JP2015028892A - Ion beam device with gas field ionization ion source, and composite charged particle beam machine with ion beam device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ion beam device with a gas field ionization ion source which is arranged so that evacuated gas can be prevented from being reversely flowed in an exhaust system and entering a gas ionization chamber of the gas field ionization ion source.SOLUTION: The present invention relates to: an ion beam device arranged to apply, to a sample, an ion beam produced by a gas field ionization ion source to observe or process the sample; and a composite charged particle beam machine with such an ion beam device, which comprises an ionization gas exhaust system for exhausting an ionization gas, provided that the ionization gas exhaust system is independent of an exhaust system for exhausting the charged particle beam device and a vacuum container such as a sample chamber to set a sample in. According to the present invention, the following are made possible: to prevent an exhausted gas from being reversely flowed in the exhaust system and consequently, entering the gas ionization chamber of the gas field ionization ion source; and to avoid an ion beam emission failure and the breaking of an emitter tip.

Description

  The present invention relates to an ion beam apparatus including a gas field ion source and having ion beam processing and observation capabilities. The present invention also relates to a composite charged particle beam apparatus in which the ion beam apparatus is combined with an ion microscope or an electron microscope.

By irradiating the sample while scanning electrons and detecting secondary charged particles emitted from the sample, the structure of the sample surface can be observed. This is called a scanning electron microscope (hereinafter abbreviated as SEM). On the other hand, the structure of the sample surface can be observed even when the sample is irradiated with the ion beam and the secondary charged particles emitted from the sample are detected. This is called a scanning ion microscope (hereinafter abbreviated as SIM).
In particular, if the sample is irradiated with a light ion species such as hydrogen or helium, the sputtering effect becomes relatively small, which is suitable for observing the sample.

  As the ion source of the ion microscope, a gas field ion source is suitable. The gas field ion source is an ion source that ionizes a gas by an electric field created by an emitter tip and emits the ion beam as an ion beam. The gas field ion source has a gas ionization chamber having a needle-like emitter tip to which a high voltage can be applied. An ionized gas is supplied from the gas source to the gas ionization chamber through a gas supply pipe. When ionized gas (or gas molecules) supplied from a gas supply pipe approaches the tip of a needle-like emitter tip to which a high voltage is applied and a strong electric field is applied, the potential of electrons in the gas (gas molecules) being reduced by the electric field By tunneling the barrier, positive ions are released. Since the gas field ion source uses this as an ion beam, an ion beam having a narrow energy width can be generated. Further, since the size of the ion generation source is small, a fine ion beam can be generated.

  In Patent Document 1, a vacuum pump for evacuating a gas field ion source of an ion microscope is a combination of a non-evaporable getter pump and an ion pump, a combination of a non-evaporable getter pump and a noble pump, or a combination of a non-evaporable getter pump and an Excel pump. Are disclosed as preferred. Also, the main evacuation pump of the sample chamber at the time of sample observation with an ion microscope is a combination of a non-evaporable getter pump and an ion pump, a combination of a non-evaporable getter pump and a noble pump, or a combination of a non-evaporable getter pump and an Excel pump, or In addition, it is disclosed that a turbo molecular pump is used for roughing vacuum from the atmosphere, and the turbo molecular pump is stopped when observing a sample with an ion beam.

International Publication No. 2009/147894

  As a result of intensive studies on the stability of the gas field ion source during exhaust, the inventors of the present application have obtained the following knowledge.

  In Patent Document 1, the pressure at the exhaust port (exhaust port) of the auxiliary pump that exhausts gas from the atmospheric pressure to a pressure at which the non-evaporable getter pump, the noble pump, or the Excel pump can be activated, or the turbo molecular pump to the specified back pressure A vacuum exhaust system including an auxiliary pump for exhausting is not disclosed.

  On the other hand, in general, in the composite charged particle beam apparatus, in order to reduce the cost and the apparatus size, it is common to use an evacuation system that shares the auxiliary pump. The exhaust system was examined.

  However, this evacuation system generally connects the evacuation system for evacuating the gas field ion source and the evacuation system for evacuating the sample chamber. The inventor of the present application has found that the gas in the air may flow back into one of the exhaust systems and enter the vacuum vessel.

  For example, when ionizing gas such as helium or hydrogen is light in mass, or ionized gas is intentionally ionized when observing a sample with an ion microscope in order to discharge impurity gas remaining on the wall of the gas field ion source. Differential exhaust from the lens opening that exhausts the ionized gas of the gas field ion source in order to extend the life of the emitter tip when the pressure is higher than the gas pressure (ordinary dose) (introduced in large quantities) In addition to increasing the amount of ionized gas introduced by adjusting the exhaust amount, the exhaust amount that can be changed can be adjusted to an appropriate exhaust amount according to the increased amount of exhaust. If the ionization gas pressure is kept at the same level as when observing the sample with an ion microscope, or the sample chamber is irradiated with an ion beam, the sample is prevented from being charged up. Gas supply means and for a case of introducing an ionizable gas than the gas (gas) to intentionally sample chamber provided with a gas supply means for supplying an etching or deposition gas to the vicinity of the sample.

