JP4234768B2 - Electron beam drawing device - Google Patents

Description

  The present invention relates to an electron beam drawing apparatus, and more particularly, to an electron beam drawing apparatus that realizes high-precision drawing by shielding a leakage magnetic field from a stage driving mechanism using a permanent magnet.

  In recent years, with the high integration of semiconductor elements, increasingly finer processing dimensions are required. The electron beam drawing apparatus is an apparatus that draws a fine pattern on the surface of a sample by moving the stage on which the sample is mounted while converging the electron beam with an electron lens and deflecting the electron beam with a deflector.

  The stage of the electron beam drawing apparatus is required to be able to operate in a high vacuum environment and to be a non-magnetic material in which the constituent members of the stage do not change the position of the electron beam on the sample.

  On the other hand, there is an Abbe error as a factor that degrades the beam position accuracy due to the laser length measurement system used for stage position control. This Abbe error is expressed by (stage posture change amount) × (offset amount between drawing position and laser measurement optical axis). For example, when the Abbe error is suppressed to 5 nm, if the offset amount of the laser measurement optical axis is 1 mm, the allowable value of the stage posture change amount is 1 second (= 5 μrad). Conventionally, rolling guides of non-magnetic cemented carbide (hereinafter referred to as cemented carbide) as described in Japanese Patent Laid-Open No. 05-198469 have been used as stage guides, but the posture of the stage changes due to straightness errors of the guides. Therefore, it is very difficult to suppress pitching, yawing and rolling to 1 second or less / 200 mm.

  Further, since the ceramic table is a softer material than the carbide rolling element, the table is slightly deformed by the movement of the rolling element. As a result, since the distance between the length measuring mirror and the sample changes on the order of nanometers, a measurement error occurs. As described above, the positional accuracy of the drawing pattern is lowered due to Abbe error and minute deformation of the stage.

JP 05-198469 A

  The decrease in the positional accuracy is caused by the change in the posture of the stage and the amount of deformation of the stage member. In consideration of such problems, when an air bearing guide that supports vacuum environment is used for the stage guide, if the surface accuracy of the guide surface plate is about submicron, it is possible to achieve a stage posture change of 1 second or less. Is possible. In addition, since it is a non-contact moving mechanism, the amount of deformation of the table is small. In the air bearing guide for a polygon mirror processing machine described in Japanese Patent Laid-Open No. 10-217053, a permanent magnet may be used inside the stage as a preload biasing means for preventing a change in stage posture. This permanent magnet is for attracting the stage main body to the guide surface plate side. Further, non-contact restraining means using a repulsive force between permanent magnets in a vacuum as described in Japanese Patent Application Laid-Open No. 10-281110 is also effective in preventing table deformation accompanying stage movement. However, in a state where the external leakage magnetic field from the permanent magnet is not shielded, when the stage moves, the static magnetic field distribution of the permanent magnet also moves, causing a positional deviation of the electron beam on the sample.

  Here, with reference to FIG. 4, the allowable magnetic field change amount is estimated from the viewpoint of the positional accuracy of the electron beam. The fluctuation of the magnetic field existing in the space between the electron lens 5 and the sample 7 changes the irradiation position of the electron beam 4. The distance from the lower surface of the electron lens 5 to the sample 7 is H, and the fluctuation amount of the magnetic field in this space is ΔB (T). Electrons that have passed through the electron lens 5 are affected by the magnetic field fluctuation, are deflected along the trajectory of the Bohr radius R at a deflection angle θ, and reach a point that is separated from the target irradiation position by ΔX.

In a range where the deflection angle θ is sufficiently small,
ΔX = H ² / (2R) (1)
Can be approximated.

Bohr radius R = mv / (eΔB) in equation (1) (2)
Where m: mass of the electron m = 9.1 × 10 ⁻³¹ (kg)
e: Electron charge e = 1.6 × 10 ^-19 (C)
v: Substituting the electron velocity,
ΔX / ΔB = eH ² / ( ² mv) (3)
Is obtained.

On the other hand, the energy of electrons is
^{E = mv 2/2 ......... (} 4)
Therefore, if v is deleted from the equations (3) and (4),
ΔX / ΔB = eH ² / (2√ ( ² mE)) (5)
Is obtained.

FIG. 5 shows the relationship between the beam misalignment and the magnetic field (calculated values) when ΔX = 10 nm and H = 25 mm and the acceleration voltage is a variable. If the magnetic field change is within 2 × 10 ⁻⁸ T and the acceleration voltage is 30 kV or more, the beam position shift is 10 nm or less. Therefore, it is necessary to shield the leakage magnetic field from the permanent magnet so that it is within 2 × 10 ⁻⁸ T.

  On the other hand, a leakage magnetic field from the electron lens always exists in the lower space of the electron lens. Since the shield member made of a ferromagnetic material moves in the leakage magnetic field of the electron lens, the magnetic field in the space from the lower surface of the electron lens to the sample is disturbed, causing a position shift of the electron beam on the sample. In order to reduce the amount of displacement, it is necessary to reduce the leakage magnetic field from the electron lens.

