Methods for filling a gap feature and semiconductor processing apparatus

Abstract

A method and related system for filling a gap member included in a substrate are disclosed. The method includes the step of providing a substrate including one or more gap members into a reaction chamber. The one or more gap members include an upper portion and a lower portion, the upper portion including an upper surface and the lower portion including a lower surface. The method further includes the steps of subjecting the substrate to a first plasma treatment and subjecting the substrate to a second plasma treatment. Thus, the upper surface is suppressed while the lower surface is substantially unaffected. Next, the method includes the step of selectively depositing a material on the lower surface.

Description

Technical Field

[0001] This invention generally relates to methods and systems suitable for forming electronic devices. More specifically, this invention relates to methods and systems that can be used to deposit a material in gaps, trenches, and the like. Prior Technology

[0002] The scaling of semiconductor devices has led to significant improvements in the speed and density of integrated circuits. However, with the miniaturization of wiring pitch in large-scale integrated devices, the hole-free filling of high aspect ratio gaps or trenches (e.g., trenches with an aspect ratio of three or higher) is becoming increasingly difficult due to limitations of existing deposition processes. Therefore, there is a need for processes that can effectively fill high aspect ratio components (e.g., gaps such as trenches) on semiconductor substrates.

[0003] Any discussion presented in this section, including discussions of problems and solutions, is included in this invention solely for the purpose of providing background context. Such discussions should not be construed as an admission that any or all information was known at the time of completion of this invention or otherwise constituted prior art. Summary of the Invention

[0004] Various embodiments of the present invention relate to gap-filling methods, structures and apparatus formed using such methods, and equipment for performing such methods and / or for forming such structures and / or apparatuses. The ways in which various embodiments of the present invention address the deficiencies of prior methods and systems are discussed in more detail below.

[0005] This invention discloses a method for filling a gap member on the surface of a substrate. The method includes, in a given sequence: a step of positioning a substrate on a substrate support in a reaction chamber; a step of subjecting the substrate to a first plasma treatment and a second plasma treatment; and a step of selectively depositing a material onto a lower surface. The substrate includes one or more gap members. The one or more gap members include an upper portion and a lower portion. The upper portion includes an upper surface, and the lower portion includes a lower surface. The steps of subjecting the substrate to the first plasma treatment and the second plasma treatment result in a suppression of the upper surface while leaving the lower surface substantially unaffected. Therefore, the material can be selectively grown in the gap in a bottom-up manner.

[0006] In some embodiments, the first plasma treatment includes generating a nitrogen-containing plasma in the reaction chamber.

[0007] In some embodiments, the nitrogen-containing plasma is a plasma containing N2.

[0008] In some embodiments, the second plasma treatment includes generating a plasma containing rare gases in the reaction chamber.

[0009] In some embodiments, the rare gas-containing plasma is an argon-containing plasma.

[0010] In some embodiments, the substrate is maintained at a temperature of at least 100°C to at most 550°C.

[0011] In some embodiments, selectively depositing a material onto the lower surface includes a cyclic deposition process. The cyclic deposition process includes a plurality of sub-cycles. A sub-cycle includes, in a given sequence: a step of exposing the substrate to a precursor, thereby forming a chemisorbed precursor on the lower surface; and a step of exposing the substrate to a third plasma treatment, thereby allowing one or more active species contained in the plasma to react with the chemisorbed precursor on the lower surface.

[0012] In some embodiments, the method includes performing a plurality of supercycles. A supercycle includes the steps of subjecting the substrate to a first plasma treatment and subjecting the substrate to a second plasma treatment; and the step of selectively depositing a material on a lower surface.

[0013] In some embodiments, the third plasma treatment includes generating an oxygen-containing plasma in the reaction chamber.

[0014] In some embodiments, the oxygen-containing plasma is an O2-containing plasma.

[0015] In some embodiments, the precursor comprises a silicon precursor.

[0016] In some embodiments, the silicon precursor comprises an alkylaminosilane.

[0017] In some embodiments, the silicon precursor is selected from bis(diethylamino)silane and diisopropylaminosilane.

[0018] In some embodiments, selectively depositing a material onto the lower surface includes a cycle process comprising a plurality of sub-cycles. A sub-cycle includes, in sequence: a step of exposing the substrate to a deficient amount of a halide precursor, thereby forming a chemisorbed halide precursor on the upper surface; a step of exposing the substrate to a second precursor, thereby forming a chemisorbed second precursor on the lower surface; a step of exposing the substrate to a nitrogen plasma comprising one or more active nitrogen species, thereby allowing the active nitrogen species to react with the chemisorbed halide precursor to form a nitrogen- and halogen-containing etchant; and a step of exposing the substrate to an oxygen plasma, thereby allowing one or more oxygen-containing active species contained in the plasma to react with the chemisorbed precursor on the lower surface to form an oxide on the lower surface.

[0019] In some embodiments, the method further includes performing a plurality of supercycles. A supercycle includes, in sequence, the steps of subjecting the substrate to a first plasma treatment and subjecting the substrate to a second plasma treatment; the step of exposing the substrate to a deficient halide precursor; the step of exposing the substrate to a second precursor; the step of exposing the substrate to a nitrogen plasma; and the step of exposing the substrate to an oxygen plasma.

[0020] In some embodiments, the halide precursor is a halide silicon precursor.

[0021] In some embodiments, the halide-containing silicon precursor comprises a halide alkoxysilane.

[0022] In some embodiments, the halide-containing silicon precursor is selected from trimethoxy(3,3,3-trifluoropropyl)silane and nonafluorohexyl-trimethoxysilane.

[0023] In some embodiments, the second precursor is a second silicon precursor.

[0024] In some embodiments, the second silicon precursor comprises Si, C, H, and N.

[0025] In some embodiments, the second silicon precursor comprises an alkylaminosilane.

[0026] In some embodiments, the second silicon precursor is selected from bis(diethylamino)silane and diisopropylaminosilane.

[0027] In some embodiments, the second silicon precursor is selected from diisopropylaminotrisilaneamine, diisopropylaminodisilane, dimethylaminopentylmethyldisilane, and diethylbutylaminodisilane.

[0028] In some embodiments, the second silicon precursor comprises an amino-substituted cyclosiloxane.

[0029] In some embodiments, the second silicon precursor comprises an alkyl and amino-substituted cyclosiloxane.

[0030] In some embodiments, the second silicon precursor comprises 2-diethylamino-2,4,6,8-tetramethylcyclotetrasiloxane.

[0031] In some embodiments, the material comprises silicon oxide, and the selective deposition of the silicon oxide on the lower surface includes a cycle process comprising a plurality of sub-cycles, each sub-cycle comprising, in a given sequence: a step of exposing the substrate to a silicon precursor, thereby forming a chemisorbed silicon precursor on the lower surface, wherein the silicon precursor comprises a compound selected from the list of alkylsilyl-substituted linear or cyclic secondary amines, alkylsilazanes, and aminoalkyl-substituted alkoxysilanes; and a step of exposing the substrate to an oxygen plasma, thereby allowing one or more oxygen-containing active species contained in the plasma to react with the chemisorbed precursor to form silicon oxide on the lower surface.

[0032] In some embodiments, the method includes performing a plurality of supercycles, each supercycle including the steps of subjecting the substrate to a first plasma treatment and subjecting the substrate to a second plasma treatment; and the step of selectively depositing silicon oxide on the lower surface.

[0033] In some embodiments, the silicon precursor comprises a compound selected from a list consisting of N-methyl-aza-2,2,4-trimethylsilacyclopentane, hexamethyldisilazane, (3-aminopropyl)trimethoxysilane, and 3-methoxypropyltrimethoxysilane.

[0034] In some embodiments, the step of selectively depositing a material onto the lower surface is performed at a growth rate of at least 0.1 Å / cycle to at most 10 Å / cycle.

