Drawing method, master plate manufacturing method and drawing device

Abstract

The present invention relates to a drawing method, a master plate manufacturing method, and a drawing device. According to one embodiment of the present invention, the drawing method includes obtaining step portion configuration information indicating the configuration state of a step portion of a substrate. The method also includes obtaining step portion height information indicating the height of the step portion. The method also includes measuring the height of the substrate. The method also includes calculating a focus map indicating the distribution of beam focus values of an electron beam corresponding to a drawing position on the substrate based on the obtained step portion configuration information and step portion height information and the measured height. The method also includes drawing a pattern on the substrate using an electron beam having a beam focus value determined based on the calculated focus map.

Description

[0001] Citation of Related Applications

[0002] This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2021-045152, filed on March 18, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0003] Embodiments of the present invention relate to a drawing method, a master manufacturing method, and a drawing device. Background Art

[0004] Sometimes, a master for semiconductor processing is produced by patterning using an electron beam. In such cases, it may be difficult to appropriately determine the beam focus value and accurately draw the pattern depending on the surface shape of the master substrate. Summary of the Invention

[0005] One embodiment provides a drawing method, a master manufacturing method, and a drawing apparatus capable of drawing a pattern with high precision regardless of the surface shape of a substrate.

[0006] According to one embodiment, a drawing method includes obtaining step configuration information indicating a configuration state of steps on a substrate. The method further includes obtaining step height information indicating the height of the step. The method further includes measuring the height of the substrate. The method further includes calculating a focus map indicating a distribution of beam focus values of an electron beam corresponding to drawing positions on the substrate based on the obtained step configuration information and step height information and the measured height. The method further includes drawing a pattern on the substrate using an electron beam having a beam focus value determined based on the calculated focus map.

[0007] According to the above configuration, it is possible to provide a drawing method, a master plate manufacturing method, and a drawing apparatus capable of drawing a pattern with high precision regardless of the surface shape of a substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is a diagram showing an example of a drawing device according to the first embodiment.

[0009] Figure 2A This is a cross-sectional view showing an example of a mask blank to which the drawing apparatus according to the first embodiment can be applied.

[0010] Figure 2B This is a cross-sectional view showing an example of a template blank to which the drawing apparatus according to the first embodiment can be applied.

[0011] Figure 2C This is a cross-sectional view showing another example of a mask blank to which the drawing apparatus according to the first embodiment can be applied.

[0012] Figure 3 This is a flowchart showing an example of the drawing method according to the first embodiment.

[0013] Figure 4 It is used to explain the drawing method of the first embodiment. Figure 3 The flowchart is an explanatory diagram of the steps of generating surface shape data.

[0014] Figure 5 This is used to explain the method of measuring the drawing in the first embodiment. Figure 3 The flowchart is an explanatory diagram of the steps of determining the height of the substrate surface.

[0015] Figure 6 It is used to explain the calculation of the drawing method in the first embodiment. Figure 3 The flowchart shown is an explanatory diagram of the steps of height distribution.

[0016] Figure 7 It is used to explain the calculation of the drawing method in the first embodiment. Figure 3 The flowchart shown is an explanatory diagram of the steps of focusing the image.

[0017] Figure 8 It is used to explain the drawing method in the first embodiment. Figure 3 An explanatory diagram of the drawing steps shown in the flowchart.

[0018] Figure 9A This is an explanatory diagram for explaining the operation of the drawing method according to the first embodiment.

[0019] Figure 9B It is an explanatory diagram for explaining the first comparative example.

[0020] Figure 9C It is an explanatory diagram for explaining the second comparative example.

[0021] Figure 10 This is used to explain the method of measuring the drawing method in the second embodiment. Figure 3 The flowchart is an explanatory diagram of the steps of determining the height of the substrate surface.

[0022] Figure 11 It is used to explain the calculation of the drawing method in the second embodiment. Figure 3 The flowchart shown is an explanatory diagram of the steps of height distribution.

[0023] Figure 12A It is used to illustrate the drawing method in the third embodiment. Figure 3 The flowchart is an explanatory diagram of the steps of generating surface shape data.

[0024] Figure 12B This is an explanatory diagram for explaining an example of calculating the inclination angle and inclination direction of the inclined portion in the drawing method according to the third embodiment.

[0025] Figure 13A It is a cross-sectional view showing a method for manufacturing a photomask according to an embodiment.

[0026] Figure 13B Then Figure 13A Cross-sectional views showing a method for manufacturing a photomask according to an embodiment.