In order to perform high-precision drawing, it is necessary to shield the leakage magnetic field from the permanent magnet and the leakage magnetic field from the electron lens, respectively, and reduce the amount of magnetic field change at the sample position to 2 × 10 ⁻⁸ T or less.

Accordingly, an object of the present invention is to provide an electron beam drawing apparatus suitable for high-precision writing, and to provide an apparatus structure capable of reducing the magnetic field change amount at the sample position to 2 × 10 ⁻⁸ T or less. Is to provide.

  In order to achieve the above object, in the present invention, regarding the reduction of the leakage magnetic field from the permanent magnet inside the stage main body, measures are taken by shielding all surfaces except the attracting surface of the permanent magnet with a ferromagnetic material. ing. In addition, regarding the reduction of the magnetic field change caused by the movement of the shield in the leakage magnetic field from the electron lens, a countermeasure is provided by providing a shield for reducing the leakage magnetic field from the electron lens on the lower surface of the electron optical column. Yes. By taking the above-mentioned two shielding measures, even if the stage moves, the external leakage magnetic field from the permanent magnet or electron lens does not affect the electron beam irradiation position, and high-precision drawing can be realized.

  According to the present invention, since the sample stage support / guide mechanism is made non-contact, it is possible to prevent the table member on which the sample is mounted from being deformed along with the stage movement and to move the stage with high accuracy. High-precision drawing can be realized.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In order to reduce the leakage magnetic field from the magnet incorporated in the stage main body as much as possible, it is preferable to configure the magnetic field lines from the magnet to be a closed loop. For example, in the case of a multipolar magnet in which N poles and S poles are alternately arranged, by attaching the magnet to a ferromagnetic yoke, the magnetic field lines of the N pole and S pole cancel each other, and leakage of the yoke mounting surface occurs. The magnetic field is greatly reduced. Similarly, by bringing the attracting surface closer to the surface plate, the magnetic field lines of the S and N poles cancel each other, and the leakage magnetic field is reduced. However, when the magnetic field of the magnet itself is 1 T or more, it is difficult to reduce the magnetic field change to an allowable value of 2 × 10 ⁻⁸ T or less.

  Therefore, in order to reduce the leakage magnetic field of the magnet, the surfaces other than the attracting surface of the magnet are shielded with a ferromagnetic material having a high magnetic permeability. Since the ferromagnetic material is magnetized at the time of machining, it is necessary to demagnetize it by performing a heat treatment after the processing.

  In order to reduce the leakage magnetic field of the permanent magnet, first, the generated magnetic field is reduced by a closed loop configuration of the lines of magnetic force, and further the generated magnetic field is shielded.

  On the other hand, in order to reduce the disturbance of the leakage magnetic field of the electron lens accompanying the movement of the magnetic field shield, a magnetic field shield is provided below the electron optical column within a range that does not affect the deflection for drawing.

By shielding the magnetic fields generated by the permanent magnet and the electron lens, the amount of magnetic field fluctuation at the sample position can be suppressed to an allowable value of 2 × 10 ⁻⁸ T or less for electron beam drawing.

<Example 1>
FIG. 1 shows a schematic configuration of a portion below the electron optical column of the electron beam lithography apparatus according to the first embodiment of the present invention.

  FIG. 2 schematically shows the overall configuration of the electron beam drawing apparatus. The inside of the electron optical column 1 and the inside of the sample chamber 2 are kept in a vacuum. The electron beam 4 from the electron gun 3 in the electron optical column 1 is converged by the electron lens 5, deflected by the deflector 6, and irradiated to a predetermined position on the sample 7. The sample 7 is mounted on the sample stage 8 in the sample chamber 2. A desired pattern can be drawn over the entire surface of the sample 7 by moving the sample stage 8 by the stage driving unit 20 and deflecting and irradiating the surface of the sample 7 with the electron beam 4.

  FIG. 3 shows a configuration example of a conventional sample stage. In FIG. 3, a sample 7 and a stage position measuring bar mirror 10 are mounted on a Y table 9. The sample position at the time of drawing can be obtained by laser length measurement of the position of the bar mirror 10.

  The Y table 9 and the X table 11 are configured in a relationship as shown in the AA ′ sectional view. Carbide guides 12 are respectively attached to the inner surface of the concave portion of the X table 11 and the outer surface of the convex portion of the Y table 9. V-grooves are provided on the opposing surfaces of both the carbide guides 12. A crossed roller 13 is inserted between the V grooves, and the Y table 9 moves relative to the X table 11 via the crossed roller 13. As shown in the enlarged view of part B in FIG. 3, the crossed roller 13 is provided with a plurality of cylindrical rollers 14 that are alternately turned 90 degrees. The X table 11 and the base 15 are similarly configured, and the X table 11 moves with respect to the base 15 via the crossed roller 13.

