1. Field of the Invention
The present invention relates to a transmission apparatus, a drawing apparatus including the same, and a method of manufacturing article.
2. Description of the Related Art
Along with the progress in microfabrication and integration of circuit patterns in semiconductor integrated circuits, a drawing apparatus that draws a pattern on a substrate using a plurality of charged particle beams (electron beams) has received attention. Since the drawing apparatus performs drawing on the substrate by each charged particle beam in a vacuum chamber, it is necessary to transmit light signals used to control the drawing from the outside of the vacuum chamber to the inside while maintaining the air-tightness of the vacuum chamber. Each of Japanese Patent Laid-Open Nos. 10-319238 and 2002-115054 proposes a transmission apparatus that transmits light signals from the outside of a vacuum chamber to the inside through the partition of the vacuum chamber while maintaining the air-tightness of the vacuum chamber.
Japanese Patent Laid-Open No. 10-319238 proposes a transmission apparatus that includes a plurality of atmosphere-side optical fibers and a plurality of vacuum-side optical fibers, and inserts a glass plate between each atmosphere-side optical fiber and a corresponding vacuum-side optical fiber. Japanese Patent Laid-Open No. 2002-115054 proposes a transmission apparatus that inserts a plurality of optical fibers for transmitting light signals into a through-hole of a vacuum chamber and fills the gap between the through-hole and the optical fibers with an adhesive material.
In recent years, the drawing apparatus is required to improve the throughput. To meet this requirement, the number of charged particle beams is dramatically increasing. Such a drawing apparatus includes, for example, a plurality of blanking deflectors for individually blanking charged particle beams. An enormous number of light signals to control the plurality of blanking deflectors are transmitted into the vacuum chamber through a number of optical fibers (transmission lines). However, when the transmission apparatus described in Japanese Patent Laid-Open No. 10-319238 uses a number of optical fibers, the interval between the plurality of optical fibers is hard to narrow because a glass plate is inserted for each optical fiber, and this may lead to an increase in the size of the transmission apparatus. In the transmission apparatus described in Japanese Patent Laid-Open No. 2002-115054, it may be difficult to maintain the air-tightness of the vacuum chamber due to aging degradation of the adhesive material.
The present invention provides a technique advantageous in transmitting light signals into a vacuum chamber through a number of transmission lines.
According to one aspect of the present invention, there is provided a transmission apparatus for transmitting a light signal between an outside and an inside of a vacuum chamber, comprising: a plurality of first transmission lines configured to transmit a plurality of light signals outside the vacuum chamber; a plurality of second transmission lines configured to transmit the plurality of light signals inside the vacuum chamber; and a light-transmissive member configured to transmit the light signals between the plurality of first transmission lines and the plurality of second transmission lines, wherein the light-transmissive member has a structure formed to isolate light paths of the plurality of light signals between the plurality of first transmission lines and the plurality of second transmission lines from each other.
Further aspects of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Exemplary embodiments of the present invention will be described below with reference to the accompanying drawings. Note that the same reference numerals denote the same members throughout the drawings, and a repetitive description thereof will not be given.
A drawing apparatus 100 using charged particle beams according to the first embodiment of the present invention will be described with reference to
A charged particle beam emitted by the charged particle gun 11 forms a crossover image 12, changes to a parallel beam by the effect of the collimator lens 14, and enters the aperture array 15. The aperture array 15 has a plurality of openings arranged in a matrix. The charged particle beam that has entered as the parallel beam is thus divided into a plurality of beams. The charged particle beams divided by the aperture array 15 enter the first electrostatic lenses 16. The charged particle beams that have passed through the first electrostatic lenses 16 form intermediate images 18 of the crossover image 12. The blanking aperture 19 having openings located in a matrix is installed on the plane where the intermediate images 18 are formed. The blanking deflectors 17 used to individually control blanking of the plurality of charged particle beams are installed between the first electrostatic lenses 16 and the blanking aperture 19. The charged particle beams deflected by the blanking deflectors 17 are shielded by the blanking aperture 19 and do not reach a substrate 22. That is, the blanking deflectors 17 switch between irradiation and non-irradiation of the substrate 22 with the charged particle beams. The charged particle beams that have passed through the blanking aperture 19 form, through the deflectors 20 and the second electrostatic lenses 21 which are used to scan the charged particle beams on the substrate 22, the images of the crossover image 12 on the substrate 22 held on the substrate stage 23. The deflector 20 preferably deflects the charged particle beam in a direction perpendicular to the scan direction of the substrate stage 23. However, the deflection direction of the charged particle beam is not limited to the direction perpendicular to the scan direction of the substrate stage 23, and the charged particle beam may be deflected to another angle.
