JP3174307B2 - Secondary charged particle analyzer and sample analysis method using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to secondary charged particles (secondary charged particles (secondary ions or primary electrons) generated from an inspected object by irradiating the inspected object with primary charged particles (primary ions or primary electrons)). The present invention relates to a secondary charged particle analyzer that forms an image of ions and secondary electrons) and analyzes secondary charged particles.

[Conventional technology]

The secondary charged particle analyzer includes a secondary ion mass spectrometer and a scanning electron microscope.

For example, when a constituent element of a semiconductor device such as an LSI is analyzed using a secondary ion mass spectrometer, the object to be inspected is irradiated with a primary ion beam, and the constituent element in an irradiation area is struck out as a secondary ion, and this secondary The mass of the ions will be analyzed. However, due to the recent ultra-high density of the LSI technology, the size of the components of the LSI, the wiring width, and the like have been realized to be 1 micron or less. In addition, the concentration of the impurity element implanted into the semiconductor device may vary depending on the location.
It changes by more than an order of magnitude. In order to analyze such a fine region with high accuracy, it is necessary to narrow the irradiation region of the primary ion beam. However, it is difficult to narrow the primary ion beam finely due to the space charge effect, and it is necessary to narrow the diameter to about several microns. Therefore, in order to solve this point, in the prior art, when performing elemental analysis of such an ultrafine region, a range of several microns in diameter is irradiated with a primary ion beam, and a secondary ion beam emitted from this range is irradiated. The ion beam is imaged through a lens system (hereinafter referred to as a secondary charged particle extraction unit), and of the obtained images, only the image of the hyperfine region to be inspected is extracted through a slit or the like and is incident on the mass analysis system. The selected area method will be adopted.
However, in the conventional simple control visual field method, for example, ³¹ P and ³⁰ S
When the mass difference is as small as 1/4000, such as i ¹ H, mass analysis itself is difficult, and it is necessary to improve the properties of a beam incident on the mass analysis system.

[Problems to be solved by the invention]

However, in the conventional secondary charged particle analysis device, the dispersion of the emission angle and position of the secondary charged particle beam extracted from the secondary charged particle extraction unit becomes large, and the analysis degree or sensitivity cannot be increased. For this reason, especially in the secondary ion mass spectrometer, elemental analysis in an ultrafine region cannot be performed.

A first object of the present invention is to provide a high-resolution and high-sensitivity secondary charged particle and an analyzer.

A second object of the present invention is to provide a secondary charged particle extraction unit having a small dispersion of the emission angle and position of the secondary charged particle beam.

[Means for solving the problem]

The above objects of the present invention are attained by correcting the trajectory of the secondary charged particles by an acceleration lens formed at the secondary charged particle extraction unit.

[Action]

FIG. 2 shows an embodiment of the secondary charged particle extracting section of the present invention,
FIG. 3 is a schematic diagram showing the operation in an equivalent optical lens configuration.

An electrostatic lens is an electric field generated between two electrodes having a potential difference, and charged particles always receive a force in the direction of the electric field. Secondary charged particles 30a sputtered with a certain angular distribution from sample 6
30b and 30c are extracted by an electrostatic lens 31 (hereinafter, referred to as an extraction lens) formed between the sample 6 and the extraction power 8,
Next, the lens is accelerated to a predetermined energy by an electrostatic lens (an electrostatic lens formed between the extraction electrode 8 and the electrode 9a, hereinafter referred to as an acceleration lens) 32. In the conventional apparatus, since the acceleration energy is fixed, the strength of the extraction lens 31 and the strength of the acceleration lens 32 are dependent and cannot be adjusted independently. Then, the electrodes 9a and 9b and the electrode 9c
The angle of incidence of the charged particles incident on the focusing lens 33 composed of the following changes each time the strength of the extraction lens 31 is changed (every time the potential of the extraction electrode 8 is changed), and the capability of the focusing lens is changed. Can't make good use of it. In particular, when the cross point 35b is formed as shown by the broken line in FIG. 3, the incident angle of the charged particles incident on the focusing lens 33 increases. The emission angle and dispersion to the secondary charged particle analysis system increase. Therefore,
By correcting the trajectory of the secondary charged particles by the formed acceleration lens, the incident angle of the charged particles incident on the focusing lens 33 can be reduced as shown by the solid line in FIG.
As a result, the ability of the focusing lens can be utilized and the emission angle and dispersion to the secondary charged particle analysis system can be reduced, so that a high-resolution and high-sensitivity secondary charged particle analyzer can be provided.

