A nano-ion probe cryo-sample stage

Abstract

This application relates to the field of nano ion probes and discloses a cryo sample stage for a nano ion probe, comprising: a cryo sample assembly, which includes a cryo sample holder and a cryo sample rack, and the cryo sample rack is installed on one side of the cryo sample holder; a room temperature sample assembly, which includes a room temperature sample holder and a room temperature sample rack, and the room temperature sample rack is installed on one side of the room temperature sample holder; a base, two sides of one surface of which are respectively connected to the cryo sample holder and the room temperature sample holder, and another surface is connected to the sample stage, and the base is located in the ion sputtering chamber, and a flange is connected to one side of the ion sputtering chamber, and a refrigeration assembly for cooling the cryo sample assembly is installed inside the flange. Through the action of the refrigeration assembly, the present invention transfers low temperature to the cryo sample holder efficiently, so that the sample is frozen to a solid state. Therefore, the present invention can achieve high-precision in-situ analysis of liquid inclusion and biomedical section samples.

Description

Technical Field

[0001] The present invention relates to the field of nano ion probes, and particularly to a cryo sample stage for nano ion probes. Background Art

[0002] Ion probe microarea analysis has significant advantages of high spatial resolution, high analysis precision, high sensitivity, and low analysis background. As the ion probe technology with the highest current spatial resolution, nano ion probes have been widely used in fields such as comparative planetology, earth science, materials science, and biomedicine. However, restricted by the analysis mechanism of secondary ion probes, the current nano ion probe technology can only analyze solid samples and cannot meet the need for in-situ analysis of non-solid samples.

[0003] In actual research, for example, the analysis requirements for fluid inclusions in oil and ore deposits and non-solid samples in biomedical research are increasing. 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, due to the lack of effective freezing and insulation designs, traditional nano ion probes cannot meet the low-temperature and high-precision analysis requirements of these special samples. Therefore, developing a nano ion probe device that can achieve cryogenic freezing of non-solid samples and meet the high-voltage insulation requirements has become the key to technological development. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a cryo sample stage for nano ion probes, which solves the problem in the prior art that the current nano ion probe technology can only analyze solid samples and cannot meet the need for in-situ analysis of non-solid samples.

[0005] To achieve the above objectives, the present invention is realized through the following technical solutions: A cryo sample stage for nano ion probes, comprising:

[0006] A cryo sample assembly, which includes a cryo sample holder and a cryo sample rack, and the cryo sample rack is installed on one side of the cryo sample holder;

[0007] A room temperature sample assembly, which includes a room temperature sample holder and a room temperature sample rack, and the room temperature sample rack is installed on one side of the room temperature sample holder;

[0008] A base, two sides of one side of which are respectively connected to the cryo sample holder and the room temperature sample holder, and the other side is connected to the sample stage. The base is located in the ion sputtering chamber, and a flange is connected to one side of the ion sputtering chamber. A refrigeration assembly for cooling the cryo sample assembly is installed inside the flange.

[0009] Preferably, the refrigeration assembly includes a liquid nitrogen cold trap, a heat-conducting copper strip, and a liquid nitrogen dewar. The liquid nitrogen cold trap is installed in the flange. One end of the heat-conducting copper strip is connected to a heat-conducting block, and the other end is connected to an aluminum nitride ceramic block. The heat-conducting block is connected to the liquid nitrogen cold trap, and the aluminum nitride ceramic block is connected to the frozen sample holder. The liquid nitrogen dewar is communicated with the flange.

[0010] Preferably, both the frozen sample holder and the frozen sample rack are made of copper.

[0011] Preferably, the base is made of zirconia ceramic.

[0012] Preferably, a high-voltage bridge wiring is arranged inside the sample stage. Both ends of the high-voltage bridge wiring penetrate through the base and are respectively connected to the frozen sample holder and the normal-temperature sample holder.

[0013] Preferably, a wire is installed on the outer wall of the ion sputtering chamber, and the wire is connected to the high-voltage bridge wiring.

[0014] 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.

[0015] Preferably, a feedthrough flange is communicated with the middle of the flange for pressurizing the ion sputtering chamber and reading the temperature of the sample in the ion sputtering chamber.

[0016] Preferably, one end of the ion sputtering chamber is communicated with the primary ion source chamber plate valve, and the other end is communicated with the secondary ion detection chamber plate valve.

[0017] Preferably, the sample stage is movably arranged in the ion sputtering chamber, and primary ions enter the ion sputtering chamber from the side of the ion sputtering chamber away from the flange.

