Method for using a microscope device

Abstract

A method for using a microscope apparatus, comprising a first step of arranging a sample within a chamber, a second step of reducing the pressure in the chamber by evacuating the interior of the chamber, a third step of removing part of the sample within the chamber by irradiating the sample with laser light through a transmission element that allows the laser light to pass through in order to perform ablation after the first and second steps, a fourth step in which ablation is performed on particles generated from the sample by irradiating the particles with laser light while the sample is in the chamber, after the first and second steps; and a fifth step in which the sample is observed with a microscope unit after the third step.

Description

Technical field

[0001] The present disclosure relates to a method for using a microscope device. State of the art

[0002] Patent literature 1 describes a laser processing method. In this method, a workpiece is held in a vacuum chamber. The vacuum chamber is provided with a window that allows a laser beam to pass through. Additionally, a laser beam emitted from a laser light source is directed through the window onto the workpiece. Consequently, an etching phenomenon occurs on the surface of the workpiece, which is referred to as ablation, and the surface of the workpiece is removed. Citation list for patent literature Patent literature 1: Japanese unexamined Patent publication no. JP 2002-248589 A Summary of the invention; Technical task

[0003] There is a need to perform ablation on a sample by irradiating the sample with laser light through a transparent element, such as the window of a vacuum container, as described in the laser processing method described in patent reference 1. When ablation is performed on the sample, particles can be generated from the sample that may adhere to the transparent element. If the ablation is carried out while the particles are adhering to the transparent element, the transmittance of the laser light through the transparent element decreases, which can impair the processing quality or lead to unintended absorption of the laser light by the transparent element, potentially damaging it.

[0004] The purpose of the present disclosure is to provide a method for using a microscope device with which a reduction in the permeability of a transparent element can be suppressed. Solution to the problem

[0005] A method for using a microscope apparatus according to the present disclosure is [1] “a method for using a microscope apparatus comprising: a first step of arranging a sample within a chamber; a second step of reducing the pressure in the chamber by evacuating the interior of the chamber; a third step of removing part of the sample within the chamber by irradiating the sample with laser light through a transmissive element that allows the laser light to pass through in order to perform ablation after the first and second steps; a fourth step in which ablation is performed on particles generated from the sample by irradiating the particles with the laser light in a state in which the sample is arranged in the chamber, after the first and second steps;and a fifth step, in which the sample is observed with a microscope unit after the third step. In the third step, a focal point of the laser light is located in a first position on the sample side with respect to the transparent element in an optical axis direction of the laser light, and in the fourth step, the focal point is located in a second position on the side of the transparent element with respect to the sample in the optical axis direction.”

[0006] In the method using a microscope device, after the sample has been positioned in the chamber and the chamber depressurized, ablation is performed on the sample by irradiating it with laser light through the transparent element. Therefore, particles generated during ablation may adhere to the transparent element (or may already be adhering to it). In contrast, this method involves ablating the particles generated from the sample by irradiating them with laser light. Consequently, particle adhesion to the transparent element can be suppressed, or material adhering to the transparent element can be removed. Therefore, a reduction in the transparency of the transparent element can be prevented. In this method, ablation is performed simultaneously with the processing of the sample and the particles generated from it.Therefore, compared to a case where thermal processing is performed using laser light, sample damage during processing is suppressed, and damage to the sample is less likely to occur even if the sample is irradiated with laser light during the processing of the particles generated from the sample. Thus, according to this method, a reduction in the transmittance of the transparent element can be suppressed while simultaneously preventing sample damage.

[0007] A method for using a microscope apparatus according to the present disclosure can be [2] “the method for using a microscope apparatus according to [1] above, wherein the fourth step is carried out after the third step”. In this case, the particles produced from the sample in the preceding third step and the substances adhering to the permeable element can be removed in the subsequent fourth step.

[0008] A method for using a microscope device according to the present disclosure can [3] be “the method for using a microscope device according to [2] above, wherein the third step is repeated after the fourth step”. In this case, for example, the adhesions removed from the transparent element in the fourth step and adhering to the sample can be removed by repeating the third step.

[0009] A method for using a microscope device according to the present disclosure can [4] be “the method for using a microscope device according to one of the above-mentioned methods 1 to 3, wherein, between the third step and the fourth step, the position of the focal point is changed between the first position and the second position by moving the chamber.” In this case, the position of the focal point of the laser light can be changed between the first position in the third step and the second position in the fourth step by moving the chamber.

[0010] A method for using a microscope device according to the present disclosure can be [5] “the method for using a microscope device according to any of the above points [1] to [4], wherein, between the third step and the fourth step, the position of the focal point is changed between the first position and the second position by moving a lens to focus the laser light onto the sample or the transparent element.” In this case, the position of the focal point of the laser light can be changed between the first position in the third step and the second position in the fourth step by moving the lens.

[0011] A method for using a microscope device according to the present disclosure can be [6] “the method for using a microscope device according to any of the above [1] to [5], wherein, between the third step and the fourth step, the position of the focal point is changed between the first position and the second position using a galvanometer scanner.” In this case, the position of the focal point of the laser light can be changed between the first position in the third step and the second position in the fourth step using the galvanometer scanner.

[0012] A method for using a microscope device according to the present disclosure can be [7] “the method for using a microscope device according to any of the above points [1] to [6], wherein, between the third step and the fourth step, the position of the focal point is changed between the first position and the second position using a spatial light modulator.” In this case, the position of the focal point of the laser light can be changed between the first position in the third step and the second position in the fourth step using the spatial light modulator.

[0013] A method for using a microscope apparatus according to the present disclosure may [8] “be the method for using a microscope apparatus according to [1] above, wherein the fourth step is carried out simultaneously with the third step”. In this case, the processing time can be reduced by processing the sample and the particles produced from the sample simultaneously.

[0014] A method for using a microscope device according to the present disclosure can be [9] “the method for using a microscope device according to [8] above, wherein the third step and the fourth step are carried out simultaneously by modulating the laser light using a spatial light modulator to form the focal point at both the first position and the second position.” In this case, the simultaneous processing of the sample and the particles produced from the sample can be carried out appropriately.

