Diamond power device, preparation method thereof and electronic device

Abstract

According to the diamond power device, the preparation method thereof and the electronic device provided by the embodiment of the invention, the field effect transistors are arranged on the two sides of one diamond single crystal epitaxy, so that the field effect transistors with double-sided structures are formed, and the cost is effectively reduced; moreover, the first source electrode and the second source electrode of the double-sided field effect transistor are electrically connected, and the first drain electrode and the second drain electrode of the double-sided field effect transistor are electrically connected, so that compared with a single-sided field effect transistor, the device disclosed by the invention can increase the current density under the condition of keeping the same high withstand voltage level; and the diamond power device with high current density and high voltage resistance is obtained at the same time.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor technology, and in particular to a diamond power device and 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 large bandgap width, high breakdown field strength, high thermal conductivity, and high carrier mobility. It has the title of the ultimate semiconductor material and has great application potential in high-temperature, high-frequency, and high-power electronic devices. Diamond is a wide bandgap semiconductor material with excellent performance. After its surface is processed, it can form different terminals, such as tin terminals, silicon terminals, hydrogen terminals, oxygen terminals, and fluorine terminals. Different terminal surfaces have different conductivity. Due to the characteristics of diamond materials, diamond power devices can maintain the stability of the device in more extreme environments, can withstand higher breakdown voltages, and have better heat dissipation, so it has become a hot spot for scientific research.

[0003] However, conventional diamond devices are all single structures with low current density, low breakdown voltage and high cost. Therefore, more investment is needed in research and development to obtain diamond devices with high breakdown voltage, high current density and low cost. Summary of the invention

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

[0005] The present disclosure provides a diamond power device and a preparation method thereof and an electronic device, and the specific scheme is as follows:

[0006] On the one hand, the 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 arranged opposite to each other, the first side includes a first diamond conductive channel region and a first isolation region located at the periphery of the first diamond conductive channel region, the second side includes a second diamond conductive channel region and a second isolation region located at the periphery of the second diamond conductive channel region;

[0007] A first source electrode and a first drain electrode are arranged on the side of the first diamond conductive channel region facing away from the second diamond conductive channel region, and a second source electrode and a second drain electrode are arranged on the 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 the thickness thereof at positions corresponding to the first isolation region and the second isolation region, the first through hole being located between the first source electrode and the second source electrode, and the second through hole being located between the first drain electrode and the second drain electrode;

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

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

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

[0013] In some embodiments, in the above-mentioned diamond power device provided in 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, and the first drain electrode of the first double-sided structure field effect transistor and the first source electrode of the second double-sided structure field effect transistor are electrically connected.

[0014] In some embodiments, in the above-mentioned diamond power device provided in 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 and the first source electrode of the second double-sided structure field effect transistor are electrically connected, and the second drain electrode of the first double-sided structure field effect transistor and the first drain electrode of the second double-sided structure field effect transistor are electrically connected.

[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 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.

[0017] In some embodiments, in the above-mentioned diamond power device provided in 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, and the second conductive line of the first double-sided structure field effect transistor and the first conductive line of the second double-sided structure field effect transistor are electrically connected.

[0018] In some embodiments, in the above-mentioned diamond power device provided in 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 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.

[0019] In some embodiments, in the above-mentioned diamond power device provided in 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] The second gate electrode is 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 arranged in the first sub-channel region and close to the side of the diamond single crystal epitaxial layer, and the first drain electrode is arranged in the second sub-channel region and close to the side 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, wherein the third drain electrode and the third source electrode are adjacent to each other and are electrically connected via a third conductive line;

[0026] The second diamond conductive channel region includes at least a third sub-channel region and a fourth sub-channel region which are arranged at intervals, the second source electrode is arranged 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 arranged in the fourth sub-channel region and close to a 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 to each other and are electrically connected through a fourth conductive line.

[0028] In some embodiments, in the above-mentioned diamond power device provided in 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 is 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 is 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] The fourth gate electrode is 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 in 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 present disclosure also provides a method for preparing a diamond power device, which is used to prepare the diamond power device provided in the present disclosure. The preparation method comprises:

[0040] forming a first diamond conductive channel region and a first isolation region located at the periphery of 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 at the periphery of the second diamond conductive channel region on the second side of the diamond single crystal epitaxial layer; the first side and the second side are arranged opposite to each other;

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

[0043] A second source electrode and a second drain electrode are prepared on both sides of the second diamond conductive channel region, the first source electrode is electrically connected to the second source electrode, and the first drain electrode is electrically connected to the second drain electrode.

[0044] In some embodiments, in the above-mentioned preparation method provided by the embodiments of the present disclosure, after preparing the first source electrode and the first drain electrode on both sides of the first diamond conductive channel region, and before preparing the second source electrode and the second drain electrode on both sides of the second diamond conductive channel region, the method 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, wherein 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 of the second diamond conductive channel region, the first connection metal filled in the first through hole and the second connection metal filled in the second through hole are formed simultaneously.