[0018] The present invention provides a nano ion probe frozen sample stage, which has the following beneficial effects:

[0019] 1. Through the action of the refrigeration assembly, the present invention efficiently transfers low temperature to the frozen sample holder, freezing the sample to a solid state. Therefore, the present invention can realize high-precision in-situ analysis of liquid inclusions and biomedical section samples, and is particularly suitable for analysis under low-temperature conditions that maintain the original state of the samples.

[0020] 2. By making the frozen sample holder and the frozen sample rack of copper, the present invention can efficiently conduct low temperature and high pressure, ensuring the temperature uniformity and stability of the frozen sample. And by utilizing the high heat conductivity and insulation characteristics of the aluminum nitride ceramic block, while ensuring the low-temperature conduction of the sample, the high-pressure environment on the sample is isolated, avoiding safety problems caused by voltage, thus ensuring the stability and safety of the analysis process.

[0021] 3. When the frozen sample does not need to be analyzed in the present invention, the frozen sample stage can be used as a vacuum cold trap. The vacuum performance of the ion sputtering chamber is improved through the refrigeration component, thereby improving the working environment of the equipment. This multifunctional design improves the practicability and economy of the instrument, can adapt to more diverse experimental requirements, and meets the application scenarios in different fields.

[0022] 4. In the present invention, a high-voltage of -8000V can be applied through a wire when using a cesium ion source and a high-voltage of +8000V can be applied when using an oxygen ion source through the high-voltage bridge wiring. Therefore, the electric potential between the frozen sample holder and the normal-temperature sample holder can be ensured to be the same, thereby avoiding the electric field distortion caused by the potential difference. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic three-dimensional structure diagram of the present invention;

[0024] Figure 2 is a schematic partial structure diagram of the normal-temperature sample assembly of the present invention;

[0025] Figure 3 is a schematic partial structure diagram of the frozen sample assembly of the present invention;

[0026] Figure 4 is a schematic partial structure diagram of the high-voltage bridge wiring of the present invention.

[0027] Wherein, 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. Normal-temperature sample assembly; 61. Normal-temperature sample holder; 62. Normal-temperature sample rack; 7. Base; 8. Sample stage; 9. Heat-conducting copper strip; 10. Heat-conducting block; 11. Aluminum nitride ceramic block; 12. Wire; 13. High-voltage bridge wiring; 14. Motor; 15. Feedthrough flange. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the specification of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0029] In order to better understand the present invention, the above content will be described in detail below with specific embodiments.

[0030] Embodiment 1: Please refer to the attached Figure 1 - attached Figure 4 , the embodiment of the present invention provides a nano ion probe frozen sample stage, including:

[0031] A frozen sample assembly 5, which includes a frozen sample carrier 51 and a frozen sample holder 52, and the frozen sample holder 52 is installed on one side of the frozen sample carrier 51;

[0032] A room-temperature sample assembly 6, which includes a room-temperature sample carrier 61 and a room-temperature sample holder 62, and the room-temperature sample holder 62 is installed on one side of the room-temperature sample carrier 61;

[0033] A base 7, on both sides of one surface of which are respectively connected to the frozen sample carrier 51 and the room-temperature sample carrier 61, and another surface is connected to a sample stage 8, and the base 7 is located in the ion sputtering chamber 1. A flange 2 is connected to one side of the ion sputtering chamber 1, and a refrigeration component for cooling the frozen sample assembly 5 is installed inside the flange 2.

[0034] The samples can be placed through the frozen sample assembly 5 and the room-temperature sample assembly 6: The room-temperature sample holder 62 can be fixed on the room-temperature sample carrier 61 through a clamp, so as to ensure that the sample is stably fixed during the analysis process. At the same time, after removing the room-temperature sample holder 62, the sample can be replaced. The frozen sample holder 52 is also fixed on the frozen sample carrier 51 through a clamp, and after removing the frozen sample holder 52, the frozen sample can be replaced; and the base 7 and the sample stage 8 can be used to support the frozen sample assembly 5 and the room-temperature sample assembly 6. At the same time, the refrigeration component can transfer the low temperature to the frozen sample assembly 5. At this time, the sample in the frozen sample assembly 5 can be frozen to become a solid. Therefore, the analysis of liquid inclusion and biomedical section samples can be realized.

[0035] The refrigeration component includes a liquid nitrogen cold trap 4, a heat-conducting copper strip 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 strip 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 carrier 51. The liquid nitrogen dewar 3 is communicated with the flange 2. Both the frozen sample carrier 51 and the frozen sample holder 52 are made of copper. The base 7 is made of zirconia ceramic.