  When the Y table 9 moves, the roller 14 moves while rotating, so that the convex portion of the Y table 9 receives a compressive force from the roller 14. When this compressive force fluctuates, the ceramic Y table 9 undergoes a minute deformation of up to about 50 nm. Due to this deformation, the position of the sample 7 and the position of the bar mirror 10 are changed, so that it is clear that the irradiation position accuracy of the electron beam 4 is lowered.

  Therefore, in the present invention, as shown in FIG. 1, the stage 16 that is levitated by the attracting force of the permanent magnet 17 is placed on the surface plate 18 while the stage 16 is levitated by the airflow force ejected from the air pad in a vacuum environment. It was configured to attract.

  First, an air pad 19 that simultaneously ejects and sucks gas is attached to the bottom surface of the stage 16. Further, as a preload urging means, the stage 16 is attracted to the surface plate 18 by the attractive force of the permanent magnet 17. The stage 16 is driven by the stage driving unit 20 and moves along the upper surface of the surface plate 18. Since the floating position of the stage 16 is determined by the balance between the attractive force of the permanent magnet 17 and the drag force (buoyancy) caused by the airflow, the rigidity of the stage 16 during travel is maintained.

  A surface other than the attracting surface of the permanent magnet 17 is shielded by a magnetic field shield 21 so that the magnetic field of the permanent magnet 17 does not affect the irradiation position of the electron beam. An electron lens leakage magnetic field shield 22 is attached to the lower surface of the electron optical column 1 in order to reduce the leakage magnetic field from the electron lens 5 into the sample chamber 2.

  FIG. 6 shows a configuration example of the air pad 19. FIG. 4A is a plan view of the air pad 19 as viewed from below, and FIG. 4B is a cross-sectional view taken along line AA ′. The air pad 19 is provided with an air inlet 23 and an air inlet 24. By ejecting gas from the air outlet 23, buoyancy is given to the stage 16 to float on the surface plate 18, and the ejected gas is collected from the air inlet 24.

  FIG. 7 shows a multipolar magnet configuration as one configuration example of the permanent magnet 17. FIG. 4A is a plan view of the permanent magnet 17 viewed from below, and FIG. 4B is a side view. The plurality of plate magnets 25 are polarized in the vertical direction (perpendicular to the surface of the surface plate), and N poles and S poles are alternately arranged on the magnet lower surface (attraction surface) side. The upper surface of the magnet (the surface opposite to the attracting surface) is fixed to the yoke 26, and the yoke 26 reduces the leakage magnetic field above the magnet.

  As shown in FIG. 8, since the poles of the plate magnet 25 are short-circuited by the yoke 26 on the yoke 26 side, there are almost no magnetic lines of force leaking from the yoke 26 to the external space. Go from N pole to S pole.

  FIG. 9 shows an arrangement configuration of the surface plate 18, the plate magnet 25, and the magnet magnetic field shield 21 when the stage 16 floats. When the distances (gap) between the plate magnet 25 and the shield 21 and the surface plate 18 are set to t1, t2 (t1, t2> 0), part of the magnetic field lines leaks to the outside space of the shield 21 through the gap. Get out. Therefore, in order to further effectively reduce the leakage magnetic field to the external space, the shield 21 may have a multiple arrangement configuration. In FIG. 10, an inner shield 27 (gap: t2) is provided just outside the yoke 26, and an outer shield 28 (gap: t3) is further provided outside the yoke 26 with a space therebetween.

  10, the leakage magnetic field to the external space when the height (gap: t1, t2, t3) of the plate magnet 25, the inner shield 27 and the outer shield 28 from the upper surface of the surface plate 18 is set to 0.1 mm. The intensity is shown in FIG. The magnetic field strength curve in FIG. 11 was calculated from an actual measured magnetic field strength value at a specific position outside the permanent magnet in the lateral direction and the following equation (6) representing that this magnetic field strength is inversely proportional to the square of the distance. It is a result.

B = Pm / (4πμ ₀ H ² ) (6)
Where B: magnetic field strength
Pm: Magnetic moment of magnetic dipole (magnet)
μ ₀ : Permeability in vacuum / μ ₀ = 1.3 × 10 ⁻⁶ (H / m)
H: Distance from magnetic dipole (magnet) From FIG. 11, at a position 100 mm away from the permanent magnet, the leakage magnetic field intensity from the permanent magnet is 1 × 10 ⁻⁶ T when no shield structure is provided. However, when the shield structure of FIG. 10 is adopted, it can be seen that it is reduced to 2 × 10 ⁻⁸ T. From this, it can be confirmed that a sufficient reduction effect (shield effect) of the leakage magnetic field from the permanent magnet can be obtained by the shield structure of FIG.

  On the other hand, as shown in FIG. 12, a leakage magnetic field from the electron lens 5 exists below the electron lens 5. When the magnet magnetic field shield 21 is placed in this leakage magnetic field, the magnetic field in the region surrounding the magnetic magnet magnetic field shield 21 made of ferromagnetic material is disturbed as shown in FIG. Due to the magnetic field change on the sample 7, the irradiation position shift of the electron beam 4 occurs. In order to prevent this magnetic field change on the sample, it is necessary to reduce the leakage magnetic field from the electron lens 5.

