A method for modifying the apertures of a hard mask and photoresist to achieve a desired critical dimension.
Directed deposition and implantation processes address the challenge of achieving accurate nanometer-scale dimensions in semiconductor devices by modifying mask openings, enhancing device performance and reliability.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- APPLIED MATERIALS INC
- Filing Date
- 2024-08-07
- Publication Date
- 2026-05-26
AI Technical Summary
Manufacturing semiconductor devices with highly accurate nanometer-scale critical dimensions is challenging due to manufacturing constraints, leading to deviations in aperture dimensions that affect device performance and reliability.
Employing directed deposition and implantation processes to modify mask openings, including methods such as pre-injection, directional deposition, and post-injection, to achieve precise critical dimensions.
Enables the formation of semiconductor device features with accurate nanometer-scale dimensions, improving device performance and reliability by ensuring precise aperture shapes and sizes.
Smart Images
Figure 2026516612000001_ABST
Abstract
Description
Technical Field
[0001] Cross - Reference to Related Applications
[0001] This application claims the benefit of priority of U.S. Application No. 18 / 243,042, filed on September 6, 2023, entitled "Methods of Modifying Openings in Hardmasks and Photoresists to Achieve Desired Critical Dimensions", which is hereby incorporated by reference in its entirety.
[0002]
[0002] Embodiments of the present disclosure generally relate to the field of semiconductor device manufacturing, and more specifically, to methods of modifying the size and shape of openings in hardmasks and photoresists to achieve desired critical dimensions.
Background Art
[0003]
[0003] Semiconductor device manufacturing uses many distinct processes to create desired features within a semiconductor substrate. Some of these processes include lithography, etching, deposition, and ion implantation. In the case of etching, a layer of material called a hardmask or photoresist is placed on the surface of the semiconductor substrate to be etched. The openings in the hardmask expose the underlying substrate. An ion beam formed by reactive plasma ions is directed at the hardmask, and the exposed portions of the underlying substrate are etched by the ion beam, creating desired features (e.g., trenches) therein, while other portions of the substrate are shielded from the ion beam by the hardmask.
[0004]
[0004] As semiconductor devices continue to expand to smaller dimensions, patterning surface features within semiconductor substrates is becoming increasingly difficult due to manufacturing constraints. For example, it is difficult to manufacture hard masks with apertures having highly accurate nanometer-scale critical dimensions (e.g., apertures with dimensions of 10 nanometers × 20 nanometers) with minimal variation. Apertures with critical dimensions that deviate from the desired value can adversely affect the performance and reliability of the finished semiconductor device.
[0005]
[0005] Improvements to this disclosure may be useful in relation to the above considerations and other considerations. [Overview of the Initiative]
[0006]
[0006] This summary is provided to introduce, in a simplified form, some of the concepts selected from those further detailed in the following "Modes for Carrying Out the Invention". This summary is not intended to identify any important or essential features of the subject matter of the claimed invention, nor is it intended to help determine the scope of the subject matter of the claimed invention.
[0007]
[0007] A method for modifying an opening in a mask to achieve a desired critical dimension according to an embodiment of the present disclosure may include directing a first radical beam to a first side of the opening to deposit a layer of material on the first side, and directing a second radical beam to a second side of the opening opposite to the first side to deposit a layer of material on the second side.
[0008]
[0008] Another method for modifying the opening of a mask to achieve a desired critical dimension according to one embodiment of the present disclosure is to perform a pre-injection of the mask to inject a dopant material into the mask, the pre-injection of which the material of the mask is densified and the opening is enlarged, to direct a first radical beam to a first side of the opening to deposit a layer of material on the first side, and to direct a second radical beam to a second side of the opening opposite to the first side to deposit a layer of material on the second side.
[0009]
[0009] Another method for modifying the opening of a mask to achieve a desired critical dimension according to embodiments of the present disclosure may include directing a first radical beam to a first side of the opening to deposit a layer of material on the first side; directing a second radical beam to a second side of the opening to deposit a layer of material on the second side; and performing a post-injection of the mask, the post-injection of which includes directing a first ion beam to the mask in a first direction to inject dopant material into the mask; and directing a second ion beam to the mask in a second direction opposite to the first direction to inject dopant material into the mask, the post-injection of which the material in the mask is densified and the opening is enlarged in the first and second directions.
