JP2007258616A - Charged particle beam drawing system, and adjusting method of charged particle beam irradiation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a charged particle beam drawing system capable of adjusting an irradiation position in a short time. <P>SOLUTION: The charged particle beam drawing system comprises: the charged particle beam irradiation device 90 provided with first and second deflectors 25a and 25b for deflecting charged particle beams so as to be transmitted through a plurality of pattern apertures and third and fourth deflectors 25c and 25d for deflecting them so as to be returned to a beam axis; a pattern selection deflection circuit 46 for impressing first-fourth deflection signals calculated from first-fourth signal ratios to the first-fourth deflectors; and a processing unit 54 for calculating the first-fourth reference deflection signals so as to irradiate the irradiation position through a reference pattern aperture and adjusting the first-fourth signal ratios from first adjustment deflection signals to be transmitted through an adjustment pattern aperture, second adjustment deflection signals to be transmitted through the reference pattern aperture, third adjustment deflection signals to be transmitted through the adjustment pattern aperture and deflected to the irradiation position and fourth adjustment deflection signals to be transmitted through the adjustment pattern aperture and deflected to the irradiation position. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a charged particle beam drawing system, and more particularly to a method for adjusting a charged particle beam irradiation apparatus that adjusts an irradiation position of a charged particle beam in character projection.

  With the miniaturization and high density of integrated circuits, charged particle beam irradiation devices that use electron beams, focused ion beams, etc. are also required to have stable operation, high throughput, and further fine workability as semiconductor device mass production equipment. . One of the drawing methods of a charged particle beam irradiation apparatus that satisfies such a requirement is a character projection (CP) method.

  In the CP method, a circuit pattern is drawn by exposing each graphic aperture corresponding to a plurality of divided drawing patterns. For example, in an electron beam drawing system, a figure aperture on an aperture mask is selected using a selective deflection unit of an electron beam irradiation apparatus, and an electron beam transmitted through the figure aperture is turned back on the beam axis. When the graphic aperture is selected by the selective deflecting unit having four stages of deflectors, the graphic aperture is selected by the first and second deflectors, and the electron beam is turned back on the beam axis by the third and fourth deflectors. The respective deflection signals of the first to fourth deflectors use the ratio of the deflection signals of the second to fourth deflectors with respect to the deflection signals of the first deflector, based on the design specifications for manufacturing the electron beam irradiation apparatus. Is set. Regardless of which figure aperture is selected, the transmitted electron beam is turned back to a certain position. Therefore, by design, it is incident on the imaging lens system at a fixed position, and the irradiation position where the electron beam is irradiated onto the substrate surface does not change.

  However, the actual first to fourth deflectors include manufacturing errors and errors that occur during installation. As a result, when a different figure aperture is selected, the position of the transmitted electron beam is shifted. Further, since the position of the electron beam incident on the imaging lens system is different, the irradiation position on the substrate surface is different. Therefore, the drawing connection accuracy of each drawing pattern is deteriorated on the substrate surface.

As a method for correcting the irradiation position of the electron beam, it has been proposed to measure the irradiation position deviation on the substrate surface in advance for each figure aperture and feed back the irradiation position deviation to the objective deflector (for example, Patent Document 1). reference.). However, the proposed correction method includes a step of obtaining an irradiation position deviation on the substrate surface when each graphic aperture is selected for all of the plurality of graphic apertures. Moreover, after selecting each figure aperture, the process of adjusting a beam axis again is included. Furthermore, the beam axis adjustment parameters must be prepared for the number of figure apertures. Therefore, when there are a large number of figure apertures, it takes an enormous amount of time to measure the irradiation position and beam axis adjustment for each figure aperture, and the amount of data including the beam axis adjustment parameters also becomes enormous.
Japanese Patent No. 3394233

  An object of the present invention is to provide a charged particle beam drawing system and a method for adjusting a charged particle beam irradiation apparatus that can adjust an irradiation position in a short time and can improve drawing connection accuracy.

