JP2003187733A - Electron beam apparatus and method for manufacturing device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve various aims, by using a complex constitution for insulating magnetic poles from the ground, for which the complex constitution for improving axial aberrations practically imposes no limitations. <P>SOLUTION: An electron beam apparatus comprises an electron gun 1a, a condenser lens 6, an electrostatic deflector 7, an E×B separator having an electrostatic deflector 10 and electromagnetic deflectors 11, 12, and an object lens 30. The object lens 30 has an upper magnetic pole 13, a lower magnetic pole 20, and a magnetization coil 15 located between the both magnetic poles. The upper magnetic pole 13 and the lower magnetic pole 20 are independently insulated from the ground. Furthermore, the electron beam apparatus comprises a negative voltage source 23 for supplying a negative voltage to a sample 21, and a switch 26 for switching between a variable negative voltage source 24 and a variable positive voltage source 25 for switching a voltage applied to the lower magnetic pole 20 between a positive voltage and a negative voltage lower than the voltage of the sample to a specified voltage in advance. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention irradiates a sample such as a wafer having a pattern with a minimum line width of 0.1 μm or less with a primary electron beam and detects a secondary electron beam emitted from the sample, The present invention relates to an electron beam apparatus that evaluates a sample based on a secondary electron image obtained in this way, and a device manufacturing method using the electron beam apparatus.

[0002]

2. Description of the Related Art With the miniaturization of semiconductor devices, there is a demand for higher precision and stabilization in the lithography process typified by steppers and the like, and a measuring SEM (scanning electron microscope) is required.
Was developed. This is a probe of a finely focused electron beam, which simultaneously scans a sample such as a semiconductor device and detects secondary electrons generated from the sample by a detector, thereby increasing the pattern size of the semiconductor device with high throughput. It is a technology that measures with precision. The electron optical system includes, for example, an electron gun, a first condenser lens, a second condenser lens,
And composed of an objective lens, the scanning of the electron beam is
It is performed by a two-stage electromagnetic coil arranged above the objective lens.
The secondary electrons generated from the sample are deflected by the E × B separator provided above the scanning coil and detected by the detector. It is possible to contribute to stabilization of the lithography process by feeding back the measurement data obtained by such a length measurement SEM to a stepper or the like to adjust various conditions. Therefore, in order to cope with further miniaturization of semiconductor devices, it is essential to improve the resolution of the length measurement SEM.
The electron optical system of the early SEM used a pure magnetic field lens, but in recent years, an electron optical system that makes full use of a lens in which a magnetic field lens and an electrostatic lens are superposed has been used.

In the superposition type electron optical system of the length measuring SEM as described above, a negative retarding voltage is applied to the sample,
It has been found that good resolution can be obtained by adopting a lettering type electron optical system in which the electron beam is decelerated immediately before entering the sample.

Further, in order to obtain a high resolution, a boosting method for increasing the electron beam energy when passing through the objective lens has been developed in addition to the conventional lettering method. In this boosting type electron optical system,
A boosting voltage is applied to the upper magnetic pole of the objective lens of the electron optical system configured as described above. By increasing the retarding and boosting voltages, the beam energy when passing through the objective lens increases, so that the chromatic aberration and the spherical aberration are reduced, and the resolution can be improved. Further, since the electric field strength of the sample surface is increased, the secondary electrons can be efficiently extracted, and the observation of a contact hole having a high aspect ratio can be dealt with.

[0005]

However, in the electron beam apparatus having both the conventional lettering method and boosting method, when the voltage applied to the upper magnetic pole is increased to a certain level or more, the axial chromatic aberration becomes rather large.
There is a limit in reducing the axial chromatic aberration. Further, in the above-mentioned conventional technique, there is a problem in that the merit obtained is smaller than that in the complicated configuration in which the magnetic pole of the magnetic lens is insulated from the ground.

The present invention has been made in view of the above facts,
By providing an objective lens that has practically no limit in improving axial chromatic aberration, and not only improving axial chromatic aberration, but also having a filter effect by the complicated configuration of insulating the magnetic pole from the ground. It is an object of the present invention to provide an electron beam device that has been set.

Another object of the present invention is to make it possible to manufacture a dynamic focus function capable of changing a focusing condition at high speed with a simple circuit. Still another object of the present invention is to provide a device manufacturing method which improves the inspection accuracy and throughput by inspecting a semiconductor device which is in the middle of manufacturing or a finished product by using the electron beam apparatus.