[0035] This document further describes a semiconductor processing apparatus comprising a reaction chamber, a heater, a first plasma gas source, a second plasma gas source, a third plasma gas source, a plasma module, one or more precursor sources, and a controller. The reaction chamber includes a substrate support for supporting a substrate including one or more gap members. The heater is configured to heat the substrate within the reaction chamber. The first plasma gas source is in fluid communication with the reaction chamber via a first plasma gas valve. The second plasma gas source is in fluid communication with the reaction chamber via a second plasma gas valve. The third plasma gas source is in fluid communication with the reaction chamber via a third plasma gas valve. The plasma module includes radio frequency power and is configured to generate a plasma within the reaction chamber. The one or more precursor sources are in fluid communication with the reaction chamber via one or more precursor valves. The controller is configured to cause the apparatus to perform the methods described herein.

[0036] These and other embodiments will become apparent to those skilled in the art from the following detailed description of certain embodiments with reference to the accompanying drawings. The invention is not limited to any of the specific embodiments disclosed. Simple Explanation of the Diagram

[0037] A more complete understanding of embodiments of the present invention can be obtained by considering the following illustrative drawings, with reference to the embodiments and the claims. [Figure 1] is a schematic diagram of a plasma-enhanced atomic layer deposition (PEALD) apparatus suitable for depositing a structure and / or performing a method according to at least one embodiment of the present invention. [Figure 2] shows a schematic diagram of a substrate (200) including a gap member (210). [Figure 3] shows a flowchart of one embodiment of the method described herein. [Figure 4] shows a flowchart of one embodiment of the method described herein. [Figure 5] shows a flowchart of one embodiment of the method described herein. [Figure 6] shows a SEM micrograph of a gap member partially filled with silicon oxide. [Figure 7] shows a schematic diagram of various steps in one embodiment of the method described herein. [Figure 8] schematically shows an embodiment of a system described herein. All figures follow the following numbers: 1 – substrate; 2 – lower stage / conductive plate electrode; 3 – reaction chamber; 4 – [missing information] 5 – Upper electrode / conductive plate electrode; 6 – Transfer chamber; 7 – Exhaust line; 8 – Interior of reaction chamber; 9 – Electrically grounded side; 10 – Circular tube; 11 – Separator plate; 12 – Interior of transfer chamber; 13 – Exhaust line; 24 – Gas line; 25 – Gas sealing line; 26 – Power supply; 27 – Substrate; 28 – Gap member; 29 – Upper portion; 200 – Lower portion; 211 – Step of positioning a substrate on a substrate support; 212 – Step of subjecting the substrate to a first plasma treatment; 313 – Plasma rinse; 314 – Step of subjecting the substrate to a second plasma treatment; 315 – Post-plasma rinse; 316 – Step of depositing a material on a surface; 317 – Post-deposition rinse; 318 – End of method; 319 – Repeat; 411 – Start; 412 – Step of exposing a substrate to a precursor; 413 414 – Rinse; 415 – Rinse; 416 – End; 417 – Repeat; 511 – Start; 512 – Expose a substrate to a insufficient amount of halide precursor; 513 – Rinse; 514 – Expose the substrate to a second precursor; 515 – Rinse; 516 – Expose the substrate to a nitrogen plasma; 517 – Rinse; 518 – Expose the substrate to an oxygen plasma The plasma steps are as follows: 519 – Rinsing; 520 – End; 521 – Repeat; 710 – Step of providing a substrate to a reaction chamber; 720 – Step of generating a nitrogen plasma and a rare gas plasma in the reaction chamber; 730 – Step of providing a first silicon precursor to the reaction chamber; 740 – Step of providing a second silicon precursor to the reaction chamber; 750 – Step of generating a nitrogen plasma and an oxygen plasma in the reaction chamber; 760 – End. It will be understood that the elements in the drawings are shown for simplicity and clarity and are not necessarily drawn to scale. For example, the dimensions of some elements in the drawings may be particularly enlarged relative to other elements to help improve the understanding of the illustrated embodiments of the invention. Implementation

[0038] The following descriptions of exemplary embodiments of methods, structures, apparatuses, and systems are exemplary and intended for illustrative purposes only; they are not intended to limit the scope of the invention or the claims. Furthermore, the listing of multiple embodiments having the stated components is not intended to exclude other embodiments having additional components or other embodiments incorporating different combinations of the stated components. For example, various embodiments are presented as exemplary embodiments and may be enumerated in the appendices. Unless otherwise noted, exemplary embodiments or their components may be combined or used separately.

[0039] In this invention, "gas" may include materials that are gases, vaporized solids, and / or vaporized liquids at ambient temperature and atmospheric pressure (NTP), and may consist of a single gas or a mixture of gases depending on the context. Gases other than process gases (i.e., gases not introduced through gas distribution assemblies, multi-port injection systems, other gas distribution devices, or the like) may be used, for example, to seal reaction spaces, and may include sealing gases such as rare gases. The terms "rare gas" and "inert gas" as used herein are used interchangeably. In some cases, the term "precursor" may refer to a compound that participates in a chemical reaction to generate another compound, and in a systemic sense, it refers to a compound that constitutes a thin film matrix or a major framework of a thin film, or is incorporated into a thin film as a component thereof; the term "reactant" may be used interchangeably with the term "precursor."

[0040] As used herein, the term "substrate" can refer to any one or more underlying materials that can be used to form or on which a device, a circuit, or a thin film is formed. A 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 overlaid or under the bulk material.

[0041] Furthermore, in this invention, any two numbers of a variable can constitute a working range of the variable, and any indicated range may include or exclude endpoints. Additionally, any numerical value of the indicated variable (regardless of whether such numerical value is indicated as "about") may refer to an exact value or an approximate value and include equivalent values, and may refer to an average, median, representative value, multiple value, or the like. Further, in some embodiments of this invention, the terms "including," "constituted by," and "having" independently mean "typically or broadly comprising," "comprising," "consisting essentially of," or "consisting of." In some embodiments of this invention, any defined meaning does not necessarily exclude the usual and conventional meaning.

[0042] As used herein, the term "comprising" means including certain components, but does not exclude the presence of other components, provided that such inclusion does not render the scope of the claim or the embodiments impossible to implement. In some embodiments, the term "comprising" includes "consisting of".

[0043] As used herein, the term "composed of" means that no other components exist in the apparatus / method / product except for those described below. When the term "composed of" is used to refer to a compound, it means that the chemical compound contains only the listed components.

[0044] As used herein, the term "rinsing" refers to a process step in which precursors and / or active species are removed from a reaction chamber. During a rinsing, an inert or substantially inert gas may be supplied to the reaction chamber. Alternatively or additionally, the reaction chamber may be vented during a rinsing.

[0045] This invention discloses a method for filling a gap member on the surface of a substrate. The method can be used during the manufacture of various semiconductor devices and is particularly suitable for filling gap members having a high aspect ratio and a specific small width (e.g., less than 10 nm). The method includes the step of providing a substrate in a reaction chamber. Specifically, the substrate is placed on a substrate support in a reaction chamber. The substrate includes one or more gap members. The one or more gap members include an upper portion and a lower portion. The upper portion includes an upper surface. The lower portion includes a lower surface. The method further includes the step of subjecting the substrate to a first plasma treatment. Then, the method further includes the step of subjecting the substrate to a second plasma treatment. It should be understood that the first and second plasma treatments are different, i.e., not identical. Optionally, the first and second plasma treatments are separated by a rinsing. It should be understood that no plasma is generated in the reaction chamber during rinsing. Following the first and second plasma treatments, a material is selectively deposited on the lower surface. In some embodiments, the gap member is completely filled with the material.

[0046] Optionally, a rinsing process precedes the step of selectively depositing material onto the lower surface. It should be understood that no plasma is generated in the reaction chamber during rinsing. Furthermore, it should be understood that the application of both plasma treatments results in inhibition of the upper surface, while the lower surface remains substantially unaffected. In other words, the reaction of the upper surface to a precursor that can subsequently be supplied to the reaction chamber can be appropriately reduced. Alternatively, subjecting the substrate to a first plasma treatment and then to a second plasma treatment can result in an inhibition gradient in the gap portion, wherein the inhibition is stronger in the upper portion of the gap than in the lower portion. In other words, the inhibition gradually decreases from the upper portion to the lower portion of the gap. In the absence of any particular theory or operating mode, it is believed that the inhibition of the upper surface is caused by the consumption of reactive surface groups such as hydroxyl and amine groups near the top of the surface. Conversely, it is believed that the reactive surface groups near the lower surface, i.e., near the bottom of the trench, are less or unaffected by the first and second plasma treatments.

