JP2014045151A - Method for setting settling time, charged particle beam lithography method and charged particle beam lithography device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for setting the suitable settling time in which a shot position accuracy of a pattern to be drawn is made more accurate.SOLUTION: A method for setting the settling time includes: a step S108 in which the settling time according to the movement amount of deflection set in a DAC (digital-analog converter) amplifier for a deflector to deflect the minimum deflection region among multi-stage deflectors to deflect charged particle beams by deflection signals from DAC amplifiers, is varied in accordance with order of shots of the charged particle beams; and a step S110 in which the varied settling time is set in the DAC amplifier for the deflector to deflect the minimum deflection region.

Description

  The present invention relates to a settling time setting method, a charged particle beam drawing method, and a charged particle beam drawing apparatus. For example, the present invention relates to a settling time setting method for a deflection amplifier that deflects an electron beam in the electron beam drawing apparatus.

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

FIG. 8 is a conceptual diagram for explaining the operation of the variable shaping type electron beam drawing apparatus.
The variable shaped electron beam (EB) drawing apparatus operates as follows. In the first aperture 410, a rectangular opening 411 for forming the electron beam 330 is formed. Further, the second aperture 420 is formed with a variable shaping opening 421 for shaping the electron beam 330 having passed through the opening 411 of the first aperture 410 into a desired rectangular shape. The electron beam 330 irradiated from the charged particle source 430 and passed through the opening 411 of the first aperture 410 is deflected by the deflector, passes through a part of the variable shaping opening 421 of the second aperture 420, and passes through a predetermined range. The sample 340 mounted on a stage that continuously moves in one direction (for example, the X direction) is irradiated. That is, the drawing area of the sample 340 mounted on the stage in which the rectangular shape that can pass through both the opening 411 of the first aperture 410 and the variable shaping opening 421 of the second aperture 420 is continuously moved in the X direction. Drawn on. A method of creating an arbitrary shape by passing both the opening 411 of the first aperture 410 and the variable shaping opening 421 of the second aperture 420 is referred to as a variable shaping method (VSB method).

  In a drawing apparatus, drawing is performed by deflecting a charged particle beam such as an electron beam with a deflector, and a DAC (digital / analog converter) amplifier is used for such beam deflection. The role of beam deflection using such a DAC amplifier includes, for example, control of the shape and size of the beam shot, control of the shot position, and beam blanking. In order to perform beam deflection, it is necessary to set the settling time of the DAC amplifier necessary to deflect the set movement amount without error. If the settling time is insufficient, an error occurs in the deflection movement amount. Also, if the settling time is too long, the throughput will deteriorate. For this reason, it is desirable to set the settling time as short as possible without causing an error.

  Here, as the accuracy and miniaturization of circuit patterns typified by semiconductor devices in recent years have progressed, electron beam lithography apparatuses are also required to have higher precision and improved throughput. For this reason, a slight positional variation of the pattern drawn at a desired position on the mask by the beam deflection described above also affects the dimensional accuracy in manufacturing the semiconductor circuit. For this reason, in the beam deflection using a DAC amplifier, the above-described settling time must be optimized particularly for shot position control (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2008-71986

  However, as the accuracy and miniaturization of recent patterns progress, the deflection voltage is applied to the deflector from the position deflection DAC amplifier that should have been set with the optimum settling time according to the amount of movement to be deflected However, it has been found that, among the beam shots deflected in the deflection region, the deflection position error is greater in the first shot than in the other shots thereafter.

  Therefore, an object of the present invention is to provide a technique for overcoming the above-described problems and setting a suitable settling time for making the shot position accuracy of a drawn pattern higher.

The settling time setting method of one embodiment of the present invention includes:
Of the multistage deflector that deflects the charged particle beam by the deflection signal from the DAC (digital / analog converter) amplifier, the settling time corresponding to the deflection movement amount set in the DAC amplifier for the deflector that deflects the minimum deflection region, Changing the charged particle beam according to the shot order;
Setting the variable settling time to a DAC amplifier for a deflector that deflects the minimum deflection region;
It is provided with.

  Further, when the settling time is varied, the offset time corresponding to the shot order is determined according to the deflection movement amount with reference to the correction table in which the offset time for correcting the settling time according to the shot order stored in the storage device is defined. It is preferable to add to the settling time.

