JP2000286186A - Charged particle beam exposure system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To expose a sample with a beam with high accuracy by the methods in which correction signals are generated by a correcting signal generation means, and the high frequency component is removed by a filtering means, then a sample is exposed to charged particle beam on the basis of the output signals. SOLUTION: A lens correcting circuit 325 calculates the correcting amount (correcting amount of rotation) of image rotation at each focus, and incorporates the calculated correcting amounts of rotation into converging data Dcd. A correcting DAC 324 converts the converging data Dcd into a correcting DAC output Sco and outputs the correcting DAC output Sco to a correcting LPF 323. The correcting LPF 323 removes high frequency components and generates a projection correcting signal Spc. An electron beam, which passes through a projection deflecting coil 25, forms an image on a wafer through a projection correcting magnetic field for exposing the wafer.

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 for exposing a circuit pattern on a wafer with a charged particle beam, and more particularly to a deflection apparatus for deflecting the charged particle beam.

[0002]

2. Description of the Related Art A charged particle beam exposure apparatus 5 is an apparatus for exposing a circuit pattern on a sample T with a charged particle beam. The charged particle beam includes an electron beam and an ion beam. The sample T includes a wafer, a mask, and a reticle. The charged particle beam exposure apparatus 5 includes a central control circuit 51 and a deflection device 52. The central control circuit 51 is a circuit that controls the entire operation of the charged particle beam exposure apparatus 5. The deflection device 52 is a device that deflects the charged particle beam to a predetermined position on the sample T. The central control circuit 51 sends a deflection command 53 indicating an exposure position to be exposed with a charged particle beam to a deflection device 52.
Output to

[0003] As shown in FIG.
A deflection coil 54, a DAC 55, and an arithmetic circuit 56 are provided. FIG. 11 is a block diagram showing functions of the conventional charged particle beam exposure apparatus 5. The deflection coil 54 is a coil that generates a deflection magnetic field 54H that deflects the charged particle beam. The deflection coil 54 generates a deflection magnetic field 54H based on the coil signal 57.

The DAC 55 is a circuit that converts the deflection data 58 into a coil signal 57 by DA conversion. The arithmetic circuit 56 is a circuit that receives the deflection command 53 and generates deflection data 58. The deflection command 53 has an exposure start position 53s
And an exposure end position 53e. The arithmetic circuit 56 has an exposure start position 53s and an exposure end position 53e.
Are calculated for a plurality of passing positions 53p. The arithmetic circuit 56 incorporates the information of each passing position 53p into the deflection data 58. The arithmetic circuit 56 performs an arithmetic operation for correcting the distortion of the charged particle beam at each passing position 53p. The arithmetic circuit 56 incorporates the correction result into the deflection data 58.

When the exposure operation is started, the central control circuit 5
1 indicates that the arithmetic circuit 56 supplies the charged particle beam to the exposure start position 53.
A deflection command 53 for deflecting linearly from s to the exposure end position 53e is output. The arithmetic circuit 56 calculates a plurality of passage positions 53p between the exposure start position 53s and the exposure end position 53e, and a correction amount of the distortion of the charged particle beam at each of the passage positions 53p. The arithmetic circuit 56 incorporates the information representing each passing position 53p and the correction amount at each passing position 53p into the deflection data 58. Then, the arithmetic circuit 56 calculates 1 for each position.
The two deflection data 58 are output to the DAC 55.

[0006] The DAC 55 converts the deflection data 58 into a coil signal 57 by DA, and converts the coil signal 57 into a deflection coil 5.
4 is output. The deflection coil 54 generates a deflection magnetic field 54H based on the coil signal 57. The charged particle beam is linearly deflected from the exposure start position 53s to the exposure end position 53e by the deflection magnetic field 54H. Then, the charged particle beam linearly exposes the sample.

[0007]

The higher the number of passing positions calculated by the arithmetic circuit, the more accurate the correction can be made.
For that purpose, the arithmetic circuit needs to calculate a plurality of positions in a short time, and to calculate the correction amount at each position in a short time. However, since the amount of operation performed by the operation circuit is enormous, the operation time is long. Since the operation time is long, the operation circuit cannot generate the deflection data in a short time.

As described above, since the arithmetic circuit cannot generate deflection data in a short time, the conventional charged particle beam exposure apparatus has a drawback that highly accurate correction cannot be performed. An object of the present invention is to solve such a drawback and to provide a charged particle beam exposure apparatus capable of exposing a sample with high accuracy.

[0009]

According to a first aspect of the present invention, there is provided a charged particle beam exposure apparatus, comprising: a correction signal generating means for generating a correction signal based on correction data corresponding to a position where a charged particle beam is exposed; It is characterized by comprising filter means for cutting high frequency components of a signal, and exposure means for exposing a sample with the charged particle beam based on an output signal of the filter means.

