JP2002221413A - Method for measuring contamination of sample in electron beam tester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for measuring contamination of a sample in an electron beam tester capable of quantitatively measuring the amount of contaminated deposits adhering on the viewing plane of the electron beam tester. SOLUTION: An electron beam B1 from an electron gun 7 in an electron gun room 1 irradiates the sample 16 disposed in a sample room 4, and secondary electrons B2 generated by the sample are detected. Thereby, the electron beam tester measures the dimension of the sample. Using this tester, the electron beam irradiates a projection or a recess formed on the surface of the sample 16, and the amount of the contaminated deposits is measured from the dimension of the projection or the recess being changed by the contaminated deposits adhering on the plane which the electron beam irradiated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring sample contamination in an electron beam inspection apparatus, and more particularly to a method for measuring sample contamination in an electron beam inspection apparatus suitable for performing semiconductor inspection.

[0002]

2. Description of the Related Art An electron beam inspection apparatus which scans an electron beam on a sample and measures and observes the size and shape of a pattern or contact hole formed on the sample based on the obtained secondary electron image or reflected electron image. As the size of the semiconductor element advances, the role of the element increases.

On the other hand, when observation is performed using an electron beam, it is known that contaminants adhere to a portion of a sample irradiated with an electron beam. In this regard, for example, "Sp
ecimen Protection in the Electron Microscope, 19
(1982) p.465, HEYWOOD JA, Pract Metallogr ”, causes of sample contamination are the hydrocarbon-based gas molecules adsorbed on the sample and the hydro- It is considered that carbon is adsorbed on a sample, and in any case, the adsorbed gas is solidified by receiving electron beam energy. As described above, when a contaminant adheres to the surface of the sample, the surface of the contaminant is observed on the outermost surface, so that a true surface image cannot be captured. In the case of a semiconductor device inspection apparatus, the purpose is to measure dimensions and inspect the appearance. Therefore, it is a serious problem that contaminants adhere during inspection and the dimensions and shape change.

[0004] Therefore, as a method of evaluating sample contamination in an electron beam inspection apparatus, for example, “Journal of the Electron Microscope Society, 16-1, (1981), p.2-10, Keiji Yada” , 19-1, (1984), 58-60, Kozue Atsuo ”, irradiates an electron beam to a fixed point on the sample surface, and attaches a cylindrical or conical There is known a method of measuring the diameter or height of a contaminant together with an electron beam irradiation time and measuring the amount of contaminant adhesion.

[0005]

However, in the conventional method for evaluating sample contamination by an electron beam inspection apparatus, an electron beam is applied to a fixed point on an observation surface when measuring the amount of adhered contaminants. However, in actual electron microscope observation, electron beam irradiation is performed while scanning the area of the surface to be observed, and thus the irradiation method of the electron beam is different. Was.

An object of the present invention is to provide a sample contamination measuring method for an electron beam inspection apparatus capable of quantitatively measuring the amount of contaminants adhering to an observation surface of the electron beam inspection apparatus.

[0007]

(1) In order to achieve the above object, according to the present invention, a sample placed in a sample chamber is irradiated with an electron beam from an electron gun in an electron gun chamber and generated from the sample. Using an electron beam inspection device that detects secondary electrons and measures the dimensions of the sample, irradiates the electron beam onto the convex or concave portion provided on the surface of the sample and attaches it to the electron beam irradiated surface. The amount of adhered contaminants is measured from the convex or concave dimensions changed by the contaminants. According to such a method, the amount of contaminants adhering to the observation surface of the electron beam inspection apparatus can be quantitatively measured.

(2) In the above (1), preferably,
The convex or concave portion provided on the surface of the sample coated with the lubricant is irradiated with an electron beam, and the size of the convex or concave shape changed by the contaminant attached to the electron beam irradiation surface indicates that the contaminant The lubricant is evaluated by measuring the adhesion amount of the lubricant.

(3) In the above (1), preferably,
Place the material intended for use in the electron beam inspection device in any sample chamber that is not irradiated with the electron beam,
Irradiate the convex or concave part provided on the surface of the sample with an electron beam and measure the amount of contaminant adhesion from the convex or concave dimension changed by the contaminant adhering to the electron beam irradiation surface. The material is evaluated based on the amount of contaminants attached.

