This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2019-132049, filed on Jul. 17, 2019, the entire contents of which are incorporated herein by reference.
Embodiments described herein relate generally to an imprinting apparatus, an imprinting method, and a semiconductor device manufacturing method.
There is a technique of supplying liquid such as resin onto a substrate and forming a supply layer corresponding to the liquid. There is also a technique of processing the supply layer in various manners such as pattern transfer, curing through application of impulses. In such techniques, it is important to control a thickness of the supply layer formed on the substrate. However, the thickness of the supply layer may vary due to conditions for supplying a liquid onto the substrate. Thus, it is desirable to estimate a film thickness of a supply layer.
Embodiments provide an imprinting apparatus, an imprinting method, and a semiconductor device manufacturing method that are directed to estimating a film thickness of a supply layer formed by a liquid supplied onto a substrate.
In general, according to an embodiment, an imprinting method includes capturing an image of a resin layer formed on a region of a first substrate with resin fluid supplied onto the first substrate from a resin fluid dispenser, determining a luminance distribution in the region in the captured image, determining a thickness distribution of the resin layer based on a relationship between a thickness of a resin layer and a luminance and the determined luminance distribution, determining a resin fluid supply condition to form a resin layer in a predetermined thickness range, based on the determined thickness distribution, and supplying resin fluid from the resin fluid dispenser onto a region of a second substrate in accordance with the determined resin fluid supply condition.
Hereinafter, with reference to the accompanying drawings, an imprinting apparatus, an imprinting method, and a semiconductor device manufacturing method according to an embodiment will be described in detail. The present disclosure is not limited to the following embodiment. An element in the following embodiment includes an element that is easily conceived of by a person skilled in the art or the substantially same element.
The imprinting apparatus 1 includes a template 12, a template stage 14, a mounting table 17, a reference mark 20, an alignment sensor 22, a stage base 24, a supply section 26, a light source 30, a mirror 31, an imaging section 32, and a controller 40.
The mounting table 17 is provided with a wafer chuck 16 and a stage 18. The wafer chuck 16 fixes a wafer 10 as a substrate or a semiconductor substrate to a predetermined position on the stage 18. The reference mark 20 is provided on the mounting table 17. The reference mark 20 is used for alignment when the wafer 10 is loaded onto the mounting table 17.
The mounting table 17 is mounted with the wafer 10, and is moved in a plane (for example, a horizontal plane) parallel to the mounted wafer 10. The movement of the mounting table 17 is performed, for example, under driving of a drive section 34.
The drive section 34 relatively moves at least one of the mounting table 17 and the supply section 26 which will be described below in a scanning direction (that is, an arrow X direction) intersecting a direction (that is, an arrow Z direction) in which the wafer 10 mounted on the mounting table 17 faces the supply section 26. In the present embodiment, the drive section 34 moves the wafer 10 toward a lower side of the supply section 26 in a scanning direction X when the supply section 26 supplies a resist 28 (which will be described below in detail) onto the wafer 10. When a pattern is transferred onto the wafer 10, the wafer 10 is moved toward the lower side of the template 12 in the scanning direction X.
In the present embodiment, the scanning direction X matches a horizontal direction. The arrow Z direction is a vertical direction (that is, an upward-downward direction) orthogonal to the scanning direction X. An arrow Y direction is orthogonal to the scanning direction X and the arrow Z direction.
The stage base 24 supports the template 12 at the template stage 14. The stage base 24 is moved in the upward-downward direction (that is, the vertical direction or the arrow Z direction), and thus presses a pattern 13 of the template 12 against the resist 28 of the wafer 10. The alignment sensor 22 is provided on the stage base 24. The alignment sensor 22 is a sensor that detects a position of the wafer 10 or a position of the template 12.
The supply section 26 supplies the resist 28 on the wafer 10 according to an applied drive voltage. The supply section 26 may be referred to as a fluid dispenser or a resin fluid dispenser. In the present embodiment, a description will be made of an example of a case where the supply section 26 is a device that drops (in other words, ejects) a liquid droplet 28A of the resist 28 onto the wafer 10 according to an ink jet method. In this case, the supply section 26 may also be referred to as a dispenser. Hereinafter, the supply of a liquid from the supply section 26 may also be referred to as the supply of the resist 28 or dropping of the resist 28.
