JP2012169291A - Beam intensity distribution measurement method of charged particle beam and charged particle beam device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a beam intensity distribution measurement method which enhances the accuracy of measurable beam resolution.SOLUTION: The beam intensity distribution measurement method of a charged particle beam measures the beam intensity distribution of a charged particle beam by scanning a metal mark, tapered at a certain angle θ from the upper surface toward the lower surface, with a charged particle beam. The metal mark is formed so that the product of the thickness t of the metal mark and the certain angle θ is equal to or smaller than a desired resolution σ of charged particle beam. According to the invention, accuracy of measurable beam resolution can be enhanced.

Description

  The present invention relates to a charged particle beam beam intensity distribution measuring method and a charged particle beam apparatus, for example, measurement of electron beam beam intensity distribution in a charged particle beam drawing apparatus that irradiates a sample with an electron beam while variably shaping the electron beam. The present invention relates to a method, a beam resolution measuring method obtained from the method, and an apparatus embodying the method.

  Lithography technology, which is responsible for the progress of miniaturization of semiconductor devices, is an extremely important process for generating a pattern among semiconductor manufacturing processes. In recent years, with the high integration of LSI, circuit line widths required for semiconductor devices have been reduced year by year. In order to form a desired circuit pattern on these semiconductor devices, a highly accurate original pattern (also referred to as a reticle or a mask) is required. Here, the electron beam (electron beam) drawing technique has an essentially excellent resolution, and is used for producing a high-precision original pattern.

FIG. 11 is a conceptual diagram for explaining the operation of a conventional variable shaping type electron beam drawing apparatus.
In a first aperture 410 in a variable shaping type electron beam drawing apparatus (EB (Electron beam) drawing apparatus), a rectangular, for example, rectangular opening 411 for forming the electron beam 330 is formed. Further, the second aperture 420 is formed with a variable shaping opening 421 for shaping the electron beam 330 having passed through the opening 411 of the first aperture 410 into a desired rectangular shape. The electron beam 330 irradiated from the charged particle source 430 and passed through the opening 411 of the first aperture 410 is deflected by the deflector, passes through a part of the variable shaping opening 421 of the second aperture 420, and passes through a predetermined range. The sample 340 mounted on a stage that continuously moves in one direction (for example, the X direction) is irradiated. That is, the drawing area of the sample 340 mounted on the stage in which the rectangular shape that can pass through both the opening 411 of the first aperture 410 and the variable shaping opening 421 of the second aperture 420 is continuously moved in the X direction. Drawn on. A method of creating an arbitrary shape by passing both the opening 411 of the first aperture 410 and the variable shaping opening 421 of the second aperture 420 is referred to as a variable shaping method.

  The accuracy and the minimum resolution size of the pattern formed using the above-described electron beam drawing apparatus are closely related to the beam resolution. On the other hand, when drawing a substrate, there are factors that effectively degrade resolution due to processes such as resist contrast of resist applied on the substrate and acid diffusion of chemically amplified resist (process resolution). In recent drawing apparatuses, the beam resolution of the drawing apparatus itself has been improved (becomes smaller), and has reached a value that is equal to or smaller than the process resolution in calculation.

  Here, the measurement of the beam intensity distribution of the electron beam 330 irradiated to the sample 340 is generally performed as follows. That is, the electron beam 330 is scanned to scan the knife edge. The signal is received and measured by a Faraday cup or the like located behind the knife edge. (For example, refer to Patent Document 1). The beam intensity distribution of the electron beam 330 applied to the sample 340 scans the electron beam 330 and irradiates the electron beam 330 to a metal mark (dot pattern) that is sufficiently smaller than the beam size of the electron beam 330. There is a method of measuring by measuring reflected electrons from a metal mark (see, for example, Patent Document 2). And the beam resolution of the electron beam 330 can be obtained from the beam intensity distribution of the electron beam 330 obtained by these.

