CN115172171A - Method for improving reverse breakdown voltage of gallium oxide diode based on neutron radiation - Google Patents

Abstract

The invention discloses a method for improving reverse breakdown voltage of a gallium oxide diode based on neutron radiation, which mainly solves the problem of low breakdown voltage of the existing gallium oxide diode. The implementation scheme is as follows: selecting neutron source equipment, setting the neutron energy of the equipment to be 0.1MeV-20MeV and the dose to be 1 multiplied by 10 MeV according to the tolerance degree of the gallium oxide material to neutron radiation ¹³ ‑1×10 ¹⁶ n/cm ² (ii) a A plurality of Ga ₂ O ₃ The diodes are horizontally and uniformly pasted on the PCB, and then the PCB pasted with the devices is vertically placed at the position of a pore channel of neutron source radiation equipment; after checking that all setting parameters of the neutron source equipment are correct, turning on a power supply to carry out neutron irradiation on the attached device until the neutron dose emitted by the neutron source reaches a preset value, turning off the power supply, and taking out Ga ₂ O ₃ And a diode. The invention effectively improves Ga ₂ O ₃ Reverse breakdown voltage of diode, applicable toHigh withstand voltage high power electronic equipment.

Description

Reverse breakdown voltage boosting method of gallium oxide diode based on neutron radiation

technical field

The invention belongs to the field of wide band gap semiconductors, in particular to a method for increasing the reverse breakdown voltage of a diode, which can be used in the field of high withstand voltage and high power power electronics.

Background technique

The gallium oxide Ga ₂ O ₃ material has a wide band gap of ~4.9eV, and the 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. Ga ₂ O ₃ power semiconductor device, as a very potential semiconductor component, plays the role of rectification, amplification and switching in the circuit, and can be used as power supply for various equipment, driving load and pulse power regulation system for electronic equipment in the future. It has important potential application value in new energy, rail transit, aerospace and other fields.

With the continuous development of space electric propulsion and power management, there is a huge demand for high-performance power electronic devices, and Ga ₂ O ₃ power devices are an important choice to meet this demand. Diode is one of the main research contents of Ga ₂ O ₃ power devices. The level of diode reverse breakdown voltage directly affects the application of the device in practice. At present, most researches mainly improve the reverse breakdown voltage by changing the structure of the diode device.

Ma Xiaohua et al. proposed in the patent document No. 202111069074.7 to form a hetero-PN junction structure with a thin NiO layer with P-type characteristics and a β-Ga ₂ O ₃ drift layer to reduce the peak electric field at the edge of the device and improve the anode metal The interface with gallium oxide reduces the reverse leakage current and improves the breakdown voltage of the gallium oxide diode.

Feng Qian et al. proposed in the patent document No. 201710057175.X to deposit a Schottky diode with a field plate structure at the edge of the organic ferrodielectric layer to reduce the electric field strength at the edge and improve the gallium oxide Schottky The reverse breakdown voltage of the diode.

Although the above two methods can improve the reverse breakdown voltage of the device, while increasing the reverse breakdown voltage of the device, it also brings a serious reduction in the forward current density of the device; in addition, these methods need to increase the process steps, The technical difficulty is relatively high, the yield is low, and the manufacturing cost is high.

Invention content:

The purpose of the present invention is to provide a method for increasing the reverse breakdown voltage of a gallium oxide diode based on neutron radiation, aiming at the deficiencies of the above-mentioned prior art, so as to ensure the forward current density and the turn-on voltage while increasing the reverse breakdown voltage. Degradation is small, device yield is improved, and manufacturing cost is reduced.

The technical scheme of the present invention is realized as follows:

1. Technical principle

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 galactic cosmic ray heavy ions and oxygen in the air. nuclear reaction with nitrogen atoms. In addition, various nuclear tests conducted by humans also produce large amounts of neutrons. At present, human beings have been able to generate neutrons of different energies through different methods such as nuclear reactors, accelerators, and spontaneous fission, which are gradually applied in various fields.

