Nanometer ion probe sample freezing table

Abstract

The invention relates to the field of nano ion probes, and discloses a nano ion probe frozen sample table, which comprises: a frozen sample assembly, which comprises a frozen sample support and a frozen sample rack, and the frozen sample rack is installed on one side of the frozen sample support; the normal-temperature sample assembly comprises a normal-temperature sample support and a normal-temperature sample rack, and the normal-temperature sample rack is mounted on one side of the normal-temperature sample support; the two sides of one face of the base table are connected with the frozen sample support and the normal-temperature sample support respectively, the other face of the base table is connected with the sample table, the base table is located in the ion sputtering cavity, a flange plate is connected to one side of the ion sputtering cavity, and a refrigeration assembly used for cooling the frozen sample assembly is installed in the flange plate. Under the action of the refrigeration assembly, low temperature is efficiently transmitted to the frozen sample holder, so that a sample is frozen to a solid state. Therefore, high-precision in-situ analysis of the liquid inclusion and the biomedical slice sample can be realized.

Description

Technical Field

[0001] The invention relates to the field of nano-ion probes, in particular to a nano-ion probe freezing sample stand. Background Art

[0002] Ion probe microanalysis has the significant advantages of high spatial resolution, high analytical accuracy, high sensitivity and low analytical background. As the ion probe technology with the highest spatial resolution, nano-ion probe has been widely used in comparative planetary science, earth science, materials science and biomedicine. However, limited by the analytical mechanism of secondary ion probe, the current nano-ion probe technology can only analyze solid samples and cannot meet the needs of in-situ analysis of non-solid samples.

[0003] In practical research, there is an increasing demand for the analysis of non-solid samples, such as fluid inclusions in oil and mineral deposits and in biomedical research. The in-situ analysis of these non-solid samples is of great significance for studying the original state, composition and distribution characteristics of the samples. However, traditional nano-ion probes cannot meet the low-temperature and high-precision analysis requirements of these special samples due to the lack of effective freezing and insulation design. Therefore, the development of a nano-ion probe device that can achieve low-temperature freezing of non-solid samples and adapt to high-voltage insulation requirements has become the key to technological development. Summary of the invention

[0004] In view of the deficiencies of the prior art, the present invention provides a nano-ion probe freezing sample stage, which solves the problem in the prior art that the current nano-ion probe technology can only analyze solid samples but cannot meet the requirements of in-situ analysis of non-solid samples.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: a nano-ion probe freezing sample stage, comprising: A frozen sample assembly, comprising a frozen sample tray and a frozen sample rack, wherein the frozen sample rack is mounted on one side of the frozen sample tray; A room temperature sample assembly, comprising a room temperature sample tray and a room temperature sample rack, wherein the room temperature sample rack is installed on one side of the room temperature sample tray; The base has two sides of one side connected to the frozen sample holder and the room temperature sample holder respectively, and another side connected to the sample table. The base is located in the ion sputtering chamber, and a flange is connected to one side of the ion sputtering chamber. A refrigeration component for cooling the frozen sample component is installed inside the flange.

[0006] Preferably, the refrigeration assembly includes a liquid nitrogen cold trap, a thermally conductive copper belt and a liquid nitrogen Dewar, the liquid nitrogen cold trap is installed in a flange, one end of the thermally conductive copper belt is connected to a thermally conductive block, and the other end is connected to an aluminum nitride ceramic block, the thermally conductive block is connected to the liquid nitrogen cold trap, the aluminum nitride ceramic block is connected to a frozen sample holder, and the liquid nitrogen Dewar is connected to the flange.

[0007] Preferably, the frozen sample tray and the frozen sample rack are both made of copper.

[0008] Preferably, the base is made of zirconia ceramic material.

[0009] Preferably, a high-voltage bridge wire is provided inside the sample stage, and both ends of the high-voltage bridge wire penetrate through the base and are respectively connected to the frozen sample holder and the room-temperature sample holder.

[0010] Preferably, a wire is installed on the outer wall of the ion sputtering chamber, and the wire is connected to the high-voltage bridge wire.

