Schottky diode and manufacturing method thereof

Abstract

The invention discloses a Schottky diode and a manufacturing method thereof, and relates to the technical field of semiconductors. The semiconductor device comprises a semiconductor substrate, a first doped region, a second doped region and a third doped region, the semiconductor substrate comprises a first surface region, the first doped region extends into the semiconductor substrate from the first surface region, and the first doped region is obtained by doping aluminum ions with a first doping concentration. The second doped region extends from the first surface region to the semiconductor substrate, and the first doped region and the second doped region are arranged in a staggered manner along the first direction of the first surface region. The second doped region is obtained by doping aluminum ions with a second doping concentration, and the first doping concentration is greater than the second doping concentration. The third doped region extends into the semiconductor substrate from the first surface region and is obtained by doping aluminum ions with the first doping concentration, and the area of the third doped region is larger than that of the first doped region. Therefore, the reverse voltage withstanding performance of the diode is improved, and the forward conduction voltage drop is reduced.

Description

Technical Field

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

[0002] In the field of high-voltage and high-power applications, Schottky barrier diodes have lower conduction losses due to the reduced forward voltage. At the same time, as a unipolar device, there is no minority carrier storage and reverse recovery phenomenon, and the switching frequency is higher. However, its Schottky barrier height is low, the reverse leakage is large, the voltage resistance is poor, and the surge resistance is poor. In order to reduce reverse leakage, improve voltage resistance and surge resistance, a method has been developed to introduce a P+ (aluminum ion with the first doping concentration) doped region to form a depletion region to shield the Schottky region electric field during reverse voltage resistance, thereby reducing reverse leakage current and improving voltage resistance. For example, silicon carbide junction barrier Schottky diodes (SiC JBS) and silicon carbide hybrid PiN / Schottky diodes (SiC MPS).

[0003] SiC MPS diodes are bipolar devices and are in unipolar working mode under low forward bias voltage. The voltage drop at this time is the forward unipolar conduction voltage drop of the device. When the forward bias voltage increases, the P+ region in the diode is turned on, the device enters the bipolar working mode, and minority carrier holes are injected into the drift layer, triggering conductivity modulation, and the on-resistance decreases. Under high forward bias voltage, in order to make the diode enter the bipolar working mode more quickly, it is necessary to reduce the node voltage value of the unipolar-bipolar conversion, that is, the forward bipolar conduction voltage drop. However, the current common methods of increasing the proportion of the P+ region area, increasing the junction depth of the P+ region, and using different Schottky metal materials to control the metal work function to increase the Schottky barrier height will cause the Schottky barrier diode to have an increased conduction voltage drop and an increased conduction loss under low forward bias. Summary of the invention

[0004] In view of the problem that the conduction voltage drop and conduction loss of the Schottky diode increase under low forward bias, the present invention is proposed to provide a Schottky diode and a manufacturing method thereof that overcomes or at least partially solves the above problems.

[0005] Based on the first aspect of the present invention, a Schottky diode is provided, the Schottky diode comprising:

[0006] a semiconductor substrate comprising a first surface region;

[0007] at least one first doped region, the first doped region extending from the first surface region into the semiconductor substrate, wherein the first doped region is doped with aluminum ions of a first doping concentration;

[0008] at least two second doping regions, wherein the second doping regions extend from the first surface region to the semiconductor substrate, and the first doping regions and the second doping regions are alternately arranged along a first direction of the first surface region, the second doping regions are doped with aluminum ions of a second doping concentration, and the junction depth of the second doping regions gradually decreases from far away from the center of the first surface region to close to the center of the first surface region in the first direction, wherein the first doping concentration is greater than the second doping concentration;

[0009] At least two third doping regions, the third doping regions extending from the first surface region into the semiconductor substrate, wherein the third doping regions are obtained by doping with aluminum ions of a first doping concentration, and the area of ​​the third doping regions is greater than the area of ​​the first doping regions.

[0010] An optional invention content is that the third doping region is distributed on both sides of the first surface area along the first direction.

[0011] An optional invention content is that along the first direction of the first surface area, the third doping region forms contact with the second doping region, and the second doping region forms contact with the first doping region.

[0012] An optional invention content is that the second doping regions are arranged at intervals along a second direction of the first surface area, wherein the first direction and the second direction are perpendicular to each other.

[0013] In an optional aspect of the invention, a distribution spacing of the second doping regions along a second direction of the first surface region is between 3 μm and 12 μm.

[0014] In an optional aspect of the invention, the junction depth of the first doped region is greater than the junction depth of the second doped region.

[0015] In an optional aspect of the invention, a first width of the first doping region in the first direction is between 1 μm and 3 μm.

[0016] In an optional aspect of the invention, a third width of the third doping region in the first direction is between 10 μm and 20 μm.

[0017] In an optional invention, the first doping concentration corresponding to the first doping region and the third doping region is 1×10 18 cm -3 ~1×10 20 cm -3 between.

[0018] In an optional invention, the second doping concentration corresponding to the second doping region is 8×10 16cm -3 ~2×10 17 cm -3 between.

[0019] According to an optional aspect of the invention, at least two first surface areas are provided.

[0020] Based on the second aspect of the present invention, a method for manufacturing a Schottky diode is also provided, the method comprising:

[0021] Providing a semiconductor substrate, and depositing a plasma enhanced tetraethyl orthosilicate layer on a first surface region of the semiconductor substrate;

[0022] Coating a photoresist on the plasma enhanced tetraethyl orthosilicate layer, and forming at least one first injection window and at least two third injection windows by photolithography;

[0023] Using the plasma enhanced tetraethyl orthosilicate layer as a mask, injecting aluminum ions of a first doping concentration into the first injection window to obtain a first doping region extending from the first surface region to the semiconductor substrate, and injecting aluminum ions of the first doping concentration into the third injection window to obtain a third doping region extending from the first surface region to the semiconductor substrate, and the area of ​​the third doping region is greater than the area of ​​the first doping region;

[0024] Forming at least two second injection windows by photolithography, and using the plasma enhanced tetraethyl orthosilicate layer as a mask, injecting aluminum ions of a second doping concentration into the second injection windows to obtain a second doping region extending from the first surface region to the semiconductor substrate, and the first doping region and the second doping region are alternately arranged along a first direction of the first surface region, wherein the first doping concentration is greater than the second doping concentration;

[0025] The second doping step is repeatedly performed to obtain at least two second doping regions, so that the junction depth of the second doping region gradually decreases from far away from the center of the first surface area to close to the center of the first surface area in the first direction.

