JP4937014B2 - Blanking apparatus and electron beam drawing apparatus - Google Patents

Description

  The present invention relates to a blanking apparatus and an electron beam drawing apparatus. More specifically, the present invention relates to a blanking apparatus that blanks an electron beam applied to a substrate, and an electron beam drawing apparatus that draws a pattern on a substrate using the electron beam. About.

  In recent years, with the digitization of information, there has been an increasing demand for large capacity optical disks and hard disks. Instead of conventional optical disks such as CD (Compact Disk) and DVD (Digital Versatile Disk), for example, the wavelength is about 400 nm. Research and development of next-generation optical discs that record and reproduce information by ultraviolet light and patterned media capable of high-density recording are being actively conducted.

  In the manufacturing process of next-generation optical disc masters (stampers) and patterned media recording media, the pattern formed on the recording layer is finer than that of conventional optical discs. Such an electron beam drawing apparatus is often used. This electron beam drawing apparatus irradiates a rotating substrate with an electron beam and draws a spiral or concentric fine pattern on the surface of the substrate, or a fine line on a substrate moving in a horizontal plane by an XY stage. A pattern is drawn.

  This type of electron beam drawing apparatus performs on / off control of the electron beam by intermittently blanking the electron beam according to the pattern to be drawn on the substrate. Affects the drawing performance and throughput performance of the apparatus. Therefore, recently, various inventions for improving the blanking accuracy and responsiveness of electron beams have been proposed (see, for example, Patent Document 1 and Patent Document 2).

  The invention described in Patent Document 1 is a device having a blanking electrode connected to a control circuit via a coaxial transmission line, and a termination resistor connected to the electrode via a coaxial transmission line. In this device, the output impedance of the control circuit and the characteristic impedance of both of the two coaxial transmission lines connected to the electrodes are almost the same, so even if a drive signal is supplied to the electrodes, there is a problem in transmission to the coaxial transmission line. Will not occur. However, since the electrode is branched into two coaxial transmission lines, the characteristic impedance of the electrode and the characteristic impedance of the coaxial transmission line cannot be matched, and a reflected wave is generated between the control circuit and the electrode. Propagated to the circuit side. As a result, overshoot and linking may occur in the voltage applied to the electrode, resulting in fluctuations in the electron beam irradiation position, resulting in inconveniences such as a pattern shape becoming a saddle shape or a tear shape. is there.

  The invention described in Patent Document 2 is an apparatus provided with an inner conductor and an outer conductor provided so as to cover the inner conductor as electrodes. In this apparatus, it is possible to improve the blanking accuracy and responsiveness of the electron beam, but the terminator is connected to an inner conductor and an outer conductor as electrodes. For this reason, in order to avoid the extension of the electrode due to heat generation in the terminator, it is necessary to cool the electrode with a refrigerant or the like, and there is an inconvenience that the device becomes complicated and consequently the cost of the device increases.

Japanese Patent No. 3801333 Japanese Patent No. 3057042

  The present invention has been made under the above circumstances, and a first object thereof is to provide a blanking device capable of accurately performing electron beam blanking without increasing the cost of the device. There is.

  A second object of the present invention is to provide an electron beam drawing apparatus capable of drawing a pattern with high accuracy on the surface of an object.

In a first aspect, the present invention is a blanking device that blanks an electron beam applied to a substrate, and includes a first electrode and a second electrode that are arranged to face each other via the electron beam. A drive circuit that generates a drive signal that generates a potential difference between the first electrode and the second electrode; a terminator that converts the drive signal into thermal energy; and the drive circuit; A first transmission path that electrically connects the blanking electrode ; a second transmission path that electrically connects the blanking electrode and the terminator; and a lens barrel that houses the blanking electrode When; wherein the driving circuit, the first transmission channel, the second channel, the blanking electrode, and terminator respective characteristic impedance Ri equivalent der, said driving circuit and said terminator is the barrel Outside Is location, the first transmission path, and said second transmission line, the transmission path of the driving signal, a blanking device which also serves as a support for supporting the blanking electrode within said barrel.

