JP2008098232A - Gas introducing device for focused ion beam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas introducing device for a focused ion beam capable of improving processing performance for a sample. <P>SOLUTION: The device capable of gas-assisted etching or metal deposition unit using a focused ion beam has a plurality of pipes 8 as a plurality of fluid delivery systems under an ion beam lens barrel. Nozzles 8a serving as exits of the pipes 8 are symmetric with an axis of a primary ion beam 17 and structured in such a form that a fluid passing inside flows toward a surface of the sample 18. Injection conditions of a gas introduced to the pipes 8 can be individually controlled, and a mechanism for coupling the pipes with one another is provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a focused ion beam gas introducing device, and more particularly to a focused ion beam gas introducing device which performs correction / repair (repair), wiring correction, and fine processing of a mask used in a semiconductor manufacturing process.

  Ion beam assisted etching or beam assisted deposition techniques called GAE (Gas Assist Etching) and MDU (Metal Deposition Unit) are becoming increasingly important as ion beam related businesses. As a conventional apparatus of this type, a technique is known in which a compound vapor having a relatively low vapor pressure is ejected in a beam shape using a nozzle (see, for example, Patent Document 1). Some nozzles are arranged such that a plurality of nozzles are arranged on the circumference so that the gas beam is ejected uniformly. In addition, when the vapor pressure of the workpiece is high, a technique is known in which the entire sample is covered with gas and a hole for allowing the beam to pass only at the entrance of the ion beam is provided (for example, see Non-Patent Document 1).

In addition, a gas introduction pipe is provided at the tip of the ion beam, and upper and lower holes are provided in the pipe. When the primary ion beam passes through one of the two holes, the gas introduced from the pipe is ionized, and the other It is known that the processing performance is further improved by irradiating a composite beam of primary ions and secondary ions from a hole (see, for example, Patent Document 2). In addition, as a fluid introduction tube system that carries the introduction gas, the tip is shaped like an inverted funnel-shaped vessel, and a focused ion beam is introduced from the narrow upper end of the fluid introduction tube to promote reaction of processing performance, etc. A technique using molecular energy is also known (see, for example, Patent Document 3).
Japanese Examined Patent Publication No. 2-25425 (2nd page, 4th line, 4th line to 44th line, FIG. 1) JP-A-8-17385 (paragraphs 0007 to 0008, FIGS. 1 and 4). Japanese Patent No. 3640261 (pages 6 to 7, FIGS. 1 and 2) RIKEN 15th Symposium "Ion Implantation and Submicron Processing" (1984) 121-124

  When the gas inlet tube (hereinafter abbreviated as nozzle) is moved three-dimensionally on the sample surface, it is difficult to make fine adjustments at micrometer or less due to minute vibration at the tip, and the nozzle and sample surface collide. Things are happening too. This is because the tip of a nozzle having a length of several tens of centimeters is moved horizontally and perpendicularly to the sample surface by several μm or less when the wafer is generally adjusted from the outside of the sample chamber. It is thought that this is caused by requesting. Further, there is a problem that it is difficult to use because the height of the nozzle once adjusted is not readjusted due to distortion or deformation of the sample through various processes.

  In particular, in order to effectively perform drilling of a sample or formation of a repair (pattern repair) film, it is necessary that the ion beam focus conditions are also appropriate, and the introduced gas is isotropic around the ion beam. It is well known to those skilled in the art that the high atmospheric concentration greatly contributes to the performance under widely spread conditions. In the invention described in Patent Document 2 and the invention described in Patent Document 3, the coincidence between the introduction gas restriction region integrated with the nozzle tip and the axis of the ion beam is confirmed on the horizontal axis, It is necessary to confirm the gap.

