Methods including deposition of topological etch selective materials

Abstract

Methods of forming patterned structures suitable for multiple patterning processes are disclosed. An exemplary method includes forming a layer over a substrate by providing a precursor to a reaction chamber for a precursor pulse period, providing a reactant to the reaction chamber for a reactant pulse period, applying a first plasma power having a first frequency for a first plasma power period, and applying a second plasma power having a second frequency for a second plasma power period, wherein the first frequency is different than the second frequency.

Description

Technical Field

[0001] This disclosure generally relates to methods and systems for forming patterned structures on the surface of a substrate. More specifically, examples of this disclosure relate to methods including the deposition of topologically etch-selective materials, systems for performing such methods, and structures formed using such methods. Background Technology

[0002] During the manufacture of electronic devices (such as semiconductor devices), fine feature patterns can be formed on the substrate surface by patterning the substrate surface using a masking material and removing the material from the unmasked areas of the substrate surface using processes such as wet etching and / or dry etching. Photoresists are commonly used as masking materials.

[0003] Photoresist patterns can be formed by: coating a photoresist layer onto the surface of a substrate, masking the surface of the photoresist, exposing the unmasked portion of the photoresist to radiation, such as ultraviolet light or an electron beam, and removing a portion of the photoresist (e.g., the unmasked or masked portion), while leaving a portion of the photoresist (e.g., another of the unmasked or masked portions) on the substrate surface. Once the photoresist is patterned, the patterned photoresist can be used as a template to etch material on the substrate surface in the area where the photoresist has been removed, to form a transfer pattern in the layer beneath the photoresist. After etching the lower layer, any remaining photoresist can be removed.

[0004] As feature sizes decrease, conventional photoresist techniques may become unsuitable for forming patterns of the desired size. In such cases, multiple patterning techniques can be used to allow for the patterning and etching of features that can be smaller than the exposure resolution of the photolithography process. Multiple patterning techniques may include forming spacers around the patterned feature (e.g., patterned photoresist), removing the patterned feature to form a patterned structure, and using the patterned structure as a mask during subsequent etching.

[0005] While this technique works relatively well in some applications, removing the spacer material between the patterned structures generally becomes increasingly difficult as the spacing between them decreases. This is especially true when using anisotropic dry etching processes, as charge can accumulate on the substrate surface. Therefore, an improved method for forming patterned structures on the substrate surface is needed. Furthermore, improved device structures incorporating patterned structures are also desired. Systems for performing this method are also desired.

[0006] Any discussion of the problems and solutions set forth in this section is contained within this disclosure and is intended only to provide background for this disclosure and should not be construed as an admission that any or all of the discussions were known in the course of making this invention. Summary of the Invention

[0007] Various embodiments of this disclosure relate to methods for forming patterned structures on the surface of a substrate, the formed structures, and systems for forming patterned structures. Patterned structures can be used to form devices, such as semiconductor devices and other electronic devices.

[0008] While various embodiments of this disclosure address the shortcomings of existing methods and systems in more detail below, in general, the various embodiments of this disclosure provide improved methods for forming patterned structures using the deposition of topologically etch-selective materials. The methods described herein, including the deposition of topologically etch-selective materials, allow for the formation of patterned structures with relatively small pitch using relatively fast etching processes, and / or allow for the use of isotropic etching, whereas the prior art might expect the use of anisotropic etching.

[0009] According to examples of this disclosure, a method for depositing a topologically etch-selective material is disclosed. An exemplary method includes providing a substrate within a reactor reaction chamber, providing the reaction chamber with at least one reactant comprising nitrogen and oxygen, providing the reaction chamber with a Group 13 metal precursor, providing a first plasma power having a first frequency and a first power for a first plasma power pulse within the reaction chamber, and providing a second plasma power having a second frequency and a second power for a second plasma power pulse within the reaction chamber, wherein the first frequency is less than the second frequency. As described in more detail below, the use of the first plasma power and the second plasma power allows the formation of the topologically etch-selective material—e.g., without the need for subsequent processing steps. The topologically etch-selective material can be readily and selectively removed relative to sidewalls from, for example, the top and / or bottom of a feature to form a desired patterned structure. According to examples of this disclosure, the steps of providing the first plasma power and providing the second plasma power substantially overlap. According to another example, the second frequency is ten times or more, or twenty times or more, than the first frequency. According to another example, the second power is greater than the first power. For example, the second power may be at least 1.5 times or at least 2.5 times greater than the first power. In some cases, the second power may be pulsed—e.g., on / high to off / low. The duty cycle of the pulse power can be between about 30% and about 70%. According to another example, providing at least one reactant includes providing a nitrogen-containing reactant and providing an oxygen-containing reactant. In this case, the flow rate of the nitrogen-containing reactant can be greater than the flow rate of the oxygen-containing reactant. For example, the flow rate of the nitrogen-containing reactant can be at least 5 times greater than the flow rate of the oxygen-containing reactant. According to another example, the method does not include an additional trimming step to remove the topologically etch-selective material from the top or bottom. Exemplary methods may also include etching the topologically etch-selective material to selectively remove it from the top and bottom relative to the sidewalls. Etching may include an isotropic etching process, such as a wet etching process.