[0027] Figure 13C Then Figure 13B Cross-sectional views showing a method for manufacturing a photomask according to an embodiment.

[0028] Figure 13D Then Figure 13C Cross-sectional views showing a method for manufacturing a photomask according to an embodiment.

[0029] Figure 13E Then Figure 13D Cross-sectional views showing a method for manufacturing a photomask according to an embodiment.

[0030] Figure 14A It is a cross-sectional view showing a method for manufacturing a template according to an embodiment.

[0031] Figure 14B Then Figure 14A A cross-sectional view showing a method for manufacturing a template according to an embodiment.

[0032] Figure 14C Then Figure 14B A cross-sectional view showing a method for manufacturing a template according to an embodiment.

[0033] Figure 14D Then Figure 14C A cross-sectional view showing a method for manufacturing a template according to an embodiment.

[0034] Figure 14E Then Figure 14D A cross-sectional view showing a method for manufacturing a template according to an embodiment. DETAILED DESCRIPTION

[0035] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Figures 1 to 14E In the drawings, the same or similar components are denoted by the same reference numerals and repeated descriptions are omitted.

[0036] (First embodiment) Figure 1 This is a diagram showing an example of the drawing device 1 according to the first embodiment. Figure 1The drawing device 1 shown can be used, for example, to draw a pattern on a substrate 6 (that is, a photoresist film 9 on the substrate 6) described later by irradiating an electron beam EB when manufacturing a master used in a semiconductor process. The specific method of the substrate 6 is not particularly limited as long as it can be used to manufacture a master by irradiating an electron beam EB. For example, Figures 2A to 2C In the embodiment, as will be described later, the substrate 6 may also be a mask blank 6A, 6C or a template blank 6B.

[0037] Figure 1 The depiction apparatus 1 shown includes a computer 2, a height measuring unit 3, a control device 4, an electron irradiation unit 5, and a stage 7. The electron irradiation unit 5 is disposed within an electron optical lens barrel (not shown). A substrate 6 is placed on the stage 7 within a vacuum chamber connected to the electron optical lens barrel. The stage 7 can be moved, for example, in the horizontal direction (X direction, Y direction) and the vertical direction (Z direction) by a drive device such as a motor. By moving the stage 7, the irradiation position of the electron beam EB on the substrate 6 on the stage 7 can be changed.

[0038] Here, before describing the components of the drawing apparatus 1 in further detail, an example of the substrate 6 to which the drawing apparatus 1 can be applied will be described. Figure 2A It is a cross-sectional view showing an example of a mask blank 6A to which the drawing apparatus 1 according to the embodiment can be applied. Figure 2B This is a cross-sectional view showing an example of a template blank 6B to which the drawing apparatus 1 according to the embodiment can be applied. Figure 2C This is a cross-sectional view showing another example of a mask blank 6C to which the drawing apparatus 1 according to the embodiment can be applied. Mask blanks 6A and 6C are examples of substrates 6 used to manufacture photomasks serving as master plates for photolithography. Template blank 6B is an example of substrate 6 used to manufacture templates serving as master plates for nanoimprint lithography.

[0039] like Figure 2A and Figure 2C As shown, the mask blanks 6A and 6C serving as the substrate 6 include a light-transmitting substrate 61 and a light-shielding film 62 formed on the light-transmitting substrate 61. The light-transmitting substrate 61 may contain, for example, quartz as a main component. The light-shielding film 62 may also contain, for example, a metal such as chromium (Cr) as a main component. Figure 2B As shown, the template blank 6B serving as the substrate 6 contains, for example, quartz as a main component, and thus has light-transmitting properties as a whole.

[0040] In the case where there is a step or tilt on the surface of a film to be processed formed on a device substrate (wafer) for a semiconductor device, it is difficult to process the film to be processed with the same good precision as when a photomask or template having a flat surface is used. Specifically, in the case of photolithography using a photomask, it is difficult to properly expose the photoresist film on the film to be processed because it is difficult to focus the exposure light on the photoresist film on the film to be processed. In the case of nanoimprint lithography using a template, it is difficult to properly press the template onto the photoresist on the film to be processed, that is, the device substrate, to transfer the pattern. As a result, it is difficult to form a circuit pattern on the film to be processed with the desired precision. Therefore, from the viewpoint of accurately processing a film to be processed having a step or tilt, the surface of the substrates 6A to 6C for the photomask or template has a surface shape that matches the surface shape of the film to be processed. Specifically, Figure 2A The surface of the mask blank 6A shown has a base portion 6a extending along an in-plane direction d1 (i.e., flat), a flat stepped portion 6b having a step zd (i.e., height difference) relative to the base portion 6a, and an inclined portion 6c connecting the base portion 6a and the stepped portion 6b. When the mask blank 6A is placed on the stage 7, the in-plane direction d1 coincides with the horizontal direction. Figure 2A The inclined portion 6c shown is a straight inclined plane, but it can also be Figure 2A As shown by reference numeral 6c', the inclined portion 6c' is an inclined curved surface. Figure 2B The template blank 6B shown and Figure 2C The surface of the mask blank 6C shown has a base portion 6a and a stepped portion 6b. In addition, the mask blank 6B may also have an inclined portion.