Japanese Patent Laid-Open No. 2004-71990 Japanese Patent Laid-Open No. 4-242919

  As described above, the beam resolution has been improved to a value equivalent to or smaller than the process resolution in terms of calculation as the performance of the apparatus has been improved. Therefore, when evaluating the accuracy and final resolution of the final pattern, it is necessary to know whether they are due to the beam resolution of the device or the process resolution. It has become important to determine the direction.

FIG. 12 is a diagram showing an example of a conventional beam intensity distribution.
In FIG. 12, the intensity distribution of the beam shows the result of measurement by scanning the electron beam on a conventional metal mark (dot pattern) and measuring the reflected electrons from the metal mark. Here, the intensity distribution of the beam is ideally defined by an error function b (x). However, even when an electron beam is scanned on a conventional metal mark, the intensity distribution of the beam obtained as a result is considerably deviated from the waveform of the error function. This is because the distribution due to scattering from the conventional metal mark is synthesized. Since the influence of such scattering from the conventional metal mark is included, there is a problem that the obtained beam resolution becomes a larger value than the original beam resolution. As a result, the measurement result reaches a peak, and the range that can be measured is limited. Therefore, even if it is attempted to know whether the above-mentioned pattern accuracy and final resolution dimension are caused by the beam resolution of the apparatus or the process resolution, it is possible to measure a resolution that is small enough to make these determinations in the first place. could not.

  Therefore, an object of the present invention is to provide a beam intensity distribution method that overcomes the above-described problems and improves the accuracy of measurable beam resolution, and a drawing apparatus that embodies the method.

The charged particle beam beam intensity distribution measuring method of one embodiment of the present invention includes:
A charged particle beam beam intensity distribution measuring method for measuring a beam intensity distribution of a charged particle beam by scanning a charged particle beam on a metal mark that becomes thinner at a predetermined angle θ from the upper surface to the lower surface,
As the above-described metal mark, a metal mark formed so that the product of the thickness t of the metal mark and the predetermined angle θ is equal to or less than a desired charged particle beam resolution σ is used.

  By using such a metal mark, the influence of scattering from the metal mark can be reduced.

  The metal mark described above is preferably formed so that the predetermined angle θ is 1.5 degrees or less.

  Moreover, it is preferable that the metal mark described above is formed so that the thickness t of the metal mark is 200 nm or less.

  Further, it is more preferable that the metal mark is formed such that the predetermined angle θ is 1.5 degrees or less and the thickness t of the metal mark is 200 nm or less.

A charged particle beam device according to one aspect of the present invention that embodies the above-described method is provided.
An irradiation unit for irradiating a charged particle beam;
A metal mark formed so as to become thinner at a predetermined angle θ from the upper surface to the lower surface, and the product of the thickness t from the upper surface to the lower surface and the predetermined angle θ is equal to or less than the desired charged particle beam resolution σ. And stage to place
A measuring unit for measuring the intensity distribution of the charged particle beam based on scanning the charged particle beam on the metal mark described above;
It is provided with.

  According to the present invention, since the influence of scattering from the metal mark can be reduced, it can be made closer to an error function. Therefore, the accuracy of measurable beam resolution can be improved. As a result, it can be determined whether the above-described pattern accuracy and final resolution dimension are caused by the beam resolution of the apparatus or the process resolution.

FIG. 4 is a flowchart showing an example of a main process of the electron beam beam resolution measuring method according to the first embodiment. 1 is a conceptual diagram illustrating a configuration of a drawing apparatus according to Embodiment 1. FIG. FIG. 3 is a conceptual diagram for explaining how to scan an electron beam in the first embodiment. FIG. 3 is a conceptual diagram for explaining a state of measuring reflected electrons in the first embodiment. 6 is a diagram illustrating an example of a detection result of reflected electrons in Embodiment 1. FIG. 6 is a diagram showing an example of a beam intensity distribution in the first embodiment. FIG. FIG. 6 is a diagram showing a relationship among measurable resolution, mark thickness, and mark side wall angle in the first embodiment. 6 is a diagram showing an example of a beam intensity distribution in the first embodiment. FIG. 6 is a conceptual diagram illustrating a configuration of a drawing apparatus according to Embodiment 2. FIG. FIG. 9 is a conceptual diagram showing a configuration of an electron microscope in a third embodiment. It is a conceptual diagram for demonstrating operation | movement of the conventional variable shaping type | mold electron beam drawing apparatus. It is a figure which shows an example of the intensity distribution of the conventional beam.

