JP2010153278A - Charged particle beam processing device - Google Patents

Abstract

【Task】
The present invention solves defective problems such as processing point position shift, focus shift, and image quality deterioration caused by beam resolution decrease, caused by reactive gas flowing into an optical column in a charged particle beam processing apparatus. About doing.
[Solution]
The present invention relates to the formation of a gas curtain in the vicinity of an objective lens to prevent the flow of reactive gas into an optical column. According to the present invention, it is possible to reduce the degree of vacuum in the optical barrel and the formation of an insulating film in the optical barrel, and to improve the processing performance and the apparatus operating rate.
[Selection] Figure 1

Description

  The present invention relates to a charged particle beam processing apparatus that performs observation and analysis of a semiconductor device or the like, or preparation of a micro sample for measurement, for example, an apparatus using an ion beam or an electron beam.

  A charged particle beam processing apparatus, for example, a FIB (Focused Ion Beam) apparatus, can finely process a sample. In addition to processing by sputtering, it is possible to perform deposition processing by irradiating a sample with an ion beam while irradiating a deposition gas. This is called the GAD (Gas Assisted Deposition) method.

  Further, by irradiating an ion beam while irradiating an etching gas, an etching rate several times as high as that obtained by only ion beam sputtering can be obtained. This is because the reactive gas generates a substance having a higher vapor pressure than the sputtered particles, thereby suppressing reattachment to the sample. This method is called a GAE (Gas Assisted Etching) method.

GAD is used for correction of wiring on a chip. An example of the deposition gas is WCO6 (tungsten hexacarbonyl). By GAD, a W deposition film can be formed to connect the wirings. Examples of other deposition films include a carbon film, a platinum film, and a silicon oxide film. Typically, TEOS (tetraethoxysilane, Si (OC ₂ H ₅ ) ₄ )) or the like is used for forming the silicon oxide film.

GAE is used when a high aspect ratio processed hole is formed in an interlayer insulating film. As the gas, a reactive gas such as XeF ₂ (xenon difluoride gas) or chlorine gas is used.

  Since the supply pressure value of the reactive gas used in GAD and GAE is higher than the pressure value inside the optical column that is high vacuum by the exhaust system such as a turbo molecular pump or ion pump, a part of the reactive gas is The pressure difference may flow into the optical column. The inflow of the reactive gas lowers the degree of vacuum in the optical column. Depending on the degree of vacuum, insulation failure or discharge of the objective lens to which a high voltage is applied may occur, causing a rapid change in contrast or focus shift. In addition, when a reactive gas adheres to the surface of the optical element in the optical column, the deposit is decomposed by electrons and ions generated by the collision between the charged particle beam and the residual gas in the optical column, and an insulating film is formed. May form. When an insulating film is generated, charge of electrons and ions accumulates on the insulating film, and the beam resolution decreases and image quality deteriorates due to increased drift due to charged particle beam and aberration due to axial deviation. .

  There are the following known examples for solving these problems.

  For example, in Japanese Patent Application Laid-Open No. 2005-222748, a reactive gas is supplied by a gas nozzle, and in the vicinity of a processing point, the reactive gas is prevented from diffusing into the sample chamber at a position facing the supply nozzle. An exhaust nozzle is provided. A heater for adsorbing and desorbing the reactive gas is provided on the surface of the gas nozzle.

  Further, in Japanese Patent Application Laid-Open No. 2007-234583, a disk-like gas supply or discharge structure having a gas supply port and an exhaust port is arranged in the vicinity of a processing point instead of a gas nozzle, and reactive gas is ejected to the processing point. ing.

  In Japanese Patent Laid-Open No. 2001-319614, volatile contaminants from an organic film, which is a sample, generated by electron beam irradiation adhere to a transmission window portion of an electron beam processing apparatus, and this attached film is electron beam energy. In order to absorb this and prevent the transmission window from being damaged, an inert gas is irradiated in the vicinity of the transmission window, and this inert gas is discharged by an exhaust pump disposed in the sample chamber.

