JP6659149B2 - Detection apparatus, detection method, lithography apparatus, and article manufacturing method - Google Patents

Description

  The present invention relates to a detection device, a detection method, a lithography device, and a method for manufacturing an article.

  The imprint apparatus includes a plurality of optical systems (so-called alignment scopes) for detecting an alignment mark provided on a mold and an alignment mark provided on a substrate at a plurality of locations in parallel (Patent Document 1). ). In an apparatus (for example, a lithography apparatus such as the above-described imprint apparatus) including a processing unit that processes an image obtained by each of the plurality of imaging units, a mark to be imaged (or an optical system corresponding thereto) and an It is necessary to link (associate) with the section.

Japanese Patent No. 4185941

  However, if the image pickup unit and the mark (or the optical system for detecting the mark) are not correctly associated with each other, it is difficult to perform alignment (overlap).

  An object of the present invention is to provide, for example, a detection device that is advantageous for specifying a correspondence between an imaging unit and an optical system.

In order to solve the above problems, the present invention is a detection device for detecting a mark, a plurality of optical systems, a plurality of imaging units that respectively image a plurality of images by the plurality of optical systems, a plurality of A control unit that obtains a correspondence relationship between one of the optical systems and one of the plurality of imaging units, and the control unit is configured to form an image on the plurality of optical systems via the reference member. The correspondence is obtained based on the magnitudes of the light amounts, which are a plurality of outputs respectively obtained by the plurality of imaging units.

  According to the present invention, for example, it is possible to provide a detection device that is advantageous for specifying the correspondence between the imaging unit and the optical system.

FIG. 2 is a schematic diagram of a detection device according to the first embodiment. It is the schematic which shows an example of a structure of an optical system and a light source part. 6 is a flowchart illustrating a flow of a process for specifying an imaging unit according to the first embodiment. FIG. 3 is a diagram illustrating a positional relationship between an optical system and a reference member. FIG. 9 is a diagram illustrating an example of an output measurement result.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(1st Embodiment)
FIG. 1 is a schematic diagram of a detection device according to the first embodiment of the present invention. In the present embodiment, the detection apparatus will be described as applied to a lithography apparatus (for example, an imprint apparatus). The detection device 10 includes imaging units (cameras) 11 to 14, optical systems 21 to 24, driving mechanisms 25 to 28, an image processing unit 30, a hub 31, a light source unit 40, and a control unit 60. Have. The imaging units 11 to 14 can be configured by elements such as a CCD and a CMOS. One of the imaging units 11 to 14 is mounted on each of the optical systems 21 to 24. In the present embodiment, the imaging unit 11 is connected to the optical system 21, the imaging unit 12 is connected to the optical system 22, the imaging unit 13 is connected to the optical system 23, and the imaging unit 14 is connected to the optical system 24. The optical systems 21 to 24 are scopes (microscopes) for measuring the alignment of the substrate W (alignment), and include a detection optical system for detecting an alignment mark on the substrate W and an illumination optical system for illuminating the mark. It can be configured to include a system. The drive mechanisms 25 to 28 can drive the optical systems 21 to 24 in a direction parallel to the XY plane for alignment measurement. Here, the optical axes of the optical systems 21 to 24 are defined as the Z axis, and a plane perpendicular to the Z axis is defined as the XY plane.

  The lithography apparatus including the detection device 10 includes a substrate stage 50 and an imprint head 70. The substrate stage 50 includes a substrate chuck 52 that holds the substrate W, and a movable chuck holder 54 that holds the substrate chuck 52 and is movable. The chuck holder 54 is moved by a drive mechanism (not shown). A reference member 51 is formed in the chuck holding section 54, and marks for various kinds of calibration are formed. The detection device 10 can be used for detecting the position of a mark on the reference member 51. Note that the reference member 51 may use a sensor configured on the substrate W or the substrate stage 50 as a substitute. The drive mechanism (not shown) can position the substrate W by controlling the position of the chuck holding section 54 with respect to six degrees of freedom. Here, the six degrees of freedom include a degree of freedom of translation along each axis of the XYZ coordinate system and a degree of freedom of rotation about each axis. Further, the lithographic apparatus includes a surface plate (not shown) for supporting the driving mechanisms 25 to 28 and a surface plate (not shown) for supporting the substrate stage 50.

