Imprinting apparatus, imprinting method, and article manufacturing method

Abstract

To provide a technique advantageous in terms of reducing the occurrence of pattern defects in an imprint device that performs imprint processing on a molding area on a substrate in which an imprint material is supplied to an adjacent area.SOLUTION: An imprint device performs processing of bringing a mold and an imprint material on a substrate into contact with each other to mold a pattern of the imprint material, on a target area that is a partial molding area of a plurality of molding areas on the substrate to which the imprint material is supplied. The imprint device comprises: an irradiation unit that irradiates the imprint material in the target area with light with the mold and an uncured imprint material in the target area in contact with each other; an adjustment unit that adjusts the concentration of a first gas for inhibiting curing of the imprint material in a mixed gas supplied from the supply unit; and the supply unit that brings the mold and the imprint material in the target area into contact with each other, and supplies the mixed gas adjusted by the adjustment unit to an imprint material outside the target area with the irradiation unit irradiating the imprint material with light.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to an imprint apparatus, an imprint method, and an article manufacturing method. [Background technology]

[0002] Imprint technology is a technology that enables the transfer of nanoscale fine patterns, and is being put to practical use as one of the nanolithography techniques for the mass production of magnetic storage media and semiconductor devices. In imprint technology, a mask on which a fine pattern is formed is used as a master to form a fine pattern on a wafer such as a silicon wafer or a glass plate. This fine pattern is formed by applying a resin (composition) onto the wafer, and then photocuring the resin while the mask pattern is pressed against the wafer via the resin.

[0003] Recently, in order to improve productivity, a method has been proposed in which resin is dispensed in advance onto multiple shot areas (molding areas) on a wafer, and then imprint processing is performed on each shot area in turn, or a method in which resin is spin-coated onto a wafer in advance. Either method aims to improve productivity by reducing the number of times the wafer travels back and forth to a dispenser that applies the resin.

[0004] In these methods, resin is also applied to the shot area adjacent to the shot area where the imprinting process is performed. When the resin on the wafer hardens, radicals generated by irradiation with light photopolymerize the resin, leading to hardening. However, the generated radicals are trapped by oxygen, and the photopolymerization reaction is hindered in an oxygen atmosphere. This phenomenon is known as oxygen inhibition. Patent Document 1 discloses an exposure apparatus that utilizes this phenomenon and performs exposure by blowing gas with a controlled oxygen concentration onto the resist to adjust the degree of hardening. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6099969 Summary of the Invention [Problem to be solved by the invention]

[0006] In an imprint apparatus, as a measure against air bubble defects, it is necessary to saturate the gap between the mask and the wafer with a gas that promotes the filling of the resin, which is highly soluble or highly diffusible in the resin, or both, such as helium. Because these gases do not contain oxygen, the resin supplied to the aforementioned adjacent shot regions may harden due to irradiation light, which may cause pattern defects in the adjacent shot regions.

[0007] Therefore, the present invention aims to provide a technology that is advantageous in reducing the occurrence of pattern defects, for example, in an imprinting apparatus that performs an imprinting process on a molding area on a substrate to which imprinting material is supplied to adjacent areas. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides a method for manufacturing a substrate by contacting a mold with an imprint material on a substrate, the imprint material being To Pattern formation vinegar Rui An imprinting device, comprising: The imprint material forming the pattern Target area In the region An irradiation unit that irradiates light; ,before In a state where the light is irradiated by the irradiation unit, Not a target area The imprint material a first gas that inhibits hardening of the imprint material toward the Supplying mixed gas R The payroll department and an adjusting unit for adjusting a concentration of the first gas contained in the mixed gas; The adjustment unit adjusts the concentration of the first gas based on the amount of light irradiated to the imprint material outside the target area when the irradiation unit irradiates light to the imprint material in the target area. Effect of the Invention

[0009] According to the present invention, for example, in an imprinting apparatus that performs an imprinting process on a molding area on a substrate to which imprinting material is supplied in an adjacent area, a technology can be provided that is advantageous in terms of reducing the occurrence of pattern defects. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic diagram showing a configuration example of a film forming apparatus according to a first embodiment. [Diagram 2] FIG. 1 is a diagram illustrating a problem that occurs when a curable composition is disposed in adjacent molding regions. [Diagram 3] 2 is a schematic diagram showing a configuration example of a gas nozzle and its periphery according to the first embodiment. FIG. [Figure 4] 11A and 11B are schematic diagrams illustrating a method for measuring illuminance outside a target area. [Diagram 5] 1 is a schematic diagram showing an example of an illuminance distribution in a target area and its surroundings; [Figure 6] 1 is a flowchart showing an example of a method for understanding the relationship between the curing of a curable composition, illuminance, and oxygen concentration. [Figure 7] FIG. 13 is a diagram illustrating an example of the relationship between the integrated light amount, the oxygen concentration, and whether or not the adjacent region is cured. [Figure 8] 4 is a flowchart showing an example of a mixed gas supply process according to the first embodiment. [Figure 9] 11A to 11C are schematic views illustrating an imprint process according to a second embodiment. [Figure 10] 13 is a schematic diagram showing an example of the configuration of a gas nozzle and its periphery according to a third embodiment. FIG. [Figure 11] 1A to 1C are diagrams for explaining a method for manufacturing an article. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In each drawing, the same reference numerals are used to refer to the same components, and duplicated explanations will be omitted.

