Method for planarizing spin-coated films and CVD deposited organic films

Abstract

The present disclosure relates to techniques and methods for planarizing substrates by amplifying and controlling z-height techniques. The variability of z-height can be modeled or measured for each device. A relative height pattern can then be formed and processed on the substrate. By using different materials with different etch rates, the planarization pattern can be transferred to the substrate or system to form a planarized substrate surface to improve lithography. In addition, the same method can be used to accurately control the transition zone slope.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims the benefit of U.S. Provisional Application No. 62 / 876,378, filed on July 19, 2019, and U.S. Application No. 16 / 784,619, filed on February 7, 2020, which are incorporated herein by reference in their entirety. Technical Field

[0003] The present disclosure relates to a method of manufacturing a semiconductor device, and more particularly to a method for planarizing spin-on films and CVD-deposited organic films. Background Art

[0004] The background description provided herein is intended to generally present the context of the present disclosure. To the extent that the work of the present inventors is described in this background section, as well as aspects of this description that may not be identified as prior art at the time of filing, no admission is made, either explicitly or implicitly, as prior art to the present disclosure.

[0005] Semiconductor manufacturing includes photolithography and patterning processes. Some photolithography processes include coating a wafer with a thin film of bottom anti-reflective coating (BARC) material, followed by coating with a resist, and then exposing the wafer to a light pattern as one of many process steps to form a microchip. Photolithography and patterning processes generally benefit from a flat surface for depositing various films and a resist for patterning and exposing the wafer. Depending on a given manufacturing process, a film can be specified to have a specific height and be flattened to within a specific size.

[0006] Planarization is usually performed using a process called chemical mechanical polishing (CMP). CMP is a process that uses corrosive chemicals and polishing pads to flatten the surface of a wafer, similar to the working principle of wet sanding. CMP can flatten insulators and conductors in multi-level structures. This planarization is used to stack more electronic devices onto another layer of the wafer, or to flatten the wafer for lithographic patterning. CMP is also used to fine-tune the lithographic exposure process by setting the resist to a known height to optimize the exposure surface. Summary of the invention

[0007] This summary is provided to introduce a series of aspects of the present disclosure in a simplified form, which are further described in the following detailed description. This summary is neither intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0008] Although chemical mechanical polishing can provide a flat surface on a wafer, there are limitations and disadvantages to using CMP. CMP is typically performed by applying spin-on-glass (SOG) to the wafer and then using corrosive chemicals and physical grinding. Therefore, CMP is a very rough and physically abrasive process compared to other microfabrication techniques. Therefore, CMP may not be used for many process steps in microfabrication of integrated circuits. For example, CMP may not be used for microfabrication of transistors and other front-end process structures, especially when the gate oxide is exposed. In addition, the CMP process is very expensive to run, challenging to perform, and often reduces the yield of functional integrated circuits.

[0009] The technology disclosed in this article provides a method for planarizing a substrate using a spin-on film and an organic film deposited by chemical vapor deposition (CVD). The technology includes a method for amplifying and controlling conventional z-height technology. The z-height varies across the wafer. This variability in z-height can be modeled or measured for each device. A relative height pattern can then be formed and processed on the substrate. By using a series of different materials with a certain etching selectivity, the planarization pattern can be transferred to the substrate or system to form a planarized substrate surface to improve lithography. In addition, the same process can be used to accurately control the slope of the transition zone. The process of this article can be used to amplify and control other emerging z-height processing technologies.

[0010] Aspects of the present disclosure provide a planarization method. The method includes: depositing a first layer on a substrate having a concave-convex pattern of structures, the first layer covering the substrate and the structures, the top surface of the first layer being non-planar and having a first z-height range over a first region of the substrate including a plurality of the structures and having a second z-height range over a second region of the substrate including fewer structures than the plurality of the structures in the first region, the first z-height range being larger than the second z-height range; depositing a second layer on the first layer, the second layer having a non-planar top surface; changing the solubility of the second layer in at least one region of the top surface of the second layer to form a soluble portion of the second layer; removing the soluble portions of the second layer to expose the first layer in the first region of the substrate including the plurality of the structures; and etching the first layer and the second layer simultaneously, so that the first layer is etched at a greater etching rate than the second layer.

[0011] In one example, when etching the first layer and the second layer simultaneously, the method further includes etching the first layer and the second layer until top surfaces of the structures are exposed.

[0012] In another example, when etching the first layer and the second layer simultaneously, the method further includes etching the first layer and the second layer until the top surfaces of the structures are flush with the top surface of the first layer.

[0013] In yet another example, when etching the first layer and the second layer simultaneously, the method further includes etching the first layer and the second layer until the top surfaces of the structures are flush with the top surface of the first layer and the second layer is completely removed.

[0014] In yet another example, the first layer includes a first material and the second layer includes a second material, wherein the first material has an etch rate different from an etch rate of the second material.