According to a second aspect of the present invention, in the charged particle beam exposure apparatus, the exposure unit includes a deflection unit that deflects the charged particle beam based on the output signal, and the correction signal generation unit includes a distortion correction signal. The correction signal is generated, and the distortion correction signal is a signal for correcting distortion generated when the deflection unit deflects the charged particle beam.

According to a third aspect of the present invention, in the charged particle beam exposure apparatus, the exposure unit moves a focal position of the charged particle beam based on the output signal, and a holding unit that movably holds the sample. Wherein the correction signal generating means generates the correction signal including a focus correction signal, and the focus correction signal indicates a change in the height of the sample caused when the holding means moves the sample. The signal is a signal for correcting the focus position based on

According to a fourth aspect of the present invention, in the charged particle beam exposure apparatus, the exposure unit includes a rotating unit that rotates the charged particle beam based on the output signal, and a holding unit that movably holds the sample. Wherein the correction signal generating means generates the correction signal including a rotation correction signal, the rotation correction signal is based on a change in the height of the sample that occurs when the holding means moves the sample, The signal is a signal for correcting the rotation of the charged particle beam.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The charged particle beam exposure apparatus 1 is an apparatus for exposing a pattern provided on a reticle R to a wafer W with an electron beam e. The charged particle beam exposure apparatus 1 will be described with reference to FIGS. First, each part of the charged particle beam exposure apparatus 1 will be described, and then the operation of the charged particle beam exposure apparatus 1 will be described. First, each part of the charged particle beam exposure apparatus 1 will be described.

As shown in FIG. 1, a charged particle beam exposure apparatus 1
Is provided with an exposure system 2 and a control system 3. FIG.
2 is a block diagram illustrating functions of the charged particle beam exposure apparatus 1. FIG. The exposure system 2 is a device that deflects the electron beam e. Reticle R and wafer W are attached to exposure system 2. The exposure system 2 includes a light source 21, an illumination deflection coil 22, an illumination correction lens 23, a reticle stage 24, a projection deflection coil 25, a projection correction lens 26, and a wafer stage 2.
7 are provided.

The light source 21 is a device that emits an electron beam e. The light source 21 stops emitting the electron beam e when the blanking signal Sb is being input. Light source 21
Emits an electron beam e when the blanking signal Sb is not input. The electron beam e emitted from the light source 21 goes to the illumination deflection coil 22. The illumination deflection coil 22 is a coil that deflects the electron beam e. Also,
The illumination deflection coil 22 corrects the distortion di of the electron beam e. The distortion di is the distortion of the electron beam e illuminating the reticle R. The illumination deflection coil 22 receives the illumination deflection signal Sid.
Generate an illumination deflection magnetic field Hid corresponding to. The illumination deflection magnetic field Hid deflects the electron beam e. The illumination deflection magnetic field Hid corrects the distortion di. The electron beam e deflected by the illumination deflection magnetic field Hid goes to the illumination correction lens 23.

The illumination correction lens 23 is a coil for forming an image of the electron beam e on the reticle R. Further, the illumination correction lens 23 is configured to control the focal position Fi of the electron beam e and the image rotation Ir.
i is corrected. The focal position Fi is the position of the focal point of the electron beam e illuminating the reticle R. Image rotation Iri
Is the rotation angle of the image of the electron beam e illuminating the reticle R. The illumination correction lens 23 generates an illumination correction magnetic field Hic corresponding to the illumination correction signal Sic. The illumination correction magnetic field Hic is determined by the focal position Fi of the electron beam e and the image rotation Ir.
i is corrected. The electron beam e deflected by the illumination correction magnetic field Hic is directed to the reticle stage 24.

The reticle stage 24 is a device for holding the reticle R. The reticle stage 24 holds the reticle R at a position where the electron beam e from the illumination correction lens 23 can be illuminated. As shown in FIG. 2, the shape of a region where the electron beam e from the illumination correction lens 23 illuminates the reticle R (hereinafter, this region is referred to as an illumination field 241) is a square. FIG. 2 is a diagram illustrating the reticle R.

The reticle R is a member for shaping the electron beam e into a pattern. As shown in FIG. 2, the reticle R includes a plurality of pattern fields Fr1, Fr2, F
r3... are provided. Pattern field Fr
Are regions where patterns to be exposed on the wafer W are provided. The shape of the pattern fields Fr1, Fr2, Fr3... Is rectangular. Pattern fields Fr1, Fr2, Fr3 ...
Is the same as the length of one side of the illumination field 241. Each pattern field Fr
Are provided at positions where their long sides are parallel to each other. The center positions of the pattern fields Fr1, Fr2, Fr3,... Are separated from each other by a field pitch 242. The field pitch 242 is longer than the length of one side of the illumination field 241. Pattern fields Fr1, Fr2, Fr3
... A direction parallel to the direction in which the long sides extend is referred to as an X direction. The direction perpendicular to the X direction is called the Y direction.