(4) In the above (1), preferably,
The measurement of the amount of attached contaminants is periodically performed, and the measured amount of attached contaminants is displayed or recorded.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for measuring sample contamination of an electron beam inspection apparatus according to a first embodiment of the present invention will be described below with reference to FIGS. First, referring to FIG.
The configuration of the electron beam inspection apparatus used in the sample contamination measurement method according to the present embodiment will be described. FIG. 1 is an overall configuration diagram showing a configuration of an electron beam inspection apparatus used for a sample contamination measurement method according to a first embodiment of the present invention.

As shown in FIG. 1, in the electron beam inspection apparatus according to the present embodiment, an electron gun chamber 1, a condenser lens chamber 2, an intermediate chamber 3, and a sample chamber 4 are arranged in a vertical direction.
A preliminary exhaust chamber 25 is arranged adjacent to the sample chamber 4.
The sample 16 is introduced from the air atmosphere into the sample chamber 4 in a vacuum atmosphere through the preliminary exhaust chamber 25.

An electron gun 7, an extraction electrode 8,
An acceleration electrode 9 and a fixed aperture 10 are provided. A condenser lens 11 is provided in the condenser lens chamber 2. The intermediate chamber 3 is provided with a deflection coil 12, an objective lens 13, and an objective lens fixed stop 14. Further, the sample chamber 4 is provided with an X stage 6 and a Y stage 6 'which are sample stages. The sample 16 is placed on the Y stage 6 '. The sample stages 6 and 6 ′ are set on the base 5. Between X stage 6 and base 5 and between Y stage 6 'and X stage 6
Between them, there is provided a sliding portion 15 of the guide mechanism,
The X stage 6 and the Y stage 6 ′ are moved by the sliding portion 15. Although not shown in the drawings, when moving in the X direction and the Y direction, a motor installed outside the sample chamber is connected to a power transmission system such as a ball screw installed inside the sample chamber and driven.

[0014] Vacuum pumps 19 and 20 are connected to the electron gun chamber 1. A vacuum pump 21 is connected to the condenser lens chamber 2. In order to obtain a stable electron beam from the electron source 7, the vacuum pumps 19, 20, and 21 perform differential evacuation, and the electron gun chamber 1 and the condenser lens chamber 2 are reduced to a pressure of 10 ⁻⁷ Pa or less. Sample room 4
Is connected to a vacuum pump 22, which is evacuated to 10 ⁻³ Pa or less.

In the intermediate chamber 3, a reflected electron / secondary electron detector 23 for detecting secondary electrons or reflected electrons B2 from the surface of the sample 16 when the sample 16 is irradiated with the electron beam B1 from the electron gun 7. Is attached. The sample chamber 4
The intermediate chamber 3 is communicated with the intermediate chamber 3 by an exhaust bypass 18.

The transport mechanism 26 transfers the sample 16 to the preliminary exhaust chamber 2
The sample is conveyed from 5 to the sample chamber 4. When introducing the sample 16 into the sample chamber 4, the sample is introduced through the preliminary exhaust chamber 25. That is, the sample 1
6 was introduced, the preliminary exhaust chamber 25 was evacuated to vacuum, and when a predetermined pressure was reached, the gate valve 17 was opened and the sample 16 was removed.
The sample is carried into the sample chamber 4, and the gate valve 17 is closed.

At the time of observation of the sample surface, the electron beam B1 emitted from the electron gun 7 is extracted by the voltage applied to the extraction electrode 8, and the extracted electron beam B1 is accelerated by the acceleration applied to the acceleration electrode 9. The desired energy is adjusted by the voltage. Further, after passing through the fixed stop 10, the electron beam B 1 is converged on the sample 16 by the condenser lens 11 and the objective lens 13. Focused electron beam B1
Scans the sample 16 with the deflection coil 12. The deflection controller 40 changes the deflection current flowing through the deflection coil 12 and scans the sample 16 with the electron beam B1.
At this time, secondary electrons and reflected electrons B2 are generated from the 16 surfaces of the sample, and these secondary electrons and reflected electrons B2 are generated.
Is detected by the backscattered electron / secondary electron detector 23,
A sample image can be displayed on the display unit 42. For normal observation of the sample surface, a clear sample image can be obtained with only secondary electrons, but if the sensitivity is low, in addition to the information on the detected secondary electrons, By superimposing the images, a better sample image can be obtained. The signal detected by the reflected electron / secondary electron detector 23 is used by the control unit 44 to measure the amount of contaminants attached. Data such as the measured adhesion amount can be transmitted to a monitoring center 50 at a remote place via the network NW.