[0012] First Embodiment FIG. 1 is a schematic diagram showing a configuration example of the film-forming apparatus IMP of the first embodiment. The film-forming apparatus IMP performs a process of contacting a plurality of droplets of the curable composition IM arranged on a substrate S with a mold M to form a film of the curable composition IM in the space between the substrate S and the mold M. Here, the substrate S and the mold M can be interchanged, and a plurality of droplets of the curable composition IM arranged on the mold M may be contacted with the substrate S to form a film of the curable composition IM in the space between the mold M and the substrate S. Therefore, more comprehensively, the film-forming apparatus IMP is an apparatus that performs a process of contacting a plurality of droplets of the curable composition IM arranged on a first member with a second member to form a film of the curable composition IM in the space between the first member and the second member. In the following, an example in which the film-forming apparatus IMP is an imprint apparatus, the first member is the substrate S, and the second member is the mold M will be described, but the first member may be the mold M and the second member may be the substrate S. In this case, the substrate S and the mold M in the following description may be interchanged.

[0013] In the imprinting apparatus, a mold M having a pattern can be used to transfer the pattern of the mold M to the curable composition IM on the substrate S. In the imprinting apparatus, a mold M having a pattern region PR on which a pattern is provided can be used. In the imprinting apparatus, the curable composition IM on the substrate S is brought into contact with the pattern region PR of the mold M, the curable composition is filled in the space between the region (molding region) of the substrate S where the pattern is to be formed and the mold M, and then the curable composition IM can be cured. As a result, the pattern of the pattern region PR of the mold M is transferred to the curable composition IM on the molding region of the substrate S. In this specification, the pattern transfer process to the molding region is referred to as an imprinting process. In the imprinting apparatus, for example, the imprinting process is performed on each of a plurality of molding regions (also called shot regions) of the substrate S, and a pattern made of a cured product of the curable composition IM can be formed on each molding region.

[0014] As the curable composition, a material that is cured by applying energy for curing may be used. The curable composition may also be called a resin in an uncured state. The curable composition used in the imprinting process may also be called an imprint material. As the energy for curing, electromagnetic waves, heat, etc. may be used. The electromagnetic waves may be, for example, light having a wavelength selected from the range of 10 nm to 1 mm, such as infrared rays, visible light, and ultraviolet rays. The curable composition may be a composition that is cured by irradiation with light or by heating. Among these, the photocurable composition that is cured by irradiation with light contains at least a polymerizable compound and a photopolymerization initiator, and may further contain a non-polymerizable compound or a solvent as necessary. The non-polymerizable compound is at least one selected from the group consisting of a sensitizer, a hydrogen donor, an internal mold release agent, a surfactant, an antioxidant, and a polymer component. The viscosity (viscosity at 25° C.) of the curable composition may be, for example, 1 mPa·s to 100 mPa·s. Examples of the material of the substrate include glass, ceramics, metals, semiconductors, and resins. If necessary, a member made of a material different from that of the substrate may be provided on the surface of the substrate. The substrate may be, for example, a silicon wafer, a compound semiconductor wafer, or quartz glass.

[0015] In this specification and the accompanying drawings, directions are shown in an XYZ coordinate system in which the direction parallel to the surface of the substrate S is the XY plane. The directions parallel to the X-axis, Y-axis, and Z-axis in the XYZ coordinate system are the X direction, Y direction, and Z direction, respectively, and the rotation around the X-axis, the Y axis, and the Z axis are θX, θY, and θZ, respectively. Control or drive regarding the X-axis, Y-axis, and Z-axis means control or drive regarding the direction parallel to the X-axis, the direction parallel to the Y axis, and the direction parallel to the Z axis, respectively. Furthermore, control or drive regarding the θX-axis, θY-axis, and θZ-axis means control or drive regarding the rotation around an axis parallel to the X-axis, the rotation around an axis parallel to the Y axis, and the rotation around an axis parallel to the Z axis, respectively. Furthermore, the position is information that can be specified based on the coordinates of the X-axis, Y-axis, and Z-axis, and the orientation is information that can be specified by the values ​​of the θX-axis, θY-axis, and θZ-axis. Positioning means controlling the position and / or orientation.

[0016] The film forming apparatus IMP may include a substrate holder SH for holding the substrate S, a substrate driving mechanism SD for driving the substrate S by driving the substrate holder SH, and a support base SB for supporting the substrate driving mechanism SD. A part of the substrate holder SH includes an illuminance measuring unit DM for measuring illuminance. The film forming apparatus IMP may also include a mold holder MH for holding the mold M, and a mold driving mechanism MD for driving the mold M by driving the mold holder MH. The substrate driving mechanism SD and the mold driving mechanism MD may constitute a relative driving mechanism for driving at least one of the substrate driving mechanism SD and the mold driving mechanism MD so that the relative position between the substrate S and the mold M is adjusted. The adjustment of the relative position by the relative driving mechanism may include contact between the curable composition IM on the substrate S and the mold M, and driving for separation of the mold M from the cured curable composition IM. The adjustment of the relative position by the relative driving mechanism may also include alignment between the substrate S and the mold M. The substrate driving mechanism SD can be configured to drive the substrate S about multiple axes (e.g., three axes, namely, the X-axis, the Y-axis, and the θZ-axis, and preferably, six axes, namely, the X-axis, the Y-axis, the Z-axis, the θX-axis, the θY-axis, and the θZ-axis). The mold driving mechanism MD can be configured to drive the mold M about multiple axes (e.g., three axes, namely, the Z-axis, the θX-axis, and the θY-axis, and preferably, six axes, namely, the X-axis, the Y-axis, the Z-axis, the θX-axis, the θY-axis, and the θZ-axis).

