A lateral boron-doped diamond diode and a batch preparation method thereof

Abstract

The present invention discloses a lateral boron-doped diamond diode and a batch preparation method thereof, belonging to the technical field of semiconductor materials and devices; the lateral boron-doped diamond diode comprises a boron-doped single crystal diamond; at least two trapezoidal through holes are provided on the boron-doped single crystal diamond; the upper bottom of the trapezoidal through hole is located on the front side of the boron-doped single crystal diamond, and the lower bottom of the trapezoidal through hole is located on the back side of the boron-doped single crystal diamond; a boron-doped polycrystalline diamond grows on the back side of the boron-doped single crystal diamond; a Schottky contact layer and an ohmic contact layer are deposited on the front side of the boron-doped single crystal diamond; the Schottky contact layer is located on the front side region of the boron-doped single crystal diamond between any two adjacent trapezoidal through holes; the ohmic contact layer is located on the front side region of the boron-doped single crystal diamond outside the two adjacent trapezoidal through holes. The diode prepared by the present invention has good voltage resistance and current carrying capacity, low preparation cost, and is beneficial to batch production.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor materials and devices, and relates to a lateral boron-doped diamond diode and a batch preparation method thereof. Background Art

[0002] The diode is one of the most basic devices in the power electronic system and plays a vital role in the safe and stable operation of the power system. Ultra-wide bandgap semiconductor diamond has excellent electrical properties and the highest thermal conductivity in nature. It is an ideal material for making high-frequency, high-power, high-temperature resistant and low-loss power electronic devices.

[0003] However, the breakdown voltage of the single-crystal diamond Schottky diode devices currently studied is far lower than the expected value of the material, which means that under actual working conditions, the device may not be able to withstand the high voltage expected during design, thus limiting its application in high-voltage and high-power situations. In addition, weak current carrying capacity is also a difficulty in current research, which directly affects the output power and efficiency of the device, limiting its application potential in large-scale power conversion and distribution systems. At the same time, due to the small size and high manufacturing cost of high-quality single-crystal diamond suitable for electronic device manufacturing, diamond Schottky diodes are difficult to apply on a large scale. Therefore, how to manufacture high-performance diamond Schottky diodes at low cost is the key to promoting their widespread application.

[0004] In summary, it is urgent to develop a diode with strong voltage resistance and current carrying capacity to meet the use requirements of high voltage and high power occasions. Summary of the invention

[0005] The purpose of the present invention is to provide a lateral boron-doped diamond diode and a batch preparation method thereof, so as to solve the technical problems in the prior art that the diamond diode has poor performance, high manufacturing cost and is difficult to mass produce.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a lateral boron-doped diamond diode, comprising a boron-doped single crystal diamond; at least two trapezoidal through holes are formed on the boron-doped single crystal diamond; the upper base of the trapezoidal through hole is located on a surface that is the front side of the boron-doped single crystal diamond, and the lower base of the trapezoidal through hole is located on a surface that is the back side of the boron-doped single crystal diamond; boron-doped polycrystalline diamond is grown on the back side of the boron-doped single crystal diamond; a Schottky contact layer and an ohmic contact layer are deposited on the front side of the boron-doped single crystal diamond; the Schottky contact layer is located in a front region of the boron-doped single crystal diamond between any two adjacent trapezoidal through holes; and the ohmic contact layer is located in a front region of the boron-doped single crystal diamond outside the two adjacent trapezoidal through holes.

[0008] Furthermore, the Schottky contact layer includes a first metal layer and a first chemically inert metal layer; the first metal layer is located on the front side of the boron-doped single crystal diamond, and the thickness of the first metal layer is 20nm~50nm; the first chemically inert metal layer is located on the first metal layer, and the thickness of the first chemically inert metal layer is 80nm~150nm.

[0009] Furthermore, the first metal layer is one or more of Pd, Ti, Pt, Au, Mo and Ta; and the first chemically inert metal layer is one or more of Au, W, Ir, Pt and Pd.

[0010] Furthermore, the ohmic contact layer includes a second metal layer and a second chemically inert metal layer; the second metal layer is located on the front side of the boron-doped single crystal diamond, and the thickness of the second metal layer is 20nm~50nm; the second chemically inert metal layer is located on the second metal layer, and the thickness of the second chemically inert metal layer is 80nm~150nm.

[0011] Furthermore, the second metal layer is one or more of Ti, Ta, and W; and the second chemically inert metal layer is one or more of Au, W, Ir, Pt, and Pd.

[0012] Furthermore, the thickness of the boron-doped single-crystal diamond is 50 μm to 200 μm; the thickness of the boron-doped polycrystalline diamond is 100 μm to 500 μm.