[0047] The methods described herein can be used in various applications, such as for seamless SiO2-filled gap components for shallow trench isolation purposes. Such seamless shallow trench isolation advantageously reduces leakage current, provides etching resistance, and improves resilience associated with chemical mechanical polishing processes. Furthermore, such SiO2 films can have an extremely low carbon content. Additionally, such SiO2 films can have an extremely low nitrogen content.

[0048] In some embodiments, the deposition of a material on the lower surface is performed at a growth rate of at least 0.1 Å / cycle to at most 10 Å / cycle, for example, at least 0.2 Å / cycle to at most 3 Å / cycle or at least 0.3 to at most 1 Å / cycle. For example, the material is deposited on the lower surface at a growth rate of at least 0.8 to at most 1.3 Å / cycle. In some embodiments, the growth rate on the upper surface is at least 2 to at most 20 times slower than that on the lower surface. In some embodiments, the growth rate on the upper surface is at least 2 to at most 5 times slower than that on the lower surface. In some embodiments, the growth rate on the upper surface is at least 5 to at most 10 times slower than that on the lower surface. In some embodiments, the growth rate on the upper surface is at least 10 to at most 20 times slower than that on the lower surface.

[0049] In some embodiments, the first plasma treatment includes generating a nitrogen plasma in the reaction chamber. A nitrogen plasma may also be referred to as a nitrogen-containing plasma.

[0050] In some embodiments, the nitrogen-containing plasma is an N2-containing plasma. In other words, in some embodiments, an N2-containing plasma gas system is used to generate a nitrogen-containing plasma.

[0051] In some embodiments, the second plasma treatment includes generating a plasma containing a rare gas in the reaction chamber. This rare gas plasma may, for example, be an argon-containing plasma. A rare gas plasma may also be referred to as a rare gas-containing plasma.

[0052] In some embodiments, the first plasma treatment includes generating a nitrogen plasma in the reaction chamber, and the second plasma treatment includes generating a rare gas plasma in the reaction chamber. In such embodiments, the shallow trench isolation material, such as silicon oxide, selectively deposited after the first and second plasma treatments, can advantageously be a component with low to negligible C residues and a high-quality film. Furthermore, when the substrate comprises Si fins, these plasma treatments advantageously limit or prevent the oxidation of such silicon fins. Additionally, using a rare gas plasma after the nitrogen plasma can advantageously reduce or eliminate the amount of N-containing surface groups, also known as nitrogen residues, on the substrate.

[0053] In some embodiments, the substrate is maintained at a temperature of at least 75°C to at most 550°C or at least 100°C to at most 300°C.

[0054] In some embodiments, the reaction chamber is maintained at a pressure of at least 0.5 Torr to at most 50 Torr, or at least 1 Torr to at most 20 Torr, or at least 2 Torr to at most 10 Torr, such as 6 Torr.

[0055] In some embodiments, the first plasma treatment includes exposing the substrate to a nitrogen plasma containing N2. In some embodiments, the N2 is supplied to the reaction chamber at a flow rate of at least 200 sccm to at most 2000 sccm, or at least 400 sccm to at most 1200 sccm, or at least 600 sccm to at most 1000 sccm. In some embodiments, the nitrogen plasma is generated by an RF generator at a plasma power of at least 100 W to at most 1000 W, for example, at least 200 W to at most 500 W. In some embodiments, the N2 plasma is generated for a duration of at least 0.1 s to at most 50 s, or for at least 1 s to at most 40 s, or for at least 5 s to at most 50 s, for example, at least 10 s to at most 20 s. In some embodiments, the N2 plasma is followed by a rinsing process lasting at least 1 s to at most 5 s. It should be understood that no plasma is generated in the reaction chamber during the flushing process.

[0056] In some embodiments, the second plasma treatment includes exposing the substrate to an argon plasma, wherein the plasma gas comprises Ar. In some embodiments, Ar is provided to the reaction chamber at a flow rate of at least 1 slm to at most 10 slm or at least 2 slm to at most 5 slm. In some embodiments, the argon plasma is generated by an RF generator at a plasma power of at least 100 W to at most 1000 W, for example, at least 200 W to at most 500 W. In some embodiments, the generation of the argon plasma lasts for at least 0.1 s to at most 50 s, or for at least 1 s to at most 40 s, or for at least 5 s to at most 50 s, for example, for at least 10 s to at most 20 s. In some embodiments, the argon plasma is followed by a rinsing lasting for at least 0.1 s to at most 2 s, for example, at least 0.2 s to at most 1 s. It should be understood that no plasma is generated in the reaction chamber during the rinsing. It should be noted that the above values ​​are given when using a 300 mm wafer as the substrate, and these values ​​can be easily adapted to different substrate sizes if needed.

[0057] In some embodiments, selectively depositing a material onto the lower surface includes a cyclic process. The cyclic process may include a plurality of sub-cycles. In some embodiments, the cyclic process includes at least 2 sub-cycles and up to 200 sub-cycles. For example, a cyclic deposition process may include 2 sub-cycles, 3 sub-cycles, 5 sub-cycles, 10 sub-cycles, 20 sub-cycles, 30 sub-cycles, 60 sub-cycles, 100 sub-cycles, 200 sub-cycles, 500 sub-cycles, 1000 sub-cycles, 2000 sub-cycles, or more. A sub-cycle may include, in sequence, a step of exposing the substrate to a precursor and a step of exposing the substrate to a third plasma treatment. Optionally, the step of exposing the substrate to a precursor is performed before a rinse. Optionally, the step of exposing the substrate to a third plasma treatment is performed before a rinse. It should be understood that no plasma is generated in the reaction chamber during rinsing. The step of exposing the substrate to a precursor results in the formation of a chemisorbed precursor on the lower surface. In other words, by exposing the substrate to the precursor, more precursor is chemisorbed onto the unpassivated lower surface compared to the plasma-passivated upper surface. In some embodiments, the first and second plasma treatments result in a passivation gradient, i.e., a gradual change in passivation density from the lower surface to the upper surface. In this example, the step of exposing the substrate to a precursor can result in a gradual change in the density of chemisorbed precursor per unit area from the lower surface to the upper surface. The step of exposing the substrate to a third plasma treatment then allows one or more active species in the plasma to react with the chemisorbed precursor to form a material. Since more precursor is chemisorbed onto the lower surface compared to the upper surface, more material is formed on the lower surface than on the upper surface. In other words, the material is selectively grown in a bottom-up manner.

[0058] In some embodiments, the third plasma treatment includes generating an oxygen-containing plasma in the reaction chamber. In some embodiments, the oxygen-containing plasma is an O2-containing plasma.

[0059] In some embodiments, the precursor comprises a silicon precursor. Therefore, the gap can be filled with a silicon-containing material. When the precursor comprises a silicon precursor and the third plasma comprises an oxygen-containing plasma such as an O2 plasma, the deposited material comprises silicon oxide. Therefore, the method of the present invention is applicable to filling a gap with silicon oxide in a bottom-up manner.

[0060] In some embodiments, the silicon precursor comprises an alkylaminosilane, such as di(diethylaminosilane), diisopropylaminosilane, diisopropylaminotrisilaneamine, diisopropylaminodisilane, dimethylaminopentylmethyldisilane, or diethylbutylaminodisilane.

[0061] In some embodiments, the silicon precursor comprises one or more alkylsilyl-substituted linear or cyclic secondary amines, alkylsilazanes, and aminoalkyl-substituted alkoxysilanes. Exemplary silicon precursors include N-methyl-NA-2,2,4-trimethylsilcyclopentane, hexamethyldisilane, (3-aminopropyl)trimethoxysilane, and 3-methoxypropyltrimethoxysilane.

[0062] In some embodiments, the silicon precursor is selected from a list including diisopropylaminotrisilaneamine, diisopropylaminodisilane, dimethylaminopentylmethyldisilane, and diethylbutylaminodisilane. Such silicon precursors allow for high growth per cycle and maximize the growth difference per cycle between the upper and lower surfaces in the interstitial space.

