Patent Publication Number: US-11643724-B2

Title: Method of forming structures using a neutral beam

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 62/875,892, filed on Jul. 18, 2019, in the United States Patent and Trademark Office, the disclosure of which is incorporated herein in its entirety by reference. 
    
    
     FIELD OF INVENTION 
     The present disclosure generally relates to methods and systems for forming structures and to structures formed using the methods. More particularly, the disclosure relates to methods of forming structures using a neutral beam, to structures formed using the methods, and to systems for performing the methods. 
     BACKGROUND OF THE DISCLOSURE 
     Conformal film deposition may be desirable for a variety of reasons. For example, during the manufacture of devices, such as semiconductor devices, it is often desirable to conformally deposit material over features formed on the surface of a substrate. Such techniques can be used for shallow trench isolation, inter-metal dielectric layers, passivation layers, and the like. However, with miniaturization of devices, it becomes increasingly difficult to conformally deposit material, particularly over high aspect ratio features, such as features having an aspect ratio of three or more. 
     Atomic layer deposition (ALD) can be used to conformally deposit material, such as dielectric material, onto a surface of a substrate. For some applications, such as when a relatively high temperature is used for ALD deposition and/or when it is desired to keep a processing temperature relatively low, it may be desirable to use plasma-enhanced ALD (PEALD). 
     Unfortunately, material deposited using PEALD can exhibit relatively poor film quality—e.g., exhibit a relatively high etch rate in a liquid or gas-phase etchant. For example, silicon oxide films deposited using PEALD can exhibit relatively high etch rates in dilute hydrofluoric acid (e.g., 1:100 by volume HF:H 2 O), compared to silicon oxide films deposited without the aid of a plasma. 
     Accordingly, improved systems and methods for forming high-quality material, such as high-quality dielectric material (e.g., silicon oxide), on a substrate and structures formed using such methods and/or systems are desired. Any discussion of problems and solutions described in this section has been included solely for the purposes of providing a context for the present invention and should not be taken as an admission that any or all of the discussion was known at the time the invention was made. 
     SUMMARY OF THE DISCLOSURE 
     Various embodiments of the present disclosure relate to methods of forming structures that include high-quality insulating or dielectric films. While the ways in which various embodiments of the present disclosure address drawbacks of prior methods and systems are discussed in more detail below, in general, various embodiments of the disclosure provide improved methods that include use of a neutral beam—during deposition of the films, during treatment of the films, or both. 
     In accordance with at least one embodiment of the disclosure, a method of forming a structure includes forming a layer, forming a neutral beam, and, exposing the layer to species generated from the neutral beam. The neutral beam can be generated from, for example, one or more gases selected from the group consisting of hydrogen-containing gases (e.g., hydrogen), He, NH 3 , O 2 , N 2 O, CO 2 , Ar, Xe, N 2 , and their mixture, such as one or more of H 2  and He, and particularly H 2 . The layer can include, for example, one or more of an oxide, a nitride, and a carbide. By way of examples, the layer can include one or more of SiO 2 , SiN, SiOC, SiCN, SiC, SiON, SiOCN, SiBN, SiBO, GeO x , GeN, AlO X , TiO 2 , and TaO 2 . The layer can be deposited using one or more of PEALD, PECVD, NBEALD, and NBECVD. The step of forming a layer can include a cyclic deposition process, and the cyclic deposition process can be repeated a number of cycles prior to the step of exposing. For example, the cyclic deposition process can be repeated a number of time until a thickness layer is greater than zero and less than 10 nm, and then the layer can be exposed to species generated from the neutral beam. The step of forming a layer (e.g., cyclic deposition process that can be repeated a number of times) and the step of exposing the layer to species generated from the neutral beam can be repeated until a desired film thickness is obtained. The desired film thickness can be greater than 10 nm. A temperature during the step of forming a layer can be less than 400° C., less than 300° C., less than 200° C., less than 100° C., about 25° C. to less than any of these temperatures, about 25-40° C., about ambient temperature, about 0 to about 100° C., about 0 to about 200° C., or about 0 to about 300° C. A pressure within the reaction chamber during the step of forming a layer can be between about 0.01 Pa and about 100 Pa, about 0.05 Pa and about 1 Pa, or about 0.1 Pa and about 0.5 Pa. A pressure within the reaction chamber during the step of forming a neutral beam can be between about 0.01 Pa and about 100 Pa, about 0.05 Pa and about 1 Pa, or about 0.1 Pa and about 2 Pa. A power of an RF power supply during the step of forming a layer can be between about 0.1 W/cm 2  and about 20 W/cm 2 , about 0.2 W/cm 2  and about 10 W/cm 2 , or about 1 W/cm 2  and about 5 W/cm 2 . A power of an RF power supply during the step of forming a neutral beam can be between about 0.1 W/cm 2  and about 20 W/cm 2 , about 1 W/cm 2  and about 15 W/cm 2 , or about 3 W/cm 2  and about 10 W/cm 2 . In some cases, a precursor used during the step of forming a layer can be selected from the group consisting of aminosilanes, such as BDEAS (SiH 2 [N(C 2 H 5 ) 2 ] 2 ), BTBAS (SiH 2 [NHC(CH 3 ) 3 ] 2 ), TDMAS (SiH[N(CH 3 ) 2 ] 3 ), HEAD (Si 2 [NHC 2 H 6 ] 6 ), 3DMASCl (Si[N(CH 3 ) 2 ] 3 Cl), 3EMAS (H 2 Si[N(C 2 H 5 )CH 3 ] 3 ), 4DMAS (Si[N(C 2 H 6 ) 2 ]) 4 ), 4DEAS (Si[N(C 2 H 6 ) 2 ] 4 ), or other Si-containing precursor, such as 4MS ((CH 3 )4Si), 2ES ((C 2 H 5 ) 2 SiH 2 ), phenyl-SiH 3 , and cyclohexyl-SiH 3 , Si(OC 2 H 5 ) 4 . A bias can be applied to an aperture plate of a neutral beam apparatus during the step of forming the layer and/or during the step of exposing the layer. The bias during the step of forming a layer can be between about 0 W/cm 2  and about 3 W/cm 2 , about 0 W/cm 2  and about 1 W/cm 2 , or about 0 W/cm 2  and about 0.5 W/cm 2 . The bias during the step of forming a neutral beam can be between about 0 W/cm 2  and about 3 W/cm 2 , about 0 W/cm 2  and about 1 W/cm 2 , or about 0.05 W/cm 2  and about 0.2 W/cm 2 . 
     In accordance with yet further exemplary embodiments of the disclosure, a method of forming a structure includes providing a substrate within a reaction chamber, providing a precursor to a gas inlet of the reaction chamber to form adsorbed species on a surface of the substrate, providing a reactant to a gas inlet of a plasma chamber, forming a neutral beam from species generated in the plasma chamber, and exposing the adsorbed species to species from the neutral beam to form a layer comprising silicon. In accordance with exemplary aspects of these embodiments, the precursor can selected from the group consisting of aminosilanes, such as BDEAS (SiH 2 [N(C 2 H 5 ) 2 ] 2 ), BTBAS (SiH 2 [NHC(CH 3 ) 3 ] 2 ), TDMAS (SiH[N(CH 3 ) 2 ] 3 ), HEAD (Si 2 [NHC 2 H 6 ] 6 ), 3DMASCl (Si[N(CH 3 ) 2 ] 3 Cl), 3EMAS (H 2 Si[N(C 2 H 5 )CH 3 ] 3 ), 4DMAS (Si[N(C 2 H 6 ) 2 ]) 4 ), 4DEAS (Si[N(C 2 H 6 ) 2 ] 4 ), or other Si-containing precursors, such as 4MS ((CH 3 ) 4 Si), 2ES ((C 2 H 5 ) 2 SiH 2 ), phenyl-SiH 3 , cyclohexyl-SiH 3 , Si(OC 2 H 5 ) 4 . Exemplary reactants include one or more of oxygen, CO, CO 2 , and NO 2 . In accordance with further exemplary aspects, methods can include exposing the layer to a neutral beam. For example, exemplary methods can include providing gas, such as one or more of a of hydrogen-containing gases (e.g., hydrogen), He, NH 3 , O 2 , N 2 O, CO 2 , Ar, Xe, N 2 , and their mixture, such as one or more of H 2  and He, and particularly H 2 , to the plasma chamber, and exposing the layer to species generated from the gas to treat the layer. Exemplary methods can include repeating the steps of providing the precursor to the gas inlet of the reaction chamber to form adsorbed species on a surface of the substrate, providing the reactant to the gas inlet of the plasma chamber, forming the neutral beam from species generated in the plasma chamber, and exposing the adsorbed species to species from the neutral beam to form the layer comprising silicon a desired number of times. These steps may be repeated until a desired film thickness—e.g., less than 10 nm—is deposited. A step of exposing the layer to species generated from the gas may then be performed to treat the layer. This process of forming a layer to less than 10 nm and treating the layer can be repeated a number of times until a desired film thickness, which can be greater than 10 nm, is obtained. A bias can be applied to an aperture plate of a neutral beam apparatus during the step of exposing the layer and/or during the step of exposing the adsorbed species. The temperatures, pressures, and bias levels can be the same or similar to those described above and elsewhere herein. 
     In accordance with yet additional examples of the disclosure, a reactor system is provided. The reactor system can be configured to perform a method as described herein. 
     In accordance with yet further exemplary embodiments of the disclosure, a structure comprises a layer formed according to a method described herein. 
     These and other embodiments will become readily apparent to those skilled in the art from the following detailed description of certain embodiments having reference to the attached figures; the invention not being limited to any particular embodiment(s) disclosed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
       A more complete understanding of exemplary embodiments of the present disclosure can be derived by referring to the detailed description and claims when considered in connection with the following illustrative figures. 
         FIG.  1    illustrates a method in accordance with at least one embodiment of the disclosure. 
         FIG.  2    illustrates another method in accordance with at least one embodiment of the disclosure. 
         FIG.  3    illustrates a reactor system in accordance with at least one embodiment of the disclosure. 
         FIGS.  4 - 7    illustrate structures in accordance with exemplary embodiments of the disclosure. 
         FIG.  8    illustrates a relationship between wet etching time in 0.1% hydrofluoric acid vs etching depth of hydrogen neutral beam-irradiated NBEALD silicon oxide films. 
     
