JP5403739B2 - Charged particle beam drawing apparatus and charged particle beam drawing method - Google Patents

Description

  The present invention relates to a charged particle beam drawing apparatus and a charged particle beam drawing method, for example, to a drawing apparatus and method for drawing a pattern on a sample to be a substrate to be drawn while variably shaping an electron beam.

  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. 12 is a conceptual diagram for explaining the operation of a conventional variable shaping type electron beam drawing apparatus. The variable shaped electron beam (EB) drawing apparatus operates as follows. In the first aperture member 410, a rectangular opening for forming the electron beam 330, for example, a rectangular opening 411 is formed. Further, the second aperture member 420 is formed with a variable shaping opening 421 for shaping the electron beam 330 that has passed through the opening 411 of the first aperture member 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 member 410 is deflected by the deflector, passes through a part of the variable shaping opening 421 of the second aperture member 420, and The sample 340 mounted on a stage that continuously moves in a predetermined direction (for example, the X direction) is irradiated. In other words, a rectangular shape that can pass through both the opening 411 of the first aperture member 410 and the variable shaping opening 421 of the second aperture member 420 has a shape of the sample 340 mounted on a stage that continuously moves in the X direction. It is drawn in the drawing area. A method of creating an arbitrary shape by passing both the opening 411 of the first aperture member 410 and the variable forming opening 421 of the second aperture member 420 is referred to as a variable forming method.

  Here, in the electron beam drawing apparatus, an operation of irradiating the sample with the beam and an operation of cutting so as not to irradiate the beam are performed. In the operation of irradiating the sample with the beam, the electron beam is passed through the opening of the blanking aperture member. Moreover, in the operation | movement cut | disconnected so that a beam is not irradiated, an electron beam is shielded by deflecting an electron beam to the shielding part of a blanking aperture member with a blanker (blanking deflector). By repeating these operations, a pattern is drawn on the sample. Since the number of figures of the drawing pattern increases with the miniaturization of the semiconductor device, a blanking mechanism capable of performing these operations at high speed is necessary to obtain high productivity. In order to realize such high speed, there is a method of connecting a terminal resistor to a blanker electrode to obtain impedance matching and suppressing a reflected wave of a blanking signal when a voltage is applied (see, for example, Patent Document 1). .

  Here, the blanker disposed on the blanking aperture member is charged up by reflected electrons or secondary electrons of the electron beam cut on the blanking aperture member. During drawing, for example, when the beam is deflected to a desired position on the sample by a multistage deflector having two main and sub stages, the main deflector irradiates the next shot to a position beyond the deflection area of the sub deflector. Settling time is required. Since the beam is OFF during the settling time to the main deflector, the blanker continues to be charged up by backscattered electrons and secondary electrons. Alternatively, if the next shot position is away from the current shot position, the sample is moved to a position beyond the deflection area in the main / sub deflector where the next shot can be performed, for example, by moving the stage. . Since the beam is turned off during the movement, the blanker continues to be charged up by reflected electrons and secondary electrons throughout the movement. As described above, when the beam is turned off for a long time, the amount of reflected electrons and secondary electrons reaching the blanker is significantly increased as compared with the normal shot cycle, and the charge-up state changes greatly. For this reason, there is a problem in that the position is shifted due to the influence of an electric field or magnetic field in which the electron beam is charged up at the next shot. For example, the above-described variable shaping method has a problem that the position of the beam irradiated on the first aperture member changes and the dimensional accuracy of the shaped beam deteriorates. In this case, an error occurs in the beam position even on the sample surface, so that not only the dimensional accuracy but also the positional accuracy may be deteriorated.

Japanese Patent Laid-Open No. 11-150055

  As described above, the stage is moved to the position beyond the deflection area of the main and sub deflectors during the settling time to the main deflector to irradiate the next shot to the position beyond the deflection area of the sub deflector. In the meantime, the blanker continues to be charged up by reflected electrons and secondary electrons. As described above, when the beam is turned off for a long time, the amount of reflected electrons and secondary electrons that reach the blanker is significantly increased compared to the normal shot cycle, and the charge-up state is within SF (subfield). It will change greatly compared to the case of continuous shots. For this reason, there is a problem in that the position of the electron beam is affected by an electric field or a magnetic field charged with the electron beam at the next shot, resulting in a positional deviation or a dimensional error. However, conventionally, a method for solving such a problem has not been established.

  The present invention provides an apparatus and a method for overcoming such problems, suppressing a change in the charge-up situation of a blanker or a member in the vicinity of the blanker, and reducing a positional deviation and a dimensional error in the next shot due to the charge-up. For the purpose.

