Inorganic resist positive tone conversion

Abstract

Embodiments described herein relate to a method for changing a tone of a metal oxide resist (MOR) layer that is patterned to have a first pattern. In an embodiment, the method includes transferring the first pattern into an underlayer below the MOR layer, forming a hardmask around the underlayer with an area selective deposition process, and removing the underlayer to form a second pattern in the hardmask. In an embodiment, the second pattern is an inverse of the first pattern.

Description

[0001] INORGANIC RESIST POSITIVE TONE CONVERSION

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of U.S. Provisional Application No. 63 / 749,593, filed on January 25, 2025, the entire contents of which are hereby incorporated by reference herein.

[0004] FIELD

[0005] Embodiments relate to the field of semiconductor manufacturing and, in particular, to a tone conversion process for a metal oxide resist (MOR) material.

[0006] DESCRIPTION OF RELATED ART

[0007] Extreme ultraviolet (EUV) photoresists allow for the continued scaling to smaller features that are patterned on a semiconductor substrate. In an EUV lithography process, EUV radiation is selectively applied to regions of the photoresist layer in order to generate a solubility switch that enables the formation of a latent image within the photoresist layer. The latent image corresponds to the portions of the photoresist layer that have undergone the solubility switch as a result of a chemical reaction that is induced by the EUV exposure. After the latent image is produced within the photoresist layer, a developing process may be used in order to generate a pattern in the photoresist layer.

[0008] There are two types of resists that are commonly used for EUV lithography: chemically amplified resist (CARs) and metal oxide resists (MORs). MORs are preferred over CARs form forming small features due to the enhanced resolution capabilities of MORs compared to CARs. However, MOR material systems are only available as a negative tone resist. That is, the exposed region of the MOR is retained after development. This allows for the formation of pillar features. However, hole patterning is not feasible with negative tone resists due to the large area that needs to be exposed in order to form a negative tone hole pattern with a tone inversion mask.

[0009] SUMMARY

[0010] Embodiments described herein relate to a method for changing a tone of a metal oxide resist (MOR) layer that is patterned to have a first pattern. In an embodiment, the method includes transferring the first pattern into an underlayer below the MOR layer, forming a hardmask around the underlayer with an area selective deposition process, and removing the underlayer to form a second pattern in the hardmask. In an embodiment, the second pattern is an inverse of the first pattern.Embodiments described herein relate to a method for changing a tone of a metal oxide resist (MOR) layer that is patterned to have a first pattern. In an embodiment, the method includes forming a mask around the MOR layer, where the mask includes carbon, and the mask is formed with a bottom-up fill process. In an embodiment, the method further includes removing the MOR layer to form a second pattern in the mask, where the second pattern is an inverse of the first pattern.

[0011] Embodiments described herein relate to a method for changing a tone of a resist layer. In an embodiment, the method includes forming a first pattern in the resist layer that includes a plurality of pillars, and transferring the first pattern into an underlayer below the resist layer. In an embodiment, the method further includes forming a hardmask around the underlayer, and removing the underlayer to define a second pattern in the hardmask, where the hardmask includes a plurality of holes.

[0012] BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figures 1 A - IF are cross-sectional illustrations that depict a process for changing a metal oxide resist (MOR) from a negative tone resist to a positive tone resist, in accordance with an embodiment.

[0014] Figure 1G is a flow diagram describing a process for changing an MOR from a negative tone resist to a positive tone resist, in accordance with an embodiment.

[0015] Figures 2A - 2D are cross-sectional illustrations that depict a process for changing an MOR from a negative tone resist to a positive tone resist, in accordance with an additional embodiment.

[0016] Figure 2E is a flow diagram describing a process for changing an MOR from a negative tone resist to a positive tone resist, in accordance with an embodiment.

[0017] Figures 3A - 3D are cross-sectional illustrations that depict a process for changing an MOR from a negative tone resist to a positive tone resist through the use of a seed layer, in accordance with an embodiment.

[0018] Figures 4A - 4D are cross-sectional illustrations that depict a process for changing an MOR from a negative tone resist to a positive tone resist through the use of seed layer, in accordance with an additional embodiment.

[0019] Figure 5 is a flow diagram describing a process for changing an MOR from a negative tone resist to a positive tone resist, in accordance with an embodiment.

[0020] Figures 6A - 6F are cross-sectional illustrations that depict a process for changing an MOR from a negative tone resist to a positive tone resist with a flowable carbon deposition process, in accordance with an embodiment.Figure 7 is a flow diagram that depicts a process for changing an MOR from a negative tone resist to a positive tone resist with a flowable carbon deposition process, in accordance with an embodiment.

[0021] Figure 8 illustrates a block diagram of an exemplary computer system that may be used in conjunction with a processing tool, in accordance with an embodiment.

[0022] DETAILED DESCRIPTION

[0023] Embodiments described herein include a tone conversion process for a metal oxide resist (MOR) material. In the following description numerous specific details are set forth in order to provide a thorough understanding of embodiments. It will be apparent to one skilled in the art that embodiments may be practiced without these specific details. In other instances, well-known aspects are not described in detail in order to not unnecessarily obscure embodiments.

[0024] Furthermore, it is to be understood that the various embodiments shown in the accompanying drawings are illustrative representations and are not necessarily drawn to scale.

[0025] Various embodiments or aspects of the disclosure are described herein. In some implementations, the different embodiments are practiced separately. However, embodiments are not limited to embodiments being practiced in isolation. For example, two or more different embodiments can be combined together in order to be practiced as a single device, process, structure, or the like. The entirety of various embodiments can be combined together in some instances. In other instances, portions of a first embodiment can be combined with portions of one or more different embodiments. For example, a portion of a first embodiment can be combined with a portion of a second embodiment, or a portion of a first embodiment can be combined with a portion of a second embodiment and a portion of a third embodiment.