[0041] Here, when a pattern is drawn on the substrate 6 in order to manufacture a master (photomask, template), a photoresist film 9 is formed on the substrate 6. Figure 13A In FIG, a photoresist film 9 is formed on a mask blank 6A as an example of a substrate 6. Figure 14A In the embodiment, a photoresist film 9 is formed on a template blank 6B as an example of a substrate 6. Then, the substrate 6 on which the photoresist film 9 is formed is irradiated with an electron beam EB, whereby a pattern is drawn on the photoresist film 9.

[0042] The substrate 6 on which the photoresist film 9 is formed is curved due to its own weight. The drawing apparatus 1 of the first embodiment is configured to perform focused pattern drawing on the surface of the substrate 6 having a curve and provided with a stepped portion.

[0043] Specifically, if Figure 1As shown, surface shape data 8 is input to computer 2. Surface shape data 8 is data related to the surface shape of substrate 6. Surface shape data includes step configuration information and step height information. Step configuration information is information indicating the configuration state (e.g., position) of the step on the surface of substrate 6. Step height information is information indicating the height of the step. Surface shape data 8 is data produced by a computer different from computer 2, for example, based on the design data of the master. In addition, as Figure 1 As shown, drawing data 10 is input into computer 2. Drawing data 10 is data used to draw a pattern on substrate 6 using electron beam EB. Drawing data 10 is data generated by a computer different from computer 2 based on, for example, the design data of a master. The method for inputting drawing data 10 and surface shape data 8 into computer 2 is not particularly limited, and may be input via data communication or via a storage medium. Surface shape data 8 will be described in more detail in the embodiment of the drawing method described later.

[0044] The height measuring unit 3 measures the surface height of the substrate 6. More specifically, the height measuring unit 3 measures the surface height of the photoresist film 9 formed on the surface of the substrate 6. More specifically, the height measuring unit 3 measures the surface height of the substrate 6 at multiple locations on the surface of the substrate 6. The height measuring unit 3 outputs the measured surface height of the substrate 6 to the computer 2. The height measuring unit 3 may also measure the surface height of the substrate 6 optically, for example, using a laser.

[0045] The computer 2 calculates a focus map indicating the distribution of focus values of the electron beam corresponding to the drawing position of the substrate 6 based on the stepped portion arrangement information and stepped portion height information obtained from the surface shape data 8 and the measured surface height of the substrate 6. The computer 2 outputs the calculated focus map to the control device 4. An example of calculation of the focus map by the computer 2 will be described in the embodiment of the drawing method described later.

[0046] The control device 4 determines the beam focus value for each drawing unit (projection) of the substrate 6 based on the focus map input from the computer 2. The control device 4 controls the electron irradiation unit 5 so that the electron beam with the determined beam focus value draws a pattern on the substrate 6.

[0047] The electron irradiation unit 5 irradiates the substrate 6 with an electron beam EB having a beam focus value determined by the control device 4, thereby drawing a pattern on the photoresist film 9 on the substrate 6. The electron irradiation unit 5 includes, for example, an electron gun for emitting the electron beam EB and an electron optical system (deflector, electromagnetic lens, etc.) for controlling the trajectory of the emitted electron beam EB.

[0048] (Drawing Method) Hereinafter, an embodiment of a drawing method using the drawing device 1 of the first embodiment will be described. Figure 3This is a flowchart showing an example of the drawing method according to the first embodiment.

[0049] like Figure 3 As shown, first, the computer 2 obtains the drawing data 10 (step S1). The drawing data 10 represents a two-dimensional area corresponding to the surface of the substrate 6 and has a pattern defined within the area. The pattern on the drawing data 10 is drawn at a position (i.e., coordinate) corresponding to the surface of the substrate 6.

