JP2022161979A - Compositions and methods using the same for deposition of silicon-containing film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide compositions and methods using the same for forming a silicon-containing film.

SOLUTION: Described herein are compositions and methods using the same for forming a silicon-containing film such as without limitation a silicon carbide, a silicon nitride, a silicon oxide, a silicon oxynitride, a carbon-doped silicon nitride, a carbon-doped silicon oxide, or a carbon doped silicon oxynitride film on at least a surface of a substrate having a surface feature. In one aspect, the silicon-containing films are deposited using a compound comprising a carbon-carbon double or carbon-carbon triple bond. A plasma source employed comprises both a remote plasma source and an in-situ plasma source operating in combination.

SELECTED DRAWING: Figure 2

COPYRIGHT: (C)2023,JPO&INPIT

Description

Described herein are processes for the manufacture of electronic devices. More specifically, described herein are compositions for forming silicon-containing films in deposition processes such as, but not limited to, fluid chemical vapor deposition. Exemplary silicon-containing films that can be deposited using the compositions and methods described herein include, but are not limited to, silicon oxide, silicon nitride, silicon carbide, silicon oxynitride, carbon-doped It includes a film of nitric oxide or carbon-doped silicon nitride.

In the fabrication of microelectronic devices, there is a need for void-free filling of narrow trenches with aspect ratios (AR) greater than 10:1 for many applications. One application is shallow trench isolation (STI). For this application, the film should have very low leakage through the trench and be of high quality (eg, wet etch rate ratio less than 2). As the dimensions of structures decrease and aspect ratios increase, post-curing methods for deposited flowable films become more difficult. The result is a film with compositional variations throughout the filled trench.

Conventional plasma-enhanced chemical vapor deposition (PECVD) of dielectric films forms "mushroom-shaped" films on top of narrow trenches. This is due to the inability of the plasma to penetrate deep trenches. That results in pinching off the narrow trench from the top and forming voids at the bottom of the trench.

In addition, silicon-containing films such as SiCO, SiCON, SiCN are widely used in the fabrication of semiconductor devices. For example, these carbon-containing gapfill films can be used for patterning applications. Due to the high carbon levels, these films typically exhibit high etch selectivities compared to oxide and nitride films. Etch selectivity can be important for gap-fill films used in patterning applications. Accordingly, there is a need for precursors and methods for depositing silicon-containing films.

US Patent Application Publication No. 2008/0025907 discloses a process for forming a silicon-containing film on a substrate by a method known as flow CVD or FCVD. FCVD processes are useful for many applications, including the deposition of gapfill films on high aspect ratio structures with small dimensions. According to the disclosed process, the precursor is exposed to reactive radicals that initiate radical-induced polymerization in the deposition chamber. Reactive radicals are created using plasma energy. The plasma can be generated or ignited within the processing chamber (eg, direct or in-situ plasma) or can be generated external to the processing chamber and flowed into the processing chamber (eg, remote plasma).

The compositions or formulations and methods of using the compositions or formulations described herein deposit silicon-containing films on at least a portion of a substrate surface that provide desirable film properties upon post-deposition processing. thereby overcoming the problems of the prior art. The compositions and methods of the present invention exhibit the following properties: i) in the range of about 10 to about 20 MPa after thermal curing, and from about 150 to about 190 MPa after ultraviolet (UV) curing, as measured using a Toho stress tool; and ii) a density in the range of about 1.35 to about 2.10 g/cm ³ as measured by X-ray reflectance.

The silicon-containing film is selected from the group consisting of silicon nitride, silicon carbide, silicon oxide, carbon-doped silicon nitride, silicon oxynitride and carbon-doped silicon oxynitride films. In certain embodiments, the substrate comprises surface features. As used herein, the term "surface features" refers to substrates or means a partially manufactured substrate. The composition may be a premix composition, a premix (mixed prior to use in the deposition process) or an in-situ mixture (mixed during the deposition process). Accordingly, the terms "mixture," "formulation," and "composition" are interchangeable in this disclosure.

In one aspect, a method is provided for depositing a silicon-containing film in a flowable chemical vapor deposition process. A substrate having surface features is placed in a reactor at one or more temperatures ranging from -20°C to about 100°C. A composition is introduced into the reactor, the composition comprising at least one compound having the formula R _n SiR ¹⁴ _-n , wherein R is a linear or branched C ₂ -C ₆ alkenyl group, a linear is selected from chain or branched C ₂ -C ₆ alkynyl groups; R ¹ is selected from hydrogen, methyl and straight or branched chain C ₂ -C ₁₀ alkyl groups; n is from 1, 2, 3 and 4 is the number selected. A plasma source is provided to at least partially react at least one compound to form a flowable liquid oligomer. The flowable liquid oligomer at least partially fills at least some of the surface features. Plasma sources include both remote plasma sources and in-situ plasma sources that work in combination.