Returning to FIG. 1, the description will be continued. The reticle stage 24 translates the reticle R in the Y direction.
The reticle stage 24 may translate the reticle R not only in the Y direction but also in the X direction. The electron beam e illuminating the reticle R is applied to the pattern fields Fr1, F
It is shaped into a pattern of r2, Fr3,.

The projection deflection coil 25 is a coil for deflecting the electron beam e. The projection deflection coil 25 corrects the distortion dp of the electron beam e. The distortion dp is the distortion of the electron beam e that exposes the wafer W. The projection deflection coil 25 generates a projection deflection magnetic field Hpd corresponding to the projection deflection signal Spd. The projection deflection magnetic field Hpd deflects the electron beam e and simultaneously corrects the distortion dp. The electron beam e deflected by the projection deflection magnetic field Hpd is directed to the projection correction lens 26.

The projection correction lens 26 is a coil for forming an image of the electron beam e on the wafer W. Further, the projection correction lens 26 is configured to control the focal position Fp of the electron beam e and the image rotation Ir
is corrected. The focal position Fp is the position of the focal point of the electron beam e for exposing the wafer W. Image rotation Irp is
The rotation angle of the image of the electron beam e for exposing the wafer W. The projection correction lens 26 generates a projection correction magnetic field Hpc corresponding to the projection correction signal Spc. Projection correction magnetic field H
pc images the electron beam e on the wafer W and simultaneously corrects the focal position Fp and the image rotation Irp. The electron beam e formed by the projection correction magnetic field Hpc is directed to the wafer stage 27.

The wafer stage 27 is a device for holding a wafer W. The wafer stage 27 holds the wafer W at a position where the electron beam e from the projection correction lens 26 can expose the wafer W. As shown in FIG.
(Hereinafter, this area is referred to as an exposure field 271) has a square shape. FIG. 4 is a diagram of the wafer W viewed from the direction in which the electron beam e travels. The wafer stage 27 translates the wafer W in the Y direction.

The wafer stage 27 may translate the wafer W not only in the Y direction but also in the X direction. next,
Returning to FIG. 1, the control system 3 will be described. The control system 3 is a device that generates a signal for controlling the exposure system 2. The control system 3 includes a light source control unit 31, a projection control unit 32, and an illumination control unit 33.
And a central control unit 34.

The light source control unit 31 outputs a blanking signal Sb
Is a circuit that outputs. The light source controller 31 outputs a blanking signal Sb when the light-off command Cb is being input. The light source controller 31 suspends the output of the blanking signal Sb when the light-off command Cb is not input. The projection control unit 32 is a circuit that controls the projection deflection coil 25, the projection correction lens 26, and the wafer stage 27. The projection control unit 32 outputs a projection deflection signal Spd and a projection correction signal Spc based on the projection command Cp.

The function of the projection control unit 32 will be described in detail with reference to FIG. FIG. 3 is a functional block diagram of the projection control unit 32. The projection control unit 32 includes a deflection LPF 32
0, deflection DAC 321, deflection correction circuit 322, and correction LP
An F323, a correction DAC 324, a lens correction circuit 325, a projection control circuit 326, a driving device 327, an interferometer 328, and a stage control circuit 329 are provided.

The deflecting LPF 320 includes a projection deflecting coil 25.
Is a low-pass filter that outputs a projection deflection signal Spd. The deflecting LPF 320 cuts the high frequency component of the deflecting DAC output Spo to generate a projection deflecting signal Spd.
The deflection DAC 321 is a circuit that outputs a deflection DAC output Spo to the deflection LPF 320. The deflection DAC 321 is
The DA converter converts the deflection data Dpd into a deflection DAC output Spo.

The deflection correction circuit 322 includes a deflection DAC 321
Is a circuit for outputting deflection data Dpd. The deflection correction circuit 322 outputs deflection data Dpd based on the deflection command Cd. The deflection command Cd includes information on an exposure start position Pps at which the electron beam e starts exposure in the main fields Fw1, Fw2, Fw3,... And an exposure end position at which exposure ends in the main fields Fw1, Fw2, Fw3,. The information about Ppe is a command that is incorporated.