[0026] An optional invention content, wherein the step of injecting aluminum ions of a first doping concentration into the first injection window to obtain a first doping region extending from the first surface region to the semiconductor substrate comprises:

[0027] A first doping concentration of 1×10 18 cm -3 ~1×10 20 cm -3Aluminum ions are removed between the first surface area and the semiconductor substrate to obtain a first doped region extending from the first surface area to the semiconductor substrate.

[0028] An optional invention content, wherein the step of injecting aluminum ions of a second doping concentration into the second injection window to obtain a second doping region extending from the first surface region to the semiconductor substrate comprises:

[0029] The second doping concentration of 8×10 16 cm -3 ~2×10 17 cm -3 Aluminum ions are removed between the first surface area and the second doped region is obtained, extending from the first surface area to the semiconductor substrate.

[0030] Compared with the prior art, the present invention includes a semiconductor substrate, a first doping region, a second doping region and a third doping region, wherein the semiconductor substrate includes a first surface region, the first doping region extends from the first surface region to the semiconductor substrate, wherein the first doping region is doped with aluminum ions of a first doping concentration. The second doping region extends from the first surface region to the semiconductor substrate, and the first doping region and the second doping region are staggered along the first direction of the first surface region, the second doping region is doped with aluminum ions of a second doping concentration, and the junction depth of the second doping region gradually decreases from away from the center of the first surface region to close to the center of the first surface region in the first direction, and the first doping concentration is greater than the second doping concentration. The third doping region extends from the first surface region to the semiconductor substrate, the third doping region is doped with aluminum ions of a first doping concentration, and the area of ​​the third doping region is greater than the area of ​​the first doping region. Thus, the reverse withstand voltage performance of the diode can be improved and the forward conduction voltage drop can be reduced. Among them, the setting of different junction depths of the second doping region can realize the continuous adjustment of the Schottky barrier height. The Schottky barrier height of the second doping region with a smaller junction depth is lower, and the spacing distribution of the second doping region can ensure the forward conduction characteristics of the diode. The second doping region with a larger junction depth can increase the Schottky barrier height, reduce the forward bipolar conduction voltage drop of the diode, and reduce the conduction loss.

[0031] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] By reading the detailed description of the preferred embodiment below, various other advantages and benefits will become clear to those of ordinary skill in the art. The accompanying drawings are only used for the purpose of illustrating the preferred embodiment and are not considered to be limitations of the present invention. In addition, the same reference symbols are used to represent the same components throughout the accompanying drawings.

[0033] In the attached picture:

[0034] Figure 1 is a schematic structural diagram of a Schottky diode provided by an embodiment of the present invention;

[0035] Figure 2 yes Figure 1 Schematic diagram of the cross-sectional structure at AA in FIG.

[0036] Figure 3 yes Figure 1 Schematic diagram of the cross-sectional structure at BB in FIG.

[0037] Figure 4 is a schematic diagram of the cross-sectional structure of another Schottky diode provided by an embodiment of the present invention;

[0038] Figure 5 It is a schematic flow chart of the steps of a method for manufacturing a Schottky diode provided by an embodiment of the present invention;

[0039] Figure 6 is a schematic structural diagram of a semiconductor substrate provided by an embodiment of the present invention;

[0040] Figure 7 is a schematic diagram of the first part of the structure of a Schottky diode provided by an embodiment of the present invention;

[0041] Figure 8 is a schematic diagram of the second part of the structure of a Schottky diode provided by an embodiment of the present invention;

[0042] Fig. 9 is a schematic diagram of the third structure of a Schottky diode provided by an embodiment of the present invention;

[0043] Figure numerals: 1, semiconductor substrate; 11, drift layer; 12, buffer layer; 13, substrate layer; 101, first surface area; 2, first doping region; 3, second doping region; 4, third doping region; 5, anode ohmic metal contact layer; 6, anode metal layer; 7, anode Schottky metal contact region; 8, cathode metal layer. DETAILED DESCRIPTION

[0044] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0045] In the field of high-voltage and high-power applications, Schottky barrier diodes have lower conduction losses due to the reduced forward voltage. At the same time, as a unipolar device, there is no minority carrier storage and reverse recovery phenomenon, and the switching frequency is higher. However, its Schottky barrier height is low, the reverse leakage is large, the voltage resistance is poor, and the surge resistance is poor. In order to reduce reverse leakage, improve voltage resistance and surge resistance, a method has been developed to introduce a P+ (aluminum ion with the first doping concentration) doped region to form a depletion region to shield the Schottky region electric field during reverse voltage resistance, thereby reducing reverse leakage current and improving voltage resistance. For example, silicon carbide junction barrier Schottky diodes (SiC JBS) and silicon carbide hybrid PiN / Schottky diodes (SiC MPS).

[0046] SiC MPS diodes are bipolar devices and are in unipolar working mode under low forward bias voltage. The voltage drop at this time is the forward unipolar conduction voltage drop of the device. When the forward bias voltage increases, the P+ region in the diode is turned on, the device enters the bipolar working mode, and minority carrier holes are injected into the drift layer, triggering conductivity modulation, and the on-resistance decreases. Under high forward bias voltage, in order to make the diode enter the bipolar working mode more quickly, it is necessary to reduce the node voltage value of the unipolar-bipolar conversion, that is, the forward bipolar conduction voltage drop. However, the current common methods of increasing the proportion of the P+ region area, increasing the junction depth of the P+ region, and using different Schottky metal materials to control the metal work function to increase the Schottky barrier height will cause the Schottky barrier diode to have an increased conduction voltage drop and an increased conduction loss under low forward bias.