[0063] In some embodiments, the silicon precursor comprises an amino-substituted cyclosiloxane, such as alkyl and amino-substituted cyclosiloxanes, such as 2-diethylamino-2,4,6,8-tetramethylcyclotetrasiloxane. Such silicon precursors allow for high growth per cycle and maximize the growth difference per cycle between the upper and lower surfaces in the interstitial space.

[0064] In some embodiments, the silicon precursor comprises one or more alkylsilane-substituted linear or cyclic secondary amines, alkylaminosilanes, alkylsilazanes, alkylsilanes, or aminoalkyl-substituted alkoxysilanes.

[0065] In some embodiments, the silicon precursor comprises an alkyl-substituted or unsubstituted heterocyclic compound having C, N, and Si in its ring structure, such as N-methyl-nitro-2,2,4-trimethylsilcyclopentane.

[0066] In some embodiments, the silicon precursor comprises an alkylsilane, such as hexamethyldisilazane.

[0067] In some embodiments, the silicon precursor comprises an aminoalkyl-substituted alkoxysilane, such as (3-aminopropyl)trimethoxysilane.

[0068] In some embodiments, the silicon precursor includes an alkoxysilane, such as 3-methoxypropyltrimethoxysilane.

[0069] In some embodiments, the steps of subjecting the substrate to a first plasma treatment and a second plasma treatment may be repeated one or more times. Therefore, in some embodiments, these methods include performing a plurality of supercycles. A supercycle includes the steps of subjecting the substrate to the first and second plasma treatments. After the steps of subjecting the substrate to the first and second plasma treatments, the supercycle includes a step of selectively depositing a material onto the lower surface. In some embodiments, the method includes performing the supercycle at least 100 times to at most 10,000 times, at least 200 times to at most 5,000 times, or at least 500 times to at most 2,000 times.

[0070] In some embodiments, the silicon precursor is provided to the reaction chamber in silicon precursor pulses, and the pulses have a duration of at least 0.1 s to at most 20 s, or at least 1 s to at most 10 s, or at least 3 s to at most 5 s. In some embodiments, the silicon precursor pulses are immediately followed by rinsing, and the rinsing has a duration of at least 0.2 s to at most 20 s, or at least 0.5 s to at most 10 s, or at least 1 s to at most 5 s. It should be understood that no plasma is generated in the reaction chamber during rinsing.

[0071] In some embodiments, the third plasma treatment includes exposing the substrate to an oxygen plasma, with O2 used as a plasma gas. In some embodiments, O2 is supplied to the reaction chamber at a flow rate of at least 100 sccm to at most 10,000 sccm, or at least 200 sccm to at most 5,000 sccm, or at least 500 sccm to at most 1,000 sccm. In some embodiments, the oxygen plasma is generated by an RF generator operating at a plasma power of at least 50 W to at most 200 W. In some embodiments, the oxygen plasma is generated during an oxygen plasma pulse for at least 0.1 s to at most 10 s, or at least 0.2 s to at most 5 s, or at least 0.5 s to at most 2 s. In some embodiments, after exposing the substrate to the oxygen plasma, a rinsing is performed, and the rinsing lasts for at least 0.2 s to at most 10 s, or at least 1 s to at most 5 s. It should be understood that no plasma is generated in the reaction chamber during the flushing process.

[0072] In some embodiments, two different precursors—a halide precursor and a second precursor—may be used to selectively deposit a material. In some embodiments, selectively depositing a material onto the lower surface comprises a cycle process. The cycle process includes a plurality of sub-cycles. For example, a sub-cycle may include 2 sub-cycles, 3 sub-cycles, 4 sub-cycles, 8 sub-cycles, 16 sub-cycles, 32 sub-cycles, 64 sub-cycles, or more. In some embodiments, the cycle process includes at least 2 sub-cycles to at most 200 sub-cycles. A sub-cycle may include, in sequence: a step of exposing the substrate to a deficient amount of halide precursor, a step of exposing the substrate to a second precursor, a step of exposing the substrate to a nitrogen plasma comprising one or more active nitrogen-containing species, and a step of exposing the substrate to an oxygen plasma. In some embodiments, the step of exposing the substrate to the deficient amount of halide precursor is performed prior to a rinse. Optionally, the step of exposing the substrate to the second precursor is performed before a rinse. Optionally, the step of exposing the substrate to the nitrogen plasma is performed before a rinse. Optionally, the step of exposing the substrate to an oxygen plasma is performed before a rinse. It should be understood that no plasma is generated in the reaction chamber during rinsing.

[0073] The step of exposing the substrate to a insufficient amount of halide precursor results in the chemisorption of the halide precursor on the upper surface, rather than, or at least to a lesser extent, on the lower surface. In effect, by making the halide precursor insufficient, the precursor does not, or substantially does not, diffuse to the bottom of the gap members contained in the substrate, but will indeed reach the upper surface of the gap. It should be understood that insufficient means exposing a substrate to a sufficiently low amount of precursor such that the chemisorption of the precursor at the lower surface of the gap is diffusion-limited, i.e., a transport-limited mechanism. Precursor chemisorption may, but does not need to, occur at the substrate surface outside the gap and at the upper surface of the gap via a self-saturation mechanism. This can be accomplished, for example, by exposing the substrate to a relatively large amount of halide precursor for a relatively short time, for example, at least 0.01 s to at most 0.2 s, or for example, about at least 0.05 s to at most 0.1 s.

[0074] The step of exposing the substrate to a second precursor results in the chemisorption of the second precursor on the lower surface of the gap. It should be understood that the second precursor is different from the first precursor. In some embodiments, the second precursor does not contain any halogens.

[0075] During the step of exposing the substrate to a nitrogen-containing plasma comprising one or more active nitrogen-containing species, the active nitrogen-containing species react with the chemisorbed halide precursor to form a nitrogen- and halogen-containing etchant, which can then be used to locally etch the surface. Exemplary halogen-containing etchants include fluorinated etchants, such as fluorinated and nitrogen-containing etchants, such as an etchant selected from NF3, NF2, and NF. In some embodiments, the fluorinated etchant comprises at least one of fluorine radicals and fluoride ions. Since the halide precursor is primarily or only chemisorbed on the upper surface of the gap, in other words, near the top of the gap, the etchant is mostly or only generated near the upper surface of the gap, in other words, near the top of the gap. Alternatively, the etchant is generated in an anisotropic manner, and therefore the etchant preferentially etches the material near the top of the gap, such as deposited material. Therefore, the formation of the etchant can enhance gap filling in a bottom-up manner without forming any substantial seams.

[0076] The step of exposing the substrate to an oxygen plasma appropriately allows one or more oxygen-containing active species contained in the plasma to react with the chemisorbed precursor on the lower surface. Therefore, an oxide is formed on the lower surface, and the oxide can grow in the gap in a bottom-up manner.

[0077] The step of exposing the substrate to an oxygen plasma causes one or more active oxygen-containing species contained in the plasma to react with the chemisorbed precursor. Therefore, silicon oxide is selectively grown on the lower surface. It should be understood that a small amount of oxide can be deposited on the lower surface in this manner, and the gap structure can be filled with oxide in a bottom-up manner by repeating the cycle an appropriate number of times. In some embodiments, subjecting the substrate to a first plasma treatment and then subjecting it to a second plasma treatment is repeated one or more times. In other words, and in some embodiments, the steps of subjecting the substrate to a first plasma treatment and subjecting it to a second plasma treatment are performed multiple times. Therefore, in some embodiments, the method includes performing one or more, such as multiple, supercycles. An ultracycle includes, in the following order: the steps of subjecting the substrate to a first plasma treatment and the steps of subjecting the substrate to a second plasma treatment; the steps of exposing the substrate to a deficient halide precursor; the steps of exposing the substrate to a second precursor; the steps of exposing the substrate to a nitrogen plasma; and the steps of exposing the substrate to an oxygen plasma.

