Method of forming a topologically controlled amorphous carbon polymer film

Abstract

The present invention relates generally to a method of forming a topologically controlled amorphous carbon polymer film, exemplary embodiments provide a method of top-selective deposition using a flowable carbon-based film on a substrate having a recess defined by a top surface, sidewalls, and a bottom, comprising the steps of: (i) depositing the flowable carbon-based film in the recess of the substrate in a reaction space until the thickness of the flowable carbon-based film in the recess reaches a predetermined thickness, then stopping the deposition step; and (ii) exposing the carbon-based film to a nitrogen plasma in an atmosphere substantially free of hydrogen and oxygen to selectively re-deposit the carbon-based film on the top surface.

Description

TECHNICAL FIELD

[0001] The present invention relates generally to a method of forming a topologically controlled carbon-based film on a patterned recess of a substrate, in particular, a method of using top-selective deposition of a flowable carbon-based film on a patterned recess. BACKGROUND

[0002] In the process of manufacturing integrated circuits such as those used for shallow trench isolation, intermetal dielectric layer, passivation layer, etc., it is often necessary to fill a trench (typically any recess having an aspect ratio of one or higher) with an insulating material. However, with the miniaturization of the wiring pitch of large scale integrated (LSI) devices, void-free filling of high aspect ratio spaces (e.g., AR > 3) becomes increasingly difficult due to the limitations of existing deposition processes.

[0003] In view of the above, the present inventors have developed a gap fill technique for depositing a flowable film and disclosed this technique in U.S. Patent Application No. 16 / 026,711 filed on July 3, 2018 and U.S. Patent Application No. 16 / 427,288 filed on May 30, 2019, the disclosure of each of which is incorporated herein by reference in its entirety, which provides full gap fill with essentially no void formation by plasma-assisted deposition using a hydrocarbon precursor under conditions in which nitrogen, oxygen, or hydrogen plasma is not required.

[0004] However, if certain applications in which a sacrificial etch stop layer or a protective layer is necessary, for example, only on the top surface of a recess, require deposition of amorphous carbon on a substrate only on the top using the gap fill technique described above, without deposition of amorphous carbon in the trench of the substrate, for example, at the bottom of the trench, there can be the following problems: i) the deposition by the gap fill technique is essentially a bottom-up deposition and thus it will inevitably deposit a certain amount of film at the bottom of the recess; ii) in the case where the recess is a super deep hole (aspect ratio, for example, greater than 10, typically 15-100) for applications such as 3D NAND, the gap fill technique can be a bottomless deposition (because the flowable material cannot reach the bottom of the recess although it will flow down) but due to the flow of the material along the sidewalls of the recess, it will inevitably deposit a certain amount of film on the sidewalls of the recess; iii) in (ii), the film is deposited on the top surface. But since the upper opening of the recess is small, the opening can be closed, eventually depositing and accumulating the film uniformly on the top surface, and iv) in the case where the upper opening of the recess is wide enough for the flowable material to flow into the recess, it can be difficult to deposit a thick film on the top surface, i.e., it can be difficult to control the thickness of the film deposited on the top surface. The present inventors provide a landmark solution to the above problems using the gap fill technique herein.

[0005] Any discussion of problems and solutions involved in the related art has been included in this disclosure solely for the purpose of providing a context for the present application, and should not be taken as an acknowledgement or any or all of the discussion being prior art to the present application. SUMMARY

[0006] In view of the foregoing, some embodiments provide a method of top selective deposition of a flowable carbon-based film on a substrate having a recess defined by a top surface, a sidewall, and a bottom, comprising the steps of: (i) depositing a flowable carbon-based film in the recess of the substrate in a reaction space until the thickness of the flowable carbon-based film in the recess reaches a predetermined thickness, then stopping the deposition step; and (ii) exposing the carbon-based film to a nitrogen plasma in an atmosphere substantially free of hydrogen and oxygen to selectively redeposit the carbon-based film on the top surface. In the foregoing, it is completely surprising that as a phenomenon, the flowable material, once accumulated in the recess, like a fluid accumulated in a container, can be moved upward and accumulated on the top surface as if a siphon is used to draw out the fluid. In one embodiment, by the combination of the flowability of the film and the nitrogen plasma, the carbon-based film can be selectively redeposited from the bottom of the recess to the top surface. In some embodiments, since the flowable film needs to be accumulated at the bottom of the recess by bottom-up deposition, the recess needs to have an aspect ratio of 2 to 30 (typically 3 to 20). Gap fill techniques for depositing the flowable film are disclosed in, for example, U.S. Patent Application No. 16 / 026,711 filed July 3, 2018 and U.S. Patent Application No. 16 / 427,288 filed May 30, 2019, the disclosure of each of which is incorporated by reference herein in its entirety, and such techniques can be applied to some embodiments of the present application.

[0007] In some embodiments, to re-deposit the carbon-based film on the top surface, the carbon-based flowable film accumulated at the bottom of the recess is exposed to a nitrogen plasma, wherein the plasma is substantially free of H2and O2, for example, the concentration of H2and O2in the atmosphere of the reaction space is less than 5%, preferably less than 1% in total. When the concentration of H2and O2in the atmosphere exceeds the above concentration, the plasma shows more ashing function rather than helping the re-deposition of the film. In addition, in some embodiments, when the carbon-based flowable film at the bottom of the recess is exposed to the plasma, the atmosphere of the reaction space can contain a noble gas such as Ar and He to the addition of the noble gas does not substantially affect the degree of re-deposition of the carbon-based film, for example, the concentration of noble gas (e.g., Ar and / or He) is less than 50%, preferably less than 30%, more preferably less than 20%, most preferably less than 15% in total. In some embodiments, the atmosphere consists essentially of or consists of nitrogen. In some embodiments, to achieve the flowability or bottom-up deposition of the carbon-based film during deposition of the carbon-based film, the deposition temperature can be adjusted, wherein the flowability of the film is inversely proportional to the deposition temperature, the deposition temperature is adjusted according to the type of precursor, for example, at a temperature lower than about 100°C, for example, about 75°C.

[0008] For purposes of summarizing the application and the accomplished advantages, certain objects and advantages of the application are described in this disclosure. Of course, it is to be understood that not necessarily all such objects or advantages can be achieved in accordance with any particular embodiment of the application. Thus, for example, those skilled in the art will recognize that the application can be practiced with

[0009] Other aspects, features, and advantages of the present application will become apparent from the following detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0010] These and other features of the present application will be described with reference to the drawings of preferred embodiments, which are intended to illustrate and not to limit the application. The drawings are greatly simplified for illustrative purposes and are not necessarily to scale.

[0011] Figure 1A is a schematic diagram of a PEALD (plasma enhanced atomic layer deposition) apparatus for depositing dielectric films that can be used in one embodiment of the present application.