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

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

[0048] On the other hand, an embodiment of the present disclosure further provides an electronic device, comprising the above-mentioned diamond power device provided by an embodiment of the present disclosure.

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

[0050] A diamond power device and a preparation method and an electronic device provided by the embodiments of the present disclosure have field effect transistors on both sides of a diamond single crystal epitaxial growth, thereby forming a double-sided field effect transistor, which effectively reduces the cost; and because the first source electrode and the second source electrode of the double-sided 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 withstand voltage level, thereby obtaining a diamond power device with both high current density and high withstand voltage performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 A schematic diagram of the structure of a diamond power device provided in an embodiment of the present disclosure;

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

[0053] Figure 3 For this disclosure alone Figure 1 A schematic diagram of a first through hole and a second through hole;

[0054] Figure 4 A schematic diagram of another structure of a diamond power device provided in an embodiment of the present disclosure;

[0055] Figure 5A schematic diagram of another structure of a diamond power device provided in an embodiment of the present disclosure;

[0056] Figure 6 A schematic diagram of another structure of a diamond power device provided in an embodiment of the present disclosure;

[0057] Figure 7 A schematic diagram of another structure of a diamond power device provided in an embodiment of the present disclosure;

[0058] Figure 8 A schematic diagram of another structure of a diamond power device provided in an embodiment of the present disclosure;

[0059] Fig. 9 A schematic diagram of another structure of a diamond power device provided in an embodiment of the present disclosure;

[0060] Fig.10 A schematic flow chart of a method for preparing a diamond power device provided in an embodiment of the present disclosure;

[0061] Figure 11A-Figure 11Q Prepare Figure 1 The schematic diagram of the structure of the diamond power device shown in each step;

[0062] Fig.12 For preparation Figure 6 The schematic diagram of the structure of the diamond power device during the execution process shown;

[0063] Fig.13 For preparation Fig. 9 The schematic diagram of the structure of the diamond power device during execution is shown. DETAILED DESCRIPTION

[0064] In order to make the purpose, technical solution and advantages of the embodiment of the present disclosure clearer, the technical solution of the embodiment of the present disclosure will be clearly and completely described in conjunction with the drawings of the embodiment of the present disclosure. It should be noted that in the drawings, the thickness of the layer, film, panel, area, etc. is magnified for clarity. In the present disclosure, exemplary embodiments are described with reference to cross-sectional views of schematic diagrams of idealized embodiments. In this way, deviations from the shape of the figure as a result of, for example, manufacturing technology and / or tolerances will be expected. Therefore, the embodiments described in the present disclosure should not be interpreted as being limited to the specific shape of the area shown in the present disclosure, but include deviations in shape caused by, for example, manufacturing. For example, an area illustrated or described as flat may typically have rough and / or nonlinear features; the illustrated sharp corners may be rounded, etc. Therefore, the areas shown in the figures are schematic in nature, and their sizes and shapes are not intended to illustrate the exact shape of the area, do not reflect the true proportion, and the purpose is only to illustrate the content of the present disclosure. And the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. In order to keep the following description of the embodiments of the present disclosure clear and concise, the present disclosure omits detailed descriptions of well-known functions and well-known components.

[0065] Unless otherwise defined, the technical terms or scientific terms used herein shall have the usual meanings understood by persons of ordinary skill in the field to which the present disclosure belongs. The words "first", "second" and similar words used in the present disclosure specification and claims do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" and the like mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" and the like are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Inside", "outside", "upper", "lower", etc. are only used to indicate relative positional relationships. When the absolute position of the described object 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 may be directly on, directly connected to, or there may be an intermediate element or intermediate layer. When an element or layer is referred to as being "disposed on one side of" another element or layer, the element or layer may be directly on one side of, directly connected to, or there may be an intermediate element or intermediate layer. However, when an element or layer is referred to as being "directly on" or "directly connected to" another element or layer, there are no intermediate elements or intermediate layers. The term "and / or" includes any and all combinations of one or more of the associated listed items.

[0067] The present disclosure provides a diamond power device, such as Figure 1 , Figure 4-Figure 9 As shown, it includes a double-sided structure field effect transistor, which includes a diamond single crystal epitaxial layer 1, and the diamond single crystal epitaxial layer 1 includes a first side A1 and a second side A2 that 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, and 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 provided on the side of the first diamond conductive channel region 11 away from the second diamond conductive channel region 13, and a second source electrode S2 and a second drain electrode D2 are provided on the side of the second diamond conductive channel region 13 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] The above-mentioned diamond power device provided by the embodiment of the present disclosure has field effect transistors on both sides of a diamond single crystal epitaxial growth, thereby forming a double-sided structure field effect transistor, which effectively reduces the cost; and because 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 the single-sided field effect transistor, the device of the present disclosure can increase the current density while maintaining the same high withstand voltage level, thereby obtaining a diamond power device with both high current density and high withstand voltage performance.