[0010]
[0010] Herein, various embodiments of the disclosed technology will be described as examples with reference to the accompanying drawings. [Brief explanation of the drawing]
[0011] [Figure 1A-1C] These are a top view, a first cross-sectional view, and a second cross-sectional view showing the semiconductor substrate and mask according to this disclosure. [Figure 2A-2C] This is a top view, a first cross-sectional view, and a second cross-sectional view illustrating a first method according to one embodiment of the present disclosure. [Figure 3A-3C] These are a top view, a first cross-sectional view, and a second cross-sectional view illustrating the first step of a second method according to an embodiment of the present disclosure. [Figure 4A-4C] These are a top view, a first cross-sectional view, and a second cross-sectional view illustrating a second step of a second method according to an embodiment of the present disclosure. [Figure 5A-5C] These are a top view, a first cross-sectional view, and a second cross-sectional view illustrating the first step of a third method according to an embodiment of the present disclosure. [Figure 6A-6C] These are a top view, a first cross-sectional view, and a second cross-sectional view illustrating the second step of the third method according to an embodiment of the present disclosure. [Figure 7A-7C] These are a top view, a first cross-sectional view, and a second cross-sectional view illustrating the first step of a fourth method according to an embodiment of the present disclosure. [Figures 8A-8C] A top view, a first cross-sectional view, and a second cross-sectional view illustrating a second step of a fourth method according to one embodiment of the present disclosure. [Modes for carrying out the invention]
[0012]
[0019] Herein, this embodiment will be described more fully with reference to the accompanying drawings, which illustrate several embodiments. The subject matter of this disclosure may be embodied in many different forms and should not be construed as being limited to the embodiments described herein. These embodiments are provided to convey to those skilled in the art certain exemplary aspects of the subject matter, so as to be comprehensive and complete. Throughout the drawings, similar numbers indicate similar elements.
[0013]
[0020] Referring to Figure 1A, a top view is shown of a hard mask or photoresist 10 (hereinafter generally referred to as "mask 10") placed on a semiconductor substrate 12. Figures 1B and 1C show cross-sectional views cut along lines AA and BB, respectively. The mask 10 has openings 14 formed therein, which allow the underlying substrate 12 to be exposed (i.e., when viewed from above). During the etching process, an ion beam formed by reactive plasma ions can be directed from above toward the mask 10. The exposed portion of the lower substrate 12 (i.e., the portion of the substrate 12 directly below the openings 14) is etched by the ion beam, creating desired features (e.g., trenches) therein, while other portions of the substrate 12 are shielded from the ion beam by the mask 10.
[0014]
[0021] In various embodiments, the mask 10 may be formed of silicon dioxide or silicon carbide. The disclosure is not limited thereto, and alternatively, the mask 10 may be formed of other hard mask or photoresist materials known to those skilled in the art.
[0015]
[0022] When the mask 10 is manufactured, the openings 14 of the mask 10 are ideally formed in a desired shape with a desired dimension, often called the “critical dimension” (CD), in order to transfer the desired etching pattern to the substrate. However, due to manufacturing constraints, it may be difficult or impossible to manufacture a mask having openings in a particular shape with nanometer-scale dimensions (in this specification, “nanometer-scale” is defined as meaning less than 1000 nanometers) with reliability and precision. For example, it has been found difficult to form a slot with a width of 10 nanometers and a length of 20 nanometers. “Width” is defined herein as the dimension measured in a direction parallel to the Y-axis of the Cartesian coordinate system shown in Figure 1A, and “length” is defined herein as the dimension measured in a direction parallel to the X-axis of the Cartesian coordinate system shown in Figure 1A. The aforementioned dimensions are not intended to be limiting and are provided for illustrative purposes only.
[0016]
[0023] Embodiments of the present disclosure aim to address issues related to manufacturing openings with accurate nanometer-scale dimensions by using directed deposition and implantation processes to modify openings formed using conventional manufacturing processes.
[0017]
[0024] Directed deposition
[0025] In a first method of the present disclosure, as shown in FIG. 1A, a mask 10 and an underlying substrate 12 are provided. The mask 10 may have a circular opening formed using a conventional manufacturing technique including, but not limited to, extreme ultraviolet (EUV) lithography. In a non-limiting example, the opening 14 may have a diameter of 20 nanometers.
