Methods and related systems and apparatus for depositing gap-filling fluids

Abstract

Provided herein are methods and systems for manufacturing a structure including a substrate. The substrate includes a plurality of recesses and a plurality of lateral spaces. The recesses and lateral spaces are at least partially filled with a gap-filling fluid.

Description

Technical Field

[0001] The present disclosure relates generally to methods and systems suitable for forming electronic devices. More particularly, the present disclosure relates to methods and systems useful for depositing gap-fill fluids in trenches and lateral spaces by plasma-assisted deposition. Background Art

[0002] The scaling of semiconductor devices has led to significant improvements in the speed and density of integrated circuits. However, as the wiring pitch of large-scale integrated devices is miniaturized, void-free filling of high aspect ratio trenches (e.g., trenches with an aspect ratio of three or higher) becomes increasingly difficult due to limitations of existing deposition processes. Therefore, there is still a need for processes that effectively fill high aspect ratio features such as trenches on semiconductor substrates. There is still a need for processes that can also fill buried spaces below the substrate surface.

[0003] International Publication No. WO 2019 / 152055 discloses a gap filling method. However, the method does not disclose the filling of the buried layer with a gap filling fluid.

[0004] Any discussion introduced in this disclosure, including the discussion of problems and solutions set forth in this section, is introduced only for the purpose of providing context for the disclosure. Such discussion should not be construed as an admission that any or all information was known or otherwise constituted prior art at the time the present invention was made. Summary of the invention

[0005] Various embodiments of the present disclosure relate to gap filling methods, structures and devices formed using such methods, and apparatus for performing the methods and / or for forming the structures and / or devices. The manner in which various embodiments of the present disclosure address the shortcomings of existing methods and systems is discussed in more detail below.

[0006] Provided herein is a method for filling a gap, comprising: introducing a substrate having a gap in a reactor chamber, the gap comprising a recess and a lateral space extending substantially laterally from the recess; introducing a precursor into the reactor chamber; introducing a co-reactant into the reactor chamber; and introducing a plasma into the reactor chamber; whereby the precursor and the co-reactant react to form a gap-filling fluid, which at least partially fills the recess and the lateral space of the gap.

[0007] In some embodiments, the co-reactant comprises nitrogen and / or ammonia.

[0008] In some embodiments, the co-reactant comprises an inert gas.

[0009] In some embodiments, the inert gas is selected from He, Ne, Ar, and Kr.

[0010] In some embodiments, the inert gas is Ar.

[0011] In some embodiments, the precursor is a cyclosilazane precursor.

[0012] In some embodiments, the reactor chamber is at a pressure of at least 700 Pa to at most 1,500 Pa and at a temperature of at least 50°C to at most 150°C.

[0013] In some embodiments, the reactor chamber is at a pressure of at least 900 Pa to at most 1,200 Pa.

[0014] In some embodiments, the reactor chamber is at a temperature of at least 50°C to at most 75°C.

[0015] In some embodiments, the cyclosilazane precursor is selected from a cyclotrisilazane precursor, a cyclotetrasilazane precursor, and a cyclopentasilazane precursor.

[0016] In some embodiments, the cyclosilazane precursor has the formula:

[0017]

[0018] wherein any one of R1 to R9 is independently selected from hydrogen and C1 to C5 branched or straight chain alkyl, alkenyl, alkynyl and alkylamine.

[0019] In some embodiments, the precursor and co-reactant are introduced simultaneously.

[0020] In some embodiments, the introduction of the co-reactant is provided continuously, the precursor is provided in a plurality of precursor pulses, and the plasma is provided in a plurality of plasma pulses, wherein each precursor pulse and each plasma pulse is separated by a purge step.

[0021] In some embodiments, the cyclosilazane precursor consists entirely of N, C, H, and Si.

[0022] In some embodiments, the cyclosilazane precursor consists entirely of N, C, and Si.

[0023] In some embodiments, the cyclosilazane precursor does not contain any oxygen.

[0024] In some embodiments, the cyclosilazane precursor does not contain any halogens.

[0025] In some embodiments, no gases other than the cyclosilazane precursor, ammonia, and nitrogen are introduced into the reactor chamber during the entire process of introducing the precursors, co-reactants, and plasma.

[0026] In some embodiments, the substrate comprises a semiconductor.

[0027] In some embodiments, the method includes completely filling the plurality of recesses with a gap-filling fluid.

[0028] In some embodiments, the method includes completely filling the one or more lateral spaces with a gap-filling fluid.

[0029] In some embodiments, the method includes curing the gap-filling fluid.

[0030] In some embodiments, the curing step involves the use of direct plasma, and the method of filling the gap includes multiple cycles in which gap filling fluid deposition and plasma treatment steps are alternated.

[0031] In some embodiments, the curing step involves the use of an indirect plasma followed by filling the gap with a gap-filling fluid.

[0032] In some embodiments, the curing step involves the use of an inert gas plasma.

[0033] In some embodiments, the curing step involves the use of a micro-pulse plasma involving the sequential application of multiple plasma-on and plasma-off pulses.

[0034] In some embodiments, the curing step includes subjecting the substrate to a micropulse plasma, including sequential application of a plurality of micropulse cycles, a micropulse cycle including a plasma-on pulse and a plasma-off pulse.

[0035] In some embodiments, the micropulse plasma employs an inert gas as the plasma gas.

[0036] In some embodiments, the substrate is a 300 mm silicon wafer and a plasma gas flow rate of at least 5.0 slm is maintained during the micropulse plasma.

[0037] Also described herein is a structure comprising a semiconductor substrate provided with a gap comprising a recess and a lateral space extending laterally from the recess, wherein the recess and the lateral space are at least partially filled with a gap-filling fluid.

[0038] In some embodiments, the lateral space has a height of at least 1.0 nm to at most 40.0 nm, or at least 2.0 nm to at most 20.0 nm, or at least 3.0 nm to at most 18.0 nm, or at least 4.0 nm to at most 16.0 nm, or at least 5.0 nm to at most 15.0 nm, or at least 6.0 nm to at most 14.0 nm, or at least 7.0 nm to at most 13.0 nm, or at least 8.0 nm to at most 12.0 nm, or at least 9.0 nm to at most 11.0 nm, or about 10.0 nm.

[0039] In some embodiments, the gap-filling fluid extends in the lateral space for a distance of at least 1.0 nm to at most 100.0 nm, or at least 1.5 nm to at most 50.0 nm, or at least 2.0 nm to at most 25.0 nm, or at least 3.0 nm to at most 20.0 nm, or at most 4.0 nm to at most 18.0 nm, or at least 5.0 nm to at most 16.0 nm, or at least 6.0 nm to at most 14.0 nm, or at least 8.0 nm to at most 12.0 nm, or about 10.0 nm.

[0040] In some embodiments, the gap-fill fluid comprises a polysilazane oligomer.

[0041] In some embodiments, the polysilazane oligomer is branched.

[0042] In some embodiments, the polysilazane oligomer comprises a plurality of oligomeric species.

[0043] In some embodiments, the gap-filling fluid completely fills at least 90%, preferably at least 95%, more preferably at least 99%, and most preferably all of the recesses.

[0044] In some embodiments, the gap-filling fluid completely fills at least 90%, preferably at least 95%, more preferably at least 99%, and most preferably all of the lateral space.

[0045] In some embodiments, the gap-filling fluid is substantially free of voids.

[0046] In some embodiments, the gap-filling fluid extends a distance of at least 3 nm in one or more lateral spaces.

[0047] In some embodiments, the recess has a depth of at least 5 nm to at most 500 nm, or at least 10 nm to at most 250 nm, or at least 20 nm to at most 200 nm, or at least 50 nm to at most 150 nm, or at least 100 nm to at most 150 nm.

[0048] In some embodiments, the recess has a width of at least 10 nm to at most 10,000 nm, or at least 20 nm to at most 5,000 nm, or at least 40 nm to at most 2,500 nm, or at least 80 nm to at most 1,000 nm, or at least 100 nm to at most 500 nm, or at least 150 nm to at most 400 nm, or at least 200 nm to at most 300 nm.

[0049] In some embodiments, the recess has a length of at least 10 nm to at most 10,000 nm, or at least 20 nm to at most 5,000 nm, or at least 40 nm to at most 2,500 nm, or at least 80 nm to at most 1000 nm, or at least 100 nm to at most 500 nm, or at least 150 nm to at most 400 nm, or at least 200 nm to at most 300 nm.

[0050] In some embodiments, the lateral space is disposed in a source and / or drain region of a gate-all-around transistor, and wherein the gap-fill fluid serves as an interlayer dielectric.

[0051] In some embodiments, the gap-filling fluid is cured.

[0052] Also described are structures comprising gaps filled according to the methods as described herein.

[0053] Also described is a gate-all-around transistor that includes a gap-fill fluid as an interlayer dielectric. In some embodiments, the gap-fill fluid is cured.

[0054] Also described herein is a system configured to perform a method of filling a gap as described herein, and / or configured to form a structure including a filled gap as described herein.

