Method and device for filling neutron conversion material in semiconductor microstructure trenches

Abstract

The present invention provides a method and device for filling neutron conversion materials in semiconductor microstructure grooves, belonging to the field of semiconductor technology. The present invention adopts a cold state technical route of wet centrifugation, and uses centrifugation to fill lithium fluoride particles in a colloid into a microstructure without heating the semiconductor. Under the action of centrifugal force, the lithium fluoride in the microstructure is filled densely and completely, meeting the process requirements of the MSND chip. In the present invention, a semiconductor (3) containing a microstructure groove is fixed to the surface of a semiconductor loader (1) by an electrostatic self-adhesive film (2). Since the semiconductor (3) itself has a low density and a small volume, it can avoid rolling or displacement caused by the flow of a solution; the semiconductor loader (1) is provided with a limit stopper (12), and the limit stopper (12) is installed in cooperation with a column (41) of a support frame (4), so that the semiconductor loader (1) can be fixed to avoid rotation or rolling of the semiconductor loader (1).

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and particularly to a method and device for filling neutron conversion materials in semiconductor microstructured trenches. Background Art

[0002] Neutrons are electrically neutral nucleons in the atomic nucleus and can be released through special nuclear reactions, playing an important role in nuclear technology applications, nuclear energy engineering, and scientific research. A neutron detector is a radiation detector sensitive to neutrons and is used to measure the physical parameters of neutrons. The performance of a neutron detector is closely related to the nuclear interaction between neutrons and conversion materials, and the magnitude of its effect physically gives the upper limit of the neutron detection efficiency. Among them, the microstructured neutron detector (MSND) based on semiconductor technology has the advantages of a mature industrial chain, a pure solid-state device, small size, high detection efficiency, and easy integration, and has become the focus of research on solid neutron detectors.

[0003] The outstanding feature of a microstructured semiconductor neutron detector is that microstructured trenches are formed on the semiconductor, and neutron conversion materials (usually lithium fluoride) are filled in the trenches. On the one hand, this greatly increases the filling amount of the neutron conversion materials, which is beneficial to improving the interaction probability of neutrons and the generation probability of secondary charged particles. On the other hand, the trenches are generally a dozen micrometers, and the secondary charged particles can easily penetrate the conversion materials to reach the silicon detector, greatly reducing the self-absorption effect of the conversion materials on charged particles and improving the detection efficiency of charged particles. The above two aspects technically ensure the excellent detection performance of the microstructured neutron detector. There are two core processes in the research and development of this type of detector. One is to make trenches that meet the requirements by etching, ensuring that the width, depth, and surface state meet the design requirements. The other is to fill the neutron conversion materials into the trenches in a suitable way to achieve a good filling effect.

[0004] Conventional microstructured lithium fluoride filling techniques include magnetron sputtering, chemical vapor deposition, mechanical pressing, ultrasonic oscillation, low-pressure condensation, melt immersion, etc. However, practice has proven that these methods all have great limitations and cannot well meet the filling requirements of lithium fluoride under semiconductor microstructured conditions. Mechanical pressing and ultrasonic oscillation involve using external forces to press materials into microstructured grooves. The main problems are as follows: 1) uneven filling; 2) the characteristic size of the microstructures is in the order of ten-odd micrometers, making fine operation difficult; 3) the silicon wafers after microfabrication are very fragile, and the action of external forces can easily damage the microstructures. Magnetron sputtering and chemical vapor deposition both decompose the lithium fluoride target first and then deposit it on the material surface. The main problems of these two methods are: 1) suitable for surface treatment, lithium fluoride accumulates on the surface of the silicon wafer and cannot be filled into the internal microstructured grooves; 2) after the decomposition of lithium fluoride, it has strong corrosiveness, causing serious pollution and corrosion to the equipment (such as vacuum chambers, pipelines, and valves, etc.); 3) low efficiency and low material utilization rate. Low-pressure condensation and melt immersion require heating lithium fluoride to the molten state first. For low-pressure condensation, the silicon wafer is placed above the lithium fluoride vapor, and lithium fluoride is collected by condensation. For melt immersion, the silicon wafer is directly immersed in liquid lithium fluoride. The problems of these two methods are: 1) high-temperature operation, the melting point of lithium fluoride is 870 °C, and the high-temperature environment can easily cause irreversible damage to the silicon wafer, affecting the electrical properties of the silicon wafer; 2) the structure of the condensed lithium fluoride is fluffy and accumulates on the surface of the silicon wafer, and there is basically no lithium fluoride inside the grooves, and actually there is no filling effect; 3) due to the non-wetting of the lithium fluoride melt and the silicon wafer, the microstructured grooves inserted into the lithium fluoride melt cannot be immersed into the internal grooves, and in actual operation, it also accumulates on the surface of the grooves, and there is no filling effect inside the grooves; 4) due to the rapid cooling and heating operation process, the thermal stress causes the microstructures of the silicon wafer to collapse, and the process cannot be implemented. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a method and device for filling neutron conversion materials in semiconductor microstructured grooves. The method and device provided by the present invention can achieve dense and complete filling of lithium fluoride, the neutron conversion material in the microstructures, without damaging the semiconductor microstructures, meeting the process requirements of MSND chips.

