JP2006210460A - Electron beam exposure device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To lay many transmission lines to a local region and to improve the frequency characteristic of a transmission line. <P>SOLUTION: The above transmission line uses an electro-optical system having a blanker array with a blanking electrode 33 individually controlling the irradiation of a plurality of electronic beams, and a transmission line which transmits a driving signal for driving the blanking electrode 33. The above transmission line has an optical transmission path, a photoelectric converter 37 for converting the drive signal into an optical signal from the electrical signal at the starting point side of the above optical transmission path, and a second photoelectric converter 35 for converting the optical signal converted by the first photoelectric converter 37 into an electrical signal at the terminal point side of the optical transmission line. The electrical signal converted by in the second photoelectric converter 35 is input into the blanking electrode 33. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electron beam exposure apparatus, and more particularly to an electron beam exposure apparatus suitable for application to a multi-beam lithography apparatus that can achieve high throughput and high accuracy.

  Among electron beam exposure apparatuses that are expected to be used in the lithography process of advanced fields and short TAT products, there are so-called multi-beam types. This type of device is expected to have higher throughput and higher accuracy than conventional single beam or cell projection type devices by using multiple beams. Various devices for obtaining a desired pattern by controlling a plurality of beams have been devised, but there is a reduction projection type device that is close to the conventional device form and is easy to introduce, except that it is a multi-beam. .

  FIG. 8 shows an example of such a reduction projection type multi-beam electron beam exposure apparatus. In the figure, reference numeral 70 denotes an electron gun, which is a light source of the drawing apparatus. The electron beam 71 emitted from this light source is converted into a substantially parallel electron beam by the condenser lens 72. The substantially parallel electron beam is incident on a multi-beam module 73 in which a plurality of element electron optical systems 74 are arranged. The element electron optical system 74 having a blanking electrode forms intermediate images 75 and 76 of a plurality of light sources in the vicinity of the opening of the blanking aperture 77 and simultaneously operates the plurality of blanking electrodes individually. A plurality of electron beams can be shielded.

  Next, the magnetic lens 79 and the magnetic lens 80 constitute a projection system with a magnetic symmetric doublet. Here, the distance between the magnetic lens 79 and the magnetic lens 80 is equal to the sum of the focal lengths of the respective lenses, and the intermediate images 75 and 76 of the light source are in the vicinity of the focal position of the magnetic lens 79. It is formed near the focal position of the lens 80. Reference numeral 83 denotes a magnetic deflector, and 84 denotes an electrostatic deflector that performs deflection by an electric field. These two deflectors deflect the electron beams from the plurality of intermediate images 75 and 76 to move the images of the plurality of intermediate images on the sample 82 in a plane. Here, the magnetic deflector 83 and the electrostatic deflector 84 are selectively used depending on the moving distance of the light source image. Reference numeral 85 denotes a dynamic focus coil for correcting a shift of the focus position due to deflection aberration generated when the deflector is operated, and reference numeral 78 denotes a dynamic stig coil for correcting astigmatism generated in the same process. Reference numeral 86 denotes an XYZ stage for moving the sample 82 in the X, Y, and Z directions. At the time of drawing, based on the pattern data, a plurality of intermediate images are projected onto the sample 82 by the projection system, and the blanking electrodes of the plurality of element electron optical systems are operated to turn on / off the plurality of electron beams. While being turned off, the entire surface of the sample 82 is scanned using the magnetic deflector 83, the electrostatic deflector 84, and the XYZ stage 86 to obtain a desired exposure pattern.

Next, FIG. 9 shows a blanking electrode of the element electron optical system 74 mounted on the multi-beam module 73 in the electron beam exposure apparatus, a driver for driving them, and a transmission path for transmitting drive signals. In the figure, a data processing system 87 that converts drawing data into an ON / OFF signal pattern for each beam and gives a desired exposure time outputs a drive signal to a driver 88. This output is connected to the interface connector 90 of the relay substrate 91 via the drive signal cable 89, passes through the electro-optical column 98 by a wiring pattern, and is input to the terminator 92 which is a drive signal termination circuit. The drive signal that has passed through the terminator 92 passes through the vacuum seal 99 and is connected to the blanking module 94 via the contact unit 93. Further, on the blanking module 94, a pair of blanking electrodes 96 are provided in each blanking opening 97, and drive signals are connected to the blanking electrodes 96 from the contact unit 93 through the wiring pattern 95. Further, the cooling liquid from the cooling device 102 flows in the order of the introduction pipe 100, the relay substrate 91, and the discharge pipe 101 to remove heat generated in the terminator 92, and the member inside the electron optical column and the vacuum seal is removed. The device which suppresses a heat deformation and a characteristic change is made | formed.
JP-A-11-176719