〔Example〕

A preferred embodiment of the present invention will be described with reference to FIGS. 1 to 7 taking a secondary ion mass spectrometer as an example.

FIG. 1 shows a configuration of a secondary ion mass spectrometer of the present invention. In this secondary ion mass spectrometer, unnecessary ion components of the ion beam 2a emitted from the primary ion source 1 are removed by the electrode 3a, and this ion beam is separated by the primary ion irradiation system electrostatic lenses 4a, 4b and the slit 5a. The beam is irradiated onto the sample 6 by the deflection lens 3b while scanning over a range of several hundred microns square. The secondary ions sputtered by the primary ions are imaged by the secondary charged particle extracting unit 50 on a slit 5b which is an outlet to the following mass spectrometry system. And this slit 5b
The secondary ions in the desired range are selected by changing the diameter of only the secondary ions, and only the secondary ions that have passed through the slit 5b enter the detector 12 from the sector electric field 10 through the sector magnetic field 11 and the slits 5c and 5d. , Mass spectrometry. The sample driving section 8 is for moving the sample right and left, front and back, or tilting, and is for positioning the position to be analyzed or changing the irradiation condition.

FIG. 2 shows the configuration of the secondary charged particle extracting section 50 in FIG. FIG. 3 shows the second
FIG. 4 is a schematic diagram showing the operation of the figure by an optical lens configuration. The secondary charged particle extraction unit 50 according to the present embodiment includes the extraction electrode 8 connected to the variable electrode 21a, and three electrodes 9a, 9b, 9c.
An einzel lens 9 serving as a focusing lens and a variable electrode connected to an electrode 9a disposed immediately after the extraction electrode 8
21c, a variable electrode 21b connected to the central electrode 9b, and control means 22 for controlling these variable electrodes 21a, 21b, 21c. In this embodiment, the electrode 9c is connected to the ground.

When the sample 6 is irradiated with the primary ion beam 2a focused to a diameter of several microns by the primary irradiation system, the sample 6
The secondary ions sputtered from are extracted toward the extraction electrode 8 by an extraction lens formed between the extraction electrode 8 and the sample 6. The secondary ions extracted by the extraction electrode 8 are accelerated by an electrostatic lens formed between the electrodes 8, 9a, and the electrostatic lens formed between the electrodes 9a, 9b and the electrodes 9b, 9c.
An image is formed on the slit 5b by a converging lens constituted by an electrostatic lens formed therebetween. A voltage corresponding to the acceleration energy of the secondary ion beam 2b is applied to the sample 6 by the power supply 20. The control means 22 adjusts the potential of each of the electrodes 8, 9a, 9b so that the secondary ion beam 2b forms an image on the slit 5b.

FIG. 4 is a diagram showing a numerical simulation result in the present embodiment. FIG. 5 shows that ± 6
This is a simulation result in which the trajectory of the secondary ions sputtered within a degree is multiplied by 100 in the vertical direction. This figure is a longitudinally enlarged view of a trajectory traced by secondary ions generated from the hyperfine region A, and corresponds to an enlarged line of two lines among the lines showing the secondary ion beam in FIG. . Sample 6
Is applied with 3.0 kV by the electrode 20, and the extraction electrode 8
2.48 kV is applied by the variable electrode 21a to the electrode 9a.
1.5 kV is applied by the variable power supply 21 c, and 2.0 kV is applied to the electrode 9 b.
Is applied by the variable power supply 21b.