[0006] To achieve the above-mentioned invention purposes, the present invention provides the following technical solutions:

[0007] The present invention provides a method for filling neutron conversion materials in semiconductor microstructured grooves, including the following steps:

[0008] Fix a semiconductor containing microstructured grooves inside a centrifuge container, add a LiF colloidal solution into the centrifuge container, and perform centrifugation to obtain a semiconductor with neutron conversion materials filled in the microstructured grooves.

[0009] Preferably, the semiconductor is a silicon-based semiconductor; the width of the microstructural trench is 15 - 30 μm.

[0010] Preferably, the method for preparing the LiF colloidal solution includes the following steps:

[0011] Ultrasonically mix LiF nano-powder with an alcohol solvent to obtain a LiF colloidal solution;

[0012] The particle size of the LiF nano-powder is 200 - 400 nm.

[0013] Preferably, the mass concentration of the LiF colloidal solution is 2‰ - 1%.

[0014] Preferably, the centrifugation is horizontal centrifugation, the centrifugation rate is 3000 - 4000 rpm, and the time is 8 - 15 min.

[0015] Preferably, after centrifugation, it further includes:

[0016] Transfer the semiconductor with a neutron conversion material filled in the microstructural trench to an alcohol solvent, and perform ultrasonic treatment to remove the excess LiF on the surface of the semiconductor.

[0017] Preferably, after centrifugation, it further includes:

[0018] Repeat the operation of mixing the semiconductor with the LiF colloidal solution - centrifugation for the semiconductor with a neutron conversion material filled in the microstructural trench.

[0019] The present invention provides a device for filling a neutron conversion material in a semiconductor microstructural trench, including a semiconductor loader 1, on the surface of the semiconductor loader 1 there is a loading groove 11, and on the surface of the loading groove 11 there is an electrostatic self-adhesive film 2; at the edge of the semiconductor loader 1 there is a limit bayonet 12;

[0020] A support frame 4 for supporting the semiconductor loader 1; the support frame 4 includes a bottom tray 42 and columns 41 vertically arranged at the edge of the bottom tray 42, and the width of the columns 41 matches the size of the limit buckle of the semiconductor loader 1.

[0021] Preferably, the material of the electrostatic self-adhesive film 2 is polyethylene, and the thickness is 0.1 mm.

[0022] Preferably, the bottom tray 42 is made of a matte material.

[0023] The present invention provides a method for filling neutron conversion materials in the microstructural trenches of a semiconductor, comprising the following steps: fixing the semiconductor with microstructural trenches inside a centrifugal container, adding a LiF colloidal solution into the centrifugal container, and performing centrifugation to obtain a semiconductor with neutron conversion materials filled in the microstructural trenches. The present invention adopts a cold-state technical route of wet centrifugation. Without heating the semiconductor, the lithium fluoride particles in the colloid are filled into the microstructure by centrifugation. Under the action of centrifugal force, the lithium fluoride in the microstructure is filled densely and completely, meeting the process requirements of the MSND chip and solving the problem that other methods are not applicable.