[0010] According to further embodiments of this disclosure, a device structure is provided. The device structure can be formed according to methods as described herein. The device structure may include a substrate and one or more patterned structures formed thereon or therein.

[0011] According to another example of this disclosure, a system is provided. As described in more detail below, the system may include a controller configured to perform the methods described herein and / or form device structures.

[0012] These and other embodiments will become apparent to those skilled in the art from the following detailed description of certain embodiments with reference to the accompanying drawings; the invention is not limited to any particular embodiment disclosed. Attached Figure Description

[0013] Exemplary embodiments of this disclosure can be more fully understood when considered in conjunction with the following illustrative drawings, and by referring to the detailed description and claims.

[0014] Figure 1 A method according to at least one embodiment of the present disclosure is shown.

[0015] Figure 2 Timing according to at least one embodiment of the present disclosure is shown.

[0016] Figures 3 to 8 The structure according to an exemplary embodiment of the present disclosure is shown.

[0017] Figure 9 A reactor system according to at least one embodiment of the present disclosure is shown.

[0018] Figure 10 Another reactor system according to at least one embodiment of the present disclosure is shown as an example of the present disclosure.

[0019] It should be understood that the elements in the accompanying drawings are shown for simplicity and clarity and are not necessarily drawn to scale. For example, the dimensions of some elements may be exaggerated relative to other elements to aid in understanding the embodiments shown in this disclosure. Detailed Implementation

[0020] Although certain embodiments and examples are disclosed below, those skilled in the art will understand that the invention extends beyond the specific embodiments and / or uses disclosed herein, as well as their obvious modifications and equivalents. Therefore, it is intended that the scope of the disclosed invention should not be limited to the specific embodiments described below.

[0021] This disclosure generally relates to methods for forming patterned structures on the surface of a substrate, device structures including patterned structures, and systems for performing methods and / or forming device structures. The patterned structures can be used as etching masks or as patterning features for forming a next set of patterned structures. Exemplary methods can be used to form structures suitable for forming electronic devices, as described in more detail below.

[0022] In this disclosure, the gas may include materials that are gases at room temperature and pressure, evaporated solids, and / or evaporated liquids, and may consist of a single gas or a mixture of gases, depending on the circumstances. Gases other than process gases, such as gases introduced without passing through gas distribution components (e.g., spray heads, other gas distribution devices, etc.), may be used, for example, to seal the reaction space, and may include sealing gases, such as rare gases or other inert gases. The term inert gas refers to a gas that does not participate in the chemical reaction to a perceptible degree and / or a gas that can excite precursors when plasma power is applied. In some cases, the terms precursor and reactant may be used interchangeably.

[0023] As used herein, the term substrate can refer to any one or more underlying materials that can be used to form or on which devices, circuits, or films are formed. A substrate can include bulk materials such as silicon (e.g., single-crystal silicon), other group IV materials (e.g., germanium), or compound semiconductor materials (e.g., GaAs), and can include one or more layers overlaid or under the bulk material. Furthermore, a substrate can include various features, such as recesses, lines, etc., formed within or on at least a portion of the layers of the substrate. As a specific example, a substrate can include a bulk semiconductor material and / or a layer to be etched.