JP 2005-222748 A JP 2007-234583 A JP 2001-319614 A

However, the prior arts 1 to 3 have the following problems.

(1) When reactive gas is ejected to a sample with a nozzle, the reactive gas spreads rapidly and diffuses in the vicinity of the processing point, so it is difficult to completely collect and exhaust with the exhaust nozzle. It has been difficult to completely prevent the inflow into the optical column.
(2) Since a reactive gas supply or exhaust structure having a shape of a disk or the like is arranged between the sample and the objective lens, secondary electrons are blocked by the reactive gas supply or discharge structure, and secondary electron detection The amount of secondary electrons that reach the container decreases, and as a result image quality deteriorates. In addition, the reactive gas may flow out of the reactive gas supply and the beam irradiation hole of the exhaust structure and the gap between the reactive gas supply and the exhaust structure and the sample and may flow into the optical column. It was.
(3) Since the inert gas flows in the sample chamber until it is exhausted by the exhaust pump in the sample chamber, the degree of vacuum in the sample chamber decreases, the charged particle beam collides with the supplied residual gas, and the electron beam There was a problem that the kinetic energy was lost, the current value gradually decreased while reaching the sample, and the sample processing speed decreased.

  The present invention has been made in view of the above-described problems of the prior art. In a charged particle beam processing apparatus, a processing point position shift and a focus shift caused by a reactive gas flowing into an optical column. In addition, the present invention relates to solving a defect problem such as image quality degradation accompanying a decrease in beam resolution.

  The present invention relates to the formation of a gas curtain in the vicinity of an objective lens to prevent the flow of reactive gas into an optical column.

  According to the present invention, it is possible to reduce the degree of vacuum in the optical barrel and the formation of an insulating film in the optical barrel, and to improve the processing performance and the apparatus operating rate.

  In the embodiment, a sample chamber in which a sample stage for holding a sample and a gas nozzle for supplying a reactive gas are arranged; a charged particle source, and a charged particle beam extracted from the charged particle source are irradiated on the sample A charged particle beam processing apparatus comprising: a gas curtain forming unit configured to form a gas curtain that prevents a reactive gas from entering the optical lens barrel via the objective lens; Disclose.

  Moreover, in an Example, it discloses that the gas curtain formation means is arrange | positioned in the vicinity of an objective lens so that a gas curtain may be formed in the front surface of an objective lens.

  In the embodiment, the charged particle beam emitted from the optical column does not substantially interfere with the gas curtain, and the reactive gas traveling from the sample side to the optical column is substantially introduced into the optical column by the gas curtain. It is disclosed to adjust the pressure and / or flow rate of the gas forming the gas curtain so that it does not flow in.

  In addition, the embodiment discloses that the gas curtain is formed by the gas supplied from the entire outer periphery of the beam that passes through the objective lens unit.

  In addition, the embodiment discloses that the gas curtain is formed of an inert gas such as argon gas, nitrogen, krypton, xenon, or neon gas, or a gas for generating charged particles.

  Moreover, in an Example, when supplying reactive gas, it discloses that a gas curtain is formed.

  In addition, the embodiment discloses that the charged particle beam is a focused ion beam, an electron beam, or a projection ion beam.

  In addition, in the embodiment, a sample chamber in which a sample stage for holding a sample and a gas nozzle for supplying a reactive gas are arranged; a charged particle source, and a charged particle beam extracted from the charged particle source are used as a sample An objective lens for irradiating; and a supply port for supplying an inert gas toward the charged particle beam irradiated from the objective lens; and an exhaust port for discharging the inert gas. Disclosed is a charged particle beam processing apparatus provided.

  In addition, the embodiment discloses that the supply port and the exhaust port are disposed in the vicinity of the objective lens so that the inert gas is supplied to the front surface of the objective lens.

  Moreover, in an Example, providing the control apparatus which adjusts the pressure and / or flow volume of the inert gas supplied from a supply port is disclosed.

  Further, the embodiment discloses that the degree of vacuum at the exhaust port is higher than the degree of vacuum inside the optical barrel.