[0017] The film-forming apparatus IMP may include a curing unit CU (irradiation unit) for curing the curable composition IM filled between the substrate S and the mold M in a state where the substrate S and the mold M are in contact with each other. The curing unit CU may irradiate the curable composition IM with curing energy through the mold M in a state where the mold M is in contact with the uncured curable composition IM on the substrate, thereby curing the curable composition IM. In the present embodiment, as an example, light is used as the curing energy. The film-forming apparatus IMP may include a transparent member TR for forming a space SP on the back side (opposite side of the surface facing the substrate S) of the mold M. The transparent member TR is made of a material that transmits the curing energy from the curing unit CU, thereby enabling irradiation of the curing energy to the curable composition IM. The film-forming apparatus IMP may include a pressure control unit PC for controlling the deformation of the mold M in the Z-axis direction by controlling the pressure of the space SP. For example, the pressure control unit PC may increase the pressure of the space SP above atmospheric pressure, so that the mold M may be deformed into a convex shape toward the substrate S.

[0018] The film-forming apparatus IMP may include a dispenser DSP for placing, supplying, or distributing the curable composition IM on the substrate S. The curable composition IM is placed in an area larger than the pattern area PR of the mold M. The film-forming apparatus IMP may be supplied with the substrate S on which the curable composition IM is placed by another apparatus, in which case the dispenser DSP may not be provided in the film-forming apparatus IMP.

[0019] The film forming apparatus IMP may further include a control unit CTR that controls each part of the film forming apparatus IMP. The control unit CTR may include a processor such as a CPU as a computer, and a storage unit such as a RAM, a ROM, and a HDD. The processor executes a computer program stored in the storage unit to control the operation of the film forming apparatus IMP. The control unit CTR also sets imprint conditions, which will be described later.

[0020] The film formation apparatus IMP is equipped with a gas nozzle NZ (gas supply unit) so as to surround the mold M held by the mold holding unit MH. The gas nozzle NZ is divided into multiple units. In this embodiment, the gas nozzle NZ is divided into four units as an example, and only two units are shown in FIG. 1. The gas nozzle NZ can blow out (supply) gas to fill the space A between the mold M and the substrate S with a desired gas.

[0021] Incidentally, there are imprinting methods in which the curable composition IM is placed in advance in a plurality of molding regions on a substrate, and then the imprinting process is performed sequentially in each molding region, or a method of spin-coating the imprinting material on the substrate S using a separate device. In such imprinting methods, the imprinting material is also placed, supplied, or applied to a molding region adjacent to the molding region (target region) that is the subject of the imprinting process. This state is shown in FIG. 2. FIG. 2 is a diagram for explaining problems when the curable composition IM is placed in adjacent molding regions. In this figure, the circle indicates the curable composition IM placed on the substrate. Also, the rectangular frames indicate the molding regions R of the substrate. Here, the curable composition IM is previously supplied to the region for two shots. FIG. 2 shows the state where the imprinting process is performed on the molding region R1 on the right side and the light for curing is irradiated. That is, the molding region R1 is the region to be processed (target region).

[0022] At this time, there is no problem if the light for curing is irradiated only to the molding region R1, but in reality, as shown by the dashed line, the light may leak outside the molding region R1 to be processed. Hereinafter, the light for curing irradiated outside the molding region to be processed is called leakage light. For this reason, among the curable compositions IM supplied to the adjacent left molding region R2, the curable compositions IM hatched with diagonal lines, that is, the curable compositions IM in the region of the molding region R2 near the molding region R1, may be irradiated with leakage light and may be cured. In this case, when performing the imprint process on the molding region R2 after the mold release from the molding region R1, the imprint process is performed on the already cured curable composition IM, which may cause unfilled defects, poor imprinting, and in extreme cases, destruction of the mold.

[0023] In this embodiment, while the mold M is in contact with the curable composition IM on the target area and the curing unit CU is irradiating the curing light, a mixed gas containing a gas that inhibits the curing of the curable composition IM is supplied from the gas nozzle NZ to the curable composition IM outside the target area, thereby inhibiting the curing of the curable composition IM outside the target area, thereby reducing the occurrence of pattern defects.

[0024] The configuration of the gas nozzle NZ and piping leading to the gas nozzle NZ in this embodiment will be described with reference to Fig. 3. Fig. 3 is a schematic diagram showing an example of the configuration of the gas nozzle NZ and its periphery according to the first embodiment.

[0025] The gas nozzle NZ according to the first embodiment is divided into four, for example. The divided gas nozzles NZ01 to 04 are arranged so as to surround the mold M held by the mold holding part MH. The gas nozzles NZ are connected to individually adjustable flow rate regulators, and the flow rates are individually adjusted. In FIG. 3, only the gas nozzle NZ01 connected to the flow rate regulator 10 is illustrated, and the flow rate regulators connected to the gas nozzles NZ02 to 04 are omitted. The configuration of the flow rate regulators connected to the gas nozzles NZ02 to 04 is the same as that of the flow rate regulator 10. The flow rate regulator 10 includes a helium flow rate regulator 11 and an oxygen flow rate regulator 12. Here, helium is not limited to this, and may be any gas that promotes the filling of the curable composition IM. In addition, oxygen may be any gas that inhibits the curing of the curable composition IM, and may be a mixed gas containing a gas that inhibits the curing of the curable composition IM. Furthermore, the flow rate regulators 11 and 12 may be, for example, mass flow controllers, or may be a combination of a flow rate regulator valve and a mass flow meter.