[0024] In some embodiments, a membrane refers to a layer extending in a direction perpendicular to the thickness direction to cover the entire target or related surface, or simply a layer covering the target or related surface. In some embodiments, a layer refers to a structure or membrane or non-membrane structure of a certain thickness formed on a surface. Layers can be continuous or discontinuous. A membrane or layer can consist of discrete single membranes or layers or multiple membranes or layers having certain properties, and the boundaries between adjacent membranes or layers may or may not be clear, and may or may not be based on the physical, chemical and / or any other properties, formation process or sequence and / or function or purpose of adjacent membranes or layers.

[0025] Features can refer to protrusions on the surface of the substrate or recesses extending into the substrate. Protrusions can be pillars, lines, etc. Recesses can be through holes, trenches, etc.

[0026] In this disclosure, "continuous" can refer to one or more of the following: without breaking the vacuum, without interruption as a timeline, without any material intervention step, without change in processing conditions, immediately following as the next step, or, in some embodiments, discrete physical or chemical structures with no intervention between the two structures other than the two structures themselves. For example, reactants and / or inert gases may be continuously supplied during two or more steps of the method and / or deposition cycles.

[0027] The term cyclic deposition process or cyclic deposition process can refer to the sequential introduction of precursors (and / or reactants) and / or plasma power pulses into or within a reaction chamber to deposit a layer on a substrate, and includes processing techniques such as atomic layer deposition (ALD), cyclic chemical vapor deposition (cyclic CVD), hybrid cyclic deposition processes including ALD and cyclic CVD components, and their plasma-enhanced variants.

[0028] As used herein, the term atomic layer deposition (ALD) can refer to a vapor deposition process in which deposition cycles, preferably multiple successive or continuous, are performed in a processing chamber. Typically, during each cycle, a precursor is introduced and can be chemisorbed onto the deposition surface (e.g., a substrate surface or a previously deposited lower layer surface, such as material from a previous ALD cycle), forming a monolayer or sub-monolayer that does not readily react with another precursor (i.e., a self-limiting reaction). Subsequently, a reactant (e.g., another precursor or a reactive gas) can be introduced into the processing chamber to convert the chemisorbed precursor into the desired material on the deposition surface. A purging step can be used during each cycle to remove excess precursor from the processing chamber and / or excess reactant and / or reaction byproducts from the processing chamber after the conversion of the chemisorbed precursor. Furthermore, the term atomic layer deposition, as used herein, is also intended to include processes specified by related terms (e.g., chemical vapor atomic layer deposition) when performed using alternating pulses of precursor, reactant, and purging gas (e.g., an inert carrier gas). PEALD refers to an ALD process in which plasma is applied during one or more ALD steps.

[0029] As used herein, the term purging can refer to the process of supplying an inert or substantially inert gas to a reaction chamber between two potentially interacting gas pulses. For example, purging can be provided between a precursor pulse and a plasma pulse to avoid or at least reduce gas-phase interactions between the precursor and the activated reactant. It should be understood that purging can be performed temporally, spatially, or both. For example, in the case of temporal purging, purging steps can be used, for instance, in a temporal sequence of supplying a first precursor to the reactor chamber, supplying a purge gas to the reactor chamber, and supplying a second precursor or reactant to the reactor chamber, wherein the substrate on which the deposition layer is deposited remains stationary. In the case of spatial purging, the purging step can, for example, take the form of moving the substrate from a first location supplying the first precursor through a purge gas curtain to a second location supplying the second precursor.

[0030] As used herein, a metal oxide refers to a material comprising at least one metal and oxygen. Metal oxides can be derived from the formula MO. x The notation indicates that M represents a metal (e.g., TiO2). In some cases, the metal oxide may not be or may include a stoichiometric metal oxide. In some cases, the metal oxide may include other elements, such as carbon, nitrogen, hydrogen, etc. Exemplary metals include Group 13 metals, such as titanium.

[0031] As used herein, the term overlap can mean relative to time and coincidence within a reaction chamber. For example, when two or more plasma power cycles overlap, there exists a time period in which the power of each of the two or more plasma power cycles is supplied to the reaction chamber. Similarly, with respect to gas pulse cycles, such as precursor pulse cycles and reactant pulse cycles, two or more gas pulse cycles can overlap when gases from the respective pulse cycles are supplied to the reaction chamber within the reaction chamber or within a time period.

