JP6000695B2 - Charged particle beam drawing apparatus and charged particle beam drawing method - Google Patents

Description

  The present invention relates to a charged particle beam writing apparatus and a charged particle beam writing method.

  With the recent high integration and large capacity of large scale integrated circuits (LSIs), circuit line widths required for semiconductor devices are becoming increasingly smaller. In order to form a desired circuit pattern on a semiconductor device, a lithography technique is used. In this lithography technique, pattern transfer using an original pattern called a mask (reticle) is performed. In order to manufacture a high-accuracy mask used for this pattern transfer, a charged particle beam drawing apparatus having an excellent resolution is used.

  As an example of this charged particle beam drawing apparatus, a drawing pattern drawn on a sample such as a mask or a blank is divided into a plurality of stripe regions, and each stripe region is divided into a number of sub-regions, and the sample is placed. A charged particle beam lithography system has been developed that moves the stage in the longitudinal direction of the stripe area, positions the electron beam in each sub-area by main deflection, and draws a figure by shooting at a predetermined position in the sub-area by sub-deflection. Yes.

  In such a charged particle beam drawing apparatus, the drawing time increases as the drawing pattern becomes finer (for example, about several tens of hours), and an earthquake may occur during the drawing. Due to the occurrence of an earthquake during the drawing, the drawing accuracy of the drawing pattern is lowered, and in some cases, a pattern error that causes the drawing accuracy to be outside the allowable range occurs. For this reason, when the seismic intensity of an earthquake becomes larger than an allowable value during drawing, the drawing is usually stopped by a manual operation, and the mask is discarded by scrap processing or the like.

  On the other hand, in addition to the drawing cancellation by the above-mentioned manual operation, a technique for executing a predetermined earthquake countermeasure operation in response to an earthquake alarm has been proposed for the purpose of facilitating recovery after the earthquake (for example, a patent) Reference 1). Alternatively, for the purpose of minimizing earthquake damage in semiconductor manufacturing equipment, earthquake vibration is predicted based on earthquake information and environmental information of the location where the semiconductor manufacturing equipment is installed, and the prediction result A technique for executing earthquake countermeasures based on this has also been proposed (see, for example, Patent Document 2). In addition, for the purpose of reducing damage to the manufacturing apparatus due to earthquake vibration, a technique for executing an earthquake countermeasure based on earthquake information and information indicating the state of the manufacturing apparatus has been proposed (for example, Patent Documents). 3).

JP 2001-134865 A JP 2008-218508 A JP 2009-10233 A

  However, with the technique as described above, drawing is stopped according to the seismic intensity of the earthquake, regardless of the drawing pattern drawing accuracy. Usually, even if the seismic intensity of the earthquake is larger than the allowable value, if the drawing accuracy required for the drawing pattern is low, a pattern error does not occur, and there is no need to stop drawing. Nevertheless, if the seismic intensity of the earthquake becomes larger than the allowable value, the drawing is stopped. In this manner, drawing efficiency is reduced because drawing is unnecessarily stopped regardless of the drawing accuracy required for the drawing pattern. On the other hand, when the drawing accuracy required for the drawing pattern is high, even if the seismic intensity of the earthquake is below the allowable value, it is necessary to stop drawing because of a pattern error, but the seismic intensity of the earthquake is larger than the allowable value. The drawing will not be stopped unless it becomes necessary. As described above, appropriate drawing according to the required drawing accuracy is not interrupted or stopped, and the drawing pattern drawing accuracy is lowered.

  Also, in drawing that irradiates the electron beam while moving the stage, even if a stop interrupt that stops the emission of the electron beam in response to the occurrence of an earthquake is instructed during drawing, the hardware is still in the drawing process. It takes time to execute the emission stop process, or the stop interrupt is delayed by software that prioritizes drawing. For this reason, since the emission stop process is not performed quickly and drawing cannot be completely stopped before the earthquake arrives, the drawing pattern drawing accuracy decreases due to vibration caused by the earthquake arrival. Further, when the emission of the electron beam is stopped, a defect due to the stop of the emission of the electron beam (for example, the stabilization waiting time of the electron beam when drawing is resumed) occurs, and the drawing efficiency is lowered. Furthermore, since the sample whose drawing has been stopped in the middle of drawing is discarded, drawing is started again from the beginning, so that drawing work that takes several tens of hours is wasted, and drawing efficiency is lowered.

  The problem to be solved by the present invention is to provide a charged particle beam drawing apparatus and a charged particle beam drawing method capable of suppressing a reduction in drawing efficiency and drawing accuracy due to earthquake vibration.

