Substrate detection method, drawing method, drawing apparatus, and identification mark

Abstract

This invention provides a substrate detection method that can reduce drawing defects in multilayer drawing. [Solution] A substrate detection method according to one embodiment is a method for detecting a substrate on which a pattern is drawn by a plurality of drawing layers. This detection method includes the steps of scanning an identification mark with a beam to identify whether any of the plurality of drawing layers are formed on the substrate before the drawing process, and recognizing, based on the result of scanning the identification mark, which of the plurality of drawing layers the drawing process will be performed on. In this inspection method, the identification mark of the (n+1) (n is a natural number)th layer is formed by scanning the identification mark of the nth drawing layer with a beam.

Description

Technical Field

[0001] The present invention relates to a substrate detection method, a drawing method, a drawing apparatus, and an identification mark.

Background Art

[0002] When multi-layer drawing in which a pattern is drawn on a substrate in multiple times is executed, when the drawing of the first layer is completed, the substrate is carried out from the drawing apparatus to a substrate processing apparatus that performs development processing or the like. When the processing in the substrate processing apparatus is completed, the substrate is carried into the drawing apparatus again, and the drawing of the second layer is performed. Thus, in multi-layer drawing, the carrying out of the substrate from the drawing apparatus and the carrying in of the substrate into the drawing apparatus are repeated.

[0003] Therefore, in order for the drawing apparatus to confirm the position of the substrate, an alignment mark is formed on the substrate. The drawing apparatus can accurately grasp the position of the substrate by reading this alignment mark.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The multi-layer drawing described above is performed in the order of the first layer drawing, the second layer drawing, etc. However, since the drawing apparatus cannot identify which layer is being drawn, the drawing is only performed by the confirmation of the operator. Therefore, for example, drawing defects such as the second layer drawing being erroneously performed on an unprocessed substrate of the first layer drawing may occur.

[0006] An object of the present invention is to provide a substrate detection method, a drawing method, a drawing apparatus, and an identification mark capable of reducing drawing defects in multi-layer drawing. [Means for solving the problem]

[0007] A substrate detection method according to one aspect of the present invention is a method for detecting a substrate on which a pattern is drawn by a plurality of drawing layers. This detection method includes the steps of scanning the substrate with a beam for identification marks that identify whether any of the plurality of drawing layers are formed on the substrate before the drawing process, and recognizing, based on the result of scanning the identification marks, which of the plurality of drawing layers the drawing process will be performed on. In this inspection method, the identification mark of the (n+1)th layer (where n is a natural number) is formed by scanning the identification mark of the nth drawing layer with a beam.

[0008] In one aspect of the present invention, a beam writing method is provided that, when the identification mark of the nth layer is detected by scanning with a beam using the substrate detection method described above, the drawing process of the nth layer pattern is permitted and executed.

[0009] A drawing apparatus according to one aspect of the present invention is a drawing apparatus for drawing a pattern on a substrate using a plurality of drawing layers, comprising: a beam source that emits a beam; and a control computer that, before the drawing process, recognizes which of the plurality of drawing layers the drawing process will be performed on based on the result of scanning the identification mark of the (n+1)th drawing layer, which is formed by scanning the identification mark of the nth (n is a natural number)th drawing layer with the beam. In this drawing apparatus, the portion of the identification mark of the nth (n is a natural number)th layer scanned by the electron beam corresponds to the identification mark of the (n+1)th layer.

[0010] An identification mark according to one aspect of the present invention is a group of identification marks formed on a substrate on which a pattern is drawn by a plurality of drawing layers, and each of these identification marks is identifiable as one of the plurality of drawing layers before the drawing process. In this identification mark, the identification mark of the nth (where n is a natural number)th drawing layer and the identification mark of the (n+1)th drawing layer intersect with each other. [Effects of the Invention]