  In the above-described conventional apparatus, the blanking electrode drive period is 100 MHz or more, and the frequency component of the drive signal reaches around 1 GHz. In addition, there is a demand for at least 1,000 electron beams and many 8,000 electron beams. In situations where speed is always required, these numbers can only be provisional values. Various devices have been devised for correctly transmitting such a large amount of signals at high speed and without variations or distortion. For example, as described above, the termination for matching the characteristic impedance of the transmission line is accompanied by heat generation, and the heat is being removed by cooling.

  However, even a slight thermal balance distortion in the vicinity of the blanker causes a geometric distortion of the structure, and as a result, it cannot be ignored in terms of drawing accuracy. In order to cope with such further improvement in accuracy, for example, in Japanese Patent Application Laid-Open No. 11-176719 (Patent Document 1), a transmission line is branched near a blanking electrode, one is a blanking electrode and the other is a transmission line. It has been proposed to connect to an auxiliary line having the same characteristic impedance, lead the auxiliary line out of the lens barrel, mount a terminal resistor at the end, and perform cooling. Patent Document 1 discloses a method in which two wires are directly connected from a blanking electrode without branching on a transmission line, and one is connected to a driver of a drive signal and the other is connected to a terminator.

  While such a device can achieve a certain effect, it places a heavy load on the mounting space such as transmission lines and blankers. At present, it may be considered that the limit is reached as the number of beams increases. Furthermore, as described above, the frequency component of the drive signal for the blanking electrode reaches the vicinity of 1 GHz as the speed of the apparatus increases. In such a signal band, the transmission line capacity and direct current resistance are greatly limited. For example, when the transmission line width is designed to be 2 μm, the line capacity excluding the blanking electrode capacitance is 1.5 PF, The allowable line length determined from other conditions is only 15 mm with a DC resistance of 300Ω. This means that a junction of 1000 to 8000 transmission lines and a low impedance line (connection line to the drive circuit) connected to them must be laid within a radius of 15 mm from the center of the blanking array. It means that.

  The present invention has been made in view of the problems as described above, and the purpose thereof is in the situation as described above in which many transmission lines must be laid in a local region and the frequency characteristics of the transmission line must be improved. An object of the present invention is to provide a fundamental solution to the problem and to provide an apparatus equipped with the solution.

To achieve the above object, the present invention provides a blanker array having a blanking electrode for individually controlling irradiation of a plurality of electron beams, and a transmission line for transmitting a drive signal for driving the blanking electrode. In an electron beam exposure apparatus for exposing a desired pattern by converging an exposure beam on a sample using an electron optical system comprising:
The transmission line includes an optical transmission line, a first signal conversion unit that converts the drive signal from an electrical signal to an optical signal on the start point side of the optical transmission line, and the first signal conversion point on the end point side of the optical transmission line. A second signal conversion unit that converts the optical signal converted by the signal conversion unit into an electrical signal, and the electrical signal converted by the second signal conversion unit is input to the blanking electrode. And In the present invention, an electron gun for emitting electrons, a molding system for processing an electron beam emitted from the electron gun into an exposure beam having desired characteristics, and a position of the exposure beam that has passed through the blanker array are controlled. And a projection system for converging the exposure beam on the sample and drawing a desired pattern.

  As described above, in the present invention, the transmission line of the drive signal that drives the blanking electrode is configured by an optical transmission line, and the drive signal is converted into an optical signal and transmitted using the optical transmission line. As a result, it is possible to perform high-speed drawing that can withstand further increase in throughput.

  In addition, according to the present invention, for example, the optical transmission line includes an optical waveguide formed on a substrate, so that not only can the frequency characteristics of the transmission line be dramatically improved, but also more transmission lines can be transmitted to a local region. It is possible to lay down and to solve the mounting problem.

