KR20080090118A - Control method of inspecting apparatus for semiconductor device - Google Patents

Abstract

A control method of a semiconductor inspecting apparatus is provided to automatically detect the variation of a probe current and to automatically adjust the probe current to a pre-set value when a change in the probe current occurs, thereby stably operating a scanning electron microscope. A control method of a semiconductor inspecting apparatus comprises the following steps of: providing an object to be inspected; irradiating an electron beam to the inspected object; measuring a first probe current based on the intensity of the electron beam reached to a surface of the inspected object; judging whether the first probe current is out of a first pre-set reference range; and resetting the amplitude of the first probe current when the first probe current is out of the first reference range. The step of resetting the amplitude of the first probe current includes the following steps: changing amplitudes of an extraction voltage and a heating current for producing the electron beam; irradiating the electron beam produced in the changed condition to the inspected object; measuring a second probe current based on the intensity of the electron beam reached to the surface of the inspected object; judging whether the second probe current is out of a second pre-set reference range; and setting the probe current when the second probe current is out of a second set reference range.

Description

Control method of inspecting apparatus for semiconductor device

1 is a block diagram illustrating a semiconductor test apparatus according to an exemplary embodiment of the present invention.

FIG. 2 is a block diagram illustrating a probe current setting operation in the semiconductor test apparatus of FIG. 1.

3 is a flowchart illustrating a semiconductor inspection method according to an embodiment of the present invention.

4 is a flowchart illustrating a probe current reset step in the semiconductor test method of FIG. 3.

Explanation of symbols on the main parts of the drawings

10: semiconductor substrate 100: semiconductor inspection device

110: electron beam source 112: electron gun

114: column 120: filament

122: extraction electrode 124: axis adjustment coil

126: aperture 128: scanning coil

130: magnetic lens 132: focusing lens

134: objective lens 140: stage

142: drive unit 144: detection unit

146: image acquisition unit 148: image processing unit

150: display unit 160: controller

B: electron beam E: secondary electron

Vo: Acceleration voltage V1: Drawout voltage

If: heating current IP: probe current

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of controlling a semiconductor inspection device, and more particularly, to a method of controlling a scanning electron microscope for measuring a line width of a semiconductor device or inspecting a defect.

In recent years, with the rapid spread of information media such as computers, semiconductor devices are also rapidly developing. In terms of its function, the semiconductor device is required to operate at a high speed and to have a large storage capacity. In response to these demands, semiconductor processing technologies have been developed in the direction of improving integration, reliability, response speed, and the like of the semiconductor device.

In general, a semiconductor device includes a Fab process for forming an electrical circuit including electrical elements on a silicon wafer used as a semiconductor substrate, and an EDS (EDS) for inspecting electrical characteristics of semiconductor devices formed in the fab process. electrical die sorting) and a package assembly process for encapsulating and individualizing the semiconductor devices with epoxy resin, respectively.

The fab process includes a deposition process for forming a film on a semiconductor substrate, a chemical mechanical polishing process for planarizing the film, a photolithography process for forming a photoresist pattern on the film, and a photoresist pattern. An etching process for forming the film into a pattern having electrical characteristics by using a film, an ion implantation process for implanting specific ions into a predetermined region of the semiconductor substrate, a cleaning process for removing impurities on the semiconductor substrate, and the film Or an inspection process for inspecting the surface of the semiconductor substrate on which the pattern is formed.

The inspection process is performed to detect defects in a film or pattern formed on the semiconductor substrate. The defects lower the operating characteristics of the semiconductor device and reduce the production efficiency for improving the competitiveness. The defects may include scratches, particles, and incompletely removed portions of a material film formed on the semiconductor substrate, and defects which are not detected through an inspection process may be defective of the semiconductor device manufactured. Act as a cause.

Various inspection apparatuses may be used in the inspection process, and may be broadly classified into an optical inspection apparatus using a light source and an image inspection apparatus using a microscope. The image inspection apparatus includes a scanning electron microscope (SEM), a transmission electron microscope (TEM), an electron beam inspection apparatus, and the like. In addition, there are secondary ion mass spectrometry (SIMS) using an ion beam and a surface inspection device using a laser beam.

