JP3198187B2 - Adjustment method of charged particle beam exposure apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of adjusting a charged particle beam exposure apparatus using a so-called charged particle beam such as an ion beam or an electron beam. More specifically, the present invention relates to an exposure method using a transmission mask plate (block mask). The present invention relates to a method for adjusting a charged particle beam exposure apparatus.

In recent years, with the increase in the density of integrated circuits, new exposure methods using charged particle beams, especially electron beam exposure, and X-rays have been studied in place of photolithography, which has been the mainstream for forming fine patterns for many years. It has come to be used for.

The electron beam exposure is characterized in that a pattern can be formed using an electron beam to form a fine pattern on the order of microns or smaller. However, since the electron beam exposure method is a so-called "one-stroke writing" exposure apparatus, its processing ability is limited.

In recent years, a method has been proposed in which a pattern such as a variable rectangle such as a rectangle, a square, or a triangle is formed in advance, and an electron beam is selected and irradiated and exposed when necessary. For example, Japanese Patent Application No. 52-119185 proposes performing exposure using a mask in which each pattern is arranged in a block shape. Further, JP-A-62-260
No. 322 proposes a method in which a repetitive pattern necessary for the shape of a memory cell or the like and a quadrangular aperture for a general-purpose rectangular pattern are formed on a diaphragm plate to perform exposure. This exposure method is effective for exposure of a memory type in which the repeated cell pattern occupies most of the exposure area. In this case, it is necessary to have a plurality of pattern groups on the transmission mask in order to perform exposure efficiently. When performing exposure, the electron beam is changed and selected for each pattern.

Under such circumstances, the present applicant has developed a so-called block exposure method in which about 20 to 40 blocks are arranged on a transmission mask, and an arbitrary position thereof is selected and exposed by a mask deflector.

[0006]

2. Description of the Related Art Conventionally, as a charged particle beam exposure apparatus, for example, an electron beam exposure apparatus as shown in FIG.

In the figure, 1 is an electron gun, 2 is an optical axis, 3 is an electron beam emitted from the electron gun 1, and 4 is a section for shaping the cross section of the electron beam 3 emitted from the electron gun 1 into a rectangle. The rectangular shaping apertures 5 and 5 are electromagnetic lenses for converging the electron beam 3 shaped by the rectangular shaping aperture 4.

Reference numeral 6 denotes a variable rectangular shaping deflector used to perform variable rectangular shaping of the rectangular shaped electron beam 3, and 7 denotes a parallel beam of the electron beam 3 passing through the variable rectangular shaping deflector 6. An electromagnetic lens for converting

Reference numeral 8 denotes a block mask formed by forming a plurality of block patterns. The block mask 8 is configured, for example, as shown in a plan view of FIG.

In FIG. 35, 9 is a substrate, 10 is an area called an area arranged in a matrix at a predetermined pitch, and 11 is an area called a block arranged in a matrix in the area. A block pattern is formed as a unit.

The area 10 has a size capable of maximally deflecting the electron beam 3 on the block mask 8, and as shown in FIG.
Six blocks 11 are set. FIG. 37 is a plan view showing an example of a block pattern, and 12 is a block pattern.

The block mask 8 has a mask area 120 of a calibration mask pattern in one area. The mask area 120 has a configuration in which mask patterns of rectangular openings are arranged in a grid pattern at a predetermined pitch, as shown in FIG.

In FIG. 34, reference numerals 13 to 16 denote a case where the cross-sectional shape of the electron beam 3 converted into a parallel beam by the electromagnetic lens 7 is shaped into the shape of the block pattern 12 formed on the block mask 8, that is, block shaping. A so-called mask deflector used in such a case.

Here, the mask deflector 13 is a mask deflector for deflecting the electron beam 3 in the direction of the selected block pattern. Also, the mask deflector 14
This is a mask deflector for deflecting the electron beam 3 deflected by the mask deflector 13 in a direction perpendicular to the block mask 8 on the selected block pattern.

The mask deflector 15 is a mask deflector for deflecting the electron beam 3 which has been block-shaped by the selected block pattern in the direction of the optical axis 2 when no deflection is performed. Further, the mask deflector 16 is a deflector for returning the electron beam 3 deflected by the mask deflector 15 onto the optical axis 2 at the time of no deflection.

The mask deflector 13 and the mask deflector 1
The mask deflector 6 and the mask deflector 14 and the mask deflector 15 are respectively arranged at mirror-symmetric positions with the block mask 8 interposed therebetween.

Reference numeral 17 denotes an electromagnetic lens for converging the electron beam 3 converted into a parallel beam by the electromagnetic lens 7, and the electromagnetic lens 17 and the electromagnetic lens 7 are positioned mirror-symmetrically with respect to the block mask 8. Are located.

Reference numeral 18 denotes a blanking electrode for controlling the passage of the electron beam 3, 19 denotes a reduction lens for reducing the electron beam image, and 20 denotes an aperture aperture.
Reference numeral 22 denotes an imaging lens for forming an electron beam image on a sample.

Reference numeral 23 denotes a main deflector for deflecting the electron beam 3 to the sub-deflection area, and reference numeral 24 denotes a sub-deflector (sub-deflector) for deflecting the electron beam 3 to the exposure position in the sub-deflection area. Deflector), 25 is a sample, and 26 is a sample stage on which the sample 25 is mounted.

The control section 50 shown in FIG. 38 controls the exposure section shown in FIG.

The control unit 50 includes a storage medium 51 for storing design data of the integrated circuit device, a CPU 52 for controlling the entire charged particle beam, for example, drawing information captured by the CPU 52, and a wafer W on which the pattern is to be drawn. An interface 53 for transferring various information such as the drawing information of the block mask 8 and the mask information of the block mask 8, a data memory 54 for storing the drawing pattern information and the mask information transferred from the interface 53; One of the transmission holes in the transmission mask
And generating mask irradiation position data P1 to P4 indicating the position of the specified transmission hole on the transmission mask, and generating wafer exposure position data S3 indicating the position on the wafer for exposing the pattern. A pattern generation unit 55 as a designating unit, a holding unit, a calculating unit, and an output unit for performing various processes including a process of calculating a correction value H according to a shape difference between a pattern shape to be drawn and a designated transmission hole shape; , an amplifier 56 for generating a corrected deflection signal HS1 from the correction value H, the voltage value from the data P ₁ ~P ₄ PS1~PS
4 and a mask moving mechanism 58 that moves the block mask 8 as necessary.

Further, upon receiving the exposure time / exposure waiting time from the pattern generating section 55, a clock control circuit 59 for generating a system clock and a blanking clock for operating the entire exposure apparatus, and a clock control circuit 59 It has a blanking control circuit 60 that generates a blanking timing upon receiving an output, and an amplifier section 61 that generates a blanking signal SB.

Further, based on the exposure start / end information transferred from the interface 53, the main differential deflection information is output to the data memory 54 via the pattern generator, and the desired stage is transmitted to the stage controller. Command to move to the position, control the stage correction unit to correct the difference between the stage movement position and the main differential deflection, and generate / stop the clock to the pattern generation unit for the clock control unit. A sequence controller 62 for controlling the general sequence of the exposure processing, such as a command, a deflection control circuit 63 for generating a main differential deflection signal S2 based on main differential deflection information from a data memory 54, a pattern generation unit 55, and a deflection control unit. Amplifier units 64 and 65 that generate exposure position determination signals S2 and S3 based on the output from the circuit 63; Receiving a stage control mechanism 66 for moving the stage in accordance with the requirements, a laser interferometer 67 for detecting the stage position, the Meindefu deflection amount from the deflection control circuit, and a stage moving position from the stage control unit,
Stage correction unit 68 for correcting the difference from the main differential deflection
And

The electron beam emitted from the electron gun 1 is shaped into a rectangular shape by the first slit, and then shaped into lenses 5 and 7.
And irradiates the light onto the transmission mask. Deflection in a relatively large range (within about 5 mm) in the transmission mask is performed by the first to fourth deflectors 13 to 16, and deflection in a relatively small range (within about 500 μm) after being selected by the deflectors. In the case of variable rectangular exposure performed by the slit deflector 6, the slit deflector 6 is used to shape the lens into an arbitrary shape (for example, an arbitrary rectangular size of 3 μm square or less).

The beam transmitted through the transmission mask 8 passes through a blanking 18. And it is reduced by the 4th lens,
Thereafter, the light is deflected by the sub deflector 24 in a small deflection area of about 100 μm. In addition, the main differential coil 23
As a result, the sub-deflector deflection area is largely deflected in an exposure field of about 2 mm.

The data to be exposed is read from the storage medium 51 by the CPU 52 and stored in the data memory 54. When exposure is started by a signal to the sequence controller 62, first, the stored main differential deflection position is sent to the deflection control circuit 63 to output deflection amount data S2, and the main differential coil 23 is output via the DAC / AMP 64.
Is output to Then, after the output value is stabilized, the sequence controller instructs the clock control circuit to generate a system clock, and as a result, the data memory 54 sends out the stored pattern data to the pattern generation unit. The pattern generating section generates shot data based on the read pattern data.

Specifically, the shot data includes P1 to P4 signals indicating the beam irradiation position on the mask, H signals indicating the amount of deflection of the beam irradiation position on the mask, and transmitting the beam through these masks. S3 signal and shot time data for deflecting the beam shaped in the above to the desired position on the wafer, and shows how long it is necessary to wait until the electrostatic deflector / electromagnetic deflector settles when these signals are applied. It consists of shot waiting time data and the like. After these signals are generated in the pattern generation section, they enter the pattern correction section. The pattern correction unit corrects a wafer rotation or the like that occurs when the exposure sample W is set on the stage. The output signals for shot generation are D
The signal is input to an AC (digital converter), converted into an analog signal, and applied to an electrode / coil through an amplifier provided as necessary.

Such an electron beam exposure apparatus is a DRAM.
When manufacturing an LSI having a repetitive pattern such as (dynamic random access memory), the electron beam 3
Block exposure can be performed by repeatedly shaping the cross-sectional shape into a pattern, so that the exposure time can be shortened.

Here, in order to perform high-precision block exposure, the electron beam 3 is accurately deflected to the position of the selected block pattern, and the deflected electron beam 3 is again deflected to the optical axis at the time of non-deflection. And turn back to aperture 2
It is necessary to control so as to pass through the aperture 20 without being shaded by zero.

In order to perform such control, what kind of relationship exists between the intensity of the deflection signal to be applied to the mask deflectors 13 to 16 and the position (coordinate) on the block mask 8? It is necessary to determine in advance the intensity of the deflection signal to be applied to each of the mask deflectors 13 to 16 according to the position of the selected block pattern.

FIG. 39 shows an example of the trajectory of the electron beam 3 from the mask deflector 13 to the aperture 20. In FIG. 39, 12A indicates a selected block pattern,
x _m and y _m are two-dimensional orthogonal axes on the block mask 8.

A shape 28 like a "floating tool" shown by a broken line is used when the electron beam 3 is deflected to a position equidistant from the intersection 27 of the optical axis 2A and the block mask 8 at the time of no deflection. This shows that the trajectory of the electron beam 3 is on the surface of the shape 28.

FIG. 40 shows the electron beam 3 shown in FIG.
Is a diagram when the trajectory of the mask deflector 13 is viewed from above the block mask 8, in which an arrow 29 indicates the deflection direction of the mask deflector 13 and θ
1 shows a deflecting direction of the mask deflector 13 at an angle between x _m-axis, the arrow 30 is deflected direction of the mask deflector 14,
θ2 shows a deflection direction of the mask deflector 14 at an angle between x _m-axis.

Further, arrows 31 deflection direction in the mask deflector 15, .theta.3 those showing the deflection direction of the mask deflector 15 at an angle between x _m-axis, the arrow 32 is deflected direction of the mask deflector 16, .theta.4 is the deflection direction of the mask deflector 16 illustrates in angle between the x _m-axis.

FIG. 41 is a diagram showing a change in the trajectory of the electron beam 3 when the deflection direction θ1 of the mask deflector 13 is changed. When θ1 is increased, the trajectory of the electron beam 3 is changed to a solid line 33. To a dashed line 34.