[0015] In yet another example, when changing the solubility of the second layer, the method further includes depositing a solubility transition agent on the second layer and diffusing the solubility transition agent into the second layer.

[0016] In yet another example, when changing the solubility of the second layer, the method further includes: exposing the second layer to a pattern of actinic radiation, the pattern of actinic radiation generating more solubility switching agent at locations of the second layer, these locations of the second layer having a z-height greater than the z-height of other locations on the second layer.

[0017] Aspects of the present disclosure also provide another planarization method. The method includes: depositing a first layer on a substrate having a concave-convex pattern of structures, the first layer covering the substrate and the structures, the top surface of the first layer being non-planar and having a first z-height range over a first region of the substrate including a plurality of the structures and having a second z-height range over a second region of the substrate including a structure less than the plurality of the structures in the first region, the second z-height range being smaller than the first z-height range; depositing a second layer on the first layer, the second layer having a non-planar top surface and having a third z-height range over the first region of the substrate and having a fourth z-height range over the second region of the substrate, the third z-height range being smaller than the fourth z-height range; changing the solubility of the second layer in at least one region of the top surface of the second layer to form a soluble portion of the second layer; removing the soluble portions of the second layer to expose the first layer in the first region of the substrate including the plurality of the structures; and etching the first layer and the second layer simultaneously, so that the second layer is etched at a greater etching rate than the first layer.

[0018] Aspects of the present disclosure also provide yet another planarization method. The method includes: depositing a first layer on a substrate having a concave-convex pattern of structures, the first layer covering the substrate and the structures, the top surface of the first layer being non-planar and having a first z-height range over a first region of the substrate including a plurality of the structures and having a second z-height range over a second region of the substrate including a structure less than the plurality of the structures in the first region, the first z-height range being larger than the second z-height range; depositing a second layer on the first layer, the second layer having a non-planar top surface; changing the solubility of the second layer in at least one region of the top surface of the second layer to form a soluble portion of the second layer; removing the soluble portions of the second layer to expose the first layer in the first region of the substrate including the plurality of the structures; and etching the first layer and the second layer simultaneously, so that the first layer is etched at the same etching rate as the second layer.

[0019] According to one aspect, before simultaneously etching the first layer and the second layer, the method further includes: depositing a third layer on the remaining portion of the second layer and the exposed portion of the first layer, the third layer having a non-flat top surface; changing the solubility of the third layer in at least one region of the top surface of the third layer to form a soluble portion of the third layer; and removing these soluble portions of the third layer to expose the first layer in the first region of the substrate including the plurality of these structures.

[0020] According to another aspect, before simultaneously etching the first layer and the second layer, the method further includes: a cyclic planarization process performing the following steps: depositing additional layers on the exposed portion of the first layer in the first region of the substrate and the remaining portion of at least one other layer in the second region of the substrate, and selectively removing portions of the corresponding layers of the additional layers after each deposition of the corresponding layers of the additional layers until the top surface of the last layer of the deposited additional layers is flush with the top surface of the first layer.

[0021] It should be noted that the Summary of the Invention section does not specify every aspect and / or incremental novel aspects of the disclosure or claimed subject matter. Instead, the Summary of the Invention only provides a preliminary discussion of different aspects and corresponding points of novelty. For additional details and / or possible viewpoints of the disclosure and aspects, the reader should consult the Detailed Description section and corresponding drawings of the disclosure as further discussed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate aspects consistent with the disclosure and, together with the description, serve to explain the principles of the disclosure.

[0023] Figure 1 Shown are cross-sectional configurations of structures during various steps of a planarization process according to one exemplary aspect of the present disclosure.

[0024] Figure 2 Shown are cross-sectional configurations of structures during various steps of a planarization process according to another exemplary aspect of the present disclosure.

[0025] Figure 3 Shown are cross-sectional configurations of structures during various steps of a planarization process according to yet another exemplary aspect of the present disclosure.

[0026] Figure 4A Shown are cross-sectional configurations of structures during various steps in a cyclic planarization process according to exemplary aspects of the present disclosure.

[0027] Figure 4B A cross-sectional configuration of a construction is shown after completing multiple cycles of a cyclic planarization process according to an exemplary aspect of the present disclosure.

[0028] Figure 5 Construction cross-sections of planarization processes for different scales are shown according to exemplary aspects of the present disclosure.

[0029] Figure 6 A flow chart of a planarization method according to an exemplary aspect of the present disclosure is shown.