[0011] Preferably, a motor is also installed on the outer wall of the ion sputtering chamber, and the motor is connected to the sample stage through a transmission rod.

[0012] Preferably, the middle portion of the flange is connected to a through-chamber flange for pressurizing the ion sputtering chamber and reading the temperature of the sample in the ion sputtering chamber.

[0013] Preferably, one end of the ion sputtering chamber is connected to the primary ion source chamber plate valve, and the other end is connected to the secondary ion detection chamber plate valve.

[0014] Preferably, the sample stage is movably arranged in the ion sputtering chamber, and the primary ions enter the ion sputtering chamber from a side of the ion sputtering chamber away from the flange.

[0015] The present invention provides a nano-ion probe freezing sample stage, which has the following beneficial effects: 1. The present invention efficiently transfers low temperature to the frozen sample holder through the function of the refrigeration component, so that the sample is frozen into a solid state. Therefore, the present invention can realize high-precision in-situ analysis of liquid inclusions and biomedical slice samples, and is particularly suitable for analysis under low temperature conditions to maintain the original state of the sample.

[0016] 2. The present invention uses copper as the material of the frozen sample holder and the frozen sample rack, so that low temperature and high pressure can be efficiently conducted to ensure the temperature uniformity and stability of the frozen sample. In addition, the high thermal conductivity and insulation properties of the aluminum nitride ceramic block are utilized to ensure the low temperature conduction of the sample while isolating the high voltage environment on the sample to avoid safety problems caused by voltage, thereby ensuring the stability and safety of the analysis process.

[0017] 3. When the frozen sample does not need to be analyzed, the frozen sample stage can be used as a vacuum cold trap. The vacuum performance of the ion sputtering chamber is improved by the freezing component, thereby improving the working environment of the equipment. This multifunctional design improves the practicality and economy of the instrument, can adapt to more diverse experimental needs, and meet application scenarios in different fields.

[0018] 4. The present invention can apply a high voltage of -8000V through a wire when using a cesium ion source, and apply a high voltage of +8000V when using an oxygen ion source, through a high-voltage bridge connection, thereby ensuring that the electric potential between the frozen sample holder and the room temperature sample holder is the same, thereby avoiding electric field distortion caused by the potential difference. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 It is a partial structural schematic diagram of the room temperature sample assembly of the present invention; Figure 3 It is a partial structural schematic diagram of the freezing sample assembly of the present invention; Figure 4 It is a schematic diagram of the structure of the high-voltage bridge wiring part of the present invention.

[0020] Among them, 1. ion sputtering chamber; 2. flange; 3. liquid nitrogen dewar; 4. liquid nitrogen cold trap; 5. frozen sample assembly; 51. frozen sample holder; 52. frozen sample rack; 6. room temperature sample assembly; 61. room temperature sample holder; 62. room temperature sample rack; 7. base; 8. sample table; 9. thermal conductive copper tape; 10. thermal conductive block; 11. aluminum nitride ceramic block; 12. wire; 13. high voltage bridge wire; 14. motor; 15. through-bin flange. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the specification of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] In order to better understand the present invention, the above contents are described in detail below in conjunction with specific embodiments.

[0023] Example 1: Please refer to the attached Figure 1 -Attached Figure 4 The embodiment of the present invention provides a nano-ion probe freezing sample stage, comprising: A frozen sample assembly 5, comprising a frozen sample tray 51 and a frozen sample rack 52, wherein the frozen sample rack 52 is mounted on one side of the frozen sample tray 51; A room temperature sample assembly 6, comprising a room temperature sample holder 61 and a room temperature sample rack 62, wherein the room temperature sample rack 62 is mounted on one side of the room temperature sample holder 61; The base 7 has two sides of one side connected to the frozen sample holder 51 and the room temperature sample holder 61 respectively, and another side connected to the sample table 8, and the base 7 is located in the ion sputtering chamber 1, and a flange 2 is connected to one side of the ion sputtering chamber 1, and a refrigeration component for cooling the frozen sample component 5 is installed inside the flange 2.

