In-situ Block Removal in Plasma Etching

Abstract

In semiconductor processing, plasma etching of a material (e.g., carbon or silicon) to form a vertically oriented high aspect ratio recessed feature can cause blockage within the recessed feature due to unwanted deposition of a masking-derived blocking material (e.g., silicon oxide). This is addressed by blockage removal, which preferably includes etching the blocking material by contacting the substrate with a halogen source within the same process chamber. After the blockage removal step, plasma etching proceeds further. The blockage removal step and the plasma etching step can be repeated as many times as necessary to etch a recessed feature of the desired depth.

Description

Technical Field

[0001] Incorporation by reference: As part of this application, a PCT application form is filed simultaneously with this specification. Each application specified in the simultaneously filed PCT application form and for which this application claims benefit or priority is hereby incorporated by reference in its entirety for all purposes into this specification.

[0002] The present invention relates to methods and apparatus for semiconductor device fabrication. Specifically, embodiments of the present invention relate to methods and apparatus for declogging concave features during plasma etching in semiconductor processing.

Background Art

[0003] In semiconductor device fabrication, deposition and etching techniques are used to form patterns of materials, such as to form metal lines embedded in a dielectric layer. Examples of deposition techniques include atomic layer deposition (ALD), chemical vapor deposition (CVD), and physical vapor deposition (PVD). Examples of etching techniques include wet etching and dry etching techniques such as plasma etching.

[0004] The etching method may be isotropic or anisotropic. Isotropic etching is characterized by etching in multiple directions (both vertical and horizontal) on the substrate, and the etching rates in different directions are substantially the same. For example, isotropic etching is required for horizontal etching. Anisotropic etching is characterized by etching mainly in one direction, such as the vertical direction, and is often used to form concave features (e.g., vias) on the substrate. Anisotropic etching is also known as "directional etching".

[0005] Directional plasma etching is often used to form concave features in a layer of target material beneath a patterned mask layer. The chemistry of the directional plasma etching is typically selected such that the target material is etched at a higher rate than the mask material.

[0006] The background description provided here is for the purpose of generally presenting the content of the present disclosure. Within the scope described in this background art section, the research by the inventors named at the present time, as well as aspects of the description that cannot be separately regarded as prior art at the time of filing, are not recognized as prior art against the present disclosure, whether explicitly or implicitly.

Summary of the Invention

[0007] Methods and apparatuses for plasma etching of materials in semiconductor device fabrication are provided. The methods, in some embodiments, enable efficient directional etching and the formation of high aspect ratio concave features, such as concave features having an aspect ratio of at least about 5:1, for example, an aspect ratio of 5:1 to 500:1. The methods can be used, for example, in the fabrication of 3D NAND devices, dynamic random access memory (DRAM) devices, and high aspect ratio (HAR) logic devices. The methods, in some embodiments, alternately utilize a plasma etching step and a block removal step, and the block removal step at least partially removes a blocking material that constricts the concave feature and impedes plasma etching.

[0008] One aspect of the present disclosure relates to a method of etching a material on a semiconductor substrate, the method comprising: (a) providing a semiconductor substrate having an exposed layer of mask material, concave features, and a layer of target material beneath the layer of mask material, wherein the target material is exposed at the bottom of the concave features; (b) etching the target material using plasma etching to thereby increase the depth of the concave feature, wherein the etching of the target material narrows or blocks the concave feature at at least one location by deposition of the blocking material, and (c) etching the blocking material by contacting the semiconductor substrate with a halogen source without contacting the substrate with an organic solvent and without contacting the substrate with water comprising.

[0009] In some embodiments, the halogen source is provided to a processing chamber that houses the substrate together with a carrier gas. In some embodiments, the halogen source is provided to a processing chamber that houses the substrate without a carrier gas. In some embodiments, the etching (b) of the target material and the etching (c) of the blocking material are performed within one processing chamber. In some such embodiments, the transition from (b) to (c) includes increasing the chamber pressure of the processing chamber.

[0010] In some embodiments, (c) includes activating the halogen source in the plasma. In some such embodiments, (c) is performed without applying an external bias to the substrate. In some such embodiments, the plasma in (c) is a transformer-coupled plasma. In some such embodiments, the power of the plasma in (c) is 500 W or less. In some embodiments, the chamber pressure of the chamber housing the substrate in (c) is from 100 mTorr to 1 Torr (13332.2 mPa to 133.3 Pa). In some such embodiments, the chamber pressure of the chamber housing the substrate in (a) is less than 100 mTorr (13332.2 mPa). In some embodiments, the plasma in (c) is pulsed.

[0011] In some embodiments, the blocking material includes silicon oxide. In some embodiments, the target material is selected from the group consisting of carbon and silicon. In some embodiments, the mask material is selected from the group consisting of silicon oxynitride, silicon nitride, silicon oxide, silicon carbide, boron nitride, boron-doped carbon, tungsten, tungsten-doped carbon, and boron-doped carbon. In some embodiments, the etching of the blocking material has an etching selectivity greater than 1 with respect to both the mask material and the target material.

[0012] In some embodiments, (c) is performed in the absence of plasma. In some such embodiments, the chamber pressure of the chamber containing the substrate during (c) is from 100 mTorr to 100 Torr (13332.2 mPa to 13332.2 Pa).

[0013] In some embodiments, the temperature of the substrate is maintained throughout the process.

[0014] Another aspect of the present disclosure relates to a method of etching a material on a semiconductor substrate, the method comprising: (a) providing a semiconductor substrate having an exposed layer of mask material, a concave feature, and a layer of target material underlying the layer of mask material, wherein the target material is exposed at the bottom of the concave feature; (b) etching the target material using plasma etching, thereby increasing the depth of the concave feature, wherein the etching of the target material narrows or blocks the concave feature at at least one location by deposition of a blocking material; (c) etching the blocking material by contacting the semiconductor substrate with a plasma generated from a vapor phase halogen source; and comprising.

[0015] In some embodiments, the etching of the target material (b) and the etching of the blocking material (c) are performed in one processing chamber. In some such embodiments, the transition from (b) to (c) includes increasing the chamber pressure of the processing chamber.

[0016] In some embodiments, the blocking material includes silicon oxide. In some embodiments, the target material is selected from the group consisting of carbon and silicon. In some embodiments, the mask material is selected from the group consisting of silicon oxynitride, silicon nitride, silicon oxide, silicon carbide, boron-doped silicon, boron-doped carbon, tungsten, tungsten-doped carbon, and boron-doped carbon. In some embodiments, the etching of the blocking material has an etching selectivity greater than 1 with respect to both the mask material and the target material.

[0017] In some embodiments, (c) is performed without externally biasing the semiconductor substrate.

[0018] In some embodiments, the method further includes repeating steps (b) to (c).

[0019] In some embodiments, the etching of the blocking material includes contacting the semiconductor substrate with a plasma generated from a halogen source and from the vapor of a liquid selected from the group consisting of an organic solvent and water.

[0020] In some embodiments, the plasma in (c) is pulsed.

[0021] In some embodiments, the etching of the blocking material includes sequentially contacting the semiconductor substrate with a halogen source and with the vapor of a liquid selected from the group consisting of an organic solvent and water.

[0022] In some embodiments, (c) further includes contacting the semiconductor substrate with an additive selected from the group consisting of an amine, a heterocyclic compound, and a difluoride source.

[0023] In some embodiments, the etching of the blocking material is performed at a pressure of about 0.01 to 1 Torr (about 1.333 to 133.322 Pa) and a temperature of about -60 to 250 °C.

[0024] In some embodiments, the concave features of the semiconductor substrate provided in (a) have a width of about 5 to 300 nm.

[0025] In some embodiments, the semiconductor substrate includes a device selected from the group consisting of a partially fabricated 3D NAND device, a DRAM device, and a logic device. In some embodiments, the aspect ratio of the concave features after completion of the etching is at least about 5:1.

[0026] In some embodiments, the halogen source is selected from the group consisting of nitrogen tribromide (NBr3), nitrogen trichloride (NCl3), chlorine trifluoride (ClF3), hydrogen fluoride (HF), hydrogen chloride (HCl), and hydrogen bromide (HBr).

[0027] In some embodiments, the plasma etching in (b) includes contacting the substrate with an oxygen-containing reactant.

[0028] These and other aspects of the embodiments of the subject matter described herein are set forth in the accompanying drawings and the following description.

Brief Description of the Drawings

[0029]

Figure 1A

Figure 1B

Figure 1C

Figure 1D

[0030]

Figure 2

[0031]

Figure 3A

[0032]

Figure 3B

[0033]

Figure 4

[0034]

Figure 5

[0035]

Figure 6

DETAILED DESCRIPTION OF THE INVENTION

[0036] A method and apparatus for etching are provided. The provided method can be used for various applications, but is particularly useful for directional plasma etching of materials for forming high aspect ratio concave features on a semiconductor substrate. For example, the provided method can be used to form concave features having a width of about 5 - 300 nm (e.g., 10 - 200 nm) and an aspect ratio of at least about 5:1 (e.g., about 5:1 - 500:1), such as at least about 10:1, at least about 50:1, or at least 100:1. The method can be used, for example, in the fabrication of 3D NAND devices, DRAM devices, and high aspect ratio (HAR) logic devices. In some embodiments, the method is used to form concave features having a width of about 5 - 30 nm in the fabrication of DRAM devices and HAR logic devices.

[0037] Plasma etching in semiconductor device fabrication for forming high aspect ratio concave features is often hindered by the inadvertent deposition of a blocking material in the concave features. The blocking can slow down the plasma etching process and increase non-uniformity. The provided method enables rapid in situ blocking removal while minimizing changes in the critical dimensions of the concave features.

[0038] The deposition of the blocking material, as used herein, includes, but is not limited to, the redistribution of material from other parts of the substrate to the concave features (e.g., by sputtering), any chemical modification of the material of the substrate that forms the blocking material, and combinations of redistribution and chemical modification. For example, the blocking material can be derived from the mask material and / or the target layer material. In some embodiments, the blocking material has a similar composition to the material of the substrate (e.g., the mask material), but is more porous. For example, in some embodiments, a silicon oxide mask material may be sputtered and redistributed during plasma etching to form a more porous silicon oxide blocking material inside the concave features.

[0039] As used herein, "clogging" refers to the narrowing of a recessed feature due to the deposition of a clogging material, or the blockage of a recessed feature at any location, such as near the opening of the recessed feature. For example, the diameter of the recessed feature at the clogging location can be reduced by at least about 10%, such as at least about 20%. The clogging material in some embodiments is selected from the group consisting of oxides (e.g., silicon oxide, tin oxide, etc.), nitrides (e.g., silicon nitride, tantalum nitride, titanium nitride, etc.), carbides (e.g., silicon carbide, etc.), carbonitrides (e.g., silicon carbonitride, etc.), oxycarbides (e.g., silicon oxycarbide, etc.), and the like. In some embodiments, the clogging material is a silicon-containing material, such as a material containing silicon (Si) and oxygen (O). In some embodiments, the clogging material is silicon oxide (SiO). Other silicon-containing materials containing silicon and oxygen include silicon oxynitride (SiON), silicon oxycarbide (SiOC), silicon oxycarbonitride (SiOCN), and the like.

[0040] In the description of a material layer (e.g., SiO, SiON, Si, C, etc.), the formula does not indicate stoichiometry, and the stoichiometry can vary. The material includes the elements listed in each formula and optionally hydrogen (H). Other elements may typically be present as dopants at low concentrations of 20 atomic% or less (excluding hydrogen), such as 10 atomic% or less (excluding hydrogen), or 5 atomic% or less (excluding hydrogen).

[0041] In some embodiments, the capping material is formed from any material of the semiconductor substrate (e.g., mask material and / or target material), with or without chemical modification. For example, the capping material can be formed from silicon-containing materials such as silicon (Si), silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON), silicon carbide (SiC), and silicon oxycarbide (SiOC). In some embodiments, the capping material is an oxygen-containing material and is formed when the semiconductor substrate is exposed to oxygen-containing reactants such as O2, O3, CO2, CO, COS, and H2O, and the oxygen-containing reactants can be activated in a plasma. For example, an oxygen-containing capping material (e.g., silicon oxide) can be formed from silicon oxynitride or silicon oxycarbide when these materials are exposed to a plasma etching chemistry containing an oxygen-containing reactant. For example, when a silicon-containing mask material is used on a substrate that undergoes plasma etching with an oxygen-containing reactant, a silicon oxide capping material may be formed by redistribution and / or chemical modification of the mask material.

[0042] As used herein, the term "semiconductor substrate" refers to a substrate at any stage of semiconductor device fabrication that includes semiconductor material anywhere within its structure. It is understood that the semiconductor material in the semiconductor substrate need not be exposed. A semiconductor wafer having multiple layers of other materials (e.g., dielectrics) covering the semiconductor material is an example of a semiconductor substrate. The following detailed description assumes that the disclosed embodiments are implemented on semiconductor wafers such as 200 mm, 300 mm, or 450 mm semiconductor wafers. However, the disclosed embodiments are not so limited. The semiconductor wafers can be of various shapes, sizes, and materials. In addition to semiconductor wafers, other types of workpieces including various articles such as printed circuit boards can utilize the disclosed embodiments.

[0043] The term "about" when used in connection with a numerical value includes the range of ±20% of the recited numerical value unless otherwise specified.

[0044] The term "a" is used herein to specify "one or more". For example, "a recessed feature" should be construed as "one or more recessed features".

[0045] The method provided employs one or more plug removal steps alternating with a plasma etching step, and the plug removal is preferably carried out in the same process chamber as the plasma etching step (in situ plug removal). Since there is no need to move the substrate to another process chamber for plug removal, the entire etching process can be carried out quickly and efficiently. Another advantage of the method provided is that the plug removal chemical provided can etch the plug material without an external bias and even without plasma activation, so that no external electrical bias of the substrate is required during the plug removal step. Performing plug removal without biasing the substrate can have the advantage of reducing substrate damage and reducing the variation in the critical dimensions of the recessed features.

[0046] The removal of blockages during plasma etching according to some embodiments is shown in FIGS. 1A-1D and FIG. 2. FIGS. 1A-1D show schematic cross-sectional views of a portion of a semiconductor substrate during processing according to embodiments provided herein. It should be noted that FIGS. 1A-1D illustrate a portion of the substrate and show one concave feature, but it is understood that the substrate may include multiple concave features as well as multiple underlying layers (not shown). FIG. 2 is a process flow diagram showing the steps of a processing method according to the embodiment shown by FIGS. 1A-1D. The process starts at step 201 by providing a substrate having a target layer under a patterned mask layer, the substrate having at least one concave feature and the target layer being exposed at the bottom of the concave feature. An example of such a substrate is shown in FIG. 1A, where the patterned mask layer 101 overlays the target layer 103, which is then disposed on the etch stop layer 105. The substrate includes the concave feature 107, and the target material of the target layer 107 is exposed at the bottom of the concave feature 107. In some embodiments, the width of the concave feature 107 is about 5 to 300 nm, such as about 10 to 100 nm. In some embodiments (e.g., in DRAM device fabrication or HAR logic device fabrication), the width of the concave feature is about 5 to 30 nm.

[0047] The materials of the mask layer 101 and the target layer 103 are preferably selected such that, with respect to the etching of the target material, the etching selectivity is greater than 1, for example greater than 2, with respect to the mask material in the desired etching direction. The material of the etching stop layer 105 is preferably selected such that, with respect to the etching of the target material, the etching selectivity is greater than 1, for example greater than 2, with respect to the etching stop material. Examples of target materials include, but are not limited to, carbon (e.g., amorphous carbon), silicon (e.g., polycrystalline silicon, amorphous silicon, and doped silicon), and other silicon-containing materials. Examples of mask materials include, but are not limited to, silicon-containing materials such as silicon nitride (SiN), silicon oxynitride (SiON), silicon oxide (SiO), silicon carbide (SiC), silicon oxycarbide (SiOC), silicon boride (SiB), tungsten-containing materials such as tungsten (W), and carbon-containing materials such as tungsten-doped carbon (WC) and boron-doped carbon (BC). The thickness of the mask layer 101 is typically smaller than the thickness of the target layer 103. In some embodiments, the mask layer 101 has a thickness of about 10 to 1500 nm, and the target layer 103 has a thickness of about 50 to 1000 nm.

[0048] The material of the target layer 103 on the provided substrate is exposed such that the gaseous reactant is accessible. The substrate is processed in any suitable apparatus having a substrate holder (e.g., pedestal) and a process chamber with an inlet for introducing the reactant, and the apparatus is configured to generate plasma directly or remotely within the process chamber. Referring to step 203 of FIG. 2, the process continues by etching the target layer 103 using plasma etching, but during the etching, a blocking material is inadvertently deposited, thereby narrowing or blocking the recessed features. The resulting substrate is shown in FIG. 1B, where during the plasma etching of the target layer 103, the blocking material 109 is deposited on the sidewalls of the recessed features 107. In the illustrated example, since the blocking material is mainly deposited on the mask layer 101, it narrows the recessed features 107 at the feature openings, but in other cases, the blocking material may deposit deeper within the recessed features 107. If the inadvertently deposited blocking material 109 is not removed, it prevents the plasma etching chemistry from contacting the target layer 103 at the bottom of the recessed features 107, resulting in slower etching (or even stopping) and a potential decrease in etching uniformity. For example, if the blocking material is allowed to remain in the recessed features, the circular holes may have a deviation from roundness and the local critical dimension uniformity (LCDU) may decrease.