[0024] Furthermore, the present invention can use a high-power optical microscope to check whether there is deposition and aggregation on the semiconductor surface. If the deposition and aggregation are serious, the surface-deposited lithium fluoride particles can be removed by ultrasonic oscillation. In addition, multiple rounds of centrifugal filling can be carried out according to the calculation of the total amount of lithium fluoride to be filled and the mass of lithium fluoride filled each time.

[0025] The present invention provides an apparatus for filling neutron conversion materials in the microstructural trenches of a semiconductor, comprising a semiconductor loader 1 and a support frame 4 for supporting the semiconductor loader 1. In the present invention, the semiconductor with microstructural trenches can be fixed on the surface of the semiconductor loader 1 through an electrostatic self-adhesive film 2. Since the semiconductor matrix itself has a low density and a small volume, it can effectively prevent the semiconductor from tumbling or displacing due to the flow of the solution. The semiconductor loader 1 is provided with a limit bayonet 12, and by cooperating with the column 41 of the support frame 4 through the limit bayonet 12, the semiconductor loader 1 can be fixed to prevent the semiconductor loader 1 from rotating or tumbling, and the support frame 4 can facilitate the installation and disassembly of the semiconductor loader 1. Further, the tray 42 of the support frame 4 is made of a frosted material, which can effectively prevent the semiconductor loader 1 from adhering to the tray 42 or the bottom of the centrifugal container due to liquid tension. Description of the Drawings

[0026] Figure 1 It is an assembly schematic diagram of the semiconductor loader 1 and the electrostatic self-adhesive film 2;

[0027] Figure 2 It is an assembly schematic diagram of the semiconductor 3, the semiconductor loader 1 and the electrostatic self-adhesive film 2;

[0028] Figure 3 It is a schematic diagram of the structure of the support frame 4;

[0029] Figure 4 It is an assembly schematic diagram of the semiconductor loader 1 and the support frame 4;

[0030] Figure 5 It is a schematic diagram of the overall structure of the assembled flat-bottom centrifugal tube;

[0031] Figure 6 Schematic cross - sectional view of a completed flat - bottom centrifuge tube for assembly;

[0032] Figure 7 SEM image of a silicon wafer filled in Example 1;

[0033] Figure 8 SEM image of a silicon wafer filled in Example 2;

[0034] Figure 9 SEM image of a silicon wafer filled in Example 3. Detailed implementation mode

[0035] The present invention provides a method for filling neutron conversion materials in semiconductor micro - structure trenches, comprising the following steps:

[0036] Fix a semiconductor with micro - structure trenches inside a centrifuge container, add a LiF colloidal solution into the centrifuge container, and perform centrifugation to obtain a semiconductor with neutron conversion materials filled in the micro - structure trenches.

[0037] In the present invention, the semiconductor is preferably a silicon - based semiconductor, and more preferably a silicon wafer. In the present invention, the width of the micro - structure trenches is preferably 15 - 30 μm; as a specific embodiment of the present invention, the width of the micro - structure trenches is 15 μm, 20 μm, 25 μm or 30 μm.

[0038] In the present invention, the centrifuge container is preferably a centrifuge tube, and more preferably a flat - bottom centrifuge tube.

[0039] In the present invention, the mass concentration of the LiF colloidal solution is preferably 2‰ - 1%, and more preferably 0.4 - 0.8%. As a specific implementation mode of the present invention, the mass concentration of the LiF colloidal solution is 0.2%, 0.4%, 0.5%, 0.6%, 0.8%, 1%.

[0040] In the present invention, the preparation method of the LiF colloidal solution preferably comprises the following steps:

[0041] Ultrasonically mix LiF nano - powder with an alcohol solvent to obtain a LiF colloidal solution.

[0042] In the present invention, the particle size of the LiF nano - powder is preferably 200 - 400 nm. In the present invention, the alcohol solvent is preferably anhydrous ethanol and / or isopropanol.

[0043] In the present invention, the power of the ultrasonic wave is preferably 500 - 1000 W, and more preferably 700 - 800 W; the time is preferably 8 - 30 min, and more preferably 8 - 15 min.