    
    
     It will be appreciated that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of illustrated embodiments of the present disclosure. 
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Although certain embodiments and examples are disclosed below, it will be understood by those in the art that the invention extends beyond the specifically disclosed embodiments and/or uses of the invention and obvious modifications and equivalents thereof. Thus, it is intended that the scope of the invention disclosed should not be limited by the particular disclosed embodiments described below. 
     The present disclosure generally relates to methods of forming structures, such as structures suitable for forming electronic devices, to reactor systems for performing the methods, and to structures formed using the methods. By way of examples, the systems and methods described herein can be used to form conformal, high-quality insulating or dielectric layers. The insulating or dielectric layers can be deposited onto a surface of a substrate, which can include high-aspect ratio features. In some cases, the layers can be formed using a cyclic process that employs a neutral beam, such as NBEALD. In some cases, the layers can additionally or alternatively be exposed to (i.e., treated with) activated species formed using a neutral beam to form a structure including high-quality layers. 
     In this disclosure, “gas” may include material that is a gas at room temperature and pressure, a vaporized solid and/or a vaporized liquid, and may be constituted by a single gas or a mixture of gases, depending on the context. A gas other than the process gas, i.e., a gas introduced without passing through a gas distribution assembly, such as a showerhead, other gas distribution device, or the like, may be used for, e.g., sealing the reaction space, and may include a seal gas, such as a rare gas. In some embodiments, the term “precursor” can refer to a compound that participates in the chemical reaction that produces another compound, and particularly to a compound that constitutes a film matrix or a main skeleton of a film; the term “reactant” can refer to a compound, other than precursors, that activates a precursor, modifies a precursor, or catalyzes a reaction of a precursor, wherein the reactant may provide an element (such as O, N, or C) to a film matrix and become a part of the film matrix, when, for example, RF power is applied. The term “inert gas” can refer to a gas that does not take part in a chemical reaction and/or a gas that excites a precursor when RF power is applied, but unlike a reactant, it may not become a part of a film matrix to an appreciable extent. Exemplary inert gases include He, Ar, N 2  and any combination thereof. 
     As used herein, the term “substrate” may refer to any underlying material or materials that may be used to form, or upon which, a device, a circuit, or a film may be formed. A substrate can include a bulk material, such as silicon (e.g., single-crystal silicon), other Group IV materials, such as germanium, or compound semiconductor materials, such as a Group II-VI or Group III-V semiconductor, and can include one or more layers overlying or underlying the bulk material. Further, the substrate can include various features, such as recesses, lines, and the like formed within or on at least a portion of a layer of the substrate. The feature can have relatively high aspect ratios, ranging from, for example, about 1 to about 50 or about 3 to about 20. 
     As used herein, the term “film” and/or “layer” can refer to any continuous or non-continuous structures and material, such as material deposited and/or treated by the methods disclosed herein. For example, film and/or layer can include two-dimensional materials, three-dimensional materials, nanorods, nanotubes, or nanoparticles or even partial or full molecular layers or partial or full atomic layers or clusters of atoms and/or molecules. A film or layer may comprise material or a layer with pinholes, which may be at least partially continuous. 
     As used herein, the term “cyclic deposition” can refer to the sequential introduction of precursors (reactants) into a reaction chamber to deposit a film over a substrate and includes deposition techniques, such as atomic layer deposition and cyclical chemical vapor deposition. 
     As used herein, the term “cyclical chemical vapor deposition” can refer to any process wherein a substrate is sequentially exposed to two or more volatile precursors, which react and/or decompose on a substrate to produce a desired deposition. 
     As used herein, the term “atomic layer deposition” (ALD) can refer to a vapor deposition process in which deposition cycles, typically a plurality of consecutive deposition cycles, are conducted in a reaction chamber. Typically, during each cycle, the precursor is chemisorbed to a deposition surface (e.g., a substrate surface or a previously deposited underlying surface such as material from a previous ALD cycle), forming a monolayer or sub-monolayer that does not readily react with additional precursor (i.e., a self-limiting reaction). Thereafter, a reactant (e.g., another precursor or reaction gas) may subsequently be introduced into the reaction chamber for use in converting the chemisorbed precursor to the desired material on the deposition surface. Typically, this reactant is capable of further reaction with the precursor. Further, purging steps may also be utilized during each cycle to remove excess precursor from the reaction chamber and/or remove excess reactant and/or reaction byproducts from the reaction chamber after conversion of the chemisorbed precursor. Further, the term “atomic layer deposition,” as used herein, is also meant to include processes designated by related terms, such as chemical vapor atomic layer deposition, atomic layer epitaxy (ALE), molecular beam epitaxy (MBE), gas source MBE, or organometallic MBE, and chemical beam epitaxy when performed with alternating pulses of precursor composition(s), reactive gas, and purge (e.g., inert carrier) gas. PEALD refers to an ALD process, in which a plasma is applied during one or more of the ALD steps. 
     As used here, a “structure” can include a substrate as described herein. Structures can include one or more layers, overlying the substrate, which formed and/or treated as described herein. 
     Further, in this disclosure, any two numbers of a variable can constitute a workable range of the variable, and any ranges indicated may include or exclude the endpoints. Additionally, any values of variables indicated (regardless of whether they are indicated with “about” or not) may refer to precise values or approximate values and include equivalents, and may refer to average, median, representative, majority, etc. in some embodiments. Further, in this disclosure, the terms “including,” “constituted by” and “having” refer independently to “typically or broadly comprising,” “comprising,” “consisting essentially of,” or “consisting of” in some embodiments. In this disclosure, any defined meanings do not necessarily exclude ordinary and customary meanings in some embodiments. 
     In this disclosure, “continuously” can refer to one or more of without breaking a vacuum, without interruption as a timeline, without any material intervening step, without changing treatment conditions, immediately thereafter, as a next step, or without an intervening discrete physical or chemical structure between two structures other than the two structures in some embodiments. 
     Turning now to the figures,  FIG.  1    illustrates a method  100  of forming a structure in accordance with at least one embodiment of the disclosure. Method  100  includes the steps of forming a layer (step  102 ), forming a neutral beam (step  104 ), and exposing the layer to species generated from the neutral beam (step  106 ). 