[0047] Based on the above technical problems, an embodiment of the present invention is proposed. The embodiment of the present invention may include a semiconductor substrate 1, at least one first doping region 2 and at least two second doping regions 3. The semiconductor substrate 1 includes a first surface region 101. The first doping region 2 extends from the first surface region 101 into the semiconductor substrate 1, wherein the first doping region 2 is doped with aluminum ions of a first doping concentration. The second doping region 3 extends from the first surface region 101 to the semiconductor substrate 1, and the first doping region 2 and the second doping region 3 are staggered along the first direction of the first surface region 101. The second doping region 3 is doped with aluminum ions of a second doping concentration, and the junction depth of the second doping region 3 gradually decreases from away from the center of the first surface region 101 to close to the center of the first surface region 101 in the first direction, and the first doping concentration is greater than the second doping concentration. The third doping region 4 extends from the first surface region 101 into the semiconductor substrate 1, and the third doping region 4 is doped with aluminum ions of a first doping concentration, and the area of ​​the third doping region 4 is greater than the area of ​​the first doping region 2. In this way, the reverse withstand voltage performance of the diode can be improved and the forward conduction voltage drop can be reduced. The different junction depths of the second doping region 3 can achieve continuous adjustment of the Schottky barrier height. The second doping region 3 with a smaller junction depth has a lower Schottky barrier height, and the spacing distribution of the second doping region 3 can ensure the forward conduction characteristics of the diode. The second doping region 3 with a larger junction depth can increase the Schottky barrier height, reduce the forward bipolar conduction voltage drop of the diode, and reduce the conduction loss.

[0048] Reference Figure 1-3 The embodiment of the present invention provides a Schottky diode, which may include a semiconductor substrate 1, at least one first doping region 2, at least two second doping regions 3, and at least two third doping regions 4. The semiconductor substrate 1 includes a first surface region 101, and the first doping region 2 extends from the first surface region 101 into the semiconductor substrate 1, wherein the first doping region 2 is doped with aluminum ions of a first doping concentration. The second doping region 3 extends from the first surface region 101 to the semiconductor substrate 1, and the first doping region 2 and the second doping region 3 are staggered along the first direction of the first surface region 101, and the second doping region 3 is doped with aluminum ions of a second doping concentration, and the junction depth of the second doping region 3 gradually decreases from far away from the center of the first surface region 101 to close to the center of the first surface region 101 in the first direction.

[0049] The third doping region 4 extends from the first surface region 101 into the semiconductor substrate 1 , wherein the third doping region 4 is doped with aluminum ions of a first doping concentration, and an area of ​​the third doping region 4 is greater than an area of ​​the first doping region 2 .

[0050] In the embodiment of the present invention, the semiconductor substrate 1 is the supporting base of the diode structure, which may be an N-type semiconductor substrate 1. The semiconductor substrate 1 may include but is not limited to a substrate layer 13, a buffer layer 12, and a drift layer 11, wherein the substrate layer 13 may be an N-type silicon carbide substrate, the buffer layer 12 may be an N-type silicon carbide buffer layer, and the drift layer 11 may be an N-type silicon carbide drift layer. The drift layer 11 may be obtained by doping nitrogen. The semiconductor substrate 1 may include a first surface area 101. The first surface area 101 may be understood as a partial area on the first surface of the semiconductor substrate 1.

[0051] The first doping region 2 and the second doping region 3 extend from the first surface area 101 to the semiconductor substrate 1, respectively. The first doping region 2 is doped with aluminum ions of a first doping concentration, and the second doping region 3 is doped with aluminum ions of a second doping concentration. The first doping region 2 can form a depletion region with the semiconductor substrate 1 during reverse withstand voltage, thereby shielding the Schottky region electric field, thereby reducing reverse leakage current and improving withstand voltage capability. Therefore, the setting of the first doping region 2 can improve the reverse withstand voltage performance of the diode and reduce the forward conduction voltage drop.

[0052] When the metal contacts the semiconductor substrate 1, the electrons in the semiconductor substrate 1 will flow toward the metal, thereby forming a depletion region near the first surface region 101 of the semiconductor and generating a built-in electric field, which is called the Schottky region electric field. The function of the Schottky region electric field is to prevent electrons from further flowing from the semiconductor substrate 1 to the metal, thereby forming an electronic potential barrier at the contact surface, which is called the Schottky barrier. The Schottky barrier has a rectifying property, that is, it only allows current to flow in one direction, which makes the Schottky diode have unidirectional conductivity.

[0053] The different junction depths of the second doping region 3 can achieve continuous adjustment of the Schottky barrier height. For example, the second doping region 3 with a smaller junction depth has a lower Schottky barrier height, and the spacing distribution of the second doping region 3 can ensure the forward conduction characteristics of the diode. The second doping region 3 with a larger junction depth can increase the Schottky barrier height, reduce the forward bipolar conduction voltage drop of the diode, and reduce the conduction loss. The junction depth can be understood as the distance from the end face of the doping region away from the first surface region 101 to the first surface region 101, refer to Figure 2 and Figure 3 As shown, the junction depth of the first doping region 2 may be H1, the junction depth of the second doping region 3 may be H2, and the junction depth of the third doping region 4 may be H3.

[0054] The first doping regions 2 and the second doping regions 3 are arranged alternately. Figure 2 and Figure 4 As shown, it can be understood that in the first direction, at least one first doping region 2 is arranged between two second doping regions 3 at adjacent positions.

[0055] The junction depth of the second doped region 3 gradually decreases in the first direction from far away from the center of the first surface area 101 to close to the center of the first surface area 101 to form a continuously adjustable Schottky barrier height. The Schottky barrier height corresponding to the second doped region 3 with a smaller junction depth is lower, which can ensure that electrons flow from the metal to the semiconductor substrate 1 more easily, thereby improving the forward conduction rate of the Schottky diode while ensuring that the current does not over-flow. The second doped region 3 with a larger junction depth can increase the Schottky barrier height and reduce the forward bipolar conduction voltage drop of the device. In addition, before the diode switches from the unipolar working mode to the bipolar working mode, the conductivity modulation effect can be triggered earlier, thereby reducing the on-resistance, reducing the conduction loss, and improving the surge resistance of the diode.

[0056] The third doping region 4 can be called a large P+ ion doping region, that is, it can be understood as a P-type doping region formed by aluminum ions with a higher doping concentration. Correspondingly, the first doping region 2 can be called a small P+ ion doping region, that is, it can be understood as a P-type doping region formed by aluminum ions with a lower reference concentration. Among them, P+ ions can be understood as aluminum ions with a higher doping concentration. The setting of the third doping region 4 can be used to improve the conduction ability of the diode under large currents, and combined with the first doping, it produces beneficial effects such as improving the reverse withstand voltage performance, surge current resistance performance of the diode and reducing the forward conduction voltage drop. Among them, surge current refers to a peak current or overload current that is much larger than the steady-state current generated at the moment when the power is turned on or when an abnormality occurs in the circuit.