[0015] A method for using a microscope device according to the present disclosure can be

[10] “the method for using a microscope device according to one of the above [1] to [9], wherein the pulse width of the laser light is 1 ps or less”. In this case, ablation treatment can be carried out effectively.

[0016] A method for using a microscope device according to the present disclosure can be

[11] “the method for using a microscope device according to any of the above points [1] to

[10] , wherein the second position is a position within 2 mm of a surface on the sample side of the transparent element.” In this way, by adjusting the position (second position) of the focal point of the laser light in the fourth step within 2 mm of the surface on the sample side of the transparent element, a laser intensity can be ensured that is capable of removing matter adhering to the surface of the transparent element.

[0017] A method for using a microscope device according to the present disclosure can be

[12] “the method for using a microscope device according to one of the above [1] to

[11] , wherein the second position is a position on one side opposite the sample with respect to a surface on the sample side of the transparent element.” In this way, by adjusting the position (second position) of the focal point of the laser light further away from the sample in the fourth step, damage to the sample can be suppressed.

[0018] A method for using a microscope device according to the present disclosure can be

[13] “the method for using a microscope device according to

[12] above, wherein the second position is a position within the transparent element”. In this way, the position (second position) of the focal point of the laser light can be set within the transparent element in the fourth step.

[0019] A method for using a microscope device according to the present disclosure can be

[14] “the method for using a microscope device according to

[12] above, wherein the second position is a position outside the transparent element.” In this way, by setting the position (second position) of the focal point of the laser light in the fourth step outside the transparent element on the side opposite the sample, a wider irradiation area of ​​the laser light on the surface on the sample side of the transparent element can be ensured.

[0020] A method for using a microscope device according to the present disclosure can be

[15] “the method for using a microscope device according to any of the above [1] to

[14] , wherein in the fourth step the sample is irradiated with the laser light that has passed through the transparent element.” As described above, in this method the probability of damage to the sample is lower, even if the sample is irradiated with some of the laser light with which the transparent element is irradiated in the fourth step, since the same laser light as the laser light used for ablating the sample is used to process the particles produced from the sample. Therefore, in the fourth step it is not necessary to move the sample or to block the laser light so that the sample is not irradiated with some of the laser light.

[0021] A method for using a microscope device according to the present disclosure can be

[16] “the method for using a microscope device according to any one of [1] to

[15] above, wherein the transparent element is an incident part for the laser light in the chamber”. In this way, the transparent element from which adhering matter is to be removed can be the incident part for the laser light in the chamber.

[0022] A method for using a microscope device according to the present disclosure can be

[17] “the method for using a microscope device according to any of the above [1] to

[15] , wherein the permeable element is a cover provided for covering the sample within the chamber”. In this way, the permeable element from which adhering substances are to be removed can be the cover provided for covering the sample.

[0023] A method for using a microscope apparatus according to the present disclosure can be

[18] “the method for using a microscope apparatus according to any of the above [1] to

[17] , wherein the fourth step and the fifth step are carried out in different chambers.” In this way, the observation of the sample in the fifth step can be carried out in a chamber that is different from the chamber in which the ablation of the particles produced from the sample is carried out in the fourth step.

[0024] A method for using a microscope apparatus according to the present disclosure may

[19] be “the method for using a microscope apparatus according to any of the above [1] to

[17] , wherein the fourth step and the fifth step are carried out in the same chambers.” In this way, the observation of the sample in the fifth step can be carried out in the same chamber as the chamber in which the ablation of the particles produced from the sample in the fourth step is carried out.

[0025] A method for using a microscope device according to the present disclosure can be

[20] “the method for using a microscope device according to any of the above points [1] to

[19] , wherein a beam pattern of the laser light has a top-hat shape”. In this case, for example, in the fourth step the particles produced from the sample can be processed more uniformly.

[0026] A method for using a microscope device according to the present disclosure may

[21] “be the method for using a microscope device according to any of the above [1] to

[20] , comprising: a first step of arranging a sample inside a chamber; a second step of reducing the pressure in the chamber by evacuating the interior of the chamber; a third step of removing part of the sample inside the chamber by irradiating the sample with laser light through a transmissive element that allows the laser light to pass through, in order to perform ablation after the first and second steps; a fourth step of removing adhering substances on the transmissive element by irradiating the transmissive element with the laser light, in order to perform ablation of the adhering substances in a state in which the sample is arranged in the chamber, after the first and second steps;and a fifth step of observing the sample using a microscope after the third step. In the third step, a focal point of the laser light is located in a first position on the sample side with respect to the transparent element in one optical axis direction of the laser light, and in the fourth step, the focal point is located in a second position on the side of the transparent element with respect to the sample in the optical axis direction.

[0027] In the method using a microscope device, after the sample has been positioned in the chamber and the chamber depressurized, ablation is performed on the sample by irradiating it with laser light through the transparent element. Therefore, particles generated during ablation may adhere to the transparent element (or may already be adhering to it). In contrast, this method removes the substance adhering to the transparent element by irradiating it with laser light to perform ablation. Consequently, a reduction in the transparency of the transparent element can be avoided. Incidentally, in this method, ablation is performed while the sample is being processed and the adhering substance is being removed.Therefore, compared to a case where thermal processing is performed using laser light, damage to the sample during processing is suppressed, and damage to the sample is less likely to occur even if the sample is irradiated with laser light during the removal of the adhering substance. Thus, according to this method, the adhering substance on the transparent element can be removed while preventing damage to the sample. Advantageous effects of the invention

[0028] According to the present disclosure, it is possible to provide a method for using a microscope device with which a reduction in the permeability of the transparent element can be suppressed. Brief description of the drawings Fig. Figure 1 is a schematic view showing part of a microscope device according to the present embodiment. Fig. 2 is a schematic view showing the remaining part of the Fig. Figure 1 shows the microscope device shown. Fig. Figure 3 is a flowchart showing an example of a method for using a microscope device according to the present embodiment. Fig. 4 is a schematic view showing one step of the procedure for using the in Fig. 3 shows the microscope device shown. Fig. 5 is a schematic view showing one step of the procedure for using the in Fig. 3 shows the microscope device shown. Fig. 6 is a schematic view showing one step of the procedure for using the in Fig. 3 shows the microscope device shown. Fig. Figure 7 is a schematic view to describe an example of simultaneous processing with two focuses. Fig. Figure 8 is a schematic view of a microscope device according to a modification example. Fig. Figure 9 is a flowchart showing each step when a permeable element is cleaned according to the permeability of the permeable element. Fig. Figure 10 is a schematic view showing a microscope device according to a further modification example. Description of embodiments

[0029] The following describes, with reference to the drawings, a method for using a microscope device according to one embodiment. In the description of the drawings, identical or corresponding elements are designated with the same reference numerals, and duplicate descriptions may be omitted.