  This is because the performance cannot be fully satisfied unless the gas can be introduced at an appropriate height and horizontal position, which is a necessary work. However, a series of routine work operations require reciprocation between the test processing area and the desired processing area of the sample and adjustment of the nozzle height. First, a place where the test can be processed with minimum damage on the sample is selected, and ion beam irradiation conditions and nozzle position adjustment are performed. Next, the gap between the nozzle and the sample is increased, and the sample as the stage or workpiece is moved to the processing position of the sample. Here, if the height of the nozzle is changed during the movement or the place where processing is desired is specified by an image, the nozzle is appropriately moved up and down in response to the change in the height of the wafer surface, and the reproducibility is not high. It is easily assumed that it is difficult to improve work quality.

  In particular, if the operation of raising or lowering the nozzle is inappropriate, a contact accident will occur somewhere on the routine work. The three-dimensional movement of the nozzle means that the tip of the nozzle is used dexterously as if the STM needle is moving independently on the sample surface. When the shaft length is long, it is very difficult to move the tip position stably due to various vibrations and thermal deformation.

  In the inventions described in Patent Document 2 and Patent Document 3, the gas nozzle is basically composed of one side. Samples to be processed have various shapes and do not always make isotropically deep grooves. In such a case, it can be dealt with by shortening the irradiation time of the primary ion beam to the part which is not desired to be cut, but if gas assist (accelerating etching or the like by introducing gas) is reduced, it will be less. There is an adverse effect that the direction you want to cut is too much. Although it is conceivable that exposure is performed with the nozzle tilted slightly obliquely, it is difficult to make fine adjustment movements to avoid collisions because it is in a delicate position. This is not realistic in such cases. That is, processing is performed with irradiation time control using only the primary ion beam without performing gas assist etching.

  Stage tilt is indispensable for complex sample processing. The tilt of the stage is a function necessary for the depth recognition of the machining amount and the desired tilt machining. For the depth recognition, the nozzle is raised and the operation is performed under the conditions that do not hinder the image observation. However, if the nozzle moves in the same direction as the ion beam axis of the lens barrel, However, there is a problem that the nozzle becomes inaccessible.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a focused ion beam gas introducing device capable of improving the processing performance of a sample.

(1) The invention according to claim 1 is an apparatus capable of performing ion beam assisted etching or beam assisted deposition using a focused ion beam, wherein a plurality of pipes as fluid delivery systems are provided under the ion beam column. A plurality of nozzles that are outlets of the pipe are symmetrical with respect to the axis of the main ion beam and the fluid passing through the nozzle is directed to the sample surface, and the injection conditions of the introduced gas into the pipe can be individually controlled. It is a structure and has a mechanism which connects between these pipes, It is characterized by the above-mentioned.
(2) The invention described in claim 2 is characterized in that the tip of the nozzle has an S-shape.
(3) The invention described in claim 3 further includes a pipe tip heating section for heating the introduced gas under the pipe, and a lower surface adjusting plate that enables proper arrangement of the spatial positional relationship between the nozzles. It is characterized by that.
(4) In the invention according to claim 4, the temperature of the bottom adjustment plate by the heater of the pipe tip heating section is set to 50 ° C. to 90 ° C., and heating up to 200 ° C. can be performed according to the operator's request. It is configured.
(5) The invention described in claim 5 is characterized in that the nozzle at the tip of the pipe moves up and down as a unit, and the height between the nozzle and the sample is at least 10 μm apart.
(6) The invention according to claim 6 limits the determination of the movable range of the pipe by the height determined by the conversion condition from the focus condition of the laser beam, the capacitance height detection device, or the objective lens. Features.
(7) The invention according to claim 7 is characterized in that it has a pipe coupling mechanism which does not have an acute angle portion on the lower surface of the pipe.
(8) The invention according to claim 8 is characterized in that the nozzle and the lower surface adjusting plate are also tilted integrally with the stage portion corresponding to the sample tilting stage capable of tilting the sample stage.
(9) The invention according to claim 9 is characterized in that the passage of the primary ion beam of the lower surface adjusting plate is an ellipse, a rectangle or a slit.
(10) The invention according to claim 10 is characterized in that the pipe connection mechanism on the lower surface of the pipe has an inclined surface at a portion facing the lower signal detector.
(11) The invention according to claim 11 is characterized in that the angle of the inclined surface is in the range of 20 ° to 50 °.