In one particular embodiment, at least one of the remote plasma source and the in-situ plasma source is a nitrogen plasma, a plasma comprising nitrogen and helium, a plasma comprising nitrogen and argon, an ammonia plasma, a plasma comprising ammonia and helium, ammonia and plasma containing argon, helium plasma, argon plasma, hydrogen plasma, plasma containing hydrogen and helium, plasma containing hydrogen and argon, plasma containing ammonia and hydrogen, organic amine plasma, plasma containing oxygen, oxygen and hydrogen including plasma sources selected from the group consisting of plasmas and combinations thereof.

In another embodiment, the plasma source for the remote plasma source and/or the in situ plasma source is a hydrocarbon plasma, a plasma containing hydrocarbons and helium, a plasma containing hydrocarbons and argon, a carbon dioxide plasma, a carbon monoxide plasma. a plasma containing hydrocarbons and hydrogen, a plasma containing hydrocarbons and a nitrogen source, a plasma containing a hydrocarbon and an oxygen source, and a carbon source plasma containing combinations thereof.

In any of the above embodiments, or alternative embodiments, the flowable liquid or oligomer is treated at one or more temperatures ranging from about 100° C. to about 1000° C. to convert at least a portion of the material to Densify.

In some embodiments, the post heat treated material is exposed to plasma, infrared light, chemical treatment, electron beam or ultraviolet light to form a dense film.

The above steps define one cycle for the methods described herein; the cycle can be repeated until the desired thickness of the silicon-containing film is obtained. In this or other embodiments, the steps of the methods described herein can be performed out of order, sequentially or simultaneously (e.g., between at least a portion of another step). and any combination thereof.

Various embodiments of the invention can be used alone or in combination with each other.

4 is a scanning electron microscope (SEM) photograph showing the results of Example 1. FIG. 4 is an SEM photograph showing the results of Example 2. FIG. 4 is a SEM photograph showing the results of Example 3. FIG. 4 is a SEM photograph showing the results of Example 5. FIG.

Described herein is an FCVD method for depositing silicon-containing films in a flowable chemical vapor deposition process, the method comprising:
placing a substrate with surface features in a reactor at one or more temperatures ranging from -20°C to about 100°C;
having the formula R _n SiR ¹ _4-n , wherein R is selected from linear or branched C ₂ -C ₆ alkenyl groups, linear or branched C ₂ -C ₆ alkynyl groups, and R ¹ is selected from hydrogen and branched C1 _{- C10} alkyl groups and n is a number selected from 1, 2, 3 and 4; and providing a plasma source in the reactor and at least partially reacting the at least one compound to form a flowable liquid oligomer, wherein the flowable liquid oligomer at least partially forms at least a portion of the surface features. and the plasma source includes both a remote plasma source and an in-situ plasma source working in combination.

Typically, films deposited by, for example, fluid chemical vapor deposition processes undergo film shrinkage during post-processing due to low process temperatures. Voids and seams may form in the film due to significant film shrinkage and increased film stress. Therefore, it has been difficult to densify the film without increasing film stress or creating voids. The compositions and methods described herein improve filling of at least some of the surface features on a substrate by using the disclosed precursors and compositions comprising the disclosed precursors. to overcome these problems.

Embodiments of the disclosure provide methods for depositing gapfill films (eg, SiC, SiCO, SiCN, SiCON) on high aspect ratio (AR) structures with small dimensions. Advantageously, some embodiments provide a method that includes cyclic deposition treatment processes that can be performed in a cluster tool environment. Advantageously, some embodiments provide high quality, seamless silicon-containing films that fill high AR trenches with small dimensions. Advantageously, some embodiments provide films containing high carbon content. Advantageously, in one or more embodiments, high carbon content films can be used in hardmask and low-k flow applications.

One or more embodiments of the disclosure are directed to processes in which flowable silicon-containing films are deposited that can fill high aspect ratio structures (eg, AR>8.1). Disclosed embodiments use F-CVD (Fluidable Chemical Vapor Deposition) to produce novel precursors for SiC, SiOC, SiCN, SiOCN, SiO and SiN flowable films for gapfill applications. I will provide a. The precursors of various embodiments contain alkenyl (vinyl) and/or alkynyl groups. In one or more embodiments, the precursor is exposed to reactive radicals that initiate radical-induced polymerization in the deposition chamber.

In one embodiment, the developed method comprises placing a substrate with surface features in a reactor at one or more temperatures ranging from -20°C to about 100°C.