  Alternatively, when the settling time is varied, the correction coefficient corresponding to the shot order is determined according to the deflection movement amount with reference to a correction table in which a correction coefficient for correcting the settling time according to the shot order stored in the storage device is defined. It is also preferable to configure so as to multiply the settling time.

The charged particle beam drawing method of one embodiment of the present invention includes:
Of the multistage deflector that deflects the charged particle beam by the deflection signal from the DAC (digital / analog converter) amplifier, the settling time corresponding to the deflection movement amount set in the DAC amplifier for the deflector that deflects the minimum deflection region, Changing the charged particle beam according to the shot order;
Setting the variable settling time to a DAC amplifier for a deflector that deflects the minimum deflection region;
Drawing a pattern on the sample by deflecting the charged particle beam using a deflector controlled with a settling time set; and
It is provided with.

The charged particle beam drawing apparatus of one embodiment of the present invention includes:
A plurality of DAC (digital-to-analog converter) amplifiers;
A multistage deflector for deflecting a charged particle beam by deflection signals from a plurality of DAC amplifiers;
A variable processing unit that varies a settling time according to a deflection movement amount set in a DAC amplifier for a deflector that deflects a minimum deflection region among multistage deflectors according to a shot order of a charged particle beam;
A setting unit for setting the variable settling time in a DAC amplifier for a deflector that deflects the minimum deflection region;
A drawing unit that draws a pattern on a sample by deflecting a charged particle beam using a deflector controlled with a settling time set, and
It is provided with.

  According to one aspect of the present invention, it is possible to set a suitable settling time that enables a pattern shot position to be drawn with higher accuracy while maintaining high throughput.

1 is a conceptual diagram illustrating a configuration of a drawing apparatus according to Embodiment 1. FIG. FIG. 3 is a conceptual diagram for explaining each region in the first embodiment. FIG. 5 is a diagram illustrating a relationship between a deflection position error and a shot order in the first embodiment. FIG. 4 is a flowchart showing main steps of the drawing method according to Embodiment 1. 6 is a diagram illustrating an example of a correction table according to Embodiment 1. FIG. FIG. 10 is a flowchart showing main steps of a drawing method according to Embodiment 2. FIG. 10 is a diagram showing an example of a correction table in the second embodiment. It is a conceptual diagram for demonstrating operation | movement of a variable shaping type | mold electron beam drawing apparatus.

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

Embodiment 1 FIG.
FIG. 1 is a conceptual diagram illustrating a configuration of a drawing apparatus according to the first embodiment. In FIG. 1, the drawing apparatus 100 includes a drawing unit 150 and a control unit 160. The drawing apparatus 100 is an example of a charged particle beam drawing apparatus. In particular, it is an example of a variable shaping type drawing apparatus. The drawing unit 150 includes an electron column 102 and a drawing chamber 103. In the electron column 102, there are an electron gun 201, an illumination lens 202, a blanking deflector 212, a blanking aperture 214, a first aperture 203, a projection lens 204, a deflector 205, a second aperture 206, and an objective lens 207. A main deflector 208 and a sub deflector 209 are arranged. An XY stage 105 is disposed in the drawing chamber 103. On the XY stage 105, a sample 101 such as a mask to be drawn at the time of drawing is arranged. The sample 101 includes an exposure mask for manufacturing a semiconductor device. Further, the sample 101 includes mask blanks to which a resist is applied and nothing is drawn yet.

  The control unit 160 includes a control computer 110, a memory 111, a deflection control circuit 120, DAC (digital / analog converter) amplifiers 130 and 132, and storage devices 140 and 142 such as a magnetic disk device. The control computer 110, the memory 111, the deflection control circuit 120, and the storage devices 140 and 142 are connected via a bus (not shown).

  In the control computer 110, a drawing data processing unit 60, a settling time calculation unit 62, a shot order acquisition unit 64, a correction value acquisition unit 66, a settling time correction unit 68, and a setting unit 69 are arranged. Functions such as the drawing data processing unit 60, the settling time calculation unit 62, the shot order acquisition unit 64, the correction value acquisition unit 66, the settling time correction unit 68, and the setting unit 69 may be configured by hardware such as an electric circuit. However, it may be configured by software such as a program for executing these functions. Alternatively, it may be configured by a combination of hardware and software. Information input to and output from the drawing data processing unit 60, settling time calculation unit 62, shot order acquisition unit 64, correction value acquisition unit 66, settling time correction unit 68, and setting unit 69 is stored in the memory 111. Stored each time.