[0050] In addition, if Figure 3 As shown, the computer 2 obtains the surface shape data 8 (step S2). The acquisition of the surface shape data 8 and the acquisition of the drawing data 10 may be performed in a reverse order or simultaneously. Figure 4 Is used to explain the acquisition Figure 3 An explanatory diagram of an example of the steps of generating surface shape data 8 as shown in the flowchart. Figure 4 As shown, the surface shape data 8 includes at least step configuration information and step height information. The step configuration information is information indicating the configuration state (e.g., position) of the step on the surface of the substrate 6. More specifically, the step configuration information indicates a two-dimensional area corresponding to the depicted data and having a step defined within the area. The step height information is information indicating the height of the step. The step height information is information indicating a relative height based on the average height of the flat base portion of the substrate surface that is not within the step as a height reference (0 [μm]). In addition, Figure 4 In the example shown, the drop portion is a concave drop with a height lower than the base portion. The drop portion may also be a convex drop with a height higher than the base portion. The absolute value of the height of the drop portion may be greater than 0.1 [μm]. The surface shape data 8 may be in the form of a graph. In addition, the height of the drop portion may also be expressed in 1 mm increments. 2 The average height per unit area of the example.

[0051] After obtaining the drawing data 10 and the surface shape data 8, Figure 3 As shown, the drawing apparatus 1 loads the substrate 6 onto the stage 7 (step S3). When the substrate 6 is loaded onto the stage 7, a photoresist film 9 has already been formed on the surface of the substrate 6.

[0052] After the substrate 6 is placed on the stage 7 , the height measuring unit 3 measures the surface height of the substrate 6 , that is, the surface height of the photoresist film 9 , in order to perform focused drawing on the curved surface of the substrate 6 (step S4 ). Figure 5 It is used to explain the drawing method in the first embodiment. Figure 3 The flowchart of the substrate surface height measurement step is shown in FIG. Figure 5 In the figure, the photoresist film 9 is omitted. In order to calculate the height distribution of the substrate 6, as shown in FIG. Figure 5As shown, the height measuring unit 3 measures the height at multiple measurement points P on the surface of the substrate 6. To prevent the stepped portion 6b from affecting the height distribution, the measurement points P are set on the surface of the substrate 6 excluding the stepped portion 6b, that is, on the base portion 6a. Based on the stepped portion configuration information obtained by the computer 2, the height measuring unit 3 sets the measurement points P only on the base portion 6a for measurement. The height measuring unit 3 measures the surface height of the substrate 6 at the measurement points P based on the time it takes for light, such as laser light, to be emitted from the emission unit 31 (light source) and reflected from the measurement points P and received by the light receiving unit 32 (sensor). Since the height is measured at each of the multiple measurement points P, the height measuring unit 3 drives the stage 7 in the X and Y directions to sequentially move the multiple measurement points P to the positions where the light from the emission unit 31 is irradiated.

[0053] After measuring the surface height of the substrate 6, as shown in FIG. Figure 3 As shown, the computer 2 calculates a height distribution indicating the distribution of the surface height of the substrate 6 based on the measured height (step S5). The height distribution indicates the degree of curvature of the substrate 6. Figure 6 It is used to explain the calculation of the drawing method in the first embodiment. Figure 3 The computer 2 uses a high-order polynomial such as Figure 6 The height distribution in the entire surface of substrate 6 is calculated as shown. Figure 6 The distribution of the surface height (Z) of the substrate 6 at each X coordinate and Y coordinate is shown.

[0054] After calculating the height distribution, such as Figure 3 As shown, the computer 2 calculates a focus map by integrating the step arrangement information and the step height information into the calculated height distribution (step S6). Figure 7 It is used to explain the calculation of the drawing method in the first embodiment. Figure 3 The flowchart of the focusing diagram is shown in the following figure. Figure 7 In the example shown, computer 2 calculates a focus map by lowering the height of the range indicated by the drop placement information in the height distribution by the height of the concave drop indicated by the drop height information. Alternatively, if the drop is a convex drop, the focus map can be calculated by simply raising the height of the range indicated by the drop placement information in the height distribution by the height of the convex drop indicated by the drop height information.

[0055] After calculating the focus map, Figure 3 As shown, the control device 4 performs drawing of the beam focus value based on the focus map (step S7). That is, the control device 4 determines the beam focus value based on the calculated focus map, and draws a pattern on the substrate 6 using the electron beam with the determined beam focus value. Figure 8It is used to explain the drawing method in the first embodiment. Figure 3 The flowchart of the drawing steps is shown in FIG. Figure 8 As shown, the electron beam EB having the beam focus value determined based on the focus map calculated in step S6 is focused on the surface of the substrate 6 at either the base portion 6 a or the stepped portion 6 b .