[0030] Fig. Figure 1 is a schematic view showing part of a microscope device according to the present embodiment. Fig. 2 is a schematic view showing the remaining part of the Fig. The microscope apparatus shown in Figure 1 is shown. One in the Fig. 1 and Fig. 2 Microscope device 1 shown is, as will be described later, a device comprising a focused ion beam (FIB) device that performs etching on a sample by irradiating the sample with focused ions (for example, Ga ions); a scanning electron microscope (SEM) device that observes the sample by irradiating the sample with an electron beam; and a laser device that performs laser processing (here: ablation processing) on ​​the sample by irradiating the sample with laser light and which, by means of the SEM device, enables the observation of a processed cross-section of the sample formed by the processing by the FIB device and / or the laser device.

[0031] The microscope apparatus 1 comprises a sample holder 2, a beam irradiation unit 3, a first microscope unit 4, a second microscope unit 5, a cover 7 (transparent element), a chamber 10, and a laser device 20. Sample A is arranged on the sample holder 2. The sample holder 2 can support sample A without securing it, as in a case where sample A is simply placed on it, or it can secure and hold sample A, for example, by attaching it or the like. Here, the sample holder 2 holds sample A. The beam irradiation unit 3 serves to irradiate sample A (hereinafter referred to as "the same") held (arranged) by the sample holder 2 with a focused ion beam. Therefore, the beam irradiation unit 3 can comprise at least one focused ion beam emission device of the FIB apparatus.

[0032] The first microscope unit 4 serves to observe sample A held by sample holder 2. More precisely, the first microscope unit 4 is configured to acquire an image of sample A (observe sample A) by irradiating sample A held by sample holder 2 with an electron beam and detecting secondary electrons or the like generated in sample A. Therefore, the first microscope unit 4 can be at least part of the SEM device, which includes an electron beam emission device and a detection device.

[0033] Similar to the first microscope unit 4, the second microscope unit 5 serves to observe sample A held by the sample holder 2. More precisely, the second microscope unit 5 can acquire information about the crystal structure or the like of sample A (observe sample A) by irradiating sample A held by the sample holder 2 with an electron beam and detecting the electron beam scattered by sample A. That is to say, as an example, the second microscope unit 5 is part of the SEM apparatus that uses an electron backscatter diffraction (EBSD) technique and can be part of the SEM apparatus that includes at least one electron beam emission device and a detection device. Incidentally, the microscope apparatus 1 can include a transmission electron microscope (TEM) apparatus instead of (or in addition to) the SEM apparatus.In this case, the first microscope unit 4 and the second microscope unit 5 can be at least part of the TEM device.

[0034] The cover 7 is made of a material that transmits the laser light L described below and serves to cover the sample A held by the sample holder 2. Accordingly, the cover 7 can be positioned at a reference position located between the sample holder 2 and the beam irradiation unit 3, the first microscope unit 4, and the second microscope unit 5 in the path of the laser light L. However, the cover 7 is configured to be movable from this reference position, meaning that the cover 7 is not always located between the sample holder 2 and the beam irradiation unit 3, the first microscope unit 4, and the second microscope unit 5.

[0035] Incidentally, the cover 7 can be box-shaped or plate-shaped. If the cover 7 is box-shaped, it can, for example, be a rectangular box with one open side or a box with one open side and a semicircular cross-section (example shown). In this case, when the sample A is located inside the box, the cover 7 can be arranged such that an open section of the box faces the bottom of the chamber 10 and a bottom of the box faces the side on which the radiation device 3, the first microscope unit 4, and the second microscope unit 5 are located. At this point, an edge region of the box forming the open section can be in contact with or spaced apart from a lower region of the chamber 10.

[0036] Chamber 10 accommodates the sample holder 2, the beam irradiation unit 3, the first microscope unit 4, the second microscope unit 5, and the cover 7. An incidence area 11 for the laser light L is formed in chamber 10, in the form of a window made of a material that transmits the laser light L. Furthermore, an evacuation section 12 for pressure reduction (creating a vacuum) by evacuating the interior of chamber 10 is provided in chamber 10. Additionally, another unit 6 for processing or viewing the sample A held by the sample holder 2 may be provided within chamber 10.

[0037] The laser device 20 comprises a laser output unit 30 and a laser optics system 40. The laser output unit 30 serves to output the laser light L with ultrashort pulses at low fluence. The pulse width of the laser light L output by the laser output unit 30 is, for example, 1 ps or less. Furthermore, the fact that the laser light L has a low fluence may indicate, for example, that the energy density of the laser light L is close to a processing threshold of the sample A, which is determined such that ablation is induced during laser processing of the sample A. The laser optics system 40 serves to irradiate the sample A, held by the sample holder 2, with the laser light L output from the laser output unit 30. The laser light L output from the laser output unit 30 is guided through the laser optics system 40 and enters the chamber 10 through the incidence area 11.

[0038] The laser optics system 40 comprises a spatial light modulator 41 and a galvanometer scanner 43. The spatial light modulator 41 modulates the laser light output by the laser output unit 30 according to a modulation pattern and emits the modulated laser light. More precisely, the spatial light modulator 41 is, for example, a liquid crystal-on-silicon spatial light modulator (LCOS-SLM) and displays a modulation pattern on a liquid crystal layer, thereby modulating the laser light L incident on and emitted by the liquid crystal layer according to the modulation pattern.