A charged particle beam drawing apparatus according to one embodiment of the present invention includes:
A stage on which a substrate to be drawn is placed;
An emission part for emitting a charged particle beam;
A first aperture member that passes the charged particle beam during the beam ON time and shields the entire charged particle beam during the beam OFF time, according to an irradiation cycle composed of the beam ON time and the beam OFF time;
A blanker disposed on the first aperture member and deflecting the entire charged particle beam to a position on the first aperture member where the entire charged particle beam is shielded during the beam OFF time according to the irradiation cycle;
A second aperture member disposed under the first aperture member and shaping a charged particle beam that has passed through the first aperture member;
A shaping deflector disposed between the first and second aperture members and deflecting the charged particle beam that has passed through the first aperture member onto the second aperture member;
A main and sub two-stage multistage deflector for deflecting a charged particle beam formed by passing through the second aperture member to a desired position on the drawing target substrate;
Charged particle beam to the shot position when the shot of the next charged particle beam is irradiated to the shot position on the drawing target substrate beyond the deflection area of the sub-deflector whose narrow area is the deflection area of the multistage deflector A calculation unit for calculating the irradiation cycle for performing a dummy shot within a predetermined time until irradiation of
During a predetermined time, a deflection control unit for the dummy shot that controls the blanker according to the irradiation cycle calculated for the dummy shot by the calculation unit,
With
The shaping deflector deflects the entire charged particle beam that has passed through the first aperture member to a position where the entire charged particle beam is shielded on the second aperture member for a predetermined time.

The charged particle beam drawing apparatus according to another aspect of the present invention includes:
A stage on which a substrate to be drawn is placed;
An emission part for emitting a charged particle beam;
A first aperture member that passes the charged particle beam during the beam ON time and shields the entire charged particle beam during the beam OFF time, according to an irradiation cycle composed of the beam ON time and the beam OFF time;
A blanker disposed on the first aperture member and deflecting the entire charged particle beam to a position on the first aperture member where the entire charged particle beam is shielded during the beam OFF time according to the irradiation cycle;
A second aperture member disposed under the first aperture member and shaping a charged particle beam that has passed through the first aperture member;
A shaping deflector disposed between the first and second aperture members and deflecting the charged particle beam that has passed through the first aperture member onto the second aperture member;
A main and sub two-stage multistage deflector for deflecting a charged particle beam formed by passing through the second aperture member to a desired position on the drawing target substrate;
Charged particle beam to the shot position when the shot of the next charged particle beam is irradiated to the shot position on the drawing target substrate beyond the deflection area of the sub-deflector whose narrow area is the deflection area of the multistage deflector A calculation unit that calculates an irradiation cycle for performing a dummy shot within a predetermined time until irradiation of
During a predetermined time, a deflection control unit for the dummy shot that controls the blanker according to the irradiation cycle calculated for the dummy shot by the calculation unit,
A coil that moves the optical axis of the charged particle beam that has passed through the first aperture member to a position where the entire charged particle beam on the second aperture member is shielded during a predetermined time;
It is provided with.

Further, the image processing apparatus further includes a storage unit that receives and stores drawing data in which drawing layout information is defined,
It is preferable that the irradiation cycle for performing the dummy shot is calculated using the drawing layout information.

  Alternatively, the irradiation cycle for performing the dummy shot is preferably calculated so as to be the same irradiation cycle as that used for the next charged particle beam shot.

The charged particle beam drawing method of one embodiment of the present invention includes:
Emitting a charged particle beam;
Depending on the irradiation cycle consisting of the beam ON time and the beam OFF time, the charged particle beam is allowed to pass during the beam ON time and the entire charged particle beam is shielded during the beam OFF time using the blanker and the first aperture member. And a process of
Forming a charged particle beam that has passed through the first aperture member using a shaping deflector and a second aperture member disposed below the first aperture member;
A step of deflecting a charged particle beam formed by passing through the second aperture member to a desired position on the drawing target substrate using a multistage deflector having two main and sub stages;
Charged particle beam to the shot position when the shot of the next charged particle beam is irradiated to the shot position on the drawing target substrate beyond the deflection area of the sub-deflector whose narrow area is the deflection area of the multistage deflector A step of calculating an irradiation cycle for performing a dummy shot within a predetermined time until irradiation of
During a predetermined time, according to the irradiation cycle calculated for the dummy shot, using the blanker and the first aperture member, the charged particle beam is allowed to pass during the beam ON time and the charged particle beam during the beam OFF time. A process of shielding the whole,
Shielding the entire charged particle beam that has passed through the first aperture member with the second aperture member for a predetermined period of time;
It is provided with.

