A high-frequency ultrafast recovery Schottky diode

Abstract

The application discloses a high-frequency ultra-fast recovery Schottky diode and relates to the technical field of semiconductor devices.The high-frequency ultra-fast recovery Schottky diode comprises a main body, a cathode electrode, an anode electrode, an identification bump and a high-voltage-resistance component, the high-voltage-resistance component is composed of a copper foil connecting layer, a silicon nitride passivation layer and the like, a core is cooperatively designed by using a GaN wide-bandgap semiconductor and a JBS structure, a reverse recovery time is less than or equal to 5 ns, the high-frequency ultra-fast recovery Schottky diode can stably work in a high-frequency scene with a frequency higher than 1 MHz, a forward conduction voltage drop is low, a reverse leakage current is small, thermal stability is excellent, the high-frequency ultra-fast recovery Schottky diode can work in a wide temperature range from-55 DEG C to 150 DEG C, a voltage resistance grade covers 600V-1700V, the high-frequency ultra-fast recovery Schottky diode balances reverse voltage resistance and high-frequency performance, is convenient to install, has high stability, and is suitable for high-end power electronic devices such as new energy automobile OBCs and 5G base station power supplies.

Description

Technical Field

[0001] This invention relates to the field of semiconductor device technology, and in particular to a high-frequency ultrafast recovery Schottky diode. Background Technology

[0002] With the rapid development of strategic emerging industries such as new energy, 5G communication, and photovoltaic new energy, power electronic systems have placed higher demands on the performance of core power devices. They not only need to have basic characteristics such as high reverse withstand voltage, low forward voltage drop, and low reverse leakage current, but also need to meet the ultra-fast recovery capability under high frequency operating conditions in order to reduce switching losses and improve system energy conversion efficiency and power density. Schottky diodes, as a type of power semiconductor device based on the Schottky barrier effect, have become the preferred device for high-frequency applications due to their advantages of unipolar conductivity (only electrons participate in conduction) and no minority carrier storage effect. Existing devices cannot simultaneously achieve both reverse withstand voltage and high-frequency performance. Pursuing high withstand voltage will lead to increased forward voltage drop, prolonged reverse recovery time (usually above 100ns), and a significant increase in switching losses. Summary of the Invention

[0003] The purpose of this invention is to at least solve one of the technical problems existing in the prior art, and to provide a high-frequency ultrafast recovery Schottky diode that can solve the above-mentioned problems.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a high-frequency ultrafast recovery Schottky diode, comprising a body, a cathode electrode fixedly connected to the top of the body, an anode electrode fixedly connected to the bottom of the body, and a high-voltage withstand component disposed on the body, the high-voltage withstand component comprising a copper foil connecting layer, the copper foil connecting layer being fixedly connected within the body.

[0005] Preferably, the main body is rectangular.

[0006] Preferably, a cathode marking protrusion is fixedly connected to the main body on the side near the cathode electrode.

[0007] Preferably, an anode marking protrusion is fixedly connected to the main body on the side near the anode electrode.

[0008] Preferably, a silicon nitride passivation layer is fixedly connected within the copper foil connection layer, and a high work function metal alloy barrier layer is disposed within the silicon nitride passivation layer, with the high work function metal alloy barrier layer fixedly connected within the silicon nitride passivation layer.

[0009] Preferably, a JBS structure layer is fixedly connected within the high work function metal alloy barrier layer, and an n-type structure layer is fixedly connected within the JBS structure layer. + -Heavy GaN doped layer.

[0010] Preferably, the n+ An unintentionally doped GaN transition layer is disposed within the heavily doped GaN layer, and the unintentionally doped GaN transition layer is fixedly connected to n. + -Inside the heavily doped GaN layer.

[0011] Preferably, an InAlN buffer layer is fixedly connected within the unintentionally doped GaN transition layer, and a GaN wide-bandgap semiconductor is fixedly connected within the InAlN buffer layer.

[0012] Compared with the prior art, the beneficial effects of the present invention are: 1. This high-frequency ultra-fast recovery Schottky diode has a reverse recovery time of ≤5ns, which is more than 50% shorter than traditional devices, almost eliminating reverse recovery losses and significantly improving the switching frequency (it can work stably in high-frequency scenarios above 1MHz).

