US-12619156-B2 - EUV light uniformity control apparatus, EUV exposure equipment including the same, and method of controlling EUV light uniformity by using the control apparatus

Abstract

An extreme ultraviolet (EUV) light uniformity control apparatus includes a plurality of nano thin-films each having a band shape extending in a first direction that is a scanning direction of EUV exposure equipment and linearly arranged under a reticle of the EUV exposure equipment in a second direction that is perpendicular to the first direction. The apparatus further includes thin film mounts fixing the nano thin-films on both sides in the first direction, and a thin film control device connected to the thin film mounts and controlling the nano thin-films. EUV light from the EUV exposure equipment is projected onto a wafer that is an exposure target, after passing through the nano thin-films twice by being incident to and reflected from the reticle, and the EUV light projected on the wafer is uniformly adjusted by using the thin film control device.

Inventors

• EUNHEE JEANG
• Jeonggil KIM

Assignees

• SAMSUNG ELECTRONICS CO., LTD.

Dates

Publication Date

20260505

Application Date

20230629

Priority Date

20221130

Claims (20)

1. 1 . An extreme ultraviolet (EUV) light uniformity control apparatus comprising: a plurality of nano thin-films each having a band shape extending in a first direction that is a scanning direction of EUV exposure equipment and linearly arranged under a reticle of the EUV exposure equipment in a second direction that is perpendicular to the first direction; thin film mounts fixing the plurality of nano thin-films on two opposite sides in the first direction; and a thin film control device connected to the thin film mounts and configured to control the plurality of nano thin-films, wherein EUV light from the EUV exposure equipment is projected onto a wafer that is an exposure target, after passing through the plurality of nano thin-films twice by being incident to and reflected from the reticle, and wherein the thin film control device is configured to adjust a uniformity of the EUV light projected on the wafer.
2. 2 . The EUV light uniformity control apparatus of claim 1 , wherein each of the plurality of nano thin-films has a transmittance of about 80% to about 99%, and wherein the thin film control device is configured to implement a transmittance of less than 80% by overlapping at least two nano thin-films of the plurality of nano thin-films.
3. 3 . The EUV light uniformity control apparatus of claim 1 , wherein each of the plurality of nano thin-films has a width of about 1 to about 15 mm in the second direction and a width of about 40 to about 100 mm in the first direction.
4. 4 . The EUV light uniformity control apparatus of claim 1 , wherein each of the plurality of nano thin-films includes one of silicon (Si), silicon carbide (SIC), silicon nitride (SiNx), and a carbon-based material.
5. 5 . The EUV light uniformity control apparatus of claim 1 , wherein the thin film control device includes a position adjusting device for moving the thin film mounts, and the thin film control device is configured to control a position of each of the plurality of nano thin-films by moving each of the thin film mounts in at least one of the first direction or the second direction.
6. 6 . The EUV light uniformity control apparatus of claim 5 , wherein the thin film control device is configured to move at least two nano thin-films of the plurality of nano thin-films along the first direction so as to overlap each other.
7. 7 . The EUV light uniformity control apparatus of claim 1 , wherein each of the plurality of nano thin-films includes a material having a transmittance that changes according to a voltage, the thin film control device includes a voltage applying device that is configured to apply a voltage to each of the plurality of nano thin-films via the thin film mounts, and the thin film control device is configured to control a transmittance of each of the plurality of nano thin-films by adjusting the voltage applied to the nano thin-film.
8. 8 . The EUV light uniformity control apparatus of claim 1 , wherein each of the thin film mounts includes a cooling device.
9. 9 . The EUV light uniformity control apparatus of claim 1 , wherein the thin film mounts fix each of the plurality of nano thin-films on two opposite sides in the first direction.
10. 10 . Extreme ultraviolet (EUV) exposure equipment comprising: an EUV source configured to generate and emit EUV light; a first optical system configured to transfer the EUV light from the EUV source to be incident on a reticle; a reticle stage on which the reticle is disposed; a second optical system configured to transfer the EUV light reflected by the reticle to a wafer that is an exposure target; and an EUV light uniformity control apparatus that is disposed under the reticle, that includes nano thin-films through which the EUV light passes, and that is configured to adjust the EUV light projected on the wafer, wherein the EUV light uniformity control apparatus comprises thin film mounts fixing each of the nano thin-films on two opposite sides in a first direction.