[0013] In a second aspect, the present invention provides a method for batch preparation of the above-mentioned lateral boron-doped diamond diode, comprising the following steps:

[0014] Slice a boron-doped single crystal diamond of any thickness, place the sliced ​​single boron-doped single crystal diamond in a laser device, and drill holes from the back side to the front side to form trapezoidal through holes with a back side hole size larger than a front side hole size, and finally obtain a plurality of boron-doped single crystal diamonds with trapezoidal through holes;

[0015] Cleaning a plurality of boron-doped single crystal diamonds having trapezoidal through holes, and then bonding a substrate to the front surfaces of the plurality of boron-doped single crystal diamonds;

[0016] Patterning a photoresist on the back of the boron-doped single-crystalline diamond using a photolithography process, and then depositing a filling layer on the back of the boron-doped single-crystalline diamond, wherein the thickness of the filling layer is the same as the thickness of the boron-doped single-crystalline diamond;

[0017] After the filling layer is deposited, the photoresist is removed, and boron-doped polycrystalline diamond is grown on the back of the boron-doped single-crystalline diamond by CVD (Chemical Vapor Deposition).

[0018] The substrate on the front side of the boron-doped single crystal diamond is removed by a debonding process, and then an ohmic contact layer and a Schottky contact layer are sequentially patterned and deposited on the front side of the boron-doped single crystal diamond to prepare a plurality of diodes;

[0019] The plurality of diodes are cut out individually through a laser slicing process to complete batch preparation of lateral boron-doped diamond diodes.

[0020] Furthermore, the doping concentration of the boron-doped single crystal diamond is 1×10 14 cm -3 ~1×10 17 cm -3 The doping concentration of the boron-doped polycrystalline diamond is 1×10 18 cm -3 ~1×10 22 cm -3 .

[0021] Furthermore, the material of the substrate is silicon, aluminum oxide or molybdenum, and the size of the substrate is 2 inches to 8 inches; the material of the filling layer is AlN or SiN.

[0022] Furthermore, in the step of removing the substrate on the front side of the boron-doped single-crystalline diamond through a debonding process, and then sequentially patterning and depositing an ohmic contact layer and a Schottky contact layer on the front side of the boron-doped single-crystalline diamond to obtain a plurality of diodes, an annealing treatment is performed after the patterning and depositing of the ohmic contact layer on the front side of the boron-doped single-crystalline diamond, and the Schottky contact layer is patterned and deposited again after the annealing is completed; the annealing treatment process is performed in a nitrogen atmosphere, an argon atmosphere, or a hydrogen atmosphere, and the annealing temperature is 400° C. to 1000° C.

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

[0024] The present invention discloses a lateral boron-doped diamond diode and a method for batch preparation thereof. By opening a trapezoidal through hole in a boron-doped single-crystal diamond, the voltage resistance of the diode is increased, so that the power device has good electrical characteristics. In addition, the present invention can cut the boron-doped single-crystal diamond substrate used to prepare the diode into multiple pieces for use, and then grow a conductive boron-doped polycrystalline diamond on the back as a supplementary supporting substrate, which can greatly reduce the cost of using single-crystal diamond. At the same time, the current can flow through the boron-doped polycrystalline diamond, which increases the current carrying capacity while playing a supporting role; and the addition of boron-doped polycrystalline diamond can further improve the performance of the device while reducing the cost of manufacturing the device. In addition, the present invention can directly adapt to existing semiconductor process lines of different sizes by combining the manufacture of lateral boron-doped diamond diodes with temporary bonding wafers, which is beneficial to batch manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 This is a schematic diagram of the preparation principle of a lateral boron-doped diamond diode according to an embodiment of the present invention;

[0027] Figure 2 This is a flow chart of a batch preparation method of lateral boron-doped diamond diodes according to an embodiment of the present invention;

[0028] Figure 3 Schematic diagram of the structure of a lateral boron-doped diamond diode according to an embodiment of the present invention.

[0029] Among them, 1-boron-doped single-crystal diamond; 2-trapezoidal through hole; 3-Schottky contact layer; 4-ohmic contact layer; 5-boron-doped polycrystalline diamond. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0031] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0032] In this article, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are for simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to have included and specifically disclosed all possible sub-ranges and individual values ​​within the range (including integers and fractions).