As described above, when the electron beam B1 is irradiated on the sample 16 installed in the sample chamber in which a large amount of gas components mainly composed of hydrocarbons remains in the sample chamber 4, the hydrocarbon-based gas is emitted. The molecule receives energy from the electron beam, and the substance mainly composed of carbon is converted into the sample 16.
Phenomenon that gradually accumulates on the surface of. The amount of deposition is very small, at most a few nm to several tens of nm.However, since another substance is deposited on the surface to be actually seen, the amount of deposition is tens of thousands times or more. , The difference in shape becomes apparent. Therefore, it is important to have a simple, quick, and quantitative evaluation method of how much contaminants adhere to the observation surface.

Next, the method for measuring sample contamination according to the present embodiment will be described with reference to FIGS. FIG. 2 and FIG. 3 are principle configuration diagrams for explaining the principle of the sample contamination measurement method according to the first embodiment of the present invention. FIG. 2 shows a cross-sectional view, and FIG. 3 shows a plan view schematically showing a view observed as an image of an electron microscope.

As shown in FIG. 2, the surface of the sample 16
A convex portion 28 is formed in advance. The convex portion 28
This is a contaminant evaluation pattern that can be called an inspection pattern or a dummy pattern. The width a0 of the convex portion 28
Has a width substantially equal to a wiring pattern in an actual semiconductor device. For example, the width a0 of the convex portion 28 is
0.5 μm. The length of the protruding portion 28 is longer than the width a0 and is a linear protrusion as shown in FIG. The protruding portion 28 may be a protruding portion having a linear planar shape or an L-shaped bent shape. Further, the plane shape may be circular.

In FIGS. 2 and 3, a region C1 indicated by a dashed line is a first visual field region. A region C2 indicated by a broken line is a second viewing region. First viewing area C1
In the second field of view C2, an electron beam is irradiated, and the surface of the sample 16 and the surface of the convex portion 28 are scanned, whereby an image of an electron microscope is obtained.

Here, the length of one side of the first viewing area C1 is n1, and the length of one side of the second viewing area C2 is n2. The length n1 of one side of the first visual field region C1 is set to be larger than the width a0 of the convex portion 28. For example, the convex portion 2
8, the width a0 of the first field of view C is 0.5 μm.
The length n1 of one side is 1.0 μm. At this time, the length n2 of one side of the second visual field region C2 is set to 2.0
μm. The length of the convex portion 28 is the first field of view C
What is necessary is that the length is longer than the length n1 of one side.

First, the control unit 44 controls the deflection control unit 40 to set an area where the electron beam B1 scans on the sample 16 as a first visual field area C1. Then, observation is performed for a predetermined time, for example, about 10 minutes in the first visual field region C1. When the electron beam B1 is irradiated for a certain period of time in an electron microscope in which a gas component mainly composed of hydrocarbons remains in the sample chamber 4, the irradiated surface, in this case, a first visual field region C1 of n1 × n1 The contaminant 29 mainly composed of carbon is deposited on the surface of the substrate as a film as shown in FIG. Contaminant 2 is also present on the side of the convex portion 28.
9 is deposited, the width of the convex portion is apparently the width a4.
And the line width increases in a convex shape. After a lapse of a predetermined time, the control unit 44 controls the deflection control unit 40 to set an area where the electron beam B1 scans on the sample 16 as a second visual field area C2. That is, the magnification of the visual field is reduced. As a result, as shown in FIG. 3, the portion where the contaminant 29 adheres and the line width becomes a4, and the convex portion 28 having the original line width a0 where the contaminant does not adhere have the same visual field. C2
Can be observed at the same time.

Since the electron beam inspection apparatus generally has a measurement and rejection function for measuring the distance between two points and the distance between two parallel lines, the portion where the line width is increased by the contaminant 29 and the original line width are used. By measuring the distance from the portion a0, the line width a1 increased by the attachment of the contaminant 29 can be measured. Further, even if the line width a4 of the portion where the line width is increased by the contaminant 29 and the line width a0 of the convex portion 28 are individually measured, the line width a1 (= (a4 −a0) / 2) can be obtained by calculation. Further, assuming that the width a0 of the convex portion 28 is known, for example, an atomic force microscope (AFM (Atomi
c Force Microscopy))
By measuring the line width a4 of the portion where the line width is increased by the contaminant 29, the line width a1 (= (a4-a0) / 2) increased by the attachment of the contaminant 29 can be obtained by calculation.