Among the inspection apparatuses described above, a scanning electron microscope is mainly used. The scanning electron microscope irradiates primary electrons (or electron beams) to an inspected object, collects secondary electrons emitted from the inspected object, and collects an image of the inspected object. It is a device to form. Then, the line width of the inspected object is measured on the image formed as described above, or defects present on the surface of the inspected object are detected.

The scanning electron microscope comprises: an electron beam source for generating an electron beam, a stage for supporting the inspected object, a driver for adjusting the position of the stage, and a secondary light emitted from an inspected region to be inspected by the inspected object And a detection unit for detecting electrons, an image acquisition unit for forming an image of the inspection area from the secondary electrons, an image processing unit for analyzing and processing the images, and a display unit for displaying the images.

The electron beam source includes a column having an electron gun for generating electrons and a magnetic lens for extracting the electrons to form an electron beam and controlling the behavior of the electron beam. The electron gun includes a filament for generating electrons and an extraction electrode for extracting the electrons. Electrons extracted through the extraction electrode are irradiated onto the inspection area through the magnetic lens. The magnetic lens includes a pair of focusing lenses for focusing the extracted electrons to form an electron beam, and an objective lens for adjusting the spot size of the electron beam irradiated onto the inspection area.

The electron beam formed by the focusing lens is deflected by a scanning coil disposed between the pair of focusing lens and the objective lens, and the deflected electron beam is irradiated onto the inspection area of the substrate through the objective lens. That is, the intensity and the spot size of the electron beam are adjusted by the magnetic and electric fields formed by the magnetic lens.

Herein, the intensity of the electron beam finally irradiated to the inspection region is called a probe current Ip. The intensity of the probe current is an important factor in determining the quality of the resolution of the image. For example, when the intensity of the probe current is small, an image having a weak contrast ratio (S / N) is formed. When the intensity of the probe current is high, an image having a low resolution is formed.

On the other hand, even if the scanning electron microscope is operated under a constant condition in the same working environment, the magnitude of the probe current changes after a predetermined time. Therefore, conventionally, after operating the scanning electron microscope for about 6000 hours, the value of the probe current was reset to a reference value.

Here, in the conventional scanning electron microscope, the operator manually sets the probe current, but it is not easy to set the probe current accurately. In addition, since the probe current value is set differently according to the operator, an error occurs in the focus and the measurement result of the scanning electron microscope, and there is a problem that the accuracy is lowered.

An object of the present invention for solving the above problems is to control and set the intensity of the probe current automatically in the scanning electron microscope, and to control the semiconductor inspection apparatus that can improve the image quality and accuracy of the inspection object To provide.

In order to achieve the object of the present invention, the method for controlling a semiconductor inspection apparatus according to the present invention includes the steps of: injecting an inspected object, irradiating an electron beam to the inspected object, and reducing the intensity of the electron beam reaching the inspected surface. Measuring a probe current, determining whether the first probe current is out of a predetermined first reference range, and resetting the magnitude of the probe current when the first probe current is out of the first reference range It may include the step.

In an embodiment, the resetting of the probe current may include changing a magnitude of a drawing voltage and a heating current for generating the electron beam, irradiating the electron beam generated under the changed condition to the object under test, the surface of the object under test. Measuring a second probe current from an intensity of an electron beam that reaches to and determining whether the second probe current falls within a preset second reference range, and wherein the second probe current falls within the second reference range In this case, the method may include setting the probe current, and resetting the second probe current when the second probe current does not belong to the second reference range.

In an exemplary embodiment, the resetting of the second probe current may include a preliminary setting step of setting the second probe current value in the semiconductor test apparatus, and detecting a change in the third probe current by measuring a third probe current for a predetermined time. And detecting a change in the third probe current until the third probe current is constantly detected.

The measuring of the third probe current may include pre-setting a value of the second probe current, measuring a third probe current for a predetermined time, and detecting whether the third probe current is changed or not. Can be repeated.

In an embodiment, the method may further include generating an error message when the first probe current is out of the first reference range.