[0055] Also described herein is a system comprising: one or more reaction chambers; a gas injection system fluidly coupled to at least one of the one or more reaction chambers; a first gas source for introducing a precursor and optionally a carrier gas into the reaction chamber; a second gas source for introducing a mixture of one or more other gases into the reaction chamber; an exhaust port; and a controller. The controller is configured to control the flow of gas into the gas injection system to perform the method of filling a gap as described herein.

[0056] According to still further examples of the present disclosure, a system is disclosed to perform a method as described herein and / or to form a structure, a device, or a part of any thereof.

[0057] According to yet further examples of the present disclosure, a controller is disclosed that is arranged to process instructions for executing a method and / or manufacturing a structure, a device or a portion thereof as described herein.

[0058] According to yet another example of the present disclosure, a data carrier having stored thereon computer-readable instructions for executing a method and / or manufacturing a structure, a device or a part thereof as described herein is disclosed.

[0059] These and other embodiments will become apparent to those skilled in the art from the following detailed description of certain embodiments taken in conjunction with the accompanying drawings.The present invention is not limited to any particular embodiment disclosed. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] A more complete understanding of embodiments of the present disclosure may be obtained by referring to the detailed description and claims when considered in conjunction with the following illustrative drawings.

[0061] Figure 1 A schematic diagram of a plasma enhanced atomic layer deposition (PEALD) apparatus suitable for depositing a structure according to at least one embodiment of the present disclosure and / or performing a method according to at least one embodiment of the present disclosure is shown.

[0062] Figure 2 A schematic diagram of a precursor supply system using a flow-pass system (FPS) useful in accordance with at least one embodiment of the present disclosure is illustrated.

[0063] Figure 3 is a scanning transmission electron microscope (STEM) micrograph of a test structure (100) comprising a channel (140), an unfilled lateral space (130), and a gap-filling fluid in the lateral space (131).

[0064] Figure 4 Further details of the filling capabilities of some embodiments of gap filling fluids for filling gaps according to at least some embodiments of methods described herein are shown.

[0065] Figure 5 It is illustrated how the top growth per cycle and the bottom growth per cycle are measured.

[0066] Figure 6 Indicates when to use N 2 and NH 3 Example of a single gap-filling fluid deposition cycle when used as a co-reactant.

[0067] Figure 7 An example of a single gap-fill fluid deposition cycle when using Ar as a co-reactant is illustrated.

[0068] Throughout the drawings, the following numbers and symbols are used: 100 - test structure; 110 - gap filling fluid; 120 - silicon oxide; 130 - lateral space; 135 - silicon nitride; 140 - channel; w t - channel width; h v -Height of lateral space; w v - Width of lateral space; h t - channel height; T t- the thickness of the gap filling fluid deposited on top of the sample; T b -The thickness of the gap filling fluid deposited in the bottom of the trench.

[0069] It should be understood that the elements in the figures are only illustrated for simplicity and clarity and are not necessarily drawn to scale. For example, the size of some elements in the figures may be exaggerated relative to other elements to help improve the understanding of the embodiments of the present disclosure illustrated. DETAILED DESCRIPTION

[0070] The descriptions of exemplary embodiments of methods, structures, devices, and systems provided below are merely exemplary and are intended for illustration purposes only; the following descriptions are not intended to limit the scope of the present disclosure or the claims. In addition, the recitation of multiple embodiments having stated features is not intended to exclude other embodiments having additional features or other embodiments incorporating different combinations of the stated features. For example, various embodiments are set forth as exemplary embodiments and may be recited in the dependent claims. Unless otherwise stated, the exemplary embodiments or their components may be combined or may be applied separately from each other.

[0071] In the present disclosure, depending on the context, "gas" may include materials that are gaseous at normal temperature and pressure (NTP), gasified solids and / or gasified liquids, and may be composed of a single gas or a mixture of gases. Gases other than process gases, i.e., gases that are not introduced through a gas distribution assembly, a multi-port injection system, other gas distribution equipment, etc., may be used, for example, to seal the reaction space, and may include sealing gases such as rare gases. As used herein, the terms "rare gas" and "inert gas" are used interchangeably. In some cases, the term "precursor" may refer to a compound that participates in a chemical reaction that produces another compound, and in particular refers to a compound that constitutes the membrane matrix or main skeleton of the membrane; the term "reactant" may be used interchangeably with the term precursor.

[0072] As used herein, the term "co-reactant" refers to a gas that reacts and / or interacts with a precursor to form a flowable gap filling layer as described herein. The co-reactant may activate precursor oligomerization. The co-reactant may be a catalyst. Although the co-reactant does interact with the precursor during the formation of the gap filling fluid, it is not necessary to introduce the co-reactant into the gap filling fluid formed. Possible co-reactants include He, Ar, N 2 , H 2 and NH 3 As used herein, alternative expressions for the term "co-reactant" may include "gas mixture", "one or more other gases", and "gas mixture comprising one or more other gases".

[0073] As used herein, the term "substrate" may refer to any one or more underlying materials that may be used to form a device, circuit, or film or on which a device, circuit, or film may be formed. The substrate may include a bulk material such as silicon (e.g., single crystal silicon), other Group IV materials such as germanium, or other semiconductor materials such as Group II-VI or Group III-V semiconductors, and may include one or more layers added above or below the bulk material.

[0074] In addition, in the present disclosure, any two numbers of a variable may constitute the working range of the variable, and any range indicated may include or exclude endpoints. In addition, any indicated variable values ​​(whether or not they are indicated with "about") may refer to exact values ​​or approximate values ​​and include equivalent values, and may refer to average values, medians, representative values, majority values, etc. In addition, in the present disclosure, in some embodiments, the terms "including", "consisting of" and "having" independently refer to "usually or broadly including", "including", "essentially consisting of" or "consisting of". In the present disclosure, in some embodiments, the meaning of any definition does not necessarily exclude common and customary meanings.

[0075] As used herein, the term "comprising" indicates that certain features are included, but it does not exclude the presence of other features as long as they do not render the claim unfeasible. In some embodiments, the term "comprising" includes "consisting of."

[0076] As used herein, the term "consisting of" indicates that other features are not present in the apparatus / method / product except the features following the phrase.

[0077] As used herein, the term "gap filling fluid", also referred to as "flowable gap fill", may refer to an oligomer that is liquid under the conditions of deposition on a substrate and has the ability to cross-link and become a solid film.

[0078] In the present disclosure, the term "filling ability" refers to the ability to fill a gap substantially free of voids (e.g., voids with a size of about 5 nm or more in diameter) and seams (e.g., seams with a length of about 5 nm or more), wherein seam-free / void-free bottom-up growth of the layer is observed. The growth at the bottom of the gap may be at least about 1.5 times faster than the growth on the sidewalls of the gap and on the top surface with the gap. Films with filling ability are also referred to as "flowable films" or "viscous films." The flowable or viscous behavior of the film often manifests itself as a concave surface at the bottom of the channel.

[0079] In the present disclosure, the recess between adjacent protrusion structures and any other recess pattern may be referred to as a "channel". That is, a channel may refer to any recess pattern comprising a hole / through hole. In some embodiments, the channel may have a width of about 20nm to about 100nm, typically about 30nm to about 50nm. When the channel has a length substantially the same as its width, it may be referred to as a hole or through hole. The hole or through hole typically has a width of about 20nm to about 100nm. In some embodiments, the channel may have a depth of about 30nm to about 100nm, typically about 40nm to about 60nm. In some embodiments, the channel has an aspect ratio of about 2 to about 10, typically about 2 to about 5. The size of the channel may vary with process conditions, film composition, intended application, etc.

[0080] As used herein, the term "lateral space" may refer to an opening in a semiconductor substrate that is fluidly connected to its surface and for which there is no straight line path to the wafer surface perpendicular to the wafer plane. In other words, lateral space refers to the subsurface space in a semiconductor wafer. In other words, lateral space is an opening that is covered by the substrate but not completely enclosed. For example, Figure 3 A test structure is shown that includes a lateral space (130) filled with a gap-filling fluid. Figure 3 The channel (140) shown in FIG. 1 is not a lateral space because it is not covered by the substrate surface. The lateral space can be filled with a gap-filling fluid according to the methods described herein. Alternatively, the "lateral space" can also be named as a "buried lateral layer", "buried layer", "buried space", "buried lateral space", "capped space" or similar terms.

[0081] As used herein, the term "height" may refer to the extent of a feature in a plane perpendicular to the surface of a substrate containing the feature in question.

[0082] As used herein, the term "width" may refer to the extent of a feature in a direction in a plane parallel to the surface of the substrate containing the feature in question.

[0083] As used herein, the term "length" may refer to the extent of a feature in a direction in a plane parallel to the surface of the substrate containing the feature in question. The directions in which "width" and "length" are measured are perpendicular to each other. It should be understood that all dimensions, including the length, width, and height of a structure, can be measured using conventional techniques such as scanning tunneling electron microscopy (STEM).