Strictly speaking, a1 measured by the present measuring method is not necessarily equal to a2 and a3, but is substantially equal, and is a simple measuring method and an index for quantitative evaluation. obtain. The magnification at the time of evaluating the deposition amount of the contaminant 29 is preferably about 1/2 since the increase amount is difficult to measure if it is too low. Pollutant 2
9 is 1 nm when the amount of contaminants is small.
To a lesser degree, the number of contaminants increases to several nm or more.

As described above, it is possible to quantitatively measure sample contamination, and to quantitatively grasp the influence of sample contamination. Also, the measurement of the amount of the contaminants attached can be performed simply, quickly and easily. further,
Such a sample contamination evaluation method can be used for inspection items and performance evaluation of an electron beam inspection apparatus.

Here, a gas mainly composed of hydrocarbons that cause sample contamination may be brought into the sample chamber 4 depending on the sample 16 to be inspected. That is, it is conceivable that the gas adsorbed on the sample 16 is desorbed in the sample chamber 3 and becomes a hydrocarbon-based residual gas. In this case, the hydrocarbon-based residual gas gradually increases depending on the number of times of introduction of the sample.
The amount of the contaminants 29 deposited on the surface 6 per unit time also gradually increases depending on the number of sample introductions.

Therefore, the above-described deposit evaluation method is periodically performed, and the measured amount of contaminants is displayed on the display section 42 of the electron beam inspection apparatus.
Record the amount of adhesion. This provides an indication of the trend of increasing contaminants and provides a measure of maintenance time. Also,
By transmitting the recording information of the amount of contaminant adhesion to the monitoring center 50 via the network NW or the like, it is possible to determine the maintenance time of the electron beam inspection apparatus even in a remote place.

As described above, according to the present embodiment, it is possible to quantitatively measure the amount of contaminants adhering to the observation surface of the electron beam inspection device.

Next, a method for measuring sample contamination of the electron beam inspection apparatus according to the second embodiment of the present invention will be described with reference to FIGS. The cause of the generation of residual gas mainly composed of hydrocarbons that cause sample contamination includes gas released from the inner wall of the sample chamber 4 and the stages 6, 6 ′.
And a power transmission mechanism such as a ball screw, a guide 15 of the stage, and not shown in the figure, and other gases emitted from various components in the sample chamber, such as sensors and wires for controlling the stage. Further, the gas adsorbed on the sample may be desorbed and become a hydrocarbon-based residual gas in the sample chamber 4 in some cases. As described above, since there are a wide variety of components that generate residual gas mainly composed of hydrocarbons that cause sample contamination, how much each component or lubricant affects the generation of contaminants 29 on the sample? Evaluation method is required.

In particular, an electron beam inspection apparatus used in an inspection apparatus for semiconductor manufacturing has an object to be inspected having a fine processing shape (pattern or hole) of a micron order or less, and a semiconductor wafer to be inspected has a diameter of, for example, 200 mm. ~ 30
Since the diameter is increased to 0 mm, the XY stage 6 in the sample chamber 3 is placed in a vacuum atmosphere of, for example, 10 ⁻² Pa or less.
Since 6 'requires very precise positioning, X
Lubricants such as vacuum lubricating oil and vacuum grease are indispensable for the guide mechanism 15 and the ball screw for driving when the Y stages 6 and 6 ′ move. In addition, parts made of a polymer compound are required for the stage drive system and the sliding part. In some of these oils and greases, the lubricant easily evaporates in a vacuum to generate hydrocarbon-based gas molecules, and some polymer compounds release hydrocarbon-based gases. Therefore, it is very important to evaluate the sample contamination of such an electron beam inspection system, and to evaluate the effect of lubricants and components used in the sample chamber on the sample contamination. You need to choose.