[0026] The pipes connected to the flow rate regulators 11 and 12 join on the way to the gas nozzle NZ, and are connected to the gas nozzle NZ arranged to surround the mold M as described above. Helium and oxygen are mixed in the pipe after the joining, and a mixed gas is generated. Here, an oxygen concentration meter 20 (oxygen concentration measuring unit) is provided in a part of the pipe after a predetermined distance after the joining. The oxygen concentration of the mixed gas can be measured by this oxygen concentration meter 20. The flow rate regulator 10 can determine the flow rate ratio of helium and oxygen so that the value of this oxygen concentration meter 20 becomes a desired value. Alternatively, a helium concentration meter (helium concentration measuring unit) that measures the concentration of helium may be provided.

[0027] After the pipes connected to the flow rate regulators 11 and 12 join, for example, a tank with a larger cross-sectional area and increased volume than the pipes is placed, or a member with an increased volume by bending the pipes multiple times is placed. This configuration is preferable because it promotes mixing of helium and oxygen. If the oxygen concentration meter 20 is placed after the gas has passed through a member such as the tank, it is possible to reduce the concern that the oxygen concentration will be measured when there is a localized oxygen concentration distribution in the mixed gas.

[0028] Next, a method for measuring illuminance outside the target area will be described with reference to FIG. 4. FIG. 4 is a schematic diagram for explaining a method for measuring illuminance outside the target area. For example, the substrate holding unit SH that holds the substrate S is provided with an illuminance measuring unit DM at its end. The illuminance measuring unit DM has a sensor capable of measuring the illuminance at one point. This figure shows a state in which the substrate holding unit SH is moved so that the illuminance measuring unit DM is located at a position outside the pattern area PR of the mold M. At this position, light is irradiated from the curing unit CU and measured by the illuminance measuring unit DM, so that the illuminance outside the target area can be measured. By repeating the illuminance measurement while moving the substrate holding unit SH so as to change the position of the illuminance measuring unit DM little by little within the range outside the target area, the illuminance distribution in the measurement range outside the target area can be obtained as a measurement result. In other words, the illuminance measuring unit DM functions as a light quantity measuring unit.

[0029] This type of illuminance measurement is also performed to obtain the illuminance distribution within the molding area. Therefore, the illuminance measurement unit DM can use the sensor used to obtain the illuminance distribution within the molding area, and there is no need to provide a new measurement unit to measure outside the molding area. In addition, the illuminance distribution outside the target area obtained by another device with the same configuration may be used.

[0030] Figure 5 shows a schematic diagram of the illuminance distribution measured in this way. Figure 5 is a schematic diagram showing an example of the illuminance distribution in the target area and its surroundings. Figure 5 shows both the inside and outside of the target area. The square shown with a thick dashed line indicates the shaping area R1, which is the target area. In other words, the outside of the shaping area R1 corresponds to the outside of the target area. In this figure, the contour lines of the illuminance distribution are shown with dashed and dotted lines. Here, the maximum illuminance is set to 100%, and the ratio of the illuminance of each part to the maximum illuminance is shown.

[0031] Even outside the target area, a slight illuminance was measured, less than 10%, indicating the presence of light leakage. On the other hand, outside the target area, in the area outside the circular area corresponding to the opening of the mold holding part MH, the illuminance is 0%, since the curing light is almost entirely blocked by the mold holding part MH. For this reason, it is sufficient to include up to the opening of the mold holding part MH as the illuminance measurement range outside the target area.

[0032] As shown in FIG. 5, when there is light leakage outside the target area, if the oxygen concentration between the mold M and the substrate S is low, the curable composition IM outside the target area may be cured when light is irradiated after the mold M is brought into contact with the curable composition IM on the target area. In addition, if the illuminance of the leaking light is high, the concern that the curable composition IM outside the target area will be cured increases. For this reason, it is desirable to adjust the oxygen concentration in the space A between the mold M and the substrate S according to the illuminance outside the target area of ​​the leaking light, and suppress the curing of the curable composition IM outside the target area. More desirably, a mixed gas with an adjusted oxygen concentration is supplied to the curable composition IM outside the target area while the mold M is brought into contact with the curable composition IM in the target area and irradiated with light for curing.

[0033] Therefore, it is desirable to experimentally grasp in advance the range of illuminance and oxygen concentration outside the target area, where the curing of the curable composition IM in the molding area (adjacent area) adjacent to the target area does not occur. A method for grasping the relationship between the curing of the curable composition IM in the adjacent area and the illuminance and oxygen concentration outside the target area will be described with reference to the flowchart of FIG. 6. FIG. 6 is a flowchart showing an example of a method for grasping the relationship between the curing of the curable composition IM, the illuminance, and the oxygen concentration. Each operation (step) shown in this flowchart can be executed by the control of each part by the control unit CTR.

[0034] First, the illuminance measuring unit DM measures the illuminance outside the target area by the method described above, and measures the maximum illuminance outside the target area (S1). The light with the illuminance measured in S1 is irradiated onto the curable composition IM in the adjacent molding area for the duration of the light irradiation in the imprinting process. In other words, the light amount (integrated light amount) expressed by illuminance x irradiation time becomes the parameter.

[0035] Next, the control unit CTR determines the total number of conditions N (S2). In order to conduct experiments under multiple light intensity conditions, it is desirable to conduct experiments under multiple irradiation time conditions. If the illuminance can be easily changed, it is even more desirable to conduct experiments under multiple illuminance conditions. It is also desirable to conduct experiments under multiple oxygen concentration conditions. If multiple irradiation time conditions and multiple oxygen concentration conditions are used, the total number of conditions N is the number of irradiation time conditions multiplied by the number of oxygen concentration conditions. If multiple illuminance conditions are also used, the total number of conditions N is the sum of the number of illuminance conditions.