[0008]

In order to solve the above problems, one aspect of the present invention is an electron beam apparatus including an objective lens for forming an image of an electron beam on a sample. , An upper magnetic pole, a lower magnetic pole, and an exciting coil arranged between both magnetic poles, and applies a negative voltage to the sample, and further applies a negative voltage lower than the sample to the lower magnetic pole. It is characterized by doing. Another aspect of the invention is
An electron beam apparatus including an objective lens for forming an image of an electron beam on a sample, wherein the objective lens includes at least an upper magnetic pole, a lower magnetic pole, and an exciting coil arranged between both magnetic poles. It is characterized in that a negative voltage is applied to the sample, and further a positive voltage is applied to the lower magnetic pole.

Yet another aspect of the present invention is an electron beam apparatus including an objective lens for forming an image of an electron beam on a sample, wherein the objective lens includes an upper magnetic pole, a lower magnetic pole, and both magnetic poles. A negative voltage is applied to the sample, and a voltage to be applied to the lower magnetic pole is specified in advance from a positive voltage to a negative voltage lower than that of the sample. It is possible to switch to the specified value.

Still another aspect of the present invention is an electron beam apparatus including an objective lens for forming an image of an electron beam on a sample, the electron beam being deflected and scanned on the sample.
The objective lens includes at least an upper magnetic pole, a lower magnetic pole, and an exciting coil disposed between the magnetic poles, and the upper magnetic pole and the lower magnetic pole are independently insulated from each other from ground.
A positive voltage and a negative voltage can be applied to the lower magnetic pole, and a voltage synchronized with a deflection voltage for deflecting the electron beam can be applied to the upper magnetic pole. .

The device manufacturing method of the present invention is characterized in that the sample as a wafer after completion of at least one wafer process is evaluated by using the electron beam apparatus of each of the above aspects.

Other advantages and effects of the present invention will be further clarified by the following description.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. (First Embodiment: Electron Beam Device) FIG. 1 shows a schematic configuration of an electron beam device according to a first embodiment of the present invention. In this embodiment, the principle of SEM (scanning electron microscope) is used, and a narrowed electron beam is simultaneously scanned on a sample such as a semiconductor device, and secondary electrons generated from the sample are detected by a detector. Thus, an example in which the present invention is applied to an electron beam apparatus for evaluating a semiconductor device will be described.

The electron beam apparatus according to this embodiment includes an electron gun 1a that emits an electron beam, a condenser lens 6 that forms a crossover from the emitted electron beam, and an objective lens that further reduces and forms an image of the crossover. 30, an electrostatic chuck 27 that electrostatically holds the sample 21 with a plurality of electrodes arranged substantially flat, and to selectively ground the electrodes of the electrostatic chuck 27 in a time-controlled manner Switch 2
2 and a negative high voltage source 23 for applying a negative potential to the sample 21.
And, including. The electron gun 1a is a LaB6 cathode 1
Is supported by the graphite heater 2 and the pressing column 3, and the anode 5 is assembled in the Wehnelt 4 with high accuracy in the center, and the cathode temperature and the Wehnelt voltage are controlled so as to operate in the space charge limited region.

The thin primary electron beam decelerated by the negative potential on the surface of the sample 21 is used as the condenser lens 6 and the objective lens 30.
Thus, a small probe irradiation spot of 0.01 to 0.1 μmφ is formed on the sample 21. Condenser lens 6
An electrostatic deflector 7 that deflects the primary electron beam so that such an irradiation spot is scanned in a predetermined range on the sample 21 is provided in the lower stage. Further, an E × B separator 29 having the electrostatic deflector 10 is arranged below the electrostatic deflector 7. The electrostatic deflectors 7 and 10 are controlled by the scanning control circuit 9. Here, the scan control circuit 9
Is a deflection voltage for deflecting the electron beam.
The output is adjusted and output for controlling the beam scanning by 0, and the synchronization signal is output to the dynamic focus power supply 16 via the synchronization signal generation circuit 9 ′ so as to output a voltage that changes in synchronization with the deflection voltage. To do.

As described above, in this embodiment, the two electrostatic deflectors 7 and 10 can be used to deflect the primary electron beam in two stages. At this time, the deflection fulcrum 28 on the electron gun side, which is a short distance from the main surface of the objective lens, is selected so that the chromatic aberration of magnification and rotation becomes small.