[0039] The spatial light modulator 41 can, for example, as will be described later, suppress the extent of a point system at the focal position of the laser light L by modulating the laser light L such that the laser light L has multiple focal points P in an optical axis direction B, or by modulating the laser light L to correct aberrations that occur when the laser light passes through the transparent element such as the cover 7 or the incidence area 11.

[0040] The galvanometer scanner 43 comprises mirrors 43a and 43b and illuminates the sample A, held by the sample holder 2, with the laser light L emitted from the spatial light modulator 41, while scanning the sample A by driving the mirrors 43a and 43b. The laser light L emitted by the galvanometer scanner 43 is focused onto the sample A by a lens 42. The lens 42 is, for example, an fθ lens.

[0041] The laser optics system 40 includes a relay optics system 44. The relay optics system 44 is arranged between the spatial light modulator 41 and the galvanometer scanner 43. The relay optics system 44 comprises a pair of lenses 44a and 44b and serves to transmit an image of the laser light L modulated by the spatial light modulator 41 to the lens 42. The beam path of the laser light L emitted by the spatial light modulator 41 and passing through the optical relay system 44 is adjusted by predetermined mirrors 56 and 57, and the laser light L is then directed to the galvanometer scanner 43.

[0042] The laser optics system 40 further comprises a collimator lens 51, an output control unit (adjustment unit) 52, a beam diameter control unit (adjustment unit) 53, a half-wave plate 54, and a polarizing beam splitter 55, which are arranged sequentially along the beam path of the laser light L from the laser output unit 30 to the spatial light modulator 41. The collimator lens 51 collimates the laser light L emitted by the laser output unit 30 and emits the collimated laser light L. Therefore, the collimated laser light L falls onto the spatial light modulator 41. The collimator lens 51 can be omitted.

[0043] The output control unit 52, for example, is an attenuator and adjusts the output of the laser light L emitted by the laser output unit 30. The beam diameter control unit 53, for example, is a beam expander and adjusts the beam diameter of the laser light L emitted by the laser output unit 30. In this way, the output control unit 52 and the beam diameter control unit 53 are arranged between the spatial light modulator 41 and the laser output unit 30 and function as adjustment units that set the power and the beam diameter of the laser light L.

[0044] The half-wave plate 54 changes the polarization direction of the laser light L emitted by the laser output unit 30. The polarizing beam splitter 55 splits the laser light L emitted by the laser output unit 30 and incident through the half-wave plate 54 into an s-polarized component and a p-polarized component. The p-polarized component (p-polarized laser light L) falls onto the spatial light modulator 41. As described above, the laser light L incident on the spatial light modulator 41 is modulated and then directed through the galvanometer scanner 43 into chamber 10 and made available for scanning the sample A.

[0045] In the microscope apparatus 1 described above, sample A can be processed using a focused ion beam from the beam irradiation unit 3 or using laser light L from the laser device 20. When a focused ion beam is used, sample A can be processed and observed with high accuracy. Conversely, when laser light L is used, a large area of ​​sample A can be processed and observed with high throughput.

[0046] A procedure for using the microscope device described above is then described. Fig. Figure 3 is a flowchart showing an example of the procedure for using a microscope device according to the present embodiment. Fig. 4 and Fig. 5 are schematic representations of the steps of the procedure for using a microscope device according to Fig. 3 show. In the Fig. 4 and Fig. 5 are the beam irradiation unit 3, the first microscope unit 4, the second microscope unit 5 and the unit 6 of the in Fig. Microscope device 1 shown is not illustrated.

[0047] As in Fig. 3 and (a) of Fig. As shown in Figure 4, in the method for using the microscope device 1 according to the present embodiment, the sample A is first arranged inside the chamber 10 (step S1, first step). In step S1, the sample A is held by the sample holder 2. Next, the chamber 10 is depressurized by evacuating the interior of the chamber 10 using the evacuation section 12 (a vacuum is created) (step S2, second step).

[0048] Next, as in Fig. 3 and (b) of Fig. As shown in Figure 4, a portion of sample A within chamber 10 is removed by irradiating sample A with laser light L through the incidence area 11 and the cover 7, which transmits the laser light L, to perform ablation (step S3, third step). At this point, particles are generated from sample A. In step S3, sample A is scanned (irradiated) with laser light L while the focal point P of the laser light L is located at a first position P1 on the side of sample A with respect to the cover 7 in the optical axis direction B of the laser light L. The first position P1 is, for example, the position at which the laser light L is focused onto a surface on the cover side 7 of sample A.

[0049] Incidentally, in the method for using the microscope device 1 according to the present embodiment, for example, the number of ablation operations performed on sample A in step S3 can be predetermined, and step S3 can be performed only that number of times. Furthermore, thermal processing is a process in which a portion of a sample is removed by melting the sample through an increase in its temperature caused by the absorption of laser light. In contrast, ablation is a type of non-thermal process in which a portion of sample A is instantaneously decomposed and dispersed within an irradiation area of ​​laser light L by breaking the bonds between the molecules or atoms of sample A using the energy of the laser light L.

[0050] Next, as in Fig. 3 and (a) of Fig. Figure 5 shows that, in a state where sample A is positioned within chamber 10, substances adhering to cover 7 are removed (cover 7 is cleaned) by irradiating cover 7 with laser light L to perform an ablation treatment on the adhering substances (step S4, fourth step). In step S4, in addition to (or instead of) the ablation treatment of the substances adhering to cover 7 by irradiating the particles (particles that can become substances adhering to cover 7) generated from sample A during the ablation treatment of sample A in step S3 with laser light L, an ablation treatment is performed on the particles. That is, in step S4, an ablation of the particles generated from sample A is performed by irradiating sample A with laser light L. In step S4, the same laser light L is used as for the ablation of sample A in step S3.In this way, in the procedure for using the microscope device 1 according to the present embodiment, step S4 is carried out after step S3.