A second charged particle beam drawing apparatus according to an embodiment of the present invention includes a stage that supports a sample, a stage moving unit that moves the stage in a plane direction, and a sample on the stage that is moved by the stage moving unit. A charged particle beam is applied to the sample on the stage by the drawing unit while moving the stage in the plane direction by the stage moving unit by the drawing unit that performs drawing by deflecting and irradiating the charged particle beam to the beam, the earthquake early warning receiving unit Is a drawing control unit that performs drawing by deflecting irradiation, and when the earthquake early warning is received by the early warning receiving unit, the stage moving by the stage moving unit is stopped, and the charged particle beam on the sample on the stopped stage is and a drawing control unit to complete the entire drawing deflection region being deflected radiation, the drawing control unit stops the movement of the stage by the stage moving section If, Ru retracts the stage by the stage moving portion in a direction opposite to the movement direction of the stage in the case of performing drawing.

  In the second charged particle beam drawing apparatus, it is preferable that the drawing control unit changes the retract distance of the stage by the stage moving unit according to the seismic intensity of the earthquake.

  According to the present invention, it is possible to suppress a reduction in drawing efficiency and drawing accuracy due to earthquake vibration.

1 is a diagram showing a schematic configuration of a charged particle beam drawing apparatus according to a first embodiment of the present invention. It is explanatory drawing for demonstrating the shot data generation which the charged particle beam drawing apparatus shown in FIG. 1 performs. It is explanatory drawing for demonstrating the allowable value and stop value of the seismic intensity for every drawing precision level which the charged particle beam drawing apparatus shown in FIG. 1 uses. 3 is a flowchart showing a flow of drawing processing performed by the charged particle beam drawing apparatus shown in FIG. 1. It is a figure which shows schematic structure of the charged particle beam drawing apparatus which concerns on the 2nd Embodiment of this invention. It is explanatory drawing for demonstrating the stage stop operation | movement which the charged particle beam drawing apparatus shown in FIG. 5 performs. It is a flowchart which shows the flow of the drawing process which the charged particle beam drawing apparatus shown in FIG. 5 performs. It is a block diagram which shows schematic structure of the modification of the drawing control part with which the charged particle beam drawing apparatus shown in FIG. 5 is provided. It is explanatory drawing for demonstrating the retraction distance level information which the drawing control part shown in FIG. 8 uses.

(First embodiment)
A first embodiment will be described with reference to FIGS.

  As shown in FIG. 1, the charged particle beam drawing apparatus 1 according to the first embodiment includes a drawing unit 2 that performs drawing using a charged particle beam, and a control unit 3 that controls the drawing unit 2. The charged particle beam drawing apparatus 1 is an example of a variable shaping type drawing apparatus using, for example, an electron beam as a charged particle beam. The charged particle beam is not limited to the electron beam, and may be another charged particle beam such as an ion beam.

  The drawing unit 2 includes a drawing chamber 2a that houses a sample W to be drawn, and an optical barrel 2b that communicates with the drawing chamber 2a. The optical barrel 2b is provided on the upper surface of the drawing chamber 2a, and shapes and deflects an electron beam and irradiates the sample W in the drawing chamber 2a.

  In the drawing chamber 2a, a stage 11 that supports the sample W, a stage moving unit 12 that moves the stage 11 in a plane direction, and an imaging unit 13 for alignment that positions the sample W with respect to the stage 11 are provided. ing. As the imaging unit 13, for example, a CCD (charge coupled device) camera or the like can be used. The stage 11 is formed to be movable in the X direction and the Y direction orthogonal to each other in a horizontal plane, and a sample W such as a mask or a blank is placed on the placement surface of the stage 11. The stage moving unit 12 is a moving mechanism that moves the stage 11 in the X direction and the Y direction within a horizontal plane. A vibration sensor 14 for detecting vibration is provided on the outer peripheral surface of the drawing chamber 2a. As this vibration sensor 14, an acceleration sensor etc. can be used, for example, The number of installation is not specifically limited.

  In the optical barrel 2b, an electron gun 21 for emitting an electron beam B, an illumination lens 22 for condensing the electron beam B, a first shaping aperture 23 for beam shaping, and a projection lens 24 for projection. A shaping deflector 25 for beam shaping, a second shaping aperture 26 for beam shaping, an objective lens 27 for focusing the beam on the sample W, and sub-deflection for controlling the beam shot position with respect to the sample W. A device 28 and a main deflector 29 are arranged.

  In such a drawing unit 2, the electron beam B is emitted from the electron gun 21 and is irradiated onto the first shaping aperture 23 by the illumination lens 22. The first shaping aperture 23 has, for example, a rectangular opening. Thereby, when the electron beam B passes through the first shaping aperture 23, the cross-sectional shape of the electron beam is shaped into a rectangular shape and projected onto the second shaping aperture 26 by the projection lens 24. The projection position can be deflected by the shaping deflector 25, and the shape and size of the electron beam B can be controlled by changing the projection position. Thereafter, the electron beam B that has passed through the second shaping aperture 26 is irradiated with the focus of the electron beam B being adjusted to the sample W on the stage 11 by the objective lens 27. The shot position of the electron beam B with respect to the sample W on the stage 11 can be controlled by the sub deflector 28 and the main deflector 29.