  According to the present invention, it is possible to suppress a change in the charge-up situation of a blanker or a member near the blanker. As a result, it is possible to reduce the positional deviation and dimensional error in the next shot due to the charge-up.

1 is a conceptual diagram illustrating a configuration of an electron beam drawing apparatus according to Embodiment 1. FIG. 6 is a conceptual diagram for explaining a state of beam deflection at the time of actual drawing in Embodiment 1. FIG. FIG. 3 is a flowchart showing an example of an irradiation cycle in the first embodiment. 6 is a diagram illustrating an example of a stage movement in a beam OFF state according to Embodiment 1. FIG. It is a figure which shows an example when the next shot position in Embodiment 1 changes to another SF. 6 is a conceptual diagram for explaining a state of beam deflection at the time of a dummy shot in Embodiment 1. FIG. 6 is a conceptual diagram for explaining an example of a difference in irradiation position depending on the presence or absence of a dummy shot in Embodiment 1. FIG. FIG. 4 is a conceptual diagram showing a configuration of an electron beam drawing apparatus in a second embodiment. FIG. 9 is a conceptual diagram showing a configuration of an electron beam drawing apparatus in a third embodiment. FIG. 10 is a conceptual diagram for explaining a state of beam deflection at the time of beam ON / OFF in the third embodiment. 10 is a conceptual diagram for explaining an example of a difference in irradiation position depending on the presence or absence of a dummy shot in Embodiment 3. FIG. It is a conceptual diagram for demonstrating operation | movement of the conventional 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.

Embodiment 1 FIG.
FIG. 1 is a conceptual diagram showing the configuration of the electron beam drawing apparatus according to the first embodiment. FIG. 2 is a conceptual diagram for explaining the state of beam deflection at the time of actual drawing in the first embodiment. 1 and 2, 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. 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 (emission part), an illumination lens 202, a blanker 212 (blanking deflector), a first aperture member 203 (first shaping aperture member), a projection lens 204, and a deflector. 205 (a shaping deflector), a second aperture member 206 (a second shaping aperture member), an objective lens 207, a sub deflector 209, and a main deflector 208 are arranged. The sub deflector 209 and the main deflector 208 constitute a multi-stage deflector having two main stages. In the drawing chamber 103, an XY stage 105 is disposed. On the XY stage 105, a sample 101 serving as a drawing target substrate is arranged. Moreover, the blanker 212 is comprised by a pair of electrode, for example. The electrodes are not limited to a pair, and need only include a pair of opposing electrodes through which the electron beam 200 passes between the electrodes, and may be a plurality of electrodes having four or more electrodes. Further, the deflector 205, the sub deflector 209, and the main deflector 208 are provided with, for example, 4-pole or 8-pole electrodes. Alternatively, a plurality of electrodes may be used.

  The arrangement order is, for example, the electron gun 201, the blanker 212, the first aperture member 203, the deflector 205, the second aperture member 206, the objective lens 207, the sub deflector 209, the main deflector 208, and the XY stage. They are arranged in the order of 105. The order of the objective lens 207, the sub deflector 209, and the main deflector 208 may be reversed or the same position. Further, the inside of the electron column 102 and the drawing chamber 103 in which the XY stage 105 is arranged are evacuated by a vacuum pump (not shown) to form a vacuum atmosphere in which the pressure is lower than the atmospheric pressure.

  The control unit 160 includes a control computer 110, a memory 111, a drawing deflection control circuit 120, a dummy shot deflection control circuit 122, digital / analog conversion amplifiers (DAC amplifiers) 130 and 132, and a storage device 140. Yes. The storage device 140 is preferably a magnetic disk device or the like, for example. The control computer 110, the memory 111, the drawing deflection control circuit 120, the dummy shot deflection control circuit 122 (deflection control unit), and the storage device 140 are connected to each other via a bus (not shown). The deflection control circuit 120 is connected to the blanker 212 via the DAC amplifier 130, and is connected to the deflector 205 via the DAC amplifier 132. The deflection control circuit 120 controls the blanker 212 and the deflector 205. In addition, drawing data input from the outside is stored in the storage device 140 (storage unit). In the control computer 110, a drawing data processing unit 112 and a dummy shot irradiation cycle (Duty) calculation unit 114 are arranged.