[0033] In this document, unless otherwise specified, “includes,” “including,” “contains,” “has,” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0034] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0035] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0036] See also Figure 3 The embodiment of the present invention discloses a lateral boron-doped diamond diode, comprising a boron-doped single crystal diamond 1; at least two trapezoidal through holes 2 are formed on the boron-doped single crystal diamond 1; the upper bottom of the trapezoidal through hole 2 is located on the front side of the boron-doped single crystal diamond 1, and the lower bottom of the trapezoidal through hole 2 is located on the back side of the boron-doped single crystal diamond 1; a boron-doped polycrystalline diamond 5 is grown on the back side of the boron-doped single crystal diamond 1; a Schottky contact layer 3 and an ohmic contact layer 4 are deposited on the front side of the boron-doped single crystal diamond 1; the Schottky contact layer 3 is located on the front side of the boron-doped single crystal diamond 1 between any two adjacent trapezoidal through holes 2. The ohmic contact layer 4 is located on the front side of the boron-doped single crystal diamond 1 outside the two adjacent trapezoidal through holes 2. It should be noted that the two adjacent trapezoidal through holes 2 here are the same as the two adjacent trapezoidal through holes 2 selected when the Schottky contact layer 3 is deposited.

[0037] In a feasible embodiment of the present invention, the Schottky contact layer 3 includes a first metal layer and a first chemically inert metal layer; the first metal layer is located on the front side of the boron-doped single crystal diamond 1, and the thickness of the first metal layer is 20nm~50nm; the first chemically inert metal layer is located on the first metal layer, and the thickness of the first chemically inert metal layer is 80nm~150nm. Preferably, the first metal layer is made of one or more materials including but not limited to Pd, Ti, Pt, Au, Mo and Ta; the first chemically inert metal layer is made of one or more materials including but not limited to Au, W, Ir, Pt and Pd.

[0038] In a feasible embodiment of the present invention, the ohmic contact layer 4 includes a second metal layer and a second chemically inert metal layer; the second metal layer is located on the front side of the boron-doped single crystal diamond 1, and the thickness of the second metal layer is 20nm~50nm; the second chemically inert metal layer is located on the second metal layer, and the thickness of the second chemically inert metal layer is 80nm~150nm. Preferably, the second metal layer is made of one or more materials including but not limited to Ti, Ta, and W; the second chemically inert metal layer is made of one or more materials including but not limited to Au, W, Ir, Pt, and Pd.

[0039] In a feasible implementation manner of the present invention, the thickness of the boron-doped single-crystal diamond 1 is 50 μm to 200 μm; the thickness of the boron-doped polycrystalline diamond 5 is 100 μm to 500 μm.

[0040] See also Figure 2 and Figure 1 The embodiment of the present invention discloses a batch preparation method of lateral boron-doped diamond diodes, comprising the following steps:

[0041] S1, slicing a boron-doped single crystal diamond 1 of any thickness, placing the sliced ​​single boron-doped single crystal diamond 1 in a laser device, and drilling holes from the back side to the front side to form trapezoidal through holes 2 whose back side hole size is larger than that of the front side hole size, and finally obtaining a plurality of boron-doped single crystal diamonds 1 having trapezoidal through holes 2;

[0042] In this step, the doping concentration of boron-doped single crystal diamond 1 is 1×10 14 cm -3 ~1×10 17 cm -3 ;

[0043] S2, cleaning a plurality of boron-doped single-crystal diamonds 1 having trapezoidal through holes 2, and then bonding a substrate to the front surfaces of the plurality of boron-doped single-crystal diamonds 1;

[0044] In this step, the material of the substrate is silicon, aluminum oxide or molybdenum, and the size of the substrate is 2 inches to 8 inches;

[0045] S3, patterning a photoresist on the back side of the boron-doped single crystal diamond 1 using a photolithography process, and then depositing a filling layer on the back side of the boron-doped single crystal diamond 1, wherein the thickness of the filling layer is the same as that of the boron-doped single crystal diamond 1;

[0046] The material of the filling layer in this step is AlN or SiN.

[0047] S4, after depositing the filling layer, removing the photoresist, and growing the boron-doped polycrystalline diamond 5 on the back side of the boron-doped single crystal diamond 1 by CVD (Chemical Vapor Deposition);

[0048] In this step, the doping concentration of the boron-doped polycrystalline diamond 5 is 1×10 18 cm -3 ~1×10 22 cm -3 .

[0049] S5, removing the substrate on the front side of the boron-doped single crystal diamond 1 by a debonding process, and then sequentially pattern-depositing an ohmic contact layer 4 and a Schottky contact layer 3 on the front side of the boron-doped single crystal diamond 1 to prepare a plurality of diodes;

[0050] In this step, after the ohmic contact layer 4 is patterned and deposited on the front side of the boron-doped single crystal diamond 1, an annealing treatment may be performed to form an ohmic contact or to increase the ohmic contact performance, and after the annealing is completed, a Schottky contact layer 3 is patterned and deposited;

[0051] The annealing treatment is carried out in a nitrogen atmosphere, an argon atmosphere or a hydrogen atmosphere at a temperature of 400° C. to 1000° C., in order to improve the reliability of the ohmic contact.