[0018]
[0026] Referring to FIGS. 2A through 2C, a directed deposition process may be performed, and a first radical beam 16 emitted from a plasma enhanced chemical vapor deposition (PECVD) source (not shown) may be projected onto the mask 10 in a first direction parallel to the Y axis of the Cartesian coordinate system shown in FIG. 2A, and a second radical beam 16 emitted from a PECVD source (not shown) may be projected onto the mask 10 in a second direction parallel to the Y axis of the Cartesian coordinate system shown in FIG. 2A, the second direction being opposite to the first direction. In various embodiments, the deposited material may be carbon. The present disclosure is not limited in this regard.
[0019]
[0027] The first and second radical beams 16, 18 may be emitted from two separate PECVD sources or continuously from one PECVD source, and the mask 10 and / or PECVD sources may be repositioned between the first and second depositions to achieve deposition on opposing portions of the mask 10. For example, the mask 10 can be rotated 180 degrees between the first and second depositions about a central axis parallel to the Z-axis of the Cartesian coordinate system shown in Figure 2B. The first and second radical beams 16, 18 may be directed toward the mask 10 at angles ranging from 30 to 60 degrees (e.g., 45 degrees) with respect to the Y-axis of the Cartesian coordinate system shown in Figure 2B (i.e., with respect to the top surface of the mask 10) to deposit a layer of material having generally uniform thickness from the top of the opening 14 furthest from the substrate 12 to the bottom of the opening closest to the substrate 12. The disclosure is not limited in this respect.
[0020]
[0028] It is understood that the round opening does not have multiple sides. However, for the purposes of the description herein, the portions of the opening 14 shown in FIG. 2A that are closest to the top and bottom of the page are referred to herein as the "sides" of the opening 14, and the portions of the opening 14 shown in FIG. 2A that are closest to the left and right of the page are referred to herein as the "longitudinal sides" of the opening 14. Thus, it may be said that the first radical beam 16 and the second radical beam 18 are directed towards opposite sides of the opening 14. As shown in FIGS. 2A - 2C, most of the material deposited by the first radical beam 16 and the second radical beam 18 may be deposited on the opposite sides of the opening onto which the first radical beam 16 and the second radical beam 18 are projected. Thus, the width of the opening 14 can be reduced to a desired width of, for example, about 10 nanometers from 20 nanometers, and thus, as best shown in FIG. 2A, the opening 14 is converted from a hole to a slot (a "slot" is defined herein to mean an opening having a length greater than its width). However, since the opening 14 is circular and the radical beam is susceptible to some spreading, some material is also deposited on the longitudinal sides of the opening 14. Of course, the amount of material deposited on the longitudinal sides of the opening 14 will be less than the amount of material deposited on the lateral sides of the opening 14, and the slot shape can still be achieved.
[0021]
[0029] After the deposition process described above is performed, an etching process may be performed, and an ion beam formed by reactive plasma ions may be directed from above towards the mask 10. The exposed portion of the underlying substrate 12 (i.e., the portion of the substrate 12 directly below the opening 14) may be etched by the ion beam, and a slot may be formed, while other portions of the substrate 12 are shielded from the ion beam by the mask 10.
[0022]
[0030] Pre - injection + Directed deposition
[0031] In a second method of this disclosure, a mask 10 and a substrate 12 are provided, as shown in Figure 1A. The mask 10 may have a round opening formed using conventional manufacturing techniques, including but not limited to EUV lithography. In a non-limiting example, the opening 14 may have a diameter of 20 nanometers.
[0023]
[0032] Referring to Figures 3A to 3C, an implantation process (pre-implantation) may be performed, in which multiple ion beams 20, one emitted from multiple ion sources (not shown), are projected onto the mask 10, and dopant material may be implanted into the mask 10. In various embodiments, the dopant material may be argon, carbon, or another material selected to increase the density of the mask 10, as will be further described below. The mask 10 and / or ion sources may be scanned, tilted, rotated, or otherwise repositioned during the implantation process to achieve uniform implantation of the mask 10. For example, the mask 10 may be rotated 180 degrees around a central axis parallel to the Z-axis of the Cartesian coordinate system shown in Figure 3A. The ion beams 20 may be directed towards the mask 10 at angles ranging from 30 to 60 degrees (e.g., 45 degrees) with respect to the Y and X axes of the Cartesian coordinate system shown in Figures 3B and 3C (i.e., with respect to the top surface of the mask 10). The disclosure is not limited in this respect.
[0024]
[0033] The injection process described above may increase the density of the mask 10 material, shrink the portion of the mask 10 between the openings 14, and enlarge the openings 14 themselves. For example, the openings 14 may be enlarged from a first diameter of 20 nanometers shown in Figures 1A-1C to a second diameter of approximately 25 nanometers shown in Figures 3A-3B. The disclosure is not limited in this respect.