Therefore, in the present invention, the electron lens leakage magnetic field shield 22 is provided below the electron lens 5. FIG. 14 shows the leakage magnetic field shielding effect in this case. The maximum magnetic field strength in the electron lens 5 (height position: h1) is 10 ⁻² T. However, the leakage magnetic field strength decreases as the distance from the lens 5 increases, and when the shield 22 is not provided, the height of the sample 7 is increased. It was 10 ^-4 T at the position h2 and 10 ^-6 T at the height position h3 of the shield 21. In this case, the amount of magnetic field fluctuation caused by the movement of the magnet magnetic field shield 21 exceeds 10 ⁻⁸ T, and the irradiation position of the electron beam 4 on the sample 7 is shifted.

On the other hand, when the shield 22 is provided according to the present invention, the leakage magnetic field intensity from the electron lens 5 can be reduced to 10 ⁻⁸ T at the position of the sample 7 and to 10 ⁻¹¹ T at the position of the shield 21. The amount of magnetic field variation caused by the movement of the magnetic field shield 21 is inevitably 10 ⁻¹¹ T or less, and this amount of magnetic field variation almost affects the irradiation position of the electron beam 4 on the sample 7. Absent.

  With the above configuration, it is possible to restrain the height position and posture of the sample stage 16 in a non-contact state, and that the leakage magnetic field from the permanent magnet 17 and the electron lens 5 affects the electron beam irradiation position. Can be prevented, and high-precision drawing can be realized.

  In the configuration of FIG. 9, in order to further enhance the shielding effect of the leakage magnetic field, the distance between the plate magnet 25 as the magnetic force restraining means and the surface plate 18 is t1, and the distance between the magnetic field shield 21 and the surface plate 18 is It is desirable that the plate magnet 25 and the magnet magnetic field shield 21 are arranged and configured with respect to the surface plate 18 so that the relationship of t1> t2 is established when the distance between them is t2. In the configuration of FIG. 10, it is desirable to satisfy t1> t2 and t1> t3 in order to further enhance the leakage magnetic field shielding effect.

<Example 2>
FIG. 15 shows the configuration of the stage portion in the electron beam lithography apparatus according to the second embodiment of the present invention. The present embodiment relates to a magnetic field shield structure when a single-axis linear motor is used for stage driving.

  In FIG. 15, the sample 7 is mounted on the upper surface of the stage 16. A roller 14 is interposed between the surface plate 18 and the stage 16. A power transmission frame 29 is attached to the stage 16 body, and a drive coil 30 is fixed to the end of the power transmission frame 29. Permanent magnets 31 and 32 are arranged on both sides of the drive coil 30. The permanent magnets 31 and 32 are attached on the inner wall of the fixed yoke 33 that also serves as a guide portion. The principle of the uniaxial linear motor shown in the figure is that a driving force is generated by an interaction between a fixed magnetic field generated by the permanent magnets 31 and 32 and a generated magnetic field generated by the movable drive coil 30.

  The leakage magnetic field from the permanent magnets 31 and 32 can be reduced by using a material having a high magnetic permeability for the fixed yoke 33 surrounding the permanent magnets 31 and 32. With respect to the magnetic field generated by the drive coil 30, the leakage magnetic field to the outside is reduced by providing the movable yoke 34 made of a high permeability material on the lower surface of the drive coil 30. Examples of the high magnetic permeability material include permalloy.

  FIG. 16 shows a cross-sectional view taken along the line CC ′ of FIG. When a current is passed through the drive coil 30 to generate a magnetic field, an attractive force acts between the drive coil 30 and the permanent magnets 35 and 36, and a repulsive force acts between the drive coil 30 and the permanent magnets 37 and 38. Due to the attractive force and the repulsive force, the drive coil 30 receives a force that moves in one direction (left direction in the figure).

  In FIG. 15, the configuration example in which the stage main body 16 is supported and guided by the roller 14 on the surface plate 18 is shown. Needless to say.

<Example 3>
FIG. 17 shows the configuration of the stage portion in the electron beam lithography apparatus according to the third embodiment of the present invention. In the present embodiment, the permanent magnets 31 and 32 constituting the stage driving linear motor are surrounded by a fixed yoke 39 made of a ferromagnetic material, thereby reducing the external leakage magnetic field from the permanent magnets 31 and 32. Further, a fixed shield 40 made of a high magnetic permeability material is provided on the outer periphery of the fixed yoke 39 to shield the leakage magnetic field outside the fixed yoke 39. The magnetic field generated from the drive coil 30 of the movable part is also reduced in the leakage magnetic field to the outside by the movable yoke 41 made of a ferromagnetic material and the movable shield 42 made of a high permeability material. Examples of the ferromagnetic material include iron-based materials, and examples of the high magnetic permeability material include permalloy.

  The double shield structure of this embodiment is more effective in preventing external leakage of a strong generated magnetic field in the linear motor.