[0036] Through the cooperation of the heat-conducting copper strip 9, the heat-conducting block 10, and the aluminum nitride ceramic block 11, low temperature can be transferred to the frozen sample assembly 5 to freeze the sample into a solid. The heat-conducting copper strip 9, the frozen sample holder 51, and the frozen sample rack 52 are made of pure copper, which has extremely high thermal conductivity, up to 400 W / (m·K), enabling it to transfer low temperature quickly and efficiently, ensuring uniform temperature distribution inside the frozen sample assembly 5. Moreover, pure copper not only has good thermal conductivity but also excellent electrical conductivity, which can effectively transmit current and avoid resistance problems in a high-voltage environment, thus improving the stability of the equipment. The aluminum nitride ceramic block 11 has extremely excellent thermal conductivity among ceramic materials, with a thermal conductivity of up to 170 - 200 W / (m·K), which is 6 - 10 times that of ordinary alumina ceramics, and can efficiently transfer the freezing temperature. Different from pure copper, aluminum nitride ceramics have excellent insulation properties, with a resistivity as high as 10 12 Ω·cm, which can effectively isolate current under high-pressure conditions, ensuring the safety of the frozen sample holder 51 in a high-voltage environment. In addition, the thermal expansion coefficient of aluminum nitride ceramics is close to that of silicon (4.5×10-6 / ℃), making it suitable for use in low-temperature environments and avoiding stress cracking or delamination caused by differences in thermal expansion coefficients. Finally, aluminum nitride ceramics have good chemical stability, can resist the erosion of liquid nitrogen or other cooling media, and ensure the stability of long-term use.

[0037] Inside the sample stage 8, there is a high-voltage bridge wiring 13. Both ends of the high-voltage bridge wiring 13 penetrate through 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 wiring 13.

[0038] When using a cesium ion source, a high voltage of -8000 V is applied; when using an oxygen ion source, a high voltage of +8000 V is applied; and the application of high voltage is to drive the cesium ion source or the oxygen ion source to generate a primary ion beam. The cesium ion source generates a negative ion beam through high voltage, while the oxygen ion source generates a positive ion beam through high voltage. The presence of high voltage enables the ion source to efficiently emit high-energy primary ion beams to the sample surface, providing the necessary energy for the sputtering process. Among them, the primary ion beam bombards the sample surface with high energy, and secondary ions are generated through sputtering. The signal intensity 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;

[0039] Therefore, the high-voltage bridge wiring 13 can keep the electric potentials of the frozen sample holder 51 and the room-temperature sample holder 61 consistent, preventing uneven charge on the sample surface caused by potential differences, which may affect the sputtering efficiency and the detection of secondary ions; at the same time, it makes the overall electric field distribution of the sample stage 8 uniform, reducing the electric field distortion caused by the high-voltage environment, thereby improving the analysis accuracy and reliability.

[0040] 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. The middle of the flange 2 is communicated with a through-chamber flange 15 for pressurizing the ion sputtering chamber 1 and reading the temperature of the sample inside the ion sputtering chamber 1. One end of the ion sputtering chamber 1 is communicated with the primary ion source chamber plate valve, and the other end is communicated with the secondary ion detection chamber plate valve. The sample stage 8 is movably arranged inside 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.

[0041] In this embodiment, by driving the motor 14, the transmission rod can be driven to operate, and then the sample stage 8 can be driven to move. Moreover, two motors 14 are provided, so the sample stage 8 and the sample can be driven to move in the directions of the X and Y axes, thereby realizing point-by-point bombardment of the sample. And by pressurizing the through-chamber flange 15, the inside of the ion sputtering chamber 1 can be pressurized. After installing the temperature measuring device inside the through-chamber flange 15, the temperature inside the ion sputtering chamber 1 can be detected, and then the temperature of the sample can be detected.

[0042] Working principle: During use, the low temperature of liquid nitrogen is transferred to the heat conduction block 10 through the liquid nitrogen dewar 3, and then the low temperature is transferred to the frozen sample holder 51 through the heat conduction copper strip 9 and the aluminum nitride ceramic block 11, thereby freezing the sample in the frozen sample rack 52 to make it a solid. Subsequently, 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, thereby driving the frozen sample assembly 5 and the normal temperature sample assembly 6 to move, so as to drive the sample to move to realize point-by-point bombardment of the sample. And the sputtered secondary ions are detected by a mass spectrometer to realize in-situ analysis of non-solid samples, so as to achieve the analysis goals of high precision, high sensitivity and low background noise.

