Method of forming a narrow slot contact

Abstract

In a method of patterning a substrate, a first relief pattern is formed based on a first layer deposited over the substrate. Openings in the first relief pattern are filled with a reverse material. The first relief pattern is then removed from the substrate and the reverse material remains on the substrate to define a second relief pattern. A fill material is deposited over the substrate, the fill material being in contact with the second relief pattern and being sensitive to photoacid generated by a photoacid generator in the second relief pattern. Selected portions of the second relief pattern are exposed to a first actinic radiation to generate photoacid in the selected portions of the second relief pattern. The photoacid is driven from the selected portions of the second relief pattern into portions of the fill material such that the portions of the fill material become soluble to a predetermined developer.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefits of U.S. Provisional Application No. 63 / 037,798, filed June 11, 2020, and U.S. Non-Provisional Application No. 17 / 221,416, filed April 2, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to microfabrication, including microfabrication of integrated circuits, and to processes involved in patterning semiconductor substrates. Background Technology

[0004] In materials processing methods such as photolithography, creating a patterned layer typically involves applying a thin layer of radiation-sensitive material (such as photoresist) to the upper surface of a substrate. This radiation-sensitive material is transformed into a patterned mask, which can be used to etch or transfer a pattern into an underlying layer on the substrate. Patterning radiation-sensitive material generally involves exposing the radiation-sensitive material to a photomask using, for example, a photolithography exposure system, by a radiation source (and associated optics). This exposure creates a latent pattern within the radiation-sensitive material, which can then be developed. Development refers to dissolving and removing a portion of the radiation-sensitive material to create an embossed pattern (morphological pattern). Depending on the photoresist hue and / or the type of developing solvent used, the removed material portion can be either an irradiated or unirradiated area of ​​the radiation-sensitive material. The embossed pattern can then be used as a mask layer defining the pattern.

[0005] The preparation and development of various films used for patterning may include heat treatment or baking. For example, newly applied films may undergo post-application baking (PAB) to evaporate solvents and / or increase structural stiffness or etch resistance. Additionally, post-exposure baking (PEB) may be performed to set a given pattern to prevent further dissolution. Processing tools used for coating and developing substrates typically include one or more baking modules. Some photolithography processes (followed by resist coating and then exposing the substrate to the light pattern) involve coating the substrate with a thin film of bottom anti-reflective coating (BARC), followed by resist coating, and then exposing the substrate to the light pattern as a process step for forming a microchip. The resulting relief pattern can then be used as a mask or template for additional processing, such as transferring the pattern to an underlying layer. Summary of the Invention

[0006] Continued miniaturization requires increased patterning resolution. One approach is a spacer technique to define sub-resolution line features by ALD (atomic layer deposition). However, a challenge is that using a spacer technique can be complex if opposite tone features are needed, including overcoat of another material, chemical mechanical planarization (CMP), and reactive ion etching (RIE) to dig the spacer material, leaving narrow trenches, which can be expensive.

[0007] Anti-spacer is a self-alignment technique that uses the diffusion length of a reactive species to define the critical dimension (CD), resulting in narrow trench. Using spatial control of the reactive species by mask exposure, then narrow slot contacts instead of narrow trenches can be formed. The corresponding CD can be adjusted by molecular weight modification of the reactive species, molecular structure of the reactive species, and bake temperature and bake time. These techniques enable narrow slot contact features in dimensions beyond the reach of advanced photolithography. However, the process requires a “freezing” step, i.e., a process that neutralizes the solubility change potential of the layer with photoacid generator. However, the freezing process is not perfect and can reduce yield. The techniques herein provide a “freezeless” anti-spacer approach that enables narrow slot contacts defined by diffusion length. These techniques include inverting the pattern and using a solubility change resistant composition.

[0008] Of course, the order of the fabrication steps disclosed herein is presented for clarity sake. Generally, the fabrication steps can be performed in any suitable order. Additionally, although each of the different features, techniques, configurations, etc. herein can be discussed with respect to different embodiments, one or more of the features, techniques, configurations, and / or

[0009] It should be noted that the Summary section of the present disclosure does not specify every embodiment and / or incremental novelty aspect of the disclosed invention or claimed invention. Rather, the Summary merely provides a preliminary discussion of the various embodiments and corresponding points of novelty over conventional technology. For additional details and / or possible points of view, the reader should refer to the Detailed Description of the Disclosure section as further discussed below and the corresponding drawings of the present disclosure.