  In addition, the present invention includes, for example, a first substrate on which the blanking electrode of the blanker array is formed, and the optical transmission path includes the first photoelectric conversion unit placed at an end point thereof and the first photoelectric conversion unit. It is possible to shorten the length of the electric signal transmission line after re-converting from the optical signal to the electric signal, and as a result, the load on the electric signal can be reduced. Therefore, the heat generation problem and further improvement in frequency characteristics can be expected.

  Further, the present invention provides, for example, a first substrate on which the blanking electrode of the blanker array is formed, and a second for relaying a drive signal to the blanking electrode formed on the first substrate. The optical transmission line may be formed on the second substrate together with the second photoelectric conversion unit placed at the end point.

  Further, in the present invention, for example, by using a power generation element for the second photoelectric conversion unit, it is possible to minimize the power for driving the blanking electrode. It is possible to suppress heat generation to a minimum.

  Furthermore, in the present invention, for example, an optical fiber that transmits an optical signal converted by the first photoelectric conversion unit, and an optical coupler that is placed at the start point of the optical waveguide and is coupled to the optical fiber. The drive signal may be introduced to the optical waveguide through the optical fiber and the optical coupler to drive the blanking electrode.

  In addition, the present invention provides a device manufacturing method comprising: a step of exposing the sample using any one of the electron beam exposure apparatuses described above; and a step of developing the exposed sample. Also applies.

  As explained above, a part or almost all of the signal transmission line is configured with an optical transmission line, and an optical waveguide is used for a part that requires a high mounting density, and the conversion from an optical signal to an electric signal is generated. By using an element, it is possible to provide a fundamental solution for laying many transmission lines in a local region and improving the frequency characteristics of the transmission line.

  Next, a preferred embodiment of the present invention will be described in detail with reference to the drawings, taking an example where the sample to be exposed is a wafer.

  FIG. 1 is a block diagram of an electron beam exposure apparatus according to Embodiment 1 of the present invention. In the figure, reference numeral 1 denotes an electron gun, which is a light source of a drawing apparatus. The electron beam 2 emitted from the light source becomes a substantially parallel electron beam by the condenser lens 3 whose front focal position is the light source position. This substantially parallel electron beam is incident on a molding system 5 in which a plurality of element electron optical systems 4 are arranged. The substantially parallel electron beam is divided into a plurality of parts in a plane perpendicular to the optical axis by the forming system 5, and the divided electron beams pass through a blanking module 6 that individually controls the ON / OFF of each electron beam. The intermediate images 7 a and 7 b of the plurality of light sources are formed in the vicinity of the opening of the blanking aperture 10. Here, the blanking module 6 has a plurality of openings and a pair of blanking electrodes provided for each of the openings, and each of these blanking electrodes is individually operated to generate a plurality of electron beams with the blanking aperture 10. Each can be shielded individually.

  Next, the magnetic lens 12 and the magnetic lens 16 constitute a reduction projection system with a magnetic symmetric doublet, and have a limiting aperture 17. Here, the distance between the magnetic lens 12 and the magnetic lens 16 is equal to the sum of the focal lengths of the respective lenses, and the intermediate images 7a and 7b of the light source are in the vicinity of the focal position of the magnetic lens 12, and these images are magnetic fields. It is formed at the focal position of the lens 16. At this time, the ratio of the focal lengths of the magnetic lens 12 and the magnetic lens 16 is the projection magnification. Further, since the magnetic fields of the magnetic lens 12 and the magnetic lens 16 are set so as to act in opposite directions, so-called five aberrations of spherical aberration, astigmatism, coma aberration, field curvature, and longitudinal chromatic aberration are provided. Other sidel aberrations and rotational and magnification chromatic aberrations have been canceled. Here, the correction lens group 11 is a functional lens group that is disposed between the magnetic lens 12 and the intermediate images 7a and 7b of the light source and finely adjusts the projection magnification, the beam convergence position, various aberration corrections, and the like. Reference numeral 13 denotes a magnetic field deflector, and reference numeral 14 denotes an electrostatic deflector that performs deflection by an electric field. These two deflectors collectively deflect a plurality of electron beams to obtain a plurality of intermediate images 7a and 7b as samples. 18 is moved in a planar manner. The magnetic deflector 13 and the electrostatic deflector 14 are selectively used depending on the moving distance of the light source image. Reference numeral 15 denotes a dynamic focus coil for correcting a shift of the focus position due to a deflection aberration generated when the deflector is operated. Reference numeral 19 denotes an XYZ stage for moving the sample 18 in the X, Y, and Z directions, and its position and moving speed are accurately controlled by a plurality of laser interferometers. A mount 20 has a function of insulating the apparatus from floor vibration while maintaining the apparatus posture.