[0030] The specific aspects of the present disclosure that have been shown by the above-mentioned drawings will be described in detail below. These drawings and descriptions are not intended to limit the scope of the present disclosure in any way, but to explain the concept of the present disclosure to those skilled in the art by referring to the specific aspects. DETAILED DESCRIPTION

[0031] The following disclosure provides many different aspects or examples for implementing the different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. Of course, these are only examples and are not intended to be limiting. For example, forming a first feature above or on a second feature in the following description may include aspects in which the first feature and the second feature are directly contacted and formed, and may also include aspects in which additional features may be formed between the first feature and the second feature so that the first feature and the second feature may not be in direct contact. In addition, the present disclosure may reuse reference numerals and / or letters in various examples. This repetition is for the purpose of simplicity and clarity, and does not itself indicate the relationship between the various aspects and / or configurations discussed. Further, for ease of description, spatially related terms such as "top", "bottom", "below", "below", "lower", "above", "upper" and the like may be used herein to describe the relationship between an element or feature and other (multiple) elements or (multiple) features as shown in the accompanying drawings. In addition to the orientations depicted in the accompanying drawings, spatially related terms are also intended to cover different orientations of the device in use or operation. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted in a like manner accordingly.

[0032] For the sake of clarity, the order of discussion of the different steps described herein has been proposed. Generally, these steps can be performed in any suitable order. In addition, although each different feature, technology, configuration, etc. in this article may be discussed in different places of the present disclosure, it is intended that each concept can be performed independently of each other or in combination with each other. Accordingly, the present disclosure can be implemented and viewed in many different ways.

[0033] With the advent of multiple patterning methods, the number of layers or process modules in which there are underlying topography that affects subsequent photolithography layers has increased. In one example, for metal definition, a method includes forming a line and space grid pattern by self-aligned double patterning (SADP) and / or self-aligned quadruple patterning (SAQP), and using a photolithography process to define and memorize cuts or blocks in the metal pattern memorized in a hard mask film. Using dual damascene processing, once the metal pattern is memorized into a single or multiple hard mask films, the corresponding via patterning can be performed directly on the patterned memory film containing significant topography.

[0034] In these cases, planarization control can be achieved by incorporating a type of spin-coated film that will inherently have some edge self-planarization capabilities compared to the more conformal deposition seen by non-spin-coating deposition methods. These so-called planarizing films can reduce the overall variation in film thickness over a given feature seen in these process modules, however, the variation reduction is not sufficient for subsequent processing. Specifically, in terms of process tolerance control, especially DOF, the reduction seen is generally not sufficient to maintain a sufficiently flat surface to support advanced lithography techniques. Planarity is also insufficient to maintain other types of non-photolithographic patterning processes, such as etching grooves down the films to reveal (expose) the underlying pattern.

[0035] A common film that has been widely used for this purpose is a spin-on carbon-containing film. These films serve three main purposes. One purpose is to be an initial planarization film for a subsequent photolithography process. Another purpose is a material with tuned n&k optical parameters that will need to absorb light from the exposure process in a way that reduces unwanted reflectivity. The third purpose is a transfer layer where higher aspect ratios can be achieved compared to conventional photoresists where the photoresist pattern is transferred through a silicon-containing film and into the spin-on carbon film during which the resist pattern is consumed in the etch transfer process to the spin-on carbon film. For typical ArF exposures, the thickness of such commercially available spin-on carbon films can vary over a wide range, but a minimum thickness of 700A is generally necessary from a reflection point of view in order to suppress any unwanted reflections.

[0036] As lithographic patterning resolution increases through the combination of immersion lithography and eventually EUV lithography, there is a greater drive to control as much as possible any factors driving defocus. This demand drives an increasing need for tighter planarization control of spin-on carbon films.

[0037] In addition, with the onset of multiple patterning processes such as anti-spacer patterning definition, tone inversion processes, generation of self-aligned blocks for metal layers, and self-aligned vias and contacts, there are applications where films such as spin-on carbon can be used as a flat light absorbing film used as part of a photolithography process in addition to the intended purpose discussed above. In these patterning applications, spin-on carbon is included as a gap-filling film that is expected to uniformly fill a given pattern density area that is equal to an area with no pattern density or a very small pattern density.

[0038] The technology herein can further enhance the subject matter of U.S. Patent Application Serial No. 62 / 760,622, entitled “Method for Planarization of Spin-On and CVD-Deposited Organic Films,” which is incorporated herein by reference in its entirety.

[0039] Figure 1 2 shows a cross-sectional view of a structure during various steps of a planarization process according to aspects of the present disclosure. Figure 1 As shown in the configuration 101 of FIG. 1 , a substrate 110 may include one or more microfabricated structures 120 formed thereon, which results in a non-planar surface. The structures 120 may be lines, mesas, or any geometric shape protruding from an underlying cladding layer.