[0010] According to an aspect of the disclosure, a method for patterning a substrate is provided. In the method, a first relief pattern can be formed based on a first layer deposited over the substrate, the first relief pattern including openings. The openings in the first relief pattern can be filled with a reverse material, where the reverse material can include a resin and a photoacid generator. The resin can be insoluble in a predetermined developer, and the resin can further be insensitive to a photoacid generated by the photoacid generator such that the resin remains insoluble in the predetermined developer when the resin is in contact with the photoacid. The first relief pattern can then be removed from the substrate such that the reverse material remains on the substrate to define a second relief pattern, the second relief pattern being an inverse of the first relief pattern. A fill material can then be deposited over the substrate. The fill material can be in contact with the second relief pattern and sensitive to the photoacid generated by the photoacid generator such that a portion of the fill material in contact with the photoacid becomes soluble in the predetermined developer. A selected portion of the second relief pattern can be exposed to a first actinic radiation such that a portion of the photoacid generator within the selected portion of the second relief pattern generates the photoacid in the selected portion of the second relief pattern. The photoacid generated in the selected portion of the second relief pattern can be further driven from the selected portion of the second relief pattern into a portion of the fill material through an interface between the selected portion of the second relief pattern and the fill material. Accordingly, the photoacid can cause the portion of the fill material to become soluble in the predetermined developer.

[0011] In the method, the soluble portion of the fill material can be removed using the predetermined developer so as to form a third relief pattern. The third relief pattern can expose an underlayer positioned between the substrate and the fill material.

[0012] In the method, the third relief pattern can be further transferred into the underlayer by an etching process.

[0013] In some embodiments, to drive the photoacid generated in the selected portion of the second relief pattern from the selected portion of the second relief pattern into the portion of the fill material, the photoacid can diffuse through the interface between the selected portion of the second relief pattern and the fill material into the fill material a predetermined distance by a diffusion process.

[0014] In some embodiments, to form the first relief pattern, the first layer can be exposed to a second actinic radiation forming a latent pattern, and the latent pattern can be developed by a developer to form the first relief pattern.

[0015] In some embodiments, the first layer can be a photoresist layer.

[0016] To fill the openings in the first relief pattern, an excess portion of the reverse material can be deposited, and the excess portion of the reverse material can be further removed.

[0017] In some embodiments, the fill material can be free of a photoacid generator.

[0018] In the method, to drive the photoacid generated in the selected portion of the second relief pattern from the selected portion of the second relief pattern into the fill material, a heat-activated diffusion process can be applied to drive the photoacid.

[0019] In some embodiments, the heat-activated diffusion process can include heating the substrate at a predetermined temperature for a predetermined duration.

[0020] In some embodiments, the fill material can include a deprotection group that makes the fill material soluble in the presence of the photoacid.

[0021] According to another aspect of the present disclosure, a method for patterning a substrate is provided. In the method, a first relief pattern can be formed based on a first layer deposited over the substrate, the first relief pattern including openings. The openings in the first relief pattern can be filled with a reversal material, where the reversal material can include a resin and a generator compound that generates a solubility-altering agent in response to exposure to actinic radiation. The resin can be insoluble in a predetermined developer and further insensitive to the solubility-altering agent such that the resin remains insoluble in the predetermined developer when the resin is in contact with the solubility-altering agent. The first relief pattern can then be removed from the substrate such that the reversal material remains on the substrate to define a second relief pattern, which can be an inverse pattern of the first relief pattern. A fill material can be deposited on the substrate, where the fill material can be in contact with the second relief pattern and sensitive to the solubility-altering agent generated by the generator compound such that a portion of the fill material in contact with the solubility-altering agent becomes soluble in the predetermined developer. A selected portion of the second relief pattern can be exposed to the actinic radiation such that a portion of the generator compound within the selected portion of the second relief pattern generates the solubility-altering agent in the selected portion of the second relief pattern. The solubility-altering agent generated in the selected portion of the second relief pattern can be driven to diffuse from the selected portion of the second relief pattern into the portion of the fill material through an interface between the selected portion of the second relief pattern and the fill material. The solubility-altering agent can cause the portion of the fill material to become soluble in the predetermined developer.