(1) According to the invention described in claim 1, ion beam assisted etching or beam assisted deposition called GAE or MDU of isotropic and anisotropy can be performed by ion beam axis symmetrical arrangement of a plurality of nozzles, and operation performance And improvement of processing performance can be expected.
(2) According to the invention described in claim 2, the flow rate of the introduced gas can be appropriately ensured by making the tip of the nozzle into an S shape.
(3) According to the invention described in claim 3, by providing the lower surface adjusting plate, it is possible to appropriately arrange the spatial positional relationship between the nozzles. In addition, by incorporating a heater in the bottom adjustment plate and controlling its temperature, it is possible to properly supply gas flow from the nozzle in a stable manner and to take into account heat radiation sensitive to the temperature.
(4) According to the invention described in claim 4, the introduction gas can be made uniform by setting the temperature of the lower surface adjusting plate by the pipe tip heating portion to 50 ° C. to 90 ° C. Further, if necessary, the temperature of the bottom adjustment plate can be freely set up to a maximum of 200 ° C.
(5) According to the fifth aspect of the present invention, since the nozzle moves up and down as a unit, the height of the nozzle and the sample can be separated by at least 10 μm, so that the nozzle is prevented from contacting the sample. can do.
(6) According to the invention described in claim 6, the height of the nozzle can be limited by determining the movable range of the nozzle by a predetermined procedure.
(7) According to the seventh aspect of the present invention, it is possible to stabilize the trajectory of the generated secondary electrons and the like by providing the pipe coupling mechanism having no acute angle portion on the lower surface of the nozzle.
(8) According to the invention described in claim 8, operability can be improved by tilting the nozzle and the lower surface adjusting plate integrally with the tilt of the sample stage.
(9) According to the ninth aspect of the present invention, the passage of the primary ion beam is an ellipse or rectangular slit, so that the sample can be irradiated with the ion beam even when the sample surface is inclined.
(10) According to the invention described in claim 10, image signal deterioration due to the proximity of the bottom adjustment plate to the sample is prevented by providing a moderately inclined surface in the diffusion control unit and assisting in reaching the signal to the detector. can do.
(11) According to the invention described in claim 11, image signal deterioration can be effectively prevented by setting the tilt angle in the range of 20 ° to 50 °.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a configuration example of a main part of the present invention. In the figure, 18 is a sample, 17 is a primary ion beam irradiated to the sample 18, 7 is an objective lens, 8 is a pipe for introducing a reactive gas into the primary ion beam 17, and its tip is It is an S-shaped nozzle 8a. As shown in the figure, a plurality of pipes 8 are provided symmetrically with respect to the optical axis. Reference numeral 23 denotes a lower surface adjusting plate provided under the nozzle 8a, and reference numeral 25 denotes a nozzle portion lower surface heater (hereinafter simply referred to as a heater) provided between the nozzle 8a and the lower surface adjusting plate 23.

  The nozzle 8a is in contact with the lower surface adjusting plate 23 and is fixed. The nozzles 8a are connected by this contact surface. And the injection conditions of the introduction gas to each nozzle 8a can be controlled individually. Reference numeral 14 denotes a fine movement device that moves the nozzle 8a formed integrally with the lower surface adjustment plate 23 up and down. WD is a distance (work distance) between the lower surface adjusting plate 23 and the sample. The operation of the thus configured apparatus will be described as follows.

The introduced gas flows from the pipe 8, and the introduced gas is ejected from the tip of the nozzle 8a. The primary ion beam 17 passes through the ejected gas, whereby the gas is ionized and the etching or repair process of the sample 18 is promoted. Here, as the gas used, for example, when depositing a metal thin film on the sample 18, for example, W (CO) ₆ gas is used, and when depositing an insulating film, for example, silicon compound gas is used.

  Here, the lower surface adjusting plate 23 is used for maintaining the uniformity of the introduced gas and limiting the diffusion region. The heater 25 is used to make the introduced gas uniform. Here, by setting the temperature of the lower surface adjustment plate 23 by the heater 25 to 50 ° C. to 90 ° C., the introduced gas can be made uniform. Furthermore, if necessary, the temperature of the bottom adjustment plate 23 can be freely set up to 200 ° C. Moreover, since the front-end | tip part of the nozzle 8a is made into S shape, the flow velocity of introduction gas can be ensured appropriately.