[0026] The embodiments illustrated and discussed in relation to the figures included herein are provided for the purpose of explaining some of the basic principles of the disclosure. However, the scope of this disclosure covers all related, potential, and / or possible, embodiments, even those differing from the idealized and / or illustrative examples presented. This disclosure covers even those embodiments which incorporate and / or utilize modern, future, and / or as of the time of this writing unknown, components, devices, systems, etc., as replacements for the functionally equivalent, analogous, and / or similar, components, devices, systems, etc., used in the embodiments illustrated and / or discussed herein for the purpose of explanation, illustration, and example.

[0027] As noted above, resists used in extreme ultraviolet (EUV) lithography are either a chemically amplified resist (CAR) or a metal oxide resist (MOR). The use of a MOR is preferred for small features. However, existing MOR systems are negative tone resists. This makes patterning holefeatures difficult with existing lithography processes.

[0028] Accordingly embodiments disclosed herein include a process for switching the tone of a MOR resist in order to generate a positive tone pattern while maintaining the good resolution properties of MOR material systems. In some embodiments, the MOR is exposed and developed to form a first pattern. The first pattern may be transferred into an underlayer below the MOR. In an embodiment, a hardmask may be formed around the remaining portions of the underlayer. The hardmask may be formed with an area selective deposition process in order to prevent the material from covering the top surfaces of the underlayer or MOR (if the MOR is not removed first). For example, a chemical contrast between exposed surfaces may be used in order to selectively form the hardmask. The selectivity may be provided by a polar layer that preferentially initiates plating of the hardmask. In an alternative embodiment, a liner may be provided over the MOR to prevent deposition of the hardmask on the MOR. In an additional embodiment, a seed layer may be used to help initiate preferential deposition of the hardmask around the MOR. Embodiments disclosed herein may also use a flowable carbon deposition process in order to provide a bottom-up deposition process that surrounds the patterned MOR layer.

[0029] Referring now to Figures 1A - IF, a series of cross-sectional illustrations depicting a process for modifying a resist layer from a negative tone resist to a positive tone resist is shown, in accordance with an embodiment.

[0030] Referring now to Figure 1 A, a cross-sectional illustration of a portion of a device 100 is shown, in accordance with an embodiment. In an embodiment, the device 100 may comprise a substrate 101. The substrate 101 may comprise a semiconductor material, such as a silicon substrate. The substrate 101 may also comprise one or more layers over a semiconductor material, such as a dielectric layer (e.g., a silicon oxide, a silicon nitride, or the like), a metallic layer, or any other layer used in the manufacture of semiconductor devices. In an embodiment, a patterning stack 105 may be provided over the substrate 101. The patterning stack 105 may comprise one or more layers that are useful for transferring a pattern defined by the resist layer into the underlying substrate 101. For example, the patterning stack 105 may comprise layers such as, a silicon hardmask layer, a carbon hardmask layer, an antireflective coating, and / or the like.

[0031] In an embodiment, an intermediate layer 107 may be provided over the patterning stack 105. The intermediate layer 107 may be a layer that enables an area selective deposition (ASD) process, as will be described in greater detail herein. In some embodiments, the intermediate layer 107 may have a polar surface. In some instances, the intermediate layer 107 may comprise a silicon based inorganic material (e.g., a silicon oxide, a silicon nitride, an amorphous silicon, or the like), a metal containing material (e.g., a tin oxide, a titanium oxide, an aluminum oxide, or the like), ora layer with a high density and / or surface coverage of surface terminations that comprise one or more of hydroxyls, carboxylic acids, amines, amic acids, aldehyde moieties, or the like. A thickness of the intermediate layer 107 may have a thickness between approximately 5 angstroms and approximately 500 angstroms. Though, a thinner or thicker intermediate layer 107 may also be used in some embodiments.

[0032] In an embodiment, an underlayer 110 may be provided over the intermediate layer 107. The material for the underlayer 110 may be a material that is compatible with patterning stack deposition processes. The underlayer 110 may comprise a carbon-based polymeric material. In some instances, the underlayer 110 may comprise fluorine. For example, the underlayer 110 may comprise C-F bonds in some embodiments. In an embodiment, the underlayer 110 may comprise a material that is sensitive to EUV or DUV radiation in order to generate species (e.g., elements, molecules, electrons, etc.) that can diffuse into the overlying resist layer 120 in order to participate in the solubility switch reaction. In an embodiment, the underlayer 110 may be deposited with a dry deposition process (e.g., chemical vapor deposition (CVD), atomic layer deposition (ALD), or the like).

[0033] In an embodiment, a resist layer 120 may be provided over the underlayer 110. The resist layer 120 may comprise an MOR material. In an embodiment the MOR material may comprise a photoresist material with one or more metals (e.g., tin, indium, hafnium, zinc, zirconium, or any combination thereof). The MOR material may also comprise an organotin-oxide photoresist material, an organoindium-oxide photoresist material, or the like. The resist layer 120 may be deposited with any suitable process. For example, the resist layer 120 may be applied with a spin coating process, or a dry deposition process (e.g., a CVD process, an ALD process, or the like). In an embodiment, the resist layer 120 may be a negative tone resist. That is, exposure to EUV and / or DUV radiation may initiate a cross-linking reaction that renders the exposed region insoluble to a developer chemistry that is configured to dissolve the unexposed regions of the resist layer 120.

[0034] Referring now to Figure IB, a cross-sectional illustration of the portion of the device 100 after an exposure process is shown, in accordance with an embodiment. In an embodiment, the exposure process may include selectively exposing portions of the resist layer 120 to radiation (e.g., EUV radiation and / or DUV radiation). The exposed regions 122 (represented with a different shading) may be cross-linked in order to provide a solubility switch that renders the exposed regions 122 insoluble to a developer chemistry. The selective exposure may be made with a mask, a reticle, direct laser writing, or the like. In a particular embodiment, a mask may be a dark field mask. Dark field masks are less susceptible to patterning defects, and may improve the patterning performance.Referring now to Figure 1C, a cross-sectional illustration of the portion of the device 100 after a developing process is shown, in accordance with an embodiment. The developing process may include applying a developer chemistry to the resist layer 120 that preferentially removes the unexposed regions of the resist layer 120 to form a first pattern 125 defined by the exposed regions 122 of the resist layer 120. In an embodiment, the exposed regions 122 may comprise a plurality of pillars across the underlayer 110.