  The control unit 3 includes a drawing data storage unit 31 that stores drawing data, a shot data generation unit 32 that processes the drawing data to generate shot data, a drawing control unit 33 that controls the drawing unit 2, an earthquake A seismic intensity receiver 34 that receives seismic intensity information, a misalignment detector 35 that detects the misalignment of the sample W on the stage 11, and a drift detector 36 that detects the drift of the electron beam B are provided. Yes. Note that the above-described units are configured by hardware, software, or both.

  The drawing data storage unit 31 is a storage unit that stores drawing data for drawing a pattern on the sample W. The drawing data is data obtained by allowing design data (layout data) created by a semiconductor integrated circuit designer or the like to be input to the charged particle beam drawing apparatus 1, that is, converted into a format for the charged particle beam drawing apparatus 1. Yes, it is input from the external device to the drawing data storage unit 31 and stored. For example, a magnetic disk device or a semiconductor disk device (flash memory) can be used as the drawing data storage unit 31.

  The design data described above usually includes a large number of minute patterns, and the amount of data is considerably large. If this design data is converted into another format as it is, the data amount after conversion further increases. For this reason, in the drawing data, the amount of data is reduced by a method such as data hierarchization or pattern array display. Such drawing data is data that defines a drawing pattern of a chip area or a drawing pattern of a virtual chip area that is virtually merged into a plurality of chip areas that have the same drawing conditions. .

  As shown in FIG. 2, the shot data generation unit 32 divides the drawing pattern P defined by the drawing data into a plurality of striped (strip-shaped) stripe regions R1, and each stripe region R1 has a matrix shape. Divide into a number of sub-regions R2. In addition, the shot data generation unit 32 determines the shape, size, position, and the like of the figure Z in each sub-region R2, and if the figure Z cannot be drawn with a single shot, the drawing is generated. The shot data is generated by dividing into a plurality of possible partial areas. The length of the stripe region R1 in the short direction (Y direction) is set to a length that allows the electron beam B to be deflected by main deflection.

  The drawing control unit 33 positions the electron beam B in each sub-region R2 by the main deflector 29 while moving the stage 11 in the longitudinal direction (X direction) of the stripe region R1 when drawing the drawing pattern P described above. Then, the figure Z is drawn by shooting at a predetermined position of the sub-region R2 by the sub-deflector 28. Thereafter, when drawing of one stripe region R1 is completed, the stage 11 is moved stepwise in the Y direction, and then the next stripe region R1 is drawn. This is repeated, and the entire drawing region of the sample W is irradiated with the electron beam B. Draw. Since the stage 11 is continuously moving in one direction during drawing, the drawing origin of the sub-region R2 is tracked by the main deflector 29 so that the drawing origin follows the movement of the stage 11. Yes.

  Thus, the irradiation position of the electron beam B is determined while following the stage 11 which is deflected by the sub deflector 28 and the main deflector 29 and continuously moves. The drawing time can be shortened by continuously moving the stage 11 in the X direction and making the shot position of the electron beam B follow the movement of the stage 11. However, in the first embodiment, the stage 11 is continuously moved in the X direction. However, the present invention is not limited to this. For example, one stage R2 is drawn while the stage 11 is stopped. However, when moving to the next sub-region R2, a step-and-repeat drawing method in which drawing is not performed may be used.

  The above-described drawing control unit 33 includes a drawing accuracy level information storage unit 33a that stores drawing accuracy level information, and an interruption position information storage unit 33b that stores interruption position information. For example, a magnetic disk device or a semiconductor disk device (flash memory) can be used as the drawing accuracy level information storage unit 33a and the interruption position information storage unit 33b.

  The drawing accuracy level information is information in which an allowable value and a stop value of seismic intensity are set for each drawing accuracy level of the drawing pattern P. The seismic intensity tolerance is a value that completely stops drawing when the seismic intensity is greater than the tolerance, and the seismic intensity stop value interrupts drawing when the seismic intensity is greater than or equal to the stopping value. It is a value to do. The interruption position information is information for specifying the stripe region R1 and the subregion R2 when the drawing is interrupted, for example, position information such as a stripe number and a subnumber. This interruption position information is used when the drawing interruption is released, and drawing is resumed from the interruption position.

  Here, for example, as shown in FIG. 3, when the drawing accuracy level of the drawing pattern P is level 1, the allowable value of seismic intensity is 5, the stop value is 4, and the drawing accuracy of the drawing pattern P When the level is level 2, the allowable value of seismic intensity is 4, the stop value is 3, and when the drawing accuracy level of the drawing pattern P is level 3, the allowable value of seismic intensity is 3. The stop value is 2. Thus, the higher the drawing accuracy level, the higher the drawing accuracy, and conversely, the seismic intensity tolerance value and the stop value become smaller.

