Method for enhancing reverse breakdown voltage of gallium oxide diode based on neutron radiation

Abstract

The present invention discloses a method for improving the reverse breakdown voltage of a gallium oxide diode based on neutron radiation, which mainly solves the problem of the low breakdown voltage of the existing gallium oxide diode. The implementation scheme is as follows: Select a neutron source device, and set the neutron energy of the device to 0.1 MeV - 20 MeV and the dose to 1×10<supgt;13< / supgt> - 1×10<supgt;16< / supgt> n / cm<supgt;2< / supgt> according to the tolerance of gallium oxide material to neutron radiation; Horizontally and evenly attach multiple Ga<subgt;2< / subgt>O<subgt;3 diodes to the PCB board, and then vertically place the PCB board with the devices attached at the pore position of the neutron source radiation device; After checking that the setting parameters of the neutron source device are correct, turn on the power to irradiate the attached devices with neutrons until the neutron dose emitted by the neutron source reaches the preset value, then turn off the power and take out the Ga<subgt;2O<subgt;3 diodes. The present invention effectively improves the reverse breakdown voltage of the Ga<subgt;2O<subgt;3 diode and can be applied to high-voltage and high-power power electronic devices.

Description

Technical Field

[0001] The present invention belongs to the field of wide-bandgap semiconductors, and particularly relates to a method for improving the reverse breakdown voltage of a diode, which can be used in the field of high-voltage and high-power power electronics. Background Art

[0002] The gallium oxide Ga2O3 material has a wide bandgap width of ~4.9 eV. Semiconductor devices developed based on this material have a high breakdown voltage and have great application advantages in power electronic devices with high operating voltages. As a very promising semiconductor component, Ga2O3 power semiconductor devices play a role in rectification, amplification, and switching in circuits. In the future, they can be used as power supplies for various devices, drive loads, and pulse power regulation systems for electronic devices, and have important potential application values in the fields of new energy, rail transit, aerospace, etc.

[0003] With the continuous development of the fields of space electric propulsion and power management, there is a huge demand for high-performance power electronic devices. Ga2O3 power devices are an important choice to meet this demand. The diode is one of the main research contents of Ga2O3 power devices, and the level of the reverse breakdown voltage of the diode directly affects the practical application of the device. Currently, most research mainly improves the reverse breakdown voltage by changing the structure of the diode device.

[0004] Ma Xiaohua et al. proposed in the patent document with the application number 202111069074.7 to form a heterojunction PN structure with a thin NiO layer with P-type characteristics and a β-Ga2O3 drift layer to reduce the peak electric field at the edge of the device, improve the interface characteristics between the anode metal and gallium oxide, reduce the reverse leakage current, and increase the breakdown voltage of the gallium oxide diode.

[0005] Feng Qian et al. proposed in the patent document with the application number 201710057175.X to deposit a Schottky diode with a field plate structure at the edge of an organic ferroelectric dielectric layer to reduce the electric field strength at the edge and increase the reverse breakdown voltage of the gallium oxide Schottky diode.

[0006] Although the above two methods can increase the reverse breakdown voltage of the device, they also cause a serious reduction in the forward current density of the device while increasing the reverse breakdown voltage of the device. In addition, since these methods both require adding process steps, the technical difficulty is large, the yield is low, and the manufacturing cost is high. Summary of the Invention

[0007] The purpose of the present invention is to address the deficiencies of the above existing technologies and provide a method for improving the reverse breakdown voltage of a gallium oxide diode based on neutron radiation, so as to ensure a small degradation of the forward current density and turn-on voltage while increasing the reverse breakdown voltage, improve the device yield, and reduce the manufacturing cost.

[0008] The technical solution of the present invention is realized as follows:

[0009] I. Technical principle

[0010] Neutrons are widely distributed in space and the Earth's atmosphere. Neutrons in space mainly come from the collision of cosmic rays with atoms on the surface of planets or in the atmosphere; neutrons in the Earth's atmosphere mainly come from nuclear reactions between heavy ions of galactic cosmic rays and oxygen and nitrogen atoms in the air. In addition, various nuclear tests conducted by humans will also produce a large number of neutrons. At present, humans can already relatively maturely produce neutrons with different energies through different methods such as nuclear reactors, accelerators, and spontaneous fission, and gradually apply them to various fields.