[0035] Referring now to Figure ID, a cross-sectional illustration of the portion of the device 100 after the first pattern 125 is transferred into the underlayer 110 is shown, in accordance with an embodiment. In an embodiment, the underlayer 110 may be etched using the exposed regions 122 as a mask layer. After the underlayer 110 is etched, the exposed regions 122 may be removed with any suitable process. The first pattern 125 may expose portions of the underlying intermediate layer 107.

[0036] Referring now to Figure IE, a cross-sectional illustration of the portion of the device 100 after an ASD process is used to selectively form a hardmask 130 around the remaining portions of the underlayer 110. In an embodiment, the hardmask 130 may comprise a metal with oxygen and / or nitrogen. For example, the hardmask 130 may comprise a titanium oxide, a titanium nitride, or the like. The hardmask 130 may comprise carbon in some embodiments. The ASD process may include a dry deposition process (e.g., an ALD process, a CVD process, or the like) that preferentially deposits on the polar surface of the intermediate layer 107.

[0037] In some embodiments, the underlayer 110 may be treated before the ASD deposition in order to improve the chemical contrast that enables the selective deposition of the hardmask 130. For example, the underlayer 110 may be exposed to an alcohol and / or a carboxylic acid to form alkyl terminations along the surfaces of the underlayer 110 that minimize deposition of the hardmask 130. As such, the hardmask 130 may preferentially deposit with a bottom-up process around the remaining portions of the underlayer 110.

[0038] Referring now to Figure IF, a cross-sectional illustration of the portion of the device 100 after the underlayer 110 is removed is shown, in accordance with an embodiment. In an embodiment, the underlayer 110 may be removed with an etching process that is selective to the underlayer 110 over the hardmask 130. After the underlayer 110 is removed, the hardmask 130 remains with a second pattern 135. The second pattern 135 may be the inverse of the first pattern 125. For example, when the first pattern 125 comprises a plurality of pillars, the second pattern 135 may comprise a plurality of holes, where the holes are located where the pillars were originally located. Further, it is to be appreciated that the patterning properties of the first pattern 125 (e.g., local critical dimension uniformity (LCDU), sidewall profile, etc.) are maintained within the second pattern 135. As such, the high resolution and patterning performance of the MORmaterial may be leveraged to form a positive tone resist pattern with processes such as those described herein.

[0039] After the second pattern 135 is defined in the hardmask 130, the second pattern 135 may be transferred into underlying layers, such as the intermediate layer 107, the patterning stack 105, and the substrate 101 using one or more etching processes.

[0040] Referring now to Figure 1G, a flow diagram depicting a process 170 for modifying a resist layer to provide a tone inversion is shown, in accordance with an embodiment. In an embodiment, the process 170 may include features and / or operations similar to those described above with respect to Figures 1A - IF.

[0041] In an embodiment, the process 170 may begin with operation 171, which comprises forming a first pattern in an MOR layer. In an embodiment, the first pattern may comprise a negative tone pattern. For example, the first pattern may comprise a plurality of pillars.

[0042] In an embodiment, the process 170 may continue with operation 172, which comprises transferring the first pattern into an underlayer below the MOR layer. In an embodiment, the underlayer may be patterned with any suitable etching process while using the patterned MOR layer as a mask. As such, the underlayer may also be patterned to provide a plurality of pillars. In an embodiment, the process 170 may continue with operation 173, which comprises forming a hardmask around the underlayer. In an embodiment, the hardmask comprises a metal, such as a metal-oxide or a metal-nitride. In an embodiment, the hardmask may be preferentially formed around the underlayer with an ASD process. In some embodiments, the underlayer may be treated before the deposition of the hardmask in order to further improve a chemical contrast between the underlayer and a layer below the underlayer. In some embodiments, the layer below the underlayer may be similar to the intermediate layer 107 described herein. That is, the layer below the underlayer may have a polar surface to improve the chemical contrast that drives the selective deposition of the hardmask.

[0043] In an embodiment, the process 170 may continue with operation 174, which comprises removing the underlayer to form a second pattern in the hardmask. In an embodiment, the second pattern is an inverse of the first pattern. That is, the second pattern may comprise a plurality of holes. The plurality of holes may be located in the same position as the plurality of pillars that were formed in the resist layer and the underlayer.

[0044] In an embodiment, the process 170 may continue with operation 175, which comprises transferring the second pattern into an underlying layer. For example, the hardmask may be used as a mask during an etching process in order to form holes in one or more underlying layers, such as an intermediate layer, a pattering stack, and / or a substrate.

[0045] Referring now to Figures 2A - 2D, a series of cross-sectional illustrations depicting a process formodifying a resist layer from a negative tone resist to a positive tone resist is shown, in accordance with an additional embodiment.

[0046] Referring now to Figure 2A, a portion of a device 200 is shown with a structure that is an intermediate step between Figures 1C and ID described in greater detail above. For example, exposed regions 222 of a resist layer are provided over a patterned underlayer 210. In an embodiment, the resist layer may be a MOR similar to resist layer 120 described above, and the underlayer 210 may be similar to the underlayer 110 described above. Additionally, the pattern 225 may be a negative tone pattern that results in the exposed regions 222 forming a plurality of pillars. The intermediate layer 207, the patterning stack 205, and / or the substrate 201 may be similar to the intermediate layer 107, the patterning stack 105, and the substrate 101, respectively.