[0024] The samples can be placed by the frozen sample assembly 5 and the room temperature sample assembly 6: the room temperature sample rack 62 can be fixed on the room temperature sample holder 61 by a clamp, so as to ensure that the sample is stably fixed during the analysis process. At the same time, the sample can be replaced after the room temperature sample rack 62 is removed, and the frozen sample rack 52 is also fixed on the frozen sample holder 51 by a clamp, and the frozen sample can be replaced after the frozen sample rack 52 is removed; and the frozen sample assembly 5 and the room temperature sample assembly 6 can be supported by the base 7 and the sample table 8. At the same time, the refrigeration assembly can transfer the low temperature to the frozen sample assembly 5, and the sample in the frozen sample assembly 5 can be frozen to make it solid, so that the analysis of liquid inclusions and biomedical slice samples can be realized.

[0025] The refrigeration assembly includes a liquid nitrogen cold trap 4, a heat-conducting copper belt 9 and a liquid nitrogen dewar 3. The liquid nitrogen cold trap 4 is installed in the flange 2. One end of the heat-conducting copper belt 9 is connected to a heat-conducting block 10, and the other end is connected to an aluminum nitride ceramic block 11. The heat-conducting block 10 is connected to the liquid nitrogen cold trap 4, and the aluminum nitride ceramic block 11 is connected to the frozen sample holder 51. The liquid nitrogen dewar 3 is connected to the flange 2. The frozen sample holder 51 and the frozen sample rack 52 are both set to copper material. The base 7 is set to zirconia ceramic material.

[0026] Through the cooperation of the thermally conductive copper strip 9, the thermally conductive block 10 and the aluminum nitride ceramic block 11, the low temperature can be transferred to the frozen sample assembly 5 and the sample can be frozen to make it solid. The thermally conductive copper strip 9, the frozen sample tray 51 and the frozen sample rack 52 are made of copper, which has extremely high thermal conductivity and can reach 400W / (m·K), so that it can quickly and efficiently transfer low temperatures and ensure that the temperature inside the frozen sample assembly 5 is evenly distributed. In addition, copper not only has good thermal conductivity, but also has excellent electrical conductivity, which can effectively transmit current and avoid resistance problems in high-voltage environments, thereby improving the stability of the equipment. The thermal conductivity of the aluminum nitride ceramic block 11 is extremely outstanding among ceramic materials, and its thermal conductivity can reach 170-200W / (m·K), which is 6-10 times that of ordinary alumina ceramics, and can efficiently transfer freezing temperatures. Unlike copper, aluminum nitride ceramics have excellent insulation properties, and their resistivity is as high as 10 12Ω·cm, which can effectively isolate the current under high pressure conditions, ensuring the safety of the cryo-sample holder 51 in a high pressure environment. In addition, the thermal expansion coefficient of aluminum nitride ceramics is close to that of silicon (4.5×10-6 / ℃), which is suitable for use in low temperature environments and can avoid stress cracking or delamination caused by differences in thermal expansion coefficients. Finally, aluminum nitride ceramics have good chemical stability and can resist the erosion of liquid nitrogen or other cooling media, ensuring stability for long-term use.

[0027] A high voltage bridge wire 13 is provided inside the sample stage 8, and both ends of the high voltage bridge wire 13 penetrate the base 7 and are respectively connected to the frozen sample holder 51 and the room temperature sample holder 61. A wire 12 is installed on the outer wall of the ion sputtering chamber 1, and the wire 12 is connected to the high voltage bridge wire 13.

