JP3267373B2 - Charged particle beam exposure system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charged particle beam exposure apparatus using a so-called charged particle beam such as an ion beam or an electron beam. In particular, when the beam irradiation time is high, such as when a high-sensitivity resist is used, even when an exposure cycle time longer than the maximum operation clock is set, no unnecessary wait time is set, and the throughput of the entire apparatus is reduced. The present invention relates to a charged particle beam exposure apparatus that improves the image quality.

In recent years, with the increase in the density of integrated circuits, a new exposure method using a charged particle beam, particularly an electron beam, has been studied instead of photolithography, which has been the mainstream of forming fine patterns for many years, and it has been considered that the method is actually used. It has become

[0003]

2. Description of the Related Art FIG. 9 shows a configuration diagram of a conventional electron beam exposure apparatus. In the figure, an electron beam exposure apparatus roughly generates an electron beam, deflects the electron beam, reduces the beam, and irradiates the beam to a material to be exposed placed on a sample mounting table. And a control unit 150 for generating exposure data, performing correction, transmitting the data, and further controlling the exposure data.

The exposure unit 110 includes a charged particle beam source 1
14, a first slit 115, a first electron lens 116, a slit deflector 117, a second lens 118, a second slit 120, a blanking 125, a third lens 126,
Aperture 127, refocus coil 128, fourth lens 129, dynamic focus coil 130, dynamic stig coil 131, fifth objective lens 13
2, main differential coil 133, sub deflector 134,
Stage 135 and first to fourth alignment coils 1
36 to 139.

The charged particle beam source 114 includes a cathode electrode 111, a grid electrode 112, and an anode electrode 1.
13. The first slit 115 shapes a charged particle (hereinafter, referred to as a beam) into, for example, a rectangular shape. The first electron lens 116 converges the shaped beam. The slit deflector 117 deflects the shaped beam onto the second slit 120 according to the deflection signal S1. The second slit 120 has a rectangular opening, and the beam deflected by the slit deflector 117 is shaped into a desired rectangular shape by overlapping the beam with the opening. The blanking 125 blocks or allows the beam to pass according to the blanking signal SB.

The third lens 126 reduces the beam, and the fifth objective lens 132 projects the beam on a sample. The main differential coil 133 and the sub deflector 134 perform beam positioning on the wafer W according to the exposure position determination signals S2 and S3 from the control unit 150. The stage 135 has a structure in which the wafer W is mounted and can be moved in the X and Y directions.

On the other hand, the control unit 150 includes a storage medium 151,
CPU 152, interface unit 153, data memory 154, pattern controller 155, DAC (Di-
gital Analog Converter), amplifier section 156, clock control circuit 157, blanking control circuit 158, DA
C and amplifier section 159, sequence controller 16
0, stage control mechanism 161, laser interferometer 162, stage correction section 163, DAC and amplifier sections 164, 16
5 and 166, and a deflection control circuit 167.

[0008] The storage medium 151 includes a disk or an MT recorder in which exposure data of the integrated circuit device is stored. C
The PU 152 controls the entire charged particle beam device. The interface unit 153 transfers, to the control unit 50, various information such as, for example, drawing information captured by the CPU 152, drawing position information on the wafer W on which the pattern is to be drawn, and mask information of the transmission mask 120. The drawing pattern information transferred from the interface unit 153 is held in the data memory 154.

The pattern control controller 155 and the deflection control circuit 167 determine the first slit 115 and the second slit 12 according to the drawing pattern information in the data memory 154.
0, a deflection signal S1 for determining a beam size is output from the result, and the deflection signal S
Information for determining which position on the sample is to be exposed to one beam, that is, processing for calculating and outputting exposure position determination signals S2 and S3, so-called data designating means, holding means, calculating means, and output means Provide functions.

[0010] The DAC and amplifier section 156 outputs the deflection signal S
1 is converted to an analog value to be applied to the deflector (slit deflector 117). The DAC and amplifier section 159 generates a blanking signal SB based on information from the blanking control circuit 158.

The sequence controller 160 is operated by the pattern controller 1
55, a signal S2 to be applied to the main differential coil 133 is output, and further, the output of the signal S3 from the pattern controller 155 is controlled after the output signal is settled,
The drawing processing sequence is controlled according to the resulting position information.

The stage control mechanism 161 controls the movement of the stage 135 as required. Laser interferometer 162 detects the position of stage 135. Further, the DAC and amplifier units 164 and 165 provide exposure position determination signals S2 and S2.
3 is converted to an analog value to be applied to the deflector (the main differential coil 133 and the sub deflector 134, respectively).

In the conventional charged particle beam exposure apparatus having such a configuration, exposure is performed as follows. That is, the electron beam emitted from the charged particle beam source 114 is shaped into a rectangular shape by the first slit 115, then converged by the first and second lenses 116 and 118, and irradiated to the second slit 120. . The beam size is determined by the balance between the first slit 115 and the second slit 120, and therefore, the deflection of the rectangular beam image passing through the first slit 115 is performed by the slit deflector 117.