[0022] In an embodiment, the solubility-altering agent can include a photoacid.

[0023] In another embodiment, the solubility-altering agent can include a photo-dissociative base.

[0024] In some embodiments, the generator compound can be a photoacid generator (PAG) that generates a photoacid in response to exposure to a first actinic radiation.

[0025] In some embodiments, the generating compound may be a photodegrading alkali generating agent that generates a photodegrading alkali in response to exposure to first photochemical radiation.

[0026] In some embodiments, in order to drive the solubility modifier generated in a selected portion of the second embossed pattern to diffuse from the selected portion of the second embossed pattern to a portion of the filling material, a thermally activated diffusion process can be applied by controlling the average diffusion length of the solubility modifier.

[0027] In some embodiments, the generating compound includes a thermogenic acid generator (TAG), wherein the thermogenic acid generator may include sulfonates derived from oximes, imides, and benzyl alcohol.

[0028] In some embodiments, the filler material may be free of generating agent compounds. Attached Figure Description

[0029] When read in conjunction with the accompanying drawings, aspects of this disclosure are best understood from the following detailed description. Note that, in accordance with standard industry practice, the various features are not drawn to scale. In fact, for clarity of discussion, the dimensions of the various features may be arbitrarily increased or decreased.

[0030] Figure 1A , Figure 1B , Figure 2A , Figure 2B , Figure 3A , Figure 3B , Figure 4A , Figure 4B , Figure 5A , Figure 5B , Figure 6A , Figure 6B , Figure 7A , Figure 7B , Figure 8A , Figure 8B , Figure 9A ,as well as Figure 9B These are cross-sectional and top views of intermediate steps in manufacturing the narrow groove contact portion according to some embodiments. Detailed Implementation

[0031] The following disclosure provides numerous different embodiments or examples for implementing various features of the provided subject matter. Specific examples of components and arrangements are described below to simplify this disclosure. These are, of course, merely examples and are not intended to be limiting. Additionally, reference numerals and / or letters may be repeated in various examples throughout this disclosure. Such repetition is for simplicity and clarity and does not in itself indicate a relationship between the various embodiments and / or configurations discussed.

[0032] Furthermore, for ease of description, spatially related terms such as “below,” “under,” “lower,” “above,” and “upper” are used herein to describe the relationship of an element or feature as shown in the accompanying drawings to one or more other elements or features. In addition to the orientations depicted in the accompanying drawings, the spatially related terms are also intended to cover different orientations of the device in use or operation. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially related descriptors used herein can be interpreted accordingly.

[0033] Throughout this specification, references to "an embodiment" or "embodiment" mean that a particular feature, structure, material, or property described in connection with an embodiment is included in at least one embodiment, but does not imply that they are present in every embodiment. Therefore, the phrase "in an embodiment" appearing throughout this specification does not necessarily refer to the same embodiment. Furthermore, in one or more embodiments, particular features, structures, materials, or properties may be combined in any suitable manner.

[0034] The techniques described herein provide a "freeze-free" anti-interval method that enables the production of narrow groove contacts defined by diffusion length. These techniques involve pattern inversion and the use of compositions resistant to solubility changes. The example embodiments described herein may use photoacids as reactive substances. However, other solubility-changing agents, such as photodegrading bases, may also be used.

[0035] This disclosure provides a method for patterning a substrate, and in particular a method for patterning a substrate to form narrow groove contacts. Figure 1A , Figure 2A , Figure 3A , Figure 4A , Figure 5A , Figure 6A , Figure 7A , Figure 8A ,as well as Figure 9A This is a cross-sectional view of an intermediate step in manufacturing the narrow groove contact portion. Figure 1B , Figure 2B , Figure 3B , Figure 4B , Figure 5B , Figure 6B , Figure 7B , Figure 8B ,as well as Figure 9B This is a top view of an intermediate step in manufacturing the narrow groove contact section. The cross-sectional view is obtained from the same plane as the vertical plane containing line A-A' in the top view.