[0028] When using a cesium ion source, a high voltage of -8000V is applied; when using an oxygen ion source, a high voltage of +8000V is applied; and the purpose of applying high voltage is to drive the cesium ion source or the oxygen ion source to produce a primary ion beam. The cesium ion source produces a negative ion beam through high voltage, while the oxygen ion source produces a positive ion beam through high voltage. The presence of high voltage enables the ion source to efficiently emit a high-energy primary ion beam to the sample surface, providing the necessary energy for the sputtering process; wherein, the primary ion beam bombards the sample surface with high energy, and produces secondary ions through sputtering. The signal strength and stability of the secondary ions are affected by the energy of the primary ion beam. By applying high voltage to the wire 12, the energy of the ion beam can be kept consistent, thereby improving the accuracy and repeatability of the sputtering process; Therefore, the high-voltage bridge wire 13 can keep the electric potential of the frozen sample holder 51 and the room temperature sample holder 61 consistent, preventing uneven charge on the sample surface due to potential difference, thereby affecting the sputtering efficiency and secondary ion detection; at the same time, it makes the overall electric field distribution of the sample stage 8 uniform, reduces the electric field distortion caused by the high-voltage environment, and thus improves the analysis accuracy and reliability.

[0029] A motor 14 is also installed on the outer wall of the ion sputtering chamber 1, and the motor 14 is connected to the sample stage 8 through a transmission rod. A through-chamber flange 15 is connected to the middle of the flange 2, which is used to pressurize the ion sputtering chamber 1 and read the temperature of the sample in the ion sputtering chamber 1. One end of the ion sputtering chamber 1 is connected to the primary ion source chamber plate valve, and the other end is connected to the secondary ion detection chamber plate valve. The sample stage 8 is movably arranged in the ion sputtering chamber 1, and the primary ions enter the ion sputtering chamber 1 from the side of the ion sputtering chamber 1 away from the flange 2.

[0030] In this embodiment, the transmission rod can be driven to operate by driving the motor 14, thereby driving the sample stage 8 to move, and two motors 14 are provided, so that the sample stage 8 and the sample can be driven to move in the direction of the X and Y axes, thereby achieving point-by-point bombardment of the sample, and the inside of the ion sputtering chamber 1 can be pressurized by pressurizing the through-chamber flange 15. After the temperature measuring device is installed inside the through-chamber flange 15, the internal temperature of the ion sputtering chamber 1 can be detected, and then the temperature of the sample can be detected.

[0031] Working principle: When in use, the low temperature of liquid nitrogen is transferred to the heat conducting block 10 through the liquid nitrogen dewar 3, and then the low temperature is transferred to the frozen sample holder 51 through the heat conducting copper belt 9 and the aluminum nitride ceramic block 11, thereby freezing the sample in the frozen sample holder 52 to make it solid. Then the primary ions enter the ion sputtering chamber 1 from the side of the ion sputtering chamber 1 away from the flange 2. At this time, the driving motor 14 drives the transmission rod to operate, and at this time the transmission rod drives the moving sample stage 8 to move and then drives the frozen sample assembly 5 and the room temperature sample assembly 6 to move, thereby driving the sample to move to achieve point-by-point bombardment of the sample. The sputtered secondary ions are detected by the mass spectrometer to achieve in-situ analysis of non-solid samples, thereby achieving the analysis goals of high precision, high sensitivity and low background noise.

[0032] Through the synergistic effect of the heat conductive block 10, the heat conductive copper belt 9 and the aluminum nitride ceramic block 11, liquid inclusions and biomedical slices can be frozen, and after they become solid, the sample analysis can be carried out using the ion source impact. The high voltage bridge wire 13 is powered by the wire 12 to ensure that the frozen sample holder 51 and the room temperature sample holder 61 have the same potential. When using the cesium ion source, a high voltage of -8000V is applied; when using the oxygen ion source, a high voltage of +8000V is applied, thereby ensuring the stability and consistency of the high voltage environment under different types of ion sources, and ensuring the accuracy and reliability of the analysis results; Example 2: When frozen samples do not need to be analyzed, the frozen sample assembly 5 can be used as a vacuum cold trap. The specific operation is as follows: Place a normal temperature sample on the normal temperature sample holder 62, and start the liquid nitrogen cold trap 4 to improve the vacuum performance of the ion sputtering chamber 1. At this time, the refrigeration assembly remains in working state, but does not freeze the sample, and is only used as a vacuum cold trap, thereby improving the vacuum performance of the instrument; Embodiment 3: For different types of non-solid samples: the design of the frozen sample rack 52 and the frozen sample holder 51 can be adjusted according to the characteristics of the sample: Liquid inclusions: A high-pressure sealed freezing sample holder 52 is used to prevent leakage of the sample during the freezing process.