  According to the first aspect of the present invention, (a) the first charged particle beam is deflected so as to pass through any one of a plurality of graphic apertures on a plane orthogonal to the beam axis of the charged particle beam. And a second deflector, and a charged particle beam irradiation apparatus having a third and a fourth deflector for deflecting the transmitted charged particle beam so as to swing back in the beam axis direction, and (b) deflecting the charged particle beam. The first to fourth deflection signals calculated from the first to fourth signal ratios defined by the ratio of the first to fourth deflection signals to the first deflection signal are respectively applied to the first to fourth deflectors. From the first to fourth signal ratios, the first to fourth signal ratios allow the charged particle beam to pass through the graphic selection deflection circuit and (c) the reference graphic aperture in the plurality of graphic apertures and irradiate the target irradiation position. 4 deflectors each The first to fourth reference deflection signals to be applied are calculated, and the first reference deflection signal is applied to the first deflector so that the charged particle beam passes through the adjustment figure aperture different from the reference figure aperture while applying the second reference deflection signal. Second adjustment deflection signal, first adjustment deflection signal, second and fourth references applied to the second deflector so that the charged particle beam passes through the reference figure aperture while applying the adjustment deflection signal and the first adjustment deflection signal. While applying the deflection signal, the third adjustment deflection signal applied to the third deflector so that the charged particle beam is deflected to the irradiation position, and the first adjustment deflection signal, the second and third reference deflection signals are being applied. A ratio of the first to fourth adjustment deflection signals to the first adjustment deflection signal is calculated using a fourth adjustment deflection signal applied to the fourth deflector so that the charged particle beam is deflected to the irradiation position. 4 signal ratio Charged particle beam writing system comprising a processing unit for integer is provided.

  According to the second aspect of the present invention, (a) the first and second deflection signals are respectively applied to the first and second deflectors to deflect the shaped charged particle beam, and the beam of the charged particle beam. One of a plurality of figure apertures on a plane orthogonal to the axis is transmitted, the third and fourth deflection signals are applied to the third and fourth deflectors, respectively, and the transmitted charged particle beam is deflected to be a beam axis. In the adjustment method of the charged particle beam irradiation apparatus that turns back in the direction, (b) the first deflection is performed so that the charged particle beam passes through the reference graphic aperture in the plurality of graphic apertures and irradiates the target irradiation position. First to fourth reference deflection signals to be applied to the first to fourth deflectors are obtained from the first to fourth signal ratios defined by the ratio of the first to fourth deflection signals to the signal, respectively. 2. Reference while applying reference deflection signal Detecting a first adjustment deflection signal applied to the first deflector so that the charged particle beam passes through an adjustment figure aperture different from the shape aperture, and (d) charging the reference figure aperture while applying the first adjustment deflection signal. A second adjustment deflection signal applied to the second deflector so that the particle beam is transmitted is detected, and (e) the adjustment figure aperture is transmitted while applying the first adjustment deflection signal, the second and fourth reference deflection signals, respectively. Detecting a third adjustment deflection signal applied to the third deflector so as to deflect the charged particle beam to the irradiation position, and (f) applying the first adjustment deflection signal and the second and third reference deflection signals, respectively. A fourth adjustment deflection signal applied to the fourth deflector is detected so as to deflect the charged particle beam transmitted through the adjustment figure aperture to the irradiation position, and (g) first to fourth adjustments with respect to the first adjustment deflection signal. Adjusting method of the charged particle beam irradiation system includes adjusting the first to fourth signal ratio by calculating the ratio of the deflection signal.

  According to the present invention, it is possible to provide a charged particle beam drawing system and a method for adjusting a charged particle beam irradiation apparatus that can adjust the irradiation position in a short time and improve the drawing connection accuracy. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and the configuration of the apparatus and system is different from the actual one. Therefore, a specific configuration should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different structures and the like are included between the drawings.

  The electron beam drawing system as the charged particle beam drawing system according to the embodiment of the present invention irradiates the surface of the substrate 60 with the electron beam EB transmitted through the first and second masks 16 and 26, as shown in FIG. And a control device 92 connected to the electron beam irradiation device (charged particle beam irradiation device) 90. The control device 92 includes a lens control circuit 42, a blanking deflection circuit 44, a figure selection deflection circuit 46, a beam deflection circuit 48, a signal processing circuit 50, a stage control circuit 52, a processing unit 54, an external memory 56, and the like.

  The electron beam irradiation apparatus 90 includes an electron gun 10 that emits an electron beam EB. The acceleration voltage of the electron gun 10 is, for example, 5 keV. A current limiting aperture mask 12 and a condenser lens 14 are disposed below the electron gun 10. By passing through the current limiting aperture mask 12 and the condenser lens 14, the current density of the electron beam EB and the Koehler illumination conditions are adjusted.