The supply section 26 may be a mechanism that supplies a liquid such as the resist 28 onto the wafer 10. For example, the supply section 26 may be a mechanism that applying a liquid such as the resist 28 onto the wafer 10 according to a well-known method.
The description is continued with reference to
The resist 28 is an example of a liquid supplied by the supply section 26. The resist 28 is a material onto which the pattern 13 is transferred, and may be referred to as a receiver material in some case. The resist 28 is a resin-based mask material, and may be a photocurable resin that is cured as a result of being irradiated with light or a thermosetting resin that is cured as a result of applying heat thereto. In the present embodiment, a description will be made of a case where the resist 28 is supposed to be a photocurable resin.
The light source 30 applies light with a wavelength region for curing the resist 28. The light source 30 irradiates the resist 28 with light via the template 12 in a state in which the template 12 is pressed against the resist 28 dropped on the wafer 10. The template 12 may be made of a material through which light with a wavelength region of the light source 30 and reflected light from the wafer 10 side are transmitted.
The mirror 31 transmits light applied to the wafer 10 from the light source 30 therethrough, and reflects observation light from the wafer 10 and a supply layer (which will be described below in detail) formed by the resist 28 dropped on the wafer 10. The mirror 31 is, for example, a dichroic mirror.
The imaging section 32 images a supply layer formed by the resist 28 that is a liquid supplied onto the wafer 10, and thus obtains a captured image of the supply layer. Specifically, observation light from the supply layer on the wafer 10 is transmitted through the template 12 to be reflected at the mirror 31, and then reaches the imaging section 32. Thus, the imaging section 32 images the supply layer on the wafer 10 via the mirror 31 and the template 12, and thus obtains the captured image.
The imaging section 32 is a well-known imaging device that obtains captured image data through imaging. In the present embodiment, the captured image data will be simply referred to as a captured image.
The controller 40 is coupled to each element of the imprinting apparatus 1 and controls each element. Specifically, the controller 40 is electrically coupled to each of a drive section (not illustrated) of the template stage 14, the drive section 34 of the mounting table 17, the supply section 26, the light source 30, and the imaging section 32, and controls each of the elements. The controller 40 may be referred to as a control circuit.
Each of the elements is controlled by the controller 40, and thus an imprinting process and semiconductor device manufacturing are performed.
First, a treatment film 11 is formed on the wafer 10. The treatment film 11 may be formed according to a well-known method. The wafer 10 on which the treatment film 11 is formed is mounted on the mounting table 17, and the mounting table 17 is moved to the lower side of the supply section 26. The wafer 10 on which the treatment film 11 is not formed may be mounted on the mounting table 17.
The controller 40 applies a drive voltage to the supply section 26, and thus the liquid droplet 28A is dropped onto the treatment film 11 of the wafer 10 from the supply section 26 (refer to
In this case, the controller 40 performs control of adjusting at least one of a voltage value of a drive voltage supplied to the supply section 26, a frequency of the drive voltage, a dropping position of the liquid droplet 28A, and the number of dropped liquid droplets 28A. Due to the adjustment, at least one of an amount of each dropped liquid droplet 28A, an amount of the liquid droplets 28A per unit area on the wafer 10, a dropping position on the wafer 10, and the number of droplets on the wafer 10 is adjusted. A dropping position and the number of droplets on the wafer 10 are defined in, for example, dropping data for defining a dropping position coordinate. The dropping data will also be referred to as a drop recipe. The controller 40 controls the supply section 26 to eject the liquid droplet 28A at a dropping position and the number of droplets defined in the dropping data, and thus the supply section 26 drops the liquid droplet 28A at the dropping position and the number of droplets defined in the dropping data.
In this case, the controller 40 controls the drive section 34, and thus a movement speed of the mounting table (that is, the wafer 10) in the scanning direction X. When the liquid droplet 28A is dropped onto the wafer 10, a movement speed of the wafer 10 in the scanning direction X is controlled, and thus a dropping interval of the liquid droplet 28A in the scanning direction X is controlled.