  Moreover, in an Example, it discloses that the exhaust port is arrange | positioned in the position facing a supply port.

  In addition, the embodiment discloses that a plurality of supply ports are provided.

  Moreover, in an Example, it discloses that the several supply port is arrange | positioned in the perimeter of the beam outer periphery which passes an objective lens.

  Moreover, in an Example, providing a some exhaust port is disclosed.

  In addition, the embodiment discloses that a control unit that controls a supply unit of the inert gas is provided so that the inert gas is supplied from the supply port when the gas nozzle is supplying the reactive gas.

  Moreover, in an Example, using the gas for charged particle production | generation as an inert gas is disclosed.

  In the embodiment, an inert gas such as nitrogen gas other than the reactive gas is ejected so as to form a gas curtain in the vicinity of the objective lens so that the reactive gas does not flow into the optical column.

  Further, in this embodiment, the supplied gas increases the pressure value in the optical column and the sample chamber, and in the process until the charged particle beam reaches the sample, the gas collides with the sample. An exhaust system is provided in the vicinity of the objective lens in order to avoid problems such as the current value gradually decreasing while it reaches and the charged beam focusing state changing.

  Further, in this embodiment, the degree of vacuum at the gas suction port of the exhaust mechanism for exhausting gas is set to be higher than the degree of vacuum inside the optical barrel, and the supplied gas leaks to other than the gas exhaust pipe. Is preventing.

  Further, in this embodiment, not only one supply and exhaust gas nozzle is used as a gas supply method, but a plurality of gas nozzles are provided, and a gas discharge port is provided at a position facing the supply port. Alternatively, the gas is ejected from the entire circumference of the charged particle beam, and the exhaust part is provided in the vicinity of the objective lens.

  In this embodiment, the gas supply pressure value and flow rate are compared with the probability of collision between the charged particle beam and the gas, and the probability of collision between the reactive gas and the gas is increased. The value does not flow into the interior.

In this embodiment, an inert gas such as N ₂ gas is selected as the gas species, so that the charged particle beam collides with the gas and the radicals and ions generated by decomposition reach the sample surface. , So as not to react with the sample surface. Further, by making the gas species the same as the charged particle beam generating gas species, radicals and ions generated by collision and decomposition with the gas are made the same as the beam species, and the influence on the sample is minimized.

  Further, in this embodiment, the flow resistance value at the gas nozzle is sufficiently larger than the resistance values other than the gas nozzle flow path so that the gas is uniformly ejected to the charged particle beam.

  Further, in this embodiment, the reactive gas is prevented from entering the optical column by ejecting the gas in the vicinity of the objective lens at least while the reactive gas is irradiated to the processing point.

  The above and other novel features and effects of the present invention will be described below with reference to the drawings. The drawings are exclusively used for understanding the invention and do not reduce the scope of rights. In addition, the embodiments can be appropriately combined.

  FIG. 1 is a cross-sectional view illustrating a configuration of a focused ion beam apparatus according to the present embodiment.

  The ion optical column 14 includes an ion source 1 and a processing optical system that guides the ion beam 2 drawn from the ion source 1 to a processing point. In the sample chamber 13, a sample holder (not shown) for mounting the sample 11, a stage 12 for moving the sample holder, and a secondary electron detector (not shown) for detecting secondary electrons generated when the ion beam 2 is irradiated. ), A gas gun 21 for ejecting the reactive gas 23 from the deposition gas nozzle 22 is disposed in the vicinity of the processing point. In addition, the focused ion beam device includes a power source (not shown), a central control device (not shown) for overall control, an exhaust system, and the like. The sample 11 here includes a magnetic head other than a wafer, a liquid crystal, and the like.

  Each part will be described below.