[0056] Figure 9A This is an explanatory diagram for explaining the operation of the drawing method according to the first embodiment. Figure 9B It is an explanatory diagram for explaining the first comparative example. Figure 9C 1 is an explanatory diagram for explaining the second comparative example. If a focus map calculated based on the surface height of the substrate 6 measured only by removing the stepped portion is used for drawing, in the case described above, Figure 9B As shown in FIG. 1 , in the stepped portion 6b having a height different from the base portion 6a on the surface of the substrate 6, a deviation in the rotation component and the magnification component occurs in the main deflection area (the area where the electron beam can be scanned) indicated by the rectangular dotted line. As a result, the electron beam is not focused in the stepped portion 6b, and the pattern drawing accuracy is deteriorated. In addition, if a focus map is calculated based on the surface height of the substrate 6 measured only including the stepped portion, in the above case, the electron beam will not be focused. Figure 9C As shown, deviations of rotational components and magnification components occur in the main deflection region in both the base portion 6a and the stepped portion 6b on the surface of the substrate 6. As a result, focus is lost in the stepped portion 6b, deteriorating the pattern drawing accuracy.

[0057] In this regard, according to the drawing device 1 of the first embodiment, a focusing map is calculated by merging the step configuration information and the step height information into the height distribution based on the surface height of the substrate 6 measured after removing the step, thereby enabling the pattern to be drawn with high precision regardless of the surface shape of the substrate 6.

[0058] Furthermore, when drawing a pattern, the beam adjustment time can be extended for locations where the beam focus value changes significantly compared to locations where the beam focus value changes less. Alternatively, the movement time of the stage 7 holding the substrate 6 can be delayed for locations where the beam focus value changes significantly compared to locations where the beam focus value changes less. This allows for appropriate pattern drawing in locations where the beam focus value changes significantly.

[0059] Alternatively, the pattern may be drawn sequentially starting from a portion where the change in beam focus value is small.

[0060] As described above, according to the first embodiment, a focusing map is calculated based on the step configuration information, the step height information, and the measurement results of the surface height of the substrate 6, and the pattern is depicted using the beam focusing value determined based on the calculated focusing map. Regardless of the surface shape of the substrate (the presence of a step), the pattern can be depicted with high precision.

[0061] In addition, according to the first embodiment, the height distribution is calculated based on the surface height of the substrate 6 measured after removing the step portion, and the step portion configuration information and the step portion height information are merged into the calculated height distribution to generate a focusing map, so that the pattern can be depicted with high precision despite the presence of the step portion.

[0062] (Second embodiment) Next, refer to Figure 10 and 11 , a second embodiment will be described in which the method of calculating the focus map differs from the first embodiment. Figure 10 This is used to explain the method of measuring the drawing method in the second embodiment. Figure 3 The flowchart is an explanatory diagram of the steps of determining the height of the substrate surface. Figure 11 It is used to explain the calculation of the drawing method in the second embodiment. Figure 3 The flowchart shown is an explanatory diagram of the steps of height distribution.

[0063] like Figure 5 As described, in the first embodiment, the surface height of the substrate 6 is measured by setting the measuring point P only on the surface of the substrate 6 with the step portion 6b removed, that is, on the base portion 6a. In contrast, in the second embodiment, instead of setting a special measuring point P that intentionally excludes the step portion 6b, the measuring point P is set according to a predetermined method (e.g., at equal intervals). As a result, several measuring points P are located on the step portion 6b. In the second embodiment, the computer 2 calculates the height distribution based on the surface height of the substrate 6 measured including the step portion 6b. Figure 11 As shown in FIG. 1 , the calculated height distribution includes the influence of the stepped portion 6 b (step S51 ). The height distribution including the influence of the stepped portion 6 b does not accurately represent the height distribution of the substrate 6 .

[0064] However, in the second embodiment, the computer 2 calculates the height distribution that removes the influence of the drop 6b from the height distribution that includes the influence of the drop 6b based on the drop configuration information and the drop height information (step S51). For example, the height of the range indicated by the drop configuration information within the height distribution that includes the influence of the drop 6b is increased by the height indicated by the drop height information. Furthermore, necessary shape completion using a high-order polynomial or the like may be performed.

[0065] After calculating the height distribution without the influence of the step 6b, Figure 3 The same steps are performed after step S6.

[0066] According to the second embodiment, the focusing diagram is calculated by calculating the height distribution after removing the influence of the step portion 6b, and merging the step portion configuration information and the step portion height information into the calculated height distribution. As in the first embodiment, the pattern can be depicted with high precision regardless of the surface shape of the substrate 6.