[0049] The process continues in step 205 by etching the blocking material using a blocking removal etching chemistry in the same process chamber as the plasma etching of the target layer. In some embodiments, the blocking removal etching chemistry includes a halogen source. The halogen source can be provided, for example, in the gas phase without plasma or as a plasma generated from a gas. In some embodiments, the halogen source is provided alone or only in combination with a carrier gas such as nitrogen, argon, or helium. In alternative embodiments, the halogen source is provided with an organic solvent and / or water, as further described below. In some embodiments, the first removal of the blockage begins after at least about 5%, such as at least about 10%, at least about 20%, at least about 30%, at least about 40% of the target depth of the concave feature has been etched by plasma etching. The etching of the blocking material may be partial or complete. The structure obtained after complete removal of the blocking material is shown in FIG. 1C, which shows that there is no blocking material 109 and the width of the concave feature 107 has recovered. It is understood that in some embodiments, it is not necessary to completely remove the blocking material, and only a part of the blocking material may be etched to widen the concave feature. The blocking removal etching chemistry in some embodiments is selective for both the mask material and the target material (i.e., etches the blocking material at a higher rate than both the mask material and the target material). In some embodiments, the etching selectivity is at least about 2 for both the mask material and the target material.

[0050] Next, in step 207, the plasma etching of the target material and the etching of the blocking material are optionally repeated a desired number of times to form a concave feature of a desired depth. For example, the etching process may include 2 to 21 cycles, such as 2 to 10 cycles, and each cycle includes one target material etching step and one blocking removal step. In some embodiments, each target material etching step removes about 10 to 300 nm of the target material. Concave features in the target material having a depth of about 100 to 2000 nm and an aspect ratio of at least about 5:1 can be formed without changing the process chamber by the provided method. In some embodiments, the blocking removal material is etched in the absence of plasma (thermal blocking removal). In other embodiments, the process is plasma-assisted. In some embodiments, the etching of the blocking material is performed without applying an external bias to the semiconductor substrate to reduce the potential for substrate damage due to ion-substrate interactions. Referring to FIG. 1D, the substrate after the etching of the target layer 103 is complete has a concave feature 107 that extends to the etch stop layer 105 exposed at the bottom of the feature. Depending on the required size of the concave feature and the nature of the blockage, the etching can be completed in one etching cycle having a single target material etching step followed by a blocking removal step, or in several cycles of alternating steps. Optionally, the process chamber can be purged between the target material etching step and the blocking removal step. In some embodiments, the entire etching process is performed at one temperature and / or pressure. In other embodiments, the temperature and / or pressure of the target material etching step is different from the temperature and / or pressure of the blocking removal step. The process temperature used for both steps is, in some embodiments, about -60 to 250 °C, such as about 0 to 175 °C. In some embodiments, a pressure of about 0.01 to 10 Torr (about 1.333 to 1333.22 Pa) is used for both steps.A certain temperature and a certain pressure each refer to a temperature within 1 °C and 1 milliTorr (133.322 mPa), respectively.

[0051] In some embodiments, the plasma etching step comprises introducing an etching process gas into a process chamber containing a substrate, the process gas including a reactant gas (e.g., an oxygen-containing reactant gas and / or a halogen-containing reactant gas) and optionally a carrier gas (e.g., nitrogen, helium, argon, etc.), and forming a plasma that activates the reactants in the plasma while providing an external bias to the substrate to perform directional etching of the target material. Next, the flow of the reactant gas is stopped, the external bias to the substrate is turned off, and a blockage removal composition is introduced into the process chamber without breaking the vacuum. In some embodiments, the plasma is maintained and the blockage removal step is plasma-assisted. In some embodiments, the plasma is generated from the blockage removal composition. In some embodiments, the plasma is turned off during the blockage removal step and the blockage removal step is performed thermally.

[0052] In some embodiments, plasma-assisted plug removal can be used to increase throughput. In embodiments where plasma-assisted plug removal is performed, this can be done with or without an organic solvent or water. In some embodiments, one or more parameters are set to improve selectivity. The parameters include relatively low plasma power. For example, a transformer-coupled plasma (TCP) source power of 500 W or less may be used. For example, a relatively high chamber pressure of 100 mTorr to 1 Torr (13332.2 mPa to 133.322 Pa) can be used. The plug removal plasma may be in continuous mode or pulsed. One or both of the plasma power and the chamber pressure may be changed from the plasma etching step 203. For example, a chamber pressure of less than 100 mTorr (13332.2 mPa) can be used for plasma etching in step 203. The transition from step 203 to 205 can be accompanied by an increase in chamber pressure. As described above, step 205 can be performed without applying a bias to the substrate.

[0053] Figures 3A and 3B illustrate an example of operation 205. In Figure 3A, the substrate is exposed to a halogen source in operation 301. This can be a non-plasma operation or a plasma operation. In the example of Figure 3A, the halogen source is provided to a plug removal gas that contains the halogen source without a solvent. In some embodiments, the plug removal gas can consist essentially of a halogen source. In some embodiments, the plug removal gas can consist essentially of a halogen source and one or more inert carrier gases such as argon (Ar). It will be understood that trace amounts of water or other impurities may be present due to ambient moisture or other ambient conditions. In some embodiments, the substrate is exposed to HF or other halogen-containing gases. This step may be performed at the same temperature as the etching in operation 203 in some embodiments.

[0054] In some embodiments, operation 301 is a non-plasma operation. In such embodiments, an etch removal gas containing a halogen source can be introduced into the chamber in a pulse flow sequence or as a continuous flow. When pulsed, a purge operation with an inert gas can be used between pulses. Exemplary chamber pressures for non-plasma operations are from 0.01 to 10 Torr (1.333 Pa). Exemplary durations of non-plasma operations are from 3 to 120 seconds.

[0055] In other embodiments, operation 301 is a plasma-assisted operation. In some embodiments, plasma-assisted etch removal can be used to increase throughput. An etch removal gas that does not contain a solvent can be provided to a plasma generator and activated in the plasma. In some embodiments, one or more plasma parameters are set to improve selectivity. Plasma parameters include relatively low plasma power such as 500 W of TCP source power and / or relatively high chamber pressures such as from 100 mTorr to 1 Torr (13332.2 mPa to 133.3 Pa). The etch removal plasma can be in continuous mode or pulsed. As described above, operation 303 can be performed without applying a bias to the substrate. Exemplary durations for plasma-activated etch removal are from 3 to 120 seconds.

[0056] Examples of halogen sources that can be used in operation 301 are provided below.

[0057] In operation 305, operation 301 can be repeated until a desired amount of etch material has been removed. In some embodiments, it is sufficient to repeat operation 301 only once. In other embodiments, there can be multiple cycles of operation 301, and each cycle includes a pulse of halogen source gas (with or without plasma activation) and a purge gas.

[0058] FIG. 3B shows a process flow diagram in which a substrate is subjected to a plug removal operation by exposing it to a plug removal gas containing a halogen source and vapors of an organic solvent (and / or water vapor). The plug removal gas may also include a carrier gas. In some embodiments, the plug removal gas includes an additive for improving etching selectivity.

[0059] In some embodiments, the vapors of the halogen source and the organic solvent (and / or water vapor) are sequentially introduced into the process chamber. The additive, when used, is typically introduced together with the vapor of the organic solvent (and / or water vapor). A carrier gas can also be included. These embodiments are illustrated by the process flow diagram of FIG. 3B. In step 311, the substrate in the plug removal step is optionally exposed to the vapor of the organic solvent and / or water with the additive for a certain period of time in the absence of the halogen source. Next, after a layer of the solvent and / or water (e.g., an adsorption layer) is formed on the substrate, the substrate is exposed to the halogen source in step 313, enabling the plug removal etching to proceed. In some embodiments, the exposure of the substrate to the halogen source involves activation of the halogen source in a plasma, while the exposure of the substrate to the solvent and / or water is performed in the absence of a plasma. Next, referring to step 315, the exposure to the solvent and / or water and the exposure to the halogen source are optionally repeated the required number of times to remove a desired amount of the plug material, completing the plug removal step. For example, each plug removal step may include 2 to 20 cycles, and each cycle includes one exposure to the solvent and / or water and one exposure to the halogen source.

[0060] In one exemplary embodiment of the method of FIGS. 3A and 3B, referring to FIG. 1A, the target layer 103 is a carbon layer (e.g., an amorphous carbon layer), and the mask layer 101 is a silicon-containing layer such as a silicon oxynitride (SiON) layer. The etching stop layer 105 may also be a silicon-containing layer such as a silicon oxide layer. In one example, the thickness of the mask layer 101 is about 300 nm, the thickness of the target layer is about 3000 nm, and the thickness of the etching stop layer is about 200 nm. The process begins by plasma etching the carbon-containing target layer using a plasma etching chemistry that is selective to both the mask material and the etching stop material. For example, the substrate may be exposed to an oxygen-containing reactant activated in the plasma. Examples of suitable oxygen-containing reactants include O2, COS, SO2, and any combination thereof. The plasma etching process gas may include additives and a carrier gas in addition to the oxygen-containing reactant. In some embodiments, the plasma is formed using an inductively coupled plasma (ICP) source. The plasma density is controlled by the plasma source power. The etching in this example also utilizes the bias provided to the substrate because anisotropic vertical etching is desired. Examples of frequencies used for the ICP source are 2 MHz, 13 MHz, 27 MHz, and 60 MHz. Examples of frequencies used for the bias are 400 KHz, 1 MHz, 2 MHz, 13 MHz, 27 MHz, and 60 MHz.

[0061] As the etching of the target material progresses (e.g., after etching 200 - 2000 nm), the silicon-containing mask material is sputter removed and redeposited on the sidewalls of the recessed features to form a blocking material. Optionally, the material may be chemically modified. For example, when a silicon oxynitride mask is used, as shown in Figure 1B, the redeposited silicon oxynitride material may react with an oxygen-containing reactant to form a porous silicon oxide blocking material at the opening of the recessed feature. Next, without breaking the vacuum, the porous silicon oxide blocking material is etched by exposing the substrate to a halogen source without applying an external bias to the substrate, as described above with reference to Figures 3A or 3B. Optionally, a vapor of an organic solvent (and / or water vapor), and optionally, an additive (e.g., an amine, a heterocyclic compound, or a difluoride source) can be used. In some embodiments, the blocking material is etched in the absence of plasma. In other embodiments, the blocking removal is plasma-assisted. After the blocking removal, the oxygen-containing plasma etching of the carbon-containing target layer can be resumed without breaking the vacuum within the same process chamber, and this can continue until the blocking material accumulates again, after which the plasma etching and blocking removal steps can be alternately repeated the desired number of times.

[0062] In another exemplary embodiment, the target layer 103 is silicon (e.g., polycrystalline silicon, amorphous silicon, or doped silicon), and the mask material is a silicon-containing mask such as silicon oxide, silicon oxynitride, silicon nitride, or silicon carbide. The silicon target material is anisotropically etched using a plasma formed in a process gas containing a halogen source (e.g., Cl2, HBr, fluorocarbon, or combinations thereof) and an oxygen source (e.g., O2), and the oxygen source is used to control the etching profile. The etching of the silicon target material in this case results in the deposition of a silicon oxide blocking material and the narrowing of the concave features, and the blocking material is derived from the mask material (e.g., via redistribution and / or chemical modification by O2). Next, the blocking material is etched using a blocking removal chemical as described herein, with or without plasma activation.

[0063] In both examples, the blocking removal etching is selective for the blocking material compared to both the mask material and the target material. In some embodiments, the etching selectivity for the target material in the desired direction with respect to both the mask material and the target material is greater than 1.5, e.g., greater than 2. For example, the silicon oxide blocking material is selectively etched in the desired direction with respect to both the carbon target layer and the silicon oxynitride mask layer. It should be noted that even when both the blocking material and the mask material are silicon oxide, the blocking removal can still proceed selectively, because the blocking silicon oxide material is typically more porous and more easily etched than the silicon oxide of the mask material (e.g., CVD-deposited silicon oxide). In another example, the silicon oxide blocking material is selectively etched in the desired direction with respect to the silicon target material and the silicon oxide or silicon oxynitride mask material.

[0064] Blocking removal chemical Clog removal is typically performed in the same process chamber as plasma etching and involves exposing the substrate to a halogen source in the gas phase to etch the clogging material. Optionally, vapors of an organic solvent and / or water vapor are used. Additives such as amines, heterocyclic compounds, or difluoride sources can be added to improve the etching selectivity for the clogging material. An inert carrier gas can also be included. The reactants are provided to the reaction chamber and exposed to the substrate in the gas phase. A remote plasma or in situ plasma may be generated from the reactants, or the reactants may be provided without plasma in thermal clog removal. Appropriate hardware may be provided to ensure that the reactants are properly vaporized before and during feeding to the reaction chamber. Two or more of the reactants can be mixed before being fed to the reaction chamber. In other embodiments, each of the reactants may be fed individually to the reaction chamber, for example, through separate lines or at separate times.

[0065] Halogen source The halogen source may be any halogen-containing (e.g., X-containing, where X is fluorine (F), chlorine (Cl), bromine (Br), or iodine (I)) compound present in the gas phase at the processing temperature. Examples include hydrogen bromide (HBr), hydrogen chloride (HCl), hydrogen fluoride (HF), fluorine (F₂), chlorine (Cl₂), bromine (Br₂), chlorine trifluoride (ClF₃), nitrogen trifluoride (NF₃), nitrogen trichloride (NCl₃), and nitrogen tribromide (NBr₃). In some embodiments, the halogen source is an organic halide, examples of which include chloroform (CHF₃), chloroform (CHCl₃), bromoform (CHBr₃), carbon tetrafluoride (CF₄), carbon tetrachloride (CCl₄), carbon tetrabromide (CBr₄), perfluorobutene (C₄F₈), and perchlorobutene (C₄Cl₈). In some embodiments, the halogen source is a silicon halide, examples of which include silicon tetrafluoride (SiF₄), silicon tetrachloride (SiCl₄), silicon tetrabromide (SiBr₄), and compounds containing SiX₆ such as H₂SiX₆. In some embodiments, the halogen source is a metal halide, examples of which include molybdenum hexafluoride (MoF₆), molybdenum hexachloride (MoCl₆), molybdenum hexabromide (MoBr₆), tungsten hexafluoride (WF₆), tungsten hexachloride (WCl₆), tungsten hexabromide (WBr₆), titanium tetrafluoride (TiF₄), titanium tetrachloride (TiCl₄), titanium tetrabromide (TiBr₄), zirconium fluoride (ZrF₄), zirconium chloride (ZrCl₄), and zirconium bromide (ZrBr₄). In some embodiments, metal oxides can be selectively etched using metal halides.

[0066] In the following description, various examples include HF as the halogen source. However, any suitable halogen source can be used. The volume and mass percentages described for HF can also be used for other halogen sources. In some embodiments, two or more halogen sources can be used.

[0067] Organic solvent: In some embodiments, an organic solvent is used, and examples thereof are provided below. Alkanes: In some embodiments, the organic solvent may be an alkane. In certain embodiments, the alkane may be an acyclic branched or unbranched hydrocarbon having the general formula C n H 2n+2 Examples of exemplary acyclic alkanes include, but are not limited to, pentane, hexane, octane, and combinations thereof. In certain other embodiments, the alkane may be a cyclic hydrocarbon. Examples of exemplary cyclic hydrocarbons include, but are not limited to, cyclopentane, cyclohexane, and combinations thereof.

[0068] Aromatic solvents: In some embodiments, the organic solvent may be an aromatic solvent. As used herein, "aromatic" means, unless otherwise specified, a cyclic conjugated group having a single ring (e.g., phenyl) or a plurality of fused rings in which at least one ring is aromatic (e.g., naphthyl, indolyl, or pyrazolopyridinyl), or a moiety of 5 to 15 ring atoms, i.e., at least one ring, and optionally a plurality of fused rings, have a continuous delocalized π - electron system. Typically, the number of out - of - plane π - electrons corresponds to the Hückel rule (4n + 2). The point of attachment to the parent structure typically occurs through the aromatic portion of the fused ring system. In some cases, the aromatic solvent may be selected from toluene and benzene.

[0069] Alcohols: In certain embodiments, the organic solvent may be an alcohol. The alcohol can be an alcohol having the formula X - C(R) n (OH) - Y, where

[0070] n is 1,

[0071] each X and Y can be independently selected from hydrogen, -[C(R 1 )2] m -C(R 2 )3, or OH, and each R1 and R 2 is independently selected from hydrogen, hydroxyl, aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combination thereof, m is an integer from 0 to 10, and each R is independently selected from hydrogen, hydroxyl, aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combination thereof.