The controller 40 controls the drive section 34 to move the mounting table 17 to the lower side of the template 12.
As illustrated in
When this state is maintained for a predetermined time, the liquid resist 28 (that is, the liquid droplet 28A) spreads between the template 12 and the wafer 10, and thus fills a recess portion of the pattern 13 of the template 12.
Next, as illustrated in
Next, as illustrated in
The pattern 13 formed on the template 12 is transferred onto the resist 28 that is an example of a receiver material on the wafer 10 through the steps in FIGS. 3B to 3D. The imprinting process is implemented through the steps in
In order to perform a semiconductor device manufacturing process, the following steps are executed (refer to
For example, the recess portion in the transfer region PA is removed through etching (refer to
Here, it is considerably important to control a film thickness of the supply layer 36 formed by the resist 28 ejected onto the wafer 10. For example, in a case of a fine pattern in which an uneven portion of the pattern 13 is in a range from several tens of nm to 100 nm, it is important to control a total amount of the resist 28 supplied onto the wafer 10.
When the inkjet supply section 26 is used as the supply section 26, a required sufficient amount of the resist 28 may be supplied onto the wafer 10 by taking into consideration a coating ratio of the fine pattern 13 of the template 12 or a dropping directivity. However, even when the inkjet supply section 26 is used, a thickness of the supply layer 36 may change due to factors such as drive waveform interference between the liquid reservoirs communicating with the holes 26A during dropping, deterioration over time, and an environmental change.
Specifically, for example, it is assumed that a supply condition for the supply section 26 is constant such that a desired dropping amount of the liquid droplet 28A is dropped from the holes 26A of the supply section 26. However, an actual amount of the dropped liquid droplet 28A may change due to an environmental change such as temperature and humidity, clogging of the hole 26A, and a status change of the imprinting apparatus 1 during startup or shutdown of the imprinting apparatus 1.
As the number of holes 26A simultaneously ejecting the liquid droplets 28A becomes larger, an amount of the liquid droplet 28A ejected from a single hole 26A may be reduced even when an identical drive voltage is applied. For example, as a gap (that is, a gap in the Y direction; refer to
Thus, there is a case where a thickness of the supply layer 36 may be non-uniform, and thus a technique of easily estimating a thickness of the supply layer 36 is desirable.
Therefore, in the imprinting apparatus 1 of the present embodiment, the controller 40 calculates a film thickness of the supply layer 36 (e.g., thickness distribution) by using a captured image of the supply layer 36.
The driving control unit 40B, the acquisition unit 40C, the luminance calculation unit 40D, the film thickness calculation unit 40E, and the correction unit 40F are realized by one or a plurality of processors. For example, each of the units may be implemented by a processor such as a central processing unit (CPU) executing a program or by software. Each of the units may be implemented by a processor such as a dedicated integrated circuit (IC), that is, hardware. Each of the units may be implemented through combined use of software and hardware. When a plurality of processors are used, each processor may implement one of the respective units, and may implement two or more of the respective units.
The storage unit 40A stores various pieces of data. In the present embodiment, the storage unit 40A stores relationship information 41A and supply condition 41B.
The relationship information 41A is information indicating a relationship between a film thickness and the luminance.
The film thickness indicated in the relationship information 41A indicates a thickness of the supply layer 36. The thickness of the supply layer 36 is a thickness of the transfer region PA of the resist 28 to which the pattern 13 of the template 12 is pressed against the liquid droplet 28A dropped on the wafer 10 to be transferred. The thickness of the transfer region PA may be a thickness of the transfer region PA after being cured due to irradiation with light from the light source 30, and may be a thickness of the transfer region PA before being cured.
In the present embodiment, a description will be made of an example of a case where the thickness of the supply layer 36 is a thickness of the transfer region PA after being cured or solidified.