  In actual drawing, on the basis of the pattern data, a drive signal is supplied from the beam control unit 22 in the control system 21 to the blanking module 6 through the transmission path 8, and each blanking electrode is operated to generate a plurality of electrons. The images of the intermediate images 7a and 7b are projected onto the sample 18 by the reduction projection system composed of the magnetic lens 12 and the magnetic lens 16 while turning on and off the beam, and the magnetic deflector 13 and the electrostatic deflector 14 are used. 18 is scanned and the XYZ stage 19 is cooperated to obtain a desired drawing pattern.

  FIG. 2 is a diagram showing details of a plurality of blanking electrodes mounted on the blanking module 6 in the electron beam exposure apparatus of FIG. 1, a beam control unit 22 for driving them, and a transmission path 8 for transmitting drive signals. is there.

  In the figure, a data processing unit 42 converts drawing data into an on / off signal pattern of each beam and provides a desired exposure time and exposure timing. Reference numeral 41 denotes a driver that sends a drive signal to the blanking electrode 33 of the blanker that is mounted on the blanking module 6 and has a beam aperture 32 for passing an electron beam, in accordance with data from the data processing unit 42. is there. Reference numeral 40 denotes a drive signal cable for connecting the drive signal to the input connector 39 of the blanker substrate 30 on which the blanking electrode 33 is placed. Reference numeral 38 denotes a wiring pattern for supplying the drive signal transmitted through the drive signal cable 40 to the first photoelectric conversion unit 37 that converts an electrical signal into an optical signal. Reference numeral 34 denotes a plurality of optical waveguides that transmit drive signals converted from electrical signals to optical signals by the first photoelectric conversion unit 37. A second photoelectric conversion unit 35 is placed at the end of each optical waveguide 34 so as to be optically coupled to the optical waveguide, and converts the drive signal from an optical signal to an electrical signal. Reference numeral 36 denotes an interconnection wiring pattern for setting one side of the plurality of blanking electrodes 33 to the same potential, and reference numeral 31 denotes a vacuum seal for maintaining a vacuum inside the lens barrel.

  Here, the drive signal output from the driver 41 has a drive cycle of 100 MHz or more, and is subjected to pulse width modulation corresponding to a resolution of about 8 bits in exposure gradation. In this embodiment, the substantial signal band of the drive signal at the time of the drawing operation is about 1 GHz. Therefore, the drive signal cable 40, the wiring pattern 38, and the like constituting the drive signal transmission line are all designed as distributed constant lines and their characteristic impedances are controlled.

  In the present embodiment, the first photoelectric conversion unit 37 is arranged in an array type in consideration of high-speed driving of the blanking electrode 33, signal attenuation in the optical waveguide 34, conversion sensitivity of the second photoelectric conversion unit 35, and the like. It consists of a laser diode and a modulator. The drive signal output from the driver 41 is input to the input connector 39 via the drive signal cable 40 and connected to the wiring pattern 38 laid on the blanker substrate 30. The wiring pattern 38 efficiently transmits a drive signal through a microstrip line, and at the same time matches the characteristic impedance, thereby forming a substantially non-reflective transmission line.

  Here, a microstrip line is used, but various selections such as a so-called coplanar line can be made according to mounting restrictions and signal characteristics. The drive signal converted from an electrical signal to an optical signal by the first photoelectric conversion unit 37 propagates while attenuating in the optical waveguide 34. In the present embodiment, the second photoelectric conversion unit 35 is a PIN type high-speed photodiode and is configured to optically couple with the optical waveguide 34 with high efficiency. When an optical signal is incident on the junction surface of the photodiode by optical coupling, a current is generated, and this current is passed through a shunt resistor with a light load built in the photodiode, thereby causing a blanking electrode 33 connected to the shunt resistor in a pattern. Apply voltage.