  Here, FIG. 1 shows a configuration necessary for explaining the first embodiment. The drawing apparatus 100 may normally have other necessary configurations. For example, the main deflector 208 and the sub-deflector 209, which are the main and sub two-stage multi-stage deflectors, are used for position deflection, but the position deflection is performed by one stage deflector or three or more stages of multi-stage deflectors. It may be the case. Further, the drawing apparatus 100 may be connected to an input device such as a mouse and a keyboard, a monitor device, an external interface circuit, and the like.

  FIG. 2 is a conceptual diagram for explaining each region in the first embodiment. In FIG. 2, the drawing area 10 of the sample 101 is virtually divided into a plurality of strip-shaped stripe areas 20 that are the Y-direction deflectable width of the main deflector 208. Each stripe region 20 is virtually divided into a plurality of subfields (SF) 30 (small regions) that are the deflectable size of the sub deflector 209. Then, shot figures 52, 54, and 56 are drawn at each shot position of each SF30.

  A digital signal for blanking control is output from the deflection control circuit 120 to a DAC amplifier for blanking control (not shown). In the DAC amplifier for blanking control, the digital signal is converted into an analog signal, amplified, and then applied to the blanking deflector 212 as a deflection voltage. The electron beam 200 is deflected by the deflection voltage, and the irradiation time (irradiation amount) of each shot is controlled.

  A digital signal for main deflection control is output from the deflection control circuit 120 to the DAC amplifier 132. The DAC amplifier 132 converts the digital signal into an analog signal, amplifies it, and applies it to the main deflector 208 as a deflection voltage. The electron beam 200 is deflected by the deflection voltage, and the beam of each shot is deflected to the reference position of the target SF 30 which is virtually divided into a mesh shape.

  A digital signal for sub-deflection control is output from the deflection control circuit 120 to the DAC amplifier 130. The DAC amplifier 130 converts the digital signal into an analog signal, amplifies it, and applies it to the sub deflector 209 as a deflection voltage. The electron beam 200 is deflected by the deflection voltage, and the beam of each shot is deflected to each shot position in the target SF 30.

  In the drawing apparatus 100, drawing processing is performed for each stripe region 20 using a multistage deflector having a plurality of stages. Here, as an example, a two-stage deflector such as a main deflector 208 and a sub deflector 209 is used. While the XY stage 105 continuously moves in the −x direction, for example, the drawing is advanced in the x direction with respect to the first stripe region 20. Then, after the drawing of the first stripe region 20 is finished, the drawing of the second stripe region 20 proceeds in the same manner or in the reverse direction. Thereafter, similarly, drawing of the third and subsequent stripe regions 20 proceeds. Then, the main deflector 208 sequentially deflects the electron beam 200 to the reference position A of the SF 30 so as to follow the movement of the XY stage 105. Further, the sub deflector 209 deflects the electron beam 200 from the reference position A of each SF 30 to each shot position of the beam irradiated into the SF 30. As described above, the main deflector 208 and the sub deflector 209 have deflection areas having different sizes. The SF 30 is a minimum deflection area among the deflection areas of the multi-stage deflector.

  In the first embodiment, a method for setting an optimum settling time to be set in the DAC amplifier 130 for the sub deflector 209 that deflects the electron beam 200 at each shot position in the SF 30 serving as the minimum deflection region will be described below. , Explain with emphasis.

  FIG. 3 is a diagram showing the relationship between the deflection position error and the shot order in the first embodiment. The settling time to be set in the DAC amplifier 130 is set to an optimum time according to the amount of movement to be deflected. The longer the amount of movement, the longer the required settling time. If the settling time set for the movement amount is short, the deflection position error becomes large. On the other hand, if the length is too long, the time taken for one shot becomes longer, and the throughput of the apparatus is reduced. Therefore, the settling time has usually been adjusted so that the error is within an allowable range with respect to the amount of movement to be deflected. However, even when a deflection voltage is applied to the sub deflector 209 from the DAC amplifier 130 that should have been set to the optimum settling time according to the amount of movement, as shown in FIG. It has been found that the shot position error becomes large. One reason for this is considered that heat is generated due to voltage fluctuation of the DAC amplifier for the first shot in the SF 30 and the voltage immediately after that is not stable. In order to avoid this, for example, if the settling time for deflecting the inside of the SF 30 is lengthened, the error becomes small even at the first shot of writing of each SF 30 as shown in FIG. In order to cope with the dependent error, the settling time of all shots must be lengthened, which greatly reduces the throughput of the apparatus. Therefore, in the first embodiment, attention is paid to the shot order of each shot in the SF 30, and the settling time is varied according to the shot order.