[0011] According to the present invention, it is possible to reduce rendering defects in multilayer rendering. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram of a drawing device according to the first embodiment of the present invention. [Figure 2] This is a plan view of a circuit board with identification marks drawn on it. [Figure 3] This flowchart shows an example of the operation procedure of the drawing device according to the first embodiment. [Figure 4] This is a plan view of the circuit board before the first layer is drawn. [Figure 5] This is a plan view of the circuit board before the second layer is drawn. [Figure 6] This is a plan view of the circuit board before the third layer is drawn. [Figure 7] This is a plan view of the substrate after the formation of the fourth identification mark. [Figure 8] This flowchart shows an example of the operation procedure of the drawing device according to the second embodiment. [Figure 9] This is a plan view of the circuit board after the first layer has been drawn. [Figure 10] This is a plan view of the substrate after the second layer has been drawn. [Figure 11] This is a plan view of the circuit board after the third layer has been drawn. [Modes for carrying out the invention]

[0013] Embodiments of the present invention will be described below with reference to the drawings. These embodiments are not intended to limit the present invention.

[0014] (First Embodiment) FIG. 1 is a schematic diagram of a drawing apparatus according to the first embodiment. The drawing apparatus 1 shown in FIG. 1 is a multi-charged particle beam drawing apparatus. In this embodiment, as an example of the charged particle beam, a configuration using an electron beam will be described. However, the charged particle beam is not limited to an electron beam, and other charged particle beams such as an ion beam may be used. Further, the drawing apparatus 1 according to this embodiment is of a multi-beam type, but may be of a single-beam type. Also, a drawing apparatus using an optical beam such as a laser may be used.

[0015] The drawing apparatus 1 according to this embodiment includes a drawing unit 10 that irradiates an electron beam onto a substrate 34 to draw a desired pattern, and a control unit 50 that controls the drawing process by the drawing unit 10. The drawing unit 10 has an electron gun 12 and a drawing chamber 30.

[0016] In the electron gun 12, an electron source 14, an illumination lens 16, a shaping aperture array member 18, a blanking aperture array plate 20, a reduction lens 22, a limiting aperture member 24, an objective lens 26, and a deflector 28 are arranged. In the drawing chamber 30, a stage 32 is arranged. On the stage 32, a substrate 34 to be drawn is placed. For the substrate 34, for example, a substrate on which mask patterns are multilayer-drawn, such as a PSM (Phase Shift Mask) substrate or an EUV (Extreme Ultra-Violet) substrate, is applied. Further, on the stage 32, a mirror 36 for measuring the position of the stage 32 is arranged.

[0017] The control unit 50 includes a control computer 51, deflection control circuits 53, 55, a stage control circuit 57, and a detection amplifier 59. The control computer 51, the deflection control circuits 53, 55, the stage control circuit 57, and the detection amplifier 59 are connected to each other via a bus.

[0018] The electron beam 40 emitted from the electron source 14 illuminates the entire molded aperture array member 18 almost vertically, for example, by the illumination lens 16. The molded aperture array member 18 has multiple openings formed in a matrix at a predetermined arrangement pitch. The electron beam 40 illuminates the region that includes all the openings of the molded aperture array member 18. As a portion of the electron beam 40 passes through each of these multiple openings, a multi-beam 40a to 40e is formed as shown in Figure 1.

[0019] The blanking aperture array plate 20 has multiple through holes (blanking aperture arrays) formed in accordance with the arrangement positions of each opening in the molded aperture array member 18, and each through hole is fitted with a blanker consisting of a pair of electrodes. The electron beams 40a to 40e passing through each through hole are deflected independently by the voltage applied to the blanker. Blanking control is performed by this deflection. In this way, multiple blankers perform blanking deflection of the corresponding beams from among the multi-beams that have passed through the multiple holes in the molded aperture array member 18.

[0020] The multi-beams 40a to 40e that have passed through the holes in the blanking aperture array plate 20 are reduced by the reduction lens 22 and proceed toward the opening formed in the limiting aperture member 24. Here, the electron beams deflected by the blanker of the blanking aperture array plate 20 are moved away from the opening of the limiting aperture member 24 and are shielded by the limiting aperture member 24. On the other hand, the electron beams that are not deflected by the blanker of the blanking aperture array plate 20 pass through the opening of the limiting aperture member 24.