In the present embodiment, the amount of contamination of the lubricant is evaluated by using the above-described method of measuring the amount of contaminants attached. The lubricant to be evaluated is applied entirely on the surface of sample 16. The convex portion 28 shown in FIG. 2 is formed on the surface of the sample 16 in advance, and a lubricant is applied to the surface of the convex portion 28 as well. In this state, the first viewing area C1 is irradiated with the electron beam B1 for a certain time. At the start of irradiation, the lubricant is diluted and used in a liquid state, and is not observed as an electron microscope image. The residual gas in the sample chamber 3 is repeatedly adsorbed and desorbed on the surface of the sample, and is considered to be solidified by the energy of the electron beam when adsorbed. Therefore, if the lubricant to be evaluated is applied to the surface of the sample in advance, when the energy of the electron beam is received, the sample is solidified and the contaminant 29 adheres. After a certain time,
FIGS. 1 to 3 show the field of view as a second field of view C2 of low magnification.
The amount of the contaminant 29 attached (the increase in the line width a1) is measured by the method described in (1). By measuring the amount of adhesion of the contaminant 29, it is possible to evaluate whether the lubricant has a composition that easily solidifies and becomes the contaminant 29 or a lubricant that has a composition that hardly forms the contaminant 29. it can. For example, when the amount of adhesion is several tens of nm, it can be said that the lubricant has a composition that tends to solidify and become the contaminant 29, and the amount of adhesion is almost 0 nm, that is, an undetectable amount of adhesion. If so, it can be evaluated as a lubricant having a composition that hardly forms the contaminant 29.

According to the present embodiment, it is possible to select a lubricant by measuring the amount of contaminants generated from the lubricant used in the apparatus.

Next, a method for measuring sample contamination of the electron beam inspection apparatus according to the third embodiment of the present invention will be described with reference to FIG. FIG. 4 is an overall configuration diagram showing the configuration of an electron beam inspection apparatus used for the sample contamination measurement method according to the third embodiment of the present invention. The same reference numerals as those in FIG. 1 indicate the same parts.

In this embodiment, another room 30 is provided so as to be connected to the sample room 4, and a part 31 to be evaluated such as a sensor, a wiring, and various polymer materials can be installed therein.

As described above, there are a wide variety of components that generate residual gas mainly composed of hydrocarbons that cause sample contamination, such as various sensors, sensor wires, and polymer materials in addition to lubricants. In the present embodiment, it is possible to evaluate how much each component affects the generation of the contaminant 29 on the sample.

After the part 31 to be evaluated is set in the room 30, a sample having a convex shape 28 of a known size (width a0) on the surface of the sample is set in the electron beam inspection apparatus.
The electron beam B1 for a predetermined time with respect to the first viewing area C1.
Is irradiated. Next, the magnification is reduced to a low value, and the increase amount a1 of the line width due to the contaminant 29 is measured as in the example shown in FIG.

Gas is released from the component 31 installed in the room 30 connected to the sample chamber 4 and flows into the sample chamber 4. It is determined whether or not the gas released from the component 31 is easily solidified by receiving the energy of the electron beam.
By measuring the contaminants 29, the evaluation can be easily performed.
Instead of providing another room 30 in the sample chamber 4, a place may be provided on the stage and components may be provided.

According to the present embodiment, to what extent various sensors, sensor wiring, polymer materials, etc., which are components that generate residual gas mainly composed of hydrocarbons that cause sample contamination, are contaminated on the sample. Can be evaluated to affect the generation of

Next, with reference to FIG. 5, a method for measuring sample contamination of the electron beam inspection apparatus according to the fourth embodiment of the present invention will be described. FIG. 5 is a principle configuration diagram for explaining the principle of the sample contamination measurement method according to the fourth embodiment of the present invention. Note that the same reference numerals as those in FIG. 2 indicate the same parts.

The configuration of the electron beam inspection apparatus used in the sample contamination measuring method according to the present embodiment is the same as that shown in FIG. In the present embodiment, the contaminant 29 is adhered using the sample 16 ′ having the concave portion 32 of a known size instead of the convex portion 28 shown in FIG. 2, and the deposition amount is evaluated. In this case, the inner width dimension a0 of the concave shape is reduced by the deposit, and as a result, the dimension becomes (a0−a1 × 2). By grasping the dimensional change quantitatively, it is possible to evaluate the carbon deposit adhering and depositing on the sample observation surface of the electron beam inspection apparatus described in each of the above embodiments. Also used to evaluate carbon deposits caused by hydrocarbon gases released from lubricating oils and polymer materials used in the equipment, and to select lubricating oils and materials that have little effect on carbon deposit formation Can be.

Next, with reference to FIG. 6, a description will be given of a sample contamination measuring method of the electron beam inspection apparatus according to the fifth embodiment of the present invention. FIG. 6 is a principle configuration diagram for explaining the principle of the sample contamination measurement method according to the fifth embodiment of the present invention. Note that the same reference numerals as those in FIG. 2 indicate the same parts.