[0033] Biomedical slice samples: Use a specially designed frozen sample holder 52 to ensure that the sample maintains its biological activity and structural integrity during the freezing process. In biomedical research, through the specially designed frozen sample holder 52 and frozen sample holder 51, high-sensitivity detection of biomedical slice samples can be achieved to ensure the biological activity and structural integrity of the samples.

[0034] Example 4: In order to meet diverse sample requirements, different types of frozen sample racks 52 and frozen sample holders 51 can be replaced to meet the analysis requirements of more non-solid samples: In petroleum and mineral deposit research, high-precision analysis of liquid inclusions can be achieved through specially made frozen sample racks 52 and frozen sample holders 51.

[0035] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A nano-ion probe freezing sample stage, characterized in that: include: A frozen sample assembly (5), comprising a frozen sample tray (51) and a frozen sample rack (52), wherein the frozen sample rack (52) is mounted on one side of the frozen sample tray (51); A room temperature sample assembly (6), comprising a room temperature sample tray (61) and a room temperature sample rack (62), wherein the room temperature sample rack (62) is mounted on one side of the room temperature sample tray (61); The base (7) has two sides of one side connected to the frozen sample holder (51) and the room temperature sample holder (61) respectively, and another side connected to the sample stage (8), and the base (7) is located in the ion sputtering chamber (1), and one side of the ion sputtering chamber (1) is connected to a flange (2), and a refrigeration component for cooling the frozen sample component (5) is installed inside the flange (2).

2. A nano-ion probe freezing sample stage according to claim 1, characterized in that: The refrigeration assembly comprises a liquid nitrogen cold trap (4), a heat-conducting copper belt (9) and a liquid nitrogen dewar (3); the liquid nitrogen cold trap (4) is installed in a flange (2); one end of the heat-conducting copper belt (9) is connected to a heat-conducting block (10) and the other end is connected to an aluminum nitride ceramic block (11); the heat-conducting block (10) is connected to the liquid nitrogen cold trap (4); the aluminum nitride ceramic block (11) is connected to a frozen sample holder (51); and the liquid nitrogen dewar (3) is connected to the flange (2).

3. The nano-ion probe freezing sample stage according to claim 1, characterized in that: The frozen sample tray (51) and the frozen sample rack (52) are both made of red copper.

4. The nano-ion probe freezing sample stage according to claim 1, characterized in that: The base (7) is made of zirconium oxide ceramic material.

5. The nano-ion probe freezing sample stage according to claim 1, characterized in that: A high-voltage bridge wire (13) is provided inside the sample stage (8), and both ends of the high-voltage bridge wire (13) penetrate the base stage (7) and are respectively connected to a frozen sample holder (51) and a room-temperature sample holder (61).

6. The nano-ion probe freezing sample stage according to claim 1, characterized in that: A wire (12) is installed on the outer wall of the ion sputtering chamber (1), and the wire (12) is connected to a high-voltage bridge wire (13).

7. The nano-ion probe freezing sample stage according to claim 1, characterized in that: A motor (14) is also installed on the outer wall of the ion sputtering chamber (1), and the motor (14) is connected to the sample stage (8) via a transmission rod.

8. The nano-ion probe freezing sample stage according to claim 1, characterized in that: The middle part of the flange plate (2) is connected to a chamber penetration flange (15) for applying pressure to the ion sputtering chamber (1) and reading the temperature of the sample in the ion sputtering chamber (1).

9. The nano-ion probe freezing sample stage according to claim 1, characterized in that: One end of the ion sputtering chamber (1) is connected to a primary ion source chamber plate valve, and the other end is connected to a secondary ion detection chamber plate valve.

10. The nano-ion probe freezing sample stage according to claim 1, characterized in that: The sample stage (8) is movably arranged in the ion sputtering chamber (1), and primary ions enter the ion sputtering chamber (1) from a side of the ion sputtering chamber (1) away from the flange (2).

Images