[0025]
[0034] Referring to Figures 4A to 4C, a directional deposition process may be performed on a high-density mask 10, and a first radical beam 16 emitted from a PECVD source (not shown) may be projected onto the mask 10 in a first direction parallel to the Y-axis of the Cartesian coordinate system shown in Figure 4A, and a second radical beam 16 emitted from a PECVD source (not shown) may be projected onto the mask 10 in a second direction parallel to the Y-axis of the Cartesian coordinate system shown in Figure 4A, the second direction being opposite to the first direction. In various embodiments, the deposited material may be carbon. The disclosure is not limited in this respect.
[0026]
[0035] The first and second radical beams 16, 18 may be emitted from two separate PECVD sources or continuously from one PECVD source, and the mask 10 and / or PECVD sources may be repositioned between the first and second depositions to achieve deposition on opposing portions of the mask 10. For example, the mask 10 can be rotated 180 degrees between the first and second depositions about a central axis parallel to the Z-axis of the Cartesian coordinate system shown in Figure 4B. The first and second radical beams 16, 18 may be directed toward the mask 10 at an angle of 30 to 60 degrees (e.g., 45 degrees) with respect to the Y-axis of the Cartesian coordinate system shown in Figure 4B to deposit a layer of material having generally uniform thickness from the top of the opening 14 furthest from the substrate 12 to the bottom of the opening closest to the substrate 12. The disclosure is not limited in this respect.
[0027]
[0036] While it is understood that a round opening does not have multiple sides, for the purposes of this specification, the portions of the opening 14 shown in Figure 4A that are closest to the top and bottom of the page are referred to herein as the “sides” of the opening 14, and the portions of the opening 14 shown in Figure 4A that are closest to the left and right sides of the page are referred to herein as the “longitudinal sides” of the opening 14. Thus, it can be said that the first radical beam 16 and the second radical beam 18 are directed toward the opposing sides of the opening 14. As shown in Figures 4A to 4C, the majority of the material deposited by the first radical beam 16 and the second radical beam 18 can be deposited toward the opposing sides of the opening toward which the first radical beam 16 and the second radical beam 18 are projected. Thus, the width of the opening 14 can be reduced from 20 nanometers to a desired width of (for example) about 10 nanometers, and thus the opening 14 can be converted from a hole to a slot, as best shown in Figure 4A. However, since the opening 14 is circular and the radical beam is susceptible to some degree of spreading, some material is deposited on the longitudinal sides of the opening 14. Naturally, the amount of material deposited on the longitudinal sides of the opening 14 is less than the amount of material deposited on the lateral sides of the opening 14, and a slot shape can still be realized.
[0028]
[0037] Furthermore, since the opening 14 had been previously enlarged by the injection process described above, the material deposited on the longitudinal side of the opening 14 reduces the opening to a length of 20 nanometers (i.e., the original "length" of the opening provided in Figures 1A-1C), thus producing a slot of the desired dimensions of 20 nanometers with a width of 10 nanometers. This should be contrasted with Method 1 described above, in which the length of the opening 14 was reduced to a value less than the desired length of 20 nanometers by deposition on the longitudinal side of the opening 14.
[0029]
[0038] After the injection and deposition processes described above are carried out, an etching process may be performed, in which an ion beam formed by reactive plasma ions may be directed from above toward the mask 10. The exposed portion of the lower substrate 12 (i.e., the portion of the substrate 12 directly below the opening 14) may be etched by the ion beam to form slots, while the rest of the substrate 12 is shielded from the ion beam by the mask 10.
[0030]
[0039] Directional pre-injection + directional deposition
[0040] In a third method of this disclosure, a mask 10 and a substrate 12 are provided, as shown in Figure 1A. The mask 10 may have a round opening formed using conventional manufacturing techniques, including but not limited to EUV lithography. In a non-limiting example, the opening 14 may have a diameter of 20 nanometers.