[0040] As shown in the configuration 102, a film may be coated or deposited on the substrate 110 to form a first layer 130 of a first material A. For example, the first layer 130 may be formed by spin coating, chemical vapor deposition (CVD), stamping, rolling, tube extrusion, spraying, jet printing, or any suitable method of coating or depositing a film on the substrate 110. The first material A may be one or a combination of SoC, PR, SiARC, SiO, HfO, TiO, AlO, TiN, or any other suitable material. The first layer 130 may cover the substrate 110 and the concave-convex pattern of the structure 120. The first layer 130 may have a non-flat top surface, thereby having a relatively large z-height over a region including the structure 120, and having a relatively small z-height over a region having relatively few structures 120 or having no structure 120. This may be the result of an isolated-dense pattern of the structure 120 on the substrate 110. In the case where the structure 120 is densely formed on the substrate 110, this density may lift certain coatings. In areas with more isolated structures 220 or without structures 220, the coating may drop. Figure 1 The structure 102 is shown.

[0041] As shown in construction 103, a second layer 140 of a second material B can then be deposited on the first layer 130. For example, the second layer 140 can be formed by spin coating, chemical vapor deposition (CVD), embossing, rolling, tube extrusion, spraying, jet printing, or any suitable method of coating or depositing a film on the first layer 130. The second material B can be one or a combination of an acid-sensitive polymer PTDPR, an acid-sensitive polymer NTDPR, an acid-sensitive polymer DARC, an acid-sensitive polymer DBARC, an acid-sensitive monomer acid catalyst crosslinking (H+), or any other suitable material. The second layer 140 can have a non-flat top surface. The material A of the first layer 130 and the material B of the second layer 140 can be selected to directly amplify the magnitude of the z height control. For example, these materials can be selected so that the material A has a greater etching rate than the material B.

[0042] A chemical planarization process may then be performed that changes the solubility of the second layer 140 at certain locations. This may include top-down diffusion of a photoacid generator or other solubility altering agent and patterned exposure to actinic radiation. For example, an acid may be applied to the second layer 140. This may be followed by a patterned exposure to light to activate the acid over the areas with greater z-height. A baking step may then drive the acid down through the second layer 140, making the affected portions of the second layer 140 soluble in a particular developer or solvent. The soluble top portions of the second layer 140 may then be removed. This exposes areas of the first layer with greater z-height, such as at Figure 1 As shown in the structure 104.

[0043] An etching process may then be performed using an etching chemistry that simultaneously etches the first material A of the first layer 130 and the second material B of the second layer 140. This etching process may also etch the first material A at a greater etching rate than the rate at which the second material B is etched. This etching rate difference allows the exposed areas of the first material A to be etched more quickly. This is advantageous when the first material A is thicker than the second material B, such as in Figure 1 As shown in the structure 105.

[0044] After successively etching the first layer 130 and the second layer 140, both layers 130, 140 may be etched down to the top surface of the structure 120, thereby creating a flat surface, as in Figure 1 106. The second layer 140 to be removed is substantially thinner than the portion to be removed of the first layer 130. The different thicknesses to be etched coupled with the different etch rates can result in the end result being a flat surface at a desired location, such as at the top surface of the microfabricated structure 120.

[0045] Figure 2 2 shows a cross-sectional view of a structure during various steps of a planarization process according to another aspect of the present disclosure. Figure 2 As shown in the configuration 201 of FIG. 1 , a substrate 210 may include one or more microfabricated structures 220 formed thereon, which results in an uneven surface. The substrate 210 may have a concave-convex pattern of structures 220, including some isolated areas having no structures 220 or having fewer structures 220 and some dense areas having many structures 220. The structures 220 may be lines, mesas, or any geometric shapes protruding from an underlying cladding layer.

[0046] As shown in construction 202, a film may be coated or deposited on substrate 210 to form a first layer 230 of a first material A. Coating may be performed by spin coating or chemical vapor deposition. The first layer 230 may cover the substrate 210 as well as the concave-convex pattern of the structures 220. The first layer 230 may have a non-planar top surface, thereby having a relatively large z-height over areas including structures 220 and a relatively small z-height over areas having relatively few structures 220 or no structures. This may be a result of an isolated-dense pattern of structures 220 on substrate 210. In the case where structures 220 are densely formed on substrate 210, this density may lift some of the coating. In areas having more isolated structures 220 or no structures 220, the coating may drop. This may be due to the fact that the coating may be formed on the substrate 210 in a manner that is not uniform. Figure 2 The structure 202 is shown.

[0047] As shown in configuration 203, a second layer 240 of a second material B may then be deposited on first layer 230. Second layer 240 may have a non-planar top surface due to the relief pattern of substrate 210, with a greater z-height over regions with relatively few or no structures 220.

[0048] A chemical planarization process that changes the solubility of the second layer 240 at certain locations can be performed. This can include top-down diffusion of a photoacid generator or other solubility-altering agent and patterned exposure to actinic radiation. For example, an acid is coated on the second layer 240. This is followed by a patterned exposure to light to activate the acid over areas of the first layer 230 that have a greater z-height. A baking step then drives the acid down through the second layer 240, rendering the affected portions of the second layer 240 soluble in a particular developer or solvent. The soluble top portion of the second layer 240 can then be removed. This exposes areas of the first layer 230 that have a greater z-height while leaving the second layer 240 to be removed with a relatively greater thickness, such as in Figure 2 As shown in the structure 204.