  The ion beam 2 extracted from the ion source 1 by the extraction electrode 3 is weakly focused by the focusing lens 4 and is irradiated to the diaphragm 5 having a plurality of holes. The ion beam that has passed through the diaphragm 5 is deflected and adjusted for astigmatism by an aligner / stagma 6. The scanning deflection electrode 9 scans the ion beam and makes it incident on the objective lens 10. The objective lens 10 focuses and irradiates the sample 11 with the beam. When the sample 11 is irradiated with a beam, reflected electrons and secondary electrons are emitted and attracted by an electric field of a scintillator (not shown) to which a positive potential is applied in a secondary electron detector (not shown) and accelerated. Light up the scintillator. The emitted light enters a photomultiplier tube by a light guide (not shown) and is converted into an electric signal. The output of the photomultiplier tube is further amplified to change the luminance of the cathode ray tube (not shown). By synchronizing with the scan, a secondary electron image at the processing point is obtained. Further, the ion beam is deflected by the blanker 7 and incident on the Faraday cup 8 to measure the ion beam current value.

  When performing GAD or GAE, the gas gun 21 irradiates the processing point with the reactive gas 23 by bringing the gas nozzle 22 close to a height of several hundred μm from the retreat position of the gas nozzle 22. As the reactive gas 23, WCO6 (tungsten carbonyl) or the like is used when a conductive film such as tungsten is formed, and TEOS (tetraethoxysilane) or the like is used when a silicon oxide film is formed.

  In order to prevent the reactive gas 23 from entering the inside of the ion optical column 14, an inert gas such as nitrogen is flowed as the gas 32 in the vicinity of the objective lens 10. By this flow, a gas curtain 34 of the gas 32 is formed. The gas 32 is supplied from a gas cylinder 25. In order to keep the pressure constant, the pressure is reduced by a regulator 26 and supplied by a flow rate adjusting valve 27, a pneumatic operation valve 28 that performs ON / OFF control of the gas 32, and a gas supply pipe A 30. The gas 32 is exhausted by the gas exhaust pipe A31 and the vacuum pump 33 which are arranged at positions opposed to it. The reason for providing the gas exhaust pipe A31 is to prevent an increase in pressure in the sample chamber due to gas supply. When the pressure in the sample chamber rises, the pressure value in the ion optical column 14 also increases due to gas inflow, and the withstand voltage in the objective lens deteriorates and the observation image deteriorates due to the occurrence of discharge.

  FIG. 2 is a diagram showing the gas supply and exhaust conditions in the vicinity of the objective lens downstream side. The exhaust speed of the vacuum pump 33 is set so that the suction by the gas exhaust pipe A31 has a higher degree of vacuum than the degree of vacuum in the ion optical column. This is to prevent the gas from flowing into the ion optical column 14 and the reactive gas from flowing in together.

  FIG. 3 is a diagram schematically showing the movement of gas molecules, deposition gas molecules, and ion beam particles. When accelerating the ion beam 2 at several tens of kV, the speed of the ion beam 2 is compared with the speed at which it flows from the gas supply pipe A30 into the gas exhaust pipe A31, depending on conditions such as the gas pressure value and flow rate to be supplied. Is quick to miss. Accordingly, when observed from the ion beam 2, the gas molecules 35 in the gas curtain 34 appear to be almost stationary due to the difference in velocity.

  On the other hand, the gas molecules 35 and the deposition gas molecules 24 have relatively close velocities compared to the ion beam 2. When the collision frequency is considered, the collision frequency becomes larger when the speed is comparable as compared with the case where one of the two is stationary. Therefore, although depending on the gas pressure value to be supplied, in a certain gas pressure range, the ion beam 2 hardly collides with the gas molecules 35 in the gas curtain 34, and most of the deposition gas molecules 24 are gas molecules 35 in the gas curtain 34. And rides on the gas flow of the gas curtain 34 and flows into the gas exhaust pipe A31. When the ion beam 2 collides with gas molecules 35 in the gas curtain 34, the gas molecules 35 are ionized. The original ion beam is neutralized and ions of gas molecules 35 in the gas curtain 34 are formed. The ion beam that reaches the sample includes ions of gas molecules 35, neutral particles, electrons, and the like. As the ion beam loses energy due to ionization, it decelerates and loses energy. Further, due to the change in the amount of charge accompanying ionization, the force acting between the particles changes, and the beam shape changes. As a result, processing speed (deposition speed, etching speed), deposition film shape change, etching processing hole shape change, and the like occur. For this reason, the supply gas pressure value and flow rate value are such that the collision frequency between the ion beam 2 and the gas molecules 35 in the gas curtain 34 is minimized, and the collision frequency between the deposition gas molecules and the gas molecules 35 in the gas curtain 34 is minimized. Needs to be as large as possible so that the deposition gas molecules 24 do not flow into the optical column.