On the other hand, FIGS. 6 and 7 show a fourth embodiment of the prior art in which the electrode 9a constituting the focusing lens of FIG.
5 and 5 correspond to FIGS. 5 and 5, respectively, in which the secondary ion acceleration voltage (voltage of the power supply 20) is 3.0 kV, the voltage of the extraction electrode 8 is 2.48 kV, and the secondary ion beam and 2b are imaged. The voltage of the center electrode 9b of the Einzel lens 9 to be made is 2.65 kV. In this case, the potential difference between the sample 6 and the extraction electrode 8 is
On the contrary, the potential difference between the extraction electrode 8 and the electrode 9a is as large as 2.48 kV. Therefore, as shown by the locus in FIG. 5, the secondary ion beam forms a crossover (convergence point) X inside the electrode 9a, that is, between the acceleration lens 32 and the focusing lens 33. For this reason, the angle of incidence on the focusing lens formed between the electrodes 9a and 9b and between the electrodes 9b and 9c increases, and the voltage applied to the central electrode 9b for focusing this secondary ion beam must be increased. Have to be. As is clear from FIG. 7, the secondary ion beam 2b emitted from above the central axis is once focused below the central axis, diffuses again, is focused by the focusing lens, and is focused. The image is formed on the upper side of. That is, under the condition that an erect image is formed by the slit 5b, the slit
The angle of incidence of the secondary ion beam on 5b becomes large, and the efficiency in the mass spectrometry system provided after the slit 5b becomes poor. In other words, the conventional secondary charged particle extraction unit must use a focusing lens having a strong focusing action, so that the dispersion of the emission angle and position of the secondary charged particles to the mass spectrometry system as shown in FIG. growing.

This problem cannot be solved by adjusting the voltage of the center electrode 9b.

On the other hand, in the present embodiment, 3.0 kV and 2.48 kV are applied to the sample 6 and the extraction electrode as in the conventional example, respectively.
b, by adjusting the variable power supplies 21c and 21b, respectively.
5 kV and 2.0 kV are applied. In this embodiment, the potential of the electrode 9a is 1.5 kV and the potential difference between the potential of the extraction electrode 8 and the potential of the extraction electrode 8 is small, that is, the focal length of the acceleration lens is long. The point X is not formed, and the adjacent secondary ion beams passing through the electrode 9a are substantially parallel to each other. Therefore, the angle of incidence of the secondary ion beam on the focusing lens becomes smaller,
Even with a weak focusing lens (the applied voltage to the electrode 9b is small), it is possible to sufficiently form an image on the slit 5b, and the aberration is reduced. Therefore, as shown in FIG. 5, the secondary ion beam 2b generated in the hyperfine region A above the central axis is converted into a substantially parallel beam by the acceleration lens 32, and is imaged below the central axis by the focusing lens. I do. The angle of incidence of the secondary ion beam on the slit 5b placed at this position in order to capture the secondary ions from the hyperfine region A is almost vertical, and the trajectory is also vertical. Accordingly, the incident angle of the entire secondary ion beam 2b becomes almost vertical, and the trajectory becomes almost vertical. As a result,
By taking the secondary ions in the imaged portion into a mass spectrometry system and analyzing the mass, a high-resolution and high-sensitivity analysis result can be obtained.

In order to draw the electric field distribution as described above, that is, the locus of the secondary ion beam, each of the variable power supplies 21a to 21c is set by the control means 22. First, the control means 22 sends a control signal 22b to the power supply 21a to set conditions for extracting secondary ions. Next, the power supply 21c and the power supply
Control signals 22c and 22b are sent to 21b, respectively, to determine the potentials of the electrodes 9a and 9b. Next, a control signal 22c is sent to the power supply 21c to finely adjust the potential of the electrode 9a, and finally, the potential of the power supply 9a is determined by finely adjusting the power supply 21b. By controlling the power supply 21c, the emission angle of the secondary ion beam is adjusted. That is, the angle of incidence on the focusing lens is adjusted. Then, the focal length is adjusted by the power supply 21b. After defining the withdrawal conditions,
Each power supply voltage is determined while finely adjusting both the variable power supplies 21b and 21c. In practice, however, a test pattern is placed at the position of the sample 6 and a detector of the secondary ion beam image at the slit 5b is provided. Adjust the power supply voltage while watching the monitor. The monitor is equipped with an auto focus device,
It is also possible to adjust the control means 22 with a feedback signal from this device.