As used herein, "substrate" refers to any substrate or material surface formed on the substrate upon which membrane treatment is performed during the manufacturing process. For example, substrate surfaces that can be treated include materials such as silicon, silicon oxide, strained silicon, silicon-on-insulator (SOI), carbon-doped silicon oxide, amorphous silicon, doped silicon, germanium, gallium arsenide. , glass, sapphire, and any other materials such as metals, metal nitrides, metal alloys, and other conductive materials, depending on the application. Substrates include, but are not limited to, semiconductor wafers. The substrate can undergo pretreatment processes to polish, etch, reduce, oxidize, hydroxylate, anneal, UV cure, e-beam cure and/or bake the substrate surface. In addition to direct film treatment to the surface of the substrate itself, some of the film treatment steps disclosed in the present invention are also applied to underlying layers formed on the substrate, as disclosed in more detail below. It can be done, and the term "substrate surface" is intended to include such underlayers when the context intends. Thus, for example, when a film/layer or partial film/layer is deposited on a substrate surface, the exposed surface of the newly deposited film/layer becomes the substrate surface.

As previously described, the method deposits a film on at least a portion of the surface of the substrate comprising the surface features. A substrate is placed in the reactor and the substrate is maintained at at least one temperature ranging from about -20°C to about 100°C. In one particular embodiment, the temperature of the substrate is lower than the temperature of the walls of the chamber. The substrate temperature is kept below 100°C, preferably below 25°C, and most preferably below 10°C and above -20°C.

As previously described, the substrate comprises one or more surface features. In one particular embodiment, the one or more surface features have a width of 1 μm or less, a width of 500 nm or less, a width of 50 nm or less, or a width of 10 nm. In this or other embodiments, the aspect ratio (depth:width ratio) of the surface features, if present, is 0.1:1 or greater, 1:1 or greater, 10:1 or greater, 20:1 or greater, or 40:1 or greater. The substrate may be a single crystal silicon wafer, a silicon carbide wafer, an aluminum oxide (sapphire) wafer, a sheet of glass, a metal foil, a film of an organic polymer, or a three-dimensional film of polymer, glass, silicon or metal. It can be an article. Substrates can be of a variety of materials well known in the art, including films of silicon oxide, silicon nitride, amorphous carbon, silicon oxycarbide, silicon oxynitride, silicon carbide, gallium arsenide, gallium nitride, and the like. can be coated. These coatings may completely coat the substrate, may be multiple layers of different materials, or may be partially etched to expose underlying layers of material. The surface may also have a photoresist material exposed in a pattern and developed to partially coat the substrate on the surface.

In one aspect of the invention, the substrate comprises at least one element selected from the group consisting of Si, _SiOx , SiN, SiGe, SiOC and SiON. In another aspect of the invention, the silicon-containing films of the invention can be used as hardmasks and can provide etch selectivity to photoresists. In further aspects of the invention, the silicon-containing films of the invention function as dielectric films between conductive materials, as barriers between conductors and other dielectrics, or as films in sandwich dielectrics. .

The method used to form the films or coatings described herein is a flowable chemical deposition process. Examples of suitable deposition processes for the methods disclosed herein include, but are not limited to, cyclic fluidized chemical vapor deposition (CFCVD) or plasma enhanced fluidized chemical vapor deposition (PEFCVD). As used herein, the term "flowable chemical vapor deposition process" means that a substrate is exposed to one or more volatile precursors, the volatile precursors reacting and/or Any process that decomposes to provide fluid oligomeric silicon-containing species, which upon further processing yields a solid film or material, and in some cases at least a portion of the oligomeric species comprise polymeric species. Say. Although the precursors, reagents and sources used herein may sometimes be described as "gaseous," the precursors may be placed directly into the reactor, with or without an inert gas. It is understood that it may be either a liquid or a solid carried by vaporization, bubbling or sublimation. In some cases, the vaporized precursor can be passed through a plasma generator. In one embodiment, the film is deposited using a plasma-based (eg, remotely generated or in-situ) CVD process. As used herein, the term "reactor" includes, but is not limited to, reaction chambers or deposition chambers.

を含むがそれらに限定されない。 The developed method also has the formula R _n SiR ¹⁴ _-n , where R is a linear or branched C ₂ -C ₆ alkenyl group, a linear or branched C ₂ -C ₆ alkynyl R ¹ is selected from hydrogen and branched C ₁ -C ₁₀ alkyl groups; n is a number selected from 1, 2, 3 and 4. Including the step of introducing into the vessel. Exemplary compounds for the above formulas are:

including but not limited to.