[0036] Figure 1A A cross-sectional view of an example substrate segment 100 is shown and Figure 1BAn example substrate section is shown in plan view, which is exposed to actinic radiation 110 through a photomask 108 to form a latent pattern 112 in a first layer 106. In some embodiments, the first layer 106 can be formed of a photoresist material or other light-sensitive material. As Figure 1A As shown in the middle, the substrate section 100 can include a substrate 102, a dielectric layer (or underlayer) 104 over the substrate 102, and a first layer 106 positioned over the dielectric layer 104. The substrate 102 can be a semiconductor substrate, such as a Si substrate. The substrate 102 can also include other semiconductors, such as germanium (Ge), silicon carbide (SiC), silicon germanium (SiGe), or diamond. Alternatively, the substrate 102 can include compound semiconductors and / or alloy semiconductors. The dielectric layer 104 can include SiO, SiN, SiCN, SiON, or other suitable dielectric material. In some embodiments, the dielectric layer 104 can be a dielectric stack including one or more dielectric layers. In some embodiments, the first layer 106 as a photoresist can be composed of a non-chemically amplified system, such as diazonaphthoquinone dissolution inhibitor and novolak polymer.

[0037] Still referring to Figure 1A and Figure 1B In an embodiment, the exposed portions of the first layer 106 (e.g., the latent pattern 112) can become soluble to a particular developer. In another embodiment, the actinic radiation 110 can make the exposed portions of the first layer 106 insoluble, depending on the material type (or tone) of the first layer 106 and the material type (or tone) of the corresponding developer.

[0038] Figure 2A and Figure 2B The result after the development step is shown. In the development step, a development chemistry in a particular developer can be applied to dissolve the exposed areas of the first layer 106 (e.g., the latent pattern 112) so that the exposed areas can be washed away from the substrate section 100. Accordingly, a first relief pattern or topography pattern 202 can be formed over the substrate 102. The first relief pattern 202 can include raised features 204 covering the underlayer 104 and openings 206 exposing other portions of the underlayer 104. The first relief pattern 202 can be formed by a photolithography process or other ways described above. In Figure 2A and Figure 2B In the example embodiment of FIG. 2, the openings 206 of the first relief pattern 202 in the substrate section 100 shown can have a trench profile. In another embodiment, the openings 206 can be trenches, grooves, holes, or any shape according to the structure of the contacts.

[0039] In Figure 3A and Figure 3BIn some embodiments, the first relief pattern 202 can be formed by a process such as photolithography. In such embodiments, the openings 206 in the first relief pattern 202 can be filled with a resist material 302. The resist material 302 can include a resin and a generator compound, such as a photoacid generator. The resin can be selected to be insensitive (in terms of solubility) to the photoacid generated by the photoacid generator and insoluble in one or more specific developers. Thus, the resist material 302 can be free of functional groups that would cause a change in solubility from the photoacid or include functional groups that prevent a change in solubility, depending on the tone scheme. In some embodiments, the resin can be a copolymer or terpolymer composed of monomers including, but not limited to, styryl, low molecular weight acrylate (e.g., methacrylic acid, methyl methacrylate, and t-butyl acrylate), lactone, norbornene, and adamantyl derivatives. The primary design rules for selecting the monomer composition and ratio are casting solvent solubility, developer solubility, and etch resistance.

[0040] In embodiments, the generator compound in the resist material 302 can include a photoacid generator (PAG) that generates a photoacid in response to exposure to actinic radiation. In another embodiment, the generator compound can include a photodestructive base generator that generates a photodestructive base in response to exposure to actinic radiation. In some embodiments, the acid source (e.g., the generator compound) in the resist material 302 can be a thermal acid generator (TAG).

[0041] A typical PAG composition includes an iodonium or sulfonium salt with a counterion, such as a fluorinated sulfonate or hexafluoroantimonate. The structure of the PAG can define the wavelength of the illumination (e.g., the actinic radiation 110) required for activation. The acid generation of the resist material 302 can occur by illumination from a broad array of wavelengths, but can also be optimally selected to coincide with the absorption of the resin in the resist material 302. Common TAGs include, but are not limited to, various sulfonic esters derived from oximes, imides, and benzoin.