[0044] After the ultrasonic mixing, the present invention preferably transfers the obtained LiF colloidal solution to a rotor stirrer for continuous stirring for standby.

[0045] In the present invention, the centrifugation is preferably horizontal centrifugation. In the present invention, the centrifugation is preferably high-speed centrifugation; the rate of the centrifugation is preferably 3000-4000 rpm, the time is preferably 8-15 min, and more preferably 10 min. The present invention preferably uses a horizontal centrifuge for the centrifugation, and the horizontal centrifuge is equipped with a horizontal rotor. As a specific embodiment of the present invention, the model of the centrifuge is TDL-5A. In the present invention, the semiconductor containing the microstructural grooves is preferably fixed at the bottom of the centrifugation container. When centrifuging, the centrifugation container is placed horizontally, and the bottom of the centrifugation container is away from the center of the centrifuge. Under the action of the centrifugal force, lithium fluoride in the microstructure fills in the microstructural grooves.

[0046] After the centrifugation, the present invention preferably uses a high-power optical microscope to check whether deposition and aggregation occur on the surface of the semiconductor. If the deposition and aggregation are serious, it further includes: transferring the semiconductor with the neutron conversion material filled in the microstructural grooves to an alcohol solvent, performing ultrasonic treatment to remove the excess LiF on the surface of the semiconductor.

[0047] In the present invention, the alcohol solvent is preferably anhydrous ethanol. In the present invention, the power of the ultrasonic treatment is preferably 500-1000 W, more preferably 760 W, the frequency is preferably 40 kHz, and the time is preferably 8-10 s. The present invention removes the deposited lithium fluoride particles on the surface by short-time ultrasonic oscillation.

[0048] After the centrifugation, the present invention preferably calculates according to the total amount of lithium fluoride to be filled and the mass of lithium fluoride filled each time, and performs multiple rounds of centrifugation filling. In the present invention, the multiple rounds of centrifugation filling specifically include: repeating the operations of mixing with the LiF colloidal solution - centrifugation for the semiconductor with the neutron conversion material filled in the microstructural grooves. The present invention has no special requirements for the number of repetitions, and corresponding calculations can be made according to the total amount of lithium fluoride to be filled and the mass of lithium fluoride filled each time. As a specific implementation manner of the present invention, the number of repetitions is 1 time, 2 times or 3 times.

[0049] In the present invention, the specific processes of the preparation of the LiF colloidal solution and the centrifugation are the same as above and will not be elaborated here.

[0050] After the centrifugation, the present invention preferably dries the obtained semiconductor with the neutron conversion material filled in the microstructural grooves. In the present invention, the drying method is preferably drying by baking.

[0051] The present invention provides a device for filling neutron conversion materials in trenches of a semiconductor microstructure, including a semiconductor loader 1. A loading groove 11 is provided on the surface of the semiconductor loader 1, and an electrostatic self-adhesive film 2 is contained on the surface of the loading groove 11; a limiting bayonet 12 is provided at the edge of the semiconductor loader 1;

[0052] A support frame 4 for supporting the semiconductor loader 1; the support frame 4 includes a bottom tray 42 and columns 41 vertically provided at the edge of the bottom tray 42, and the width of the columns 41 matches the size of the limiting buckle of the semiconductor loader 1.

[0053] In the present invention, the loading groove 11 on the surface of the semiconductor loader 1 is preferably a hollow structure, and the electrostatic self-adhesive film 2 is adhered to the bottom surface of the semiconductor loader 1, so that the surface of the loading groove 11 exposes the electrostatic self-adhesive film 2.

[0054] In the present invention, preferably one or more loading grooves 11 are provided on the surface of the semiconductor loader 1, and the number of the loading grooves 11 is preferably 1 to 4. In the present invention, the size of a single loading groove 11 is preferably 1×1 (cm). In the present invention, the shape of the semiconductor loader 1 is preferably the same as the cross-sectional shape of the centrifuge container, and the size is slightly smaller than the cross-sectional size of the centrifuge container 5. The present invention does not make special requirements for the material of the semiconductor loader 1.