In the above formula and throughout the specification, the term "linear or branched alkyl" represents a linear functional group having 1 to 10, 3 to 10 or 1 to 6 carbon atoms. In the above formula and throughout the specification, the term "branched alkyl" refers to straight chain functional groups having 3 to 10 or 1 to 6 carbon atoms. Exemplary straight or branched chain alkyl groups are methyl (Me), ethyl (Et), isopropyl (Pr ⁱ ), isobutyl (Bu ⁱ ), sec-butyl (Bu ^s ), tert-butyl (Bu ^t ). , isopentyl, tert-pentyl (am), isohexyl and neohexyl. In certain embodiments, an alkyl group has one or more functional groups attached thereto, such as, but not limited to, alkoxy groups, dialkylamino groups, or combinations thereof. you can In other embodiments, an alkyl group does not have one or more functional groups attached to it. Alkyl groups may be saturated or, alternatively, unsaturated.

In the above formula and throughout the specification, the term "cyclic alkyl" represents a cyclic group having 3-10 or 5-10 carbon atoms. Exemplary cyclic alkyl groups include, but are not limited to, cyclobutyl, cyclopentyl, cyclohexyl and cyclooctyl groups. In certain embodiments, a cyclic alkyl group may have one or more C ₁ -C ₁₀ straight chain, branched chain, or substituents containing oxygen or nitrogen atoms. In this or other embodiments, the cyclic alkyl group may be substituted with one or more straight or branched chain alkyl or alkoxy groups, such as methylcyclohexyl or methoxycyclohexyl groups.

In the above formula and throughout the specification, the term "aryl" represents an aromatic cyclic functional group having 3-10 carbon atoms, 5-10 carbon atoms or 6-10 carbon atoms. Exemplary aryl groups include, without limitation, phenyl, benzyl, chlorobenzyl, tolyl and o-xylyl.

In the above formulas and throughout the specification, the term "alkenyl group" has one or more carbon-carbon double bonds and has 2 to 12, 2 to 10 or 2 to 6 carbon atoms. represents a group having Exemplary alkenyl groups include, but are not limited to vinyl or allyl groups.

The term “alkynyl group” refers to groups having one or more carbon-carbon triple bonds and having from 2 to 12 or from 2 to 6 carbon atoms.

The term "alkylene group" denotes a group derived from alkyl by the removal of two hydrogen atoms. Exemplary alkylene groups include, but are not limited to, methylene (--CH ₂ --) or ethylene (--CH ₂ CH ₂ --) groups.

As used herein in the formulas above and throughout the specification, the term "unsaturated" means that a functional group, substituent, ring or bridge has one or more carbon double or triple bonds means to have Examples of unsaturated rings may be, but are not limited to, aromatic rings such as phenyl rings. The term "saturated" means that a functional group, substituent, ring or bridge does not have one or more double or triple bonds.

In certain embodiments, one or more of the alkyl groups, alkenyl groups, alkynyl groups, aryl groups and/or cyclic alkyl groups in the above formulas are "substituted" or substituted for, for example, a hydrogen atom. may have one or more atoms or groups of atoms substituted with Exemplary substituents include, but are not limited to oxygen, sulfur, halogen atoms (eg F, Cl, I or Br), nitrogen, alkyl groups and phosphorus. In other embodiments, one or more of the alkyl, alkenyl, alkynyl, aromatic and/or aryl groups in the above formulas can be unsubstituted.

The silicon precursor compound is preferably substantially free of halogen-based ions such as chlorine or metal ions such as Al. As used herein, the term "substantially free" refers to halogen-based ions (or halides) such as chloride, fluoride, bromide and iodide, Al ³⁺ ions, Fe ²⁺ , When referring to Fe ³⁺ , Ni ²⁺ , Cr ³⁺ , it means less than 5 ppm (by mass), preferably less than 3 ppm, more preferably less than 1 ppm, most preferably 0 ppm. Chloride or metal ions are known to act as decomposition catalysts for silicon precursors. Significant levels of chloride in the final product can decompose the silicon precursor. Slow decomposition of the silicon precursor can directly impact the film deposition process making it difficult to meet film specifications for semiconductor manufacturing. In addition, shelf life or stability is negatively impacted by the higher decomposition rate of the silicon precursor, making it difficult to guarantee a shelf life of 1-2 years. Additionally, silicon precursors are known to form flammable and/or pyrophoric gases such as hydrogen and silane upon decomposition. Accordingly, the accelerated decomposition of the silicon precursor raises safety and performance concerns related to the formation of these flammable and/or pyrophoric gaseous by-products.