According to this, it becomes possible to perform the blanking accuracy better electron beam. Also, it is possible to reduce the size and cost of the equipment.

  According to a second aspect of the present invention, there is provided an electron beam drawing apparatus for drawing a pattern on a substrate using an electron beam, the electron source emitting the electron beam; and the electron beam emitted from the electron source An electron beam drawing apparatus comprising:

  According to this, since the electron beam emitted from the electron source can be blanked with high accuracy by the blanking device of the present invention, it is possible to draw a pattern on the substrate with high accuracy.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a schematic configuration of an electron beam drawing apparatus 100 according to the present embodiment. The electron beam lithography apparatus 100 irradiates a substrate W coated with a resist material with an electron beam in an environment having a degree of vacuum of about 10 ⁻⁶ Pa to 10 ⁻⁷ Pa, for example. An electron beam drawing apparatus for drawing a pattern.

  As shown in FIG. 1, the electron beam drawing apparatus 100 accommodates an irradiation apparatus 10 that irradiates a substrate with an electron beam, a rotary table unit 30 that includes a rotary table 31 on which the substrate is placed, and a rotary table unit 30. A vacuum chamber 40 and a control device 50 for comprehensively controlling each of the above parts are provided.

  The vacuum chamber 40 is a rectangular parallelepiped hollow member, and a circular opening is formed on the upper surface.

  The rotary table unit 30 is disposed on the bottom wall surface inside the vacuum chamber 40. The turntable unit 30 supports the turntable 31 on which the substrate W is placed, the turntable 31 horizontally, a spindle motor 32 that rotates through a shaft 32a at a predetermined rotation number, and the spindle motor 32. In addition, a slide unit 33 that is driven with a predetermined stroke in the X-axis direction is provided.

  The irradiation device 10 includes a casing 11 whose longitudinal direction is the Z-axis direction, and an electron gun 12, a magnetic lens 13, a blanking device 20, and a scanning electrode 16, which are sequentially arranged from the upper side to the lower side of the casing 11. , And an objective lens 17.

  The casing 11 is a cylindrical casing that is open at the bottom, and is fitted into an opening formed on the upper surface of the vacuum chamber 40 from above without any gap. And the part located in the inside of the vacuum chamber 40 is a taper shape in which the diameter becomes small toward -Z direction. The casing 11 is provided so as to surround the lens barrel 11b and a cylindrical lens barrel 11b whose longitudinal direction is the Z-axis direction, as can be seen with reference to FIG. 2 which is an XY sectional view of the irradiation device 10. The electromagnetic shield 11a is provided.

The lens barrel 11b is a vacuum space whose internal space is maintained at a predetermined degree of vacuum (for example, about 10 ⁻⁶ Pa to 10 ⁻⁷ Pa). The vacuum space includes an electron gun 12, a magnetic lens, and the like. 13, the blanking electrodes 14a and 14b included in the blanking device 20, the aperture member 15, the scanning electrode 16, the objective lens 17, and the like are accommodated. The electromagnetic shield 11a is a shield that shields electromagnetic waves and the like, and blocks the influence of the equipment accommodated in the lens barrel 11b from electromagnetic waves and geomagnetism from external equipment.

  Returning to FIG. 1, the electron gun 12 is disposed inside the casing 11. The electron gun 12 is a thermal field emission type electron gun that emits electrons extracted from the cathode by heat and an electric field, and emits, for example, an electron beam having a diameter of about 20 to 50 nm downward (−Z direction).

  The magnetic field lens 13 is an annular lens disposed below the electron gun 12, and acts on the electron beam emitted downward from the electron gun 12 in a focusing direction.

  The blanking device 20 is an electrostatic deflection blanking device, and deflects an electron beam traveling downward in the + X direction or the −X direction based on an instruction from the control device 50, thereby blanking the electron beam. I do. The configuration and operation of the blanking device 20 will be described later.