The beam that has passed through the second slit 120 is
After passing through the blanking 125, the light is reduced by the third lens 126.
It is deflected in a small deflection area of about [μm]. At the stage before the actual exposure, the exposure position determination signal S2 is output according to the instruction of the sequence controller 160, and the main deflector coil 133 is deflected, so that the sub deflector deflection area (subfield) is 2 [mm]. It is largely deflected within a range of exposure fields.

Next, the above description will be described from the standpoint of the control unit 150 side. The data to be exposed is stored in the CPU 1 prior to exposure.
52, the data is read from the storage medium 151. This is because it takes time to read data from the storage medium 151, and if it is performed during exposure, the throughput is reduced.

When the exposure is started, first, the main differential deflection data S2 stored under the instruction of the sequence controller 160 is read from the data memory 154,
It is output to the main differential coil 133. After the output value is stabilized (the time until the output value is stabilized is managed by the sequence controller 160), the sequence controller 160 outputs the deflection signal S1 and the exposure position determination signal S3 stored in the data memory 154. .

Data originally read from the storage medium 151 (that is, data stored in the data memory 154 before the start of exposure) is pattern data. For this reason,
When the start signal is output from the sequence controller 160, the pattern controller 155 reads data from the data memory 154, and a pattern generator in the pattern controller 155 generates shot data from the pattern data.

Further, the generated shot data is supplied to a pattern correction section for correcting rotation or the like generated when the object to be exposed is mounted on a stage, and is actually supplied to each DAC and amplifier section 15.
6, 164, 165, and 166 are created as deflection data. After that, each deflection data is
And supplied to the amplifiers 156, 164, 165, and 166 and applied to each electrode and coil.

As described above, when performing exposure,
A main differential is set using a main differential coil 133 at a position on the sample to be exposed where exposure is to be performed, and a beam is deflected using a sub-deflector 134 in the main differential to perform exposure for each shot data.

The exposure time for performing the exposure for each shot, that is, the exposure cycle time PT, is the time during which the beam should be irradiated onto the exposed sample, ie, the beam irradiation time ET, and the time during which the beam is not irradiated onto the exposed sample, ie, the waiting time. Time WT.

The beam irradiation time ET is determined by an exposure amount (hereinafter referred to as “dose amount”) determined in the exposure process input as exposure data, a proximity effect correction coefficient, and the like. Desired. In the proximity effect correction, a dose that is about 1 to 10 times the normal dose for a specified specific shot is set. The setting of the correction coefficient is performed in the data processing, and the value after the correction is input as exposure data. Therefore, the exposure apparatus only needs to perform other corrections, for example, correction using a block mask at the time of block exposure. .

On the other hand, the waiting time WT is determined by the amount of change in the amount of voltage applied to the sub-deflector 134 generated when the exposure shifts from the n-th shot to the (n + 1) -th shot,
The amount of change in the amount of voltage required to change the shot size and the amount of change in the amount of current required to change the output value of the refocus coil 128 for correcting the amount of beam blur performed for each shot Is determined. That is, the output values of these deflectors are set to Vn at the time of the exposure of the n-th shot, and it is necessary to change the output value to Vn + 1 at the time of the exposure of the next (n + 1) -th shot. A settling time that depends on the performance of the amplifier, the output load, and the like occurs until the settling is performed at a desired value from the above.

This waiting time WT is usually obtained by comparing output values (digital values) before and after in the pattern generation process, obtaining a difference, and obtaining an output change amount, and setting an amplifier settling time for the change amount. Do it by getting. Normally, the amplifier settling time is proportional to the amount of change. These output change amounts are independently performed on output data for the sub deflector 134, output data for the slit deflector 117, output data for the refocus coil 128, and output data for the mask deflector when performing block exposure. It waits for the sum of the wait times determined from the output change amounts or the maximum wait time of each output change amount.

In the case of irradiating one shot, it takes time to add the beam irradiation time ET and the waiting time WT. However, the system clock SCLK for operating the control unit 150 needs to be an integral multiple of the LSB of the reference clock for generating the system clock SCLK, and the calculation for that is performed and determined.

The actual exposure time is usually set at a dose of 100 [μm].
C], since the current density is about 40 [A / cm ² ],
The exposure operation frequency is about 1 [MHz] or less. on the other hand,
The control unit 150 of the exposure apparatus normally takes about 100 [nsec] because it performs pipeline processing and requires a multiplier to correct rotation and the like. This means that the maximum exposure frequency of the control unit 150 is 10 [MHz], which is sufficiently higher than the exposure operation frequency, so that no problem occurred.

[0026]

However, due to recent advances in technology, the performance of the exposure unit 110 (column) has been improved, so that about 50 [A / cm ² ] can be obtained without any problem.
High-sensitivity resists have also been developed, and exposure can be performed at a maximum of about 1 [μC]. Accordingly, the actual exposure time is about 20 [nsec], and the amplifier settling time is also 20 to 100 [nsec] at minimum when the analog technology is improved.
c]). As a result, the exposure time PT is
Under 100 [nsec] (= 10 [MHz]), when the system operation maximum frequency of the exposure apparatus is 10 [MHz],
The problem of not being able to keep up has arisen.