[0021] In this way, the limiting aperture member 24 shields each beam that has been deflected by the blanker of the blanking aperture array plate 20 so that it is in the beam-off state. The beam that has passed through the limiting aperture member 24 from the time it is turned ON until it is turned OFF constitutes one shot of beam. The multi-beams 40a to 40e that have passed through the limiting aperture member 24 are focused by the objective lens 26 to form a pattern image with the desired reduction ratio.

[0022] Each beam (the entire multi-beam system) that has passed through the limiting aperture member 24 is deflected in the same direction by the deflector 28 and directed to its respective irradiation position on the substrate 34. When the stage 32 is moving continuously, the deflector 28 tracks the irradiation position of the beams so that it follows the movement of the stage 32. The position of the stage 32 is controlled by the stage control circuit 57.

[0023] The multi-beams irradiated at once are ideally arranged at a pitch obtained by multiplying the arrangement pitch of the multiple holes in the molded aperture array member 18 by the desired reduction ratio described above. This drawing device performs drawing operations using a raster scan method in which shot beams are irradiated sequentially, and when drawing a desired pattern, the necessary beams are controlled to turn ON by blanking control according to the pattern. When the stage 32 is moving continuously, the beam irradiation position is controlled by the deflector 28 so as to follow the movement of the stage 32.

[0024] The control computer 51 generates shot data, including the irradiation amount (irradiation time) for each pixel, from the drawing data (rasterized data) calculated from the pattern data, and outputs commands to the blanking control circuit 53 regarding the ON / OFF control of the blanking aperture array plate 20 based on the shot data. The control computer 51 also outputs commands to the deflection control circuit 55 regarding the deflection control of the deflector 28 and commands to the stage control circuit 57 regarding the movement control of the stage 32 based on the shot data. Furthermore, the control computer 51 determines the presence or absence of identification marks on the substrate 34 placed on the stage 32 from the output of the detector 29.

[0025] The storage device 60 stores various types of data. These various types of data include, for example, drawing data for each layer that is drawn in multiple layers on the substrate 34.

[0026] In the drawing device 1 configured as described above, multilayer drawing is performed in which the mask pattern is drawn on the substrate 34 in multiple steps. In this multilayer drawing, for example, the second layer may be mistakenly drawn on the substrate 34 before the first layer (initial drawing) has been processed. This situation can lead to drawing defects.

[0027] Therefore, in this embodiment, an identification mark for identifying which layer is being drawn (drawing layer) is formed at a predetermined position in the peripheral region 342 located around the drawing region 341 on the substrate 34 where the mask pattern is drawn, as described below.

[0028] In addition, the surrounding area 342 is used to draw, for example, an ID (Identifier) ​​to distinguish the substrate 34 from other substrates, and alignment marks for positioning the substrate 34.

[0029] As shown in Figure 2, one end of the first identification mark 351 intersects with one end of the second identification mark 352. The other end of the second identification mark 352 intersects with one end of the third identification mark 353. One end of the third identification mark 353 intersects with the scan processing mark 361 in addition to the second identification mark 352. The scan processing mark 361 extends parallel to the second identification mark 352 but does not intersect with the first identification mark 351. The other end of the third identification mark 353 intersects with one end of the fourth identification mark 354. One end of the fourth identification mark 354 intersects with the scan processing mark 362 in addition to the third identification mark 353. The scan processing mark 362 extends parallel to the third identification mark 353 but does not intersect with the second identification mark 352. Although four identification marks are shown in Figure 2, the number of identification marks is set according to the number of drawing layers in the multilayer drawing of the first region 341.

[0030] Figure 3 is a flowchart showing an example of the operation procedure of the drawing device 1 according to the first embodiment. Before performing the drawing process for the first layer, the drawing device 1 first performs the 1-1 scan process (step S100).

[0031] Figure 4 is a plan view of the substrate 34 before the first layer drawing process. At this point, no identification marks have been formed on the substrate 34 to be drawn.

[0032] In the first-first scan process, it is confirmed that the identification mark (second identification mark 352) formed in the first layer drawing process has not been formed (step S100). The electron beam 40 is scanned at the position where the first identification mark 351 is formed (first-first scan). The irradiated electron beam 40 is reflected by the substrate 34, and the reflected electrons are detected by the detector 29. Because the substrate 34 and the identification marks 351 to 354 have different reflectivity, the amount of electrons detected changes. The electrical signal based on the amount of electrons detected by the detector 29 is amplified by the detection amplifier 59 and input to the control computer 51.