     Step  102  can include forming an insulating or dielectric material layer. For example, step  102  can include forming one or more of an oxide, a nitride, and a carbide layer. By way of particular examples, the layer can be or include one or more of SiO 2 , SiN, SiOC, SiCN, SiC, SiON, SiOCN, SiBN, SiBO, GeO x , GeN, AlO X , TiO 2 , and TaO 2 . The layer can be formed using one or more of ALD, CVD, PEALD, PECVD, neutral beam enhanced ALD (NBEALD), and neutral beam enhanced CVD (NBECVD), for example, one or more of PEALD, PECVD, NBEALD, and NBECVD, or one or more of NBEALD and NBECVD. 
     A temperature within a reaction chamber during step  102  may be relatively low. For example, a temperature can be less than 400° C., less than 300° C., less than 200° C., less than 100° C., about 25-40° C., about ambient temperature, about 0 to about 100° C., about 0 to about 200° C., or about 0 to about 300° C. A pressure within the reaction chamber can be between about 0.01 Pa and about 100 Pa, about 0.05 Pa and about 1 Pa, or about 0.1 Pa and about 0.5 Pa. 
     In some cases, step  102  can include a plasma-enhanced deposition process. The plasma can be formed in a plasma chamber. When step  102  includes a plasma-enhanced deposition process, a power of an RF generator used to form the plasma can be between about 0.1 W/cm 2  and about 20 W/cm 2 , about 0.2 W/cm 2  and about 10 W/cm 2 , or about 1 W/cm 2  and about 5 W/cm 2 . When the plasma is formed within a plasma chamber, a bias can be applied to, for example, an aperture plate of a neutral beam apparatus. The bias can be between about 0 W/cm 2  and about 3 W/cm 2 , about 0 W/cm 2  and about 1 W/cm 2 , or about 0 W/cm 2  and about 0.5 W/cm 2 . 
     In some cases, step  102  includes a cyclic deposition process, such as one or more of PEALD, PECVD, NBEALD, and NBCVD. In these cases, step  102  can be repeated or can include repeating a number of cycles to form a layer of desired thickness. For example, a layer having a thickness of greater than zero and less than 10 nm can be formed during step  102 . 
     In accordance with further examples of the disclosure, the layer formed during step  102  includes silicon. In these cases, a precursor used to form the layer can selected from the group consisting of aminosilanes, such as BDEAS (SiH 2 [N(C 2 H 5 ) 2 ] 2 ), BTBAS (SiH 2 [NHC(CH 3 ) 3 ] 2 ), TDMAS (SiH[N(CH 3 ) 2 ] 3 ), HEAD (Si 2 [NHC 2 H 6 ] 6 ), 3DMASCl (Si[N(CH 3 ) 2 ] 3 Cl), 3EMAS (H 2 Si[N(C 2 H 5 )CH 3 ] 3 ), 4DMAS (Si[N(C 2 H 6 ) 2 ]) 4 ), 4DEAS (Si[N(C 2 H 6 ) 2 ] 4 ), and other Si-containing precursors, such as 4MS ((CH 3 ) 4 Si), 2ES ((C 2 H 5 ) 2 SiH 2 ), phenyl-SiH 3 , cyclohexyl-SiH 3 , Si(OC 2 H 5 ) 4 . Additionally or alternatively, the reactant (e.g., an oxidant) can be selected from one or more of oxygen, CO, CO 2 , and NO 2 . 
     During step  104 , a neutral beam is generated by introducing a gas to a plasma chamber, forming activated species within the plasma chamber, and passing the activated species through an aperture plate of a neutral beam apparatus to generate the neutral beam. In accordance with exemplary aspects of these embodiments, the neutral beam can be generated from one or more gases selected from the group consisting a of hydrogen-containing gases (e.g., hydrogen), He, NH 3 , O 2 , N 2 O, CO 2 , Ar, Xe, N 2 , and their mixture, such as one or more of H 2  and He, and particularly H 2 . By way of particular examples, the neutral beam can be generated from one or more hydrogen-containing gases (e.g., H 2 ) and helium. In these cases, the gas can include about 1 to about 100, about 10 to about 100, or about 90 to about 100 percent hydrogen and about 1 to about 100, about 10 to about 100, or about 90 to about 100 percent helium. 
     During step  106 , the layer formed during step  102  is exposed to species generated from the neutral beam during step  104 . Although separately illustrated, steps  104  and  106  can overlap and/or occur substantially at the same time. That is, as species are formed (e.g., within a plasma chamber) during step  104 , the (e.g., activated) species can be introduced to the reaction chamber (e.g., through the aperture plate), such that the layer is exposed to the species generated from the neutral beam. 
     A temperature within a reaction chamber during steps  104  and/or  106  may be relatively low. For example, a temperature can be less than 400° C., less than 300° C., less than 200° C., less than 100° C., about 25-40° C., about ambient temperature, about 0 to about 100° C., about 0 to about 200° C., or about 0 to about 300° C. A pressure within the reaction chamber can be between about 0.01 Pa and about 100 Pa, about 0.05 Pa and about 1 Pa, or about 0.1 Pa and about 2 Pa. 
     During step  106 , a bias can be applied to an aperture plate of an aperture plate of a neutral beam apparatus during the step of exposing the layer. By way of examples, the bias can range from about 0 W/cm 2  to about 3 W/cm 2 , about 0 W/cm 2  to about 1 W/cm 2 , or about 0.05 W/cm 2  to about 0.2 W/cm 2 . 
     A power of an RF generator used to form the plasma during step  106  can be between about 0.1 W/cm 2  and about 20 W/cm 2 , about 1 W/cm 2  and about 15 W/cm 2 , or about 3 W/cm 2  and about 10 W/cm 2 . 
     In accordance with exemplary aspects of these embodiments, steps  102 - 106  can be performed within the same reaction chamber. 
       FIG.  2    illustrates another method  200  in accordance with exemplary embodiments of the disclosure. Method  200  includes the steps of providing a substrate within a reaction chamber (step  202 ), providing a precursor of the reaction chamber to form adsorbed species on a surface of the substrate (step  204 ), providing a reactant to a plasma chamber (step  206 ), forming a neutral beam from species generated in the plasma chamber (step  208 ), and exposing the adsorbed species to species from the neutral beam to form a layer comprising silicon (step  210 ). 
     During step  202 , a substrate is provided within a reaction chamber. The reaction chamber can form part of one or more of an ALD, CVD, PEALD, PECVD, NBEALD, and NBECVD reactor system. For example, the reaction chamber can form part of one or more of PEALD, PECVD, NBEALD and NBECVD reactor system or one or more of NBEALD and NBECVD reactor system. Exemplary reactor systems can include one or more reaction chambers. 
     During step  202 , a substrate or a susceptor upon which a substrate is placed, can be brought to a desired temperature. For example, the susceptor can be brought to a temperature of less than 400° C., less than 300° C., less than 200° C., less than 100° C., about 25-40° C., about ambient temperature, about 0 to about 100° C., about 0 to about 200° C., or about 0 to about 300° C. A pressure within the reaction chamber during step  202  can be brought to between about 0.01 Pa and about 100 Pa, about 0.05 Pa and about 1 Pa, or about 0.1 Pa and about 0.5 Pa. 
     During step  204 , a precursor is provided to a gas inlet of the reaction chamber. The precursor can react with species on a surface of a substrate to form adsorbed species on the surface of the substrate. In accordance with examples of the disclosure, the precursor is selected from the group consisting of aminosilanes, such as BDEAS (SiH 2 [N(C 2 H 5 ) 2 ] 2 ), BTBAS (SiH 2 [NHC(CH 3 ) 3 ] 2 ), TDMAS (SiH[N(CH 3 ) 2 ] 3 ), HEAD (Si 2 [NHC 2 H 6 ] 6 ), 3DMASCl (Si[N(CH 3 ) 2 ] 3 Cl), 3EMAS (H 2 Si[N(C 2 H 5 )CH 3 ] 3 ), 4DMAS (Si[N(C 2 H 6 ) 2 ]) 4 ), 4DEAS (Si[N(C 2 H 6 ) 2 ] 4 ), and other Si-containing precursors, such as 4MS ((CH 3 )4Si), 2ES ((C 2 H 5 ) 2 SiH 2 ), phenyl-SiH 3 , cyclohexyl-SiH 3 , and Si(OC 2 H 5 ) 4 . 
     A flowrate of the precursor, alone or diluted with a carrier (e.g., an inert gas) to the reaction chamber can range from about 1 sccm to about 50 sccm, about 2 sccm to about 20 sccm, or about 4 sccm to about 10 sccm. 
     During step  204 , a substrate or a susceptor upon which a substrate is placed, can be brought to or maintained at a desired temperature, such as a temperature set forth above in connections with step  202 . A pressure within the reaction chamber can be the same or similar to the pressure recited above in connection with step  202 . 