  If the exhausted gas flows backward through the exhaust system and enters the gas ionization chamber of the ion field ion source of the ion microscope due to the mass of the exhausted gas, the exhaust amount, or both, the ion beam Emission may become unstable or the emitter tip may be destroyed, causing serious malfunctions and making it impossible to observe the ion microscope image.

An object of the present invention relates to preventing the exhausted gas from flowing back into the exhaust system and entering the gas ionization chamber of the gas field ion source.

  The present invention relates to, for example, an ion beam apparatus for observing or processing a sample by irradiating the sample with an ion beam generated from a gas field ion source, or a charged particle beam apparatus including the ion beam apparatus. And an ionized gas exhaust system that exhausts ionized gas independent from an exhaust system that exhausts other vacuum vessels such as a sample chamber in which a sample is placed.

Further, the present invention relates to, for example, an ion beam device that observes or processes a sample by irradiating the sample with an ion beam generated from a gas field ion source, or a charged particle beam device including the ion beam device. The present invention relates to the provision of an ionized gas exhaust system that exhausts an ionized gas that is not connected to an exhaust system that exhausts other vacuum containers such as a wire device and a sample chamber in which a sample is placed.

According to the present invention, it is possible to prevent the exhausted gas from flowing back into the exhaust system and entering the gas ionization chamber of the gas field ion source, thereby avoiding an ion beam emission defect and an emitter tip breakdown. it can.

1 is a schematic configuration diagram of an ion beam apparatus according to Embodiment 1. FIG. FIG. 3 is a schematic configuration diagram of an ion beam apparatus according to a second embodiment. FIG. 6 is a schematic configuration diagram of an ion beam apparatus according to Example 3. FIG. 6 is a schematic configuration diagram of an ion beam apparatus according to Example 4; FIG. 6 is a schematic configuration diagram of an ion beam apparatus according to a fifth embodiment. FIG. 10 is a schematic configuration diagram of an ion beam apparatus according to Example 6. FIG. 10 is a schematic configuration diagram of an ion beam apparatus according to Example 7. FIG. 10 is a schematic configuration diagram of an ion beam apparatus according to an eighth embodiment. FIG. 10 is a schematic configuration diagram of an ion beam apparatus according to Example 9. FIG. 10 is a schematic configuration diagram of an ion beam apparatus according to Example 10; It is a schematic block diagram of the ion beam apparatus concerning Example 11. FIG. FIG. 12 is a schematic configuration diagram of an ion beam apparatus according to Example 12;

  The ion beam apparatus described in the embodiment is more sensitive to information on the sample surface than an apparatus using an electron beam. This is because the excitation region of the secondary charged particles is localized on the sample surface as compared with the irradiation of the electron beam. In addition, since the electron beam property cannot be ignored in the electron beam, aberration occurs due to the diffraction effect. On the other hand, since the ion beam is heavier than electrons, the diffraction effect can be ignored.

  As an ion beam apparatus taking advantage of these features, for example, there is a scanning ion microscope. A scanning ion microscope is an apparatus that observes the structure of a sample surface by irradiating a sample while scanning an ion beam to detect secondary charged particles emitted from the sample. In particular, if the sample is irradiated with a light ion species such as hydrogen or helium, the sputtering effect becomes relatively small, which is suitable for observing the sample.

  In addition, if an ion beam is irradiated on a sample and ions that have passed through the sample are detected, information reflecting the structure inside the sample can be obtained. This is called a transmission ion microscope. In particular, if the sample is irradiated with a light ion species such as hydrogen or helium, the rate of transmission through the sample is increased, which is suitable for observation.

  Conversely, if the sample is irradiated with a heavy ion species such as argon, xenon, or gallium, it is suitable for processing the sample by sputtering. In particular, a focused ion beam apparatus (Focused Ion Beam, hereinafter abbreviated as FIB) using a liquid metal ion source (hereinafter abbreviated as LMIS) is known as a focused ion beam processing observation apparatus. Furthermore, in recent years, a FIB-SEM apparatus that is a combined machine of a scanning electron microscope (SEM) and a focused ion beam (FIB) is also used. In the FIB-SEM apparatus, the cross section can be observed by SEM by irradiating the FIB and forming a square hole at a desired location. The sample can also be processed by generating gas ions such as argon and xenon by a plasma ion source or a gas field ion source and irradiating the sample.

  In an embodiment, in a combined charged particle beam apparatus including an ion beam apparatus that irradiates a sample with an ion beam generated from a gas field ion source and observes or processes the sample, and a charged particle beam apparatus, the gas field ion ion An emitter tip serving as an anode, an extraction electrode serving as a cathode, a vacuum container containing at least the emitter tip, and a gas inlet for supplying ionized gas to a space between the tip of the emitter tip and the extraction electrode; A gas exhaust port for exhausting ionized gas, and an ionized gas exhaust system for exhausting ionized gas independent of an exhaust system for exhausting a charged particle beam device and a sample chamber in which a sample is disposed. .

  In the embodiment, in an ion beam apparatus for observing or processing a sample by irradiating the sample with an ion beam generated from the gas field ion source, the gas field ion source becomes an emitter tip and a cathode. An extraction electrode; a vacuum vessel that houses at least the emitter tip; a gas introduction port that supplies ionized gas to a space between the tip of the emitter tip and the extraction electrode; and a gas exhaust port that exhausts the ionized gas. Disclosed is an ionized gas exhaust system that exhausts an ionized gas that is not connected to an exhaust system that exhausts a sample chamber in which a sample is disposed.

