CN113990846B - SOI device capable of resisting total dose irradiation and preparation method thereof - Google Patents

Abstract

An SOI device resistant to total dose irradiation and a preparation method thereof belong to the field of radiation protection materials. The present invention solves the problems that the current high and low Z alternately laminated coating process is complicated, needs to be coated and dried for many times, takes a long time, and has limited protection capability; it also cannot realize the technical problem of flexibility. In the invention, the MAX phase ceramic matrix is etched to obtain a Ti ₃ C ₂ T _x material with a layered structure, and then a high-Z metal is deposited into the Mxene layered structure by atomic layer deposition technology to obtain a composite material, and then the composite material is obtained. The material is mixed with the resin matrix and then coated on the surface of the SOI device to obtain a radiation protection coating. The material of the present invention can be used for radiation protection suits in daily life, medical aspects, and required and protective fields in nuclear reactions.

Description

A kind of SOI device resistant to total dose irradiation and preparation method thereof

technical field

The invention belongs to the field of radiation protection materials, and in particular relates to an SOI device resistant to total dose irradiation and a preparation method thereof.

Background technique

The total dose effect refers to the degradation of device performance due to trapped charges induced in the oxide layer by radiation. For SOI devices, radiation not only generates trapped charges and interface state charges in the gate oxide, but also in other dielectrics such as field isolation oxides and buried oxides. These radiation-induced charges will increase the off-state leakage and edge leakage of the device, resulting in increased static power consumption and even functional failure of the integrated circuit. Therefore, only by solving the problem of total dose-resistance reinforcement of SOI materials and devices can we remove obstacles for the military application of SOI technology and better apply it to radiation-hardened microelectronic products.

At present, the shielding of the total dose effect is usually completed by metals such as lead or alternately laminated with some low-Z metals. However, due to its high density and mass, lead increases the load of the overall structure in some applications. At the same time, lead has certain toxicity and is harmful to human beings and the environment. However, the current coating process of alternating high and low Z layers is complex, requiring multiple coatings and drying, which takes a long time and has limited protective ability. And another limitation of the currently used materials is that they basically have a certain shape and strength, and if you want them to have a certain flexibility, it may not be possible.

SUMMARY OF THE INVENTION

The invention provides a total dose effect radiation protection material prepared by using an ALD method to deposit a high-Z metal in a Mxene laminated structure, using the natural accordion laminated structure of Mxene to grow the high-Z metal into the laminated layer by atomic layer deposition, The Mxene/high Z metal composite material with alternating high and low Z was prepared, and then mixed with the resin matrix and then coated on the surface of the SOI device to prepare a radiation protection coating with flexibility and shielding the effect of the total dose.

In order to solve the above technical problems, the metal-doped Mxene material for shielding the total dose effect of the present invention is to deposit high-Z metal oxides into the Mxene layered structure by atomic layer deposition technology.

Further limited, the high Z metal oxide is one of Bi ₂ O ₃ , HfO ₂ , and TaO ₂ or a combination of several of them.

To further define, Mxene is prepared by hydrofluoric acid etching, HCl and LiF etching or NaOH hydrothermal etching.

The preparation method of the above-mentioned metal-doped Mxene material is completed by the following steps:

Step 1. The Mxene material is placed in the cavity of the atomic layer deposition device;

Step 2, re-feeding the reaction precursor to deposit high-Z metal oxide in a vacuum environment, and then purging and cleaning the reaction environment with a cleaning gas;

Step 3, feeding an oxygen source to carry out deposition, and cleaning the reaction environment with cleaning gas after the deposition is completed;

Step 4: Repeat the operations of Steps 2 to 3; namely, obtain the metal-doped Mxene material that shields the effect of the total dose.

To further limit, in step 2, [(CH ₃ )C ₂ H ₅ )N] ₄ Hf, tris(diethylamine) bismuth (TDEABi), tetra(dimethylamine) hafnium, penta(dimethylamine) tantalum One or more of the reaction precursors are used as reaction precursors, in a vacuum environment of 0.10-0.20torr, the reaction temperature is 150°C-225°C, the pulse time is 0.15s, and the reaction time is 6s.

Further limited, in step 3, high-purity water, deionized water or ozone is used as the oxygen source, in a vacuum environment of 0.10-0.20torr, the reaction temperature is 150°C-225°C, the pulse time is 0.015S～0.02s, and the reaction time is 0.015s～0.02s. for 6S.

The purpose of introducing the cleaning gas is to clean the pipeline on the one hand, and to clean the remaining precursors and by-products produced by the reaction during the reaction on the other hand. The cleaning gas refers to a gas that does not react with reactants or products. To further define, the cleaning gas described in steps 2 and 3 is high-purity nitrogen (99.999%).

To be further limited, the operations of steps 2 to 3 are repeated 49 to 499 times.