[0031]
[0041] Referring to Figures 5A to 5C, a directional injection process ("directional pre-injection") may be performed, injecting dopant material into the mask 11 by projecting one or more ion beams 20 emitted from one or more ion sources (not shown) onto the mask 10 in a direction parallel to the X-axis of the Cartesian coordinate system shown in Figure 5A (or in two opposing directions). In various embodiments, the dopant material may be argon, carbon, or another material selected to increase the density of the mask 10, as will be further described below. The mask 10 and / or one or more ion sources may be scanned, tilted, rotated, or otherwise repositioned during the injection process to achieve injection in a direction parallel to the X-axis of the Cartesian coordinate system (or in two opposing directions). For example, the mask 10 may be rotated 180 degrees around a central axis parallel to the Z-axis of the Cartesian coordinate system shown in Figure 5A. The ion beam 20 can be directed toward the mask 10 at an angle ranging from 30 to 60 degrees (e.g., 45 degrees) with respect to the X-axis of the Cartesian coordinate system shown in Figure 5C (i.e., with respect to the top surface of the mask 10). The disclosure is not limited in this respect.
[0032]
[0042] The injection process described above densifies the material of the mask 10 in a direction parallel to the X-axis of the Cartesian coordinate system, thereby causing the portion of the mask 10 between the openings 14 to contract in a direction parallel to the X-axis of the Cartesian coordinate system, while the openings 14 themselves expand in a direction parallel to the X-axis of the Cartesian coordinate system. In particular, unlike the embodiment of Method 2 described above, the ion beam 20 is not projected onto the mask 10 in a direction parallel to the Y-axis of the Cartesian coordinate system, and therefore the openings are not expanded in a direction parallel to the Y-axis of the Cartesian coordinate system (i.e., the openings 14 lengthen but do not widen). For example, the openings 14 can be expanded from a first length of 20 nanometers shown in Figures 1A-1C to a second length of 25 nanometers shown in Figures 5A-5B, while the original width of the openings 14 is maintained. The present disclosure is not limited in this respect.
[0033]
[0043] Referring to Figures 6A to 6C, a directional deposition process may be performed on a high-density mask 10, and a first radical beam 16 emitted from a PECVD source (not shown) may be projected onto the mask 10 in a first direction parallel to the Y-axis of the Cartesian coordinate system shown in Figure 6A, and a second radical beam 16 emitted from a PECVD source (not shown) may be projected onto the mask 10 in a second direction parallel to the Y-axis of the Cartesian coordinate system shown in Figure 6A, the second direction being opposite to the first direction. In various embodiments, the deposited material may be carbon. The disclosure is not limited in this respect.
[0034]
[0044] The first and second radical beams 16, 18 may be emitted from two separate PECVD sources or continuously from one PECVD source, and the mask 10 and / or PECVD sources may be repositioned between the first and second depositions to achieve deposition on opposing portions of the mask 10. For example, the mask 10 can be rotated 180 degrees between the first and second depositions about a central axis parallel to the Z-axis of the Cartesian coordinate system shown in Figure 6B. The first and second radical beams 16, 18 may be directed toward the mask 10 at angles ranging from 30 to 60 degrees (e.g., 45 degrees) with respect to the Y-axis of the Cartesian coordinate system shown in Figure 6B (i.e., with respect to the top surface of the mask 10) to deposit a layer of material having generally uniform thickness from the top of the opening 14 furthest from the substrate 12 to the bottom of the opening closest to the substrate 12. The disclosure is not limited in this respect.
[0035]
[0045] While it is understood that a round opening does not have multiple sides, for the purposes of this specification, the portions of the opening 14 shown in Figure 6A that are closest to the top and bottom of the page are referred to herein as the “sides” of the opening 14, and the portions of the opening 14 shown in Figure 6A that are closest to the left and right sides of the page are referred to herein as the “longitudinal sides” of the opening 14. Thus, it can be said that the first radical beam 16 and the second radical beam 18 are directed toward the opposing sides of the opening 14. As shown in Figures 6A to 6C, most or all of the material deposited by the first radical beam 16 and the second radical beam 18 may be deposited toward the opposing sides of the opening toward which the first radical beam 16 and the second radical beam 18 are projected. Thus, the width of the opening 14 can be reduced from 20 nanometers to a desired width of (for example) about 10 nanometers, and thus the opening 14 is converted from a hole to a slot, as best shown in Figure 6A. However, since the opening 14 is circular and the radical beam is susceptible to some degree of spreading, some material may accumulate on the longitudinal sides of the opening 14. Naturally, the amount of material accumulated on the longitudinal sides of the opening 14 will be less than the amount of material that would otherwise accumulate on the longitudinal sides of the opening 14, and the slot shape can still be realized.