11. 11 . The EUV exposure equipment of claim 10 , wherein each of the nano thin-films has a band shape extending in the first direction, wherein the first direction is a scanning direction of the EUV exposure equipment, wherein the nano thin-films are linearly arranged under the reticle in a second direction that is perpendicular to the first direction, and wherein the EUV light uniformity control apparatus comprises: a thin film control device connected to the thin film mounts and configured to control the nano thin-films, wherein the EUV light uniformity control apparatus is configured such that the EUV light is projected onto the wafer, after passing through the nano thin-films twice by being incident on and reflected from the reticle, and wherein the EUV light uniformity control apparatus is configured to adjust the EUV light projected on the wafer to be uniform by using the thin film control device.
12. 12 . The EUV exposure equipment of claim 11 , wherein each of the nano thin-films has a transmittance of about 80% to about 99%, and wherein the thin film control device is configured to implement a transmittance less than 80% by overlaying at least two nano thin-films of the nano thin-films.
13. 13 . The EUV exposure equipment of claim 11 , wherein each of the nano thin-films includes one of silicon (Si), silicon carbide (SiC), silicon nitride (SiNx), and a carbon-based material.
14. 14 . The EUV exposure equipment of claim 11 , wherein the thin film control device includes a position adjusting device for moving the thin film mounts, and the thin film control device is configured to control a position of each of the nano thin-films by moving the thin film mounts in at least one of the first direction or the second direction.
15. 15 . The EUV exposure equipment of claim 11 , wherein each of the nano thin-films includes a material having a transmittance that changes according to a voltage, the thin film control device includes a voltage applying device configured to apply a voltage to each of the nano thin-films via the thin film mounts, and the thin film control device is configured to control a transmittance of each of the nano thin-films by adjusting the voltage applied to the nano thin-film.
16. 16 . The EUV exposure equipment of claim 11 , further comprising: a measurement device for measuring an intensity of the EUV light on a wafer stage on which the wafer is disposed; and a signal processing unit configured to: calculate a uniformity of the EUV light on the wafer and a transmittance for each of the nano thin-films at a certain position under the reticle based on the intensity, and transfer a control signal to the thin film control device based on the transmittance for each of the nano thin-films.
17. 17 . The EUV exposure equipment of claim 16 , wherein the signal processing unit is configured to, for each EUV exposure equipment of a plurality of the EUV exposure equipment: analyze a uniformity of EUV light generated by the EUV exposure equipment, control nano thin-films in the EUV exposure equipment based on the uniformity of the EUV light generated by the EUV exposure equipment, and manage the uniformity of the EUV light generated by the EUV exposure equipment.
18. 18 . Extreme ultraviolet (EUV) exposure equipment comprising: an EUV source configured to generate and emit EUV light; a first optical system configured to transfer the EUV light from the EUV source to be incident to a reticle; a reticle stage on which the reticle is disposed; a second optical system configured to transfer the EUV light reflected by the reticle to a wafer that is an exposure target; a wafer stage on which the wafer is disposed; and an EUV light uniformity control apparatus disposed under the reticle and configured to adjust a uniformity of the EUV light on the wafer, wherein the EUV light uniformity control apparatus comprises: a plurality of nano thin-films each having a band shape extending in a first direction that is a scanning direction of the EUV exposure equipment and linearly arranged under the reticle in a second direction that is perpendicular to the first direction; thin film mounts fixing each of the plurality of nano thin-films on two opposite sides in the first direction; and a thin film control device connected to the thin film mounts and configured to control the plurality of nano thin-films, wherein; the EUV light is projected onto the wafer, after passing through the nano thin-films twice by being incident on and reflected from the reticle, the EUV light uniformity control apparatus is configured to adjust the EUV light to be uniform by using the thin film control device, the EUV light being projected on the wafer, and the thin film control device comprises at least one of a position adjusting device configured to move the thin film mounts or a voltage applying device configured to apply voltages to the plurality of nano thin-films via the thin film mounts.
19. 19 . The EUV exposure equipment of claim 18 , wherein the thin film control device includes the position adjusting device, and the position adjusting device is configured to move at least two nano thin-films of the plurality of nano thin-films along the first direction so as to overlap each other.
20. 20 . The EUV exposure equipment of claim 18 , wherein each of the plurality of nano thin-films includes a material having a transmittance that changes is according to a voltage, the thin film control device includes the voltage applying device, and the voltage applying device is configured to change a transmittance of each of the plurality of nano thin-films by adjusting a voltage applied to the nano thin-film.