[0013] 2. This high-frequency ultra-fast recovery Schottky diode has a forward voltage drop to 0.8V@1200V, a reverse leakage current ≤1μA, and excellent thermal stability, allowing it to operate stably in a wide temperature range of -55℃ to 150℃.

[0014] 3. This high-frequency ultra-fast recovery Schottky diode achieves a balance between reverse withstand voltage and high-frequency performance through structural optimization. The withstand voltage range covers 600V~1700V series, which is suitable for different power level applications. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of a high-frequency ultrafast recovery Schottky diode according to the present invention; Figure 2 The right side is a schematic diagram of a high-frequency ultrafast recovery Schottky diode according to the present invention; Figure 3 This is a schematic diagram of a high-frequency ultrafast recovery Schottky diode according to the present invention; Figure 4 This is a schematic cross-sectional view of a high-frequency ultrafast recovery Schottky diode according to the present invention; Figure 5 For the present invention Figure 4 Enlarged view of point A in the middle; Figure 6 This is a side view of the main body of the invention.

[0016] Reference numerals: 1. Main body; 2. Anode marking bump; 3. Cathode marking bump; 4. Cathode electrode; 5. Anode electrode; 6. GaN wide bandgap semiconductor; 7. InAlN buffer layer; 8. Unintentionally doped GaN transition layer; 9. n +- GaN heavily doped layer; 10. JBS structure layer; 11. High work function metal alloy barrier layer; 12. Silicon nitride passivation layer; 13. Copper foil interconnect layer. Detailed Implementation

[0017] This section will describe in detail specific embodiments of the present invention. Preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0018] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0019] In the description of this invention, terms such as greater than, less than, and exceeding are understood to exclude the stated number, while terms such as above, below, and within are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0020] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0021] Please see Figure 1-6 The present invention provides a technical solution: a high-frequency ultrafast recovery Schottky diode, including a body 1, a cathode electrode 4 fixedly connected to the top of the body 1, an anode electrode 5 fixedly connected to the bottom of the body 1, and a high-voltage withstand component disposed on the body 1, the high-voltage withstand component including a copper foil connecting layer 13, the copper foil connecting layer 13 being fixedly connected inside the body 1; The main body 1 provides a stable installation space for each internal functional layer, while increasing the heat dissipation area to conduct and dissipate the heat generated when the device is working, ensuring that the device works stably in a wide temperature range, avoiding structural interference, and improving the overall structural stability. A cathode marking protrusion 3 is fixedly connected to the side of the main body 1 near the cathode electrode 4, and an anode marking protrusion 2 is fixedly connected to the side of the main body 1 near the anode electrode 5. The anode marking bump 2 and the cathode marking bump 3 work together to quickly distinguish the positive and negative terminals of the diode, avoiding reverse installation that could cause device breakdown and damage, and improving assembly efficiency and accuracy; The cathode electrode 4 receives electrons conducted by the copper foil connecting layer 13 and outputs them outward, which facilitates connection with external circuits and enables smooth current transmission. It is placed above and below the anode electrode 5 to avoid short circuit between the positive and negative electrodes and ensure the stability of unidirectional current conduction. A silicon nitride passivation layer 12 is fixedly connected inside the copper foil connection layer 13. A high work function metal alloy barrier layer 11 is disposed inside the silicon nitride passivation layer 12. The high work function metal alloy barrier layer 11 is fixedly connected inside the silicon nitride passivation layer 12. The copper foil connection layer 13 enables smooth connection between the internal functional layer and the external electrode, conducts current while dispersing the electric field, avoids local electric field concentration, and synergistically improves the reverse withstand voltage capability of the device. At the same time, it quickly conducts internal heat to the main body 1, which helps to dissipate heat. A JBS structure layer 10 is fixedly connected within the high work function metal alloy barrier layer 11, and an n-type structure is fixedly connected within the JBS structure layer 10. + -GaN heavily doped layer 9; n + An unintentionally doped GaN transition layer 8 is disposed within the heavily doped GaN layer 9, and the unintentionally doped GaN transition layer 8 is fixedly connected to n. + -GaN heavily doped layer 9; n + - The heavily doped GaN layer 9 provides a stable mounting base for the JBS structure layer 10, and together with the high work function metal alloy barrier layer 11, it further optimizes the device's conduction performance and high-frequency response characteristics. JBS structural layer 10 has periodic P inside. + The shielding area does not affect electron conduction when forward biased, and precisely shields the high electric field of the barrier region when reverse biased, suppressing the barrier reduction effect, avoiding the increase of reverse leakage current, and achieving a balance between high voltage and high frequency performance. The high work function metal alloy barrier layer 11 and the JBS structure layer 10 form a stable Schottky barrier. When forward biased, the barrier height is reduced, allowing carriers to pass through quickly. When reverse biased, the barrier is rapidly raised to achieve fast turn-off. At the same time, the carrier transport path is shortened, which helps the device achieve ultrafast recovery of ≤5ns and almost eliminates reverse recovery loss. The silicon nitride passivation layer 12 reduces the interface state density, further suppresses reverse leakage current, improves reverse turn-off stability, and protects the internal functional layer from external environmental factors such as dust and moisture, thus extending the device's lifespan. An InAlN buffer layer 7 is fixedly connected inside an unintentionally doped GaN transition layer 8, and a GaN wide bandgap semiconductor 6 is fixedly connected inside the InAlN buffer layer 7. GaN wide bandgap semiconductor 6 is the starting carrier of electron conduction. By utilizing its high electron mobility and high critical breakdown electric field characteristics, it reduces the carrier storage effect, improves the reverse breakdown voltage capability and thermal stability of the device, and lays the foundation for high-frequency, low-loss operation. The InAlN buffer layer 7 can compensate for the growth stress of each internal layer, reduce crystal defects, optimize the electronic conduction environment, avoid structural damage caused by stress concentration, and at the same time reduce leakage current and improve device stability. Unintentionally doped GaN transition layer 8 can smooth the band structure of each internal layer, reduce interlayer scattering of charge carriers, improve electron transport efficiency, provide a smooth path for rapid electron conduction, help the device achieve high-frequency conduction, and optimize the overall electrical performance in conjunction with the GaN substrate. The main body 1 is rectangular.