  Such drawing accuracy level information is stored in advance in the drawing accuracy level information storage unit 33a, and the allowable value and stop value of seismic intensity are set using the drawing accuracy level information. For example, when the drawing accuracy level of the drawing pattern P to be drawn is level 1, the allowable value of seismic intensity is set to 5, and further, the stop value of seismic intensity is set to 4. Similarly, in the case of other drawing accuracy levels, an allowable value and a stop value of seismic intensity are set according to the drawing accuracy level. Thereafter, the set seismic intensity tolerance and stop value are used, and the drawing process is executed. Thus, the allowable value and stop value of seismic intensity are set according to the drawing accuracy level of the drawing pattern P. In addition, the allowable value and the stop of the seismic intensity can be changed by an operator's input operation on an input unit (not shown) such as a keyboard or a mouse.

  The seismic intensity receiving unit 34 receives earthquake early warning or earthquake information from the vibration sensor 14. For example, the earthquake information of the earthquake early warning includes various types of information such as seismic intensity information about the seismic intensity of the earthquake and arrival time information about the arrival time. The earthquake information from the vibration sensor 14 is seismic intensity information related to the seismic intensity of the earthquake, for example, acceleration information. Therefore, the seismic intensity receiving unit 34 acquires the seismic intensity of the earthquake from the seismic intensity information of the emergency earthquake warning, or obtains the seismic intensity of the earthquake based on the seismic intensity information (for example, acceleration information) of the vibration sensor 14. The correlation between seismic intensity and acceleration is stored in advance by the seismic intensity receiving unit 34 as information such as graphs and tables, and acceleration is converted into seismic intensity from the correlation information and acceleration information.

  The displacement amount detection unit 35 detects the displacement amount of the sample W on the stage 11. The positional deviation amount detection unit 35 receives the image captured by the imaging unit 13 and detects the positional deviation amount of the sample W based on the received image (for example, a sample edge image). The imaging unit 13 is provided for alignment for positioning the sample W with respect to the stage 11 and images the edge of the sample W. Therefore, by comparing the edge image captured before drawing with the edge image captured immediately before resuming drawing, the amount of displacement of the sample W due to the earthquake during drawing is calculated based on the amount of deviation of the edge images. It is possible to detect.

  The drift amount detector 36 scans and detects a reference mark (not shown) on the stage 11 to determine and determine the drift amount of the electron beam B from the difference between the current mark position and the previous mark position. The obtained drift amount is transmitted to the drawing control unit 33 as drift detection result data. The drift detection result data is saved by the drawing control unit 33 as necessary. The drawing controller 33 calculates a drift correction amount based on the received drift detection result data, controls the deflection amount of the electron beam B based on the calculated drift correction amount, and corrects the drift of the electron beam B. .

  Here, the reference mark is a mark for obtaining the drift amount, and is formed on the surface of the stage 11. For example, the reference mark is formed in a cross shape, and is formed of a material having a reflectance different from that of the surface. The detecting means for detecting the drift amount may be any means capable of obtaining the drift amount, and the means is not particularly limited.

  Next, a drawing process (drawing operation) performed by the above-described charged particle beam drawing apparatus 1 will be described.

  As shown in FIG. 4, first, drawing data is read from the drawing data storage unit 31, and drawing is started (step S1). Next, the drawing control unit 33 defines the drawing accuracy level of the drawing data based on the read drawing data (step S2).

  Here, the drawing data includes the drawing accuracy level of the drawing data, and the drawing control unit 33 defines the drawing accuracy level of the drawing data to be drawn from the drawing accuracy level. Based on the drawing accuracy level, an allowable value and a stop value of seismic intensity are set from the drawing accuracy level information stored in the drawing accuracy level information storage unit 33a.

  For example, when the drawing accuracy level included in the drawing data is level 1, the drawing accuracy level of the drawing pattern to be drawn is defined as level 1, and further corresponds to level 1 as shown in FIG. The seismic intensity tolerance is set to 5, and the seismic intensity stop value is set to 4. In addition, since the drawing accuracy of the drawing pattern depends on, for example, the line width of the circuit pattern, a circuit pattern with a narrow line width becomes a cut state depending on the amount of deviation of the pattern when the amount of deviation due to vibration increases. There is a tendency for higher drawing accuracy.

  Next, after the process of step S2, it is determined whether or not drawing has been completed (step S3). If it is determined that drawing has not been completed (NO in step S3), whether or not an earthquake (vibration) has occurred. Is determined (step S4), and if it is determined that an earthquake has not occurred (NO in step S4), drawing is executed (step S5), and the process returns to step S3. Thereby, drawing is continued until drawing is completed or an earthquake occurs. The occurrence of an earthquake is determined, for example, by whether or not earthquake information, in particular, seismic intensity information has been received by the seismic intensity receiver 34.

  Thereafter, when it is determined in step S3 that the drawing has been completed (YES in step S3), the drawing is stopped (step S6), and the process ends. If it is determined in step S4 that an earthquake has occurred (YES in step S4), it is determined whether or not the seismic intensity of the earthquake is greater than the allowable value set above (step S7). The seismic intensity of the earthquake is acquired from the seismic intensity information received by the seismic intensity receiving unit 34.