Description

CROSS-REFERENCE TO RELATED APPLICATION A claim of priority under 35 U.S.C. § 119 is made to Korean Patent Application No. 10-2022-0165098, filed on Nov. 30, 2022, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety. BACKGROUND The inventive concept relates to extreme ultra-violet (EUV) exposure equipment, and in particular, an EUV light uniformity control apparatus capable of adjusting the uniformity of EUV light, and EUV exposure equipment that includes the control apparatus. As line widths of a semiconductor circuit have become finer, a light source of shorter wavelength is required. For example, EUV light is used as an exposure source. Due to an absorption characteristic of EUV light, a reflective-type EUV mask is generally used in an EUV exposure process. Also, illumination optics for transferring the EUV light to an EUV mask and projection optics for projecting EUV light reflected by the EUV mask onto an exposure target may include a plurality of mirrors. Due to increased complexity of an exposure process, even a small error occurring on the EUV mask or mirrors may lead to a severe error in forming of patterns on a wafer. SUMMARY The inventive concept provides an extreme ultra-violet (EUV) light uniformity control apparatus capable of uniformly adjusting EUV light projected onto a wafer, EUV exposure equipment including the control apparatus, and a method of controlling EUV light uniformity by using the control apparatus. It will be appreciated by one of ordinary skill in the art that that the objectives and effects that could be achieved with the inventive concept are not limited to what has been particularly described above and other objectives of the inventive concept will be more clearly understood from the following detailed description. According to an aspect of the inventive concept, an extreme ultraviolet (EUV) light uniformity control apparatus is provided that includes a plurality of nano thin-films each having a band shape extending in a first direction that is a scanning direction of EUV exposure equipment and linearly arranged under a reticle of the EUV exposure equipment in a second direction that is perpendicular to the first direction. The apparatus further includes thin film mounts fixing the nano thin-films on both sides in the first direction, and a thin film control device connected to the thin film mounts and controlling the nano thin-films. EUV light from the EUV exposure equipment is projected onto a wafer that is an exposure target, after passing through the nano thin-films twice by being incident to and reflected from the reticle, and the EUV light projected on the wafer is uniformly adjusted by using the thin film control device. According to an aspect of the inventive concept, an extreme ultraviolet (EUV) exposure equipment is provided that includes an EUV source generating and emitting EUV light, a first optical system transferring the EUV light from the EUV source to be incident on a reticle, a reticle stage on which the reticle is disposed, a second optical system transferring the EUV light reflected by the reticle to a wafer that is an exposure target, and an EUV light uniformity control apparatus that is disposed under the reticle, that includes nano thin-films through which the EUV light passes, and that adjusts the EUV light projected on the wafer. According to an aspect of the inventive concept, an extreme ultraviolet (EUV) exposure equipment is provided that includes an EUV source generating and emitting EUV light, a first optical system transferring the EUV light from the EUV source to be incident to a reticle, a reticle stage on which the reticle is disposed, a second optical system transferring the EUV light reflected by the reticle to a wafer that is an exposure target, a wafer stage on which the wafer is disposed, and an EUV light uniformity control apparatus disposed under the reticle and adjusting uniformity of the EUV light on the wafer. The EUV light uniformity control apparatus includes a plurality of nano thin-films each having a band shape extending in a first direction that is a scanning direction of the EUV exposure equipment and linearly arranged under the reticle in a second direction that is perpendicular to the first direction, thin film mounts fixing the nano thin-films on both sides in the first direction, and a thin film control device connected to the thin film mounts and controlling the nano thin-films. The EUV light is projected onto the wafer, after passing through the nano thin-films twice by being incident on and reflected from the reticle, the EUV light uniformity control apparatus adjusts the EUV light to be uniform by using the thin film control device, the EUV light being projected on the wafer, and the thin film control device comprises at least one of a position adjusting device for moving the thin film mounts or a voltage applying device for applying voltages to the