FIG. 42 is a diagram showing a change in the trajectory of the electron beam 3 when the deflection direction θ2 of the mask deflector 14 is changed. When θ2 is increased, the trajectory of the electron beam 3 changes from the solid line 35 It changes like the broken line 36.

FIG. 43 is a diagram showing a change in the trajectory of the electron beam 3 when the deflection directions θ3 and θ4 of the mask deflectors 15 and 16 are changed. When θ3 is increased, the trajectory of the electron beam 3 becomes larger. When the angle θ4 is increased from the solid line 37 to the broken line 38, the trajectory of the electron beam 3 is changed from the solid line 39 to the broken line 40.

FIG. 44 is a diagram showing a change in the plane on which the trajectory of the electron beam 3 exists when the deflection intensity G1 of the mask deflector 13 is changed. When G1 is increased, the trajectory of the electron beam 3 becomes larger. The existing surface changes from the shape surface indicated by the solid line 41 to the shape surface indicated by the dashed line.

FIG. 45 is a diagram showing a change in the plane on which the trajectory of the electron beam 3 exists when the deflection intensity G2 of the mask deflector 14 is changed. When G2 is increased, the trajectory of the electron beam 3 becomes larger. The existing surface changes from the shape surface indicated by the solid line 43 to the shape surface indicated by the one-dot chain line 44.

FIG. 46 shows a change in the plane on which the trajectory of the electron beam 3 exists when the deflection intensity G3 of the mask deflector 15 is changed and the deflection intensity G4 of the mask deflector 16.
FIG. 9 is a diagram showing a surface on which the trajectory of the electron beam 3 exists when G is changed. When G3 is increased, the surface on which the trajectory of the electron beam 3 exists changes from the shape shown by the solid line 45 to the shape shown by the one-dot chain line 46. When the surface changes and G4 is increased, the trajectory of the electron beam 3 exists on the shape surface indicated by the dashed line 47.

[0041] Here, among the intensity of the deflection signals to be applied to the mask deflector 13 to 16, the X _m-axis direction component BSX
i, and BSYi the y _m-axis direction component, for example, offset term, gain term, low tension section only necessary to consider only orthogonality correction term, if not taken into account any more higher-order terms, the mask deflection BSXi, BSYi of the deflection signal to be applied to the devices 13 to 16 and the deflected electron beam 3
Can be expressed as shown in equation 1 below, with the position (x _m , y _m ) on the block mask 8 through which.

[0042]

(Equation 1)

That is, when determining the deflection signal intensities BSXi and BSYi in accordance with the relationship shown in the equation (1), the electron beam 3 is accurately deflected to the position of the selected block pattern, and then is deflected at the time of no deflection. It is possible to return to the optical axis and pass through the aperture 20 without being shaded by the aperture 20.

In equation (1), the matrices on the right and left sides are called correction coefficient matrices.
O _Xi and O _Yi are offset term correction coefficients, G _Xi and C _Yi are gain term correction coefficients, R _Xi and R _Yi are rotation tension correction coefficients, and H _Xi and H _Yi are orthogonality correction terms correction coefficients. It is.

In addition, i takes a value of 1 to 4. When i = 1, the equation (1) expresses the intensity BSX1, BSY1 of the deflection signal to be applied to the mask deflector 13 and the electron beam 3
(X _m , y _m ) on the block mask 8 at which the light should be deflected
Will be shown.

When i = 2, the equation (1) becomes
Intensity BSX of deflection signal to be applied to mask deflector 14
2, the relationship between BSY2 and the position (x _m , y _m ) on the block mask 8 where the electron beam 3 is to be deflected.

When i = 3, the equation (1) becomes
Intensity BSX of deflection signal to be applied to mask deflector 15
3, the relationship between BSY3 and the position (x _m , y _m ) on the block mask 8 where the electron beam 3 is to be deflected.

When i = 4, the equation (1) becomes
Intensity BSX of deflection signal to be applied to mask deflector 16
4, the relationship between BSY4 and the position (x _m , y _m ) on the block mask 8 where the electron beam 3 is to be deflected.

Therefore, if a correction coefficient matrix is obtained for each of the mask deflectors 13 to 16, the electron beam 3
After being accurately deflected to the position of the selected block pattern, it can be returned to the non-deflection optical axis and passed through the aperture 20 without being shaded by the aperture 20.

Here, when the correction coefficient matrix is obtained, as a first step, the electron beam 3 is deflected to an appropriate position on the plane on which the block mask 8 is originally arranged without using the block mask 8. Then, it is necessary to consider the case where the electron beam 3 is returned to the optical axis at the time of no deflection and passes through the aperture 20 again, and the deflection conditions (deflection intensity and deflection direction) in this case need to be obtained.

This is carried out by simulation. If the deflection conditions are not appropriate, the electron beam 3 is shaded by the aperture 20. Therefore, whether the deflection conditions are appropriate depends on the sample current value, specifically, Is sample 2
The determination can be made based on whether or not the output current value of the Faraday cup set in place of 5 is the maximum value. Therefore, in this simulation, a procedure for searching for a deflection condition that maximizes the sample current value is executed.

In this case, since the mask deflector 13 and the mask deflector 16 and the mask deflector 14 and the mask deflector 15 are arranged at mirror-symmetric positions with the block mask 8 interposed therebetween, θ1 = θ4, θ2 = θ3, G1 = G
4, it is appropriate to provide the condition that G2 = G3.

Here, FIGS. 47 and 48 show that the electron beam 3 is deflected to an appropriate position on the plane on which the block mask 8 is originally disposed without using the block mask 8, and again,
A main routine for obtaining a deflection condition when the electron beam 3 is returned to the optical axis at the time of non-deflection and passes through the aperture 20 is shown. FIGS. 49 and 50 show a subroutine.

This simulation is based on the premise that the position on the block mask 8 before the calibration (calibration) is performed is indicated by Xm and Ym as deflection parameters, and first, as shown in FIG. = Ym =
0, that is, the electron beam 3 is applied to the mask deflector 13
A sample current value when the sample is passed through the aperture 20 in a state in which the sample is not deflected at １６16 is measured, and the measured value is set to I ₀ (step P1).

Next, an initial setting is performed. Xm = ΔXm, Ym = ΔYm, θ1 _min = θ2
_min = 0, θ1 _max = θ2 _max = 2π, G2 _min = 0,
G2 _{ma x} = {[BSX2 _max) ² + (BSY
2 _max ) ² ] / (Xm ² + Ym ² )｝ ^1/2 (Step P2).

Here, ΔXm is a value smaller than the size of the electron beam 3 on the block mask 8 in the X direction, and ΔYm is a value smaller than the size of the electron beam 3 on the block mask 8 in the Y direction.

Next, according to step P2, the positions Xm, Y
After the deflection position is changed to m, the sample current value is measured,
The value is set to I (step P3), and it is determined whether the absolute value of the difference between the current value I and the current value I ₀ is smaller than a predetermined convergence condition E (step P4). This convergence condition E
Is specified by the user, but is specified within the range of the accuracy of the ammeter for measuring the sample current value.

Here, when the absolute value of the difference between the current value I and the current value I0 is larger than the convergence condition E (N at step P4)
O), Imax = I, Δθ1 = (θ1max−θ1)
min) / N, ΔG2 = (G2max−G2min) / N, Δ
θ2 = (θ2max−θ2min) / N, and FIG.
The subroutine shown at 50 is executed. Note that N is a value of 4 or more specified by the user.

In the subroutine, Xm, Ym, θ
1_min, Θ1_max, G2_min, G2 _max, Θ2_min, Θ
2_max, Δθ1, ΔG2, Δθ2, I_maxIs entered
(Step N1), G1 = G4 = 1.0, G2 = G3 =
G2_min, Θ1 = θ4 = θ1_{mi n}, Θ2 = θ3 = θ2
_minThe initialization is performed (step N2). G
1 = G4 = 1.0 is fixed to G1, G2, G
For 3 and G4, it is enough to know the relative values
Because.

Next, the deflection conditions (θ
1, G2, θ2) is changed, the sample current value is measured,
The value is set to I (step N3). Then, this current value I is greater or not than a current value I _max stored in step P5 of the main routine shown in FIG. 21 is determined (step N4).

As a result, if the current value I is larger than the current value I _max stored in step P5 of the main routine shown in FIG. 47 (YES in step N4),
It means that more appropriate deflection condition is obtained, the data I _max to be output, .theta.1 _out, G2 _out, as _{θ2 out, I max = I,} θ1 out = θ1, G2 out = G2, θ
2 _out = θ2 is stored (step N5).

[0062] When contrast, the current value I measured in step N3 is smaller than the current value I _max stored in step P5 of the main routine shown in FIG. 47 (Step N
4 is NO) and when step N5 is completed, G1 = G4 = 1.0, G2 = G3 = G2 _min , θ2
In order to search for better deflection conditions for θ1 and θ4 under = θ3 = θ2 _min , θ1 ← θ1 + Δθ1, θ4
= Θ1 (FIG. 24, step N6).

[0063] Subsequently, .theta.1 is .theta.1 _max greater whether it is determined than (step N7), .theta.1 is (NO at Step N7) less during than theta _max, the step N3
~N6 is repeated, in a case where .theta.1 is greater than .theta.1 _max (YES in step N7), G1 = G
4 = 1.0, θ2 = θ3 = θ2 _min , θ1, θ
4, θ2 at which the sample current value becomes the maximum value by varying θ2
In order to search for θ4 and G2, θ1 = θ4 = θ1 _min ,
G2 ← G2 + ΔG2, G3 = G2 (step N
8).

Subsequently, it is determined whether or not G2 is larger than G2 _max (step N9). If G2 is smaller than G2 _max (NO in step N9), step N9 is executed.
3~N8 is repeated, if G2 is greater than G2 _max (YES in step N9) is, G1 =
Under G4 = 1.0, θ1, G2, θ2 is varied by specimen current value is the maximum value of .theta.1, G2, in order to search for _{θ2, G2 = G3 = G2 min} , θ2 ← θ2 + Δθ2, θ
3 = θ2 (step N10).

[0065] Subsequently, .theta.2 is .theta.2 _max greater whether it is determined than (Step N11), (NO in step N11) .theta.2 between is less than .theta.2 _max, the step N3~N10 is repeated, If .theta.2 is greater than .theta.2 _max (YES in step N11), θ1 _out stored at step N5, G2 _out, θ
2 _out and I _max are returned to the main routine, and the subroutine ends (step N12).

[0066] Therefore, in the main routine, I _max returned from the _{subroutine, θ1 out, G2 out, θ2} out
On the basis _{of, I = I max, θ1 max} = θ1 out + Δθ
1, θ1 _min = θ1 _out -Δθ1, G2 _max = G2 _out
+ ΔG2, G2 _min = G2 _out −ΔG2, θ2 _max = θ
2 _out + Δθ2, θ2 _min = θ2 _out −Δθ2,
Returning to step P3, steps P3 to P6 are repeated until Xm and Ym reach the maximum deflection range, and the optimum deflection condition is searched for while gradually narrowing the search range for the deflection condition.

If Xm and Ym exceed the maximum deflection range (YES in step P8), the latest θ1 stored in step N5 of the subroutine shown in FIG.
_out , G2 _out and θ2 _out are the optimum deflection conditions, and θ1
= Θ4 = θ1 _out , G2 = G3 = G2 _out , θ2 = θ3
= Θ2 _out and the process ends (step P9).

Here, the deflection intensities G1 and G4 of the mask deflectors 13 and 16 are set to 1.0, and the electron beam is deflected without using a block mask to return the electron beam to the non-deflection optical axis. Deflection intensity G2, G3 of mask deflectors 14, 15
And the deflection directions θ of the mask deflectors 13, 14, 15, 16
1, θ2, θ3, and θ4.

Then, in order to determine the relationship between the intensity BSXi, BSYi of the deflection signal to be applied to the mask deflectors 13 to 16 and the deflection parameters Xm, Ym, the deflection intensities G1 to G1 of the mask deflectors 13 to 16 are determined. G4 and deflection direction θ1
Equations (2) to (17) are used to calculate the correction coefficients G _xi ′ and G _Yi ′ for each gain term and the correction coefficients R _xi ′ and R _Yi ′ for the _rotation term. Ask.