  A first mask 16 is disposed below the condenser lens 14. The first mask 16 shapes the shape of the electron beam EB into, for example, a rectangle. A projection lens 22 is disposed below the first mask 16.

  A second mask 26 is disposed below the projection lens 22. An image of the first mask 16 formed by irradiation with the electron beam EB is formed on the second mask 26 by the projection lens 22. The second mask 26 shapes the shape of the electron beam EB into the shape of a drawing pattern for drawing a circuit pattern.

  An imaging lens system 34 including a reduction lens 28 and an objective lens 32 is disposed below the second mask 26. By passing through the imaging lens system 34, the shape of the electron beam EB is reduced to 1/5, for example.

  A stage 38 for holding the substrate 60 is disposed below the objective lens 32. On the surface of the substrate 60, a resist film such as a resin having sensitivity to a charged particle beam is applied. The stage 38 is movable on a plane orthogonal to the incident direction of the electron beam EB. On the stage 38, a mark base 36 for measuring an electron beam and a Faraday cup 40 are arranged.

  A detector 35 is disposed between the imaging lens system 34 and the stage 38. The detector 35 scans the mark table 36 with respect to the reduced-projected electron beam EB, and detects a reflected electron signal from the mark table 36.

  A blanking deflection unit 18 and a blanking aperture mask 20 are disposed between the first mask 16 and the projection lens 22. When stopping the irradiation of the electron beam EB to the resist film on the substrate 60, the blanking deflection unit 18 deflects the electron beam EB transmitted through the first mask 16 onto the blanking aperture mask 20, and the electron beam EB is transferred to the substrate. The resist film on the upper surface 60 is prevented from reaching. The irradiation time of the electron beam EB imaged on the resist film on the substrate 60 is adjusted by stopping the irradiation of the electron beam EB to the resist film on the substrate 60 with the blanking deflector 18 and the blanking aperture mask 20. The irradiation amount of the electron beam EB at the irradiation position is adjusted.

  A selective deflection unit 24 is disposed between the projection lens 22 and the reduction lens 28 with the second mask 26 interposed therebetween. The selective deflection unit 24 controls the irradiation position of the electron beam EB on the second mask 26 by deflecting the electron beam EB transmitted through the projection lens 22, and the traveling direction of the electron beam EB transmitted through the second mask 26 is reduced. Deflection is performed in parallel with the beam axis of the lens 28. In this way, a drawing shape to be transferred to the resist film on the substrate 60 is selected.

  An objective deflection unit 30 is disposed in the vicinity of the objective lens 32. The objective deflection unit 30 deflects the electron beam EB formed by the first mask 16 and the second mask 26 and controls the irradiation position of the electron beam EB on the resist film surface on the substrate 60.

  The lens control circuit 42 of the control device 92 is connected to the condenser lens 14, the projection lens 22, the reduction lens 28, and the objective lens 32, and controls conditions such as illumination, projection, reduction, and image formation. The blanking deflection circuit 44 applies a deflection signal to the blanking deflection unit 18 and controls the irradiation amount of the electron beam EB to the resist film on the substrate 60. The figure selection deflection circuit 46 applies a deflection signal to the selection deflection unit 24 and selects a drawing shape of the electron beam EB irradiated on the resist film on the substrate 60. The beam deflection circuit 48 applies a deflection signal to the objective deflection unit 30 and controls the irradiation position of the electron beam EB irradiated on the resist film on the substrate 60.

  Since the deflector used in the selective deflection unit 24 and the objective deflection unit 30 needs to deflect the electron beam EB with high accuracy and high speed, an electrostatic deflector is used. The selective deflection unit 24 and the objective deflection unit 30 are configured by a plurality of deflectors in order to deflect the electron beam EB with high throughput and high accuracy. Furthermore, each deflector is provided with a plurality of deflection electrodes for minimizing deflection aberration.

  The stage control circuit 52 selects the substrate 60, the mark base 36, or the Faraday cup 40 by moving the stage 38. The signal processing circuit 50 processes the reflected electron signal from the mark base 36 detected by the detector 35 based on the scanning signal of the stage control circuit 52, and calculates the irradiation position and drawing shape of the electron beam EB.