[0012] Figure 1A is a schematic diagram illustrating a precursor supply system using a flow through system (FPS) that can be used in one embodiment of the present application.

[0013] Figure 2Figure showing a schematic cross-sectional view of a trench to illustrate the process of top selective deposition according to an embodiment of the present application ((a)→(b)→(c)).

[0014] Figure 3 Figure showing a schematic cross-sectional view of a trench to illustrate the intended mechanism of top selective deposition according to an embodiment of the present application ((a)→(b)→(c)→(d)).

[0015] Figure 4 Figure showing the shrinkage of a film exposed to plasma of different gases.

[0016] Figure 5 STEM photographs showing cross-sectional views of a trench, where original (a) represents a trench subjected to full fill deposition of flowable film, original (b) represents the trench shown in (a) after O2 / Ar ashing, original (c) represents the trench shown in (a) after N2 / H2 ashing, column (1) represents the trench at high magnification (scale bar represents 60 nm), column (2) represents the trench at low magnification (scale bar represents 300 nm).

[0017] Figure 6 STEM photographs showing: (a) cross-sectional view of a trench subjected to flowable film deposition at 75 °C followed by exposure to N2 plasma according to one embodiment of the present application, and (b) cross-sectional view of a trench subjected to almost flowable film deposition at 100 °C followed by exposure to N2 plasma.

[0018] Figure 7 STEM photographs showing according to one embodiment of the present application: (a) cross-sectional view of a trench subjected to flowable film deposition followed by exposure to N2 plasma for 10 seconds, and (b) cross-sectional view of a trench subjected to flowable film deposition followed by exposure to N2 plasma for 60 seconds.

[0019] Figure 8 STEM photographs showing cross-sectional view of a trench subjected to top selective deposition according to one embodiment of the present application.

[0020] Figure 9 Fourier transform infrared (FTIR) spectra of a flowable amorphous carbon polymer film in as-deposited state ("STD") and a re-deposited amorphous carbon polymer film treated with N2 plasma ("N2-CK") according to one embodiment of the present application.

[0021] Figure 10FIG. 1 is a diagram illustrating a top select film formation process sequence according to one embodiment of the present application, where the width of each column does not necessarily represent actual time duration, and the raising of the lines in each row represents an ON state, while the lowering of the lines in each row represents an OFF state. DETAILED DESCRIPTION

[0022] In the present disclosure, depending on the context, "gas" can include vaporized solids and / or liquids and can be composed of a single gas or a mixture of gases. Also, depending on the context, the article "a" refers to one species or a genus including multiple species. In the present disclosure, a process gas introduced to a reaction chamber through a showerhead can comprise, consist essentially of, or consist of a silane-free precursor and an additive gas. The additive gas can include a plasma generating gas for exciting the precursor to form an amorphous carbon polymer when RF power is applied to the additive gas. The additive gas can be an inert gas, which can be fed to the reaction chamber as a carrier gas and / or a dilution gas. The additive gas can be free of a reactive gas for oxidizing or nitriding the precursor. Alternatively, the additive gas can contain a reactive gas for oxidizing or nitriding the precursor to an extent that does not interfere with the plasma polymerization to form an amorphous carbon-based polymer. Further, in some embodiments, the additive gas contains only a plasma generating gas (e.g., a noble gas). The precursor and the additive gas can be introduced to the reaction space as a mixed gas or separately to the reaction space. The precursor can be introduced with a carrier gas such as a noble gas. A gas other than a process gas, i.e., a gas that is not introduced through the showerhead, can be used, for example, to seal the reaction space, which includes a seal gas such as a noble gas. In some embodiments, the term "precursor" generally refers to a compound that participates in a chemical reaction to produce another compound, and specifically refers to a compound that constitutes a matrix or a major skeleton of a film, while the term "reactant" refers to a compound other than the precursor that activates, modifies, or catalyzes the reaction of the precursor, where the reactant can provide elements (e.g., O, C, N) to the matrix of the film and, when in an excited state, becomes part of the matrix of the film. The term "plasma generating gas" refers to a compound other than the precursor and the reactant that generates a plasma when exposed to electromagnetic energy, where the plasma generating gas can not provide elements (e.g., O, C, N) to the matrix of the film that become part of the matrix of the film. The term "plasma ashing gas" refers to a gas that ashed a film when in a state of direct excitation (direct plasma) or remote excitation (remote plasma). In some embodiments, the "plasma ashing gas" is a single gas or a mixture of two or more gases. The term "ashing" refers to the removal of organic matter using a plasma, leaving mineral components as a residue (ash), which is typically removed with a vacuum pump.

[0023] In some embodiments, "film" refers to a layer that extends continuously in a direction perpendicular to the thickness direction that substantially lacks pinholes that covers an entire target or relevant surface, or simply refers to a layer that covers a target or relevant surface. In some embodiments, "layer" refers to a structure formed on a surface having a certain thickness, or a synonym for a film or non-film structure. A film or layer can be composed of discrete individual films or layers having certain characteristics or by multiple films or layers, and the boundaries between adjacent films or layers can or can not be transparent and can be established based on physical, chemical, and / or any other characteristics, formation processes or sequences, and / or the function or purpose of the adjacent films or layers. Furthermore, in the present disclosure, since a workable range can be determined based on routine work, any two numbers of a variable can constitute a workable range of the variable, and any range indicated can include or exclude endpoints. In addition, any indicated values of a variable, whether or not they are indicated with "about," can refer to exact or approximate values and include equivalent values, and in some embodiments can refer to average values, median values, representative values, majority values, etc. Furthermore, in the present disclosure, in some embodiments, the terms "consisting of and "having" independently refer to "typically or broadly includes," "includes," "substantially consists of," or "consists of." In the present disclosure, in some embodiments, any defined meaning does not necessarily exclude the ordinary and customary meaning.

[0024] In the present disclosure, in some embodiments, "continuously" refers to not breaking a vacuum, not interrupting in a time axis, no intervening steps of any material, not immediately changing a processing condition as a next step after, or no discrete physical or chemical structure intervening between two structures other than the two structures.

[0025] In the present disclosure, the term "filling ability" (also referred to as "flowability") refers to the ability to fill a gap substantially without voids (e.g., without voids having a dimension of about 5 nm or more in diameter) or seams (e.g., without seams having a length of about 5 nm or more), where a seamless / voidless bottom-up growth of a layer is observed when depositing a film in a wide trench having an aspect ratio of about 1 or more.

[0026] Flowability is often manifested as a concave film surface at the bottom of a wide trench before filling the trench, and also as a substantially planar film top surface (planarization) when continuously deposited after completely filling the trench. Such deposition is referred to as "bottom-up deposition."