[0011] As the most penetrating particle among various radiation particles, neutrons have strong penetrability to most substances, and neutrons themselves are electrically neutral and mainly produce effects by undergoing nuclear reactions with atoms or molecules of the irradiated substance. It is commonly used in medical radiotherapy for tumors, such as boron neutron capture therapy; it is also commonly used in industrial material modification, such as neutron doping.

[0012] Based on the physical properties of neutrons being electrically neutral and having strong penetrability, the present invention modifies gallium oxide materials by neutron radiation to increase the reverse breakdown voltage of gallium oxide diodes. It irradiates the gallium oxide diode device by setting the energy and dose parameters of the neutrons emitted by the neutron source device, so that the neutrons irradiating the gallium oxide diode device undergo nuclear reactions with the atoms in the gallium oxide lattice to generate vacancy defects. These vacancy defects exist in the form of impurity compensation traps, which can reduce the doping concentration of the gallium oxide material, resulting in an increase in the depletion region width of the device at the doping concentration and a decrease in the peak electric field at the edge of the device, thereby achieving an increase in the reverse breakdown voltage.

[0013] II. Technical solution

[0014] According to the above principle, a method for increasing the reverse breakdown voltage of a gallium oxide diode based on neutron radiation of the present invention is characterized by including the following steps:

[0015] Select a neutron source device and set the neutron energy of the device to 0.1 MeV - 20 MeV and the dose to 1×10 13 -1×10 16 n / cm 2 ;

[0016] Horizontally and evenly attach multiple Ga2O3 diodes to a PCB board, and then vertically place the PCB board with the devices at the pore position of the neutron source radiation device;

[0017] After checking that the setting parameters of the neutron source device are correct, turn on the power to irradiate the attached device with neutrons until the neutron dose emitted by the neutron source reaches the preset value, then turn off the power and take out the Ga2O3 diode to increase its reverse breakdown voltage.

[0018] Further, the multiple Ga2O3 diodes are evenly attached to the PCB board horizontally. The multiple Ga2O3 diode devices are fixed on the PCB board in a single-layer flat or multi-layer stacked manner in a circle with the same size as the radiation channel of the neutron source device, ensuring that the neutrons emitted by the neutron source device can be incident perpendicular to the electrodes into the device.

[0019] Further, the neutron parameter setting of the neutron source device is determined by the Monte Carlo simulation results. That is, after modeling the structure of the device in the software, input the energy and dose values of the neutrons into the above simulation software, and evaluate the damage of the neutron radiation to the device at this energy and dose through the calculation results of the software. Select the neutron parameters that cause the forward current density degradation amplitude of the device to be between 5% and 50%, so as to determine that the neutron energy emitted by the neutron source is 0.1 MeV - 20 MeV, and the dose is 1×10 13 -1×10 16 n / cm 2 .

[0020] Since the present invention does not require additional process steps, it has a relatively small technical difficulty, a high yield rate, and a low manufacturing cost.

[0021] The test results show that while significantly increasing the reverse breakdown voltage of the device, the present invention causes the forward current density of the device to decrease by less than 20%, and the turn-on voltage only increases by 0.05 V ± 0.01 V. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a flowchart for implementing the present invention;

[0023] Figure 2 is a comparison chart of the reverse breakdown voltage of the Ga2O3 diode before and after neutron irradiation using the present invention;

[0024] Figure 3 is a comparison chart of the I-V test of the Ga2O3 diode before and after neutron irradiation using the present invention at low voltages. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The following further describes the specific examples and effects of the present invention in detail with reference to the accompanying drawings, but the implementation manners of the present invention are not limited thereto.

[0026] Refer to Figure 1 , and the present invention gives the following three embodiments.

[0027] Example 1, the arrangement of the gallium oxide Schottky diode devices is set to be a single-layer tiled layout, the neutron energy emitted by the neutron source is 1 MeV, and the dose is 1×10 14 n / cm 2 。

[0028] Step 1, set the neutron energy and dose of the neutron source device.

[0029] After modeling the structure of the gallium oxide Schottky diode in Monte Carlo software, input the neutron energy and dose values into the simulation software. Through the calculation results of the software, evaluate the damage of the neutron radiation with an energy of 1 MeV and a dose of 1×10 14 n / cm 2 to the device. The evaluation results show that under this condition, the degradation amplitude of the forward current density of the device is about 17%. Based on this, determine that the energy of the neutrons emitted by the neutron source is 1 MeV and the dose is 1×10 14 n / cm 2 。

[0030] Step 2, set the arrangement of the devices to be a single-layer tiled layout.