  If it is determined that the seismic intensity of the earthquake is greater than the allowable value (YES in step S7), the process proceeds to step S6. On the other hand, if it is determined that the seismic intensity of the earthquake is not greater than the allowable value, that is, is less than or equal to the allowable value (NO in step S7), it is determined whether or not the seismic intensity of the earthquake is greater than or equal to the stop value set above. (Step S8).

  If it is determined that the seismic intensity of the earthquake is not equal to or greater than the stop value (NO in step S8), the process proceeds to step S5. On the other hand, if it is determined that the seismic intensity is equal to or greater than the stop value (YES in step S8), the drawing is temporarily stopped (step S9).

  When the drawing is interrupted, the drawing control unit 33 completes the drawing of the sub-region R2 in the middle of drawing and then stops drawing by the drawing unit 2, and further, the stripe region R1 in which drawing by the drawing unit 2 is stopped and Information for specifying the sub-region R2, for example, position information such as a stripe number and a sub-number, is stored as interruption position information in the interruption position information storage unit 33b.

Thereafter, it is determined whether drawing can be resumed (step S10). If it is determined that drawing cannot be resumed (NO in step S10), the process proceeds to step S6.
On the other hand, if it is determined that drawing can be resumed (YES in step S10), calibration is performed (step S11), and the process proceeds to step S5.

  Here, in determining whether drawing can be resumed in step S <b> 10, it is determined whether the earthquake has converged based on the earthquake information from the vibration sensor 14. At this time, it is confirmed that the vibration is equal to or less than a predetermined allowable value, and the convergence of the earthquake is specified. In addition, it is confirmed whether or not the positional deviation amount of the sample W detected by the positional deviation amount detection unit 35 is equal to or smaller than a predetermined allowable value. If it is greater than the value, drawing is stopped. Furthermore, drawing is also stopped when the maximum seismic intensity detected from the earthquake information from the vibration sensor 14, that is, when the maximum acceleration is greater than a predetermined allowable value. Each allowable value is set in advance in the drawing control unit 33, but can be changed by an operator's input operation on an input unit (not shown) such as a keyboard or a mouse.

  In the calibration in step S <b> 11, the drift amount detection unit 36 detects the drift amount, that is, measures, and transmits the drift detection result data to the drawing control unit 33. The drawing control unit 33 obtains a drift correction amount based on the received drift detection result data, and further regenerates shot data from the restarted stripe region and sub-region based on the interruption position information, thereby obtaining the obtained drift correction. Drawing is performed while correcting the drift of the electron beam B based on the amount.

  As described above, according to the first embodiment, when seismic intensity information is received by the seismic intensity receiving unit 34, the drawing accuracy of the drawing pattern being drawn by the drawing unit 2 and the seismic intensity receiving unit 34 have received it. Drawing by the drawing unit 2 is stopped according to the seismic intensity of the seismic intensity information. Thereby, drawing is stopped according to the drawing accuracy required for the drawing pattern P in addition to the seismic intensity of the earthquake. Therefore, even if the seismic intensity of the earthquake is high, the required drawing accuracy of the drawing pattern is low, so that it is possible to suppress a reduction in drawing efficiency without causing a pattern error without stopping drawing. On the other hand, even if the seismic intensity of the earthquake is low, the required drawing accuracy of the drawing pattern is high, so that drawing is stopped and the occurrence of a pattern error is prevented, so that a reduction in drawing accuracy can be prevented.

  Further, when the drawing pattern P is divided into a plurality of stripe regions R1, the stripe region R1 is divided into a plurality of sub-regions R2, and drawing is performed by the drawing unit 2 for each stripe region R1, seismic intensity information is received by the seismic intensity receiving unit 34. If received, the drawing by the drawing unit 2 is stopped after the drawing of the sub-region R2 in the middle of drawing is completed, so that the drawing position before and after the drawing interruption is matched within the drawing interruption sub-region R2 when drawing is resumed. This eliminates the need to perform a simple process and allows drawing to be started easily when drawing is resumed, thereby improving drawing efficiency.

  In addition, by storing information specifying the stripe region R1 and the sub-region R2 where drawing by the drawing unit 2 has been stopped, it is possible to easily grasp the position where drawing was interrupted when drawing was resumed. Thereby, drawing can be restarted accurately from the position where drawing was interrupted, and as a result, highly accurate drawing can be performed. Furthermore, since it is possible to easily grasp the drawing restart position when drawing is resumed, drawing can be resumed immediately, and as a result, drawing efficiency can be improved.

  Further, when the drawing by the drawing unit 2 is resumed in accordance with the amount of positional deviation of the sample W detected by the positional deviation amount detection unit 35, the sample W is greatly displaced from a predetermined allowable value due to earthquake vibration. In this case, drawing is not resumed for the sample W. Accordingly, even if drawing is resumed, if drawing failure such as a pattern error occurs, drawing is not resumed, so that it is possible to prevent unnecessary drawing. Therefore, generation of useless drawing time can be suppressed and drawing efficiency can be improved.