[0057] In some embodiments, reference Figure 1 and Figure 2 As shown, two third doping regions 4 may be provided, and the two third doping regions 4 may be respectively distributed on both sides of the first surface area 101 along the first direction.

[0058] An optional embodiment of the invention, referring to Figure 2As shown, along the first direction of the first surface area 101 , the third doping region 4 is in contact with the second doping region 3 , and the second doping region 3 is in contact with the first doping region 2 .

[0059] In the embodiment of the present invention, along the first direction of the first surface area 101, for example, the X-axis direction, the first doping region 2, the second doping region 3 and the third doping region 4 are arranged continuously, so that the second doping region 3 can be introduced between the first doping region 2 and the third doping region 4, or between two first doping regions 2, and the Schottky barrier height can be continuously adjustable in combination with the setting of different junction depths of the second doping region 3. The Schottky barrier height of the second doping region 3 with a smaller junction depth is lower, which can ensure the forward conduction characteristics of the diode, that is, a small increase in the forward unipolar conduction voltage drop and a reduction in the reverse leakage current of the diode. The second doping region 3 with a larger junction depth can increase the Schottky barrier height, reduce the forward bipolar conduction voltage drop of the diode, and reduce the conduction loss.

[0060] An optional embodiment of the invention, referring to Figure 1 and Figure 3 The second doping regions 3 are arranged at intervals along a second direction of the first surface region 101 , wherein the first direction and the second direction are perpendicular to each other.

[0061] In the embodiment of the present invention, the interval distribution setting of the second doping region 3 can increase the Schottky area of ​​the non-second doping region 3, so that the relationship between the forward bipolar conduction voltage drop and the forward unipolar conduction voltage drop can be balanced, that is, the forward bipolar conduction voltage drop can be reduced by increasing the forward unipolar conduction voltage drop by a small amount. The distribution spacing of the second doping region 3 along the second direction of the first surface area 101 is between 3μm and 12μm. For example, the distribution spacing of the second doping region 3 along the second direction of the first surface area 101 can be 3μm, 5μm, 8μm, and 12μm. Those skilled in the art can determine the specific distribution spacing according to actual design requirements, and no excessive restrictions are made here. Among them, the first direction can be Figure 1 The X-axis direction shown in , the second direction can be Figure 1 In the Z-axis direction shown in , the first surface area 101 is arranged parallel to a plane formed by the first direction and the second direction.

[0062] An optional embodiment of the invention, referring to Figure 3 As shown, the third width of the third doping region 4 in the first direction is between 10 μm and 20 μm. The first width of the first doping region 2 in the first direction is between 1 μm and 3 μm.

[0063] In the embodiment of the present invention, the first width W1 of the first doping region 2 in the first direction is set to 1 μm, 2 μm, 3 μm, etc. The third width W2 of the third doping region 4 in the first direction is set to 10 μm, 15 μm, 20 μm, etc. The third width can be selected within this width range according to the diode's ability to withstand surge current. For example, the ratio of the third width to the first width can be 5.

[0064] In some embodiments, when the semiconductor substrate 1 includes at least two first surface regions 101, the third doping regions 4 distributed on two adjacent first surface regions 101 form contact to form an overall doping region, and the overall width of the overall doping region in the first direction is equal to the sum of two third widths, that is, the overall width of the overall doping region in the first direction is between 20 μm and 40 μm, including values ​​such as 20 μm and 40 μm.

[0065] In some embodiments, the junction depth of the first doping region 2 and the junction depth of the third doping region 4 can be adjusted according to the specifications of the diode. For example, the junction depth of the third doping region 4 is greater than the junction depth of the first doping region 2 .

[0066] In an optional embodiment of the invention, the junction depth of the first doping region 2 is greater than the junction depth of the second doping region 3 .

[0067] In the embodiment of the present invention, the junction depth of the first doping region 2 is greater than the junction depth of the second doping region 3, which can limit the maximum junction depth of the second doping region 3. The second doping region 3 is mainly used to increase the Schottky barrier height to reduce the bipolar conduction voltage drop of the diode, and it is not the main withstand voltage position.

[0068] This can avoid the problem that the Schottky barrier height is too large, which causes the forward unipolar conduction voltage drop of the diode to increase too much, which is not conducive to the diode turning on. This achieves a good balance between the forward conduction characteristics and the reverse withstand voltage characteristics of the device, ensuring that the unipolar conduction voltage drop increases slightly while reducing the forward bipolar conduction voltage drop.

[0069] In an optional embodiment of the invention, the doping concentration of the first doping region 2 and the third doping region 4 is 1×10 18 cm -3 ~1×10 20 cm -3 (number of ions per cubic centimeter).

[0070] In the embodiment of the present invention, the doping concentration of the first doping region 2 and the doping concentration of the third doping region 4 can be kept consistent, and the doping concentration is at least greater than 1×1018 cm -3 Therefore, it can be ensured that both the first doping region 2 and the third doping region 4 are doped with high concentration, thereby improving the reverse withstand voltage performance and surge current resistance performance of the diode.

[0071] In an optional embodiment of the invention, the doping concentration of the second doping region 3 is 8×10 16 cm -3 ~2×10 17 cm -3 between.

[0072] In the embodiment of the present invention, when the doping concentration of the second doping region 3 is too high, a higher concentration of holes will be introduced in the second doping region 3, thereby introducing an additional load center, increasing the forward unipolar conduction voltage drop and leakage current of the diode, and at the same time changing the internal electric field distribution of the diode, causing the electric field peak to deviate from the expected position, thereby increasing the risk of diode breakdown.

[0073] Moreover, when the doping concentration of the second doping region 3 is too low, it will lead to uneven distribution of doping atoms, reduce the ion activation rate and increase the residual resistivity, affecting the operating stability of the diode. Therefore, the doping concentration of the second doping region 3 should be set in the range of 1% to 10% of the doping concentration corresponding to the first doping region 2.

[0074] In a preferred embodiment of the invention, at least two first surface areas 101 are provided.