  Hereinafter, in the embodiment, a configuration using an electron beam will be described as an example of a charged particle beam. However, the charged particle beam is not limited to an electron beam, and a beam using charged particles such as an ion beam may be used.

  In addition, although the beam resolution depends on the definition, it may be defined as the resolution with the parameter σ approximated by an intensity distribution error function. Or, the width (length) from a position that becomes 10% of the maximum beam intensity to the position that becomes 90%, or the width (length) from a position that becomes 20% of the maximum beam intensity to a position that becomes 80%. Sometimes defined. Hereinafter, in the embodiment, approximation is performed using an intensity distribution error function, and the parameter σ is defined as beam resolution.

Embodiment 1 FIG.
FIG. 1 is a flowchart showing an example of a main process of the electron beam beam resolution measuring method according to the first embodiment.
In FIG. 1, the electron beam intensity distribution measuring method performs a series of steps of an irradiation step (S102), a reflected electron measurement step (S104), and a beam intensity distribution calculation step (S106). The electron beam beam resolution measurement method performs a series of steps called a beam resolution calculation step (S108) in addition to the steps of the beam intensity distribution measurement method.

FIG. 2 is a conceptual diagram illustrating a configuration of the drawing apparatus according to the first embodiment.
In FIG. 2, a drawing apparatus 100 as an example of a charged particle beam drawing apparatus includes an electron column 102, an XY stage 105, an electron gun 201 (irradiation unit), an illumination lens 202, and a first aperture 203 constituting a drawing unit 150. , A projection lens 204, a deflector 205, a second aperture 206, an objective lens 207, a deflector 208, and a detector 218 (measuring unit), and as a control unit 160, a control computer (CPU) 310, an interface circuit 320, a memory 312, an amplifier 326, and an A / D converter 328.

  In the electron column 102, there are an electron gun 201, an illumination lens 202, a first aperture 203, a projection lens 204, a deflector 205, a second aperture 206, an objective lens 207, a deflector 208, and a detector 218. Has been placed. In FIG. 1, description of components other than those necessary for describing the first embodiment is omitted. It goes without saying that the drawing apparatus 100 usually includes other necessary configurations.

  An electron beam 200 as an example of a charged particle beam emitted from the electron gun 201 illuminates the entire first aperture 203 having a rectangular hole, for example, a rectangular hole by an illumination lens 202. Here, the electron beam 200 is first formed into a rectangle, for example, a rectangle. Then, the electron beam 200 of the first aperture image that has passed through the first aperture 203 is projected onto the second aperture 206 by the projection lens 204. The position of the first aperture image on the second aperture 206 is controlled by the deflector 205, and the beam shape and size can be changed. Then, the electron beam 200 of the second aperture image that has passed through the second aperture 206 is focused by the objective lens 207, deflected by the deflector 208, and silicon (Si) on the movable XY stage 105. ) Irradiation is performed so as to scan the dot mark 10 which is a metal mark on the substrate 20. The deflector 208 is controlled by the control computer 310 via the interface circuit 320. Input / output data such as results calculated by the control computer 310 is stored in the memory 312.

  Using the drawing apparatus 100, the beam intensity distribution and beam resolution of the electron beam irradiated by the drawing apparatus 100 are measured. Hereinafter, a method for measuring the beam intensity distribution and the beam resolution will be described. In addition, each operation and arithmetic processing in the following steps are controlled by the control computer 310.

  First, the Si substrate 20 on which the dot mark 10 as an example of the sample is formed is disposed on the XY stage 105. Then, the XY stage 105 is moved and adjusted so that the electron beam 200 irradiates the Si substrate 20. The Si substrate 20 may be transferred onto the XY stage 105 from the outside of the apparatus, or may be fixed on the XY stage 105 in advance. In the case of fixing on the XY stage 105 in advance, it may be fixed and arranged at a position that does not interfere with the arrangement of mask blanks or the like to be originally drawn.