  FIG. 4 is a flowchart showing main steps of the drawing method according to the first embodiment. 4, in the drawing method according to the first embodiment, a settling time calculation step (S102), a shot order acquisition step in SF (S104), a shot order dependent settling offset acquisition step (S106), and a settling time correction step ( A series of steps of S108), a setting step (S110), and a drawing step (S112) are performed. Among these steps, the settling time of the DAC amplifier includes a settling time calculation step (S102), an intra-SF shot order acquisition step (S104), a shot order dependent settling offset acquisition step (S106), and a settling time correction. A series of steps of the step (S108) and the setting step (S110) are performed.

  FIG. 5 is a diagram illustrating an example of a correction table in the first embodiment. First, a settling offset value corresponding to the shot order is obtained in advance by experiments or the like before drawing. Such an offset value depends on the shot order and is determined as a value that does not depend on the deflection movement amount. For example, shots having the same movement amount are shot in order within the SF 30, and the position error of each shot is measured. Then, the difference in position error between each shot is obtained. Then, an offset value (time) corresponding to the difference may be obtained. In the example of FIG. 5, for the first (first) beam shot in the SF, the offset value added to the appropriate settling time according to the deflection movement amount is, for example, 400 ns. For the second beam shot, the offset value added to the appropriate settling time according to the deflection movement amount is, for example, 200 ns. For the third beam shot, the offset value added to the appropriate settling time according to the deflection movement amount is, for example, 100 ns. For the fourth beam shot, the offset value added to the appropriate settling time according to the deflection movement amount is, for example, 70 ns. For the fifth beam shot, the offset value added to the appropriate settling time according to the deflection movement amount is, for example, 50 ns. For the sixth beam shot, the offset value added to the appropriate settling time according to the deflection movement amount is, for example, 30 ns. ... For the tenth and subsequent beam shots, for example, the offset value added to the appropriate settling time according to the deflection movement amount is 0 ns, for example. A correction table in which the correlation between the shot order and the settling offset value is defined is stored in the storage device 144.

  In performing the drawing process, the drawing data processing unit 60 first reads the drawing data from the storage device 140 and performs a plurality of stages of data conversion processing to generate apparatus-specific shot data. A plurality of graphic patterns are defined in the drawing data. However, in order to draw a graphic pattern with the drawing apparatus 100, it is necessary to divide the graphic pattern defined in the drawing data into a size that can be irradiated with a single beam shot. Therefore, the drawing data processing unit 60 generates shot figures by dividing each figure pattern into a size that can be irradiated with one beam shot in order to actually draw. Then, shot data is generated for each shot figure. In the shot data, for example, graphic data such as a graphic type, a graphic size, and an irradiation position are defined. In addition, the irradiation time according to the dose is defined. Shot data is defined by sorting in shot order. The generated shot data is stored in the storage device 142. By dividing into shot figures and generating shot data, the shot order of shot figures shot by each SF 30 can be known.

As the settling time calculation step (S102), the settling time calculation unit 62 is a DAC for the sub deflector 209 that deflects the minimum deflection area among the multistage deflectors that deflect the electron beam by the deflection signals from the DAC amplifiers 130 and 132. A settling time T corresponding to the deflection movement amount ΔL set in the amplifier 130 is calculated. The settling time T (normal settling time) set in the DAC amplifier 130 is a value obtained by adding the correction time α (ΔL) depending on the deflection movement amount ΔL to the minimum settling time T ₀ required for the DAC amplifier 130. Can be sought. The settling time T is calculated by the following equation (1) depending on the deflection movement amount ΔL.
(1) T = T ₀ + α (ΔL)