  Moreover, in an Example, it discloses that the gas exhaust port and / or the gas inlet port are provided in the structure having the ground potential.

  In addition, the embodiment discloses that a temperature raising mechanism capable of raising the temperature of the lowest temperature portion of the gas ionization chamber by 5K or more is provided.

  Moreover, in an Example, it discloses that the exhaust system of the vacuum vessel which accommodates the said liquid metal ion source is provided with the vacuum pump which can exhaust an inert gas in the ion beam apparatus provided with the liquid metal ion source.

  Moreover, in an Example, it discloses that the exhaust system of the vacuum container which accommodates the said liquid metal ion source is provided with a Noble pump or an Excel pump in the ion beam apparatus provided with the liquid metal ion source.

  Moreover, in an Example, it discloses that a gas field ionization ion source is provided with the valve | bulb which isolate | separates the vacuum vessel which accommodates at least an emitter tip, and another vacuum vessel.

  Moreover, in an Example, disclosing providing the independent exhaust system which exhausts the space between the ion source chamber of a gas field ionization ion source, and a sample chamber.

The above and other novel features and effects of the present invention will be described below with reference to the drawings. It should be noted that the drawings are used exclusively for understanding the invention and do not reduce the scope of rights. In addition, the embodiments can be appropriately combined, and such a combination form is also disclosed in this specification.

  With reference to FIG. 1, the structure of the ion beam apparatus concerning a present Example is demonstrated.

The ion beam apparatus includes an ion source chamber 5 having an emitter tip 1, an extraction electrode 2, a gas supply pipe 4, a gas exhaust port 52, a cooling mechanism 60, and a cooling conduction mechanism 61, and for evacuating the ion source chamber 5 to a vacuum. Ion source chamber vacuum pump 21, auxiliary vacuum pump 22, valve 30, ionized gas source 15, sample chamber 10, FIB column 31, FIB vacuum pump 26, FIB ion source exhaust valve 27, A sample chamber evacuation pump 23, an auxiliary evacuation pump 24, and a gas supply means 40 are provided. The gas supply pipe 4 and the gas introduction port 16 are collectively referred to as a gas introduction part. In this embodiment, the gas exhaust port 52 is referred to as a gas exhaust unit. In the present embodiment, the sample chamber vacuum pump 23 and the auxiliary vacuum pump 24 also serve as auxiliary pumps for exhausting the gas in the vacuum container of the FIB column 31 from the atmospheric pressure. An exhaust system may be provided. The ion source chamber 5 and the sample chamber 10 are connected via an opening 18. The ion source is a gas field ion source. An ionized gas is supplied from a gas source 15 through a gas supply pipe 4 to a gas ionization chamber 6 having a needle-like emitter tip 1 to which a high voltage (power supply is not shown in the figure) can be applied. When the ionized gas (or gas molecule) supplied from the gas supply pipe 4 approaches the tip of the needle-like emitter tip 1 to which a high electric field is applied and a strong electric field is applied, electrons in the gas (gas molecule) are reduced by the electric field. By tunneling the potential barrier, positive ions are released. In a gas field ion source, this is used as an ion beam.
In this embodiment, the space surrounded by the ion source chamber 5 also serves as the gas ionization chamber 6 that ionizes the gas. That is, it can be said that the gas ionization chamber 6 is a structure in which gas is introduced into one or more members so as to surround at least the emitter tip 1.

  When introducing ionized gas (or gas molecules) into the gas ionization chamber 6, the valve 30 is closed and the ionized gas (or gas molecules) is held in the gas ionization chamber 6. The opening 18 also serves as the gas exhaust port 52, and the ionized gas (or gas molecules) in the gas ionization chamber 6 is differentially exhausted through the opening 18. The introduced amount of ionized gas (or gas molecules) to be introduced is differentially exhausted through the opening 18 so as to be a predetermined ionized gas pressure (varies depending on the purpose and purpose such as sample observation and analysis by an ion microscope). The amount is adjusted to balance the displacement.

  Further, the amount of ionized gas (or gas molecules) to be introduced is increased as compared with the case of introducing the ionized gas (or gas molecules), and the increased amount is exhausted through the valve 30 by adjusting the opening amount without completely closing the valve 30. Thus, the displacement may be adjusted so as to obtain a predetermined ionized gas pressure. In this case, the exhaust amount of the ionized gas is the sum of the differential exhaust amount through the opening 18 and the exhaust amount through the valve 30 with the valve opening amount adjusted. In order to extend the lifetime of the emitter tip, it is preferable to introduce ionized gas (or gas molecules) by this method. However, since there is a disadvantage that a large amount of ionized gas is consumed, it is necessary to use properly depending on the purpose. If the exhaust system is not independent, adverse effects due to the backflow of the exhausted ionized gas become significant in this method. The exhausted ionized gas is mixed with various impurity gases (here, impurity gas is a gas other than ionized gas (or gas molecule)) from the exhaust path. This will cause emission failure and destruction of the emitter tip.

  Although not shown in the drawing, an ion beam irradiation optical system is installed in a space connected to the sample chamber 10 through the opening 18, and the sample chamber 10 is obtained from the sample by ion beam irradiation. A detector for detecting a signal, a sample stage on which a sample is placed, and a sample stage for moving the sample are installed.