Further, the E × B separator 29 is the electrostatic deflector 1
In addition to 0, an electromagnetic deflector (magnetic field generation coil) 11 (for X-direction deflection) and 12 (for Y-direction deflection) is included to form an E × B structure that makes an electric field and a magnetic field orthogonal to each other. Therefore, if an electromagnetic field is selectively applied, it is possible to create a condition (Vienna condition) in which the effects of the electric field and the magnetic field cancel each other out. The beam travels substantially straight and irradiates the sample 21 vertically, and the secondary electron beam incident from the opposite direction is deflected in a direction forming a predetermined angle with respect to the optical axis of the primary optical system. Separated from. A detector 8 for detecting the intensity of the secondary electron beam is arranged in the deflection direction of the secondary electron beam. Based on the detection signal and the deflection signals of the deflectors 7 and 10, the detector 8 detects
It is connected to an image processing unit (not shown) for forming a secondary electron image, and the defect or the like of the sample 21 can be evaluated from the secondary electron image.

Next, the detailed structure of the objective lens 30 will be described. The objective lens 30 includes an upper magnetic pole 13 and a lower magnetic pole 2.
0 and an exciting coil 15 arranged between both magnetic poles 13 and 20. The upper magnetic pole 13 and the lower magnetic pole 20 are independently insulated from the ground and further insulated from each other by an insulating spacer 14. The exciting coil 15 is wound around a bobbin (not shown) surrounded by alumina, and the magnetic pole 13,
Isolated from 20 and grounded. The upper magnetic pole 13 and the lower magnetic pole 20 of the objective lens 30 are both supported by an insulating cylinder 17 and vacuum-sealed by an O-ring 18. A shield cylinder 19 is attached to the lower magnetic pole 20 so that even if the surface of the insulator is charged, its potential does not leak in the optical axis direction.

As shown in the figure, the position of the deflection fulcrum 28 of the primary electron beam by the deflector 7 and the E × B electrostatic deflector 10 is selected to be substantially the same height as the upper magnetic pole 13. This is slightly closer to the electron gun than the lens main surface, which is the middle point of the magnetic pole, and this position can be easily calculated by simulation.

At the time of deflection, in order to dynamically correct the change of the field curvature due to the change of the deflection angle, the deflectors 7 and E
A synchronization signal synchronized with the deflection voltage of the × B electrostatic deflector 10 that changes at high speed is applied to the dynamic focus power supply 16, and the power supply 16 applies the dynamic focus voltage to the upper magnetic pole 13. The upper magnetic pole 13 has a function as an electrostatic lens because different voltages are applied to the upper magnetic pole and the lower magnetic pole. As described above, in the present embodiment, the objective lens 30 has not only the magnetic lens function but also the electrostatic lens function. Since the voltage applied to the upper magnetic pole 13 is close to the ground, the dynamic focus voltage can be driven at high speed.

One end of a switch 26 is connected to the lower magnetic pole 20. The switch 26 is configured to be able to switch the connection between the other end and either the negative variable high voltage source 24 or the positive variable high voltage source 25.
That is, the lower magnetic pole 20 of the objective lens 30 can selectively apply either a positive high voltage or a negative high voltage. Moreover, the absolute value of the applied voltage can be adjusted.

Next, the operation of the electron beam apparatus according to this embodiment will be described. A crossover image is formed by the condenser lens 6 on the electron beam emitted from the electron gun 1 a, and the crossover image is formed on the upper and lower magnetic poles 1 of the objective lens 30.
It is further reduced by the action of the magnetic field created by 3, 20. The reduced primary electron beam is irradiated on the surface of the sample 21 while being decelerated by the negative high potential of the sample 21 connected to the negative voltage source 23, and a small irradiation spot of 0.01 to 0.1 μmφ. Are formed on the surface of the sample 21. Since the irradiation spot scans the sample, the electrostatic deflectors 7 and 10 deflect the primary electron beam within a predetermined angle range around the deflection fulcrum 28. As a result, the irradiation spot is scanned on the surface of the sample 21. Further, since the voltage from the dynamic focus power supply 16 is applied to the upper magnetic pole 13 of the objective lens 30, the fluctuation of the field curvature due to the deflection is corrected.

A secondary electron beam is emitted from the area of the sample 21 scanned by the irradiation spot. The emitted secondary electron beam passes through the objective lens 30, and the E × B separator 2
It is deflected so as to be separated from the primary electron beam at 9, and detected by the detector 8.