  FIG. 4 is a diagram showing gas flow timings in the FIB apparatus shown in FIG. While the reactive gas 23 is flowing, it is necessary to flow the gas 32 at least. First, the gas 32 whose flow rate or pressure value has been adjusted by the flow rate adjusting valve 27 or the regulator 26 is supplied so that the pressure differential valve 28 is opened from the closed state and the gas curtain 34 is formed in the vicinity of the objective lens 10. . Next, the deposition gas nozzle 22 is moved from the retracted position to the processing point, the valve (not shown) is opened, and the reactive gas 23 is irradiated. The diaphragm 5 is moved to a predetermined position, an ion beam having a relatively large size for processing is taken out, and the sample 11 is imaged and scanned. By GAD, a deposit film is formed on the sample surface. Similarly, when GAE is performed by supplying an etching gas, it is possible to perform drilling at high speed. After the processing, the deposition or etching nozzle is returned to the retracted position, the deposition gas is turned off, and the compressed air differential valve 28 is closed from the open state. The diaphragm 5 is moved, an ion beam having a relatively small size is taken out, an observation image with a high resolution is obtained, and the processing finish is observed.

  According to the present embodiment, it is possible to solve problems such as processing defects such as processing point position shift and focus shift and image quality deterioration due to beam resolution reduction, and improve the processing performance of the apparatus. Further, the operating rate of the apparatus can be improved by extending the life of the optical element. This makes it possible to provide a charged particle beam device with high performance and high availability.

  In this embodiment, a gas curtain is formed by a plurality of gas supply pipes and gas exhaust pipes instead of one gas supply pipe as shown in the first embodiment. Hereinafter, the main differences from the first embodiment will be mainly described.

  FIG. 5A shows a case where the gas 32 is irradiated from the left half toward the center of the ion beam 2 and the gas 32 is exhausted from the right half of the outer periphery of the ion beam 2 by a plurality of gas supply pipes. Yes. Gas is supplied from one gas supply pipe B40 connected to the five gas nozzles. Similarly, a plurality of exhaust gas nozzles 42 are arranged at positions facing this, collected by one gas exhaust pipe B41, and sucked by the vacuum pump 33. The state of the gas flow path resistance in each gas flow path at this time is schematically shown in FIG. The flow path resistance value varies depending on the gas supply pressure value, but is substantially determined by the shape of the gas flow path.

  FIG. 6 is a diagram in which the flow path resistance of the gas flow in FIG. 5B is replaced with a simple electric circuit. The gas supply pressure corresponds to the voltage V. The flow rate of the gas flowing through each flow path corresponds to the value of the current flowing through each resistor in FIG. In order to make the gas flow rate flowing through each gas nozzle uniform (I3a≈I3b≈I3c≈I3d≈I3e), it is understood that the resistance value may be expressed by the following equation.

R3a, b, c, d, e >> R1, R2a, b, c, d
This can be realized by making the pipe inner diameter of each gas nozzle 42 sufficiently smaller than the inner diameter of the gas supply pipe B40 and increasing the length. Such microfabrication can be performed by MEMS (Micro Electro Mechanical Systems) using silicon.

  In this embodiment, gas is ejected from the entire circumference of the ion beam. Hereinafter, the main differences from the above-described embodiment will be mainly described.

  FIG. 7 is a diagram showing a case where the gas 32 is ejected from the entire outer periphery of the ion beam 2 and the gas exhaust is performed by the gas exhaust pipe 41B provided downstream. The gas exhaust pipe B41 is not provided with a gas nozzle, and gas is exhausted from the inner surface of the gas exhaust pipe B41. Thereby, efficient gas exhaust becomes possible.