     During step  206 , a reactant is provided to a gas inlet of a plasma chamber. Exemplary reactants include one or more of oxygen, CO, CO 2 , and NO 2 , which can be provided to the inlet of the plasma chamber alone, or in combination with a carrier gas. A flowrate of the reactant gas can range between about 10 sccm and about 3000 sccm, about 20 sccm and about 1000 sccm, or about 30 sccm and about 50 sccm. 
     During step  206 , activated species can be generated from the reactant. In these cases, a bias can be applied to an aperture plate of a neutral beam apparatus during step  206 . The bias can be between about 0 W/cm 2  and about 3 W/cm 2 , about 0 W/cm 2  and about 1 W/cm 2 , or about 0 W/cm 2  and about 0.5 W/cm 2 . 
     Although illustrated with step  204  preceding step  206 , in some cases, step  206  can precede step  204 . In other words, the substrate can be contacted with a reactant first and then a precursor. 
     As illustrated, steps  204  and  206  can be repeated, as illustrated by loop  212 . For example, steps  204  and  206  can be repeated a number of time until a desired thickness of material is deposited. In some cases, the desired thickness is less than 10 nm. 
     During step  208 , activated species from a neutral beam are formed. The conditions and reactants for step  208  can be the same or similar to the conditions and reactants described above in connection with step  104 . By way of example, step  208  can include providing gas comprising one or more of a such as one or more of a of hydrogen-containing gases (e.g., hydrogen), He, NH 3 , O 2 , N 2 O, CO 2 , Ar, Xe, N 2 , and their mixture, such as one or more of H 2  and He, and particularly H 2  to the plasma chamber and exposing the layer to species generated from the gas comprising one or more of a such as one or more of a of hydrogen-containing gases (e.g., hydrogen), He, NH 3 , O 2 , N 2 O, CO 2 , Ar, Xe, N 2 , and their mixture. 
     Similarly, the conditions and reactants for step  210  can be the same or similar to the conditions and reactants described above in connection with step  106 . For example, a bias applied to an aperture plate of a neutral beam apparatus during the step of exposing the layer can be between about 0 W/cm 2  and about 3 W/cm 2 , about 0 W/cm 2  and about 1 W/cm 2 , or about 0.05 W/cm 2  and about 0.2 W/cm 2 . 
     Steps  204 - 210 , including loop  212 , can be repeated until a layer of desired thickness is obtained, as illustrated by loop  214 . The thickness can be greater than 10 nm. 
       FIG.  3    illustrates a cross-sectional view of a reactor system  300  in accordance with exemplary embodiments of the disclosure. Reactor system  300  can be configured to perform the steps according to methods described herein. 
     In the illustrated example, reactor system  300  includes a reactor  302  including a reaction chamber  304 , a susceptor  306 , a plasma chamber  308 , an aperture plate  310 , antenna  312 , a plasma generation power source  314 , and a bias power source  316 . Reactor system  300  can also include a precursor gas inlet  318 , a reactant gas inlet  320 , and an outlet  322 , and a controller  328 . 
     Reactor  302  can include any suitable gas-phase reactor. Exemplary reactors include ALD reactors and CVD reactors, such as those available in systems provided by ASM International. 
     Susceptor  306  can be capable of moving vertically to load and unload a substrate  324 . Lift pins and a robot arm (not shown) can be used to load and unload the substrate from the surface of susceptor  306 . 
     Plasma chamber  308  includes an interior region  326  that is in is in fluid communication with reaction chamber  304 . Plasma generation power source  314  and antenna  312  can be used to provide, for example, provide radio frequency (RF) power within plasma chamber  308 . The RF power can be used to form a plasma that includes activated species generated from gas (e.g., reactant gas and/or gas used for treatment of a layer) provided to interior region using, for example, reactant gas inlet  320 . Plasma chamber  308  can form part of an inductively coupled plasma (ICP), a capacitively coupled plasma (CCP), electron cyclotron resonance (ECR), surface-wave-sustained discharge (SWP), or neutral loop discharge (NLD) plasma apparatus. 
     Aperture plate  310  can be used to neutralize the activated species formed within plasma chamber  308  prior to activated species entering reaction chamber  304 . To facilitate flow of activated species from plasma chamber  304  toward susceptor  306  and/or substrate  324 , bias power source  316  can be used to apply a bias voltage to aperture plate  310  to attract ionized species formed within a plasma. Activated species, even though neutralized by aperture plate  310  can continue to flow toward substrate  324  due, at least in part, to the kinetic energy of the species. 
     Aperture plate  310  can be formed of an electric conductor, such as graphite. Aperture plate  310  can include a plurality of apertures, which can be configured in, for example, a hexagonal configuration. 
     Precursor gas inlet  318  is used to introduce a precursor gas and/or a purge gas into reaction chamber  304 . Although only one precursor gas inlet  318  is illustrated, reactor system  300  can include more than one precursor gas inlet  318 . For example, multiple precursor gas inlets can be used to introduce one or more precursors to reaction chamber  304  and/or one or more precursors and one or more purge gases to reaction chamber  304 . 
     Reactant gas inlet  320  is used to introduce a reactant gas and/or a treatment gas into interior region  326  of plasma chamber  308 . Although only one reactant gas inlet  320  is illustrated, reactor system  300  can include more than one reactant gas inlet  320 . 
     Controller  328  can include one or more devices to control power to plasma generation power source  314  and/or bias power source  316 . Controller  328  can also be used to control flow of gases—e.g., one or more gases to precursor gas inlet  318  and/or reactant gas inlet  320 , control pressure within reaction chamber  304 , control pressure within plasma chamber  308 , and the like. For example, a pressure within reaction chamber  304  can be controlled by controlling flowrate(s) of gas(es) into reaction chamber  304  and/or plasma chamber  308  and controlling flow through outlet  322 . In accordance with various examples of the disclosure, controller  328  is configured to have system  300  perform methods as described herein. 
     In accordance with additional examples of the disclosure, a structure, such as a structure illustrated in  FIGS.  4 - 7    is provided. The structure can include a substrate and a layer deposited thereon. Exemplary deposition and treatment conditions for depositing and treating a layer are provide below in the examples. 
     EXAMPLES 
     The examples provided below are meant to be illustrative. Unless otherwise noted, embodiments of the disclosure are not limited to the specific examples provided below. 
     Example 1 
     For the structures formed according to example 1, an NBEALD process was used to deposit a layer onto a substrate. Here, a neutral beam apparatus with 20-cm-diameter aperture plate was used. The NBEALD process included cyclic repeat of following steps: (1) supplying precursor (aminosilane) to process a chamber and adsorption of the precursor on a substrate, (2) stopping a flow of the precursor supply to the reaction chamber, (3) supplying a reactant (e.g., oxidant) gas to a plasma chamber, (4) generating a neutral beam from the reactant gas and providing activated species from the neutral beam to the substrate, and (5) stopping generation of neutral beam and reactant gas supply. Table 1 shows detail of NBEALD conditions used in example 1. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 NBEALD conditions. 
               