[0036] Thereafter, the control unit CTR sets the irradiation time and oxygen concentration of the recipe (imprint conditions) of the imprint device, which is the film forming device IMP (S3). At this time, if the illuminance can be easily changed in the film forming device IMP, the illuminance is also set.

[0037] Next, the dispenser DSP supplies the curable composition IM to the target area of ​​the substrate S and a molding area adjacent to the target area (S4).

[0038] Then, the control unit CTR controls each part of the film forming device IMP to perform imprint processing on the target area (S5). The imprint processing on the target area is performed according to the above-mentioned recipe in a state where the curable composition IM is placed (supplied) in the adjacent molding area.

[0039] Then, it is determined whether the curable composition IM in the adjacent molding region has cured (S6). This is repeated under multiple conditions in which the irradiation time of the curing light, the oxygen concentration, or the illuminance is changed, and the experiment is terminated when the total number of conditions N determined in advance is reached (S7).

[0040] Here, whether the curable composition IM in the adjacent region has cured or not may be judged by visual inspection or observation with an optical microscope. The cured curable composition IM will have an appearance change such as turning black, so this method can also be used to judge. Alternatively, the substrate S may be left for a while and then observed again. The cured curable composition IM will remain even after the passage of time, but the uncured curable composition IM will volatilize over time and will not remain. By observing this, it is also possible to judge whether the composition has cured or not.

[0041] Alternatively, when carrying out the above-mentioned experiment, the imprint process may be performed on the adjacent area in addition to the target area, and defects in the adjacent area may be observed. More specifically, the number of defects may be measured by a defect inspection device, and the defects in the adjacent area may be observed by a SEM (Scanning Electron Microscope). If the number of defects in the adjacent area is increased compared to the target area, it can be determined that the adjacent area has been cured. Furthermore, if the distribution is similar to or correlated with the illuminance distribution outside the target area, it can be more easily determined that the adjacent area has been cured. In addition, the defects in the adjacent area may be observed by SEM to check whether there is any sign of insufficient filling. For example, if the droplets of the curable composition IM are not crushed and there is any sign of insufficient filling, it can be determined that the adjacent area has been cured.

[0042] FIG. 7 is a diagram showing an example of the relationship between the accumulated light amount, the oxygen concentration, and whether or not the adjacent region is cured. Such a diagram can be obtained by an experiment of the flow shown in FIG. 6. The horizontal axis shows the accumulated light amount, and the vertical axis on the left shows the oxygen concentration. Here, the accumulated light amount is the amount of light represented by the maximum illuminance outside the target region x irradiation time, as described above. If it is determined that the curable composition IM in the adjacent region has cured, it is shown with an X, and if it is determined that it has not cured, it is shown with an ◯. As shown in FIG. 7, it can be seen that the higher the oxygen concentration and the smaller the accumulated light amount, the more difficult it is for the curable composition IM outside the target region to cure, and the lower the oxygen concentration and the larger the accumulated light amount, the more easily the curable composition IM outside the target region is cured. That is, it can be seen that the threshold value of the oxygen concentration for the accumulated light amount is approximately around the dashed line T1.

[0043] Usually, when performing imprint processing, the maximum illuminance outside the target area is determined by the device state, and the irradiation time is determined by the imprint conditions, so the integrated light amount is a known amount. Therefore, in order to prevent the curable composition IM on the adjacent molding area from curing, it is sufficient to set the mold M and the mixed gas with the oxygen concentration based on the relationship shown in Figure 7 to be supplied from the gas nozzle NZ. In this way, it is possible to reduce the curable composition IM supplied to the adjacent molding area from being cured by the irradiation light to the target area.

[0044] In FIG. 7, the horizontal axis is the integrated light amount expressed by the maximum illuminance outside the target area x the exposure time. However, the integrated light amount may be any amount expressed by the product of a function of the maximum illuminance outside the target area and the exposure time, for example, the square root of the maximum illuminance outside the target area x the exposure time. In this case, the horizontal axis should be changed to the integrated light amount expressed by the square root of the maximum illuminance outside the target area x the exposure time. Even with such a diagram, it is possible to determine the oxygen concentration conditions at which the adjacent area does not harden in the same way.

[0045] Moreover, the vertical axis on the right side of Fig. 7 indicates the helium concentration. In this embodiment, a gas mixture of helium and oxygen is blown (supplied) into the space A between the mold M and the substrate S, so the helium concentration is a value obtained by subtracting the oxygen concentration from 100%. In other words, the lower the oxygen concentration, the higher the helium concentration, and vice versa. For this reason, if the oxygen concentration is set too high to leave the curable composition IM in the adjacent molding region uncured, the helium concentration will be low, increasing the possibility of unfilled defects occurring in the target region.

[0046] Therefore, in an experiment to create a diagram as shown in FIG. 7 showing the relationship between the accumulated light amount, the oxygen concentration, and the curable composition IM in the adjacent molding region, it is desirable to measure the number of unfilled defects in the target region in addition to judging whether the curable composition IM in the adjacent region is cured. Since the imprint process on the target region has already been performed to judge whether the adjacent region is cured, there is no need to perform an additional experiment. The helium concentration region T2 in which the measured number of unfilled defects is below an allowable threshold is shown by hatching in FIG. 7. The occurrence of unfilled defects can be reduced by determining the helium concentration so that the helium concentration is not below the threshold, in other words, by determining the helium ratio so that the ratio of helium in the mixed gas is not below the threshold. Furthermore, since the occurrence of curing in the adjacent region can be reduced in the region above the dashed line T1, that is, if the oxygen concentration in the mixed gas is above the threshold, the oxygen concentration can be specified within a range that satisfies this.