The data processing system 30 includes, for example, lens control circuits 31 and 32, a drawing data conversion unit 33, a blanking control unit 34, a deflection signal generation unit 35, a deflection control unit 36, and a controller 37. The lens control circuits 31 and 32 control the lenses 13, 17, and 21. The drawing data conversion unit 33 converts design data supplied from the controller 37 into drawing data used to perform blanking control of the charged particle beams. The blanking control unit 34 is included inside the vacuum chamber 24 and controls the blanking deflectors 17 based on the drawing data supplied from the drawing data conversion unit 33. The deflection signal generation unit 35 generates a deflection signal from the design data supplied from the controller 37 and supplies the deflection signal to the deflection control unit 36 via a deflection amplifier (not shown). The deflection control unit 36 is included inside the vacuum chamber 24 and controls the deflectors 20 based on the deflection signal. The controller 37 supplies the design data to the drawing data conversion unit 33 and the deflection signal generation unit 35 and controls the whole drawing operation.
In recent years, the drawing apparatus is required to improve the throughput. To meet this requirement, the number of charged particle beams is dramatically increasing. For this reason, the amount of data to individually control the plurality of charged particle beams is enormous. This data needs to be transmitted to the charged particle optical system 13 at a high speed. For example, assume that the charged particle beam emitted by the charged particle gun 11 is divided into several tens of thousands to several hundreds of thousands of charged particle beams by the aperture array 15, and the charged particle beams undergo blanking control by the individual blanking deflectors 17. When performing blanking control of such several tens of thousands to several hundreds of thousands of charged particle beams by the blanking deflectors 17, an enormous size of drawing data generated by the drawing data conversion unit 33 needs to be transmitted to the blanking control unit 34 at a high speed. To transmit the enormous size of drawing data at a high speed, an optical fiber hardly affected by electromagnetically induced noise and capable of long-distance data transmission is effective for use as a transmission line to transmit the drawing data. A method of transmitting drawing data from the drawing data conversion unit 33 to the blanking control unit 34 by an optical fiber will be described with reference to
The transmission apparatus 40 in the drawing apparatus 100 according to the first embodiment will be described with reference to
A through-hole 24a is formed in the partition of the vacuum chamber 24 of the drawing apparatus 100 to transmit the light signals between the inside and the outside of the vacuum chamber 24. The through-hole 24a is covered with the light-transmissive member 43 larger than it. The first fixing member 44 having almost the same size as the light-transmissive member 43 is fixed to an atmosphere-side surface 43a of the light-transmissive member 43 using an adhesive material or the like. The first fixing member 44 and the light-transmissive member 43 are attached together to the partition of the vacuum chamber 24 by screws 47 while inserting a sealing member 46 such as an O-ring between them. A plurality of holes 44a are formed in the first fixing member 44 at a predetermined interval. The first transmission lines 41 are respectively inserted in the holes 44a and fixed. The first transmission lines 41 are thus connected to the atmosphere-side surface 43a of the light-transmissive member 43. On the other hand, the second fixing member 45 smaller than the through-hole 24a of the vacuum chamber 24 is fixed to a vacuum-side surface 43b of the light-transmissive member 43 using an adhesive material or the like. A plurality of holes 45a are formed in the second fixing member 45 at a predetermined interval. The second transmission lines 42 are respectively inserted in the holes 45a and fixed. The second transmission lines 42 are thus connected to the vacuum-side surface 43b of the light-transmissive member 43. Each first transmission line 41 and a corresponding second transmission line 42 are located such that a central axis 41′ of the first transmission line 41 and a central axis 42′ of the corresponding second transmission line 42 are aligned. This makes it possible to suppress attenuation of the light signal caused by the misalignment between the first transmission line 41 and the second transmission line 42 and efficiently transmit the light signal between the first transmission line 41 and the second transmission line 42. The light-transmissive member 43 is formed from a member of silica glass or a plastic whose refractive index is almost the same as that of the core portion of the optical fiber. The light-transmissive member 43 has a structure formed to isolate the light paths of the plurality of light signals between the plurality of first transmission lines 41 and the plurality of second transmission lines 42 from each other. The light-transmissive member 43 according to the first embodiment has trenches 43c as the structure. In