            
           
           
               
               
               
            
               
                   
                 Value in this 
                   
               
               
                 Parameter 
                 example 
                 Range 
               
               
                   
               
               
                 Precursor gas 
                 Aminosilane 5 sccm 
                 Aminosilane 1-50 
               
               
                 supply 
                   
                 sccm; carrier gas (e.g., 
               
               
                   
                   
                 He, Ar, and/or N 2 ) may 
               
               
                   
                   
                 be used 
               
               
                 Oxidant gas 
                 O 2  30 sccm 
                 One or plural of 
               
               
                 supply 
                   
                 oxidizing gas (e.g., O 2 , 
               
               
                   
                   
                 CO, CO 2 , or NO 2 ) and 
               
               
                   
                   
                 none, one, or plural of 
               
               
                   
                   
                 inert gas (e.g., He, Ar, 
               
               
                   
                   
                 N 2 ), 10-3000 sccm 
               
               
                 Type of plasma 
                 ICP 
                 ICP, CCP, ECR, SWP, NLD 
               
               
                 generator 
               
            
           
           
               
               
               
               
            
               
                 Frequency of 
                 13.56 
                 MHz 
                 400 kHz-3 GHz  
               
               
                 plasma generation 
               
               
                 RF power source 
               
            
           
           
               
               
               
            
               
                 Power of plasma 
                 1000 W (3.2 W/cm 2 ) 
                 0.1 W/cm2-20 W/cm 2   
               
               
                 generation RF 
               
               
                 power source 
               
            
           
           
               
               
               