[0042] The deposition of such resist material 302 can typically result in an excess portion of the resist material over the first layer 106, especially when the resist material 302 is deposited by spin-on deposition. The excess portion can be removed by any planarization process, such as chemical mechanical planarization (CMP), controlled wet etchback (e.g., by using TMAH), and chemical amplification planarization using a top-down acid diffusion in a specific location in the developer scheme that can cause a change to (i.e., the diffusion of the acid, the acid causes a change in material properties and is soluble) soluble in the planarization developer scheme. Alternatively, a selective deposition technique can be used that deposits the resist material 302 into the openings 206 without depositing the resist material onto the raised features 204 of the first relief pattern 202. Figure 3A and Figure 3BAn example result after excess portions of the reverse material 302 have been removed is shown.

[0043] Next, the first relief pattern 202 can be removed from the substrate section 100. As shown in FIG. 2B, the raised features 204 formed from the first layer 106 in the first relief pattern 202 are removed, and the reverse material 302 remains. Figure 4A and Figure 4B The raised features 204 formed from the first layer 106 in the first relief pattern 202 are removed, and the reverse material 302 remains. To remove the first relief pattern 202 without etching the reverse material 302, a wet back-etch process can be applied. The wet back-etch process can apply a solvent system in which the reverse material 302 is weakly soluble relative to the first relief pattern 202. An example solvent system can include a diluted aqueous developer or a solution consisting of the casting solvent. As the first relief pattern 202 is removed, the reverse material 302 correspondingly forms a second relief pattern 402 that is substantially the inverse of the first relief pattern 202. As shown in FIG. 2C, the second relief pattern 402 can have raised features 406 formed from the reverse material 302 and openings 404 that expose the underlying layer 104. Figure 4A and Figure 4B The raised features 204 formed from the first layer 106 in the first relief pattern 202 are removed, and the reverse material 302 remains. To remove the first relief pattern 202 without etching the reverse material 302, a wet back-etch process can be applied. The wet back-etch process can apply a solvent system in which the reverse material 302 is weakly soluble relative to the first relief pattern 202. An example solvent system can include a diluted aqueous developer or a solution consisting of the casting solvent. As the first relief pattern 202 is removed, the reverse material 302 correspondingly forms a second relief pattern 402 that is substantially the inverse of the first relief pattern 202. As shown in FIG. 2C, the second relief pattern 402 can have raised features 406 formed from the reverse material 302 and openings 404 that expose the underlying layer 104.

[0044] A fill material 502 can then be deposited on the substrate section 100 (and on the second relief pattern 402) to fill the openings 404 defined by the second relief pattern 402. The fill material 502 can be selected or include a material that is sensitive to photoacid that can be generated within the reverse material 302. Thus, the fill material 502 can be an acid-sensitive resist. The fill material 502 becomes soluble in a particular developer upon contact with photoacid generated by a photoacid generator in the reverse material 302. Any excess portions of the fill material 502 can subsequently be removed using planarization techniques described above in removing excess portions of the reverse material 302. Figure 5A and Figure 5B An example embodiment of the deposition of the fill material 502 is shown. The fill material 502 can be a co- or ter-polymer designed similarly to the reverse material 302, with the primary design requirements being casting solvent solubility, developer solubility, and etch resistance to maximize contrast between the fill material 502 and the reverse material 302. A range of common monomers include styrene-based, low molecular weight acrylate, and lactone similar to the reverse material 302, but the proportions of the monomers can vary significantly.