  The processing unit 54 controls the lens control circuit 42, blanking deflection circuit 44, figure selection deflection circuit 46, beam deflection circuit 48, stage control circuit 52, etc. based on the design specifications of the electron beam irradiation apparatus 90, and The beam EB is irradiated onto the substrate 60, the mark base 36, or the Faraday cup 40.

  An external memory 56 and the like are connected to the processing unit 54. The external memory 56 includes pattern data such as circuit patterns and drawing patterns of the semiconductor device, position data of a plurality of graphic apertures of the second mask 26, design specifications of the electron beam irradiation apparatus 90, processing procedures for adjusting the irradiation position of the electron beam, and the like. Is stored.

  As shown in FIG. 2, the second mask 26 is provided with a plurality of irradiation areas 127a, 127b,. As shown in FIGS. 3 to 5, graphic apertures 27 a, 27 b,..., 27 n are provided in each of the plurality of irradiation areas 127 a to 127 n. Each of the plurality of graphic apertures 27a to 27n has a shape corresponding to a graphic of a drawing pattern that is frequently used when a circuit pattern of a semiconductor device is transferred.

  As shown in FIG. 6, the first deflector 25 a and the second deflector 25 b of the selective deflection unit 24 are provided on the first mask 16 side with respect to the second mask 26. The third deflector 25 c and the fourth deflector 25 d are provided on the opposite side of the first mask 16 with respect to the second mask 26.

  The figure selection deflection circuit 46 includes a signal control circuit 45, output circuits 47a, 47b, 47c, 47d and the like connected to the signal control circuit 45, respectively. The signal control circuit 45 is connected to the processing unit 54. Each of the output circuits 47a to 47d is connected to the first to fourth deflectors 25a to 25d. The processing unit 54 includes a control unit 70, a position detection unit 72, a signal detection unit 74, a calculation unit 76, an internal memory 80, and the like.

  The first mask 16 has a rectangular shaped aperture 17. An image of the shaping aperture 17 is formed on the second mask 26 by irradiating the first mask 16 with the electron beam EB. The image of the shaping aperture 17 on the second mask 26 substantially corresponds to the shape of each of the plurality of irradiation regions 127a to 127n. The position of the image of the shaping aperture 17 is arbitrarily set by the first and second deflectors 25a and 25b.

  An image of the rectangular shaped aperture 17 is formed around the first graphic aperture 27c or the second graphic aperture 27d among the plurality of graphic apertures 27a to 27n on the second mask 26. For example, the electron beam EB transmitted through the first graphic aperture 27c is returned to the beam axis by the third and fourth deflectors 25c and 25d. As a result, the electron beam EB formed into a drawing pattern having a shape corresponding to the first graphic aperture 27c is reduced and irradiated onto the substrate 60.

  The first deflector 25a receives the electron beam EB transmitted through the projection lens 22 shown in FIG. 1 toward the position on the second mask 26 where the image of the shaping aperture 17 is projected by the applied first deflection signal. To deflect. The second deflector 25b swings back the electron beam EB so that the electron beam EB is perpendicularly incident on the second mask 26 by the applied second deflection signal. The third deflector 25c deflects the electron beam EB transmitted through the second mask 26 toward the beam axis by the applied third deflection signal. The fourth deflector 25d swings back the electron beam EB so that the traveling direction of the electron beam EB is parallel to the beam axis by the applied fourth deflection signal.

  The voltage values of the first to fourth deflection signals vary depending on the position of the figure aperture to be selected in the second mask 26 plane. However, the ratio of the voltage values of the first to fourth deflection signals to the first deflection signal is constant even if the voltage values of the first to fourth deflection signals change. Accordingly, the position signal data corresponding to the positions of the graphic apertures 27a to 27n of the second mask 26 and the first to first voltages defined by the ratio of the respective voltage values of the first to fourth deflection signals with respect to the first deflection signal. The selective deflection unit 24 can be controlled by the fourth signal ratio.

  In the signal control circuit 45 of the figure selection deflection circuit 46, first to fourth signal ratios described in advance in the design specifications of the electron beam irradiation apparatus 90 are set. The signal control circuit 45 acquires the position signal data of the graphic aperture selected from the plurality of graphic apertures 27a to 27n via the processing unit 54, and generates a position signal corresponding to the position of the selected graphic aperture. To do. The first to fourth deflection signals calculated from the position signal and the first to fourth signal ratios are applied to the first to fourth deflectors 25a to 25d via the output circuits 47a to 47d.