  In this embodiment, an application example to an ion beam apparatus using a Butler lens is shown. Hereinafter, the main differences from the above-described embodiment will be mainly described.

  FIG. 8 shows a diagram in which the objective lens 10 is constituted by three Butler lenses, and the gas supply pipe B40 and the gas exhaust pipe B41 are arranged inside the objective lens 10. FIG. Of the three lenses, only the middle one is given a potential by the power supply 50, and the ion beam is focused by this electric field distribution. The main influence on the focusing of the ion beam 2 is the electric field distribution in the vicinity of the hole through which the ion beam passes. If the gas supply pipe and the exhaust pipe are arranged at positions away from the vicinity of the hole, the ion beam focusing state is affected. It is possible to minimize the influence without giving a large influence. In FIG. 8, a gas nozzle is used as the gas supply method, but a plurality of gas nozzles shown in FIGS. 5 and 7 may be used.

  In this embodiment, an application example to a scanning electron microscope apparatus is shown. Hereinafter, the main differences from the above-described embodiment will be mainly described.

  FIG. 9 is a cross-sectional view illustrating the configuration of the scanning electron microscope apparatus according to the present embodiment. The electron beam 60 extracted from the SE (Schottky emission) electron source 51 by the extraction electrode 3 and the acceleration electrode 52 is focused by the focusing lens 53A in the vicinity of the aperture 54 having a plurality of holes. Unnecessary parts are cut. Astigmatism is corrected by further converging the electron beam 60 of only the central portion by the converging lens 53B, and changing the electron beam shape from an ellipse to a circle by the astigmatism corrector 57. An electromagnetic beam is scanned by the scanning deflection coil 58, is incident on the objective lens 59, and forms an image on the surface of the sample 11. The primary electron beam is not deflected by the orthogonal electromagnetic field generator 56, and secondary electrons (not shown) emitted from the sample 11 when the electron beam is incident have a relatively low energy of several electron volts. Therefore, it rises while rotating spirally by the magnetic field of the objective lens. Since the direction of motion is opposite to that of the primary electron beam, it is deflected and incident on the secondary electron detector 55 side. The secondary electron signal is processed by a microcomputer (not shown) in synchronization with scanning of the electron beam, and is displayed as a sample image on an image display (not shown). The GAD by the electron beam is the same as that described in FIG. While the reactive gas is irradiated, the gas forming the gas curtain is caused to flow in the vicinity of the objective lens 59. Considering the collision frequency between gas molecules and ions and gas molecules and electrons, since the electron radius is negligibly smaller than that of gas molecules, the collision probability between gas molecules and electrons is compared with the collision between gas molecules and ions. It becomes about 1/4. The electron beam has less interference with the gas layer than the ion beam, and reaches the sample surface.

  In this embodiment, an application example to an objective lens constituted by an excitation coil and a magnetic yoke will be described. Hereinafter, the main differences from the above-described embodiment will be mainly described.

  FIG. 10 shows a view in which the objective lens 59 is constituted by an exciting coil 61 and a magnetic yoke 62, and a gas supply pipe B40 and a gas exhaust pipe B41 are arranged inside the objective lens. It is the electric field distribution in the vicinity of the hole of the magnetic yoke 62 through which the electron beam 60 passes that mainly affects the degree of focusing of the electron beam 2. If the gas supply pipe and the exhaust pipe are arranged at positions away from the vicinity of the hole, The influence can be minimized without greatly affecting the focusing state of the electron beam. In this figure, a gas nozzle is used as a gas supply method, but it may be constituted by a plurality of gas nozzles shown in FIGS.

  In this embodiment, an application example to a projection ion beam processing apparatus is shown. Hereinafter, the main differences from the above-described embodiment will be mainly described.