  Further, according to the present invention, the nozzle 8a and the lower surface adjusting plate 23 are moved up and down as a unit by the fine movement device 14, so that the height of the nozzle 8a and the sample 18 can be separated by at least 10 μm. Contact with the sample can be prevented.

  In addition, according to the present invention, the determination of the movable range of the nozzle 8a can be limited by the height determined by the conversion condition from the focus condition of the laser beam or the electrostatic capacitance height detector or the objective lens. In this way, it is possible to reliably limit the height of the nozzle 8a. Further, according to the present invention, it is possible to provide a pipe coupling mechanism that does not have an acute angle portion on the lower surface of the nozzle 8a. In this way, the trajectory of secondary electrons generated when the ion beam strikes the sample can be stabilized, and image noise is reduced. This is because when there is an acute angle portion, extra secondary electrons are generated by collision of reflected electrons or the like on the surface, or the trajectory of secondary electrons to be detected by the surface electric field at the acute angle portion is bent, This is to avoid a decrease in the detection rate.

  When the apparatus having the configuration shown in FIG. 1 is used, isotropic processing and anisotropic processing can be performed. FIG. 2 is an explanatory diagram of isotropic processing. The same components as those in FIG. 1 are denoted by the same reference numerals. In this embodiment, by arranging the nozzles 8a while maintaining symmetry with the optical axis, the surface of the sample 18 is etched while maintaining symmetry by injecting gas uniformly from all the nozzles 8a. Or it can be repaired. In FIG. 2, reference numeral 30 denotes a regulating member for regulating the gas injected from the nozzle 8a so as not to diffuse too much. θ is an inclination angle with respect to the optical axis of the nozzle 8a.

  FIG. 3 is an explanatory diagram of anisotropic processing. The same components as those in FIG. 2 are denoted by the same reference numerals. For example, gas injection is stopped for one of the two nozzles 8a, and gas is injected only from the remaining nozzles 8a. By doing so, the gas diffusion region is formed only on one side, and the etching process on only one side can be promoted.

  FIG. 4 is an explanatory diagram of foreign matter removal by anisotropic etching. Reference numerals 31 to 33 are wiring patterns, and 34 is a foreign substance attached to the wiring pattern 32. Due to the foreign matter 34, the wiring patterns 32 and 33 become conductive. Therefore, anisotropic etching is performed when removing the foreign matter. For example, the nozzle 8a is adjusted so that the gas diffuses only on the surface to which the foreign material 34 is attached. As a result, only the vicinity of the foreign matter 34 is filled with the gas, and the foreign matter 34 is removed as shown in FIG.

  FIG. 5 is a view showing a cross section taken along line XX of FIG. The same components as those in FIG. 1 are denoted by the same reference numerals. (A) is the case where there are two nozzles 8a, (b) is the case where there are three, and (c) is the case where there are four. As shown in the figure, the nozzle need not be axially symmetric with respect to the optical axis, but only needs to be symmetrical with respect to the optical axis. For example, in the case of (b), although it is not axially symmetric, the three nozzles 8a are arranged symmetrically at an angle of 120 degrees with respect to the optical axis.

  Hereinafter, the operation of the focused ion beam apparatus (FIB) will be described. FIG. 6 is a block diagram showing an embodiment of the focused ion beam apparatus according to the present invention. The same components as those in FIG. 1 are denoted by the same reference numerals. In the figure, reference numeral 40 denotes a lens barrel, and most of the elements constituting the focused ion beam device are included in the lens barrel. Reference numeral 1 denotes an ion source, 17 denotes an ion beam emitted from the ion source 1, 3 denotes a gun aperture, 4 denotes a focusing lens for focusing the ion beam 17, 5 denotes an aperture for narrowing the passing amount of the ion beam 17, and 6 denotes an on-sample. 8 is an objective lens for finely focusing the ion beam 17 on the sample, 8a is a nozzle provided on the lower surface of the objective lens 7, and 23 is a lower surface provided on the lower surface of the nozzle 8a. It is an adjustment plate.