FIG. 8 is a configuration diagram showing a second embodiment of the secondary charged particle extracting section of the present invention. The secondary charged particle extracting section 51 according to the present embodiment is different from the secondary charged particle extracting section 50 of the first embodiment.
The only difference is that the electrode 9b and its variable power supply 21b are omitted. This embodiment is suitable when the control range of the voltage of the extraction electrode 8 is limited to a certain range. In this case, the electrode 9a
It is possible to form the secondary charged particles on the slit 5b simply by adjusting the voltage of the secondary charged particles. In particular, by adjusting the voltage of the electrode 9a, it is possible to adjust the strength of the acceleration lens formed between the extraction electrode 8 and the electrode 9a and the two focusing lenses formed between the electrode 9a and the power supply 9c. There is an advantage that the adjustment can be performed easily and with high sensitivity as compared with the example.

FIG. 9 is a configuration diagram of a second embodiment of the secondary charged particle extracting section 50 of the present invention. The secondary charged particle extracting unit according to the present embodiment is different from the first embodiment only in that a voltage automatic adjustment control unit 40 is added. In the present embodiment, at the time of voltage adjustment for obtaining the optimum voltage condition, a finely drivable line source 41 for generating a particle beam including an α-ray or a β-ray having a diameter of several microns is arranged at a sample position. From the extraction electrode 8, and the particle beam is formed on a wire detector (adjustable wire spacing) 42 provided at the slit position.

First, by determining the voltage of the extraction electrode 8, parameters are set in the control means 22 so that the voltages of the power supplies 21b and 21c are uniquely determined according to a certain predetermined function. Then, the source 41 is placed at the sample position and the particle beam is extracted from the extraction electrode 8.
To form an image on the wire detector 42. The wire detector 42 measures the current or the number of pulses. In this measurement, the position of two wires stretched at right angles to the particle beam is adjusted, and the position where the current or pulse count is maximized is determined. Next, fix the wire in this position and fix the electrodes 9a, 9
Fine-tune the voltage applied to b and examine the conditions that maximize the current or pulse count. The conditions obtained in this way are the optimum conditions, and these optimum conditions are referred to as automatic voltage adjustment control means.
It is stored in the memory of 40.

When the actual sample is placed at the position of the source 41 and the slit is measured at the position of the wire detector 42, the setting parameters of the control means 22 are stored in the memory in the automatic voltage adjustment control means 40. By modifying, the variable power supply 21
b, 21c are adjusted to perform high-accuracy voltage control.

According to this embodiment, the voltage of each electrode can be adjusted so that the dispersion of the incident angle and position of the secondary ion beam automatically entering the mass spectrometry system is reduced.

In each of the above-described embodiments, the emission angle of the secondary ion beam is adjusted by changing the voltage applied to the electrode 9a disposed immediately after the extraction electrode 8, but the position of the electrode 9a relative to the extraction electrode 8 (both electrodes 8a). , 9a) can be adjusted mechanically to adjust the emission angle. FIG.
FIG. 13 is a diagram illustrating a configuration of a secondary charged particle extracting unit according to a fourth embodiment of the present invention based on this viewpoint. The difference between the third embodiment (FIG. 9) and the third embodiment (FIG. 9) is that the portion of the electrode 9a facing the extraction electrode 8 is cut off to form a movable electrode 9d, so that the space between the electrodes 8 and 9d is reduced. The driving means 24 for mechanically adjusting the distance is provided to adjust the emission angle. That is,
By changing the distance between the extraction electrode 8 and the electrode 9a, the potential distribution of both electrodes changes, and the focal length of the acceleration lens can be made variable. If the focal length is adjusted as in the second embodiment, the same effects as in the above embodiments can be obtained. still,
In this embodiment, the electrode 9a is moved, but it is also possible to move only the electrode 8 or both electrodes 8, 9 by the same means.