[0075] In the embodiment of the present invention, refer to Figure 1 As shown, at least two first surface regions 101 may be provided, so that the number of the first surface regions 101 may be determined according to the specifications of the diode. Correspondingly, each first surface region 101 is respectively provided with a first doping region 2, a second doping region 3, and a third doping region 4 extending to the semiconductor substrate 1.

[0076] In an optional embodiment of the invention, referring to Figure 6As shown, the semiconductor substrate 1 may include a drift layer 11, a buffer layer 12 and a substrate layer 13, wherein the buffer layer 12 is located between the drift layer 11 and the substrate layer 13, and the first surface region 101 is arranged on the end face of the drift layer 11 away from the buffer layer 12. For example, a first epitaxial growth is performed on the upper surface of the substrate layer 13 to obtain the buffer layer 12. The epitaxial growth is performed by chemical vapor deposition technology to activate high-temperature gas molecules to cause them to undergo a chemical reaction on the upper surface of the substrate layer 13 to generate silicon carbide compounds, which are deposited on the upper surface of the substrate layer 13 to form a silicon carbide film, thereby obtaining the buffer layer 12. The substrate layer 13 may be one of 4H-SiC (tetrahydrogenated silicon), 6H-SiC (hexahydrogenated silicon) or 3C-SiC (cubic silicon carbide) single crystal substrates.

[0077] The thickness L1 of the substrate layer 13 is set between 325μm and 375μm (micrometers). For example, the thickness of the substrate layer 13 can be 325μm, 350μm, 375μm, etc., and the thickness L2 of the buffer layer 12 is set between 0.5μm and 1.5μm (micrometers). For example, the thickness of the buffer layer 12 can be 0.5μm, 1μm, and 1.5μm. On the one hand, it can avoid that the thickness of the buffer layer 12 is too thick, which leads to an increase in the internal resistance and thermal resistance in the semiconductor substrate 1, and changes the internal electric field distribution in the semiconductor substrate 1, thereby affecting the key parameters such as the withstand voltage and leakage current of the diode. On the other hand, if the thickness of the buffer layer 12 is too thin, it will cause its performance in blocking the defects of the substrate layer 13 to decrease, thereby affecting the device performance and operational reliability of the diode. At the same time, when the thickness of the buffer layer 12 is too thin, it will also increase the process difficulty and production cost, and increase the product defect rate.

[0078] Then, a second epitaxial growth is performed on the end surface of the buffer layer 12 away from the substrate layer 13 (also referred to as the upper surface of the buffer layer 12) to obtain a drift layer 11, thereby forming the semiconductor substrate 1. The thickness L3 of the drift layer 11 is set between 5μm and 8μm (micrometers). For example, the thickness of the drift layer 11 can be set to 5μm, 6μm, and 8μm. Those skilled in the art can determine the specific thickness according to actual design requirements, and no excessive restrictions are made here.

[0079] In summary, the embodiment of the present invention discloses a Schottky diode, which may include a semiconductor substrate 1, at least one first doping region 2 and at least two second doping regions 3, wherein the semiconductor substrate 1 includes a first surface region 101, and the first doping region 2 extends from the first surface region 101 into the semiconductor substrate 1, wherein the first doping region 2 is doped with aluminum ions of a first doping concentration. The second doping region 3 extends from the first surface region 101 to the semiconductor substrate 1, and the first doping region 2 and the second doping region 3 are staggered along the first direction of the first surface region 101, the second doping region 3 is doped with aluminum ions of a second doping concentration, and the junction depth of the second doping region 3 gradually decreases from away from the center of the first surface region 101 to close to the center of the first surface region 101 in the first direction. The third doping region 4 extends from the first surface region 101 into the semiconductor substrate 1, the third doping region 4 is doped with aluminum ions of a first doping concentration, and the area of ​​the third doping region 4 is greater than the area of ​​the first doping region 2. Thus, the reverse withstand voltage performance of the diode can be improved and the forward conduction voltage drop can be reduced. The different junction depths of the second doping region 3 can realize the continuous adjustment of the Schottky barrier height. The Schottky barrier height of the second doping region 3 with a smaller junction depth is lower, which can ensure the forward conduction characteristics of the diode. The second doping region 3 with a larger junction depth can increase the Schottky barrier height, reduce the forward bipolar conduction voltage drop of the diode, and reduce the conduction loss.

[0080] Reference Figure 5 As shown, the embodiment of the present invention further discloses a method for manufacturing a Schottky diode, the method comprising:

[0081] S501 , providing a semiconductor substrate 1 , and depositing a plasma enhanced tetraethyl orthosilicate layer on a first surface region 101 of the semiconductor substrate 1 .

[0082] In the embodiment of the present invention, the plasma enhanced tetraethyl orthosilicate layer (PETEOS layer) may be formed by chemical vapor deposition technology, and may cover the first surface region 101 , thereby improving the radiation resistance of the semiconductor substrate 1 .

[0083] S502 , coating a photoresist on the plasma enhanced tetraethyl orthosilicate layer, and forming at least one first injection window and at least two third injection windows by photolithography.

[0084] S503 , using the plasma enhanced tetraethyl orthosilicate layer as a mask, injecting aluminum ions of a first doping concentration into the first injection window to obtain a first doping region 2 extending from the first surface area 101 to the semiconductor substrate 1 .

[0085] In the embodiment of the present invention, a photoresist can be coated on the end face of the PETEOS layer away from the first surface area 101, wherein the photoresist is also called a photoresist, which refers to an etch-resistant film material whose solubility changes by irradiation or radiation of ultraviolet light, electron beam, ion beam, X-ray, etc. Thus, the first injection window, the second injection window and the third injection window can be obtained by a photolithography process. For example, after the photoresist is exposed and developed, the exposed part is dissolved, the unexposed part is not dissolved, and the dissolved area can form the first injection window, or the second injection window, or the third injection window.

[0086] Therefore, refer to Figure 7 As shown, the PETEOS layer can be used as a mask to remove the photoresist, and aluminum ions with a first doping concentration can be injected into the first injection window to obtain a first doping region 2 extending from the first surface area 101 to the semiconductor substrate 1.

[0087] S504 , injecting aluminum ions of a first doping concentration into the third injection window to obtain a third doping region 4 extending from the first surface area 101 to the semiconductor substrate 1 .