[0027] When the trench is narrow and deep, even if the film is flowable, the film can not reach the bottom of the trench. In this case, the flowability often manifests as a generally or substantially conformal film along the sidewalls of the trench, with substantially no film at the bottom of the trench and the top opening of the trench generally closed by the film. Because the film is flowable, the sidewall film flows and extends down the sidewalls, forming a thin film, where the ratio of the average thickness of the substantially conformal portion of the film (except for the top portion that closes the top opening of the trench, which is subsequently removed by ashing) to the depth of the film in the trench (the length extending down the sidewalls toward the bottom) can be in the range of 0.1% to 10% (typically 0.5% to 5%). This deposition is referred to as "bottomless deposition."

[0028] In the present disclosure, the recess between adjacent protrusion structures and any other recess pattern is referred to as a "trench." That is, a trench is any recess pattern that contains a hole / via. For bottom-up deposition, in some embodiments, a trench has a width (where it can be referred to as a hole / via when the trench has substantially the same length as width) of about 20 nm to about 100 nm (typically about 30 nm to about 50 nm), a depth of about 30 nm to about 100 nm (typically about 40 nm to about 60 nm), and an aspect ratio of about 2 to about 10 (typically about 2 to about 5). The appropriate dimensions of a trench can vary with process conditions, flowability of the film, film composition, intended application, etc. By, for example, adjusting the flowability of the film, bottom-up deposition can be achieved in trenches having dimensions different from those described above.

[0029] In the present disclosure, the terms "substantially no deposition," "substantially no film," and the like refer to an amount that is functionally equivalent to zero, an amount that is immaterial or negligible, an amount that does not materially interfere with subsequent processes (e.g., ashing), an amount that is below a detectable or observable amount, etc.

[0030] In the present disclosure, in some embodiments, any defined meaning is not necessarily exclusive of the ordinary and customary meaning followed in the art. Also, in the present disclosure, "the invention" means at least one of the embodiments or aspects expressly, inherently, or inherently disclosed herein.

[0031] Embodiments will be described with reference to the preferred embodiments. However, the present invention is not intended to be limited to these preferred embodiments.

[0032] Some embodiments provide a method for top-selective deposition of a flowable carbon-based film on a substrate having a recess defined by a top surface, sidewalls, and a bottom, comprising the steps of: (i) depositing a flowable carbon-based film in the recess of the substrate in a reaction space until the thickness of the flowable carbon-based film in the recess reaches a predetermined thickness, then stopping the deposition step; and (ii) exposing the carbon-based film to a nitrogen plasma in an atmosphere substantially free of hydrogen and oxygen to selectively redeposit the carbon-based film on the top surface. The carbon-based film can generally be an amorphous carbon polymer film that is a flowable film, but the carbon-based film can be any other suitable carbon-based film that can be derived from a precursor and plasma-polymerized, and can be deposited in a flowable manner. The carbon-based film can or can not contain Si (e.g., polycarbosilane polymer or hydrocarbon polymer derived from cyclopentene).

[0033] When forming an amorphous carbon polymer film by using a plasma-assisted method, the resulting amorphous carbon polymer film is composed of a hydrogenated amorphous carbon polymer. In the present disclosure, the hydrogenated amorphous carbon polymer can be simply referred to as an amorphous carbon polymer, which can also be referred to as "aC:H" or simply the abbreviation "aC". Furthermore, in the present disclosure, unless otherwise stated, SiC, SiCO, SiCN, SiCON, and the like are abbreviations that indicate the film type (simply indicated by the main constituent element) in a non-stoichiometric manner.

[0034] In some embodiments, steps (i) and (ii) are repeated a plurality of times (e.g., 1 to 100 times, typically 2 to 20 times) until the thickness of the carbon-based film on the top surface reaches a desired final thickness (e.g., 1 to 100 nm, typically 2 to 20 nm), which can vary depending on its intended use and application. When the carbon-based film reaches the final thickness and steps (i) and (ii) are stopped, the flowable carbon-based film at the bottom of the recess can be completely removed, although its thickness has been reduced by step (ii), as desired; however, preferably, the final thickness of the carbon-based film on the top surface is greater than the thickness of the flowable carbon-based film at the bottom, such that some thickness of the top carbon-based film can be preserved when plasma ashing (anisotropic) is performed to further or completely remove the carbon-based film at the bottom.

[0035] In some embodiments, the predetermined thickness in step (i) is greater than a monolayer thickness, but is 15 nm or less (preferably 7.5 nm or less, more preferably 5 nm or less), and steps (i) and (ii) are repeated a plurality of times.

[0036] Deposition of flowable films is known in the art; however, conventional deposition of flowable films uses chemical vapor deposition (CVD) with continuous application of RF power, as pulsed plasma assisted deposition such as PEALD is well known for depositing conformal films that are films having characteristics that are completely opposite to those of flowable films. In some embodiments, the flowable film is a silicon-free carbon-containing film composed of amorphous carbon polymer, and although any suitable hydrocarbon precursor or precursors can be candidates, in some embodiments the precursor includes an unsaturated or cyclic hydrocarbon having a vapor pressure of 1,000 Pa or more at 25 °C. In some embodiments, the precursor is at least one selected from C2-C8 alkyne (C n H 2n-2 ), C2-C8 alkene (C n H 2n ), C2-C8 diene (C n H n+2 ), C3-C8 cycloalkene, C3-C8 wheel alkene (C n H n ), C3-C8 cycloalkane, and substituted hydrocarbons of the foregoing. In some embodiments, the precursor is ethylene, acetylene, propylene, butadiene, pentene, cyclopentene, benzene, styrene, toluene, cyclohexene, and / or cyclohexane.

[0037] In some embodiments, as a gap fill technique for depositing flowable films, the methods disclosed in U.S. Patent Application Nos. 16 / 026,711 and 16 / 427,288 can be used, which provide complete gap fill with essentially no void formation by using plasma assisted deposition of a hydrocarbon precursor under conditions in which a nitrogen, oxygen, or hydrogen plasma is not required, the disclosures of which are incorporated by reference herein in their entireties. The deposition processes disclosed in the above references use an ALD-like work procedure (e.g., feed / purge / plasma strike / purge) in which the purge after the feed is voluntarily heavily shortened to retain a high partial pressure of the precursor during the plasma strike. This is distinctly different from ALD chemistry or mechanism. The above processes can be based on pulsed plasma CVD, which also imparts good fill capability to the resulting film, but as discussed later, an ALD-like work procedure can be more beneficial. In some embodiments, step (i) is by a cyclic nitrogen plasma deposition such as ALD-like deposition or pulsed plasma CVD using a nitrogen plasma.

[0038] In some embodiments, the atmosphere in step (ii) is in the same reaction space used in step (i), i.e., step (i) and step (ii) are conducted consecutively in the same reaction space. Alternatively, in other embodiments, the atmosphere in step (ii) is in another reaction space different from the reaction space used in step (i).