[0072] In some embodiments, each R, R 1 , and R 2 is independently selected from alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, haloalkyl, haloalkenyl, haloalkynyl, haloheteroalkyl, haloheteroalkenyl, haloheteroalkynyl, aryl, heterocyclyl, heteroaryl, alkyl-aryl, alkenyl-aryl, alkynyl-aryl, alkyl-heterocyclyl, alkenyl-heterocyclyl, alkynyl-heterocyclyl, alkyl-heteroaryl, alkenyl-heteroaryl, alkynyl-heteroaryl, heteroalkyl-aryl, heteroalkenyl-aryl, heteroalkynyl-aryl, heteroalkyl-heterocyclyl, heteroalkenyl-heterocyclyl, heteroalkynyl-heterocyclyl, heteroalkyl-heteroaryl, heteroalkenyl-heteroaryl, heteroalkynyl-heteroaryl, or any combination thereof. In certain disclosed embodiments, the alcohol may be further substituted with one or more substituents such as alkoxy, amide, amine, thioether, thiol, acyloxy, silyl, alicyclic, aryl, aldehyde, ketone, ester, carboxylic acid, acyl, haloacyl, cyano, halogen, sulfonate, nitro, nitroso, quaternary amine, pyridinyl (or pyridinyl where the nitrogen atom is functionalized with an aliphatic or aryl group), haloalkyl, or any combination thereof.

[0073] In other embodiments, X or Y = -[C(R1 )2] m -C(R 2 )3 or at least one of R is hydrogen, and when m is 1, the alcohol can be a C3 alcohol. For example, when at least one R 1 and one R 2 are absent, the C3 alcohol can be a C3 alkenol (e.g., allyl alcohol). In another example, R and one R 2 can combine to form a ring (such as a cycloaliphatic ring), in which case the C3 alcohol can be cyclopropanol or 2-cyclopropenol.

[0074] In still other embodiments, X or Y = -[C(R 1 )2] m -C(R 2 )3 or at least one of R is hydrogen, and when m is 2, the alcohol can be a C4 alcohol. For example, when at least one R 1 and one R 2 are absent, the C4 alcohol can be a C4 alkenol (e.g., 2-buten-1-ol or 3-buten-1-ol). In another example, R and one R 2 can combine to form a ring (such as a cycloaliphatic ring), in which case the C4 alcohol can be a C4 cyclic alcohol (e.g., cyclobutanol or cyclopropylmethanol). In yet another example, when both X and Y are not OH, the C4 alcohol can be a C4 branched alcohol (e.g., 2-butanol, isobutanol, or tert-butanol).

[0075] In some cases, when X = OH and Y = -[C(R 1 )2] m -C(R 2 )3, the alcohol can be a diol. In other examples, at least one X or Y = -[C(R 1 )2] m -C(R 2 )3 and at least one R 1 =OH or one R 2When =OH or R = OH, the alcohol can be a diol. Exemplary diols include, but are not limited to, 1,4 - butanediol, propylene - 1,3 - diol, and the like.

[0076] In other examples, when X = Y = OH, the alcohol can be a triol. In still other examples, when X = R = OH, the alcohol can be a triol. In some cases, at least one of X or Y is -[C(R 1 )2] m -C(R 2 )3 and one R 1 and at least one R 2 is OH, the alcohol can be a triol. In other examples, R = OH and X = -[C(R 1 )2] m -C(R 2 )3 and one R 1 and at least one R 2 is OH, the alcohol can be a triol. Exemplary triols include, but are not limited to, glycerol or its glycerin derivatives.

[0077] In certain embodiments, when R = cycloheteroaliphatic, heterocyclyl, heteroaryl, alkyl - heterocyclyl, alkenyl - heterocyclyl, alkynyl - heterocyclyl, heteroalkyl - heterocyclyl, heteroalkenyl - heterocyclyl, or heteroalkynyl - heterocyclyl, the alcohol can be a heterocyclyl alcohol (e.g., furfuryl alcohol, etc., or an optionally substituted heterocyclyl further substituted with additional hydroxyls). In other embodiments, at least one of X or Y is -[C(R 1 )2] m -C(R 2 )3 and one R 1 and at least one R 2When it is cycloheteroaliphatic, heterocyclyl, heteroaryl, alkyl - heterocyclyl, alkenyl - heterocyclyl, alkynyl - heterocyclyl, heteroalkyl - heterocyclyl, heteroalkenyl - heterocyclyl, or heteroalkynyl - heterocyclyl, the alcohol can be a heterocyclyl alcohol.

[0078] In various embodiments, the alcohol may have 1 to 10 carbon atoms. The alcohol may be a primary alcohol, a secondary alcohol, or a tertiary alcohol. Optionally, the alcohol may be selected from the group consisting of methanol, ethanol, 1 - propanol, 2 - propanol, 1 - butanol, 2 - butanol, t - butanol, 1 - pentanol, 1 - hexanol, 1 - heptanol, 1 - octanol, 1 - nonanol, 1 - decanol, and combinations thereof.

[0079] Laboratory solvents: In these or other cases, the organic solvent may include laboratory - type solvents such as acetonitrile, dichloromethane, carbon tetrachloride, or combinations thereof.

[0080] Ketones: In some embodiments, the organic solvent may be a ketone.

[0081] The organic solvent can be a ketone having the formula X - [C(O)] n -Y, where

[0082] n is an integer from 1 to 2,

[0083] each X and Y can be independently selected from -C(R 1 )3, -R 2 , or -[C(R 3 )2] m -C(O)-R 4 and each R 1 , R 2 , R 3 , and R 4can be independently selected from hydrogen, hydroxyl, aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combination thereof,

[0084] R 3 and R 4 together with the atoms to which each is attached can optionally form an alicyclic or cycloheteroaliphatic, and X and Y together with the atoms to which each is attached can optionally form an alicyclic or cycloheteroaliphatic,

[0085] m is an integer from 0 to 10.

[0086] In some embodiments, each R 1 R 2 R 3 and R 4is, independently, alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, haloalkyl, haloalkenyl, haloalkynyl, haloheteroalkyl, haloheteroalkenyl, haloheteroalkynyl, aryl, heterocyclyl, heteroaryl, alkyl-aryl, alkenyl-aryl, alkynyl-aryl, alkyl-heterocyclyl, alkenyl-heterocyclyl, alkynyl-heterocyclyl, alkyl-heteroaryl, alkenyl-heteroaryl, alkynyl-heteroaryl, heteroalkyl-aryl, heteroalkenyl-aryl, heteroalkynyl-aryl, heteroalkyl-heterocyclyl, heteroalkenyl-heterocyclyl, heteroalkynyl-heterocyclyl, heteroalkyl-heteroaryl, heteroalkenyl-heteroaryl, heteroalkynyl-heteroaryl, or any combination thereof. In certain disclosed embodiments, the organic solvent may be further substituted with one or more substituents such as aldehyde (-C(O)H), oxo (=O), alkoxy, amide, amine, hydroxyl, thioether, thiol, acyloxy, silyl, alicyclic, aryl, aldehyde, ketone, ester, carboxylic acid, acyl, halogenated acyl, cyano, halogen, sulfonate, nitro, nitroso, quaternary amine, pyridinyl (or pyridinyl where the nitrogen atom is functionalized with an aliphatic or aryl group), halogenated alkyl, or any combination thereof. One exemplary ketone is acetone.

[0087] In some embodiments, when X and Y, together with the atoms to which each is attached, form an alicyclic or cycloheteroaliphatic, the organic solvent can be a cyclic ketone. Exemplary cyclic ketones include cyclohexanone, cyclopentanone, and the like.

[0088] In other embodiments, at least one of X or Y = -[C(R 3 )2] m -C(O)-R 4When this is the case, the organic solvent can be a diketone. Exemplary diketones include diacetyl, 2,3-pentanedione, 2,3-hexanedione, 3,4-hexanedione, acetylacetone, acetonylacetone, etc., as well as their halogenated forms such as hexafluoroacetylacetone.

[0089] In a further embodiment, at least one of X or Y = -[C(R 3 )2] m -C(O)-R 4 and when X and Y, together with the atoms to which each is attached, form an alicyclic or cycloheteroaliphatic, the organic solvent can be a cyclic diketone. Exemplary cyclic diketones include dimedone, 1,3-cyclohexanedione, etc.

[0090] In some cases, when X = -CH3, the organic solvent can have Y = -C(R 1 )3 and at least one R 1 is C 2-10 hydroxyl, aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combination thereof. Exemplary materials can include methyl propyl ketone, methyl butyl ketone, hydroxyacetone, etc.

[0091] In other examples, when X = -CH3, the organic solvent can have Y = -R 2 and at least one R 2 is C2 alkenyl, C 3-10 aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combination thereof. Exemplary materials can include methyl vinyl ketone, methyl propyl ketone, methyl butyl ketone, etc.

[0092] In yet other examples, when at least one of X or Y = aromatic, or aliphatic-aromatic, or heteroaliphatic-aromatic, the organic solvent can be an aromatic ketone. Exemplary materials include acetophenone, benzophenone, benzylacetone, 1,3-diphenylacetone, cyclopentyl phenyl ketone, and the like.

[0093] In certain embodiments where the organic solvent contains a ketone, the ketone may be selected from acetone and acetophenone. One or more additional ketones and / or other organic solvents described herein may also be provided as well.

[0094] Ether: In some embodiments, the organic solvent may be an ether having the formula X-O-Y or X-O-[C(R)2] n -O-Y, where

[0095] n is an integer from 1 to 4,

[0096] each X and Y is independently selected from -[C(R 1 )2] m -C(R 2 )3 or -R 3 or -[C(R 4 )2] p -O-[C(R 5 )2] m -C(R 6 )3, and each of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , and each R is independently selected from hydrogen, hydroxyl, aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combination thereof, m is an integer from 0 to 10, p is an integer from 1 to 10,

[0097] X and Y, together with the atoms to which each is attached, can optionally form a cycloheteroaliphatic group.

[0098] In some embodiments, each R, R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 is independently selected from alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, haloalkyl, haloalkenyl, haloalkynyl, haloheteroalkyl, haloheteroalkenyl, haloheteroalkynyl, aryl, heterocyclyl, heteroaryl, alkyl-aryl, alkenyl-aryl, alkynyl-aryl, alkyl-heterocyclyl, alkenyl-heterocyclyl, alkynyl-heterocyclyl, alkyl-heteroaryl, alkenyl-heteroaryl, alkynyl-heteroaryl, heteroalkyl-aryl, heteroalkenyl-aryl, heteroalkynyl-aryl, heteroalkyl-heterocyclyl, heteroalkenyl-heterocyclyl, heteroalkynyl-heterocyclyl, heteroalkyl-heteroaryl, heteroalkenyl-heteroaryl, heteroalkynyl-heteroaryl, or any combination thereof. In certain disclosed embodiments, the ether may be further substituted with one or more substituents such as alkoxy, amide, amine, thioether, thiol, acyloxy, silyl, alicyclic, aryl, aldehyde, ketone, ester, carboxylic acid, acyl, acyl halide, cyano, halogen, sulfonate, nitro, nitroso, quaternary amine, pyridinyl (or pyridinyl where the nitrogen atom is functionalized with an aliphatic or aryl group), haloalkyl, or any combination thereof.

[0099] In some embodiments, when X and Y together with the atoms to which each is attached form a cycloheteroaliphatic group, the organic solvent is a cyclic ether such as an acetal, dioxane, or dioxolane. In some embodiments, when n = 1 and each R = H, X and Y together form a 6-, 7-, 8-, 9-, or 10-membered ring. Exemplary ethers include, but are not limited to, 1,3-dioxolane, or a derivative thereof. In other embodiments, when n = 2 and R = H, X and Y form a 7-, 8-, 9-, or 10-membered ring. Exemplary ethers include, but are not limited to, 1,4-dioxane, or a derivative thereof. In still other embodiments, when n = 1 or n = 2, R is aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combination thereof. Exemplary cyclic ethers include tetrahydrofuran, 2-methyltetrahydrofuran, 2-methyl-1,3-dioxolane, and the like.

[0100] In other embodiments, when at least one of X or Y is aromatic, the organic solvent can be an aromatic ether. Exemplary aromatic ethers include anisole, diphenyl ether, and the like.

[0101] In some embodiments, when at least one of X or Y is cycloaliphatic, the organic solvent can be a cycloalkyl ether. Exemplary cycloalkyl ethers include cyclopentylmethyl ether, cyclohexylmethyl ether, and the like.

[0102] In other embodiments, when at least one of X or Y is -[C(R 4 )2-O] p -C(R 6)When it is 3, the organic solvent can be a glycol-based ether. Exemplary glycol-based ethers include diethylene glycol diethyl ether, dipropylene glycol dimethyl ether, poly(ethylene glycol) dimethyl ether, etc., including methyl, ethyl, propyl, and butyl monoethers and diethers of ethylene glycol.

[0103] Nitrile: In some cases, the organic solvent is a nitrile having the formula R-C≡N,

[0104] wherein R is aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, or heteroaliphatic-aromatic.

[0105] In certain embodiments, R can be optionally substituted with a hydroxyl group (for example, in one example, R can be CH3-CH(OH)-CH2-, and the organic solvent can be CH3-CH(OH)-CH2-CN).

[0106] One exemplary nitrile is acetonitrile as described above.

[0107] In some embodiments, the organic solvent may include two or more of the organic solvents or types of organic solvents described herein. In some embodiments, water may be provided instead of or in addition to the organic solvent.

[0108] Carrier gas When used, the carrier gas may be an inert gas. In some cases, the carrier gas is a noble gas. In certain embodiments, the carrier gas can be selected from the group consisting of N2, He, Ne, Ar, Kr, and Xe. In some such embodiments, the carrier gas may be selected from the group consisting of N2, He, and Ar.

[0109] Additive When used, the additive can be selected from a number of different types of additives. For example, in some cases, the additive may be a heterocyclic compound, a heterocyclic aromatic compound, a halogen-substituted heterocyclic aromatic compound, a heterocyclic aliphatic compound, an amine, a fluoroamine, an amino acid, an organic phosphorus compound, an oxidizing agent, a difluoride source, ammonia, an aldehyde, a carbene, or an organic acid. In some cases, a plurality of additives may be used. In some embodiments, the additive may be a boron-containing Lewis acid or Lewis adduct. Boron trifluoride (BF3) is an example of a Lewis acid that forms the acid-base adduct BF4 - . In some cases, the additive can be classified into two or more of the categories listed above. In various embodiments, the additive serves the purpose of accelerating the reaction rate and enhancing the reaction selectivity.

[0110] Heterocyclic aromatic compound: In certain embodiments, the additive is a heterocyclic aromatic compound. The term "aromatic" is defined above. A heterocyclic aromatic compound is an aromatic compound containing a 5-, 6-, or 7-membered ring containing 1, 2, 3, or 4 non-carbon heteroatoms (e.g., independently selected from the group consisting of nitrogen, oxygen, phosphorus, sulfur, or halogen) unless otherwise specified. Exemplary heterocyclic aromatic compounds that can be used include, but are not limited to, picoline, pyridine, pyrrole, imidazole, thiophene, N-methylimidazole, N-methylpyrrolidone, benzimidazole, 2,2-bipyridine, dipicolinic acid, 2,6-lutidine, 4-N,N-dimethylaminopyridine, and azulene. In some cases, the heterocyclic aromatic compound may be methylated. In some cases, the heterocyclic aromatic compound can follow Hückel's 4n + 2 rule. In some cases, the additive is a halogen-substituted aromatic compound. A halogen-substituted aromatic compound is an aromatic compound containing at least one halogen bonded to the aromatic ring. As used herein, halogen or halo refers to F, Cl, Br, or I. Exemplary halogen-substituted aromatic compounds include, but are not limited to, 4-bromopyridine, chlorobenzene, 4-chlorotoluene, fluorobenzene, and the like.

[0111] Heterocyclic aliphatic compound: In some embodiments, the additive is a heterocyclic aliphatic compound. As used herein, "aliphatic" means a hydrocarbon group having at least 1 carbon atom to 50 carbon atoms (C 1-50 ), e.g., 1 to 25 carbon atoms (C 1-25 ), or 1 to 10 carbon atoms (C 1-10 ), which includes alkanes (or alkyls), alkenes (or alkenyls), alkynes (or alkynyls), including their cyclic versions, and further includes straight-chain and branched-chain arrangements, as well as all stereoisomers and positional isomers. A heterocyclic aliphatic compound is an aliphatic compound containing a 5-, 6-, or 7-membered ring containing 1, 2, 3, or 4 non-carbon heteroatoms (e.g., independently selected from the group consisting of nitrogen, oxygen, phosphorus, sulfur, or halogen), unless otherwise specified. Exemplary heterocyclic aliphatic compounds include pyrrolidine, piperidine, and the like.

