diamond conductive channel region 11 and the second diamond conductive channel region 13 are tin terminals.

[0151] The preparation of the diamond power device as shown in Figure 6 specifically includes the following steps:

[0152] 1. Use the above steps (1)-(15) to form a single-sided field-effect transistor on the first side A1 of the diamond single-crystal epitaxial layer 1.

[0153] 2. Without perforating the diamond single crystal epitaxial layer 1, directly fabricate a second source electrode S2, a second drain electrode D2, a second gate dielectric layer 41, and a second gate electrode G2 on the second side A2 of the diamond single crystal epitaxial layer 1. In this way, multiple field effect transistors are formed on the second side A2 of the diamond single crystal epitaxial layer 1, that is, the Figure 12 shown double-sided field effect transistor is formed.

[0154] It should be noted that Figure 12 only one group of double-sided field effect transistors in the double-sided field effect transistor is schematically shown. In step 2, both the first side A1 and the second side A2 of the actually fabricated diamond single crystal epitaxial layer 1 include multiple field effect transistors, that is, both the first side A1 and the second side A2 form a field effect transistor array. The planar schematic diagrams of the multiple field effect transistors on the first side A1 and the second side A2 can both be as Figure 11N shown. Figure 12 Different from Figure 1 is that the field effect transistors on both sides are not connected.

[0155] 3. Next, slice the double-sided field effect transistor array made in step 2. The slicing can be performed by laser cutting. Use a pulsed laser operating at 532 nm or 1064 nm to longitudinally slice the isolation region of the diamond single crystal epitaxial layer through an electric control machine tool to obtain Figure 12 the single double-sided field effect transistor with one field effect transistor on each side as shown.

[0156] 4. Electrically connect the first source electrode S1 and the second source electrode S2 with a first wire 31, and electrically connect the first drain electrode D1 and the second drain electrode D2 with a second wire 32, then the Figure 6 shown diamond power device can be formed.

[0157] Specifically, specifically, connect two Figure 6 shown double-sided parallel field effect transistors in series, then the Figure 7 shown series integrated device can be formed.

[0158] Specifically, connect two Figure 6 shown double-sided parallel field effect transistors in parallel, then the Figure 8 shown parallel integrated device can be formed.

[0159] Next, taking the preparation of the Figure 9 shown diamond power device as an example, the above preparation method provided by the embodiments of the present disclosure will be described in detail. Among them, both the first diamond conductive channel region 11 and the second diamond conductive channel region 13 are tin terminals.

[0160] The preparation of the Figure 9 shown diamond power device specifically includes the following steps:

[0161] 1. Form a single-sided field-effect transistor on the first side A1 of the single-crystal diamond epitaxial layer 1 by using the above steps (1)-(15).

[0162] 2. Without drilling holes in the single-crystal diamond epitaxial layer 1, directly fabricate a second source electrode S2, a second drain electrode D2, a second gate dielectric layer 41, and a second gate electrode G2 on the second side A2 of the single-crystal diamond epitaxial layer 1. In this way, multiple field-effect transistors are formed on the second side A2 of the single-crystal diamond epitaxial layer 1, that is, the Figure 13 shown double-sided field-effect transistor is formed.

[0163] It should be noted that Figure 13 only two groups of double-sided field-effect transistors in the double-sided field-effect transistor are schematically shown. In step 2, both the first side A1 and the second side A2 of the actually fabricated single-crystal diamond epitaxial layer 1 include multiple field-effect transistors, that is, both the first side A1 and the second side A2 form a field-effect transistor array. The planar schematic diagrams of the multiple field-effect transistors on the first side A1 and the second side A2 can both be as Figure 11N shown. Figure 13 Different from Figure 1 is that the field-effect transistors on both sides are not connected.

[0164] 3. Then, slice the double-sided field-effect transistor array made in step 2. The slicing can be performed by using a laser cutting method. Use a pulsed laser operating at 532 nm or 1064 nm to longitudinally slice the isolation region of the single-crystal diamond epitaxial layer through an electric control machine tool to obtain Figure 13 the structure in which each side includes at least two field-effect transistors as shown.