[0084] As used herein, the term "lateral" may refer to features or directions that extend in the plane of the substrate containing the feature in question.

[0085] As used herein, the expression “lateral direction” may refer to a direction extending in the direction of the plane of the wafer.

[0086] An object of the present invention is to provide a method of forming a film comprising silicon, nitrogen, and optionally carbon having a filling capacity. Films produced by such a method and structures comprising such films are also provided. In some embodiments, the film may be formed by impinging, for example, N in a chamber filled with a volatile precursor. 2 and / or NH 3 The filling capability is achieved by forming a viscous material in the gas phase by plasma, wherein the volatile precursor can be polymerized within certain parameter ranges. Optionally, in addition to N 2 and / or NH 3 In addition, the gas phase also contains other gases, such as inert gases or H 2 . The parameters may include, for example, the partial pressure of the precursor during the plasma strike and the wafer temperature. As used herein, polymerization may include the formation of longer molecules and does not necessarily include carbon-carbon bonds. In practice, polymerization may include, for example, the formation of Si-Si bonds, Si-C bonds, and / or Si-N bonds. The viscous material forms a viscous phase on the bottom of the substrate and is able to flow in the channel on the substrate. Suitable substrates include silicon wafers. Thus, the viscous material seamlessly fills the channel in a bottom-up manner.

[0087] When volatile precursors such as alkylsilanes are polymerized by plasma and deposited on the surface of a substrate, a flowable film can be temporarily obtained, wherein the gaseous precursor (e.g., monomer) is activated or fragmented by the energy provided by the plasma gas discharge to initiate polymerization, and when the resulting material is deposited on the surface of the substrate, the material exhibits temporary flowable behavior. According to an exemplary embodiment, when the deposition step is completed, the flowable film is no longer flowable, but solidified, and therefore does not require a separate solidification process. In other embodiments, the flowable film is densified and / or solidified after deposition.

[0088] The gap filling fluid deposited herein may contain hydrogen, but it is not required to contain hydrogen. In some embodiments, the gap filling fluid deposited herein contains between 0.1% and 10.0%, or between 0.2% and 5.0%, or between 0.5% and 2.5%, or between 1.0% and 2.0% hydrogen, wherein all percentages are given in atomic percentages. Thus, when, for example, the gap filling fluid is referred to as SiCN, the term "SiCN" is intended to encompass SiCN:H, i.e., SiCN containing hydrogen, e.g., containing up to 10 atomic percent hydrogen.

[0089] In some embodiments, the volatile precursor is polymerized within a certain parameter range, which is mainly defined by the precursor partial pressure during plasma strike, the wafer temperature, and the total pressure in the reaction chamber. In order to adjust the "precursor partial pressure", an indirect process knob (dilution gas flow) can be used to control the precursor partial pressure. Controlling the fluidity of the deposited film may not require the absolute number of the precursor partial pressure, but the ratio of the flow rate of the precursor to the flow rate of the remaining gases and the total pressure in the reaction space at the reference temperature can be used as the actual control parameters.

[0090] The gap in the substrate may refer to a patterned recess or channel in the substrate. Accordingly, an exemplary method of filling a patterned recess or channel on a substrate includes providing a substrate including a recess / channel in a reaction space, providing a precursor to the reaction space to fill the recess with the precursor, and providing plasma to form a viscous phase of the precursor in the recess, wherein the viscous phase of the precursor flows and deposits or forms a deposited material in a bottom of the recess relative to the sidewalls and / or a top of the substrate away from the recess.

[0091] The method disclosed herein is particularly suitable for filling gaps comprising lateral spaces connected to recessed fluids. Therefore, a method for manufacturing a structure is provided herein. The structure comprises a substrate, which in turn comprises a plurality of recesses and a plurality of lateral spaces. The substrate preferably comprises a semiconductor. Suitable substrates include semiconductor wafers, such as silicon wafers. The plurality of recesses are connected to one or more lateral space fluids. The method comprises the step of at least partially filling the plurality of recesses and the one or more lateral spaces with a gap filling fluid.

[0092] Alternatively or additionally, methods for filling a gap by means of a gap filling fluid are provided herein. These methods include introducing a substrate into a reactor chamber. The substrate is provided with a gap. The gap includes a recess and a lateral space extending substantially laterally from the recess. After the substrate has been introduced into the chamber, the method includes introducing a precursor into the reactor chamber and introducing a co-reactant into the reactor chamber. The method also includes generating a plasma in the reactor chamber. When the plasma is applied, the precursor and the co-reactant react to form a gap filling fluid, which at least partially fills the recess and the lateral space of the gap.

[0093] Therefore, gaps including lateral spaces in the substrate can be effectively filled.

[0094] In some embodiments, the methods of the present disclosure include the use of radio frequency (RF) plasma and utilize pulsed precursor flow and pulsed RF plasma. Preferably, the precursor pulses and plasma pulses are separated by purge gas pulses. Preferably, a co-reactant is used as the purge gas. In such embodiments, desirable aspects regarding the fluidity of the deposited film include: 1) having a sufficiently high partial pressure during the entire RF on period to allow polymerization to proceed; 2) having enough energy to activate the reaction during the not too long RF period (defined by the RF on period and the RF power); and 3) the temperature and pressure of the polymerization / chain growth are set above the melting point of the flowable phase and below the boiling point of the flowable phase.

[0095] In some embodiments, the process of filling a gap with a gap filling fluid comprises the following sub-steps. In step a., a substrate comprising a gap is positioned in a reactor chamber. The gap comprises a recess connected to one or more lateral space fluids. Step b. comprises introducing a precursor into the reactor. Step c. comprises introducing a gas mixture comprising one or more other gases into the reactor. The gas mixture comprising one or more other gases comprises a co-reactant. In some embodiments, the gas mixture comprising one or more other gases consists of a co-reactant. Step d. comprises maintaining a plasma in the reactor. Step e. comprises reacting the precursor on the one hand with nitrogen and / or ammonia on the other hand to form a gap filling fluid on the substrate. Step f. comprises allowing the gap filling fluid to at least partially fill the multiple recesses and the one or more lateral spaces.

[0096] In some embodiments, steps b and c are performed simultaneously.

[0097] In some embodiments, step b precedes step c, and step c precedes step d.

[0098] In some embodiments, step c precedes step b, and step b precedes step d.

[0099] In some embodiments, all of steps b, c, and d are performed simultaneously.

[0100] It will be appreciated that when steps b, c and / or d are performed in a sequential manner, ie cyclically, a small amount of material may be deposited per cycle and the sequence of steps may be repeated until a layer having a desired thickness is obtained.

[0101] In some embodiments, the process is performed cyclically and steps b and d are separated by a purge gas pulse.

[0102] In some embodiments, neither the precursor nor the co-reactant contains any chalcogens or halogens. Preferably, neither the precursor nor the co-reactant contains oxygen or chlorine.

[0103] In some embodiments, the method of the present disclosure involves intermittently providing a precursor to the reaction space and continuously applying a plasma. In some embodiments, the method of the present disclosure involves intermittently providing a precursor to the reaction space and intermittently applying a plasma. The latter embodiment is therefore characterized in that a precursor pulse and a plasma pulse are sequentially applied to the reaction space. Preferably, the precursor pulse and the plasma pulse are separated by a purge gas pulse.

[0104] In some embodiments, the methods of the present disclosure involve continuously providing precursors to the reaction space throughout the deposition step and continuously or cyclically applying plasma, for example, by applying RF power. The plasma can be continuous or pulsed, and it can be direct or remote.

[0105] In a preferred mode of operation, the flowable film is deposited by employing alternating precursor and plasma pulses.

[0106] In some embodiments, a pulsed plasma, such as a pulsed RF plasma, is applied. In some embodiments, the period of RF power application (i.e., the period during which the reactants in the reactor are exposed to the plasma) is in the range of at least 0.7 seconds to at most 2.0 seconds, such as at least 0.7 seconds to at most 1.5 seconds.

[0107] In some embodiments, the plasma exposure time is adjusted by changing the distance between the upper and lower electrodes. In fact, by increasing this distance, when the flow rate of the precursor entering the reaction space is kept constant, the retention time of the precursor in the reaction space between the upper and lower electrodes will be extended. In some embodiments, the distance between the upper and lower electrodes is at least 5.0 mm to at most mm, or at least 10.0 mm to at most 25.0 mm, or at least 15.0 mm to at most 20.0 mm.

[0108] In some embodiments, the plasma is an RF plasma. In some embodiments, the RF power is provided at a frequency of 13.56 MHz. In some embodiments, the RF power provided for flowable film deposition is at least 50 W to at most 1000 W, or at least 100 W to at most 900 W, or at least 200 W to at most 800 W, or at least 300 W to at most 700 W, or at least 400 W to at most 600 W, or at least 500 W to at most 550 W. It should be understood that these powers are provided for the special case of 300 mm wafers. They can be easily converted to units of W / cm 2 To obtain equivalent RF power values ​​for different wafer sizes.