  In S (step) 102, an electron beam 200 having a beam size smaller than the width dimension of the dot mark 10 is used as an irradiation process using, for example, a rectangular dot mark 10 as an example of a dot pattern formed on the Si substrate 20. Irradiation is performed so as to move from the front of the dot mark 10 to the dot mark 10.

FIG. 3 is a conceptual diagram for explaining a method of scanning an electron beam in the first embodiment.
For example, a rectangular dot mark 10 which is an example of a metal mark is formed on the Si substrate 20. Then, the electron beam 200 shaped from the direction orthogonal to the edge on the outer periphery of the dot mark 10 is scanned toward the dot mark 10.

  The dot mark 10 uses a material having a higher reflectance than Si used as a material for the Si substrate 20. For example, it is preferable to use a refractory metal such as tungsten (W) or tantalum (Ta) or a heavy metal such as gold (Au) or platinum (Pt). Since the dot mark 10 can be manufactured by a semiconductor manufacturing process, the pattern shape can be formed more accurately than a knife edge component to be machined. As a result, the edge linearity, roughness, and the like can be improved as compared with a knife edge component that is machined. And since it can manufacture by a semiconductor manufacturing process, it can manufacture in large quantities cheaply compared with a knife edge. Here, it is preferable to use a sufficiently large mark for the dot mark 10 with respect to the shaped electron beam 200.

FIG. 4 is a conceptual diagram for explaining how the reflected electrons are measured in the first embodiment.
As shown in FIG. 4, the dot mark 10 is formed so as to become narrower at a mark side wall angle (predetermined angle) θ from the upper surface to the lower surface, and the product of the thickness t of the dot mark 10 and the predetermined angle θ. Is less than the desired beam resolution σ of the electron beam 200. In particular, the mark side wall angle θ is preferably formed to be 1.5 degrees or less. Further, it is preferable that the thickness t of the dot mark 10 is formed to be 200 nm or less. Conventionally, since the relationship between the thickness t of the dot mark 10 and the mark side wall angle θ has not been taken into account, the influence of scattering from the dot mark 10 is eliminated when the electron beam 200 is scanned on the dot mark 10. I could not. In the present embodiment, the influence of scattering from the dot mark 10 can be reduced or eliminated by considering the relationship between the thickness t of the dot mark 10 and the mark sidewall angle θ. The Si substrate 20 is a substrate having a thickness of 625 μm, for example.

In S104, as the reflected electron measurement step, the reflected electrons reflected from the dot mark 10 by the irradiation of the electron beam 200 are measured.
For example, as shown in FIG. 4, an electron beam 200 formed into a square shape as shown in FIG. 3 is scanned toward the dot mark 10, and when the electron beam 200 hits the dot mark 10, as shown in FIG. Reflected electrons 12 jump out of the mark 10. The reflected electrons 12 that jump out are detected by the detector 218. The signal detected by the detector 218 is amplified by the amplifier 326, converted to digital information by the A / D converter 328, and sent to the control computer 310.

In S106, as the beam intensity distribution calculation step, the beam intensity I of the electron beam 200 is calculated from the detection result of the A / D converter 328.
FIG. 5 is a diagram illustrating an example of the detection result of reflected electrons in the first embodiment.
In FIG. 5, the vertical axis is converted into the beam intensity I. The horizontal axis indicates the beam position. When the end of one electron beam hits the dot mark 10, reflected electrons 12 proportional to the intensity are detected. As the electron beam 200 moves, the beam intensity increases. In FIG. 5, the rising section of the beam profile is “α”, the section while the beam intensity reaches the top position (the portion where the beam is flat) is “β”, and the falling section of the beam profile is “γ”. ".

FIG. 6 is a diagram showing an example of the beam intensity distribution in the first embodiment.
The beam intensity distribution shown in FIG. 6 can be obtained by differentiating the beam intensity I shown in FIG. 5 and taking the absolute value thereof.