[0165] 4. Electrically connect the first source electrode S1 and the second source electrode S2 in Figure 13 by using a first conducting wire 31, electrically connect the first drain electrode D1 and the second drain electrode D2 in Figure 13 by using a second conducting wire 32, electrically connect the third drain electrode D3 and the third source electrode S3 in Figure 13 by using a third conducting wire 33, and electrically connect the fourth drain electrode D4 and the fourth source electrode S4 in Figure 13 by using a fourth conducting wire 34, then a diamond power device as Figure 9 shown can be formed.

[0166] It should be noted that, in the above preparation method provided by the embodiments of the present disclosure, the lithography process involved in forming each layer structure may include not only some or all of the process steps such as deposition, photoresist coating, mask with a mask plate, exposure, development, etching, and photoresist stripping, but also other process steps, which are specifically determined by the pattern required in the actual manufacturing process and are not limited herein. For example, a post-baking process may be included after development and before etching. Among them, the deposition process may be chemical vapor deposition, plasma-enhanced chemical vapor deposition, or physical vapor deposition, which is not limited herein; the mask plate used in the masking process may be a half-tone mask, a single-slit mask, or a gray-tone mask, which is not limited herein; the etching may be dry etching or wet etching, which is not limited herein.

[0167] Based on the same inventive concept, the embodiments of the present disclosure provide an electronic device, including the above diamond power device provided by the embodiments of the present disclosure. Since the principle of solving problems by this electronic device is similar to that of the above diamond power device, therefore, the implementation of this electronic device provided by the embodiments of the present disclosure can refer to the implementation of the above diamond power device provided by the embodiments of the present disclosure, and the repeated parts will not be elaborated.

[0168] In some embodiments, the above electronic device provided by the embodiments of the present disclosure may include, but is not limited to: radio frequency amplifiers, mixers, radars, satellites, power supplies, automotive electronics, energy-saving lamps, household appliances, etc. Of course, in addition to transistors, the electronic device provided by the present disclosure may also include other structures. For example, when the electronic device is a radar, it further includes structures such as a transmitter, an antenna, and a receiver; when the electronic device is a mixer, it further includes structures such as an input port and an output port.

[0169] For a diamond power device, its preparation method, and an electronic device provided by the embodiments of the present disclosure, since field effect transistors are provided on both sides of a single-crystal diamond epitaxy, a double-sided structure field effect transistor is formed, effectively reducing the cost; and, since the first source electrode and the second source electrode of the double-sided structure field effect transistor are electrically connected, and the first drain electrode and the second drain electrode are electrically connected, compared with a single-sided field effect transistor, the device of the present disclosure can increase the current density while maintaining the same high breakdown voltage level, and obtain a diamond power device with both a large current density and high breakdown voltage performance.

[0170] Although the preferred embodiments of the present disclosure have been described, those skilled in the art can make additional changes and modifications once they learn the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present disclosure.

[0171] Obviously, those skilled in the art can make various changes and modifications to the present disclosure without departing from the spirit and scope of the present disclosure. Thus, if these modifications and variations of the present disclosure fall within the scope of the claims of the present disclosure and their equivalent technologies, the present disclosure is also intended to cover these modifications and variations.

Claims

1. A diamond power device, characterized in that, Comprising a double-sided structure field-effect transistor, the double-sided structure field-effect transistor includes a single-crystal diamond epitaxial layer, the single-crystal diamond epitaxial layer includes a first side and a second side arranged oppositely, the first side includes a first diamond conductive channel region and a first isolation region located outside the first diamond conductive channel region, and the second side includes a second diamond conductive channel region and a second isolation region located outside the second diamond conductive channel region; On a side of the first diamond conductive channel region facing away from the second diamond conductive channel region, a first source electrode and a first drain electrode are provided. On a side of the second diamond conductive channel region facing away from the first diamond conductive channel region, a second source electrode and a second drain electrode are provided. The first source electrode and the second source electrode are electrically connected, and / or the first drain electrode and the second drain electrode are electrically connected.