[0049] An etching process may then be performed using an etching chemistry that simultaneously etches the first material A of the first layer 230 and the second material B of the second layer 240. This etching process may also etch the first material A at a slower etching rate than the rate at which the second material B is etched. This etching rate difference allows the exposed areas of the first material A to be etched more slowly. This is advantageous when the first material A is thinner than the second material B, such as in Figure 2 As shown in the structure 205.

[0050] After successively etching the first layer 230 and the second layer 240, both layers 230, 240 may be etched down to the top surface of the structure 220, thereby creating a flat surface, as in Figure 2 206. The second layer 240 of the second material B to be removed is substantially thicker than the portion to be removed of the first layer 230 of the first material A. The different thicknesses to be etched coupled with the different etch rates can result in the end result being a flat surface at a desired location, such as at the top surface of the microfabricated structure 220.

[0051] Figure 3 2 shows a cross-sectional view of a structure during various steps of a planarization process according to yet another aspect of the present disclosure. Figure 3 As shown in the configuration 301 of FIG. 3 , a substrate 310 may include one or more microfabricated structures 320 formed thereon, which results in an uneven surface. The substrate 310 may have a concave-convex pattern of structures 320, including some isolated areas having no structures 320 or having fewer structures 320 and some dense areas having many structures 320. The structures 320 may be lines, mesas, or any geometric shapes protruding from the underlying cladding layer.

[0052] As shown in configuration 302, a film may be coated or deposited on substrate 310 to form a first layer 330 of a first material A. Coating may be performed by spin coating or chemical vapor deposition. The first layer 330 may cover substrate 310 and the concave-convex pattern of structures 320. The first layer 330 may have a non-planar top surface, thereby having a relatively large z-height over areas including structures 320 and a relatively small z-height over areas with relatively few structures 320 or without the structures. This may be a result of an isolated-dense pattern of structures 320 on substrate 310. In the case where structures 320 are densely formed on substrate 310, this density may lift some of the coating. In areas with more isolated structures 320 or without structures 320, the coating may drop. This may be due to the fact that the coating may be formed on the substrate 310 in a manner that is not uniform. Figure 3 The structure 302 is shown.

[0053] As shown in configuration 303, a second layer 340 of a second material B can then be deposited on the first layer 330. The second layer 340 can have a non-planar top surface. The material A of the first layer 330 and the material B of the second layer 340 can be selected to directly amplify the magnitude of the z-height control. For example, the materials can be selected so that material A has a greater etch rate than material B.

[0054] A chemical planarization process may then be performed that changes the solubility of the second layer 340 at certain locations. This may include top-down diffusion of a photoacid generator or other solubility altering agent and patterned exposure to actinic radiation. For example, an acid may be applied to the second layer 340. This may be followed by a patterned exposure to light to activate the acid over areas with greater z-heights. A baking step may then drive the acid downward through the second layer 340, making the affected portions of the second layer 340 soluble in a particular developer or solvent. The soluble top portion of the second layer 340 may then be removed. This exposes areas of the first layer 330 with greater z-heights, such as at Figure 3 This results in the removal of substantially equal thicknesses of the first material A of the first layer 330 and the second material B of the second layer 340 above the top surface of the structure 320.

[0055] An etching process may then be performed using an etching chemistry that simultaneously etches the first material A of the first layer 330 and the second material B of the second layer 340. This etching process may also etch both the first material A and the second material B at the same rate. In the case where each material has an equal thickness, both materials may be etched at the same rate to result in a flat surface remaining above the top surface of the structure 320, such as in Figure 3 As shown in the structure 305.

[0056] After successively etching the first layer 330 and the second layer 340, both layers 330, 340 may be etched down to the top surface of the structure 320, thereby creating a flat surface, as in Figure 3 The second layer 340 is deposited such that the final thickness over isolated areas with few or no structures 320 is equal to the thickness of the first layer 320 over dense areas of structures 320.

[0057] Figure 4A Shown are cross-sectional configurations of structures during various steps in a cyclic planarization process 400 in accordance with aspects of the present disclosure. Figure 4A The configurations 401, 402, 403, 404 and their corresponding features shown in FIG. 4 may correspond, for example, to Figure 1In this cyclic planarization process 400, the deposition of a layer (e.g., the second layer 140) and the selective position-based solubility and development steps can be cycled to achieve a desired result, such as Figure 4B The results are shown in . Figure 1 , Figure 2 and Figure 3 Any one or combination of aspects of the described planarization processes and corresponding configurations may be used in the cyclic planarization process 400 .