  In addition, the ion beam apparatus includes a control unit that controls the operation of each part and an image generation unit that generates an image based on a signal output from the detector. The control unit and the image generation unit may be configured as hardware by a dedicated circuit board, or may be configured by a program executed by a computer connected to the ion beam apparatus.

In this embodiment, an exhaust system provided with an ion source chamber vacuum exhaust pump 21 and an auxiliary vacuum exhaust pump 22 for evacuating a gas ionization chamber of a gas field ion source of an ion microscope, and other vacuum vessels are exhausted. Since the FIB evacuation pump 26, the sample chamber evacuation pump 23, and the evacuation system provided with the auxiliary evacuation pump 24 are independent, the ion source chamber evacuation pump 21 and the auxiliary evacuation pump 22 are provided. A gas mixture of ionized gas (or gas molecules) exhausted from the installed exhaust system and the impurity gas mixed in the exhaust process flows backward from the exhaust system exhausting other vacuum vessels, and the gas field ionized ions of the ion microscope Intrusion into the gas ionization chamber 6 of the source can be prevented, and defective emission of the ion beam and emitter tip destruction can be avoided.
Further, a gas for preventing charge-up of the sample when the sample chamber 10 is irradiated with an ion beam, or an etching gas or a deposition gas in the vicinity of the sample (these gases are gases (gases) other than the ionized gas, Even if it is introduced into the sample chamber 10 from the gas supply means 40, a gas (gas) other than this ionized gas exhausted by the sample chamber vacuum pump 23 is used as the ion source chamber vacuum pump. It is possible to prevent the system 21 from flowing back and entering the gas ionization chamber 6.

  With reference to FIG. 2, the structure of the ion beam apparatus concerning a present Example is demonstrated. In the following description, differences from the first embodiment will be mainly described.

  In this embodiment, a voltage is applied to the emitter tip 1 by the acceleration power supply 7, and a voltage is applied to the extraction electrode 2 from the extraction power supply 8. The ion source chamber 5 is fixed to the ground potential (GND) regardless of the operation of the ion beam apparatus. The ion source chamber 5 is a vacuum container configured to surround the emitter tip 1. In the present embodiment, as in the first embodiment, the space surrounded by the ion source chamber 5 also serves as the gas ionization chamber 6 for ionizing the gas. That is, it can be said that the gas ionization chamber 6 is a structure in which gas is introduced into one or more members so as to surround at least the emitter tip 1.

  The gas inlet 16 of the gas supply pipe 4 is installed in the ion source chamber 5 having a ground potential (GND). The gas inlet 16 may be directly fixed to the ion source chamber 5 or may be fixed to another member, but it is important that the gas inlet 16 is at a ground potential (GND). The gas exhaust port 52 is installed in the ion source chamber 5 at the ground potential (GND). The gas exhaust port 52 may be directly fixed to the ion source chamber 5 or may be fixed to another member, but it is important that the gas exhaust port 52 is at a ground potential (GND).

  Focusing on the gas ionization chamber 6, the gas pressure of the gas introduced from the gas source 15 through the gas supply pipe 4 into the gas ionization chamber 6 is highest in the vicinity of the ionization gas inlet 16. It is known that if the gas pressure is increased, the current of the ion beam also increases. Conventionally, the extraction electrode 2 to which a voltage is applied, that is, a portion floating at a high voltage, or in the vicinity thereof, an ionization gas inlet 16. Therefore, if the gas pressure in the gas ionization chamber 6 is increased, a glow discharge is generated in the vicinity of the ionization gas inlet 16 and it is difficult to increase the ion pressure by increasing the gas pressure of the ionization gas. Met. Therefore, in this embodiment, the ionization gas inlet 16 is set to the ground potential (GND). Thereby, even if the gas pressure introduced into the gas ionization chamber 6 is increased, the occurrence of glow discharge at the ionization gas inlet 16 can be suppressed. Therefore, the ion beam apparatus of the present embodiment can increase the ion current by increasing the gas pressure of the ionized gas.

Further, since the gas pressure locally increases as the displacement increases near the gas exhaust port 52, glow discharge may occur when the gas exhaust port is at a high voltage. In the present embodiment, since the gas exhaust port of the ionization gas exhaust means is installed in the structure having the ground potential (GND), a high voltage is present in the vicinity of the gas exhaust port of the ionized gas where the gas pressure is locally high. Is not applied, and glow discharge can be suppressed even when the gas displacement is increased.

  A schematic configuration of the ion beam apparatus according to the present embodiment will be described with reference to FIG. In the following description, differences from the first and second embodiments will be mainly described.