[0109] In a preferred embodiment, the method of the present disclosure involves providing a precursor in a pulse and providing RF power in another pulse, wherein the two pulses do not overlap. Preferably, the precursor pulse and the plasma pulse are separated by a purge gas pulse. Therefore, in some embodiments, the method of filling the gap includes a plurality of deposition cycles, wherein the deposition cycle includes alternating pulses in which a precursor is provided and pulses in which RF power is provided to generate a plasma. Preferably, these precursor pulses and plasma pulses are separated by purge pulses in which a purge gas is flowed. In the following paragraphs, process conditions for a reactor chamber volume of 1 liter and a 300 mm wafer are given. The technician will understand that these values ​​can be easily extended to other reactor chamber volumes and wafer sizes.

[0110] In some embodiments, the method of filling the gap comprises at least 10 to at most 300 deposition cycles, or at least 20 to at most 200 deposition cycles, or at least 50 to at most 150 deposition cycles, or at least 75 to at most 125 deposition cycles, for example, 100 deposition cycles. 3 As a co-reactant, the method of filling the gap preferably includes at least 10 to at most 125 deposition cycles, or at least 25 to at most 100 deposition cycles, or at least 50 to at most 75 deposition cycles. When Ar is used as a co-reactant, the method of filling the gap preferably includes at least 25 to at most 300 deposition cycles, or at least 50 to at most 250 deposition cycles, or at least 100 to at most 200 deposition cycles, for example, 150 deposition cycles.

[0111] In some embodiments, the co-reactant is supplied to the reactor chamber as a carrier gas, i.e., as a gas to entrain the precursor, and / or as an additional gas. In some embodiments, the carrier gas is provided at a flow rate of at least 0.2 to at most 2.0 slpm, or at least 0.3 to at most 1.5 slpm, or at least 0.4 to at most 1.0 slpm, or at least 0.5 to at most 0.7 slpm. In some embodiments, the co-reactant is NH 3 and / or N 2 Preferably, N 2 As carrier gas. 2 The carrier gas is preferably provided at a flow rate of at least 0.2 to at most 2.0 slpm, or at least 0.3 to at most 1.5 slpm, or at least 0.4 to at most 1.0 slpm, or at least 0.5 to at most 0.7 slpm. In some embodiments, the co-reactant is composed of an inert gas (preferably Ar), and the carrier gas is provided at a flow rate of at least 0.2 slpm to at most 2.0 slpm, or at least 0.3 slpm to at most 1.5 slpm, or at least 0.4 slpm to at most 1.0 slpm, or at least 0.6 slpm to at most 0.8 slpm.

[0112] In some embodiments, in addition to N used as a carrier gas, 2 In addition, additional N 2 In some embodiments, this additional N 2 The flow rate is at least 0.1 slpm to at most 2.0 slpm, or at least 0.2 slpm to at most 1.5 slpm, or at least 0.3 slpm to at most 1.0 slpm, or at least 0.4 slpm to at most 0.6 slpm.

[0113] Preferably, NH 3 In some embodiments, NH 3 Provided at a flow rate of at least 0.1 slpm to 0.5 slpm, or at least 0.15 slpm to at most 0.3 slpm.

[0114] In some embodiments, the pressure in the reactor chamber is at least 700 Pa to at most 2000 Pa, or at least 1000 Pa to at most 1800 Pa, or at least 1300 Pa to at most 1500 Pa. 3 / N 2 This pressure range applies both when an inert gas such as Ar is used as a carrier gas and when an inert gas such as Ar is used as a carrier gas.

[0115] In some embodiments, the plasma is an RF plasma. In some embodiments, the RF power used is at least 50 W to at most 1000 W, or at least 75 W to at most 500 W, or at least 100 W to at most 300 W, or at least 150 W to at most 200 W. When using NH 3 and / or N 2 When Ar is used as a co-reactant, the RF power is at least 200 W to at most 800 W, or at least 250 W to at most 700 W, or at least 300 W to at most 600 W, or at least 400 W to at most 500 W. When Ar is used as a co-reactant, the RF power is preferably at least 50 W to at most 200 W, or at least 75 W to at most 150 W, or at least 100 W to at most 125 W.

[0116] In some embodiments, the distance between electrodes used to generate the RF plasma is at least 5 mm to at most 20 mm, or at least 7 mm to at most 15 mm.

[0117] In some embodiments, a deposition cycle consists of a continuously repeated sequence of precursor pulse, precursor purge, plasma pulse, and plasma post-purge.

[0118] In some embodiments, the duration of the precursor pulse, i.e., the precursor feed time, is at least 0.25 s to at most 4.0 s, or at least 0.5 s to at most 2.0 s, or at least 1.0 s to at most 1.5 s. When an inert gas Ar is used as a co-reactant, the precursor feed time is preferably at least 0.5 s to at most 1.5 s, such as 1.0 s. When NH 3 and / or N 2 When used as a co-reactant, the precursor feed time is preferably at least 0.25 s to at most 4.0 s, or at least 0.5 s to at most 2.0 s, or at least 1.0 s to at most 1.5 s.

[0119] In some embodiments, the duration of the purge step directly following the precursor pulse, i.e., the precursor purge time, is at least 0.025 s to at most 2.0 s, or at least 0.05 s to at most 0.8 s, or at least 0.1 s to at most 0.4 s, or at least 0.2 s to at most 0.3 s. 2 and / or NH 3 This time setting applies both when using as a co-reactant and when using an inert gas such as Ar as a co-reactant.

[0120] In some embodiments, the RF on time, i.e., the duration of the plasma pulse, which is the time during which RF power is provided during the plasma pulse, is at least 0.5 s to at most 4.0 s, or at least 0.7 s to at most 3.0 s, or at least 1.0 s to at most 2.0 s, or at least 1.25 s to at most 1.75 s, or about 1.5 s. 2 and / or NH 3 When used as a co-reactant, the duration of the plasma pulse is preferably at least 0.75 to at most 3.0 s, or at least 1.0 to at most 2.0 s.

[0121] In some embodiments, the plasma post-purge time, ie, the duration of the purge performed after applying a plasma pulse, is at least 0.5 s to at most 2.0 s, or at least 0.75 to at most 1.5 s, or at least 0.9 to at most 1.1 s, for example 1.0 s.

[0122] In some embodiments, during a deposition cycle, the substrate rests on a susceptor in a reactor chamber and the susceptor temperature is at least 50°C to at most 100°C, or at least 60°C to at most 80°C, or at least 65°C to at most 75°C.

[0123] The gap filling fluid provided currently solidifies spontaneously by compounding after deposition. Therefore, no separate cooling step is required. However, in order to improve one or more favorable film properties such as shrinkage resistance at high temperature and low wet etch rate, a curing step such as a plasma curing step may be advantageous.

[0124] Accordingly, in some embodiments, the method includes a step of curing the gap filling fluid. This step increases the thermal resistance of the gap filling fluid. In other words, it increases the resistance of the gap filling fluid to deformation and / or mass loss at high temperatures. Additionally or alternatively, the curing step may solidify the gap filling fluid.

[0125] In some embodiments, the method further comprises exposing the substrate to a plasma as a post-deposition treatment after the deposition of the film having filling capability is completed. Additionally or alternatively, a periodic plasma may be applied. Additionally or alternatively, H 2 Plasma, He plasma, H 2 / He plasma, Ar plasma, Ar / H 2 Plasma or Ar / He / H 2 Plasma treatment. Optionally, the gap filling fluid is annealed after depositing the gap filling fluid and before the curing step. Suitable annealing times include at least 10.0 seconds to at most 10.0 minutes, such as at least 20.0 seconds to at most 5.0 minutes, such as at least 40.0 seconds to at most 2.5 minutes. Suitably, the annealing is performed in a process comprising one or more selected from N 2 , He, Ar and H 2 Preferably, the annealing is carried out in a gas mixture containing N 2 In some embodiments, the annealing is performed at a temperature of at least 200°C, or at a temperature of at least 250°C, or at a temperature of at least 300°C, or at a temperature of at least 350°C, or at a temperature of at least 400°C, or at a temperature of at least 450°C.

[0126] Alternatively or additionally, solidification may occur upon contact with the substrate, wherein the reaction is thermally activated. With respect to precursor gas ratios, high precursor gas ratios are preferred for fluidity because at low precursor partial pressures, although polymerization may occur, the supply is too low to form polymer chains long enough to flow, i.e. long enough to have liquid-like behavior.

[0127] In some embodiments, the cured gap filling fluid is a SiCN layer. The SiCN layer may be substantially composed of silicon, carbon, nitrogen, and optionally hydrogen. In some embodiments, the SiCN layer comprises more than 5 wt % N, such as at least 8.0 wt % N to at most 20.0 wt % N, or at least 10.0 wt % N to at most 18.0 wt % N, or at least 12.0 wt % N to at most 15.0 wt % N. These compositions provided herein are measured by Rutherford backscattering spectroscopy (RBS).

[0128] In some embodiments, the SiCN layer is oxidized after the SiCN layer is deposited, for example, 2In plasma.