FIG. 11 is a diagram showing a configuration of a secondary charged particle extracting unit according to a fifth embodiment of the present invention. The present embodiment shows an example of application to a secondary charged particle extracting portion composed of two Einzel lenses 8 and 9. The front Einzel lens 8 constitutes an extraction electrode. The electrode 8a of the extraction electrode facing the sample 6 extracts and accelerates the secondary ion beam by being grounded. Variable power supply 2 for electrodes 8b and 8c
1a and 21c are connected to adjust the incident angle of the secondary ion beam incident on the focusing lens 9. The focusing lens 9 has electrodes
The secondary ion beam is focused on the slit 5b by controlling the voltage of 9b. In particular, by setting the electrodes 8c and 9a to the same voltage, the secondary ion beam emitted from the electrode 8c can be decelerated, that is, the focal point distance can be lengthened. The angle can be adjusted to a nearly parallel beam. For this reason, after passing through the focusing lens 9, the secondary ion beam can be made to enter the slit 5b almost perpendicularly. In this embodiment, three variable power supplies 21a, 21b, and 21c are used. However, even if the electrodes 8b and 8c are set to the same potential or the electrodes 9a and 9b are set to the same potential, almost the same focusing is performed. Since high performance can be obtained, the number of variable power supplies can be reduced to two.

FIG. 12 is a configuration diagram of a secondary charged particle extracting section according to a sixth embodiment of the present invention. In the present embodiment, the secondary charged particle extraction unit includes an electromagnetic lens 23 provided between the extraction electrode 8 and the electrode 9a, and a variable power supply 21d for varying the current supplied to the electromagnetic lens 23 and varying the focal length. The point provided is different from the above embodiment. That is, in the first to fifth embodiments, the variable focal length acceleration lens is formed between the extraction electrode 8 and the electrode 9a. In this embodiment, the same effect can be obtained by providing the variable distance electromagnetic lens 23.When the electromagnetic lens is provided, the electromagnetic field is not changed by, for example, a superconductor so that the magnetic field does not adversely affect other measurement systems. The lens 23 needs to be magnetically shielded. In this embodiment, the extraction electrode 8 and the electrode
Although 9a and 9a are connected to a common variable power supply 21a so as to have the same potential, it goes without saying that they can be connected to different variable power supplies and set to different potentials.

In the above embodiment, the description has been made mainly on the fact that the secondary ion beam is almost perpendicularly incident on the slit 5b. In the following embodiment, an embodiment that achieves high resolution and high sensitivity by changing the size of an image, that is, the magnification will be described.

FIG. 13 is a view showing the configuration of the secondary charged particle extracting portion of the seventh embodiment of the present invention viewed from this viewpoint. This embodiment is the same as the fourth embodiment. In the fourth embodiment, by moving the movable focusing electrode 9d closer to or away from the end 81 of the extraction electrode 8, the focal length is changed mainly without changing the position of the acceleration lens 32. That is, since the place where the potential distribution is dense is between the end portion 81 of the extraction electrode and the variable focusing electrode, controlling the position of the variable focusing electrode 9d reduces the dense range, that is, the width of the lens. It changes the focusing distance. On the other hand, in this embodiment, the acceleration lens 32 is changed by inserting the movable focusing electrode 9d into the cylindrical extraction electrode 8. If the extraction electrode 8 and the movable focusing electrode 9d are formed as a double cylinder as shown in FIG. 13, since the dense potential distribution becomes the tip of the movable focusing electrode 9d,
By changing the position of the movable focusing electrode 9d, the acceleration lens
32 positions can be changed.