  Here, for example, the deflection movement in the x direction among the x and y directions in the deflection region is described. In this case, since the maximum deflection movement amount in the SF 30 is the SF 30 size, the deflection movement amount ΔL may be set to, for example, the SF 30 size. Therefore, one settling time T set for one DAC amplifier 130 for the sub deflector 209 is obtained here. In FIG. 1, each deflector is shown as a pair of electrodes. For example, 8 deflectors with four pairs of 0 degree direction, 45 degree direction, 90 degree direction, and 135 degree direction with respect to the x direction. It is preferable that the electrode is composed of polar electrodes. One DAC amplifier is prepared for each electrode of each pole. Then, a settling time T is obtained for each DAC amplifier. By using a unique settling time T for one DAC amplifier 130 for the sub deflector 209, the amount of data set can be reduced.

  As the in-SF shot order acquisition step (S104), the shot order acquisition unit 64 refers to the shot data and acquires the shot order in the rendered SF 30 for each shot figure.

  As the shot order-dependent settling offset acquisition step (S106), the correction value acquisition unit 66 refers to a correction table in which an offset time for correcting the settling time according to the shot order stored in the storage device 144 is defined for each shot graphic. Then, the offset time corresponding to the shot order in the SF 30 is acquired.

As the settling time correction step (S108), the settling time correction unit 68 (variable processing unit) sets the settling time T according to the deflection movement amount set in the DAC amplifier 130 for the sub deflector 209 to the SF of the electron beam 200. The correction is made by varying in accordance with the order of shots. Specifically, the settling time correction unit 68 refers to the correction table in which the offset time is defined, and sets the offset time β (i) corresponding to the shot order i to the settling time T (= Add to T ₀ + α (ΔL)).

As the setting step (S110), the setting unit 69 sets the corrected settling time T ′ (= T ₀ + α (ΔL) + β (i)) in the DAC amplifier 130 for the sub deflector 209. Specifically, the setting unit 69 outputs a control signal for setting the corrected settling time T ′ to the deflection control circuit 120, and the deflection control circuit 120 sets the corrected settling time T ′ to the DAC amplifier 130. To do.

  In the drawing step (S112), the drawing unit 150 draws a pattern on the sample 101 by deflecting the electron beam 200 using the sub deflector 209 controlled by the settling time T '. Specifically, it operates as follows. The deflection control circuit 120 reads shot data from the storage device 142 and generates main deflection data and sub deflection data for each shot figure in accordance with irradiation position data defined in the shot data. The main deflection data is output to the DAC amplifier 132. The sub deflection data is output to the DAC amplifier 130. At this time, a control signal is output to the DAC amplifier 130 so that the settling time T ′ of the DAC amplifier 130 becomes the time T ′ corrected depending on the above-described shot order. Further, the deflection control circuit 120 generates blanking data for each shot figure in accordance with the irradiation time defined in the shot data, and outputs the blanking data to a blanking DAC amplifier (not shown). Further, the deflection control circuit 120 generates shaping data according to the figure type and figure size defined in the shot data, and outputs them to a beam shaping DAC amplifier (not shown). Then, based on the signals from the DAC amplifiers controlled by the control circuit 122 and the deflection control circuit 120, the drawing unit 150 draws the graphic pattern on the sample 100 using the electron beam 200. Specifically, it operates as follows.

  The electron beam 200 emitted from the electron gun 201 (emission unit) is turned on by a blanking deflector 212 controlled by a deflection signal from a blanking DAC amplifier when passing through the blanking deflector 212. In this state, the beam is controlled to pass through the blanking aperture 214, and in the beam OFF state, the entire beam is deflected so as to be shielded by the blanking aperture 214. The electron beam 200 that has passed through the blanking aperture 214 until the beam is turned off after the beam is turned off becomes one shot of the electron beam. The blanking deflector 212 controls the direction of the passing electron beam 200 to alternately generate a beam ON state and a beam OFF state. For example, the voltage may be applied to the blanking deflector 212 when the beam is OFF, without applying a voltage when the beam is ON. The irradiation amount per shot of the electron beam 200 irradiated on the sample 101 is adjusted at the irradiation time t of each shot.