[0055] In the present invention, the material of the electrostatic self-adhesive film 2 is preferably polyethylene, and the thickness is preferably 0.1 to 0.2 mm, more preferably 0.1 mm.

[0056] In the present invention, the size of the bottom tray 42 is preferably the same as that of the semiconductor loader 1. In the present invention, the bottom tray 42 is preferably a frosted material. As a specific embodiment of the present invention, the material of the bottom tray 42 is aluminum alloy, and the frosted roughness Ra is preferably 1.5 to 3 µm.

[0057] In the present invention, the number of the columns 41 is preferably 2 to 4; the height of the columns 41 is preferably the same as the height of the centrifuge container.

[0058] In the present invention, a fixing structure 43 is preferably further provided above the columns 41 for connecting and fixing a plurality of columns 41, and at the same time facilitating grasping for installation and unloading.

[0059] The device for filling neutron conversion material in the semiconductor microstructure trench provided by the present invention preferably further includes a centrifuge container 5, and the centrifuge container 5 is preferably a flat-bottom centrifuge tube. In the present invention, when filling the neutron conversion material in the semiconductor microstructure trench, the semiconductor 3 is bonded to the surface of the loading groove 11 of the semiconductor loader 1 through the electrostatic self-adhesive film 2, and the semiconductor loader 1 loaded with the semiconductor 3 is engaged with the column 41 through the limit bayonet 12 and fixed on the surface of the bottom tray 42 of the support frame 4. The assembled semiconductor loader 1 and the support frame 4 are placed in the centrifuge container 5 for centrifugation.

[0060] As a specific embodiment of the present invention, the assembly schematic diagram of the semiconductor loader 1 and the electrostatic self-adhesive film 2 is as Figure 1 shown; the assembly schematic diagram of the semiconductor 3, the semiconductor loader 1 and the electrostatic self-adhesive film 2 is as Figure 2 shown; the structural schematic diagram of the support frame 4 is as Figure 3 shown; the assembly schematic diagram of the semiconductor loader 1 and the support frame 4 is as Figure 4 shown; the overall structural schematic diagram of the assembled flat-bottom centrifuge tube is as Figure 5 shown; the sectional schematic diagram of the assembled flat-bottom centrifuge tube is as Figure 6 shown. Figures 1 - 6 In the figure, 1 is the semiconductor loader, 2 is the electrostatic self-adhesive film, 3 is the semiconductor, 4 is the support frame, 5 is the centrifuge container, 11 is the loading groove, 12 is the limit bayonet, 41 is the column, 42 is the bottom tray, and 43 is the fixing structure.

[0061] The following describes in detail the method and device for filling neutron conversion material in the semiconductor microstructure trench provided by the present invention in conjunction with embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0062] Embodiment 1

[0063] Taking a silicon wafer as the semiconductor material, the semiconductor loader correspondingly is a silicon wafer loader.

[0064] The loading method of the silicon wafer is as follows: Adhere the electrostatic self-adhesive film 2 to the bottom surface of the semiconductor loader 1, confirm that there are no air bubbles remaining at the bonding place, gently place the silicon wafer (semiconductor 3) in the loading groove 11, engage the obtained silicon wafer loader through the limit bayonet 12 into the column 41 around the support frame 4, and place it on the bottom tray 42 of the support frame 4. Place the obtained support frame 4 in the flat-bottom centrifuge tube (centrifuge container 5). Through the above steps, a flat-bottom centrifuge tube with the silicon wafer loaded is obtained.