Originally, in order to solve such a problem, it is sufficient to increase the control speed. In a digital circuit,
One of the solutions is to implement an LSI. However, in the case of an electron beam exposure apparatus, if the accuracy is pursued, it is necessary to increase the number of data bits in order to improve the resolution, and it is necessary to align the data with a clock during the pipeline processing. For this reason, it is necessary to prepare a register of several hundred bits for each processing stage of the pipeline, and furthermore, it is necessary to make the input / output interface correspond to a large number of bits.

Therefore, as a means for solving the above problems, conventionally, when performing exposure using a high-sensitivity resist,
The exposure cycle time PT is adjusted by adding an offset to the entire waiting time WT. First, in the case of exposing a resist of 1 [μC], since the current density can be predicted, the shortest beam irradiation time ET is obtained from this. For example, when the current density is 50 [A / cm ² ], about 20 [n]
sec]. Next lowest waiting time WT
Is added to the actual exposure time to determine the shortest exposure time PT. Since the beam must be deflected by the sub-deflector 134 at least between one shot and the next shot, a time during this time, for example, 20 [nsec] is added to the actual exposure time. In the case of this example, the shortest exposure clock is 40 [nsec]. Thereafter, the difference is compared with the maximum possible clock of the hardware (circuit) itself of the device, and the difference is added to the waiting time.

That is, the maximum operation clock is 100 [ns]
c], the difference from the exposure time PT is 60 [n]
sec] to the uniform waiting time WT. As a result,
The shortest exposure shot is 100 [nsec].
It is set as such, but also for all exposures.
[Nsec] is added. For example, as a result of the proximity effect correction, the exposure time is 160 [nsec], and the actual settling waiting time is 500 [nsec] due to the large jump amount of the amplifier. Even in the case of a shot, if it is true, it is 660 [nsec], and even though it is within the operation limit time of the control unit 150, a situation has occurred in which an extra wait is required.

The present invention solves the above problems,
It is an object of the present invention to provide a charged particle beam exposure apparatus capable of improving the throughput of the entire apparatus without setting a useless waiting time even when an exposure cycle time longer than the maximum operation clock is set.

[0031]

In order to solve the above-mentioned problems, a charged particle beam exposure apparatus according to the first aspect of the present invention comprises:
As shown in FIGS. 1 and 5 , exposure data having at least a starting point of a pattern to be exposed, the size of the pattern, shape information of the pattern, and exposure time information as one pattern information is held. Data management means 1 for outputting the exposure data, shot decomposition means 3 for decomposing the exposure data from the data management means 1 into shot data, and a waiting time WT for each shot based on information from the shot decomposition means 3 And a beam irradiation time E based on the exposure time information.
Irradiation time setting means 7 for setting T, and the waiting time WT
And an exposure cycle time PT of one shot is determined based on the beam irradiation time ET, and when the exposure cycle time PT is shorter than a predetermined reference time JT, the exposure cycle time PT becomes longer than the reference time JT. a correction unit 9 for resetting the the exposure cycle time PT, as the set
A constant beam irradiation time ET, based on, and reconfigure <br/> constant been EXPOSURE cycle time PT by the correction means 9, a clock signal SCLK for driving the respective components in the charged particle beam exposure apparatus And a clock generating means 10 for generating the same.

The charged particle beam exposure apparatus according to the second feature of the present invention is as shown in FIGS. 1, 6, 7 and 8.
Ku, the starting point of the pattern to be at least exposed, the pattern
Size, shape information of the pattern, and exposure time information
Holding exposure data as one pattern information,
Data management means for outputting the exposure data upon exposure
1 and the exposure data from the data management means 1.
Shot decomposing means 3 for decomposing into shot data;
When waiting for each shot based on information from the disassembly means 3
Waiting time setting means 5 for setting the interval WT, and the exposure time
Irradiation time setting to set beam irradiation time ET based on information
Setting means 7, the set waiting time WT, and a predetermined
The waiting time WT is reset based on the quasi-time JT.
Correction means 9 and the waiting time reset by said correction means 9
Between the WT and the set beam irradiation time ET.
Drive each component in the charged particle beam exposure apparatus.
Clock generating means for generating the operating clock signal SCLK
And a step 10 .

Further, the third charged particle beam exposure device of the aspect of the present invention, a charged particle beam exposure apparatus according to claim 2, as shown in FIG. 6, the correcting unit 9, a predetermined
Set by the reference time JT1 and the irradiation time setting means 7
For obtaining a difference ΔA1 from the obtained beam irradiation time ET
Set by the difference means 17 and the waiting time setting means 5
Second ratio comparing the obtained waiting time WT with the difference ΔA1
Comparing means 19 and the result of the second comparing means 19,
If ΔA1 is equal to or less than the waiting time WT, WT is calculated as the difference
If ΔA1 exceeds the waiting time WT, the difference Δ
A value equal to or greater than the value of A1 is assigned to the waiting time WT.
Instead, a first waiting time reset for resetting the waiting time WT
And a setting unit 21 .