[0070] In some embodiments, in the above-mentioned diamond power device provided in the embodiments of the present disclosure, if 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 the thickness thereof at positions corresponding to the first isolation region 12 and the second isolation region 13, wherein 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, short-circuiting 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 the first connection 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 the second connection metal 22 located in the second through hole V2. 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 disclosed in the present invention can increase the current density to 2 times while maintaining the same high withstand voltage level, thereby obtaining a double-sided structure field effect transistor with both high current density and high withstand voltage performance.

[0073] like Figure 2 As shown, Figure 2 This is a schematic diagram of the prior art using only the laser drilling process to form a through hole H on the diamond single crystal epitaxial layer 1. It can be seen that the side wall surface of the through hole H forms non-diamond impurities NG (such as graphite) on the side wall surface of the through hole H due to the laser process. 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 morphology defects on the side wall surface of the through hole H, resulting in reduced reliability and transmission efficiency of metal filling interconnection.

[0074] In some embodiments, in the above-mentioned diamond power device provided in the embodiments of the present disclosure, if Figure 3 As shown, Figure 3 For this disclosure alone Figure 1The schematic diagram of the first through hole V1 and the second through hole V2 in the present disclosure can be formed by laser drilling process and reactive ion etching process in sequence. For example, in the embodiment 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 in sequence by laser drilling process and reactive ion etching process, so that the cross-sectional width of the first through hole V1 corresponding to the first side A1 is greater than the cross-sectional width thereof 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 the cross-sectional width thereof corresponding to the second side A2, and the side wall surface roughness of the first through hole V1 and the second through hole V2 are both less than 0.1 μm. Therefore, compared with the use of reactive ion etching and focused ion etching alone for drilling, the present invention uses laser drilling to improve the diamond drilling efficiency. The reactive ion etching process after laser drilling can effectively remove non-diamond impurities (such as graphite) formed on the side walls of the through holes due to the laser process. At the same time, after reactive ion etching, the surface of the through hole can be made smooth, the morphological defects of the hole can be removed, and the reliability and transmission efficiency of the metal-filled 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 embodiment of the present disclosure can be interchangeable. Figure 1 The upper side of the diamond single crystal epitaxial layer 1 is the first side A1, and the lower side is the second side A2; of course, the lower side of the diamond single crystal epitaxial layer 1 may also be the first side A1, and the upper side may be the second side A2.

[0076] Specifically, a femtosecond laser with a pulse repetition frequency of 2kHz, a pulse width of 120fs, and a power of 0.35W can be used to drill holes in the isolation area of ​​the diamond single crystal epitaxial layer 1 to form a first through hole and a 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, wherein the reaction gas is H2 / Ar, the H2 gas flow rate is 20-40sccm, the Ar gas flow rate is 10-30sccm, the microwave input power is 800-1200W, the reaction gas pressure is 0.8-2kPa, the bias voltage applied to the diamond single crystal epitaxial layer is -400--200V, and the etching time is 1-2h.

[0077] Optionally, the material of the first source electrode S1 , the second source electrode S2 , the first drain electrode D1 and the second drain electrode D2 may be Ti / Au, but is certainly not limited thereto.

[0078] In some embodiments, in the above-mentioned diamond power device provided in the embodiments of the present disclosure, if Figure 1 As shown, the double-sided structure field effect transistor also 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 may be Ti / Au, but is certainly not limited thereto;

[0081] The 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 is in contact with the second source electrode S2 and the second drain electrode D2, 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;

[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 both be single conductive terminals, and the first diamond conductive channel region 11 and the second diamond conductive channel region 13 can be the same conductive terminal or different conductive terminals. Optionally, the first diamond conductive channel region 11 is one of a hydrogen terminal, a tin terminal or a silicon terminal, and the second diamond conductive channel region 13 is one of 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 may also be composite conductive terminals. For example, the first diamond conductive channel region 11 may be a composite structure of at least two conductive terminals selected from hydrogen terminals, tin terminals or silicon terminals, and the second diamond conductive channel region 13 may also be a composite structure of at least two conductive terminals selected from 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 first connection metal 21 and the second connection metal 22 may be made of the same material as the first source electrode S1 and the first drain electrode D1 , that is, the first connection metal 21 and the second connection 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 in the embodiments of the present disclosure, if Figure 4 As 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 can be electrically connected by a fifth conductive line 100, that is, the embodiment of the present disclosure Figure 4 The structure shown is to combine two Figure 1 The single double-sided field effect transistors shown are connected in series with wires to form a series integrated device. Figure 4 The two double-sided field effect transistors are connected in series. Figure 1 Compared with the single double-sided structure field effect transistor shown in Figure 4 The voltage resistance of the series integrated device shown can be increased by 2 times, and the current density can be increased by 2 times, so as to obtain a diamond power device with high voltage resistance, large current density and good heat dissipation.

[0088] In some embodiments, three or more Figure 1 The single double-sided field effect transistors shown are connected in series, thereby obtaining a high-current diamond power device with a multiple times higher withstand voltage.