[0039] In some embodiments, step (ii) includes: feeding N2 into the atmosphere without feeding hydrogen and oxygen; and applying RF power to the atmosphere in a manner that generates nitrogen plasma. Applying RF power to the atmosphere can be achieved using a conductive-coupled plasma (CCP) reactor or an inductively coupled plasma (ICP) reactor, and in some embodiments, the nitrogen plasma can be generated remotely using a remote plasma unit. In some embodiments, the RF power is 0.14 W / cm² per unit area of ​​substrate. 2 Up to 1.41 W / cm 2 (Preferably 0.3 to 0.9 W / cm) 2 The duration of step (ii) is within the range of 10 seconds to 300 seconds (preferably 30 seconds to 120 seconds).

[0040] In some embodiments, the method further includes removing the flowable carbon-based film at the bottom by plasma ashing after step (ii) using O2, H2, O2 / Ar, or N2 / H2, thereby fully achieving the target topology, wherein the carbon-based film is deposited primarily or substantially only on the top surface of the substrate in the top surface, sidewalls, and bottom of the recess. In some embodiments, plasma ashing is performed using direct or remote oxygen or hydrogen plasma. In some embodiments, the direct or remote oxygen or hydrogen plasma is a direct or remote plasma of a gas selected from: entirely H2; a mixture of Ar and H2 (Ar / H2 flow ratio of 0.005 to 0.995, typically 0.05 to 0.75); a mixture of He and H2 (He / H2 flow ratio of 0.005 to 0.995, typically 0.05 to 0.75); a mixture of N2 and H2 (N2 / H2 flow ratio of 0.005). The carbon-based film is deposited on a substrate top surface that is made of silicon. The carbon-based film is then redeposited on. The carbon-based film is either entirely O2, a mixture of O2 and Ar (O2 / Ar flow ratio of 0.005 to 0.995, typically 0.05 to 0.75), a mixture of O2 and He (O2 / He flow ratio of 0.005 to 0.995, typically 0.05 to 0.75), or a mixture of O2 and N2 (O2 / N2 flow ratio of 0.005 to 0.995, typically 0.05 to 0.75). In some embodiments, the top surface of the substrate on which the carbon-based film is redeposited is made of silicon.

[0041] In some embodiments, the substrate has a plurality of recesses with an aspect ratio of 2 to 30 (typically 3 to 20), wherein the recesses are filled with the film in step (i) in a bottom-up manner, wherein there is a change in surface topology due to a loading effect. However, in some embodiments, the height of the carbon-based film re-deposited on the top surface is approximately the same regardless of the width of the trench (no loading effect). This can be attributed to the volumetric nature of the growth, i.e., the amount of material deposited in each trench prior to the N2treatment is approximately the same regardless of the width of the trench (provided that the difference in width is not large).

[0042] Embodiments will be illustrated in connection with the accompanying drawings. However, the present application is not intended to be limited to these drawings.

[0043] Figure 2 For a diagram illustrating a schematic cross-sectional view of a trench, the process of top-selective deposition according to embodiments of the present application is shown based on the phenomenon ((a)→(b)→(c)). First, a bottom-up deposition is performed on a substrate with trenches, wherein the substrate 21 has trenches 20 with a width wide enough to allow the flowable film to flow into the trench and with a depth small enough to allow the flowable film to reach the bottom of the trench 20. Thus, the flowable film is deposited mainly as a bottom flowable film 23 at the bottom of the trench 20 and partially as a top flowable film 22 on the top surface of the trench 20. For example, suitable trench dimensions are described in the present disclosure and can be selected depending on, for example, the flowability of the film. It is noted that the trench dimensions are not limited to the dimensions shown in the figures. Figure 2 In (a) of FIG. 1, a bottom-up deposition is performed on a substrate with trenches, wherein the substrate 21 has trenches 20 with a width wide enough to allow the flowable film to flow into the trench and with a depth small enough to allow the flowable film to reach the bottom of the trench 20. Thus, the flowable film is deposited mainly as a bottom flowable film 23 at the bottom of the trench 20 and partially as a top flowable film 22 on the top surface of the trench 20. For example, suitable trench dimensions are described in the present disclosure and can be selected depending on, for example, the flowability of the film. It is noted that the trench dimensions are not limited to the dimensions shown in the figures. Figure 2 are greatly simplified and not to scale.

[0044] Next, in the re-deposition process in (b), the bottom flowable film 23 is exposed to a nitrogen plasma, which generates gaseous species in the trench 20. The gaseous species are trapped in the trench 20 and occupy the trench 20, thereby reaching the top surface of the trench 20 (see FIG. 2 for a more detailed explanation). Figure 3 In (c), the gaseous species are deposited (or re-deposited) on the top surface of the trench 20 and accumulate thereon as a top film 24. This is achieved in a manner similar to molecular beam epitaxial growth. It is noted that the above theory is a non-limiting theory of the re-deposition and does not necessarily impose any limitation on the re-deposition process.

[0045] Figure 3 For a diagram illustrating a schematic cross-sectional view of a trench, the expected mechanism of top-selective deposition according to embodiments of the present application is further shown based on the expected mechanism ((a)→(b)→(c)→→(d)). Step (a) in this figure is the same as step (a) of FIG. 1. Figure 2

[0046] ​In (b), when the bottom flowable film 23 is exposed to the nitrogen plasma (anisotropic), etching of the bottom flowable film 23 (as well as the top film 22) and formation of gaseous CxNyHz species (each of x, y, and z is a non-zero integer, constituting a stoichiometric chemical form) occurs instantaneously, forming a high density of gaseous CxNyHz species 25 over the etched bottom flowable film 23’ in the trench 20, while a low density of gaseous CxNyHz species 25’ is formed over the top surface. This occurs because the untreated flowable material constituting the flowable film is relatively fragile / low mass.

[0047] In (c), the nitrogen plasma causes ion-beam-like deposition because the nitrogen plasma is very directional (causing ion-assisted effects) in certain pressure regimes, for example, in the range of 100 to 1000 Pa, preferably 200 to 800 Pa, more preferably 300 to 700 Pa. The ion-beam-like deposition occurs instantaneously, causing re-deposition of a top film 24’ on the top surface, leaving a bottom flowable film 23”. The top-selective re-deposition occurs likely because (a) there is very little or no deposition layer left on the top surface, while re-deposition occurs primarily on the top surface because the sticking coefficient of the CxNyHz species on the pattern material (in this case, silicon) is higher than on the original flowable film, and (b) in the trench 20, the density of gaseous species is high, so there are not enough ions that can penetrate through the cloud of gaseous species in the trench to the extent of participating in ion-beam-like deposition at the bottom. It should be noted that the above theory is a non-limiting theory of the re-deposition, and does not necessarily impose any limitation on the re-deposition process.