[0034] The fourth charged particle beam exposure device of the aspect of the present invention, a charged particle beam exposure apparatus according to claim 2, as shown in FIG. 7, the correction unit 9, a predetermined
Set by the reference time JT2 and the waiting time setting means 5
Second difference method for calculating the difference ΔA2 with the set waiting time WT
Stage 23 and a third comparison comparing the zero value with the difference ΔA2
Means 25 and the result of the third comparing means 25, the difference Δ
If A2 is equal to or less than zero, zero, and the difference ΔA2 exceeds zero
If the value is greater than the value of the difference ΔA2,
Add to the waiting time WT and reset the waiting time WT
It has a second waiting time resetting means 27 .

[0035] The fifth charged particle beam exposure device of the aspect of the present invention, a charged particle beam exposure apparatus according to claim 2, as shown in FIG. 8, the correction means 9 is predetermined
Set by the reference time JT2 and the waiting time setting means 5
Fourth comparing means 29 for comparing the set waiting time WT with
As a result of the fourth comparing means 29, the waiting time WT is
If the value is smaller than the reference time JT2, the reference time JT
2 is reset as the waiting time WT.
And a setting unit 31 .

A charged particle beam exposure apparatus according to a sixth aspect of the present invention is the charged particle beam exposure apparatus according to any one of claims 1 to 5 , wherein the waiting time setting step is performed.
Step 5 is performed by the shot decomposing means 3 for each shot.
Information about the shot jump amount and slit size.
And wait independently determined by each physical quantity.
The calculated value or the maximum wait time is set as the wait time WT.
And the irradiation time setting means 7 sets the exposure time information and
Exposure amount and proximity effect correction coefficient, and the exposure amount and
Beam irradiation is performed based on the current density determined from the proximity effect correction coefficient.
Set the firing time ET.

[0037]

[Action] In the first charged particle beam exposure device of the features of the present invention, as shown in FIG. 1,及 Beauty Figure 5, the correction means 9 Odor
To the set waiting time WT and beam irradiation time ET
The exposure cycle time PT for one shot is determined based on the
Exposure cycle time PT is shorter than predetermined reference time JT
In this case, the exposure cycle time PT is longer than the reference time JT.
The exposure cycle time PT is reset so that it becomes longer,
An exposure cycle time PT reset by the correction means 9;
Clock generation with the beam irradiation time ET set above
The charged particle beam exposure apparatus.
Generate clock signal SCLK for driving each component
Like that.

[0038]

Thus, for example, if the maximum operation clock is given as the reference time JT of the apparatus, the exposure cycle time PT shorter than the maximum operation clock of the charged particle beam exposure apparatus can be obtained.
Is set, the exposure cycle time PT is extended beyond the reference time JT, and no useless waiting time is set even when the exposure cycle time PT that is longer than the maximum operation clock is set. . Therefore, unlike the conventional case, there is no useless time, and the throughput can be improved.

The second, third , fourth and fourth embodiments of the present invention
5 , the charged particle beam exposure apparatus of FIG.
As shown in FIGS. 7 and 8, the waiting time WT and the beam irradiation time ET finally set by the correction means 9 are supplied to the clock generation means 10, and the components in the charged particle beam exposure apparatus are used. A driving clock signal SCLK is generated.

In the charged particle beam exposure apparatus having the third characteristic, the difference ΔA1 (= JT1-ET) between the reference time JT1 and the beam irradiation time ET is obtained by the first difference means 17,
The second comparing means 19 compares the difference value ΔA1 with the waiting time WT, and based on the result of the second comparing means 19, the first waiting time resetting means 21 sets WT when ΔA1 ≦ WT,
When ΔA1> WT, the difference value ΔA1 is replaced with the new waiting time W
It is set to T. In this case, an operation limit time of the exposure apparatus is given as the reference time JT1.

In the charged particle beam exposure apparatus according to the fourth feature of the present invention, the reference time JT
The difference ΔA2 (= JT2−WT) between the second waiting time WT and the waiting time WT is obtained, and the second waiting time resetting means 27 determines “0” when ΔA2 ≦ 0 based on the comparison result of the third comparing means 25.
When ΔA2> 0, the difference value ΔA2 is added to the waiting time WT. In this case, the difference between the beam irradiation time estimated from the dose amount and the current density and the maximum operation time during which the control unit 50 of the exposure apparatus can operate is given to the reference time JT2.

Further, in the charged particle beam exposure apparatus according to the fifth aspect of the present invention, the reference time JT
2 and the waiting time WT, and the third waiting time resetting means 31 resets the reference time JT2 as the waiting time WT when WT <JT2. Also in this case, the reference time JT2 is a difference between the beam irradiation time expected from the dose amount and the current density and the maximum operation time during which the control unit 50 of the exposure apparatus can operate.