[0112] Amine: In some embodiments, the additive is an amine having the formula NR 1 R 2 R 3 , where

[0113] each of R 1 , R 2 , and R 3 is independently selected from hydrogen, hydroxyl, aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combination thereof,

[0114] R 1 and R 2 can together with the atoms to which each is attached optionally form a cycloheteroaliphatic,

[0115] each of R 1 , R 2 , and R 3can, together with the atoms to which each is attached, optionally form a cycloheteroaliphatic.

[0116] In some embodiments, each of R 1 , R 2 , and R 3 is independently selected from alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, haloalkyl, haloalkenyl, haloalkynyl, haloheteroalkyl, haloheteroalkenyl, haloheteroalkynyl, aryl, heterocyclyl, heteroaryl, alkyl-aryl, alkenyl-aryl, alkynyl-aryl, alkyl-heterocyclyl, alkenyl-heterocyclyl, alkynyl-heterocyclyl, alkyl-heteroaryl, alkenyl-heteroaryl, alkynyl-heteroaryl, heteroalkyl-aryl, heteroalkenyl-aryl, heteroalkynyl-aryl, heteroalkyl-heterocyclyl, heteroalkenyl-heterocyclyl, heteroalkynyl-heterocyclyl, heteroalkyl-heteroaryl, heteroalkenyl-heteroaryl, heteroalkynyl-heteroaryl, or any combination thereof. In certain disclosed embodiments, the amine may be further substituted with one or more substituents such as alkoxy, amide, amine, hydroxyl, thioether, thiol, acyloxy, silyl, alicyclic, aryl, aldehyde, ketone, ester, carboxylic acid, acyl, halogenated acyl, cyano, halogen, sulfonate, nitro, nitroso, quaternary amine, pyridinyl (or pyridinyl where the nitrogen atom is functionalized with an aliphatic or aryl group), halogenated alkyl, or any combination thereof.

[0117] In some embodiments, each of R 1 , R 2 , and R 3When at least one of them is aliphatic, haloaliphatic, haloheteroaliphatic, or heteroaliphatic, the additive is an alkylamine. The alkylamine can include dialkylamine, trialkylamine, and their derivatives. Exemplary alkylamines include dimethylisopropylamine, N-ethyldiisopropylamine, trimethylamine, dimethylamine, methylamine, triethylamine, t-butylamine, etc.

[0118] In other embodiments, R 1 、R 2 、and R 3 When at least one of them contains a hydroxyl group, the additive is an alcoholamine. In one example, R 1 、R 2 、and R 3 At least one of them is an aliphatic group substituted with one or more hydroxyl groups. Exemplary alcoholamines include 2-(dimethylamino)ethanol, 2-(diethylamino)ethanol, 2-(dipropylamino)ethanol, 2-(dibutylamino)ethanol, N-ethyldiethanolamine, N-tert butyldiethanolamine, etc.

[0119] In some embodiments, R 1 and R 2 When they combine with the atoms to which each is attached to form a cycloheteroaliphatic group, the additive can be a cyclic amine. Exemplary cyclic amines include piperidine, N-alkylpiperidine (e.g., N-methylpiperidine, N-propylpiperidine, etc.), pyrrolidine, N-alkylpyrrolidine (e.g., N-methylpyrrolidine, N-propylpyrrolidine, etc.), morpholine, N-alkylmorpholine (e.g., N-methylmorpholine, N-propylmorpholine, etc.), piperazine, N-alkylpiperazine, N,N-dialkylpiperazine (e.g., 1,4-dimethylpiperazine), etc.

[0120] In other embodiments, R 1 、R 2 、and R 3When at least one of them contains an aromatic group, the additive is an aromatic amine. In some embodiments, R 1 , R 2 , and R 3 at least one of is aromatic, aliphatic-aromatic, or heteroaliphatic-aromatic. In other embodiments, both R 1 and R 2 contain an aromatic group. In still other embodiments, R 1 and R 2 , and optionally R 3 each together with the atom to which it is attached, are derived from a cycloheteroaliphatic that is aromatic. Exemplary aromatic amines include aniline, histamine, pyrrole, pyridine, imidazole, pyrimidine, and derivatives thereof.

[0121] In some embodiments, the additive may include an amine selected from the group consisting of methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, isopropylamine, 1,2-ethylenediamine, aniline (and aniline derivatives such as N,N-dimethylaniline), N-ethyldiisopropylamine, tert-butylamine, and combinations thereof.

[0122] In some embodiments, the additive may include a fluoroamine. A fluoroamine is an amine having one or more fluorinated substituents. Exemplary fluoroamines that may be used include, but are not limited to, 4-trifluoromethylaniline.

[0123] In some embodiments, the additive may be a nitrogen analog of carbonic acid having the formula R 1 N-C(NR 2 )-NR 3 . Exemplary additives may include, but are not limited to, guanidine or derivatives thereof.

[0124] In some embodiments, the additive may be a relatively low molecular weight amine having a molecular weight of less than 200 g / mol or less than 100 g / mol in certain embodiments. In some embodiments, a high molecular weight amine containing a heterocyclic compound having a long chain and / or an aromatic ring can be used.

[0125] Amino acid: In some embodiments, the additive may include an amino acid. The amino acid may have the formula R-CH(NR’2)-COOH,

[0126] each R and R’ is independently hydroxyl, aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combination thereof.

[0127] Exemplary amino acids that can be used include, but are not limited to, histidine, alanine, and derivatives thereof.

[0128] Organic phosphorus compound: In some embodiments, the additive may include an organic phosphorus compound. The organic phosphorus compound may be a phosphate ester, phosphoric acid amide, phosphonic acid, phosphinic acid, phosphonate, phosphinate, phosphine oxide, phosphine imide, or phosphonium salt. Exemplary organic phosphorus compounds include phosphoric acid and trialkyl phosphate. In some cases, the organic phosphorus compound is a phosphazene. A phosphazene is an organic phosphorus compound containing phosphorus(V) having a double bond between P and N. The phosphazene may have the formula RN=P(NR2)3 (each of R and R2 is independently selected from hydroxyl, aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combination thereof). In some cases, the phosphazene may have the formula n [X2PN] (X is a halide, alkoxide, or amide). Other types of phosphazenes can be used as desired.

[0129] Oxidizing agent: In some embodiments, the additive includes an oxidizing agent. As used herein, an oxidizing agent is a material having the ability to oxidize another substance (e.g., receive electrons therefrom). Exemplary oxidizing agents that may be used include, but are not limited to, hydrogen peroxide, sodium hypochlorite, and tetramethylammonium hydroxide.

[0130] Difluoride source: In some embodiments, the additive includes a difluoride source. A difluoride source is a material that contains or generates difluoride (HF2 - ). Exemplary difluoride sources that may be used include, but are not limited to, ammonium fluoride, aqueous HF, gaseous HF, buffered oxide etchant mixtures (e.g., mixtures of HF and buffers such as ammonium fluoride), and hydrogen fluoride pyridine. In some embodiments, the difluoride source (and / or one or more of the other additives listed herein) may react before or after feeding to the reaction chamber to form HF2 - .

[0131] Aldehyde: In some embodiments, the additive includes an aldehyde having the formula X-[C(O)]-H,

[0132] where X can be selected from hydrogen, -R 1 , -C(R 2 )3, or -[C(R 3 )2] m -C(O)H, and each R 1 , R 2 , and R 3 is independently selected from hydrogen, aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combination thereof, and m is an integer from 0 to 10.

[0133] In some embodiments, R 1 , R 2, and R 3 Each of which is independently alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, haloalkyl, haloalkenyl, haloalkynyl, haloheteroalkyl, haloheteroalkenyl, haloheteroalkynyl, aryl, heterocyclyl, heteroaryl, alkyl-aryl, alkenyl-aryl, alkynyl-aryl, alkyl-heterocyclyl, alkenyl-heterocyclyl, alkynyl-heterocyclyl, alkyl-heteroaryl, alkenyl-heteroaryl, alkynyl-heteroaryl, heteroalkyl-aryl, heteroalkenyl-aryl, heteroalkynyl-aryl, heteroalkyl-heterocyclyl, heteroalkenyl-heterocyclyl, heteroalkynyl-heterocyclyl, heteroalkyl-heteroaryl, heteroalkenyl-heteroaryl, heteroalkynyl-heteroaryl, or any combination thereof. In certain disclosed embodiments, the aldehyde or ketone may be further substituted with one or more substituents such as aldehyde (-C(O)H), oxo (=O), alkoxy, amide, amine, hydroxyl, thioether, thiol, acyloxy, silyl, alicyclic, aryl, aldehyde, ketone, ester, carboxylic acid, acyl, halogenated acyl, cyano, halogen, sulfonate, nitro, nitroso, quaternary amine, pyridinyl (or pyridinyl in which the nitrogen atom is functionalized with an aliphatic or aryl group), halogenated alkyl, or any combination thereof.

[0134] In some embodiments, when X = aromatic, the additive can be an aromatic aldehyde. Exemplary aromatic aldehydes include benzaldehyde, 1-naphthaldehyde, phthalaldehyde, and the like.

[0135] In other embodiments, when X = aliphatic, the additive can be an aliphatic aldehyde. Exemplary aliphatic aldehydes include acetaldehyde, propionaldehyde, butyraldehyde, isovaleraldehyde, and the like.

[0136] In yet other embodiments, X = -[C(R 3 )2] m -C(O)H, and when m is from 0 to 10, or when X is an aliphatic or heteroaliphatic substituted with -C(O)H, the additive can be a dialdehyde. Exemplary dialdehydes include glyoxal, phthalaldehyde, glutaraldehyde, malondialdehyde, succinaldehyde, and the like.

[0137] In some examples, the aldehyde used as the additive may be selected from the group consisting of acrolein, acetaldehyde, formaldehyde, benzaldehyde, propionaldehyde, butyraldehyde, cinnamaldehyde, vanillin, and tolualdehyde. In these or other cases, the aldehyde used as the additive may be selected from the aldehydes described in this section and the aldehydes described in the section on aldehydes and organic solvents.

[0138] Carbene: In some embodiments, the additive comprises a carbene. The carbene may have the formula X-(C:)-Y,

[0139] where each of X and Y is independently selected from H, halo, -[C(R 1 )2] m -C(R 2 )3, -C(O)-R 1 , or -C(=NR 1 )-R 2 , -NR 1 R 2 , -OR 2 , -SR 2 , or -C(R 2 )3, and each of R 1 and R 2 is independently selected from hydrogen, hydroxyl, aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combination thereof, m is an integer from 0 to 10,

[0140] R 1and R 2 can each, together with the atom to which it is attached, optionally form a cycloheteroaliphatic group,

[0141] X and Y can each, together with the atom to which it is attached, optionally form an alicyclic group or a cycloheteroaliphatic group.

[0142] Furthermore, the additive can be a carbocation having the formula R 1 -C + (R)-R 2 wherein each of R, R 1 , and R 2 is independently selected from hydrogen, aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combination thereof.

[0143] In some embodiments, each R, R 1 , and R 2is independently selected from alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, haloalkyl, haloalkenyl, haloalkynyl, haloheteroalkyl, haloheteroalkenyl, haloheteroalkynyl, aryl, heterocyclyl, heteroaryl, alkyl-aryl, alkenyl-aryl, alkynyl-aryl, alkyl-heterocyclyl, alkenyl-heterocyclyl, alkynyl-heterocyclyl, alkyl-heteroaryl, alkenyl-heteroaryl, alkynyl-heteroaryl, heteroalkyl-aryl, heteroalkenyl-aryl, heteroalkynyl-aryl, heteroalkyl-heterocyclyl, heteroalkenyl-heterocyclyl, heteroalkynyl-heterocyclyl, heteroalkyl-heteroaryl, heteroalkenyl-heteroaryl, heteroalkynyl-heteroaryl, or any combination thereof. In certain disclosed embodiments, the carbene may be further substituted with one or more substituents such as alkoxy, amide, amine, hydroxyl, thioether, thiol, acyloxy, silyl, alicyclic, aryl, aldehyde, ketone, ester, carboxylic acid, acyl, halogenated acyl, cyano, halogen, sulfonate, nitro, nitroso, quaternary amine, pyridinyl (or pyridinyl in which the nitrogen atom is functionalized with an aliphatic or aryl group), halogenated alkyl, or any combination thereof. In any embodiment of the carbene, R 1 and R 2 can each be independently selected.

[0144] In some embodiments, when at least one of X or Y is halo, the additive can be a halocarbene. Exemplary non-limiting halocarbenes include dihalocarbenes such as dichlorocarbene, difluorocarbene, and the like.

[0145] In some embodiments, when X = Y = -NR 1 R 2 the additive can be a diaminocarbene. In one example, R 1 and R 2Each of is independently aliphatic. Exemplary diaminocarbenes include bis(diisopropylamino)carbene, and the like.

[0146] In another embodiment, at least one of X or Y = -NR 1 R 2 and R in X or Y 1 and R 2 When both of the aryl groups, taken together with the nitrogen atom to which each is attached, form a cycloheteroaliphatic group, the additive can be a cyclic diaminocarbene. Exemplary cyclic diaminocarbenes include bis(N-piperidyl)carbene, bis(N-pyrrolidinyl)carbene, and the like.

[0147] In one example, X=Y=-NR 1 R 2 and R from X 1 R from the group and Y 2 When the groups are taken together with the nitrogen atom to which each is attached to form a cycloheteroaliphatic group, the additive is an N-heterocyclic carbene. Exemplary N-heterocyclic carbenes include imidazol-2-ylidene (e.g., 1,3-dimesityl imidazol-2-ylidene, 1,3-dimesityl-4,5-dichloroimidazol-2-ylidene, 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene, 1,3-di-tert-butylimidazol-2-ylidene, etc.), imidazolidin-2-ylidene (e.g., 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene), triazol-5-ylidene (e.g., 1,3,4-triphenyl-4,5-dihydro-1H-1,2,4-triazol-5-ylidene), etc.

[0148] In some embodiments, X=-NR 1 R 2 and Y=-SR 2 and R from X 1 R from the group and Y 2When the groups, together with the nitrogen atoms to which each is attached, form a cycloheteroaliphatic group, the additive is an acyclic thioalkylaminocarbene. Exemplary cyclic thioalkylaminocarbenes include thiazol-2-ylidene (e.g., 3-(2,6-diisopropylphenyl)thiazol-2-ylidene, etc.).

[0149] In some embodiments, X = -NR 1 R 2 and Y = -C(R 2 )3, and when the R 1 group from X and the R 2 group from Y, together with the atoms to which each is attached, form a cycloheteroaliphatic group, the additive is a cyclic alkylaminocarbene.

[0150] Exemplary cyclic alkylaminocarbenes include pyrrolidin-2-ylidene (e.g., 1,3,3,5,5-pentamethyl-pyrrolidin-2-ylidene, etc.) and piperidin-2-ylidene (e.g., 1,3,3,6,6-pentamethyl-piperidin-2-ylidene, etc.).

[0151] Further exemplary carbenes and their derivatives include compounds having a thiazole-2-ylidene moiety, a dihydroimidazole-2-ylidene moiety, an imidazole-2-ylidene moiety, a triazole-5-ylidene moiety, or a cyclopropenylidene moiety. Still other carbenes and carbene analogs include aminothiocarbene compounds, aminooxycarbene compounds, diamino carbene compounds, heteroaminocarbene compounds, 1,3-dithiolium carbene compounds, mesoionic carbene compounds (e.g., imidazolin-4-ylidene compounds, 1,2,3-triazolylidene compounds, pyrazolinylidene compounds, tetrazole-5-ylidene compounds, isoxazole-4-ylidene compounds, thiazole-5-ylidene compounds, etc.), cyclic alkylaminocarbene compounds, boranylidene compounds, silylene compounds, stannylene compounds, nitrene compounds, phosphinidene compounds, phoir carbene compounds, etc. Further exemplary carbenes include dimethylimidazole-2-ylidene, 1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazole-2-ylidene, (phosphanyl)(trifluoromethyl)carbene, bis(diisopropylamino)carbene, bis(diisopropylamino)cyclopropenylidene, 1,3-dimesityl-4,5-dichloroimidazole-2-ylidene, 1,3-diadamantylimidazole-2-ylidene, 1,3,4,5-tetramethylimidazole-2-ylidene, 1,3-dimesitylimidazole-2-ylidene, 1,3-dimesitylimidazole-2-ylidene, 1,3,5-triphenyltriazole-5-ylidene, bis(diisopropylamino)cyclopropenylidene, bis(9-anthryl)carbene, norbornene-7-ylidene, dihydroimidazole-2-ylidene, methylidene carbene, etc.