  The electron beam EB deflected by the first and second deflectors 25a and 25b and transmitted through any of the plurality of graphic apertures 27a to 27n of the second mask 26 is turned back by the third and fourth deflectors 25c and 25d. Then, it proceeds toward the substrate 60 in parallel with the beam axis. Therefore, even if the electron beam EB is largely deflected by the first and second deflectors 25a and 25b on the second mask 26, the error of the irradiation position of the electron beam EB on the substrate 60 can be suppressed within an allowable range. It becomes.

  However, the transmitted electrons when different graphic apertures are selected due to errors that occur during the manufacture and attachment of the first to fourth deflectors 25a to 25d, or due to changes over time of the first to fourth deflectors 25a to 25d. The irradiation position of the beam may be shifted. For example, as shown in FIG. 7, the irradiation position of the electron beam EBa transmitted through the first graphic aperture 27c is shifted from the position x of the beam axis to (x + Δa) on the surface of the substrate 60. The irradiation position of the electron beam EBb transmitted through the second graphic aperture 27d is shifted to (x + Δb) on the surface of the substrate 60. As a result, the drawing connection accuracy of each drawing pattern on the surface of the substrate 60 deteriorates. When the drawing connection accuracy of the drawing pattern exceeds the allowable error range, the irradiation position of the electron beam irradiation device 90 is adjusted.

  The control means 70 of the processing unit 54 controls the irradiation position adjustment processing of the electron beam performed by the figure selection deflection circuit 46 based on the irradiation position adjustment processing procedure acquired from the external memory 56. The position detection means 72 detects the irradiation position of the electron beam EB that is deflected and adjusted by the figure selection deflection circuit 46 from the signal processing circuit 50. The signal detection unit 74 detects first to fourth deflection signals applied to the first to fourth deflectors 25 a to 25 d of the selection deflection unit 24 from the figure selection deflection circuit 46. The calculating unit 76 calculates the ratio of the first to fourth deflection signals with respect to the first deflection signal and adjusts the first to fourth signal ratios.

  The processing unit 54 may be configured as a part of a central processing unit (CPU) of a normal computer system. The control means 70, the position detection means 72, the signal detection means 74, and the calculation means 76 may each be configured by dedicated hardware, and use a CPU of a normal computer system, and are substantially equivalent functions in software. You may have. The internal memory 80 temporarily stores data being calculated or being processed during processing in the processing unit 54.

  The irradiation position adjustment of the electron beam irradiation apparatus 90 is performed as follows by controlling the signal control circuit 45, the position detection means 72, the signal detection means 74, and the calculation means 76 by the control means 70. In the description of the irradiation position adjustment, the first graphic aperture 27c and the second graphic aperture 27d are used as the reference graphic aperture and the adjustment graphic aperture, respectively.

  First, the first to fourth signals are obtained from the position signal corresponding to the position data of the first graphic aperture 27c selected as the reference graphic aperture from the plurality of graphic apertures 27a to 27n and the first to fourth signal ratios set in advance. A fourth reference deflection signal is calculated. Each of the first to fourth reference deflection signals is applied to the first to fourth deflectors 25a to 25d. The irradiation position (x + Δa) of the electron beam irradiated through the reference graphic aperture is detected.

  While applying each of the second to fourth reference deflection signals to the second to fourth deflectors 25b to 25d, the first deflector so that the electron beam is transmitted through the second graphic aperture 27d selected as the adjustment graphic aperture. The first adjustment deflection signal is applied to 25a. The applied first adjustment deflection signal is detected.

  While applying the first adjustment deflection signal and the third and fourth reference deflection signals to the first, third and fourth deflectors 25a, 25c, and 25d, respectively, the electron beam is transmitted through the first graphic aperture 27c. The second adjustment deflection signal is applied to the second deflector 25b. The applied second adjustment deflection signal is detected.

  While applying the first adjustment deflection signal, the second and fourth reference deflection signals to the first, second and fourth deflectors 25a, 25b and 25d, the electron beam transmitted through the second graphic aperture 27d is irradiated. A third adjustment deflection signal is applied to the third deflector 25c so as to irradiate (x + Δa). The applied third adjustment deflection signal is detected.