[0048] By repeating steps (a) to (c), the final structure shown in (d) is obtained, where a final top film 24 (“re-deposited film”) is re-deposited on the top surface, while there is substantially no film or almost no film left at the bottom of the trench. The composition and properties of the re-deposited film 24 are different from those of the top flowable film 22 or the bottom flowable film 23 prior to the nitrogen plasma treatment, where, in some embodiments, the re-deposited film 24 has a higher density (or higher RI), a lower contact angle, a higher compressive stress, a lower thermal shrinkage, a lower carbon content, a higher nitrogen content, etc. compared to those of the flowable film 22 or 23. Thus, in some embodiments, the re-deposited film is composed of a nitrogen-carbon based film compared to a flowable film composed of a hydrocarbon based film.

[0049] Figure 10 A diagram to illustrate the process sequence of top-selective film formation according to one embodiment of the present application, where the width of each column does not necessarily represent actual time length, the raising of the line in each row represents an ON state, while the sinking of the line in each row represents an OFF state.

[0050] This process sequence includes the deposition process “ax(aC depo)” (“feed” → “purge 1” → “RF” (plasma polymerization) → “purge 2”; performed a times, i.e., repeated (a-1) times), the redeposition process “N2 treatment” (“N2-entry” (stabilization) → “N2 treatment” (redeposition) → “purge 3”), and the optional plasma ashing process “O2 / Ar or N2 / H2 descumbing” (“N2 / H2-entry” → “trimming / descumbing” (plasma ashing) → “purge 4”). The thickness of the film redeposited on the top surface during a single exposure to nitrogen plasma is limited because the amount of gaseous species generated from the flowable film during a single exposure to nitrogen plasma is limited, which is attributed to factors such as… Figure 3 The ions from the nitrogen-containing plasma shown reach a limited depth (e.g., no more than 15 nm, 7.5 nm, or 5 nm) of the flowable membrane via the gaseous species cloud in the trenches and / or are attributed to the limited depth of the flowable membrane generated by the gaseous species due to the redeposition nature. Since fluidity is relatively rapidly lost during continuous exposure to plasma for deposition and / or redeposition, the flowable membrane does not need to maintain its fluidity during exposure to nitrogen plasma (although it may maintain fluidity in some embodiments). The ability to redeposit may depend on the properties of the flowable membrane, for example, that the membrane is an oligomer, a soft / low-density material compared to typical carbon-based membranes, and that this property makes it readily react with nitrogen plasma and allows for the redeposition process. In some embodiments, the thickness of the redeposited membrane during a single exposure to nitrogen plasma is in the range of 2 to 20 nm, typically 5 to 15 nm, but this range varies widely depending on the area of ​​the top surface between adjacent trenches, the size of the reservoir (i.e., the opening size), the depth of the flowable membrane in the trenches, the degree of adhesion of the gaseous species, and other conditions / parameters. Accordingly, repeatable... Figure 3 Steps (a) to (c) shown in the figure are used to obtain the following: Figure 3 The final film with the desired thickness is shown in (d). Figure 10 In this process, when the deposition process, nitrogen plasma treatment process, and optional plasma ashing process constitute a redeposition cycle (the entire cycle), this cycle can be performed b times (i.e., repeated (b-1) times, where b is an integer from 1 to 100, typically from 2 to 15). Instead of performing the ashing process for each complete cycle, the ashing process can be performed intermittently as needed relative to the desired topology of the final film.

[0051] In some embodiments, the plasma polymerization process comprises deposition of an amorphous carbon polymer film on a substrate with trenches by PEALD-like deposition using Si- and metal-free, C-containing precursors and a plasma generating gas generating a plasma by applying RF power (RF) between two electrodes, the substrate being placed parallel to the two electrodes between the two electrodes, wherein the RF power is applied in each sublayer deposition cycle of the PEALD-like deposition, wherein the plasma generating gas and the carrier gas are continuously flowing and also act as a purge gas during “purge 1” and during “purge 2”. The above process is a PEALD-like process, one cycle of which forming a sublayer (typically thicker than one monolayer) is performed a times (e.g. a is an integer from 1 to 30, typically from 2 to 15) until the thickness of the film reaches more than the monolayer thickness but 15 nm or less (e.g. 1 nm to 7.5 nm).

[0052] In some embodiments, the feed time is in the range of 0.3 to 10 seconds (typically 0.6 to 2 seconds), the purge time after the feed is in the range of 0 to 0.1 seconds (typically 0 to 0.5 seconds), the RF time is in the range of 0.5 to 4 seconds (typically 0.8 to 2 seconds), the purge time after the RF is in the range of 0 to 0.5 seconds (typically 0 to 0.1 seconds), the carrier gas flow is in the range of 0 to 0.8 slm (typically 0.1 to 0.3 slm), the plasma generating gas flow is in the range of 0 to 0.5 slm (typically 0.1 to 0.3 slm), and the RF power is in the range of 50 to 400 W (typically 75 to 200 W) for a 300-mm wafer (for wafers of different sizes, the above watt numbers are applied per unit area (cm 2 ) of each wafer).

[0053] When, for example, a volatile hydrocarbon precursor is polymerized and deposited on the surface of a substrate by a plasma, a flowability of the film will be temporarily obtained, wherein the gaseous monomer (precursor) is activated or fragmented by the energy provided by the plasma gas discharge to initiate polymerization, and when the resulting polymer material is deposited on the surface of the substrate, the material shows a temporarily flowable behavior. When the deposition step is completed, the flowable film is no longer flowable, but is solidified, and thus no separate solidification process is required.

[0054] Next, a re-deposition process is started, which includes stopping the feed of dilution He and starting the feed of nitrogen gas ("N2-in"), while continuously feeding carrier He (or, alternatively, in some embodiments, Ar and / or N2 can be used as carrier gas), which should be limited to, for example, less than 50% of the gas mixture in the reaction space, preferably less than 30%, more preferably less than 20%, typically less than 15%, to achieve efficient re-deposition. In some embodiments, the nitrogen gas flow is in the range of 0.5 to 20 slm, typically 1 to 3 slm. RF power is then applied to the reaction space to generate a nitrogen plasma and expose the flowable amorphous carbon polymer film to it ("N2-treatment"), with the RF power in the range of 100 to 1,000 W (preferably 200 to 800 W, more preferably 300 to 700 W) for a 300-mm wafer (for wafers of different sizes, the above-mentioned watt numbers are applied per unit area (cm2) of the wafer), with a pressure of 100 to 1,000 Pa (preferably 600 Pa or below, more preferably 400 Pa or below) for a duration of 5 to 300 seconds (preferably 20 to 120 seconds, more preferably 30 to 90 seconds). Thereafter, a purge is started ("purge 3"), with the purge time after the nitrogen plasma treatment in the range of 0 to 60 seconds (preferably 10 to 30 seconds). During the re-deposition process, the gas mixture is essentially free of H2 and O2 during the re-deposition treatment, for example, preferably less than 5%, more preferably less than 1% or essentially 0%, since the addition of H2 to the N2 plasma only results in ashing (without contributing to re-deposition and top selectivity). 2 ) of the wafer), with a pressure of 100 to 1,000 Pa (preferably 600 Pa or below, more preferably 400 Pa or below) for a duration of 5 to 300 seconds (preferably 20 to 120 seconds, more preferably 30 to 90 seconds). Thereafter, a purge is started ("purge 3"), with the purge time after the nitrogen plasma treatment in the range of 0 to 60 seconds (preferably 10 to 30 seconds). During the re-deposition process, the gas mixture is essentially free of H2 and O2 during the re-deposition treatment, for example, preferably less than 5%, more preferably less than 1% or essentially 0%, since the addition of H2 to the N2 plasma only results in ashing (without contributing to re-deposition and top selectivity).