[0022] Working principle: When the diode is forward biased (anode electrode 5 is connected to a high potential and cathode electrode 4 is connected to a low potential), an external voltage is applied between the high work function metal alloy barrier layer 11 and the JBS structure layer 10, breaking the Schottky barrier and realizing unidirectional current conduction. After a forward voltage is applied, the height of the Schottky barrier formed by the high work function metal alloy barrier layer 11 and the JBS structure layer 10 decreases, allowing charge carriers to pass through the barrier rapidly. Electrons originate from the GaN wide-bandgap semiconductor 6, passing sequentially through the InAlN buffer layer 7, the unintentionally doped GaN transition layer 8, and the n... + -GaN heavily doped layer 9, quickly reaching JBS structure layer 10; Periodic P in JBS structural layer 10 + The shielding area is now positively biased, which does not affect electron conduction. Electrons pass smoothly through the JBS structure layer 10 and reach the high work function metal alloy barrier layer 11. After passing through the high work function metal alloy barrier layer 11, electrons pass through the silicon nitride passivation layer 12 and the copper foil connection layer 13, and are finally output through the cathode electrode 4, completing the forward conduction. Because it uses GaN, a wide bandgap semiconductor, it has high electron mobility, and n + - The heavily doped GaN layer has low parasitic resistance, and the forward voltage drop can be controlled at a low level, while the conduction speed is fast. When the diode is reverse biased (cathode 4 is connected to a high potential and anode 5 is connected to a low potential), the Schottky barrier rises, preventing carrier conduction and achieving rapid turn-off. When a reverse voltage is applied, the Schottky barrier between the high work function metal alloy barrier layer 11 and the JBS structure layer 10 rises rapidly, and electrons cannot cross the barrier, so the forward current is immediately cut off. Periodic P in JBS structural layer 10 + The shielding area plays a core role in precisely shielding the high electric field of the barrier region under reverse bias, suppressing the barrier reduction effect, avoiding an increase in reverse leakage current, and improving reverse withstand voltage performance. The high work function metallic alloy barrier layer 11 shortens the carrier transport path, in conjunction with n+ The low resistance of the GaN heavily doped layer 9 shortens the reverse recovery time to less than 5ns, achieving ultrafast recovery and almost eliminating reverse recovery loss, ensuring that the diode can operate stably in high-frequency scenarios above 1MHz. The silicon nitride passivation layer 12 covers the surface of the functional layer, reduces the interface state density, further suppresses reverse leakage current, improves the stability of reverse turn-off, and protects the internal structure from the influence of the external environment. Except for P in JBS structure layer 10 + In addition to the shielding effect, the GaN wide bandgap semiconductor 6 itself has high critical breakdown electric field characteristics. Combined with the stress compensation effect of the InAlN buffer layer 7, crystal defects are reduced, further improving the reverse breakdown voltage capability. The copper foil connection layer 13 can disperse the electric field and avoid local electric field concentration, thus achieving high breakdown voltage in a coordinated manner. The small amount of heat generated during the turn-on and turn-off process is conducted to the main body 1 through the copper foil connection layer 13. The main body 1 increases the heat dissipation area and dissipates the heat to the external environment, ensuring that the diode can work stably in a wide temperature range of -55℃ to 150℃ and avoiding performance degradation caused by high temperature.