[0129] In some embodiments, the gap filling fluid is SiCN and after deposition, for example, in O 2 The gap filling fluid is oxidized in the plasma. Optionally, the oxidation step is performed after the gap filling fluid has solidified. This is to obtain SiO 2 Advantageous way of layer.

[0130] In some embodiments, the curing step involves the use of a cyclic plasma treatment. When a cyclic plasma treatment is performed, deposition cycles and plasma curing cycles are performed alternately. The term "plasma curing cycle" refers to a plasma treatment step in which the gap filling fluid is cured. In some embodiments, the cyclic plasma treatment involves the use of a gas mixture that does not contain nitrogen.

[0131] In some embodiments, the cyclic plasma treatment uses direct plasma. In such an embodiment, the process of filling the gap preferably includes multiple cycles, that is, wherein the gap filling fluid deposition and plasma treatment steps are alternately performed. Such a cyclic process has the advantage that a larger portion of the gap filling fluid is solidified: the direct plasma generally has a penetration depth of about 2 to 7 nm, so that the direct plasma treatment after deposition will only solidify the top layer of the gap filling fluid. In contrast, the alternating deposition and plasma steps allow the solidification of a larger portion of the gap filling fluid or even the entire gap filling fluid. It should be noted that in the case where the lateral space extends a large lateral distance, such as a lateral distance of 10.0 μm or greater, the entire solidification of the gap filling fluid by the cyclic plasma treatment does not occur. This is not necessarily a problem, because in many applications, the potential unsolidified portion of the gap filling fluid is encapsulated by the solidified gap filling fluid in the walls of the recess and the lateral space. In some embodiments, the direct plasma is a He plasma applied at a pressure of 600.0 Pa for 20.0 s. When used to process the gap filling fluid on a 300 mm wafer, a plasma power of 200 W is suitable.

[0132] In certain embodiments, the curing step involves the use of remote plasma. The free radicals produced by the remote plasma have a penetration depth significantly higher than that provided by the direct plasma, for example, significantly higher than the size of the gap filled by means of the currently provided method. Therefore, a remote plasma treatment can be advantageously applied after all gap-filling fluids have been deposited. Nevertheless, remote plasma curing can also be applied cyclically with alternating plasma curing and gap-filling fluid deposition steps, similar to the operation with direct plasma. The large penetration depth advantage of remote plasma is that they allow effective curing of gap-filling fluids in the lateral space. In certain embodiments, the plasma gas adopted in the remote plasma comprises an inert gas, for example, an inert gas selected from He and Ar.

[0133] In some embodiments, cyclic plasma treatment involves the use of Ar and / or He as plasma gases. In some embodiments, cyclic plasma curing is used with a flowable gap-fill fluid derived from a silylamine precursor, such as a silylamine precursor selected from Ar, N 2 Silylamine precursors used with a co-reactant of He. These gap filling fluids have excellent properties.

[0134] In some embodiments, the curing step involves the use of a micropulse plasma. Micropulse plasma is a plasma process that includes the application of multiple on-off micropulses in rapid succession. In other words, in some embodiments, micropulse plasma includes subjecting the substrate to a micropulse plasma that includes multiple micropulse cycles, one micropulse cycle including a plasma on pulse and a plasma off pulse.

[0135] In some embodiments, the method described in the present disclosure comprises a plurality of alternating cycles, one cycle comprising a gap filling fluid deposition step and a curing step, wherein the curing step comprises subjecting the substrate to a direct plasma. Suitably, the direct plasma is an inert gas plasma. In other words, and in some embodiments, the direct plasma employs an inert gas such as Ar as a plasma gas. In some embodiments, the curing step comprises subjecting the substrate to a micropulse plasma, the micropulse plasma comprising a plurality of micropulse cycles, one micropulse cycle comprising a plasma on pulse and a plasma off pulse.

[0136] For example, the on micropulse in the micropulse plasma may last from at least 1.0 μs to at most 1.0 s, or from at least 2.0 μs to at most 0.50 s, or from at least 5.0 μs to at most 250 ms, or from at least 10.0 μs to at most 100.0 ms, or from at least 25.0 μs to at most 50.0 ms, or from at least 50.0 μs to at most 25.0 ms, or from at least 100.0 μs to at most 10.0 ms, or from at least 250.0 μs to at most 5.0 ms, or from at least 0.50 ms to at most 2.5 ms. For example, the closed micropulse in the micropulse plasma can last at least 1.0 μs to at most 2.0 s, or at least 2.0 μs to at most 1.0 s, or at least 5.0 μs to at most 500 ms, or at least 10.0 μs to at most 250.0 ms, or at least 25.0 μs to at most 100.0 ms, or at least 50.0 μs to at most 50.0 ms, or at least 100.0 μs to at most 25.0 ms, or at least 200.0 μs to at most 10.0 ms, or at least 500.0 μs to at most 5.0 ms, or at least 1.0 ms to at most 2.0 ms. The micropulse plasma can be used cyclically and / or as a post-deposition treatment. In other words, the process of filling the gap can have alternating cycles of gap filling fluid deposition and micropulse plasma. Additionally or alternatively, the micropulse plasma can be applied as a post-deposition treatment after all of the gap filling fluid has been deposited.

[0137] Preferably, the micropulse plasma is applied together with a plasma gas flow rate above a predetermined threshold. The combination of micropulse plasma and these high flows will minimize the redeposition of volatile byproducts released during the plasma-induced crosslinking of the deposited gap-filling fluid. In some embodiments, the flow rate of the plasma gas during the micropulse plasma treatment is at least 5.0 slm (standard liters per minute), preferably at least 10.0 slm. The technician will understand that this flow rate depends on the reactor chamber volume and the substrate size, and the values ​​provided here for a 300 mm wafer and a 1 liter reactor chamber volume can be easily transferred to other substrate sizes and / or reactor volumes. Preferably, an inert gas is used as the plasma gas during the micropulse plasma treatment. In some embodiments, the inert gas is selected from He and Ar.

[0138] In some embodiments, the method includes completely filling the plurality of recesses with a gap-filling fluid.

[0139] In some embodiments, the method includes completely filling the one or more lateral spaces with a gap-filling fluid.

[0140] In some embodiments, the method includes filling the plurality of recesses and the one or more lateral spaces with a gap filling fluid without forming voids. In other words, in some embodiments, deposition according to the method of the present disclosure is continued until the plurality of recesses and the one or more lateral spaces are completely filled with a film having a filling capability, and substantially no voids are formed in the filled recesses. The presence of voids can be observed by studying the formed film in a scanning transmission electron microscope.

[0141] In some embodiments, the co-reactant comprises nitrogen and / or ammonia. These one or more other gases are generally referred to as co-reactants.

[0142] In some embodiments, all gases supplied to the reaction space in any one of steps b to f are: precursor; optional carrier such as N 2 , Ar and / or He; and an optional plasma ignition gas, which may be or may include Ar, He, N 2 and / or H 2 .

[0143] In some embodiments, throughout steps a to f, no gas is introduced into the reactor except the precursor, ammonia, and nitrogen.

[0144] In some embodiments, the co-reactant is Ar, He, H 2 Or any combination thereof. In some embodiments, the co-reactant comprises one or more gases that do not contain any nitrogen. Such co-reactants produce particularly good results in combination with a precursor selected from trisilylamine, dichlorosilane, trichlorosilane, and silylamine.

[0145] The silylamine precursor is particularly suitable for use with a plasma containing an aqueous solution selected from Ar, N 2 In some embodiments, the cyclic plasma treatment involves the use of a gas mixture that does not contain nitrogen. In some embodiments, the cyclic plasma treatment involves the use of an inert gas. In some embodiments, the cyclic plasma treatment involves the use of Ar and / or He.

[0146] In some embodiments, the precursor is selected from silazanes, cyclosilazanes, and silylamines. In some embodiments, the precursor is selected from bis(diethylamino)silane, bisdimethylaminosilane, hexylethylaminosilane, tetraethylaminosilane, tert-butylaminosilane, bis-tert-butylaminosilane, bisdimethylaminodimethylaminosilane, heptamethylsilazane, trimethylsilyldiethylamine, trimethylsyledimethlamine, trimethyltoribinylcycletrisilazane, trimethylhydroxylamine, bisdimethylaminomethylsilane, and dimethylsilyldimethylamine. These precursors are particularly suitable for use with plasmas selected from Ar, N 2 In addition, the gap-filling fluid resulting from the deposition involving the use of these precursors and co-reactants is preferably subjected to a curing step as described elsewhere herein.

[0147] Preferably, the precursor is a cyclosilazane precursor. A gap-filling layer using a cyclosilazane precursor provides a layer with particularly good lateral flow, ie particularly good flow in the lateral space.

[0148] In some embodiments, the cyclosilazane precursor does not contain any oxygen.

[0149] In some embodiments, the cyclosilazane precursor does not contain any halogens.

[0150] In some embodiments, the cyclosilazane precursor is selected from a cyclotrisilazane precursor, a cyclotetrasilazane precursor, and a cyclopentasilazane precursor.