As shown in FIG. 4, the main field Fw
.., Fw2, Fw3,...
Are areas of the wafer W to be exposed. Main fields Fw1, Fw2, Fw3 ...
Is the pattern field Fr1, Fr2, Fr
It is almost similar to the shape of 3 ... Main field F
The length of the short side of w1, Fw2, Fw3,... is the same as the length of one side of the exposure field 271. Each of the main fields Fw1, Fw2, Fw3,... Is provided at a position where their long sides are parallel to each other. The central positions of the main fields Fw1, Fw2, Fw3,... Are separated from each other by a field pitch 272. The field pitch 272 corresponds to the exposure field 2
71 is the same length as one side.

Exposure start position Pps and exposure end position Ppe
Is the center position of the exposure field 271. The deflection correction circuit 322 calculates the positions of a plurality of passing points Pp1 to Pp7 arranged from the exposure start position Pps to the exposure end position Ppe while referring to the position of the wafer stage 27. The passing points Pp1 to Pp7 correspond to the exposure field 27.
1 is a position on the wafer W through which the center passes. Passing point Pp1
The interval in which .about.Pp7 are arranged is determined mainly by the lower of the calculation speed of the deflection correction circuit 322 and the calculation speed of the lens correction circuit 325. The interval at which the passing points Pp1 to Pp7 are arranged is short when both of these calculation speeds are fast, and long when one of them is slow.

The positions of the passing points Pp1 to Pp7 are not limited to the deflection correction circuit 322, but may be calculated by the projection control circuit 326 or the central control unit 34. Further, the passing points Pp1 to Pp
7 is obtained not only by calculation but also in advance by the deflection correction circuit 322, the projection control circuit 326, and the central control unit 3.
4 may be stored. The deflection correction circuit 322
A distortion correction amount for correcting the distortion dp of each of the passing points Pp1 to Pp7 is calculated with reference to the position of the wafer stage 27. FIG. 9 shows a graph of the distortion correction amount. FIG.
FIG. 7 is a diagram illustrating a distortion correction amount. Deflection correction circuit 322
Are the passing points Pp1 to Pp7 in one deflection data Dpd.
The information on one of the positions and the distortion correction amount therein are incorporated. The deflection correction circuit 322 calculates the passing point P
The same number of deflection data Dpd as p1 to Pp7 is output to the deflection DAC 321.

The correction LPF 323 is connected to the projection correction lens 26
Is a low-pass filter that outputs a projection correction signal Spc. The correction LPF 323 cuts the high frequency component of the correction DAC output Sco to generate a projection correction signal Spc.
The correction DAC 324 is a circuit that outputs a correction DAC output Sco to the correction LPF 323. The correction DAC 324 is
The condensed data Dcd is DA-converted into a corrected DAC output Sco.

The lens correction circuit 325 includes the correction DAC 32
4 is a circuit for outputting the condensed data Dcd. The lens correction circuit 325 outputs the light collection data Dcd based on the light collection command Cc. The focusing command Cc is a command in which information on the exposure start position Pps and information on the exposure end position Ppe are incorporated. The lens correction circuit 325 calculates the positions of the plurality of passing points Pp1 to Pp7 from the exposure start position Pps and the exposure end position Ppe represented by the light collection command Cc while referring to the position of the wafer stage 27. Then, the lens correction circuit 32
5 calculates the focus correction amount and the rotation correction amount at each of the passing points Pp1 to Pp7 with reference to the position of the wafer stage 27. The focus correction amount is calculated for each passing point Pp1 to Pp7.
Is the amount by which the focal position Fp is corrected. The rotation correction amount is an amount for correcting the image rotation Irp at each focal position Fp. FIG. 5 shows the focus correction amount. FIG. 7 shows the rotation correction amount.

The focus correction amount and the rotation correction amount are not limited to the lens correction circuit 325, but may be calculated by the projection control circuit 326 or the central control unit 34. Further, the focus correction amount and the rotation correction amount are not only obtained by calculation, but also in advance, the lens correction circuit 325, the projection control circuit 326, the central control unit 3
4 may be stored. Lens correction circuit 325
Incorporates one focus correction amount and one rotation correction amount into one condensed data Dcd. Lens correction circuit 325
Is the same number of condensed data D as the number of passing points Pp1 to Pp7.
cd is output to the correction DAC 324.

The projection control circuit 326 determines whether the projection command Cp
Is a circuit that outputs a deflection command Cd and a light-condensing command Cc based on the following. The projection command Cp is a command in which information on the center position of the main fields Fw1, Fw2, Fw3,... Is incorporated. The projection control circuit 326 calculates an exposure start position Pps and an exposure end position Ppe from the center positions of the main fields Fw1, Fw2, Fw3,... Incorporated in the projection command Cp. The projection control circuit 326 calculates the exposure start position Pps
Information about the exposure end position Ppe
It is incorporated in the deflection command Cd, and outputs the deflection command Cd to the deflection correction circuit 322. Further, the projection control circuit 3
26 incorporates the information on the exposure start position Pps and the information on the exposure end position Ppe into the focusing command Cc, and outputs the focusing command Cc to the lens correction circuit 325.