[0036]
[0046] Since the opening 14 was not initially widened as in Method 2 (i.e., expanded in a direction parallel to the Y-axis of the Cartesian coordinate system), the amount of deposit required to reduce the width of the opening 14 to the desired value (e.g., 10 nanometers) is reduced compared to Method 2. Consequently, the amount of lateral deposit on the longitudinal side of the opening 14 is also reduced compared to Method 2. In other words, the opening 14 can be initially stretched to a length less than in Method 2 to realize a slot with the same desired dimensions (e.g., 20 nanometers in length × 10 nanometers in width).
[0037]
[0047] After the injection and deposition processes described above are carried out, an etching process may be performed, in which an ion beam formed by reactive plasma ions may be directed from above toward the mask 10. The exposed portion of the lower substrate 12 (i.e., the portion of the substrate 12 directly below the opening 14) may be etched by the ion beam to form slots, while the rest of the substrate 12 is shielded from the ion beam by the mask 10.
[0038]
[0048] Directional deposition + directional post-injection
[0049] A fourth method of this disclosure provides a mask 10 and a substrate 12, as shown in Figure 1A. The mask 10 may have a round opening formed using conventional manufacturing techniques, including but not limited to EUV lithography. In a non-limiting example, the opening 14 may have a diameter of 20 nanometers.
[0039]
[0050] Referring to Figures 7A to 7C, a directed deposition process can be performed similarly to Method 1 described above, where a first radical beam 16 emitted from a plasma chemical vapor deposition (PECVD) source (not shown) may be projected onto the mask 10 in a first direction parallel to the Y-axis of the Cartesian coordinate system shown in Figure 7A, and a second radical beam 16 emitted from a PECVD source (not shown) may be projected onto the mask 10 in a second direction parallel to the Y-axis of the Cartesian coordinate system shown in Figure 7A, the second direction being opposite to the first direction. In various embodiments, the deposited material may be carbon. The disclosure is not limited in this respect.
[0040]
[0051] The first and second radical beams 16, 18 may be emitted from two separate PECVD sources or continuously from one PECVD source, and the mask 10 and / or PECVD sources may be repositioned between the first and second depositions to achieve deposition on opposing portions of the mask 10. For example, the mask 10 can be rotated 180 degrees between the first and second depositions about a central axis parallel to the Z-axis of the Cartesian coordinate system shown in Figure 7B. The first and second radical beams 16, 18 may be directed toward the mask 10 at angles ranging from 30 to 60 degrees (e.g., 45 degrees) with respect to the Y-axis of the Cartesian coordinate system shown in Figure 7B (i.e., with respect to the top surface of the mask 10) to deposit a layer of material having generally uniform thickness from the top of the opening 14 furthest from the substrate 12 to the bottom of the opening closest to the substrate 12. The disclosure is not limited in this respect.
[0041]
[0052] While it is understood that a round opening does not have multiple sides, for the purposes of this specification, the portions of the opening 14 shown in Figure 7A that are closest to the top and bottom of the page are referred to herein as the “sides” of the opening 14, and the portions of the opening 14 shown in Figure 7A that are closest to the left and right sides of the page are referred to herein as the “longitudinal sides” of the opening 14. Thus, it can be said that the first radical beam 16 and the second radical beam 18 are directed toward the opposing sides of the opening 14. As shown in Figures 7A to 7C, the majority of the material deposited by the first radical beam 16 and the second radical beam 18 can be deposited toward the opposing sides of the opening toward which the first radical beam 16 and the second radical beam 18 are projected. Thus, the width of the opening 14 can be reduced from 20 nanometers to a desired width of (for example) about 10 nanometers, and thus the opening 14 can be converted from a hole to a slot (wherein “slot” is defined herein to mean an opening having a length greater than its width), as is best shown in Figure 7A. However, since the aperture 14 is circular and the radical beam is susceptible to some degree of spreading, some material is deposited on the longitudinal sides of the aperture 14. Naturally, the amount of material deposited on the longitudinal sides of the aperture 14 is less than the amount deposited on the lateral sides of the aperture 14, and a slot shape can still be realized. Nevertheless, the deposition on the longitudinal sides of the aperture 14 can reduce the length of the aperture to below a desired value. For example, the length of the aperture 14 can be shortened from 20 nanometers to a desired value of about 15 nanometers.