2. The diamond power device according to claim 1, wherein The first diamond conductive channel region and the second diamond conductive channel region are symmetrically arranged with respect to the single-crystal diamond epitaxial layer, and the first isolation region and the second isolation region are symmetrically arranged with respect to the single-crystal diamond epitaxial layer; The single-crystal diamond epitaxial layer has a first through hole and a second through hole penetrating through its thickness at positions corresponding to the first isolation region and the second isolation region. The first through hole is located between the first source electrode and the second source electrode, and the second through hole is located between the first drain electrode and the second drain electrode; The first source electrode and the second source electrode are electrically connected by a first connecting metal located in the first through hole, and the first drain electrode and the second drain electrode are electrically connected by a second connecting metal located in the second through hole.

3. The diamond power device according to claim 2, wherein, The cross-sectional width of the first through hole corresponding to the first side is greater than its cross-sectional width corresponding to the second side, and the cross-sectional width of the second through hole corresponding to the first side is greater than its cross-sectional width corresponding to the second side.

4. The diamond power device according to claim 3, characterized in that, The surface roughness of the side walls of the first through hole and the second through hole is less than 0.1 μm.

5. The diamond power device according to any one of claims 2-4, characterized in that The double-sided structure field-effect transistor includes at least a first double-sided structure field-effect transistor and a second double-sided structure field-effect transistor, and the first drain electrode of the first double-sided structure field-effect transistor is electrically connected to the first source electrode of the second double-sided structure field-effect transistor.

6. The diamond power device according to any one of claims 2-4, characterized in that, The double-sided structure field-effect transistor includes at least a first double-sided structure field-effect transistor and a second double-sided structure field-effect transistor. The second source electrode of the first double-sided structure field-effect transistor is electrically connected to the first source electrode of the second double-sided structure field-effect transistor, and the second drain electrode of the first double-sided structure field-effect transistor is electrically connected to the first drain electrode of the second double-sided structure field-effect transistor.

7. The diamond power device according to claim 1, characterized in that, The first diamond conductive channel region and the second diamond conductive channel region are symmetrically arranged with respect to the single-crystal diamond epitaxial layer, and the first isolation region and the second isolation region are symmetrically arranged with respect to the single-crystal diamond epitaxial layer; The first source electrode and the second source electrode on both sides of the diamond single crystal epitaxial layer are electrically connected through a first peripheral conductive line, and the first drain electrode and the second drain electrode on both sides of the diamond single crystal epitaxial layer are electrically connected through a second peripheral conductive line.

8. The diamond power device according to claim 7, wherein, The double-sided structure field effect transistor includes at least a first double-sided structure field effect transistor and a second double-sided structure field effect transistor, and the second conductive line of the first double-sided structure field effect transistor is electrically connected to the first conductive line of the second double-sided structure field effect transistor.

9. The diamond power device according to claim 7, wherein, The double-sided structure field effect transistor includes at least a first double-sided structure field effect transistor and a second double-sided structure field effect transistor, the first conductive line of the first double-sided structure field effect transistor is electrically connected to the first conductive line of the second double-sided structure field effect transistor, and the second conductive line of the first double-sided structure field effect transistor is electrically connected to the second conductive line of the second double-sided structure field effect transistor.

10. The diamond power device according to any one of claims 1-4, 7-9, characterized in that, The double-sided structure field effect transistor further includes: a first gate dielectric layer, covering the first source electrode and the first drain electrode and covering the first diamond conductive channel region between the first source electrode and the first drain electrode; a first gate electrode, located on a side of the first gate dielectric layer facing away from the diamond single crystal epitaxial layer; a second gate dielectric layer, covering the second source electrode and the second drain electrode and covering the second diamond conductive channel region between the second source electrode and the second drain electrode; The second gate electrode is located on a side of the second gate dielectric layer away from the diamond single crystal epitaxial layer.

11. The diamond power device according to claim 7, characterized in that, The first diamond conductive channel region includes at least a first sub-channel region and a second sub-channel region spaced apart from each other, the first source electrode is disposed in the first sub-channel region and close to a side surface of the diamond single crystal epitaxial layer, and the first drain electrode is disposed in the second sub-channel region and close to a side surface of the diamond single crystal epitaxial layer; A third drain electrode is further provided on one side of the first sub-channel region, and a third source electrode is further provided on one side of the second sub-channel region, wherein the third drain electrode and the third source electrode are adjacent to each other and electrically connected via a third conductive line; The second diamond conductive channel region includes at least a third sub-channel region and a fourth sub-channel region that are spaced apart from each other, the second source electrode is disposed in the third sub-channel region and close to a side surface of the diamond single crystal epitaxial layer, and the second drain electrode is disposed in the fourth sub-channel region and close to a side surface of the diamond single crystal epitaxial layer; A fourth drain electrode is further provided on one side of the third sub-channel region, and a fourth source electrode is further provided on one side of the fourth sub-channel region. The fourth drain electrode and the fourth source electrode are adjacent to each other and are electrically connected through a fourth conductive line.