[0045] Figure 6A and Figure 6B Exposure of the second relief pattern to a pattern of second actinic radiation 506 is shown. The pattern of second actinic radiation 506 can expose selected portions (or all) of the raised features (e.g., 406) in the second relief pattern 402 based on the mask 504. In Figure 6Aand Figure 6B In exemplary embodiments of the second relief pattern 402, the selected portions 508 of the raised features 406 in the second relief pattern 402 can be exposed by the second actinic radiation 506, where the reverse material 302 is formed by the raised features 406. Accordingly, the photoacid generator can generate acid (or photoacid) within the selected portions (e.g., 508) of the raised features 406 in the second relief pattern 402 in accordance with the second actinic radiation 506. After the acid (or photoacid) is generated, the photoacid can diffuse into the surrounding material, which can be, for example, the fill material 502. The acid diffusion from the second relief pattern 402 to the fill material 502 can be precisely controlled. The length or distance of the acid diffusion, for example, can be controlled by the type of acid and / or by the time and temperature of a heat-activated diffusion process (e.g., a diffusion bake) that drives the photoacid to diffuse from the second relief pattern 402 to the fill material 502. In Figure 6B In exemplary embodiments of the second relief pattern 402, the selected portions 508 can be rectangular segments of the raised features 406 in the second relief pattern 402. Accordingly, the photoacid generator can generate acid in such rectangular segments. By applying a heat-activated diffusion process, the acid can further diffuse into the fill material 502 through the interface 510 between the selected portions 508 of the second relief pattern 402 and the fill material 502. When the heat-activated diffusion process is complete, the acid can be disposed in the trench-shaped regions 502' of the fill material 502. The photoacid can make the trench-shaped regions 502' of the fill material 502 soluble to a developer. Figure 6B The narrow trench-shaped regions 502' are shown to be formed in the fill material 502 and to be formed by driving the acid generated in the selected portions (e.g., 508) of the second relief pattern 402 into the fill material 502.

[0046] In Figure 7A and Figure 7B The substrate section 100 can then be developed with a particular developer to remove the trench-shaped regions 502' of the fill material 502. Example developers can include an aqueous solution of 0.26N tetramethylammonium hydroxide (TMAH), a dilution of the TMAH aqueous solution such as 0.13N, or a TMAH aqueous solution with various surfactants added. The particular developer can dissolve the trench-shaped regions 502' of the fill material 502 and subsequently form trench-shaped openings 602 in the fill material 502 adjacent to the reverse material 302. As Figure 7A and Figure 7BAs shown in FIG. 6B, the slot-shaped openings 602 can expose portions of the lower layer 104. The slot-shaped openings 602 can have a critical dimension (or width) defined by an acid diffusion length of the photoacid diffused from the selected portions of the second relief pattern (e.g., 508) to the fill material 502. The acid diffusion length can be controlled to a fraction of a nanometer. It should be noted that the particular developer has very little effect on the resist material 302. Thus, the resist material 302 is not affected when the substrate section 100 is developed with the particular developer.

[0047] Still referring to FIG. 6B, Figure 7A and Figure 7B when the slot-shaped openings 602 are formed in the fill material 502, a third relief pattern 802 can be subsequently formed to include the slot-shaped openings 602 as well as the raised features formed by the resist material 302 and the fill material 502. In Figure 8A and Figure 8B the third relief pattern 802 can be transferred into the lower layer 104 by an etching process to form the openings 702. In Figure 7A and Figure 7B exemplary embodiments, the openings 702 can be slot-shaped openings 702. The slot-shaped openings 702 can extend through the fill material 502 and the lower layer 104 such that the substrate 102 can be exposed. The etching process can be a wet etch or a dry etch (e.g., anisotropic plasma etch). During the etching process, the fill material 502, the slot-shaped openings 602 positioned in the fill material 502, and the resist material 302 can act as a combined etch mask for transferring the slot-shaped pattern defined by the slot-shaped openings 602 into the lower layer 104.

[0048] It should be noted that, Figure 7A and Figure 7B are exemplary embodiments of the third relief pattern 802. The third relief pattern 802 can include hole-shaped openings, line-shaped openings, or openings having other shapes. Thus, the third relief pattern 802 can be transferred into the lower layer 104 to form holes, trenches, or openings of the corresponding shapes as shown in Figure 8A and Figure 8B .

[0049] In Figure 9A and Figure 9B the resist material 302 and the fill material 502 can be removed by a plasma process, such as an O2 ashing process. During the plasma process, a portion of the openings 702 in the fill material 502 can be removed, and a portion of the openings 702 in the lower layer 104 can still remain. The portion of the openings 702 in the lower layer 104 that remains can become the openings 902. As described above, the openings 902 can be slot-shaped, hole-shaped, trench-shaped, or other shapes according to the third relief pattern 802.