[0088] In the embodiment of the present invention, after the ion implantation of the second doping region 3 is completed, the above-mentioned photolithography process can be repeated, the PETEOS layer is used as a mask, the photoresist is removed, and a third implantation window is formed. Thus, aluminum ions of the first doping concentration are implanted into the third implantation window to obtain a third doping region 4 extending from the first surface region 101 to the semiconductor substrate 1. The area of ​​the third doping region 4 is greater than the area of ​​the first doping region 2.

[0089] S505, performing a second doping step, the second doping step comprising forming at least two second injection windows by photolithography, and using the plasma enhanced tetraethyl orthosilicate layer as a mask to inject aluminum ions of a second doping concentration into the second injection windows to obtain a second doping region 3 extending from the first surface area 101 to the semiconductor substrate 1, and the first doping region 2 and the second doping region 3 are alternately arranged along the first direction of the first surface area 101, wherein the first doping concentration is greater than the second doping concentration.

[0090] In the embodiment of the present invention, after the ion implantation of the first doping region 2 is completed, the above-mentioned photolithography process can be repeated, using the PETEOS layer as a mask to remove the photoresist and form a second implantation window. Figure 8As shown, aluminum ions of a second doping concentration are injected into the second injection window to obtain a second doping region 3 extending from the first surface region 101 to the semiconductor substrate 1. After the injection, the first doping regions 2 and the second doping regions 3 are alternately arranged in the first direction of the first surface region 101. That is, in the first direction, at least one first doping region 2 is arranged between two second doping regions 3 at adjacent positions.

[0091] S506, repeating the second doping step to obtain at least two second doping regions 3, so that the junction depth of the second doping region 3 gradually decreases from far away from the center of the first surface area 101 to close to the center of the first surface area 101 in the first direction.

[0092] In the embodiment of the present invention, the junction depth of the second doping region 3 gradually decreases from far away from the center of the first surface region 101 to close to the center of the first surface region 101 in the first direction. The second doping region 3 with different junction depths can be formed by using different implantation energies and performing aluminum ion implantation according to the second doping concentration during each execution of the second doping step.

[0093] In an optional embodiment of the invention, the step of injecting aluminum ions of a first doping concentration into the first injection window to obtain a first doping region 2 extending from the first surface region 101 to the semiconductor substrate 1 comprises:

[0094] A first doping concentration of 1×10 18 cm -3 ~1×10 20 cm -3 A first doping region 2 extending from the first surface region 101 to the semiconductor substrate 1 is obtained by adding aluminum ions with a first doping concentration between the first surface region 101 and the ...

[0095] In the embodiment of the present invention, the first doping region 2 is mainly used to improve the reverse withstand voltage capability and reduce the leakage current of the MPS diode. The doping concentration of the P+ ions is usually greater than 10 18 cm -3 or equal to 10 18 cm -3 Order of magnitude. The third doping region 4 is used to improve the reverse withstand voltage and surge current resistance of the diode, and reduce the forward conduction voltage drop of the diode. In some embodiments, the injection energy of the P+ ions is between 40KeV and 400KeV (kiloelectron volts), wherein the ion injection energy can be adjusted according to the specifications of the diode to ensure the balance between the conduction voltage drop and the reverse leakage current. For example, the higher the injection energy, the deeper the junction depth of the first doping region 2 formed, or the deeper the junction depth of the third doping region 4.

[0096] The doping concentration of the first doping region 2 and the doping concentration of the third doping region 4 can be consistent, and the doping concentration is at least greater than 1×10 18 cm -3 Thus, it can be ensured that both the first doping region 2 and the third doping region 4 are doped with high concentration (also referred to as P+ ion doping), thereby improving the reverse withstand voltage performance of the diode and enhancing the surge current resistance performance.

[0097] In an optional embodiment of the invention, the step of injecting aluminum ions of a second doping concentration into the second injection window to obtain a second doping region 3 extending from the first surface region 101 to the semiconductor substrate 1 comprises:

[0098] The second doping concentration of 8×10 16 cm -3 ~2×10 17 cm -3 A second doping region 3 extending from the first surface region 101 to the semiconductor substrate 1 is obtained by adding aluminum ions with a second doping concentration between the first surface region 101 and the ...

[0099] In the embodiment of the present invention, when the doping concentration of the second doping region 3 is too high, a higher concentration of holes will be introduced in the second doping region 3, thereby introducing an additional load center, increasing the forward unipolar conduction voltage drop and leakage current of the diode, and at the same time changing the internal electric field distribution of the diode, causing the electric field peak to deviate from the expected position, thereby increasing the risk of diode breakdown.

[0100] Moreover, when the doping concentration of the second doping region 3 is too low, it will lead to uneven distribution of doping atoms, reduce the ion activation rate and increase the residual resistivity, affecting the operating stability of the diode. Therefore, the second doping concentration corresponding to the second doping region 3 should be set in the range of 1% to 10% of the doping concentration corresponding to the first doping region 2. Therefore, the aluminum ions of the second doping concentration can also be called P-ions (low-concentration aluminum ions).

[0101] In some embodiments, the injection energy of P- ions is between 40KeV and 300KeV (kiloelectron volts), and the injection energy of the second doping region 3 is less than the injection energy of the first doping region 2, so that the junction depth of the first doping region 2 is greater than the junction depth of the second doping region 3, and the maximum junction depth of the second doping region 3 can be limited. The second doping region 3 is mainly used to increase the Schottky barrier height to reduce the bipolar conduction voltage drop of the diode, and it is not the main withstand voltage position.

[0102] This can avoid the problem that the Schottky barrier height is too large, which causes the forward unipolar conduction voltage drop of the diode to increase too much, which is not conducive to the diode turning on. It also balances the forward conduction characteristics and reverse withstand voltage characteristics of the device well, ensuring that the unipolar conduction voltage drop increases slightly while reducing the forward bipolar conduction voltage drop.

[0103] In some embodiments, reference Figure 6 As shown, the semiconductor substrate 1 may include a drift layer 11, a buffer layer 12 and a substrate layer 13, wherein the buffer layer 12 is located between the drift layer 11 and the substrate layer 13, and the first surface region 101 is arranged on the end face of the drift layer 11 away from the buffer layer 12. For example, a first epitaxial growth is performed on the upper surface of the substrate layer 13 to obtain the buffer layer 12. The epitaxial growth is performed by chemical vapor deposition technology to activate high-temperature gas molecules to cause them to undergo a chemical reaction on the upper surface of the substrate layer 13 to generate silicon carbide compounds, which are deposited on the upper surface of the substrate layer 13 to form a silicon carbide film, thereby obtaining the buffer layer 12. The substrate layer 13 may be one of 4H-SiC (tetrahydrogenated silicon), 6H-SiC (hexahydrogenated silicon) or 3C-SiC (cubic silicon carbide) single crystal substrates.