[0047] In creating a diagram showing the relationship between the cumulative light amount, the oxygen concentration, and whether or not the adjacent region is cured, which corresponds to FIG. 7, if the process conditions such as RLT (Residual Layer Thickness) and the thickness of the base film of the substrate are different, it is desirable to create the diagram again. It is possible that the oxygen contained in the curable composition IM itself or the oxygen contained in the base film applied to the substrate may affect the curing or uncuring due to the leakage of light into the curable composition IM in the adjacent region. It is expected that the amount of this oxygen is greater when the amount of the curable composition IM is large, that is, when the RLT is thick or the base film is thick. For this reason, if these base layers change, there is a concern that the judgment of whether the curable composition IM in the adjacent molding region is cured or uncured will also change. For this reason, it is desirable to create a diagram showing the relationship between the cumulative light amount, the oxygen concentration, and whether or not the adjacent molding region is cured again. That is, it is more desirable to determine the oxygen concentration based on the thickness of the base layer.

[0048] In addition, the concentration of oxygen may be changed to a higher concentration after the curable composition IM is mixed with the mold M and the target area, and the filling of the concave and convex portions of the pattern area PR of the mold M with the curable composition IM is completed. Then, while the curable composition IM on the target area is irradiated with light by the curing unit CU, oxygen having a higher concentration than the gas filled in the space A before the mold M comes into contact with the curable composition IM on the target area is sprayed onto the curable composition IM outside the target area. By adopting such a configuration, the curing of the curable composition IM in the adjacent area can be further reduced. This process will be described with reference to the flowchart of FIG. 8.

[0049] 8 is a flowchart showing an example of a mixed gas supply process according to the first embodiment. Each operation (step) shown in this flowchart can be executed by the control of each part by the control unit CTR.

[0050] First, the flow rate adjusting unit 10 determines the oxygen concentration of the mixed gas to be supplied based on the amount of light irradiated outside the target area when the curing unit CU irradiates light onto the curable composition IM in the target area (S101).

[0051] Next, the dispenser DSP supplies the curable composition IM to a plurality of molding areas including the target area and adjacent areas of the substrate S (S102).

[0052] Then, the substrate S is moved by the substrate driving mechanism SD so that the target area of ​​the substrate S is positioned under the pattern area PR of the mold M (S103).

[0053] Next, a first mixed gas containing oxygen at a concentration adjusted based on the amount of light irradiated outside the target region is supplied from the gas nozzle NZ to the space A between the mold M and the substrate S (S104).

[0054] When filling of the first mixed gas into the space A is completed (S105, Yes), the mold M is moved in the -Z direction by the mold driving mechanism MD, and the curable composition IM on the target area of ​​the substrate S is brought into contact with the pattern region PR (S106). At this time, the substrate S may be moved in the +Z direction, or both the mold M and the substrate S may be moved. Then, the curable composition IM is filled into the uneven portion of the pattern region PR of the mold M (S107).

[0055] When filling of the curable composition IM into the uneven portion of the pattern region PR is completed (S108, Yes), the curing unit CU irradiates the curable composition IM in the target region with light for curing. At this time, the second mixed gas adjusted by the flow rate adjustment unit 10 is supplied to the curable composition IM outside the target region (S109). The oxygen concentration in the second mixed gas may be the same as the oxygen concentration in the first mixed gas, or may be higher than the oxygen concentration in the first mixed gas.

[0056] Next, the mold M is moved in the +Z direction by the mold driving mechanism MD, and the mold M is separated (released) from the cured curable composition IM (S110).

[0057] Then, the control unit CTR judges whether there is another molding area to which the curable composition IM has been supplied (S111). If there is another molding area to which the curable composition IM has been supplied (Yes), the processes of S103 to S111 are repeated. If there is no other molding area to which the curable composition IM has been supplied (No), the control unit CTR judges whether there is an unprocessed molding area to which the imprint process has not been performed (S112). If there is an unprocessed molding area (Yes), A curable composition IM is supplied to an unprocessed region by a dispenser DSP (S102), and the processes of S103 to S111 are repeated until the imprint process is completed on all molding regions of the substrate S.

[0058] As described above, according to this embodiment, even when performing an imprint process on a target area to which the curable composition IM is supplied in an adjacent area, it is possible to reduce the hardening of the curable composition IM in the adjacent area, thereby reducing the occurrence of pattern defects.

[0059] <Second embodiment> Next, an imprinting apparatus according to a second embodiment will be described with reference to FIG. 9. FIG. 9 is a schematic diagram for explaining an imprinting process according to the second embodiment. In the second embodiment, a process for imprinting a partial field (hereinafter referred to as PF) will be described. The multiple molding regions of the substrate S may include a molding region (full field (hereinafter referred to as FF)) arranged in the center of the substrate S, and a molding region (partial field) arranged in the peripheral portion of the substrate S so as to include the edge (rim) of the substrate S and partially missing. The PF is also called a missing region or partial region, and has a smaller area than the full field. When performing an imprinting process on the PF, only a portion of the pattern region PR of the mold M comes into contact with the curable composition IM on the molding region.