  Here, instead of incorporating a shunt resistor in the photodiode, a resistor may be connected in series to the blanking electrode 33 and a combination of the blanking electrode 33 and the resistor in series may be used as the shunt resistor. In that case, the capacitance of the blanking electrode 33 is added to the shunt resistor as a load, but the capacitance is sufficiently small (in this embodiment, 0.05 pF or less), and sufficient high-speed response performance even if the resistance load is reduced. Is obtained. Here, it is possible to use an optical switch, a so-called phototransistor type photoelectric conversion device, but since this type of device is a switch and requires a power supply, a power supply pattern must be laid, and the output-side transistor has a certain degree. It is possible to adopt this method in consideration of the fact that the response speed cannot be increased unless the load is added, and that the signal transmission rate cannot be increased.

  The electron beam passing through the beam aperture 32 is converted into an optical signal by the first photoelectric conversion unit 37 via the drive signal cable 40 from the drive signal output from the driver 41, propagates through the optical waveguide 34, and is subjected to the second photoelectric conversion. When converted into an electrical signal again by the unit 35 and a voltage is applied between the blanking electrodes, the blanking state is obtained due to the deflection action. At this time, in order to apply a voltage to one side of the blanking electrode 33 and deflect the electron beam passing through the beam opening 32, it is necessary to determine the electrode potential of the opposing electrode. In this embodiment, the opposing electrodes are connected to each other by the interconnection wiring pattern 36 and further connected to an earth point (not shown) on the blanker substrate 30 to give a ground potential.

  Further, the blanker substrate 30 is designed to constitute a part of the vacuum partition inside the electron optical column, and a vacuum seal 31 for that purpose is placed on the periphery of the blanker substrate 30. The inside of the vacuum seal 31 is vacuum and the outside is atmospheric pressure, and the optical waveguide 34 also plays a role of so-called feedthrough. In this way, the first photoelectric conversion unit 37 is installed on the atmospheric pressure side, and heat generated by the light emitting elements in the first photoelectric conversion unit is efficiently removed. In this example, there was no need for forced cooling by suppressing the heat generation amount low and increasing the distance between the first photoelectric conversion unit 37 and the vacuum seal 31 and taking a sufficient heat radiation area. If the output of the light emitting element must be increased according to the required specifications, or if the blanker substrate 30 cannot be increased in terms of mounting, heat generation is removed by circulating cooling water around the outer periphery of the blanker substrate 30. It is also possible.

  An electron beam exposure apparatus according to Embodiment 2 of the present invention will be described with reference to FIGS. 3 and 4 show another example of a plurality of blanking electrodes mounted on the blanking module 6 in the electron beam exposure apparatus of FIG. 1, a beam control unit 22 for driving them, and a transmission path 8 for transmitting a drive signal. It is a figure showing an aspect.

  In FIG. 3, as in the first embodiment, a data processing unit 42 converts drawing data into an ON / OFF signal pattern for each beam and provides a desired exposure time and exposure timing. A driver 41 drives a blanker in the blanking module 6 according to data from the data processing unit 42. A signal relay board 45 supports a blanker device board, which will be described later, and relays a blanking electrode drive signal to the board. Reference numeral 46 denotes a vacuum seal, and reference numeral 47 denotes a through hole that passes through the signal relay substrate 45 and allows an electron beam to pass therethrough. Reference numeral 49 denotes a bonding electrode for connecting a blanker device to be described later and the signal relay substrate 45.

  A blanker device substrate 56 is mounted on the bonding electrode 49, and its outline is shown in FIG. In the figure, reference numeral 56 denotes a device-specific blanker device substrate on which only blanker deflection electrodes are mounted. A beam opening 57 for allowing an electron beam to pass therethrough and blanking electrodes 58a and 58b facing each other are formed on the substrate. Bonding pads are provided on the back surface of the substrate 56 at positions corresponding to the bonding electrodes of the signal relay board 45.

  Returning to FIG. 3, reference numeral 48 denotes an interconnection wiring pattern for bringing one side of a plurality of blanking electrodes to the same potential via the junction electrode, and reference numerals 50, 51 and 52 denote a second photoelectric conversion unit and a light guide, respectively. A waveguide and a first photoelectric conversion unit are the same as those in the first embodiment. The electron beam passes through a beam opening 57 placed on the blanker device substrate 56 and a through-hole 47 on the signal relay substrate 45 to become an exposure beam. The driver 41 outputs a drive signal, inputs it to the signal relay board 45 via the drive signal cable 40, converts it to an optical signal by the first photoelectric conversion unit 52, propagates through the optical waveguide 51, When converted into an electric signal again by the photoelectric conversion unit 50 and applied to the blanking electrode 58a on the blanker device substrate 56 via the bonding electrode 49, the electron beam is subjected to a deflection action and is in a blanked state.