[0047] Referring now to Figure 2B, a cross-sectional illustration of the portion of the device 200 after a liner 223 is formed over the exposed regions 222 of the resist layer is shown, in accordance with an embodiment. In an embodiment, the liner 223 may be a deposition inhibitor material that minimizes deposition of a subsequent hardmask over surfaces of the exposed regions 222. In an embodiment, -OH terminations at the surfaces of the exposed regions 222 may be reacted to form a non-polar surface. That is, the liner 223 may refer to surface chemistry as opposed to a solid material layer in some embodiments. The use of such a liner 223 improves the chemical contrast between the intermediate layer 207 and the exposed regions 222 in order to improve the selectivity of the ASD deposition process. Further, surfaces of the underlayer 210 may be neutralized (e.g., similar to the process described with respect to Figure IE above).

[0048] Referring now to Figure 2C, a cross-sectional illustration of the portion of the device 200 after a hardmask 230 is deposited is shown, in accordance with an embodiment. In an embodiment, an ASD process is used to selectively form a hardmask 230 around the remaining portions of the underlayer 210 and the exposed regions 222. In an embodiment, the hardmask 230 may comprise a metal with oxygen and / or nitrogen. For example, the hardmask 230 may comprise a titanium oxide, a titanium nitride, or the like. The hardmask 230 may comprise carbon in some embodiments. The ASD process may include a dry deposition process (e.g., an ALD process, a CVD process, or the like) that preferentially deposits on the polar surface of the intermediate layer 207.

[0049] Referring now to Figure 2D, a cross-sectional illustration of the portion of the device 200 after the underlayer 210 and exposed regions 222 are removed is shown, in accordance with an embodiment. In an embodiment, the underlayer 210 and the exposed regions 222 may be removed with one or more etching processes that are selective to the underlayer 210 and / or the exposed regions 222 over the hardmask 230. After the underlayer 210 and the exposed regionsare removed, the hardmask 230 remains with a second pattern 235. The second pattern 235 may be the inverse of the first pattern 225. For example, when the first pattern 225 comprises a plurality of pillars, the second pattern 235 may comprise a plurality of holes, where the holes are located where the pillars were originally located. Further, it is to be appreciated that the patterning properties of the first pattern 225 (e.g., LCDU, sidewall profile, etc.) are maintained within the second pattern 235. As such, the high resolution and patterning performance of the MOR material may be leveraged to form a positive tone resist pattern with processes such as those described herein.

[0050] After the second pattern 235 is defined in the hardmask 230, the second pattern 235 may be transferred into underlying layers, such as the intermediate layer 207, the patterning stack 205, and the substrate 201 using one or more etching processes.

[0051] In Figures 2A - 2D, the hardmask 230 is formed after the underlayer 210 is patterned. In other embodiments, the hardmask 230 may be formed after the resist layer is developed, but before the first pattern 225 is transferred into the underlayer 210. That is, the hardmask 230 may formed around only the exposed regions 222 in some embodiments. Thereafter, the exposed regions 222 are removed and the second pattern 235 is transferred into the underlayer 210 and the other underlying layers.

[0052] Referring now to Figure 2E, a flow diagram depicting a process 270 for modifying a resist layer to provide a tone inversion is shown, in accordance with an embodiment. In an embodiment, the process 270 may include features and / or operations similar to those described above with respect to Figures 2A - 2D.

[0053] In an embodiment, the process 270 may begin with operation 271, which comprises forming a first pattern in an MOR layer. In an embodiment, the first pattern may comprise a negative tone pattern. For example, the first pattern may comprise a plurality of pillars.

[0054] In an embodiment, the process 270 may continue with operation 272, which comprises forming a liner over the MOR layer. In an embodiment, the liner may be a deposition inhibitor layer that prevents deposition of a hardmask onto the MOR layer in a subsequent operation. The liner may be a chemical surface treatment in some embodiments that provides a more charge neutral condition to the MOR layer surfaces.

[0055] In an embodiment, the process 270 may continue with operation 273, which comprises forming a hardmask around the MOR layer. In an embodiment, the hardmask comprises a metal, such as a metal-oxide or a metal-nitride. In an embodiment, the hardmask may be preferentially formed around the MOR layer with an ASD process. In some embodiments, the first pattern may be transferred into an underlayer below the MOR layer before the deposition of the hardmask. In such an embodiment, the hardmask may be formed around both the underlayer and the MORlayer (e.g., similar to the embodiment shown in Figure 2C). In such embodiments, the underlayer may also be treated before the deposition of the hardmask in order to further improve a chemical contrast between the underlayer and a layer below the underlayer. In some embodiments, the layer below the underlayer may be similar to the intermediate layer 207 described herein. That is, the layer below the underlayer may have a polar surface to improve the chemical contrast that drives the selective deposition of the hardmask.

[0056] In an embodiment, the process 270 may continue with operation 274, which comprises removing the MOR layer (and the underlayer if the hardmask is also formed around the underlayer) to form a second pattern in the hardmask. In an embodiment, the second pattern is an inverse of the first pattern. That is, the second pattern may comprise a plurality of holes. The plurality of holes may be located in the same position as the plurality of pillars that were formed in the resist layer and the underlayer.

[0057] In an embodiment, the process 270 may continue with operation 275, which comprises transferring the second pattern into an underlying layer. For example, the hardmask may be used as a mask during an etching process in order to form holes in one or more underlying layers, such as the underlayer (if the underlayer is not already patterned), an intermediate layer, a pattering stack, and / or a substrate.

[0058] Referring now to Figures 3A - 3D, a series of cross-sectional illustrations depicting a process for modifying a resist layer from a negative tone resist to a positive tone resist is shown, in accordance with an embodiment.

[0059] Referring now to Figure 3A, a portion of a device 300 is shown with a structure that is formed with processes similar to those to provide the device 100 shown in Figure 1C described in greater detail above. For example, exposed regions 322 of a resist layer are provided over an underlayer 310. In an embodiment, the resist layer may be an MOR similar to resist layer 120 described above, and the underlayer 310 may be similar to the underlayer 110 described above. Additionally, the pattern 325 may be a negative tone pattern that results in the exposed regions 322 forming a plurality of pillars. The intermediate layer 307, the patterning stack 305, and / or the substrate 301 may be similar to the intermediate layer 107, the patterning stack 105, and the substrate 101, respectively.