[0152] Organic acid: In some embodiments, the additive comprises an organic acid. The organic acid may have the formula R-CO2H, where R is selected from hydrogen, aliphatic, haloaliphatic, haloheteroaliphatic, heteroaliphatic, aromatic, aliphatic-aromatic, heteroaliphatic-aromatic, or any combination thereof. In certain embodiments, R is alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, haloalkyl, haloalkenyl, haloalkynyl, haloheteroalkyl, haloheteroalkenyl, haloheteroalkynyl, aryl, heteroaryl, alkyl-aryl, alkenyl-aryl, alkynyl-aryl, alkyl-heteroaryl, alkenyl-heteroaryl, alkynyl-heteroaryl, heteroalkyl-aryl, heteroalkenyl-aryl, heteroalkynyl-aryl, heteroalkyl-heteroaryl, heteroalkenyl-heteroaryl, heteroalkynyl-heteroaryl, or any combination thereof. In certain disclosed embodiments, R may be further substituted with one or more substituents such as alkoxy, amide, amine, thioether, hydroxyl, thiol, acyloxy, silyl, alicyclic, aryl, aldehyde, ketone, ester, carboxylic acid, acyl, halogenated acyl, cyano, halogen, sulfonate, nitro, nitroso, quaternary amine, pyridinyl (or pyridinyl where the nitrogen atom is functionalized with an aliphatic or aryl group), halogenated alkyl, or any combination thereof. In certain embodiments, the organic acid may be selected from formic acid and acetic acid.

[0153] Substitution: Any of the exemplary materials described herein includes unsubstituted and / or substituted forms of the compounds. Non-limiting exemplary substituents include, for example, 1, 2, 3, 4, or more substituents independently selected from the group consisting of: (1) C 1-6 alkoxy (e.g., -O-R, where R is C 1-6 alkyl), (2) C 1-6 alkylsulfinyl (e.g., -S(O)-R, where R is C 1-6 alkyl), (3) C 1-6Alkylsulfonyl (e.g., -SO2-R, where R is C 1-6 alkyl), (4) amine (e.g., -C(O)NR 1 R 2 or -NHCOR 1 , R 1 and R 2 each is independently selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, or any combination thereof as defined herein, or R 1 and R 2 together with the nitrogen atom to which each is attached form a heterocyclyl group as defined herein), (5) aryl, (6) arylalkoxy (e.g., -O-L-R, where L is alkyl and R is aryl), (7) aroyl (e.g., -C(O)-R, where R is aryl), (8) azide (e.g., -N3), (9) cyano (e.g., -CN), (10) aldehyde (e.g., -C(O)H), (11) C 3-8 cycloalkyl, (12) halo, (13) heterocyclyl (e.g., a 5-, 6-, or 7-membered ring containing 1, 2, 3, or 4 non-carbon heteroatoms as defined herein), (14) heterocyclyloxy (e.g., -O-R, where R is a heterocyclyl as defined herein), (15) heterocyclylcarbonyl (e.g., -C(O)-R, where R is a heterocyclyl as defined herein), (16) hydroxyl (e.g., -OH), (17) N-protected amino, (18) nitro (e.g., -NO2), (19) oxo (e.g., =O), (20) C 1-6 thioalkoxy (e.g., -S-R, where R is C 1-6 alkyl), (21) thiol (e.g., -SH), (22) -CO2R 1 , R 1 is (a) hydrogen, (b) C 1-6 alkyl, (c) C 4-18 aryl, and (d) C 1-6 alkyl-C 4-18 aryl (e.g., -L-R, where L is C 1-6 alkyl and R is C 4-18selected from the group consisting of aryl), (23)-C(O)NR 1 R 2 、R 1 and R 2 each independently is (a) hydrogen, (b) C 1-6 alkyl, (c) C 4-18 aryl, and (d) C 1-6 alkyl-C 4-18 aryl (e.g., -L-R, L is C 1-6 alkyl and R is C 4-18 aryl), selected from the group consisting of (24)-SO2R 1 、R 1 is (a) C 1-6 alkyl, (b) C 4-18 aryl, and (c) C 1-6 alkyl-C 4-18 aryl (e.g., -L-R, L is C 1-6 alkyl and R is C 4-18 aryl), selected from the group consisting of (25)-SO2NR 1 R 2 、R 1 and R 2 each independently is (a) hydrogen, (b) C 1-6 alkyl, (c) C 4-18 aryl, and (d) C 1-6 alkyl-C 4-18 aryl (e.g., -L-R, L is C 1-6 alkyl and R is C 4-18 selected from the group consisting of), and (26)-NR 1 R 2 、R 1 and R 2 each independently is (a) hydrogen, (b) N-protecting group, (c) C 1-6 alkyl, (d) C 2-6 alkenyl, (e) C 2-6 alkynyl, (f) C 4-18 aryl, (g) C 1-6 alkyl-C 4-18 aryl (e.g., -L-R, L is C 1-6 alkyl and R is C 4-18 aryl), (h) C3-8 Cycloalkyl, and (i) C 1-6 alkyl-C 3-8 Cycloalkyl (e.g., -L-R, where L is C 1-6 alkyl and R is C 3-8 cycloalkyl) selected from the group consisting of, and in one embodiment, there are also no two groups bonded to the nitrogen atom via a carbonyl group or a sulfonyl group.

[0154] In certain embodiments, the additive acts as a proton acceptor and can promote the formation of HF2 - In some such cases, HF2 - can actively etch one or more materials on a substrate such as an oxide material or another material.

[0155] Etching The gas-phase species fed into the reaction chamber may collectively be referred to as a gas mixture. The non-inert species (e.g., reactants other than the carrier gas) fed into the reaction chamber may collectively be referred to as a reactant mixture. The gas mixture includes the reactant mixture and the carrier gas. In some cases, the reactant mixture and / or the gas mixture may have a specific composition. For example, the halogen source may be provided in the reactant mixture at a concentration of about 20-100% (volume ratio), or about 20-99% (volume ratio). In these or other cases, the halogen source may be provided in the gas mixture at a concentration of about 0.5-20% (volume ratio). The organic solvent and / or water may be provided in the reactant mixture at a concentration of about 10-100% (volume ratio), or about 10-99% (volume ratio). In these or other cases, the organic solvent and / or water may be provided in the gas mixture at a concentration of about 0-10% (volume ratio), for example about 1-10% (volume ratio). The additive may be provided in the reactant mixture at a concentration of about 0.2-5% (volume ratio). In these or other cases, the additive may be provided in the gas mixture at a concentration of about 0-0.2%, or about 0.0001-0.2% (volume ratio). The carrier gas may be provided in the gas mixture at a concentration of about 0-99% (volume ratio).

[0156] In some embodiments, the additive and the organic solvent and / or water are mixed such that the additive is about 0.1-5% (by weight) of the additive / organic solvent and / or water mixture. The reactant mixture can be characterized in that, regardless of the order of mixing, the additive is about 0.1-5% (by weight) of the total amount of the additive and the organic solvent and / or water.

[0157] In the same or alternative embodiments, the reactant mixture can be characterized by the ratio of the halogen source to the additive (by volume). As will be further described below, in some embodiments, the selectivity can be adjusted by the volume ratio of the halogen source to the additive, and the selectivity increases with an increase in the amount of the additive (and thus a decrease in the ratio). In some embodiments, the ratio of the halogen source to the additive is 10 or less. In some embodiments, the ratio of the halogen to the source additive is greater than 10.

[0158] According to various embodiments, the reactant mixture can include a halogen source, an alcohol, and an amine, and the amine is 0.1-5 wt% of the total amount of the alcohol and the amine. In some embodiments, the volume ratio of the halogen source to the amine is 10 or less. In other embodiments, the volume ratio of the halogen source to the amine is 10 or more.

[0159] As described above, according to various embodiments, the etching can be selective to one material on the substrate as compared to another material. In other embodiments, the etching can be non-selective with respect to a plurality of materials on the substrate.

[0160] Additional definition This section presents additional definitions that can be used in this specification. Some of the materials described in this section may overlap with materials presented elsewhere in this application.

[0161] The terms "acyl" or "alkanoyl", when used interchangeably herein, refer to a group of 1, 2, 3, 4, 5, 6, 7, 8 or more carbon atoms of linear, branched, cyclic configuration, saturated, unsaturated, and aromatic, and combinations thereof, or hydrogen, bonded to a parent molecular group via a carbonyl group as defined herein. This group is exemplified by formyl, acetyl, propionyl, isobutyryl, butanoyl, etc. In some embodiments, the acyl group or alkanoyl group is -C(O)-R, where R is hydrogen, an aliphatic group, or an aromatic group as defined herein.

[0162] "Acyl halide" means -C(O)X, where X is a halogen such as Br, F, I, or Cl.

[0163] "Aldehyde" means the -C(O)H group.

[0164] "Aliphatic" means a hydrocarbon group having at least 1 carbon atom to 50 carbon atoms (C 1-50 ), for example 1 to 25 carbon atoms (C 1-25 ), or 1 to 10 carbon atoms (C 1-10 ), and includes alkanes (or alkyls), alkenes (or alkenyls), alkynes (or alkynyls), including their cyclic versions, as well as straight and branched chain arrangements, and all stereoisomers and positional isomers.

[0165] "Alkyl-aryl", "alkenyl-aryl", and "alkynyl-aryl" mean an aryl group as defined herein that is coupled (or bonded) to, or can be coupled (or bonded) to, a parent molecular group via an alkyl group, an alkenyl group, or an alkynyl group, respectively, as defined herein. An alkyl-aryl group, an alkenyl-aryl group, and / or an alkynyl-aryl group can be substituted or unsubstituted. For example, an alkyl-aryl group, an alkenyl-aryl group, and / or an alkynyl-aryl group can be substituted with one or more substituents as described herein for alkyl, alkenyl, alkynyl, and / or aryl. Exemplary unsubstituted alkyl-aryl groups are those having 7 to 16 carbons (C 7-16 alkyl-aryl), as well as those having an alkyl group having 1 to 6 carbons and an aryl group having 4 to 18 carbons (i.e., C 1-6 alkyl-C 4-18 aryl). Exemplary unsubstituted alkenyl-aryl groups are those having 7 to 16 carbons (C 7-16 alkenyl-aryl), as well as those having an alkenyl group having 2 to 6 carbons and an aryl group having 4 to 18 carbons (i.e., C 2-6 alkenyl-C 4-18 aryl). Exemplary unsubstituted alkynyl-aryl groups are those having 7 to 16 carbons (C 7-16 alkynyl-aryl), as well as those having an alkynyl group having 2 to 6 carbons and an aryl group having 4 to 18 carbons (i.e., C 2-6 alkynyl-C 4-18Those having an aryl group. In some embodiments, the alkyl-aryl group is -L-R, where L is an alkyl group as defined herein and R is an aryl group as defined herein. In some embodiments, the alkenyl-aryl group is -L-R, where L is an alkenyl group as defined herein and R is an aryl group as defined herein. In some embodiments, the alkynyl-aryl group is -L-R, where L is an alkynyl group as defined herein and R is an aryl group as defined herein.

[0166] "Alkenyl" means an unsaturated monovalent hydrocarbon having at least 2 to 50 carbon atoms (C 2-50 ), for example 2 to 25 carbon atoms (C 2-25 ), or 2 to 10 carbon atoms (C 2-10 ), and having at least one carbon-carbon double bond, and the unsaturated monovalent hydrocarbon can be obtained by removing one hydrogen atom from one carbon atom of the parent alkene. The alkenyl group can be branched, straight-chain, cyclic (e.g., cycloalkenyl), cis, or trans (e.g., E or Z). Exemplary alkenyls include optionally substituted C 2-24 alkyl groups having one or more double bonds. The alkenyl group can become monovalent or polyvalent (e.g., divalent) by removing one or more hydrogens to form a suitable bond to the parent molecular group or a suitable bond between the parent molecular group and another substituent. The alkenyl group can be substituted or unsubstituted. For example, the alkenyl group can be substituted with one or more of the substituents described herein for alkyl.

[0167] "Alkyl-heteroaryl" means a heteroaryl group as defined herein attached to a parent molecular group via an alkyl group as defined herein. In some embodiments, the alkyl-heteroaryl group is -L-R, where L is an alkyl group as defined herein and R is a heteroaryl group as defined herein.

[0168] "Alkyl - heterocyclyl", "alkenyl - heterocyclyl", and "alkynyl - heterocyclyl" mean a heterocyclyl group as defined herein that is coupled (or bonded) to a parent molecular group through an alkyl group, alkenyl group, or alkynyl group as defined herein, respectively, or can be coupled (or bonded). The alkyl - heterocyclyl group, alkenyl - heterocyclyl group, and / or alkynyl - heterocyclyl group can be substituted or unsubstituted. For example, the alkyl - heterocyclyl group, alkenyl - heterocyclyl group, and / or alkynyl - heterocyclyl group can be substituted with one or more substituents described herein for alkyl, alkenyl, alkynyl, and / or heterocyclyl. Exemplary unsubstituted alkyl - heterocyclyl groups are those having 2 to 16 carbons (C 2-16 alkyl - heterocyclyl), as well as those having an alkyl group with 1 to 6 carbons and a heterocyclyl group with 1 to 18 carbons (i.e., C 1-6 alkyl - C 1-18 heterocyclyl). Exemplary unsubstituted alkenyl - heterocyclyl groups are those having 3 to 16 carbons (C 3-16 alkenyl - heterocyclyl), as well as those having an alkenyl group with 2 to 6 carbons and a heterocyclyl group with 1 to 18 carbons (i.e., C 2-6 alkenyl - C 1-18 heterocyclyl). Exemplary unsubstituted alkynyl - heterocyclyl groups are those having 3 to 16 carbons (C 3-16 alkynyl - heterocyclyl), as well as those having an alkynyl group with 2 to 6 carbons and a heterocyclyl group with 1 to 18 carbons (i.e., C 2-6 alkynyl - C 1-18Those having a (heterocyclyl). In some embodiments, the alkyl-heterocyclyl group is -L-R, where L is an alkyl group as defined herein and R is a heterocyclyl group as defined herein. In some embodiments, the alkenyl-heterocyclyl group is -L-R, where L is an alkenyl group as defined herein and R is a heterocyclyl group as defined herein. In some embodiments, the alkynyl-heterocyclyl group is -L-R, where L is an alkynyl group as defined herein and R is a heterocyclyl group as defined herein.

[0169] "Alkoxy" means -OR, where R is an optionally substituted aliphatic group as described herein. Exemplary alkoxy groups include, but are not limited to, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, t-butoxy, sec-butoxy, n-pentoxy, trihaloalkoxy, such as trifluoromethoxy, etc. The alkoxy group can be substituted or unsubstituted. For example, the alkoxy group can be substituted with one or more substituents as described herein for alkyl. Exemplary unsubstituted alkoxy groups include C 1-3 、C 1-6 、C 1-12 、C 1-16 、C 1-18 、C 1-20 、or C 1-24 alkoxy groups.

