1. Field of the Invention
The present invention relates to a drawing apparatus and a method of manufacturing an article.
2. Description of the Related Art
With miniaturization and large-scale integration of the circuit pattern of a semiconductor integrated circuit, a drawing apparatus which draws a pattern on a substrate with a plurality of charged particle beams (electron beams) is attracting a great deal of attention. In recent years, in the drawing apparatus, a demand for improving the throughput has arisen, so the number of charged particle beams is dramatically increasing to meet this demand. In such a drawing apparatus, a large number of optical signals for controlling blanking deflectors which blank a plurality of charged particle beams are transmitted to the blanking deflectors via a large number of optical fibers.
However, when a large number of optical fibers (transmission lines) are used, if an optical fiber has a problem associated with the connection state such as disconnection or improper connection between a blanking deflector and a blanking controller which controls it, it may become difficult to find a portion having the problem. To solve this problem, Japanese Patent No. 4246374 proposes a drawing apparatus including a detector which detects the irradiated position of a charged particle beam having passed through a blanking deflector. In the drawing apparatus described in Japanese Patent No. 4246374, the connection state of an optical fiber can be confirmed by detecting, using a detector, whether a charged particle beam is normally deflected by controlling the blanking deflector.
In the drawing apparatus described in Japanese Patent No. 4246374, the connection state of an optical fiber, such as disconnection or improper connection, is confirmed by detecting, using a detector, whether a charged particle beam is normally deflected. In this case, the connection state of an optical fiber is confirmed using a charged particle beam, so it is necessary to evacuate a space through which the charged particle beam passes, thus taking a long time to confirm the connection state of the optical fiber.
The present invention provides a drawing apparatus advantageous in confirming the connection state of a transmission line.
According to one aspect of the present invention, there is provided a drawing apparatus for performing drawing on a substrate with a plurality of charged particle beams, comprising: a blanker array including a plurality of groups each including one light-emitting element and at least one blanker; and a plurality of transmission lines configured to transmit control signals to the plurality of groups, respectively, wherein each light-emitting element emits light when a signal is transmitted via a transmission line connected to a group including the light-emitting element out of the plurality of transmission lines.
Further features 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. Also, in each drawing, directions orthogonal to each other on a substrate surface are the X- and Y-directions, and a direction perpendicular to the substrate surface is the Z-direction.
A drawing apparatus 100 in the first embodiment of the present invention will be described with reference to
A charged particle beam 13 emitted by the charged particle gun 11 forms a crossover image 12, is converted into a collimated beam by the action of the collimator lens 14, and enters the aperture array 15. The aperture array 15 has a plurality of apertures arrayed in a matrix, and splits a charged particle beam incident as a collimated beam into a plurality of charged particle beams. The charged particle beams split by the aperture array 15 enter the first electrostatic lenses 16. The charged particle beams having passed through the first electrostatic lenses 16 form intermediate images 18 of the crossover image 12, and the blanking deflector 17 including a plurality of blankers is set on the plane on which the intermediate images 18 are formed. The blanking deflector 17 individually deflects the plurality of charged particle beams, and the charged particle beams deflected by the blanking deflector 17 are blocked by the stopper 19 set in the succeeding stage of the blanking deflector 17 and do not reach the surface of a substrate 22. That is, the blanking deflector 17 switches between ON and OFF of the irradiation of the substrate 22 with the charged particle beams. The charged particle beams having passed through the stopper 19 form images of the crossover image 12 on the substrate 22, held on the movable substrate stage 23, through the deflector 20 and second electrostatic lenses 21 for scanning the charged particle beams on the substrate 22. Note that the deflector 20 can deflect the charged particle beams in a direction perpendicular to the scanning direction of the substrate stage 23, but the deflection direction of the charged particle beams is not limited to a direction perpendicular to the scanning direction of the substrate stage 23, and may be another direction.
The blanking deflector 17 will be described herein, together with the arrangement of a plurality of charged particle beams.
The control unit 30 includes, for example, lens control circuits 31 and 32, drawing data conversion circuit 33, blanking control circuit 34, deflection signal generation circuit 35, deflector control circuit 36, light detection control circuit 37, stage control circuit 38, and controller 39. The lens control circuits 31 and 32 control the respective lenses 14, 16, and 21. The drawing data conversion circuit 33 converts design data supplied from the controller 39 into drawing data for blanking control of each charged particle beam. The blanking control circuit 34 controls the blanking deflector 17 based on the drawing data supplied by the drawing data conversion circuit 33. The deflection signal generation circuit 35 generates a deflection signal from the design data supplied from the controller 39, and supplies the deflection signal to the deflector control circuit 36 via a deflection amplifier (not shown). The deflector control circuit 36 controls the deflector 20 based on the deflection signal. The light detection control circuit 37 controls light detection by a light detector 28 (to be described later). The stage control circuit 38 controls movement of the substrate stage 23. Also, the controller 39 supplies design data to the drawing data conversion circuit 33 and deflection signal generation circuit 35, and controls the overall drawing operation.