[0065] The filling method of the LiF powder adopts the following steps:

[0066] 1) Preparation of LiF colloidal solution: Inject 100 parts of main material anhydrous ethanol into a clean beaker, add 0.2 parts of LiF nano powder with a particle size of 200 - 400 nm. After sealing the beaker, place it in an ultrasonic water bath and ultrasonically vibrate at 750 W for 30 min. Stop ultrasonic vibration when there is no obvious particle aggregation in the solution to obtain the LiF colloidal solution, and transfer it to a rotor stirrer for continuous stirring for standby;

[0067] 2) High-speed centrifugation: Transfer 50 g of the above LiF colloidal solution into a flat-bottom centrifuge tube. Transfer the obtained flat-bottom centrifuge tube to a centrifuge, set the centrifugation speed to 4000 rpm and the time to 10 min. After the centrifuge completes the centrifugation operation, obtain a preliminarily filled silicon wafer;

[0068] 3) Ultrasonic cleaning: Inject 10 parts of anhydrous ethanol into a clean beaker. Transfer the silicon wafer filled by centrifugation above into the anhydrous ethanol solution. Place the beaker in an ultrasonic water bath and ultrasonically vibrate for 10 s, with an ultrasonic power of 760 W and a frequency of 40 kHz to remove the LiF particles deposited on the surface of the silicon wafer;

[0069] 4) Natural drying: After the ultrasonic cleaning in the above steps is completed, take out the silicon wafer and place it in a dryer for natural drying to obtain a filled silicon wafer.

[0070] Example 2

[0071] Load the silicon wafer in the same way as in Example 1.

[0072] The filling method of LiF powder adopts the following steps:

[0073] 1) Preparation of LiF colloidal solution: Inject 100 parts of main material anhydrous ethanol into a clean beaker, add 0.5 parts of LiF nano powder with a particle size of 200 - 400 nm. After sealing the beaker, place it in an ultrasonic water bath and ultrasonically vibrate at 750 W for 30 min. Stop ultrasonic vibration when there is no obvious particle aggregation in the solution to obtain the LiF colloidal solution, and transfer it to a rotor stirrer for continuous stirring for standby;

[0074] 2) High-speed centrifugation: Transfer 50 g of the above LiF colloidal solution into a flat-bottom centrifuge tube. Transfer the obtained flat-bottom centrifuge tube to a centrifuge, set the centrifugation speed to 4000 rpm and the time to 10 min. After the centrifuge completes the centrifugation operation, obtain a preliminarily filled silicon wafer;

[0075] 3) Ultrasonic cleaning: Inject 10 parts of anhydrous ethanol into a clean beaker. Transfer the silicon wafer filled by centrifugation above into the anhydrous ethanol solution. Place the beaker in an ultrasonic water bath and ultrasonically vibrate for 10 s, with an ultrasonic power of 760 W and a frequency of 40 kHz to remove the LiF particles deposited on the surface of the silicon wafer;

[0076] 4) Natural drying: After the ultrasonic cleaning is completed in the above steps, take out the silicon wafer, place it in a dryer and dry it naturally to obtain a silicon wafer with filling completed.

[0077] Example 3

[0078] Load the silicon wafer in the same way as in Example 1.

[0079] The filling method of LiF powder adopts the following steps:

[0080] 1) Preparation of LiF colloidal solution: Inject 100 parts of main material anhydrous ethanol into a clean beaker, add 1 part of LiF nano powder with a particle size of 200 - 400 nm. After sealing the beaker, place it in an ultrasonic water bath and ultrasonically vibrate for 30 min at 750 W. Stop ultrasonic vibration when there is no obvious particle aggregation in the solution to obtain LiF colloidal solution, and transfer it to a rotor stirrer for continuous stirring for standby;

[0081] 2) High - speed centrifugation: Transfer 50 g of the above - mentioned LiF colloidal solution into a flat - bottom centrifuge tube, and transfer the obtained flat - bottom centrifuge tube to a centrifuge. Set the centrifugation speed to 4000 rpm and the time to 10 min. After the centrifuge completes the centrifugation operation, obtain a silicon wafer with preliminary filling completed;

[0082] 3) Ultrasonic cleaning: Inject 10 parts of anhydrous ethanol into a clean beaker, transfer the silicon wafer with centrifugal filling completed above into the anhydrous ethanol solution, place the beaker in an ultrasonic water bath, and ultrasonically vibrate for 10 s to remove the LiF particles deposited on the surface of the silicon wafer;

[0083] 4) Natural drying: After the ultrasonic cleaning is completed in the above steps, take out the silicon wafer, place it in a dryer and dry it naturally to obtain a silicon wafer with filling completed.