[0060] However, Figure 3 A differs from Figure 1C in that a seed layer 313 may be provided between the intermediate layer 307 and the underlayer 310. In an embodiment, the seed layer 313 may comprise an electrically conductive seed material (e.g., comprising one or more of copper, titanium, ruthenium, etc.). The seed layer may also comprise a high density and / or high surface coverage of reactive species, such as hydroxyls, carboxylic acids, amines, amic acids, aldehyde moieties, and / or the like. The seed layer 313 may have a thickness between approximately Inmand approximately 5nm. Though, the seed layer 313 may have any suitable thickness in other embodiments.

[0061] Referring now to Figure 3B, a cross-sectional illustration of the portion of the device 300 after the first pattern 325 is transferred into the underlayer 310 is shown, in accordance with an embodiment. In an embodiment, the underlayer 310 may be etched using the exposed regions 322 as a mask layer. After the underlayer 310 is etched, the exposed regions 322 may be removed with any suitable process. The first pattern 325 may expose portions of the underlying seed layer 313.

[0062] Referring now to Figure 3C, a cross-sectional illustration of the portion of the device 300 after an ASD process is used to selectively form a hardmask 330 around the remaining portions of the underlayer 310 is shown, in accordance with an embodiment. In an embodiment, the hardmask 330 may comprise a metal. The hardmask 330 may also comprise a metal with oxygen and / or nitrogen. For example, the hardmask 330 may comprise a titanium oxide, a titanium nitride, or the like. The hardmask 330 may comprise carbon in some embodiments. The ASD process may include a dry deposition process (e.g., an ALD process, a CVD process, or the like) that preferentially deposits on the seed layer 313. The seed layer 313 may allow for easier nucleation that provides better hardmask 330 plating and / or a faster deposition process.

[0063] In some embodiments, the underlayer 310 may be treated before the ASD deposition in order to improve the chemical contrast that enables the selective deposition of the hardmask 330. For example, the underlayer 110 may be exposed to an alcohol and / or a carboxylic acid to form alkyl terminations along the surfaces of the underlayer 310 that minimize deposition of the hardmask 330. As such, the hardmask 330 may preferentially deposit in with a bottom-up process around the remaining portions of the underlayer 310.

[0064] Referring now to Figure 3D, a cross-sectional illustration of the portion of the device 300 after the underlayer 310 is removed is shown, in accordance with an embodiment. In an embodiment, the underlayer 310 may be removed with an etching process that is selective to the underlayer 310 over the hardmask 330. After the underlayer 310 is removed, the hardmask 330 remains with a second pattern 335. The second pattern 335 may be the inverse of the first pattern 325. For example, when the first pattern 325 comprises a plurality of pillars, the second patern 335 may comprise a plurality of holes, where the holes are located where the pillars were originally located. Further, it is to be appreciated that the patterning properties of the first pattern 325 (e.g., local critical dimension uniformity (LCDU), sidewall profile, etc.) are maintained within the second patern 335. As such, the high resolution and patterning performance of the MOR material may be leveraged to form a positive tone resist pattern with processes such as those described herein.After the second pattern 335 is defined in the hardmask 330, the second pattern 335 may be transferred into underlying layers, such as the seed layer 313, the intermediate layer 307, the patterning stack 305, and the substrate 301 using one or more etching processes.

[0065] Referring now to Figures 4A - 4D, a series of cross-sectional illustrations depicting a process for modifying a resist layer from a negative tone resist to a positive tone resist is shown, in accordance with an additional embodiment.

[0066] Referring now to Figure 4A, a portion of a device 400 is shown with a structure that is formed with processes similar to those to provide the device 300 shown in Figure 3C described in greater detail above. For example, exposed regions 422 of a resist layer are provided over an underlayer 410. In an embodiment, the resist layer may be a MOR similar to any of the resist layers described herein, and the underlayer 410 may be similar to any of the underlayers described above. Additionally, the pattern 425 may be a negative tone pattern that results in the exposed regions 422 forming a plurality of pillars. In an embodiment, the pattern 425 may be transferred into the underlayer 410 with a suitable etching process with the use of the exposed regions 422 as a mask layer. In an embodiment, the intermediate layer 407, the patterning stack 405, and / or the substrate 401 may be similar to the intermediate layer 307, the patterning stack 305, and the substrate 301, respectively.

[0067] However, Figure 4A differs from Figure 3 A in that the seed layer 413 is provided between the patterning stack 405 and the substrate 401. In an embodiment, the seed layer 413 may comprise an electrically conductive seed material (e.g., comprising one or more of copper, titanium, ruthenium, etc.). The seed layer 413 may also comprise a high density and / or high surface coverage of reactive species, such as hydroxyls, carboxylic acids, amines, amic acids, aldehyde moieties, and / or the like. The seed layer 413 may have a thickness between approximately Inm and approximately 5nm. Though, the seed layer 413 may have any suitable thickness in other embodiments.

[0068] Referring now to Figure 4B, a cross-sectional illustration of the portion of the device 400 after the first pattern 425 is transferred into the patterning stack 405 is shown, in accordance with an embodiment. In an embodiment, the patterning stack 405 may be etched using the exposed regions 422 and / or the underlayer 410 as a mask layer. After the patterning stack 405 is etched, the exposed regions 422 and / or the underlayer 410 may be removed with any suitable process. The first pattern 425 may expose portions of the underlying seed layer 413.