[0052] S6, cutting out the plurality of diodes individually through a laser slicing process, thereby completing batch preparation of lateral boron-doped diamond diodes.

[0053] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0054] The following examples use conventional instruments and equipment in the art. The experimental methods in the following examples where specific conditions are not specified are usually carried out under conventional conditions or under conditions recommended by the manufacturer. The various raw materials used in the following examples are conventional commercial products unless otherwise specified, and their specifications are conventional specifications in the art. In the specification of the present invention and the following examples, unless otherwise specified, "%" means weight percentage, "part" means weight part, and ratio means weight ratio.

[0055] Embodiment 1:

[0056] 1) Select a boron-doped single crystal diamond 1 of arbitrary thickness (doping concentration is 1×10 14 cm -3 ), sliced ​​into several boron-doped single crystal diamonds 1 with a thickness of 50 μm;

[0057] 2) placing the boron-doped single crystal diamond 1 in a laser device and drilling holes from the back to the front to form two trapezoidal through holes 2 whose back hole size is larger than the front hole size;

[0058] 3) Cleaning the boron-doped single crystal diamond 1 using standard organic and inorganic cleaning processes;

[0059] 4) using a substrate to bond to the front side of a number of prepared boron-doped single crystal diamonds 1, the substrate material is silicon and the size is 2 inches;

[0060] 5) patterning photoresist on the back side of the boron-doped single crystal diamond 1 using a photolithography process;

[0061] 6) Using magnetron sputtering to deposit a filling layer on the back of the boron-doped single crystal diamond 1, the deposition thickness is consistent with the thickness of the boron-doped single crystal diamond 1, and the material is AlN;

[0062] 7) After the deposition is completed, the boron-doped single crystal diamond 1 is taken out and the photoresist is removed, leaving the boron-doped single crystal diamond 1 that fills the filling layer. (If the filling layer is too thick, it can be thinned to ensure that the thickness of the filling layer is consistent with the thickness of the boron-doped single crystal diamond 1.)

[0063] 8) Boron-doped polycrystalline diamond 5 with a thickness of 200 μm and a doping concentration of 1×10 18 cm -3 ;

[0064] 9) The substrate is removed by a debonding process to obtain a wafer with the same size as the substrate; then an ohmic contact layer 4 is patterned and deposited on the upper layer of the front area of ​​the boron-doped single crystal diamond 1 outside the two trapezoidal through holes 2 by an electron beam evaporation process; the ohmic contact layer 4 is a W film (with a thickness of 25 nm) and a Au layer (with a thickness of 100 nm); after completion, an annealing treatment is performed in a nitrogen atmosphere at a temperature of 500°C.

[0065] 10) Using electron beam evaporation technology, a Schottky contact layer 3 is patterned and deposited on the upper layer of the front area of ​​the boron-doped single crystal diamond 1 between the two trapezoidal through holes 2. The Schottky contact layer 3 is a layer of Al film (thickness is 25nm) and a layer of Au (thickness is 100nm), completing the production of several lateral boron-doped diamond diodes.

[0066] 11) A plurality of lateral boron-doped diamond diodes prepared simultaneously are individually cut out by a laser slicing process, thereby completing the batch manufacturing of the lateral boron-doped diamond diodes of the present invention.

[0067] The volt-ampere characteristics of many lateral boron-doped diamond diodes prepared in this embodiment were tested at 1 A / cm 2 The current is used as the basis for device breakdown, and the test results show that the average breakdown voltage reaches about 3250 V.

[0068] Embodiment 2:

[0069] 1) Select a boron-doped single crystal diamond 1 of arbitrary thickness (doping concentration is 1×10 17 cm -3 ), sliced ​​into several boron-doped single crystal diamonds 1 with a thickness of 100 μm;

[0070] 2) placing the boron-doped single crystal diamond 1 in a laser device and drilling holes from the back to the front to form two trapezoidal through holes 2 whose back hole size is larger than the front hole size;

[0071] 3) Cleaning the boron-doped single crystal diamond 1 using standard organic and inorganic cleaning processes;

[0072] 4) using a substrate to bond to the front side of a number of prepared boron-doped single crystal diamonds 1, the substrate material is molybdenum and the size is 4 inches;

[0073] 5) patterning photoresist on the back side of the boron-doped single crystal diamond 1 using a photolithography process;

[0074] 6) Using magnetron sputtering to deposit a filling layer on the back of the boron-doped single crystal diamond 1, the deposition thickness is consistent with the thickness of the boron-doped single crystal diamond 1, and the material is SiN;

[0075] 7) After the deposition is completed, the boron-doped single crystal diamond 1 is taken out and the photoresist is removed, leaving the boron-doped single crystal diamond 1 that fills the filling layer. (If the filling layer is too thick, it can be thinned to ensure that the thickness of the filling layer is consistent with the thickness of the boron-doped single crystal diamond 1.)