[0078] In some embodiments, the halide precursor is a halide silicon precursor. This is particularly useful for interstitial systems filled with silicon oxide. Suitable halide silicon precursors include haloalkoxysilanes, such as trimethoxy(3,3,3-trifluoropropyl)silane and nonafluorohexyl-trimethoxysilane.

[0079] In some embodiments, the second precursor is a second silicon precursor. In other words, in some embodiments, the second precursor comprises silicon. This is particularly useful for interstitial systems filled with silicon oxide. In some embodiments, the second silicon precursor comprises Si, C, H, and N. In some embodiments, the second silicon precursor comprises an alkylaminosilane, such as bis(diethylaminosilane) or diisopropylaminosilane. In some embodiments, such alkylaminosilanes may suitably be produced at a growth rate of at least 0.1 Å / cycle to at most 10 Å / cycle, for example, a growth rate of 1 Å / cycle.

[0080] In some embodiments, the second silicon precursor is selected from a list including diisopropylaminotrisilaneamine, diisopropylaminodisilane, dimethylaminopentylmethyldisilane, and diethylbutylaminodisilane. Such silicon precursors allow for high growth per cycle and maximize the growth difference per cycle between the upper and lower surfaces in the interstitial space.

[0081] In some embodiments, the second silicon precursor comprises an amino-substituted cyclosiloxane, such as alkyl and amino-substituted cyclosiloxanes, such as 2-diethylamino-2,4,6,8-tetramethylcyclotetrasiloxane. Such silicon precursors allow for high growth per cycle and maximize the growth difference per cycle between the upper and lower surfaces in the interstitial space.

[0082] In some embodiments, the second silicon precursor comprises one or more alkylsilane-substituted linear or cyclic secondary amines, alkylaminosilanes, alkylsilazanes, alkylsilanes, or aminoalkyl-substituted alkoxysilanes.

[0083] In some embodiments, the second silicon precursor comprises an alkyl-substituted or unsubstituted heterocyclic compound having C, N, and Si in its ring structure, such as N-methyl-nitro-2,2,4-trimethylsilcyclopentane.

[0084] In some embodiments, the second silicon precursor comprises an alkylsilane, such as hexamethyldisilazane.

[0085] In some embodiments, the second silicon precursor comprises an aminoalkyl-substituted alkoxysilane, such as (3-aminopropyl)trimethoxysilane.

[0086] In some embodiments, the second silicon precursor comprises an alkoxysilane, such as 3-methoxypropyltrimethoxysilane.

[0087] In some embodiments, the second silicon precursor comprises an alkylaminosilane, particularly an alkylamine-substituted monosilane, such as bis(diethylaminosilane) and diisopropylaminosilane. Using such precursors, a growth rate of approximately 1 Å / cycle can be obtained.

[0088] In some embodiments, the second silicon precursor comprises a higher-order silane, such as an alkylamine-substituted higher-order silane, such as an alkylamine-substituted disilane or trisilane. For example, the second silicon precursor may comprise a dialkylamine-substituted disilane or trisilane, such as diisopropylaminotrisilane, diisopropylaminodisilane, dimethylaminopentylmethyldisilane, and diethylbutylaminodisilane. Alternatively, the second silicon precursor comprises a cyclosiloxane, such as an alkyl and alkylamine-substituted cyclosiloxane. For example, the silicon precursor may comprise an alkyl and dialkylamine-substituted cyclosiloxane, such as 2-diethylamino-2,4,6,8-tetramethylcyclotetrasiloxane. Advantageously, such precursors can provide a high growth rate, for example, exceeding 1 Å / cycle. Furthermore, the use of such precursors can advantageously increase the growth rate difference of a silicon-containing material, such as silicon oxide between the upper surface of a gap member and the lower surface of a gap member.

[0089] In some embodiments, the material comprises silicon oxide, and the silicon oxide can be selectively deposited on the lower surface of the trench using a silicon precursor with relatively low reactivity. Therefore, in some embodiments, the material comprises silicon oxide, and the selective deposition of the silicon oxide on the lower surface comprises a cycle process. This cycle process includes a plurality of sub-cycles, such as 2 sub-cycles, 3 sub-cycles, 4 sub-cycles, 8 sub-cycles, 16 sub-cycles, 32 sub-cycles, 64 sub-cycles, or more. In some embodiments, the cycle process includes at least 2 sub-cycles and up to 200 sub-cycles. A sub-cycle includes, in a given sequence, a step of exposing the substrate to a silicon precursor and a step of exposing the substrate to an oxygen plasma. Optionally, the step of exposing the substrate to a silicon precursor is performed before a rinse. Optionally, the step of exposing the substrate to an oxygen plasma is performed before a rinse. It should be understood that no plasma is generated in the reaction chamber during the flushing process.

[0090] The step of exposing the substrate to a silicon precursor results in the formation of a chemisorbed silicon precursor on the lower surface. In other words, the silicon precursor is preferentially chemisorbed onto the lower surface relative to the upper surface. The silicon precursor may suitably comprise one or more alkylsilane-substituted linear or cyclic secondary amines, alkylsilazanes, and aminoalkyl-substituted alkoxysilanes. Exemplary silicon precursors include substituted or unsubstituted heterocyclic compounds containing C, N, and Si in their ring structure, such as N-methyl-NA-2,2,4-trimethylsilcyclopentane; alkyl-substituted linear or cyclic silazanes, such as hexamethyldisilazane; aminoalkyl-substituted alkoxysilanes, such as (3-aminopropyl)trimethoxysilane; and alkoxysilanes, such as 3-methoxypropyltrimethoxysilane. Advantageously, such precursors can exhibit relatively low reactivity to surface groups, such as hydroxyl or amine, under suitable conditions. Accordingly, weaker chemisorption occurs, particularly on plasma-suppressed surfaces where chemisorption is at most very limited. Consequently, the growth rate on the upper surface of a gap member can be very low, thereby increasing the selectivity of growth on the lower surface of the gap member.

[0091] In some embodiments, subjecting the substrate to a first plasma treatment followed by a second plasma treatment is repeated one or more times. In other words, and in some embodiments, the steps of subjecting the substrate to a first plasma treatment and a second plasma treatment are performed multiple times. Therefore, in some embodiments, the method includes performing one or more, for example, multiple supercycles. A supercycle includes, in sequence, the steps of subjecting the substrate to a first plasma treatment and a second plasma treatment; and the step of selectively depositing the silicon oxide onto the lower surface. Therefore, even if the effects of the first and second plasma treatments disappear after a certain number of cycles, very deep gaps can still be effectively filled.

[0092] This document further describes a semiconductor processing apparatus. The semiconductor processing apparatus is adapted to perform a method as disclosed herein. The semiconductor processing apparatus includes a reaction chamber comprising a substrate support for supporting a substrate. The substrate includes one or more gaps. The semiconductor processing apparatus further includes a heater, a first plasma gas source, a second plasma gas source, a third plasma gas source, a plasma module, and a controller. The heater is configured to heat the substrate in the reaction chamber. The first, second, and third plasma gas sources are in fluid communication with the reaction chamber via first, second, and third plasma gas valves. The plasma module includes a radio frequency power source and is configured to generate a plasma in the reaction chamber. The semiconductor processing apparatus further includes at least one precursor source in fluid communication with the reaction chamber via one or more precursor valves. Suitably, the semiconductor processing apparatus may further include an exhaust pipe for discharging reaction products, carrier gases, and unused precursors and co-reactants. The controller may include suitable electronic components, such as one or more memory modules and a processor, and is configured, i.e. programmed, to enable the device to perform the methods described herein. It should be understood, as those skilled in the art will appreciate, that the controller communicates with various power supplies, heating systems, pumps, robotic systems, and gas flow controllers or valves of the reactor.

[0093] In some embodiments, the semiconductor processing apparatus includes a precursor source. In some embodiments, the semiconductor processing apparatus includes two precursor sources.

[0094] Optionally, the system is configured to supply at least one of the precursors to the reaction chamber via a carrier gas. Suitable carrier gases include rare gases. In other words, in some embodiments, the semiconductor processing system includes a gas injection system comprising a precursor delivery system that uses a carrier gas to deliver the precursor to one or more reaction chambers.