G_xi'= G1 × cos θ1 (2) R_xi′ = G1 × sin θ1 (3) G_Yi′ = G1 × cos θ1 (4) R_Yi′ = −G1 × sin θ1 (5) G_x2′ = −G2 × cos θ2 (6) R_x2′ = −G2 × sin θ2 (7) G_Y2′ = −G2 × cos θ2 (8) R_Y2′ = G2 × sin θ2 (9) G_X3′ = −G3 × cos θ3 (10) R_x3′ = G3 × sin θ3 (11) G_Y3′ = −G3 × cos θ3 (12) R_Y3′ = −G3 × sin θ3 (13) G_x4′ = G4 × cos θ4 (14) R_x4′ = −G4 × sin θ4 (15) G_Y4′ = G4 × cos θ4 (16) R_Y4'= G4 × sin θ4 (17) where, in this case, a correction coefficient for obtaining an offset term
O_Xi’, O_Yi'And a correction unit for obtaining the orthogonality correction term
Number H_Xi, H_YiIs, for convenience, O_Xi’= O_Yi’= H _Xi’= H
_Yi′ = 0.

Here, from the equations (2) to (17), the intensity BSXi, of the deflection signal to be applied to the mask deflectors 13 to 16,
The relationship between BSYi and the deflection parameters Xm, Ym can be displayed as shown in equation (18).

[0072]

(Equation 2)

Then, calibration is performed by preparing a block mask 52 on which rectangular transmission patterns 48 to 51 for calibration as shown in FIG. 51 are formed. In addition, 53 to 56 indicate the positions (reference points) of the transmission patterns 48 to 51.

Here, the position of the transmission pattern k (k = 48 to 51) for calibration is represented by x _m (k), y
_m (k), the deflection parameter X required to deflect the electron beam 3 into the transmission pattern k
If m and Ym are represented by Xm (k) and Ym (k), the correction coefficient matrix shown in Expression (1) can be obtained by the relational expression shown in Expression (19). Note that BSXi (k) and BSYi (k) in Expression (19) can be obtained by the relational expression shown in Expression 20.

[0075]

(Equation 3)

In this way, the correction coefficient matrix shown in the equation (1) is obtained for each of the mask deflectors 13 to 16, and the intensity of the deflection signal to be applied to each of the mask deflectors 13 to 16 according to the equation (1). Is determined, the electron beam 3 is accurately deflected to the position of the selected block pattern, and the deflected electron beam 3 is turned back to the non-deflection optical axis and passed through the aperture 20 again. be able to.

[0077]

Here, the operation of the conventional calibration will be described with respect to, for example, the transmission pattern 48. As shown in FIG. 52A, the electron beam 3 is transferred to the transmission pattern 48. The electron beam 3
The deflection parameters Xm and Ym are adjusted while judging how the light is transmitted, and the electron beam 3 is adjusted as shown in FIG.
As shown in the figure, the reference point (origin) 57 of the electron beam 3 is deflected so as to overlap the reference point 53 of the transmission pattern 48. At this time, the deflection parameters Xm and Ym change the electron beam 3 to the position x of the transmission pattern 48. _m (48), y _m (4
8) The deflection parameter Xm (4
8), Ym (48).

In this case, if the correction coefficient matrix shown in equation (18) is close to the true correction coefficient matrix, Xm (k) = x _m (k) + Δx _m , Ym (k) = y
By moving Δx _m and Δy _m in a narrow area as _m (k) + Δy _m , Xm (k) and Ym (k) can be quickly searched.

However, there is no guarantee that the correction coefficient matrix shown in equation (18) is close to the true correction coefficient matrix. This is because the work of setting the directions and scales of the Xm axis and the Ym axis used when obtaining the correction coefficient matrix shown in Expression (18) has not been performed yet, and this work is performed for the first time by calibration. .

For this reason, the operation of deflecting the electron beam 3 into the transmission patterns 48 to 51 for calibration cannot be performed easily and quickly, and the mask deflectors 13 to 51 cannot be used.
There is a problem that it is not possible to obtain a correction coefficient matrix for adjusting the intensity BSXi, BSYi of the deflection signal given to the H.16 simply and quickly.

[0081] That is, [Delta] X _m, [Delta] Y _m must be an amount that does not lose sight of the aperture passing current, in order to satisfy a predetermined maximum deflection range X _m, Y _m is 21 to 24
X _m / ΔX
It has to be repeated _m times, resulting in a huge amount of calculation and a long adjustment time. Δθ1 to Δθ4, ΔG
The same applies to 1 to ΔG4, where the values Δθ1 to Δθ
4, .DELTA.G1 to .DELTA.G4 must also be small enough not to lose sight of the aperture passing current, which also increases the amount of calculation and lengthens the adjustment time.

On the other hand, G1 = G4, G2 = G3, θ1 = θ4, θ2 = θ3 used in the above-mentioned conventional adjustment method.
The adjustment assumptions described above are based on the assumption that the upper and lower lens optical systems and the deflection system disposed with the mask block interposed therebetween are configured to be mirror symmetrical. When the symmetry is broken due to the occurrence of the above, the above assumption is not satisfied, and there is a problem that it is not possible to obtain an optimal deflection for an actual system.

Further, to adjust the aperture passing current to the maximum is because the beam perpendicular incidence to the round aperture is not satisfied, so that when a different pattern on the mask block is selected, the position at the irradiation position on the sample is changed. There has been a problem that displacement occurs.

The above method is applied to the case where the trajectory of the beam near the block mask is as simulated.
That is, it is effective when the effective arrangement of the mask deflector and the magnetic field generated by the lens are mirror-symmetric with respect to the block mask. However, in reality, this symmetry is not strictly satisfied due to the mechanical precision of the lens barrel production and the interaction with other optical systems located below the block mask. Also, no consideration is given to the offset amount of the pattern position that occurs when the block mask is moved to replace the block mask or to use a block pattern in a different mask area.

Therefore, the effective arrangement of the mask deflector,
Adjustment under the assumption that the magnetic field created by the lens is mirror-symmetric with respect to the block mask will not produce the correct adjustment result, and even if a block pattern is selected with the mask deflector, the current loss at the aperture will be large. In addition, there is a problem that the beam is misaligned on the sample surface.

When the block mask is moved,
There is a problem that the output value of the mask deflector must be obtained again to compensate for the offset amount of the pattern position.

FIG. 53 shows the pattern generating means 55 of the conventional control section.

The pattern generating means 55 has a pattern generating section 80 and a mask memory 81.

The mask memory 81 stores deflection data for each pattern consisting of deflection signals BSXi and BSYi to the deflectors 13 to 16 calculated by the above-described method. Each pattern is assigned, and its address is calculated and referenced by a pattern data code.

The pattern generator 80 is provided in the data memory 54
, And reads predetermined deflection data in the mask memory 81 from the pattern data code included in the exposure data.

The read deflection data is added to the amplifier 57, and the deflection signal is sent from the amplifier 57 to each of the deflectors 13 and 1.
4, 15 and 16.

Here, the intensity of the deflection signal BSXi, BSY
Reference is made to the above-mentioned equation (1) representing i.

Matrix on the right side of equation (1)

[0094]

(Equation 4)

Is a correction coefficient matrix for representing the relationship between the current position of the block mask 8 and the deflection signal to be applied to each of the mask deflectors 13-16.

For this reason, by moving the block mask,
When positioning is performed in another mask area on the block mask, it is necessary to recalculate all the above correction coefficients. The correction coefficient exists separately for each deflector, the number of which is enormous, and recalculating the correction coefficient takes a long time of about half a day.

When a block mask is used, FIG.
As shown in step 83 _-1 to 83 _-4 4, sometimes the block mask in order to select a different mask area is moved, each time re-adjustment.

During the readjustment, the exposure position is stopped, and the stop time is about half a day.

As a result, it takes about half a day to readjust each time the block mask is moved.
The time during which the exposure apparatus is stopped is prolonged, the operation efficiency of the exposure apparatus is stopped, and as a result, the throughput of the semiconductor device is reduced.

The present invention has been made in view of the above points, and it is possible to easily and quickly adjust a mask deflector of a charged particle beam exposure apparatus configured to perform a block exposure. An object of the present invention is to provide a method for adjusting a charged particle beam exposure apparatus.

[0101]

A charged particle beam generating means for generating a charged particle beam, and a polygonal shaping plate disposed at a position where the charged particle beam passes and for shaping the charged particle beam are provided. And a transmission hole mask plate on which one or more transmission hole patterns having an arbitrary shape are formed,
When the charged particle beam generating means is disposed at an upper position, a pair of first and second mirrors are disposed so as to be mirror-targeted one above the other with the transmission hole mask plate interposed therebetween, and deflect the charged particle beam.
In a method of adjusting a charged particle beam exposure apparatus having a first to a fourth deflecting means and a round aperture provided below the first to the fourth deflecting means, the apparatus is arranged at a position closest to the polygonal shaping plate. A first step of driving only the first deflecting means provided to determine a deflecting phase and a deflecting amount of a crossover image on a round aperture by the first deflecting means; and a position below the first deflecting means. Driving only the second deflecting means disposed above the transmission hole mask plate, and determining the deflection phase and the deflection amount of the crossover image on the round aperture by the second deflecting means. And when the first and second deflecting means are simultaneously driven, the deflection difference between the first and second deflecting means is set such that the deflection efficiency of the crossover image on the round aperture becomes zero. A third step of obtaining a deflection amount ratio, and driving only a third deflection means disposed below the transmission hole mask plate, and deflecting a crossover image on a round aperture by the third deflection means. A fourth step of determining the phase and the deflection amount, and driving only the fourth deflection means disposed below the third deflection means, and a crossover image on the round aperture by the fourth deflection means. A fifth step of calculating the deflection phase and the deflection amount of the third and fourth deflection means, and simultaneously driving the third and fourth deflection means so that the deflection efficiency of the crossover image on the round aperture becomes zero. A sixth step of calculating the deflection difference and the deflection amount ratio of the deflecting means, and driving the first to fourth deflecting means to make the charged particle beam most perpendicularly incident on the round aperture; A seventh step of calculating the relative angle between the first and second deflecting means and the third and fourth deflecting means without changing the direction ratio; Driving the deflecting means so that the charged particle beam is most perpendicularly incident on the round aperture, and the first and second deflecting means and the third and fourth deflecting means without changing the deflecting phase difference and the deflecting amount ratio; Using the relative deflection amount and relative phase difference of the first to fourth deflecting means to determine the relative intensity of the deflection coordinate and the deflection direction of the deflection coordinates on the transmission hole mask plate, A ninth step of selecting a transmission hole pattern on the hole mask plate.

[0102]

According to the above-mentioned adjusting method, first, the first step performs the first step.
The deflection phase and the deflection amount of the deflection means are determined, and the deflection phase and the deflection amount of the second deflection means are determined in the second step. The deflection phase and the deflection amount of the deflection means obtained in each step are defined as a shift amount from a normal beam passage position on the round aperture, and are shift amounts including error factors such as an assembly error of the apparatus.

Therefore, by adjusting the first and second deflecting means so that the charged particle beam comes to the normal beam passage position on the round aperture, it is possible to collectively correct the error factor. .

In the present invention, the first and second steps are performed in the third step.
Are simultaneously driven, and the deflection phase and the deflection amount of the first deflection means obtained in the first step and the deflection phase and the deflection amount of the second deflection means obtained in the second step are mutually different. By adjusting the first and second deflecting means so as to cancel each other (ie, to make the deflection efficiency of the crossover image on the round aperture zero), the charged particle beam can pass through the normal beam passing position on the round aperture. It is configured to adjust to come.

As described above, by performing the first to third steps, in a state where the third and fourth deflecting means are not driven, how the first and second deflecting means are changed Even when the charged particle beam is driven, the charged particle beam is always irradiated to a regular beam passing position on the round aperture.