  The functions of the drawing data processing unit 112 and the dummy shot duty calculation unit 114 may be configured by software that causes a computer to operate, or may be configured by hardware using an electric circuit. Alternatively, a combination of both may be used. Alternatively, a combination of software and firmware may be used. Information input to the control computer 110 and information calculated in the control computer 110 are stored in the memory 111 each time.

  In FIG.1 and FIG.2, description is abbreviate | omitted except the component required when describing Embodiment 1. FIG. It goes without saying that other configurations may be included for the drawing apparatus 100.

  First, the drawing data processing unit 112 performs a plurality of stages of data processing on the drawing data. As a result, the drawing data is converted into shot data and output to the deflection control circuit 120. In the deflection control circuit 120, a control signal for controlling the blanker 212 and the deflector 205 is generated using shot data. Then, the electron beam 200 emitted from the electron gun 201 controlled by another control circuit (not shown) or the like is opened by the illumination lens 202 in the first aperture member 203 having a rectangular hole (opening 222). The entire 222 is illuminated. Here, the electron beam 200 is first formed into a rectangle, for example, a rectangle. Then, the electron beam 200 of the first aperture member image that has passed through the first aperture member 203 is projected onto the second aperture member 206 by the projection lens 204. The position of the first aperture image on the second aperture member 206 is controlled by the deflector 205 controlled by the deflection control circuit 120, and the beam shape and size can be changed. That is, a beam for one shot is formed. The electron beam 200 passes through both the opening 222 of the first aperture member 203 and the variable shaping opening 224 of the second aperture member 206 to change the beam shape and size. Then, the electron beam 200 of the second aperture image that has passed through the second aperture member 206 is reduced by a predetermined magnification, then focused by the objective lens 207, and deflected by the main deflector 208 and the sub deflector 209. Then, a desired position on the sample 101 to which the resist on the XY stage 105 arranged so as to be movable is applied is irradiated. Thus, a desired pattern is drawn on the sample 101 by irradiating the electron beam 200 of the second aperture image to a desired position.

  The drawing area of the sample 101 is virtually divided into strip-like stripe areas having a width that can be deflected by the main deflector 208, and drawing is performed for each stripe area. At the time of drawing, the XY stage 105 is drawn while continuously moving in a certain direction (for example, the X direction) for each stripe region. Then, the main deflector 208 deflects the beam to a reference position on the subfield (SF) that becomes a deflection area deflectable by the sub deflector 209, and the sub deflector 209 deflects the electron beam of each shot to a desired position in the SF. To deflect. The main deflector 208 continues to adjust the deflection position to the reference position on the SF while following the movement of the XY stage 105 until drawing in the corresponding SF is completed.

  FIG. 3 is a flowchart showing an example of an irradiation cycle in the first embodiment. The irradiation cycle includes a beam ON time and a beam OFF time. When the beam is ON (during the beam ON time), the voltage is set to 0 V in the blanker 212, and the electron beam 200 emitted from the electron gun 201 is moved by the illumination lens 202 to the solid line in FIG. 1 or FIG. Illuminate the entire first aperture member as shown in FIG. Then, the shaped electron beam 200 is irradiated to a desired position of the sample 101 through the trajectory as described above.

  On the other hand, when the beam is OFF (the blanking voltage is Vb) (during the beam OFF time), the blanking signal output from the deflection control circuit 120 is converted into an analog signal (voltage) by the DAC amplifier 130 and amplified. And then applied to the blanker 212. The counter electrode of the blanker 212 is applied with a voltage having a sign opposite to that of the other. When a voltage is applied to the blanker 212, the electron beam 200 is deflected, and as shown in the dotted line of FIG. 1 or FIG. 2B, the entire electron beam 200 is opened to the opening 222 of the first aperture member 203 on the downstream side. Irradiate other shielding areas. As a result, the entire electron beam 200 is cut by the first aperture member 203 and is not irradiated thereafter.

  By turning on / off the beam as described above, one shot is irradiated on the sample surface, and a shot of the electron beam 200 having a required irradiation amount can be performed at a required position. By adopting such a configuration, a variable forming die (VSB type) EB drawing apparatus can be obtained. A desired pattern is drawn on the sample 101 by sequentially irradiating the shaped electron beam 200 of each shot while repeating ON / OFF of the beam.

  Here, during the beam OFF time, the reflected electrons and secondary electrons of the electron beam 200 irradiated on the shielding portion of the first aperture member 203 reach the blanker 212, and the blanker 212 is charged up. The irradiation cycle described above is arbitrarily set depending on the positional relationship between the front and rear shot positions and the resist material to be used. However, as long as the shot is repeated within the same SF, the charge-up situation to the blanker 212 due to the difference in the irradiation cycle. Change is acceptable. However, when the beam OFF time is significantly long, the state of charge up to the blanker 212 changes greatly.