  The apparatus shown in the figure is a two-stage lens system including a focusing lens 4 and an objective lens 7. In the case of an ion beam apparatus, an electrostatic lens is used as the electron lens. This is because ions with heavy mass cannot be bent well by electromagnetic coils. 9 is a heater, 10 is a container, 11 is a gas source, 12 is a valve connected to the nozzle 8a to inject gas, 13 is a valve control mechanism for adjusting the opening angle of the valve 12, and 14 is a minute amount of the nozzle 8a. A fine movement device for moving the sample up and down, 15 a detector for detecting particles emitted from the sample, 16 a sample fine movement device for moving the sample, and 18 a sample. The operation of the apparatus configured as described above will be described as follows.

  Although the two-stage lens system is used in FIG. 6 as described above, the basic ion optical system is not limited to this. An appropriate acceleration voltage is applied to the ion source 1 to extract ions to be a primary ion beam from the ion source 1 such as a liquid metal ion source. The extracted ions are subjected to beam diffusion restriction by the gun aperture 3, and a desired irradiation beam is extracted from the aperture 5. The primary ion beam emitted from the ion source 1 forms a necessary imaging system by the focusing lens 4, deflects this with the scanning electrode 6, performs beam scanning, and the necessary primary on the sample 18 with the objective lens 7. The beam is imaged.

  Secondary electrons and the like emitted from the sample 18 are detected by the detector 15, output as an image signal to the control system of the lens barrel 40, and displayed on a monitor (not shown). In such an ion beam optical system, when the sample 18 is continuously irradiated with the ion beam for a long time, unlike the electron beam, the sample can be scraped off by ion mass, ionization, or the like. Introduction of a fluid or gas having a catalytic role for promoting the processing reaction has attracted attention as a technique called ion beam assisted etching or beam assisted deposition.

  Here, as shown in FIG. 1, a plurality of nozzles are arranged symmetrically with the primary ion beam, and the introduced gas or fluid is ejected uniformly from here to achieve the function of homogeneous ion beam assisted etching or beam assisted deposition. It is to provide. The symmetry of this arrangement is not limited to the rotationally symmetric system, and may be axially symmetric with respect to the stage moving axis of the sample to be processed. The plurality of nozzles are preferably as close to the sample as possible. However, as shown in FIG. 2 or FIG. 3, the primary ion beam 17 comes most in the center of the Gaussian distribution shape drawn by the introduced fluid on the sample surface. preferable. This depends on the shape of the tip of the nozzle 8a, and it is necessary for the shape of the nozzle tip to ensure the flow rate of the introduced fluid appropriately. Therefore, it is preferable that the tip has an S-shape.

  The tangent line seen from the center at the end of the arc at the tip of the nozzle tube can be assumed to be the direction in which the fluid directly travels, and the portion where this direction and the primary beam directly intersect is the part to be processed. It can be the most appropriate condition. That is, the distance between the nozzle tip and the sample surface is as close as possible, and the closer the nozzle 8a to the primary beam axis contributes to deep processing support.

  When the tip of the nozzle 8a and the tangent line of the pipe are determined in this way, interference with the casing of the objective lens 7 occurs in the case of a straight pipe. In order to avoid this, the curve is dominant, and if the shape disturbance at the tip is abrupt, the accuracy of the turbulent flow of the fluid becomes stronger, and uneven irradiation spread can be considered when the sample of the introduced fluid is irradiated. Therefore, since the continuous change is most preferable, the S-shape is obtained. In addition, in the case of the S-shape, there are advantages such as easy coupling with the lower surface adjustment plate 23 and optimization of the nozzle temperature by incorporating a heater into the lower surface adjustment plate 23.