  The scanning electrode 16 is disposed below the blanking device 20. The scanning electrode 16 has a pair of electrodes arranged so as to face each other in the X-axis direction and a pair of electrodes arranged so as to face each other in the Y-axis direction. The electron beam that has passed through the aperture member 15 is deflected in the X-axis direction or the Y-axis direction according to the voltage applied by.

  The objective lens 17 is disposed below the scanning electrode 16 and converges the electron beam that has passed through the scanning electrode 16 on the surface of the substrate placed on the rotary table 31.

  Next, the above-described blanking device 20 will be described. The blanking device 20 is an electrostatic deflection blanking device. As can be seen from FIGS. 1 and 2, the blanking device 20 is electrically connected to a set of blanking electrodes 14a and 14b and blanking electrodes 14a and 14b. A drive circuit 21 and a terminator 25 connected to each other; a first coaxial transmission line 24A and a second coaxial transmission line 24B that electrically connect the blanking electrodes 14a and 14b to the drive circuit 21 and the terminator 25; The aperture member 15 is arranged below the ranking electrodes 14a and 14b.

  FIG. 3 is a cross-sectional view of the first coaxial transmission line 24A and the second coaxial transmission line 24B. 3 and 2, the first coaxial transmission line 24A includes a cylindrical inner conductor 24a whose longitudinal direction is the Y-axis direction, and the + Y side surrounding the inner conductor 24a. And an outer conductor 24b having a stepped flange 24c formed at the end. The outer diameter of the inner conductor 24a is sufficiently smaller than the inner diameter of the outer conductor 24b. For example, as shown in FIG. 4, a ceramic insulator 23c provided at the + Y side end of the outer conductor 24b. The inner conductor 24a is supported in a non-contact manner with respect to the outer conductor 24b, whereby the inner conductor 24a and the outer conductor 24b are electrically insulated.

  The first coaxial transmission line 24A configured as described above has the flange portion 24c in a state where the inner conductor 24a and the outer conductor 24b are inserted from the + Y side into the opening portion 11c formed on the + Y side of the lens barrel 11b. Is attached to the lens barrel 11b by being fitted into the opening 11c without a gap. Even in this state, the O-ring disposed between the flange portion 24c provided on the first coaxial transmission line 24A and the outer wall surface of the lens barrel 11b, and between the inner conductor 24a and the outer conductor 24b. The airtightness of the internal space of the lens barrel 11b is maintained by the lever 23c arranged in the frame.

  The second coaxial transmission line 24B has the same configuration as the first coaxial transmission line 24A described above, and the inner conductor 24a and the outer conductor are formed from the + Y side into the opening 11c formed on the -Y side of the lens barrel 11b. In the state where 24b is inserted, the flange portion 24c is fitted to the opening portion 11c without a gap, thereby being attached to the lens barrel 11b.

  Each of the pair of blanking electrodes 14a and 14b is a rectangular plate electrode disposed so as to be opposed to each other at a predetermined interval in the X-axis direction. As shown in FIG. 2, the blanking electrode 14a has a + Y side end connected to the inner conductor 24a of the first coaxial transmission line 24A and a -Y side end connected to the inner conductor 24a of the second coaxial transmission line 24B. As a result, the Z-axis direction is supported as the longitudinal direction. Further, the blanking electrode 14b has a + Y side end connected to the outer conductor 24b of the first coaxial transmission line 24A and a −Y side end connected to the outer conductor 24b of the second coaxial transmission line 24B. A Z-axis direction is supported as a longitudinal direction on the + X side of the ranking electrode 14a.

  The drive circuit 21 is formed on an electronic board or the like disposed on the outer wall surface on the + Y side of the electromagnetic shield 11a as an example, and generates a potential difference between the pair of blanking electrodes 14a and 14b based on instructions from the control device 50. A rectangular wave drive signal for giving is output. As shown in FIG. 4 as an example, the drive circuit 21 includes a coaxial cable 22 connected to a BNC connector 23A including a pin 23a and an external connector 23b provided at the + Y side end of the first coaxial transmission line 24A. It is electrically connected to the first coaxial transmission line 24A via (see FIG. 2).