<Example 4>
FIG. 18 shows the configuration of the stage portion in the electron beam lithography apparatus according to the fourth embodiment of the present invention. In this embodiment, the magnetic field generated by the permanent magnets 31 and 32 inside the stage driving linear motor is reduced by the fixed yoke 43 made of a high permeability material. Further, the shield is made by a fixed shield 45 made of a high magnetic permeability material through a spacer 44 made of a nonmagnetic material. The magnetic field generated from the drive coil 30 of the movable part is also provided with a movable shield 46 made of a high permeability material to reduce the leakage magnetic field to the outside. For example, a permalloy material can be used as the high magnetic permeability material. The double shield configuration of this embodiment can more effectively prevent the magnetic field from the stage drive system from leaking directly to the outside.

<Example 5>
FIG. 19 shows the configuration of the stage portion in the electron beam lithography apparatus according to the fifth embodiment of the present invention. The present embodiment relates to a configuration example that can make the shield member smaller and lighter.

  In this embodiment, a movable yoke 60 made of a high magnetic permeability material is fixed to the end of the power transmission frame 29 connecting the sample stage and the linear motor on the linear motor side, and permanent magnets are disposed on the mutually opposing inner wall surfaces of the movable yoke 60. 31 and 32 are attached. Between the opposing surfaces of the permanent magnets 31 and 32, the drive coil 30 is fixed on the surface plate 18 via a fixed yoke 61. That is, in this embodiment, unlike the previous embodiment, the yoke 60 and the permanent magnets 31 and 32 side of the linear motor are the movable parts, and the yoke 61 and the drive coil 30 side are the fixed parts. The drive coil 30 is an air-core coil and does not have a ferromagnetic magnetic core. Therefore, the drive coil 30 does not generate a magnetic field unless energized.

  FIG. 20 shows a DD ′ cross-sectional structure of FIG. In FIG. 20, the drive coil is composed of a plurality of drive coils 30a to 30f. The length of the movable yoke 60 in the moving direction is set to a length that can surround the drive coils that interact with the permanent magnets 31 and 32 (two drive coils 30c and 30d that are energized for driving). Thus, the leakage magnetic field generated when the stage is electromagnetically driven can be shielded.

  As described above, the drive coils (30a, 30b, 30e, and 30f in FIG. 20) that are not surrounded by the movable yoke 60 are not energized, so no magnetic field is generated, and magnetic field leakage from those portions occurs. It is because it is not obtained. Therefore, in Examples 2 to 4 described above, it was necessary to shield an area substantially equal to the entire moving range of the stage with a member made of a high magnetic permeability material, but in this example, the moving permanent magnets 31 and 32 are provided. Since only two drive coils (30c and 30d in FIG. 20) interacting (energized) with both permanent magnets need to be shielded, as compared with the above-described Examples 2 to 4, The required shield range is narrowed, and the shield member can be made smaller and lighter. Further, by supporting only both ends of the drive coil group consisting of 30a, 30b, 30c, 30d, 30e and 30f in FIG. 20, the movable yoke of FIG. The closed shape can be obtained, and the leakage magnetic field from the permanent magnets 31 and 32 in the movable yoke can be further reduced.

<Example 6>
FIG. 21 shows the configuration of the stage portion in the electron beam lithography apparatus according to the sixth embodiment of the present invention. (A) of the same figure is the top view which looked at the stage part from the top, (b) of the same figure is sectional drawing of the EE 'part. In this embodiment, the stage in which the leakage magnetic field shield of the preload biasing permanent magnet in Embodiment 1 is driven by the linear motor of Embodiment 2, Embodiment 3, Embodiment 4 or Embodiment 5 is configured. is doing.

  In this embodiment, as shown in FIG. 21, three uniaxial linear motors are combined in an H shape so that the sample stage 16 can be driven two-dimensionally in the X and Y directions. That is, the stage 16 is driven in the Y direction by two linear motors Y1 and Y2, and the stage is driven in the X direction by another linear motor X1.

  In the linear motor Y1, the Y1 movable body 48 moves in the Y direction on the Y1 guide portion 47, and in the linear motor Y2, the Y2 movable body 50 moves in the Y direction on the Y2 guide portion 49. Both ends of the X1 guide 51 of the linear motor X1 are coupled to the Y1 movable body 48 and the Y2 movable body 50, and the linear motor X1 is moved in the Y direction by the synchronous operation of the Y1 movable body 48 and the Y2 movable body 50. . In the linear motor X1, the X1 movable body 52 on which the sample stage 16 is placed moves on the X1 guide portion 51 in the X direction.

  With the above drive unit configuration, the sample stage 16 can be moved two-dimensionally in the X and Y directions, and drawing over the entire surface of the sample 7 can be realized. The position in the two-dimensional direction of the sample stage 16 is measured by measuring the lengths of the two bar mirrors 10 fixedly installed on the sample stage 16 in the X and Y directions.

  Note that the leakage magnetic field intensity from the linear motor decreases as the distance from the X1 movable body 52 increases, and is attenuated to a level that does not affect the irradiation position accuracy of the electron beam at the position of the sample 7 on the stage 16.