  FIG. 4 is a diagram showing an example of moving the stage in the beam OFF state in the first embodiment. As shown in FIG. 4, for example, a pattern of chip A and chip B is drawn on the sample 101. Then, after the drawing of the area of the chip A is completed, the irradiation position is set to the drawing start position of the chip B. Usually, the distance between the position A1 where the drawing of the area of the chip A is finished and the drawing start position B1 of the chip B is generally away from the main deflection area, so the XY stage 105 is moved. Therefore, it is necessary to move the sample 101 to a position where it can be deflected by the main deflector 208. Since it is necessary to prevent the beam from reaching the sample 101 during the moving time, the beam is cut by the first aperture 203 when no measures are taken. In such a case, the blanker 212 will continue to be charged up during the travel time. As a result, the situation changes greatly from the charge-up situation of the blanker 212 when the inside of the SF is continuously shot. Therefore, the electron beam 200 is deflected by the influence of the electric field and magnetic field generated due to the charge-up at the first shot at the drawing start position of the chip B. As a result, an error occurs in the beam shape and position.

  FIG. 5 is a diagram illustrating an example when the next shot position in the first embodiment changes to another SF. As shown in FIG. 5, after the drawing in the SF 10 is completed, another SF 12, for example, the adjacent SF 12 is drawn. At that time, after the last shot 20 in the SF 10, the irradiation position is set to the position of the first shot 22 in the SF 12. When the SF changes, the main deflector 208 needs settling time. Since it is necessary to prevent the beam from reaching the sample 101 during the settling time, the beam is cut by the first aperture 203 when no measures are taken. In such a case, the blanker 212 will continue to be charged up during the settling time. As a result, the situation changes greatly from the charge-up situation of the blanker 212 when the inside of the SF 10 is shot continuously. Therefore, the electron beam 200 is deflected by the influence of the electric field or magnetic field generated due to the first shot 22 in the SF 12 being charged up. As a result, an error occurs in the beam shape and position.

  Therefore, in the first embodiment, the charge-up situation of the blanker 212 and the members in the vicinity of the blanker 212 is greatly different from the charge-up situation of the blankers 212 and the members in the vicinity when the same SF is shot continuously. The operation is as follows so that does not change.

  FIG. 6 is a conceptual diagram for explaining a state of beam deflection at the time of a dummy shot in the first embodiment. In the first embodiment, when the movement time for moving the XY stage 105 to a position where the main deflector 208 can deflect with the original beam OFF shown in FIG. 4 occurs, or as shown in FIG. When 208 settling time occurs, a dummy shot (also referred to as a dummy scan) is performed. In other words, until the next shot of the electron beam 200 is irradiated onto the shot position on the sample 101 that exceeds the SF serving as the deflection region of the sub deflector 209, the electron beam 200 can be irradiated to the shot position. During the predetermined time, a dummy shot is performed. In the dummy shot, as shown in FIGS. 6A and 6B, the blanker 212 is caused to perform the beam ON / OFF operation even during the time when the beam is originally turned off. The beam ON / OFF irradiation cycle is repeated at a frequency equivalent to that during actual drawing. Due to such a dummy shot, the charge-up status of the blanker 212 and the members in the vicinity of the blanker 212 during this time is the same as the charge-up status of the blanker 212 and the members in the vicinity when the same SF was shot continuously. The situation can be prevented from changing greatly. As a result, even when moving from the dummy shot to the actual drawing, it is equivalent that there is substantially no change in the charge-up state, so that there is almost no fluctuation in the electric field or magnetic field, and errors in the beam shape and position can be prevented.

  Here, as shown in FIG. 6B, during the beam OFF time at the time of dummy shot, the beam is cut by the first aperture 203 as in the case of continuous shot in the same SF. become. However, during the beam ON time during the dummy shot, the beam may reach the sample 101 unless any countermeasure is taken. Therefore, in the first embodiment, the deflector 205 passes through the first aperture member 203 at a position where the entire electron beam 200 is shielded on the second aperture member 206 during the dummy shot. The entire electron beam 200 is deflected. As a result, the beam can be cut even when the beam is ON, and the arrival of the beam on the sample 101 can be prevented.