  In the present embodiment, unlike the first embodiment, the blanking module 6 includes a blanker device substrate 56 and a signal relay substrate 45. The main reason is that the manufacturing process of the blanking electrode and the beam aperture is different from the manufacturing process of the optical waveguide and the photoelectric conversion device. In this embodiment, even in such a case, the optical waveguide 51 on the signal relay substrate 45 is laid down to the vicinity of the bonding electrode 49, photoelectric conversion is performed at the end thereof, and the path for propagation as an electric signal is designed to be the shortest. did. As a result, the capacitance and DC resistance of the wiring pattern and the junction electrode 49 are sufficiently small, and the substantial frequency characteristics of the drive system are the capacitance between the opposing blanking electrodes 58a and 58b and the second photoelectric conversion unit. The value of the shunt resistance placed in the 50 photodiodes becomes dominant, and the characteristics almost as designed are obtained.

  Furthermore, an electron beam exposure apparatus according to Embodiment 3 of the present invention will be described with reference to FIG. FIG. 5 shows still another aspect of a plurality of blanking electrodes mounted on the blanking module 6 in the electron beam exposure apparatus of FIG. 1, a beam control unit 22 for driving them, and a transmission path 8 for transmitting a drive signal. FIG.

  In FIG. 5, as in the first embodiment, a data processing unit 42 converts drawing data into ON / OFF signal patterns for each beam and provides a desired exposure time and exposure timing. A driver 65 drives the blanker in the blanking module 6 according to the data from the data processing unit 42. Reference numeral 60 denotes a blanker substrate having a beam aperture on which a blanking electrode, a second photoelectric conversion unit, an optical waveguide, a vacuum seal, and the like are placed. Reference numeral 62 denotes an optical coupler for coupling the optical fiber cable 63 and the optical waveguide 61. Reference numeral 64 is mounted on a driver 65, and a first driving signal for driving a blanking electrode is converted from an electric signal to an optical signal. 1 is a photoelectric conversion unit.

  Since the configuration of the blanker substrate 60 is the same as that of the first embodiment except for the end of the optical waveguide 61, the description thereof is omitted. In the present embodiment, the first photoelectric conversion unit 64 is mounted on the driver 65. At this stage, the drive signal of the blanking electrode is converted from an electric signal to an optical signal, and there is an intention that almost all signal transmission paths are constituted by optical transmission paths. As in the other embodiments, the first photoelectric conversion unit 64 is composed of an array type laser diode and a modulator so as to be compatible with high speed and wide bandwidth. Since the heat generated here can be efficiently removed in the container in which the driver 65 is housed, the light output of the first photoelectric conversion unit 64 is increased to near the maximum value. The blanking electrode drive signal converted into the optical signal propagates through the optical fiber cable 63. The optical fiber cable 63 is a bundle of a plurality of optical fibers corresponding to the blanking electrodes. In this embodiment, in consideration of the arrangement pattern of the optical waveguide 61, the finished outer diameter and the flexibility, etc., 256 cables are made into one bundle, and two bundles are made into one set to constitute a cable. The optical signal propagating through the optical fiber cable 63 is optically coupled to the optical waveguide 61 on the blanker substrate 60 by the optical coupler 62. Details of this optical coupling are shown in FIG.

  In FIG. 6, 66 is an optical coupler housing, and 63 is an optical fiber cable having an end inserted into the housing 66. 67 is a reflector for changing the angle of the signal light, 68 is a condenser lens, and 61 is an optical waveguide mounted on the blanker substrate 60.

  The optical signal propagating through the optical fiber cable 63 is 90 ° direction so that it is perpendicularly incident on the surface on which the optical waveguide 61 is placed by the reflector 67 placed inside the housing 66 of the optical coupler 62. And is introduced into the optical waveguide 61 through the condenser lens 68. The power and working distance of the condensing lens 68 are determined so that the spot diameter of the output light matches the size of the optical waveguide 61, so as to suppress the loss that occurs during optical coupling and maximize the coupling efficiency. Designed. At the end of the optical waveguide 61 facing the condenser lens 68, a reflective layer is placed on a surface processed at 45 ° with respect to the incident light, and the incident light is introduced into the waveguide. If the diameters of the optical transmission lines are comparable and there are no other special factors, the loss due to such a coupling method can usually be within -3 dB. In this embodiment, since there is a considerable difference between the diameter of each optical fiber constituting the optical fiber cable 63 and the size of the optical waveguide 61, the actual loss is about −9 dB.