               
               
            
               
                 Pressure of 
                 0.11 
                 Pa 
                 0.01-100 
                 Pa 
               
               
                 reaction chamber 
               
               
                 during neutral 
               
               
                 beam irradiation 
               
            
           
           
               
               
               
               
            
               
                 Pressure of 
                 0.41 
                 Pa 
                 Any pressure which can 
               
               
                 plasma chamber 
                   
                   
                 generate plasma 
               
               
                 during neutral 
                   
                   
                 (depending on plasma 
               
               
                 beam irradiation 
                   
                   
                 type) 
               
            
           
           
               
               
               
            
               
                 Number of cycles 
                 90 
                 any number, depending 
               
               
                   
                   
                 on desired thickness 
               
            
           
           
               
               
               
               
               
            
               
                 Frequency of bias 
                 150 
                 kHz 
                 50-2000 
                 kHz 
               
               
                 RF power source 
               
            
           
           
               
               
               
               
            
               
                 Power of bias RF 
                 0 or 100 W (0 or 
                 0-3 
                 W/cm 2   
               
               
                 power source 
                 0.32 W/cm 2 ) 
               
            
           
           
               
               
               
               
            
               
                 Stage temperature 
                 30° 
                 C. 
                 0-100° C., or 0-200° C., 
               
               
                   
                   
                   
                 or 0-300° C. 
               
               
                   
               
            
           
         
       
     
     After formation of the film, a hydrogen neutral beam was irradiated to the sample using the same apparatus without transferring the sample. The condition for the neutral beam treatment of the film is shown in Table 2. 
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 Hydrogen neutral beam irradiation condition. 
               
            
           
           
               
               
               
            
               
                   
                 Value in 
                   
               
               
                 Parameter 
                 example 1 
                 Range 
               
               
                   
               
               
                 Gas supply 
                 Hydrogen 75 sccm 
                 H2, He, NH 3 , O 2 , 
               
               
                   
                   
                 N 2 O, CO 2 , Ar, Xe, N 2 , 
               
               
                   
                   
                 and their mixture gas, 
               
               
                   
                   
                 preferably H 2  or He, 
               
               
                   
                   
                 more preferably H 2 , 
               
               
                   
                   
                 10-3000 sccm 
               
               
                 Type of plasma 
                 ICP 
                 ICP, CCP, ECR, 
               
               
                 generator 
                   
                 SWP, NLD 
               
            
           
           
               
               
               
               
            
               
                 Frequency of 
                 13.56 
                 MHz 
                 400 kHz-3 GHz  
               
               
                 plasma generation 
               
               
                 RF power 
               
            
           
           
               
               
               
            
               
                 Power of plasma 
                 1300 W (4.1 W/cm 2 ) 
                 0.1 W/cm2-20 W/cm 2   
               
               
                 generation RF 
               
               
                 power 
               
            
           
           
               
               
               
               
               
            
               
                 Frequency of 
                 150 
                 kHz 
                 50-2000 
                 kHz 
               
               
                 bias RF power 
               
            
           
           
               
               
               
            
               
                 Power of bias 
                 0, 20, 40, 60 W (0, 0.064, 
                 0-0.5 W/cm 2 , 
               
               
                 RF power 
                 0.127, 0.191 W/cm 2 ) 
                 preferably 0.08-0.16 
               
               
                   
                   
                 W/cm 2   
               
            
           
           
               
               
               
               
               
            
               
                 Pressure of 
                 1.1 
                 Pa 
                 0.01-100 
                 Pa 
               
               
                 reaction chamber 
               
            
           
           
               
               
               
               
            
               
                 Pressure of 
                 1.8 
                 Pa 
                 Any pressure which can 
               
               
                 plasma chamber 
                   
                   
                 generate plasma 
               
               
                   
                   
                   
                 (depending on plasma 
               
               
                   
                   
                   
                 type) 
               
               
                 Irradiation time 
                 10-40 
                 minutes 
                 10 seconds or more 
               
               
                 Stage temperature 
                 30° 
                 C. 
                 0-100° C., 0-200° C., 
               
               
                   
                   
                   
                 0-300° C., or room 
               
               
                   
                   
                   
                 temperature 
               
               
                   
               
            
           
         
       
     
     WER (wet etch rates) for layers deposited according to the conditions set forth above in 0.1% hydrofluoric acid were measured. The WER results are shown in Table 3. Data for a plasma ALD film and a thermal oxide film are also shown in Table 3. As shown, WER of NBEALD film (10 nm) was decreased from 1.39 nm/min to 0.39, 0.37, 0.30 nm/min by hydrogen neutral beam irradiation without bias of 10, 25, 40 minutes. These values correspond to wet etch rate ratios (WERR) of 1.63, 1.54, 1.25. These values are even lower than high temperature (390° C.) PEALD (0.43 nm/min). 
     Bias application during hydrogen neutral beam irradiation was also tested and results are shown in Table 3. Without bias, WERR was 1.25. By applying 20 and 40 W bias, WERR was improved (decreased) to 1.21 and 1.17. However, by applying 60 W bias, WERR was increased to 1.67. Note that this value is still smaller (better) than no-H 2 -neutral-beam-treatment result of 5.79. These results indicate that the best bias power, for the conditions set forth above, is 40 W. 
     Hydrogen plasma irradiation has been used to reform PEALD silicon oxide to reduce WER in 1:1000 (0.05%) HF down to 0.1 nm/min (top, side) and 0.2 nm/min (bottom). Since WER of thermal oxide in 1:1000 HF is about 0.04 nm/min, these results correspond WERR of 2.5-5. This means that hydrogen neutral beam irradiation can achieve lower WERR. There are several possible reasons why neutral beam obtained better results than plasma, including: (1) plasma (ion) irradiation causes charge-up of target film and prevents further introduction of coming ions, while neutral beam irradiation does not cause charge-up and (2) plasma irradiates strong ultraviolet light which may cause defect generation in target film, while neutral beam irradiates much less ultraviolet light and does not generate defects. 
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 WER and WERR (wet etch rate ratio against thermal oxide) of various silicon oxide films 
               
               
                 (with and without hydrogen neutral beam irradiation) formed on blanket silicon wafer. 
               