In this embodiment, a temperature raising mechanism 62 is added to the ion beam apparatus of the first embodiment. In this embodiment, the lowest temperature part of the gas ionization chamber 6 is a connection part between the cooling mechanism 60 and the cooling conduction mechanism 61. Therefore, the temperature raising mechanism 62 is installed at a connection portion between the cooling mechanism 60 and the cooling conduction mechanism 61. As the temperature raising mechanism 62, for example, a heater or the like can be used.
Therefore, a case where a heater is used as the temperature raising mechanism 62 will be described. The emitter tip 1 is formed by forming a platinum film on the tip of tungsten. Note that the emitter tip is not limited to this combination, and may be a combination disclosed in Patent Document 1, for example. The platinum atom is moved to the tip of the emitter tip under high temperature heating, and the heater of the temperature raising mechanism 62 is energized and heated to form the lowest temperature in the gas ionization chamber 6 before forming a nanometer-order pyramid structure with platinum atoms. Increase the temperature of the part by 5K or more. Then, the impurity gas stored in the lowest temperature portion of the gas ionization chamber 6 by the cryo effect is released from the lowest temperature portion and is discharged to the outside of the gas ionization chamber 6 by the ion source chamber vacuum exhaust pump 9. After this treatment, the emitter tip is heated to a high temperature by, for example, energization heating of the emitter tip. The amount of impurity gas to be produced is very small and does not hinder the formation of a pyramid structure of nanometer order.

When the cooling mechanism 60 is a mechanical refrigerator, there is a method in which the temperature raising mechanism 62 is not a heater but a simple temperature measuring mechanism, and the cooling mechanism 60 is stopped and the temperature is naturally raised. The temperature raising mechanism 62 only confirms whether or not the temperature has increased by 5K or more. This method has an advantage that the number of components such as a heater and a heater power source can be reduced. However, there are also disadvantages that the temperature control becomes rough and cannot be applied to direct cooling with liquid nitrogen. Which method to select can be determined according to the purpose.

  With reference to FIG. 4, the structure of the ion beam apparatus concerning a present Example is demonstrated. In the following description, differences from the first to third embodiments will be mainly described.

When observing an ion microscope image, the ionized gas (or gas molecules) in the gas ionization chamber 6 is differentially exhausted through the opening 18. In observation of an ion microscope image, a rare gas is often used as an ionization gas. The differentially evacuated ionized gas (or gas molecules) enters the FIB column 31 through the sample chamber 10 with a small amount due to the difference in the degree of vacuum between the sample chamber 10 and the FIB column 31. Usually, the FIB column 31 uses an ion pump as the FIB vacuum exhaust pump 26, and the FIB ion source exhaust system valve is used to increase the vacuum degree of the vacuum vessel of the ion source (often LMIS) in the FIB column 31. 27 is closed. When the FIB vacuum exhaust pump is an ion pump having a poor rare gas exhaust capability, the rare gas accumulates in the FIB column, and the degree of vacuum of the FIB column 31 gradually deteriorates. Deterioration of the degree of vacuum may cause FIB emission failure and is a phenomenon that should be avoided. Therefore, in this embodiment, the FIB vacuum pump 26 of the first embodiment is replaced with a rare gas-compatible FIB vacuum pump 28 to avoid this problem. As the rare gas-compatible FIB vacuum pump 28, for example, a noble pump or an Excel pump is used.

  With reference to FIG. 5, the structure of the ion beam apparatus concerning a present Example is demonstrated. In the following description, differences from the first to fourth embodiments will be mainly described.

In the present embodiment, an opening valve 9 is added to the opening 18 of the first embodiment. When gas is supplied from the gas supply means 40 to the vicinity of the sample and gas-assisted etching or ion-induced deposition is performed by FIB, the gas supplied from the gas supply means 40 into the sample chamber 10 passes through the opening 18 to form a gas. There is a possibility of entering the ionization chamber 6. Therefore, the opening valve 9 is provided in the opening 18, and the gas is supplied from the gas supply means 40 into the sample chamber 10 while the opening valve 9 is closed while performing gas-assisted etching or ion-induced deposition by FIB. The gas is prevented from entering the gas ionization chamber 6.

  With reference to FIG. 6, the structure of the ion beam apparatus concerning a present Example is demonstrated. FIG. 6 shows only the ion source chamber 5 of the gas field ion source and the exhaust system for evacuating the ion source chamber 5 and the gas ionization chamber 6. In the following description, differences from the first to fifth embodiments will be mainly described.

  In this embodiment, a lens electrode 3 for accelerating or focusing an ion beam generated inside the gas ionization chamber 6 is provided, and a gas ionization chamber 6 is further provided in a vacuum container constituting the ion source chamber 5. The gas exhaust pipe 51 and the gas exhaust port 52 are provided in the gas ionization chamber 6 (the gas exhaust pipe 51 and the gas exhaust port 52 are collectively referred to as a gas exhaust unit), the gas exhaust The pipe 51 is provided with a variable valve 50, a gas ionization chamber vacuum exhaust pump 20 and an auxiliary vacuum exhaust pump 33 for exhausting the gas ionization chamber 6 to a vacuum, and the gas ionization chamber 6. The lens evacuation system is independent, the lens electrode opening 17 also serves as the gas exhaust 52, and the ionized gas (or gas molecules) in the gas ionization chamber 6 passes through the lens electrode opening 17. That is differentially pumped Te, the position of the lowest temperature portion is changed in terms of gas ionization chamber 6 to be described later, the first embodiment in that heating mechanism 62 is provided differently.

  In this embodiment, when the introduction amount of ionized gas (or gas molecules) to be introduced is increased as described in Embodiment 1 to extend the life of the emitter tip, the opening of the variable valve 50 is opened instead of adjusting the opening amount of the valve 30. By adjusting the amount, the amount of ionized gas (or gas molecules) to be introduced, the amount of differential exhaust through the lens electrode opening 17 and the amount of exhaust through the variable valve 50 with the valve opening adjusted are added. The amount of exhausted ionized gas is increased, and the amount of exhaust is adjusted so that a predetermined ionized gas pressure is obtained.