[0031] The radiation channel of the neutron source device is a circle with a fixed size, and only within this circle is the effective neutron irradiation area. To make the most of this area, in this experiment, 150 rectangular Ga2O3 Schottky diode devices in TO257 packages are arranged in a single-layer tiled layout within a circle with the same size as the radiation channel of the neutron source device, with the long sides of the devices adjacent to each other and the short sides adjacent to each other, and fixed on the PCB board. Then, the PCB board with the devices is placed vertically at the channel position of the neutron source radiation device to ensure that the neutrons emitted by the neutron source device can be incident perpendicularly to the electrodes into the devices.

[0032] Step 3, turn on the neutron source device and irradiate the devices.

[0033] After checking that the neutron energy, dose, and all setting parameters of the device under normal operation of the neutron source device are correct, turn on the main power supply and irradiate the devices with neutrons until the neutron dose emitted by the neutron source reaches 1×10 14 n / cm 2 Then turn off the power supply and take out the Ga2O3 diode to achieve the improvement of its reverse breakdown voltage.

[0034] Example 2, the arrangement of the gallium oxide Schottky diode devices is set to be a multi-layer stack, the neutron energy emitted by the neutron source is 1 MeV, and the dose is 3×10 14 n / cm 2 。

[0035] Step 1, set the neutron energy and dose of the neutron source device.

[0036] After modeling the structure of the gallium oxide Schottky diode in Monte Carlo software, the neutron energy and dose values are input into the simulation software, and through the calculation results of the software, it is evaluated that the damage of the device caused by neutron radiation with an energy of 1 MeV and a dose of 3×10 14 n / cm 2 The evaluation results show that under this condition, the degradation amplitude of the forward current density of the device is about 49%. Based on this, it is determined to select a neutron source with an energy of 1 MeV and a dose of 3×10 14 n / cm 2 .

[0037] Step 2: Set the arrangement of the devices as multi-layer stacking. [[ID=!4]]

[0038] 2.1) Arrange 150 rectangular Ga2O3 Schottky diode devices in TO257 packages. First, arrange them in a single layer and fix them on the PCB board within a circular range with the same size as the radiation channel of the neutron source device in a way that the long sides of the devices are closely aligned with each other and the short sides are also closely aligned with each other.

[0039] 2.2) Repeat the arrangement method in 2.1) to arrange and fix the devices on n PCB boards respectively, where n < 50.

[0040] 2.3) Place the n PCB boards with 150 devices each vertically at the position of the radiation channel of the neutron source device with a spacing of 2 cm to ensure that the neutrons emitted by the neutron source device can be incident perpendicularly to the electrodes into the devices.

[0041] Step 3: Turn on the neutron source device and irradiate the devices.

[0042] After checking that the neutron energy, dose, and all setting parameters of the device under normal operation are correct, turn on the main power supply and irradiate the devices with neutrons until the neutron dose emitted by the neutron source reaches 3×10 14 n / cm 2 Then turn off the power supply and take out the Ga2O3 diode to achieve an increase in its reverse breakdown voltage.

[0043] Example 3: Set the arrangement of the gallium oxide Schottky diode devices as multi-layer stacking, the neutron energy emitted by the neutron source is 1 MeV, and the dose is 3×10 13 n / cm 2 .

[0044] Step A: Set the neutron energy and dose of the neutron source device.

[0045] After modeling the structure of the gallium oxide Schottky diode in Monte Carlo software, the neutron energy and dose values are input into the simulation software, and the damage of the device caused by neutron radiation with an energy of 1 MeV and a dose of 3×10 13 n / cm 2 is evaluated through the calculation results of the software. The evaluation results show that under this condition, the degradation amplitude of the forward current density of the device is about 5%. Based on this, it is determined to select a neutron source with an emitted energy of 1 MeV and a dose of 3×10 13 n / cm 2 .

[0046] Step B: Set the arrangement mode of the devices as multi-layer stacking.

[0047] The specific implementation of this step is the same as that of Step 2 in Embodiment 2.

[0048] Step C: Turn on the neutron source device and irradiate the devices.