[0050] The openings 902 can be further filled with a conductive material to form narrow trench contacts that can connect the substrate 102 and active regions (e.g., source, drain, or doped regions) of other components (e.g., transistors, metal wires, or capacitors) on the substrate 102.

[0051] The above-described method demonstrates a gapless patterning process for manufacturing narrow trench contacts without a dissolution neutralization process. The gapless patterning process in the present disclosure provides a “no freeze” gapless patterning method that enables narrow trench contacts defined by diffusion length to be obtained by inverting the pattern and using a dissolution resistance varying composition. The gapless patterning process herein enables a pattern resolution far below the theoretical limit of 365 nm and 248 nm photolithography used at 200 mm locations. The CD defined by acid diffusion of the inversion material allows for precise control to achieve a pattern resolution on the order of 40-100 nm. Aspect ratios below 10:1 can be particularly advantageous to improve etch performance and mitigate pattern collapse. Conventional i-line resists can be coated at thicknesses below 400 nm. Additional processing allows for thinner coatings, providing a wider process window to further reduce trench CD. Novolac photoresists are a mature technology, enabling high sidewall angles, which help maximize aspect ratio to form sub-resolution trenches.

[0052] In the preceding description, specific details have been set forth, such as a particular geometry of a processing system, and descriptions of various components and processes used therein. It should be understood, however, that techniques herein can be practiced in other embodiments that depart from these specific details, and that such details are for

[0053] Various techniques have been described as a number of discrete operations, which can be performed in other sequences than the order described. It is to be understood that the order of operations can be changed, and that certain operations can be performed in other orders. Additional operations can be added, and / or existing operations can be modified or deleted.

[0054] As used herein, "substrate" or "target substrate" generally refers to the object being processed according to the present application. The substrate can include any material portion or structure of a device, particularly a semiconductor or other electronic device, and can be, for example, a base substrate structure (such as a semiconductor wafer, reticle), or a layer on or over a base substrate structure (such as a thin film). Thus, the substrate is not limited to any particular base structure, underlayer, or overlayer that is patterned or unpatterned, but is contemplated to include any such layers or base structures, as well as any combination of layers and / or base structures. The description can refer to a particular type of substrate, but this is for illustrative purposes only.

[0055] Those skilled in the art will further appreciate that the technology illustrated above can be altered by a wide variety of changes without departing from the same goais of the present application. The scope of the present disclosure is intended to cover all such changes and modifications. Accordingly, the foregoing description of embodiments of the present application is not intended to be limiting. Rather, any limitations with regard to the application embodiments presented in the following claims are intended to cover all applications that would fall within the prior art.

Claims

1. A method for patterning a substrate, the method comprising: A first relief pattern is formed based on a first layer deposited on a substrate, the first relief pattern including an opening; The openings in the first relief pattern are filled with a reversing material, the reversing material being deposited to fill the openings comprising a resin and a photoacid generator, the resin being insoluble in a predetermined developer without any post-deposition dissolution and neutralization treatment, and the resin being further insensitive to the photoacid generated by the photoacid generator, such that when the resin comes into contact with the photoacid without any post-deposition dissolution and neutralization treatment, the resin remains insoluble in the predetermined developer. The first relief pattern is removed from the substrate, such that the inverted material remains on the substrate to define a second relief pattern, which is the inverted pattern of the first relief pattern. A filler material is deposited on the substrate, which is in contact with the second relief pattern and is sensitive to the photoacid generated by the photoacid generator, such that the portion of the filler material in contact with the photoacid becomes soluble in the predetermined developer; The selected portion of the second relief pattern is exposed to first photochemical radiation, such that a portion of the photoacid generator in the selected portion of the second relief pattern generates the photoacid in the selected portion of the second relief pattern. as well as The photoacid generated in the selected portion of the second embossed pattern is driven from the selected portion of the second embossed pattern to the portion of the filler material through the interface between the selected portion of the second embossed pattern and the filler material, and the photoacid makes these portions of the filler material soluble in the predetermined developer.