[0055] Next, depending on the target topology of the final carbon-based film, an optional plasma ashing process is started, which includes feeding an ashing gas (H2 or O2, or mixtures of the foregoing with N2, Ar and / or He) to the reaction space ("N2 / H2-in"), which is excited by RF power to generate a plasma and ash the amorphous carbon polymer film ("trimming / descumming"), followed by a purge ("purge 4"), with the feed of dilution He being started while continuously feeding the carrier gas to the reaction space. In some embodiments, the RF power for the plasma ashing is in the range of 50 to 500 W, typically 50 to 200 W, with a pressure of 100 Pa to 1000 Pa, typically 200 to 600 Pa, for a duration of 5 to 200 seconds, typically 10 to 100 seconds, with a stabilization time in the range of 5 to 60 seconds, typically 10 to 30 seconds, with a purge time after the RF in the range of 5 to 60 seconds, typically 10 to 30 seconds, with an ashing gas flow in the range of 0.1 to 10 slm, typically 0.5 to 2 slm.

[0056] In some embodiments, the carrier gas is continuously fed to the reaction space throughout the process. Additionally, the temperature of the process is adjusted to achieve flowability of the amorphous carbon polymer film and allow for re-deposition of the nitrogen-doped hydrocarbon polymer film, for example, in the range of -50°C to 175°C (preferably 35°C to 150°C).

[0057] The continuous flow of carrier gas can be achieved using a flow through system (FPS) in which the carrier gas line is provided with a bypass line having a precursor reservoir (bottle) and switching between the main line and the bypass line, in which the bypass line is closed when only carrier gas is intended to be fed to the reaction chamber, while the main line is closed when both carrier gas and precursor gas are intended to be fed to the reaction chamber, the carrier gas flows through the bypass line and out of the bottle together with the precursor gas. In this way, the carrier gas can continuously flow into the reaction chamber and can carry the precursor gas in pulses by switching between the main line and the bypass line. Figure 1B A precursor supply system using a flow through system (FPS) according to one embodiment of the present application is illustrated (black valves indicate that the valves are closed). As Figure 1B As shown in (a) in the above, when feeding precursor to the reaction chamber (not shown), the first carrier gas, such as Ar (or He), flows through the gas line having valves b and c, and then enters the bottle (reservoir) 26. The carrier gas flows out of the bottle 26, while carrying an amount of precursor gas corresponding to the vapor pressure inside the bottle 26, through the gas line having valves f and e, and then is fed to the reaction chamber together with the precursor. In the above, valves a and d are closed. When only carrier gas (noble gas) is fed to the reaction chamber, as shown in (b) in the above, the carrier gas flows through the gas line having valve a, while bypassing the bottle 26. In the above, valves b, c, d, e, and f are closed. Figure 1B As shown in (a) in the above, when feeding precursor to the reaction chamber (not shown), the first carrier gas, such as Ar (or He), flows through the gas line having valves b and c, and then enters the bottle (reservoir) 26. The carrier gas flows out of the bottle 26, while carrying an amount of precursor gas corresponding to the vapor pressure inside the bottle 26, through the gas line having valves f and e, and then is fed to the reaction chamber together with the precursor. In the above, valves a and d are closed. When only carrier gas (noble gas) is fed to the reaction chamber, as shown in (b) in the above, the carrier gas flows through the gas line having valve a, while bypassing the bottle 26. In the above, valves b, c, d, e, and f are closed.

[0058] The process cycle can be carried out using any suitable device, including, for example Figure 1A A device as illustrated in (a) in the above. Figure 1AA schematic of a PEALD apparatus, which can be used in some embodiments of the present application, in combination with a controller programmed to carry out the sequences described below. In this figure, a plasma is ignited between a pair of parallel and facing conductive flat electrodes 4, 2 provided in the interior 11 (reaction zone) of a reaction chamber 3, by applying HRF power (13.56 MHz - 2000 MHz) 25 to one side and electrically grounding the other side 12. A temperature regulator is provided in the lower electrode 2 and maintains the temperature of a substrate 1 placed thereon constant at a given temperature. The upper electrode 4 also serves as a shower plate and introduces reactant gas and / or diluent gas (if any) and precursor gas into the reaction chamber 3 through gas lines 27 and 28, respectively, via the shower plate 4. Additionally, in the reaction chamber 3, an annular tube 13 with an exhaust line 7 is provided to exhaust the gas in the interior 11 of the reaction chamber 3. Additionally, a transfer chamber 5 disposed below the reaction chamber 3 is provided with a seal gas line 29 to introduce a seal gas into the interior 11 of the reaction chamber 3 via the interior 16 (transfer zone) of the transfer chamber 5, which is provided with a separation plate 14 (the gate valve through which wafers are transferred into or out of the transfer chamber 5 is omitted in this figure) for separating the reaction zone and the transfer zone. The transfer chamber is also provided with an exhaust line 6. In some embodiments, deposition of a multi-element film and surface treatment are carried out in the same reaction space, so that all steps can be carried out continuously without exposing the substrate to air or other oxygen-containing atmosphere.

[0059] In some embodiments, in the apparatus depicted in Figure 1A In the system for switching the flow of inactive gas and the flow of precursor gas, illustrated in Figure 1B The system for switching the flow of inactive gas and the flow of precursor gas, illustrated in the foregoing, can be used to introduce the precursor gas in pulsed form without substantially fluctuating the pressure of the reaction chamber.

[0060] The skilled artisan will recognize that the apparatus includes one or more controllers (not shown) programmed or otherwise configured to enable the deposition and reactor cleaning processes described elsewhere herein to be carried out. As the skilled artisan will appreciate, the one or more controllers can be in communication with various power sources, heating systems, pumps, robotic devices, and gas flow controllers or valves of the reactor.

[0061] In some embodiments, a dual chamber reactor (for processing two portions or compartments of wafers disposed next to each other) can be used, in which the reactive gas and the noble gas can be supplied through a shared line while the precursor gas is supplied through a non-shared line.

[0062] Fillable films can be applied to a variety of semiconductor devices, including but not limited to cell isolation, self-aligned vias, dummy gates (replacing current polycrystalline Si), reverse tone patterning, PC RAM isolation, diced hard masks, and DRAM memory node contact (SNC) isolation in 3D cross-point memory devices.