[0067] (Third embodiment) Next, refer to Figure 12A and Figure 12B , a third embodiment in which a focus map is calculated taking the inclined portion into consideration will be described. Figure 12A It is used to illustrate the drawing method in the third embodiment. Figure 3 The flowchart is an explanatory diagram of the steps of generating surface shape data. Figure 12B This is an explanatory diagram for explaining an example of calculating the inclination angle and inclination direction of the inclined portion in the drawing method according to the third embodiment.

[0068] In the third embodiment, the surface shape data 8 includes the tilt portion configuration information, tilt angle information, and tilt direction information. The tilt portion configuration information is information indicating the configuration state of the tilt portion on the surface of the substrate 6. Figure 12A As shown in FIG, the tilt angle information is information indicating the tilt angle θ of the tilt portion. The tilt direction information is information indicating the direction of the tilt portion. More specifically, Figure 12A In the example shown, the tilt direction information is information representing the direction in which the height of the tilt portion decreases in two dimensions, expressed as an angle with respect to the two-dimensional reference direction d2. Figure 12A The inclined portion C1 shown in the figure has an inclined direction of 0 degrees because the two-dimensional direction in which the height of the inclined portion C1 decreases coincides with the reference direction d2. Figure 12A The inclined portion C4 shown has an inclined direction of 180 degrees because the two-dimensional direction in which the height of the inclined portion C4 decreases is opposite to the reference direction d2.

[0069] In the third embodiment, the computer 2 calculates a focus map by combining the drop configuration information and drop height information with the slope configuration information, slope angle information, and slope direction information in the height distribution. Specifically, the computer 2 calculates the focus map by reducing the height of the range indicated by the drop configuration information in the height distribution by the height indicated by the drop height information, and further reducing the height of the range indicated by the slope configuration information by the height indicated by the slope angle information and slope direction information.

[0070] Figure 12BThis is a diagram for explaining an example of calculating the tilt angle and tilt direction of the tilt portion in the drawing method of the third embodiment. When the surface shape data 8 does not include tilt angle information and tilt direction information, the computer 2 can calculate the tilt angle and tilt direction of the tilt portion based on the tilt portion configuration information and the step height information, and calculate the focus map using the calculated tilt angle and tilt direction. For example, Figure 12B As shown, the tilt angle θ and the tilt direction d3 can also be calculated based on the X coordinate (x1) and Z coordinate (z1) of the lower end of the tilt portion and the X coordinate (x2) and Z coordinate (z2) of the upper end of the tilt portion shown in the tilt portion configuration information and height information. Figure 12B In the example shown, the inclination angle θ is the inverse tangent (tan) of the slope (z2-z1) / (x2-x1) of the linear function connecting the coordinates of the lower end (x1, z1) and the upper end (x2, z2) of the inclined portion. -1 ). In addition, Figure 12B In the example shown, the tilt direction d3 is a direction from x2 toward x1 in which the Z value of the linear function decreases.

[0071] According to the third embodiment, by calculating a focus map that takes into account not only the stepped portion but also the inclined portion, a pattern can be drawn with high accuracy regardless of the presence or absence of the stepped portion and the inclined portion.

[0072] (Master Manufacturing Method) Figures 3 to 12B The drawing method of the embodiment described can be used to manufacture a master. Hereinafter, as a master manufacturing method to which the drawing method of the embodiment is applied, an embodiment of a method for manufacturing a photomask and an embodiment of a method for manufacturing a template will be described in order.

[0073] Figure 13A 1 is a cross-sectional view showing a method for manufacturing a photomask according to an embodiment of the present invention. Figure 13A As shown, in Figure 2A The photoresist film 9 is formed on the mask blank 6A. The formation of the photoresist film 9 includes coating the photoresist film 9 and pre-baking after coating. Figure 13A In the example shown, the photoresist film 9 is a positive type. The photoresist film 9 may also be a negative type.

[0074] Figure 13B Then Figure 13A A cross-sectional view showing a method for manufacturing a photomask according to an embodiment of the present invention. Figure 13B As shown, the electron beam EB having the beam focus value determined by the drawing method of the embodiment is irradiated by the drawing apparatus 1. As a result, the portion of the photoresist film 9 irradiated with the electron beam EB is exposed.