The driving device 327 is a device for moving the wafer stage 27 in the Y direction. The driving device 327 controls the wafer stage 27 based on the wafer stage signal Sws.
Is moved in the Y direction. The interferometer 328 is a device that measures the position of the wafer stage 27. The interferometer 328 irradiates the wafer stage 27 with laser light Lw, detects reflected light from the wafer stage 27, and
Is measured in the Y direction. The interferometer 328 incorporates information of the measured position into the position pulse signal Swp,
The position pulse signal Swp is output.

The stage control circuit 329 is a circuit that outputs a wafer stage signal Sws based on the wafer stage command Cws and the position pulse signal Swp.
The wafer stage command Cws is transmitted to the wafer stage 27.
The information about the position of is the command that is embedded. Upon receiving wafer stage command Cws, stage control circuit 329 outputs wafer stage signal Sws until the position of wafer stage 27 indicated by position pulse signal Swp is substantially equal to the position of wafer stage 27 indicated by wafer stage command Cws. I do. FIG.
And the description of the control system 3 will be continued.

The illumination controller 33 is a circuit for controlling the illumination deflection coil 22, the illumination correction lens 23, and the reticle stage 24. The illumination control unit 33 outputs an illumination deflection signal Sid and an illumination correction signal Sic based on the illumination command Ci and the reticle stage command Crs. Further, the illumination control unit 33 moves the reticle stage 24 based on the illumination command Ci and the reticle stage command Crs.

The functions of the illumination control section 33 are as follows: an illumination command Ci corresponding to the projection command Cp is input, a reticle stage command Crs corresponding to the wafer stage command Cws is input, and an illumination deflection corresponding to the projection deflection signal Spd is input. And outputs an illumination correction signal Sic corresponding to the projection correction signal Spc.
The function is the same as that of the projection control unit 32 except that the reticle stage 24 corresponding to is moved and the laser light Ls corresponding to the laser light Lw is output.

The central control unit 34 is a circuit that outputs a turn-off command Cb, an illumination command Ci, a reticle stage command Crs, a projection command Cp, and a wafer stage command Cws. When illuminating the pattern fields Fr1, Fr2, Fr3..., The central control unit 34 sets the pattern fields Fr1, Fr2, Fr3.
, A reticle stage command Crs for moving the reticle stage 24 to a position where the light can be illuminated, an illumination command Ci representing the center position of the pattern fields Fr1, Fr2, Fr3.
The output of b is interrupted. When the pattern fields Fr1, Fr2, Fr3,... Are not illuminated, the central control unit 34 outputs a turn-off command Cb.

The central control unit 34 has a main field Fw.
, Fw2, Fw3... Are exposed, a wafer stage command Cws for moving the wafer stage 27 to a position where the main fields Fw1, Fw2, Fw3. The projection command Cp representing the center position of Fw1, Fw2, Fw3,... Is output. Next, the charged particle beam exposure apparatus 1
Will be described.

The operation of the charged particle beam exposure apparatus 1 is a repetition of the operation of exposing the pattern of each pattern field of the reticle R to each of the main fields Fw1, Fw2, Fw3,.
The operation of exposing this pattern to the main field Fw1 will be described, and the description of the subsequent operation will be omitted. As shown in FIG. 1, first, the central control unit 34 sets the light-off command Cb
Is output. When the light-off command Cb is output, the light source control unit 31 outputs a blanking signal Sb. When the blanking signal Sb is output, the light source 21 stops emitting the electron beam e.

The central control unit 34 controls the pattern field F
A reticle stage command Crs for moving the reticle stage 24 to a position where r1 can be illuminated is output. The illumination control unit 33 moves the reticle stage 24 based on the reticle stage command Crs. Central control unit 34
Outputs an illumination command Ci representing the center position of the pattern field Fr1.

The illumination controller 33 outputs an illumination deflection signal Sid and an illumination correction signal Sic based on the illumination command Ci. The illumination deflection coil 22 receives the illumination deflection signal Sid.
, An illumination deflection magnetic field Hid is generated. The illumination correction lens 23 generates an illumination correction magnetic field Hic based on the illumination correction signal Sic. The central control unit 34 suspends the output of the light-off command Cb. When the output of the light-off command Cb is interrupted, the light source control unit 31
The output of b is interrupted. When the output of the blanking signal Sb is interrupted, the light source 21 emits an electron beam e.