[0042]
[0053] To realize slots having a desired length (e.g., 20 nanometers), a directed injection process ("directed post-injection") may be performed, referring to Figures 8A-8C, in which one or more ion beams 20 emitted from one or more ion sources (not shown) are projected onto the mask 10 in a direction parallel to the X-axis of the Cartesian coordinate system shown in Figure 8A (or two opposite directions) to inject dopant material into the mask 10. In various embodiments, the dopant material may be argon, carbon, or another material selected to increase the density of the mask 10, as will be further described below. The mask 10 and / or one or more ion sources may be scanned, tilted, rotated, or otherwise repositioned during the injection process to achieve injection in a direction parallel to the X-axis of the Cartesian coordinate system (or two opposite directions). For example, the mask 10 may be rotated 180 degrees around a central axis parallel to the Z-axis of the Cartesian coordinate system shown in Figure 8A. The ion beam 20 can be directed toward the mask 10 at an angle ranging from 30 to 60 degrees (e.g., 45 degrees) with respect to the X-axis of the Cartesian coordinate system shown in Figure 8C (i.e., with respect to the top surface of the mask 10). The disclosure is not limited in this respect.
[0043]
[0054] The injection process described above densifies the material of the mask 10 in a direction parallel to the X-axis of the Cartesian coordinate system, thereby causing the portion of the mask 10 between the openings 14 to contract in a direction parallel to the X-axis of the Cartesian coordinate system, while the openings 14 themselves expand in a direction parallel to the X-axis of the Cartesian coordinate system. In particular, unlike the embodiment of Method 2 described above, the ion beam 20 is not projected onto the mask 10 in a direction parallel to the Y-axis of the Cartesian coordinate system, and therefore the openings are not expanded in a direction parallel to the Y-axis of the Cartesian coordinate system (i.e., the openings 14 lengthen but do not widen). Thus, in the directed deposition process shown in Figures 7A-7B, the openings 14 are shortened from a first length of 20 nanometers to a second length of about 15 nanometers, and in the directed injection process shown in Figures 8A-8B, the openings can be extended to a third length of about 20 nanometers (i.e., the desired length) while maintaining a desired width (e.g., 10 nanometers).
[0044]
[0055] After the above-described deposition and injection processes are performed, an etching process may be carried out, in which an ion beam formed by reactive plasma ions may be directed from above toward the mask 10. The exposed portion of the lower substrate 12 (i.e., the portion of the substrate 12 directly below the opening 14) may be etched by the ion beam to form slots, while the rest of the substrate 12 is shielded from the ion beam by the mask 10.
[0045]
[0056] Directional pre-injection + directional deposition + directional post-injection
[0057] Further embodiments of the present disclosure are envisioned in which a hybrid of Method 3 and Method 4 described above may be implemented. Specifically, such embodiments may include performing directional pre-injection (as described above in Method 3 and shown in Figures 5A-5C), performing a directional deposition process (as described above in Method 3 and shown in Figures 6A-6C), and subsequently performing directional post-injection (as described above in Method 4 and shown in Figures 8A-5C). Such a hybrid method may be suitable in situations where, after performing the pre-injection and deposition processes of Method 3, there is excessive lateral deposition on the longitudinal side of the opening 14, and therefore a slot shorter than the desired value (e.g., 20 nanometers) is generated. By additionally performing the post-injection of Method 4, the slot can be expanded in a direction parallel to the X-axis of the Cartesian coordinate system to achieve the desired length.
[0046]
[0058] This disclosure should not be limited in scope by any specific embodiment described herein. In fact, in addition to the embodiments described herein, various other embodiments and variations of this disclosure will be apparent to those skilled in the art from the foregoing description and accompanying drawings. Thus, such other embodiments and variations are also intended to be included within the scope of this disclosure. Furthermore, while this publication describes this disclosure in terms of specific implementations in specific environments for specific purposes, those skilled in the art will recognize that the usefulness of this disclosure is not limited to these. Embodiments of this disclosure can be usefully implemented for any number of purposes in any number of environments. Accordingly, the claims set forth below should be interpreted in terms of the entire scope and essence of this disclosure as described herein.
Claims
1. A method for modifying the opening of a mask to achieve a desired critical dimension, By directing a first radical beam to the first side surface of the opening, a layer of material is deposited on the first side surface, By directing a second radical beam to the second side of the opening, which is opposite to the first side, a layer of material is deposited on the second side. Methods that include...
2. The method according to claim 1, wherein the length of the opening is reduced by a first amount, and the width of the opening is reduced by a second amount, wherein the second amount is greater than the first amount.