[0075] Figure 13C Then Figure 13BA cross-sectional view showing a method for manufacturing a photomask according to an embodiment of the present invention. After the photoresist film 9 is exposed and the exposed photoresist film 9 is post-dried, Figure 13C As shown, the photoresist film 9 is developed. The development of the photoresist film 9 is performed by a wet process using a chemical solution. The exposed portion of the photoresist film 9 is removed by the development, and the light shielding film 62 is partially exposed at the position where the photoresist film 9 is removed.

[0076] Figure 13D Then Figure 13C A cross-sectional view showing a method for manufacturing a photomask according to an embodiment of the present invention: After developing the photoresist film 9, the developed photoresist film 9 is used as a mask to etch (ie, process) the light shielding film 62. The etching is performed by a dry process.

[0077] Figure 13E Then Figure 13D A cross-sectional view showing a method for manufacturing a photomask according to an embodiment of the present invention. Figure 13E As shown, the photoresist film 9 is removed. Thus, a photomask 60A can be obtained.

[0078] Figures 14A to 14E 1 is a cross-sectional view showing a method for manufacturing the template 60B according to the embodiment. Figures 14A to 14E As shown, the method for manufacturing the template 60B is basically the same as the method for manufacturing the photomask 60A. The method for manufacturing the template 60B differs from the method for manufacturing the photomask 60A in that the object to be processed by etching is the template blank 6B instead of the light shielding film 62.

[0079] The method for manufacturing photomask 60A and template 60B according to the embodiment enables high-precision patterning regardless of the substrate surface shape. By applying photomask 60A and template 60B, which have been patterned with high precision, to semiconductor processes, patterns of precise dimensions can be formed on device substrates with surface elevations or inclinations, enabling the appropriate manufacture of semiconductor devices.

[0080] Figure 1 At least a portion of the computer 2 shown may be composed of hardware or software. In the case of being composed of software, a program that implements at least a portion of the functions of the computer 2 may be stored in a recording medium such as a floppy disk or a CD-ROM (Compact Disk-Read Only Memory), and the computer may read and execute the program. The recording medium is not limited to removable media such as a disk or an optical disk, but may also be a fixed recording medium such as a hard disk device or a memory. In addition, the program that implements at least a portion of the functions of the computer 2 may be distributed via a communication line such as the Internet (including wireless communication). In addition, the same program may be distributed via a wired line such as the Internet or a wireless line, or stored in a recording medium, in a state where the program is encrypted, modulated, or compressed.

[0081] While several embodiments have been described above, these embodiments are provided as examples and are not intended to limit the scope of the invention. The novel devices and methods described in this specification can be implemented in various other ways. Furthermore, various omissions, substitutions, and modifications may be made to the devices and methods described in this specification without departing from the spirit of the invention. The scope of the appended claims and their equivalents are intended to encompass such aspects and variations as fall within the scope and spirit of the invention.

[0082] (Supplementary Notes) (1) A drawing method comprising: obtaining step configuration information indicating a configuration state of a step portion of a substrate; obtaining step height information indicating a height of the step portion; measuring the height of the substrate; calculating a focus map indicating a distribution of beam focus values of an electron beam corresponding to a drawing position of the substrate based on the obtained step configuration information and step height information and the measured height; and drawing a pattern on the substrate using an electron beam having a beam focus value determined based on the calculated focus map. (2) The drawing method according to (1), wherein the height measurement is performed without the step portion, and the calculation of the focus map comprises: calculating a height distribution indicating a distribution of the height of the substrate based on the height measured excluding the step portion, and adding the step configuration information and the step height information to the calculated height distribution. (3) The drawing method according to (1), wherein the height is measured including the step portion, and the calculation of the focus map includes calculating a first height distribution representing the distribution of the height of the substrate based on the height measured including the step portion, calculating a second height distribution by removing the influence of the height of the step portion from the calculated first height distribution, and adding the step portion configuration information and the step portion height information to the calculated second height distribution. (4) The drawing method according to any one of (1) to (3), further including obtaining tilt portion configuration information representing the configuration state of the tilt portion of the substrate, and calculating the tilt angle and tilt direction of the tilt portion based on the obtained tilt portion configuration information and the step portion height information. (5) The drawing method according to any one of (1) to (3), further including obtaining tilt angle information representing the tilt angle of the tilt portion of the substrate, and obtaining tilt direction information representing the tilt direction of the tilt portion. (6) The drawing method according to any one of (1) to (5), wherein the drawing of the pattern includes extending the beam adjustment time at a portion where the beam focus value changes significantly compared to a portion where the beam focus value changes slightly. (7) The drawing method according to any one of (1) to (6), wherein the drawing of the pattern includes delaying the movement time of the stage on which the substrate is mounted at a portion where the beam focus value changes significantly compared to a portion where the beam focus value changes slightly. (8) The drawing method according to any one of (1) to (7), wherein the drawing of the pattern is performed sequentially starting from a portion where the beam focus value changes slightly. (9) The drawing method according to (4) or (5), wherein the inclined portion has an inclined flat surface. (10) The drawing method according to (4) or (5), wherein the inclined portion has an inclined curved surface. (11) A master plate manufacturing method comprising forming a pattern on a substrate using the drawing method according to any one of (1) to (10).(12) The master manufacturing method according to (11), further comprising forming a photoresist film on the substrate, wherein measuring the height of the substrate is measuring the surface height of the photoresist film, and the pattern is drawn on the photoresist film. (13) The master manufacturing method according to (12), further comprising developing the photoresist film on which the pattern is drawn, processing the substrate using the developed photoresist film as a mask, and removing the photoresist film from the processed substrate. (14) The master manufacturing method according to any one of (11) to (13), wherein the master is a photomask. (15) The master manufacturing method according to any one of (11) to (13), wherein the master is a template for nanoimprint lithography. (16) A drawing method comprising: an acquiring unit for acquiring step portion configuration information indicating a configuration state of a step portion of a substrate and step portion height information indicating a height of the step portion; a measuring unit for measuring the height of the substrate; a calculating unit for calculating a focusing map indicating a distribution of beam focusing values of an electron beam corresponding to a drawing position of the substrate based on the acquired step portion configuration information and step portion height information and the measured height; and a drawing unit for drawing a pattern on the substrate using an electron beam having a beam focusing value determined based on the calculated focusing map.