As the most penetrating particle among all kinds of radiation particles, neutrons have strong penetrability to most substances, and neutrons themselves are not charged, and are mainly produced by nuclear reactions with atoms or molecules of irradiated substances. effect. It is commonly used in radiation therapy of tumors in medicine, such as boron neutron capture therapy; it is also commonly used in material modification in industry, such as neutron doping.

The invention is based on the non-charged and strong penetrating physical properties of neutrons, and uses neutron radiation to modify the gallium oxide material to improve the reverse breakdown voltage of the gallium oxide diode. 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 irradiated on the gallium oxide diode device react with 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 width of the depletion region of the device under the doping concentration, and a decrease in the peak electric field at the edge of the device, thereby achieving reverse breakdown. increase in voltage.

Second, technical solutions

According to the above principle, the method for boosting the reverse breakdown voltage of a gallium oxide diode based on neutron radiation of the present invention is characterized in that it includes the following steps:

Neutron source equipment is selected, and according to the tolerance of gallium oxide material to neutron radiation, the neutron energy of the equipment is set to 0.1MeV-20MeV, and the dose is 1×10 ¹³ -1×10 ¹⁶ n/cm ² ;

A plurality of Ga ₂ O ₃ diodes are evenly attached to the PCB board horizontally, and then the PCB board with the devices is placed vertically in the hole position of the neutron source radiation device;

After checking that the setting parameters of the neutron source equipment 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 Ga ₂ O ₃ diode to achieve increase its reverse breakdown voltage.

Further, the plurality of Ga ₂ O ₃ diodes are evenly and horizontally attached to the PCB board, and the plurality of Ga ₂ O ₃ diode devices are tiled in a single layer or stacked in multiple layers according to the same size as the radiation channel of the neutron source device. It is fixed on the PCB board to ensure that the neutrons emitted by the neutron source device can be incident into the device perpendicular to the electrodes.

Further, the neutron parameter setting of the neutron source device is determined by the results of Monte Carlo simulation, that is, after modeling the structure of the device in the software, the energy and dose values of neutrons are input into the above simulation software, The calculation results of the software evaluate the damage of the neutron radiation to the device under the energy and dose, and select the neutron parameters that cause the degradation of the forward current density of the device to be 5%-50%, so as to determine the neutron source output. The neutron energy is 0.1MeV-20MeV, and the dose is 1×10 ¹³ -1×10 ¹⁶ n/cm ² .

Since the present invention does not need to increase the process steps, the technical difficulty is small, the yield is high, and the manufacturing cost is low.

The test results show that the present invention significantly improves the reverse breakdown voltage of the device, while the forward current density of the device decreases by less than 20%, and the turn-on voltage only increases by 0.05V±0.01V.

Description of drawings

Fig. 1 is the realization flow chart for the present invention;

Fig. 2 is the contrast change diagram of the reverse breakdown voltage of Ga ₂ O ₃ diode before and after the neutron irradiation of the present invention;

FIG. 3 is a comparison diagram of IV test under low voltage of Ga ₂ O ₃ diodes before and after neutron irradiation using the present invention.

Detailed ways

Specific examples and effects of the present invention will be described in further detail below with reference to the accompanying drawings, but the embodiments of the present invention are not limited thereto.

1, the present invention provides the following three embodiments.

In Example 1, the arrangement of the gallium oxide Schottky diode devices is set as a single-layer tile, the neutron energy emitted by the neutron source is 1MeV, and the dose is 1×10 ¹⁴ n/cm ² .

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

After modeling the structure of the gallium oxide Schottky diode in Monte Carlo software, the neutron energy and dose values were input into the simulation software, and the calculation results of the software estimated that the energy was 1MeV and the dose was 1×10 ¹⁴ n/ cm ² neutron radiation damage to the device, the evaluation results show that the forward current density of the device is degraded by about 17% under this condition, so the energy of the selected neutron source is 1MeV, and the dose is 1× 10 ¹⁴ n/cm ² .