According to the present invention, the probe current can be automatically set in the scanning electron microscope for inspecting the semiconductor device, and the probe current is measured before the inspection of the semiconductor device and automatically set to a preset value when an abnormality occurs, thereby improving image quality. In addition, the accuracy and reliability of the test can be improved by minimizing measurement errors.

Hereinafter, a method of controlling a semiconductor inspection apparatus according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

With respect to the embodiments of the present invention disclosed in the text, specific structural to functional descriptions are merely illustrated for the purpose of describing the embodiments of the present invention, the embodiments of the present invention may be embodied in various forms and It should not be construed as limited to the embodiments described.

As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between. Other expressions describing the relationship between components, such as "between" and "immediately between," or "neighboring to," and "directly neighboring to" should be interpreted as well.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof that is described, and that one or more other features It should be understood that it does not exclude in advance the possibility of the presence or addition of numbers, steps, operations, components, parts or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

1 is a block diagram illustrating a semiconductor test apparatus according to an exemplary embodiment of the present invention. FIG. 2 is a block diagram illustrating a control method of the semiconductor test apparatus of FIG. 1.

Hereinafter, the semiconductor inspection apparatus will be described in detail with reference to FIGS. 1 and 2. Hereinafter, a scanning electron microscope for obtaining an image of a semiconductor device using secondary electrons will be described as an example. However, the semiconductor inspection apparatus is not limited thereto, and may include an electron beam inspection apparatus such as a transmission electron microscope, an ion beam inspection apparatus, or the like.

1 and 2, the semiconductor inspection apparatus 100 controls an electro-optical system for accommodating and inspecting a semiconductor substrate 10, which is a test object, and various devices and power supplies constituting the electro-optical system. A scanning electron microscope (SEM) including a control unit for forming an image through a signal detected from the semiconductor substrate 10.

Meanwhile, the semiconductor inspection apparatus 100 is accommodated in a housing (not shown) in a vacuum or low vacuum state. In this case, the semiconductor inspection apparatus 100 is operated in a vacuum state in order to prevent the electron beam B from being scattered by colliding with molecules in the air until it is irradiated to the object under test. For example, the inside of the housing may be maintained in a vacuum of about 10 ⁻⁷ torr or more.

The electron optical system includes an electron beam source 110 for generating an electron beam B, a stage 140 and a driver 142 in which the semiconductor substrate 10 is accommodated, and a signal emitted from the semiconductor substrate 10. It includes a detection unit 144 for detecting the. The controller includes an image acquisition unit 146 for amplifying a signal obtained from the detection unit 144 and forming an image, an image processing unit 148, a display unit 158 for displaying the image, and the like.

The electron beam source 110 forms an electron gun 112 for generating primary electrons, accelerates the primary electrons toward an anode to which a high voltage is applied, and forms an electron beam B, and the electron beam B is And a column 114 for irradiating the surface of the semiconductor substrate 10.

The electron gun 112 may include a filament 120 for generating primary electrons and an extraction electrode 122 for extracting the electrons. For example, tungsten may be mainly used as the filament 120.

Specifically, when the drawing voltage V1 of about 1 to 50 kV is applied to the filament 120, the filament 120 is heated to a temperature of about 2000 K, and a plurality of primary electrons are emitted from the filament 120.

Here, primary electrons emitted from the filament 120 are focused and accelerated in a beam form through the column 114 to be described later and irradiated onto the semiconductor substrate 10.

The column 114 includes an axial adjustment coil 124, a magnetic lens 130, an aperture 126, a scanning coil 128, and the like.

For reference, a voltage having a predetermined magnitude for accelerating primary electrons emitted from the electron gun 112 is applied to the column 114, and a voltage applied to the column 114 is called an acceleration voltage Vo. The acceleration voltage Vo is one of important factors influencing the resolution of the image acquired by the inspection apparatus 100, and the image quality such as brightness and contrast.

The magnetic lens 130 is a cylindrical electromagnet in which a coil is wound, and serves to focus electrons by forming a magnetic field. For example, the electron beam B generated by the electron gun 112 has a cross-sectional area of 10 to 50 μm, and the spot size of the electron beam B irradiated on the semiconductor substrate 10 is about 5 to 200. May have a size of nm.