The compounds disclosed herein can be transported into the flowable chemical vapor deposition reactor in a variety of ways including, but not limited to, vapor abstraction, bubbling or direct liquid injection (DLI). . In one embodiment, a liquid transport system is utilized. In another embodiment, the reactor can be equipped with dual plenum showerheads to keep the remotely generated plasma species separate from the gas phase of the precursor, which means that they until they combine to deposit a flowable liquid. In an alternate embodiment, a combined liquid transport and flash vaporization process device, such as a turbo vaporizer manufactured by MSP Corporation of Shoreview, Minn., can be used, and low volatility materials can be volumetrically transported. , resulting in reproducible transport and deposition without thermal decomposition of the precursor. In liquid delivery formulations, the precursors described herein can be delivered in pure liquid form or alternatively can be used in solvent formulations or compositions containing the precursors. Thus, in certain embodiments, the precursor formulation may include a solvent component of suitable properties that may be desirable and advantageous in a given end-use application for forming a film on a substrate.

In certain embodiments, the substrate is subjected to one or more pre-deposition treatments, including but not limited to plasma treatment, thermal treatment, chemical treatment, ultraviolet light exposure, electron beam exposure, and combinations thereof. In response, one or more properties of the membrane can be affected. These pre-deposition treatments can occur under an atmosphere selected from inert, oxidizing and/or reducing.

The method of the present development comprises providing a plasma source in a reactor and at least partially reacting at least one compound having the formula R _n SiR ¹⁴ _-n to form a flowable liquid oligomer; The liquid oligomer at least partially fills at least some of the surface features, and the plasma sources include both remote plasma sources and in-situ plasma sources working in combination.

The developed process uses two plasma sources - a remote plasma source and an in-situ RF plasma source (e.g. capacitively coupled) - and has the best gap-fill properties, e.g. when viewed by scanning electron microscopy (SEM). resulting in a film after deposition and curing that is substantially free of visible voids. A remote plasma source and an in-situ plasma source working in combination means that both plasma sources are activated at least part of the time during deposition. In other embodiments, both plasma sources are activated for at least 1/4 of the time during deposition. In other embodiments, both plasma sources are activated for at least half the time during deposition. In other embodiments, both plasma sources are activated for at least 3/4 of the time during deposition. In yet another embodiment, both plasma sources are activated the entire time during deposition.

The plasma power applied to the remote plasma source (RPS) is 1000-3000W, preferably 2000-3000W. The plasma power to the in-situ plasma source is 100-1000W, preferably 200-300W.

Energy is applied to at least one compound having the formula _RnSiR14-n ^and _the plasma source to induce a reaction to form a flowable silicon-containing film or coating on the substrate. Such energies include, but are not limited to, thermal, plasma, pulsed plasma, helicon wave plasma, high density plasma, inductively coupled plasma, x-ray, electron beam, photon, remote plasma methods, and their Can be provided by a combination. In certain embodiments, a second RF frequency source can be used to alter the plasma properties at the substrate surface. In embodiments in which the deposition involves plasma, the plasma generation process may be a direct plasma generation process, in which the plasma is generated directly in the reactor, or alternatively, a remote plasma, in which the plasma is generated outside the reactor and fed into the reactor. It may include developmental processes.

At least one of the remote plasma source and the in-situ plasma source may contain nitrogen. Nitrogen-containing plasmas include nitrogen plasma, nitrogen/hydrogen plasma, nitrogen/helium plasma, nitrogen/argon plasma, ammonia plasma, ammonia/helium plasma, ammonia/argon plasma, ammonia/nitrogen plasma, NF3 _, NF3 plasma _, organic It can be selected from the group consisting of amine plasmas and combinations thereof. The at least one compound and the nitrogen source react to form a (non-stoichiometric) silicon nitride or silicon carbonitride film on the surface features and at least a portion of the substrate. As used herein, the term "organic amine" refers to organic compounds having at least one nitrogen atom. Examples of organic amines include, but are not limited to: methylamine, ethylamine, propylamine, isopropylamine, tert-butylamine, sec-butylamine, tert-amylamine, ethylenediamine, dimethylamine, trimethylamine, diethylamine, pyrrole, 2 , 6-dimethylpiperidine, di-n-propylamine, di-isopropylamine, ethylmethylamine, N-methylaniline, pyridine and triethylamine.

At least one of the remote plasma source and the in-situ plasma source may contain carbon. In such embodiments, the plasma source is a hydrocarbon plasma, a plasma containing hydrocarbons and helium, a plasma containing hydrocarbons and argon, a carbon dioxide plasma, a carbon monoxide plasma, a plasma containing hydrocarbons and hydrogen, a hydrocarbon and plasmas containing nitrogen sources, plasmas containing hydrocarbon and oxygen sources, and carbon source plasmas containing combinations thereof. at least one compound reacts with a carbon source to form a (non-stoichiometric) silicon carbide film, silicon carbonitride film, silicon oxynitride film, silicon oxycarbide film or silicon oxycarbonitride film on the surface features and substrate; at least part of the

In different embodiments, the plasma source is selected from, but not limited to, hydrogen plasma, helium plasma, argon plasma, xenon plasma and combinations thereof. At least one compound reacts with the plasma to form a silicon nitride film, silicon carbide film, or silicon carbonitride film on at least a portion of the surface features and the substrate.