  Furthermore, the electron beam transmitted through the second graphic aperture 27d is applied to the irradiation position (x + Δa) while applying the first adjustment deflection signal, the second and third reference deflection signals to the first to third deflectors 25a to 25c, respectively. The fourth adjustment deflection signal is applied to the fourth deflector 25d so as to irradiate the light. The applied fourth adjustment deflection signal is detected.

  Thereafter, the ratio of the first to fourth adjustment deflection signals to the first adjustment deflection signal is calculated. The first to fourth signal ratios set in the signal control circuit 45 are adjusted by the calculated ratio. As a result, as shown in FIG. 8, the electron beams EBa and EBb deflected so as to pass through the first and second graphic apertures 27c and 27d by the first and second deflectors 25a and 25d, And it can irradiate to a fixed irradiation position by turning back to the beam axis by the fourth deflectors 25c and 25d.

  In the electron beam drawing system according to the embodiment, the adjustment of the irradiation position of the electron beam irradiation apparatus 90 is performed using the arbitrary two graphic apertures of the plurality of graphic apertures 27a to 27n to obtain the first to fourth signal ratios. Implemented by correcting. The electron beam transmitted through each of the plurality of graphic apertures 27a to 27n is controlled by the corrected first to fourth signal ratios to project the pattern of the selected graphic aperture onto a certain irradiation position. As a result, it is possible to improve the drawing connection accuracy of a pattern transferred to the surface of the substrate 60 using a plurality of graphic apertures.

  In addition to the irradiation position, the beam axis is also adjusted by adjusting the first to fourth signal ratios. Therefore, it is not necessary to measure the irradiation position and adjust the beam axis for all of the plurality of graphic apertures, and the irradiation position of the electron beam can be adjusted in a short time.

  In the embodiment, the selective deflection unit 24 including the first to fourth deflectors 25a to 25d is used. However, the selective deflection unit may be configured by only the first and second deflectors 25a and 25b. In this case, the deflector of the objective deflection unit 30 may be used in place of the third and fourth deflectors 25c and 25d.

  Next, an adjustment method and a semiconductor device manufacturing method according to the embodiment will be described with reference to a flowchart shown in FIG. In the signal control circuit 45 of the figure selection deflection circuit 46, the first to fourth signal ratios described in the design specifications of the electron beam irradiation apparatus 90 are set in advance. The control means 70 of the processing unit 54 acquires the irradiation position adjustment processing procedure stored in the external memory 56 and controls a series of adjustment processing.

  (A) In step S100, the signal control circuit 45, the reference position signal corresponding to the position data of the reference figure aperture selected from the plurality of figure apertures 27a to 27n, and the preset first to fourth signals. The first to fourth reference deflection signals are calculated from the ratio. Each of the first to fourth reference deflection signals is applied to the first to fourth deflectors 25a to 25d via the output circuits 47a to 47d. The signal processing circuit 50 calculates the reference irradiation position of the electron beam irradiated through the reference graphic aperture based on the reflected electron signal and the scanning signal received from the detector 35 and the stage control circuit 52. The position detection means 72 detects the reference irradiation position of the electron beam irradiated from the signal processing circuit 50 through the reference graphic aperture.

  (B) In step S101, the signal control circuit 45 applies an adjustment figure aperture different from the reference figure aperture to the electron beam while applying each of the second to fourth reference deflection signals to the second to fourth deflectors 25b to 25d. The first adjustment deflection signal is applied to the first deflector 25a so as to pass through. The signal detection unit 74 detects the first adjustment deflection signal from the signal control circuit 45.

  (C) In step S102, the signal control circuit 45 applies the first adjustment deflection signal and the third and fourth reference deflection signals to the first, third, and fourth deflectors 25a, 25c, and 25d, respectively. A second adjustment deflection signal is applied to the second deflector 25b so that the electron beam is transmitted through the reference graphic aperture. The signal detection unit 74 detects the second adjustment deflection signal from the signal control circuit 45.