12. The diamond power device according to claim 11, wherein The double-sided structure field effect transistor further includes: a first gate dielectric layer, covering the first source electrode and the third drain electrode and covering the first sub-channel region between the first source electrode and the third drain electrode; a first gate electrode, located on a side of the first gate dielectric layer facing away from the diamond single crystal epitaxial layer; A second gate dielectric layer, covering the second source electrode and the fourth drain electrode and covering the third sub-channel region between the second source electrode and the fourth drain electrode; A second gate electrode, located on a side of the second gate dielectric layer facing away from the diamond single crystal epitaxial layer; A third gate dielectric layer, covering the third source electrode and the first drain electrode and covering the second sub-channel region between the third source electrode and the first drain electrode; A third gate electrode, located on a side of the third gate dielectric layer facing away from the diamond single crystal epitaxial layer; A fourth gate dielectric layer, covering the fourth source electrode and the second drain electrode and covering the fourth sub-channel region between the fourth source electrode and the second drain electrode; A fourth gate electrode, located on a side of the fourth gate dielectric layer facing away from the diamond single crystal epitaxial layer.

13. The diamond power device according to claim 1, wherein The first diamond conductive channel region is a single conductive terminal or a composite conductive terminal, and the second diamond conductive channel region is a single conductive terminal or a composite conductive terminal.

14. The diamond power device according to claim 13, wherein The conductive terminal includes a hydrogen terminal, a tin terminal or a silicon terminal.

15. A method for preparing a diamond power device, which is used to prepare the diamond power device according to any one of claims 1-14, characterized in that, The preparation method includes: Forming a first diamond conductive channel region and a first isolation region located outside the first diamond conductive channel region on a first side of the diamond single crystal epitaxial layer; Forming a second diamond conductive channel region and a second isolation region located outside the second diamond conductive channel region on a second side of the diamond single crystal epitaxial layer; the first side and the second side are oppositely arranged; Preparing a first source electrode and a first drain electrode on two sides within the first diamond conductive channel region; Preparing a second source electrode and a second drain electrode on two sides within the second diamond conductive channel region, the first source electrode and the second source electrode are electrically connected, and the first drain electrode and the second drain electrode are electrically connected.

16. The preparation method according to claim 15, characterized in that, After preparing the first source electrode and the first drain electrode on two sides within the first diamond conductive channel region and before preparing the second source electrode and the second drain electrode on two sides within the second diamond conductive channel region, it further includes: sequentially performing a laser drilling process and a reactive ion etching process on the diamond single crystal epitaxial layer at the positions of the first isolation region and the second isolation region to form a first through hole and a second through hole, the first through hole overlaps with the first source electrode, and the second through hole overlaps with the first drain electrode; When preparing the second source electrode and the second drain electrode on two sides within the second diamond conductive channel region, simultaneously forming a first connecting metal filled in the first through hole and a second connecting metal filled in the second through hole.

17. The preparation method according to claim 16, characterized in that, The laser drilling process uses a femtosecond laser with a pulse repetition frequency of 2 kHz, a pulse width of 120 fs, and a power of 0.35 W; The reactive ion etching process is carried out in a microwave chemical vapor deposition system, wherein the reaction gas is H2 / Ar, the flow rate of the H2 gas is 20 - 40 sccm, the flow rate of the Ar gas is 10 - 30 sccm, the microwave input power is 800 - 1200 W, the reaction pressure is 0.8 - 2 kPa, the bias voltage applied to the diamond single crystal epitaxial layer is -400 - -200 V, and the etching time is 1 - 2 h.

18. An electronic device, characterized in that, Comprising a diamond power device as described in any one of claims 1-14.

Images