[0058] Figure 4B Shown in the completion Figure 4A A cross-sectional configuration 407 is shown after multiple cycles of the cyclic planarization process 400. Configuration 407 may include Figure 1 The substrate 110, the structure 120 and the first layer 130 shown in FIG. Figure 2 and Figure 3 The substrate 410, the structure 420 and the first layer 430 of the corresponding features shown in FIG. As for the second layer 440, Figure 4B 4 shows how several cycles of material deposition and removal according to the foregoing aspects can be combined to produce a second layer 440 having a desired thickness. The second layer 440 may include a first cycle layer 441, a second cycle layer 442, and a third cycle layer 443, which may be deposited during the first cycle, the second cycle, and the third cycle of the cyclic planarization process 400, respectively. Based on the number of cycles performed by the cyclic planarization process 400, the second layer 440 may include a plurality of layers. Figure 4B In addition, each cycle layer may include the same or different materials relative to each other (e.g., any one of SoC, PR, SiARC, SiO, HfO, TiO, AlO, TiN, acid-sensitive polymer PTD PR, acid-sensitive polymer NTD PR, acid-sensitive polymer DARC, acid-sensitive polymer DBARC, acid-sensitive monomer acid catalyst cross-linking (H+), or a combination thereof) and may have the same or different thicknesses.

[0059] Figure 5A cross-sectional configuration of a planarization process for different scales according to aspects of the present disclosure is shown. Specifically, configurations 501, 502, 503, 504, and 505 show how adjustments can be made based on the scale of planarization. For example, aspects of the disclosed planarization process can be used on a nanometer scale, such as having a height difference in the range of 10-100 nanometers, as shown in configuration 504. Aspects of the disclosed planarization process can also be used to planarize layers with micrometer-scale height differences (such as having a height difference in the range of 10-100 microns, as shown in configuration 501). Aspects of the disclosed planarization process can also be used to planarize height differences less than 100 nm, less than 10 microns, or greater than 1 micron.

[0060] In light of the foregoing description, the disclosed planarization process can be used to effectively planarize substrates, films, and layers of various materials using a combination of position-based development and etch rate differences without using any mechanical grinding.

[0061] Figure 6 1 is a flow chart of a planarization method according to an exemplary aspect of the present disclosure. In step S601, a structure is provided on a surface of a substrate. For example, Figures 1 to 3 As shown in , structures 120 , 220 , 320 may be formed on substrates 110 , 210 , 310 , respectively.

[0062] In step S602, a first layer of a first material is deposited on the substrate and the structure. Figures 1 to 3 As shown in , the first layer 130, 230, 330 can be formed on the substrate 110, 210, 310, respectively, so as to cover both the corresponding substrate 110, 210, 310 and the structure 120, 220, 320 on the substrate. The first layer forms a non-planar surface above the substrate based on the concave-convex pattern of the underlying structure 120, 220, 320. The first material can be a first material A, such as SoC, PR, SiARC, SiO, HfO, TiO, AlO, TiN or any other suitable material.

[0063] In step S603, a second layer of a second material is deposited on top of the first layer as the top layer. Figures 1 to 3 As shown in , the second layer 140, 240, 340 can be formed on the first layer 130, 230, 330, respectively. The second material can be a second material B, such as an acid-sensitive polymer PTD PR, an acid-sensitive polymer NTD PR, an acid-sensitive polymer DARC, an acid-sensitive polymer DBARC, an acid-sensitive monomer acid catalyst cross-linking (H+), or any other suitable material. In addition, the second layer can be deposited in such a manner to have a non-flat top surface: the non-flat top surface is referred to as Figures 1 to 3The described approach varies in z-height over the region of the first layer.

[0064] In step S604, the solubility of a portion of the topmost or most recently deposited layer (such as the second layer) may be changed. Figures 1 to 3 As shown in , the solubility of the second material B of the second layer 140, 240, 340 can be changed at certain locations by the chemical planarization process. The location of the changed solubility of the topmost layer (e.g., the second layer) can vary based on the desired resulting configuration of the topmost layer and the thickness of the topmost layer relative to the first layer.

[0065] In step S605, the topmost layer whose solubility has been changed by the chemical planarization process (ie, the soluble portion) is then removed. Figures 1 to 3 As shown in , various dissolvable portions of the second layers 140, 240, 340 can be removed to reveal regions of the first layers 130, 230, 330, respectively. The specific portions of the topmost layer that are removed and the specific regions of the first layer that are exposed can be controlled based on the desired resulting configuration of the topmost layer and the thickness and z-height of the topmost layer relative to the first layer, as shown in Figures 1 to 3 This is illustrated in the illustrated configurations 104, 204, 304. The timing and intensity of the removal process may also be controlled to achieve desired results.