  The electron beam 200 of each shot generated by passing through the blanking deflector 212 and the blanking aperture 214 as described above illuminates the entire first shaping aperture 203 having a rectangular hole by the illumination lens 202. Here, the electron beam 200 is first shaped into a rectangle. Then, the electron beam 200 of the first aperture image that has passed through the first shaping aperture 203 is projected onto the second shaping aperture 206 by the projection lens 204. The deflector 205 controls the deflection of the first aperture image on the second shaping aperture 206 and can change the beam shape and dimensions (variable shaping is performed). Such variable shaping is performed for each shot, and is usually shaped into different beam shapes and dimensions for each shot. Then, the electron beam 200 of the second aperture image that has passed through the second shaping aperture 206 is focused by the objective lens 207, deflected by the main deflector 208 and the sub deflector 209, and continuously moved. The desired position of the sample 101 arranged at 105 is irradiated. FIG. 1 shows a case in which multi-stage deflection of main and sub two stages is used for position deflection. In such a case, the main deflector 208 deflects the electron beam 200 of the corresponding shot while following the stage movement to the reference position of the SF 30, and the sub deflector 209 deflects the beam of the corresponding shot applied to each irradiation position in the SF. do it. By repeating such an operation and connecting the shot figures of the respective shots, a figure pattern defined in the drawing data is drawn.

  According to the first embodiment, the settling time set in the DAC amplifier 130 is not all increased, but only the first shot in the SF 30 or a limited number of shots from the start of writing to a predetermined number of times is increased. , The effect on throughput can be reduced. Then, it is possible to suppress the deflection position error that has occurred in the first shot in the SF 30 or a very limited shot from the beginning of writing to the predetermined number. Therefore, it is possible to set a more suitable settling time while minimizing the influence on the throughput. As a result, a pattern with high throughput and high accuracy can be drawn.

Embodiment 2. FIG.
In the first embodiment, the settling time corresponding to the shot order is corrected by adding the offset value to the settling time corresponding to the deflection movement amount. However, the present invention is not limited to this. In the second embodiment, a case where correction is performed using a correction coefficient will be described.

  The configuration of the drawing apparatus 100 is the same as that shown in FIG. Further, the contents not specifically described below are the same as those in the first embodiment.

  FIG. 6 is a flowchart showing main steps of the drawing method according to the second embodiment. 6, in the drawing method according to the second embodiment, instead of the shot order dependent settling offset acquisition step (S106), the shot order dependent settling correction coefficient acquisition step (S107) is used instead of the settling time correction step (S108). 4 except that a settling time correction step (S109) is provided.

  FIG. 7 is a diagram illustrating an example of a correction table according to the second embodiment. First, a settling correction coefficient corresponding to the shot order is obtained in advance by experiments before drawing. Such a correction coefficient is determined as a value that depends on the shot order and does not depend on the deflection movement amount. For example, shots having the same movement amount are shot in order within the SF 30, and the position error of each shot is measured. Then, the difference in position error between each shot is obtained. Then, a correction coefficient corresponding to the difference may be obtained. In the example of FIG. 7, for the first (first) beam shot in the SF, the correction coefficient multiplied by an appropriate settling time according to the deflection movement amount is, for example, 10 times. For the second beam shot, the correction coefficient multiplied by an appropriate settling time corresponding to the deflection movement amount is, for example, 5 times. For the third beam shot, for example, the correction coefficient multiplied by an appropriate settling time corresponding to the deflection movement amount is tripled. For the fourth beam shot, for example, the correction coefficient multiplied by an appropriate settling time corresponding to the deflection movement amount is doubled. For the fifth beam shot, the correction coefficient multiplied by an appropriate settling time according to the deflection movement amount is, for example, 1.5 times. For the sixth beam shot, the correction coefficient multiplied by an appropriate settling time corresponding to the deflection movement amount is 1.3 times, for example. ... And, for the 10th and subsequent beam shots, for example, the correction coefficient multiplied by an appropriate settling time corresponding to the deflection movement amount is, for example, 1 time. A correction table in which the correlation between the shot order and the correction coefficient is defined is stored in the storage device 144.

  As the shot order-dependent settling correction coefficient acquisition step (S107), the correction value acquisition unit 66 creates a correction table in which a correction coefficient for correcting the settling time according to the shot order stored in the storage device 144 is defined for each shot graphic. Referring to the correction coefficient corresponding to the shot order in the SF 30.