  The terminator 25 includes a terminating resistor whose both ends are electrically connected to a set of blanking electrodes 14a and 14b. For example, as shown in FIG. 2, the terminator 25 is electrically connected to the -Y side end of the second coaxial transmission line 24B via a BNC connector 23B.

  In this embodiment, the coaxial cable 22 having a characteristic impedance of 50Ω is used, and the characteristic impedances of the first coaxial transmission line 24A, the second coaxial transmission line 24B, and the blanking electrodes 14a and 14b are 50Ω, respectively. The output impedance of the drive circuit 21 and the impedance (resistance value) of the terminator 25 are adjusted to 50Ω.

For example, regarding the first coaxial transmission line 24A and the second coaxial transmission line 24B, the outer diameter of the inner conductor 24a is 2a (m), the inner diameter of the outer conductor 24b is 2b (m), and the inner space of the lens barrel 11b is transparent. When the magnetic susceptibility and the dielectric constant are μ ₀ and ε ₀ , the characteristic impedance Z ₀ (Ω) of the first coaxial transmission line 24A and the second coaxial transmission line 24B is expressed by the following equation (1). Therefore, in the present embodiment, the inner conductor 24a is designed to have an outer diameter of 2.0 × 10 ⁻³ (m) and the outer conductor 24b has an inner diameter of 4.6 × 10 ⁻³ (m). The characteristic impedance of 24A and the second coaxial transmission line 24B is 50Ω.

For the blanking electrodes 14a and 14b, the gap length (distance) of the opposing blanking electrodes 14a and 14b is d (m), the dimension of the blanking electrodes 14a and 14b in the Y-axis direction is w (m), Ranking electrodes 14a, the relative permeability mu _r between 14b, blanking electrodes 14a, when the relative dielectric constant of between 14b and epsilon _r, the blanking electrodes 14a, the characteristic impedance _{Z 0} of 14b is represented by the following formula (2) It is. Therefore, in this embodiment, the gap length (distance) of the blanking electrodes 14a and 14b is 2.0 × 10 ⁻³ (m), and the dimension of the blanking electrodes 14a and 14b in the Y-axis direction is 15.0 × 10 ^{−. 3} Designed as (m), and the characteristic impedance at the blanking electrodes 14a and 14b is 50Ω.

  Returning to FIG. 1, the aperture member 15 is a plate-like member having an opening through which an electron beam passes in the center. The aperture member 15 is arranged so that the opening is located in the vicinity of the point where the electron beam that has passed through the blanking electrodes 14a and 14b converges.

  As shown in FIG. 1, in the irradiation device 10 configured as described above, the electron beam emitted from the electron gun 12 is focused by passing through the magnetic lens 13, and the aperture member 15 of the blanking device 20. Is once crossed in the vicinity of the opening (hereinafter referred to as a crossover point). Next, the beam diameter of the electron beam that has passed the crossover point is shaped by passing through the aperture 16 while diverging. Then, the light is converged on the surface of the substrate W placed on the rotary table 31 by the objective lens 17.

  In parallel with the above operation, the drive circuit 21 of the blanking device 20 is driven to generate a potential difference between the blanking electrodes 14a and 14b, thereby deflecting the electron beam in the X-axis direction. Thus, the electron beam can be shielded and blanking of the electron beam with respect to the substrate W can be performed. Further, the electron beam irradiation position on the substrate W can be adjusted by controlling the voltage applied to the scanning electrode 16 to deflect the electron beam in the X-axis direction or the Y-axis direction. .

  The control device 50 is, for example, a control computer that includes a CPU and a memory that stores programs and parameters for controlling the above-described units. The control device 50 comprehensively controls the irradiation device 10 and the rotary table unit 30 based on, for example, a command from the user.