[0066] In step S606, it is determined whether the desired top layer structure has been achieved by the chemical planarization and removal process in step S605. If the desired structure has been achieved, the method proceeds to step S608. Otherwise, if the desired structure has not been achieved, the method proceeds to step S607, resulting in a cyclic planarization process 400, as described in reference to FIG. FIG. 4A to FIG. 4B As described.

[0067] In step S607, an additional layer is deposited as a new topmost layer over the exposed areas of the first layer and the remaining portions of the second layer (i.e., the previously formed, processed, and partially removed topmost layer). The method then proceeds through steps S604, S605, S606 as part of a cycle of the cyclic planarization process 400 until the desired configuration of the topmost layer is achieved. For example, as in FIG. 4A to FIG. 4B As shown in FIG. 4 , the cyclic planarization process 400 proceeds from step S607 and returns through steps S604, S605, S606 to deposit, develop, and remove additional layers of one or more of the cyclic layers 441, 442, 443 to achieve a desired structural result (such as in FIG. Figure 4B Expected construction result shown in ).

[0068] In step S608, once the desired configuration has been achieved, etching is performed to planarize the first layer and the top layer to obtain a flat surface at a desired level. Figures 1 to 3As shown in , chemical etching can continuously etch the first material A of the first layer and the second material B of the second layer at respective etching rates appropriate relative to each other to obtain a final configuration with a flat surface at a desired location (e.g., at the level of the top surface of the exposed structure 120, 220, 320). The etching rate difference between the first material and the second material is controlled based on the type of material and the respective thickness of the first layer and the topmost layer. An example of the etching difference is shown in the following progression: Figure 1 From structure 104 to structure 106; Figure 2 From construction 204 to construction 206; and Figure 3 From structure 1304 to structure 306.

[0069] In this manner, the disclosed planarization methods can be used to effectively planarize substrates, films, and layers of various materials using a combination of position-based development and etch rate differences while avoiding the use of harsh and physically abrasive processes.

[0070] In the foregoing description, specific details have been set forth, such as the specific geometry of the processing system and the description of the various components and processes used therein. However, it should be understood that the technology herein can be practiced in other aspects that are separated from these specific details, and these details are for the purpose of explanation rather than limitation. The aspects disclosed herein have been described with reference to the accompanying drawings. Similarly, for the purpose of explanation, specific numbers, materials, and configurations have been set forth in order to provide a thorough understanding. However, aspects can be practiced without these specific details. Components having substantially the same functional structure are represented by similar reference numerals, and any redundant description can therefore be omitted.

[0071] Various techniques have been described as multiple independent operations to help understand various aspects. The order of description should not be interpreted as meaning that these operations must be dependent on the order. In fact, these operations do not need to be performed in the order presented. The described operations can be performed in an order different from the described aspects. In additional aspects, various additional operations can be performed and / or the described operations can be omitted.

[0072] As used herein, "substrate" or "target substrate" generally refers to an object that is processed according to the present disclosure. A substrate may include any material portion or structure of a device (particularly a semiconductor or other electronic device), and may be, for example, a base substrate structure (such as a semiconductor wafer, a mask), or a layer (such as a thin film) on or overlying a base substrate structure. Thus, a substrate is not limited to any particular base structure, underlying layer, or overlying layer, patterned or unpatterned, but is contemplated to include any such layer or base structure, and any combination of layers and / or base structures. The description may refer to a specific type of substrate, but this is for illustrative purposes only.

[0073] Those skilled in the art will also appreciate that many changes may be made to the operation of the above-mentioned techniques while still achieving the same purpose of the present disclosure. The scope of the present disclosure is intended to include these changes. Therefore, the foregoing description of the aspects of the present disclosure is not intended to be restrictive. On the contrary, any limitation to the aspects of the present disclosure is presented in the appended claims.

Claims

1. A planarization method, the method include: depositing a first layer on a substrate having a relief pattern of structures, the first layer covering the substrate and the structures, the top surface of the first layer being non-planar and having a first z-height range over a first region of the substrate including a plurality of the structures and having a second z-height range over a second region of the substrate including fewer structures than the plurality of the structures in the first region, the first z-height range being larger than the second z-height range; depositing a second layer on the first layer, the second layer having a non-planar top surface; changing the solubility of the second layer in at least one region of the top surface of the second layer to form a soluble portion of the second layer; removing the soluble portions of the second layer to expose the first layer in the first region of the substrate including the plurality of the structures; as well as The first layer and the second layer are etched simultaneously such that the first layer is etched at a greater etching rate than the second layer, wherein the second layer to be removed is thinner than a portion of the first layer to be removed.

2. The method according to claim 1, in, Etching the first layer and the second layer simultaneously includes etching the first layer and the second layer until top surfaces of the structures are exposed.

3. The method according to claim 2, in, Etching the first layer and the second layer simultaneously further includes etching the first layer and the second layer until the top surfaces of the structures are flush with the top surface of the first layer.