[0076] 8) Boron-doped polycrystalline diamond 5 with a thickness of 100 μm is grown on the back of boron-doped single crystal diamond 1 by CVD method, and the doping concentration is 1×10 19 cm -3 ;

[0077] 9) The substrate is removed by a debonding process to obtain a wafer with the same size as the substrate; then an ohmic contact layer 4 is patterned and deposited on the upper surface of the boron-doped single crystal diamond 1 outside the two trapezoidal through holes 2 by an electron beam evaporation process; the ohmic contact layer 4 is a Ti film (with a thickness of 45 nm) and a W film (with a thickness of 90 nm); after completion, an annealing treatment is performed in a nitrogen atmosphere at a temperature of 800°C.

[0078] 10) Using electron beam evaporation process, a Schottky contact layer 3 is patterned and deposited on the upper layer of the front area of ​​the boron-doped single crystal diamond 1 between the two trapezoidal through holes 2. The Schottky contact layer 3 is a Zr film (thickness is 45nm) and a W layer (thickness is 90nm), and the production of several lateral boron-doped diamond diodes is completed.

[0079] 11) A plurality of lateral boron-doped diamond diodes prepared simultaneously are individually cut out by a laser slicing process, thereby completing the batch manufacturing of the lateral boron-doped diamond diodes of the present invention.

[0080] The volt-ampere characteristics of many lateral boron-doped diamond diodes prepared in this embodiment were tested at 1 A / cm 2 The current is used as the basis for device breakdown, and the test results show that the average breakdown voltage reaches about 2300 V.

[0081] Embodiment 3:

[0082] 1) Select a boron-doped single crystal diamond 1 of arbitrary thickness (doping concentration is 1×10 15 cm -3 ), sliced ​​into several boron-doped single crystal diamonds 1 with a thickness of 80 μm;

[0083] 2) placing the boron-doped single crystal diamond 1 in a laser device and drilling holes from the back to the front to form two trapezoidal through holes 2 whose back hole size is larger than the front hole size;

[0084] 3) Cleaning the boron-doped single crystal diamond 1 using standard organic and inorganic cleaning processes;

[0085] 4) using a substrate to bond with the front side of a number of prepared boron-doped single crystal diamonds 1, the substrate material is alumina and the size is 5 inches;

[0086] 5) patterning photoresist on the back side of the boron-doped single crystal diamond 1 using a photolithography process;

[0087] 6) Using PECVD (Plasma Enhanced Chemical Vapor Deposition) to deposit a filling layer on the back of the boron-doped single crystal diamond 1, the deposition thickness is consistent with the thickness of the boron-doped single crystal diamond 1, and the material is SiN;

[0088] 7) After the deposition is completed, the boron-doped single crystal diamond 1 is taken out and the photoresist is removed, leaving the boron-doped single crystal diamond 1 that fills the filling layer. (If the filling layer is too thick, it can be thinned to ensure that the thickness of the filling layer is consistent with the thickness of the boron-doped single crystal diamond 1.)

[0089] 8) Boron-doped polycrystalline diamond 5 with a thickness of 250 μm is grown on the back of boron-doped single crystal diamond 1 by CVD (Chemical Vapor Deposition) method, and the doping concentration is 1×10 21 cm -3 ;

[0090] 9) The substrate is removed by a debonding process to obtain a wafer with the same size as the substrate; then a magnetron sputtering process is used to pattern-deposit an ohmic contact layer 4 on the upper surface area of ​​the boron-doped single crystal diamond 1 outside the two trapezoidal through holes 2; the ohmic contact layer 4 is a W film (30 nm thick) and an Ir film (110 nm thick); after completion, an annealing treatment is performed in an argon atmosphere at a temperature of 700°C.

[0091] 10) A Schottky contact layer 3 is patterned and deposited on the upper surface of the boron-doped single crystal diamond 1 between the two trapezoidal through holes 2 using a magnetron sputtering process. The Schottky contact layer 3 is a Pt film (30 nm thick) and an Ir film (110 nm thick), thereby completing the fabrication of several lateral boron-doped diamond diodes.

[0092] 11) A plurality of lateral boron-doped diamond diodes prepared simultaneously are individually cut out by a laser slicing process, thereby completing the batch manufacturing of the lateral boron-doped diamond diodes of the present invention.

[0093] The volt-ampere characteristics of many lateral boron-doped diamond diodes prepared in this embodiment were tested at 1 A / cm 2 The current is used as the basis for device breakdown, and the test results show that the average breakdown voltage reaches about 3130 V.