[0089] In some embodiments, in the above-mentioned diamond power device provided in the embodiments of the present disclosure, if Figure 5 As shown, the double-sided structure field effect transistor may include at least 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 using a sixth conductive line 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 using a seventh conductive line 300, that is, in the embodiment of the present disclosure, Figure 5The structure shown is to combine two Figure 1 The single double-sided field effect transistors shown are connected in parallel with wires to form a parallel integrated device. Figure 5 Compared with the single-sided field effect transistor, the two double-sided field effect transistors in parallel integrated device shown in the figure are Figure 5 The current density of the parallel integrated device shown can be increased to 4 times, obtaining a diamond power device with high current density, high voltage resistance and good heat dissipation.

[0090] In some embodiments, three or more Figure 1 The single double-sided field effect transistors shown are connected in parallel to obtain a diamond power device with a multiple times higher current.

[0091] In some embodiments, in the above-mentioned diamond power device provided in the embodiments of the present disclosure, if Figure 6 As shown, Figure 6 The structure shown is Figure 1 The structures shown are basically the same, except 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 can be electrically connected through the first conductive wire 31 on the periphery, 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 conductive wire 32 on the periphery. 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 the single-sided field effect transistor, the present invention Figure 6 The structure shown can increase the current density by 2 times while maintaining the same high withstand voltage level, thus obtaining a diamond power device with both high current density and high withstand voltage performance.

[0092] In some embodiments, in the above-mentioned diamond power device provided in the embodiments of the present disclosure, if Figure 7 As 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 second conductive line 32 of the first double-sided structure field effect transistor M1 is electrically connected to the first conductive line 31 of the second double-sided structure field effect transistor M1. Figure 7 The structure shown is to combine two Figure 6 The single parallel double-sided structure field effect transistors shown are connected in series to form a series integrated device. Therefore, Figure 7 The two double-sided field effect transistors are connected in series. Figure 6 Compared with the single parallel double-sided structure field effect transistor shown in Figure 7 The voltage resistance of the series integrated device shown can be increased by 2 times, and the current density can be increased by 2 times, so as to obtain a diamond power device with high voltage resistance, large current density and good heat dissipation.

[0093] In some embodiments, three or more Figure 6 The single parallel double-sided structure field effect transistors shown are connected in series, thereby obtaining a high-current diamond power device with a multiple times higher withstand voltage.

[0094] In some embodiments, in the above-mentioned diamond power device provided in the embodiments of the present disclosure, if Figure 8 As 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, the first conductive line 31 of the first double-sided structure field effect transistor M1 is electrically connected to the first conductive line 31 of the second double-sided structure field effect transistor M2, and the second conductive line 32 of the first double-sided structure field effect transistor M1 is electrically connected to the second conductive line 32 of the second double-sided structure field effect transistor M2. Figure 8 The structure shown is to combine two Figure 6 The single parallel double-sided structure field effect transistors shown are connected in parallel to form a parallel integrated device. Figure 8 Compared with the single-sided field effect transistor, the two double-sided field effect transistors in parallel integrated device shown in the figure are Figure 8 The current density of the parallel integrated device shown can be increased to 4 times, obtaining a diamond power device with high current density, high voltage resistance and good heat dissipation.

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

[0096] In some embodiments, in the above-mentioned diamond power device provided in the embodiments of the present disclosure, if Fig. 9 As 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, a first source electrode S1 is arranged in the first sub-channel region 111 and close to the side of the diamond single crystal epitaxial layer 1, and a first drain electrode D1 is arranged in the second sub-channel region 112 and close to the side of the diamond single crystal epitaxial layer 1;

[0097] A third drain electrode D3 is further disposed on one side of the first sub-channel region 111, and a third source electrode S3 is further disposed on one side of the second sub-channel region 112. The third drain electrode D3 and the third source electrode S3 are adjacent to each other and are electrically connected through a third conductive line 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 which are arranged at intervals, the second source electrode S2 is arranged in the third sub-channel region 131 and close to the side of the diamond single crystal epitaxial layer 1, and the second drain electrode D2 is arranged in the fourth sub-channel region 132 and close to the side of the diamond single crystal epitaxial layer 1;

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

[0100] In some embodiments, in the above-mentioned diamond power device provided in the embodiments of the present disclosure, if Fig. 9 As shown, the double-sided structure field effect transistor also 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 certainly not limited thereto;

[0102] 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 may be Ti / Au, but is certainly not limited thereto;

[0103] The 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 contacts 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 certainly not limited thereto;

[0104] The 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 may be Ti / Au, but is certainly not limited thereto;

[0105] The 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 certainly 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 may be Ti / Au, but is certainly not limited thereto;

[0107] The fourth gate dielectric layer 44 covers the fourth source electrode S4 and the second drain electrode D2 and covers 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 is certainly not limited thereto;

[0108] The fourth gate electrode G4 is located on a 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 may be Ti / Au, but is certainly not limited thereto.