As shown in FIG. 2, when the electron beam e is emitted from the light source 21, the electron beam e
The pattern field Fr1 is illuminated while moving in the X direction from is to the illumination end position Pie. The electron beam e illuminating the pattern field Fr1 is shaped into the pattern of the pattern field Fr1. The shaped electron beam e is directed to the projection deflection coil 25.

Returning to FIG. 1, the description will be continued. The central control unit 34 issues a wafer stage command C for moving the wafer stage 27 to a position where the main field Fw1 can be exposed.
ws is output. The stage control circuit 329 moves the wafer stage 27 to a position where the electron beam e can expose the wafer W based on the wafer stage command Cws.

The central control unit 34 controls the main field Fw
The projection command Cp representing the center position of 1 is output to the projection control circuit 326. The projection control circuit 326 calculates an exposure start position Pps and an exposure end position Ppe from the center position of the main field Fw1 represented by the projection command Cp. As shown in FIG. 3, the projection control circuit 326 incorporates information about the exposure start position Pps and information about the exposure end position Ppe into a deflection command Cd, and outputs the deflection command Cd to the deflection correction circuit 322.

The deflection correction circuit 322 determines the exposure start position Pp
From s to the exposure end position Ppe, the positions of the passing points Pp1 to Pp7 arranged in a straight line are obtained. The deflection correction circuit 322 calculates a distortion correction amount for correcting the distortion dp at each of the passing points Pp1 to Pp7. Deflection correction circuit 3
22 incorporates information on the positions of the passing points Pp1 to Pp7 and the distortion correction amounts at the passing points Pp1 to Pp7 into the deflection data Dpd. FIG. 9 shows a waveform of the correction information of the distortion dp. The deflection correction circuit 322 calculates the deflection data D
pd is output to the deflection DAC 321.

The deflection DAC 321 converts the deflection data Dpd into a deflection DAC output Spo. Deflection data Dp
Since d includes the correction information of the distortion dp, the deflection DAC output Spo includes a distortion correction component. The distortion correction component is a signal component obtained by DA-converting the correction information of the distortion dp. The waveform of the distortion correction component included in the deflection DAC output Spo is shown by a solid line in FIG. FIG. 10 is a diagram illustrating a waveform of a distortion correction component. As shown in FIG.
The waveform of the distortion correction component contains many high-frequency components, and has many errors with respect to the distortion dp correction information shown in FIG.

This is because, for the rate of change of the distortion dp,
Since the calculation speed of the deflection correction circuit 322 is low, the speed at which the deflection correction circuit 322 outputs the deflection data Dpd is equal to the distortion d.
The cause is that it is slower than the changing speed of p. Deflection DAC
321 outputs the deflection DAC output Spo to the deflection LPF 320. The deflection LPF 320 has a deflection DAC output Spo.
To generate a projection deflection signal Spd. The waveform of the distortion correction component included in the projection deflection signal Spd is shown by a broken line in FIG. As shown in FIG. 10, the waveform of the distortion correction component included in the projection deflection signal Spd has a small amount of high-frequency components and a small error with respect to the distortion dp correction information shown in FIG. That is, the distortion dp is accurately corrected.

The deflection LPF 320 outputs the projection deflection signal Spd.
Is output to the projection deflection coil 25. Projection deflection coil 25
Is based on the projection deflection signal Spd,
generates d. Since the projection deflection signal Spd includes a distortion correction component, the projection deflection magnetic field Hpd includes a magnetic field component for correcting the distortion dp. The electron beam e from the reticle R is deflected by the projection deflection magnetic field Hpd, and at the same time, the distortion dp is corrected by a correction magnetic field component for correcting the distortion dp included in the projection deflection magnetic field Hpd. Since the distortion correction component included in the projection deflection signal Spd corrects the distortion accurately, the distortion dp of the electron beam e is accurately corrected.

The projection control circuit 326 incorporates information about the exposure start position Pps and information about the exposure end position Ppe into the light collection command Cc, and outputs the light collection command Cc to the lens correction circuit 325. The lens correction circuit 325 calculates the positions of the passing points Pp1 to Pp7 through which the electron beam e passes based on the focusing command Cc. The lens correction circuit 325 calculates the focal position Fp at the passing points Pp1 to Pp7. FIG. 5 shows the focal position F
The waveform of p is shown. FIG. 5 is a diagram illustrating the focal position Fp. The lens correction circuit 325 determines whether each of the passing points Pp1 to Pp7
, The correction amount of the focal position Fp (hereinafter, referred to as a focus correction amount) is calculated. The lens correction circuit 325 incorporates the calculated focus correction amount into the collected light data Dcd.