Claims

1. A drawing method, comprising: obtaining step portion configuration information indicating a configuration state of a step portion of a substrate; obtaining step portion height information indicating a height of the step portion; measuring the height of the substrate; calculating a focus map indicating a distribution of beam focus values of an electron beam corresponding to a drawing position of the substrate based on the obtained step portion configuration information and step portion height information and the measured height; and drawing a pattern on the substrate using an electron beam having a beam focus value determined based on the calculated focus map; wherein The height is measured including the step portion, and The focus map is calculated as: calculating a first height distribution indicating a distribution of the height of the substrate based on the height measured including the stepped portion, calculating a second height distribution from the calculated first height distribution based on the acquired step arrangement information and step height information, removing the influence of the step height; The step arrangement information and the step height information are added to the calculated second height distribution.

2. The drawing method according to claim 1 further comprises obtaining inclined portion configuration information indicating a configuration state of the inclined portion of the substrate, and calculating an inclination angle and an inclination direction of the inclined portion based on the obtained inclined portion configuration information and the step portion height information. 3 . The drawing method according to claim 1 , further comprising acquiring tilt angle information indicating a tilt angle of the tilted portion of the substrate, and acquiring tilt direction information indicating a tilt direction of the tilted portion. 4 . The drawing method according to claim 1 , wherein drawing the pattern includes extending a beam adjustment time at a portion where a change in the beam focus value is large compared to a portion where a change in the beam focus value is small.

5. The drawing method according to any one of claims 1 to 3, wherein the drawing of the pattern includes delaying the movement time of the stage on which the substrate is mounted at a portion where the beam focus value changes more significantly than at a portion where the beam focus value changes less significantly. 6 . The drawing method according to claim 1 , wherein the drawing of the pattern is performed sequentially starting from a portion where a change in the beam focus value is smaller.

7. A method for manufacturing a master, comprising forming a pattern on a substrate using the writing method according to any one of claims 1 to 6.

8. A drawing device comprising: an acquisition unit for acquiring step portion configuration information indicating a configuration state of a step portion of a substrate and step portion height information indicating the height of the step portion; a measurement unit for measuring the height of the substrate; a calculation unit for calculating a focus map indicating a distribution of beam focusing values of an electron beam corresponding to a drawing position of the substrate based on the acquired step portion configuration information and step portion height information and the measured height; and a drawing unit for drawing a pattern on the substrate using an electron beam having a beam focusing value determined based on the calculated focus map; wherein The measuring portion measures the height including the step portion, and The calculation unit calculates a first height distribution representing the distribution of the height of the substrate based on the height measured including the step portion, calculates a second height distribution by removing the influence of the height of the step portion from the calculated first height distribution based on the acquired step portion configuration information and step portion height information, and adds the step portion configuration information and the step portion height information to the calculated second height distribution, thereby calculating the focusing map.

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