[0095] The method provided by the present invention can be performed in any suitable apparatus, including in one embodiment of a semiconductor processing system as shown in FIG1. ​​FIG1 is a schematic diagram of a plasma-enhanced atomic layer deposition (PEALD) apparatus that can be used in some embodiments of the present invention. In this diagram, a plasma can be generated between the electrodes by arranging a pair of conductive plate electrodes (2, 4) parallel to each other and facing each other in the interior (11) (reaction zone) of a reaction chamber (3), applying RF power (e.g., 13.56 MHz and / or 27 MHz) from a power source (25) to one side and electrically grounding the other side (12). Of course, the semiconductor processing apparatus does not need to generate plasma during the step of providing a precursor to the reaction chamber, nor does it need to apply RF power to either of the electrodes during the steps. A temperature regulator may be provided in a lower stage (2), i.e., in the lower electrode. A substrate (1) is placed thereon, and its temperature is kept constant at a given temperature. The upper electrode (4) can also serve as a spray plate, and various gases, such as a plasma gas, a reactant gas, and / or, if present, a dilution gas and a precursor gas, can be introduced into the reaction chamber (3) via a gas line (21) and a gas line (22) and via the spray plate (4), respectively. In addition, a circular pipe (13) with an exhaust line (7) is provided in the reaction chamber (3), and the gas system inside the reaction chamber (3) (11) is discharged through the circular pipe. In addition, a transfer chamber (5) is provided below the reaction chamber (3) and has a gas sealing line (24) to introduce sealing gas into the inside of the reaction chamber (3) (11) via the inside (16) of the transfer chamber (5), wherein a separation plate (14) is provided for separating the reaction zone and the transfer zone. It should be noted that the gate valve is omitted in this figure. The wafer can be transferred to or from the transfer chamber (5) via the gate valve. The transfer chamber also has an exhaust line (6). In some embodiments, the silicon oxide deposition and surface treatment are performed in the same reaction space so that all steps can be performed continuously without venting the reaction chamber, evacuating the reaction chamber, or exposing the substrate to the atmosphere for intermediate steps.

[0096] Figure 2 shows a schematic diagram of a substrate (200) including a gap member (210). The gap member (210) includes an upper portion (211) and a lower portion (212). The upper portion (211) includes an upper surface, and the lower portion (212) includes a lower surface. By subjecting the substrate (200) to a first plasma treatment and a second plasma treatment, the upper surface can be substantially suppressed. In other words, compared to the lower surface, the first and second plasma treatments can appropriately make the upper surface less reactive to a precursor.

[0097] Figure 3 shows a schematic diagram of an embodiment of the method as described herein. The method includes a step (311) of positioning a substrate on a substrate support. The substrate includes a gap member. The substrate is then subjected to a first plasma treatment as described herein (312). Optionally, the reaction chamber is then rinsed using a plasma flush (313). The flushing may be performed, for example, by a substantially inert gas such as a rare gas. Suitable rare gases include He, Ne, Ar, Xe, and Kr. The method further includes a step (314) of subjecting the substrate to a second plasma treatment as described herein. Optionally, the reaction chamber is then rinsed using a post-plasma flush (315). The method further includes a step (316) of depositing a material on the lower surface of the gap member using the techniques described herein. Optionally, the reaction chamber is then rinsed using a post-deposition flush (317). It should be understood that no plasma is generated in the reaction chamber during the flushing. The steps of subjecting the substrate to a first plasma treatment (312) to depositing a material on the lower surface of the gap member can be selectively repeated (319) one or more times, thereby resulting in a plurality of supercycles including subsequent first and second plasma treatments and a subsequent deposition. Thus, a material is deposited in the gap member. The method ends (318) when a desired amount of material has been deposited in the gap.

[0098] Figure 4 is a schematic diagram showing one embodiment of a method for selectively depositing a material on the lower surface of a gap member included in a substrate. The portion of the method shown in Figure 4 corresponds to step (316) of depositing a material on a lower surface as shown in Figure 3, and begins after a step of subjecting the substrate to a first plasma treatment and a second plasma treatment, or alternatively, after a rinse immediately following such steps (411). The substrate is exposed to a precursor (412), which is chemisorbed onto the lower surface as described herein. Optionally, the reaction chamber is then rinsed (413). The method then includes a step of subjecting the substrate to a third plasma treatment (414). Optionally, the reaction chamber is then rinsed (415). It should be understood that no plasma is generated in the reaction chamber during rinsing. The steps from exposing the substrate to a precursor (412) to subjecting the substrate to a third plasma treatment (414) can be selectively repeated (417) one or more times, thereby resulting in multiple sub-cycles. Therefore, a material is deposited in the gap component. The method ends when a required amount of material has been deposited in the gap (416).

[0099] In an exemplary embodiment of the method according to Figure 4, the first plasma treatment uses a nitrogen plasma, the second plasma treatment uses a rare gas plasma, the precursor is a silicon precursor, the third plasma comprises an oxygen plasma, and the material comprises silicon oxide. Specifically, the silicon precursor may be selected from an alkyl-substituted or unsubstituted heterocyclic compound containing C, N, and Si in its ring structure, such as N-methyl-NA-2,2,4-trimethylsilane; an alkylsilane, such as hexamethyldisilazane; and an alkoxysilane, such as (3-aminopropyl)trimethoxysilane or 3-methoxypropyltrimethoxysilane. Using an O₂ plasma as the oxygen plasma, silicon oxide was grown on an unpassivated hydroxyl-terminated surface at the following growth rates: 0.6 Å / cycle when N-methyl-N-2,2,4-trimethylsilcyclopentane was used as the silicon precursor at a substrate temperature of 300°C; 0.25 Å / cycle when hexamethyldisilazane was used as the silicon precursor at a substrate temperature of 100°C; 0.63 Å / cycle when (3-aminopropyl)trimethoxysilane was used as the silicon precursor at a substrate temperature of 100°C; and 0.39 Å / cycle when 3-methoxypropyltrimethoxysilane was used as the silicon precursor at a substrate temperature of 100°C. Therefore, these precursors exhibit a relatively low growth rate, implying weak reactivity to the plasma-suppressed surface. Therefore, such precursors can be advantageously used in the methods described herein, and allow gap components to be filled in a bottom-up manner without forming seams.

[0100] Figure 5 is a schematic diagram illustrating a portion of an embodiment of a method for selectively depositing a material on the lower surface of a gap member included in a substrate. The portion of the method shown in Figure 5 corresponds to step (316) of depositing a material on a lower surface as shown in Figure 3, and begins after a step of subjecting the substrate to a first plasma treatment and a second plasma treatment, or alternatively, after a rinse immediately following such steps (511). The method then includes a step of exposing the substrate to a deficient amount of a halide precursor as described herein (512). Optionally, this step is followed immediately by a rinse (513). Next, the method includes a step of exposing the substrate to a second precursor (514). Optionally, this step is followed immediately by a rinse (515). Next, the substrate is subjected to a nitrogen plasma (516). Optionally, this step is followed immediately by a rinse (517). Next, the substrate is subjected to an oxygen plasma (518). Optionally, this step is followed immediately by a rinse (519). The steps from exposing the substrate to a insufficient amount of halide precursor (512) to subjecting the substrate to an oxygen plasma (518) can be selectively repeated (521) one or more times, thereby resulting in multiple sub-cycles. Optionally, subsequent sub-cycles can be separated by an inter-cycle rinse. It should be understood that no plasma is generated in the reaction chamber during the rinse. Therefore, a material is deposited in the gap member. The method ends (520) when a desired amount of material has been deposited in the gap.

[0101] Figure 6 is a cross-sectional scanning electron microscope (SEM) image showing a partially filled gap component using an embodiment of the disclosed method. Specifically, panel a) shows the results of a comparative process in which a gap component is filled with silicon oxide using a sequential deposition process comprising alternating argon plasma treatments for suppressing the upper surface of the gap component and a deposition sequence for depositing silicon oxide on the lower surface of the gap. Panel b) shows the results of an embodiment of the method described herein, in which a gap component is filled with silicon oxide using a sequential deposition process comprising alternating two-step plasma treatments for suppressing the gap component and a deposition sequence for depositing silicon oxide on the lower surface of the gap. The two-step plasma treatment includes a nitrogen plasma application followed by an immediate argon plasma application.