[0069] Referring now to Figure 4C, a cross-sectional illustration of the portion of the device 400 after an ASD process is used to selectively form a hardmask 430 around the remaining portions of the patterning stack 405 is shown, in accordance with an embodiment. In an embodiment, the hardmask 430 may comprise a metal. The hardmask 430 may also comprise a metal with oxygenand / or nitrogen. For example, the hardmask 430 may comprise a titanium oxide, a titanium nitride, or the like. The hardmask 430 may comprise carbon in some embodiments. The ASD process may include a dry deposition process (e.g., an ALD process, a CVD process, or the like) that preferentially deposits on the seed layer 413. The seed layer 413 may allow for easier nucleation that provides better hardmask 430 plating and / or a faster deposition process.

[0070] Referring now to Figure 4D, a cross-sectional illustration of the portion of the device 400 after the patterning stack 405 is removed is shown, in accordance with an embodiment. In an embodiment, the patterning stack 405 may be removed with one or more etching processes that are selective to the patterning stack 405 layers over the hardmask 430. After the patterning stack 405 is removed, the hardmask 430 remains with a second pattern 435. The second pattern 435 may be the inverse of the first pattern 425. For example, when the first pattern 425 comprises a plurality of pillars, the second pattern 435 may comprise a plurality of holes, where the holes are located where the pillars were originally located. Further, it is to be appreciated that the patterning properties of the first pattern 425 (e.g., local critical dimension uniformity (LCDU), sidewall profile, etc.) are maintained within the second pattern 435. As such, the high resolution and patterning performance of the MOR material may be leveraged to form a positive tone resist pattern with processes such as those described herein. After the second pattern 435 is defined in the hardmask 430, the second pattern 435 may be transferred into underlying layers, such as the seed layer 413 and the substrate 401 using one or more etching processes.

[0071] Referring now to Figure 5, a flow diagram of a process 570 for modifying a resist layer to provide a tone inversion is shown, in accordance with an embodiment. In an embodiment, the process 570 may include features and / or operations similar to those described above with respect to Figures 3A - 3D and / or Figures 4A - 4D.

[0072] In an embodiment, the process 570 may begin with operation 571, which comprises forming a first pattern in an MOR layer. In an embodiment, the first pattern may comprise a negative tone pattern. For example, the first pattern may comprise a plurality of pillars.

[0073] In an embodiment, the process 570 may continue with operation 572, which comprises transferring the first pattern into an underlayer below the MOR layer. In an embodiment, the underlayer may be patterned with any suitable etching process while using the patterned MOR layer as a mask. As such, the underlayer may also be patterned to provide a plurality of pillars. In an embodiment, the process 570 may continue with operation 573, which comprises forming a hardmask around the underlayer with a plating process initiated at a seed layer below the underlayer. In an embodiment, the seed layer may be directly below the underlayer. In other embodiments, the seed layer may be separated from the underlayer by one more layers that are below the underlayer. In such instances, the first pattern may also be transferred into the one ormore layers below the underlayer to expose the seed layer.

[0074] In an embodiment, the hardmask comprises a metal, such as a metal-oxide or a metal-nitride. In an embodiment, the hardmask may be preferentially formed around the underlayer with an ASD process. In some embodiments, the underlayer may be treated before the deposition of the hardmask in order to further improve a chemical contrast between the underlayer and a layer below the underlayer.

[0075] In an embodiment, the process 570 may continue with operation 574, which comprises removing the underlayer to form a second pattern in the hardmask. In an embodiment, the second pattern is an inverse of the first pattern. That is, the second pattern may comprise a plurality of holes. The plurality of holes may be located in the same position as the plurality of pillars that were formed in the resist layer and the underlayer.

[0076] In an embodiment, the process 570 may continue with operation 575, which comprises transferring the second pattern into an underlying layer. For example, the hardmask may be used as a mask during an etching process in order to form holes in one or more underlying layers, such as an intermediate layer, a pattering stack, and / or a substrate.

[0077] Referring now to Figures 6A - 6F, a series of cross-sectional illustrations depicting a process for modifying a resist layer from a negative tone resist to a positive tone resist is shown, in accordance with an embodiment.

[0078] Referring now to Figure 6A, a cross-sectional illustration of a portion of a device 600 is shown, in accordance with an embodiment. In an embodiment, the device 600 may comprise a substrate 601 with a patterning stack 605 over the substrate 601. In an embodiment, an underlayer 610 may be provided over the patterning stack 605. A resist layer 620 may be provided over the underlayer 610. The resist layer 620 may comprise a MOR material. In an embodiment, the substrate 601, the patterning stack 605, the underlayer 610, and / or the resist layer 620 may be similar to corresponding features described in greater detail herein.

[0079] Referring now to Figure 6B, a cross-sectional illustration of the portion of the device 600 after an exposure and develop process is shown, in accordance with an embodiment. In an embodiment, the exposure process may include selectively exposing portions of the resist layer 620 to radiation (e.g., EUV radiation and / or DUV radiation). The exposed regions 622 (represented with a different shading) may be cross-linked in order to provide a solubility switch that renders the exposed regions 622 insoluble to a developer chemistry. The developing process may include applying a developer chemistry to the resist layer 620 that preferentially removes the unexposed regions of the resist layer 620 to form a first pattern 625 defined by the exposed regions 622 of the resist layer 620. In an embodiment, the exposed regions 622 may comprise a plurality of pillars across the underlayer 610.Referring now to Figure 6C, a cross-sectional illustration of the portion of the device 600 after a hardmask 640 is formed over the underlayer 610 around the pillars of the exposed regions 622 of the resist layer 620. In an embodiment, the hardmask 640 may comprise a carbon-based material. The hardmask 640 may be filled around the exposed regions 622 with a bottom-up fill process. For example, the hardmask 640 may be formed with a flowable carbon deposition process. For example, plasma properties set during a dry deposition process (e.g., a CVD process) may be chosen so that the carbon polymerizes in relatively short chains to enable a “flowable” film. As such, the carbon hardmask 640 will fill the pattern 625 from the bottom up, without significant deposition over the top surfaces of the exposed regions 622. In an embodiment, the hardmask 640 may be cured or set in order to lock the flowable carbon in position.