[0060] The substrate holding part SH has a surface that is approximately the same height as the surface of the substrate S held by the substrate holding part SH on the side where the curable composition IM is placed. However, this surface is not exactly the same height as the surface of the substrate S held by the substrate holding part SH, but is slightly lower than the surface of the substrate S held by the substrate holding part SH. For this reason, when performing imprint processing on the PF, the volume of the space A between the mold M and the substrate S and the substrate holding part SH becomes larger than when performing imprint processing on the FF, i.e., compared to the first embodiment.

[0061] Therefore, even if the mixed gas of helium and oxygen with the same concentration and flow rate as that in the case of performing imprint processing is supplied from the gas nozzle NZ to the FF, there is a concern that the concentration of helium and oxygen in the space A will differ from the concentration blown out from the gas nozzle NZ. As shown by the wavy line in Fig. 9, this is because the gas remaining in the area where there is a difference in height between the surface of the side of the substrate S facing the mold M and the surface of the substrate holder SH corresponding to the mold M will flow into the space A between the mold M and the substrate S. For this reason, even if the oxygen concentration conditions are such that unfilled defects or adjacent shot hardening do not occur in the FF, there is a concern that unfilled defects or adjacent shot hardening may occur in the PF.

[0062] Therefore, the flow rate adjusting unit 10 changes the flow rates of oxygen and helium while maintaining the ratio of the mixed gas. Specifically, when the target area is PF, a mixed gas of helium and oxygen with the same concentration as when the target area is FF may be supplied from the gas nozzle NZ at a flow rate higher than when the target area is FF, preferably at a sufficiently high flow rate. Here, a sufficiently high flow rate is a flow rate increased to be equal to or higher than the ratio of the volume of the space A between the mold M and the substrate S when the target area is FF to the volume of the space A between the mold M and the substrate S and the substrate holder SH when the target area is PF. For example, when the volume of the space A between the mold M and the substrate S and the substrate holder SH when the target area is PF is 1.5 times the volume of the space A between the mold M and the substrate S when the target area is FF, the flow rates of oxygen and helium to be supplied are also increased to 1.5 times.

[0063] In this way, even if the target region is a PF, the concentrations of helium and oxygen in the space A will be the same as the concentrations of helium and oxygen blown out from the gas nozzle NZ. Therefore, even in the PF, the occurrence of pattern defects can be reduced.

[0064] As shown in FIG. 9, an oxygen concentration meter OS (oxygen concentration measuring unit) may be provided around the substrate S of the substrate holder SH, in other words, at a position close to the edge of the substrate S. When the target area is FF, there is a concern that the oxygen concentration in the space A may not be measured correctly because the distance from the oxygen concentration meter OS to the space A is long when the target area is FF. On the other hand, when the target area is PF, the distance between the oxygen concentration meter OS and the space A becomes short during the imprint process, so that the oxygen concentration in the space A can be measured more accurately. In order to make the oxygen concentration meter OS reach the desired oxygen concentration, the flow rate of the mixed gas may be changed without changing the concentration of the mixed gas, that is, while maintaining the mixture ratio of oxygen in the mixed gas. This makes it possible to more reliably confirm that the oxygen concentration in the space A when performing the imprint process in the PF is the desired concentration, and the imprint process can be performed well even in the PF. <Third embodiment>

[0065] Next, an imprint apparatus according to a third embodiment will be described with reference to Fig. 10. Fig. 10 is a schematic diagram showing a configuration example of a gas nozzle NZ and its periphery according to the third embodiment. The flow rate adjustment unit 30 of this embodiment differs from the imprint apparatuses of the first and second embodiments in that it is capable of supplying CDA (clean dry air) instead of oxygen, as shown in Fig. 10.

[0066] CDA is readily available in clean rooms in semiconductor factories. It is a mixture of nitrogen and oxygen in a ratio of approximately 8:2, similar to normal air. Therefore, in a configuration similar to that of the first and second embodiments, as shown in FIG. 10, the mixed gas can be supplied after determining the flow rate ratio of the mixed gas of helium gas and CDA using an oxygen concentration meter. However, since CDA contains 80% nitrogen, it is necessary to lower the concentration of helium gas in order to achieve the same oxygen concentration as when oxygen gas is flowed alone. CDA is extremely inexpensive compared to oxygen gas, so it is advantageous in terms of cost compared to using oxygen gas.

[0067] Alternatively, instead of CDA, a mixed gas of helium and oxygen, or a mixed gas of helium, nitrogen, and oxygen may be supplied. Since oxygen gas has a combustion-supporting property, it is not necessarily easy to handle it alone. By supplying a mixed gas in which oxygen concentration has been reduced by mixing it with helium gas in advance in this way, handling becomes easier than handling oxygen gas alone. Furthermore, compared to supplying CDA, there is less concern about the concentration of helium gas decreasing, and therefore there is less concern about unfilled defects.

[0068] <Embodiment of the article manufacturing method> The pattern of the cured product formed by using the imprinting apparatus is used permanently on at least a part of various articles, or temporarily when manufacturing various articles. The articles include electric circuit elements, optical elements, MEMS, recording elements, sensors, and molds. Examples of the electric circuit elements include volatile or non-volatile semiconductor memories such as DRAM, SRAM, flash memory, and MRAM, and semiconductor elements such as LSI, CCD, image sensors, and FPGA. Examples of the molds include molds for imprinting.

[0069] The pattern of the cured product is used as it is as at least a part of a component of the article, or is used temporarily as a resist mask, which is removed after etching or ion implantation in the wafer processing step.