  FIG. 11 is a cross-sectional view illustrating the configuration of the projection ion beam processing apparatus according to the present embodiment. As the ion source 1, a duoplasmatron was used. When oxygen gas 71 is allowed to flow through the cathode 72 to obtain a gas pressure of several Torr and a DC voltage is applied between the cathode 72 and the anode electrode (not shown), glow discharge occurs during this time and ions collide with the cathode 72. The electrons are accelerated to the anode electrode. The accelerated electrons ionize and ionize the gas before colliding with the anode electrode. Since electrons and ions are confined by a magnetic field generated by a permanent magnet (not shown), a high density plasma is generated. From this plasma, the ion beam 2 is extracted from the anode button 73 by an electric field with the extraction electrode 74 having a ground potential. As the gas, an inert gas such as argon gas, nitrogen, krypton, xenon, or neon gas can be used in addition to the above oxygen gas.

  The above ion source was an example of a duoplasmatron that confines plasma by a magnetic field and an electric field, but a monoplasmatron that confines plasma by either a magnetic field or an electric field, The present invention can be similarly applied to a PIG type ion source, a microwave ion source, and the like.

  The processing optical system includes a mass separator (not shown), a deflector (not shown), a focusing lens 4, a projection mask 76 having a plurality of processing pattern holes, an astigmatism corrector 77, a blanker 7, a Faraday cup 8, The scanning deflection electrode 9 and the projection lens 78 are used.

  The ion beam 2 drawn out from the ion source 1 is focused in the vicinity of the principal point of the projection lens 78 in order to reduce aberrations by the focusing lens 4 constituted by three Butler lenses. The ion beam that has passed through the projection mask 76 is imaged on the surface of the sample 11 at a reduction ratio of about 1/16 by a projection lens 78 that is also composed of three Butler lenses. It is also possible to scan with the scanning deflection electrode 9 to form an image for observation and processing.

  The projection mask 76 has a U-shaped opening for microsampling extraction, an opening mainly for a deposition, an opening hole mainly used for observation, etc., and other vertical and width for thin film processing (not shown). A slit-like opening hole having a relatively large aspect ratio is formed, and only the ion beam that has passed through the hole is transferred onto the sample 11 for observation or processing.

  As described above, in order to prevent the reactive gas 23 from entering the inside of the ion beam optical column 14, an inert gas such as nitrogen is flowed in the vicinity of the objective lens 10 to form a curtain 34 of the gas 32. The reactive gas 23 is prevented from flowing into the ion optical column 14.

1 is a diagram illustrating an overall configuration of a charged particle beam apparatus according to Embodiment 1. FIG. FIG. 3 is a diagram showing a gas supply and exhaust method used in Example 1. The figure which shows the motion of the gas molecule in Example 1, a deposition gas molecule | numerator, and an ion beam particle. FIG. 3 is a diagram showing a sample processing flow in Example 1; The figure which shows the gas supply and exhaust method used in Example 2. FIG. The figure which replaced the channel resistance in the gas channel pipe in Example 2 with the electric circuit. FIG. 10 is a diagram illustrating another gas supply and exhaust method used in the third embodiment. FIG. 10 is a diagram illustrating a state where a gas supply / exhaust unit is provided inside an objective lens according to a fourth exemplary embodiment. FIG. 10 is a diagram illustrating an overall configuration of a charged particle beam apparatus according to a fifth embodiment. FIG. 10 is a diagram illustrating a state where a gas supply / exhaust unit is provided inside an objective lens according to a sixth exemplary embodiment. FIG. 10 is a diagram illustrating an overall configuration of a charged particle beam apparatus according to a seventh embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ion source 2 Ion beam 3,74 Extraction electrode 4,53A, 53B Focusing lens 5,54 Diaphragm 6 Aligner, Stagma 7 Blanker 8 Faraday cup 9 Scanning deflection electrode 10, 59 Objective lens 11 Sample 12 Stage 13 Sample chamber 14 Ion Optical barrel 21 Gas gun 22, 42 Gas nozzle 23 Reactive gas 24 Deposition gas molecule 25 Gas cylinder 26 Regulator 27 Flow adjustment valve 28 Pneumatic differential valve 30 Gas supply pipe A
31 Gas exhaust pipe A
32, 71 Gas 33 Vacuum pump 34 Gas curtain 35 Gas molecule 40 Gas supply pipe B
41 Gas exhaust pipe B
50 Power supply 51 Electron source 52 Accelerating electrode 55 Secondary electron detector 56 Orthogonal electromagnetic field generators 57 and 77 Astigmatism corrector 58 Scanning deflection coil 60 Electron beam 61 Excitation coil 62 Magnetic yoke 72 Cathode 73 Anode button 76 Projection mask 78 Projection lens