  Here, if the influence of scattering from the dot mark 10 is sufficiently reduced, the beam profile indicating the beam intensity distribution can be approximated by an error function b (x) represented by the following equation (Equation 1). .

Here, A indicates a coefficient indicating the beam intensity, and the maximum beam intensity is 2 × A. X ₀ and x ₁ indicate positions where the beam intensity is A, that is, ½ of the maximum beam intensity. The beam size is defined as a range in which the beam intensity is ½ of the maximum beam intensity, in other words, A. Therefore, when the beam profile here is the error function b (x), x ₁ −x ₀ is the beam size.

In S108, as the beam resolution calculation step, the beam resolution is calculated from the beam intensity distribution of the electron beam 200 based on the above-described equation 1.
When the beam intensity distribution is obtained as shown in FIG. 6, the maximum beam intensity of 1/2 (50%) and a A and 1/2 (50%) of the maximum beam intensity a position _{x 0} and _{x 1} is obtained It is done. Therefore, based on Expression 1, a value σ that is a parameter of an error function that becomes beam resolution can be obtained.

FIG. 7 is a diagram showing a relationship among measurable resolution, mark thickness, and mark sidewall angle in the first embodiment.
As shown in FIG. 7, when the thickness t of the dot mark 10 is reduced, the contrast with the underlying Si deteriorates and the S / N ratio cannot be obtained. For example, when the desired beam resolution σ is 10 nm or less, the combination of the mark sidewall angle θ and the mark thickness t that is 10 nm or more results in insufficient resolution. As for the mark side wall angle θ, there is a limit to the range that can be processed with high accuracy as the mark thickness t increases. Therefore, a region that satisfies all of these conditions shown in FIG. 7 is a usable region of the dot mark 10. Here, in FIG. 7, the mark thickness and the mark side wall angle are in arbitrary units [a. u. However, in any of the above-described materials for the dot mark 10, it is preferable that the mark sidewall angle θ is 1.5 degrees or less and the thickness t of the dot mark 10 is 200 nm or less. is there. By forming the mark side wall angle θ to 1.5 degrees or less and the thickness t of the dot mark 10 to 200 nm or less, a beam resolution σ of 10 nm or less can be obtained.

  Here, when the mark sidewall angle θ is 1.5 degrees or less and the thickness t of the dot mark 10 is 200 nm or less, the product of the thickness t of the dot mark 10 and the predetermined angle θ is about 0.8. In practice, however, the scattering from the dot mark 10 cannot be completely eliminated. Therefore, when the desired beam resolution σ of the electron beam 200 is 10 nm or less, the mark side wall angle θ is 1.5 degrees or less, and the dot mark 10 It is preferable that the thickness t is 200 nm or less. Higher beam resolution σ can be obtained as the mark sidewall angle θ approaches a value of 0 degree (that is, the sidewall of the dot mark 10 is perpendicular to the upper surface) at a thickness t at which the S / N ratio can be obtained.

FIG. 8 is a diagram showing an example of a beam intensity distribution in the first embodiment.
By using the dot mark 10 as described above and scanning the dot mark 10 with an electron beam, a beam intensity distribution as shown in FIG. 8 can be obtained. As shown in FIG. 8, the intensity distribution of the beam can be made substantially coincident with the error function b (x). Therefore, the accuracy of measurable beam resolution can be improved. As a result, it can be determined whether the above-described pattern accuracy and final resolution dimension are caused by the beam resolution of the apparatus or the process resolution.

Embodiment 2. FIG.
In the first embodiment, the electron beam 200 is scanned toward the dot mark 10, and as shown in FIG. 4, the reflected electrons 12 that have jumped out when the electron beam 200 hits the dot mark 10 are detected by the detector 218. However, the measurement method is not limited to this. In the second embodiment, the electron beam 200 may be scanned toward the dot mark 10, and the electron transmitted through the electron beam 200 without hitting the dot mark 10 may be detected by a detector.