  FIG. 2 shows the positional relationship between two nozzles of isotropic ion beam assisted etching or beam assisted deposition with symmetrical configurations as shown in FIG. FIG. 3 shows the positional relationship of two nozzles for anisotropic ion beam assisted etching or beam assisted deposition. A gas or fluid is irradiated on the sample surface with only one nozzle.

  By the way, stage tilt is indispensable for complex processing of samples. The tilt of the stage is a function necessary for confirming the depth of machining and for desired tilt machining. In order to confirm the depth, it is preferable to raise the nozzle and carry out under conditions that do not hinder the image observation.However, if the movement of the nozzle is in the same direction as the ion beam axis of the lens barrel, it is inclined at a wide angle. The nozzle for processing cannot be approached. Therefore, as shown in FIG. 7 or FIG. 8, there is a useful effect in a configuration in which the base plate and the nozzle of the tilt corresponding stage are integrally tilted. The optimum height adjustment of the nozzle is determined only by the sample surface, which is advantageous in that the height can be adjusted regardless of the inclination.

  FIG. 7 is a view showing a state when the stage is tilted. The same components as those in FIG. 1 are denoted by the same reference numerals. FIG. 7 shows a yz section. In the figure, 50 is a base plate, 51 is a stage mounted on the base plate 50, 52 is a stage driving device for driving the stage 51, 18 is a sample placed on the stage 41, and 7 is an objective lens. When etching is performed with an ion beam while the sample is tilted in this manner, the sample 18 can be etched in an oblique direction.

  FIG. 8 is a diagram showing the state when the stage is not tilted. The same components as those in FIG. 1 are denoted by the same reference numerals. FIG. 8 shows an xz cross section. The same parts as those in FIGS. 1 and 7 are denoted by the same reference numerals. As described above, according to the present invention, the operability can be improved by allowing the nozzle and the lower surface adjusting plate to be tilted integrally with the tilt of the sample stage. FIG. 9 is an enlarged view of the vicinity of the bottom adjustment plate, and shows a view from above. The same components as those in FIG. 1 are denoted by the same reference numerals. In the figure, A indicates the horizontal primary ion beam irradiation position, and B indicates the gas irradiation region when the stage is horizontal.

  As shown in FIG. 10 or FIG. 11, if the shape of the primary ion beam passage hole is an ellipse, a slit, or a rectangle, even if the lower surface adjustment plate 23 is inclined integrally with the stage, the primary ion beam is irradiated. Without damaging the function, the function of ion beam assisted etching or beam assisted deposition at the nozzle can be realized. FIG. 10 is an enlarged view of the lower surface adjusting plate and the primary ion beam. Reference numeral 17 denotes a primary ion beam, 23 denotes a lower surface adjusting plate, and 45 denotes the above-described primary beam passage hole. In the figure, the bottom surface adjustment plate 23 is shown in a flat state. On the other hand, the example shown in FIG. 11 shows a state where the lower surface adjustment plate 23 is inclined.

  Although there may be a case where the primary ion beam 17 and the fluid irradiation center are shifted due to a subtle difference in the sample height, in the apparatus of the present invention, it is preferable that the nozzle 8a corresponds only to vertical movement because of the relationship with the stage. It is appropriate to slightly shift the ion beam axis on the lens barrel 40 side. Such position adjustment occurs depending on the sample surface height and the tilt amount. Calculation of the movement amount of the ion beam will be described.

  FIG. 12 is an explanatory diagram of movement amount calculation. In the figure, 18 is a sample, 23 is a lower surface adjustment plate, L is a reference height position, ΔH is a deviation of the sample 18 from the reference height position L, and ΔD is a distance between the sample 18 and the lower surface adjustment plate 23. θ is the tilt angle of the stage (sample). In the eucentric stage as shown in the figure, when the sample height is lower than the optimum reference height L by ΔH, the Y coordinate of the primary ion beam corresponding to ΔH · sin θ is calculated from the tilt angle θ of the stage. By shifting, it is possible to realize irradiation at the same position. In the case of a standard sample, since ΔH is ± 50 μm or less, the amount of movement correction is also well below ± 50 μm. Since this amount can be dealt with by image shift of the primary beam, it can be sufficiently realized by a standard apparatus.