[0051] The cover 7 comprises a surface 7a on the side of the sample A and a surface 7b, which is a surface on the side opposite surface 7a (incidence area 11) and which is an incidence surface for the laser light L. As in (b) of Fig. As shown in Figure 5, in step S4 the focal point P of the laser light L is located at a second position P2 on the cover 7 side with respect to sample A in the optical axis direction B, and the surface 7a of the cover 7 is scanned (irradiated) with the laser light L. Thus, the distance between the first position P1, where the focal point P of the laser light L is located in step S3, and sample A is shorter than the distance between the first position P1 and the cover 7, and the distance between the second position P2, where the focal point P of the laser light L is located in step S4, and the cover 7 is shorter than the distance between the second position P2 and sample A. This means that the first position P1 is located on the side of sample A with respect to the second position P2.

[0052] The second position P2 is a position within a predetermined distance D from surface 7a on the sample side A of the cover 7. For example, the distance D is 2 mm. Furthermore, the second position P2 can be a position closer to sample side A than to surface 7a of the cover 7, or a position on the side opposite sample side A with respect to surface 7a of the cover 7. If the second position P2 is a position on the side opposite sample A with respect to surface 7a of the cover 7, it can be a position inside or outside the cover 7. The irradiation area of ​​the laser light L on surface 7a can be extended by shifting the second position P2 (i.e., the focal point P) from surface 7a along the optical axis direction B.In particular, the amount of the displacement of the focal point P from the surface 7a along the optical axis direction B can be adjusted so that the irradiation area of ​​the laser light L on the surface 7a is extended, while the energy density of the laser light L on the surface 7a is kept at a level equal to or greater than a threshold for removing adhering substances.

[0053] Incidentally, step S4 is performed in a state where sample A is arranged inside chamber 10. Therefore, in step S4, some of the laser light L irradiating the cover 7 can pass through the cover 7 and irradiate sample A. Furthermore, for example, in the method for using the microscope device 1 according to the present embodiment, the number of ablation operations performed in step S4 on the substances adhering to the cover 7 (or ablation operations on the particles generated from sample A) can be predetermined, and step S4 can be performed only that many times.

[0054] As described above, in the method for using the microscope device 1 according to the present embodiment, the position of the focal point P of the laser light L is changed (switched) between the first position P1 and the second position P2 between step S3 and step S4. Various methods can be used to switch the position of the focal point P of the laser light L.

[0055] For example, between steps S3 and S4, the position of the focal point P can be changed between the first position P1 and the second position P2 by controlling a stage to hold the chamber 10 in order to move the chamber 10. Additionally, between steps S3 and S4, the position of the focal point P can be changed between the first position P1 and the second position P2 by moving the lens 42 to focus the laser light L towards the sample A or the cover 7.

[0056] Alternatively, between steps S3 and S4, the position of the focal point P can be changed between the first position P1 and the second position P2 using the galvanometer scanner 43. Additionally, between steps S3 and S4, the position of the focal point P can be changed between the first position P1 and the second position P2 using the spatial light modulator 41. Furthermore, a combination of at least two of the methods described above can also be used.

[0057] The next step determines whether the intended processing of sample A is complete (step S5). For example, in step S5, the number of laser processing operations performed (e.g., the number of executions of step S3) and whether the laser processing was completed the specified number of times can be determined. If step S5 determines that the intended processing of sample A is not complete (step S5: NO), steps S3 to S5 are repeated. Conversely, if step S5 determines that the intended processing of sample A is complete (step S5: YES), sample A is processed as described in... Fig. 6 shown, using the first microscope unit 4 or the second microscope unit 5 arranged inside chamber 10, observed (step S6, fifth step).

[0058] In step S6, the cover 7 is first moved from the reference position so that the cover 7 is no longer located between the sample A and the first microscope unit 4 and the second microscope unit 5. The sample A can then be observed by irradiating it with an electron beam E from the first microscope unit 4 or the second microscope unit 5 (in the illustrated example, the first microscope unit 4).

[0059] As described above, in the method for using the microscope device 1 according to the present embodiment, after the sample A has been arranged in the chamber 10 and the chamber 10 has been depressurized, an ablation treatment is carried out on the sample A by irradiation with the laser light L through the cover 7. Therefore, the particles generated during the ablation treatment can adhere to the cover 7 (or may already have adhered to the cover 7).

[0060] In contrast, in the method for using the microscope device 1 according to the present embodiment, an ablation treatment is performed on the particles generated from sample A by irradiation with laser light L. Accordingly, the adhesion of the particles to the cover 7 can be suppressed, or substances adhering to the cover 7 can be removed. Consequently, a reduction in the permeability of the cover 7 can be prevented. Since, in this method, the cover 7 can be used continuously due to the lower replacement frequency, large-volume removal treatment can be performed on a single sample A, or several samples A can be treated without interrupting the vacuum inside the chamber 10. Incidentally, in this method, an ablation treatment is performed when the sample and the particles generated from the sample are treated.Therefore, compared to a case where thermal processing is performed using laser light L, damage to sample A during processing is suppressed, and it is less likely that damage will occur in sample A even if sample A is irradiated with laser light L during the processing of the particles produced from sample A. Therefore, in this method, a reduction in the transmittance of cover 7 can be suppressed while simultaneously preventing damage to sample A.

[0061] Furthermore, in the method for using the microscope device 1 according to the present embodiment, substances adhering to the cover 7 are removed by irradiating the cover 7 with laser light L to perform an ablation treatment of the adhering substances. This prevents a reduction in the transmittance of the cover 7. Therefore, according to this method, the substance adhering to the cover 7 can be removed while preventing damage to the sample A.

[0062] Incidentally, the wavelength L of the laser light during the ablation of sample A can be either an absorbed wavelength or an unabsorbed wavelength. If the wavelength L of the laser light is an absorbed wavelength, damage to sample A is suppressed compared to thermal processing. Furthermore, if the wavelength L of the laser light is an unabsorbed wavelength, damage to sample A is suppressed even further.