[0109] Specifically, Fig. 9 The structure shown is that at least two spaced field effect transistors are formed on both sides of the diamond single crystal epitaxial layer 1, and the field effect transistors on each side are connected in series in pairs through the corresponding third conductive wires 33 or fourth conductive wires 34, and the outermost first source electrode S1 and the second source electrode S2 are electrically connected through the outer first conductive wires 31, and the outermost first drain electrode D1 and the second drain electrode D2 are electrically connected through the outer second conductive wires 32 to form a series integrated device. Compared with a single double-sided field effect transistor, Fig. 9 The withstand voltage of the series integrated device shown can be increased by at least 2 times, and the current density can be increased by at least 2 times, thereby obtaining a diamond power device with high withstand voltage, high current density and good heat dissipation.

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

[0111] Based on the same inventive concept, an embodiment of the present disclosure provides a method for preparing the above-mentioned diamond power device. Since the principle of solving the problem by the preparation method is similar to the principle of solving the problem by the above-mentioned diamond power device, the implementation of the preparation method provided by the embodiment of the present disclosure can refer to the implementation of the above-mentioned diamond power device provided by the embodiment of the present disclosure, and the repeated parts will not be repeated.

[0112] In some embodiments, the method for preparing the diamond power device provided in the embodiments of the present disclosure is as follows: Fig.10 As shown, it may include:

[0113] S1001, 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;

[0114] S1002, 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 arranged opposite to each other;

[0115] S1003, preparing a first source electrode and a first drain electrode on both sides of the first diamond conductive channel region;

[0116] S1004, preparing a second source electrode and a second drain electrode on both sides of 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-mentioned 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 of 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 of the second diamond conductive channel region, the method 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, wherein 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 of the second diamond conductive channel region, the first connection metal filled in the first through hole and the second connection metal filled in the second through hole are simultaneously formed.

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

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

[0121] The following is prepared Figure 1 Taking the diamond power device shown as an example, the above preparation method provided by the embodiment of the present disclosure is described in detail, wherein the first diamond conductive channel region 11 and the second diamond conductive channel region 13 are both tin terminals.

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

[0123] (1) Polishing and cleaning the surface of the diamond single crystal to obtain a treated diamond single crystal 10; specifically, first, cutting and polishing the diamond single crystal so that the surface roughness reaches 0 to 10 nm; secondly, inorganic cleaning and organic cleaning are performed on the polished diamond single crystal, and the polished diamond single crystal is rinsed in flowing deionized water and then blown dry with a nitrogen gun. Optionally, inorganic cleaning may include: using a heated sulfuric acid and nitric acid mixed solution to clean the polished diamond single crystal; organic cleaning may include: using acetone, ethanol or isopropanol and deionized water for ultrasonic cleaning for 0 to 30 minutes respectively.

[0124] (2) Fig.11A As shown, a first SnO2 film 20 is deposited on the surface of the treated diamond single crystal 10 by electron beam evaporation, thermal evaporation, magnetron sputtering, atomic layer deposition or chemical vapor deposition; the thickness of the first SnO2 film 20 can be 0 to 600nm, for example, 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, etc.

[0125] It should be noted that step (2) of the embodiment of the present disclosure takes the deposition of SnO2 thin film as an example, but of course, SnO thin film can also be deposited.

[0126] (3) Fig. 11B As shown, a first photoresist layer 30 is formed on a side of the first SnO 2 film 20 away from the diamond single crystal 10 , and the thickness of the first photoresist layer 30 may be 1-10 μm.

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

[0128] (5) Fig.11D As shown, with the first photoresist pattern 30' as a mask, the first SnO2 film 20 is etched by reactive ion etching (RIE) to form a patterned first SnO2 layer 20', wherein the first SnO2 layer 20' includes a first SnO2 retention area 201 and a first SnO2 removal area 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 gas pressure can be 4-10mTorr.

[0129] (6) Fig.11E As shown, the first photoresist pattern 30 ′ is removed, that is, a first SnO 2 layer 20 ′ including a first SnO 2 retained region 201 and a first SnO 2 removed region 202 is formed.

[0130] (7) Fig.11FAs shown, 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 device (MPCVD), wherein the temperature in the MPCVD is set to 800°C to 1200°C, the pressure is set to 100 to 200 mbar, and a mixed gas of H2, CH4 and N2 is introduced into the MPCVD, wherein the H2 flow rate is 200 to 600 sccm, the CH4 flow rate is 0 to 100 sccm, and the N2 flow rate is 0.01 to 1 sccm, so that 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', and the thickness of the diamond single crystal epitaxial layer 1 can be The thickness of the first SnO2 layer 20' is 300μm to 1000μm, for example, 300μm, 400μm, 500μm, 600μm, 700μm, 800μm, 900μm, 1000μm, etc.; due to the high temperature in the MPCVD, the Sn in the first SnO2 layer 20' undergoes thermal diffusion to replace the C in the diamond single crystal epitaxial layer 1 to form a carbon-tin bond, so that the first side A1 of the diamond single crystal epitaxial layer 1 facing the diamond single crystal 10 can form 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. Afterwards, the temperature inside the microwave plasma chemical vapor deposition equipment is lowered, and the growing diamond single crystal epitaxial layer 1 will have uneven stress to achieve self-stripping, so that the diamond single crystal epitaxial layer 1 formed with the first diamond conductive channel region 11 and the first isolation region 12 is peeled off from the first SnO2 layer 20'.