[0094] Embodiment 4:

[0095] 1) Select a boron-doped single crystal diamond 1 of arbitrary thickness (doping concentration is 1×10 16 cm -3 ), sliced ​​into several boron-doped single crystal diamonds 1 with a thickness of 150 μm;

[0096] 2) placing the boron-doped single crystal diamond 1 in a laser device and drilling holes from the back to the front to form two trapezoidal through holes 2 whose back hole size is larger than the front hole size;

[0097] 3) Cleaning the boron-doped single crystal diamond 1 using standard organic and inorganic cleaning processes;

[0098] 4) using a substrate to bond with the front side of a number of prepared boron-doped single crystal diamonds 1, the substrate material is molybdenum and the size is 7 inches;

[0099] 5) patterning photoresist on the back side of the boron-doped single crystal diamond 1 using a photolithography process;

[0100] 6) Using magnetron sputtering to deposit a filling layer on the back of the boron-doped single crystal diamond 1, the deposition thickness is consistent with the thickness of the boron-doped single crystal diamond 1, and the material is AlN;

[0101] 7) After the deposition is completed, the boron-doped single crystal diamond 1 is taken out and the photoresist is removed, leaving the boron-doped single crystal diamond 1 that fills the filling layer. (If the filling layer is too thick, it can be thinned to ensure that the thickness of the filling layer is consistent with the thickness of the boron-doped single crystal diamond 1.)

[0102] 8) Boron-doped polycrystalline diamond 5 with a thickness of 150 μm and a doping concentration of 1×10 20 cm -3 ;

[0103] 9) The substrate is removed by a debonding process to obtain a wafer with the same size as the substrate; then a magnetron sputtering process is used to pattern-deposit an ohmic contact layer 4 on the upper surface area of ​​the boron-doped single crystal diamond 1 outside the two trapezoidal through holes 2; the ohmic contact layer 4 is a Ta film (thickness 40nm) and a Pt layer (thickness 140nm); after completion, an annealing treatment is performed, and the annealing treatment is performed in a hydrogen atmosphere at an annealing temperature of 900°C.

[0104] 10) A Schottky contact layer 3 is patterned and deposited on the upper surface of the boron-doped single crystal diamond 1 between the two trapezoidal through holes 2 using a magnetron sputtering process. The Schottky contact layer 3 is a layer of Au film (40 nm thick) and a layer of Pt (140 nm thick), thereby completing the fabrication of several lateral boron-doped diamond diodes.

[0105] 11) A plurality of lateral boron-doped diamond diodes prepared simultaneously are individually cut out by a laser slicing process, thereby completing the batch manufacturing of the lateral boron-doped diamond diodes of the present invention.

[0106] The volt-ampere characteristics of many lateral boron-doped diamond diodes prepared in this embodiment were tested at 1 A / cm 2 The current is used as the basis for device breakdown, and the test results show that the average breakdown voltage reaches about 2660V.

[0107] Embodiment 5:

[0108] 1) Select a boron-doped single crystal diamond 1 of arbitrary thickness (doping concentration is 1×10 15 cm -3 ), sliced ​​into several boron-doped single crystal diamonds 1 with a thickness of 200 μm;

[0109] 2) placing the boron-doped single crystal diamond 1 in a laser device and drilling holes from the back to the front to form three trapezoidal through holes 2 whose back hole size is larger than the front hole size;

[0110] 3) Cleaning the boron-doped single crystal diamond 1 using standard organic and inorganic cleaning processes;

[0111] 4) using a substrate to bond with the front side of a number of prepared boron-doped single crystal diamonds 1, the substrate material is alumina and the size is 8 inches;

[0112] 5) patterning photoresist on the back side of the boron-doped single crystal diamond 1 using a photolithography process;

[0113] 6) Using magnetron sputtering to deposit a filling layer on the back of the boron-doped single crystal diamond 1, the deposition thickness is consistent with the thickness of the boron-doped single crystal diamond 1, and the material is AlN;

[0114] 7) After the deposition is completed, the boron-doped single crystal diamond 1 is taken out and the photoresist is removed, leaving the boron-doped single crystal diamond 1 that fills the filling layer. (If the filling layer is too thick, it can be thinned to ensure that the thickness of the filling layer is consistent with the thickness of the boron-doped single crystal diamond 1.)

[0115] 8) Boron-doped polycrystalline diamond 5 with a thickness of 400 μm and a doping concentration of 1×10 22 cm -3 ;

[0116] 9) The substrate is removed by a debonding process to obtain a wafer with the same size as the substrate; then an ohmic contact layer 4 is patterned and deposited on the upper surface of the boron-doped single crystal diamond 1 outside any two adjacent trapezoidal through holes 2 by an electron beam evaporation process; the ohmic contact layer 4 is a Ta film (50 nm thick) and a Pd film (130 nm thick); after completion, an annealing treatment is performed in a nitrogen atmosphere at a temperature of 1000°C.