In the following fourth step, the deflection phase and the deflection amount of the fourth deflection means are obtained, and in the fifth step, the deflection phase and the deflection amount of the fifth deflection means are obtained. The deflection phase and the deflection amount of the deflection means obtained in each step are also defined as a shift amount from a normal beam passage position on the round aperture, and are shift amounts including error factors such as an assembly error of the apparatus.

Therefore, similarly to the adjustment of the first and second deflecting means, the third and fourth deflecting means are adjusted so that the charged particle beam comes to a regular beam passage position on the round aperture. , It is possible to collectively correct the error factors.

In the present invention, in the sixth step, the deflection phase and the deflection amount of the third deflection means obtained in the fourth step, and the deflection phase and the deflection amount of the fourth deflection means obtained in the fifth step are obtained. , So that the third and fourth
(That is, the deflection efficiency of the crossover image on the round aperture is set to zero), so that the charged particle beam is adjusted to come to a regular beam passing position on the round aperture. I have.

As described above, by performing the fourth to sixth steps, the charged particle beam can be moved to the regular beam passing position on the round aperture no matter how the third and fourth deflecting means are driven. Is always irradiated.

In the state where the first to sixth steps have been completed, the charged particle beam is always irradiated to the regular beam passage position on the round aperture no matter how the first to fourth deflecting means are driven. Configuration. However,
What the charged particle beam exposure apparatus actually wants to perform the exposure of the charged particle beam is not on the round aperture, but on a sample disposed below the round aperture.

Therefore, simply irradiating the charged particle beam to the regular beam passage position on the round aperture does not always irradiate the charged particle beam to a predetermined position on the sample. The charged particle beam that has proceeded obliquely to the beam passage position is applied to a position on the sample that is significantly shifted from a predetermined position.

In the seventh and eighth steps, the first and second deflecting means, the third and the fourth deflecting means, which make the charged particle beam most perpendicularly incident on the round aperture and do not change the deflecting phase difference and the deflecting amount ratio. By determining the relative angle and relative intensity with the fourth deflecting means, a predetermined position on the sample is irradiated with the charged particle beam.

When the first to eighth steps are completed, the charged particle beam emitted from the charged particle beam generating means can be applied to the sample no matter how the first to fourth deflecting means are driven. It is configured to always irradiate a predetermined position.

However, the completion of the first to eighth steps completes the adjustment of the first to fourth deflecting means, the round aperture, and the sample (the adjusted components are collectively referred to as an apparatus system). However, no adjustment of the device system for the transmission hole mask plate has been made. Therefore, in the ninth step, the deflection amount and the deflection direction of the deflection coordinates on the transmission hole mask plate are adjusted to match the coordinate system of the apparatus system.
Accordingly, it is possible to prevent occurrence of an error when selecting a transmission hole pattern on the transmission hole mask plate, and it is possible to perform a highly accurate charged particle beam irradiation process.

[0115]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a charged particle beam exposure apparatus 30 (electron beam exposure apparatus) which is adjusted by the method of the present invention. 34, the same components as those of the charged particle beam exposure apparatus described with reference to FIG. 34 are denoted by the same reference numerals, and description thereof will be omitted.

In the figure, reference numeral 31 denotes an electromagnetic lens.
A charged particle beam (hereinafter, referred to as an electron beam) rectangularly shaped by the slit deflector 6 is rounded by a round aperture 20.
It has the function of forming an image on top. Therefore, the electron beam incident on the electromagnetic lens 31 is focused on a predetermined position according to the focal length of the electromagnetic lens 31. In addition, the block mask 8 has a so-called lens-in-mask configuration in which the block mask 8 is integrated with the electromagnetic lens 31. With this configuration, the size of the charged particle beam exposure apparatus 30 can be reduced.

Next, a specific adjusting method of the charged particle beam exposure apparatus 30 having the above configuration will be described.

FIG. 2 is an enlarged view showing the vicinity of the block mask 8 in FIG. It should be noted that only the components related to the adjustment method of the present invention are shown in FIG. 1 and the drawings used in the following description, and other components are not shown.

To adjust the charged particle beam exposure apparatus 30, first, as a first step, only the first mask deflector 13 is driven, and the electron beam 1 is emitted from the electron gun 1. At this time, the voltage applied to the first mask deflector 13 is set to V1.

By driving the first mask deflector 13, the electron beam 3 is deflected. The electron beam 3 passes through a predetermined block pattern 12 formed on the block mask 8 and is turned back by the electromagnetic lens 31. The light is irradiated onto the round aperture 20. FIG. 3 is a view of the round aperture 20 as viewed from the position where the electron gun 1 is disposed (that is, the upper position).

For example, by driving only the first mask deflector 13, the electron beam 3 is changed to a white circle in FIG.
It is assumed that the position indicated by the mark V1 is irradiated to form a crossover image. In the present embodiment, and the use of vector representation to represent the irradiation position, the magnitude of the vector V1 (hereinafter, referred to as deflection amount) counterclockwise angle with respect to the r1, X _R-axis (hereinafter, referred to as deflection phase) and θ1.

This vector V1 includes an error factor such as an assembly error of the charged particle beam exposure apparatus 30. If there is no error factor, the electron beam 3 is returned to the lens 31 and the round aperture 2
It should pass through the aperture 20a formed at the center position of 0 (corresponding to the origin in FIG. 3). Therefore, in order to perform high-precision exposure processing by the charged particle beam exposure apparatus 30, it is necessary to adjust the apparatus 30 so that the deflection amount r1 becomes zero.

Subsequently, as a second step, only the second mask deflector 14 is driven to emit the electron beam 3 from the electron gun 1. At this time, the voltage applied to the second mask deflector 14 is set to V2. By driving the second mask deflector 14, the electron beam 3 is deflected. As in the first step, the electron beam 3 passes through a predetermined block pattern 12 formed on the block mask 8, and And is irradiated onto the round aperture 20.

For example, by driving only the second mask deflector 14, the electron beam 3 becomes black in FIG.
It is assumed that the light is irradiated to the position indicated by the mark V2. When this irradiation position is represented by a vector, the amount of deflection of the vector V2 is r
2. The deflection phase can be represented as θ2. Note that this vector V2 also includes error factors such as an assembly error of the charged particle beam exposure apparatus 30 as in the case of the above-described vector V1, and therefore, it is necessary for the charged particle beam exposure apparatus 30 to perform high-precision exposure processing. It is necessary to adjust the device 30 so that the deflection amount r2 becomes zero.

In the subsequent third step, the deflection amounts r1, r
2 is set to zero. In the present invention, in order to set the deflection amounts r1 and r2 to zero, the vectors V1 and V2
2 is used. Hereinafter, the vectors V1,
A method for canceling V2 will be described with reference to FIG.

By the first and second steps, the first or the second
Are separately driven to drive the vector V
When the first and second mask deflectors 13 and 14 are obtained in the third step, the vector V
2 is moved to a position symmetrical about the origin with respect to the vector V1, and the magnitude of the vector V2 is
Adjustment processing is performed so as to have the same size as.

Specifically, the vector V2 is changed to the vector V1.
To move to a symmetrical position with respect to the origin
Angle difference (hereinafter, this angle difference is referred to as a deflection phase difference).
And the magnitude of the vector V1 and the magnitude of the vector V2.
A deflection amount correction coefficient G1 for obtaining the same magnitude is obtained.
The deflection amount correction coefficient G1 is obtained by the following equation: G1 = r1 / r2 (21).
Make the size of V1 and the size of vector V2 the same
Can be. The deflection phase difference is indicated by an arrow θ in FIG. _d1Indicated by
Value.

When the deflection amount correction coefficient G1 and the deflection phase difference θ _d1 are obtained as described above, the second mask deflector 1 corresponds to the deflection amount correction coefficient G1 and the deflection phase difference θ _d1.
4 and the phase of the power supply are controlled. Second
By controlling the phase of the power supply applied to the mask deflector 14 to correspond to the deflection phase difference θ _d1 , the vector V
2 moves as shown by the two-dot chain line arrow in FIG. 3B, and controls the voltage applied to the second mask deflector 14 so as to correspond to the deflection amount correction coefficient G1, thereby obtaining the vector V1. And a vector V2 ′ (a vector indicated by a dashed line in FIG. 4) symmetrical with respect to the origin.

Now, the voltage applied to the second mask deflector 14 to generate the vector V2 'is V2', and the voltage V1 applied to the first mask deflector 13 and the second mask V2 ' Voltage V2 ′ applied to deflector 14
Is defined as a deflection amount ratio (V1: V2 ′).

Then, control is performed so as to correspond to the phase deflection phase difference θ _d1 of the power supply applied to the second mask deflector 14,
By controlling the deflection amount ratio such that V1: V2 'is always established, the vector V1 generated by the first mask deflector 13 and the vector V2' generated by the second mask deflector 14 cancel each other. is, the origin of always combining vector of the vectors V1 and vector V2 'X _R -Y _R coordinate.

By controlling the second mask deflector 14 based on the deflection phase difference θ _d1 and the deflection amount ratio (V1: V2 ′), the first and second mask deflectors 13 and
No matter how the electron beam 3 is driven, the electron beam 3 always passes through the aperture 20 a formed in the round aperture 20, that is, the first and second mask deflectors 13 and 14.
Are simultaneously driven, the deflection efficiency of the crossover image on the round aperture 20 can be made zero.

The first and second adjustments are performed by the above series of adjustment processing.
The adjustment of the mask deflectors 13 and 14 is completed. Subsequently, a method of adjusting the third and fourth mask deflectors 15 and 16 will be described.

In order to adjust the third and fourth mask deflectors 15 and 16, as a fourth step, only the third mask deflector 13 is driven, and the electron gun 1 emits the electron beam 3 ( FIG. 4 shows this state). At this time, the voltage applied to the third mask deflector 15 is set to V3.

The third and fourth mask deflectors 15, 1
In the present embodiment, the first and second mask deflectors 13 and 14 are not driven when the adjustment is performed. However, as described above, the charged particle beam exposure apparatus 30 adjusted in the present embodiment is an electromagnetic lens. Reference numeral 31 denotes an apparatus having a configuration in which a lens swingback system is provided. Therefore, the electron beam 3 enters the aperture 20 a of the round aperture 20 irrespective of how the first and second mask deflectors 13 and 14 are driven as long as the adjustment in the first to third steps is completed. Therefore, it is also possible to adjust the third and fourth mask deflectors 15 and 16 while driving the first and second mask deflectors 13 and 14. However, for convenience of explanation, the following description will be made on the assumption that the first and second mask deflectors 13 and 14 are not driven.

When the first and second mask deflectors 13 and 14 are not driven, the electron beam 3 emitted from the electron gun 1 is irradiated on the block mask 8 along the optical axis 2 to form a predetermined block pattern. The light passes through to the third mask deflector 15.

Since the third mask deflector 15 is driven as described above, the electron beam 3 is deflected by the third mask deflector 15 as shown, for example, by a solid arrow A in FIG. . In the fourth step, since the fourth mask deflector 16 is not driven, the electron beam 3 travels as shown by the dashed arrow B and irradiates the round aperture 20. FIG. 5 shows the round aperture 20 connected to the electron gun 1.
FIG. 3 is a view as viewed from an arrangement position side (that is, an upper position).

Now, it is assumed that the electron beam 3 is applied to the position indicated by the white circle V3 in the figure by driving only the third mask deflector 15 to form a crossover image. Then, in the same manner as described above, the vector display is used to represent the irradiation position, and the vector V3
The amount of deflection r3, and θ3 (angle counterclockwise with respect to X _R-axis) deflection phase. The vector V3 also includes an error factor such as an assembly error of the charged particle beam exposure apparatus 30.

Subsequently, as a fifth step, only the fourth mask deflector 16 is driven to emit the electron beam 3 from the electron gun 1. At this time, the voltage applied to the fourth mask deflector 16 is set to V4, and the first to third mask deflectors 13
15 are not driven.

By driving the fourth mask deflector 16, the electron beam 3 is deflected as shown by the dashed line arrow C in FIG. 4 and is irradiated onto the round aperture 20. Now, it is assumed that the electron beam 3 is applied to a position indicated by a black mark V4 in FIG. 5 by driving only the fourth mask deflector 16. When this irradiation position is expressed as a vector, the deflection amount of the vector V4 can be expressed as r4, and the deflection phase can be expressed as θ4. The vector V2 also includes an error factor such as an assembly error of the charged particle beam exposure apparatus 30.