Therefore, the charged particle beam exposure apparatus having the second, third , fourth , and fifth characteristics can also achieve the same effects as the charged particle beam exposure apparatus having the first characteristic. Furthermore , a charged particle beam exposure apparatus according to a sixth aspect of the present invention.
Then, the waiting time setting means 5 sets a shot for each shot.
Information from the shot disassembly means 3 includes the amount of shot
And slit size are determined independently, and each physical quantity
The sum of the waiting times determined from
The waiting time WT is set, and the irradiation time setting means 7 is set.
The exposure time and proximity effect correction
And the amount determined by the exposure amount and the proximity effect correction coefficient.
The beam irradiation time ET is set based on the flow density.

[0045]

Next, an embodiment according to the present invention will be described with reference to the drawings. First Embodiment FIG. 1 shows a configuration diagram of a charged particle beam exposure apparatus according to a first embodiment of the present invention.

In the figure, the charged particle beam exposure apparatus of the present embodiment roughly generates and deflects an electron beam.
An exposure unit 110 that reduces the beam and irradiates the material to be exposed placed on the sample mounting table with the beam, and generates and transmits data to be exposed to the exposure unit 110 for correction and transmission, and further controls. And a control unit 50.

The configuration of the exposure unit 110 (see FIG. 9) and the function of each component are the same as those described in the prior art. Also in the control unit 50, in the same manner as the control unit 150 in the conventional example (see FIG. 9), the storage medium 1 shown in FIG. 9
51, CPU 152, DAC and amplifier unit 15
6, 164, and 165, a pattern controller 155 (not shown), a blanking control circuit 158, D
AC and amplifier section 159, sequence controller 16
0, a stage control mechanism 161, a laser interferometer 162, a stage correction unit 163, a DAC and amplifier unit 166, a deflection control circuit 167, and the like.

In FIG. 1, the control unit 50 in the charged particle beam exposure apparatus of the present embodiment includes
A buffer memory 2 for holding exposure data having at least a starting point of a pattern to be exposed, a size of the pattern, shape information of the pattern, and exposure time information as one pattern information; Data management means 1 for outputting data, shot decomposition means 3 for decomposing exposure data from data management means 1 into shot data, shot correction means 4 for further performing shot correction, shot decomposition means 3 and shot correction means 4 A waiting time setting means 5 for setting a waiting time WT for each shot based on information from the camera; an irradiation time setting means 7 for setting a beam irradiation time ET based on exposure time information;
An exposure cycle time PT for one shot is determined based on the waiting time WT and the beam irradiation time ET. When the exposure cycle time PT is shorter than a predetermined reference time JT, the exposure cycle time PT is longer than the reference time JT. Correction means 9 for resetting the exposure cycle time PT so as to be as follows, and at least two of the waiting time WT, beam irradiation time ET, and exposure cycle time PT finally set by the correction means 9. And a clock generating means 10 for generating a clock signal SCLK for driving each component in the charged particle beam exposure apparatus.

FIG. 2 is a view for explaining the data structure of the exposure data held in the buffer memory 2. Figure (1)
As shown in the figure, the data of one pattern includes an operation code OPi (i indicates a pattern number), an X coordinate P0Xi of a pattern start point, and a Y coordinate P0Y of a pattern start point.
i, the size PSXi of the pattern in the X direction, and the size PSYi of the pattern in the Y direction. Also,
The operation code OPi includes a shape code, an exposure amount code such as exposure time information, and the like, as shown in FIG.

FIG. 3 is a conceptual diagram for explaining the operation of the irradiation time setting means 7. As shown in the figure, the irradiation time setting means 7 includes an irradiation time setting section 7A and a correction section 7B.

The irradiation time setting section 7A receives the set exposure amount DA1 and the proximity effect correction coefficient DA2 as exposure time information from the data management means 1, and obtains a current density determined from the exposure amount and the proximity effect correction coefficient or a measured value. The beam irradiation time ET is set based on the current density DA3. The correction unit 7B further performs correction using the block information DA4 and resets the beam irradiation time ET.

In the proximity effect correction, a dose that is about 1 to 10 times the normal dose for a specified specific shot is set. The setting of the correction coefficient is performed in data processing, and the value after the correction is input as exposure data. Therefore, the exposure apparatus only needs to perform other corrections, for example, correction using a block mask.

FIG. 4 is a conceptual diagram for explaining the operation of the waiting time setting means 5. The waiting time setting means 5 receives, for each shot, the shot jump amount as information from the shot resolving means 3 and the slit size and the mask differential amount in the case of block exposure as information from the shot correcting means 4, respectively. The detection S1, the slit size detection S2, and the mask differential detection S3 are performed independently. Wait time WT1, W from each physical quantity
Set T2 and WT3 (D1, D2 and D3),
The sum of these values or the maximum wait time is referred to as wait time W
Set as T. In the conceptual diagram of FIG.
Waiting time WT by selecting the maximum waiting time according to CO2 and
Is set as

The data to be considered by the waiting time setting means 5 is output data whose output changes in an analog manner between one shot and one shot. In general, the above data may be used. May include a stig focus correction output which is generated when mask differential deflection occurs.