At least one of the remote plasma source and the in-situ plasma source may contain oxygen. In such embodiments, the oxygen-containing source is water ( _H2O ), oxygen ( _O2 ), oxygen plasma, ozone (O3) _, NO, NO2, carbon monoxide ₍ CO), carbon dioxide (CO ₂ ), N ₂ O plasma, carbon monoxide (CO) plasma, carbon dioxide (CO ₂ ) plasma and combinations thereof.

Further, after the silicon-containing film is deposited, the substrate is subjected to the above-described process conditions sufficient for the silicon nitride film to form a silicon oxide, silicon oxynitride, or carbon-doped silicon oxide film. can be treated (ie, optionally treated) with an oxygen-containing source that

In certain embodiments, the reactor is at sub-atmospheric pressure, at a pressure of 750 torr (10 ⁵ Pascals (Pa)) or less, or at a pressure of 100 torr (13332 Pa) or less. In other embodiments, the reactor pressure is maintained in the range of about 0.1 torr (13 Pa) to about 10 torr (1333 Pa).

Flowable films are generally not stable when deposited, but stabilize when exposed to atmospheric conditions. Flowable films of some embodiments are deposited with a radical form of a silicon-containing precursor and, for example, NH ₃ /O ₂ as a co-reactant. These films are then cured by ozone/UV/vapor anneal/ _NH3 anneal, etc. to produce cured films.

In certain embodiments, the flowable liquid or oligomer is treated at one or more temperatures ranging from about 100° C. to about 1000° C. to densify at least a portion of the material. In another embodiment, the flowable liquid or oligomer is an oxygen-containing source of: are treated by exposure to at least one of Oxygen-containing sources include water ( _H2O ), oxygen ( _O2 ), oxygen plasma, ozone (O3) _, NO, N2O, carbon monoxide ₍ CO), carbon dioxide _{( CO2} ), N2O. It can be selected from the group consisting of plasma, carbon monoxide (CO) plasma, carbon dioxide ( _CO2 ) plasma and combinations thereof.

In some embodiments, the post heat treated material is subjected to plasma, infrared light, chemical treatment, electron beam or ultraviolet light to form a dense film. In one embodiment of the invention, post-processing, including exposure to ultraviolet light, is performed under conditions that produce gaseous by-products.

The above steps define one cycle for the methods described herein; the cycle can be repeated until the desired thickness of the silicon-containing film is obtained.

This development demonstrates the use of precursor selection to provide films with the desired silicon:carbon ratio (Si:C). Film deposition using tetravinylsilane (TVS) provides a Si:C ratio of about 1:4. The precursor has 1:8 Si:C. Selection of precursors with many Si atoms contained in the ring structure yields higher Si:C, such as found in 1,1,3,3-tetravinyl-1,3-disilacyclobutane. A membrane with The chemical structure is expected to provide 1:3 Si:C. The use of precursors such as allyl-substituted disilacyclobutanes can potentially lead to low Si:C, sometimes 1:1, based on the improved potential of allyl groups as leaving groups during deposition or film curing. Si:C up to 1 can be provided.

Flowable membrane 150 can be formed at any suitable temperature. In some embodiments, flowable film 150 is formed at temperatures ranging from about -20°C to about 100°C. The temperature can be kept low so as to maintain the temperature budget of the device being formed. In some embodiments, flowable film formation occurs at temperatures below about 300°C, 250°C, 200°C, 150°C, 100°C, 75°C, 50°C, 25°C, or 0°C.

Films with high carbon content can have many applications, such as in hard mask patterning and for flowable low K films. In some embodiments, flowable films using the precursors disclosed herein can deposit films with high carbon content. In some embodiments, the film has a carbon content of up to about 85 at%. In one or more embodiments, the flowable film has a carbon content of greater than about 40, 45, 50, 55, 60, 65, 70, 75 or 80 at% and less than about 95, 90 or 85 at%. have. In some embodiments, the flowable film has a carbon content in the range of about 40 to about 85 at%, in the range of about 50 to about 85 at%, or in the range of about 60 to about 80 at%.