The light path of the optical fiber will be explained first with reference to
The trenches 43c formed in the light-transmissive member will be described with reference to
A method of manufacturing the light-transmissive member 43 with the trenches 43c in the transmission apparatus 40 according to the first embodiment will be described with reference to
As described above, in the transmission apparatus 40 according to the first embodiment, the trenches 43c are formed in the light-transmissive member 43 inserted between the first transmission lines 41 and the second transmission line 42 so as to surround the light paths of light signals transmitted between the first transmission lines 41 and the second transmission lines 42. Each second transmission line 42 receives only the light signal of the corresponding first transmission line 41. It is therefore possible to suppress interference between the light signals and obtain correct data on the light signal receiving side even when the optical fibers are located at a narrow interval.
A transmission apparatus 60 according to the second embodiment of the present invention will be described with reference to
In the second embodiment, a through-hole 24a is formed in the vacuum chamber 24, and the first fixing member 64 larger than the through-hole 24a is attached to the partition of the vacuum chamber 24 by screws 67 or the like while inserting a sealing member 66 such as an O-ring between them. Holes 64a to fix the plurality of first transmission lines 61 are formed in the first fixing member 64 at a predetermined interval. The first transmission lines 61 are respectively inserted in the holes 64a and thus fixed to the first fixing member 64. The light-transmissive member 63 is designed to be smaller than the through-hole 24a and fixed to a vacuum-side surface 64b of the first fixing member 64 by an adhesive material or the like. Trenches 63c are formed in the light-transmissive member 63, as in the light-transmissive member 43 of the first embodiment, thereby suppressing each light signal from entering the second transmission lines 62 adjacent to the target second transmission line 62. The second fixing member 65 having almost the same size as the light-transmissive member 63 is fixed, by an adhesive material or the like, to a surface 63b of the light-transmissive member 63 opposite to a surface 63a fixed to the first fixing member 64. A plurality of holes 65a are formed in the second fixing member 65 at a predetermined interval. When the second transmission lines 62 are respectively inserted in the holes 65a and fixed, the second transmission lines 62 are connected to the vacuum-side surface 63b of the light-transmissive member 63.
As described above, in the transmission apparatus 60 according to the second embodiment, the first fixing member 64 is directly attached to the partition of the vacuum chamber 24 without intervening the light-transmissive member 63. Since the light-transmissive member 63 made of silica glass or the like rarely breaks, it can be made as thin as possible. This can eventually suppress attenuation of light signals passing through the light-transmissive member 63 and largely improve the light signal transmission performance.
<Embodiment of Article Manufacturing Method>
An article manufacturing method according to the embodiment of the present invention is suitable to, for example, manufacture an article such as a micro device such as a semiconductor device or an element having a microstructure. The article manufacturing method according to this embodiment includes a step of forming a latent image pattern on a photoresist applied to a substrate using the above-described drawing apparatus (a step of performing drawing on a substrate), and a step of developing the substrate on which the latent image pattern is formed in the above-described step. The manufacturing method also includes other known steps (for example, oxidation, film formation, vapor deposition, doping, planarization, etching, resist removal, dicing, bonding, and packaging). The article manufacturing method according to this embodiment is more advantageous in terms of at least one of the performance, quality, productivity, and production cost of an article than the conventional method.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2012-183591 filed on Aug. 22, 2012, which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | Kind |
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2012-183591 | Aug 2012 | JP | national |