In recent years, in the drawing apparatus, a demand for improving the throughput has arisen, so the number of charged particle beams is dramatically increasing to meet this demand. Therefore, data for individually controlling a plurality of charged particle beams is enormous, and must be transmitted to the drawing unit 10 at high speed via a plurality of transmission lines. For example, the charged particle beam 13 emitted by the charged particle gun 11 is divided into several ten thousand to several hundred thousand charged particle beams by the aperture array 15, and each charged particle beam undergoes blanking control by the blanking deflector 17. When such an enormous number of charged particle beams are controlled by the blanking deflector 17, drawing data which has a very large size and is generated by the drawing data conversion circuit 33 must be transmitted to the blanking deflector 17 at high speed via the blanking control circuit 34. As a transmission line used to transmit drawing data with a very large size at high speed, an optical fiber which is less subject to electromagnetic induction noise and capable of long-distance data transmission. A method of transmitting drawing data by an optical fiber from the blanking control circuit 34 to the blanking deflector 17 in the drawing apparatus 100 of the first embodiment will be described herein.
A method of transmitting drawing data in the drawing apparatus 100 of the first embodiment will be described with reference to
In this way, the blanking control circuit 34 and blanking deflector 17 are connected to each other via a plurality of optical fibers 43 so as to supply a signal to one group in the blanker array 17a via one optical fiber 43. Therefore, if improper connection has occurred in connecting the blanking control circuit 34 and blanking deflector 17 using the plurality of optical fibers 43, data is transmitted to a group different from that to be controlled. Also, if disconnection or connection failure has occurred in one optical fiber 43, an accurate signal cannot be transmitted in the group corresponding to this optical fiber 43. That is, if a problem associated with the connection state of the optical fiber 43 is present, it becomes impossible to accurately deflect the charged particle beams, and, in turn, to perform correct drawing in the drawing apparatus. As for the problem associated with the connection state of the optical fiber 43, it may become difficult to find a portion having the problem when a large number of optical fibers 43 are used. In the conventional drawing apparatus, the connection state of the optical fiber 43 is confirmed using a charged particle beam, but in this case, it is necessary to evacuate a space through which the charged particle beam passes, thus taking a long time to confirm the connection state of the optical fiber 43. To solve this problem, the drawing apparatus 100 in the first embodiment includes light-emitting elements 25 which emit light beams by a signal supplied to each group of the blanker array 17a via the optical fiber 43, and an optical fiber 43 having a problem associated with the connection state can be specified by the light emitted by the light-emitting element 25.
An LED (Light Emitting Diode), for example, is used as the light-emitting element 25, and light-emitting elements 25a to 25f are arranged near the plurality of blankers 17b in each of the groups 24a to 24f, as shown in
Although the plurality of blankers 17b are grouped for each optical fiber 43 which supplies a signal to them in the first embodiment, they may be grouped for each optical connector 27. When, for example, two optical fibers 43 are connected to the blanking deflector 17 by the optical connector 27, the plurality of blankers 17b in the blanker array 17a are divided into the groups 24a, 24c, and 24e, as shown in
An example of a method of confirming, using the light-emitting element 25 in the drawing apparatus 100 of the first embodiment, whether a problem associated with the connection state of the optical fiber 43 is present will be described with reference to
In step S50, the control unit 30 controls the blanking control circuit 34 to supply a signal to an optical fiber (to be referred to as “an optical fiber to be confirmed” hereinafter), the connection state of which is to be confirmed, of the plurality of optical fibers 43. In step S51, the control unit 30 controls the stage control circuit 38 to move the substrate stage 23 so as to set the light detector 28 at the position where it can receive light from a light-emitting element 25 that is to emit light by a signal supplied through the optical fiber 43 to be confirmed. In step S52, the control unit 30 controls the light detection control circuit 37 to detect light on the light detector 28. In step S53, the control unit 30 executes determination as to whether light is detected by the light detector 28. If light is detected by the light detector 28, this means that a problem associated with the connection state between the optical fiber to be confirmed and the light-emitting element to be connected is not present, so the confirmation of the connection state ends. On the other hand, if no light is detected by the light detector 28, this means that disconnection or improper connection has occurred in the optical fiber to be confirmed, so the process advances to step S54. In step S54, the control unit 30 controls the stage control circuit 38 to move the substrate stage 23 so as to set the light detector 28 at the position where it can receive light from a light-emitting element 25 other than that which is to emit light. In step S55, the control unit 30 controls the light detection control circuit 37 to detect light on the light detector 28. In step S56, the control unit 30 executes determination as to whether light is detected by the light detector 28. If light is detected by the light detector 28, the process advances to step S57; otherwise, the process advances to step S58. In step S57, the control unit 30 specifies a light-emitting element 25, connected to the optical fiber to be confirmed, based on the position of the substrate stage 23, and the confirmation of the connection state ends. In step S58, the control unit 30 executes determination as to whether light emission is detected by the light detector 28 at a position where it can receive light beams from all light-emitting elements 25. If light emission is not detected at a position where it can receive light beams from all light-emitting elements 25, the process returns to step S54, in which the control unit 30 sets the light detector 28 at a position where it can receive light from a light-emitting element 25, light from which is not detected by the light detector 28. On the other hand, if light emission is detected for all light-emitting elements 25, the confirmation of the connection state ends. If no light is detected at a position where light beams from all light-emitting elements 25 can be received, the optical fiber 43 to be confirmed may be suffering from disconnection. This sequence is performed for all optical fibers.