The composition of the flowable membrane can be adjusted by changing the composition of the reactive gas. In some implementations, the flowable film comprises one or more of SiC, SiCO, SiCN, SiCON, SiO and SiN. To form an oxygen-containing film, the co-reactant may include one or more of oxygen, ozone, or water, for example. To form a nitrogen-containing film, the co-reactant may include, for example, one or _more of ammonia, hydrazine, NO2 or _N2 . To form a carbon-containing film, the reactive gas may include one or more of propylene and acetylene, for example. Those skilled in the art will appreciate that other species combinations can be included in the reactive gas mixture to alter the composition of the flowable film.

Flowable films can be deposited on the wafer (wafer temperature can be from -10°C to 200°C), and due to their fluidity, the polymers flow through trenches and gap fills. . These films then undergo a curing step, eg ozone/UV/vapor anneal/ _NH3 anneal to obtain stable films. In some embodiments, the method provides one or more of SiC, SiCO, SiCN, SiCON, SiO and/or SiN flowable films. Thus, after formation of the fluent film 150, the film can be cured to solidify the fluent film and form a substantially seamless gapfill. In one or more embodiments, curing the fluent film includes exposing the fluent film to one or more of ozone, ultraviolet light, steam anneal, ammonia anneal, and oxygen plasma. In some embodiments, the flowable film is cured by exposing the film to a UV curing process. The UV curing process can be performed at temperatures ranging from about 10°C to about 550°C. The UV curing process can be performed for any suitable time frame required to sufficiently solidify the flowable film. UV curing can be performed under various parameters such as power, temperature, environment, and the like. In some embodiments, UV curing occurs in an acetylene/ethylene environment.

In one aspect, a method is provided for depositing a silicon-containing film in a flowable chemical vapor deposition process, the method comprising exposing a substrate comprising surface features to one or more _placing in ^a _reactor at _{multiple temperatures} ; at least one compound selected from ₂ to C ₆ alkynyl groups, wherein R ¹ is selected from hydrogen and branched C ₁ to C ₁₀ alkyl groups, and n is a number selected from 1, 2, 3 and 4; and providing a plasma source into the reactor to at least partially react at least one compound to form a flowable liquid oligomer, the flowable liquid comprising: the oligomer at least partially fills at least some of the surface features, and the plasma source includes both a remote plasma source and an in-situ plasma source working in combination.

The following examples are provided to illustrate certain embodiments of the invention and are not intended to limit the scope of the appended claims.

Flowable chemical vapor deposition (FCVD) films were deposited on medium resistivity (8-12 Ωcm) single crystal silicon wafer substrates and Si patterned wafers. In certain embodiments, the resulting silicon-containing film or coating is subjected to pre-deposition treatments such as, but not limited to, plasma treatment, thermal treatment, chemical treatment, ultraviolet light exposure, infrared exposure, electron beam exposure. and/or subjected to other treatments that affect one or more properties of the membrane.

Deposition in a modified FCVD chamber in an Applied Materials Precision 5000 system can be performed using either silane or TEOS process kits. The chamber has direct liquid injection (DLI) transport capability. A precursor is a liquid with a transport temperature that depends on the boiling point of the precursor. For initial flowable nitride film deposition, typical liquid precursor flow rate is 100-5000 mg/min, power density of in-situ plasma is 0.25-3.5 W/cm ² and pressure is 0. 0.75 to 12 Torr. To densify the as-deposited flowable film, the film is thermally annealed at 100-1000° C., preferably 300-400° C., in vacuum using a modified PECVD chamber, and/or Or UV cured. The thickness and refractive index (RI) at 632 nm were measured by SCI reflectometer or Woollam ellipsometer. Typical film thicknesses ranged from 10 to 2000 nm. Bonding properties and hydrogen content (Si—H, CH and NH) of silicon-based films were measured and analyzed by a Nicolet Transmission Fourier Transform Infrared Spectroscopy (FTIR) tool. All density measurements were made using X-ray reflectometry (XRR). X-ray photoelectron spectroscopy (XPS) analysis and secondary ion mass spectroscopy (SIMS) were performed to determine the elemental composition of the films. Flow and gap-fill effects in patterned wafers were observed by cross-sectional scanning electron microscopy (SEM) observation using a Hitachi S-4700 system with a resolution of 2.0 nm.

Fluid CVD deposition was performed according to the following conditions.

Example 1: Deposition conditions - 3000 W remote plasma source (RPS); 200 W in situ; 2 torr; 1500 sccm _NH3 ; 1500 mg/min tetravinylsilane (TVS). Referring to FIG. 1, the film shows voids after curing.

Example 2: Deposition conditions - 3000 W RPS; 200 W in situ; 2 torr; 1000 sccm _NH3 ; 1500 mg/min TVS. Referring to FIG. 2, less NH ₃ flow reduces film voids.