In addition, since the reference height deviation of the lower surface adjustment plate 23 of the nozzle is ΔD−ΔH,
If the length of the ellipse is ensured by (ΔD−ΔH) · tan θ, interference between the primary ion beam and the lower surface adjusting plate 23 does not occur. If the stage tilt amount is about 60 ° at the maximum due to realistic restrictions, and the maximum nozzle separation range from the tilt reference height L of the eucentric stage is 3 mm, the minimum shape such as a rectangle or an ellipse is 3 × tan θ = 5.2 mm, the length of the ellipse or rectangle etc. is about twice as long as the maximum separation range even if the beam spread is taken into account, and the end surface of the axis in the horizontal state is a rectangle or ellipse A position of about 0.3 to 0.5 mm is a substantial constraint condition of the apparatus. According to this embodiment, the passage of the primary ion beam is an ellipse or rectangular slit, so that the sample can be irradiated with the ion beam even when the sample surface is inclined.

  As described above, according to the present invention, an ion beam assisted etching called GAE or MDU having isotropic and anisotropy due to an arrangement in which ion beams of a plurality of nozzles are symmetrical with respect to the optical axis. Alternatively, beam-assisted deposition or the like can be performed, and improvement in operation performance and processing performance can be expected.

  As already explained, there is an appropriate geometric relationship between the nozzle and the primary ion beam and the sample surface, and what is important for realizing this relationship is the relationship between the height of the sample surface and the lower surface of the nozzle. Distance relationship. The nozzle and the lower surface are configured as a single unit, and the center of the lower surface needs to be arranged coaxially with the axis of the ion beam column. Moreover, the movement of this lower surface only moves up and down appropriately.

  The amount of movement should be limited by the height of the sample surface. For detection of the height of the sample surface, the focus of the ion beam with a laser height detector, a capacitance height detector, or an objective lens is used. It is appropriate to determine the conditions. To calculate the sample surface from the objective lens conditions, prepare a function table for the appropriate objective lens voltage conditions and sample surface height based on conditions such as a predetermined irradiation current, and adjust the height according to the actual focus conditions. This is a method of performing conversion. However, with this method, if the focus in a deep groove or the like is automatically used as a reference, an incorrect result will be obtained in terms of height, so an instruction to perform this height calculation under conditions deemed appropriate by the operator It is necessary to do this automatically or manually. Thus, according to the present invention, the nozzle height can be limited by obtaining the movable range of the nozzle by a predetermined procedure.

  A normal apparatus having this nozzle is singular. For example, the invention described in Patent Document 2 is a type in which the tip is flattened and the beam passes through the upper and lower small holes, and the invention described in Patent Document 3 is an inverted funnel shape at the tip. It is a type that has Such a type can be used only for isotropic etching, but in the case where the content to be processed is an oblique groove, an inclination of the sample surface is required. When the sample is moved, a positional shift caused by the stage moving accuracy leads to a reduction in processing accuracy. Therefore, it is useful that the anisotropic gas or fluid as described in the present invention can be appropriately introduced easily.

  There is also a method in which the nozzle tip is not deformed. This method is already well known. The present invention has a plurality of nozzles that do not deform the tip, and these nozzles are arranged so as to be symmetric with respect to the main axis of the ion beam (see FIG. 5). There is a gas or fluid supply source at the root of the nozzle. By making the conductance (reciprocal of the fluid resistance) of the nozzle tip and the fluid control unit formed by this pipe the same, multiple nozzles from one supply source The same amount of fluid can be supplied to the sample surface via. Here, even when the fluid to be supplied is different, it can be dealt with by preparing a gas selection switching unit in the middle of the supply unit. However, since mixing of fluids or gases in the pipe piping may be a problem, when there are four nozzles, it is desirable that the two symmetrical ones be independent fluid supply units.