[0170] "Alkyl" means from at least 1 carbon atom to 50 carbon atoms (C 1-50 ), for example from 1 to 25 carbon atoms (C 1-25 ), or from 1 to 10 carbon atoms (C 1-10means a saturated monovalent hydrocarbon having, and the saturated monovalent hydrocarbon can be obtained by removing one hydrogen atom from one carbon atom of a parent compound (for example, an alkane). The alkyl group can be branched, straight-chain, or cyclic (for example, cycloalkyl). Exemplary alkyls include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, s-pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, eicosyl, tetracosyl, etc., branched or unbranched saturated hydrocarbon groups having 1 to 24 carbon atoms. The alkyl group can be substituted or unsubstituted. The alkyl group can become monovalent or polyvalent (for example, divalent) by removing one or more hydrogens to form an appropriate bond to a parent molecular group or an appropriate bond between a parent molecular group and another substituent. For example, the alkyl group can be substituted with 4 substituents in the case of an alkyl group of 1, 2, 3, or 2 or more carbons independently selected from the group consisting of: (1) C 1-6 Alkoxy (for example, -O-R, where R is C 1-6 alkyl), (2) C 1-6 Alkylsulfinyl (for example, -S(O)-R, where R is C 1-6 alkyl), (3) C 1-6 Alkylsulfonyl (for example, -SO2-R, where R is C 1-6 alkyl), (4) Amine (for example, -C(O)NR 1 R 2 or -NHCOR 1 , where each of R 1 and R 2 is independently selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, or any combination thereof as defined herein, or R 1 and R 2(which, together with the nitrogen atom to which each is attached, forms a heterocyclyl group as defined herein), (5) aryl, (6) arylalkoxy (e.g., -O-L-R, where L is alkyl and R is aryl), (7) aroyl (e.g., -C(O)-R, where R is aryl), (8) azide (e.g., -N3), (9) cyano (e.g., -CN), (10) aldehyde (e.g., -C(O)H), (11) C 3-8 cycloalkyl, (12) halo, (13) heterocyclyl (e.g., a 5-, 6-, or 7-membered ring containing 1, 2, 3, or 4 non-carbon heteroatoms as defined herein), (14) heterocyclyloxy (e.g., -O-R, where R is a heterocyclyl as defined herein), (15) heterocyclylcarbonyl (e.g., -C(O)-R, where R is a heterocyclyl as defined herein), (16) hydroxyl (e.g., -OH), (17) N-protected amino, (18) nitro (e.g., -NO2), (19) oxo (e.g., =O), (20) C 1-6 thioalkoxy (e.g., -S-R, where R is alkyl), (21) thiol (e.g., -SH), (22) -CO2R 1 , R 1 is selected from the group consisting of (a) hydrogen, (b) C 1-6 alkyl, (c) C 4-18 aryl, and (d) C 1-6 alkyl-C 4-18 aryl (e.g., -L-R, where L is C 1-6 alkyl and R is C 4-18 aryl), (23) -C(O)NR 1 R 2 , R 1 and R 2 each independently is selected from the group consisting of (a) hydrogen, (b) C 1-6 alkyl, (c) C 4-18 aryl, and (d) C 1-6 alkyl-C 4-18 aryl (e.g., -L-R, where L is C 1-6 alkyl and R is C 4-18 aryl), (24) -SO2R 1 , R1 is selected from the group consisting of (a) C 1-6 alkyl, (b) C 4-18 aryl, and (c) C 1-6 alkyl-C 4-18 aryl (e.g., -L-R, where L is C 1-6 alkyl and R is C 4-18 aryl), and each of (25) -SO2NR 1 R 2 and R 1 and R 2 is independently selected from the group consisting of (a) hydrogen, (b) C 1-6 alkyl, (c) C 4-18 aryl, and (d) C 1-6 alkyl-C 4-18 aryl (e.g., -L-R, where L is C 1-6 alkyl and R is C 4-18 aryl), and each of (26) -NR 1 R 2 and R 1 and R 2 is independently selected from the group consisting of (a) hydrogen, (b) an N-protecting group, (c) C 1-6 alkyl, (d) C 2-6 alkenyl, (e) C 2-6 alkynyl, (f) C 4-18 aryl, (g) C 1-6 alkyl-C 4-18 aryl (e.g., -L-R, where L is C 1-6 alkyl and R is C 4-18 aryl), (h) C 3-8 cycloalkyl, and (i) C 1-6 alkyl-C 3-8 cycloalkyl (e.g., -L-R, where L is C 1-6 alkyl and R is C 3-8 aryl), and in one embodiment, there are also no two groups bonding to the nitrogen atom via a carbonyl group or a sulfonyl group. The alkyl group can be a primary, secondary, or tertiary alkyl group substituted with one or more substituents (e.g., one or more halo or alkoxy). In some embodiments, the unsubstituted alkyl group is C 1-3 C1-6 , C 1-12 , C 1-16 , C 1-18 , C 1-20 , or C 1-24 is an alkyl group.

[0171] "Alkylsulfinyl" means an alkyl group as defined herein, bonded to the parent molecular group via an -S(O)- group. In some embodiments, an unsubstituted alkylsulfinyl group is C 1-6 or C 1-12 alkylsulfinyl group. In other embodiments, the alkylsulfinyl group is -S(O)-R, where R is an alkyl group as defined herein.

[0172] "Alkylsulfonyl" means an alkyl group as defined herein, bonded to the parent molecular group via an -SO2- group. In some embodiments, an unsubstituted alkylsulfonyl group is C 1-6 or C 1-12 alkylsulfonyl group. In other embodiments, the alkylsulfonyl group is SO2-R, where R is optionally substituted alkyl (e.g., optionally substituted C 1-12 alkyl, haloalkyl, or perfluoroalkyl as described herein).

[0173] "Alkynyl" means an unsaturated monovalent hydrocarbon having at least 2 carbon atoms to 50 carbon atoms (C 2-50 ), e.g., 2 to 25 carbon atoms (C 2-25 ), or 2 to 10 carbon atoms (C 2-10 ), and at least one carbon-carbon triple bond, and the unsaturated monovalent hydrocarbon can be obtained by removing one hydrogen atom from one carbon atom of the parent alkyne. The alkynyl group can be branched, straight-chain, or cyclic (e.g., cycloalkynyl). Exemplary alkynyls include optionally substituted C 2-24An alkyl group is exemplified. An alkynyl group can be cyclic or acyclic and is exemplified by ethynyl, 1-propynyl, etc. An alkynyl group can become monovalent or polyvalent (e.g., divalent) by removing one or more hydrogens to form an appropriate bond to the parent molecular group or an appropriate bond between the parent molecular group and another substituent. An alkynyl group can be substituted or unsubstituted. For example, an alkynyl group can be substituted with one or more of the substituents described herein for alkyl.

[0174] "Amide" means -C(O)NR 1 R 2 or -NHCOR 1 and each of R 1 and R 2 is independently selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, or any combination thereof as defined herein, or R 1 and R 2 together with the nitrogen atom to which each is attached form a heterocyclyl group as defined herein.

[0175] "Amine" means -NR 1 R 2 and each of R 1 and R 2 is independently selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, or any combination thereof as defined herein, or R 1 and R 2 together with the nitrogen atom to which each is attached form a heterocyclyl group as defined herein.

[0176] "Aminoalkyl" means an alkyl group as defined herein substituted by an amine group as defined herein. In some embodiments, the aminoalkyl group is -L-NR 1 R 2 where L is an alkyl group as defined herein and R 1 and R2 Each of which is independently selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, or any combination thereof as defined herein, or R 1 and R 2 together with the nitrogen atom to which each is attached form a heterocyclyl group as defined herein. In other embodiments, the aminoalkyl group is -L-C(NR 1 R 2 )(R 3 )-R 4 wherein L is a covalent bond or an alkyl group as defined herein, and each of R 1 and R 2 is independently selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, or any combination thereof as defined herein, or R 1 and R 2 together with the nitrogen atom to which each is attached form a heterocyclyl group as defined herein, and each of R 3 and R 4 is independently H or alkyl as defined herein.

[0177] "Aromatic", unless otherwise specified, means a cyclic conjugated group or a moiety of 5 to 15 ring atoms having a monocyclic (e.g., phenyl) or multiple condensed rings where at least one ring is aromatic (e.g., naphthyl, indolyl, or pyrazolopyridinyl), i.e., at least one ring and optionally multiple condensed rings have a continuous delocalized π electron system. Typically, the number of out-of-plane π electrons corresponds to the Hückel rule (4n + 2). The point of attachment to the parent structure typically occurs through the aromatic portion of the fused ring system.

[0178] "Aryl" means a monocyclic or multiple condensed rings having at least 5 carbon atoms to 15 carbon atoms (C 5-15 ), e.g., 5 to 10 carbon atoms (C 5-10means an aromatic carbocyclic group, and its fused ring may or may not be aromatic when the bonding point to the remaining positions of the compounds disclosed herein is through an atom of the aromatic carbocyclic group. The aryl group may be substituted with one or more groups other than hydrogen, such as aliphatic, heteroaliphatic, aromatic, other functional groups, or any combination thereof. Exemplary aryl groups include, but are not limited to, benzyl, naphthalene, phenyl, biphenyl, phenoxybenzene, etc. The term aryl also includes heteroaryl, which is defined as a group containing an aromatic group having at least one heteroatom incorporated within the ring of the aromatic group. Examples of heteroatoms include, but are not limited to, nitrogen, oxygen, sulfur, and phosphorus. Similarly, the term non-heteroaryl, which is also included in the term aryl, defines a group containing an aromatic group that does not contain a heteroatom. The aryl group may be substituted or unsubstituted. The aryl group can be substituted with 1, 2, 3, 4, or 5 substituents independently selected from the group consisting of: (1) C 1-6 alkanoyl (e.g., -C(O)-R, where R is C 1-6 alkyl), (2) C 1-6 alkyl, (3) C 1-6 alkoxy (e.g., -O-R, where R is C 1-6 alkyl), (4) C 1-6 alkoxy-C 1-6 alkyl (e.g., -L-O-R, where each of L and R is independently C 1-6 alkyl), (5) C 1-6 alkylsulfinyl (e.g., -S(O)-R, where R is C 1-6 alkyl), (6) C 1-6 alkylsulfinyl-C 1-6 alkyl (e.g., -L-S(O)-R, where each of L and R is independently C 1-6 alkyl), (7) C 1-6 alkylsulfonyl (e.g., -SO2-R, where R is C 1-6 alkyl), (8) C 1-6 alkylsulfonyl-C 1-6 alkyl (e.g., -L-SO2-R, where each of L and R is independently C 1-6is alkyl), (9) aryl, (10) amine (e.g., -NR 1 R 2 , R 1 and R 2 each is independently selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, or any combination thereof as defined herein, or R 1 and R 2 together with the nitrogen atom to which each is attached form a heterocyclyl group as defined herein), (11) C 1-6 aminoalkyl (e.g., -L 1 -NR 1 R 2 or -L 2 -C(NR 1 R 2 )(R 3 )-R 4 , L 1 is C 1-6 alkyl, L2 is a covalent bond or C 1-6 alkyl, and each of R 1 and R 2 is independently selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, or any combination thereof as defined herein, or R 1 and R 2 together with the nitrogen atom to which each is attached form a heterocyclyl group as defined herein, and each of R 3 and R 4 is independently H or C 1-6 alkyl), (12) heteroaryl, (13) C 1-6 alkyl-C 4-18 aryl (e.g., -L-R, L is C 1-6 alkyl, and R is C 4-18 aryl), (14) aroyl (e.g., -C(O)-R, R is aryl), (15) azide (e.g., -N3), (16) cyano (e.g., -CN), (17) C 1-6 azidoalkyl (e.g., -L-N3, L is C 1-6is alkyl), (18) aldehyde (e.g., -C(O)H), (19) aldehyde-C 1-6 alkyl (e.g., -L-C(O)H, L is C 1-6 alkyl), (20) C 3-8 cycloalkyl, (21) C 1-6 alkyl-C 3-8 cycloalkyl (e.g., -L-R, L is C 1-6 alkyl and R is C 3-8 cycloalkyl), (22) halo, (23) C 1-6 haloalkyl (e.g., -L 1 -X or -L 2 -C(X)(R 1 )-R 2 , L 1 is C 1-6 alkyl, L 2 is a covalent bond or C 1-6 alkyl, X is fluoro, bromo, chloro, or iodo, and each of R 1 and R 2 is independently H or C 1-6 alkyl), (24) heterocyclyl (e.g., a 5-, 6-, or 7-membered ring containing 1, 2, 3, or 4 non-carbon heteroatoms as defined herein), (25) heterocyclyloxy (e.g., -O-R, R is heterocyclyl as defined herein), (26) heterocyclylcarbonyl (e.g., -C(O)-R, R is heterocyclyl as defined herein), (27) hydroxyl (-OH), (28) C 1-6 hydroxyalkyl (e.g., -L 1 -OH or -L 2 -C(OH)(R 1 )-R 2 , L 1 is C 1-6 alkyl, L 2 is a covalent bond or alkyl, and each of R 1 and R 2 is independently H or C 1-6 alkyl as defined herein), (29) nitro, (30) C 1-6 nitroalkyl (e.g., -L1 -NO or -L 2 -C(NO)(R 1 )-R 2 , L 1 is C 1-6 alkyl, L 2 is a covalent bond or alkyl, R 1 and R 2 each is independently H or C 1-6 alkyl as defined herein), (31) N - protected amino, (32) N - protected amino - C 1-6 alkyl, (33) oxo (e.g., =O), (34) C 1-6 thioalkoxy (e.g., -S - R, R is C 1-6 alkyl), (35) thio - C 1-6 alkoxy - C 1-6 alkyl (e.g., -L - S - R, each of L and R is independently C 1-6 alkyl), (36) -(CH2) r CO2R 1 , r is an integer from 0 to 4, R 1 is selected from the group consisting of (a) hydrogen, (b) C 1-6 alkyl, (c) C 4-18 aryl, and (d) C 1-6 alkyl - C 4-18 aryl (e.g., -L - R, L is C 1-6 alkyl, R is C 4-18 aryl), (37) -(CH2) r CONR 1 R 2 , r is an integer from 0 to 4, each R 1 and R 2 is independently selected from the group consisting of (a) hydrogen, (b) C 1-6 alkyl, (c) C 4-18 aryl, and (d) C 1-6 alkyl - C 4-18 aryl (e.g., -L - R, L is C 1-6 alkyl, R is C 4-18 aryl), (38) -(CH2) r SO2R 1 , r is an integer from 0 to 4, R1 is selected from the group consisting of (a) C 1-6 alkyl, (b) C 4-18 aryl, and (c) C 1-6 alkyl-C 4-18 aryl (e.g., -L-R, where L is C 1-6 alkyl and R is C 4-18 aryl), (39)-(CH2) r SO2NR 1 R 2 , r is an integer from 0 to 4, and each of R 1 and R 2 is independently selected from the group consisting of (a) hydrogen, (b) C 1-6 alkyl, (c) C 4-18 aryl, and (d) C 1-6 alkyl-C 4-18 aryl (e.g., -L-R, where L is C 1-6 alkyl and R is C 4-18 aryl), (40)-(CH2) r NR 1 R 2 , r is an integer from 0 to 4, and each of R 1 and R 2 is independently selected from the group consisting of (a) hydrogen, (b) an N-protecting group, (c) C 1-6 alkyl, (d) C 2-6 alkenyl, (e) C 2-6 alkynyl, (f) C 4-18 aryl, (g) C 1-6 alkyl-C 4-18 aryl (e.g., -L-R, where L is C 1-6 alkyl and R is C 4-18 aryl), (h) C 3-8 cycloalkyl, and (i) C 1-6 alkyl-C 3-8 cycloalkyl (e.g., -L-R, where L is C 1-6 alkyl and R is C 3-8 cycloalkyl), and in one embodiment, there are no two groups bonded to the nitrogen atom via a carbonyl group or a sulfonyl group, (41) thiol (e.g., -SH), (42) perfluoroalkyl (e.g., -(CF2)n CF3, where n is an integer from 0 to 10), (43) perfluoroalkoxy (e.g., -O-(CF2) n CF3, where n is an integer from 0 to 10), (44) aryloxy (e.g., -O-R, where R is aryl), (45) cycloalkoxy (e.g., -O-R, where R is cycloalkyl), (46) cycloalkylalkoxy (e.g., -O-L-R, where L is alkyl and R is cycloalkyl), and (47) arylalkoxy (e.g., -O-L-R, where L is alkyl and R is aryl). In certain embodiments, the unsubstituted aryl group is C 4-18 , C 4-14 , C 4-12 , C 4-10 , C 6-18 , C 6-14 , C 6-12 , or C 6-10 aryl group.

[0179] "Arylalkoxy" means an alkyl-aryl group as defined herein bonded to the parent molecular group through an oxygen atom. In some embodiments, the arylalkoxy group is -O-L-R, where L is an alkyl group as defined herein and R is an aryl group as defined herein.

[0180] "Aryloxy" means -OR, where R is an optionally substituted aryl group as described herein. In some embodiments, the unsubstituted aryloxy group is C 4-18 or C 6-18 aryloxy group.

[0181] "Aroyl" means an aryl group bonded to the parent molecular group through a carbonyl group. In some embodiments, the unsubstituted aroyl group is C 7-11 aroyl or C 5-19 aroyl group. In other embodiments, the aroyl group is -C(O)-R, where R is an aryl group as defined herein.

[0182] "Azido" means an -N3 group.

[0183] "Alkyl azide" means an azide group bonded to a parent molecular group via an alkyl group as defined herein. In some embodiments, the alkyl azide group is -L-N3, where L is an alkyl group as defined herein. "Azo" means an -N=N- group.

[0184] "Carbene" means H2C: and its derivatives having a carbon bearing two non-bonding electrons or (C:). In some embodiments, the carbene is R 1 R 2 (C:), where each of R 1 and R 2 is independently selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, or any combination thereof as defined herein, or R 1 and R 2 together with the atom to which each is attached form a cycloaliphatic group as defined herein.

[0185] "Carbenium cation" means H3C + and its derivatives having a carbon bearing a +1 formal charge or C + . In some embodiments, the carbenium cation is R 1 -C + (R)-R 2 , where each of R, R 1 , and R 2 is independently selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, or any combination thereof as defined herein, or R 1 and R 2 , and optionally R, together with the atom to which each is attached form a cycloaliphatic group as defined herein.

[0186] "Carbonyl" means a -C(O)- group and can also be represented as >C=O.

[0187] "Carboxyl" means a -CO2H group or its anion.

[0188] "Cyano" means a -CN group.

[0189] "Alicyclic" means a cyclic aliphatic group as defined herein.

[0190] "Cycloalkoxy" means a cycloalkyl group as defined herein bonded to a parent molecular group through an oxygen atom. In some embodiments, the cycloalkoxy group is -O-R, where R is a cycloalkyl group as defined herein.

[0191] "Cycloalkylalkoxy" means an alkyl-cycloalkyl group as defined herein bonded to a parent molecular group through an oxygen atom. In some embodiments, the cycloalkylalkoxy group is -O-L-R, where L is an alkyl group as defined herein and R is a cycloalkyl group as defined herein.