[0063] Furthermore, in the method for using the microscope device 1 according to the present embodiment, step S4 is performed after step S3. Therefore, the adhering substance (or the particles produced from sample A) generated in the preceding step S3 and adhering to the cover 7 can be removed in the subsequent step S4.

[0064] Furthermore, in the method for using the microscope device 1 according to the present embodiment, the position of the focal point P between the first position P1 and the second position P2 can be changed between step S3 and step S4 by moving the chamber 10. In this case, the position of the focal point P of the laser light L between the first position P1 in step S3 and the second position P2 in step S4 can be changed by moving the chamber 10.

[0065] Furthermore, in the method for using the microscope device 1 according to the present embodiment, the position of the focal point P can be changed between the first position P1 and the second position P2 between step S3 and step S4 by moving the lens 42 to focus the laser light L onto the sample A or the cover 7. In this case, the position of the focal point P of the laser light L can be changed between the first position P1 in step S3 and the second position P2 in step S4 by moving the lens 42.

[0066] Furthermore, in the method for using the microscope device 1 according to the present embodiment, the position of the focal point P between the first position P1 and the second position P2 can be changed between step S3 and step S4 using the galvanometer scanner 43. In this case, the position of the focal point P of the laser light L between the first position P1 in step S3 and the second position P2 in step S4 can be changed using the galvanometer scanner 43.

[0067] Furthermore, in the method for using the microscope device 1 according to the present embodiment, the position of the focal point P between the first position P1 and the second position P2 can be changed between step S3 and step S4 using the spatial light modulator 41. In this case, the position of the focal point P of the laser light L between the first position P1 in step S3 and the second position P2 in step S4 can be changed using the spatial light modulator 41.

[0068] Furthermore, in the method for using the microscope device 1 according to the present embodiment, the pulse width of the laser light L is 1 ps or less. Therefore, the ablation procedure can be carried out effectively.

[0069] Furthermore, in the method for using the microscope device 1 according to the present embodiment, the second position P2 can be a position within 2 mm of the surface 7a on the sample side A of the cover 7. In this way, by setting the position (second position P2) of the focal point P of the laser light L in step S4 within 2 mm of the surface 7a on the sample side A of the cover 7, a laser intensity can be ensured that is capable of removing substances adhering to the surface 7a of the cover 7.

[0070] Furthermore, in the method for using the microscope device 1 according to the present embodiment, the second position P2 can be a position on the side opposite sample A with respect to surface 7a on the sample side A of the cover 7. In this way, by adjusting the position (second position P2) of the focal point P of the laser light L further away from sample A in step S4, damage to sample A can be suppressed.

[0071] Furthermore, in the method for using the microscope device 1 according to the present embodiment, the second position P2 can be a position within the cover 7. In this way, the position (second position P2) of the focal point P of the laser light L can be set within the cover 7 in step S4.

[0072] Furthermore, in the method for using the microscope device 1 according to the present embodiment, the second position P2 can be a position outside the cover 7. In this way, by setting the position (second position P2) of the focal point P of the laser light L in step S4 outside the cover 7 on the side opposite the sample A, a wider irradiation area of ​​the laser light L on the surface 7a on the sample side A of the cover 7 can be ensured.

[0073] Furthermore, in the method for using the microscope device 1 according to the present embodiment, in step S4 the sample A can be irradiated with the laser light L that has passed through the cover 7. As described above, in this method the same laser light L as the laser light L used for ablation of sample A is used to process the particles produced from sample A, so that even if sample A is irradiated with some of the laser light L used to irradiate the cover 7 in step S4, damage to sample A is less likely to occur. Therefore, in step S4 it is not necessary to move sample A or to block the laser light L so that sample A is not irradiated with some of the laser light L.

[0074] Furthermore, in the method for using the microscope device 1 according to the present embodiment, steps S4 and S6 are performed in the same chamber 10. In this way, the observation of sample A in step S5 can be carried out in the same chamber 10 as the chamber in which the ablation processing of the particles generated from sample A is performed in step S4. In this case, the movement of sample A between step S4 and step S6 becomes unnecessary, thus enabling highly precise processing and observation.

[0075] The above embodiment has described one aspect of the method for using a microscope device according to the present invention. Therefore, the method for using a microscope device according to the present invention is not limited to the method for using microscope device 1 described above and can be modified as desired. Examples of modifications are described below.

[0076] In the embodiment described above, an example was given in which step S4 is performed after step S3; however, the order of steps S3 and S4 is not limited to this. For example, if the microscope device 1 has already been used, material may already be adhering to the cover 7. Therefore, step S4 can be performed before step S3.

[0077] Furthermore, step S3 can be repeated after steps S3 and S4 have been performed sequentially. In this case, the residues removed from cover 7 in step S4 and adhering to sample A can be removed by repeating step S3.

[0078] Furthermore, steps S3 and S4 can be executed simultaneously. In this case, the focal point P of the laser light L is formed at both the first position P1 and the second position P2. To achieve this, for example, as shown in Fig. Figure 7 shows that the laser light L is modulated by the spatial light modulator 41 such that the focal point P of the laser light L is formed at each of the first position P1 and the second position P2 at overlapping positions along the optical axis direction B (dual-focus simultaneous processing). That is, steps S3 and S4 can be performed simultaneously by modulating the laser light L using the spatial light modulator 41 to form the focal point P at both the first position P1 and the second position P2. Incidentally, when performing dual-focus simultaneous processing, the laser light L can be modulated by the spatial light modulator 41 such that the respective focal points P of the laser light L at the first position P1 and the second position P2 are formed in such a way that they do not overlap along the optical axis direction B (i.e.,are shifted from each other in a plane direction that intersects the optical axis direction B).

[0079] As another example, steps S3 and S4 can be performed simultaneously by using an optical element with a light-branching function to split the laser light L into two branched beams and to focus each of the two branched beams to form the focal point P at the first position P1 and the second position P2, respectively. Again, the respective focal points P at the first position P1 and the second position P2 may or may not overlap along the optical axis direction B.