[0032] Furthermore, in this disclosure, any two numbers of a variable may constitute a feasible range of the variable, and any indicated range may include or exclude endpoints. Additionally, any value of the indicated variable (whether or not it is indicated by the term "approx.") may refer to an exact value or an approximation and include equivalents, and may refer to an average, median, representative value, multi-value, etc. For example, the term "approx." may refer to + / - 20%, 10%, 5%, 2%, or 1% of a value. The terms "comprising," "including," "consisting of," and "having" independently mean "generally or broadly comprising," "including," "substantially constitutes," or "consisting of" in some embodiments. In this disclosure, the meaning of any definition does not necessarily exclude the common and customary meanings in some embodiments.

[0033] Although numerous example materials are given throughout the embodiments of this disclosure, it should be noted that the chemical formulas given for each example material should not be construed as limiting. Unless otherwise stated, the non-limiting example materials given should not be limited by the given example stoichiometry.

[0034] Now turn to the attached image. Figure 1 A method 100 for depositing a topologically etched selective material according to an example of this disclosure is shown. Method 100 can be used for various purposes, such as forming patterned structures (e.g., using a multiple patterning process). As shown, method 100 includes the steps of: providing a substrate comprising at least one feature in a reaction chamber of a reactor (step 102); providing at least one reactant (step 104); providing a Group 13 metal precursor to the reaction chamber (step 106); providing a first plasma power (step 108); and providing a second plasma power (step 110). Method 100 may also include etching (step 116), removing the mandrel (step 118), and etching the underlying layer (step 120). Although steps 102-120 are shown, the exemplary method does not need to include all of these steps, but may include any subset of these steps.

[0035] During step 102, a substrate comprising a surface having at least one characteristic is provided within the reaction chamber of the reactor system. Figure 3 An exemplary substrate 300 used during step 102 is illustrated. In this example, the substrate includes a first layer or bulk material 304, a second layer 306 (e.g., a layer to be etched), and a surface 302 including patterned features 308, 310. The first layer or bulk material 304 may include, for example, silicon or other semiconductor materials; the second layer 306 may include one or more materials, for example, having etch selectivity relative to the material used to form the patterned structure (e.g., a metal oxide). Referring to feature 308, one or more features may include a top 312, a bottom 314, and (e.g., across) a sidewall 316 therebetween. Features 308, 310 may be recesses, trenches, vias, etc., and may be at least partially defined by mandrels 318, 320, 322. Mandrels 318, 320, 322 may be formed as or include one or more of, for example, photoresist, carbon hard mask material, amorphous silicon, amorphous carbon, polycrystalline silicon, etc.

[0036] Return to Figure 1 The reaction chamber used during step 102 may be or include a reaction chamber of a chemical vapor deposition reactor system configured to perform a cyclic deposition process. The reaction chamber may be a standalone reaction chamber or part of a cluster of tools. Exemplary reaction chambers suitable for step 102 are described in more detail below.

[0037] Step 102 may include heating the substrate to a desired deposition temperature within the reaction chamber. In some embodiments of this disclosure, step 102 includes heating the substrate to a temperature below 400°C. For example, in some embodiments of this disclosure, heating the substrate to the deposition temperature may include heating the substrate to a temperature between about 50°C and about 400°C, or between about 20°C and about 250°C, or between about 40°C and about 220°C. In addition to controlling the substrate temperature, the pressure within the reaction chamber may also be adjusted. For example, in some embodiments of this disclosure, the pressure within the reaction chamber during step 102 may be less than 760 Torr, or between 0.2 Torr and 760 Torr, or between about 1.5 Torr and 10 Torr. In some cases, during steps 102 and / or steps 104-110, the pressure within the reaction chamber is greater than 400 Pa, or between greater than 400 Pa and about 500 Pa, or between about 100 Pa and about 500 Pa, or between about 200 Pa and about 400 Pa.

[0038] During steps 104-110, a layer is formed covering the substrate provided in step 102 (e.g., Figure 4 Layer 402 (shown as layer 402). Layer 402 can be or includes, for example, a metal oxide, such as a Group 13 metal oxide. Layer 402 can be relatively thin, for example, less than about 20 nm. Compared to layer 306, layer 402 can exhibit high etch selectivity.