FIG. 9 is a conceptual diagram illustrating a configuration of a drawing apparatus according to the second embodiment.
In FIG. 9, a drawing apparatus 100 as an example of a charged particle beam drawing apparatus includes an electron column 102, an XY stage 105, an electron gun 201 (irradiation unit), an illumination lens 202, and a first aperture 203 constituting a drawing unit 150. , A projection lens 204, a deflector 205, a second aperture 206, an objective lens 207, and a deflector 208. As a control unit 160, a control computer (CPU) 310, an interface circuit 320, a memory 312, an amplifier 326, an A / D A converter 328 is provided.

  In the electron barrel 102, an electron gun 201, an illumination lens 202, a first aperture 203, a projection lens 204, a deflector 205, a second aperture 206, an objective lens 207, and a deflector 208 are arranged. . In the XY stage 105, a detector 214 (measurement unit) is incorporated and arranged. In FIG. 9, description of components other than those necessary for describing the second embodiment is omitted. It goes without saying that the drawing apparatus 100 usually includes other necessary configurations.

  9 is the same as FIG. 1 except that the detector 218 is replaced with the detector 214 incorporated in the XY stage 105 and the Si substrate 20 is replaced with the Si substrate 22. Therefore, the description of the same parts as those in Embodiment 1 is omitted.

  First, the Si substrate 22 on which the dot mark 10 as an example of the sample is formed is disposed on the XY stage 105, particularly on the detector 214. Then, the XY stage 105 is moved and adjusted so that the electron beam 200 irradiates the Si substrate 22. The Si substrate 22 may be transferred onto the XY stage 105 from the outside of the apparatus, or may be fixed on the XY stage 105 in advance. When the Si substrate 22 is fixed on the XY stage 105 in advance, the detector 214 is fixed and arranged at a position that does not interfere with the arrangement of the mask blanks or the like to be originally drawn, and is arranged above the detector. Good.

  In the second embodiment, since it is a transmission type detection method, it is preferable that the Si thickness of the Si substrate 22 which is the base of the dot mark 10 is 1 μm or less. Further, the Si substrate 22 may be a membrane type in which a thin film remains, or a stencil type in which a boundary portion with the dot mark 10 penetrates.

  Then, the electron beam 200 formed into, for example, a quadrangle as shown in FIG. 3 is scanned toward the dot mark 10, and the electron beam 200 that has been transmitted until just before the electron beam 200 hits the dot mark 10 is detected by the detector 214. To detect. The signal detected by the detector 214 is amplified by the amplifier 326, converted into digital information by the A / D converter 328, and sent to the control computer 310. In the second embodiment, since the electron beam 200 cannot be detected by the detector 214 while it is hitting the dot mark 10, the calculation may be performed after reversing the presence or absence of signal detection in the first embodiment.

Embodiment 3 FIG.
FIG. 10 is a conceptual diagram showing the configuration of the electron microscope in the third embodiment.
In FIG. 10, an electron microscope (SEM) 500, which is an example of a charged particle beam apparatus, includes an electron column 522, an XY stage 525, an electron gun 501 (irradiation unit), an illumination lens 502, and a projection lens 504 that constitute an optical system 550. , A deflector 505, an objective lens 507, and a detector 518. The control unit 160 includes a control computer (CPU) 510, a memory 512, an amplifier 526, an A / D converter 528, and a monitor 524.

  In the electron column 522, an electron gun 501, an illumination lens 502, a projection lens 504, a deflector 505, an objective lens 507, and a detector 518 are arranged. On the XY stage 525, the Si substrate 20 on which the dot marks 10 are arranged is placed as in the first embodiment. In FIG. 10, the description of components other than those necessary for describing the third embodiment is omitted. Needless to say, the electron microscope 500 normally includes other necessary configurations.

  An electron beam 200 as an example of a charged particle beam emitted from the electron gun 501 is projected downstream by an illumination lens 502 and a projection lens 204. Then, the position is controlled by the deflector 205, the focus is adjusted by the objective lens 207, and irradiation is performed so as to scan on the dot mark 10 that becomes a metal mark on the Si substrate 20 on the XY stage 525 that is movably disposed. The Input / output data such as results calculated by the control computer 510 is stored in the memory 512.