3. The method according to claim 1, further comprising rotating the mask between directing a first radical beam to the first side surface of the opening and directing a second radical beam to the second side surface of the opening.
4. The method according to claim 1, wherein the first radical beam and the second radical beam are directed to the first side surface of the opening and the second side surface of the opening, respectively, at an angle ranging from 30 to 60 degrees with respect to the upper surface of the mask.
5. The method according to claim 1, wherein the material deposited by at least one of the first radical beam and the second radical beam is carbon.
6. A method for modifying the opening of a mask to achieve a desired critical dimension, Performing a pre-injection into the mask in order to inject a dopant material into the mask, wherein the pre-injection is performed such that the material of the mask is made denser and the opening is enlarged. By directing a first radical beam to the first side surface of the opening, a layer of material is deposited on the first side surface, By directing a second radical beam to the second side of the opening, which is opposite to the first side, a layer of material is deposited on the second side. Methods that include...
7. The method according to claim 6, wherein the dopant material is selected from argon and carbon.
8. The aforementioned pre-injection Directing the first ion beam towards the mask in a first direction and injecting the dopant material into the mask, Directing a second ion beam towards the mask in a second direction opposite to the first direction, thereby injecting the dopant material into the mask, This is a directional pre-injection that includes, in the directional pre-injection, The method according to claim 6, wherein the material of the mask is made denser and the opening is enlarged in the first direction and the second direction.
9. The method according to claim 8, wherein the first ion beam is directed toward the mask at an angle ranging from 30 to 60 degrees relative to the upper surface of the mask.
10. The method according to claim 9, wherein the second ion beam is directed toward the mask at an angle ranging from 30 to 60 degrees relative to the upper surface of the mask.
11. The method according to claim 6, wherein the length of the opening is reduced by a first amount, and the width of the opening is reduced by a second amount, wherein the second amount is greater than the first amount.
12. The method according to claim 6, further comprising rotating the mask between directing a first radical beam to the first side surface of the opening and directing a second radical beam to the second side surface of the opening.
13. The method according to claim 6, wherein the first radical beam and the second radical beam are directed to the first side surface of the opening and the second side surface of the opening, respectively, at an angle ranging from 30 to 60 degrees with respect to the upper surface of the mask.
14. The method according to claim 6, wherein the material deposited by at least one of the first radical beam and the second radical beam is carbon.
15. A method for modifying the opening of a mask to achieve a desired critical dimension, By directing a first radical beam to the first side surface of the opening, a layer of material is deposited on the first side surface, By directing a second radical beam to the second side of the opening, which is opposite to the first side, a layer of material is deposited on the second side. The mask is to be injected afterwards, The post-injection includes, Directing the first ion beam towards the mask in a first direction and injecting the dopant material into the mask, The post-injection includes directing a second ion beam towards the mask in a second direction opposite to the first direction, thereby injecting a dopant material into the mask, The material of the mask is made denser, and the opening is enlarged in the first and second directions. method.
16. The method according to claim 15, wherein at least one of the dopant material implanted by the first ion beam and the dopant material implanted by the second ion beam is selected from argon and carbon.
17. The method according to claim 15, wherein the first ion beam is directed toward the mask at an angle ranging from 30 to 60 degrees relative to the upper surface of the mask.
18. The method according to claim 15, wherein the second ion beam is directed toward the mask at an angle ranging from 30 to 60 degrees relative to the upper surface of the mask.
19. The method according to claim 15, wherein the length of the opening is reduced by a first amount, and the width of the opening is reduced by a second amount, wherein the second amount is greater than the first amount.
20. The method according to claim 15, further comprising rotating the mask between directing a first radical beam to the first side surface of the opening and directing a second radical beam to the second side surface of the opening.
21. The method according to claim 15, wherein the first radical beam and the second radical beam are directed to the first side surface of the opening and the second side surface of the opening, respectively, at an angle ranging from 30 to 60 degrees with respect to the upper surface of the mask.
22. The method according to claim 15, wherein the material deposited by at least one of the first radical beam and the second radical beam is carbon.
23. The further includes performing a pre-injection on the mask, wherein the pre-injection is Directing the first ion beam towards the mask in the first direction and injecting the dopant material into the mask, The pre-injection includes directing a second ion beam to the mask in a second direction opposite to the first direction, thereby injecting a dopant material into the mask, The method according to claim 15, wherein the material of the mask is made denser and the opening is enlarged in the first direction and the second direction.