[0080] As another example, steps S3 and S4 can be performed simultaneously by emitting two laser beams L from the laser output unit 30 and focusing each of the two laser beams L to form the focal point P at each of the first position P1 and the second position P2. Again, the respective focal points P at the first position P1 and the second position P2 may or may not overlap along the optical axis direction B. As described above, if steps S3 and S4 are performed simultaneously, the sample A and the particles generated from the sample A are processed concurrently, thus reducing the processing time.

[0081] Furthermore, in the embodiment described above, the cover 7 was provided as an example of a transparent element for the laser light L from which adhering substances are to be removed. However, if the microscope device 1 does not contain a cover 7, or if the microscope device 1 does contain a cover 7 but adhering substances can also be present at the incidence area 11 of the chamber 10, the transparent element to be cleaned can be the incidence area 11 (and the cover 7).

[0082] Furthermore, in the embodiment described above, an example case was given in which all processing steps and observations, including step S3, step S4, and step S6, are performed within the same chamber 10. However, step S6 and both step S3 and step S4 can be performed in different chambers. In this way, the observation of sample A in step S6 can be carried out in a different chamber than the chamber 10 in which the ablation processing in steps S3 and S4 is performed. In this case, the adhesion of the particles generated during the ablation processing to the first microscope unit 4 and the second microscope unit 5 is suppressed, and a reduction in the accuracy of the observation of sample A is avoided.

[0083] Furthermore, the beam pattern of the laser light L can have a top-hat shape. In this case, for example, the particles produced from sample A can be processed more uniformly in step S4. Moreover, in this case, compared to using laser light L with a Gaussian distribution, processing can be carried out over a larger area.

[0084] Furthermore, in the embodiment described above, an example is provided in which, after performing the ablation processing on sample A in step S3, the cleaning of the permeable element (in the embodiment described above, cover 7) (ablation processing of the particles generated from sample A) is carried out in step S4 only the predetermined number of times. According to this method, adhering substances that accumulate on the permeable element when step S3 is performed multiple times can be efficiently removed, and the permeability of the permeable element can be effectively maintained. On the other hand, after performing step S3, the permeability of the permeable element can be measured, and step S4 can also be performed according to the measurement result to clean the permeable element.

[0085] In this case, the microscope device 1 can be used as shown in Fig. Figure 8 shows a configuration for measuring the permeability of the permeable element. Fig. Figure 8 represents the beam irradiation unit 3, the first microscope unit 4, the second microscope unit 5, and unit 6 is not illustrated. Furthermore, in Fig. Figure 8 shows the entry area 11 of chamber 10 as an example of a permeable element to be cleaned.

[0086] In the example of Fig. The microscope device 1 comprises a laser output unit 60, a dichroic mirror 61, a beam splitter 62, a mirror 63 and a detector 64. In addition, for example, the laser light L emitted by the laser output unit 30 passes through the laser optics system 40 (not shown), is reflected by the mirror 57, passes through the dichroic mirror 61 onto the lens 58 and is focused onto the sample A or the incidence area 11.

[0087] The laser output unit 60 emits laser light L0 for measurement, the wavelength of which differs from that of the laser light L for processing, which is emitted by the laser output unit 30. The laser light L0 emitted from the laser output unit 60 passes through the beam splitter 62 onto the dichroic mirror 61, is reflected, and focused by the lens 58 onto the incidence area 11. A portion of the laser light L0 incident on the incidence area 11 is reflected by a surface 11a on the sample side A of the incidence area 11. The reflected light of the laser light L0 is guided through the lens 58, the dichroic mirror 61, the beam splitter 62, and the mirror 63 and falls onto the detector 64, where it is detected. In this way, the transmittance of the incidence area 11 is measured.

[0088] Fig. Figure 9 is a flowchart showing each step when the permeable element (incidence area 11) is cleaned according to the permeability of the permeable element. As in Fig. As shown in Figure 9, steps S1, S2, and S3 are performed here similarly to the embodiment described above. The permeability of the incidence area 11 is then determined using the method described in Figure 9. Fig. The configuration shown in step 8 is measured, and it is determined whether the measured permeability has decreased by a predetermined threshold or more (step S14).

[0089] If, in step S14, it is determined that the transmittance of the incidence area 11 has not decreased by the predetermined threshold or more (step S14: NO), step S6 (observation of sample A) is performed similarly to the embodiment described above. However, if, in step S14, it is determined that the transmittance of the incidence area 11 has decreased by the predetermined threshold or more (step S14: YES), the incidence area 11 is cleaned similarly to the embodiment described above (step S4). That is, by irradiating the incidence area 11 with laser light L, an ablation process is performed on the adhering substances on the surface on sample side A of the incidence area 11, and the adhering substances are removed.

[0090] Incidentally, after the determination in step S14 and before the execution of step S6, it can be determined, similarly to step S5, whether the intended processing of sample A is complete. In this case, by first determining the number of laser processing operations performed (e.g., the number of executions of step S3) and by ascertaining whether the laser processing has been completed the specified number of times, it can be determined whether the intended processing of sample A is complete. If it is then determined that the intended processing of sample A is complete, the observation of sample A described above in step S6 can be carried out.

[0091] As described above, by cleaning the entry area 11 based on the permeability of the entry area 11, the entry area 11 can be cleaned efficiently as often and sufficiently as necessary.

[0092] The configuration for measuring the transmittance of the incidence area 11 is not based on the example in Fig. 8 limited, but can, for example, be in Fig. The configuration shown in section 10 will be used. In the example of... Fig. The microscope device 1 comprises the laser output unit 60, the beam splitter 62, the mirror 63, the detector 64, a dichroic mirror 65, and a galvanometer scanner 70. The dichroic mirror 65 and the galvanometer scanner 70 are arranged sequentially along the laser light path L. Accordingly, for example, the laser light L emitted by the laser output unit 30 passes through the laser optics system 40 (not shown) and the dichroic mirror 65, is reflected by the galvanometer scanner 70, falls on the lens 58, and is focused onto the sample A or the incidence area 11.