[0039] According to the examples of this disclosure, steps 104-110 are used to deposit a topological etch-selective material. Steps 104-110 or steps 106-110 may be repeated once or more, as shown in cycles 114 (e.g., including steps 104-110) and 112 (e.g., including steps 106-110, where step 104 continues through steps 106-110). Furthermore, one or more steps 104-110 may be repeated once or more before method 100 proceeds to the next step.

[0040] During step 104, at least one reactant comprising nitrogen and oxygen is supplied to the reaction chamber. Exemplary reactants comprising nitrogen and oxygen include, for example, N₂O, N₂O₂, NO₂, etc. In some cases, supplying at least one reactant includes supplying a nitrogen-containing reactant and supplying an oxygen-containing reactant. The nitrogen-containing reactant may include, for example, N₂, N₂O, N₂O₂, NO₂, etc. The oxygen-containing reactant may include, for example, O₂, CO₂, O₃, CO, N₂O, N₂O₂, NO₂, etc. According to examples of this disclosure, the flow rate of the nitrogen-containing reactant is greater than the flow rate of the oxygen-containing reactant. For example, the volumetric flow rate ratio and / or the atomic ratio of N to O may be at least 5. The reactant may be supplied continuously during one or more deposition cycles 112 or 114 (e.g., before, during, and after). The reactant gas flow rate may be in the range of about 100 to about 10,000 sccm.

[0041] During step 106, a Group 13 metal precursor is supplied to the reaction chamber for the metal precursor pulse. Exemplary metal precursors may include alkoxides and / or alkylamino compounds. For example, a titanium precursor may be at least one compound selected from titanium alkoxides and alkylamino titaniums. As a specific example, the precursor may be or include one or more of the following: Ti(OR)4, where R is independently C. x H y (x=0, 1, 2, 3, 4 or 5, y=2) x+1 And each R can be different (e.g., Ti(OCH3)2(OC2H5)(OC3H7)); Ti(NR2)4, where R is independently C x H y (x=0, 1, 2, 3, 4 or 5, y=2) x+1 The precursors, including titanium oxide and other metal oxides, can be selected from any suitable compound. Generally, alkylamino precursors (e.g., tetra-dimethylaminotitanium (TDMAT)) can provide higher film growth rates than alkoxy precursors (e.g., tetraisopropoxidetitanium (TTIP)) because precursors with smaller molecular sizes (e.g., TDMAT) tend to have less steric hindrance, resulting in more adsorption sites compared to precursors with larger molecular sizes (e.g., TTIP). The precursor flow rate with the carrier gas can be in the range of about 500 to about 5000 sccm. The duration of step 106 can be in the range of about 0.05 to about 5 seconds.

[0042] During steps 108 and / or 110, plasma is formed. The plasma can be a direct plasma formed within the reaction chamber.

[0043] During step 108, a first plasma power with a first frequency and a first power is provided in the reaction chamber for a first plasma power pulse. According to the example described herein, the frequency of the power provided during step 108 is lower than the frequency of the power provided during step 110. For example, the frequency of the power provided during step 108 may be less than 1 MHz or less than 500 kHz. For example, the frequency of the power provided during step 108 may be 430 kHz. According to another example, the power provided during step 108 may be pulsed on and off and / or pulsed high and low (e.g., 20% or less than a high power value). For one or more (e.g., multiple) cycles, the duty cycle of the pulsed power may be between about 30% and about 70%. The duty cycle may be defined as the percentage of plasma power on time / (on time + off time); on and off in the preceding equation can be replaced by high and low. The frequencies of the multiple cycles may be between about 1 kHz and about 30 kHz. According to another example, the first power may be at least 50 W.

[0044] During step 110, a second plasma power having a second frequency and a second power is provided in the reaction chamber for the second plasma power pulse. As described above, the second frequency can be greater than the first frequency. For example, the second frequency can be ten times or more, or twenty times or more, or between approximately 10 and 200 times the first frequency. As an example, the second frequency can be greater than 1 MHz or greater than 10 MHz or between approximately 10 MHz and approximately 100 MHz. According to various examples, the second power is greater than the first power. For example, the second power can be at least 1.5 times or at least 2.5 times greater than the first power, or between approximately 1 and approximately 20 times greater than the first power. For example, the second power can be at least 50 W. As discussed in more detail below, steps 108 and 110 of providing the first plasma power and providing the second plasma power substantially overlap.