[0080] In some embodiments, the flowable carbon process may be a high temperature process (e.g., around 400°C or higher). In such embodiments, the underlayer 610 may not be compatible with such temperatures. As such, a thermally stable layer (not shown) may be provided under the resist layer 620. For example, an amorphous silicon layer, an oxide layer (e.g., a TEOS oxide layer), a silicon-oxygen-nitride layer, or the like may be provided immediately under the resist layer 620.

[0081] Referring now to Figure 6D, a cross-sectional illustration of the portion of the device 600 after the exposed regions 622 are removed is shown, in accordance with an embodiment. In an embodiment, the exposed regions 622 may be removed with a halogen based chemistry (e.g., HBr or the like). After the exposed regions are removed, the hardmask 640 remains with a second pattern 645. The second pattern 645 may be the inverse of the first pattern 625. For example, when the first pattern 625 comprises a plurality of pillars, the second pattern 645 may comprise a plurality of holes, where the holes are located where the pillars were originally located. Further, it is to be appreciated that the patterning properties of the first pattern 625 (e.g., local critical dimension uniformity (LCDU), sidewall profile, etc.) are maintained within the second pattern 645. As such, the high resolution and patterning performance of the MOR material may be leveraged to form a positive tone resist pattern with processes such as those described herein. After the second pattern 645 is defined in the hardmask 640, the second pattern 645 may be transferred into underlying layers, such as the underlayer 610, the patterning stack 605, and the substrate 601 using one or more etching processes.

[0082] Alternatively, the process may continue with the deposition of a second hardmask 650 around the first hardmask 640, as shown in Figure 6E. The use of a second hardmask 650 may be used to reduce line width roughness (LWR) and / or to reduce the number of films in the patterning process flow. For example, the second hardmask 650 may be used in place of one or more layers of the patterning stack 605. As shown, in Figure 6E, the second hardmask 650 may beselectively deposited around the first hardmask 640 with an ASD process. That is, the first hardmask 640 may be a deposition inhibiting layer, and the second hardmask 650 preferentially deposits over the exposed portions of the underlayer (e.g., as a result of a chemical contrast between the underlayer 610 and the first hardmask 640). In an embodiment, the second hardmask 650 may comprise a silicon nitride material, an aluminum nitride material, and aluminum oxide material, or the like.

[0083] Referring now to Figure 6F, a cross-sectional illustration of the portion of the device 600 after the first hardmask 640 is removed is shown, in accordance with an embodiment. The first hardmask 640 may be removed with an etching process that is selective to the first hardmask 640 over the second hardmask 650. In an embodiment, the removal of the first hardmask 640 may result in the second hardmask 650 defining the first pattern 625 again. That is, the second hardmask 650 may comprise a plurality of pillars in some embodiments. However, the etch resistance and / or the LWR of the second hardmask 650 is better than the etch resistance and / or the LWR of the original exposed regions 622. After the first hardmask 640 is removed, the first pattern 625 may be transferred into underlying layers with one or more etching processes.

[0084] Referring now to Figure 7, a flow diagram of a process 770 for modifying a resist layer to provide a tone inversion is shown, in accordance with an embodiment. In an embodiment, the process 770 may include features and / or operations similar to those described above with respect to Figures 6A - 6F.

[0085] In an embodiment, the process 770 may begin with operation 771, which comprises forming a first pattern in an MOR layer. In an embodiment, the first pattern may comprise a negative tone pattern. For example, the first pattern may comprise a plurality of pillars.

[0086] In an embodiment, the process 770 may continue with operation 772, which comprises forming a hardmask around the MOR layer. In an embodiment, the hardmask comprises a carbon-based material. In an embodiment, the hardmask may be preferentially formed around the MOR layer with a flowable carbon process.

[0087] In an embodiment, the process 770 may continue with operation 773, which comprises removing the MOR layer to form a second pattern in the hardmask. In an embodiment, the second pattern is an inverse of the first pattern. That is, the second pattern may comprise a plurality of holes. The plurality of holes may be located in the same position as the plurality of pillars that were formed in the resist layer and the underlayer. After the second pattern is formed, the second pattern may be transferred into underlying layers of the device.

[0088] In an alternative embodiment, the process 770 may continue with operation 774, which comprises applying a second hardmask around the hardmask with an ASD process. In an embodiment, the hardmask works as an inhibiting layer that prevents deposition of the secondhardmask on the previously applied hardmask. The second hardmask may comprise a silicon nitride material, an aluminum nitride material, and aluminum oxide material, or the like. In some embodiments, the first hardmask may then be removed to provide the first pattern that is defined by the second hardmask. The first pattern may then be transferred into underlying layers with one or more etching processes.

[0089] Referring now to Figure 8, a block diagram of an exemplary computer system 800 of a processing tool is illustrated in accordance with an embodiment. In an embodiment, computer system 800 is coupled to and controls processing in the processing tool. Computer system 800 may be connected (e.g., networked) to other machines in a Local Area Network (LAN), an intranet, an extranet, or the Internet. Computer system 800 may operate in the capacity of a server or a client machine in a client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. Computer system 800 may be a personal computer (PC), a tablet PC, a set-top box (STB), a Personal Digital Assistant (PDA), a cellular telephone, a web appliance, a server, a network router, switch or bridge, or any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that machine. Further, while only a single machine is illustrated for computer system 800, the term “machine” shall also be taken to include any collection of machines (e.g., computers) that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies described herein.

[0090] Computer system 800 may include a computer program product, or software 822, having a non-transitory machine-readable medium having stored thereon instructions, which may be used to program computer system 800 (or other electronic devices) to perform a process according to embodiments. A machine-readable medium includes any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer). For example, a machine-readable (e.g., computer-readable) medium includes a machine (e.g., a computer) readable storage medium (e.g., read only memory (“ROM”), random access memory (“RAM"), magnetic disk storage media, optical storage media, flash memory devices, etc.), a machine (e.g., computer) readable transmission medium (electrical, optical, acoustical or other form of propagated signals (e.g., infrared signals, digital signals, etc.)), etc.