Here, the magnetic lens 130 includes a pair of condenser lens 132 and one objective lens (134). The pair of focusing lenses 132 focus the electron beam B generated from the electron gun 112 and adjust the intensity of the electron beam B. FIG. The objective lens 134 adjusts the spot size and the focal length of the electron beam B irradiated onto the surface of the semiconductor substrate 10, and determines the resolution of the scanning electron microscope 100. In addition, the distance between the objective lens 134 and the semiconductor substrate 10 is called a working distance, and the shorter the working distance, the smaller the spot size of the electron beam B, and the resolution of the image. Is increased.

The axis adjustment coil 124 is disposed between the extraction electrode 122 and the magnetic lens 130, the center of the magnetic lens 130 is the electron beam (B) formed by the extraction electrode 122. It serves to match the axis.

The aperture 126 and the scan coil 128 are disposed between the pair of focusing lenses 132 and the objective lens 134. The aperture 126 has a light transmitting part having a predetermined diameter, and is combined with the focusing lens 132 to determine the intensity of the electron beam B. For example, the stop 126 may have a hole-shaped light transmitting unit having different diameters. The scan coil 128 serves to deflect the electron beam B so that the electron beam B can scan the substrate 10. Here, by changing the amplitude of the current applied to the scan coil 128, it is possible to freely adjust the magnification of the scan electron microscope 100.

The stage 140 supports the semiconductor substrate 10, and the driving unit 142 is connected to the stage 140 so that the electron beam is disposed on a predetermined region on the semiconductor substrate 10 or on the entire surface of the semiconductor substrate 10. The position of the stage 140 is moved so that (B) can be irradiated. For example, the driving unit 142 may be a robot moving in Cartesian coordinates on one plane. Although not shown, a second driver (not shown) for adjusting the height of the stage 140 may be provided below the stage 140. For example, the second driver may include a piezoelectric element.

When the electron beam B is irradiated, secondary electrons E, reflection electrons, X-rays, and backscattered electrons are generated from the surface of the semiconductor substrate 10, and the absorbed electrons absorbed by the semiconductor substrate 10 and the semiconductor substrate Signals such as transmitted electrons passing through (10) are generated.

The detector 144 may detect the secondary electrons E generated from the semiconductor substrate 10 to measure the line width of the semiconductor substrate 10 or to inspect the defects.

For example, in the present exemplary embodiment, the detector 144 detects secondary electrons E emitted from the semiconductor substrate 10. In addition, the detector 144 converts the current signal corresponding to the detected secondary electrons E into a voltage signal and amplifies the signal. Here, the detector 144 is applied with a bias voltage to detect the secondary electron (E).

Specifically, the secondary electrons E are emitted from the semiconductor substrate 10 at various angles. In addition, since the detector 144 is positively charged, the secondary electrons E are collected by the detector 144. For example, the secondary electron E is applied with a voltage of about -100 to + 300V and is led to a Faraday cage surrounding the detector 144. In addition, since the detection unit 144 has a voltage of about +12,000 V, a strong attraction force acts between the detection unit 144 as the secondary electron E approaches the detection unit 144, and thus the secondary force is applied to the detection unit 144. A strong collision occurs so that the electron E can pass through the thin aluminum film formed in the detector 144. In addition, the secondary electrons E passing through the aluminum layer collide with phosphorescent scintillator materials and emit fluorescence. The fluorescence is incident on the photo multiplier and is converted into a strong electrical signal through the amplification process from the photo multiplier.

The image acquisition unit 146 is connected to the detection unit 144 and converts the voltage signal amplified by the detection unit 144 into image information corresponding to the inspection area of the semiconductor substrate 10. Here, the image information includes gray levels of pixels corresponding to the inspection area. That is, the image acquisition unit 146 functions as an analog digital convertor for converting an analog voltage signal into digital image information.

The image processing unit 148 is connected to the image acquisition unit 146, and serves to process the image or to measure the line width of the pattern or detect whether the pattern is defective from the image. For example, the image processor 148 may detect a defect present on the semiconductor substrate 10 by comparing the gray levels of the pixels constituting the reference image with the gray levels of the pixels constituting the inspection image. Can be.