  Further, a drift correction amount for correcting the drift amount of the electron beam B detected by the drift amount detection unit 36 is obtained, and drawing by the drawing unit 2 is resumed, so that the drawing of the electron beam B is resumed based on the drift correction amount after resuming drawing. Since drift can be corrected, drawing can be performed with high accuracy even after drawing is resumed.

(Second Embodiment)
A second embodiment will be described with reference to FIGS. In the second embodiment, differences from the first embodiment will be described, the same parts as those described in the first embodiment will be denoted by the same reference numerals, and the description thereof will also be omitted.

  As illustrated in FIG. 5, the charged particle beam drawing apparatus 1 according to the second embodiment does not include the imaging unit 13, the positional deviation amount detection unit 35, and the drift amount detection unit 36 according to the first embodiment ( (See FIG. 1). The drawing control unit 33 does not include the drawing accuracy level information storage unit 33a and the interruption position information storage unit 33b according to the first embodiment (see FIG. 1). The seismic intensity receiving unit 34 functions as a breaking news receiving unit that receives emergency earthquake breaking news (breaking news transmitted from an organization such as the Japan Meteorological Agency before arrival of main motion).

  The drawing control unit 33 stops the movement of the stage 11 by the stage moving unit 12 in response to the reception of the earthquake early warning by the seismic intensity receiving unit 34. Specifically, the drawing control unit 33 stops the movement of the stage 11 by the stage moving unit 12 when an earthquake early warning is received by the seismic intensity receiving unit 34, and the electron beam on the sample W on the stopped stage 11. All drawing in the deflection area where B is deflected, that is, the main deflection area is completed, and then the stage 11 is retracted in the direction opposite to the moving direction when drawing is performed.

  Here, as shown in FIG. 6, drawing is sequentially performed on the stripe region R1 in the drawing progress direction D1 (opposite to the moving direction of the stage 11 during drawing) (see the upper diagram in FIG. 6). . In FIG. 6, in the stripe region R1, a hatched region is a drawn region R1a, and a non-hatched region is an undrawn region R1b. Drawing is performed for each sub-region R2 with respect to the stripe region R1 in the main deflection region A1 called a window frame. Specifically, for example, the sub-region R2 is sequentially drawn from the bottom to the top in FIG. 6 on a part of the stripe region R1 that has entered the main deflection region A1 according to the movement of the stage 11. Go. The main deflection area A1 is an area of the sample W on the stage 11 that is irradiated with the electron beam B deflected by the main deflector 29.

  During such drawing, when an earthquake early warning is received by the seismic intensity receiver 34, the movement of the stage 11 by the stage moving unit 12 is stopped, and within the main deflection area A1 of the sample W on the stage 11 at the stop position. In other words, all the drawing of all sub-regions R2 in the main deflection region A1 is completed (see the central view in FIG. 6). That is, when the stage 11 stops, the drawing is in a window frame waiting state after sufficiently drawing a pattern that can be drawn at the stop position (all patterns in the main deflection area A1).

  The drawing time for drawing the vertical row (vertical row in FIG. 6) of the sub-region R2 described above is, for example, 250 ms (milliseconds), and is usually several hundred ms, which is 1 second or less. After the stage 11 is stopped, all the sub-regions R2 in the main deflection region A1 to be drawn become a vertical row of the sub-region R2 at the maximum, and the minimum is one of the sub-regions R2. Therefore, the time required to complete the drawing of all the sub-regions R2 in the main deflection region A1 from the stop of the stage 11 is several hundred ms at most and is one second or less. For this reason, there is a problem of the distance between the epicenter and the place where the charged particle beam drawing apparatus 1 is installed, but it takes at least several seconds to reach the earthquake if the installation location is several tens of kilometers away from the epicenter. It is sufficiently possible to complete all the drawing of all the sub-regions R2 in the main deflection region A1. As an example, the vertical width (length in the vertical direction in FIG. 6) of the stripe region R1 is 512 μm, and the horizontal width (length in the horizontal direction in FIG. 6) of the sub-region R2 is 25.6 μm.

  When the drawing after the stop of the stage 11 is completed, the stage 11 is retracted in the direction opposite to the moving direction when drawing is performed while the window frame waiting state is maintained. That is, the main deflection area A1 is drawn in the drawing traveling direction. It moves in the direction D2 opposite to D1 (see the lower diagram in FIG. 6). At this time, if the stage 11 retreats in the same direction as the moving direction when drawing, drawing is resumed. In order to prevent this, it is necessary to retract the stage 11 in the direction opposite to the moving direction for drawing.

  Here, the retreat distance of the stage 11 is set in advance in the drawing control unit 33 as a predetermined distance, but is not limited to this. For example, the retraction distance of the stage 11 is determined by the drawing control unit 33 according to the seismic intensity of the earthquake. May be changed. In this case, it is possible to grasp the seismic intensity of the earthquake using the seismic intensity information in the earthquake early warning.