The thickness of the supply layer 36 may be any one of an average thickness of the transfer region PA to which the uneven pattern 13 is transferred, a thickness of a recess portion, and a thickness of a protrusion portion in the supply layer 36. In the present embodiment, a description will be made of an example of a case where the thickness of the supply layer 36 is a thickness (refer to a thickness L in
The luminance indicated in the relationship information 41A indicates the luminance of the transfer region PA of the supply layer 36. The luminance of the transfer region PA may be average luminance of the whole transfer region PA, and average luminance of a specific region in the transfer region PA. The specific region may be a region set at a predefined location and having predefined size and range in the transfer region PA. For example, the specific region is preferably a region corresponding to a plurality of pixels (for example, two or more pixels). In the present embodiment, a description will be made of an example of a case where the luminance of the transfer region PA is average luminance of a specific region in the transfer region PA (that is, a region to which the pattern 13 is transferred) after being cured or solidified.
As illustrated in
In the imprinting apparatus 1, a relationship between a film thickness of the supply layer 36 and the luminance of the transfer region PA of the supply layer 36 may be measured in advance, to be stored in advance in the storage unit 40A as the relationship information 41A. The film thickness defined in the relationship information 41A may be derived, for example, by actually measuring a thickness of the transfer region PA of the supply layer 36. The luminance defined in the relationship information 41A may be derived, for example, by calculating the luminance of a captured image of the transfer region PA of the supply layer 36 formed on the wafer 10 according to a well-known method.
The description will be continued referring to
The driving control unit 40B is coupled to each element of the imprinting apparatus 1 and controls each element. The driving control unit 40B controls each of the drive section (not illustrated) of the template stage 14, the drive section 34 of the mounting table 17, the supply section 26, the light source 30, and the imaging section 32 such that the imprinting process or the semiconductor device manufacturing process is executed.
The driving control unit 40B controls the supply section 26 and the drive section 34 when the resist 28 is dropped onto the wafer 10.
Specifically, the driving control unit 40B controls the supply section 26 and the drive section 34 based on the supply condition 41B.
The supply condition 41B is information indicating control conditions for each of the elements when the resist 28 is dropped onto the wafer 10. The supply condition 41B includes at least one of, for example, a voltage value of a drive voltage applied to the supply section 26, a frequency of the drive voltage, a scanning speed (movement speed) of the mounting table 17 mounted with the wafer 10, a dropping position (that is, a supply position) of the liquid droplet 28A on the wafer 10, and the number of dropped liquid droplets 28A (that is, the number of supplied liquid droplets 28A) per unit area.
The driving control unit 40B controls the elements based on the supply condition 41B, and thus the liquid droplet 28A is dropped onto the wafer 10 from each of the plurality of holes 26A of the supply section 26.
The acquisition unit 40C acquires the captured image 50 from the imaging section 32. The captured image 50 is captured image data obtained by imaging the supply layer 36. For example, the driving control unit 40B controls the imaging section 32 to image the transfer region PA of the supply layer 36 formed by the resist 28 to which the pattern 13 of the template 12 is transferred and which is cured by light applied from the light source 30. The driving control unit 40B may control the imaging section 32 to image at least the transfer region PA of the supply layer 36 when the supply layer 36 to which the pattern 13 is transferred and which is the cured resist 28 is in a state of being formed on the wafer 10 (refer to
The description will be continued referring to
The description will be continued referring to
In the above-described way, the luminance calculation unit 40D calculates the luminance of the specific region 52 in the transfer region PA of the pattern 13, that is, a region obtained by imaging the uneven portion of the pattern 13, in the captured image 50.
The film thickness calculation unit 40E calculates a film thickness of the supply layer 36 based on the relationship information 41A. The film thickness calculation unit 40E calculates the film thickness of the supply layer 36 by specifying a film thickness corresponding to the luminance calculated by the luminance calculation unit 40D from the relationship information 41A.
The correction unit 40F corrects the supply condition 41B such that the film thickness calculated by the film thickness calculation unit 40E becomes a desired film thickness.
The desired film thickness is information indicating a desired film thickness of the specific region 52. The desired film thickness may be set in advance. The desired film thickness may be changeable as appropriate through a user's operation input on an input section such as a keyboard.