[0117] 10) Using electron beam evaporation process, a Schottky contact layer 3 is patterned and deposited on the upper surface area of ​​the boron-doped single crystal diamond 1 between the two adjacent trapezoidal through holes 2 selected in step 9), and the Schottky contact layer 3 is a Mo film (thickness is 50nm) and a Pd layer (thickness is 130nm), thereby completing the production of several lateral boron-doped diamond diodes.

[0118] 11) A plurality of lateral boron-doped diamond diodes prepared simultaneously are individually cut out by a laser slicing process, thereby completing the batch manufacturing of the lateral boron-doped diamond diodes of the present invention.

[0119] The volt-ampere characteristics of many lateral boron-doped diamond diodes prepared in this embodiment were tested at 1 A / cm 2 The current is used as the basis for device breakdown, and the test results show that the average breakdown voltage reaches about 3050V.

[0120] Embodiment 6:

[0121] 1) Select a boron-doped single crystal diamond 1 of arbitrary thickness (doping concentration is 1×10 15 cm -3 ), sliced ​​into several boron-doped single crystal diamonds 1 with a thickness of 170 μm;

[0122] 2) placing the boron-doped single crystal diamond 1 in a laser device and drilling holes from the back to the front to form two trapezoidal through holes 2 whose back hole size is larger than the front hole size;

[0123] 3) Cleaning the boron-doped single crystal diamond 1 using standard organic and inorganic cleaning processes;

[0124] 4) using a substrate to bond with the front side of a number of prepared boron-doped single crystal diamonds 1, the substrate material is alumina and the size is 3 inches;

[0125] 5) patterning photoresist on the back side of the boron-doped single crystal diamond 1 using a photolithography process;

[0126] 6) Using magnetron sputtering to deposit a filling layer on the back of the boron-doped single crystal diamond 1, the deposition thickness is consistent with the thickness of the boron-doped single crystal diamond 1, and the material is AlN;

[0127] 7) After the deposition is completed, the boron-doped single crystal diamond 1 is taken out and the photoresist is removed, leaving the boron-doped single crystal diamond 1 that fills the filling layer. (If the filling layer is too thick, it can be thinned to ensure that the thickness of the filling layer is consistent with the thickness of the boron-doped single crystal diamond 1.)

[0128] 8) Boron-doped polycrystalline diamond 5 with a thickness of 450 μm and a doping concentration of 1×10 20 cm -3 ;

[0129] 9) The substrate is removed by a debonding process to obtain a wafer with the same size as the substrate; then an ohmic contact layer 4 is patterned and deposited on the upper surface of the boron-doped single crystal diamond 1 outside the two trapezoidal through holes 2 by an electron beam evaporation process; the ohmic contact layer 4 is a Ta film (with a thickness of 40 nm) and a Pd film (with a thickness of 150 nm); after completion, an annealing treatment is performed in a nitrogen atmosphere at a temperature of 600°C.

[0130] 10) Using electron beam evaporation technology, a Schottky contact layer 3 is patterned and deposited on the upper layer of the front area of ​​the boron-doped single crystal diamond 1 between the two trapezoidal through holes 2. The Schottky contact layer 3 is a Cr film (40 nm thick) and a Pd layer (150 nm thick), completing the production of several lateral boron-doped diamond diodes.

[0131] 11) A plurality of lateral boron-doped diamond diodes prepared simultaneously are individually cut out by a laser slicing process, thereby completing the batch manufacturing of the lateral boron-doped diamond diodes of the present invention.

[0132] The volt-ampere characteristics of many lateral boron-doped diamond diodes prepared in this embodiment were tested at 1 A / cm 2 The current is used as the basis for device breakdown, and the test results show that the average breakdown voltage reaches about 2950V.

[0133] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A lateral boron-doped diamond diode, characterized in that: The invention comprises a boron-doped single crystal diamond (1); at least two trapezoidal through holes (2) are formed on the boron-doped single crystal diamond (1); a filling layer is deposited in the trapezoidal through hole (2); the thickness of the filling layer is the same as the thickness of the boron-doped single crystal diamond (1), and the material of the filling layer is AlN or SiN; the upper bottom of the trapezoidal through hole (2) is located on the surface of the front side of the boron-doped single crystal diamond (1), the lower bottom of the trapezoidal through hole (2) is located on the surface of the back side of the boron-doped single crystal diamond (1), and ... The size is larger than that of the upper base; a boron-doped polycrystalline diamond (5) is grown on the back of the boron-doped single crystal diamond (1); a Schottky contact layer (3) and an ohmic contact layer (4) are deposited on the front of the boron-doped single crystal diamond (1); the Schottky contact layer (3) is located in the front area of ​​the boron-doped single crystal diamond (1) between any two adjacent trapezoidal through holes (2); and the ohmic contact layer (4) is located in the front area of ​​the boron-doped single crystal diamond (1) outside the two adjacent trapezoidal through holes (2).