FIG. 14 schematically shows the operation principle of the above embodiment. The secondary ion beam emitted from the sample 6 and extracted to the extraction lens 31 is deflected by the acceleration lens 32, but the deflection angle changes depending on the position of the acceleration lens 32. For example, if the accelerating lens is brought closer to the sample 6 like 33Z, the deflection angle becomes larger as shown by the broken line, and the position of incidence on the focusing lens 33 is further away from the central axis, so that the image formed on the slit 5b also becomes larger. The lens magnification increases. If the magnification is large, the position resolution can be improved, that is, the resolution can be increased by changing the width of the slit 5b. If a higher resolution can be achieved, the boundary can be discriminated even if the impurity element concentration changes greatly, so that noise due to other elements disappears and high sensitivity can be realized.

In the above embodiment, only the focusing electrode 9d is movable, but a similar effect can be obtained even if the extraction electrode 8 and the entire focusing electrode 9d are movable. However, in this case, since the strength of the extraction lens 31 between the sample 6 and the extraction electrode 8 also changes, it is necessary to control the voltage applied to the sample in conjunction with the movement of the movable part.

FIG. 15 shows an eighth embodiment in which the magnification is changed by moving the accelerating lens 32 in the seventh embodiment, but the magnification is changed by changing the position of the focusing lens 9. It is. In this embodiment, two sets of focusing lenses, 9,9Z are provided. Therefore, by switching the focusing lens operated by using the switch 21Z to 9 or 9Z, the slit
The size of the image of the secondary ion beam on 5b can be varied.

FIG. 16 schematically shows the operation principle of the above embodiment. The secondary ions extracted from the sample 6 at the size α of the output image are almost parallel after passing through the extraction lens 31 and the acceleration lens 32 (that is, the condition that the focal point is on the right side of the slit 5b).
Then, the light is made incident on the focusing lens 33. The secondary ion beam 30 is focused by the focusing lens 33 so as to be almost perpendicularly incident on the slit 5b.
Focus. The size of the image is β, and the overall magnification of the lens is β / α. By causing the secondary ion beam 30 emitted from one point on the sample to enter the converging lens 33 almost in parallel, when the converging lens position is moved to the converging lens 33Z shown by a broken line, the image size becomes β '. , The magnification of the lens becomes β ′ / α, and the magnification can be made variable. In this case, the focusing lens is switched, but the magnification can be continuously changed by making the position of the focusing lens 9 movable.

In the seventh and eighth embodiments, the magnification is made variable and the angle of incidence of the secondary charged particle beam incident on the focusing lens is made substantially parallel. Of course, only the means for making the magnification variable can be used. At least the first and second objects of the present invention can be achieved.

In the embodiments described so far, the secondary ion mass spectrometer has been described. However, by providing each of the secondary charged particle extraction sections in a scanning electron microscope, a scanning electron microscope with high resolution and high sensitivity can be provided.

FIG. 17 is a configuration diagram of this scanning electron microscope. The electron beam emitted from the electron gun 55 is applied to the irradiation lenses 4a and 4b.
The sample 6 is squeezed by the light and the slit 5a.
At this time, the electron beam is scanned on the sample 6 by the deflection electrode 3b which has received the scanning signal from the scanning power supply 56. Sample 6
Secondary electrons exiting the detector are detected by the secondary electron extraction device 50
An image is formed on the 62 detection surface. The monitor device 63 can display a high-resolution and high-sensitivity image by scanning the detection signal of the detector 62 with the scanning signal from the scanning power supply 56 and displaying the image as an image.