  As described above, drawing is performed on a part of the stripe region R1 that has entered the main deflection region A1. For this reason, even if the stage 11 is stopped, the earthquake is large to some extent, and when the stage 11 vibrates after reaching the earthquake and a part of the stripe region R1 enters the main deflection region A1, drawing is resumed. . In this case, since the drawing is executed even after the earthquake arrives, the drawing accuracy is lowered. However, by retracting the stage 11 as described above, it is possible to prevent a part of the stripe region R1 from entering the main deflection region A1 due to the vibration of the stage 11 after reaching the earthquake. As a result, it is possible to suppress drawing execution after the arrival of the earthquake, that is, drawing execution during vibration, so that a reduction in drawing accuracy can be suppressed.

  Note that the drawing control unit 33 may stop the irradiation of the electron beam B on the sample W, for example, in addition to retracting the stage 11 described above. As an example, the drawing control unit 33 controls the shaping deflector 25 so that the electron beam B emitted from the electron gun 21 does not pass through the second shaping aperture 26. As a result, the electron beam B is blocked by the second shaping aperture 26, and the irradiation of the electron beam B on the sample W is stopped. Note that the emission of the electron beam B from the electron gun 21 may be stopped in order to more surely prevent the execution of drawing during vibration. However, a malfunction caused by the stop of the emission of the electron beam B (for example, drawing) In view of the occurrence of the stabilization waiting time of the electron beam B at the time of resumption, it is preferable that the stage 11 is retracted or blocked by the second shaping aperture 26 described above.

  Next, a drawing process (drawing operation) performed by the above-described charged particle beam drawing apparatus 1 will be described.

  As shown in FIG. 7, the drawing data is read from the drawing data storage unit 31, and drawing is started (step S21). Next, it is determined whether drawing has been completed (step S22). If it is determined that drawing has been completed (YES in step S22), the process ends. On the other hand, if it is determined that drawing has not been completed (NO in step S22), it is determined whether or not an earthquake (vibration) has occurred (step S23), and this determination is repeated until an earthquake occurs (step S23). NO of S23).

  In this way, the occurrence of earthquakes is constantly detected during drawing. The determination of the occurrence of the earthquake is made, for example, by determining whether or not an earthquake early warning is received by the seismic intensity receiving unit 34, and if it is determined that the earthquake early warning is received by the seismic intensity receiving unit 34, an earthquake has occurred. It is judged.

  Thereafter, when it is determined that an earthquake has occurred (YES in step S23), the stage 11 is stopped (step S24), and all drawing in the main deflection region A1 in the sample W on the stopped stage 11 is completed. (Step S25) In response to the completion, the stage 11 moves by a predetermined retraction distance in the direction opposite to the drawing movement direction (drawing movement direction) (Step S26).

  Next, it is determined whether or not drawing resumption is instructed (step S27), and this determination is repeated until drawing resumption is instructed (NO in step S27). If it is determined that drawing resumption is instructed (YES in step S27), the stage 11 moves in the drawing movement direction (step S28), drawing is resumed, and the process returns to step S22.

  Here, the drawing resumption instruction described above may be performed, for example, by the operator pressing the resumption button of the input unit after the earthquake has stopped, and the earthquake information from the vibration sensor 14, that is, The seismic intensity information may be received by the seismic intensity receiving unit 34, and it may be determined by determining from the seismic intensity information that the earthquake has stopped (for example, the vibration has become a predetermined value or less). In any case, the drawing control unit 33 determines whether or not the earthquake has stopped based on pressing of the restart button or seismic intensity information, and moves the stage 11 in the drawing moving direction when determining that the earthquake has stopped. To resume drawing.

  As described above, according to the second embodiment, when an earthquake early warning is received by the seismic intensity receiving unit 34, the stage moving unit 12 stops moving the stage 11, and the sample on the stopped stage 11 is stopped. In W, the entire drawing in the deflection region to which the electron beam B is deflected, that is, the main deflection region A1, is completed. Thereby, all the drawing in the main deflection area A1 is completed before the earthquake arrives, and the drawing is quickly stopped, so that it is possible to prevent the drawing accuracy from being lowered. Further, since the drawing is stopped only by stopping the movement of the stage 11, it is possible to prevent the occurrence of problems due to the stop of the emission of the electron beam B (for example, the stabilization waiting time of the electron beam B when drawing is resumed). As a result, a reduction in drawing efficiency can be suppressed. In addition, there is no need to discard samples that have been stopped during drawing, so there is no need to redo the drawing from the beginning, and drawing work that takes tens of hours is not wasted. can do.

  Further, by retreating the stage 11 by the stage moving unit 12 in the direction opposite to the moving direction of the stage 11 when drawing, the drawing restart due to the vibration of the stage 11 after the arrival of the earthquake is prevented as described above, and the arrival of the earthquake Since subsequent drawing execution, that is, drawing execution during vibration can be suppressed, it is possible to reliably prevent a reduction in drawing accuracy. In addition, when changing the retreat distance of the stage 11 by the stage moving part 12 according to the seismic intensity of an earthquake, since it becomes possible to suppress drawing execution during a vibration reliably, the fall of drawing accuracy is suppressed more reliably. can do. In addition, even when the irradiation of the electron beam B to the sample W by the drawing unit 2 is stopped, it is possible to suppress drawing execution during vibration, and thus it is possible to reliably prevent a reduction in drawing accuracy.