  Here, the shot data processed by the drawing data processing unit 112 is also output to the dummy shot duty calculation unit 114. Then, the dummy shot duty calculation unit 114 calculates an irradiation cycle (Duty) for performing a dummy shot.

  The deflection control circuit 122 serving as a dummy shot deflection control unit controls the blanker 212 in accordance with the irradiation cycle calculated for the dummy shot by the dummy shot duty calculation unit 114 during the dummy shot time. . During the beam OFF time during the dummy shot, the blanking signal output from the deflection control circuit 122 is converted into an analog signal (voltage) by the DAC amplifier 132, amplified, and applied to the blanker 212. The counter electrode of the blanker 212 is applied with a voltage having a sign opposite to that of the other. When a voltage is applied to the blanker 212, the electron beam 200 is deflected, and as shown in the dotted line of FIG. 1 or FIG. 6B, the entire electron beam 200 is downstream of the opening 222 of the first aperture member 203. Irradiate other shielding areas. As a result, the entire electron beam 200 is cut by the first aperture member 203 and is not irradiated thereafter.

  Further, the deflection control circuit 122 causes the deflector 205 to move the entire electron beam 200 on the second aperture member 206 as shown in the dotted line of FIG. 1 or as shown in FIG. Control is performed so that the entire electron beam 200 that has passed through the first aperture member 203 is deflected to a position to be shielded. During the dummy shot time, the control signal (blanking signal) output from the deflection control circuit 122 is converted into an analog signal (voltage) by the DAC amplifier 132, amplified and applied to the deflector 205. . When a blanking voltage is applied to the deflector 205, the electron beam 200 is deflected, and the entire electron beam 200 is variable in the second aperture member 206 as shown in the dotted line in FIG. 1 or in FIG. Irradiation is applied to shielding portions other than the molding opening 224. As a result, the entire electron beam 200 is cut by the second aperture member 206 and is not irradiated thereafter.

  In the drawing data, drawing layout information is defined. Therefore, it is preferable that the irradiation cycle when performing the dummy shot is calculated using the drawing layout information. For example, the dummy shot duty calculation unit 114 obtains the average value of the irradiation cycles determined by the drawing layout obtained from the drawing layout information as the irradiation cycle for performing the dummy shot. Alternatively, it is also preferable to calculate so that the irradiation cycle is the same as the irradiation cycle used for the next shot of the electron beam 200 after the dummy shot. For example, the irradiation cycle for the first shot in the SF may be obtained from the data of the SF to be shot next.

  FIG. 7 is a conceptual diagram for explaining an example of a difference in irradiation position depending on the presence or absence of a dummy shot in the first embodiment. When the dummy shot is not performed, as shown in FIG. 7A, the irradiation position of the electron beam 200 on the first aperture member 203 is shifted at the time of drawing transition from the long beam OFF state. As a result, the entire opening 222 may not be irradiated. Even if such a first aperture image is formed by the second aperture member 206, the beam shape does not become a desired shape. On the other hand, by performing the dummy shot in the first embodiment, as shown in FIG. 7B, the irradiation position of the electron beam 200 does not shift at the time of drawing transition from the long beam OFF state. Irradiated. As a result, the second aperture member 206 can be formed into a desired shape.

  As described above, according to the first embodiment, the blanker 212 and the members near the blanker are charged up by operating so as to maintain a certain irradiation cycle even during a period in which the beam does not reach the surface of the sample 101. The change of the situation can be suppressed. As a result, it is possible to avoid the next shot due to charge-up, that is, a sudden beam drift such as a positional deviation or dimensional error at the time of drawing transition.

Embodiment 2. FIG.
In the first embodiment, blanking at the time of a dummy shot is performed by the beam shaping deflector 205, but the present invention is not limited to this.

  FIG. 8 is a conceptual diagram showing the configuration of the electron beam drawing apparatus according to the second embodiment. 8 is the same as FIG. 1 except that an alignment coil 216 and a coil control circuit 124 are added.

  In the second embodiment, the electron beam 200 that has passed through the first aperture member 203 at a position where the entire electron beam 200 on the second aperture member 206 is shielded during the time when the alignment coil 216 performs a dummy shot. Move the optical axis. The coil control circuit 124 receives a control signal from the deflection control circuit 122, and causes a blanking current to flow through the alignment coil 216 during the dummy shot time in accordance with the control signal. When a blanking current is passed through the alignment coil 216, the optical axis of the electron beam 200 moves, and the entire electron beam 200 is other than the variable shaping opening 224 of the second aperture member 206 as shown by the dotted line in FIG. Irradiated to the shielding part. As a result, the entire electron beam 200 is cut by the second aperture member 206 and is not irradiated thereafter. Other contents are the same as those in the first embodiment.