[0091] In an embodiment, computer system 800 includes a system processor 802, a main memory 804 (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM) or Rambus DRAM (RDRAM), etc.), a static memory 806 (e.g., flash memory, static random access memory (SRAM), etc.), and a secondary memory 818 (e.g., a data storage device), which communicate with each other via a bus 830.

[0092] System processor 802 represents one or more general-purpose processing devices such as amicrosystem processor, central processing unit, or the like. More particularly, the system processor may be a complex instruction set computing (CISC) microsystem processor, reduced instruction set computing (RISC) microsystem processor, very long instruction word (VLIW) microsystem processor, a system processor implementing other instruction sets, or system processors implementing a combination of instruction sets. System processor 802 may also be one or more special-purpose processing devices such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal system processor (DSP), network system processor, or the like. System processor 802 is configured to execute the processing logic 826 for performing the operations described herein.

[0093] The computer system 800 may further include a system network interface device 808 for communicating with other devices or machines. The computer system 800 may also include a video display unit 810 (e.g., a liquid crystal display (LCD), a light emitting diode display (LED), or a cathode ray tube (CRT)), an alphanumeric input device 812 (e.g., a keyboard), a cursor control device 814 (e.g., a mouse), and a signal generation device 816 (e.g., a speaker).

[0094] The secondary memory 818 may include a machine-accessible storage medium 831 (or more specifically a computer-readable storage medium) on which is stored one or more sets of instructions (e.g., software 822) embodying any one or more of the methodologies or functions described herein. The software 822 may also reside, completely or at least partially, within the main memory 804 and / or within the system processor 802 during execution thereof by the computer system 800, the main memory 804 and the system processor 802 also constituting machine-readable storage media. The software 822 may further be transmitted or received over a network 861 via the system network interface device 808. In an embodiment, the network interface device 808 may operate using RF coupling, optical coupling, acoustic coupling, or inductive coupling.

[0095] While the machine -accessible storage medium 831 is shown in an exemplary embodiment to be a single medium, the term “machine-readable storage medium” should be taken to include a single medium or multiple media (e.g., a centralized or distributed database, and / or associated caches and servers) that store the one or more sets of instructions. The term “machine-readable storage medium” shall also be taken to include any medium that is capable of storing or encoding a set of instructions for execution by the machine and that cause the machine to perform any one or more of the methodologies. The term “machine-readable storage medium” shall accordingly be taken to include, but not be limited to, solid-state memories, and optical and magnetic media.

[0096] In the foregoing specification, specific exemplary embodiments have been described. It will be evident that various modifications may be made thereto without departing from the scope of thefollowing claims. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.

Claims

CLAIMSWhat is claimed is:

1. A method for changing a tone of a metal oxide resist (MOR) layer that is patterned to have a first pattern, comprising:transferring the first pattern into an underlayer below the MOR layer;forming a hardmask around the underlayer with an area selective deposition process; and removing the underlayer to form a second pattern in the hardmask, wherein the second pattern is an inverse of the first pattern.

2. The method of claim 1, wherein the underlayer is provided over a polar layer, and wherein the area selective deposition process selectively deposits the hardmask on the polar layer.

3. The method of claim 2, wherein the polar layer comprises an inorganic material comprising silicon, a material comprising a metal, or a material with a polarizing surface layer that comprises one or more of hydroxyl groups, carboxylic acid groups, amine groups, amic acid groups, or aldehyde moieties.

4. The method of claim 1, wherein the hardmask comprises a metal and one or both of oxygen or nitrogen.

5. The method of claim 4, wherein the metal comprises titanium.

6. The method of claim 1 , further comprising:forming a liner over the MOR layer after the MOR layer is patterned to have the first pattern.

7. The method of claim 1, further comprising:removing the MOR layer from over the underlayer before forming the hardmask.

8. The method of claim 1, further comprising:forming the hardmask around the underlayer and the MOR layer.

9. The method of claim 1 , wherein the hardmask is plated up from a seed layer below the underlayer.

10. A non-transitory computer readable medium comprising instractions that, when executed by at least one processor, cause a processing tool to perform the method of claim 1.

11. A method for changing a tone of a metal oxide resist (MOR) layer that is patterned to have a first pattern, comprising:forming a mask around the MOR layer, wherein the mask comprises carbon, and wherein the mask is formed with a bottom-up fill process; andremoving the MOR layer to form a second pattern in the mask, wherein the second pattern is an inverse of the first pattern.

12. The method of claim 11, wherein the bottom-up fill process is a flowable carbon fill process.

13. The method of claim 11, further comprising:transferring the second pattern into a layer below the mask with an etching process.

14. The method of claim 11, further comprising:forming a hardmask around the mask with an area selective deposition process.

15. The method of claim 14, wherein the hardmask comprises silicon nitride, aluminum nitride, or aluminum oxide.

16. The method of claim 14, further comprising:removing the mask to provide the first pattern in the hardmask; andtransferring the first pattern into a layer under the hardmask with an etching process.

17. A method for changing a tone of a resist layer, comprising:forming a first pattern in the resist layer, wherein the first pattern comprises a plurality of pillars;transferring the first pattern into an underlayer below the resist layer;forming a hardmask around the underlayer; andremoving the underlayer to define a second pattern in the hardmask, wherein the hardmask comprises a plurality of holes.

18. The method of claim 17, wherein the resist layer comprises a metal oxide resist (MOR) material.

19. The method of claim 17, further comprising:forming a liner over the resist layer before forming the hardmask, wherein the liner comprises a material that inhibits deposition of the hardmask on the resist layer.

20. The method of claim 17, further comprising:a seed layer under the underlayer, and wherein the hardmask is plated up from the seed layer.

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