In this embodiment, by switching the switch 26 and adjusting the voltages of the voltage sources 24 and 25, it is possible to operate at least for the following purposes. (When measuring the potential contrast with a filter action) When measuring the potential contrast of the secondary electron beam, the switch 26 is switched to the negative voltage source 24 side, and the voltage of the negative voltage source 24 is set to the negative potential (negative (Voltage of the voltage source 23). That is, a negative voltage lower than the negative potential of the sample 21 is applied to the lower magnetic pole 20,
A negative potential barrier is formed between 0 and the sample 21. Thus, only the secondary electrons having kinetic energy exceeding this negative potential barrier can reach the detector 8, and the space above the sample can have a filter action for detecting secondary electrons.

For example, as shown in FIG.
Since the secondary electrons 43 generated from the pattern 41 having a potential lower than the predetermined value on 1 are accelerated, they can have kinetic energy exceeding the negative potential barrier 40 formed by the lower magnetic pole 20, and detection It is detected by the container 8.
On the other hand, the secondary electrons 44 generated from the pattern 42 having a higher potential cannot have the kinetic energy exceeding the negative potential barrier 40 formed by the lower magnetic pole 20, so that the secondary electrons 44 follow the sample 21. Returned and not detected by detector 8. Therefore, lower potential pattern 4
The detected image of 1 is bright, and the detected image of the pattern 42 of higher potential is dark. Thus, a potential contrast image of the inspected region of the sample 21 is obtained. If the brightness and the potential of the detected image are calibrated in advance, the potential of the pattern can be measured from the detected image. Then, the defective portion of the pattern can be evaluated from this potential distribution. (When obtaining an SEM image of a sample that easily discharges) Sample 21
Is a wafer that easily discharges like a wafer with vias, and its SEM image (or potential contrast image)
In order to obtain, the switch 26 is switched to the negative voltage source 24 side, and the voltage of the negative voltage source 24 is adjusted to a negative voltage slightly higher than the negative potential of the sample 21 (voltage of the negative voltage source 23). That is, a negative voltage slightly higher than the negative potential of the sample 21 is applied to the lower magnetic pole 20, and between the lower magnetic pole 20 and the sample 21,
The negative potential barrier as described above is not formed. Thus, the SEM image can be obtained while suppressing the discharge from the sample 21 to the lower magnetic pole 20. Even in this case (that is, without the filter function as described above), the potential contrast image can be obtained. (When obtaining an SEM image of a sample that is difficult to discharge) Sample 21
However, in the case of a wafer that is difficult to discharge and the SEM image (or potential contrast image) of the wafer is obtained, the switch 26 is switched to the positive voltage source 25 side. That is, a positive high voltage is applied to the lower magnetic pole 20. This high positive voltage increases the beam energy of the electrons passing through the objective lens 30 and thus reduces the axial chromatic aberration. In addition, the upper magnetic pole 13
The main surface of the lens between the magnetic poles formed by the lower magnetic pole 20 and the lower magnetic pole 20 is in the middle of these poles, while the main surface of the electrostatic lens formed by the lower magnetic pole 20, the sample 21, and the upper magnetic pole 13, which are high-voltage electrodes. The surface is near the lower magnetic pole below the main surface. Therefore, the main surface of composition of the electrostatic lens and the electromagnetic lens is lowered,
Thus, since the image plane distance of the entire lens system becomes small, the fact that the beam energy when passing through the lens is high is superimposed, and the axial chromatic aberration becomes smaller and smaller.

If the dielectric strength of the lower magnetic pole 20 of the objective lens 30 is increased, the voltage of the positive variable power source 25 can be adjusted accordingly so that the positive potential applied to the lower magnetic pole 20 becomes higher. Therefore, axial chromatic aberration can be further reduced, and the beam can be narrowed down.

In the electron beam apparatus according to this embodiment, the evaluation of the sample 21 such as the wafer is executed as follows based on the formed SEM image. After pattern matching, the method of inspecting the pattern defect of the sample 21 is such that the control unit (not shown) actually detects the secondary electron beam reference image of the defect-free wafer stored in the memory in advance. The secondary electron beam image is compared and collated, magnification correction,
After the rotation and parallel movement corrections, the similarity between the two is calculated. For example, if the degree of similarity is less than or equal to the threshold value, it is determined that there is a defect, and if it exceeds the threshold value, it is determined that there is no defect. At this time, the detected image may be displayed on a display (not shown) or the like. This allows the operator to
It is possible to finally confirm and evaluate whether or not the sample 21 actually has a defect. Further, the partial areas of the image may be compared and collated to automatically detect the area where the defect exists.
At this time, it is preferable to display an enlarged image of the defective portion on the display.