The composite coating material for shielding the effect of the total dose in the present invention is to uniformly disperse the above-mentioned nano-rare earth oxide composite powder or the metal-doped Mxene material prepared by the above-mentioned method into an organic resin matrix. Specifically, follow the steps below:

Step 1. Mix the metal-doped Mxene material that shields the effect of the total dose and the organic resin matrix, and stir on a Sankun grinder for 5min-10min;

Step 2. After the grinding, the slurry obtained by mixing is applied on the surface of the object to be protected (such as SOI device) by scraping, spin coating or spraying.

Step 3, then place in a vacuum drying oven, and dry at 30°C to 100°C for 6 to 8 hours; that is, the composite material is obtained.

To be further defined, the metal-doped Mxene material accounts for 10% to 50% of the mass of the composite coating material for shielding the effect of the total dose.

Further limited, the organic resin matrix is selected from epoxy resin, cyanate ester, polyurethane, and high density polyethylene.

Further limited, the coating thickness may be 100um˜1cm.

The invention adopts the atomic layer deposition (ALD) method to deposit high atomic number metal materials into the layered structure of Mxene, and simplifies the preparation process of the coating material according to the shielding mechanism of the total dose effect by utilizing the layered structure of the Mxene material itself. , while obtaining more effective shielding materials;

The Mxene material of the present invention is the composition of Ti ₃ C ₂ T _x obtained by etching Al with the MAX ceramic phase Ti ₃ AlC ₂ . Due to different etching processes, T _x can be different end groups, such as -F, -OH, etc., It is also possible to add other groups through surface treatment and modification to change the wettability of the Mxene material and the resin matrix, so that it can be more uniformly dispersed in the resin matrix.

The present invention can effectively shield the effect of the total dose and better shield the effect of the Mxene when it interacts with the material or substance through the combination of the high-Z metal material and the low-Z Mxene material, and the excellent layered structure of the Mxene material itself. cause radiation.

In the present invention, the high-Z metal ALD is deposited between the stacks by utilizing the stack structure of the Mxene material itself to form a stack material with alternating high and low Z layers. It simplifies the preparation process of traditional materials in structure;

The Mxene material of the present invention not only has its own excellent structural properties, but also contains Ti element in its chemical composition. Ti is a low-Z metal with good shielding performance of the total dose effect. The introduction of this material satisfies the requirements of the shielding material. From the requirements of structure and chemical elements;

Through the introduction of atomic layer deposition technology in the present invention, high-Z metal can be fully deposited between Mxene stacks. Compared with other methods such as liquid phase methods, this method does not require subsequent washing and drying, and can still uniformly deposit high-Z metal materials. grown between stacks of Mxene materials.

The material of the present invention can be used for radiation protection suits in daily life, medical aspects, and required and protective fields in nuclear reactions.

Description of drawings

Fig. 1 is the SEM photograph of the HfO ₂ /Mxene composite coating obtained by the method of Example 1;

Fig. 2 is the EDS photograph of the HfO ₂ /Mxene composite coating obtained by the method of Example 1;

FIG. 3 is a physical diagram of the HfO ₂ /Mxene composite coating obtained by the method of Example 1. FIG.

Detailed ways

The following examples describe embodiments of the present invention. If the specific conditions are not indicated in the examples, the conventional conditions or the conditions suggested by the manufacturer are used. If the reagents or instruments do not indicate the manufacturer, they are all conventional products that can be purchased from the market.

The following embodiments provide a metal-doped Mxene composite coating material. After etching the MAX phase ceramic matrix, a layered Ti ₃ C ₂ T _x material is obtained, and then the high-Z metal is deposited by atomic layer deposition technology. The composite material is obtained by depositing it into the Mxene layered structure, and then the composite material is mixed with the resin matrix to obtain a total dose effect protective coating with a certain mass fraction.

In the present invention, the etching method of the MAX phase can be carried out by one of the following methods:

1. Hydrofluoric acid etching:

Select a HF solution with a concentration of 10% to 40%, measure 30-50ml of hydrofluoric acid and place it in a clean polytetrafluoroethylene beaker, place the beaker on a magnetic stirring device and set the rotation speed to 200-700rpm, and then put it in a hydrogen Slowly add 3-5g Ti ₃ AlC ₂ (MAX phase) to the hydrofluoric acid. This process needs to be carried out slowly to prevent the initial reaction from being too fast and exothermic to cause the mixture to splash out. The addition process takes about 0.3-0.5h. The Mxene material can be prepared by reacting at room temperature for 18-24 h. The prepared Mxene was washed by centrifugation, and dried under vacuum at 60°C to obtain Mxene powder.