[0151] In some embodiments, the cyclosilazane precursor consists entirely of N, C, H, and Si. In some embodiments, the cyclosilazane precursor consists entirely of N, C, and Si.

[0152] In some embodiments, the cyclosilazane precursor has the structure of formula (i):

[0153]

[0154] Preferably, any one of R1 to R9 is independently selected from hydrogen and C1 to C5 branched or straight chain alkyl, alkenyl, alkynyl and alkylamine.

[0155] In some embodiments, the cyclosilazane precursor has the structure of formula (ii):

[0156]

[0157] In some embodiments, the precursor comprises trisilylamine (TSA). Such precursors are particularly suitable for use with a plasma selected from N 2 NH 3 Preferably, the one or more other gases include 1) N 2 and NH 3 any one of and 2) any one of Ar and He.

[0158] In some embodiments, the precursor comprises a silylamine. For example, a suitable precursor is tetramethyldisilazane.

[0159] The silylamine precursor may be particularly suitable for use with a 2 Used with He co-reactants.

[0160] The present invention is not bound by theory or any particular mode of operation, it is believed that the deposited material ideally remains viscous or liquid throughout the deposition process and should not easily solidify or evaporate. It is also believed that under the desired reaction conditions, the vapor pressure of the liquid phase, rather than the vapor pressure of the precursor, should be lower than the total reactor pressure. Therefore, it is believed that the reactor temperature and pressure should be maintained under conditions where the flowable reaction product exists as a liquid and the precursor exists as a gas.

[0161] In some embodiments, all steps b to f are performed at a pressure of at least 500 Pa, preferably at a pressure of at least 700 Pa. More preferably, all steps b to f are performed at a pressure of at least 900 Pa. This will enhance the gap-filling properties of the gap-filling fluid provided by the present disclosure.

[0162] In some embodiments, all steps b to f are performed at a temperature of at least -50°C to at most 200°C, preferably at a temperature of at least 50°C to at most 150°C. More preferably, all steps b to f are performed at a temperature of at least 50°C to at most 75°C. This will enhance the gap filling properties of the gap filling fluid provided by the present disclosure.

[0163] In some embodiments, all steps b to f are performed at a pressure of at least 500 Pa to at most 10,000 Pa and at a temperature of at least -50°C to at most 200°C. In some embodiments, all steps b to f are performed at a pressure of at least 700 Pa and at a temperature of at least 50°C to at most 150°C. Preferably, all steps b to f are performed at a pressure of at least 900 Pa, and all steps b to f are performed at a temperature of at least 50°C to at most 75°C. This particular combination of temperature and pressure will particularly enhance the gap filling properties of the gap filling fluid provided by the present disclosure.

[0164] In some embodiments, the substrate comprises a semiconductor. In some embodiments, the semiconductor comprises silicon.

[0165] Also provided herein is a structure comprising a semiconductor substrate, the semiconductor substrate comprising a plurality of recesses, the plurality of recesses being fluidly connected to one or more lateral spaces, and the plurality of recesses and the one or more lateral spaces being at least partially filled with a gap-filling fluid.

[0166] In some embodiments, the gap-filling fluid completely fills at least 90%, preferably at least 95%, more preferably at least 99%, and most preferably all of the plurality of recesses.

[0167] In some embodiments, the gap-filling fluid completely fills at least 90%, preferably at least 95%, more preferably at least 99%, and most preferably all of the lateral spaces. In other words, the gap-filling fluid preferably fills all of each lateral space to be filled with the gap-filling fluid.

[0168] In some embodiments, the gap-filling fluid is substantially free of voids.

[0169] In some embodiments, the lateral space has a height of at least 1.0 nm to at most 40.0 nm, or at least 2.0 nm to at most 20.0 nm, or at least 3.0 nm to at most 18.0 nm, or at least 4.0 nm to at most 16.0 nm, or at least 5.0 nm to at most 15.0 nm, or at least 6.0 nm to at most 14.0 nm, or at least 7.0 nm to at most 13.0 nm, or at least 8.0 nm to at most 12.0 nm, or at least 9.0 nm to at most 11.0 nm, or about 10.0 nm.

[0170] In some embodiments, the gap-filling fluid extends in the lateral space for a distance of at least 1.0 nm to at most 200.0 nm, or at least 1.5 nm to at most 150.0 nm, or at least 2.0 nm to at most 100.0 nm, or at least 2.5 nm to at most 50.0 nm, or at least 3.0 nm to at most 25.0 nm, or at least 4.0 nm to at most 20.0 nm, or at least 5.0 nm to at most 18.0 nm, or at least 6.0 nm to at most 16.0 nm, or at least 7.0 nm to at most 14.0 nm, or at least 8.0 nm to at most 12.0 nm, or about 10.0 nm.

[0171] In some embodiments, the gap-filling fluid extends in the lateral space for a distance of at least 3 nm, or at least 5.0 nm, or at least 10.0 nm, or at least 25 nm, or at least 50 nm, or at least 100 nm, or at least 250 nm, or at least 500 nm, or at least 1 μm.

[0172] In some embodiments, the recess has a depth of at least 5 nm to at most 500 nm, or at least 10 nm to at most 250 nm, or at least 20 nm to at most 200 nm, or at least 50 nm to at most 150 nm, or at least 100 nm to at most 150 nm.

[0173] In some embodiments, the recess has a depth of at least 10 nm to at most 10,000 nm, or at least 20 nm to at most 5,000 nm, or at least 40 nm to at most 2,500 nm, or at least 80 nm to at most 1000 nm, or at least 100 nm to at most 500 nm, or at least 150 nm to at most 400 nm, or at least 200 nm to at most 300 nm.

[0174] In some embodiments, the recess has a length of at least 10 nm to at most 10,000 nm, or at least 20 nm to at most 5,000 nm, or at least 40 nm to at most 2,500 nm, or at least 80 nm to at most 1000 nm, or at least 100 nm to at most 500 nm, or at least 150 nm to at most 400 nm, or at least 200 nm to at most 300 nm.

[0175] In some embodiments, the distance that the gap-filling fluid extends into a particular recess is equal to at least 1.0 times to at most 10.0 times the height of the recess. In some embodiments, the distance that the gap-filling fluid extends into a particular recess is equal to at least 1.5 times to at most 9.0 times the height of the recess. In some embodiments, the distance that the gap-filling fluid extends into a particular recess is equal to at least 2.0 times to at most 8.0 times the height of the recess. In some embodiments, the distance that the gap-filling fluid extends into a particular recess is equal to at least 3.0 times to at most 6.0 times the height of the recess. In some embodiments, the distance that the gap-filling fluid extends into a particular recess is equal to at least 4.0 times to at most 6.0 times the height of the recess. In some embodiments, the distance that the gap-filling fluid extends into a particular recess is equal to about 5.0 times the height of the recess.

[0176] In some embodiments, the gap-fill fluid comprises a polysilazane oligomer.

[0177] In some embodiments, the polysilazane oligomer is branched.

[0178] In some embodiments, the polysilazane oligomer comprises a plurality of oligomeric species.

[0179] In some embodiments, the structure comprises a plurality of lateral spaces, wherein the lateral spaces are present in source and / or drain regions of a gate-all-around transistor, and wherein the gap-fill fluid acts as an interlayer dielectric.

[0180] In some embodiments, the gap filling fluid is cured. The term "curing" refers to the cross-linking process of the deposited gap filling fluid oligomers. Suitable curing means include a plasma curing process as described herein.

[0181] In some embodiments, the cured gap-filling fluid consists entirely of Si, N, H, and C. In some embodiments, the cured gap-filling fluid consists entirely of Si, N, and C.

[0182] Preferably, the cured gap filling fluid is a thermosetting resin.

[0183] There is also provided a structure formed by the method as described herein.

[0184] The methods and structures disclosed herein relate to the manufacture and / or provision of gap filling fluids. Such gap filling fluids, i.e. fluids with filling capability, can be applied to various semiconductor devices, including but not limited to cell isolation in 3D cross-point memory devices, self-aligned vias, pseudo gates (replacing current poly-Si), reverse tone patterning, PC RAM isolation, cutting hard mask, and DRAM storage node contact (SNC) isolation.

[0185] A gate-all-around transistor is also provided, which includes a gap-fill fluid as an interlayer dielectric.

[0186] In some embodiments, the gap-filling fluid is cured, preferably, the gap-filling fluid is cured by means of a method as described herein.

[0187] Also provided is the use of a gap-fill fluid as an interlayer dielectric in a gate-all-around transistor.Gate-all-around transistors and interlayer dielectrics are as known in the art and described, for example, in US Pat. No. 9,087,915.

[0188] Also provided is the use of the solidified gap-fill fluid as an interlayer dielectric in an all-around gate transistor.

[0189] Also provided is a system configured to perform a method as described herein and / or configured to form a structure as described herein.