The waiting time WT and the beam irradiation time ET obtained by the waiting time setting means 5 and the irradiation time setting means 7
Are supplied to the correction means 9 to be corrected. In FIG.
Correction means 9 in charged particle beam exposure apparatus of the present embodiment
FIG.

In the figure, a correction means 9A includes an exposure time setting means 11 for determining an exposure cycle time PT for one shot by adding these, for example, based on a waiting time WT and a beam irradiation time ET; The first comparison means 13 compares the exposure cycle time PT determined by the following formula with a predetermined reference time JT. As a result of the first comparison means 13, if the exposure cycle time PT is shorter than the reference time JT, the exposure cycle time PT Resetting means 15 for resetting the exposure cycle time PT so that PT becomes longer than the reference time JT.

In the charged particle beam exposure apparatus of the present invention, the system clock SCLK for operating the control unit 50
Several methods are conceivable as a method of generating. The data required to generate the clock is
The waiting time WT and the beam irradiation time ET are used to set the beam exposure cycle time PT. However, the output of the clock generation means 10, that is, the system clock SCLK is the cycle (= exposure cycle time PT) and the beam irradiation time ET or the waiting time WT occupied in the cycle.
The finally set waiting time WT and beam irradiation time E
The system clock SCLK is generated by inputting at least two of T and the exposure cycle time PT.

The beam irradiation time ET and the exposure cycle time PT are supplied from the correcting means 9A of this embodiment. As described above, in the charged particle beam exposure apparatus of the present embodiment, the exposure cycle time P
T can be set. That is, for example, assuming that the reference time JT of the apparatus is the maximum operation clock, if the exposure cycle time PT shorter than the maximum operation clock of the apparatus is set, the exposure cycle time PT is extended beyond the reference time JT, and Even when the exposure cycle time PT equal to or longer than the maximum operation clock is set, useless waiting time is not set. Therefore, unlike the conventional case, there is no useless time, and the throughput can be improved. Second Embodiment FIG. 6 shows a configuration diagram of a correcting means 9 in a charged particle beam exposure apparatus according to a second embodiment of the present invention. The other components of the apparatus are the same as in the first embodiment.

In the figure, a correction means 9 B comprises a first difference means 17 for obtaining a difference ΔA 1 between a predetermined reference time JT 1 and a beam irradiation time ET set by the irradiation time setting means 7, and a waiting time setting means 5. Second comparing means 19 for comparing the set waiting time WT with the difference ΔA1, and as a result of the second comparing means 19, a value of WT if the difference ΔA1 is equal to or less than the waiting time WT, and a value of the difference ΔA1 exceeding the waiting time WT. Then, a first waiting time resetting means 21 for resetting the waiting time WT by replacing the value greater than or equal to the difference ΔA1 with the waiting time WT.

The first waiting time resetting means 21 calculates the difference ΔA1 and the waiting time W based on the comparison result of the second comparing means.
Selector SE for selecting T as a new waiting time WT
1.

When the exposure is performed, an increase in the exposure cycle time PT is usually added to the waiting time WT.
This is because, if added to the beam irradiation time ET, the actual irradiation time on the sample becomes longer, resulting in a dose over. Therefore, the same effect as that of the first embodiment can be obtained by comparing the reference time JT1 with the irradiation time ET to obtain a difference and comparing the difference with the waiting time WT as in the present embodiment. Can be

In this embodiment, the difference ΔA1 (= JT1-ET) between the reference time JT1 and the beam irradiation time ET is obtained,
The difference value ΔA1 is compared with the waiting time WT, and ΔA1 ≦ W
When T, WT, when ΔA1> WT, the difference value ΔA1,
The waiting time WT is replaced. in this case,
As the reference time JT1, an operation limit time of the exposure apparatus, for example, 100 [nsec] is given. Third Embodiment FIG. 7 shows a configuration diagram of a correcting means 9 in a charged particle beam exposure apparatus according to a third embodiment of the present invention. The other components of the apparatus are the same as in the first embodiment.

In the figure, the correction means 9C includes a second difference means 23 for obtaining a difference ΔA2 between a predetermined reference time JT2 and the waiting time WT set by the waiting time setting means 5.
Comparing means 25 for comparing the zero value with the difference ΔA2
As a result of the third comparing means 25, if the difference ΔA2 is equal to or less than zero, zero is added, and if the difference ΔA2 exceeds zero, a value equal to or greater than the difference ΔA2 is added to the waiting time WT. And a second waiting time resetting means 27 for resetting the WT.

The second waiting time resetting means 27 outputs a selector SE2 for outputting either the zero value or the difference ΔA2 based on the result of the third comparing means 25, the waiting time WT and the selector SE.
It comprises an adder AD1 for adding two outputs.

In this embodiment, the difference ΔA2 (= JT2−WT) between the reference time JT2 and the waiting time WT is obtained, and the difference ΔA2
When ≦ 0, WT, when ΔA2> 0, difference value ΔA2,
This is added to the waiting time WT. In this case, the reference time JT2 includes a beam irradiation time expected from the dose amount and the current density, for example, 20 [nsec], and a maximum operation time in which the control unit 50 of the exposure apparatus can operate, for example, 100
A difference from [nsec], for example, 80 [nsec] is given. Fourth Embodiment FIG. 8 shows a configuration diagram of a correcting means 9 in a charged particle beam exposure apparatus according to a fourth embodiment of the present invention. The other components of the apparatus are the same as in the first embodiment.