[0063] Example

[0064] In the following examples where conditions and / or structures are not specified, those skilled in the art can readily provide such conditions and / or structures through routine experiments, in light of this disclosure. Those skilled in the art will recognize that the apparatus used in the examples includes one or more controllers (not shown) programmed or otherwise configured to enable deposition and the reactor cleaning processes described elsewhere herein. As those skilled in the art will understand, the one or more controllers may be connected to various power sources, heating systems, pumps, robotic devices, and gas flow controllers or valves of the reactor.

[0065] Reference Example 1 Figure 4 )

[0066] Using the PEALD-like process defined in U.S. Patent Applications Nos. 16 / 026,711 and 16 / 427,288, a flowable amorphous carbon polymer film (aC blanket) with a thickness of 100-150 nm is deposited on a Si substrate (with a diameter of 300 mm and a thickness of 0.7 mm) using cyclopentene, and then... Figure 1A The device shown and Figure 1B The gas supply system (FPS) shown is operated under the conditions indicated in Table 1 below. Figure 10 The deposition process is illustrated in Table 1 below. Flowable amorphous carbon polymer films were subjected to post-deposition plasma treatment under the conditions shown in Table 1, in the same reaction chamber as the deposition process, to evaluate the film shrinkage effect caused by each post-deposition treatment.

[0067] Table 1 (Values ​​are approximate)

[0068]

[0069]

[0070] also, Figure 10 All the data on ashing reported in the article were done on layers that did not undergo nitrogen plasma treatment cycles.

[0071] Figure 4 A graph showing the shrinkage results of membranes exposed to plasmas of different gases. (See figure.) Figure 4 As shown, the effect of post-deposition plasma treatment on the flowable aC blanket varies with the following gas types:

[0072] Ar: small thickness reduction (this effect saturates if the treatment is prolonged) -> densification;

[0073] H2: extreme thickness loss (this effect does not saturate if the treatment is prolonged but it greyed out all the film) -> "normal" grey / dry etching effect;

[0074] N2 / H2: extreme thickness loss (this effect does not saturate if the treatment is prolonged but it greyed out all the film, see also Figure 5 ) -> "normal" grey / dry etching effect;

[0075] O2 / Ar: extreme thickness loss (this effect does not saturate if the treatment is prolonged but it greyed out all the film, see also Figure 5 ) -> "normal" grey / dry etching effect; and

[0076] N2: thickness increase -> opposite to "normal" grey / dry etching effect.

[0077] Surprisingly, the nitrogen plasma treatment of the flowable a-C film induces a re-deposition (sticking) of gaseous species generated by the plasma.

[0078] Reference Example 2 Figure 5 )

[0079] A flowable amorphous carbon polymer film (a-C film) was deposited on a Si substrate (having a diameter of 300 mm and a thickness of 0.7 mm) having trenches with openings of about 25 to 100 nm and having a depth of about 85 nm (aspect ratio of about 3.4 to 0.85) in a bottom-up manner by a PEALD-like process in the same way as those in Reference Example 1 under the same conditions except that the deposition was continued until the trenches were completely filled and the top surface of the a-C film became planar. Thereafter, the post-deposition plasma treatment was performed in the same way as those in Reference Example 1 using O2 / Ar and N2 / H2 under the same conditions except that the plasma treatment was continued until all the film was removed.

[0080] Figure 5 STEM photographs showing cross-sectional views of trenches, where original (a) represents a trench on which a complete filling deposition of a flowable film was performed, original (b) represents the trench shown in (a) after O2 / Ar grey, original (c) represents the trench shown in (a) after N2 / H2 grey, column (1) represents the trenches at high magnification (scale bar represents 60 nm), column (2) represents the trenches at low magnification (scale bar represents 300 nm). It was confirmed that both O2 / Ar grey and N2 / H2 grey can lead to a complete removal of the film.

[0081] Example 1 and Comparative Example 1 Figure 6 )

[0082] In Example 1, a flowable amorphous carbon polymer film (a-C film) was deposited on a Si substrate with trenches (having a diameter of 300 mm and a thickness of 0.7 mm) in a bottom-up manner by PEALD-like process in the same manner and under the same conditions as those in Reference Example 1, except that the deposition cycle was performed 36 times (3 x 12 deposition cycles + N2 plasma treatment). In Comparative Example 1, the amorphous carbon polymer film was deposited in the same manner as in Example 1, except that the deposition temperature (temperature of susceptor and wall) was 100 °C instead of 75 °C in Example 1. Thereafter, each film was subjected to a cyclic nitrogen plasma treatment in the same manner and under the same conditions as those in Reference Example 1 using N2 as the post-treatment gas, except that the nitrogen plasma treatment was performed for 60 seconds.

[0083] Figure 6 STEM photographs of cross-sectional views of trenches in which film deposition was performed at 75 °C followed by exposure to N2 plasma in Example 1, and (b) STEM photographs of cross-sectional views of trenches in which film deposition was performed at 100 °C followed by exposure to N2 plasma in Comparative Example 1 are shown. From Figure 6 It can be seen that the nitrogen plasma treatment is not the only parameter that determines the top selectivity, i.e., although both films were subjected to the same deposition cycle treatment and the same nitrogen plasma treatment, one (Example 1) was deposited at 75 °C while the other (Comparative Example 1) was deposited at 100 °C, resulting in a significant topographical difference in the final films. Considering that the flowability of the deposited film is inversely proportional to the deposition temperature and that the film deposited at 75 °C is flowable while the film deposited at 100 °C is almost non-flowable, the cause of the above topographical difference is expected to be that only the flowable (weak, fragile, low mass) layer can form gaseous species that will result in re-deposition and top selectivity upon receiving N2 plasma. By adjusting not only the deposition temperature but also other process parameters, a film can be deposited while maintaining flowability, and upon exposure to nitrogen plasma, a top selectivity topography of the final film can be obtained. Such conditions and / or structures can be readily provided by routine experimentation by one skilled in the art in view of the present disclosure.

[0084] Example 2 and Comparative Example 2 Figure 7 )

[0085] In Example 2, a flowable amorphous carbon polymer film (a-C film) was deposited on a Si substrate (having a diameter of 300 mm and a thickness of 0.7 mm) with trenches having openings of about 70 to 100 nm and having a depth of about 85 nm (aspect ratio of about 1.2 to 0.85) in a bottom-up manner by a PEALD-like process in the same manner as and under the same conditions as those in Example 1. Thereafter, the film was subjected to a post-deposition nitrogen plasma treatment in the same manner as and under the same conditions as in Example 1. In Comparative Example 2, the same process was performed under the same conditions as in Example 2 except that the nitrogen plasma treatment was performed for 10 seconds instead of 60 seconds in Example 2.