[0033] Next, the control computer 51 determines whether or not the second identification mark 352 has been detected based on the input electrical signal (step S101).

[0034] If it is determined that the second identification mark 352 was not detected (step S101: NO), the first-to-second scan process is performed. If it is determined that the second identification mark 352 was detected (step S101: YES), the substrate 34 has already undergone the first layer drawing process and is not the target substrate for the first layer drawing process, so the drawing process is stopped.

[0035] In the first-to-second scan process, the electron beam 40 is scanned in a direction intersecting the scan direction of the first-to-first scan process, specifically along the formation position of the second identification mark 352 (first-to-second scan). Similar to the first-to-first scan process, the irradiated electron beam 40 is reflected by the substrate 34, and the reflected electrons are detected by the detector 29. The electrical signal indicating the detection result of the detector 29 is amplified by the detection amplifier 59 and input to the control computer 51.

[0036] The control computer 51 determines whether the third identification mark 353 has been detected or not in the same manner as during the first-first scan process (step S103). The irradiated electron beam 40 is reflected by the substrate 34, and the reflected electrons are detected by the detector 29. Since the substrate 34 and the identification marks 351 to 354 have different reflectivity, the amount of electrons detected changes. The electrical signal based on the amount of electrons detected by the detector 29 is amplified by the detection amplifier 59 and input to the control computer 51.

[0037] Next, the control computer 51 determines whether or not the third identification mark 353 has been detected based on the presence or absence of peaks characteristic of the signal waveforms of the identification marks 351 to 354 in the input electrical signal (step S103).

[0038] If it is determined that the third identification mark 353 is not detected (step S103: NO), the first layer drawing process is performed (step S104). If it is determined that the first identification mark 351 and the third identification mark 353 are detected (step S103: YES), the substrate 34 is not the substrate to be drawn for the first layer, so the drawing process is stopped.

[0039] In this embodiment, as described above, the 1-1 scan process and the 1-2 scan process are performed, and a linear pattern is drawn in the peripheral region 342 by irradiation (exposure) with an electron beam. After the drawing process of the first layer is completed, the substrate 34 is transported from the drawing apparatus 1 to a substrate processing apparatus that performs developing and other processes.

[0040] The exposed portion (chromium) of the electron beam 40 is removed by the development process of the substrate processing apparatus described above, forming a mask pattern for the first layer drawing process, and a linear pattern is formed in the second region 342. The linear pattern formed at this time is used as a second identification mark 352 to detect that the substrate has had the first layer drawn on it before the second layer is drawn. Once the processing in the substrate processing apparatus is complete, the substrate 34 is brought back into the drawing apparatus 1.

[0041] Next, the drawing device performs a second-first scan before performing the drawing process for the second layer (step S105).

[0042] Figure 5 is a plan view of the substrate 34 before the second layer drawing process. Before the second layer drawing process, as shown in Figure 5, a linear second identification mark 352 is formed in the second region 342 so as to intersect with the first identification mark 351.

[0043] In the 2-1 scan process, the electron beam 40 is scanned parallel to and separated from the second identification mark 352. Specifically, the electron beam 40 is scanned along the scan process mark 361 (see Figure 2). As in the 1-1 scan process, the irradiated electron beam 40 is reflected by the substrate 34, and the reflected electrons are detected by the detector 29. The electrical signal indicating the detection result of the detector 29 is amplified by the detection amplifier 59 and input to the control computer 51.

[0044] Next, the control computer 51 determines whether or not the third identification mark 353 has been detected based on the input electrical signal (step S106).

[0045] If it is determined that the third identification mark 353 was not detected (step S106: NO), the second-second scan process is performed (step S107). If it is determined that the third identification mark 353 was detected (step S106: YES), the substrate 34 has already undergone the second layer drawing process and is not the substrate to be used for the second layer drawing process, so the drawing process is stopped.