  In the present embodiment, the lowest temperature portion of the gas ionization chamber 6 is a connection portion between the lens electrode 3 and the cooling conduction mechanism 61. Therefore, the temperature raising mechanism 62 is installed at the connection portion between the lens electrode 3 and the cooling conduction mechanism 61. The rest is the same as in the third embodiment. Although not shown in FIG. 6, the temperature raising mechanism 62 is installed at the connection portion between the cooling mechanism 60 and the cooling conduction mechanism 61, which is the same as that of the third embodiment, and the gas ionization chamber is thermally conducted via the cooling conduction mechanism 61. The temperature of the lowest temperature part 6 may be increased by 5K or more.

  In addition, the lens electrode 3 of the present embodiment also serves as a radiation shield that reduces heat inflow due to heat radiation to the emitter tip 1 that is being cooled. When hydrogen or helium is used as the ionized gas, it is necessary to cool the emitter tip 1 to an extremely low temperature. Therefore, it is desirable to have a radiation shield that reduces heat inflow due to heat radiation to the emitter tip 1. Since this radiation shield is provided so as to surround the emitter tip 1, as compared with the case where there is nothing between the room temperature wall of the ion source chamber 5 and the emitter tip 1 as in the first embodiment, Heat inflow due to thermal radiation from the room temperature wall to the emitter tip can be effectively reduced. In addition, since the lens electrode 3 serves as the gas ionization chamber 6 and the radiation shield, it contributes to downsizing of the apparatus.

  Focusing on the space through which the ion beam passes in the ion source chamber 5, the gas introduced into the gas ionization chamber 6 is ionized by the emitter tip 1, extracted by the extraction electrode 2, and then accelerated and focused by the lens electrode 3. The ion beam passes through the opening 18 toward the sample chamber 10. The gas pressure in the vicinity of the emitter tip 1 is desired to maintain a high gas pressure in order to efficiently ionize the gas. On the contrary, the space through which the ionized gas passes as an ion beam is desired to be maintained at a lower gas pressure in order to prevent the ion beam from colliding with the gas and being scattered. Therefore, the gas inlet 16 is installed at the same height as the tip of the emitter tip 1 or above the tip of the emitter tip 1, and the gas exhaust port 52 is installed below the tip of the emitter tip 1. .

  In this embodiment, the lens is only one lens electrode 3, but the lens electrode may be composed of a plurality of electrodes. In the case of a plurality of electrode configurations, a voltage is applied to a lens electrode that does not constitute the gas ionization chamber 6 that is a structure in which the gas introduction port 16 and the gas exhaust port 52 are installed, for example, to adjust the virtual image point position. Anyway. This can be applied to the following embodiments.

In this embodiment, the temperature raising mechanism 62 is provided, but may be omitted as in the first embodiment.

  With reference to FIG. 7, the structure of the ion beam apparatus concerning a present Example is demonstrated. FIG. 7 shows only the ion source chamber 5 of the gas field ion source and the exhaust system for evacuating the ion source chamber 5 and the gas ionization chamber 6. In the following description, differences from the first to sixth embodiments will be mainly described.

In this embodiment, a potential state is added to the sixth embodiment. A desired potential is applied to the emitter tip 1 from the acceleration power source 7 and the extraction electrode 7 from the extraction power source 8.
The gas ionization chamber is at ground potential (GND).

  In this embodiment, the lens electrode 3 is fixed to the ground potential (GND) regardless of the operation of the ion beam apparatus. The lens electrode 3 is configured to surround the emitter tip 1 and the extraction electrode 2, and a space surrounded by the lens electrode 3 is a gas ionization chamber 6 for ionizing a gas. That is, the gas ionization chamber 6 of the present embodiment is configured by the lens electrode 3 which is a ground potential structure provided with the gas introduction port 16 and the gas exhaust port 52.

The gas introduction port 16 of the gas supply pipe 4 is installed in the lens electrode 3 having a ground potential (GND). The gas inlet 16 may be directly fixed to the ion source chamber 5 or may be fixed to another member, but it is important that the gas inlet 16 is at a ground potential (GND). The gas exhaust port 52 is installed in the lens electrode 3 having a ground potential (GND). The gas exhaust port 52 may be directly fixed to the ion source chamber 5 or may be fixed to another member, but it is important that the gas exhaust port 52 is at a ground potential (GND).

  With reference to FIG. 8, the structure of the ion beam apparatus concerning a present Example is demonstrated. FIG. 8 shows only the ion source chamber 5 of the gas field ion source and the exhaust system for evacuating the ion source chamber 5 and the gas ionization chamber 6. In the following description, differences between the first to seventh embodiments will be mainly described.

  In this embodiment, the lens electrode 3 and the radiation shield 12 are installed as different structures.

  The gas exhaust port 52 is the same as in the above-described embodiment. A cooling conduction mechanism 61 is connected to the radiation shield 12 so that the radiation shield 12 can be cooled. The temperature raising mechanism 62 is installed at a connection portion between the cooling mechanism 60 and the cooling conduction mechanism 61.