[0070] Next, a specific method for manufacturing an article will be described. As shown in Fig. 11(A), a wafer 1z such as a silicon wafer is prepared with a workpiece 2z such as an insulator formed on its surface. Next, an imprint material 3z is applied (supplied) to the surface of a plurality of molding regions of the workpiece 2z by an inkjet method or the like. Here, a state in which a plurality of droplets of the imprint material 3z are applied onto the wafer is shown.

[0071] As shown in FIG. 11(B), the mold 4z for imprinting is placed with its side on which the concavo-convex pattern is formed facing the imprint material 3z in a target area, which is a part of the multiple molding areas on the wafer to which the imprint material is applied. As shown in FIG. 11(C), the wafer 1z in the target area to which the imprint material 3z is applied and the mold 4z are brought into contact and pressure is applied. The imprint material 3z fills the gap between the mold 4z and the workpiece 2z. When light is irradiated through the mold 4z as energy for hardening in this state, the imprint material 3z is hardened. At this time, as in the first to third embodiments, the concentration of the first gas in the mixed gas supplied to the imprint material is adjusted to a predetermined concentration. This makes it possible to suppress hardening of the imprint material outside the target area, and pattern defects are less likely to occur when imprinting the next target area.

[0072] 11(D), after the imprint material 3z is cured, the mold 4z and the wafer 1z are separated, and a pattern of the cured product of the imprint material 3z is formed on the wafer 1z. In this cured product pattern, the concave portions of the mold correspond to the convex portions of the cured product, and the concave portions of the mold correspond to the convex portions of the cured product, i.e., the concave-convex pattern of the mold 4z is transferred to the imprint material 3z.

[0073] As shown in Fig. 11(E), when etching is performed using the pattern of the cured material as an etching-resistant mask, the portion of the surface of the workpiece 2z where there is no cured material or where only a thin layer remains is removed, forming a groove 5z. As shown in Fig. 11(F), when the pattern of the cured material is removed, an article having grooves 5z formed on the surface of the workpiece 2z can be obtained. Here, the pattern of the cured material is removed, but it may be used as an interlayer insulating film included in a semiconductor element or the like, that is, a component of an article, without being removed after processing.

[0074] <Other embodiments> Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0075] 10, 30 Flow rate adjustment section NZ Gas Nozzle CU hardened part IMP film forming equipment M type S-substrate

Claims

1. An imprinting apparatus that brings a mold into contact with an imprinting material on a substrate to form a pattern in the imprinting material, comprising: an irradiation unit that irradiates a target area of ​​the imprint material to form the pattern with light; a supply unit that supplies a mixed gas including a first gas that inhibits hardening of the imprint material toward the imprint material outside the target area, which is not the target area, while the light is being irradiated by the irradiation unit; an adjusting unit that adjusts a concentration of the first gas contained in the mixed gas, An imprinting apparatus characterized in that the adjustment unit adjusts the concentration of the first gas based on the amount of light irradiated to the imprinting material outside the target area when the irradiation unit irradiates light to the imprinting material in the target area.

2. a light amount measuring unit that measures an amount of light irradiated onto the imprint material outside the target area; The imprint apparatus according to claim 1 , wherein the adjustment unit adjusts a concentration of the first gas based on a measurement result of the light amount measurement unit.

3. 3. The imprint apparatus according to claim 1, wherein the first gas contains oxygen.

4. 4. The imprint apparatus according to claim 1, wherein the adjustment unit generates the mixed gas by mixing the first gas with a second gas in order to adjust a concentration of the first gas, and the second gas contains helium.

5. The imprint apparatus according to claim 4 , wherein the adjustment unit increases the mixing ratio of the first gas as the amount of the light irradiated to the imprint material outside the target area increases.

6. 6. The imprint apparatus according to claim 4, wherein the adjustment unit determines the ratio of the first gas such that the ratio of the second gas does not become equal to or lower than a predetermined threshold value.

7. 7. The imprint apparatus according to claim 4, wherein the adjustment unit changes the flow rates of the first gas and the second gas while maintaining a mixture ratio of the first gas and the second gas, depending on the position of the target region on the substrate.

8. The imprint apparatus of claim 7 , wherein the adjustment unit increases the flow rates of the first gas and the second gas when the target area includes the edge of the substrate compared to when the target area does not include the edge of the substrate.

9. 7. The imprint apparatus according to claim 4, further comprising a concentration measurement unit capable of measuring a concentration of at least one of the first gas and the second gas contained in the mixed gas.

10. 10. The imprint apparatus according to claim 4, wherein the mixed gas contains clean dry air.

11. a base layer on a surface of the substrate on which the imprint material is supplied; The imprint apparatus according to claim 1 , wherein the adjustment unit determines the concentration of the first gas based on a thickness of the underlayer.

12. 1. An imprinting method for forming a pattern in an imprint material by contacting a mold with an imprint material on a substrate, comprising the steps of: an irradiation step of irradiating a target area of ​​the imprint material to form the pattern with light; an adjusting step of adjusting a concentration of a first gas that is contained in the mixed gas and inhibits hardening of the imprint material; a supply step of supplying the mixed gas adjusted in the adjustment step toward the imprint material outside the target area, which is not the target area, while the irradiation step is being performed; An imprinting method, comprising: adjusting, in the adjustment step, a concentration of the first gas based on an amount of light irradiated to the imprint material outside the target area in the irradiation step.

13. A forming step of forming a pattern in an imprint material on a substrate by using the imprint apparatus according to any one of claims 1 to 11; a processing step of processing the substrate on which the pattern has been formed in the forming step.

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