As described above, in the fourth step, the vector V
The deflection amount r3 and the deflection phase of the vector V4 are obtained in the fifth step.
Is required. At this time, the deflection amounts r1 and r2 and the deflection phases θ1 and θ2 determined in the first and second steps described above.
Is used as an initial value for obtaining the deflection amounts r3, r4 and the deflection phases θ3, θ4, thereby shortening the processing time.

This is because the vectors V1 and V2 also include error factors such as an assembly error of the device 30, and the deflection amount r
1, r2 and the deflection phases θ1, θ2 are values for correcting these. Therefore, the deflection amounts r3, r4 and the deflection phases θ3, θ
4 is also likely to take values approximating the deflection amounts r1, r2 and the deflection phases θ1, θ2, and thus the deflection amounts r1, r2 and the deflection phase θ determined in the first and second steps as initial values.
By using 1, θ2, the processing time can be reduced.

In the subsequent sixth step, an adjustment process for setting the deflection amounts r3 and r4 of the vectors V3 and V4 obtained in the fourth and fifth steps to zero is performed. By performing this adjustment process, the electron beam 3 can be guided to the aperture 20 a of the round aperture 20 regardless of how the third and fourth mask deflectors 15 and 16 are driven.

In the present invention, similar to the third step,
In order to set the deflection amounts r3 and r4 to zero, the vector V
3, V4 is offset. Hereinafter, a method of canceling the vectors V3 and V4 will be described with reference to FIG.

By the fourth and fifth steps, the third or fourth step is performed.
Are separately driven to drive the vector V
In the sixth step, the third and fourth mask deflectors 15 and 16 are simultaneously driven, and the vector V
4 is moved to a position symmetrical about the origin with respect to the vector V3, and the magnitude of the vector V4 is
Adjustment processing is performed so as to have the same size as.

Specifically, the vector V4 is changed to the vector V3
, A deflection phase difference θ _d2 for moving to a position symmetrical with respect to the origin is determined, and a deflection amount correction coefficient G2 for equalizing the magnitude of the vector V3 and the magnitude of the vector V4 is determined. Incidentally, the deflection amount correction coefficient G2 is obtained by G1 = r3 / r4 (22), and the size of the vector V3 and the size of the vector V4 can be made the same by multiplying r4 by G2.

When the deflection amount correction coefficient G2 and the deflection phase difference θ _d2 are obtained as described above, the fourth mask deflector 1 corresponds to the deflection amount correction coefficient G2 and the deflection phase difference θ _d2.
6 and the phase of the power supply are controlled. 4th
By controlling the phase of the power supply applied to the mask deflector 16 to correspond to the deflection phase difference θ _d2 , the vector V
4 moves as shown by the two-dot chain line arrow in FIG. 5B, and controls the voltage applied to the fourth mask deflector 16 so as to correspond to the deflection amount correction coefficient G2. And a vector V4 ′ (a vector shown by a dashed line in FIG. 4) symmetrical with respect to the origin.

Now, the voltage applied to the fourth mask deflector 16 to generate the vector V4 'is V4',
In this case, the ratio between the voltage V3 applied to the third mask deflector 15 and the voltage V4 'applied to the fourth mask deflector 16 is defined as a deflection amount ratio (V3: V4').

Then, control is performed so as to correspond to the phase deflection phase difference θ _d2 of the power supply applied to the fourth mask deflector 16,
By controlling the deflection amount ratio such that V3: V4 ′ is always established, the vector V3 generated by the third mask deflector 15 and the vector V4 ′ generated by the fourth mask deflector 16 cancel each other. It is synthetic vector V3 and the vector V4 'is always the origin of X _R -Y _R coordinate.

This is because the fourth and fourth mask deflectors 16 and 15 are controlled by controlling the fourth mask deflector 16 based on the deflection phase difference θ _d2 and the deflection amount ratio (V3, V4 ′).
No matter how the electron beam 3 is driven, the electron beam 3 always passes through the aperture 20 a formed in the round aperture 20, that is, the third and fourth mask deflectors 15 and 16.
Are simultaneously driven, the deflection efficiency of the crossover image on the round aperture 20 can be made zero.

After the above-described first to sixth steps are completed,
By adjusting the mask deflectors 13 to 16, the electron beam 3 emitted from the electron gun 1 always passes through the aperture 20a of the round aperture 20.

However, even if the electron beam 3 passes through the aperture 20a of the round aperture 20, the electron beam 3 does not always form a shaped beam image at a predetermined position on the sample 25. This will be described with reference to FIG. As shown in the figure, there are various modes in which the electron beam 3 passes through the aperture 20a, and the electron beam 3 is obliquely incident on the aperture 20a as shown by two-dot chain arrows D and E. And the throttle hole 20a as shown by the solid arrow F.
May be incident perpendicularly.

The exposure position of the electron beam 3 on the sample 25 (indicated by the arrow H in the figure) is configured to face the aperture 20a of the round aperture 20, so that the electron beam 3 is positioned with respect to the aperture 20a. When the light is obliquely incident, a shaped beam image is formed at a position deviated from the predetermined exposure position H, and proper exposure processing cannot be performed. Therefore, in order to perform an appropriate exposure process, it is necessary to make the electron beam 3 perpendicularly enter the aperture 20 a of the round aperture 20.

The seventh and eighth steps are adjustment processes for causing the electron beam 3 to be perpendicularly incident on the aperture 20a of the round aperture 20. In the seventh and eighth steps, the current value passing through the round aperture 20 is maximized, and when a different block pattern formed on the block mask 8 is selected, the beam position shift on the sample 25 is minimized. This is a process for adjusting the first to fourth deflection means 13 to 16 as described above. First, the adjustment principle will be described.

As described above, in order to make the electron beam 3 incident on the aperture 20a of the round aperture 20, the coordinate system X _R -Y _R is assumed on the round aperture 20, and the driving of each of the mask deflectors 13 to 16 is performed. and configured to converge in the generated origin vector V1~V4 are offset from each other by the coordinate system X _R -Y _R (corresponding to the arrangement position of the throttle hole 20a) by.

The electron beam 3 is irradiated onto the sample 25 at a predetermined exposure position H.
In the adjustment for irradiating the laser beam, adjustment similar to the above-described adjustment method is performed. That is, as shown by two-dot chain arrows E and F in FIG. 6, when the electron beam 3 is not perpendicularly incident on the aperture 20a, the electron beam 3 is shifted to a predetermined exposure position H. 3 is irradiated. Thus, assuming a coordinate system X _S -Y _S whose origin predetermined exposure position H on the sample 25, the electron beam 3 is irradiated may perform adjustment so as to converge to the origin of the coordinate system X _S -Y _S .

The deflection phase difference θ _d1 obtained in the first to third steps _{, the} deflection amount ratio (V1: V2 ′), and the fourth
Or deflection phase difference theta _d2 obtained by the sixth _step, the deflection amount ratio (V3: V4 '), since the electron beam 3 when not maintain the value does not enter the aperture hole 20a, the deflection phase difference theta _{d1 ,} theta _d2, deflection amount ratio (V1: V2 _'), the deflection amount ratio (V3: V4') of the electron beam 3 without changing the performs processing to converge to the origin of the coordinate system X _S -Y _S. Less than,
A specific adjustment method will be described.

In order to adjust the electron beam 3 to be perpendicularly incident on the aperture 20a, first, the first mask deflector 13 and the second mask deflector 14 are simultaneously driven to emit the electron beam 3 from the electron gun 1. Let it. At this time, since the deflection phase difference θ _{d1 and the} deflection amount ratio (V1: V2 ′) set between the first and second mask deflectors 13 and 14 are maintained as described above, the electron beam 3 is irradiated onto the sample 25 through the aperture 20a. At this time, the third and fourth
Are not driven.

FIG. 7 is a view of the sample surface 25 as viewed from the position where the electron gun 1 is disposed (that is, the upper position). Now, by simultaneously driving the first and second mask deflectors 13 and 14, the electron beam 3 is set to X _S set on the sample 25.
It is assumed that a shaped beam image is formed by irradiating the position (V1: V2 ′) indicated by a white square in the −Y _S coordinate (in the following description, the lower left corner of the shaped beam image indicated by the square is Reference point).

As described above, vector display is used to represent the irradiation position, and the vector (V
1: a deflection amount of V2 ') r5, the deflection phase (angle counterclockwise with respect to X _S axis) and .theta.5.

Subsequently, the first and second mask deflectors 1
3 and 14 are stopped, and the third and fourth mask deflectors 15 and 16 are simultaneously driven to emit the electron beam 3 from the electron gun 1. At this time, since the deflection phase difference θ _{d2 and the} deflection amount ratio (V3: V4 ′) set between the third and fourth mask deflectors 15 and 16 are maintained as described above, the electron beam 3 is irradiated on the sample 25 through the aperture 20 a of the round aperture 20.

Now, the third and fourth mask deflectors 1
By driving the electron beams 3 and 5, the electron beam 3 is turned on as shown in FIG.
It is assumed that the light is irradiated at the position (V3: V4 ′) indicated by the square in the satin finish. When this irradiation position is expressed as a vector, the deflection amount of the vector (V3: V4 ′) is r6, and the deflection phase is θ6.
It can be expressed as.

As described above, the vectors (V1: V2 '),
The deflection amounts r5 and r6 and the deflection phase of (V3: V4 ′) are θ
Once the values of θ5 and θ6 are obtained, the deflection amounts r5 and r6
Is adjusted to zero.

By performing this adjustment process, the electron beam 3 can be vertically incident on the aperture 20a of the round aperture 20 regardless of how the first to fourth mask deflectors 13 to 16 are driven. Thus, a crossover image can be formed at a predetermined exposure position H (the position indicated by a hatched area in FIG. 7).

In the present invention, the vectors (V1: V2 ') and (V3: V4') are converted to the sample 25 in order to make the deflection amounts r3 and r4 zero, as in the above-described steps.
The offsetting technique is used above. Hereinafter, a method of canceling the vectors (V1: V2 ′) and (V3: V4 ′) will be described with reference to FIG.

The vectors (V1: V2 '), (V3: V
When 4 ′) is obtained, the third and fourth mask deflectors 15 and 16 are simultaneously driven as a seventh step, and the vector (V3: V4 ′) is centered on the vector (V1: V2 ′) with respect to the origin. A relative angle θ _d3 for moving to a symmetric position is obtained.

Subsequently, the vector (V1:
V2 ') and the magnitude of the vector (V3: V4') are made equal to each other to obtain a relative intensity G3. The relative intensity G3 is obtained by the following equation: G1 = (V1: V2 ′) / (V3: V4 ′) (23), and by multiplying r6 by G3, the magnitude of the vector (V1: V2 ′) and the vector (V3 : V4 ')
Can have the same size. When the magnitudes of the vector (V1: V2 ′) and the vector (V3: V4 ′) become the same, the third and fourth mask deflectors 15, and
The value of the voltage applied to 16 is (V3: V4 ′) ′.

As described above, the relative intensity G3 and the relative angle θ
_{When d3} is obtained, the relative intensity G3 and the relative angle θ _d3
The third and fourth mask deflectors 15 and 1 correspond to
6 and the phase of the power supply are controlled. Third
By controlling the phase of the power supply applied to the first and fourth mask deflectors 15 and 16 so as to correspond to the relative angle θ _d3 , the vector (V3: V4 ′) becomes a two-dot chain line in FIG. By moving as indicated by the arrows and controlling the voltages applied to the third and fourth mask deflectors 15 and 16 to correspond to the relative intensity G3, the vector (V1: V
2 ') and a vector symmetrical with respect to the origin (V3: V4') '
(A vector indicated by a dashed line in the figure) is generated.