  In the electron beam drawing apparatus 100 described above, when a drawing start command is input or notified, the control device 50 first drives the rotary table unit 30 to thereby move the substrate W in the + X direction with a predetermined rotational speed. Rotate with Next, the irradiation apparatus 10 is driven to irradiate the surface of the substrate W with the electron beam modulated by blanking the electron beam based on the drawing pattern, and the surface of the substrate W is concentrically or spirally formed. The pattern is formed.

  As described above, in the blanking device 20 according to the present embodiment, the drive circuit 21 and the terminator are connected to the blanking electrodes 14a and 14b by the first coaxial transmission line 24A and the second coaxial transmission line 24B. 25 is electrically connected. In this embodiment, the output impedance of the drive circuit 21, the characteristic impedance of the coaxial cable 22, the first coaxial transmission line 24A, the second coaxial transmission line 24B, the blanking electrodes 14a and 14b, and the terminator 25 are 50Ω. ing.

  Therefore, the drive signal output from the drive circuit 21 reaches the terminator 25 without being reflected by the first coaxial transmission line 24A, the second coaxial transmission line 24B, and the blanking electrodes 14a and 14b. 25 is absorbed by being converted to heat. As a result, overshoot and linking do not occur in the drive signal, and electron beam blanking can be performed with high accuracy.

  FIG. 5A shows a mark M formed on the substrate W when a rectangular wave voltage is applied between the blanking electrodes 14a and 14b. In the present embodiment, as described above, the output impedance of the drive circuit 21, the characteristic impedance of the coaxial cable 22, the first coaxial transmission line 24A, the second coaxial transmission line 24B, the blanking electrodes 14a and 14b, and the terminator 25 are as follows. 50Ω is available. Therefore, the drive signal is not reflected between the drive circuit 21 and the terminator 25, and the voltage between the blanking electrodes 14a and 14b is the off time T1 output from the drive circuit 21 and the on time T2. It becomes equivalent to the rectangular-wave drive signal. Therefore, when the value of the drive signal is low level L (0 V), the mark M is formed on the substrate as shown in FIG.

  On the other hand, FIG. 5B shows a mark M formed on the substrate W when a voltage having poor settling including overshoot and linking components is applied between the blanking electrodes 14a and 14b. is there. When the reflected wave component of the drive signal is included in the voltage applied to the blanking electrode 14a, a tear shape is formed as in the example shown in FIG. In the electron beam drawing apparatus 100 according to the present embodiment, a rectangular wave voltage with good settling is applied to the blanking electrodes 14a and 14b by the blanking apparatus 20 as shown in FIG. 5A as an example. Therefore, it is possible to accurately draw a pattern made of the mark M on the substrate W.

  In the present embodiment, the blanking electrodes 14a and 14b are connected to the drive circuit 21 and the terminator 25 that serve as heat sources via the first coaxial transmission line 24A and the second coaxial transmission line 24B. Therefore, the blanking electrodes 14 a and 14 b are not affected by the heat generated in the drive circuit 21 and the terminator 25. Furthermore, the drive circuit 21 and the terminator 25 are disposed outside the casing 11. As a result, the effect of heat radiation to the atmosphere can be improved, and as a result, there is no need to attach a cooling mechanism or the like to the apparatus, and the apparatus can be reduced in size and cost.

  In the present embodiment, each of the blanking electrodes 14a and 14b is electrically connected to the drive circuit 21 and the terminator 25 by the first coaxial transmission line 24A and the second coaxial transmission line 24B, and the lens barrel 11b. It is supported at the center of the inside. For this reason, it is not necessary to support an electrode with another support member etc., and it becomes possible to simplify the structure of an apparatus.

  Further, the first coaxial transmission line 24A and the second coaxial transmission line 24B have the same configuration. Therefore, the mechanical characteristics are symmetric with respect to the blanking electrodes 14a and 14b, and the change in posture due to the weight of the blanking electrodes 14a and 14b can be minimized. Therefore, stable blanking control with reproducibility can be performed on the electron beam, and as a result, a pattern can be drawn on the substrate W with high accuracy.