  The imprint head 70 moves (for example, moves up and down) the mold holding unit (mold chuck) for holding the imprinting mold and the mold holding unit to perform pressing and releasing with respect to the substrate (upper imprint material). ). Further, it may include a curing unit for curing the imprint material with the mold in contact with the imprint material (for example, an irradiation unit that irradiates the imprint material with ultraviolet rays).

  The imaging units 11 to 14 are connected to the image processing unit 30 via the hub 31. The light emitted from the light source unit 40 enters the reference member 51 via the optical systems 21 to 24 and is reflected. The reflected light from the reference member 51 enters the imaging units 11 to 14 via the optical systems 21 to 24. The imaging units 11 to 14 convert incident light (input) into an electric signal and output the electric signal to the image processing unit 30.

  Control unit 60 may include a computer as information processing means. The control unit 60 can control the image processing unit 30, the light source unit 40, the driving mechanisms 25 to 28, and the driving mechanism of the substrate stage 50. 1, a connection line between the control unit 60 and each unit is partially omitted. Further, the control unit 60 may include the image processing unit 30 as a part thereof.

  FIG. 2 is a schematic diagram illustrating an example of the configuration of the optical system and the light source unit. For simplicity, only the optical system 21 among the optical systems 21 to 24 is illustrated. The optical system 21 includes a detection optical system 210 and an illumination optical system 220. The illumination optical system 220 includes a light blocking unit 221 and a prism 211. The detection optical system 210 includes a prism 211 and a lens 212. The prism 211 is shared by the detection optical system 210 and the illumination optical system 220, and is arranged on or near the pupil plane of each system. The prism 211 may be a half prism having a semi-permeable film on a bonding surface. Alternatively, a plate-like optical element having a reflective film formed on the surface may be used. The illumination optical system 220 illuminates the reference member 51 with light from the light source unit 40 via the prism 211 and the like. The light (reflected light) reflected by the reference member 51 is imaged on an image sensor in the image pickup unit 11 via the detection optical system 210. The light shielding unit 221 is controlled by the control unit 60.

  The light source unit 40 includes light sources 401 to 404, ND filters 411 to 414, and diffusion plates 421 to 424. As the light sources 401 to 404, for example, at least one of a halogen lamp, an LED, a semiconductor laser (LD), a high-pressure mercury lamp, and a metal halide lamp can be used. The ND filters 411 to 414 are elements for adjusting the intensity of passing light.

  The light emitted from the light sources 401 to 404 passes through the ND filters 411 to 414 and the light amount is adjusted. Each of the ND filters 411 to 414 includes a plurality of filters having different transmittances, and selectively inserts the filters into the optical path according to a required light amount. Alternatively, a filter whose transmittance changes continuously or stepwise depending on the position in the filter may be used to adjust the position in the filter through which the light beam passes according to the required amount of light. Further, the light amount adjustment may be performed by operating the drive current of the light sources 401 to 404 alone or in combination. The light that has passed through the ND filter 411 passes through the diffusion plates 421 to 424, enters the fiber 450, and is introduced into the optical systems 21 to 24 via the fiber 450. Each element of the light source unit 40 is prepared in the same number as the number of optical systems, and the amounts of light introduced into the optical systems 21 to 24 can be adjusted independently. The light source does not need to be provided in each of the optical systems 21 to 24, and may be configured to be shared by a plurality of optical systems.

  In the present embodiment, a USB (Universal Serial Bus) is employed as an interface used to connect the image processing unit 30 and the imaging units 11 to 14. According to the USB connection, up to 127 devices (imaging units) can be connected to a computer (image processing unit 30) due to the standard. When the connection ports of the computer are insufficient, a means for increasing the connection ports using the hub 31 is used. The image processing unit and each imaging unit recognize the imaging unit when communication between the host and the slave is established, and the individual imaging unit that has recognized any one of the optical systems 21 to 24 (A physical correspondence between the imaging unit and the optical system) cannot be determined. This is the same even when another interface (such as a wireless system) is used.