[0093] The laser light L0 emitted by the laser output unit 60 passes through the beam splitter 62 onto the dichroic mirror 65, is successively reflected by the dichroic mirror 65 and the galvanometer scanner 70, and focused by the lens 58 onto the incidence area 11. A portion of the laser light L0 incident on the incidence area 11 is reflected by the surface 11a on the sample side A of the incidence area 11. The reflected light of the laser light L0 is guided through the lens 58, the galvanometer scanner 70, the dichroic mirror 65, the beam splitter 62, and the mirror 63, and falls onto the detector 64, where it is detected. In this way, the transmittance of the incidence area 11 is measured. Incidentally, in the Fig. In the configuration shown in Figure 10, a reflective spatial light modulator 80 is provided instead of the galvanometer scanner 70.

[0094] Incidentally, the beam irradiation unit 3 is not strictly necessary in the microscope device 1 and can be omitted. Additionally, the microscope device 1 can include a cooling section for cooling the spatial light modulator 41. In this case, the thermal influence on the spatial light modulator 41 is suppressed.

[0095] Furthermore, the laser optics system 40 in the microscope device 1 includes the collimator lens 51 to direct the collimated laser light L onto the spatial light modulator 41. However, if collimated light is emitted from the laser output unit 30, the collimator lens 51 can be omitted.

[0096] Furthermore, either the first microscope unit 4 or the second microscope unit 5 can be omitted in the microscope device 1, and it is sufficient if at least one microscope unit is provided. Additionally, the output control unit 52 and / or the beam diameter control unit 53 and the relay optics system 44 can also be omitted in the microscope device 1.

[0097] Furthermore, in the embodiment described above, step S6 gives an example case in which sample A is observed using the first microscope unit 4 or the second microscope unit 5, which are arranged inside chamber 10. However, in step S6, the present invention is not limited to observation using the first microscope unit 4 or the second microscope unit 5, which are arranged inside chamber 10, and sample A can be viewed using a microscope unit located outside chamber 10. In this case, at least one of the first microscope unit 4 and the second microscope unit 5 can be located outside chamber 10 (for example, in a chamber separate from chamber 10) and used for observation in step S6. List of reference symbols 1 microscope device, 4 first microscope unit (microscope unit), 5 second microscope unit (microscope unit), 7 Cover (permeable element), 10 chambers, 11. Ingress area (permeable element), 41 spatial light modulator, 42 lens, 43 galvanometer scanners. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2002-248589 A

[0002]

Claims

[1] Method for using a microscope apparatus, comprising: a first step in arranging a sample within a chamber; a second step of pressure reduction in the chamber by evacuating the interior of the chamber; a third step of removing part of the sample inside the chamber by irradiating the sample with laser light through a transparent element that allows the laser light to pass through, in order to perform ablation processing after the first and second steps; a fourth step in which ablation processing is performed on particles generated from the sample by irradiating the particles with laser light in a state in which the sample is located inside the chamber, after the first and second steps; and a fifth step in which the sample is observed after the third step using a microscope unit, wherein in the third step a focal point of the laser light is arranged at a first position on the sample side with respect to the transparent element in an optical axis direction of the laser light, and In the fourth step, the focal point is positioned at a second position on the side of the transparent element with respect to the sample in the optical axis direction. [2] Method for using a microscope device according to claim 1, wherein the fourth step is carried out after the third step. [3] Method for using a microscope device according to claim 2, wherein the third step is repeated after the fourth step. [4] Method for using a microscope device according to one of claims 1 to 3, wherein between the third step and the fourth step a position of the focal point is changed between the first position and the second position by moving the chamber. [5] Method for using a microscope device according to any one of claims 1 to 4, wherein between the third step and the fourth step a position of the focal point is changed between the first position and the second position by moving a lens to focus the laser light onto the sample or the transparent element. [6] Method for using a microscope device according to any one of claims 1 to 5, wherein between the third step and the fourth step a position of the focal point is changed between the first position and the second position using a galvanometer scanner. [7] Method for using a microscope device according to any one of claims 1 to 6, wherein between the third step and the fourth step a position of the focal point is changed between the first position and the second position using a spatial light modulator. [8] Method for using a microscope device according to claim 1, wherein the fourth step is carried out simultaneously with the third step. [9] Method for using a microscope device according to claim 8, wherein the third step and the fourth step are carried out simultaneously by modulating the laser light using a spatial light modulator to form the focal point at both the first position and the second position. [10] Method for using a microscope device according to any one of claims 1 to 9, wherein the pulse width of the laser light is 1 ps or less. [11] Method for using a microscope device according to any one of claims 1 to 10, wherein the second position is a position within 2 mm of a surface on the sample side of the transparent element. [12] Method for using a microscope device according to any one of claims 1 to 11, wherein the second position is a position on one side opposite the sample with respect to a surface on the sample side of the transparent element. [13] Method for using a microscope device according to claim 12, wherein the second position is a position within the transparent element. [14] Method for using a microscope device according to claim 12, wherein the second position is a position outside the transparent element. [15] Method for using a microscope device according to any one of claims 1 to 14, wherein in the fourth step the sample is irradiated with the laser light that has passed through the transparent element. [16] Method for using a microscope device according to any one of claims 1 to 15, wherein the transparent element is an incidence area for the laser light in the chamber. [17] Method for using a microscope device according to any one of claims 1 to 15, wherein the permeable element is a cover provided for covering the sample inside the chamber. [18] Method for using a microscope device according to any one of claims 1 to 17, wherein the fourth step and the fifth step are carried out in different chambers. [19] Method for using a microscope device according to any one of claims 1 to 17, wherein the fourth step and the fifth step are carried out in the same chambers. [20] Method for using a microscope device according to any one of claims 1 to 19, wherein the beam pattern of the laser light has a top-hat shape. [21] Method for using a microscope device according to any one of claims 1 to 20, wherein in the fourth step adhering matter on the transparent element is removed by irradiating the transparent element with laser light to perform an ablation treatment on the adhering matter.

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