The lens correction circuit 325 determines each focal position Fp
Is calculated. FIG. 7 shows the image rotation Irp at each focal position Fp. FIG. 7 shows the image rotation I
It is a figure showing rp. Then, the lens correction circuit 325
Calculates the correction amount of the image rotation Irp at each focal position Fp (hereinafter, referred to as the rotation correction amount). The lens correction circuit 325 incorporates the calculated rotation correction amount into the collected light data Dcd.

The lens correction circuit 325 calculates the condensed data Dc
d is output to the correction DAC 324. Correction DAC 324
Converts the collected light data Dcd into a corrected DAC output Sco. Each of the passing points Pp1 to Pp
7 and the rotation correction amount at each focus position Fp, the correction DAC output Sco includes a correction component of the focus position Fp as shown by a solid line in FIG. 6, and a solid line in FIG. And a correction component of the image rotation Irp as shown by the following. FIG. 6 is a diagram illustrating a waveform of a correction component of the focal position Fp. FIG. 8 is a diagram illustrating a correction component of the image rotation Irp.

As shown by the solid line in FIG. 6, the correction component of the focal position Fp contains many high-frequency components, and has many errors with respect to the focal position Fp shown in FIG. This is because the speed of the change of the focal position Fp depends on the lens correction circuit 325.
This is because the calculation speed of the lens correction circuit 325 cannot follow the change in the focal position Fp because the calculation speed of the lens correction circuit 325 is low.

Further, as shown by the solid line in FIG.
The rp correction component contains many high-frequency components,
There are many errors with respect to the image rotation Irp shown in FIG. This is because the calculation speed of the lens correction circuit 325 is lower than the change speed of the image rotation Irp.
Is not able to follow the change in the image rotation Irp.

The correction DAC 324 outputs the correction DAC output Sc.
is output to the correction LPF 323. Correction LPF323
Cuts the high frequency component of the corrected DAC output Sco,
A projection correction signal Spc is generated. Corrected DAC output Sco
Includes a correction component for the focal position Fp and a correction component for the rotation angle, so that the projection correction signal Spc includes a correction component for the focal position Fp as indicated by a broken line in FIG. And a correction component of the image rotation Irp as shown by the following. As shown in FIG. 6, the correction component of the focal position Fp included in the projection correction signal Spc has a small high-frequency component.
The error is small with respect to the focal position Fp shown in FIG. That is, the projection correction signal Spc accurately corrects the focal position Fp.

As shown in FIG. 8, the projection correction signal S
The correction component of the image rotation Irp included in pc has a small high-frequency component and a small error with respect to the image rotation Irp shown in FIG. That is, the projection correction signal Spc accurately corrects the image rotation Irp. The correction LPF 323 outputs the projection correction signal Spc to the projection correction lens 26. The projection correction lens 26 generates a projection correction magnetic field Hpc based on the projection correction signal Spc. Since the projection correction signal Spc includes a correction component for the focal position Fp and a correction component for the image rotation Irp, the projection correction magnetic field Hpc includes a magnetic field component for correcting the focal position Fp and a magnetic field component for correcting the image rotation Irp. And
included.

The focus position Fp of the electron beam e passing through the projection deflection coil 25 is corrected by the correction magnetic field component of the focus position Fp included in the projection correction magnetic field Hpc. At the same time, the electron beam e passing through the projection deflection coil 25
The image rotation Irp is corrected by a magnetic field component for correcting the image rotation Irp included in the projection correction magnetic field Hpc. Since the correction component of the focal position Fp included in the projection correction signal Spc accurately corrects the focal position Fp, the focal position F of the electron beam e between the passing points Pp1 to Pp7.
p is accurately corrected. Further, the correction component of the image rotation Irp included in the projection correction signal Spc is exactly the image rotation Ir.
Since p is corrected, the image rotation Irp of the electron beam e between the passing points Pp1 to Pp7 is accurately corrected.

The electron beam e passing through the projection deflection coil 25 is imaged on the wafer W by the projection correction magnetic field Hpc. The electron beam e for exposing the wafer W in this manner exposes the main field Fw1 from the exposure start position Pps to the exposure end position Ppe through the passing points Pp1 to Pp7, as shown in FIG.

Since the electron beam e for exposing the wafer W is shaped into the pattern of the pattern field Fr1 of the reticle R, the pattern of the pattern field Fr1 of the reticle R is exposed on the main field Fw1. Since the distortion dp, the focal position Fp, and the image rotation Irp of the electron beam e for exposing the wafer W are accurately corrected, the pattern exposed on the wafer W has the distortion dp, the focal position Fp, and the image rotation Irp. Is accurately corrected.

Thus, the charged particle beam exposure apparatus 1
Exposes the pattern of the pattern field Fr1 of the reticle R to the main field Fw1 of the wafer W. When the exposure of the main field Fw1 is completed, the central controller 34 sets the wafer stage 27 to the field pitch 272.
A wafer stage command Cws moving only in the Y direction is output to the stage control circuit 329, and exposure of the main field Fw2 is started.