[0192] "Cycloalkyl", unless otherwise specified, means a monovalent saturated or unsaturated non-aromatic cyclic hydrocarbon group having 3 to 8 carbons, exemplified by cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, bicyclo[2.2.1]heptyl, etc. The cycloalkyl group can be substituted or unsubstituted. For example, the cycloalkyl group can be substituted with one or more groups including those described herein for alkyl.

[0193] "Cycloheteroaliphatic" means a cyclic heteroaliphatic group as defined herein.

[0194] "Ester" means -C(O)OR or -OC(O)R, where R is selected from aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, or any combination thereof as defined herein.

[0195] "Halo" means F, Cl, Br, or I.

[0196] "Haloaliphatic" means an aliphatic group as defined herein, where one or more of the 1 to 10 hydrogen atoms, such as 1 to 10 hydrogen atoms, are independently replaced by halogen atoms such as fluoro, bromo, chloro, or iodo.

[0197] "Haloalkyl" means an alkyl group as defined herein, where one or more of the 1 to 10 hydrogen atoms, such as 1 to 10 hydrogen atoms, are independently replaced by halogen atoms such as fluoro, bromo, chloro, or iodo. In an independent embodiment, the haloalkyl can be a -CX3 group, where each X can independently be selected from fluoro, bromo, chloro, or iodo. In some embodiments, the haloalkyl group is -L-X, where L is an alkyl group as defined herein and X is fluoro, bromo, chloro, or iodo. In other embodiments, the haloalkyl group is -L-C(X)(R 1 )-R 2 where L is a covalent bond or an alkyl group as defined herein, X is fluoro, bromo, chloro, or iodo, and each of R 1 and R 2 is independently H or alkyl as defined herein.

[0198] "Haloheteroaliphatic" means a heteroaliphatic as defined herein, where one or more of the 1 to 10 hydrogen atoms, such as 1 to 10 hydrogen atoms, are independently replaced by halogen atoms such as fluoro, bromo, chloro, or iodo.

[0199] "Heteroaliphatic" means an aliphatic group as defined herein, containing at least 1 heteroatom to 20 heteroatoms, such as 1 to 15 heteroatoms, or 1 to 5 heteroatoms, which can be selected from, but are not limited to, oxygen, nitrogen, sulfur, silicon, boron, selenium, phosphorus, and their oxidized forms within the group.

[0200] "Heteroalkyl", "heteroalkenyl", and "heteroalkynyl" each mean an alkyl group, alkenyl group, or alkynyl group (which may be branched, straight-chain, or cyclic) as defined herein, and contain from at least 1 to 20 heteroatoms, for example from 1 to 15 heteroatoms, or from 1 to 5 heteroatoms, which can be selected from, but are not limited to, oxygen, nitrogen, sulfur, silicon, boron, selenium, phosphorus, and their oxidized forms within the group.

[0201] "Heteroalkyl-aryl", "heteroalkenyl-aryl", and "heteroalkynyl-aryl" mean an aryl group as defined herein that is coupled to, or can be coupled to, a compound disclosed herein, and the aryl group is coupled to, or is to be coupled to, via a heteroalkyl group, heteroalkenyl group, or heteroalkynyl group as defined herein, respectively. In some embodiments, the heteroalkyl-aryl group is -L-R, where L is a heteroalkyl group as defined herein and R is an aryl group as defined herein. In some embodiments, the heteroalkenyl-aryl group is -L-R, where L is a heteroalkenyl group as defined herein and R is an aryl group as defined herein. In some embodiments, the heteroalkynyl-aryl group is -L-R, where L is a heteroalkynyl group as defined herein and R is an aryl group as defined herein.

[0202] "Heteroalkyl - heteroaryl", "heteroalkenyl - heteroaryl", and "heteroalkynyl - heteroaryl" mean heteroaryl groups as defined herein that are coupled to or can be coupled to the compounds disclosed herein, and the heteroaryl group is coupled to or becomes coupled through a heteroalkyl group, a heteroalkenyl group, or a heteroalkynyl group, each as defined herein. In some embodiments, the heteroalkyl - heteroaryl group is -L-R, where L is a heteroalkyl group as defined herein and R is a heteroaryl group as defined herein. In some embodiments, the heteroalkenyl - heteroaryl group is -L-R, where L is a heteroalkenyl group as defined herein and R is a heteroaryl group as defined herein. In some embodiments, the heteroalkynyl - heteroaryl group is -L-R, where L is a heteroalkynyl group as defined herein and R is a heteroaryl group as defined herein.

[0203] "Heteroaryl" means an aryl group containing at least 1 to 6 heteroatoms, such as 1 to 4 heteroatoms, which can be selected from, but are not limited to, oxygen, nitrogen, sulfur, silicon, boron, selenium, phosphorus, and their oxidized forms within the ring. Such heteroaryl groups can have a monocyclic or multiple fused rings, and the fused rings may or may not be aromatic when the point of attachment is through an atom of the aromatic heteroaryl group and / or may contain heteroatoms. The heteroaryl group may be substituted with one or more groups other than hydrogen, such as aliphatic, heteroaliphatic, aromatic, other functional groups, or any combination thereof. Exemplary heteroaryls include a subset of the heterocyclyl groups as defined herein that are aromatic, i.e., contain 4n + 2 π electrons within a monocyclic or polycyclic ring system.

[0204] "Heteroatom" means an atom other than carbon, such as oxygen, nitrogen, sulfur, silicon, boron, selenium, or phosphorus. In certain disclosed embodiments, such as when valence constraints are not allowed, the heteroatom does not include a halogen atom.

[0205] "Heterocyclyl", unless otherwise specified, means a 5-, 6-, or 7-membered ring containing 1, 2, 3, or 4 non-carbon heteroatoms (independently selected from the group consisting of, for example, nitrogen, oxygen, phosphorus, sulfur, or halogen). The 5-membered ring has 0 to 2 double bonds, and the 6-membered and 7-membered rings have 0 to 3 double bonds. The term "heterocyclyl" also includes bicyclic, tricyclic, and tetracyclic groups, and any of the above heterocycles is condensed to one, two, or three rings independently selected from the group consisting of an aryl ring, a cyclohexane ring, a cyclohexene ring, a cyclopentane ring, a cyclopentene ring, and another monocyclic heterocycle such as indolyl, quinolyl, isoquinolyl, tetrahydroquinolyl, benzofuryl, benzothienyl, etc. Examples of heterocycles include thianyl, thietanyl, tetrahydrothienyl, thianyl, thiepanyl, aziridinyl, azetidinyl, pyrrolidinyl, piperidinyl, azepanyl, pyrrolyl, pyrrolinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl, imidazolyl, imidazolinyl, imidazolidinyl, pyridyl, homopiperidinyl, pyrazinyl, piperazinyl, pyrimidinyl, pyridazinyl, oxazolyl, oxazolidinyl, oxazolidonyl, isoxazolyl, isoxazolidinyl, morpholinyl, thiomorpholinyl, thiazolyl, thiazolidinyl, isothiazolyl, isothiazolidinyl, indolyl, quinolinyl, isoquinolinyl, benzimidazolyl, benzothiazolyl, benzoxazolyl, furyl, thienyl, thiazolidinyl, isothiazolyl, isoindazolyl, triazolyl, tetrazolyl, oxadiazolyl, uracil, thiadiazolyl, pyrimidyl, tetrahydrofuranyl, dihydrofuranyl, dihydrothienyl, dihydroindolyl, tetrahydroquinolyl, tetrahydroisoquinolyl, pyranyl, dihydropyranyl, tetrahydropyranyl, dithiazolyl, dioxanyl, dioxinyl, dithianyl, trithianyl, oxazinyl, thiazinyl, oxothiolanyl, triazinyl, benzofuryl, benzothienyl, etc.

[0206] "Heterocyclyloxy" means a heterocyclyl group as defined herein that is bonded to a parent molecular group through an oxygen atom. In some embodiments, the heterocyclyloxy group is -O-R, where R is a heterocyclyl group as defined herein.

[0207] "Heterocyclyloyl" means a heterocyclyl group as defined herein that is bonded to a parent molecular group through a carbonyl group. In some embodiments, the heterocyclyloyl group is -C(O)-R, where R is a heterocyclyl group as defined herein.

[0208] "Hydroxyl" means -OH.

[0209] "Hydroxyalkyl" means an alkyl group as defined herein that is substituted by one to three hydroxyl groups, provided that no more than one hydroxyl group is bonded to a single carbon atom of the alkyl group, and examples of this group include hydroxymethyl, dihydroxypropyl, etc. In some embodiments, the hydroxyalkyl group is -L-OH, where L is an alkyl group as defined herein. In other embodiments, the hydroxyalkyl group is -L-C(OH)(R 1 )-R 2 where L is a covalent bond or an alkyl group as defined herein, and each of R 1 and R 2 is independently H or alkyl as defined herein.

[0210] "Ketone" means -C(O)R, where R is selected from aliphatic, heteroaliphatic, aromatic, or any combination thereof as defined herein.

[0211] "Nitro" means the -NO2 group.

[0212] "Nitroalkyl" means an alkyl group as defined herein substituted by one to three nitro groups. In some embodiments, the nitroalkyl group is -L-NO, where L is an alkyl group as defined herein. In other embodiments, the nitroalkyl group is -L-C(NO)(R 1 )-R 2 , where L is a covalent bond or an alkyl group as defined herein, and each of R 1 and R 2 is independently H or alkyl as defined herein.

[0213] "Oxo" means the =O group.

[0214] "Oxy" means -O-.

[0215] "Perfluoroalkyl" means an alkyl group as defined herein having each hydrogen atom replaced by a fluorine atom. Exemplary perfluoroalkyl groups include trifluoromethyl, pentafluoroethyl, and the like. In some embodiments, the perfluoroalkyl group is -(CF2) n CF3, where n is an integer from 0 to 10.

[0216] "Perfluoroalkoxy" means an alkoxy group as defined herein having each hydrogen atom replaced by a fluorine atom. In some embodiments, the perfluoroalkoxy group is -O-R, where R is a perfluoroalkyl group as defined herein.

[0217] "Salt" means an ionic form of a compound or structure (e.g., any formula, compound, or composition described herein) that includes a cationic or anionic compound that forms an electrically neutral compound or structure. Salts are well known in the art. For example, non-toxic salts are described in Berge S M et al., "Pharmaceutical salts," J. Pharm. Sci. 1977 January; 66(1):1-19, and "Handbook of Pharmaceutical Salts: Properties, Selection, and Use," Wiley-VCH, April 2011 (2nd rev. ed., eds. P. H. Stahl and C. G. Wermuth). Salts can be prepared separately during the final isolation and purification of the compounds of the invention in-situ, or by reacting the free base group with a suitable organic acid (thereby producing an anionic salt), or by reacting an acid group with a suitable metal or organic salt (thereby producing a cationic salt).Representative anion salts include acetate, adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bicarbonate, bisulfate, bitartrate, borate, bromide, butyrate, camphorate, camphorsulfonate, chloride, citrate, cyclopentanepropionate, digluconate, dihydrochloride, diphosphate, dodecyl sulfate, edetate, ethanesulfonate, fumarate, glucoheptonate, gluconate, glutamate, glycerophosphate, hemisulfate, heptonate, hexanoate, hydrobromide, hydrochloride, hydroiodide, hydroxyethanesulfonate, hydroxynaphthoate, iodide, lactate, lactobionate, laurate, lauryl sulfate, malate, maleate, malonate, mandelate, mesylate, methanesulfonate, methyl bromide, methyl nitrate, methyl sulfate, mucate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, polygalacturonate, propionate, salicylate, stearate, subacetate, succinate, sulfate, tannate, tartrate, theophyllineate, thiocyanate, triethiodide, toluenesulfonate, undecanoate, valerate, etc. Representative cation salts include metal salts, such as alkali or alkaline earth salts, such as barium, calcium (e.g., calcium edetate), lithium, magnesium, potassium, sodium, etc.; other metal salts, such as aluminum, bismuth, iron, and zinc; and, without limitation, non-toxic ammonium, quaternary ammonium, and amine cations, including ammonium, tetramethylammonium, tetraethylammonium, methylamine, dimethylamine, trimethylamine, triethylamine, ethylamine, pyridinium, etc. Other cation salts include organic salts such as chloroprocaine, choline, dibenzylethylenediamine, diethanolamine, ethylenediamine, methylglucamine, and procaine, etc.Still other salts include ammonium, sulfonium, sulfoxonium, phosphonium, iminium, imidazolium, benzimidazolium, amidinium, guanidinium, phosphazininium, phosphazenium, pyridinium, and the like, as well as other cationic groups described herein (e.g., optionally substituted isoxazolium, optionally substituted oxazolium, optionally substituted thiazolium, optionally substituted pyrrolium, optionally substituted furanium, optionally substituted thiophenium, optionally substituted imidazolium, optionally substituted pyrazolium, optionally substituted isothiazolium, optionally substituted triazolium, optionally substituted tetrazolium, optionally substituted furazanium, optionally substituted pyridinium, optionally substituted pyrimidinium, optionally substituted pyrazinium, optionally substituted triazinium, optionally substituted tetrazinium, optionally substituted pyridazinium, optionally substituted oxazinium, optionally substituted pyrrolidinium, optionally substituted pyrazolidinium, optionally substituted imidazolinium, optionally substituted isoxazolidinium, optionally substituted oxazolidinium, optionally substituted piperazinium, optionally substituted piperidinium, optionally substituted morpholinium, optionally substituted azepanium, optionally substituted azepinium, optionally substituted indolium, optionally substituted isoindolium, optionally substituted indolidinium, optionally substituted indazolium, optionally substituted benzimidazolium, optionally substituted isoquinolinium, optionally substituted quinolidinium, optionally substituted dehydroquinolinidinium, optionally substituted quinolinium, optionally substituted isoindolinium, optionally substituted benzimidazolinium, and optionally substituted purinium).

[0218] "Sulfo" means -S(O)2OH group.

[0219] "Sulfonyl" or "sulfonate" means a -S(O)2- group or -SO2R, where R is selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, or any combination thereof as defined herein.

[0220] "Thioalkoxy" means an alkyl group as defined herein bonded to a parent molecular group through a sulfur atom. Exemplary unsubstituted thioalkoxy groups include C 1-6 thioalkoxy. In some embodiments, the thioalkoxy group is -S-R, where R is an alkyl group as defined herein.

[0221] "Thiol" means a -SH group.

[0222] One of ordinary skill in the art will recognize that the above definitions are not intended to include unacceptable substitution patterns (e.g., methyl substituted with five different groups, etc.). Such unacceptable substitution patterns are readily recognized by one of ordinary skill in the art. Any functional group disclosed and / or defined herein may be substituted or unsubstituted, unless otherwise indicated.

[0223] Apparatus The etching methods described herein can be performed in a variety of apparatuses. Suitable apparatuses include a process chamber, a substrate holder within the process chamber configured to hold a substrate in a predetermined position during etching, an inlet to the process chamber for introducing one or more reactants, and a plasma generation mechanism configured to generate a plasma that activates one or more reactants in the process gas. Optionally, the etching apparatus also has the ability to perform deposition.

[0224] Examples of suitable apparatuses include, but are not limited to, inductively coupled plasma (ICP) reactors. Although ICP reactors are described in detail herein, it should be understood that capacitively coupled plasma reactors can also be used.

[0225] FIG. 1 schematically shows a cross-sectional view of an inductively coupled plasma integrated etching apparatus suitable for implementing the etching method described in this specification. An example thereof is a Kiyo (registered trademark) reactor manufactured by Lam Research Corporation in Fremont, California. The apparatus includes a chamber 132 including a chamber body 114, a chuck 116, and a dielectric window 106. The chamber 132 includes a processing region, and the dielectric window 106 is disposed above the processing region. The chuck 116 can be an electrostatic chuck for supporting the substrate 112 and is disposed in the chamber below the processing region. In some embodiments, an internal Faraday shield (not shown) is disposed in the chamber 100 below the dielectric window 106. A transformer coupled plasma (TCP) coil 134 is disposed above the dielectric window 106 and is connected to the matching circuit 102.

[0226] The system includes a bias RF generator 120 that can be defined from one or more generators. When multiple generators are provided, different frequencies can be used to achieve various adjustment characteristics. A bias matching unit 118 is coupled between the RF generator 120 and a conductive plate of the assembly that defines the chuck 116. The chuck 116 also includes electrostatic electrodes that enable chucking and de-chucking of the wafer. Broadly speaking, filters and a DC clamp power supply are provided. Other control systems for lifting the wafer from the chuck 116 can also be provided.

[0227] In various embodiments, the bias voltage of the electrostatic chuck may be set to about 50 Vb, or may be set to different bias voltages according to the process implemented according to the disclosed embodiments. For example, the bias voltage during plasma etching may be about 20 Vb to about 100 Vb, or about 30 Vb to about 150 Vb.

[0228] The first gas injector 104 provides two different channels and injects into the chamber two separate streams of process gas or liquid precursor (in vapor form) from the top of the chamber. It should be understood that multiple gas supply units may be provided to supply different gases to the chamber for various types of operations such as process operations on the wafer, waferless automatic cleaning (WAC) operations, and other operations. The second gas injector 110 provides another gas stream that enters the chamber from the side rather than from the top.