[0046] In the second-to-second scan process, the electron beam 40 is scanned in a direction intersecting the second identification mark 352, specifically along the formation position of the third identification mark 353 (second-to-second scan). Similar to the first-to-second scan process, the irradiated electron beam 40 is reflected by the substrate 34, and the reflected electrons are detected by the detector 29. The electrical signal indicating the detection result of the detector 29 is amplified by the detection amplifier 59 and input to the control computer 51.

[0047] The control computer 51 determines whether the second identification mark 352 has been detected or not in the same manner as during the first-to-second scan process (step S108).

[0048] If it is determined that the second identification mark 352 has been detected (step S105: YES), the control computer 51 determines whether or not the fourth identification mark 354 has been detected (step S109). If it is determined that the fourth identification mark 354 has not been detected (step S109: NO), the second layer drawing process is performed (step S110).

[0049] If it is determined that the second identification mark 352 was not detected (step S108: NO), or if it is determined that the fourth identification mark 354 was detected (step S109: YES), the drawing process is stopped because the substrate 34 either has not had its first layer drawn or has had its third layer drawn and is not a substrate to be used for the second layer drawing process.

[0050] In this embodiment, as described above, a second scan is performed to detect the second identification mark 352. During this second scan, the irradiation (exposure) of the electron beam draws two linear patterns parallel to and intersecting the second identification mark 352 in the surrounding area 342. After the second layer drawing process is completed, the substrate 34 is transported from the drawing apparatus 1 to a substrate processing apparatus that performs developing and other processes.

[0051] The exposed portion (chromium) of the electron beam 40 is removed by the development process of the substrate processing apparatus described above, forming a mask pattern for the second layer drawing process, and two linear patterns are formed in the second region 342. Of the linear patterns formed at this time, the linear pattern that intersects with the second identification mark 352 is used as a third identification mark 353 to detect that the substrate has had the second layer drawn on it before the third layer is drawn. Once the processing in the substrate processing apparatus is complete, the substrate 34 is brought back into the drawing apparatus 1.

[0052] Next, before performing the drawing process for the third layer, the drawing device 1 performs the third-first scan process (step S111).

[0053] Figure 6 is a plan view of the substrate 34 before the third layer drawing process. Before the third layer drawing process, as shown in Figure 6, a linear third identification mark 353 is formed in the second region 342 so as to intersect with the second identification mark 352 and the scan processing mark 361.

[0054] In the 3-1 scan process, the electron beam 40 is scanned parallel to the 3rd identification mark 353, separated from it. Specifically, the electron beam 40 is scanned along the scan process mark 362 (see Figure 2). As in the 1-1 scan process, the irradiated electron beam 40 is reflected by the substrate 34, and the reflected electrons are detected by the detector 29. The electrical signal indicating the detection result of the detector 29 is amplified by the detection amplifier 59 and input to the control computer 51.

[0055] Next, the control computer 51 determines whether or not the fourth identification mark 354 has been detected based on the input electrical signal (step S112).

[0056] If it is determined that the fourth identification mark 354 was not detected (step S112: NO), the third-second scan process is performed (step S113). If it is determined that the fourth identification mark 354 was detected (step S112: YES), the third layer drawing process has already been performed on the substrate 34, and since it is not the substrate to be used for the third layer drawing process, the drawing process is stopped.

[0057] In the 3-2 scan process, the electron beam 40 is scanned in a direction intersecting the third identification mark 353, specifically along the formation position of the fourth identification mark 354 (3-2 scan). Similar to the 1-2 scan process, the irradiated electron beam 40 is reflected by the substrate 34, and the reflected electrons are detected by the detector 29. The electrical signal indicating the detection result of the detector 29 is amplified by the detection amplifier 59 and input to the control computer 51.

[0058] Next, the control computer 51 determines whether or not the third identification mark 353 has been detected, in the same manner as during the first-to-second scan process (step S114).

[0059] If it is determined that the third identification mark 353 has been detected (step S114: YES), the drawing process for the third layer is performed (step S115). If it is determined that the third identification mark 353 has not been detected (step S114: NO), or if it is determined that the fourth identification mark 354 has been detected (step S112: YES), the drawing process is stopped because the substrate 34 either has not had the second layer drawn or has had the third layer drawn and is not a substrate that is subject to the drawing process for the third layer.