Claims (18)

A sample chamber in which a sample stage for holding a sample and a gas nozzle for supplying a reactive gas are disposed;
An optical column having a charged particle source, and an objective lens that irradiates the sample with a charged particle beam extracted from the charged particle source;
Having
A charged particle beam processing apparatus comprising gas curtain forming means for forming a gas curtain for preventing the reactive gas from entering the optical column through the objective lens. The charged particle beam processing apparatus according to claim 1,
The apparatus characterized in that the gas curtain forming means is disposed in the vicinity of the objective lens so that the gas curtain is formed on the front surface of the objective lens. The charged particle beam processing apparatus according to claim 1,
The charged particle beam emitted from the optical column does not substantially interfere with the gas curtain, and the reactive gas from the sample side toward the optical column substantially flows into the optical column by the gas curtain. The apparatus is characterized in that the pressure and / or flow rate of the gas forming the gas curtain is adjusted. The charged particle beam processing apparatus according to claim 1,
The apparatus is characterized in that the gas curtain is formed by the gas supplied from the entire circumference of the beam outer circumference passing through the objective lens section. The charged particle beam processing apparatus according to claim 1,
The gas curtain is formed of an inert gas or a gas for generating charged particles. The charged particle beam processing apparatus according to claim 1,
The apparatus is characterized in that the gas curtain is formed when a reactive gas is supplied. The charged particle beam processing apparatus according to claim 1,
The charged particle beam is a focused ion beam, an electron beam, or a projection ion beam. A sample chamber in which a sample stage for holding a sample and a gas nozzle for supplying a reactive gas are disposed;
An optical column having a charged particle source, and an objective lens that irradiates the sample with a charged particle beam extracted from the charged particle source;
Having
A supply port for supplying an inert gas toward the charged particle beam irradiated from the objective lens;
A charged particle beam processing apparatus comprising: an exhaust port for discharging the inert gas. The charged particle beam processing apparatus according to claim 8,
The apparatus is characterized in that the supply port and the exhaust port are disposed in the vicinity of the objective lens so that an inert gas is supplied to the front surface of the objective lens. The charged particle beam processing apparatus according to claim 8,
A device comprising a control device for adjusting the pressure and / or flow rate of the inert gas supplied from the supply port. The charged particle beam processing apparatus according to claim 8,
The apparatus according to claim 1, wherein the degree of vacuum at the exhaust port is higher than the degree of vacuum inside the optical column. The charged particle beam processing apparatus according to claim 8,
The apparatus is characterized in that the exhaust port is arranged at a position facing the supply port. The charged particle beam processing apparatus according to claim 8,
An apparatus comprising a plurality of supply ports. The charged particle beam processing apparatus according to claim 8,
An apparatus characterized in that a plurality of supply ports are arranged on the entire circumference of the outer periphery of the beam passing through the objective lens. The charged particle beam processing apparatus according to claim 8,
An apparatus comprising a plurality of exhaust ports. The charged particle beam processing apparatus according to claim 8,
An apparatus comprising control means for controlling an inert gas supply means so that an inert gas is supplied from the supply port when the gas nozzle is supplying a reactive gas. The charged particle beam processing apparatus according to claim 8,
An apparatus using a gas for generating charged particles as an inert gas. The charged particle beam processing apparatus according to claim 8,
The charged particle beam is a focused ion beam, an electron beam, or a projection ion beam.

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