2. The method of claim 1, further comprising: The predetermined developer is used to remove these portions of the filler material in order to form a third relief pattern that exposes the underlying layer positioned between the substrate and the filler material.

3. The method of claim 2, further comprising: The third relief pattern is transferred to the lower layer using an etching process.

4. The method of claim 1, wherein, The photoacid generated in the selected portion of the second relief pattern is driven from the selected portion of the second relief pattern to these portions of the filler material by a diffusion process through the interface between the selected portion of the second relief pattern and the filler material to diffuse the photoacid into the filler material a predetermined distance.

5. The method of claim 1, wherein, Forming the first relief pattern involves exposing the first layer to second photochemical radiation that forms the potential pattern, and developing the potential pattern with a developer to form the first relief pattern.

6. The method of claim 1, wherein, The first layer is a photoresist layer.

7. The method of claim 1, wherein, Filling these openings in the first relief pattern involves depositing excess portions of the inverted material and removing excess portions of the inverted material.

8. The method of claim 1, wherein, The filler material does not contain the photoacid generator.

9. The method of claim 1, wherein, The photoacid generated in a selected portion of the second relief pattern is driven from the selected portion of the second relief pattern into the filler material by applying a thermally activated diffusion process to drive the photoacid.

10. The method of claim 9, wherein, The thermally activated diffusion process involves heating the substrate at a predetermined temperature for a predetermined duration.

11. The method of claim 1, wherein, The filler material includes deprotected groups that make the filler material soluble in the presence of the photoacid.

12. A method for patterning a substrate, the method comprising: A first relief pattern is formed based on a first layer deposited on a substrate, the first relief pattern including an opening; The openings in the first relief pattern are filled with a reversing material, the reversing material being deposited to fill the openings comprising a resin and a generating compound that generates a solubility modifier in response to exposure to photochemical radiation. The resin is insoluble in a predetermined developer without any post-deposition dissolution and neutralization treatment, and the resin is further insensitive to the solubility modifier, such that when the resin comes into contact with the solubility modifier without any post-deposition dissolution and neutralization treatment, the resin remains insoluble in the predetermined developer. The first relief pattern is removed from the substrate, such that the inverted material remains on the substrate to define a second relief pattern, which is the inverted pattern of the first relief pattern. A filler material is deposited on the substrate, which is in contact with the second relief pattern and is sensitive to the solubility modifier generated by the generating compound, such that the portion of the filler material in contact with the solubility modifier becomes soluble in the predetermined developer. The selected portion of the second relief pattern is exposed to photochemical radiation, causing a portion of the generating compound within the selected portion of the second relief pattern to generate the solubility modifier in the selected portion of the second relief pattern. as well as The solubility modifier generated in the selected portion of the second embossed pattern is driven through the interface between the selected portion of the second embossed pattern and the filler material to diffuse from the selected portion of the second embossed pattern into the portion of the filler material, and the solubility modifier makes these portions of the filler material soluble in the predetermined developer.

13. The method of claim 12, wherein, The solubility modifier includes photoacid.

14. The method of claim 12, wherein, The solubility modifier includes a photodegradable alkali.

15. The method of claim 13, wherein, The generating compound is a photoacid generator (PAG) that generates photoacid in response to exposure to the photochemical radiation, and the photoacid generator includes an iodonium salt or sulfonium salt having counterions.

16. The method of claim 14, wherein, The generating compound is a photodegrading alkali generating agent that generates the photodegrading alkali in response to exposure to the photochemical radiation.

17. The method of claim 12, wherein, Driving the solubility modifier generated in the selected portion of the second relief pattern to diffuse from the selected portion of the second relief pattern into those portions of the filler material includes applying a thermally activated diffusion process by controlling the average diffusion length of the solubility modifier.

18. The method of claim 12, wherein, The generating compound includes thermogenic acid generator (TAG).

19. The method of claim 18, wherein, The thermogenic acid generators include sulfonates derived from oximes, imides, and benzyl alcohol.

20. The method of claim 12, wherein, The filler material does not contain the generating compound.

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