[0229] The delivery system 128 includes, in one embodiment, an etching gas delivery system 127 and a liquid delivery system 129. The manifold 122 is used to select, switch, and / or mix the outputs from the respective delivery systems. As will be described in more detail below, the etching gas delivery system is configured to output an etchant gas optimized for etching one or more layers of the material of the substrate. The manifold 122 is further optimized to perform plasma etching and plug removal operations in response to control from the controller 108.

[0230] In the embodiment of FIG. 4, independent gas streams can be delivered to the chamber. One stream can be injected through the center of the injector 104. The second stream can also be injected through the injector 104, but can also be injected through a different path surrounding the center of the injector 104. The third stream may be injected into the side of the chamber through the side injector 110. In one embodiment, the gas injector 104 also provides optical access to the process chamber along an axial path from a diagnostic endpoint outside the process chamber, for example, through an optical access window.

[0231] To illustrate that etching gas and / or liquid precursors can be provided to the chamber from various locations, various methods of injecting gas into the chamber have been described. In some cases, only injector 104 is used. In other cases, only side injector 110 is used. In other cases, both injector 104 and side injector 110 can be used. In one configuration, manifold 122 controls which gas is supplied to each of the three different gas lines. The manifold 122 enables any type of gas to be provided to any of the three different gas lines. The gas can be fed into the chamber without mixing, or can be mixed with other gases before being introduced into the chamber. In some embodiments, the halogen source and the vaporized organic solvent are fed into the process chamber via separate inlets. In other embodiments, they may be fed via a single inlet.

[0232] Referring back to FIG. 4, vacuum pump 130 is connected to chamber 132 and is capable of controlling the vacuum pressure during operation of the plasma process and removing gaseous by-products from the chamber. Valve 126 is disposed between exhaust port 124 and vacuum pump 130 to control the amount of vacuum suction applied to the chamber.

[0233] The dielectric window 106 can include a ceramic material or a ceramic-like material. Other dielectric materials are possible as long as they can withstand the conditions of the semiconductor etching chamber. Typically, the chamber operates at a temperature in the range of -60 degrees Celsius to about 250 degrees Celsius. The apparatus also typically includes a heater and a temperature control mechanism. The temperature varies depending on the etching process operation and the particular recipe. Chamber 132 also operates under vacuum conditions in the range of about 1 mTorr (mT) to about 10 Torr (133.322 mPa to 1333.22 Pa).

[0234] Although not all are specifically shown, when chamber 132 is installed in either a clean room or a fabrication facility, it is typically coupled to the facility. The facility includes, among other things, piping that provides process gas, vacuum, temperature control, and environmental particle control. These facilities are coupled to chamber 132 when installed in the fabrication facility of interest. Additionally, chamber 132 can be coupled to a transfer chamber that allows a robot to use automated motion to move semiconductor wafers in and out of chamber 132.

[0235] To control the operation of chamber 132 and its associated components, a programmable controller 108 is provided. Broadly speaking, controller 108 can be programmed to execute chamber operations defined by a recipe. A given recipe can specify various parameters for operation, such as application of power to the TCP coil, flow of gas into the chamber, application of vacuum, etc. It should be understood that timing, duration, magnitude, or any other adjustable parameter or controllable feature can be defined by the recipe and executed by the controller to control the operation of chamber 132 and its associated components. Additionally, it is possible to program a series of recipes into controller 108. In one embodiment, the recipe is configured to process an etching operation and includes program instructions for implementing any of the methods provided herein.

[0236] In some embodiments, system controller 108 (which can include one or more physical or logical controllers) controls some or all of the operation of the process chamber. System controller 108 can include one or more memory devices and one or more processors. In some embodiments, the apparatus includes a switching system for controlling the flow rate of process gas. Controller 108 includes, in some embodiments, program instructions for causing any of the steps of the methods provided herein.

[0237] In some embodiments, system controller 108 is part of the system, and such a system may be part of the example described above. Such a system can include semiconductor processing equipment that includes one or more processing tools, one or more chambers, one or more processing platforms, and / or specific processing components (such as wafer pedestals, gas flow systems, etc.). These systems may be integrated with electronics for controlling system operation before, during, and after processing of semiconductor wafers or substrates. Such electronics may be integrated with system controller 108 and may control various components or sub-components of one or more systems. The system controller may be programmed to control any of the processes disclosed herein, depending on the processing parameters and / or the type of system. Such processes include feeding of process gases, temperature setting (e.g., heating and / or cooling), pressure setting, vacuum setting, power setting, radio frequency (RF) generator setting, RF matching circuit setting, frequency setting, flow rate setting, fluid feed setting, position and motion setting, loading and unloading of wafers to and from tools connected or interfaced with a particular system and other transfer tools, and / or loading and unloading of wafers to and from a load lock.

[0238] In a broad sense, system controller 108 may be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operations, enable cleaning operations, enable endpoint measurements, etc. The integrated circuits may include a chip in the form of firmware that stores program instructions, a digital signal processor (DSP), a chip defined as an application-specific integrated circuit (ASIC), and / or one or more microprocessors, i.e., a microcontroller that executes program instructions (e.g., software). The program instructions are instructions communicated to the system controller in the form of various individual settings (or program files) that may define the operating parameters for performing a particular process on or for a semiconductor wafer or for the system. The operating parameters may, in some embodiments, be part of a recipe defined by a process engineer to implement one or more processing steps in the fabrication or removal of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or wafer dies.

[0239] In some embodiments, system controller 108 may be part of a computer that is integrated or coupled with the system or otherwise network-connected to the system, or may be coupled to such a computer, or may be a combination thereof. For example, the controller may be within the "cloud" or may be all or part of a fab host computer system. This enables remote access to wafer processing. The computer enables remote access to the system, monitors the current progress of the fabrication operation, considers the history of past fabrication operations, considers trends or performance criteria from multiple fabrication operations, changes the parameters of the current process, sets the processing steps following the current process, or may initiate a new process. In some examples, a remote computer (e.g., a server) can provide a process recipe to the system through a network. Such a network may include a local network or the Internet. The remote computer may include a user interface that enables entry or programming of parameters and / or settings, and such parameters and / or settings are then communicated from the remote computer to the system. In some examples, system controller 430 receives instructions in the form of data. Such data identifies the parameters for each processing step to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process being performed and the type of tools that the controller is configured to interact with or control. Thus, as described above, system controller 108 may be distributed, for example, by including one or more individual controllers that are network-connected to each other and cooperate towards a common purpose (such as the processes and controls described herein).As an example of a distributed controller for such purposes, one or more integrated circuits on a chamber, which are remotely located (e.g., at the platform level or as part of a remote computer) and are combined to control the process in the chamber, could communicate with one or more integrated circuits.

[0240] Exemplary systems can include, but are not limited to, plasma etching chambers or modules, deposition chambers or modules, spin rinse chambers or modules, metal plating chambers or modules, cleaning chambers or modules, bevel edge etching chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, ALD chambers or modules, ALE chambers or modules, ion implantation chambers or modules, tracking chambers or modules, and any other semiconductor processing systems that may be associated with or used in the fabrication and / or manufacture of semiconductor wafers.

[0241] As described above, depending on one or more process steps performed by a tool, the controller may communicate with one or more other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools located throughout the factory, the main computer, another controller, or a tool used for material transport to load and unload wafer containers to and from tool locations and / or load ports within a semiconductor manufacturing factory.

[0242] In some embodiments, the controller includes program instructions for (i) etching a target material using plasma etching on a semiconductor substrate having an exposed layer of mask material, a concave feature, and a layer of target material beneath the layer of mask material (the target material being exposed at the bottom of the concave feature), thereby increasing the depth of the concave feature, and (ii) etching a blocking material deposited during plasma etching by contacting the semiconductor substrate with a vapor of a liquid selected from the group consisting of a halogen source and an organic solvent and water, to narrow or block the concave feature.

[0243] FIG. 5 is a schematic diagram showing further details of a liquid delivery system according to an embodiment. The liquid delivery system enables the delivery of an organic solvent and / or water in vapor form to the process chamber. As shown in FIG. 5, the liquid delivery system 129 includes a liquid source (e.g., a solvent or water) 308, a liquid flow controller 310, and a vaporizer 312. The liquid source 308 can be fluidly coupled in communication with a facility that provides a suitable liquid solvent or water. As described above, it is possible to use various organic solvents such as alkanes, ketones, and alcohols. The liquid organic solvent or water flows from the source 308 to the liquid flow controller 310, and the liquid flow controller 310 adjusts the flow rate based on instructions received from the controller 108. The liquid flows from the liquid flow controller 310 to the vaporizer 312, and the vaporizer 312 converts the liquid solvent or water from a liquid state to a vapor state. The vaporized precursor flows to the manifold 122, and the manifold 122 supplies the vaporized solvent or water to the gas injector 104 (e.g., see FIG. 4) at an appropriate time based on control received from the controller 108. The vaporized solvent or water flows through the gas injector 104 into the chamber 132 defined by the chamber body 114 (e.g., see FIG. 4). In some embodiments, the vaporized solvent and / or water is delivered to the process chamber through a first inlet, while the halogen source is delivered through a separate inlet. In other embodiments, all components of the etch removal mixture are delivered to the process chamber through a common inlet.

[0244] FIG. 6 illustrates a semiconductor process cluster architecture having various modules that interface with a vacuum transfer module 1038 (VTM). The arrangement of various modules for “transferring” wafers between multiple storage facilities and processing modules is sometimes referred to as a “cluster tool architecture” system. An airlock 1030, also known as a load lock or transfer module, interfaces with the VTM 1038, which then interfaces with four processing modules 1020a - 1020d that can be individually optimized for performing various fabrication processes. By way of example, the processing modules 1020a - 1020d can be implemented to perform substrate etching, deposition, ion implantation, wafer cleaning, sputtering, and / or other semiconductor processes. In some embodiments, plasma etching of a target layer and patterning of a mask layer are performed in the same module. In some embodiments, plasma etching of a target layer and patterning of a mask layer are performed in different modules of the same tool. One or more of the substrate etching processing modules (any of 1020a - 1020d) can be implemented for, e.g., plasma etching of a target layer and other suitable functions according to the disclosed embodiments. The airlock 1030 and the processing modules 1020a - 1020d are sometimes referred to as “stations”. Each station has a facet 1036 that interfaces the station to the VTM 1038. Inside each facet, sensors 1 - 18 are used to detect the passage of the wafer 1026 as it moves between the respective stations.

[0245] Robot 1022 transfers the wafer 1026 between stations. In one embodiment, robot 1022 has one arm, and in another embodiment, robot 1022 has two arms, and each arm has an end effector 1024 for picking up wafers such as the transfer wafer 1026. The front-end robot 1032 in the atmospheric transfer module (ATM) 1040 is used to transfer the wafer 1026 from the cassette or the front opening unified pod (FOUP) 1034 in the load port module (LPM) 1042 to the air lock 1030. The module center 1028 in the processing modules 1020a - 1020d is a place for placing the wafer 1026. The aligner 1044 in the ATM 1040 is used to align the wafer.

[0246] In an exemplary processing method, the wafer is placed in one of the FOUPs 1034 in the LPM 1042. The front-end robot 1032 transfers the wafer from the FOUP 1034 to the aligner 1044, whereby the wafer 1026 can be properly centered before being etched or processed. After being aligned, the wafer 1026 is moved into the air lock 1030 by the front-end robot 1032. Since the air lock 1030 has the ability to match the environment between the ATM 1040 and the VTM 1038, the wafer 1026 can move between the two pressure environments without being damaged. From the air lock 1030, the wafer 1026 is moved by the robot 1022 through the VTM 1038 to one of the processing modules 1020a - 1020d. To achieve this wafer transfer, the robot 1022 uses the end effector 1024 at each of its arms. When the wafer 1026 is processed, it is moved from the processing modules 1020a - 520d to the air lock 1030 by the robot 1022. From here, the wafer 1026 can be moved to one of the FOUPs 1034 or the aligner 1044 by the front-end robot 1032.

[0247] The computer that controls the movement of the wafer may be local to the cluster architecture, or may be located outside the cluster architecture within the manufacturing floor, or at a remote location and connected to the cluster architecture via a network. Note that the controller described above with respect to FIG. 4 can be implemented using the tool of FIG. 6. A machine-readable medium containing instructions for controlling process operations in accordance with the present invention can be coupled to the system controller.

[0248] In some embodiments, a system for processing a semiconductor substrate includes one or more etching chambers and a system controller having program instructions for performing any of the processes or subprocesses described herein.

[0249] In some embodiments, an apparatus is provided that includes a process chamber having a substrate holder configured to hold a semiconductor substrate during etching, an inlet for introducing one or more reactants into the process chamber, optionally a plasma generator configured to generate plasma in a process gas, and a controller. The controller includes program instructions for implementing any of the methods described herein.

[0250] In another aspect, a non-transitory computer machine-readable medium is provided that includes code for causing any of the methods described herein to be performed.

[0251] Further embodiments The apparatuses and processes described herein may be used in conjunction with lithographic patterning tools or processes, for example, for the fabrication or manufacture of semiconductor devices, displays, LEDs, solar panels, and the like. Typically, although not necessarily, such apparatuses and processes are used or executed together in a common fabrication facility. Lithographic patterning of a film typically includes some or all of the following steps, each step enabled by a number of tools available: (1) applying a photoresist to a workpiece (i.e., a substrate) using a spin-on tool or a spray-on tool; (2) curing the photoresist using a hot plate or an oven or a UV curing tool; (3) exposing the photoresist with visible light or UV light or X-ray light using a tool such as a wafer stepper; (4) developing the resist to selectively remove the resist using a tool such as a wet bench, thereby patterning the resist; (5) transferring the resist pattern to the underlying film or workpiece by using a dry etching tool or a plasma-assisted etching tool; and (6) removing the resist using a tool such as an RF or microwave plasma resist stripper. In some embodiments, these steps are performed to form a patterned mask layer prior to etching of the target layer.

Claims

1. A method for etching a material on a semiconductor substrate, (a) To provide a semiconductor substrate having an exposed layer of mask material, a concave feature, and a layer of target material beneath the layer of mask material, wherein the target material is exposed at the bottom of the concave feature, (b) Etching the target material using plasma etching to increase the depth of the concave feature, wherein the etching of the target material narrows or blocks the concave feature at least at one location by deposition of a blocking material, (c) Etching the blocking material by bringing the semiconductor substrate into contact with a halogen source without bringing the substrate into contact with an organic solvent and without bringing the substrate into contact with water. Methods that include...

2. The method according to claim 1, The halogen source is provided together with a carrier gas in a processing chamber containing the substrate.

3. The method according to claim 1, The halogen source is provided in a processing chamber containing the substrate without a carrier gas.

4. The method according to claim 1, A method wherein the etching of the target material in (b) and the etching of the occlusion material in (c) are carried out in a single processing chamber.

5. The method according to claim 1, (c) is a method comprising activating the halogen source in the plasma.

6. The method according to claim 5, The method described in (c) above is carried out without applying an external bias to the substrate.

7. The method according to claim 5, The method wherein the plasma in (c) is a trans-coupled plasma.

8. The method according to claim 7, The method wherein the power of the plasma in (c) above is 500 W or less.

9. The method according to claim 5, The method wherein the chamber pressure of the chamber housing the substrate in (c) is 100 mTorr to 1 Torr (13332.2 mPa to 133.3 Pa).

10. The method according to claim 9, The method wherein the chamber pressure of the chamber housing the substrate in (a) is less than 100 mTorr (13332.2 mPa).

11. The method according to claim 1, The method described in (c) above is carried out without applying an external bias to the semiconductor substrate.

12. The method according to claim 5, The plasma in (c) above is pulsed, by a method.

13. The method according to claim 4, A method comprising increasing the chamber pressure in the processing chamber, wherein the transition from (b) to (c) is described above.

14. The method according to claim 1, The method wherein the occluding material comprises silicon dioxide.

15. The method according to claim 1, The method wherein the target material is selected from the group consisting of carbon and silicon.

16. The method according to claim 1, The method wherein the mask material is selected from the group consisting of silicon oxynitride, silicon nitride, silicon oxide, silicon oxycarbide, silicon boride, tungsten, tungsten-doped carbon, and boron-doped carbon.

17. The method according to claim 1, A method for etching the occlusion material, wherein the etching selectivity is greater than 1 for both the mask material and the target material.

18. The method according to claim 1, (c) above is a method carried out in the absence of plasma.

19. The method according to claim 18, The method wherein the chamber pressure of the chamber housing the substrate in (c) is 100 mTorr to 100 Torr (13332.2 mPa to 13332.2 Pa).

20. The method according to claim 1, A method in which the temperature of the substrate is maintained throughout the entire process.

21. The method according to claim 1, A method further comprising repeating steps (b) to (c) described above.

Images