  The gas inlet 16 is installed in the radiation shield 12 having a ground potential (GND). The gas inlet 16 may be directly fixed to the radiation shield 12 or may be fixed to another member, but it is important that the gas inlet 16 is at a ground potential (GND). The gas exhaust port 52 is also installed in the radiation shield 12 having the ground potential (GND). The gas exhaust port 52 may be directly fixed to the radiation shield 12 or may be fixed to another member, but it is important that the gas exhaust port 52 is at a ground potential (GND). This suppresses the occurrence of glow discharge in the vicinity of the gas inlet 16 and the gas outlet 52 of the ionized gas when the gas pressure is increased.

  The gas ionization chamber 6 of this embodiment includes a radiation shield 12 that is a ground potential structure provided with a gas introduction port 16 and a gas exhaust port 52, and an extraction electrode 2.

The extraction electrode 2 can not only extract ions, but also function as a radiation shield by, for example, thermal insulation and cooling. For example, when the voltage applied to the emitter tip 1 and the extraction electrode 2 is relatively low and the insulation structure is simple, the gas ionization chamber 6 for storing gas can be downsized by using this embodiment. Since the ion beam apparatus itself can be reduced in size, it is effective from the viewpoint of efficiency of evacuation and energy saving.

  With reference to FIG. 9, the structure of the ion beam apparatus concerning a present Example is demonstrated. This embodiment is an embodiment of an ion microscope having observation and processing capabilities, except for the FIB column 31, the FIB vacuum exhaust pump 26, and the FIB ion source exhaust system valve 27 from the first embodiment. In the following description, differences from the first to eighth embodiments will be mainly described.

In this embodiment, an exhaust system provided with an ion source chamber vacuum exhaust pump 21 and an auxiliary vacuum exhaust pump 22 for evacuating a gas ionization chamber of a gas field ion source of an ion microscope, and other vacuum vessels are exhausted. Since the sample chamber evacuation pump 23 and the evacuation system provided with the auxiliary evacuation pump 24 are independent of each other, they are discharged from the evacuation system provided with the ion source chamber evacuation pump 21 and the auxiliary evacuation pump 22. A mixed gas of a large amount of ionized gas (or gas molecules) and an impurity gas mixed in the exhaust process flows backward from the exhaust system exhausting other vacuum vessels and passes through the sample chamber 10 and the opening 18 to the ion microscope. Intrusion into the gas ionization chamber 6 of the gas field ion source can be prevented, and ion beam emission failure and emitter tip breakdown can be avoided. Further, a gas for preventing charge up of the sample when the sample chamber 10 is irradiated with an ion beam, or an etching gas or a deposition gas in the vicinity of the sample (these gases are gases (gases) other than the ionized gas, Even if the impurity gas is introduced into the sample chamber 10 from the gas supply means 40, a gas (gas) other than the ionized gas exhausted by the sample chamber vacuum pump 23 is discharged from the ion source chamber vacuum pump. It is possible to prevent the system 21 from flowing back and entering the gas ionization chamber 6. In this case, in order to reduce the amount of etching gas and deposition gas that enters the gas ionization chamber 6 of the gas field ion source of the ion microscope through the opening 18 to a level that does not adversely affect the emission, ionization is performed. The gas (or molecule) gas pressure is adjusted according to the amount of etching gas or deposition gas.

  With reference to FIG. 10, the structure of the ion beam apparatus concerning a present Example is demonstrated. The present embodiment is an embodiment of an ion microscope having observation and processing capabilities except for the FIB column 31, the FIB vacuum exhaust pump 26, and the FIB ion source exhaust system valve 27 from the second embodiment. In the following description, differences from the first to ninth embodiments will be mainly described.

  The gas inlet 16 of the gas supply pipe 4 is installed in the ion source chamber 5 having a ground potential (GND). The gas inlet 16 may be directly fixed to the ion source chamber 5 or may be fixed to another member, but it is important that the gas inlet 16 is at a ground potential (GND). The gas exhaust port 52 is installed in the ion source chamber 5 at the ground potential (GND). The gas exhaust port 52 may be directly fixed to the ion source chamber 5 or may be fixed to another member, but it is important that the gas exhaust port 52 is at a ground potential (GND).

In order to reduce the amount of etching or deposition gas that enters the gas ionization chamber 6 of the gas field ion source of the ion microscope through the opening 18 to a level that does not adversely affect emissions, the ionization gas (or molecules) Even if the gas pressure is increased in accordance with the amount of etching gas or deposition gas, glow discharge can be suppressed because the high gas pressure portion is at the ground potential (GND).

  With reference to FIG. 11, the structure of the ion beam apparatus concerning a present Example is demonstrated. The present embodiment is an embodiment of an ion microscope having observation and processing capabilities except for the FIB column 31, the FIB vacuum pump 26, and the FIB ion source exhaust system valve 27 from the third embodiment.

Since the present embodiment has the temperature raising mechanism 62, the impurity gas accumulated by the cryo effect can be reduced as follows. The heater of the temperature raising mechanism 62 is energized and heated to raise the temperature of the lowest temperature portion of the gas ionization chamber 6 by 5K or more. Then, the impurity gas stored in the lowest temperature portion of the gas ionization chamber 6 by the cryo effect is released from the lowest temperature portion and is discharged to the outside of the gas ionization chamber 6 by the ion source chamber vacuum exhaust pump 9. After this treatment, the emitter tip is heated to a high temperature by, for example, energization heating of the emitter tip. The amount of impurity gas to be produced is very small and does not hinder the formation of a pyramid structure of nanometer order.