[0102] The following process conditions were used in a comparative process, and the results are shown on panel a): Si precursor pulse time: 4 s; Si precursor post-pulse rinse time: 2 s; Ar flow rate: 3.7 slm; O 2 flow rate: 800 sccm; RF plasma power during Ar plasma: 300 W; instantaneous Ar plasma: 15 s; Ar plasma post-rinse time: 0.5 s; RF plasma power during O 2 plasma: 100 W; instantaneous oxygen plasma: 1 s; oxygen plasma post-rinse time: 2 s; pressure: 5 torr; support temperature; number of cycles: 428.

[0103] The following process conditions were used in one embodiment of the method described herein, and the results are shown on panel b): N2 flow rate: 800 sccm; RF plasma power during N2 plasma: 300 W; instantaneous N2 plasma: 15 s; post-N2 plasma rinse time: 2 s; Ar flow rate: 3.7 slm; RF plasma power during Ar plasma: 300 W; instantaneous Ar plasma: 15 s; post-Ar plasma rinse time: 0.5 s; Si precursor pulse time: 4 s; post-Si precursor pulse rinse time: 2 s; O2 flow rate: 800 sccm; RF plasma power during O2 plasma: 100 W; instantaneous oxygen plasma: 1 s; post-oxygen plasma rinse time: 2 s; pressure: 5 torr; support temperature: 300°C; number of cycles: 645. It should be noted that the above values ​​are given for 300 mm wafers, and these values ​​can be easily adapted to other substrate sizes.

[0104] In the experiments, as shown in Figure 6, it can be observed that sequential inhibition significantly suppresses the top surface at an extremely low growth rate of 0.27 Å / cycle, compared to the example of Ar plasma suppression alone with a growth rate of 0.49 Å / cycle at the top surface. Without inhibition, a growth rate of approximately 1 Å / cycle was observed. This invention is not limited to any particular theory or mode of operation; it is believed that minimal chemisorption of the Si precursor occurs when using consecutive N₂ plasma and Ar plasma suppression. Furthermore, a thick bottom profile was observed, indicating a thicker film deposited on the bottom of the sidewalls by sequential inhibition. Therefore, this sequential, i.e., two-step plasma suppression, contributes to achieving seamlessly filled gap components, such as in shallow trench isolation reduction.

[0105] In another experiment, N 1s XPS (X-photon imaging) measurements were performed on a SiO 2 film deposited using one embodiment of the method described herein. An N 2 plasma and a subsequent Ar plasma application device were present. The XPS measurements indicated that no N 2 residues were observed in the SiO 2 film under study. The following process conditions are used in this embodiment of the method as described herein: N2 flow rate: 100 sccm; RF plasma power during N2 plasma: 300 W; instantaneous N2 plasma: 15 s; post-N2 plasma rinse time: 2 s; Ar flow rate: 3.7 slm; RF plasma power during Ar plasma: 300 W; instantaneous Ar plasma: 15 s; post-Ar plasma rinse time: 0.5 s; Si precursor pulse time: 4 s; post-Si precursor pulse rinse time: 2 s; O2 flow rate: 800 sccm; RF plasma power during O2 plasma: 500 W; instantaneous oxygen plasma: 1 s; post-oxygen plasma rinse time: 2 s; pressure: 5 torr; support temperature: 300°C; number of cycles: 555. Such SiO2 films were found to exhibit a wet etching rate of only 2.4 Å / min in diluted HF (0.5 wt. % HF, in H2O), thus indicating excellent film quality and eliminating the need for any post-deposition annealing. This is particularly useful when SiO2 is deposited on a substrate containing a thin silicon film: because post-deposition annealing is not required, there is no risk of unintentional oxidation of the fins.

[0106] Figure 7 illustrates a specific embodiment of the method shown in Figure 5. Specifically, the halide precursor is a halide silicon precursor, and the second precursor is a second silicon precursor. In these embodiments, the method of Figure 5 is particularly advantageous for seamlessly filling gap members with silicon oxide. Specifically, the method includes a step (710) of positioning a substrate on a substrate support in a reaction chamber. The substrate includes one or more gap members. The one or more gap members include an upper portion and a lower portion, the upper portion including an upper surface and the lower portion including a lower surface. The method further includes a step (720) of subjecting the substrate to a first plasma treatment and a second plasma treatment. Thus, while keeping the lower surface substantially unaffected, the upper surface is suppressed. Under the method of the present invention, which is not limited to any particular theory or mode of operation, it is believed that the sequence of a first plasma treatment, such as a nitrogen plasma, and a second plasma treatment, such as a rare gas plasma, can lead to the formation of reaction sites with lower reactivity than hydroxyl groups and dangling bonds, such as surface amine groups. The top of the trench is more affected by plasma inhibition than the bottom, which allows for seamless deposition. The method further includes a step (730) of providing a halide-containing silicon precursor to the reaction chamber. In particular, the halide-containing silicon precursor is provided in insufficient quantity, that is, a relatively low amount of halide-containing silicon precursor is provided to the reaction chamber, thereby causing the surface reaction of the halide-containing silicon precursor to occur in a non-self-saturating mechanism. This results in more chemisorption of the halide-containing silicon precursor on the surface above the interstitial member compared to the surface below the interstitial member. In other words, the halide-containing silicon precursor is preferably chemisorbed on the top of an interstitial member, such as a trench. Next, the method includes a step (740) of providing a second silicon precursor to the reaction chamber. The second silicon precursor is preferably halogen-free and is provided to the reaction chamber via a chemisorption-saturation mechanism. Since the halide-containing silicon precursor already occupies a reaction surface position at the top of the interstitial components, the second silicon precursor is preferentially chemisorbed at the bottom of the interstitial components. Next, the method includes a further plasma treatment step (750) involving the application of a nitrogen plasma and an oxygen plasma. The nitrogen plasma is generated in the reaction chamber and can lead to the formation of etchants such as NFx, NClx, NBrx, NIx, and halide radicals. Since the etchants are generated via the interaction of the N2 plasma with the chemisorbed halide-containing silicon precursor, such etchants are preferentially generated at the top of the trench. Therefore, any silicon oxide formed at the top of the trench during the previous cycle can be anisotropically etched, meaning it can be preferentially etched at the top of the trench. Following the nitrogen plasma, an oxygen plasma is generated in the reaction chamber, and the active species in the oxygen plasma can react with a second silicon precursor preferentially chemisorbed at the bottom of the interstitial components to form silicon oxide. Thus, silicon oxide is grown in the interstitial components in a bottom-up manner.Steps (720) to (750) can be repeated any desired number of times to achieve the desired amount of silicon oxide deposition in the interstitial component. Optionally, step (720) of generating a nitrogen and argon plasma in the reaction chamber can be omitted during one or more cycles. Optionally, the nitrogen plasma can be omitted in step (720) during one or more of the cycles. Optionally, the argon plasma can be omitted in step (720) during one or more of the cycles. The process stops (760) when the desired amount of silicon oxide has been deposited in the interstitial component.

[0107] Figure 8 shows selected components of an embodiment of a plasma-enhanced atomic layer deposition (PEALD) apparatus (800) that can be used to perform one of the methods described herein. The apparatus (800) includes a gas line (810), a bypass valve (820), a bypass line (830), a reactor (840), and an exhaust line (850). Such apparatus, including a bypass valve (820), can suitably increase throughput in the methods described herein. In particular, the bypass valve (820) can be used to allow continuous gas flow, even when a specific process gas is not required in the reaction chamber. Therefore, using a bypass valve (820) allows the avoidance of a gas stabilization step during the processing of multiple wafers and makes it easier to switch to different gas compositions for processing steps, thereby increasing throughput.

[0108] Furthermore, the bypass valve system allows for the continuous flow of certain gases and reduces particulate contamination by avoiding pressure pulse channels. Moreover, the flow can be initiated in bypass mode, thus preventing initial particle bursts into the chamber at the start (first wafer effect, pre-recipe requirements, etc.).