The correction unit 40F determines whether or not the film thickness calculated by the film thickness calculation unit 40E matches the desired film thickness. The correction unit 40F may determine that the thicknesses match each other when one of the calculated film thickness and the desired film thickness has a value within a preset range (for example, within a range of ±10%) with respect to the other thereof.
When it is determined that the film thickness calculated by the film thickness calculation unit 40E matches the desired film thickness, the correction unit 40F does not correct the supply condition 41B. On the other hand, when it is determined that the film thickness calculated by the film thickness calculation unit 40E does not match the desired film thickness (that is, the calculated film thickness is different from the desired film thickness), the correction unit 40F corrects the supply condition 41B such that the film thickness of the supply layer 36 matches the desired film thickness.
Specifically, when the film thickness calculated by the film thickness calculation unit 40E is smaller than the desired film thickness, the correction unit 40F corrects the supply condition 41B such that a thickness of the resist 28 formed by the liquid droplet 28A ejected from the supply section 26 is larger than the current thickness. Specifically, the correction unit 40F corrects the supply condition 41B such that at least one of an amount of each liquid droplet 28A ejected from the supply section 26, the number of dropped liquid droplets 28A per unit area on the wafer 10, and a density of dropped liquid droplets 28A on the wafer 10 is increased compared with the current state.
On the other hand, when the film thickness calculated by the film thickness calculation unit 40E is larger than the desired film thickness, the correction unit 40F corrects the supply condition 41B such that a thickness of the resist 28 formed by the liquid droplet 28A ejected from the supply section 26 is smaller than the current thickness. Specifically, the correction unit 40F corrects the supply condition 41B such that at least one of an amount of each liquid droplet 28A ejected from the supply section 26, the number of dropped liquid droplets 28A per unit area on the wafer 10, and a density of dropped liquid droplets 28A on the wafer 10 is decreased compared with the current state.
As illustrated in
As illustrated in
As illustrated in
Thus, the resist 28 is thickened or thinned by adjusting a relative movement speed (that is, a scanning speed) between the wafer 10 and the supply section 26 in the scanning direction X.
As illustrated in
As illustrated in
The description will be continued referring to
In other words, the correction unit 40F changes and updates the supply condition 41B stored in the storage unit 40A such that the supply condition 41B after being corrected are obtained.
Thus, the driving control unit 40B controls the supply section 26 and the drive section 34 according to the supply condition 41B stored in the storage unit 40A, and can thus execute measurement of a film thickness of the supply layer 36 and control for matching the film thickness of the supply layer 36 with a desired film thickness during the imprinting process or the semiconductor device manufacturing process.
Next, a description will be made of an example of a flow of information processing executed by the controller 40.
The acquisition unit 40C acquires the captured image 50 of the transfer region PA of the supply layer 36 from the imaging section 32 (step S100).
The luminance calculation unit 40D calculates the luminance of the captured image 50 acquired in step S100 (step S102). As described above, in the present embodiment, the luminance calculation unit 40D calculates the luminance of the specific region 52 in the transfer region PA in the captured image 50.
The film thickness calculation unit 40E calculates a film thickness of the supply layer 36 based on the luminance calculated in step S102 (step S104). The film thickness calculation unit 40E calculates the film thickness of the supply layer 36 by acquiring a film thickness corresponding to the luminance calculated in step S102 from the relationship information 41A.
Next, the correction unit 40F determines whether or not the film thickness calculated in step S104 matches a desired film thickness (step S106). When it is determined that the film thickness calculated in step S104 matches the desired film thickness (step S106: Yes), the present routine is finished.
On the other hand, when it is determined that the film thickness calculated in step S104 does not match the desired film thickness (step S106: No), the flow proceeds to step S108.
In step S108, the correction unit 40F corrects the supply condition 41B such that the film thickness calculated in step S104 matches the desired film thickness (step S108). Through the process in step S108, the driving control unit 40B controls the supply section 26 and the drive section 34 according to the supply condition 41B after being corrected, and thus executes measurement of a film thickness of the supply layer 36 and control for matching the film thickness of the supply layer 36 with the desired film thickness during the imprinting process or the semiconductor device manufacturing process. The present routine is finished.