By providing the light-emitting elements 25 and light detector 28 in this way, each optical fiber 43 can be associated with a group including a light-emitting element 25 which emits light by a signal supplied by this optical fiber 43. For example, referring to
As described above, in the drawing apparatus 100 of the first embodiment, the light-emitting elements 25 are provided to each group 24 in the blanker array 17a of the blanking deflector 17. Also, the light detector 28 is provided on the substrate stage 23 to detect light beams emitted by the light-emitting elements 25 of each group 24. Providing the light-emitting elements 25 and light detector 28 in this way makes it easy to confirm the connection state of the optical fiber 43 between the blanking control circuit 34 and the blanking deflector 17, thus considerably shortening the time to confirm this connection state. Although light emission of each light-emitting element 25 is confirmed by the light detector 28 set on the substrate stage 23 in the first embodiment, a mirror may be set on the substrate stage 23 to allow a human to directly confirm it. In this case, a viewport for confirming light emission of each light-emitting element 25 through a mirror is desirably set on the side wall of the drawing unit 10. Also, although the light-emitting elements 25 and light detector 28 are used in the drawing apparatus 100 of the first embodiment, another configuration in which, for example, an element that generates a radio wave with high directionality, and a detector that detects the radio wave are used may be employed.
A drawing apparatus in the second embodiment of the present invention will be described. In the drawing apparatus of the second embodiment, even if a disconnected optical fiber is present, a signal can be correctly supplied to each group in a blanker array 17a.
In the drawing apparatus in the second embodiment, unlike the drawing apparatus 100 in the first embodiment, a plurality of switching units 29 are included in the blanking deflector 17, and a switching control circuit 44 is included in the blanking control circuit 34. The switching unit 29 is arranged between an optical transceiver 26a and a serial/parallel converter 26b in each group of the blanker array 17a, and is controlled by the switching control circuit 44 so as to switch the connection between the optical transceiver 26a and the serial/parallel converter 26b. For example, a serial/parallel converter 26b1 is wired so as to be connected to an optical transceiver 26a1 or 26a2, and its connection can be switched by a switching unit 29a. Also, control circuits 40 larger in number than groups in the blanker array 17a are included in the blanking control circuit 34, and are connected to an optical transceiver 26g in the blanking deflector 17 via an optical fiber and an optical connector. For example, not only control circuits 40a to 40c corresponding to the groups 24a to 24c, respectively, in the blanking deflector 17, but also a control circuit 40g is included in the blanking control circuit 34 shown in
First, the optical transceiver 26a1 and serial/parallel converter 26b1 are connected to each other by the switching unit 29a, the optical transceiver 26a2 and a serial/parallel converter 26b2 are connected to each other by a switching unit 29b, and an optical transceiver 26a3 and serial/parallel converter 26b3 are connected to each other by a switching unit 29c. In a state in which the optical transceivers 26a are connected to the corresponding serial/parallel converters 26b, the groups corresponding to optical fibers 43a to 43c are confirmed based on the flowchart shown in
The optical fiber 43b is disconnected. For this reason, the optical transceiver 26a3 is connected to the serial/parallel converter 26b2 by the switching unit 29b, and the optical transceiver 26g is connected to the serial/parallel converter 26b3 by the switching unit 29c. In this state, the groups corresponding to the optical fibers 43c and 43g can be confirmed based on the flowchart shown in
As described above, in the drawing apparatus of the second embodiment, the blanking deflector 17 includes the switching unit 29 for switching the connection between the optical transceiver 26a and the serial/parallel converter 26b. The blanking control circuit 34 includes control circuits 40 larger in number than the number of groups in the blanker array 17a. When the blanking deflector 17 and the blanking control circuit 34 are arranged as described above, even if the optical fiber 43 is disconnected, a correct signal can be supplied to each group 24 without replacement or reconnection of the optical fiber.
A drawing apparatus 300 according to the third embodiment of the present invention will be described with reference to
A drawing apparatus 400 of the fourth embodiment of the present invention will be described with reference to
<Embodiment of Method of Manufacturing Article>
A method of manufacturing an article according to an embodiment of the present invention is suitable for manufacturing various articles including a microdevice such as a semiconductor device and an element having a microstructure. The method of manufacturing an article according to this embodiment includes a step of forming a latent image pattern on a photosensitive agent, applied onto a substrate, using the above-mentioned drawing apparatus (a step of performing drawing), and a step of developing the substrate having the latent image pattern formed on it in the forming step. This manufacturing method also includes subsequent known steps (for example, oxidation, film formation, vapor deposition, doping, planarization, etching, resist removal, dicing, bonding, and packaging). The method of manufacturing a device according to this embodiment is more advantageous in terms of at least one of the performance, quality, productivity, and manufacturing cost of a device 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. 2012-183594 filed on Aug. 22, 2012, which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | Kind |
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2012-183594 | Aug 2012 | JP | national |