  When the electron beam 200 hits the dot mark 10, reflected electrons jump out of the dot mark 10 by irradiation of the electron beam 200. The reflected electrons that have jumped out are detected by the detector 518. The signal detected by the detector 518 is amplified by the amplifier 526, converted into digital information by the A / D converter 528, and sent to the control computer 510. Such a signal is displayed on the monitor 524 as an image. Here, as in the above-described embodiment, the beam intensity I of the electron beam 200 is calculated from the detection result of the A / D converter 528, so that the beam resolution can be obtained from the beam intensity distribution of the electron beam and the beam intensity distribution. Obtainable.

  As described above, the present technique can be similarly applied not only to the drawing apparatus as in the above-described embodiment but also to an electron microscope as in this embodiment.

The embodiments have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. For example, in the embodiment described above, the beam resolution is defined as the parameter a is a value σ of the error function, to the position x _b to be 90% from the position x _a which is 10% of the maximum beam intensity of the beam resolution In this case, the beam resolution (x _b −x _a ) can be expressed as 1.8σ. Therefore, when the beam resolution is defined by a value other than the value σ that is a parameter of the error function, it can be estimated by multiplying the value σ by an appropriate coefficient. Therefore, when considering the relationship between the thickness t of the dot mark 10 and the mark sidewall angle θ, the value σ, which is a parameter of the error function, may be obtained from the defined beam resolution.

  In addition, although descriptions are omitted for parts and the like that are not directly required for the description of the present invention, such as a device configuration and a control method, a required device configuration and a control method can be appropriately selected and used. For example, although the description of the control unit configuration for controlling the drawing apparatus 100 is omitted, it goes without saying that the required control unit configuration is appropriately selected and used.

  In addition, a beam intensity distribution measurement method, a charged particle beam beam resolution measurement method, a charged particle beam drawing method, and a charged particle beam drawing apparatus that include elements of the present invention and that can be appropriately modified by those skilled in the art. And charged particle beam devices including electron microscopes are included within the scope of the present invention.

10 Dot mark 12 Reflected electrons 20, 22 Si substrate 100 Drawing apparatus 102, 522 Electron column 105, 525 XY stage 150 Drawing unit 160, 560 Control unit 200 Electron beam 201, 501 Electron gun 202, 502 Illumination lens 203, 410 One aperture 204, 504 Projection lens 205, 208, 505 Deflector 206, 420 Second aperture 207, 507 Objective lens 214, 218, 518 Detector 310, 510 Control computer 312, 512 Memory 320 Interface circuit 326, 526 Amplifier 328, 528 A / D converter 330 Electron beam 340 Sample 411 Aperture 421 Variable shaped aperture 430 Charged particle source 500 Electron microscope 524 Monitor 550 Optical system

Claims (2)

A charged particle beam beam intensity distribution measuring method for measuring a beam intensity distribution of the charged particle beam by scanning a charged particle beam on a metal mark that becomes thinner at a predetermined angle θ from the upper surface to the lower surface,
In order to obtain a beam resolution of 10 nm or less by approximating the beam intensity distribution with an error function using the parameter σ and using the parameter σ of the error function as the beam resolution, the predetermined angle θ is 1.5 degrees as the metal mark. In the following, a method for measuring a beam intensity distribution of a charged particle beam, wherein a metal mark of tantalum formed so that the thickness t of the metal mark is 200 nm or less is used. An irradiation unit for irradiating a charged particle beam;
The beam intensity distribution is approximated by an error function using the parameter σ, and the parameter σ of the error function is used as the beam resolution to obtain a beam resolution of 10 nm or less. A stage on which a tantalum metal mark formed so that a predetermined angle θ is 1.5 degrees or less and a thickness t from an upper surface to a lower surface is 200 nm or less;
A measurement unit for measuring the intensity distribution of the charged particle beam based on scanning the charged particle beam on the metal mark;
A charged particle beam apparatus comprising:

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