[0109] The gas line (810) may be a line for transporting any of the gases described herein, such as a precursor gas line, a rare gas line, a nitrogen gas line, or an oxygen gas line. Advantageously, the device (800) includes multiple gas lines, such as a precursor gas line, a rare gas line, a nitrogen gas line, and an oxygen gas line.

[0110] Therefore, in some embodiments, during the step of subjecting the substrate to a plasma pretreatment, a precursor is transferred through a precursor bypass channel.

[0111] Alternatively, during the step of selectively forming material on the lower surface, a plasma gas system is transferred through a plasma gas bypass conduit.

[0112] In some embodiments, during the step of selectively forming a material on the lower surface, a bypass valve is used to transfer the plasma gas used during the first plasma pretreatment.

[0113] In some embodiments, during the step of selectively forming a material on the lower surface, a bypass valve is used to transfer the plasma gas used during the second plasma pretreatment.

[0114] In some embodiments, during the step of selectively forming a material on the lower surface, a bypass valve is used to transfer the plasma gas used during the first and second plasma pretreatments.

[0115] In some embodiments, during at least one of the first and second plasma pretreatments, a bypass valve is used to transfer a precursor.

[0116] The exemplary embodiments described herein do not limit the scope of the invention. Since these embodiments are merely examples of embodiments of the invention, the scope of the invention is defined by the claims and their legal equivalents described below. Any equivalent embodiments are intended to fall within the scope of the invention. In fact, in addition to what is shown and described herein, various modifications disclosed herein will be apparent to those skilled in the art from this specification, such as substitutions of described elements and combinations thereof. Such modifications and embodiments are also intended to fall within the scope of the claims described below.

[0117] In this invention, where conditions and / or structures are not specified, those skilled in the art can readily provide such conditions and / or structures that fall under routine experimental matters, in view of this description.

[0118] 1:Substrate 2: Lower platform / conductive plate electrode 3: Reaction Chamber 4: Upper electrode / conductive plate electrode 5: Transfer Room 6: Exhaust pipe 7: Exhaust pipe 11: The interior of the reaction chamber 12: Electrical grounding side 13: Round tube 14: Divider 16: The interior of the transfer chamber 21: Gas Piping 22: Gas Piping 24: Gas-tight piping 25: Power Supply 200:Substrate 210: Clearance component 211: Upper part 212: Lower part 311: Steps for positioning a substrate on a substrate support 312: Step of subjecting the substrate to a first plasma treatment 313: Plasma Room Flushing 314: Step of subjecting the substrate to a second plasma treatment 315: Post-plasma rinsing 316: Steps for depositing a material on the following surface 317: Post-sedimentation flushing 318: End of Method 319: Repeat 411: Begin 412: Step of exposing a substrate to a precursor 413: Rinse 414: Step of subjecting the substrate to a third plasma treatment 415: Rinse 416: End 417: Repeat 511: Start 512: Step of exposing a substrate to an insufficient amount of a halide precursor 513: Rinse 514: Step of exposing the substrate to a second precursor 515: Rinse 516: The substrate is subjected to a nitrogen plasma. 517: Rinse 518: Step of subjecting the substrate to plasma 519: Rinse 520: End 521: Repeat 710: Step of providing a substrate to a reaction chamber 720: The steps for generating a nitrogen plasma and a rare gas plasma in the reaction chamber. 730: Step of providing a first silicon precursor to the reaction chamber 740: Step of providing a second silicon precursor to the reaction chamber 750: The steps for generating a nitrogen plasma and an oxygen plasma in the reaction chamber. 760: End 800: Equipment 810: Gas Piping 820: Bypass valve 830: Bypass pipe 840: Reactor 850: Exhaust pipe

Claims

1. A method for filling a gap in a substrate surface, the method comprising, in a given order: The method comprises: a step of positioning a substrate on a substrate support in a reaction chamber, the substrate including one or more gap members, the one or more gap members including an upper portion and a lower portion, the upper portion including an upper surface and the lower portion including a lower surface; a step of subjecting the substrate to a first plasma treatment and a second plasma treatment, thereby suppressing the upper surface and simultaneously leaving the lower surface substantially unaffected; and a step of selectively depositing a material on the lower surface, wherein selectively depositing a material on the lower surface includes a cycle process, the cycle process including a plurality of sub-cycles, a sub-cycle including, in the following order: a step of exposing the substrate to an under-dosed halide precursor, thereby forming a chemisorbed halide precursor on the upper surface; and a step of exposing the substrate to a second precursor, thereby forming a chemisorbed second precursor on the lower surface. A step of exposing the substrate to a nitrogen plasma comprising one or more active nitrogen-containing species, thereby allowing the active nitrogen-containing species to react with the chemisorbed halide precursor to form a nitrogen- and halogen-containing etchant; and a step of exposing the substrate to an oxygen plasma, thereby allowing one or more oxygen-containing active species in the plasma to react with the chemisorbed precursor on the lower surface to form an oxide on the lower surface.

2. The method as described in claim 1, wherein the first plasma treatment includes generating a nitrogen-containing plasma in the reaction chamber.

3. The method as described in claim 1 or 2, wherein the second plasma treatment includes generating a plasma containing a rare gas in the reaction chamber.

4. The method as described in claim 1 or 2, wherein the first plasma treatment includes generating a diatomic nitrogen plasma in the reaction chamber.

5. The method as described in claim 1 or 2, comprising executing a plurality of superloops, each superloop comprising: The steps of subjecting the substrate to a first plasma treatment and subjecting the substrate to a second plasma treatment; And the step of selectively depositing a material on the lower surface.

6. The method as claimed in claim 1 or 2, wherein the step of exposing the substrate to the oxygen plasma includes generating a diatomic oxygen plasma in the reaction chamber.

7. The method as described in claim 4, wherein the halide precursor comprises a halide silicon precursor.

8. The method as described in claim 7, wherein the halide-containing silicon precursor is selected from trimethoxy(3,3,3-trifluoropropyl)silane and nonafluorohexyl-trimethoxysilane.

9. The method as described in claim 2, further comprising executing a plurality of superloops, each superloop comprising, in the following order: The steps of subjecting the substrate to a first plasma treatment and subjecting the substrate to a second plasma treatment; the step of exposing the substrate to a insufficient amount of a halide precursor; the step of exposing the substrate to a second precursor; the step of exposing the substrate to a nitrogen plasma; and the step of exposing the substrate to an oxygen plasma.

10. The method as claimed in claim 1, wherein the halide-containing silicon precursor comprises a halide alkoxysilane.

11. The method as described in claim 1, wherein the second precursor is a second silicon precursor.

12. The method as claimed in claim 11, wherein the second silicon precursor comprises an alkylaminosilane.

13. The method as claimed in claim 11, wherein the second silicon precursor comprises an amino-substituted cyclosiloxane.

14. The method as described in claim 1 or 2, wherein the material comprises silicon oxide.

15. The method as described in claim 11, wherein the second silicon precursor comprises Si, C, H and N.

16. The method as claimed in claim 11, wherein the second silicon precursor is selected from bis(diethylamino)silane and diisopropylaminosilane.

17. The method as claimed in claim 1 or 2, wherein during at least one of the steps of subjecting the substrate to a first plasma pretreatment and subjecting the substrate to a second plasma pretreatment, the halide precursor and / or the second precursor is transferred through a precursor bypass channel.

18. The method as claimed in claim 1 or 2, wherein during the step of selectively depositing a material on the lower surface, a plasma gas system is transferred through a plasma gas bypass conduit.

19. A semiconductor processing apparatus, comprising: A reaction chamber includes a substrate support for supporting a substrate including one or more gap members; a heater configured to heat the substrate in the reaction chamber; a first plasma gas source fluidly connected to the reaction chamber via a first plasma gas valve; a second plasma gas source fluidly connected to the reaction chamber via a second plasma gas valve; a third plasma gas source fluidly connected to the reaction chamber via a third plasma gas valve; a plasma module including a radio frequency power source configured to generate a plasma in the reaction chamber; one or more precursor sources fluidly connected to the reaction chamber via one or more precursor valves; and a controller configured to cause the device to perform a method as described in any one of claims 1 to 18.

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