The defective portion can be detected by comparing the detected images of the detected dies with each other without using the reference image as described above. In this case, in pattern matching, only parallel movement correction needs to be performed. For example,
FIG. 2A shows an image 31 of the die detected first and an image 32 of the other die detected second. If it is judged that the die image 31 and the die image 32 are not similar to each other and the image of another die detected third is the same as or similar to the first image 31, the second die image 32 has a defect. It is determined to have. If a more detailed comparison / matching algorithm is used, the defective portion 3 of the second die image 32 is
It is also possible to detect 3.

FIG. 2B shows an example of measuring the line width of the pattern formed on the wafer. The actual secondary electron intensity signal when the actual pattern 34 on the wafer is scanned in the direction of 35 is 36, and this signal continuously exceeds the threshold level 37 which is previously calibrated and determined. Can be measured as the line width of the pattern 34. If the line width thus measured is not within the predetermined range, it can be determined that the pattern has a defect.

The line width measuring method of FIG. 2B can also be applied to the measurement of the alignment accuracy between layers when the wafer 9 is formed of a plurality of layers. For example, a second alignment pattern formed by the second layer lithography is formed in advance in the vicinity of the first alignment pattern formed by the first layer lithography. These two
The pattern interval of the book is measured by applying the method of FIG. 2B, and the accuracy of alignment between the two layers can be determined by comparing the measured value with the design value. Of course, it can be applied to the case of three or more layers. In this case, if the spacing between the first and second alignment patterns is set to be approximately equal to the spacing between adjacent beams of the plurality of primary electron beams of the electron beam apparatus, the alignment accuracy can be minimized with the minimum scanning amount. Can be measured. Second Embodiment: Semiconductor Device Manufacturing Method In this embodiment, the electron beam apparatus shown in the above embodiment is applied to wafer evaluation in a semiconductor device manufacturing process.

An example of the device manufacturing process will be described with reference to the flowchart of FIG. This manufacturing process example includes the following main processes. Wafer manufacturing process for manufacturing wafer 9 (or preparatory process for preparing wafer) (step 100) Mask manufacturing process for manufacturing mask used for exposure (or mask preparing process for preparing mask) (step 1)
01) Wafer processing step for performing necessary processing on the wafer (step 102) Chip assembling step for cutting out the chips formed on the wafer one by one and making them operable (step 1)
03) Chip inspection step of inspecting assembled chip (step 104) Each step further comprises some sub-steps.

Of these main processes, the main process that has a decisive influence on the performance of the semiconductor device is the wafer processing process. In this step, the designed circuit patterns are sequentially stacked on the wafer to form a large number of chips that operate as memories and MPUs. This wafer processing step includes the following steps. Thin film forming process (using CVD, sputtering, etc.) to form a dielectric thin film to be an insulating layer, a wiring part, or a metal thin film to form an electrode part. Oxidation process to oxidize a formed thin film layer or wafer substrate. Lithography process that forms a resist pattern using a mask (reticle) to selectively process a wafer substrate Etching process that processes a thin film layer or substrate according to a resist pattern (for example, using a dry etching technique) Ion / impurity implantation Diffusion Step Resist Stripping Step Inspection Step for Inspecting Processed Wafer In addition, the wafer processing step is repeated by the required number of layers to manufacture a semiconductor device that operates as designed.

FIG. 4 is a flow chart showing the lithography process which is the core of the wafer processing process. This lithography step includes the following steps. A resist coating step (step 2) of coating a resist on the wafer on which the circuit pattern is formed in the previous step.
00) Exposure step of exposing the resist (step 201) Development step of developing the exposed resist to obtain a resist pattern (step 202) Annealing step for stabilizing the developed pattern (step 203) Semiconductors above Well-known processes are applied to the device manufacturing process, the wafer processing process, and the lithography process.

In the above wafer inspection process, when the evaluation apparatus according to each of the above embodiments of the present invention is used, even a semiconductor device having a fine pattern can be evaluated with high throughput and high accuracy. It is possible to improve the yield and prevent the shipment of defective products.