  As described above, the same effects as those of the first embodiment can be obtained even when blanking is performed during dummy shots using a coil such as the alignment coil 216.

Embodiment 3 FIG.
In the first and second embodiments, the first aperture member 203 originally used for beam shaping is used and the electron beam 200 is shielded when the beam is turned off. However, the present invention is not limited to this.

  FIG. 9 is a conceptual diagram showing a configuration of the electron beam drawing apparatus according to the third embodiment. 9 is the same as FIG. 1 except that a blanking aperture member 214 is added. In FIG. 9, a blanking aperture member 214 is further disposed between the blanker 212 and the first aperture member 203.

  FIG. 10 is a conceptual diagram for explaining the state of beam deflection at the time of beam ON / OFF in the third embodiment. In the case of the beam ON (during the beam ON time), the voltage is set to 0 V in the blanker 212, and the electron beam 200 emitted from the electron gun 201 is transmitted by the illumination lens 202 as shown by the solid line in FIG. 9 and FIG. It passes through the opening of the blanking aperture member 214. Then, the shaped electron beam 200 is irradiated to a desired position of the sample 101 through the trajectory as described above.

  On the other hand, when the beam is OFF (the blanking voltage is Vb) (during the beam OFF time), the blanking signal output from the deflection control circuit 120 is converted into an analog signal (voltage) by the DAC amplifier 130 and amplified. And then applied to the blanker 212. The counter electrode of the blanker 212 is applied with a voltage having a sign opposite to that of the other. When a voltage is applied to the blanker 212, the electron beam 200 is deflected, and the entire electron beam 200 is applied to a shielding portion other than the opening of the blanking aperture member 214 on the downstream side as shown in the dotted line in FIG. 9 and FIG. Irradiated. As a result, the entire electron beam 200 is cut by the blanking aperture member 214 and is not irradiated thereafter.

  Also in the configuration shown in FIG. 9, when the beam is OFF, reflected electrons and secondary electrons from the blanking aperture member 214 reach the blanker 212. Therefore, as in the first and second embodiments, the electron beam to the shot position when the shot of the next electron beam 200 is irradiated to the shot position on the sample 101 that exceeds the SF serving as the deflection region of the sub deflector 209. A dummy shot is performed for a predetermined time until 200 irradiation is possible. Other contents are the same as those in the first embodiment.

  FIG. 11 is a conceptual diagram for explaining an example of a difference in irradiation position depending on the presence or absence of a dummy shot in the third embodiment. When the dummy shot is not performed, as shown in FIG. 11A, the irradiation position of the electron beam 200 on the blanking aperture member 214 is shifted at the time of drawing transition from the long beam OFF state. As a result, a part of the beam that should originally pass is cut. Even if such a beam is formed by the first and second aperture members, the beam shape may not be a desired shape. On the other hand, by performing the dummy shot in the first embodiment, as shown in FIG. 11B, the irradiation position of the electron beam 200 does not shift at the time of drawing transition from the long beam OFF state. Everything passes through the opening. As a result, it is possible to perform drawing with high accuracy.

  As described above, the same effect as that of the first embodiment can be obtained even if blanking is performed at the time of dummy shot using the restriction aperture dedicated to blanking.

  The embodiments have been described above with reference to specific examples. However, the present invention is not limited to these specific examples.

  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 charged particle beam drawing apparatuses, drawing methods, and charged particle beam optical axis misalignment correction methods 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.

10,12 SF
20, 22 Shot 100 Drawing device 102 Electronic column 103 Drawing room 105 XY stage 110 Control computer 111 Memory 112 Drawing data processing unit 114 Dummy shot duty calculation unit 120, 122 Deflection control circuit 124 Coil control circuit 130, 132 DAC amplifier 140 Memory Device 150 Drawing unit 160 Control unit 200 Electron beam 201 Electron gun 202 Illumination lenses 203 and 410 First aperture member 204 Projection lens 205 Deflector 206 and 420 Second aperture member 207 Objective lens 208 Main deflector 209 Sub deflector 212 Blanker 214 Blanking aperture member 216 Alignment coil 222 Opening 224, 421 Variable shaping opening 330 Electron beam 340 Sample 411 Opening 430 Charged particle source

Claims (5)