  Here, the case where the retreat distance of the stage 11 is changed according to the seismic intensity of the earthquake will be described in detail with reference to FIGS.

  As shown in FIG. 8, the drawing control unit 33 includes a retreat distance level information storage unit 33c that stores retreat distance level information. As the retreat distance level information storage unit 33c, for example, a ROM (Read Only Memory), a RAM (Random Access Memory), a semiconductor disk device (flash memory), a magnetic disk device, or the like can be used.

  As shown in FIG. 9, the retreat distance level information is information in which a retreat distance is set for each seismic intensity of the earthquake. In FIG. 9, as an example, when the seismic intensity is 1, the retreat distance is 5 cm, when the seismic intensity is 2, the retreat distance is 10 cm, and when the seismic intensity is 3, the retreat distance is 15 cm. Yes, when the seismic intensity is 4, the evacuation distance is 20 cm, when the seismic intensity is 5, the evacuation distance is 30 cm, and when the seismic intensity is 6, the evacuation distance is 40 cm and the seismic intensity is 7 In this case, the evacuation distance is 50 cm. As the seismic intensity increases, the retract distance of the stage 11 increases. The retreat distance level information is stored in advance in the retreat distance level information storage unit 33c.

  The drawing control unit 33 selects and determines the retreat distance corresponding to the seismic intensity of the earthquake grasped from the seismic intensity information from the retreat distance level information in the retreat distance level information storage unit 33c. For example, when the seismic intensity is 1, the retreat distance 5 cm corresponding to the seismic intensity 1 is selected, and the retreat distance is determined to be 5 cm. Similarly, when the seismic intensity is 5, the retreat distance 30 cm corresponding to the seismic intensity 5 is selected, and the retreat distance is determined to be 30 cm.

  In addition, as the evacuation distance level information, information in which the evacuation distance is set for each seismic intensity of the earthquake is used. However, the present invention is not limited to this. For example, the evacuation distance is set for each predetermined seismic intensity range. Information may be used. In this case, the drawing control unit 33 selects and determines the retreat distance corresponding to a predetermined seismic intensity range including the seismic intensity of the earthquake grasped from the seismic intensity information from the retreat distance level information.

  As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  In the first or second embodiment described above, the vibration sensor 14 is provided on the outer peripheral surface of the drawing chamber 2a. However, the present invention is not limited to this. For example, the site of the factory where the charged particle beam drawing apparatus 1 is installed. They may be provided at the four corners. The number of the vibration sensors 14 and the number of the four corners in the site are not limited. Of course, the installation location of the vibration sensor 14 is not limited.

DESCRIPTION OF SYMBOLS 1 Charged particle beam drawing apparatus 2 Drawing part 2a Drawing room 2b Optical barrel 3 Control part 11 Stage 12 Stage moving part 13 Imaging part 14 Vibration sensor 21 Electron gun 22 Illumination lens 23 First shaping aperture 24 Projection lens 25 Molding deflector 26 Second shaping aperture 27 Objective lens 28 Sub deflector 29 Main deflector 31 Drawing data storage unit 32 Shot data generation unit 33 Drawing control unit 33a Drawing accuracy level information storage unit 33b Interruption position information storage unit 33c Retraction distance level information storage Section 34 Seismic intensity receiving section 35 Position shift amount detection section 36 Drift amount detection section A1 Main deflection area B Electron beam D1 Drawing direction D2 Reverse direction of drawing progress R1 Stripe area R1a Drawn area R1b Undrawn area R2 Sub area W Sample

Claims (2)

A stage for supporting the sample;
A stage moving unit for moving the stage in a plane direction;
A drawing unit that performs drawing by deflecting a charged particle beam to the sample on the stage; and
A breaking news receiver for receiving earthquake early warnings;
A drawing control unit that performs drawing by deflecting and irradiating a sample on the stage with the drawing unit while moving the stage in a plane direction by the stage moving unit, and the emergency report receiving unit performs the emergency earthquake A drawing control unit for stopping the movement of the stage by the stage moving unit when a preliminary report is received, and completing the entire drawing in the deflection region where the charged particle beam is deflected and irradiated on the sample on the stopped stage; , equipped with a,
The drawing control unit, when stopping the movement of the stage by the stage moving portion, and wherein Rukoto by removing all the stage by the stage moving portion in a direction opposite to the movement direction of the stage for performing the drawing Charged particle beam writing device. The charged particle beam drawing apparatus according to claim 1 , wherein the drawing control unit changes a retreat distance of the stage by the stage moving unit according to a seismic intensity of the earthquake.

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