Step 2, set the arrangement of the devices to be single-layer tiling.

The radiation channel of the neutron source device is a circle with a fixed size, and only within the circle is the effective neutron irradiation area. In order to maximize the use of this area, in this experiment, 150 rectangular Ga ₂ O ₃ Schottky diode devices packaged in TO257 are aligned according to the long side and the long side of the devices, and the wide side and the wide side are closely aligned. The single-layer tile is arranged in the same circumferential range as the radiation channel of the neutron source device and fixed on the PCB board, and then the PCB board with the device is placed vertically on the channel position of the neutron source radiation device. In order to ensure that the neutrons emitted by the neutron source device can be incident into the device perpendicular to the electrodes.

Step 3, turn on the neutron source equipment and irradiate the device.

After checking the neutron energy and dose of the neutron source equipment and the setting parameters of the equipment under normal operation, turn on the main power supply and irradiate the attached device with neutrons until the neutron dose emitted by the neutron source reaches 1× After 10 ¹⁴ n/cm ² , the power was turned off, and the Ga ₂ O ₃ diode was taken out to improve its reverse breakdown voltage.

In Example 2, the arrangement of the gallium oxide Schottky diode devices is set to be multi-layer stacking, the neutron energy emitted by the neutron source is 1MeV, and the dose is 3×10 ¹⁴ n/cm ² .

Step 1: Set the neutron energy and dose of the neutron source equipment.

After modeling the structure of the gallium oxide Schottky diode in Monte Carlo software, the neutron energy and dose values were input into the simulation software, and the calculation results of the software estimated that the energy was 1MeV and the dose was 3×10 ¹⁴ n/ cm ² neutron radiation damage to the device, the evaluation results show that the degradation of the forward current density of the device is about 49% under this condition, so the energy of the selected neutron source is 1MeV, and the dose is 3× 10 ¹⁴ n/cm ² .

In step 2, the arrangement of the devices is set as multi-layer stacking.

2.1) Arrange 150 rectangular Ga ₂ O ₃ Schottky diode devices in a TO257 package, and arrange them in a single-layer tile according to the method that the long side and the long side of the devices are closely aligned, and the wide side and the wide side are closely aligned. Within the same circumference as the radiation channel of the neutron source device and fixed on the PCB;

2.2) Repeat the arrangement of 2.1) to arrange and fix the devices on n PCB boards respectively, n<50;

2.3) Place n PCB boards with 150 devices respectively placed in the hole position of the neutron source radiation device at a distance of 2cm to ensure that the neutrons emitted by the neutron source device can be incident into the device perpendicular to the electrodes.

Step 3, turn on the neutron source equipment, and irradiate the device.

After checking the neutron energy and dose of the neutron source equipment and the setting parameters of the equipment under normal operation, turn on the main power supply and irradiate the attached device with neutrons until the neutron dose emitted by the neutron source reaches 3× After 10 ¹⁴ n/cm ² , the power was turned off, and the Ga ₂ O ₃ diode was taken out to improve its reverse breakdown voltage.

In Example 3, the arrangement of the gallium oxide Schottky diode devices is set to be multi-layer stacking, the neutron energy emitted by the neutron source is 1MeV, and the dose is 3×10 ¹³ n/cm ² .

Step A, setting the neutron energy and dose of the neutron source device.

After modeling the structure of the gallium oxide Schottky diode in Monte Carlo software, the neutron energy and dose values were input into the simulation software, and the calculation results of the software estimated that the energy was 1MeV and the dose was 3×10 ¹³ n/ cm ² neutron radiation damage to the device, the evaluation results show that the degradation of the forward current density of the device is about 5% under this condition, so the energy of the selected neutron source is 1MeV, and the dose is 3× 10 ¹³ n/cm ² .

In step B, the arrangement of the devices is set as a multi-layer stack.