2. A lateral boron-doped diamond diode according to claim 1, characterized in that: The Schottky contact layer (3) comprises a first metal layer and a first chemically inert metal layer; the first metal layer is located on the front side of the boron-doped single crystal diamond (1), and the thickness of the first metal layer is 20nm-50nm; the first chemically inert metal layer is located on the top of the first metal layer, and the thickness of the first chemically inert metal layer is 80nm-150nm.

3. The lateral boron-doped diamond diode according to claim 2, characterized in that: The first metal layer is one or more of Pd, Ti, Pt, Au, Mo and Ta; the first chemically inert metal layer is one or more of Au, W, Ir, Pt and Pd.

4. The lateral boron-doped diamond diode according to claim 1, characterized in that: The ohmic contact layer (4) comprises a second metal layer and a second chemically inert metal layer; the second metal layer is located on the front side of the boron-doped single crystal diamond (1), and the thickness of the second metal layer is 20nm-50nm; the second chemically inert metal layer is located on the second metal layer, and the thickness of the second chemically inert metal layer is 80nm-150nm.

5. The lateral boron-doped diamond diode according to claim 4, characterized in that: The second metal layer is one or more of Ti, Ta, and W; the second chemically inert metal layer is one or more of Au, W, Ir, Pt, and Pd.

6. The lateral boron-doped diamond diode according to claim 1, characterized in that: The thickness of the boron-doped single-crystal diamond (1) is 50 μm to 200 μm; the thickness of the boron-doped polycrystalline diamond (5) is 100 μm to 500 μm.

7. A method for batch preparation of lateral boron-doped diamond diodes according to claim 1, characterized in that: The following steps are involved: Slicing a boron-doped single crystal diamond (1) of any thickness, placing the sliced ​​single boron-doped single crystal diamond (1) in a laser device, and drilling holes from the back side to the front side to form trapezoidal through holes (2) with a back side hole size larger than a front side hole size, and finally obtaining a plurality of boron-doped single crystal diamonds (1) having trapezoidal through holes (2); Cleaning a plurality of boron-doped single-crystal diamonds (1) having trapezoidal through holes (2), and then bonding a substrate to the front surfaces of the plurality of boron-doped single-crystal diamonds (1); Patterning a photoresist on the back of the boron-doped single crystal diamond (1) using a photolithography process, and then depositing a filling layer on the back of the boron-doped single crystal diamond (1), wherein the thickness of the filling layer is the same as the thickness of the boron-doped single crystal diamond (1); After depositing the filling layer, the photoresist is removed, and a boron-doped polycrystalline diamond (5) is grown on the back side of the boron-doped single-crystalline diamond (1) by a CVD method; The substrate on the front side of the boron-doped single crystal diamond (1) is removed by a debonding process, and then an ohmic contact layer (4) and a Schottky contact layer (3) are sequentially patterned and deposited on the front side of the boron-doped single crystal diamond (1) to prepare a plurality of diodes; The plurality of diodes are cut out individually through a laser slicing process to complete batch preparation of lateral boron-doped diamond diodes.

8. The method for batch preparation of lateral boron-doped diamond diodes according to claim 7, characterized in that: The doping concentration of the boron-doped single crystal diamond (1) is 1×10 14 cm -3 ~1×10 17 cm -3 The doping concentration of the boron-doped polycrystalline diamond (5) is 1×10 18 cm -3 ~1×10 22 cm -3 .

9. The method for batch preparation of lateral boron-doped diamond diodes according to claim 7, characterized in that: The material of the substrate is silicon, aluminum oxide or molybdenum, and the size of the substrate is 2 inches to 8 inches; the material of the filling layer is AlN or SiN.

10. The method for batch preparation of lateral boron-doped diamond diodes according to claim 7, characterized in that: In the step of preparing a plurality of diodes by removing the substrate on the front side of the boron-doped single crystal diamond (1) through a debonding process, and then sequentially patterning and depositing an ohmic contact layer (4) and a Schottky contact layer (3) on the front side of the boron-doped single crystal diamond (1), an annealing treatment is performed after the patterning and depositing of the ohmic contact layer (4) on the front side of the boron-doped single crystal diamond (1), and then patterning and depositing the Schottky contact layer (3) after the annealing is completed; the annealing treatment process is performed in a nitrogen atmosphere, an argon atmosphere or a hydrogen atmosphere, and the annealing temperature is 400° C. to 1000° C.

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