[0060] In this embodiment, as described above, a third-second scan is performed to detect the third identification mark 353. During this third scan, the irradiation (exposure) of the electron beam draws a linear pattern parallel to / intersecting the third identification mark 352 in the surrounding area 342. After the third layer drawing process is completed, the substrate 34 is transported from the drawing apparatus 1 to a substrate processing apparatus that performs developing and other processes.

[0061] The exposed portion (chromium) of the electron beam 40 is removed by the development process of the substrate processing apparatus described above, forming a mask pattern for the third layer drawing process, and two linear patterns are formed in the second region 342. Of the linear patterns formed at this time, the linear pattern that intersects with the third identification mark 353 is used as a fourth identification mark 354 to detect that the substrate has had the third layer drawn on it before the fourth layer is drawn. Once the processing in the substrate processing apparatus is complete, the substrate 34 is brought back into the drawing apparatus 1.

[0062] Figure 7 is a plan view of the substrate 34 after the formation of the fourth identification mark 354. As shown in Figure 7, a linear fourth identification mark 354 is formed in the second region 342 so as to intersect with the third identification mark 353 and the scan processing mark 362.

[0063] According to the embodiment described above, on the substrate 34, an identification mark for identifying whether it is a substrate to be used for drawing the nth layer (where n is a natural number) can be formed simultaneously with the mask pattern by scanning an identification mark for identifying whether it is a substrate to be used for drawing the nth layer. Then, before performing the drawing process for each layer, it is possible to check whether or not the identification mark corresponding to each layer has been detected. In this way, it is possible to recognize whether or not it is a substrate to be drawn on before drawing, so that drawing on substrates 34 that are not to be drawn on can be avoided.

[0064] Furthermore, in this embodiment, by performing a scan to check for the presence or absence of an identification mark for the (n+1)th layer before drawing the (n+1)th layer, it is possible to recognize that the (n+1)th layer has already been drawn and that it is not the substrate to be drawn on.

[0065] Therefore, it becomes possible to reduce mask discarding in multi-layer rendering.

[0066] (Second Embodiment) A second embodiment of the present invention will now be described. The configuration of the drawing apparatus according to the second embodiment is the same as that of the first embodiment described above, so the description will be omitted. On the other hand, in this embodiment, the shape of the identification mark formed on the substrate 34 and the method for determining the drawing layer of the substrate 34 based on this identification mark differ from those of the first embodiment.

[0067] Figure 8 is a flowchart showing an example of the operation procedure of the drawing apparatus according to the second embodiment. First, the drawing apparatus according to this embodiment performs a first scan process before performing the drawing process of the first layer (step S201).

[0068] Figure 9 is a plan view of the substrate 44 before the first layer drawing process. At this point before the first layer drawing process, the identification marks 451 to 453 are not formed in the peripheral region 442 of the substrate 44 to be drawn.

[0069] Similar to the first embodiment, a first scan process is performed. In the first scan process, the electron beam 40 is scanned in two intersecting directions (XY direction) (first scan). Similar to the first scan process, the irradiated electron beam 40 is reflected by the substrate 44, and the reflected electrons are detected by the detector 29. The electrical signal indicating the detection result of the detector 29 is amplified by the detection amplifier 59 and input to the control computer 51.

[0070] Next, the control computer 51 determines whether or not any identification marks have been detected based on the presence or absence of peaks characteristic of the signal waveform of the identification marks in the input electrical signal (step S202).

[0071] If it is determined that no identification marks were detected in the X and Y directions (Step S202: YES), the first layer drawing process is performed (Step S203). If it is determined that one or more identification marks were detected (Step S202: NO), the substrate 34 is not the substrate to be drawn for the first layer, so the drawing process is stopped.

[0072] In this embodiment, as described above, a first scan is performed, and a cross-shaped pattern is drawn in the peripheral region 442 by irradiation (exposure) with an electron beam. After the first layer drawing process is completed, the substrate 44 is transported from the drawing apparatus 1 to a substrate processing apparatus that performs developing and other processes.