  (D) In step S103, the signal control circuit 45 applies the first adjustment deflection signal and the second and fourth reference deflection signals to the first, second, and fourth deflectors 25a, 25b, and 25d, respectively. A third adjustment deflection signal is applied to the third deflector 25c so that the electron beam transmitted through the adjustment figure aperture is irradiated to the reference irradiation position. The signal detection unit 74 detects the third adjustment deflection signal from the signal control circuit 45.

  (E) In step S104, the signal control circuit 45 transmits the adjustment graphic aperture while applying the first adjustment deflection signal, the second and third reference deflection signals to the first to third deflectors 25a to 25c, respectively. A fourth adjustment deflection signal is applied to the fourth deflector 25d so that the electron beam irradiated to the reference irradiation position. The signal detection unit 74 detects the fourth adjustment deflection signal from the signal control circuit 45.

  (F) In step S105, the calculation means 76 calculates the ratio of the first to fourth adjustment deflection signals to the first adjustment deflection signal to adjust the first to fourth signal ratios.

  (G) In step S106, the calculation means 76 sets the corrected first to fourth signal ratios in the signal control circuit 45.

  (H) In step S107, the pattern of the plurality of graphic apertures 27a to 27n is transferred to the resist film applied to the surface of the substrate 60 such as a semiconductor substrate by the electron beam drawing system in which the irradiation position of the electron beam is adjusted. The semiconductor device is manufactured by processing the substrate 60 using the transferred pattern as a mask.

  As a result, as shown in FIG. 8, the electron beams EBa and EBb deflected so as to pass through the first and second graphic apertures 27c and 27d by the first and second deflectors 25a and 25d, And it can irradiate to a fixed irradiation position by turning back to the beam axis by the fourth deflectors 25c and 25d.

  In the adjustment method according to the embodiment, the adjustment of the irradiation position of the electron beam irradiation apparatus 90 adjusts the first to fourth signal ratios using any two graphic apertures among the plurality of graphic apertures 27a to 27n. Is implemented. The electron beam transmitted through each of the plurality of graphic apertures 27a to 27n is controlled by the corrected first to fourth signal ratios to project the pattern of the selected graphic aperture onto a certain irradiation position. As a result, it is possible to improve the drawing connection accuracy of a pattern transferred to the surface of the substrate 60 using a plurality of graphic apertures.

  In addition to the irradiation position, the beam axis is also adjusted by correcting the first to fourth signal ratios. It is not necessary to measure the irradiation position and adjust the beam axis for all of the plurality of graphic apertures. Therefore, the irradiation position of the electron beam can be adjusted in a short time.

(Other embodiments)
Although the embodiments of the present invention have been described as described above, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  In the embodiment of the present invention, the electron beam lithography system has been described as the charged particle beam lithography system. However, the charged particle beam is not limited to an electron beam. For example, an ion beam or the like may be used as the charged particle beam.

  As described above, the present invention naturally includes various embodiments that are not described herein. Accordingly, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

It is the schematic which shows an example of the electron beam drawing system which concerns on embodiment of this invention. It is the schematic which shows an example of the 2nd mask used for description of embodiment of this invention. It is the schematic which shows an example of the figure aperture used for description of embodiment of this invention. It is the schematic which shows the other example of the figure aperture used for description of embodiment of this invention. It is the schematic which shows the other example of the figure aperture used for description of embodiment of this invention. It is the schematic which shows an example of control of the selection deflection | deviation part which concerns on embodiment of this invention. It is the schematic which shows an example of the electron beam deflected before the adjustment by the selective deflection part which concerns on embodiment of this invention. It is the schematic which shows an example of the electron beam deflected after adjustment in the selective deflection part concerning an embodiment of the invention. It is a flowchart which shows an example of the adjustment method which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Electron gun 12 ... Current limiting aperture mask 14 ... Condenser lens 16 ... 1st mask 17 ... Molding aperture 18 ... Blanking deflection part 20 ... Blanking aperture mask 22 ... Projection lens 24 ... Selection deflection part 25a ... 1st deflector 25b ... second deflector 25c ... third deflector 25d ... fourth deflector 26 ... second mask 27a, 27b, 27n ... graphic aperture 27c ... first graphic aperture 27d ... second graphic aperture 28 ... reducing lens 30 ... objective Deflection section 32 ... Objective lens 34 ... Imaging lens system 35 ... Detector 36 ... Mark stand 38 ... Stage 40 ... Faraday cup 42 ... Lens control circuit 44 ... Blanking deflection circuit 45 ... Signal control circuit 46 ... Graphic selection deflection circuit 47a ˜47d: output circuit 48: beam deflection circuit 50: signal processing circuit 2 ... stage control circuit 54 ... processing unit 56 ... external memory 60 ... substrate 70 ... control means 72 ... position detecting means 74 ... signal detecting means 76 ... calculating means 80 ... internal memory 90 ... electron beam irradiation device 92 ... control device