Although the above-mentioned embodiments have been described above, the present invention is not limited to the above-mentioned examples, and can be suitably modified within the scope of the present invention. For example, the inspection sample 9
As an example, a semiconductor wafer is given as an example, but the sample to be inspected of the present invention is not limited to this, and any sample having a pattern capable of detecting defects by an electron beam, such as a mask, should be an evaluation target. You can

[0036]

As described in detail above, according to the electron beam apparatus of the present invention, the following excellent effects can be obtained. 1. If the dielectric strength of the lower magnetic pole of the objective lens is strengthened,
Accordingly, the axial chromatic aberration of the lens can be reduced. 2. By applying a negative voltage lower than the sample surface to the lower magnetic pole of the objective lens, it is possible to give an energy filter action to secondary electrons, and the axial chromatic aberration at that time is the case of a lens with a conventional energy filter. Can be smaller. 3. By changing the potential applied to the lower magnetic pole of the objective lens, a potential contrast image can be obtained (negative high voltage). It is possible to obtain a pattern image of a wafer that easily discharges, such as a wafer with a via. High negative high voltage) It is possible to operate for various purposes such as observing a sample that is difficult to discharge (positive high voltage). 4. Dynamic focusing is possible with a power supply voltage close to ground.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an electron beam apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a method of evaluating a sample, including (a)
Shows a pattern defect detection method by die-to-die comparison according to the present invention, (b) shows line width measurement, and (c) shows potential contrast measurement.

FIG. 3 is a flowchart showing a semiconductor device manufacturing process.

FIG. 4 is a flowchart showing a lithography process of the semiconductor device manufacturing process of FIG.

[Explanation of symbols]

1a electron gun 6 condenser lens 7 Electrostatic deflector 8 detectors 9 Scan control circuit 10 Electrostatic deflector 11 X-direction electromagnetic deflector 12 Y-direction electromagnetic deflector 13 Upper magnetic pole 14 Insulating spacer 15 Excitation coil 17 Insulated cylinder 18 O-ring 19 Shield cylinder 20 lower magnetic pole 21 Sample (wafer) 22 switch 23 Negative high voltage source 24 Negative variable high voltage source 25 Positive variable high voltage source 26 switch 29 E × B separator 30 objective lens

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shinji Noji             11-1 Haneda Asahi-cho, Ota-ku, Tokyo Co., Ltd.             Inside the EBARA CORPORATION (72) Inventor Toru Satake             11-1 Haneda Asahi-cho, Ota-ku, Tokyo Co., Ltd.             Inside the EBARA CORPORATION F term (reference) 2F067 AA21 BB04 CC15 HH06 JJ05                       KK04 LL00                 4M106 AA01 BA02 CA39 DB05                 5C033 DD02 DD09 UU02 UU03

Claims (5)

[Claims] 1. An electron beam apparatus including an objective lens for forming an image of an electron beam on a sample, wherein the objective lens is an upper magnetic pole, a lower magnetic pole, and an exciting coil arranged between both magnetic poles. An electron beam apparatus comprising: at least, a negative voltage is applied to the sample, and a voltage having a lower potential than that of the sample is applied to the lower magnetic pole. 2. An electron beam apparatus including an objective lens for forming an image of an electron beam on a sample, wherein the objective lens is an upper magnetic pole, a lower magnetic pole, and an exciting coil arranged between both magnetic poles. An electron beam apparatus comprising: at least, applying a negative voltage to the sample, and further applying a positive voltage to the lower magnetic pole. 3. An electron beam apparatus including an objective lens for forming an image of an electron beam on a sample, wherein the objective lens is an upper magnetic pole, a lower magnetic pole, and an exciting coil arranged between both magnetic poles. At least, a negative voltage can be applied to the sample, and the voltage applied to the lower magnetic pole can be switched to a predetermined value from a positive voltage to a negative voltage lower than the sample. An electron beam device characterized by being present. 4. An electron beam apparatus including an objective lens for forming an image of an electron beam on a sample, wherein the electron beam is deflected and scanned on the sample, wherein the objective lens is an upper magnetic pole, At least a lower magnetic pole and an exciting coil arranged between both magnetic poles are provided, wherein the upper magnetic pole and the lower magnetic pole are independently insulated from each other, and a positive voltage and a negative voltage are applied to the lower magnetic pole. Is applied to the upper magnetic pole, and a voltage that changes in synchronization with a deflection voltage for deflecting the electron beam can be applied to the upper magnetic pole. 5. A device manufacturing method, characterized in that the electron beam apparatus according to any one of claims 1 to 4 is used to evaluate the sample as a wafer after completion of at least one wafer process. .