2. HCl+LiF etching:

Add 2g LiF to 20ml concentrated HCl, the concentration of hydrochloric acid can be 9mol/L～12mol/L, stir with a magnetic stirrer for 3-5min until dissolved, then slowly add 2g Ti ₃ AlC ₂ (MAX phase) to the above mixed solution, Stir at 25～50 ℃ for 24～36h. The resulting mixture was divided into two centrifuge tubes, washed with deionized water, centrifuged at 3000-5000 rpm for 3-5 min, and the centrifugal washing was repeated 6-7 times until the pH of the supernatant was 7. The precipitate was dried in a vacuum drying oven at 80-120° C. overnight to remove excess water, and Mxene powder was obtained after drying.

3. NaOH hydrothermal etching:

Take 1g of Ti ₃ AlC ₂ (MAX phase) in a 50ml reactor liner, then add 30ml of NaOH solution with a concentration of 27.5mol/L into it, and perform a hydrothermal reaction at 250～270℃ for 12～24h, after cooling to room temperature , centrifugally wash the precipitate in the reaction kettle until the pH of the supernatant is 6-7, then collect the precipitate and dry it in a vacuum drying oven to obtain Mxene powder.

Example 1:

The Mxene etching was completed by method 1 (hydrofluoric acid etching), and then the Mxene was transferred into the cavity of the atomic layer deposition apparatus, and the high Z metal oxide HfO ₂ was coated and modified on it. The reaction temperature should be controlled at 200°C, the pressure during the reaction should be controlled at 0.155torr, the high Z metal oxide source should be [(CH ₃ )C ₂ H ₅ )N] ₄ Hf, the pulse time should be 0.15s, and the reaction time should be 6s , pulse, after the reaction is completed, use high-purity nitrogen (99.999%) to purge the residual reactants and by-products in the pipeline and chamber for 60s. Then high-purity water was used as the oxygen source, the pulse time was 0.015s, and the reaction time was 6s. After the pulse reaction was completed, high-purity nitrogen (99.999%) was used to purge the residual reactants and by-products in the pipeline and chamber for 60s. The high-Z metal oxide source and the oxygen source are alternately fed into the reaction chamber as a cycle. One cycle takes 2 minutes, and the modified Mxene powder material can be obtained after 50 cycles.

The modified Mxene powder material is mixed with epoxy resin, wherein the mass fraction of powder is 50% and the mass fraction of epoxy resin is 50%. Pour the mixed powder and resin into a Sankun grinder, grind and stir for 10 minutes. The uniformly stirred slurry is coated on the polyimide film by means of blade coating. The film material was obtained by drying at 30°C for 6 h in a vacuum drying oven, see Figures 1 and 2.

The physical diagram of the HfO ₂ /Mxene composite coating obtained by the method of this example is shown in FIG. 3 , and it can be seen from FIG. 3 that the composite coating has flexibility.

Example 2: Method 2 (HCl+LiF etching) was used to complete the Mxene etching, and then the Mxene was transferred into the cavity of the atomic layer deposition device, and the high Z metal oxide HfO ₂ was coated and modified. The reaction temperature should be controlled at 150°C, the pressure during the reaction should be controlled at 0.155torr, the high-Z metal oxide source should be [(CH ₃ )C ₂ H ₅ )N] ₄ Hf, the pulse time should be 0.15s, and the reaction time should be 6s , pulse, after the reaction is completed, use high-purity nitrogen (99.999%) to purge the residual reactants and by-products in the pipeline and chamber for 60s. Then high-purity water was used as the oxygen source, the pulse time was 0.015s, and the reaction time was 6s. After the pulse reaction was completed, high-purity nitrogen (99.999%) was used to purge the residual reactants and by-products in the pipeline and chamber for 60s. The high-Z metal oxide source and the oxygen source are alternately fed into the reaction chamber as a cycle. One cycle takes 2 minutes, and the modified Mxene powder material can be obtained after 150 cycles.

The modified Mxene powder material is mixed with epoxy resin, wherein the mass fraction of powder is 50% and the mass fraction of epoxy resin is 50%. Pour the mixed powder and resin into a Sankun grinder, grind and stir for 10 minutes. The uniformly stirred slurry is coated on the polyimide film by means of blade coating. The film material can be obtained by drying at 30°C for 6h in a vacuum drying oven.

Example 3: Method 3 (NaOH hydrothermal etching) was used to complete the Mxene etching, and then the Mxene was transferred to the cavity of the atomic layer deposition device, and the high Z metal oxide HfO ₂ was coated and modified. The reaction temperature should be controlled at 180°C, the pressure during the reaction should be controlled at 0.155torr, the high Z metal oxide source should be [(CH ₃ )C ₂ H ₅ )N] ₄ Hf, the pulse time should be 0.15s, and the reaction time should be 6s , pulse, after the reaction is completed, use high-purity nitrogen (99.999%) to purge the residual reactants and by-products in the pipeline and chamber for 60s. Then high-purity water was used as the oxygen source, the pulse time was 0.015s, and the reaction time was 6s. After the pulse reaction was completed, high-purity nitrogen (99.999%) was used to purge the residual reactants and by-products in the pipeline and chamber for 60s. The high-Z metal oxide source and the oxygen source are alternately fed into the reaction chamber as a cycle. One cycle takes 2 minutes, and the modified Mxene powder material can be obtained after 300 cycles.