[0104] The thickness L1 of the substrate layer 13 is set between 325μm and 375μm (micrometers). For example, the thickness of the substrate layer 13 can be 325μm, 350μm, 375μm, etc., and the thickness L2 of the buffer layer 12 is set between 0.5μm and 1.5μm (micrometers). For example, the thickness of the buffer layer 12 can be 0.5μm, 1μm, and 1.5μm. On the one hand, it can avoid that the thickness of the buffer layer 12 is too thick, which leads to an increase in the internal resistance and thermal resistance in the semiconductor substrate 1, and changes the internal electric field distribution in the semiconductor substrate 1, thereby affecting the key parameters such as the withstand voltage and leakage current of the diode. On the other hand, if the thickness of the buffer layer 12 is too thin, it will cause its performance in blocking the defects of the substrate layer 13 to decrease, thereby affecting the device performance and operational reliability of the diode. At the same time, when the thickness of the buffer layer 12 is too thin, it will also increase the process difficulty and production cost, and increase the product defect rate.

[0105] Then, a second epitaxial growth is performed on the end surface of the buffer layer 12 away from the substrate layer 13 (also referred to as the upper surface of the buffer layer 12) to obtain the drift layer 11, thereby forming the semiconductor substrate 1. The thickness L3 of the drift layer 11 is set between 5μm and 8μm (micrometers). For example, the thickness of the drift layer 11 can be set to 5μm, 6μm, and 8μm. Those skilled in the art can determine the specific thickness according to actual design requirements, and no further restrictions are made here. The doping concentration of the drift layer 11 is set to 5×10 15 cm -3 ~5×10 16 cm -3 between.

[0106] That is, the thickness of the drift layer 11 is greater than that of the buffer layer 12, and the thickness of the drift layer 11 is less than that of the substrate layer 13. The thickness ratios in the following figures are only for reference, and the specific thickness limits are subject to the above-mentioned thickness limits, and no further limits are given here.

[0107] In some optional embodiments of the invention, after forming the first doping region 2, the second doping region 3 and the third doping region 4, a carbon film may be formed on the upper surface of the drift layer 11 (the first surface region 101), and the carbon film serves to protect the surface of the drift layer 11 during thermal annealing. Thermal annealing is then performed to activate the ions in different doping regions and then remove the carbon film.

[0108] Then, a metal layer is sputtered on the upper surface of the drift layer 11, wherein the metal layer material can be at least one of the following materials: nickel, titanium, and nickel-titanium alloy. A photoresist is spin-coated on the upper surface of the drift layer 11, and after photolithography development, the exposed metal layer is removed by dry etching, and then the photoresist is removed and the metal layer is thermally annealed to form an anode ohmic metal contact layer 5. Fig. 9 As shown, the thickness L4 of the anode ohmic metal contact layer 5 is set at 0.1 μm to 0.5 μm.

[0109] A titanium metal layer is sputtered on the upper surface of the drift layer 11, and an aluminum metal layer is sputtered on the titanium metal layer. Then, a photoresist is spin-coated on the upper surface of the aluminum metal layer. After photolithography development, the exposed aluminum metal layer is removed by dry etching or wet etching. The exposed titanium metal layer is removed by dry etching. Then, the photoresist is removed and the metal layer is thermally annealed to form an anode metal layer 6 composed of titanium metal and aluminum metal layers, as shown in FIG. Fig. 9 As shown, the thickness L5 of the anode metal layer 6 is set between 4 μm and 6 μm. The Schottky barrier described in the above embodiment of the invention is formed between the anode metal layer 6 and the semiconductor substrate.

[0110] The lower surface of the substrate layer 13 (the end face of the substrate layer 13 away from the buffer layer 12) is cut to reduce the thickness of the substrate layer 13 to between 100 μm and 180 μm. The cutting method may be one of the following: mechanical grinding, chemical etching, ICP (Inductively Coupled Plasma) etching, and sonic cutting technology. Considering the difficulty of controlling the growth quality of the substrate and the limitation of manufacturing costs, the method for forming the substrate layer 13 is mainly to cut a plurality of substrates from a larger silicon carbide ingot. Since different devices have different requirements for the thickness of the substrate, the thickness of the substrate may be adjusted in the subsequent process to meet the requirements of the electrical parameters of the device. Therefore, a thicker substrate layer 13 is cut and then thinned according to different requirements to achieve precise control of the device parameters. Thus, the resistance of the substrate layer 13 can be reduced by reducing the thickness of the substrate layer 13.

[0111] Finally, a cathode ohmic metal contact layer is formed on the lower surface of the thinned substrate layer 13 by sputtering or evaporation, and an aluminum metal layer is deposited on the lower surface of the cathode ohmic metal contact layer to form a cathode metal layer 8 consisting of the cathode ohmic metal contact layer and the aluminum metal layer. Figure 2 , Figure 3 as well as Figure 4 As shown, the material of the cathode ohmic metal contact layer is at least one of the following: nickel, titanium and silver. The anode metal layer 6 and the cathode metal layer 8 can be led out as pins of the diode.

[0112] In summary, the embodiment of the present invention discloses a Schottky diode and a manufacturing method thereof. The embodiment of the present invention may include a semiconductor substrate 1, at least one first doping region 2 and at least two second doping regions 3. The semiconductor substrate 1 includes a first surface region 101. The first doping region 2 extends from the first surface region 101 into the semiconductor substrate 1, wherein the first doping region 2 is doped with aluminum ions of a first doping concentration. The second doping region 3 extends from the first surface region 101 to the semiconductor substrate 1, and the first doping region 2 and the second doping region 3 are staggered along the first direction of the first surface region 101. The second doping region 3 is doped with aluminum ions of a second doping concentration, and the junction depth of the second doping region 3 gradually decreases from away from the center of the first surface region 101 to close to the center of the first surface region 101 in the first direction, and the first doping concentration is greater than the second doping concentration. The third doping region 4 extends from the first surface region 101 into the semiconductor substrate 1, and the third doping region 4 is doped with aluminum ions of a first doping concentration, and the area of ​​the third doping region 4 is greater than the area of ​​the first doping region 2. Thus, the reverse withstand voltage performance of the diode can be improved and the forward conduction voltage drop can be reduced, wherein the setting of different junction depths of the second doping region 3 can realize the continuous adjustment of the Schottky barrier height. The Schottky barrier height of the second doping region 3 with a smaller junction depth is lower, and the interval distribution of the second doping region 3 can ensure the forward conduction characteristics of the diode. The second doping region 3 with a larger junction depth can increase the Schottky barrier height, reduce the forward bipolar conduction voltage drop of the diode, and reduce the conduction loss.