  According to the present embodiment, by supporting the sample stage 16 in a non-contact manner, the portion holding the sample 7 is not easily deformed, so that the sample 7 is not distorted, so that highly accurate drawing can be realized. Further, the outer dimensions of the sample chamber can be limited to the stage moving range and the installation area of the linear motor unit, and a compact apparatus configuration can be realized.

<Example 7>
FIG. 22 shows the configuration of the stage portion in the electron beam lithography apparatus according to the seventh embodiment of the present invention. The configuration of the linear motor unit is the same as in the case of the sixth embodiment.

  In the configuration of the sixth embodiment, the sample stage 16 may move directly below the electron optical column during drawing. Immediately below this electron optical column is the position where the leakage magnetic field from the electron lens is the largest, and when the X1 movable body 52 moves to this position, it is strong depending on the magnitude of the leakage magnetic field from the electron lens and the stage speed. An eddy current flows inside the magnetic X1 movable body 52. The magnetic field generated by this eddy current also becomes a factor that degrades the electron beam irradiation position accuracy on the sample surface.

  Therefore, in the seventh embodiment, in order to suppress the eddy current from flowing through the X1 movable body 52, the X1 movable body 52 is attached to the side surface of the main body of the stage 16, and the X1 movable body 52 is electro-optic within the stage moving range. It is configured not to come directly under the lens barrel. With such an arrangement, it is possible to reduce the influence of a magnetic field generated by an eddy current flowing through the X1 movable body 52, and to realize highly accurate drawing.

<Example 8>
FIG. 23 shows the configuration of the stage portion in the electron beam lithography apparatus according to the eighth embodiment of the present invention.

  In the stage configuration of the previous embodiment 7, when the stage 16 is accelerated or decelerated in the X direction, the inertial force of the stage 16 acts on the X1 movable body 52, and the posture of the stage 16 is likely to change in the yawing direction. Accordingly, in this embodiment, two linear motors X1 and X2 for driving in the X direction are arranged on both sides of the stage 16 main body. In the linear motor X1, the X1 movable body 52 moves in the X direction on the X1 guide portion 51, and in the linear motor X2, the X2 movable body 71 moves in the X direction on the X2 guide portion 70. Further, both end portions of the X1 guide portion 51 and the X2 guide portion 70 are coupled to the Y1 movable body 48 and the Y2 movable body 50, respectively, so that the support rigidity and drive rigidity of the stage 16 are increased.

  With the above configuration, it is possible to suppress the influence of the leakage magnetic field from the linear motor on the irradiation position accuracy of the electron beam, realize a stage movement with high support rigidity in the X direction, and perform high-speed and high-precision drawing.

<Example 9>
FIG. 24 shows the configuration of the stage portion in the electron beam lithography apparatus according to the ninth embodiment of the present invention.

  In the present embodiment, the influence of the leakage magnetic field of the preload biasing permanent magnet 17 applied to the first embodiment and the leakage magnetic field of the linear motor X1 movable body 52 applied to the second to eighth embodiments is reduced. Therefore, a permanent magnet is not used, a completely constrained air bearing guide is used, and the linear motor is placed away from the sample 7.

  As shown in FIG. 25, the uniaxial air bearing includes a static pressure guide 72 and a static pressure moving body 73, and an air pad 19 is attached to the inside of the static pressure moving body 73. The air pad 19 has an air inlet 23 and an air inlet 24, and a drag force (buoyancy) is obtained by a force for ejecting gas from the air outlet 23. The degree of freedom other than the moving direction of the static pressure moving body 73 is constrained by the balance of the drag of the four air pads 19. The ejected gas is collected from the intake port 24.

  The air bearing Y1 in FIG. 24 includes a Y1 static pressure guide portion 74 and a Y1 static pressure moving body 75, and the Y1 static pressure moving body 75 is a mechanism that can move without sliding relative to the Y1 static pressure guide portion 74. ing. Similarly, the air bearing Y2 includes a Y2 static pressure guide portion 76 and a Y2 static pressure moving body 77. An X1 static pressure guide 78 is fixed to the Y1 static pressure moving body 75 and the Y2 static pressure moving body 77, and the X1 static pressure moving body 79 can move relative to the X1 static pressure guide 78. Yes.

  The air bearing Y1 static pressure moving body 75 is driven by a linear motor Y1. The linear motor Y1 movable body 48 is coupled to the Y1 static pressure moving body 75. The linear motor Y1 guide 47 is arranged in parallel with the air bearing Y1 static pressure guide 74. Although some parallelism errors occur when the Y1 static pressure guide part 74 and the Y1 guide part 47 are arranged in parallel, the positional deviation between the Y1 movable body 48 and the Y1 guide part 47 can be tolerated to several millimeters. The body 48 follows the trajectory of the Y1 static pressure moving body 75. Further, in this embodiment, in order to suppress the generation of the magnetic field due to the linear motor leakage magnetic field and eddy current, the linear motor Y1 is disposed at a position opposite to the sample 7 with respect to the air bearing Y1, that is, a position further away from the sample 7. ing.