[0190] A system is also provided, comprising: one or more reaction chambers; a gas injection system fluidly connected to at least one of the one or more reaction chambers; a first gas source for introducing a precursor and optionally a carrier gas into the one or more reactor chambers; a second gas source for introducing a mixture of one or more other gases into the one or more reactor chambers; an exhaust port; and a controller, wherein the controller is configured to control the flow of gas entering the gas injection system to perform the method described herein.

[0191] In certain embodiments, the gas injection system includes a precursor delivery system, and the precursor delivery system adopts carrier gas to carry the precursor to one or more reactor chambers. In certain embodiments, the continuous flow of carrier gas is realized using a circulation system, wherein the carrier gas line is provided with a bypass line with a precursor storage tank (bottle), and switched between the main line and the bypass line, wherein when only intending to feed carrier gas to the reaction chamber, the bypass line is closed, and when intending to feed carrier gas and precursor gas to the reaction chamber, the main line is closed, and the carrier gas flows through the bypass line and flows out from the bottle together with the precursor gas. Like this, carrier gas can flow into the reaction chamber continuously and can carry the precursor gas in a pulsed form by switching the main line and the bypass line.

[0192] The skilled artisan will recognize that the apparatus includes one or more controllers (not shown) programmed or otherwise configured to enable the deposition and reactor cleaning processes described elsewhere herein to be performed. As the skilled artisan will appreciate, the one or more controllers may be in communication with various power supplies, heating systems, pumps, robotic devices, and gas flow controllers or valves of the reactor.

[0193] In the present disclosure, when conditions and / or structures are not specified, those skilled in the art can easily provide such conditions and / or structures according to routine experiments based on the present disclosure.

[0194] The example embodiments of the present disclosure described herein do not limit the scope of the present invention, as these embodiments are merely examples of embodiments of the present invention, which are defined by the appended claims and their legal equivalents. Any equivalent embodiments are intended to be included within the scope of the present invention. In fact, various modifications of the present disclosure, such as alternative available combinations of the elements described, in addition to those shown and described herein, will be apparent to those skilled in the art from the specification. Such modifications and embodiments are also intended to fall within the scope of the appended claims.

[0195] As one example of a use case, the gap-fill layer of the present disclosure may be used as an interlayer in a gate-all-around transistor.

[0196] As an example of another use case, the gap fill layer of the present disclosure may be used as a dielectric fill layer over a self-aligned contact.

[0197] The methods provided in the present disclosure may be performed in any suitable apparatus, including in Figure 1 Similarly, the structures provided by the present disclosure can be manufactured in any suitable device, including Figure 1 The reactor shown in FIG. Figure 1 Schematic diagram of a PEALD apparatus, preferably in combination with a controller programmed to perform the sequence described below, which can be used in some embodiments of the present invention. In this figure, a pair of conductive plate electrodes (2, 4) connected in parallel and facing each other are provided in the interior (11) (reaction zone) of a reaction chamber (3), RF power (e.g., at 13.56 MHz or 27 MHz) is applied to one side from a power supply (25), and the other side (12) is electrically grounded, and a plasma is ignited between the electrodes. A temperature regulator can be provided in the lower part (2), i.e., the lower electrode. The substrate (1) is placed thereon and its temperature is kept constant at a given temperature. The upper electrode (4) can also be used as a shower plate, and reactant gas and / or dilution gas (if any) and precursor gas can be introduced into the reaction chamber (3) through gas lines (21) and gas lines (22) and through the shower plate (4), respectively. In addition, in the reaction chamber (3), an annular pipe (13) having an exhaust line (17) is provided, through which the gas in the interior (11) of the reaction chamber (3) is exhausted. In addition, a transfer chamber (5) arranged below the reaction chamber (3) is provided with a gas sealing line (24) to introduce a sealing gas into the interior (11) of the reaction chamber (3) via the interior (16) of the transfer chamber (5), and a separation plate (14) for separating the reaction zone and the transfer zone is provided in the transfer chamber. It should be noted that the gate valve through which the wafer can be transferred to or from the transfer chamber (5) is omitted in this figure. The transfer chamber is also provided with an exhaust line (6). In some embodiments, deposition and surface treatment of a multi-element film are performed in the same reaction space, so that all steps can be performed continuously without exposing the substrate to air or other oxygen-containing atmospheres.

[0198] In some embodiments, Figure 1 In the device depicted in Figure 2 The system for switching the flow of the inert gas and the flow of the precursor gas shown in FIG. 1 is used to introduce the precursor gas in a pulsed form without substantially fluctuating the pressure of the reaction chamber.

[0199] Indeed, the continuous flow of the carrier gas can be achieved using a flow-through system (FPS), wherein the carrier gas line is provided with a bypass line with a precursor tank (bottle), and switching is performed between the main line and the bypass line, wherein when only the carrier gas is intended to be fed to the reaction chamber, the bypass line is closed, and when both the carrier gas and the precursor gas are intended to be fed to the reaction chamber, the main line is closed, the carrier gas flows through the bypass line and flows out of the bottle together with the precursor gas. In this way, the carrier gas can flow continuously into the reaction chamber and can carry the precursor gas in pulses by switching the main line and the bypass line. Figure 2 FIG. 4 illustrates a precursor supply system using a flow-through system (FPS) according to one embodiment of the present invention (a black valve indicates that the valve is closed). Figure 2 As shown in (a), when a precursor is fed to a reaction chamber (not shown), a first carrier gas such as Ar (or He) flows through a gas line having valves b and c, and then enters a bottle (storage) (20). The carrier gas flows out of the bottle (20), while carrying an amount of precursor gas corresponding to the vapor pressure inside the bottle (20), flows through a gas line having valves f and e, and then is fed to the reaction chamber together with the precursor. In the above, valves a and d are closed. When only a carrier gas (inert gas) is fed to the reaction chamber, as shown in FIG. Figure 2 As shown in (b), the carrier gas flows through the gas line having valve a while bypassing bottle (20). In the above, valves b, c, d, e and f are closed.

[0200] The skilled artisan will recognize that the apparatus includes one or more controllers (not shown) programmed or otherwise configured to enable the deposition and reactor cleaning processes described elsewhere herein to be performed. As the skilled artisan will appreciate, the one or more controllers may be in communication with various power supplies, heating systems, pumps, robotic devices, and gas flow controllers or valves of the reactor.

[0201] Optionally, a dual chamber reactor may be used. A dual chamber reactor comprises two sections or compartments for processing wafers disposed close to each other. In such a dual chamber reactor, the reactant gases and inert gases may be supplied via a shared line, while the precursor-containing gas is provided by means of a non-shared line.

[0202] In yet another example, reference Figure 3 , which shows an exemplary test structure (100). The test structure is used to demonstrate the efficacy of a gap filling fluid with excellent lateral flowability, more particularly a SICN layer. The SICN layer in this example comprises a plurality of branched polysilazane oligomeric species. It is used as

[0203] The process conditions shown in Table 12 were deposited using the following precursor molecules:

[0204]

[0205]

[0206] In the test structure (100), the gap filling fluid (110) fills the trench (140). In addition, the gap filling fluid (110) completely fills the lateral space (130). The width w of the trench t = 210 nm. The height of the channel (140) is 445 nm. The height of the lateral space (130) is h t = 36 nm. The width w of the lateral space (130) filled by the gap filling fluid (110) v This corresponds to the total width of the lateral space (130), and therefore, for a lateral space (130) with a height of 36 nm, 160 nm is the lower limit of the lateral gap filling capability of the gap filling fluid used in this example.

[0207] In yet another example, reference Figure 4 Using process condition 3 of Table 1, vertical filling capability in narrow and high aspect ratio structures is shown.

[0208] In yet another example, reference Figure 5 The figure shows how the thickness T of the gap filling fluid deposited on top of the sample can be measured by means of thickness measurement using a scanning transmission electron microscope (STEM) on a sample cross section. t and the thickness T of the gap-filling fluid deposited in the bottom of the trench b The thickness T of the gap-filling fluid deposited on top of the sample t The thickness T of the gap filling fluid deposited at the bottom of the trench b The ratio of will give the ratio of growth per cycle at the top of the sample to growth per cycle at the bottom. Values ​​close to zero or at least less than one indicate good flowability.

[0209] In yet another example, an exemplary method as provided herein is discussed. The method relates to filling a gap in a silicon wafer. The gap includes a recess and a lateral space connected to a fluid in the recess. The method includes at least partially filling the recess and the lateral space with a gap filling fluid. Preferably, the recess and the lateral space are completely filled with the gap filling fluid.

[0210] At least partially filling the gap with a gap-filling fluid may include: introducing a substrate having a gap in a reactor chamber, wherein the gap includes a recess and a lateral space extending substantially laterally from the recess; introducing a precursor into the reactor chamber; introducing a co-reactant into the reactor chamber; and introducing a plasma into the reactor chamber; whereby the precursor and the co-reactant react to form a gap-filling fluid in the recess and the lateral space of the gap.