[0023] Structural Description: Main body 1: As the core carrier and protection carrier of the entire diode, it has a rectangular structure and is used to fix and install the cathode electrode 4, anode electrode 5 and high voltage withstand components. At the same time, it provides a stable installation space for each internal functional layer. The rectangular structure can increase the heat dissipation area, which can facilitate the rapid dissipation of heat generated during conduction and turn-off to the external environment, ensuring that the diode works stably in a wide temperature range. It also enables the orderly assembly of each component, avoids structural interference, and improves the overall structural stability of the device. Anode marking bump 2: It is fixedly connected to the side of the main body 1 near the anode electrode 5. It is used to clearly mark the position of the anode electrode 5, which can quickly distinguish the positive and negative terminals of the diode, avoid reverse connection during installation, prevent device breakdown and damage due to reverse connection of positive and negative terminals, improve installation efficiency, and ensure assembly accuracy. Cathode marking bump 3: It is fixedly connected to the side of the main body 1 near the cathode electrode 4. It is used to clearly mark the position of the cathode electrode 4. It works with the anode marking bump 2 to clearly distinguish the positive and negative terminals of the diode, guide the correct installation, avoid installation errors, and simplify the positive and negative terminal identification process during subsequent maintenance, thus improving the convenience of maintenance. Cathode electrode 4: Fixedly connected to the top of the main body 1, serving as the core component for diode current output, receiving electrons conducted from the copper foil connection layer 13 and outputting them outward. Installed on the top of the main body 1, it is convenient to connect to external circuits to achieve smooth current output. At the same time, it is placed on the upper and lower sides of the main body 1 separately from the anode electrode 5 to avoid short circuit between the positive and negative electrodes and ensure the stability of unidirectional current conduction. Anode electrode 5: Fixedly connected to the bottom of the main body 1, serving as the core component for diode current input, receiving external high-potential current and conducting it to the internal functional layer. It is arranged symmetrically with cathode electrode 4 to form a clear current conduction path, facilitating external circuit wiring. At the same time, it ensures that the current can be quickly input into the internal circuit when forward biased, thereby improving the conduction response speed. GaN wide bandgap semiconductor 6: Fixedly connected inside InAlN buffer layer 7, serving as the core substrate layer of the entire diode and the starting carrier of electron conduction. Utilizing its excellent characteristics, it reduces carrier storage effect, improves electron mobility, and enhances the reverse breakdown voltage and thermal stability of the diode, laying the foundation for high-frequency, low-loss operation of the device. InAlN buffer layer 7: It is fixedly connected inside the unintentionally doped GaN transition layer 8 and wraps the GaN wide bandgap semiconductor 6. It can compensate for the growth stress between the internal layers, reduce crystal defects, optimize the electronic conduction environment, avoid structural damage caused by stress concentration, and improve the stability and service life of the device. Unintentionally doped GaN transition layer 8: fixedly connected to n + -The GaN heavily doped layer 9 is encased in an InAlN buffer layer 7, which can smooth the band structure of each internal layer, reduce carrier scattering between layers, improve electron transport efficiency, provide a smooth path for rapid electron conduction, and help the device achieve high-frequency conduction. n + -Heavy GaN doped layer 9: Fixedly connected inside the JBS structure layer 10 and wrapped with unintentionally doped GaN transition layer 8, which can reduce the parasitic resistance of the device, accelerate the electron conduction speed, and provide a stable mounting base for the JBS structure layer 10. Together with the high work function metal alloy barrier layer 11, it further optimizes the conduction performance and high frequency response characteristics of the device. JBS structural layer 10: fixedly connected inside the high work function metal alloy barrier layer 11, and encapsulating n + -GaN heavily doped layer 9, with periodic P-type elements inside. + The shielding area does not affect electron conduction when forward biased, and can precisely shield the high electric field of the barrier region when reverse biased, suppressing the barrier reduction effect, avoiding the increase of reverse leakage current, and significantly improving the reverse withstand voltage performance of the diode, ensuring stable operation of the device under high voltage conditions. High work function metal alloy barrier layer 11: It is fixedly connected inside the silicon nitride passivation layer 12 and wraps the JBS structure layer 10. It forms a stable Schottky barrier with the JBS structure layer 10. When forward biased, it can reduce the barrier height and allow carriers to pass through quickly. When reverse biased, it can quickly raise the barrier to achieve fast turn-off. At the same time, it shortens the carrier transport path, helps the device achieve ultra-fast recovery, and almost eliminates reverse recovery loss, making it suitable for high frequency operating scenarios. Silicon nitride passivation layer 12: It is fixedly connected inside the copper foil connection layer 13 and wraps the high work function metal alloy barrier layer 11. It can cover the surface of all internal functional layers, reduce the interface state density, further suppress reverse leakage current, improve the stability of reverse turn-off, and at the same time play a protective role, preventing the internal functional layers from being affected by external environmental factors such as dust and moisture, and extending the service life of the device. Copper foil connection layer 13: It is fixedly connected inside the main body 1 and wrapped with silicon nitride passivation layer 12. It is a core component of high voltage withstand device. It can realize the smooth connection between internal functional layer and external electrode, conduct current and disperse electric field, avoid local electric field concentration, and synergistically improve the reverse voltage withstand capability of device. At the same time, it can quickly conduct the heat generated inside to the main body 1, help heat dissipation, and ensure stable operation of device.