  The driving method of the air bearing Y2 static pressure moving body 77 is the same as described above. The Y2 static pressure moving body 77 is driven by a linear motor Y2 including a Y2 guide portion 49 and a Y2 movable body 50.

  The air bearing X1 static pressure moving body 79 is driven by a linear motor X1. Both ends of the linear motor X1 guide 51 are coupled to a Y1 static pressure moving body 75 and a Y2 static pressure moving body 77, respectively. Also for the linear motor X1, the linear motor X1 is disposed below the air bearing X1 in order to reduce the generation of magnetic fields due to leakage magnetic fields and eddy currents therefrom.

  As described above, by driving the XY stage, which is levitated and restrained by a completely constrained air bearing guide, with three linear motors provided away from the sample 7 position, the leakage magnetic field from the linear motor is reduced and linear Generation of a magnetic field due to eddy current when the motor movable body (ferromagnetic body) is moved can be suppressed, and high-precision drawing can be realized.

<Example 10>
FIG. 26 shows a manufacturing process of a semiconductor integrated circuit device using the electron beam drawing apparatus of the present invention as a tenth embodiment of the present invention. 26A to 26D are element sectional views showing the manufacturing process.

  Here, an experimental example is shown, and the drawing method using the electron beam drawing apparatus of the present invention is not applied to all the pattern forming steps, but the photosensitive agent in FIG. The electron beam writing method according to the present invention was applied only to the 109 patterning steps, and the conventional drawing method was used in the other steps to confirm the effect of the present invention.

  First, a P-well layer 101, a P layer 102, a field oxide film 103, a polycrystalline silicon / silicon oxide film gate 104, a P high-concentration diffusion layer 105, and an N high-concentration diffusion layer are formed on an N minus silicon substrate 100 by a normal method. 106 etc. were formed ((a) of FIG. 26).

  Next, an insulating film 107 of phosphorus glass (PSG) was deposited, and the insulating film 107 was dry etched to form a contact hole 108 (FIG. 26B).

  Next, a W / TiN electrode wiring 110 material is applied by a normal method, a photosensitive agent 109 is applied thereon, and the photosensitive agent 109 is patterned by an electron beam drawing method using the electron beam drawing apparatus of the present invention. It was. Then, the W / TiN electrode wiring 110 was formed by dry etching or the like ((c) of FIG. 26).

  Next, an interlayer insulating film 111 is formed, a hole pattern 112 is formed by a normal method, a W plug is embedded in the hole pattern 112, and an Al second wiring 113 is connected thereto ((c) in FIG. 26). . Conventional methods were used for the subsequent passivation steps.

  In the present embodiment, only the main manufacturing process has been described, but the same process as the conventional method is used except that the electron beam drawing method of the present invention is used in the lithography process for forming the W / TiN electrode wiring. Through the above steps, a fine pattern can be formed with high accuracy, and a CMOS LSI can be manufactured with a high yield. As a result of manufacturing a semiconductor integrated circuit element using the electron beam lithography apparatus of the present invention, it was possible to prevent the occurrence of poor resolution of wiring, and the yield of non-defective products was greatly improved.

1 is a diagram showing a schematic configuration of a portion below an electron optical column of an electron beam drawing apparatus according to a first embodiment of the present invention. The figure which shows typically the whole structure of an electron beam drawing apparatus. The figure which shows the example of 1 structure of the conventional sample stage. The figure for demonstrating a mode that the orbit of an electron beam changes with the uniform magnetic field which exists in sample upper space. The figure which shows the relationship between the irradiation position shift | offset | difference of an electron beam, and a magnetic field change amount. The figure which shows the structural example of the air pad in a 1st Example. The figure which shows the structural example of the permanent magnet (multipolar magnet) in a 1st Example. The figure which shows the discharge | release state of the magnetic force line from the multipolar magnet shown in FIG. The figure which shows the arrangement configuration of the single layer shield in a 1st Example. The figure which shows the arrangement configuration of the multiple shield in a 1st Example. The figure which shows the reduction effect of the magnet leakage magnetic field by the magnet magnetic field shield structure in a 1st Example. The figure which shows the influence which the electron lens leakage magnetic field has on a magnet magnetic field shield structure in a 1st Example. The figure which shows disorder of the uniform magnetic field by the magnet magnetic field shield made from a ferromagnetic material. The figure which shows the shielding effect of an electronic lens leakage magnetic field shield. The figure which shows the structure of the sample stage part in the electron beam drawing apparatus which becomes the 2nd Example of this invention. The figure which shows CC 'cross-section in FIG. The figure which shows the structure of the sample stage part in the electron beam drawing apparatus which becomes the 3rd Example of this invention. The figure which shows the structure of the sample stage part in the electron beam drawing apparatus which becomes the 4th Example of this invention. The figure which shows the structure of the sample stage part in the electron beam drawing apparatus which becomes the 5th Example of this invention. The figure which shows DD 'cross-section in FIG. The figure which shows the structure of the sample stage part in the electron beam drawing apparatus which becomes the 6th Example of this invention. The figure which shows the structure of the sample stage part in the electron beam drawing apparatus which becomes the 7th Example of this invention. The figure which shows the structure of the sample stage part in the electron beam drawing apparatus which becomes the 8th Example of this invention. The figure which shows the structure of the sample stage part in the electron beam drawing apparatus which becomes the 9th Example of this invention. The G section enlarged view for showing the detailed structure of the G section in FIG. The manufacturing process figure which shows the manufacturing method of the semiconductor integrated circuit element using the electron beam drawing apparatus of this invention as a 10th Example of this invention.