The correction process for the supply condition 41B in step S108 is applied to the following case.
Specifically, when the process illustrated in
When the process illustrated in
As described above, the imprinting apparatus 1 of the present embodiment includes the acquisition unit 40C, the luminance calculation unit 40D, and the film thickness calculation unit 40E. The acquisition unit 40C acquires the captured image 50 of the supply layer 36 formed by a liquid (that is, the resist 28) supplied onto a substrate (that is, the wafer 10). The luminance calculation unit 40D calculates the luminance of the captured image 50. The film thickness calculation unit 40E calculates a film thickness of the supply layer 36 based on the relationship information 41A indicating a relationship between a film thickness and luminance, and the calculated the luminance.
As mentioned above, the imprinting apparatus 1 of the present embodiment calculates a film thickness of the supply layer 36 based on the luminance of the captured image 50.
Thus, it is possible to easily calculate a film thickness of the supply layer 36 without actually measuring the film thickness of the supply layer 36 formed on the wafer 10.
Therefore, the imprinting apparatus 1 of the present embodiment can easily estimate a film thickness of the supply layer 36 formed by the resist 28 (that is, a liquid) supplied onto the wafer 10 (that is, a substrate).
The imprinting apparatus 1 of the present embodiment corrects the supply condition 41B for a liquid (that is, the resist 28) onto the wafer 10 such that a calculated film thickness matches a desired film thickness.
Thus, the supply section 26 and the drive section 34 are controlled based on the corrected supply condition 41B, and thus a supply condition for the resist 28 can be easily adjusted such that a film thickness of the supply layer 36 matches a desired film thickness.
The relationship information 41A may indicate different relationships depending on imaging conditions for the supply layer 36. For example, the luminance of the transfer region PA of the supply layer 36 may differ depending on the type or a structure of a layer (for example, the wafer 10 or the treatment film 11) present in a lower layer of the supply layer 36 during imaging of the supply layer 36. The luminance of the transfer region PA of the supply layer 36 may change depending on a wavelength of light applied during imaging of the transfer region PA, or the type of a light source that applies light when the light is applied during imaging.
Therefore, in the imprinting apparatus 1, the relationship information 41A corresponding to an imaging condition may be measured in advance for each imaging condition for the supply layer 36, to be stored in the storage unit 40A in advance in correlation with the imaging condition.
In this case, the film thickness calculation unit 40E may read the relationship information 41A corresponding to the imaging condition related to the captured image 50 acquired by the acquisition unit 40C from the storage unit 40A, and may calculate a film thickness of the supply layer 36 based on the read relationship information 41A in the same manner as described above.
Next, a description will be made of an example of a hardware configuration of the controller 40 provided in the imprinting apparatus 1.
The controller 40 of the embodiment includes a CPU 60, storage devices such as a read only memory (ROM) 62, a random access memory (RAM) 64, and a hard disk drive (HDD) 66, an I/F unit 68 that is an interface with various apparatuses, and a bus 69 connecting the respective elements to each other, and has a hardware configuration using a typical computer.
In the controller 40 of the embodiment, the CPU 60 reads a program from the ROM 62 to the RAM 64, and executes the program, and thus the units are implemented on the computer.
A program for executing each process executed by the controller 40 of the embodiment may be stored in the HDD 66. The program for executing each process executed by the controller 40 of the embodiment may be incorporated into the ROM 62 to be provided.
The program for executing each process executed by the controller 40 of the embodiment may be stored on a computer readable storage medium such as a CD-ROM, a CD-R, a memory card, a digital versatile disk (DVD), or a flexible disk (FD) in a file with an installable form or an executable form, to be provided as a computer program product. The program for executing each process executed by the controller 40 of the embodiment may be stored on a computer coupled to a network such as the Internet, and may be downloaded via the network to be provided. The program for executing each process executed by the controller 40 of the embodiment may be provided or distributed via a network such as the Internet.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.
Number | Date | Country | Kind |
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2019-132049 | Jul 2019 | JP | national |