The configuration of the electron beam inspection apparatus used in the sample contamination measuring method according to the present embodiment is the same as that shown in FIG. Further, in the present embodiment, an electron beam inspection device capable of obliquely observing a sample is used as the electron beam inspection device.

The sample 16 is irradiated with an electron beam perpendicularly, and thereafter, the sample 16 is tilted, and observation is performed at a reduced magnification so that the entire portion irradiated with the electron beam can be first observed. When the sample 16 is observed only from the vertical direction, the dimension a
Although only 1 is an evaluation target of the amount of deposition of the contaminant 29, when an electron beam inspection device that can observe the sample while tilting it is used, the thicknesses a2 and a3 of the contaminant 29 can be observed. , The tilt angle of the sample 16 and the dimension a of the observed image
2, a3, the actual dimensions a2, a3 can be calculated by geometric calculation. Therefore, the thickness of the deposited contaminants 29 can be evaluated. Note that the angle of inclination during observation is, for example, 45 degrees.

According to the present embodiment, it is possible to accurately measure the thickness of each part of the contaminant.

[0046]

According to the present invention, the amount of contaminants adhering to the observation surface of the electron beam inspection apparatus can be quantitatively measured.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing a configuration of an electron beam inspection apparatus used for a sample contamination measurement method according to a first embodiment of the present invention.

FIG. 2 is a principle configuration diagram for explaining the principle of the sample contamination measurement method according to the first embodiment of the present invention.

FIG. 3 is a principle configuration diagram for explaining the principle of the sample contamination measurement method according to the first embodiment of the present invention.

FIG. 4 is an overall configuration diagram showing a configuration of an electron beam inspection apparatus used for a sample contamination measurement method according to a third embodiment of the present invention.

FIG. 5 is a principle configuration diagram for explaining the principle of a sample contamination measurement method according to a fourth embodiment of the present invention.

FIG. 6 is a principle configuration diagram for explaining a principle of a sample contamination measurement method according to a fifth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 4 ... Sample room 12 ... Deflection coil 16 ... Sample 23 ... Reflection electron / secondary electron detector 28 ... Convex part 29 ... Contaminant 30 ... Room 31 ... Parts 32 ... Concave part 40 ... Deflection control part 42 ... Display part 44 ... Control unit

Continued on the front page (72) Inventor Minoru Shimizu 882 Ma, Hitachinaka-shi, Ibaraki F-term in the measuring instruments group of Hitachi, Ltd. TT02 2G001 AA03 BA07 BA15 CA03 GA06 HA13 JA16 KA01 KA11 LA04 PA07 4M106 AA01 BA02 CA41 DB05 DJ23 DJ40 5C033 UU04 UU05 UU06

Claims (4)

[Claims] An electron beam inspection apparatus for irradiating a sample placed in a sample chamber with an electron beam from an electron gun in an electron gun chamber, detecting secondary electrons generated from the sample, and measuring the dimensions of the sample. By irradiating the convex or concave portion provided on the surface of the sample with an electron beam, the size of the convex or concave shape changed by the contaminant adhering to the electron beam irradiation surface indicates that the contaminant adheres. A method for measuring sample contamination, comprising measuring the amount. 2. The method according to claim 1, wherein the convex or concave portion provided on the surface of the sample coated with a lubricant is irradiated with an electron beam. A method for measuring contamination of a sample, comprising measuring an amount of contaminants adhered from a dimension of a convex or concave shape changed by contaminants adhering to an irradiation surface, and evaluating a lubricant. 3. A sample contamination measuring method for an electron beam inspection apparatus according to claim 1, wherein a material intended for use in the electron beam inspection apparatus is placed in an arbitrary sample chamber not irradiated with an electron beam. The convex or concave portion provided on the surface of the sample is irradiated with an electron beam, and the amount of the contaminant is measured from the convex or concave dimension changed by the contaminant adhering to the electron beam irradiation surface. A method for measuring sample contamination, wherein the material is evaluated based on the amount of contaminants attached. 4. The method for measuring contamination of a sample of an electron beam inspection apparatus according to claim 1, wherein the measurement of the amount of attached contaminants is periodically performed, and the measured amount of attached contaminants is displayed or recorded. Sample contamination measurement method.