The modified Mxene powder material is mixed with epoxy resin, wherein the mass fraction of powder is 50% and the mass fraction of epoxy resin is 50%. Pour the mixed powder and resin into a Sankun grinder, grind and stir for 10 minutes. The uniformly stirred slurry is coated on the polyimide film by means of blade coating. The film material can be obtained by drying in a vacuum drying oven at 30°C for 6 hours.

For the coatings prepared in the above examples, the following tests were carried out to measure the radiation protection performance. The above coatings were used to conduct irradiation tests on the total dose effect. The composite coating material was irradiated with a ²⁴¹ Am (60Kev) source, and the irradiation time was 10s. According to the test data (Table 1), it can be known that the linear attenuation coefficient of the coating under ray irradiation can be up to 1.83μ/cm ^-1 , which has good shielding performance.

Table 1

It can be seen from Table 1 that it has better shielding performance.

Example 4: The Mxene powder material modified in Example 3 was mixed with epoxy resin, wherein the powder mass fraction was 50% and the epoxy resin mass fraction was 50%. Pour the mixed powder and resin into a Sankun grinder, grind and stir for 10 minutes. The uniformly stirred slurry was applied on the SOI device by means of blade coating. The SOI device resistant to total dose irradiation can be obtained by drying at 30 °C for 6 h in a vacuum drying oven.

Claims (8)

1. an SOI device of resistance to total dose irradiation, is characterized in that described SOI device coating comprises metal-doped Mxene material, and described metal-doped Mxene material is to deposit high Z metal oxide by atomic layer deposition technology into the Mxene layered structure; Wherein, the high-Z metal oxide is one of Bi ₂ O ₃ , HfO ₂ , TaO ₂ or a combination of several thereof; The preparation method of the metal-doped Mxene material is completed through the following steps: Step 1. The Mxene material is placed in the cavity of the atomic layer deposition device; Step 2, re-feeding the reaction precursor to deposit high-Z metal oxide in a vacuum environment, and then purging and cleaning the reaction environment with a cleaning gas; Step 3, feeding an oxygen source to carry out deposition, and cleaning the reaction environment with cleaning gas after the deposition is completed; Step 4: Repeat the operations from Steps 2 to 3; namely, the metal-doped Mxene material is obtained. 2. The SOI device according to claim 1, wherein Mxene is prepared by hydrofluoric acid etching, HCl and LiF etching or NaOH hydrothermal etching. 3 . The SOI device according to claim 1 , wherein in step 2, [(CH ₃ )(C ₂ H ₅ )N] ₄ Hf, tris(diethylamine)bismuth (TDEABi), tetrakis(diethylamine) bismuth (TDEABi), One or more of methylamine) hafnium and penta(dimethylamine) tantalum are used as reaction precursors. In a vacuum environment of 0.10-0.20torr, the reaction temperature is 150℃-225℃, the pulse time is 0.15s, and the reaction time is 6S; in step 3, high-purity water, deionized water or ozone is used as the oxygen source, in a vacuum environment of 0.10-0.20torr, the reaction temperature is 150℃-225℃, the pulse time is 0.015S～0.02s, and the reaction time is 6S; the cleaning gas described in steps two and three is high-purity nitrogen (99.999%). 4 . The SOI device according to claim 1 , wherein the operations of steps 2 to 3 are repeated 49 to 499 times. 5 . 5. The composite coating material for SOI devices that resists total dose irradiation, wherein the composite coating material uniformly disperses the metal-doped Mxene material prepared by the method of any one of claims 1-4 into an organic resin matrix middle. 6 . The composite coating material according to claim 5 , wherein the metal-doped Mxene material accounts for 10% to 50% of the mass of the composite coating material. 7 . 7 . The composite coating material according to claim 5 , wherein the organic resin matrix is selected from epoxy resin, cyanate ester, polyurethane, and high-density polyethylene. 8 . 8. the method for preparing SOI device with the described composite coating material of claim 5, 6 or 7, is characterized in that the preparation method of described SOI device is carried out according to the following steps: Step 1. Mix the metal-doped Mxene material with the organic resin matrix, and stir on a Sankun grinder for 5min-10min; Step 2. After the grinding, the slurry obtained by mixing is applied on the surface of the SOI device by scraping, spin coating or spraying; Step 3, then place in a vacuum drying oven, and dry at 30°C to 100°C for 6 to 8 hours; namely, an SOI device resistant to total dose irradiation is obtained.

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