Therefore, the third and fourth mask deflectors 1
5 and 16 are controlled so as to correspond to the relative angle θ _d3 , and the first and second mask deflectors 1
The ratio of the voltage applied to the third and fourth mask deflectors 15 and 16 to the voltage applied to the third and fourth mask deflectors 15 and 16 is always (V1: V
2 ′): By controlling (V3: V4 ′) ′ to be satisfied, the (V1: V2 ′) generated by the first and second mask deflectors 13 and 14 and the third and fourth are generated. (V) generated by the mask deflectors 15 and 16
3: V4 ')' cancel each other out, and the vector (V1: V
2 ′) and the vector (V3: V4 ′) ′ always become the origin of the X _S −Y _S coordinates.

By controlling the first to fourth mask deflectors 13 to 16 as described above, the first to fourth mask deflectors 13 to 16 are controlled.
No matter how the mask deflectors 13 to 16 are driven,
The electron beam 3 is perpendicularly incident on the aperture 20 a formed in the round aperture 20, and is irradiated on a predetermined exposure position H on the sample 25.

After the above series of adjustment steps, the adjustment operation of the charged particle beam exposure apparatus 30 itself is completed.
As described above, the adjustment according to the method of the present invention selectively drives the first to fourth mask deflectors 13 to 16 and irradiates the round aperture 20 or the sample 25 with an error factor of the apparatus. After the position of the electron beam 3 is displayed as a vector, the apparatus 30 is adjusted by canceling the vector indicating the irradiation position for each set of the mask deflectors 13 to 16. Therefore, since the adjustment process can be performed by measuring the irradiation position of the electron beam 3 once in each step, it can be performed in an extremely short time as compared with the conventional method of collecting data for adjustment many times. Adjustment work can be performed.

On the other hand, the adjustment operation of the charged particle beam exposure apparatus 30 itself is completed by performing the first to eighth steps, but the position adjustment between the charged particle beam exposure apparatus 30 and the block mask 8 is still performed. Not. Therefore, in the ninth step, as shown in FIG. 8, the deflection coordinates (coordinates indicated by XY in the figure) set in advance in the block mask 8 and the mask coordinates (coordinates indicated in XY in the figure) set in the device 30 (Coordinates indicated by X _m -Y _m in the figure).

As a result, the block mask 8 and the device 30
Are coordinated with each other, the electron beam 3 is reliably exposed to the predetermined exposure position H even when any of the plurality of block patterns 12 formed on the block mask 8 is selected.
And the occurrence of deviation of the irradiation position on the sample 25 can be prevented.

In the above-described embodiment, the voltage and phase of the first mask deflector 13 are fixed and the characteristics of the second mask deflector 14 are changed in the third step. The configuration may be such that the mask deflector 14 is fixed and the characteristics of the first mask deflector 13 are changed. Also,
As described above, when adjusting the pair of mask deflectors, it is only necessary to fix one of them and change the other, and the mask deflector to be fixed is not limited to the sixth step and the seventh and eighth steps. The same can be said for.

In the above, when an arbitrary point on the block mask 8 is selected, the electron beam passes through the point and passes vertically through the aperture 20a of the round aperture 20 to reach the exposure position H. The method of adjusting the deflection signal to be applied to the first to fourth deflectors 13 to 16 has been described.

Next, a description will be given of a mask deflector adjustment method performed by developing the above-described adjustment method.

In the block mask exposure apparatus, the mask deflector is adjusted before the first operation after the installation. After operating once, the mask deflector is readjusted each time a new mask area is selected by moving the block mask.

The method of adjusting the charged particle beam exposure apparatus according to the present invention is characterized in that the items to be obtained are divided into two items, that is, the relative relationship between the deflection means and the output value-beam coordinate position relationship.

As shown in FIG. 9, the adjustment method roughly comprises a deflector relative relationship obtaining step 84-1 and a first deflector deflection output value-beam coordinate positional relationship obtaining step 84-2. .

The deflector relative relationship obtaining step 84-1 includes the first, second, third and third steps for irradiating the charged particle beam through the round aperture 20 to the reference position on the sample surface.
Regarding the deflection value output to be applied to the fourth deflectors 13, 14, 15, 16 the second, third, and fourth deflectors 14, 15, 1, 1 with respect to the deflection value output to the first deflector 13 are described.
6 is a step of obtaining a relative relationship of the deflection value output to the block mask 6 excluding the constraint condition for the block mask 8.

In the first deflector deflection output value-beam coordinate positional relationship obtaining step 84-2 , the deflection output value to the first deflector 13 and the deflection output value to the first deflector 13 are added. This is a step of obtaining the relationship between the charged particle beam and the coordinate position on the block mask 8 at the time of the irradiation.

The relative positional relationship between the deflectors is determined irrespective of the position of the block 8. Therefore, even when the block mask 8 is moved to select another mask area,
The relationship determined in 84-1 is alive. For this reason, readjustment only needs to be performed in step 84-2 .

In order to perform the block exposure using the electron beam exposure apparatus shown in FIGS. 1 and 38, prior to the exposure, the electron beam emitted from the electron gun 1 at that time correctly passes through the designated block pattern and the exposure position. in order to to reach the, corresponds to the state of the electronic gun 1 at that time, to adjust the deflection signals to be applied to the first to fourth deflector 13 to 16.

The mask deflector adjustment method is performed in this adjustment step.

Here, for convenience of explanation, an electron beam exposure apparatus to which the above-described mask deflector adjustment method is applied will be described.

The electron beam exposure apparatus differs from FIG. 38 only in the pattern generating means.

As shown in FIG. 10, the pattern generator 55A is supplied with exposure data from the data memory 54 and generates a pattern data code.
0, a mask memory 81A for storing the coordinates of the block pattern arrangement position of the block mask 8, a mask area correction circuit 85, and a mask deflector relative correction circuit 86.

The mask area correction circuit 85 has a coefficient part, receives the block pattern arrangement position data X _m and Y _m from the mask memory 81, performs the operation of the expression 25 described later, and performs the first mask deflection. Output value X _ma to the detector 13,
Output _Yma .

This output is applied to the first mask deflector 13 via the AMP unit 57.

The mask deflector relative correction circuit 86 receives the output from the mask area correction circuit 85, performs the operation of Expression 24 to be described later, and sends it to the second, third, and fourth mask deflectors 14, 15, and 16. The deflection output value is output.

This output is applied to the second, third, and fourth mask deflectors 14, 15, and 16 via the AMP unit 57.

Next, a method of adjusting the mask deflector will be described.

FIG. 11 shows the adjustment procedure .

[0194] Figure 15 and equation (24) in FIG. 16 the deflection output value applied to the mask deflector to Table Wa (25).

In FIG. 11 , the mask deflector relative correction coefficient is a coefficient that gives a relative relationship between two mask deflectors among the first to fourth mask deflectors 13 to 16.

In FIG. 16, a mask area correction coefficient is a coefficient that gives a relation between coordinates on one mask area of the block mask 8 having a plurality of mask areas and output data to the first mask deflector 13. is there. In other words, the mask area correction coefficient is a correction coefficient determined for each mask area.

The mask area is an area in which the electron beam can reach by the deflection by the first and second mask deflectors 13 and 14.

Adjusting the mask deflector means that no matter which block pattern is selected, the mask deflector relative correction is performed so that it is not shaded by the aperture and there is no displacement on the sample surface. Determining the coefficients;
When replacing the block mask or moving the block mask to use a different mask area,
That is, a mask area correction coefficient for the mask area is determined. This is shown in FIG.

The adjustment of the mask deflector is performed by obtaining the relative relationship between the mask deflectors without any constraint, and the relationship between the output data to the first mask deflector and the position on the block mask 8. Is divided into two items.

The mask deflector relative correction coefficient is measured and determined according to the procedure shown in FIG. 11 (step 90).

The relative relationship of the second mask deflector 14 is determined with reference to the first mask deflector 13 (Step 90 _{-1 in} FIG. 11).

At this time, the block mask 8 has been removed.

Here, as shown in FIG. 18, when an arbitrary deflection is performed by the first mass deflector 13, the electron beam is displaced by the second mask deflector 14 so as to pass through the round aperture 20. Ask for a relationship to return.

More specifically, the operation is performed as described below.
(Steps 100 to 104 in FIG. 12).

-1 Third mask deflector 15 and fourth mask deflector 15
The mask deflector 16 is turned off.

An appropriate deflection output value is applied to the first mask deflector 13 so that the electron beam passes through the measurement point shown in FIG.

A deflection output value is applied to the second mask deflector 14 while measuring the sample current, and the electron beam is turned back. The deflection output value applied to the second mask deflector 14 when the electron beam is turned back and passes through the hole 20a of the round aperture 20, that is, when the sample current value reaches a maximum, is measured.

Subsequently, the deflection output value applied to the first mask deflector 13 is changed so that the electron beam passes through the measurement point, and the second mask deflector when the sample current value reaches a maximum. The deflection output value applied to 14 is measured.

This is performed for measurement points... This is defined as one unit.

Further, as shown by the arrow in FIG. 19, the measurement points are gradually expanded outward, and the above-described operation of one unit is repeated.

This operation is performed up to the maximum portion of the maximum area (mask area) where the measurement point can select a pattern.

As a result, a map which is a set of deflection output values to the second mask deflector 14 is obtained.

-2 Substituting the obtained map into Equation 26 in FIG. 20 to obtain a first coefficient for providing a deflection output value of the second mask deflector 14 corresponding to the deflection output value of the first mask deflector 13 A (see FIG. 17) is obtained. This coefficient is referred to as a relative correction coefficient of the second mask deflector 14 with respect to the first mask deflector 13.

Here, since the coefficients are obtained based on the map, the coefficients can be obtained with high accuracy.

The relative relationship of the third mask deflector 15 is determined with reference to the fourth mask deflector 16 (step 90 _{-2 in} FIG. 11).

At this time, the block mask 8 has been removed.

Here, as shown in FIG. 21, when an arbitrary deflection is performed by the fourth mask deflector 16, the third mask deflector 15 allows the electron beam to pass through the round aperture 20. Find the function to swing in the opposite direction in advance. Specifically, this is performed as described below (steps 105 to 109 in FIG. 13).

-1 First Mask Deflector 13 and Second Mask Deflector 13
The mask deflector 14 is turned off.

An appropriate deflection output value is applied to the fourth mask deflector 16 so that the electron beam passes through the measurement point shown in FIG.

While measuring the sample current, the deflection output value is applied to the third mask deflector 15 so that the electron beam is swung in the opposite direction in advance. The deflection output value applied to the third mask deflector 15 when the electron beam is shaken and passes through the hole 20a of the round aperture 20, that is, when the sample current is maximized, is measured.

Subsequently, the deflection output value applied to the fourth mask deflector 16 is changed so that the electron beam passes through the measurement point, and the third mask deflector when the sample current value becomes maximum is obtained. Measure the deflection output value applied to 15.

This is performed for measurement points... This is defined as one unit.

Further, as shown by the arrow in FIG. 22, the measurement points are gradually expanded outward, and the above-described operation of one unit is repeated.

This operation is performed up to the maximum portion of the maximum area (mask area) where the measurement point can select a pattern.

As a result, a map which is a set of deflection output values to the third mask deflector 15 is obtained.

(2) Substituting the obtained map into Equation 27 in FIG. 23 to obtain a second coefficient for providing the deflection output value of the third mask deflector 15 corresponding to the deflection output value of the fourth mask deflector 16 B ₁ (see FIG. 21) is obtained. This coefficient is referred to as a relative correction coefficient of the third mask deflector 15 with respect to the fourth mask deflector 16.

Here, since the coefficients are obtained based on the map, the coefficients can be obtained with high accuracy.

The relationship between the first mask deflector 13 and the position on the block mask 8 is determined (Step 90 in FIG. 11).
_-3 ).

Here, the beam position on the block mask when the electron beam is deflected by the first mask deflector 13 and the second mask deflector 14 according to the above relationship, and the first mask deflector 13 To obtain the relationship with the deflection output value.

More specifically, the processing is performed as follows (steps 110 to 112 in FIG. 14).

-1 As shown in FIG. 24, the block mask 8 is set, and the calibration mask pattern mask area 120 is set as the center.

Calibration mask area 120
Has a configuration in which rectangular opening patterns are arranged in a grid at a predetermined pitch, as shown in FIG.