As the settling time correction step (S109), the settling time correction unit 68 (variable processing unit) sets the settling time T according to the deflection movement amount set in the DAC amplifier 130 for the sub deflector 209 to the SF of the electron beam 200. The correction is made by varying in accordance with the order of shots. Specifically, the settling time correction unit 68 refers to the correction table in which the offset time is defined, and sets the correction coefficient γ (i) corresponding to the shot order i to the settling time T (= Multiply by T ₀ + α (ΔL)).

As the setting step (S110), the setting unit 69 sets the corrected settling time T ′ (= γ (i) (T ₀ + α (ΔL))) in the DAC amplifier 130 for the sub deflector 209. Specifically, the setting unit 69 outputs a control signal for setting the corrected settling time T ′ to the deflection control circuit 120, and the deflection control circuit 120 sets the corrected settling time T ′ to the DAC amplifier 130. To do.

As described above, even when the correction coefficient γ (i) is multiplied by the settling time T (= T ₀ + α (ΔL)) corresponding to the deflection movement amount ΔL, the same effect as in the first embodiment can be obtained. it can.

  The embodiments have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. In the above-described example, the settling time is corrected for a plurality of shots with limited writing start in each SF. However, the present invention is not limited to this, and the entire shot in each SF may be corrected according to the shot order.

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

  In addition, all settling time setting methods, charged particle beam drawing methods, and charged particle beam drawing apparatuses that include elements of the present invention and that can be appropriately modified by those skilled in the art are included in the scope of the present invention.

10 Drawing area 20 Stripe area 30 SF
52, 54, 56 Shot figure 60 Drawing data processing unit 62 Settling time calculation unit 64 Shot order acquisition unit 66 Correction value acquisition unit 68 Settling time correction unit 69 Setting unit 100 Drawing apparatus 101, 340 Sample 102 Electron barrel 103 Drawing chamber 105 XY stage 110 control computer 111 memory 120 deflection control circuit 122 control circuit 130, 132 DAC amplifier 140, 142 storage device 150 drawing unit 160 control unit 200 electron beam 201 electron gun 202 illumination lens 203, 410 first aperture 204 projection lens 205 Deflectors 206 and 420 Second aperture 207 Objective lens 208 Main deflector 209 Sub deflector 212 Blanking deflector 214 Blanking aperture 330 Electron beam 411 Opening 421 Variable shaping opening 430 Charged particle source

Claims (5)

Of the multistage deflector that deflects the charged particle beam by the deflection signal from the DAC (digital / analog converter) amplifier, the settling time corresponding to the deflection movement amount set in the DAC amplifier for the deflector that deflects the minimum deflection region, Changing the charged particle beam according to the shot order;
Setting the variable settling time to a DAC amplifier for a deflector that deflects the minimum deflection region;
A settling time setting method characterized by comprising:   When changing the settling time, the offset time corresponding to the shot order is determined according to the deflection movement amount with reference to the correction table in which the offset time for correcting the settling time according to the shot order stored in the storage device is defined. 2. The settling time setting method according to claim 1, wherein the settling time is added to the settling time.   When changing the settling time, the correction coefficient corresponding to the shot order is determined according to the deflection movement amount with reference to a correction table in which a correction coefficient for correcting the settling time according to the shot order stored in the storage device is defined. 2. The settling time setting method according to claim 1, wherein the settling time is multiplied. Of the multistage deflector that deflects the charged particle beam by the deflection signal from the DAC (digital / analog converter) amplifier, the settling time corresponding to the deflection movement amount set in the DAC amplifier for the deflector that deflects the minimum deflection region, Changing the charged particle beam according to the shot order;
Setting the variable settling time to a DAC amplifier for a deflector that deflects the minimum deflection region;
Drawing a pattern on the sample by deflecting the charged particle beam using a deflector controlled with a settling time set; and
A charged particle beam drawing method comprising: A plurality of DAC (digital-to-analog converter) amplifiers;
A multistage deflector for deflecting a charged particle beam by a deflection signal from the plurality of DAC amplifiers;
A variable processing unit that varies a settling time according to a deflection movement amount set in a DAC amplifier for a deflector that deflects a minimum deflection region of the multistage deflector according to a shot order of a charged particle beam;
A setting unit for setting the variable settling time in a DAC amplifier for a deflector that deflects the minimum deflection region;
A drawing unit that draws a pattern on a sample by deflecting a charged particle beam using a deflector controlled with a settling time set, and
A charged particle beam drawing apparatus comprising:

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