4. The method according to claim 2, in, Etching the first layer and the second layer simultaneously further includes etching the first layer and the second layer until the top surfaces of the structures are flush with the top surface of the first layer and the second layer is completely removed.

5. The method according to claim 1, in, The first layer includes a first material and the second layer includes a second material, wherein the first material has an etch rate different than an etch rate of the second material.

6. The method according to claim 1, in, Changing the solubility of the second layer includes depositing a solubility shift agent on the second layer and diffusing the solubility shift agent into the second layer.

7. The method according to claim 1, in, Changing the solubility of the second layer includes exposing the second layer to a pattern of actinic radiation that generates more solubility shifting agent at locations of the second layer having greater z-heights than other locations on the second layer.

8. A planarization method, the method comprising: include: depositing a first layer on a substrate having a relief pattern of structures, the first layer covering the substrate and the structures, the top surface of the first layer being non-planar and having a first z-height range over a first region of the substrate including a plurality of the structures and having a second z-height range over a second region of the substrate including fewer structures than the plurality of the structures in the first region, the second z-height range being smaller than the first z-height range; depositing a second layer on the first layer, the second layer having a non-planar top surface and having a third z-height range above the first region of the substrate and a fourth z-height range above the second region of the substrate, the third z-height range being smaller than the fourth z-height range; changing the solubility of the second layer in at least one region of the top surface of the second layer to form a soluble portion of the second layer; removing the soluble portions of the second layer to expose the first layer in the first region of the substrate including the plurality of the structures; as well as The first layer and the second layer are simultaneously etched such that the second layer is etched at a greater etching rate than the first layer, wherein the second layer to be removed is thinner than the portion of the first layer to be removed.

9. The method according to claim 8, in, Etching the first layer and the second layer simultaneously includes etching the first layer and the second layer until top surfaces of the structures are exposed.

10. The method according to claim 9, in, Etching the first layer and the second layer simultaneously further includes etching the first layer and the second layer until the top surfaces of the structures are flush with the top surface of the first layer.

11. The method according to claim 9, in, Etching the first layer and the second layer simultaneously further includes etching the first layer and the second layer until the top surfaces of the structures are flush with the top surface of the first layer and the second layer is completely removed.

12. The method according to claim 8, in, Changing the solubility of the second layer includes depositing a solubility shift agent on the second layer and diffusing the solubility shift agent into the second layer.

13. The method according to claim 8, in, Changing the solubility of the second layer includes exposing the second layer to a pattern of actinic radiation that generates more solubility shifting agent at locations of the second layer having a z-height less than other locations on the second layer.

14. A planarization method, the method comprising: include: depositing a first layer on a substrate having a relief pattern of structures, the first layer covering the substrate and the structures, the top surface of the first layer being non-planar and having a first z-height range over a first region of the substrate including a plurality of the structures and having a second z-height range over a second region of the substrate including fewer structures than the plurality of the structures in the first region, the first z-height range being larger than the second z-height range; depositing a second layer on the first layer, the second layer having a non-planar top surface; changing the solubility of the second layer in at least one region of the top surface of the second layer to form a soluble portion of the second layer; removing the soluble portions of the second layer to expose the first layer in the first region of the substrate including the plurality of the structures; as well as The first layer and the second layer are etched simultaneously such that the first layer is etched at the same etching rate as the second layer, wherein the second layer to be removed is thinner than the portion of the first layer to be removed.

15. The method of claim 14, in, Etching the first layer and the second layer simultaneously includes etching the first layer and the second layer until top surfaces of the structures are exposed.

16. The method of claim 15, in, Etching the first layer and the second layer simultaneously further includes etching the first layer and the second layer until the top surfaces of the structures are flush with the top surface of the first layer.

17. The method of claim 14, in, Changing the solubility of the second layer includes depositing a solubility shift agent on the second layer and diffusing the solubility shift agent into the second layer.

18. The method of claim 14, in, Removing the dissolvable portions of the second layer causes the remaining portions of the second layer to be flush with the exposed portions of the first layer.

19. The method of claim 14, in, Prior to simultaneously etching the first layer and the second layer, the method further comprises: depositing a third layer on the remaining portion of the second layer and the exposed portion of the first layer, the third layer having a non-planar top surface; changing the solubility of the third layer in at least one region of the top surface of the third layer to form a soluble portion of the third layer; and The soluble portions of the third layer are removed to expose the first layer in the first region of the substrate including the plurality of the structures.

20. The method of claim 14, in, Prior to simultaneously etching the first layer and the second layer, the method further comprises: A cyclic planarization process performing the following steps: depositing additional layers on the exposed portion of the first layer in the first region of the substrate and the remaining portion of at least one other layer in the second region of the substrate, and selectively removing portions of corresponding ones of the additional layers after each deposition of a corresponding one of the additional layers until the top surface of the last one of the deposited additional layers is flush with the top surface of the first layer.

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