  FIG. 7 shows another method relating to this optical coupling, in which 66 is a housing of an optical coupler, 63 is an optical fiber cable having an end inserted into the housing 66, and 69 is a condenser lens. , 61 are optical waveguides placed on the blanker substrate 60.

  Here, the optical waveguide 61 is formed of a laminated type and is processed so that the end thereof is flush with the end of the blanker substrate 60. A condensing lens 69 is placed on the same surface, and the light output emitted from the optical fiber cable 63 is introduced into the optical waveguide 61. The diameter of each optical fiber constituting the optical fiber cable 63 is smaller than that of the optical fiber employed in FIG. When it is necessary to use an optical fiber having a large diameter, another condensing lens is additionally placed on the surface of the housing 66 where the end of the optical fiber is exposed, and the concentrator placed on the end surface of the lens and the blanker substrate 60. The coupling efficiency can be increased by cooperating with the optical lens 69.

  Returning to FIG. 5, the optical signal introduced into the optical waveguide 61 on the blanker substrate 60 by the optical coupler 62 goes through the same process as in the first embodiment, drives the blanking electrode, deflects the electron beam, and blocks the light. Perform ranking operation. As described above, in this embodiment, the driving signal for the blanking electrode is converted from an electric signal to an optical signal in the driver 65, and optical transmission is performed over the entire signal transmission line. In particular, the optical fiber cable 63 has a length of about 8 m in this embodiment because the flexibility of the length can be greatly increased. When the route to the blanker board or signal relay board is transmitted as an electrical signal, the length of the drive signal cable is limited to about 1 m in consideration of signal distortion due to delay of the drive signal and increase in capacitive load. It was. Further, even when signal transmission is performed while coupling different optical transmission lines, it is known that the loss due to coupling can be suppressed to a level with no problem in practice by devising the coupling method. According to this, in this embodiment, the optical coupling of the transmission line was one place, but an optimal mounting form can be obtained by performing optical coupling many times depending on the structure of the device and the structure of the blanker module. become.

  Next, a semiconductor device manufacturing process using the electron beam exposure apparatus according to the above embodiment will be described. FIG. 10 is a diagram showing a flow of an entire manufacturing process of a semiconductor device. In step 1 (circuit design), a semiconductor device circuit is designed. In step 2 (EB data conversion), exposure control data for an electron beam drawing (exposure) apparatus is created based on the designed circuit pattern.

  On the other hand, in step 3 (wafer manufacture), a wafer is manufactured using a material such as silicon. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer using lithography using the exposure apparatus and wafer to which the exposure control data has been input. The next step 5 (assembly) is called a post-process, and is a process for forming a semiconductor chip using the wafer produced in step 4, and is an assembly process (dicing, bonding), packaging process (chip encapsulation), etc. Process. In step 6 (inspection), the semiconductor device manufactured in step 5 undergoes inspections such as an operation confirmation test and a durability test. A semiconductor device is completed through these processes, and is shipped in Step 7.

  The wafer process in step 4 includes the following steps. An oxidation step for oxidizing the surface of the wafer, a CVD step for forming an insulating film on the wafer surface, an electrode formation step for forming electrodes on the wafer by vapor deposition, an ion implantation step for implanting ions on the wafer, and applying a photosensitive agent to the wafer The resist processing step, the exposure step for printing and exposing the circuit pattern onto the wafer after the resist processing step by the above-described exposure apparatus, the development step for developing the wafer exposed in the exposure step, and the etching for removing portions other than the resist image developed in the development step Step, resist stripping step to remove resist that is no longer needed after etching. By repeating these steps, multiple circuit patterns are formed on the wafer.