[0024] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A high-frequency ultrafast recovery Schottky diode, comprising a main body (1), characterized in that: The top of the main body (1) is fixedly connected to a cathode electrode (4), the bottom of the main body (1) is fixedly connected to an anode electrode (5), and a high-pressure resistant component is provided on the main body (1). The high-pressure resistant component includes a copper foil connecting layer (13), which is fixedly connected inside the main body (1).

2. The high-frequency ultrafast recovery Schottky diode according to claim 1, characterized in that: The main body (1) is rectangular.

3. The high-frequency ultrafast recovery Schottky diode according to claim 1, characterized in that: A cathode marking protrusion (3) is fixedly connected to the main body (1) on the side near the cathode electrode (4).

4. A high-frequency ultrafast recovery Schottky diode according to claim 1, characterized in that: An anode marking protrusion (2) is fixedly connected to the main body (1) on the side near the anode electrode (5).

5. A high-frequency ultrafast recovery Schottky diode according to claim 1, characterized in that: A silicon nitride passivation layer (12) is fixedly connected inside the copper foil connecting layer (13), and a high work function metal alloy barrier layer (11) is disposed inside the silicon nitride passivation layer (12). The high work function metal alloy barrier layer (11) is fixedly connected inside the silicon nitride passivation layer (12).

6. A high-frequency ultrafast recovery Schottky diode according to claim 5, characterized in that: A JBS structure layer (10) is fixedly connected within the high work function metal alloy barrier layer (11), and n is fixedly connected within the JBS structure layer (10). + -GaN heavily doped layer (9).

7. A high-frequency ultrafast recovery Schottky diode according to claim 6, characterized in that: The n + An unintentionally doped GaN transition layer (8) is disposed within the heavily doped GaN layer (9), and the unintentionally doped GaN transition layer (8) is fixedly connected to n. + - GaN heavily doped layer (9) inside.

8. A high-frequency ultrafast recovery Schottky diode according to claim 7, characterized in that: An InAlN buffer layer (7) is fixedly connected inside the unintentionally doped GaN transition layer (8), and a GaN wide bandgap semiconductor (6) is fixedly connected inside the InAlN buffer layer (7).

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