The display unit 150 displays an image formed by the image processor 148 or a defect detected by the image processor 148.

Meanwhile, the intensity of the electron beam B incident on the surface of the semiconductor substrate 10 is called an incident current or a probe current Ip (hereinafter referred to as a probe current). The probe current Ip may be measured as the sum of backscattered electrons, secondary electrons and absorbed electrons in the Faraday cup. For example, it is possible to measure the intensity of the electron beam B, that is, the size of the probe current Ip, through the detector 144.

Here, the probe current Ip is an important factor in determining the quality and resolution of the image. In addition, factors for determining the intensity of the probe current Ip include the drawing voltage V1 and the heating current If applied to the filament 120 and the electron gun 112. That is, it is possible to control the intensity of the probe current Ip by adjusting the drawing voltage V1 and the heating current If.

Referring to FIG. 2, when the probe current Ip is measured through the detector 144 and the magnitude of the measured probe current Ip deviates from a preset reference current range, the semiconductor substrate 10 that follows. ), The probe current Ip may be reset.

For example, in the method of adjusting the probe current Ip, the magnitudes of the drawing voltage V1 and the heating current If are gradually changed to a constant magnitude, and the probe current Ip is measured again. The probe current Ip is measured while changing the drawing voltage V1 and the heating current If until the probe current Ip shows a constant value. Here, a controller 160 for changing the magnitude of the drawing voltage V1 and the heating current If is provided. The controller 160 is connected to the scanning electron microscope 100 to change the magnitude of the drawing voltage V1 and the heating current If, and is provided with the size of the probe current Ip. It is electrically connected to the detector 144. Preferably, the controller 160, the scanning electron microscope 100, and the detection unit 144 may form a closed circuit that circulates. That is, the controller 160 receives the feedback value of the probe current Ip that is changed as the drawing voltage V1 and the heating current If change in the controller 160. It will be possible to automatically adjust the probe current Ip.

Therefore, according to the present invention, when a change occurs in the probe current Ip value, the probe current Ip can be automatically adjusted.

 3 is a flowchart illustrating a semiconductor inspection method according to an embodiment of the present invention. 4 is a flowchart for describing a probe current reset method of FIG. 3.

Hereinafter, a semiconductor inspection method according to an embodiment of the present invention will be described in detail.

Referring to FIG. 3, first, the semiconductor substrate 10 to be inspected or measured is introduced into the inspection apparatus 100 (S10). In addition, a recipe corresponding to the semiconductor substrate 10 and suitable for the purpose of inspection is selected from among a plurality of recipes stored in the inspection apparatus 100 (S20).

Here, the recipe includes the number and position information of the detection points corresponding to the semiconductor substrate 10, the operating conditions of the semiconductor inspection apparatus (eg, the acceleration voltage Vo of the scanning electron microscope, and the heating current If). And other conditions) are stored.

When the recipe is selected, the semiconductor substrate 10 is introduced into the inspection chamber of the semiconductor inspection apparatus 100, and the electron beam B is irradiated onto the semiconductor substrate 10 (S30).

The first probe current is measured from the intensity of the electron beam B reaching the surface of the semiconductor substrate 10 (S40).

Here, it is determined whether the first probe current is within a preset reference range (S50), and when the value of the first probe current is constantly measured, the first probe current is measured by the inspection apparatus 100. The probe current Ip is set at (S60). After the probe current Ip is set as described above, a subsequent measurement process for the semiconductor substrate 10 is performed (S70). For example, the reference range may be 4 ~ 17㎀.

However, when the first probe current is out of a preset reference range or when the value of the first probe current is changed (S50), an error message is generated (S80), and the probe current Ip is It is reset (S100).

Hereinafter, the resetting of the probe current Ip will be described in detail with reference to FIG. 4.

The size of the heating current If and the drawing voltage V1 is changed through the controller 160 (S100).

For example, the magnitude of the heating current If may be increased / decreased by 0.1A. Then, the electron beam B generated through the changed heating current If is irradiated to the semiconductor substrate 10, and a second probe current is generated from the intensity of the electron beam B reaching the surface of the semiconductor substrate 10. Measure (S120). For example, the second probe current may be measured after 15 minutes.