[0073] The exposed portion (chromium) of the electron beam 40 is removed by the development process of the substrate processing apparatus described above, forming a mask pattern for the first layer drawing process, and two cross-shaped patterns are formed in the second region 442. The cross-shaped patterns formed at this time are used as a first identification pattern, a first identification mark 451, to detect that the substrate has had the first layer drawn on it before the second layer is drawn.

[0074] Once processing in the substrate processing apparatus is complete, the substrate 44 is brought back into the drawing apparatus 1.

[0075] Next, the drawing apparatus according to this embodiment performs a second scan process before performing the second layer drawing process (step S204).

[0076] Figure 10 is a plan view of the substrate 44 before the second layer drawing process. Before the second layer drawing process, a cross-shaped first identification mark 451, consisting of two intersecting linear portions, is pre-placed in the peripheral region 442 of the substrate 44 to be drawn.

[0077] Similar to the first scan process, the second scan process scans the electron beam 40 in directions (XY directions) that intersect with each of the two linear portions of the cross-shaped first identification mark 451 (second scan). As in the first scan process, the irradiated electron beam 40 is reflected by the substrate 44, and the reflected electrons are detected by the detector 29. The electrical signal indicating the detection result of the detector 29 is amplified by the detection amplifier 59 and input to the control computer 51.

[0078] The control computer 51 determines whether or not the first identification mark 351 has been detected in the same manner as in Embodiment 1 (step S205).

[0079] If it is determined that one mark (first identification mark 451) is detected in each of the X and Y directions (step S205: YES), the second layer drawing process is performed (step S205). If it is determined that no marks are detected in the X and Y directions (the first identification mark 451 is not detected, or two or more marks are detected) (step S205: NO), the drawing process is stopped because the first layer of this substrate 44 has not been drawn, or the second layer or later has already been drawn, and it is not a substrate that is subject to the second layer drawing process.

[0080] In this embodiment, as described above, a second scan is performed to detect the first identification mark 451. During this first scan, the electron beam irradiation (exposure) draws a cross-shaped pattern in the surrounding area 442 that intersects with the first identification mark 451. After the second layer drawing process in step S206 is completed, the substrate 44 is transported from the drawing apparatus 1 to a substrate processing apparatus that performs developing and other processes.

[0081] The exposed portion (chromium) of the electron beam 40 is removed by the development process of the substrate processing apparatus described above, forming a mask pattern for the second layer drawing process, and a cross-shaped pattern is formed in the second region 342. The cross-shaped pattern formed at this time is used as a second identification mark 352 to detect that the substrate has had the second layer drawn on it before the third layer is drawn. Once the processing in the substrate processing apparatus is complete, the substrate 44 is brought back into the drawing apparatus 1.

[0082] Next, the drawing apparatus according to this embodiment performs a third scan process before performing the third layer drawing process (step S207).

[0083] Figure 11 is a plan view of the substrate 44 before the third layer drawing process. Before the third layer drawing process, the peripheral region 442 of the substrate 44 to be drawn has a cross-shaped first identification mark 451 consisting of two intersecting linear portions, and a cross-shaped second identification mark 452 formed to intersect these linear portions.

[0084] Similar to the first scan process, the third scan process, as in the first embodiment, scans the electron beam 40 in directions (XY directions) that intersect with each of the two linear portions of the cross-shaped first identification mark 451 and second identification mark 452 (third scan). Similar to the first scan process, the irradiated electron beam 40 is reflected by the substrate 44, and the reflected electrons are detected by the detector 29. The electrical signal indicating the detection result of the detector 29 is amplified by the detection amplifier 59 and input to the control computer 51.

[0085] The control computer 51 determines whether the first and second identification marks 453 have been detected in the same manner as in Embodiment 1 (step S208).

[0086] If it is determined that two marks (first identification mark 451, second identification mark 452) have been detected in the X and Y directions respectively (step S208: YES), the second layer drawing process is performed (step S209). If it is determined that none of the marks have been detected (none of the first to third identification marks 451 to 453 have been detected, or three or more marks have been detected) (step S208: NO), the drawing process is stopped because this substrate 44 has either not had its first layer drawn, or has had its third layer drawn, and is not a substrate that is subject to the third layer drawing process.