[0086] Figure 7 STEM photographs of cross-sectional views of trenches subjected to flowable film deposition followed by exposure to N2 plasma for 10 seconds in Comparative Example 2, and (b) STEM photographs of cross-sectional views of trenches subjected to flowable film deposition followed by exposure to N2 plasma for 60 seconds in Example 2 are shown. From Figure 7 It can be seen that a longer N2 plasma treatment is beneficial for topological selectivity. By adjusting the duration of the nitrogen plasma treatment, the film can be deposited in a top-selective manner. Such conditions and / or structures can be readily provided by routine experimentation by one of skill in the art in view of the present disclosure.

[0087] Example 3 (Table 2, Figure 9 )

[0088] In Example 3, an amorphous carbon polymer film was formed in the same manner as and under the same conditions as in Example 1, and then subjected to a nitrogen plasma treatment in the same manner as and under the same conditions as in Example 1 to obtain a re-deposited amorphous carbon polymer film on the top surface of the trenches. The properties of the resulting amorphous carbon polymer film were evaluated. The results are shown in Table 2 and Figure 9 below.

[0089] Table 2 (values are approximate)

[0090]

[0091] As shown in Table 2, the thermal shrinkage of the amorphous carbon polymer film treated with nitrogen plasma ("re-deposited film") was significantly lower than that of the amorphous carbon polymer film not treated with plasma ("STD film"), indicating that the thermal stability of the re-deposited film was improved. In addition, the composition analysis showed that the re-deposited film was a nitrogen-doped hydrocarbon film, while the standard film was a hydrocarbon film. Furthermore, the re-deposited film had a higher RI (higher density), a lower contact angle, and a higher compressive stress than the standard film. In addition, Figure 10Fourier transform infrared (FTIR) spectra of the as-deposited amorphous carbon polymer film ("STD") and the re-deposited amorphous carbon polymer film treated with N2 plasma ("N2-CK") are shown. As shown in Figure 9 As shown in Table 2, the re-deposited film produced -NH bonds and -R-N-C bonds, and given the results shown in Table 2, it is likely that the re-deposited film promoted further polymerization of the film matrix and doped it with nitrogen, thereby reducing thermally unstable hydrogen-related moieties, such as methyl and / or methylene moieties from the as-deposited amorphous carbon polymer film. It should be noted that oxygen atoms were detected in each film, and this can be because the films were exposed to air after the substrates were removed from the reaction chamber.

[0092] In some embodiments, the standard film is a hydrogenated amorphous carbon polymer having a composition consisting of greater than 50% carbon atoms and greater than 35% but less than 50% hydrogen atoms (as measured using, for example, Rutherford backscattering spectroscopy (RBS)), and the re-deposited film is a nitrogen-doped hydrogenated amorphous carbon polymer having a composition consisting of greater than 35% but less than 50% carbon atoms and greater than 35% but less than 50% hydrogen atoms and greater than 10% but less than 20% nitrogen atoms.

[0093] Example 4 Figure 8 )

[0094] In Example 4, a flowable amorphous carbon polymer film (a-C film) was deposited on a Si substrate with trenches (having a diameter of 300 mm and a thickness of 0.7 mm) in a bottom-up manner by a PEALD-like process in the same manner as and under the same conditions as those in Example 1, the trenches having openings of about 70 to 100 nm and having a depth of about 85 nm (aspect ratio of about 1.2 to 0.85). Thereafter, the film was subjected to a post-deposition nitrogen plasma treatment in the same manner as and under the same conditions as in Example 1. However, in Example 4, the entire cycle was performed 25 times (12 deposition cycles + N2 plasma treatment).

[0095] Figure 8 A STEM photograph showing a cross-sectional view of the trenches on which top selective deposition was performed in Example 4 is shown. As shown in Figure 8 As shown in Table 2, the re-deposited film produced -NH bonds and -R-N-C bonds, and given the results shown in Table 2, it is likely that the re-deposited film promoted further polymerization of the film matrix and doped it with nitrogen, thereby reducing thermally unstable hydrogen-related moieties, such as methyl and / or methylene moieties from the as-deposited amorphous carbon polymer film. It should be noted that oxygen atoms were detected in each film, and this can be because the films were exposed to air after the substrates were removed from the reaction chamber.

[0096] Those skilled in the art will appreciate that many and various modifications can be made to the application without departing from the spirit of the application. Therefore, it should be clearly understood that the form of the application is only illustrative and that it is not intended to limit the scope of the application.

Claims

1. A method for top selective deposition on a substrate using a flowable carbon-based film, the substrate having a recess defined by a top surface, sidewalls, and a bottom, the method comprising the steps of: (i) depositing a flowable carbon-based film in the recess of the substrate in the reaction space until the thickness of the flowable carbon-based film in the recess reaches a predetermined thickness, and then stopping the deposition step; and (ii) exposing the carbon-based film to a nitrogen plasma in an atmosphere free of hydrogen and oxygen to deposit carbon-based film in the recess, wherein the carbon-based film is selectively re-deposited on the top surface; and (iii) removing a portion of the carbon-based film on the bottom by plasma ashing, wherein the plasma ashing does not remove all of the carbon-based film on the top surface, and repeating steps (i), (ii), and (iii) to form a top selectively deposited carbon-based film.

2. The method of claim 1, wherein steps (i) and (ii) are repeated a plurality of times until a thickness of the portion of the carbon-based film on the top surface reaches a desired final thickness.

3. The method of claim 1, wherein the predetermined thickness in step (i) is greater than 1 nm and less than or equal to 15 nm.

4. The method of claim 1, wherein the atmosphere in step (ii) is in the same reaction space used in step (i).

5. The method of claim 1, wherein the atmosphere in step (ii) is in a different reaction space than the reaction space used in step (i).

6. The method of claim 1, wherein step (ii) comprises: feeding N2 into the atmosphere without feeding hydrogen and oxygen; and applying RF power to the atmosphere in a manner to generate the nitrogen plasma.

8. The method of claim 1, wherein step (i) is performed by cyclic nitrogen plasma deposition.

7. The method of claim 6, wherein the power density of the RF power is 0.14 W / cm 2 to 1.41 W / cm 2 and the duration of step (ii) is in the range of 10 seconds to 300 seconds.

9. The method of claim 1, wherein the substrate top surface on which the carbon-based film is re-deposited is comprised of silicon.

10. The method of claim 1, further comprising removing the flowable carbon-based film at the bottom after step (ii) by O2, H2, O2 / Ar, or N2 / H2 plasma ashing.

11. The method of claim 1, wherein the carbon-based film is an amorphous carbon film.

12. The method of claim 1, wherein the deposited flowable carbon-based film is comprised of hydrogenated amorphous carbon polymer, and the re-deposited carbon-based film is comprised of nitrogen-doped hydrogenated amorphous carbon polymer. ​

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