  In the present invention, the nozzle 8a is inclined with respect to the optical axis as shown in FIG. In the example shown in the figure, the inclination angle is θ. Reference numeral 30 denotes a regulating member for preventing diffusion of gas injected from the nozzle 8a. In this way, by causing the jet to be inclined at an angle θ with respect to the optical axis, it is possible to eliminate the deterioration factor of the image signal due to the proximity of the lower surface adjustment plate 23 to the sample 18. Here, the inclination angle θ is preferably 20 ° or less in consideration of gas or fluid diffusion and deep groove processing, but is practically in the range of 20 ° to 50 °. By setting the range of such an inclination angle, it is possible to effectively prevent the deterioration of the image signal. FIG. 14 is a diagram showing the arrangement of the nozzles and the bottom surface adjustment plate. The nozzle 8a is inclined with respect to the optical axis and gas is ejected.

It is a figure which shows the structural example of the principal part of this invention. It is explanatory drawing of isotropic processing. It is explanatory drawing of anisotropic processing. It is explanatory drawing of the foreign material removal by anisotropic etching. It is a figure which shows the XX cross section of FIG. It is a figure which shows the structural example of the focused ion beam apparatus which concerns on this invention. It is a figure which shows the appearance at the time of stage inclination. It is a figure which shows the appearance at the time of a stage non-tilt. It is a lower surface adjustment board vicinity enlarged view. It is an enlarged view of a lower surface adjustment plate and a primary beam. It is the vicinity enlarged view of a lower surface adjustment plate and a primary beam. It is explanatory drawing of movement amount calculation. It is a figure which shows the incident angle of a nozzle. It is a figure which shows arrangement | positioning of a nozzle and a lower surface adjustment plate.

Explanation of symbols

7 Objective lens 8 Pipe 8a Nozzle 17 Primary ion beam 23 Lower surface adjustment plate 25 Nozzle portion lower surface heater

Claims (11)

In an apparatus capable of performing ion beam assisted etching or beam assisted deposition using a focused ion beam,
A plurality of pipes as a plurality of fluid delivery systems are provided under the ion beam column, and the nozzles that are outlets of the pipes are configured symmetrically with the axis of the main ion beam and the fluid passing through the inside faces the sample surface The focused ion beam gas introducing device is characterized in that the injection conditions of the introduced gas into the pipe can be individually controlled and has a mechanism for connecting the pipes to each other.   The focused ion beam gas introducing device according to claim 1, wherein the tip of the nozzle has an S shape.   The converging unit according to claim 1, further comprising a pipe front end heating unit for heating the introduced gas under the pipe and a lower surface adjusting plate that enables proper arrangement of the spatial positional relationship between the nozzles. Ion beam gas introduction device.   The temperature of the lower surface adjusting plate by the heater of the pipe tip heating unit is set to 50 ° C to 90 ° C, and can be heated up to 200 ° C according to an operator's request. 3. A focused ion beam gas introducing apparatus according to 3.   The focused ion beam gas introducing device according to any one of claims 1 to 4, wherein the nozzle at the tip of the pipe moves up and down as a unit, and the height of the nozzle and the sample is at least 10 μm apart.   5. The focused ion beam according to claim 4, wherein the determination of the movable range of the nozzle is limited by a height determined by a conversion condition from a focus condition of a laser beam, a capacitance height detector, or an objective lens. Gas introduction device.   The focused ion beam gas introducing device according to claim 1, further comprising a pipe coupling mechanism having no acute angle portion on a lower surface of the nozzle.   The focused ion according to any one of claims 1 to 7, wherein the nozzle and the lower surface adjusting plate are also tilted integrally with the stage portion in correspondence with the sample tilting stage capable of tilting the sample stage. Beam gas introduction device.   9. The focused ion beam gas introducing device according to claim 8, wherein the primary ion beam passage portion of the lower surface adjusting plate is an ellipse, a rectangle, or a slit.   The focused ion beam gas introducing device according to any one of claims 1 to 7, wherein the pipe connection mechanism on the lower surface of the pipe has an inclined surface at a portion facing the lower signal detector.   11. The focused ion beam gas introducing device according to claim 10, wherein an angle of the inclined surface is in a range of 20 ° to 50 °.

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