  With reference to FIG. 12, the structure of the ion beam apparatus concerning a present Example is demonstrated. In the following description, differences from the first to eleventh embodiments will be mainly described.

  In this embodiment, an intermediate chamber which is a space between the ion source chamber 5 and the sample chamber 10 is provided with an intermediate chamber vacuum exhaust pump 34 and an auxiliary vacuum exhaust pump 35, and independent exhaust for exhausting the intermediate chamber. Added system.

As described above, when gas assisted etching or ion induced deposition is performed by supplying a gas from the gas supply means 40 to the vicinity of the sample, the gas supplied from the gas supply means 40 into the sample chamber 10 passes through the opening 18. There is a possibility that the gas ionization chamber 6 may enter via, but by providing an independent exhaust system for exhausting the intermediate chamber, before the etching gas or deposition gas enters the gas ionization chamber 6, These gases are exhausted and removed.

DESCRIPTION OF SYMBOLS 1 Emitter tip 2 Extraction electrode 3 Lens electrode 4 Gas supply piping 5 Ion source chamber 6 Gas ionization chamber 7 Acceleration power supply 8 Extraction power source 9 Opening valve 10 Sample chamber 12 Radiation shield 15 Gas source 16 Gas introduction port 17 Lens electrode opening 18 Opening 19 Extraction electrode opening 20 Gas ionization chamber vacuum pump 21 Ion source vacuum pump 22 Auxiliary vacuum pump 23 Sample chamber vacuum pump 24 Auxiliary vacuum pump 26 FIB vacuum pump 27 FIB ion Source exhaust system valve 28 Noble gas compatible FIB vacuum pump 30 Valve 31 FIB column 33 Auxiliary vacuum exhaust pump 34 Intermediate chamber vacuum exhaust pump 35 Auxiliary vacuum exhaust pump 40 Gas supply means 50 Variable valve 51 Gas exhaust pipe 52 Gas Exhaust port 60 Cooling mechanism 61 Cooling transmission Mechanism 62 heating mechanism

Claims (10)

In a composite charged particle beam apparatus comprising: an ion beam apparatus that observes or processes a sample by irradiating the sample with an ion beam generated from a gas field ion source; and a charged particle beam apparatus.
The gas field ion source is
An emitter tip to be the anode,
An extraction electrode serving as a cathode;
A vacuum vessel containing at least an emitter tip;
A gas inlet for supplying ionized gas to the space between the tip of the emitter tip and the extraction electrode;
A gas exhaust port for exhausting ionized gas,
A composite charged particle beam apparatus comprising: an ionized gas exhaust system that exhausts an ionized gas independent from an exhaust system that exhausts a charged particle beam apparatus and a sample chamber in which a sample is disposed.
The composite charged particle beam apparatus according to claim 1,
A composite charged particle beam apparatus, wherein a gas discharge port and / or a gas inlet port is provided in a structure having a ground potential.
The composite charged particle beam apparatus according to claim 1,
A composite charged particle beam apparatus comprising a temperature raising mechanism capable of raising the temperature of a lowest temperature portion of a gas ionization chamber by 5K or more.
The composite charged particle beam apparatus according to claim 1,
The charged particle beam device is an ion beam device provided with a liquid metal ion source,
A composite charged particle beam apparatus characterized in that an exhaust system of a vacuum container that accommodates the liquid metal ion source includes a vacuum pump that can exhaust an inert gas.
The composite charged particle beam apparatus according to claim 1,
The charged particle beam device is an ion beam device provided with a liquid metal ion source,
A composite charged particle beam apparatus characterized in that an exhaust system of a vacuum container that accommodates the liquid metal ion source includes a noble pump or an Excel pump.
The composite charged particle beam apparatus according to claim 1,
The gas field ion source includes a valve that separates at least a vacuum vessel that houses an emitter tip from another vacuum vessel.
In an ion beam apparatus for observing or processing a sample by irradiating the sample with an ion beam generated from a gas field ion source,
The gas field ion source is
An emitter tip to be the anode,
An extraction electrode serving as a cathode;
A vacuum vessel containing at least an emitter tip;
A gas inlet for supplying ionized gas to the space between the tip of the emitter tip and the extraction electrode;
A gas exhaust port for exhausting ionized gas,
An ion beam apparatus comprising: an ionized gas exhaust system that exhausts an ionized gas that is not connected to an exhaust system that exhausts a sample chamber in which a sample is disposed.
The ion beam apparatus according to claim 7.
An ion beam apparatus characterized in that a gas exhaust port and / or a gas inlet port is provided in a ground potential structure.
The ion beam apparatus according to claim 7.
An ion beam apparatus comprising a temperature raising mechanism capable of raising the temperature of a lowest temperature portion of a gas ionization chamber by 5K or more.
The ion beam apparatus according to claim 7.
An ion beam apparatus comprising an independent exhaust system for exhausting a space between an ion source chamber and a sample chamber of a gas field ion source.