[0113] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0114] It is easy for a person skilled in the art to think that any combination of the above embodiments is feasible, so any combination of the above embodiments is an implementation scheme of the present invention. However, due to space limitations, this specification will not describe them in detail here.

[0115] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0116] Similarly, it should be understood that in order to streamline the present invention and aid in understanding one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof.

[0117] In addition, those skilled in the art will appreciate that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present invention and form different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.

Claims

1. A Schottky diode, characterized in that: The Schottky diode comprises: A semiconductor substrate (1), the semiconductor substrate (1) comprising a first surface area (101); at least one first doping region (2), the first doping region (2) extending from the first surface region (101) into the semiconductor substrate (1), wherein the first doping region (2) is obtained by doping with aluminum ions of a first doping concentration; at least two second doping regions (3), the second doping regions (3) extending from the first surface region (101) to the semiconductor substrate (1), and the first doping regions (2) and the second doping regions (3) being arranged alternately along a first direction of the first surface region (101), the second doping regions (3) being doped with aluminum ions of a second doping concentration, and the junction depth of the second doping regions (3) gradually decreases from being away from the center of the first surface region (101) to being close to the center of the first surface region (101) in the first direction, wherein the first doping concentration is greater than the second doping concentration; At least two third doping regions (4), the third doping regions (4) extending from the first surface region (101) into the semiconductor substrate (1), wherein the third doping regions (4) are obtained by doping with aluminum ions of a first doping concentration, and the area of ​​the third doping regions (4) is greater than the area of ​​the first doping regions (2).

2. The Schottky diode according to claim 1, characterized in that: The third doping region (4) is distributed on both sides of the first surface region (101) along the first direction.

3. The Schottky diode according to claim 1, characterized in that: Along the first direction of the first surface area (101), the third doping region (4) forms contact with the second doping region (3), and the second doping region (3) forms contact with the first doping region (2).

4. The Schottky diode according to claim 1, characterized in that: The second doping regions (3) are arranged at intervals along a second direction of the first surface region (101), wherein the first direction and the second direction are perpendicular to each other.

5. The Schottky diode according to claim 4, characterized in that: The distribution spacing of the second doping regions (3) along the second direction of the first surface region (101) is between 3 μm and 12 μm.

6. The Schottky diode according to claim 1, characterized in that: The junction depth of the first doping region (2) is greater than the junction depth of the second doping region (3).

7. The Schottky diode according to claim 1, characterized in that: The first width of the first doping region (2) in the first direction is between 1 μm and 3 μm.

8. The Schottky diode according to claim 7, characterized in that: The third width of the third doping region (4) in the first direction is between 10 μm and 20 μm.

9. The Schottky diode according to claim 1, characterized in that: The first doping concentration corresponding to the first doping region (2) and the third doping region (4) is 1×10 18 cm -3 ~1×10 20 cm -3 between.

10. The Schottky diode according to claim 1, characterized in that: The second doping concentration corresponding to the second doping region (3) is 8×10 16 cm -3 ~2×10 17 cm -3 between.

11. The Schottky diode according to claim 1, characterized in that: At least two first surface areas (101) are provided.

12. A method for manufacturing a Schottky diode, characterized in that: The method comprises: A semiconductor substrate (1) is provided, and a plasma enhanced tetraethyl orthosilicate layer is deposited on a first surface region (101) of the semiconductor substrate (1); Coating a photoresist on the plasma enhanced tetraethyl orthosilicate layer, and forming at least one first injection window and at least two third injection windows by photolithography; Using the plasma enhanced tetraethyl orthosilicate layer as a mask, aluminum ions of a first doping concentration are injected into the first injection window to obtain a first doping region (2) extending from the first surface region (101) to the semiconductor substrate (1), and aluminum ions of the first doping concentration are injected into the third injection window to obtain a third doping region (4) extending from the first surface region (101) to the semiconductor substrate (1), and the area of ​​the third doping region (4) is greater than the area of ​​the first doping region (2); Performing a second doping step, the second doping step comprising: At least two second injection windows are formed by photolithography, and aluminum ions of a second doping concentration are injected into the second injection windows using the plasma enhanced tetraethyl orthosilicate layer as a mask, so as to obtain a second doping region (3) extending from the first surface region (101) to the semiconductor substrate (1), and the first doping region (2) and the second doping region (3) are arranged alternately along a first direction of the first surface region (101), wherein the first doping concentration is greater than the second doping concentration; The second doping step is repeatedly performed to obtain at least two second doping regions (3), so that the junction depth of the second doping region (3) gradually decreases from far away from the center of the first surface area (101) to close to the center of the first surface area (101) in the first direction.

13. The method for manufacturing a Schottky diode according to claim 12, characterized in that: The step of injecting aluminum ions of a first doping concentration into the first injection window to obtain a first doping region (2) extending from the first surface region (101) into the semiconductor substrate (1) comprises: The first doping concentration of 1×10 18 cm -3 ~1×10 20 cm -3 Aluminum ions are removed between the first surface region (101) and the second surface region (102) to obtain a first doped region (2) extending from the first surface region (101) to the semiconductor substrate (1).

14. The method for manufacturing a Schottky diode according to claim 12, characterized in that: The step of injecting aluminum ions of a second doping concentration into the second injection window to obtain a second doping region (3) extending from the first surface region (101) into the semiconductor substrate (1) comprises: The second doping concentration of 8×10 16 cm -3 ~2×10 17 cm -3 Aluminum ions are removed between the first surface region (101) and the second doped region (3) is obtained, extending from the first surface region (101) to the semiconductor substrate (1).

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