-2 As shown in FIG. 24, the first mask deflector 13 and the second mask deflector 14 are linked to each other according to the relationship obtained above (Equation (24) in FIG. 15). Select a pattern for use.

-3 based on the position of each calibration mask pattern on the mask area 120 and the deflection output value to the first mask deflector 1 required to select this position, from the equation 28 shown in FIG. And the mask area correction coefficient D (see FIG. 17).

First and second mask deflectors 13 and 1
Then, the relative relationship between No. 4 and the third and fourth mask deflectors 15 and 16 is obtained (step 90 _{-4 in} FIG. 11).

Here, when the electron beam is arbitrarily deflected by the first mask deflector 13 and the second mask deflector 14 in accordance with the relation (Equation (24) in FIG. 15) obtained above, the sample surface In the above, the third mask deflector 15 and the fourth mask deflector 16 deflect while maintaining the relation (Equation 27 in FIG. 23) determined by the third mask deflector 15 and the fourth mask deflector 16 so as to eliminate the displacement of the electron beam. First and second mask deflectors 13 and 14 and third and fourth mask deflectors 15 and 1
6. Determine the relative relationship with 6.

More specifically, the processing is performed as follows (steps 113 to 117 in FIG. 14).

-1 As shown in FIG. 27, the calibration pattern 122 at the mask coordinate origin 121 (see FIG. 25) is selected according to the relation (Equation (25) in FIG. 16) obtained above, and As shown in an enlarged view at 28, a measurement beam 124 which is considerably thinner than the electron beam 123 in the mask deflector is formed. This is to increase the measurement accuracy.

By using this beam 124 to perform mark detection on the surface of the sample 25, a reference beam position 125 on the surface of the sample is measured. Since the measurement beam 124 is narrow, the beam position 125 is measured with high accuracy.

Then, as shown in FIG. 29, another calibration pattern other than the pattern 122 in FIG. 25 is selected in accordance with the relation (Equation (25) in FIG. 16) obtained above. The measurement beam 124 is formed in the same manner as described above, the position 126 of the mark on the sample surface irradiated with the beam 124 is detected, and the deviation δ of the position 126 from the reference beam position 125 is measured.

The beam position deviation δ becomes zero so that
According to the relationship obtained above (Equation 27 in FIG. 23), the third
And the fourth mask deflector 16 are linked with each other.

As a result, the beam 124 changes from the state shown by the solid line in FIG. 29 to the state shown by the two-dot chain line.

When the beam displacement becomes zero, the third
The deflection output value to the fourth mask deflector 16 and the deflection output value to the fourth mask deflector 16 are measured.

The above is performed for each of the plurality of calibration patterns other than the pattern 122.

As a result, a map of the deflection output value to the third mask deflector 15 and a map of the deflection output value to the fourth mask deflector 16 are obtained.

-3 The map of the deflection output value to the first mask deflector 13 when each calibration pattern is selected, the map of the deflection output value to the third mask deflector 15 and the fourth map From the map of the deflection output value to the mask deflector 16, the first value is obtained by the equation (29) shown in FIG.
A mask deflector relative correction coefficient B (see FIG. 17) which gives the deflection output value of the third mask deflector 15 with respect to the deflection output value of the mask deflector 13 of FIG. , The deflection output value of the fourth mask deflector 16 for the mask deflector relative correction coefficient C (FIG.
7).

As described above, the relative correction coefficients A, B, and C in FIG. 17 have been obtained.

Next, step 91 in FIG. 11 is performed.

Here, the block mask 8 is moved to position a mask area used for block exposure at the center of the exposure apparatus, and a mask area correction coefficient D ₁ of this mask area is obtained.

Specifically, this is performed as shown in FIG.

First, according to the mask deflector correction coefficients A, B and C, all the mask deflectors 13 to 16 are linked to select one rectangular opening pattern existing in the new mask area (step 120).

Next, the position of the selected rectangular opening pattern on the block mask 8 and the first necessary
Based on the output value to the mask deflector 13, a new mask area correction coefficient is calculated by Expression 30 shown in FIG. 32 (Step 121).

The time required to calculate a new mask area correction coefficient is as short as about 1 minute.

Next, steps 92 and 93 in FIG. 11 are performed. In step 92, the mask area correction coefficient D ₁ is
It is set to the coefficient part of the mask area correction circuit 85 in which the value is 0.

In step 93, the mask deflector relative correction coefficients A, B, and C are set in the coefficient section of the mask deflector relative correction circuit 86 in FIG.

Thus, preparations before exposure are completed.

Thereafter, block exposure 93 is started.

In the case where the block mask 8 has a configuration in which the block mask pattern is mixed in the calibration mask pattern mask area, FIG.
Step 91 is unnecessary, and the block exposure can be started by setting the mask area correction coefficient D obtained in step _90-3 in the coefficient section of the mask area correction circuit 85.

If there is no desired mask pattern in the currently selected mask area of the mounted block mask 8, the block mask 8 is moved and positioned around another mask area.

In this case, it is necessary to readjust the mask deflector.

The operation at this time will be described below.

Here, the mask deflector relative correction coefficient A,
Since B and C are determined independently of the block mask 8, it is not necessary to recalculate the mask deflector relative correction coefficients A, B and C. What is necessary is just to recalculate the mask area correction coefficient for the other mask area.

As shown in FIG. 33, first, all the mask deflectors 13 to 13 are set in accordance with the mask deflector correction coefficients A, B, and C.
16 are linked, and one rectangular opening pattern existing in another mask area is selected (step 130).

Next, the position of the selected rectangular opening pattern on the block mask 8 and the first necessary
3 based on the deflection output value to the mask deflector 13 of FIG.
A new mask area correction coefficient is calculated by Expression 30 shown in Equation 2 (Step 131).

Next, another calculated mask area correction coefficient D ₂ is set in the coefficient section of the mask area correction circuit 85 in FIG. 10 (step 132).

Thereafter, block exposure is restarted (step 1).
33).

The time required for readjustment after moving the block mask can be as short as about 1 minute.

Conventionally, in addition to the coefficient similar to the mask area correction coefficient, a coefficient similar to the mask deflector relative correction coefficient has to be obtained again, which takes about half a day.

For this reason, according to this embodiment, when the electron beam exposure apparatus is continuously moved, the time for interrupting the block exposure due to the movement of the block mask is greatly reduced as compared with the conventional case. As a result, the operation efficiency of the electron beam exposure apparatus can be improved, and the throughput of the semiconductor device can be improved as compared with the related art.

[0270]

As described above, according to the first aspect of the present invention, the adjustment processing of the apparatus can be reliably performed in a short adjustment time.

The invention according to claim 4 has a configuration in which the step of obtaining the relative relationship of the deflection means and the step of obtaining the first deflection means deflection output value-beam coordinate position relationship are performed. This is a configuration in which the arrangement of the transmission hole mask plate is not taken into account.

For this reason, in the case where the transmission hole mask plate is moved to select another mask area or the case where the transmission hole mask plate is replaced with another one, readjustment of the relative relationship between the deflection means is necessary. It is not necessary to recalculate, but it is sufficient to recalculate only the first deflection means deflection output value-beam coordinate positional relationship.

Therefore, the time required for readjustment is about 15
Minutes, which is much shorter than in the past, which took about half a day. During the readjustment, the charged particle beam exposure apparatus is stopped.

Here, considering that the readjustment is performed at relatively short intervals, the operation efficiency of the charged particle beam exposure apparatus can be greatly improved as compared with the related art, and the throughput of the semiconductor device as a product can be improved. .

The invention of claim 5 has the same effect as the invention of claim 1.

According to the invention of claim 6, readjustment during operation can be performed in a short time, and a device with high operation efficiency can be realized.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of an electron beam exposure apparatus that performs adjustment according to the method of the present invention.

FIG. 2 is an enlarged view showing the vicinity of a block mask for describing first to third steps.

FIG. 3 is a diagram for explaining an adjustment method in first to third steps.

FIG. 4 is an enlarged view showing the vicinity of a block mask for describing fourth to sixth steps.

FIG. 5 is a diagram for explaining an adjustment method in fourth to sixth steps.

FIG. 6 is an enlarged view showing the vicinity of a block mask for describing seventh and eighth steps.

FIG. 7 is a diagram for explaining an adjustment method in seventh and eighth steps.

FIG. 8 is a diagram for explaining a ninth step.

FIG. 9 is a diagram showing an outline of the present invention.

FIG. 10 is a diagram showing a configuration of a pattern generation unit 55A in a control unit of an embodiment of the electron beam exposure apparatus of the present invention.

FIG. 11 is a diagram showing a procedure for adjusting a mask deflector.

[12] In FIG. 11, a flowchart of the process 91 _-1.

[13] In FIG. 11, a flowchart of the process 90 _-2.

In Figure 14 Figure 11, step 90 _-3, which is a flowchart of 90 _-4.

FIG. 15 is a diagram showing an arithmetic expression for calculating a deflection output value to a mask deflector.

FIG. 16 is a diagram showing an expression representing a deflection output value of the first mask deflection to 13;

FIG. 17 is a diagram illustrating adjustment of a mask deflector.

[18] In FIG. 11 is a diagram illustrating a process 90 _-1.

[19] In FIG. 11 is a diagram illustrating a process 90 _-1.

FIG. 20 is a diagram showing an equation for calculating a relative correction coefficient A of the second mask deflector 14 with respect to the first mask deflector 13;

FIG. 21 is a diagram illustrating a step _90-2 in FIG. 11;

FIG. 22 is a diagram illustrating a step _90-2 in FIG. 11;

FIG. 23 is a diagram showing an equation for calculating a relative coefficient B ₁ of the fourth mask deflector 16 with respect to the third mask deflector 15;

FIG. 24 is a view for explaining step _90-3 in FIG. 11;

FIG. 25 is a diagram showing a mask area of a calibration mask pattern in FIG. 35;

FIG. 26 is a diagram showing an equation for calculating a mask area correction coefficient.

FIG. 27 is a diagram showing a reference position measurement of a sample surface.

FIG. 28 is a diagram showing shaping of a measurement beam.

FIG. 29 is a diagram illustrating measurement of a beam position shift.

FIG. 30 shows the first of the third and fourth mask deflectors 15 and 16;
FIG. 9 is a diagram showing an equation for calculating mask deflector relative correction coefficients C and B for the mask deflector 13 of FIG.

FIG. 31 is a view for explaining step 91 in FIG. 11;

FIG. 32 is a diagram showing an equation for calculating a new mask area correction coefficient.

FIG. 33 is a diagram showing readjustment when another mask area is set by moving a block mask.

FIG. 34 is a conceptual diagram illustrating an example of an electron beam exposure apparatus.

FIG. 35 is a plan view showing a block mask.

FIG. 36 is a plan view showing one area portion of a block mask.

FIG. 37 is a plan view showing an example of a block pattern.

FIG. 38 is a diagram showing a control unit of the electron beam exposure apparatus together with an exposure unit.

FIG. 39 is a diagram showing the trajectory of the electron beam from the mask deflector at the most upstream position to the aperture.

40 is a diagram when the trajectory of the electron beam shown in FIG. 38 is viewed from above a block mask.

FIG. 41 is a diagram showing a change in the trajectory of the electron beam when the deflection direction of the mask deflector arranged on the most upstream side is changed.

FIG. 42 is a diagram showing a change in the trajectory of the electron beam when the deflection direction of the mask deflector arranged second from the most upstream side is changed.

FIG. 43 is a diagram showing a change in the trajectory of the electron beam when the deflection direction of the third and fourth mask deflectors from the most upstream side is changed.

FIG. 44 is a diagram showing a change in the plane on which the trajectory of the electron beam exists when the deflection intensity of the mask deflector arranged on the most upstream side is changed.

FIG. 45 is a diagram showing a change in the plane on which the trajectory of the electron beam exists when the deflection intensity of the mask deflector arranged second from the most upstream side is changed.

FIG. 46 shows a change in the plane on which the trajectory of the electron beam exists when the deflection intensity of the mask deflector arranged third from the most upstream side is changed, and the mask deflector arranged fourth from the most upstream side. FIG. 4 is a diagram showing a plane on which the trajectory of an electron beam exists when the deflection intensity of the electron beam is changed.