Explanation of symbols

  1: electron optical column, 2: sample chamber, 3: electron gun, 4: electron beam, 5: electron lens, 6: deflector, 7: sample, 8: sample stage, 9: Y table, 10: bar mirror, 11: X table, 12: Guide, 13: Crossed roller, 14: Roller, 15: Base, 16: Sample stage, 17: Permanent magnet, 18: Surface plate, 19: Air pad, 20: Stage drive unit, 21: Magnetic field shield, 22: Magnetic field shield, 23: Air inlet, 24: Air inlet, 25: Plate magnet, 26: York, 27: Inner shield, 28: Outer shield, 29: Power transmission frame, 30: Drive coil, 31: Permanent magnet 32: Permanent magnet 33: Fixed yoke 34: Movable yoke 35: Permanent magnet 36: Permanent magnet 37: Permanent magnet 38: Permanent magnet 39: Fixed yoke 40: Fixed shield 41: Movable yoke, 42: Movable shield, 43: Fixed yoke, 44: Nonmagnetic spacer, 45: Fixed shield, 46: Movable shield, 47: Y1 guide part, 48: Y1 movable part, 49: Y2 guide part, 50 : Y2 movable body, 51: X1 guide section, 52: X1 movable body, 60: movable yoke, 61: fixed yoke, 70: X2 guide section, 71: X2 movable body, 72: static pressure guide section, 73: static pressure Moving body, 74: Y1 static pressure guide section, 75: Y1 static pressure guide section, 76: Y2 static pressure guide section, 77: Y2 static pressure guide section, 78: X1 static pressure guide section, 79: X1 static pressure guide section, 100 : Silicon substrate, 101: P well layer, 102: P layer, 103: oxide film, 104: gate, 105: P high concentration diffusion layer, 106: N high concentration diffusion layer, 107: PSG insulating film, 108: contact hole 109: Photosensitizer, 110: Electricity Polar wiring, 111: interlayer insulating film, 112: hole pattern, 113: Al second wiring.

Claims (7)

A stage device used in an electron beam drawing apparatus,
A sample stage on which the sample is mounted;
Stage driving means for driving the sample stage,
The stage driving means comprises a mover and a stator,
The mover includes a coil and first fixing means for fixing the coil,
The stator has a plurality of magnetic force generating means arranged in a uniaxial direction on both sides facing the coil, and a second fixing means for fixing the plurality of magnetic force means,
The second fixing means has an opening extending along the driving direction of the sample stage formed by the two ends of the second fixing means facing each other, and has a periphery of the plurality of magnetic force generating means. Surrounding
The first fixing means is provided in the opening of the second fixing means, and forms a space in which the coil and the magnetic force means are surrounded by the first fixing means and the second fixing means,
The stage apparatus characterized in that the first fixing means and the second fixing means are made of a leakage magnetic field shield member. The second fixing means includes a fixed yoke that fixes the plurality of magnetic force means, a fixed shield that covers the periphery of the fixed yoke, and a spacer that provides a space between the fixed yoke and the fixed shield. The stage apparatus according to claim 1, wherein a part of the first fixing means is provided in the space. A stage device used in an electron beam drawing apparatus,
A sample stage on which the sample is mounted;
Stage driving means for driving the sample stage,
The stage driving means comprises a mover and a stator,
The stator has a coil array composed of a plurality of coils arranged in a uniaxial direction and first fixing means for fixing the coil array;
The mover includes magnetic means disposed on both sides facing the coil array, and second fixing means for fixing the magnetic means.
The length of the coil stage in the driving direction of the sample stage is longer than the length of the second fixing means in the driving direction of the sample stage,
The second fixing means has an opening in the driving direction of the sample stage formed by the two ends of the second fixing means facing each other and surrounds the magnetic force means,
The first fixing means is provided in the opening of the second fixing means, and forms a space in which the coil and the magnetic force means are surrounded by the first fixing means and the second fixing means,
The stage apparatus characterized in that the first fixing means and the second fixing means are made of a leakage magnetic field shield member. The stage apparatus according to claim 1, wherein the leakage magnetic field shield member is a yoke. The stage apparatus according to claim 3, wherein the coil surrounded by the second fixing means is energized in the coil array. Having guide means for guiding the movement of the material stage by the stage driving means;
The stage apparatus according to claim 1, wherein the guide unit includes an air bearing and is disposed between the stage driving unit and the material stage. An electron beam drawing apparatus using the stage apparatus according to claim 1.

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