In the figure, a correcting means 9D compares a predetermined reference time JT2 with the waiting time WT set by the waiting time setting means 5; If the time WT is a value smaller than the reference time JT2, a third waiting time resetting means 31 for resetting the reference time JT2 as the waiting time WT is provided.

The fourth comparing means 29 comprises a subtractor SB1 for subtracting the waiting time WT from the reference time JT2, and a comparator CO3 for comparing a zero value with the output of the subtractor SB1. In the present embodiment, the reference time JT2 is compared with the waiting time WT, and when WT <JT2, the reference time JT2 is reset as the waiting time WT. Again, in this case,
The reference time JT2 is a difference between the beam irradiation time expected from the dose amount and the current density and the maximum operation time during which the control unit 50 of the exposure apparatus can operate.

[0068]

As described above , the first feature of the present invention is as follows.
In symptoms of the charged particle beam exposure apparatus, the correction means,
The set waiting time (WT) and beam irradiation time (E
Exposure cycle time (PT) for one shot based on T)
If the exposure cycle time (PT) is shorter than a predetermined reference time (JT), the exposure cycle time (P
T) is to reconfigure the exposure cycle time (PT) to be longer than the reference time (JT), in the correction unit 9
The reset exposure cycle time PT and the
Supply the beam irradiation time ET to the clock generation means 10
Then, a clock signal for driving each component in the charged particle beam exposure apparatus is generated. For example, if a maximum operation clock is given as a reference time (JT) of the apparatus, the maximum operation of the charged particle beam exposure apparatus can be performed. When the exposure cycle time (PT) shorter than the clock is set, the exposure cycle time (PT) is extended beyond the reference time (JT), and the exposure cycle time (PT) which is longer than the maximum operation clock is set. It is possible to provide a charged particle beam exposure apparatus capable of improving the throughput of the entire apparatus without setting a useless waiting time even when the exposure is performed. Also,
The charged particle beam according to any one of the second to fifth aspects of the present invention.
In the exposure system, the waiting time finally set by the correction means
Clock (WT) and beam irradiation time (ET)
The charged particle beam exposure apparatus.
Generate clock signal SCLK for driving each component
Therefore, the charged particle web according to the first feature of the present invention is described above.
The same effect as that of the beam exposure apparatus can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a charged particle beam exposure apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a data structure of exposure data.
FIG. 2A shows the data structure of the exposure data, and FIG. 2B shows the record format of the operation code.

FIG. 3 is a conceptual diagram illustrating an operation of an irradiation time setting unit.

FIG. 4 is a conceptual diagram illustrating the operation of a waiting time setting unit.

FIG. 5 is a configuration diagram of a correction unit in the charged particle beam exposure apparatus of the first embodiment.

FIG. 6 is a configuration diagram of a correction unit in the charged particle beam exposure apparatus of the second embodiment.

FIG. 7 is a configuration diagram of a correction unit in a charged particle beam exposure apparatus according to a third embodiment.

FIG. 8 is a configuration diagram of a correction unit in a charged particle beam exposure apparatus according to a fourth embodiment.

FIG. 9 is a configuration diagram of a conventional charged particle beam exposure apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Data management means 3 ... Shot decomposition means 4 ... Shot correction means 5 ... Waiting time setting means 7 ... Irradiation time setting means 7A ... Irradiation time setting part 7B ... Correction parts 9, 9A, 9B, 9C, 9D ... Correction means 10 ... Clock generation means 11 ... Exposure time setting means 13 ... First comparison means 15 ... Resetting means 17 ... First difference means 19 ... Second comparison means 21 ... First waiting time resetting means 23 ... Second difference means 25 ... Third comparing means 27 ... Second waiting time resetting means 29 ... Fourth comparing means 31 ... Third waiting time resetting means 50 ... Control unit 110 ... Exposure unit 111 ... Cathode electrode 112 ... Grid electrode 113 ... Anode electrode 114 ... Charged particle beam generation source 115: first slit 116: first electron lens 117: slit deflector 118: second lens 120: second slit (transmission mask) 125) Blanking 126 ... Third lens 127 ... Aperture 128 ... Refocus coil 129 ... Fourth lens 130 ... Dynamic focus coil 131 ... Dynamic stig coil 132 ... Fifth objective lens 133 ... Main differential coil 134 ... Sub deflector 135 ... Stages 136 to 139 first to fourth alignment coils 150 control unit 151 storage medium 152 CPU 153 interface unit 154 data memory 155 pattern control controller 156, 159, 164 to 166 DAC and amplifier unit 157 … Clock control circuit 158… blanking control circuit 160… sequence controller 161… stage control mechanism 162… laser interferometer 163… stage correction unit 167… deflection control circuit SE1 SE2 selector AD1 adder SB1 subtractor CO3 comparator WT wait time ET beam irradiation time PT exposure cycle time JT, JT1, JT2 reference time ΔA1, ΔA2 difference SCLK system clock (clock signal) OPi: Operation code P0Xi: X coordinate of pattern start point P0Yi: Y coordinate of pattern start point PSXi: Size of pattern in X direction PSYi: Size of pattern in Y direction DA1: Setting exposure amount DA2: Proximity effect correction coefficient DA3: Current Density DA4 Block information WT1 to WT3 Waiting time CO1, CO2 Comparison means W Wafer SB Blanking signal S1 Deflection signal S2, S3 Exposure position determination signal