Example 3: Deposition conditions - 3000 W RPS; 0 W in situ; 2 torr; 1000 sccm _NH3 ; 1500 mg/min TVS. Referring to FIG. 3, it can be seen that turning off the in-situ plasma causes pinch-off at the top of the feature.

₂ torr; 1000 sccm _NH3 ; 1500 mg/min TVS; TVS + trisilylamine (TSA); 3000 W RPS; 200 W in situ; TVS + 900 sccm TSA. Referring to Table 1, it can be seen that adding TSA to the chamber does not increase the incorporation of N into the membrane. That activates the membrane with respect to environmental oxidation.

Additional note for Example 4: Chemical composition was determined by X-ray photoelectron spectroscopy (XPS). Some surface oxidation was observed in the TVS film. The bulk of the film had slight oxidation. Surface and bulk oxidation were very severe in the TVS+TSA film.

8 torr; 400 sccm _NH3 ; 2000 mg/min TVS; 200 sccm He; Although the deposited films exhibited flowability when using , after curing they exhibited visible porosity in the filled features. Compared to FIG. 2, these films appear to be significantly less dense in features.

While certain principles of the invention have been described above in conjunction with aspects or embodiments, it is clearly understood that this description is by way of example only and is not intended to limit the scope of the invention.

Claims (11)

A method for depositing a silicon-containing film in a flowable chemical vapor deposition process comprising:
placing a substrate with surface features in a reactor at one or more temperatures ranging from -20°C to about 100°C;
having the formula R _n SiR ¹ _4-n , wherein R is selected from linear or branched C ₂ -C ₆ alkenyl groups, linear or branched C ₂ -C ₆ alkynyl groups, and R ¹ is selected from hydrogen, methane and linear or branched C ₂ -C ₁₀ alkyl groups and n is a number selected from 1, 2, 3 and 4 in a reactor. introducing into;
providing a plasma source in the reactor and at least partially reacting the at least one compound to form a flowable liquid oligomer, the flowable liquid oligomer at least partially covering at least a portion of the surface features; A method comprising filling and wherein the plasma source includes both a remote plasma source and an in-situ plasma source working in combination. At least one of the remote plasma source and the in-situ plasma source is a nitrogen plasma, a plasma containing nitrogen and hydrogen, a plasma containing nitrogen and helium, a plasma containing nitrogen and argon, an ammonia plasma, a plasma containing ammonia and helium, ammonia and argon. 2. The method of claim 1, comprising a plasma source selected from the group consisting of a plasma containing A, a plasma containing ammonia and nitrogen, a NF3 plasma _, an organic amine plasma, and combinations thereof. at least one of the remote plasma source and the in-situ plasma source is a hydrocarbon plasma, a plasma containing hydrocarbons and helium, a plasma containing hydrocarbons and argon, a carbon dioxide plasma, a carbon monoxide plasma, a plasma containing hydrocarbons and hydrogen; 2. The method of claim 1, comprising a carbon source plasma selected from the group consisting of a plasma containing a hydrocarbon and nitrogen source, a plasma containing a hydrocarbon and an oxygen source, and combinations thereof. 2. The method of claim 1, wherein at least one of the remote plasma source and the in-situ plasma source is selected from the group consisting of hydrogen plasma, helium plasma, argon plasma, xenon plasma and combinations thereof. At least one of the remote plasma source and the in-situ plasma source is water (H ₂ O) plasma, oxygen plasma, ozone (O ₃ ) plasma, NO plasma, N ₂ O plasma, carbon monoxide (CO) plasma, carbon dioxide ( 2. The method of claim 1, comprising an oxygen-containing plasma source selected from the group consisting of _CO2 ) plasmas and combinations thereof. 2. The method of claim 1, further comprising treating the flowable liquid oligomer at one or more temperatures ranging from about 100°C to about 1000°C to cure the flowable liquid oligomer to form a cured film. Method. 2. The method of claim 1, wherein the reactor pressure is kept below 100 torr. 2. The method of claim 1, wherein the silicon-containing film is selected from the group consisting of films of silicon carbide, silicon nitride, silicon oxide, carbon-doped silicon nitride, carbon-doped silicon oxide, silicon oxynitride and carbon-doped silicon oxynitride. . at least one compound is

2. The method of claim 1, selected from the group consisting of: 10. The method of claim 9, wherein at least one compound comprises tetravinylsilane. The silicon-containing film has at least the following characteristics: i) a film tensile stress in the range of about 150 to about 190 MPa after UV curing; and ii) a density in the range of about 1.35 to about 2.10 g/cm ³ . A method according to any one of claims 1 to 10, comprising one.

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