The specific implementation of this step is the same as the second step in Embodiment 2.

In step C, the neutron source device is turned on, and the device is irradiated.

After checking the neutron energy and dose of the neutron source equipment and the setting parameters of the equipment under normal operation, turn on the main power supply and irradiate the attached device with neutrons until the neutron dose emitted by the neutron source reaches 3× After 10 ¹³ n/cm ² , the power was turned off, and the Ga ₂ O ₃ diode was taken out to improve its reverse breakdown voltage.

The above descriptions are only three specific examples of the present invention, and do 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, some simple inferences or substitutions can be made, which should be regarded as belonging to the protection scope of the present invention.

The effect of the present invention can be further illustrated by the following measured data:

1. Test conditions

Select semiconductor analyzer equipment, set the test voltage of the I-V test to 0-2V, and the test accuracy to 0.01V; set the voltage of the reverse breakdown voltage of the test device to -1000-0V, the test accuracy to 1V, and set the limit current to 0.1 mA

2. Test content

Test 1, prepare twenty Ga ₂ O ₃ Schottky diodes of the same preparation process, select ten of them, and connect the positive and negative poles of these devices to the semiconductor analyzer equipment in turn. Under the above conditions, test the irradiation The IV curve of the former device; after the ten devices selected in the test are irradiated by the method of the present invention, the positive and negative poles of these devices are connected to the semiconductor analyzer equipment in turn, and under the above conditions, the devices after irradiation are tested. The IV curve of the results is shown in Figure 2.

It can be seen from Fig. 3 that the turn-on voltage of the device after neutron irradiation is only degraded by 0.05V, and the forward current density is only degraded by 17%, indicating that the degradation of the turn-on voltage and forward current density of the device is small by the method of the present invention .

Test 2, prepare another twenty Ga ₂ O ₃ Schottky diodes of the same preparation process, select ten of them, and connect the positive and negative poles of these devices to the semiconductor analyzer equipment in turn. Under the above conditions, test The reverse breakdown voltage before irradiation; after the other ten devices not selected in the test are irradiated by the method of the present invention, the positive and negative poles of these devices are connected to the semiconductor analyzer equipment in turn. Under the above conditions , test the reverse breakdown voltage of the device after irradiation, and the results are shown in Figure 3.

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

Claims (3)

1. a gallium oxide diode reverse breakdown voltage boosting method based on neutron radiation, is characterized in that, comprises the steps: Neutron source equipment is selected, and according to the tolerance of gallium oxide material to neutron radiation, the neutron energy of the equipment is set to 0.1MeV-20MeV, and the dose is 1×10 ¹³ -1×10 ¹⁶ n/cm ² ; A plurality of Ga ₂ O ₃ diodes are evenly attached to the PCB board horizontally, and then the PCB board with the devices is placed vertically in the hole position of the neutron source radiation device; After checking that the setting parameters of the neutron source equipment 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 Ga ₂ O ₃ diode to achieve increase its reverse breakdown voltage. 2. The method according to claim 1, characterized in that: the multiple Ga ₂ O ₃ diodes are evenly affixed on the PCB board horizontally, and the multiple Ga ₂ O ₃ diode devices are arranged according to the radiation with the neutron source equipment. The circular single-layer tile or multi-layer stack with the same hole size is fixed on the PCB board to ensure that the neutrons emitted by the neutron source equipment can be incident into the device perpendicular to the electrodes. 3. method according to claim 1 is characterized in that: the neutron parameter setting of neutron source equipment is determined by Monte Carlo simulation result, namely after the structure of device is modeled in software, the neutron The energy and dose values are input into the above simulation software, and the damage to the device caused by the neutron radiation under the energy and dose is evaluated through the calculation results of the software. The sub-parameters are used to determine that the neutron energy emitted by the neutron source is 0.1MeV-20MeV, and the dose is 1×10 ¹³ -1×10 ¹⁶ n/cm ² .

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