[0211] The co-reactant may comprise nitrogen and / or ammonia, and the precursor may be a cyclosilazane precursor having a structure according to the following formula:

[0212]

[0213] wherein any one of R1 to R9 is independently selected from hydrogen and C1 to C5 branched or straight chain alkyl, alkenyl, alkynyl and alkylamine.

[0214] No gas other than the cyclosilazane precursor, ammonia, and nitrogen may be introduced into the reactor.In addition, the pressure in the reactor may be at least 900 Pa to at most 1,800 Pa and the temperature in the reactor may be at least 50° C. to at most 75° C.

[0215] Also provided herein is a structure comprising a semiconductor substrate comprising a plurality of recesses, wherein the plurality of recesses are fluidly connected to one or more lateral spaces, and the plurality of recesses and the one or more lateral spaces are filled with a curable gap-filling fluid, wherein the gap-filling fluid is substantially void-free.

[0216] The lateral space may have a height of at least 1.0 nm to at most 40.0 nm. The gap filling fluid may extend a distance of at least 5.0 nm in the lateral space. The recess may have a depth of at least 5 nm to at most 500 nm, a width of at least 10 nm to at most 10,000 nm, and a length of at least 10 nm to at most 10,000 nm.

[0217] The gap-filling fluid may include a branched polysilazane oligomer including a plurality of oligomeric species. In other words, the branched polysilazane oligomer may include a plurality of different macromolecules having different morphologies.

[0218] As another example, an exemplary curing step is discussed. The curing step can use a continuous direct plasma for 20 seconds. The gap filling fluid deposition step and this direct plasma curing step can be performed cyclically. This allows effective curing of all or at least a large portion of the gap filling fluid. In order to cure the gap filling fluid in the gap on the 300mm substrate, each direct plasma curing step has 20 seconds of He plasma, whose RF power is 200W and the operating pressure is 600Pa. The reactor volume is about 1 liter and the He flow rate is 2slm.

[0219] As yet another example, another exemplary curing step is discussed. The curing step may involve the use of a micropulse plasma. In this example, the curing step may be performed cyclically, i.e., using alternating cycles of gap filling fluid deposition and micropulse RF plasma, but a post-deposition microplasma curing process is also possible. The application of cyclic gap filling fluid deposition and plasma steps allows effective curing of all or at least a large portion of the gap filling fluid. In order to cure the gap filling fluid in the gap on a 300mm substrate, each direct curing step may have 200 micropulses, the micropulses comprising a plasma on time of 0.1 seconds and a plasma off time of 0.5 seconds. The curing step may use a 400Pa He plasma. The RF power provided may be 200W. A He flow rate of 10slm may be used.

[0220] The gap-filling fluid may include a branched polysilazane oligomer that includes a plurality of oligomeric species. In other words, the branched polysilazane oligomer includes a plurality of different macromolecules that may have different morphologies.

[0221] In yet another example, reference Figure 6 and Table 1.

[0222] Figure 6 A sequence of deposition cycles for an exemplary gap fill fluid deposition process is shown. The process may employ a gas mixture consisting of nitrogen and ammonia as co-reactants. The co-reactants are continuously provided to the reactor chamber at a constant flow rate. The precursor pulses and RF turn-on pulses may be applied sequentially and may be separated by purge pulses. Table 1 shows exemplary process conditions that produce particularly good results for a 300 mm substrate. In this table: the "Condition" column shows the process condition reference number; the "Deposition Cycles" column shows the number of deposition cycles for each process condition; the "NH 3 The “Flow” column shows the ammonia flow rate for each process condition in standard liters per minute (slpm); 2 The column "Carrier gas flow rate" shows the nitrogen carrier gas flow rate for each process condition, that is, the flow rate of nitrogen provided together with the precursor, in slpm; the column "Reactor pressure" shows the reactor chamber pressure for each process condition, in Pa; the column "Plasma power" shows the RF plasma used for each process condition, in W; the column "Electrode gap" shows the distance between the electrodes between which the RF plasma is generated, in mm; "N 2The column "Gas Flow" shows the flow rate of dinitrogen supplied to the reactor chamber in addition to that supplied as a carrier under each process condition, in slpm; the column "Precursor Feed Time" shows the time, in seconds, during which the precursor is supplied during each deposition cycle; the column "Precursor Purge Time" shows the time, in seconds, during which only the co-reactant, N, is supplied to the reactor chamber after each precursor feed pulse. 2 and NH 3 The column "RF on time" shows the time in seconds that RF power is supplied during each deposition cycle under each process condition; the column "post-purge time" shows the time that only the co-reactant, i.e., N, is supplied to the reactor chamber after each plasma on pulse. 2 and NH 3 The time without applying plasma is in seconds; the "Top GPC" column shows the top growth of each cycle under each process condition, in nm / cycle; the "Bottom GPC" column shows the bottom growth of each cycle under each process condition, in nm / cycle; the "Top GPC / Bottom GPC" column shows the ratio of the top growth of each cycle to the bottom growth of each cycle under each process condition.

[0223] Figure 7 A deposition cycle sequence for an exemplary gap filling fluid deposition process is shown. The process uses a gas mixture containing argon as a co-reactant. The co-reactant can be continuously provided to the reactor chamber at a constant flow rate. The precursor pulse and the RF on pulse are applied sequentially and separated by a purge pulse. Table 2 shows exemplary process conditions that produce particularly good results for a 300 mm substrate. In this table, the legends of the columns have similar meanings to those of Table 1 after mutatis mutandis.

[0224]

Claims

1. A method for filling a gap, the method comprising: introducing a substrate provided with a gap in a reactor chamber, the gap comprising a recess and a lateral space extending substantially laterally from the recess; introducing a precursor into the reactor chamber; introducing a co-reactant into the reactor chamber; generating a plasma in the reactor chamber; whereby the precursor and the co-reactant react to form a gap-filling fluid that at least partially fills the recessed portion and the lateral space of the gap; as well as The gap-filling fluid is cured, and wherein fixing the gap-filling fluid comprises subjecting the substrate to a plasma after the gap has been filled with the gap-filling fluid.

2. The method of claim 1, wherein the co-reactant comprises at least one of nitrogen and ammonia.

3. The method of claim 1, wherein the co-reactant comprises an inert gas. The method of claim 3 , wherein the inert gas comprises Ar.

5. The method according to any one of claims 1 to 4, wherein the precursor comprises a cyclosilazane precursor.

6. The process according to any one of claims 1 to 5, wherein the reactor chamber is maintained at a pressure of at least 900 Pa to at most 1200 Pa.

7. The process according to any one of claims 1 to 6, wherein the reactor chamber is maintained at a temperature of at least 50°C to at most 75°C.

8. The method according to any one of claims 5 to 7, wherein the cyclosilazane precursor is selected from a cyclotrisilazane precursor, a cyclotetrasilazane precursor and a cyclopentasilazane precursor.

9. The method according to any one of claims 5 to 8, wherein the cyclosilazane precursor has a structure of formula (i): wherein any one of R1 to R9 is independently selected from hydrogen and C1 to C5 branched or straight chain alkyl, alkenyl, alkynyl and alkylamine.

10. The method according to any one of claims 1 to 9, wherein the introduction of the precursor and the co-reactant is carried out simultaneously.

11. The method of any one of claims 1 to 10, wherein the co-reactant is provided continuously, wherein the precursor is provided in a plurality of precursor pulses, wherein the plasma is generated in a plurality of plasma pulses, and wherein the precursor pulses and the plasma pulses are separated by a purge step.

12. The method according to any one of claims 5 to 11, wherein the cyclosilazane precursor does not contain any oxygen.

13. The method according to any one of claims 5 to 12, wherein the cyclosilazane precursor does not contain any halogen.

14. The method of any one of claims 1 to 13, wherein no gas other than the cyclosilazane precursor, ammonia and nitrogen is introduced into the reactor chamber while introducing the precursor, introducing the co-reactant and generating the plasma.

15. The method according to any one of claims 1 to 14, wherein the method comprises a plurality of cycles, a cycle comprising a gap filling fluid deposition step and a curing step, wherein the curing step comprises subjecting the substrate to a direct plasma. The method of claim 15 , wherein the direct plasma is an inert gas plasma.

17. The method of claim 15 or 16, wherein the curing step comprises subjecting the substrate to a micropulse plasma comprising a plurality of micropulse cycles, a micropulse cycle comprising a plasma-on pulse and a plasma-off pulse.

18. The method of claim 17, wherein the substrate is a 300 mm silicon wafer, and wherein a plasma gas flow rate of at least 5.0 slm is maintained during the micropulse plasma.

19. The method of any one of claims 1 to 14, wherein curing the gap-fill fluid comprises subjecting the substrate to an indirect plasma.

20. A system, comprising: one or more reaction chambers; a gas injection system fluidly coupled to at least one of the one or more reaction chambers; a first gas source for introducing a precursor and optionally a carrier gas into the reactor chamber; a second gas source for introducing a mixture of one or more other gases into the reactor chamber; Exhaust port; and Controller, The controller is configured to control the gas flow into the gas injection system to perform the method according to any one of claims 1 to 19.

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