[0131] (8) Fig.11G As shown, Fig.11G for Fig.11F Schematic diagram of a plan view showing that a first diamond conductive channel region 11 and a first isolation region 12 are formed on a first side A1 of the diamond single crystal epitaxial layer 1 after peeling.

[0132] (9) Fig.11H As shown, a second SnO2 film 50 is deposited on the second side A2 of the diamond single crystal epitaxial layer 1 by electron beam evaporation, thermal evaporation, magnetron sputtering, atomic layer deposition or chemical vapor deposition, and the second side A and the first side A1 are arranged relative to each other; optionally, the thickness of the second SnO2 film 50 can be 0 to 600nm, for example, 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, etc.

[0133] (10) Fig.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, the specific steps of forming the second SnO2 layer 50' can be referred to Figure 11B-11E The steps are not described here.

[0134] (11) Fig.11J As shown, a microwave plasma chemical vapor deposition system is used to perform plasma hydrogenation treatment on the diamond single crystal epitaxial layer 1 formed with the second SnO2 layer 50'. The temperature of the plasma hydrogenation treatment is 900-1200°C, the hydrogen flow rate is 400-600sccm, the gas pressure is 110-130Torr, and the treatment time is 10-30min. In this way, the second side A2 of the diamond single crystal epitaxial layer 1 corresponding to the second SnO2 retention area 501 is converted into a second diamond conductive channel region 13 (i.e., a tin terminal) by utilizing the strong reduction and thermal environment of hydrogen plasma, and the second SnO2 removal area 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) Figure 11K As 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-terminated diamond with good conductivity. Optionally, the acid solution used for pickling can be diluted hydrochloric acid with a concentration of 2 mol / L, and the cleaning time can be about 20 minutes.

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

[0137] (14) Fig.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 expose part of the first source electrode S1 and part of the first drain electrode D1, and then SiO2 is deposited, and then the remaining photoresist is washed away, so as to form a first gate dielectric layer 41 covering the middle area of ​​the corresponding first diamond conductive channel region 11 and covering part of the first source electrode S1 and part of the first drain electrode D1. The first gate dielectric layer 41 covers part of the first source electrode S1 and part of the first drain electrode D1, which can reduce the electric field and increase the breakdown voltage.

[0138] (15) Fig.11N As shown, first, a layer of photoresist is 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, and then a metal material (such as Ti / Au) is deposited on the side of the first gate dielectric layer 41 away from the diamond single crystal epitaxial layer 1 using an electron beam evaporation device, and then the remaining photoresist is washed away, thereby forming a first gate electrode G1 covering the middle area of ​​the first gate dielectric layer 41, and forming a Schottky contact, thereby forming a single-sided field effect transistor on the first side A1 of the diamond single crystal epitaxial layer 1.

[0139] like Fig.11O As shown, Fig.11O for Fig.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, a second source electrode S2 and a second drain electrode D2 are prepared on both sides of each second diamond conductive channel region 13 of the second side A2 of the diamond single crystal epitaxial layer 1, and a first connection metal 21 filled in the first through hole V1 and a second connection metal 22 filled in the second through hole V2 are formed at the same time. Since the second isolation region 14 at this time is a hydrogen terminal, and the hydrogen terminal is conductive, in order to prevent the formed device from leaking electricity, the hydrogen terminal needs to be converted into an insulating region, so a second photoresist layer can be formed on the side of the second source electrode and the second drain electrode away from the tin terminal diamond, and the second photoresist layer is exposed and developed to form a second photoresist pattern including a second photoresist completely retained area and a second photoresist completely removed area; wherein the second photoresist completely retained area corresponds to the second diamond conductive channel region and the second source electrode S2 and the second drain electrode D2, and the second photoresist completely removed area corresponds to the remaining hydrogen terminal; using the second photoresist pattern as a mask, the hydrogen terminal is subjected to oxygen plasma treatment to convert the hydrogen terminal into an oxygen terminal; and the second photoresist pattern is removed. In this way, the hydrogen terminal is removed by oxygen plasma to form a second isolation region for the oxygen terminal to prevent device leakage.

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

[0143] (18) Figure 1 As 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 diamond single crystal epitaxial layer 1, and the second gate dielectric layer 41 covers the middle area 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 diamond single crystal epitaxial layer 1, and the second gate electrode G2 covers the middle area of ​​the second gate dielectric layer 42. In this way, a field effect transistor is formed on the second side A2 of the diamond single crystal epitaxial layer 1, that is, a field effect transistor is formed. Figure 1 The double-sided field effect transistor shown is a double-sided field effect transistor in which the upper and lower field effect transistors are connected in parallel.