FIG. 47 is a flowchart showing a main routine in a case where deflection conditions necessary for deflecting an electron beam and returning to an optical axis at the time of no deflection are obtained by simulation.

FIG. 48 is a flowchart showing a main routine in a case where deflection conditions necessary for deflecting an electron beam and returning to an optical axis at the time of no deflection are obtained by simulation.

FIG. 49 is a flowchart showing a subroutine in a case where deflection conditions necessary for deflecting an electron beam and returning to the optical axis at the time of no deflection are obtained by simulation.

FIG. 50 is a flowchart showing a subroutine for deflecting an electron beam and obtaining, by simulation, deflection conditions necessary for returning the electron beam to the optical axis at the time of no deflection.

FIG. 51 is a plan view showing a conventional block mask having a pattern for calibration.

FIG. 52 is a plan view for explaining a calibration method using the block mask shown in FIG. 25;

FIG. 53 is a diagram showing a conventional pattern generating means.

FIG. 54 is a diagram illustrating a relationship between movement of a block mask and readjustment.

[Explanation of symbols]

Reference Signs List 1 electron gun 2 optical axis 3 electron beam 6 slit deflector 8 block mask 13 first mask deflector 14 second mask deflector 15 third mask deflector 16 fourth mask deflector 25 sample 30 charged particle beam Exposure device (electron beam exposure device) 31 Electromagnetic lens 50 Control unit 51 Storage medium 52 CPU 53 Interface 54 Data memory unit 55 Pattern generation unit 57 DAC / AMP unit 58 Mask moving mechanism 70 Deflector relative relationship obtaining step 71 First Deflection output value to deflector-beam coordinate position 120 Calibration mask pattern mask area 121 Mask coordinate origin 122 Calibration mask pattern 123 Electron beam 124 Measurement beam 125 Reference beam position

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Junko Hatta 1015 Uedanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Kiichi Sakamoto 1015 Kamikodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited (56) References JP-A-4-53221 (JP, A) JP-A-3-232217 (JP, A) JP-A-3-46320 (JP, A) JP-A-4-144119 (JP, A) JP-A-4-123419 (JP, A) JP-A-2-250311 (JP, A) JP-A-6-163377 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21 / 027 G03F 7/20

Claims (6)

(57) [Claims] 1. A charged particle beam generating means (1) for generating a charged particle beam (3), and a polygon arranged at a position through which the charged particle beam (3) passes and shaping the charged particle beam (3) A shaping plate (6), a transmission hole mask plate (8) on which at least one transmission hole pattern (12) having an arbitrary shape is formed, and an arrangement position of the charged particle beam generating means (1) is an upper part. In this case, a pair of first to fourth deflecting means (13 to 4) are disposed so as to be substantially mirror-symmetrical one above the other through the transmission hole mask plate (8) and deflect the charged particle beam (3). 1
6) and a method of adjusting a charged particle beam exposure apparatus having a round aperture (20) disposed below the first to fourth deflecting means (13 to 16), wherein the polygonal shaping plate is provided. (1) The first one located closest to (6)
Of the crossover image on the round aperture (20) by the first deflecting means (13) and the deflection amount (r1).
And driving only the second deflecting means (14) disposed below the first deflecting means (13) and above the transmission hole mask plate (8), A second step of calculating the deflection phase (θ2) and the deflection amount (r2) of the crossover image on the round aperture (20) by the deflecting means (14), and the first and second deflecting means (13, 14) simultaneously driving the first and second such that the deflection efficiency of the crossover image on the round aperture (20) becomes zero.
A third step of obtaining a deflection difference (θd ₁ ) and a deflection amount ratio (V1: V2 ′) of the deflecting means (13, 14); and a third step disposed at a position below the transmission hole mask plate (8). A fourth step of driving only the deflecting means (15) to determine the deflection phase (θ3) and the deflection amount (r4) of the crossover image on the round aperture (20) by the third deflecting means (15). A fourth deflector disposed at a lower position of the third deflecting means (15).
Of the crossover image on the round aperture (20) by the fourth deflecting means (16) and the deflection amount (r4).
A fifth step of obtaining the cross-over image on the round aperture (20) when the third and fourth deflecting means (15, 16) are simultaneously driven. 3rd and 4th
A sixth step of calculating the deflection difference (θd ₂ ) and the deflection amount ratio (V3: V4 ′) of the deflecting means (15, 16); and driving the first to fourth deflecting means (13 to 16); The charged particle beam (3) is most perpendicularly incident on the round aperture (20) and the first and second deflecting means (13, 14) and A seventh step of determining a relative angle (θd ₃ ) with the third and fourth deflecting means (15, 16); and, after determining the relative angle, the first to fourth deflecting means (13 to 16). To drive the charged particle beam (3) most perpendicularly into the round aperture (20), and to change the first and second deflecting means (13, 14) and the relative strength (G3) between the third and fourth deflecting means (15, 16). Using the relative deflection amount and the relative phase difference of the first to fourth deflection means (13 to 16) to deflect the deflection coordinates and deflection of the deflection coordinates on the transmission hole mask plate (8). A ninth step of selecting the transmission hole pattern (12) on the transmission hole mask plate (8) by matching the directions.
And a method for adjusting the charged particle beam exposure apparatus. 2. In the fourth step and the fifth step, the deflection phase and the deflection amount already obtained in the first and second steps are replaced with the deflection phase and third deflection means (15, 16). 2. The method for adjusting a charged particle beam exposure apparatus according to claim 1, wherein the method is used as an initial value when obtaining a deflection amount. 3. In the seventh step and the eighth step, a current value passing through the round aperture (20) is maximized, and different through-hole patterns (12) formed on the through-hole mask plate (8) are formed. If selected, the sample (2
5) The charged particle beam exposure according to claim 1 or 2, wherein the deflection phases and the deflection amounts of the first to fourth deflecting means (13 to 16) are determined so that the upper beam position shift is minimized. How to adjust the device. 4. A charged particle beam generating means (1) for generating a charged particle beam (3), and a polygon arranged at a position through which the charged particle beam (3) passes and shaping the charged particle beam (3) A shaping plate (6), a transmission hole mask plate (8) on which at least one transmission hole pattern (12) having an arbitrary shape is formed, and an arrangement position of the charged particle beam generating means (1) is an upper part. In this case, first and second deflecting means (13, 14) disposed above the transmission hole mask plate (8) for deflecting the charged particle beam (3); And third and fourth deflecting means (15, 1) disposed on the lower side for deflecting the charged particle beam (3).
6) and a method for adjusting a charged particle beam exposure apparatus having a round aperture (20) disposed below the fourth deflecting means (16), wherein the charged particle beam is irradiated with the round aperture (20). )
The first, second, third, and fourth deflecting means (13, 14, 15, 15
16), the deflection value output to the second, third, and fourth deflection means (14, 15, 16) with respect to the deflection value output to the first deflection means (13). Remove the through-hole mask plate (8) from the relative relationship.
Determining relative relationship between deflection means determined under the conditions (84-1)
A deflection output value to the first deflection means, and a coordinate position on the transmission hole mask plate (8) of the charged particle beam when the deflection output value is applied to the first deflection means. A method for adjusting a charged particle beam exposure apparatus, wherein the method is divided into a first deflection means deflection output value-beam coordinate position relationship obtaining step (84-2) for obtaining a relationship. 5. A charged particle beam generating means (1) for generating a charged particle beam (3), and a polygon arranged at a position where the charged particle beam (3) passes and shaping the charged particle beam (3) A shaping plate (6), a transmission hole mask plate (8) on which at least one transmission hole pattern (12) having an arbitrary shape is formed, and an arrangement position of the charged particle beam generating means (1) is an upper part. In this case, first and second deflecting means (13, 14) disposed above the transmission hole mask plate (8) for deflecting the charged particle beam (3); And third and fourth deflecting means (15, 1) disposed on the lower side for deflecting the charged particle beam (3).
6) and a method of adjusting a charged particle beam exposure apparatus having a round aperture (20) disposed below the fourth deflecting means (16), wherein the first mask deflector (13) The deflection output value applied to the second mask deflector (14) when the sample current value becomes maximum is measured for each of the plurality of deflection output values applied to the second mask, and the second mask A map of the deflection output value to the deflector (14) is obtained, and from the map, the deflection output to the second mask deflector (14) with respect to the deflection output value to the first mask deflector (13). Step (90-1, 100-1) of obtaining a first mask deflector relative correction coefficient (A) for giving a value
04), the plurality of deflection output values applied to the fourth mask deflector (16) are added to the third mask deflector (15) when the sample current value is maximized. By measuring the deflection output value obtained, a map of the deflection output value to the third mask deflector (15) is obtained, and from the map, a map of the deflection output value to the fourth mask deflector (16) is obtained. Step (90-2, 105-1) of obtaining a second mask deflector relative correction coefficient (B1) for giving a deflection output value to the third mask deflector (15).
09), the deflection is performed by the first mask deflector (13), and the deflection is performed by the second mask deflector (14) according to the first coefficient (A). Deflecting a plurality of beam positions on the aperture mask plate (8),
A map of deflection output values to the first mask deflector (13) corresponding to the plurality of beams is obtained, and from the map, the map is sent to the first mask deflector (13) for the beam position on the transmission hole mask. and obtaining a Masukue rear compensation coefficient giving the deflection output value (D) (90-3,110～112), performs deflected by the first mask deflector (13), said first coefficient ( When the charged particle beam is deflected to a plurality of positions on the transmission hole mask plate (8) by the deflection by the second mask deflector (14) according to A), the beam is misaligned on the sample surface. The third mask deflector (15) determined according to the map of the deflection output value applied to the fourth mask deflector (16) and the second coefficient (B1) and the second coefficient (B1). Get a map of the deflection output values to From the two maps, a third mask deflector relative correction coefficient (B) which gives a deflection output value to the third mask deflector (15) with respect to a deflection output value to the first mask deflector (13); , The first mask deflector (1
The fourth mask deflector (1) for the deflection output value to 3)
Step (90-4, 113 to 11) for obtaining a fourth mask deflector relative correction coefficient (C) that gives the deflection output value to 6).
7), the first mask deflector relative correction coefficient (A), the mask area correction coefficient (D), the third mask deflector relative correction coefficient (B), and the fourth mask deflector relative correction coefficient. A configuration in which a deflection output value to the first, second, third and fourth mask deflectors for a desired transmission hole pattern of the transmission hole mask plate (8) is determined according to the correction coefficient (C). A method for adjusting a charged particle beam exposure apparatus. 6. A charged particle beam generating means (1) for generating a charged particle beam (3), and a polygon arranged at a position where the charged particle beam (3) passes and shaping the charged particle beam (3) A shaping plate (6), a transmission hole mask plate (8) on which at least one transmission hole pattern (12) having an arbitrary shape is formed, and an arrangement position of the charged particle beam generating means (1) is an upper part. In this case, first and second deflecting means (13, 14) disposed above the transmission hole mask plate (8) for deflecting the charged particle beam (3); And third and fourth deflecting means (15, 1) disposed on the lower side for deflecting the charged particle beam (3).
6) and a charged particle beam exposure apparatus having a round aperture (20) disposed below the fourth deflecting means (16), wherein arrangement coordinates of each transmission hole pattern of the transmission hole mask plate are stored. When the charged particle beam is to be formed in a desired through-hole pattern, storage means (81) for outputting the arrangement coordinates of the through-hole pattern; and a mask area correction coefficient ( D) is set in the coefficient section, the coordinates of the transmission hole pattern arrangement are input from the storage means, and a deflection output value for deflecting the charged particle beam to the desired transmission hole pattern is output to the first deflecting means. A mask area correcting means (85) for setting the relative values of the first, third, and fourth mask deflector relative correction coefficients (A, B, C) obtained in claim 5 in a coefficient section; A deflection output value from the correcting means to the first deflecting means is input, and the beam formed by the desired transmission hole pattern is sent to the second, third, and fourth deflecting means at the reference position of the sample. A charged particle beam exposure apparatus, comprising: a mask deflector correcting means (86) for outputting a deflection output value for guiding.