[0084] Place the silicon wafer with filling completed under an optical microscope. Fix the eyepiece magnification at 10X and observe the deposition on the surface of the silicon wafer at 10X, 20X, and 50X respectively. Further, split the silicon wafer along the vertical direction of the etching groove by the cleavage method, and use a scanning electron microscope (SEM) to observe the side profile of the etching groove of the silicon wafer to evaluate key parameters such as the filling amount, filling uniformity, and filling density of LiF. The SEM images of the silicon wafers with filling completed in Example 1 are as Figure 7 shown, the SEM images of the silicon wafers with filling completed in Example 2 are as Figure 8 shown, and the SEM images of the silicon wafers with filling completed in Example 3 are as Figure 9 shown.

[0085] The mass concentration of the LiF colloidal solution in Example 1 is two - thousandths. After observing the side profile of the silicon wafer by SEM, the LiF is filled tightly, the filling effect is good, the filling amount is about 50%, and the filling uniformity is relatively high.

[0086] The mass density of the LiF colloidal solution in Example 2 is five per thousand. By observing the side profile of the silicon wafer through SEM, the LiF is tightly filled, the filling effect is good, the filling amount is about 20%, and the filling uniformity is good.

[0087] The mass density of the LiF colloidal solution in Example 3 is one percent. By observing the side profile of the silicon wafer through SEM, the filling effect is poor, the filling amount is about 2%, and the filling uniformity is average.

[0088] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A device for filling neutron conversion material in a semiconductor microstructure groove, characterized in that: It comprises a semiconductor loader (1), wherein a loading slot (11) is provided on the surface of the semiconductor loader (1), and the surface of the loading slot (11) contains an electrostatic self-adhesive film (2); and a limit stopper (12) is provided on the edge of the semiconductor loader (1); A support frame (4) supporting the semiconductor loader (1); the support frame (4) comprises a bottom tray (42) and a column (41) vertically arranged at the edge of the bottom tray (42), the width of the column (41) being consistent with the size of the limiting buckle of the semiconductor loader (1); The bottom tray (42) is made of frosted material.

2. The device according to claim 1, characterized in that The electrostatic self-adhesive film (2) is made of polyethylene and has a thickness of 0.1-0.2 mm.

3. A method for filling a neutron conversion material in a semiconductor microstructure groove based on the device according to claim 1 or 2, characterized in that: The following steps are involved: The semiconductor containing the microstructure groove is bonded to the surface of the loading slot (11) of the semiconductor loader (1) through an electrostatic self-adhesive film (2); the semiconductor loader (1) loaded with the semiconductor is engaged with the column (41) through a limit stopper (12) and fixed to the surface of the bottom tray (42) of the support frame (4); The assembled semiconductor loader (1) and the support frame (4) are placed in a centrifugal container, and a LiF colloidal solution is added into the centrifugal container, and centrifugation is performed to obtain a semiconductor in which the microstructure grooves are filled with neutron conversion materials.

4. The method according to claim 3, characterized in that The semiconductor is a silicon-based semiconductor; the width of the microstructure groove is 15-30 μm.

5. The method according to claim 3, characterized in that: The preparation method of the LiF colloidal solution comprises the following steps: Ultrasonic mixing of LiF nanopowder and alcohol solvent to obtain LiF colloidal solution; The particle size of the LiF nanopowder is 200-400 nm.

6. The method according to claim 3 or 5, characterized in that: The mass concentration of the LiF colloidal solution is 2‰~1%.

7. The method according to claim 3, characterized in that The centrifugation is horizontal centrifugation, the speed of the centrifugation is 3000-4000 rpm, and the time is 8-15 min.

8. The method according to claim 3, characterized in that The centrifugation also includes: The semiconductor filled with neutron conversion material in the microstructure grooves is transferred into an alcohol solvent and ultrasonicated to remove excess LiF on the semiconductor surface.

9. The method according to claim 3, characterized in that: The centrifugation also includes: The semiconductor filled with the neutron conversion material in the microstructure grooves is repeatedly subjected to the operation of mixing with the LiF colloidal solution and centrifuging.

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