〔The invention's effect〕

As described above, according to the present invention, a high-resolution, high-sensitivity secondary charged particle analyzer can be provided. In addition, it is possible to provide a secondary charged particle extraction unit with small dispersion of the emission angle and position of the secondary charged particle beam. Furthermore, since it is not necessary to increase the degree of focusing of the focusing lens so much, it is not necessary to apply a high voltage to the electrodes, and it is possible to prevent a discharge accident.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a secondary ion mass spectrometer according to one embodiment of the present invention, FIG. 2 is a configuration diagram of a secondary charged particle extracting section according to the first embodiment of the present invention, and FIG. FIGS. 4 and 5 are schematic diagrams showing the secondary charged particle extracting portion shown in FIG. 2 with an optical lens, and FIGS. 4 and 5 are numerical simulation diagrams of the electric field distribution and the secondary ion beam trajectory of the embodiment shown in FIG. FIGS. 7 and 8 are numerical simulation diagrams of the electric field distribution and the secondary ion beam trajectory in the conventional secondary charged extraction unit, FIG. 8 is a configuration diagram of the secondary charged particle extraction unit according to the second embodiment, and FIG. Figure 3
FIG. 10 is a configuration diagram of a secondary charged particle extraction unit according to the fourth embodiment. FIG. 10 is a configuration diagram of a secondary charged particle extraction unit according to the fourth embodiment.
The figure is a configuration diagram of a secondary charged particle extraction unit according to the fifth embodiment,
FIG. 12 is a configuration diagram of a secondary charged particle extracting unit according to a sixth embodiment using an electromagnetic lens, and FIG. 13 is a diagram of a secondary charged particle extracting unit according to a seventh embodiment that changes the position of an acceleration lens. Diagram,
FIG. 14 is a schematic view of the operation principle of the seventh embodiment, and FIG. 15 is a configuration diagram of the secondary charged particle extracting portion of the eighth embodiment in which the position of the focusing lens is changed and the magnification is changed. FIG. 17 is a schematic view of the operation principle of the eighth embodiment, and FIG. 17 is a diagram showing an embodiment of the present invention in a scanning electron microscope. DESCRIPTION OF SYMBOLS 1 ... Primary ion source, 2 ... Ion beam, 3 ... Deflection electrode, 4 ... Electrostatic lens, 5 ... Slit, 6 ... Sample, 8 ... Extraction electrode, 9 ... Focusing electrode, 10 ... ... Sector electric field, 11 ... Sector magnetic field, 12 ... Detector, 21 ... Variable power supply, 50 ... Secondary charged particle extraction unit.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-64-35844 (JP, A) JP-A-58-142285 (JP, A) Fully open 1984-180361 (JP, U) Really open Showa 56- 138463 (JP, U) Japanese Utility Model Showa 51-217791 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01J 37/244 H01J 37/26 H01J 49/26

Claims (3)

(57) [Claims] 1. A primary charged particle generation source, means for irradiating an object to be inspected with primary charged particles from the primary charged particle generation source, and a drawer for extracting secondary charged particles emitted from the object to be inspected A first electrode that forms an electric field with the object to be inspected, a second electrode that forms an accelerating electric field with the first electrode, and an imaging lens with the second electrode A secondary charge particle extraction portion including a third electrode, a slit for passing a specific secondary charged particle from the secondary charged particles imaged by the imaging lens, and a secondary charge passing through the slit In a sample analysis method using a secondary charged particle analyzer having an analysis unit for analyzing particles, a first step of adjusting a voltage to be applied to the first electrode and setting extraction conditions of the secondary charged particles , Before adjusted in the first step Depending on the voltage applied to the first electrode,
A sample using a secondary charged particle analyzer, comprising a second step of adjusting a voltage applied to the second electrode so that a potential difference between the first and second electrodes is reduced. analysis method. 2. The method according to claim 1, wherein the voltage applied to the third electrode is changed according to the voltage applied to the first and second electrodes adjusted in the first step and the second step. A sample analysis method using a secondary charged particle analyzer, which comprises adjusting. 3. A primary charged particle generation source, means for irradiating the inspection target with primary charged particles from the primary charged particle generation source, and a drawer for extracting secondary charged particles emitted from the inspection target A first electrode that forms an electric field with the object to be inspected, a second electrode that forms an accelerating electric field with the first electrode, and an imaging lens with the second electrode A secondary charged particle extraction portion including a third electrode, a slit for passing a specific secondary charged particle from the secondary charged particles imaged by the imaging lens, and a secondary charged particle passing through the slit In the secondary charged particle analyzer having an analysis unit for analyzing particles, after adjusting the voltage applied to the first electrode and setting the extraction conditions of the secondary charged particles,
According to the adjusted applied voltage to the first electrode,
A secondary charged particle analyzer, comprising: a control unit that adjusts a voltage applied to the second electrode so that a potential difference between the first and second electrodes is reduced.