            
           
           
               
               
            
               
                   
                 Deposition method 
               
            
           
           
               
               
            
               
                   
                 thermal 
               
            
           
           
               
               
               
               
            
               
                   
                 NBEALD 
                 PEALD 
                 SiO 2   
               
            
           
           
               
               
            
               
                   
                 Deposition condition 
               
            
           
           
               
               
               
               
            
               
                   
                 Bias 
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 No bias 
                 100 W 
                 390° C. 
                 — 
               
            
           
           
               
               
            
               
                   
                 H 2  neutral beam condition 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                 No 
                 No 
                 No 
                 Bias 
                 Bias 
                 Bias 
                   
                   
                   
               
               
                   
                   
                 bias, 
                 bias, 
                 bias, 
                 20 W, 
                 40 W, 
                 60 W, 
                   
                   
                   
               
               
                   
                 N/A 
                 10 min 
                 25 min 
                 40 min 
                 30 min 
                 30 min 
                 30 min 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 WER 
                 1.39 
                 0.39 
                 0.37 
                 0.30 
                 0.29 
                 0.28 
                 0.40 
                 1.01 
                 0.43 
                 0.24 
               
               
                 (nm/min) 
               
               
                 WERR 
                 5.79 
                 1.63 
                 1.54 
                 1.25 
                 1.21 
                 1.17 
                 1.67 
                 4.21 
                 1.79 
                 — 
               
               
                   
               
            
           
         
       
     
     Application of RF bias power (400 kHz, 100 W) can also decrease WER to 1.01 nm/min. However, hydrogen neutral beam irradiation can achieve much lower WER. 
     Wet etching using 0.1% hydrofluoric acid was applied also for trench pattern sample.  FIG.  4 - 7    illustrate cross-sectional STEM images of structures  402 - 708 , including layers deposited according to conditions set forth above, before and after wet etching. 
       FIG.  4    illustrates structure  402  having features  420 ,  422  formed within a substrate  418  and a layer  410  formed overlying substrate  418  and structure  404  having features  424 - 430  and a layer  412  overlying substrate  418 —both without wet etching and structure  406  with features  432  and  434  and a layer  414  overlying substrate  418  and structure  408  having features  436 - 442  with a layer  416  overlying substrate  418 —both with wet etching. No neutral beam irradiation was performed on the samples illustrated in  FIG.  4   . 
       FIG.  5    illustrates structure  502  having features  520 ,  522  formed within a substrate  418  and a layer  510  formed overlying substrate  418  and structure  504  having features  524 - 530  and a layer  512  overlying substrate  418 —both without wet etching and structure  506  with features  532  and  534  and a layer  514  overlying substrate  418  and structure  508  having features  536 - 542  with a layer  516  overlying substrate  418 —both after wet etching. Hydrogen neutral beam irradiation without bias was applied to the deposited material to form layers  510 - 516 . 
       FIG.  6    illustrates structure  602  having features  620 ,  622  formed within a substrate  418  and a layer  610  formed overlying substrate  418  and structure  604  having features  624 - 630  and a layer  612  overlying substrate  418 —both without wet etching and structure  606  with features  632  and  634  and a layer  614  overlying substrate  418  and structure  608  having features  636 - 642  with a layer  616  overlying substrate  418 —both after wet etching. Hydrogen neutral beam irradiation with a bias of about 20 W was applied to the deposited material to form layers  610 - 616 . 
       FIG.  7    illustrates structure  702  having features  720 ,  722  formed within a substrate  418  and a layer  710  formed overlying substrate  418  and structure  704  having features  724 - 730  and a layer  712  overlying substrate  418 —both without wet etching and structure  706  with features  732  and  734  and a layer  714  overlying substrate  418  and structure  708  having features  736 - 742  with a layer  716  overlying substrate  418 —both after wet etching. Hydrogen neutral beam irradiation with a bias of about 40 W was applied to the deposited material to form layers  710 - 716 . 
     Table 4 summarizes the wet etching results of layers  410 - 416 ,  510 - 516 ,  610 - 616 , and  710 - 716 . As illustrated and as set forth in Table 4, WER of a feature (e.g., trench) sidewall, in addition to the WER of the top and bottom of the feature, is decreased by neutral beam irradiation. WERIR at different positions (top, side, bottom) are similar. This shows effect of H 2 —NB irradiation is isotropic (conformal). Indeed, WER-decreasing effect is even a bit stronger (larger WERIR) at sidewall than top and bottom. This may be because WER at sidewall is larger and there is larger margin for decrease of WER, while decrease of WER at top and bottom saturates. Also, this result shows that WER of bottom of trench pattern with relatively high aspect ratio of 3.3 was decreased with similar WERIR. 
     
       
         
           
               
             
               
                 TABLE 4 
               
             
            
               
                   
               
               
                 WER and WERR of NBEALD silicon oxide with/without 
               
               
                 H 2  NB deposited on trench pattern. 
               
            
           
           
               
               
               
               
               
            
               
                   
                 w/o 
                 H 2 -NB 
                 H 2 -NB 
                 H 2 -NB 
               
               
                   
                 H 2 -NB 
                 no bias 
                 bias 20 W 
                 bias 40 W 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 WER 
                 top 
                 1.68 
                 0.27 
                 0.24 
                 0.23 
               
               
                 (nm/min) 
                 side 
                 2.42 
                 0.35 
                 0.29 
                 0.27 
               
               
                   
                 bottom 
                 1.77 
                 0.26 
                 0.26 
                 0.21 
               
               
                 WERR (—) 
                 top 
                 8.16 
                 1.31 
                 1.18 
                 1.11 
               
               
                   
                 side 
                 11.76 
                 1.70 
                 1.43 
                 1.33 
               
               
                   
                 bottom 
                 8.58 
                 1.25 
                 1.28 
                 1.04 
               
               
                 WERIR (—) 
                 top 
                 — 
                 6.2 
                 6.9 
                 7.4 
               
               
                   
                 side 
                 — 
                 6.9 
                 8.2 
                 8.9 
               
               
                   
                 bottom 
                 — 
                 6.8 
                 6.7 
                 8.2 
               
               
                   
               
               
                 WER = wet etch rate 
               
               
                 WERR = wet etch rate ratio, WER(target)/WER(thermal oxide) 
               
               
                 WERIR = wet etch rate improvement ratio, WER(w/o H 2 -NB)/WER(target) 
               
            
           
         
       
     
       FIG.  8    shows relationship  800  between remaining film thickness and hydrofluoric acid etching time for 10 minutes (line  802 ), 25 minutes (lines  804 ), and 40 minutes (lines  806 ). The relationship was linear, at least, up to 20 minutes (6-8 nm depth). This means the effect of hydrogen neutral beam irradiation can reach at least 6-8 nm depth. By considering penetration depth of hydrogen plasma into silicon dioxide, the effect may reach up to about 10 nm depth. So, by repeating deposition of silicon oxide film by NBEALD (or other technique) to a thickness of less than 10 nm and exposing a formed layer to neutral beam treatment, high-quality silicon oxide film with thickness more than 10 nm can be obtained. 
     Example 2 
     For the structures formed according to example 2, SiO 2  layers were deposited by PEALD onto a substrate. The substrate included planar surface and trench patterns. The deposition conditions for the PEALD layers are shown in Table 5. 
     
       
         
           
               
             
               
                 TABLE 5 
               
             
            
               
                   
               
               
                 PEALD SiO 2  deposition condition. 
               