A stage on which a substrate to be drawn is placed;
An emission part for emitting a charged particle beam;
A first aperture member that passes the charged particle beam during the beam ON time and shields the entire charged particle beam during the beam OFF time, according to an irradiation cycle composed of a beam ON time and a beam OFF time;
It is disposed on the first aperture member, and deflects the entire charged particle beam to a position where the entire charged particle beam is shielded on the first aperture member during the beam OFF time according to the irradiation cycle. With a blanker,
A second aperture member that is disposed under the first aperture member and that shapes the charged particle beam that has passed through the first aperture member;
A shaping deflector arranged between the first and second aperture members and deflecting the charged particle beam that has passed through the first aperture member onto the second aperture member;
A main and sub two-stage multi-stage deflector for deflecting the charged particle beam formed by passing through the second aperture member to a desired position on the drawing target substrate;
When the shot position of the next charged particle beam is irradiated onto the shot position on the drawing target substrate that exceeds the deflection area of the sub-deflector whose narrow area is the deflection area of the multistage deflector, the shot position is charged. A calculation unit that calculates the irradiation cycle for performing a dummy shot within a predetermined time until irradiation of the particle beam becomes possible,
During the predetermined time, a deflection control unit for a dummy shot that controls the blanker according to the irradiation cycle calculated for the dummy shot by the calculation unit;
With
The shaping deflector deflects the entire charged particle beam that has passed through the first aperture member to a position where the entire charged particle beam is shielded on the second aperture member during the predetermined time. A charged particle beam drawing apparatus. A stage on which a substrate to be drawn is placed;
An emission part for emitting a charged particle beam;
A first aperture member that passes the charged particle beam during the beam ON time and shields the entire charged particle beam during the beam OFF time, in accordance with an irradiation cycle composed of a beam ON time and a beam OFF time;
It is disposed on the first aperture member, and deflects the entire charged particle beam to a position where the entire charged particle beam is shielded on the first aperture member during the beam OFF time according to the irradiation cycle. With a blanker,
A second aperture member that is disposed under the first aperture member and that shapes the charged particle beam that has passed through the first aperture member;
A shaping deflector arranged between the first and second aperture members and deflecting the charged particle beam that has passed through the first aperture member onto the second aperture member;
A main and sub two-stage multi-stage deflector for deflecting the charged particle beam formed by passing through the second aperture member to a desired position on the drawing target substrate;
When the shot position of the next charged particle beam is irradiated onto the shot position on the drawing target substrate that exceeds the deflection area of the sub-deflector whose narrow area is the deflection area of the multistage deflector, the shot position is charged. A calculation unit that calculates the irradiation cycle for performing a dummy shot within a predetermined time until irradiation of the particle beam becomes possible,
During the predetermined time, a deflection control unit for a dummy shot that controls the blanker according to the irradiation cycle calculated for the dummy shot by the calculation unit;
A coil that moves the optical axis of the charged particle beam that has passed through the first aperture member to a position where the entire charged particle beam is shielded on the second aperture member during the predetermined time period;
A charged particle beam drawing apparatus comprising: The image processing apparatus further includes a storage unit that receives and stores drawing data in which drawing layout information is defined,
3. The charged particle beam drawing apparatus according to claim 1, wherein the irradiation cycle for performing the dummy shot is calculated using the drawing layout information.   3. The charged particle beam according to claim 1, wherein the irradiation cycle for performing the dummy shot is calculated to be the same irradiation cycle as that used for the next shot of the charged particle beam. Drawing device. Emitting a charged particle beam;
In accordance with an irradiation cycle composed of a beam ON time and a beam OFF time, the charged particle beam is allowed to pass through the beam ON time using a blanker and a first aperture member, and the charged particle beam is used at the beam OFF time. A process of shielding the whole,
Forming the charged particle beam that has passed through the first aperture member using a shaping deflector and a second aperture member disposed below the first aperture member;
Deflecting the charged particle beam formed by passing through the second aperture member to a desired position on the substrate to be drawn, using a multistage deflector having two main and sub stages;
When the shot position of the next charged particle beam is irradiated onto the shot position on the drawing target substrate that exceeds the deflection area of the sub-deflector whose narrow area is the deflection area of the multistage deflector, the shot position is charged. Calculating the irradiation cycle for performing a dummy shot within a predetermined time until the irradiation of the particle beam becomes possible;
During the predetermined time, according to the irradiation cycle calculated for the dummy shot, the charged particle beam is allowed to pass during the beam ON time using the blanker and the first aperture member. Shielding the entire charged particle beam during OFF time;
Shielding the entire charged particle beam that has passed through the first aperture member with the second aperture member during the predetermined time; and
A charged particle beam drawing method comprising:

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