Thereafter, as in the case of the pattern field Fr1, the central control section 34 exposes the patterns of the pattern fields Fr2, Fr3, Fr4... To the main fields Fw2, Fw3, Fw4.

[0063]

According to the first aspect of the present invention, there is provided a charged particle beam exposure apparatus, comprising: a correction signal generating means for generating a correction signal based on correction data corresponding to a position where a charged particle beam is exposed; and a high frequency component of the correction signal. And an exposure unit that exposes the sample with the charged particle beam based on an output signal of the filter unit.

Therefore, the charged particle beam can be corrected with high accuracy. 3. The charged particle beam exposure apparatus according to claim 2, wherein the exposure unit includes a deflecting unit that deflects the charged particle beam based on the output signal, and the correction signal generating unit includes a correction unit that includes a distortion correction signal. A signal is generated, and the distortion correction signal is a signal for correcting distortion generated when the deflection unit deflects the charged particle beam.

Therefore, the distortion of the charged particle beam can be corrected with high accuracy. 4. The charged particle beam exposure apparatus according to claim 3, wherein the exposure unit has a focus moving unit that moves a focal position of the charged particle beam based on the output signal, and a holding unit that movably holds the sample. The correction signal generation unit generates the correction signal including a focus correction signal, and the focus correction signal is based on a change in the height of the sample that occurs when the holding unit moves the sample. , A signal for correcting the focal position.

Accordingly, the focal position of the charged particle beam can be corrected with high accuracy. 5. The charged particle beam exposure apparatus according to claim 4, wherein the exposure unit includes: a rotation unit configured to rotate the charged particle beam based on the output signal; and a holding unit configured to movably hold the sample. The signal generation unit generates the correction signal including a rotation correction signal, and the rotation correction signal is based on a change in the height of the sample that occurs when the holding unit moves the sample. The signal is a signal for correcting rotation of a line.

Therefore, the rotation of the charged particle beam can be corrected with high accuracy.

[Brief description of the drawings]

FIG. 1 is a block diagram showing functions of a charged particle beam exposure apparatus 1.

FIG. 2 is a diagram showing a reticle R;

FIG. 3 is a functional block diagram of a projection control unit 32;

FIG. 4 is a view of the wafer W as viewed from a direction in which an electron beam e travels.

FIG. 5 is a diagram showing a focal position Fp.

FIG. 6 is a diagram illustrating a waveform of a correction component of a focal position Fp.

FIG. 7 is a diagram showing an image rotation Irp.

FIG. 8 is a diagram showing a correction component of image rotation Irp.

FIG. 9 is a diagram showing a distortion correction amount.

FIG. 10 is a diagram showing a waveform of a distortion correction component.

FIG. 11 is a block diagram showing functions of a conventional charged particle beam exposure apparatus 5.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 charged particle beam exposure device 2 exposure system 3 control system 5 conventional charged particle beam exposure device 25 projection deflection coil 26 projection correction lens 27 wafer stage 32 projection control unit 33 illumination control unit 320 deflection LPF 321 deflection DAC 322 deflection correction circuit 323 Correction LPF 324 Correction DAC 325 Lens correction circuit 326 Projection control circuit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/30 541B

Claims (4)

[Claims] 1. A correction signal generating means for generating a correction signal based on correction data corresponding to a position where a charged particle beam is exposed, a filter means for cutting a high frequency component of the correction signal, An exposure means for exposing a sample with the charged particle beam based on an output signal. 2. The apparatus according to claim 1, wherein said exposure means has a deflection means for deflecting said charged particle beam based on said output signal, and said correction signal generation means generates said correction signal including a distortion correction signal. 2. The charged particle beam exposure apparatus according to claim 1, wherein the distortion correction signal is a signal for correcting a distortion generated when the deflection unit deflects the charged particle beam. 3. The exposure means comprises: a focus moving means for moving a focus position of the charged particle beam based on the output signal;
Holding means for movably holding the sample, wherein the correction signal generating means generates the correction signal including a focus correction signal, and wherein the focus correction signal indicates that the holding means moves the sample. 2. The charged particle beam exposure apparatus according to claim 1, wherein the signal is a signal for correcting the focal position based on a change in the height of the sample that occurs in the case. 4. The exposure means has a rotation means for rotating the charged particle beam based on the output signal, and a holding means for movably holding the sample. Generating the correction signal including a correction signal;
2. The rotation correction signal according to claim 1, wherein the rotation correction signal is a signal for correcting rotation of the charged particle beam based on a change in height of the sample that occurs when the holding unit moves the sample. Charged particle beam exposure equipment.