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/027

Claims (6)

(57) [Claims] 1. at least a starting point of a pattern to be exposed;
Data management means (1) for holding exposure data having a size of the pattern, shape information of the pattern, and exposure time information as one pattern information, and outputting the exposure data upon exposure; Shot decomposing means (3) for decomposing the exposure data from (1) into shot data, and a waiting time setting means (WT) for setting a waiting time (WT) for each shot based on information from the shot decomposing means (3). 5), an irradiation time setting means (7) for setting a beam irradiation time (ET) based on the exposure time information, and the waiting time (WT) and the beam irradiation time (ET).
The exposure cycle time (PT) of one shot is determined based on the exposure cycle time (PT), and the exposure cycle time (PT) is set to a predetermined reference time (J).
A correction means (9) for resetting the exposure cycle time (PT) so that the exposure cycle time (PT) is longer than the reference time (JT) when the exposure cycle time is shorter than T) . beam irradiation time (ET), said correcting means (9) in reconfigured eXPOSURE cycle time (PT),
And a clock generating means (10) for generating a clock signal (SCLK) for driving each component in the charged particle beam exposure apparatus based on the above. (2) at least a starting point of a pattern to be exposed;
The size of the pattern, shape information of the pattern, and exposure
Exposure data having time information as one pattern information
During exposure, and outputs the exposure data during exposure.
Data management means (1) and exposure data from the data management means (1).
Shot decomposing means (3) for decomposing into data, and each shot based on information from the shot decomposing means (3).
Waiting time setting means for setting a waiting time (WT) for each unit
And (5) setting a beam irradiation time (ET) based on the exposure time information.
A constant irradiation time setting hand stage (7), the set wait time (WT), the predetermined reference time
(JT) and reset the waiting time (WT) based on
And a waiting time (WT) reset by the correcting means (9).
And the set beam irradiation time (ET) based on
Drive each component in the charged particle beam exposure system
Generation of a clock signal (SCLK) to be generated
The charged particle beam exposure device, characterized by chromatic and means (10). 3. The correction means (9) comprises a predetermined reference time (JT1) and the irradiation time setting means.
Difference from beam irradiation time (ET) set by (7)
First difference means (17) for calculating the minute (ΔA1), and the waiting time set by the waiting time setting means (5)
(WT) and the difference (ΔA1).
As a result of the step (19) and the second comparing means (19), the difference (ΔA1)
Is less than the waiting time (WT), WT is calculated as the difference
If (ΔA1) exceeds the waiting time (WT),
The values equal to or greater than the difference (ΔA1),
The waiting time (WT) in place of the waiting time (WT)
The charged particle beam exposure apparatus according to claim 2 , further comprising a first waiting time resetting means (21) for performing the setting . 4. The method according to claim 1, wherein the correcting means includes a predetermined reference time (JT2) and the waiting time setting means.
The difference (Δ) from the waiting time (WT) set by (5)
A2) second difference means (23), and third comparison means for comparing a zero value with the difference (ΔA2).
(25) and the result of the third comparing means (25), the difference (ΔA2)
Is zero or less, and the difference (ΔA2) exceeds zero
If the value is greater than the value of the difference (ΔA2),
The waiting time (WT) is added to the waiting time (WT).
3. A charged particle beam exposure apparatus according to claim 2 , further comprising a second waiting time resetting means (27) for resetting the time . 5. The method according to claim 1, wherein the correcting means includes a predetermined reference time (JT2) and the waiting time setting means.
Compare with the waiting time (WT) set by (5)
As a result of the fourth comparing means (29) and the fourth comparing means (29), the waiting time (W
If T) is smaller than the reference time (JT2),
The reference time (JT2) is used as the waiting time (WT) again.
The charged particle beam exposure apparatus according to claim 2 , further comprising a third waiting time resetting means (31) for setting . 6. The waiting time setting means (5) includes:
The information from the shot disassembly means (3)
Independent of the shot jump amount and slit size
Calculated, the sum of the waiting times determined from each physical quantity,
Alternatively, the maximum waiting time is set as a waiting time (WT), and the irradiation time setting means (7) sets the exposure time information as the exposure time information.
Exposure amount and proximity effect correction coefficient, and
Beam irradiation based on current density determined from contact effect correction coefficient
From claim 1, and sets the time (ET)
6. The charged particle beam exposure apparatus according to any one of 5 .