[0087] In this embodiment, as described above, a first scan is performed to detect the first identification mark 451 and the second identification mark 452. During this first scan, the electron beam irradiation (exposure) draws a linear pattern in the peripheral region 442 that intersects with the second identification mark 452. After the third layer drawing process in step S210 is completed, the substrate 44 is transported from the drawing apparatus 1 to a substrate processing apparatus that performs developing and other processes.

[0088] According to the embodiment described above, similar to the first embodiment, an identification mark for identifying whether a substrate is to be used for drawing the nth layer can be formed on the substrate 44 simultaneously with the mask pattern by scanning an identification mark for identifying whether a substrate is to be used for drawing the nth layer (where n is a natural number) during the drawing of the nth layer. Furthermore, it is possible to check whether the identification mark corresponding to each layer has been detected before performing the drawing process for each layer. In this way, it is possible to recognize whether a substrate is to be drawn on before drawing, and thus it is possible to avoid drawing on substrates 34 that are not to be drawn on.

[0089] Furthermore, in this embodiment, when performing the nth scan, identification marks formed before the (n-1)th scan can also be scanned, making it possible to recognize that all multilayer drawing has been performed. This makes it possible to avoid drawing on objects where not only the (n-1)th layer but also some layers of the multilayer drawing are not drawn.

[0090] Therefore, it becomes possible to reduce mask discarding due to rendering errors in multi-layer rendering.

[0091] It should be noted that the present invention is not limited to the embodiments described above. While the charged particle beam apparatus of one embodiment of the present invention utilized multiple beams, it is not limited to this, and it is also possible to utilize a single beam. In the implementation stage, the components can be modified and implemented without departing from the gist of the invention. Furthermore, various inventions can be formed by appropriately combining the multiple components disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiments. Moreover, components from different embodiments may be appropriately combined. [Explanation of Symbols]

[0092] 1:Drawing device 14: Electron source 34: Circuit board 51: Control computer

Claims

1. A method for detecting a substrate on which a pattern is drawn using multiple drawing layers, Before the drawing process, a step is taken to scan the substrate with a beam to identify which of the plurality of drawing layers is formed on the substrate, The process includes a step of recognizing, based on the result of scanning the identification mark, which of the plurality of drawing layers the drawing process will be performed on, A substrate detection method wherein the identification mark of the (n+1) (n is a natural number) layer is formed by scanning the identification mark of the n-th layer drawing layer with the beam.

2. The substrate detection method according to claim 1, further comprising the step of scanning a predetermined position on the substrate with a beam before the drawing process of the first drawing layer, and detecting that the identification mark for identifying the first drawing layer has not been formed.

3. The substrate detection method according to claim 1, wherein identification marks from the first layer to the nth layer are formed at predetermined intervals in the X and Y directions, and the identification marks from the first layer to the nth layer are detected by a single scan in the X and Y directions.

4. A beam drawing method in which, when an identification mark of the nth layer is detected by scanning with the beam using the substrate detection method of claim 1 or claim 2, a drawing process for the pattern of the nth layer is performed.

5. The beam drawing method according to claim 4, wherein if the identification mark of the (n+1)th layer is not detected by scanning with the beam, the pattern of the nth layer is drawn.

6. A drawing apparatus that draws a pattern on a substrate using multiple drawing layers, A beam source that emits a beam, A control computer recognizes, before the drawing process, which of the multiple drawing layers the drawing process will be performed on, based on the result of scanning the identification mark of the (n+1)th drawing layer, which is formed by scanning the identification mark of the nth (where n is a natural number) drawing layer with the beam, before the drawing process is performed. A drawing device equipped with the following features.

7. A group of identification marks formed on a substrate on which a pattern is drawn by multiple drawing layers, each of which is distinguishable as one of the multiple drawing layers before the drawing process, wherein the identification mark of the nth (where n is a natural number)th drawing layer and the identification mark of the (n+1)th drawing layer intersect each other.

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