[0049] After checking that the emitted neutron energy, dose of the neutron source device and each setting parameter under normal operation of the device are correct, turn on the main power supply and irradiate the attached devices with neutrons until the neutron dose emitted by the neutron source reaches 3×10 13 n / cm 2 , then turn off the power supply and take out the Ga2O3 diode to achieve the improvement of its reverse breakdown voltage.

[0050] The above description is only three specific examples of the present invention and does not constitute any limitation to the present invention. For those of ordinary skill in the technical field to which the present invention pertains, without departing from the concept of the present invention, several simple inferences or substitutions can still be made, which should all be regarded as belonging to the protection scope of the present invention.

[0051] The effects of the present invention can be further illustrated by the following measured data:

[0052] I. Test conditions

[0053] Select a semiconductor analyzer device, set the test voltage for I-V test to 0 - 2V with a test accuracy of 0.01V; set the voltage for testing the reverse breakdown voltage of the test device to -1000 - 0V with a test accuracy of 1V, and set the limit current to 0.1 mA

[0054] II. Test content

[0055] Test 1: Prepare twenty Ga2O3 Schottky diodes with the same preparation process. Select ten of these devices and successively connect the positive and negative electrodes of these devices to a semiconductor analyzer device. Under the above conditions, test the I-V curve of the device before irradiation; then irradiate the ten devices selected in this test using the method of the present invention, and successively connect the positive and negative electrodes of these devices to a semiconductor analyzer device. Under the above conditions, test the I-V curve of the device after irradiation. The results are as follows Figure 2 .

[0056] It can be seen from Figure 3 that after neutron irradiation, the turn-on voltage of the device only degenerates by 0.05 V, and the forward current density only degenerates by 17%, indicating that the method of the present invention causes less degradation to the turn-on voltage and forward current density of the device.

[0057] Test 2: Prepare another twenty Ga2O3 Schottky diodes with the same preparation process. Select ten of these devices and successively connect the positive and negative electrodes of these devices to a semiconductor analyzer device. Under the above conditions, test the reverse breakdown voltage before irradiation; then irradiate the other ten devices not selected in this test using the method of the present invention, and successively connect the positive and negative electrodes of these devices to a semiconductor analyzer device. Under the above conditions, test the reverse breakdown voltage of the device after irradiation. The results are as follows Figure 3 .

[0058] It can be seen from Figure 2 that the reverse breakdown voltage of the device before neutron irradiation is 540 V, and the reverse breakdown voltage of the device after neutron irradiation is 925 V. It shows that the method of the present invention can increase the reverse breakdown voltage of the device by nearly 400 V.

Claims

1. A method for increasing the reverse breakdown voltage of a gallium oxide diode based on neutron radiation, characterized in that, The steps include the following: Select a neutron source device and set the neutron energy of the device to 0.1 MeV - 20 MeV and the dose to 1×10 13 -1×10 16 n / cm 2 ; Horizontally and evenly attach multiple Ga2O3 diodes to a PCB board, and then vertically place the PCB board with the attached Ga2O3 diodes at the channel position of a neutron source radiation device; After checking that the setting parameters of the neutron source device are correct, turn on the power to irradiate the attached Ga2O3 diodes with neutrons until the neutron dose emitted by the neutron source reaches a preset value, then turn off the power and take out the Ga2O3 diodes to achieve an increase in their reverse breakdown voltage.

2. The method according to claim 1, wherein: The step of horizontally and evenly attaching multiple Ga2O3 diodes to a PCB board means that multiple Ga2O3 diodes are fixed on the PCB board in a single-layer flat or multi-layer stack in a circle with the same size as the radiation channel of the neutron source device, ensuring that the neutrons emitted by the neutron source device can be incident on the device perpendicular to the electrodes.

3. The method according to claim 1, wherein: The neutron parameter settings of the neutron source device are determined through Monte Carlo simulation results. That is, after modeling the structure of the device in the software, the energy and dose values of neutrons are input into the above software, and the damage of neutron radiation to the device at this energy and dose is evaluated through the calculation results of the software. Neutron parameters that cause the forward current density degradation of the device to be in the range of 5%-50% are selected, and based on this, the neutron energy emitted by the neutron source is determined to be 0.1 MeV - 20 MeV, and the dose is 1×10 13 -1×10 16 n / cm 2 .

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