Claims (5)

First and second deflectors for deflecting the shaped charged particle beam so as to transmit any of a plurality of graphic apertures on a plane orthogonal to the beam axis of the charged particle beam, and the transmitted charged particle beam A charged particle beam irradiation apparatus having third and fourth deflectors for deflecting the beam so as to swing back in the beam axis direction;
Each of the first to fourth deflection signals calculated from the first to fourth signal ratios defined by the ratio of the first to fourth deflection signals to the first deflection signal so as to deflect the charged particle beam. A figure selection deflection circuit to be applied to each of the first to fourth deflectors;
From the first to fourth signal ratios to the first to fourth deflectors so that the charged particle beam passes through a reference graphic aperture in the plurality of graphic apertures and irradiates a target irradiation position. First to fourth reference deflection signals to be applied are calculated and applied to the first deflector so that the charged particle beam passes through an adjustment figure aperture different from the reference figure aperture while applying the second reference deflection signal. A first adjustment deflection signal to be applied; a second adjustment deflection signal to be applied to the second deflector so that the charged particle beam passes through the reference graphic aperture while applying the first adjustment deflection signal; and the first adjustment. A third adjustment deflection signal applied to the third deflector so that the charged particle beam is deflected to the irradiation position while applying a deflection signal, the second and fourth reference deflection signals; and Using the fourth adjustment deflection signal applied to the fourth deflector so that the charged particle beam is deflected to the irradiation position while applying the first adjustment deflection signal and the second and third reference deflection signals. A charged particle beam drawing system comprising: a processing unit that calculates a ratio of the first to fourth adjustment deflection signals to the first adjustment deflection signal to adjust the first to fourth signal ratios.   The charged particle beam drawing system according to claim 1, wherein the charged particle beam is an electron beam. The first and second deflection signals are respectively applied to the first and second deflectors to deflect the shaped charged particle beam, and any one of a plurality of graphic apertures on a plane orthogonal to the beam axis of the charged particle beam. Adjustment of the charged particle beam irradiation apparatus which transmits the first and fourth deflection signals to the third and fourth deflectors, deflects the transmitted charged particle beam and returns it to the beam axis direction. In the method
The ratio of the first to fourth deflection signals with respect to the first deflection signal is defined so that the charged particle beam passes through a reference graphics aperture in the plurality of graphics apertures and irradiates a target irradiation position. Obtaining the first to fourth reference deflection signals to be applied to the first to fourth deflectors, respectively, from the first to fourth signal ratios,
Detecting a first adjustment deflection signal applied to the first deflector so that the charged particle beam passes through an adjustment figure aperture different from the reference figure aperture while applying the second reference deflection signal;
Detecting a second adjustment deflection signal applied to the second deflector so that the charged particle beam passes through the reference graphic aperture while applying the first adjustment deflection signal;
Applying a first adjustment deflection signal, a second reference deflection signal, and a fourth reference deflection signal to the third deflector so as to deflect the charged particle beam transmitted through the adjustment figure aperture to the irradiation position; Detect the adjustment deflection signal,
Applying a first adjustment deflection signal, a second reference deflection signal, and a third reference deflection signal to the fourth deflector so as to deflect the charged particle beam transmitted through the adjustment figure aperture to the irradiation position; Detect the adjustment deflection signal,
A method for adjusting a charged particle beam irradiation apparatus, comprising: calculating a ratio of the first to fourth adjustment deflection signals to the first adjustment deflection signal to adjust the first to fourth signal ratios.   4. The method for adjusting a charged particle beam irradiation apparatus according to claim 3, wherein the charged particle beam is an electron beam.   The first to fourth deflection signals are calculated from a position signal corresponding to a position in the plane of a graphic aperture selected from the plurality of graphic apertures and the first to fourth signal ratios. The method for adjusting a charged particle beam irradiation apparatus according to claim 3 or 4,

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