[0043] Through the synergistic effect of the heat conduction block 10, the heat conduction copper strip 9 and the aluminum nitride ceramic block 11, the liquid inclusions and biomedical sections can be frozen. After they become solids, the ion source can be used to impact for sample analysis. The high-voltage bridge wiring 13 is powered through the wire 12 to ensure that the frozen sample holder 51 and the normal temperature sample holder 61 have the same electric potential. 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, so as to ensure the stability and consistency of the high-voltage environment under different types of ion sources and ensure the accuracy and reliability of the analysis results;

[0044] Example 2: When it is not necessary to analyze frozen samples, the frozen sample assembly 5 can be used as a vacuum cold trap. The specific operation is as follows: Place a normal room-temperature sample on the room-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 still remains in the working state, but does not freeze the sample, and is only used as a vacuum cold trap to improve the vacuum performance of the instrument;

[0045] Example 3: And for different types of non-solid samples: The designs of the frozen sample holder 52 and the frozen sample carrier 51 can be adjusted according to the sample characteristics:

[0046] Liquid inclusions: A high-pressure sealed frozen sample holder 52 is used to prevent the sample from leaking during the freezing process.

[0047] Biomedical section samples: A specially designed frozen sample holder 52 is used 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 the frozen sample carrier 51, high-sensitivity detection of biomedical section samples can be achieved, ensuring the biological activity and structural integrity of the sample.

[0048] Example 4: In order to meet the diverse sample requirements, different types of frozen sample holders 52 and frozen sample carriers 51 can be replaced to adapt to the analysis requirements of more non-solid samples: In petroleum and ore deposit research, through the specially designed frozen sample holder 52 and the frozen sample carrier 51, high-precision analysis of liquid inclusions can be achieved.

[0049] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A nano-ion probe cryo-sample stage, characterized in that Comprising: A cryogenic sample assembly (5), which includes a cryogenic sample holder (51) and a cryogenic sample rack (52), and the cryogenic sample rack (52) is installed on one side of the cryogenic sample holder (51); A room-temperature sample assembly (6), which includes a room-temperature sample holder (61) and a room-temperature sample rack (62), and the room-temperature sample rack (62) is installed on one side of the room-temperature sample holder (61); A base (7), the two sides of one surface of which are respectively connected to the cryogenic sample holder (51) and the room-temperature sample holder (61), and another surface is connected to a sample stage (8), and the base (7) is located inside the ion sputtering chamber (1). One side of the ion sputtering chamber (1) is connected to a flange (2), and a refrigeration component for cooling the cryogenic sample assembly (5) is installed inside the flange (2); The refrigeration component includes a liquid nitrogen cold trap (4), a heat-conducting copper strip (9) and a liquid nitrogen dewar (3). The liquid nitrogen cold trap (4) is installed inside the flange (2). One end of the heat-conducting copper strip (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 the cryogenic sample holder (51), and the liquid nitrogen dewar (3) is communicated with the flange (2); Both the cryogenic sample holder (51) and the cryogenic sample rack (52) are made of copper; A high-voltage bridge wiring (13) is arranged inside the sample stage (8), and both ends of the high-voltage bridge wiring (13) penetrate through the base (7) and are respectively connected to the cryogenic 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 wiring (13); 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; The middle of the flange (2) is communicated with a feedthrough flange (15) for pressurizing the ion sputtering chamber (1) and reading the temperature of the sample inside the ion sputtering chamber (1); One end of the ion sputtering chamber (1) is communicated with a primary ion source chamber plate valve, and the other end is communicated with a secondary ion detection chamber plate valve; The sample stage (8) is movably arranged inside the ion sputtering chamber (1), and primary ions enter the ion sputtering chamber (1) from the side of the ion sputtering chamber (1) away from the flange (2); During 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 cryogenic sample holder (51) through the heat-conducting copper strip (9) and the aluminum nitride ceramic block (11), so as to freeze the sample in the cryogenic sample rack (52) to make it a solid; then 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 rotate, and at this time the transmission rod drives the moving sample stage (8) to move, thereby driving the cryogenic sample assembly (5) and the room-temperature sample assembly (6) to move, so as to drive the sample to move to realize point-by-point bombardment of the sample; and the sputtered secondary ions are detected by a mass spectrometer to realize in-situ analysis of non-solid samples; Through the synergistic effect of the heat conduction block (10), the heat conduction copper strip (9) and the aluminum nitride ceramic block (11), the liquid inclusion and the biomedical section can be frozen. After they become solids, sample analysis can be carried out by ion source impact; the high-voltage bridge wiring (13) is powered through the wire (12) to ensure that the frozen sample holder (51) and the normal-temperature sample holder 61 have the same electric 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, so as to ensure the stability and consistency of the high-voltage environment under different types of ion sources; When the frozen sample does 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 the ordinary normal-temperature sample on the normal-temperature sample rack (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 still remains in the working state, but does not freeze the sample and is only used as a vacuum cold trap.

2. The cryo sample stage of a nano ion probe according to claim 1, characterized in that, The base (7) is made of zirconia ceramic material.

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