  FIG. 3 is a flowchart illustrating a flow of a process for specifying the imaging unit according to the present embodiment. In step S1, the control unit 60 selects an optical system (target optical system) to be driven in step S2. In step S2, the control unit 60 drives the target optical system to a position where the reflected light from the reference member 51 is received.

  4A to 4C are diagrams showing the positional relationship between the optical systems 21 to 24 and the reference member 51. FIG. 4A is a schematic diagram illustrating a case where the reference member 51 simultaneously covers the light incident areas from the optical systems 21 to 24. FIG. 4B is a schematic diagram illustrating a case where the reference members 51 are individually arranged corresponding to light incident areas from the respective optical systems. In these cases, the driving of the optical system by the control unit 60 in step S2 is not essential. On the other hand, FIG. 4C is a diagram illustrating a case where the optical system 21 is driven to a position where the reflected light from the reference member 51 can be received. In this case, for example, when the optical system 22 is selected in step S1, the control unit 60 needs to drive the optical system 22 in step S2. The control unit 60 stores (stores) such drive mode information in a storage unit (not shown) in advance as necessary, and drives the optical system based on the information in step S2. sell.

  In step S3, the control unit 60 controls the light shielding unit 221 included in the light source unit 40 or an optical system other than the target optical system so that light is incident only on the target optical system. For example, if the target optical system is the optical system 21, the ND filters 412 to 414, the light shielding units inside the optical systems 22 to 24, or the light sources 402 to 404 in the light source unit 40 are controlled. In step S <b> 4, the signal output from each imaging unit to the image processing unit 30 is stored in a storage unit (not shown) included in the control unit 60 via the image processing unit 30.

  FIG. 5 is a diagram illustrating an example of data stored in step S4. The control unit 60 associates (associates) the imaging unit with the optical system based on the data (measurement result table). In FIG. 5, light quantity measurement 1 shows the measurement result in the first process of steps S1 to S4. The light quantity measurement 2 shows the measurement results in the second time, the light quantity measurement 3 shows the measurement results in the third time, and the light quantity measurement 4 shows the measurement results in the fourth time steps S1 to S4. The numbers in the table indicate the magnitudes of the outputs (for example, average pixel values) of the imaging units 11 to 14.

  In step S5, the control unit 60 determines whether steps S1 to S4 have been performed for all the imaging units. If the execution has been completed (Yes), the processing is terminated, and if not (No), the processing is repeated from step S1.

  Based on the measurement result table shown in FIG. 5, the imaging unit and the optical system can be linked (a correspondence relationship can be obtained). In the present embodiment, the imaging unit associated with the target optical system 21 in the first measurement (light amount measurement 1) is the imaging unit 11 having the maximum output. Similarly, the imaging unit 12 is linked to the optical system 22, the imaging unit 14 is linked to the optical system 23, and the imaging unit 13 is linked to the optical system 24.

  The obtained correspondence between the imaging unit and the optical system is stored in a storage unit (not shown) in the control unit 60. The lithography apparatus refers to the information stored in the storage unit without performing the processing in FIG. 3 at the time of restarting, unless the connection relationship between the imaging unit and the optical system is changed. Can be specified.

  As described above, the detection device of the present embodiment does not need to add a special configuration for associating the imaging unit with the optical system. According to the present embodiment, it is possible to provide a detection device that is advantageous for specifying the correspondence between the imaging unit and the optical system.

  In the above embodiment, the reflected light from the reference member 51 is measured using the reference member 51 as a secondary light source. It is possible. In the above embodiment, an imprint apparatus has been described as an example of a lithographic apparatus, but the present invention can be applied to any other lithographic apparatus.

  Further, in the above-described embodiment, the imaging unit corresponding to the specific optical system is specified based on the output size (average pixel value) of each imaging unit. It can also be specified based on the shape, number, arrangement, etc. of the marks to be made. In this case, the data stored in step S4 is data corresponding to the shape, number, or arrangement of the mark obtained by each imaging unit.