It is determined whether the measured second probe current falls within a preset reference range (S130). For example, the reference range may be 4 ~ 17㎀.

When the second probe current falls within the reference range, the second probe current is preliminarily set to the probe current Ip value of the inspection apparatus 100 (S140). Alternatively, it may be possible to set the probe current Ip value to a predetermined fixed value. For example, the probe current Ip may be set to 10 mA.

When the second probe current is out of the reference range, the magnitude of the drawing voltage V1 and / or the heating current If is changed until the second probe current falls within the reference range. It is made (S110). That is, whether or not the second probe current fluctuates while gradually changing the magnitude of the heating current If or the drawing voltage V1 until the value of the second probe current is detected as a value within a preset reference range. Can be monitored.

After a predetermined time elapses in the state where the probe current Ip is preset, it is monitored whether the magnitude of the probe current Ip is constantly detected (S150).

Specifically, the third probe current is measured from the intensity of the electron beam B reaching the surface of the semiconductor substrate 10 in a state in which the probe current Ip is preset, and the third probe current is changed for a predetermined time. Will be judged. In this case, when the third probe current is detected to have a constant magnitude without change, the setting of the probe current Ip of the inspection apparatus 100 is completed (S60), and the measuring step is performed on the semiconductor substrate 10. do.

On the other hand, when the value of the third probe current changes during the time period, the value of the third probe current is reset after changing the value of the preset probe current Ip, and the third probe current is measured, and whether the value is changed for a predetermined time. Can be monitored. Alternatively, the magnitude of the third probe current is changed by measuring the third probe current after changing the magnitude of the drawing voltage V1 and / or the heating current If, and the third probe current is a constant value. It may be possible to find the magnitude of the drawing voltage V1 and / or the heating current If detected as and to set the probe current Ip in the inspection apparatus 100 (S110). That is, the intensity of the electron beam B reaching the surface of the semiconductor substrate 10 while gradually changing the magnitude of the heating current If or the drawing voltage V1 until the third probe current is stably detected. By monitoring the, the probe current Ip can be stably maintained within the reference range. In addition, even when a change occurs in the probe current Ip, the change of the probe current Ip may be automatically sensed and the magnitude of the probe current Ip may be adjusted.

As described above, according to embodiments of the present invention, the probe current can be automatically measured and set before the semiconductor device is inspected in the scanning electron microscope for inspecting the semiconductor device, so that the probe current can be accurately set. In addition, the accuracy and stability of the inspection result and the image can be improved. In addition, it is possible to automatically detect whether or not the probe current fluctuates, and automatically set the preset value when the fluctuation occurs. Therefore, the scanning electron microscope can operate stably, and can improve the accuracy and reliability of the test results. In addition, it is possible to prevent the occurrence of defects or defects depending on the operator who sets the scanning electron microscope.

While the foregoing has been described with reference to preferred embodiments of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. It will be appreciated.

Claims (5)

Inputting a subject; Irradiating an electron beam to the test object; Measuring a first probe current from an intensity of an electron beam that reaches the surface of the test object; Determining whether the first probe current is out of a predetermined first reference range; And And resetting the magnitude of the probe current when the first probe current is out of the first reference range. The method of claim 1, wherein resetting the probe current comprises: Varying magnitudes of the drawing voltage and heating current for generating the electron beam; Irradiating the electron beam generated under the changed condition with the test subject; Measuring a second probe current from the intensity of the electron beam reaching the surface of the test object; Determining whether the second probe current falls within a preset second reference range; Setting the probe current when the second probe current falls within the second reference range; And And resetting the second probe current when the second probe current does not belong to the second reference range. The method of claim 2, wherein the second probe current reset step, A preliminary setting step of setting the second probe current value to a semiconductor inspection device; Detecting a change in the third probe current by measuring a third probe current for a predetermined time; And Detecting a change in the third probe current until the third probe current is constantly detected. The method of claim 3, wherein the measuring of the third probe current comprises: Presetting a value of the second probe current; Detecting a change in the third probe current by measuring a third probe current for a predetermined time; And And repeating the above steps. 2. The method of claim 1, further comprising generating an error message when the first probe current is out of the first reference range. 3.

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