1 is an elevational view illustrating a schematic configuration of an electron beam exposure apparatus according to Embodiment 1 of the present invention. It is the top view which showed the blanking module of the electron beam exposure apparatus which concerns on Example 1 of this invention, and its peripheral circuit. It is a top view showing the blanking opening of the electron beam exposure apparatus which concerns on Example 2 of this invention, the transmission line around a blanking electrode, and a drive part. It is a top view showing the blanker device board | substrate with which the blanking electrode of the electron beam exposure apparatus which concerns on Example 2 of this invention was formed. It is a top view showing the blanking opening of the electron beam exposure apparatus which concerns on Example 3 of this invention, the transmission line around a blanking electrode, and a drive part. It is a figure showing the detail of the structure of the optical coupling part vicinity which concerns on Example 3 of this invention. It is a figure showing the detail of another structure of the optical coupling part vicinity based on Example 3 of this invention. It is a figure showing the outline | summary of the conventional multi-beam type | mold electron beam exposure apparatus. It is a figure showing the blanking module of the conventional multi-beam type electron beam exposure apparatus. It is a figure which shows the flow of the whole manufacturing process of a semiconductor device.

Explanation of symbols

1: Electron gun 2: Electron beam 3: Condenser lens 4: Element electron optical system 5: Molding system 6: Blanking module 7a, 7b: Intermediate image 8: Transmission path 10: Blanking aperture 11: Correction lens group 12, 16 : Magnetically symmetric doublet lens (magnetic lens)
13: Magnetic deflector 14: Electrostatic deflector 15: Dynamic focus coil 17: Restriction aperture 18: Sample 19: XYZ stage 20: Mount 21: Control system 22: Beam controller 30: Blanker substrate 31: Vacuum seal 32: Beam Opening 33: Blanking electrode 34: Optical waveguide 35: Second photoelectric conversion unit 36: Interconnection wiring pattern 37: First photoelectric conversion unit 38: Wiring pattern 39: Input connector 40: Drive signal cable 41: Driver 42: Data processing unit 45: Signal relay substrate 46: Vacuum seal 47: Through hole 48: Interconnection wiring pattern 49: Bonding electrode 50: Second photoelectric conversion unit 51: Optical waveguide 52: First photoelectric conversion unit 56: Blanker device Substrate 57: Beam aperture 58a, 58b: Blanking electrode 60: Blanker substrate 6 1: Optical waveguide 62: Optical coupler 63: Optical fiber cable 64: First photoelectric conversion unit 65: Driver 66: Housing 67: Reflector 68, 69: Condensing lens

Claims (7)

An exposure beam is produced using an electron optical system including a blanker array having a blanking electrode for individually controlling irradiation of a plurality of electron beams and a transmission line for transmitting a drive signal for driving the blanking electrode. In an electron beam exposure apparatus that converges on a sample and exposes a desired pattern,
The transmission line includes an optical transmission line, a first signal conversion unit that converts the drive signal from an electrical signal to an optical signal on the start point side of the optical transmission line, and the first signal conversion point on the end point side of the optical transmission line. A second signal conversion unit that converts the optical signal converted by the signal conversion unit into an electrical signal, and the electrical signal converted by the second signal conversion unit is input to the blanking electrode. An electron beam exposure apparatus.   The electron beam exposure apparatus according to claim 1, wherein the optical transmission path has an optical waveguide formed on a substrate.   A first substrate on which the blanking electrode is formed, and the optical transmission path is formed on the first substrate together with the second photoelectric conversion unit placed at an end point thereof. The electron beam exposure apparatus according to claim 2, wherein:   A first substrate on which the blanking electrode is formed; and a second substrate for relaying a drive signal to the blanking electrode formed on the first substrate, wherein the optical transmission path is The electron beam exposure apparatus according to claim 2, wherein the electron beam exposure apparatus is formed on the second substrate together with the second photoelectric conversion unit placed at the end point.   The electron beam exposure apparatus according to claim 1, wherein the second photoelectric conversion unit is a power generation element.   An optical fiber that transmits the optical signal converted by the first photoelectric conversion unit; and an optical coupler that is placed at a starting point of the optical waveguide and is coupled to the optical fiber, and the drive signal is 6. The electron beam exposure apparatus according to claim 2, wherein the electron beam exposure apparatus is introduced into the optical waveguide through the optical fiber and via the optical coupler to drive the blanking electrode.   7. A device manufacturing method comprising: a step of exposing the sample using the electron beam exposure apparatus according to claim 1; and a step of developing the exposed sample. .

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