            
           
           
               
               
            
               
                 Parameter 
                 Value in example 2 
               
               
                   
               
               
                 Precursor 
                 Aminosilane (carrier gas: Ar 2 slm) 
               
               
                 Gas supply 
                 O 2  2 slm, Ar (carrier 
               
               
                   
                 gas for precursor) 2 slm 
               
            
           
           
               
               
               
            
               
                 Pressure 
                 400 
                 Pa 
               
               
                 Frequency of plasma generation RF 
                 13.56 
                 MHz 
               
               
                 power 
               
            
           
           
               
               
            
               
                 Power of plasma generation RF 
                 50 W (0.071 W/cm 2 ) 
               
               
                 power 
               
            
           
           
               
               
               
            
               
                 Discharge time of plasma generation 
                 1.2 
                 s 
               
               
                 RF power for each ALD cycle 
               
               
                 State temperature 
                 300° 
                 C. 
               
               
                   
               
            
           
         
       
     
     The deposited layers were then exposed to activated species from a helium neutral beam. Here, a neutral beam apparatus with 10-cm-diameter aperture plate was used. Irradiation conditions are shown in Table 6. 
     
       
         
           
               
             
               
                 TABLE 6 
               
             
            
               
                   
               
               
                 Helium neutral beam irradiation condition. (Exemplary 
               
               
                 ranges of parameters are provided in Table 2, above.) 
               
            
           
           
               
               
               
            
               
                   
                 Parameter 
                 Value in this example 2 
               
               
                   
                   
               
               
                   
                 Gas supply 
                 Helium 10-20 sccm 
               
               
                   
                 Type of plasma generator 
                 ICP 
               
            
           
           
               
               
               
               
            
               
                   
                 Frequency of plasma 
                 13.56 
                 MHz 
               
               
                   
                 generation RF power 
               
            
           
           
               
               
               
            
               
                   
                 Power of plasma generation 
                 500 W (6.4 W/cm 2 ) 
               
               
                   
                 RF power 
               
            
           
           
               
               
               
               
            
               
                   
                 Pressure of reaction 
                 0.16-0.30 
                 Pa 
               
               
                   
                 chamber 
               
            
           
           
               
               
               
            
               
                   
                 Pressure of plasma chamber 
                 Pa 
               
            
           
           
               
               
               
               
            
               
                   
                 Irradiation time 
                 5-40 
                 minutes 
               
            
           
           
               
               
               
            
               
                   
                 Stage temperature 
                 Room temperature or 200° C. 
               
               
                   
                   
               
            
           
         
       
     
     WER of the treated layers in 0.25% hydrofluoric acid were measured. The WER are shown in Table 7. As a shown, WERR of the layer was decreased from 8.6 to 7.2, 5.1, 4.4, and 3.2 by helium neutral beam irradiation of 5, 10, 20, and 40 minutes at 300° C. In case of room temperature, WERR was decreased from 8.6 to 6.8, 6.4, 6.1, and 4.1 by helium neutral beam irradiation of 5, 10, 20, and 40 minutes. It is shown that He neutral beam irradiation can decrease WER of silicon oxide, though, in the illustrative examples, the range of decrease is smaller than the rage of decrease obtained using H 2  neutral beam irradiation. 
     
       
         
           
               
             
               
                 TABLE 7 
               
               
                   
               
               
                 WERR of PEALD silicon oxide films with and without He neutral 
               
               
                 beam irradiation formed on blanket silicon wafer 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
            
               
                   
                 He flow 
               
            
           
           
               
               
               
            
               
                   
                 10 sccm 
                 20 sccm 
               
            
           
           
               
               
            
               
                   
                 Pressure 
               
            
           
           
               
               
               
            
               
                   
                 0.16 Pa 
                 0.30 Pa 
               
            
           
           
               
               
               
            
               
                   
                   
                 Temperature 
               
               
                   
                   
                 300° C. 
               
               
                   
                 (No 
                 Irradiation time 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 irradiation) 
                 5 min 
                 10 min 
                 20 min 
                 40 min 
                 20 min 
               
               
                   
               
               
                 WERR 
                 8.6 
                 7.2 
                 5.1 
                 4.4 
                 3.2 
                 6.1 
               
               
                   
               
            
           
           
               
               
            
               
                   
                 He flow 
               
            
           
           
               
               
               
            
               
                   
                 10 sccm 
                 20 sccm 
               
            
           
           
               
               
            
               
                   
                 Pressure 
               
            
           
           
               
               
               
            
               
                   
                 0.16 Pa 
                 0.30 Pa 
               
            
           
           
               
               
               
            
               
                   
                   
                 Temperature 
               
               
                   
                   
                 Room temperature 
               
               
                   
                 (No 
                 Irradiation time 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 irradiation) 
                 5 min 
                 10 min 
                 20 min 
                 40 min 
                 20 min 
               
               
                   
               
               
                 WERR 
                 8.6 
                 6.8 
                 6.4 
                 6.1 
                 4.1 
                 6.5 
               
               
                   
               
            
           
         
       
     
     Table 8 shows WERR of PEALD silicon oxide film deposited on top, side, bottom of trench structure. WERR of top, side, and bottom was decreased by helium neutral beam irradiation. In case of helium, WERIR of top is a bit larger than that of side and bottom, indicating that, for this illustrative example, He neutral beam irradiation may modify the top of structure more strongly than side and bottom surface, unlike H 2  neutral beam irradiation. 
     
       
         
           
               
             
               
                 TABLE 8 
               
             
            
               
                   
               
               
                 WERR of PEALD silicon oxide with/without He 
               
               
                 NB deposited on trench pattern. Values in parentheses 
               
               
                 show WERIR (WER improvement ratio). 
               
            
           
           
               
               
               
            
               
                   
                 with He-NB 
                   
               
            
           
           
               
               
               
               
            
               
                   
                 without He-NB 
                 300° C., 
                 Room temperature, 
               
               
                 Position 
                 — 
                 20 minutes 
                 20 minutes 
               
               
                   
               
            
           
           
               
               
               
               
            
               
                 Top 
                 9.9 
                 3.75 (2.6) 
                 5.63 (1.8) 
               
               
                 Side 
                 8.9 
                 4.13 (2.2) 
                 6.13 (1.5) 
               
               
                 bottom 
                 9.3 
                 4.38 (2.1) 
                 6.50 (1.4) 
               
               
                   
               
            
           
         
       
     
     The example embodiments of the disclosure described above do not limit the scope of the invention, since these embodiments are merely examples of the embodiments of the invention. Any equivalent embodiments are intended to be within the scope of this invention. Indeed, various modifications of the disclosure, in addition to the embodiments shown and described herein, such as alternative useful combinations of the elements described, may become apparent to those skilled in the art from the description. Such modifications and embodiments are also intended to fall within the scope of the appended claims.