[0144] It should be noted that the method for preparing the second source electrode, the second drain electrode, the second gate dielectric layer and the second gate electrode can refer to the aforementioned method for preparing the first source electrode, the first drain electrode, the first gate dielectric layer and the first gate electrode, and will not be repeated here.

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

[0146] (19) Slicing the double-sided field effect transistor array prepared in step (18) can be performed by laser cutting, using a pulsed laser operating at 532nm or 1064nm, and longitudinally slicing the isolation region of the diamond single crystal epitaxial layer through an electric-controlled machine tool to obtain Figure 1 A single parallel double-sided field effect transistor is shown including one field effect transistor on each side.

[0147] Thus, through the above steps (1) to (19), a Figure 1 The diamond power device shown.

[0148] Specifically, the two Figure 1 The double-sided parallel field effect transistors shown are connected in series with wires to form Figure 4 The series integrated device shown.

[0149] Specifically, the two Figure 1 The double-sided parallel field effect transistors shown are connected in parallel with wires to form Figure 5 The parallel integrated devices shown.

[0150] The following is prepared Figure 6 Taking the diamond power device shown as an example, the above preparation method provided by the embodiment of the present disclosure is described in detail, wherein the first diamond conductive channel region 11 and the second diamond conductive channel region 13 are both tin terminals.

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

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

[0153] 2. There is no need to drill holes in the diamond single crystal epitaxial layer 1. A second source electrode S2 and a second drain electrode D2, a second gate dielectric layer 41, and a second gate electrode G2 are directly prepared on the second side A2 of the diamond single crystal epitaxial layer 1. In this way, a plurality of field effect transistors are formed on the second side A2 of the diamond single crystal epitaxial layer 1. Fig.12 The double-sided field effect transistor shown.

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

[0155] 3. Next, the double-sided field effect transistor array prepared in step 2 is sliced. The slicing can be performed by laser cutting. A pulsed laser operating at 532nm or 1064nm is used to slice the isolation area of ​​the diamond single crystal epitaxial layer longitudinally through an electric machine tool to obtain Fig.12 A single double-sided field effect transistor is shown including one field effect transistor on each side.

[0156] 4. Use the first conductive wire 31 to electrically connect the first source electrode S1 to the second source electrode S2, and use the second conductive wire 32 to electrically connect the first drain electrode D1 to the second drain electrode D2, so as to form Figure 6 The diamond power device shown.

[0157] Specifically, the two Figure 6 The double-sided parallel field effect transistors shown are connected in series to form Figure 7 The series integrated device shown.

[0158] Specifically, the two Figure 6 The double-sided parallel field effect transistors shown are connected in parallel to form Figure 8 The parallel integrated devices shown.

[0159] The following is prepared Fig. 9 Taking the diamond power device shown as an example, the above preparation method provided by the embodiment of the present disclosure is described in detail, wherein the first diamond conductive channel region 11 and the second diamond conductive channel region 13 are both tin terminals.

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

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

[0162] 2. There is no need to drill holes in the diamond single crystal epitaxial layer 1. A second source electrode S2 and a second drain electrode D2, a second gate dielectric layer 41, and a second gate electrode G2 are directly prepared on the second side A2 of the diamond single crystal epitaxial layer 1. In this way, a plurality of field effect transistors are formed on the second side A2 of the diamond single crystal epitaxial layer 1. Fig.13 The double-sided field effect transistor shown.

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

[0164] 3. Next, the double-sided field effect transistor array prepared in step 2 is sliced. The slicing can be performed by laser cutting. A pulsed laser operating at 532nm or 1064nm is used to slice the isolation area of ​​the diamond single crystal epitaxial layer longitudinally through an electric machine tool to obtain Fig.13 The structure shown includes at least two field effect transistors on each side.

[0165] 4. Use the first conductive wire 31 to Fig.13 The first source electrode S1 and the second source electrode S2 are electrically connected, and the second conductive line 32 is used to connect Fig.13 The first drain electrode D1 and the second drain electrode D2 are electrically connected, and the third conductive line 33 is used to connect Fig.13 The third drain electrode D3 and the third source electrode S3 are electrically connected, and the fourth conductive line 34 is used to connect Fig.13 The fourth drain electrode D4 and the fourth source electrode S4 are electrically connected to form Fig. 9 The diamond power device shown.

[0166] It should be noted that in the above-mentioned preparation method provided in the embodiment of the present disclosure, the patterning process involved in forming each layer structure may include not only part or all of the process such as deposition, photoresist coating, mask masking, exposure, development, etching, photoresist stripping, etc., but also other process, which is subject to the graphics of the required composition formed in the actual production process, and is not limited here. For example, a post-baking process may also 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 here; the mask used in the mask process may be a half-tone mask (Half Tone Mask), a single slit diffraction mask (Single Slit Mask) or a gray tone mask (Gray Tone Mask), which is not limited here; etching may be dry etching or wet etching, which is not limited here.