(Embodiment related to article manufacturing method)
The method for manufacturing an article according to the embodiment of the present invention is suitable for manufacturing an article such as a micro device such as a semiconductor device or an element having a fine structure. The method for manufacturing an article according to the present embodiment includes a step of forming a pattern on a substrate using the above-described lithography apparatus and a step of processing the substrate on which the pattern is formed in this step (for example, removal of a residual film (when the lithography apparatus is If the lithographic apparatus is an exposure or drawing apparatus, the method includes a developing step instead of the above-mentioned processing step. Film, vapor deposition, doping, flattening, etching, resist stripping, dicing, bonding, packaging, etc.) The method of manufacturing an article according to the present embodiment is superior to the conventional method in the performance, quality, and productivity of the article. Advantageous in at least one of the production costs.

(Other embodiments)
The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist.

11 to 14 imaging unit 21 to 24 optical system 51 reference member 60 control unit

Claims (12)

A detection device for detecting a mark,
Multiple optics,
A plurality of imaging units that respectively image a plurality of images by the plurality of optical systems,
A control unit that obtains a correspondence between one of the plurality of optical systems and one of the plurality of imaging units ;
With
Wherein, when having formed an image on the plurality of optical systems through the reference member, based on the magnitude of the light intensity of a plurality of outputs respectively obtained by the plurality of imaging units, the relationship A detection device characterized by obtaining. A detection device for detecting a mark,
Multiple optics,
A plurality of imaging units that respectively image a plurality of images by the plurality of optical systems,
A control unit that obtains a correspondence relationship between one of the plurality of optical systems and one of the plurality of imaging units;
With
The control unit, when an image is formed on the plurality of optical systems via a reference member , based on a feature of a mark recognized from each of a plurality of outputs respectively obtained by the plurality of imaging units , dETECTION dEVICE you and obtaining a relationship. The detection device according to claim 2 , wherein the feature includes at least one of a shape, an arrangement, and a number of the marks. The control unit acquires the plurality of outputs in a state in which an image formed by a component other than the target optical system among the plurality of optical systems is controlled so as not to be captured by a corresponding imaging unit. The detection device according to claim 1. Further comprising a plurality of light shielding portions provided corresponding to each of the plurality of optical systems,
The control unit controls the plurality of light shielding units so that an image formed by a component other than the target optical system of the plurality of optical systems is not captured by a corresponding imaging unit. The detection device according to claim 4.   The detection device according to any one of claims 1 to 4, further comprising a storage unit that stores the correspondence. The reference member includes a light source,
Wherein the plurality of each of the image, the detection device according to any one of claims 1 to 6, characterized in that it is formed by the light source.   The detection device according to any one of claims 1 to 7, wherein each of the plurality of imaging units and the control unit are connected via a USB. In a detection device that detects a mark using a plurality of optical systems and a plurality of imaging units that respectively capture images of a plurality of images by the plurality of optical systems, one of the plurality of optical systems and the plurality of A method for obtaining a correspondence relationship with one of the imaging units,
When order to form an image on the plurality of optical systems through the reference member, based on the magnitude of the light intensity of a plurality of outputs respectively obtained by the plurality of imaging units, characterized by obtaining the correspondence relation And how. In a detection device that detects a mark using a plurality of optical systems and a plurality of imaging units that respectively capture images of a plurality of images by the plurality of optical systems, one of the plurality of optical systems and the plurality of A method for obtaining a correspondence relationship with one of the imaging units,
When an image is formed on the plurality of optical systems via a reference member, the correspondence is obtained based on a feature of a mark recognized from each of a plurality of outputs obtained by the plurality of imaging units. Features method. A lithographic apparatus for forming a pattern on a substrate, comprising:
A lithographic apparatus comprising the detection device according to any one of claims 1 to 8, which detects a mark formed on the substrate. A step of a pattern formed on the substrate using a lithographic apparatus according to claim 1 1,
Processing the substrate on which the pattern is formed in the step,
A method for producing an article, comprising:

Images