  Further, since the first coaxial transmission line 24A and the second coaxial transmission line 24B have the same configuration, the first coaxial transmission line 24A and the second coaxial transmission line 24A and the second coaxial transmission line 24A are generated by heat generated from the drive circuit 21 and the terminator 25. Even when the coaxial transmission line 24B is thermally expanded, both of them are thermally expanded equally, so that the displacement of the electrode position can be avoided. Therefore, stable blanking control with reproducibility can be performed on the electron beam, and as a result, a pattern can be drawn on the substrate W with high accuracy.

  As described above, the blanking device of the present invention is suitable for blanking the electron beam irradiated on the substrate. The electron beam drawing apparatus of the present invention is suitable for drawing a pattern on a substrate.

1 is a diagram illustrating a schematic configuration of an electron beam lithography apparatus 100 according to an embodiment of the present invention. It is XY sectional drawing of the irradiation apparatus 10. FIG. It is a figure showing a section of the first coaxial transmission line 24A and the second coaxial transmission line 24B. It is sectional drawing of BNC connector 23A provided in the 1st coaxial transmission line 24A. 5A and 5B are diagrams for explaining the relationship between the voltage applied between the blanking electrodes 14a and 14b and the shape of the mark formed on the substrate.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Irradiation device, 11 ... Casing, 11a ... Electromagnetic shield, 11b ... Lens barrel, 12 ... Electron gun, 13 ... Magnetic lens, 14a, 14b ... Blanking electrode, 15 ... Aperture member, 16 ... Scanning electrode, 17 ... Objective Lens, 20 ... Blanking device, 21 ... Drive circuit, 22 ... Coaxial cable, 23A, 23B ... BNC connector, 23a ... Pin, 23b ... External connector, 23c ... Insulator, 24A ... First coaxial transmission line, 24B ... Second Coaxial transmission path, 24a ... inner conductor, 24b ... outer conductor, 24c ... flange, 25 ... terminator, 30 ... rotary table unit, 31 ... rotary table, 32 ... spindle motor, 32a ... shaft, 33 ... slide unit, 40 ... Vacuum chamber, 50 ... Control device, 100 ... Electron beam drawing apparatus, W ... Substrate.

Claims (6)

A blanking device for blanking an electron beam irradiated on a substrate,
A blanking electrode having a first electrode and a second electrode arranged to face each other via the electron beam;
A drive circuit for generating a drive signal for generating a potential difference between the first electrode and the second electrode;
A terminator for converting the drive signal into thermal energy;
A first transmission line that electrically connects the drive circuit and the blanking electrode;
A second transmission line that electrically connects the blanking electrode and the terminator;
A lens barrel in which the blanking electrode is accommodated;
It said drive circuit, said first transmission line, the second transmission path, the blanking electrode, and terminator respective characteristic impedance Ri equivalent der,
The drive circuit and the terminator are arranged outside the lens barrel,
The first transmission path and the second transmission path are blanking devices that serve as a transmission path for the drive signal and a support that supports the blanking electrode inside the lens barrel .   The first transmission path is a coaxial transmission path composed of an inner conductor and an outer conductor, and one of the inner conductor and the outer conductor is connected to the first electrode, and the other is connected to the second electrode. The blanking apparatus according to claim 1, wherein the blanking apparatus is provided.   The second transmission path is a coaxial transmission path composed of an inner conductor and an outer conductor, and one of the inner conductor and the outer conductor is connected to the first electrode, and the other is connected to the second electrode. The blanking device according to claim 1, wherein the blanking device is provided. The blanking device according to any one of claims 1 to 3, wherein the first transmission path and the second transmission path are symmetrical in mechanical characteristics with respect to the blanking electrode. . The blanking device according to any one of claims 1 to 4 , wherein the first transmission path and the second transmission path are symmetrical in thermal characteristics with respect to the blanking electrode. . An electron beam drawing apparatus for drawing a pattern on a substrate using an electron beam,
An electron source for emitting the electron beam;
An electron beam drawing apparatus comprising: a blanking device according to any one of claims 1 to 5 for blanking an electron beam emitted from the electron source.

Images