[0167] Based on the same inventive concept, an embodiment of the present disclosure provides an electronic device, including the diamond power device provided in the embodiment of the present disclosure. Since the principle of solving the problem by the electronic device is similar to the principle of solving the problem by the diamond power device, the implementation of the electronic device provided in the embodiment of the present disclosure can refer to the implementation of the diamond power device provided in the embodiment of the present disclosure, and the repeated parts will not be repeated.

[0168] In some embodiments, the electronic devices provided by the embodiments of the present disclosure may include, but are not limited to: radio frequency amplifiers, mixers, radars, satellites, power supplies, automotive electronics, energy-saving lamps, household appliances, etc. Of course, the electronic devices provided by the present disclosure may include other structures in addition to transistors. For example, when the electronic device is a radar, it also includes: transmitters, antennas, receivers, etc.; when the electronic device is a mixer, it also includes: input ports, output ports, etc.

[0169] A diamond power device and a preparation method and an electronic device provided by the embodiments of the present disclosure have field effect transistors on both sides of a diamond single crystal epitaxial growth, thereby forming a double-sided field effect transistor, which effectively reduces the cost; and because the first source electrode and the second source electrode of the double-sided 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 withstand voltage level, thereby obtaining a diamond power device with both high current density and high withstand voltage performance.

[0170] Although the preferred embodiments of the present disclosure have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and 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 equivalents, the present disclosure is also intended to include these modifications and variations.

Claims

1. A diamond power device, characterized in that: A double-sided field effect transistor is provided, wherein the double-sided field effect transistor comprises a diamond single crystal epitaxial layer, wherein the diamond single crystal epitaxial layer comprises a first side and a second side which are arranged opposite to each other, wherein the first side comprises a first diamond conductive channel region and a first isolation region located at the periphery of the first diamond conductive channel region, and the second side comprises a second diamond conductive channel region and a second isolation region located at the periphery of the second diamond conductive channel region; A first source electrode and a first drain electrode are arranged on the side of the first diamond conductive channel region facing away from the second diamond conductive channel region, and a second source electrode and a second drain electrode are arranged on the 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.

2. 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 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; The diamond single crystal epitaxial layer has a first through hole and a second through hole penetrating the thickness thereof at positions corresponding to the first isolation region and the second isolation region, the first through hole being located between the first source electrode and the second source electrode, and the second through hole being located between the first drain electrode and the second drain electrode; The first source electrode and the second source electrode are electrically connected via a first connection metal located in the first through hole, and the first drain electrode and the second drain electrode are electrically connected via a second connection metal located in the second through hole.

3. The diamond power device according to claim 2, characterized in that: A cross-sectional width of the first through hole corresponding to the first side is greater than a cross-sectional width thereof corresponding to the second side, and a cross-sectional width of the second through hole corresponding to the first side is greater than a cross-sectional width thereof 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 to 4, characterized in that: 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 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 to 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 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; 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, characterized in that: 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 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, 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 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 to 4 and 7 to 9, characterized in that: The double-sided structure field effect transistor also 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 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 which are 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 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, wherein the third drain electrode and the third source electrode are adjacent to each other and are 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 which are arranged at intervals, the second source electrode is arranged 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 arranged 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 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 to each other and are electrically connected through a fourth conductive line.

12. The diamond power device according to claim 11, characterized in that: The double-sided structure field effect transistor also 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 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 is located on a side of the second gate dielectric layer 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 is located on a side of the third gate dielectric layer 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; The fourth gate electrode is located on a side of the fourth gate dielectric layer away from the diamond single crystal epitaxial layer.

13. The diamond power device according to claim 1, characterized in that: 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, characterized in that: The conductive terminal includes a hydrogen terminal, a tin terminal or a silicon terminal.

15. A method for preparing a diamond power device, used for preparing the diamond power device according to any one of claims 1 to 14, characterized in that: The preparation method comprises: forming a first diamond conductive channel region and a first isolation region located at the periphery of 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 at the periphery of the second diamond conductive channel region on the second side of the diamond single crystal epitaxial layer; the first side and the second side are arranged opposite to each other; Preparing a first source electrode and a first drain electrode on both sides of the first diamond conductive channel region; A second source electrode and a second drain electrode are prepared on both sides of the second diamond conductive channel region, the first source electrode is electrically connected to the second source electrode, and the first drain electrode is electrically connected to the second drain electrode.

16. The preparation method according to claim 15, characterized in that: After preparing a first source electrode and a first drain electrode on both sides of the first diamond conductive channel region, and before preparing a second source electrode and a second drain electrode on both sides of the second diamond conductive channel region, the method 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, wherein 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 both sides of the second diamond conductive channel region, the first connection metal filled in the first through hole and the second connection metal filled in the second through hole are formed simultaneously.

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

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

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