[0045] Figure 2 Timing 200 suitable for use as steps 104-110 of method 100 is shown. Timing 200 is intended to be illustrative and not necessarily a limitation on the description of method 100.

[0046] During timing 200, a precursor is provided during precursor pulse 202. The precursor, flow rate, and / or pulse duration can be as described above.

[0047] Although not in Figure 1As shown, however, method 100 / timing 200 may include providing a dilution gas to the reaction chamber, as shown in step 204. Exemplary dilution gases include, for example, any combination of argon, nitrogen, or helium. The flow rate of the dilution gas to the reaction chamber may be between about 0.1 and about 100 SLM or between about 0.5 and 5 SLM. Step 204 may begin before step / pulse 202. In some cases, the dilution gas may also be a carrier gas used to provide the precursor during precursor pulse 202.

[0048] Steps 206 and 208 can be the same as or similar to step 104 as described above. Figure 2 In the example shown, the first reactant and the second reactant are continuously supplied through one or more deposition cycles 214.

[0049] like Figure 2 As shown, in some cases, the step of applying the first plasma power (first plasma power cycle 210) and the step of applying the second plasma power (second plasma power cycle 212) overlap. In some cases, steps 210 and 212 substantially coincide (e.g., they begin and / or end within 0.1 seconds or less of each other).

[0050] Table 1 illustrates exemplary process conditions according to specific examples of this disclosure. This table is intended to illustrate exemplary conditions and is not intended to limit the scope of this disclosure.

[0051] Table 1

[0052]

[0053] Figure 4Structure 400 is shown after steps 102-110 / timing 200. Structure 400 is similar to structure 300, except that structure 400 includes a topology-etch-selective material layer 402 deposited on structure 300. The topology-etch-selective material layer 402 includes regions 404-412 with relatively poor film quality and regions 414-420 with relatively good or high film quality. As shown, topology-etch-selective regions 404, 408, 412 may be located on top of features 422, 424, topology-etch-selective regions 406, 410 may be located on the bottom of features 422, 424, and relatively etch-resistant regions 414-420 may be formed along (e.g., across) the sidewalls (e.g., sidewall 316) of the respective features. The thickness of layer 402 may be conformal. In this context, conformal coverage can mean a stepped coverage equal to or greater than about 50%, or greater than about 80%, or greater than about 90%, or greater than about 95%, or greater than about 98%, or even greater than 100%. In this case, stepped coverage can be defined as the ratio of the layer thickness along the sidewalls or bottom of the feature to the layer thickness in the open region without the feature. The density or film quality of layer 402 is not conformal. For example, the etching rates of regions 406, 410 and / or regions 404, 408, 412 (e.g., using the etching process described below) can be 2, 3, 5, or more times greater than the etching rates of the layers in regions 414-420.

[0054] return Figure 1 Once steps 104-110 (e.g., timing 200) are completed, during step 116, portions of layer 402 (e.g., in regions 404, 406, 408, 410, and 412) are selectively removed to form structure 500 including patterned structures 502-506, as shown. Figure 5 As shown. Patterned structures 502-506 include mandrels or cores 508-512 (e.g., as shown above in combination). Figure 3 (as described) and spacers 514-518 on the corresponding sidewalls of the spindle / core 508-512.

[0055] Any suitable wet or dry etching can be used to selectively remove portions of layer 402. Step 116 may include etching the topologically etchable selective material to selectively remove the topologically etchable selective material from the top and bottom relative to the sidewalls. A wet etching process may include a fluorinated chemical (e.g., HF) or SC1 solution, or alternatively any wet chemical etching formulation—whether acidic, basic, oxidizing, reducing, chelating, or surfactant-enhanced—that can provide selectivity greater than about 5:1 between the target material and the surrounding material. For films of uniform mass (not layer 402), wet etching processes are generally considered isotropic. A dry etching process may include the use of activated fluorine. Reactants during a dry etching process may include, for example, NF3 at about 50°C to about 300°C. Because regions 404, 406, 408, 410 and 412 have different film qualities than regions 414-420, a portion of layer 402 in regions 404, 406, 408, 410 and 412 can be selectively removed relative to regions 414-420 using typical isotropic etching (for films of uniform quality).

[0056] During step 118, the mandrel / core 508-512 may be removed. For example, an ashing process may be used to remove the mandrel 508-512 to form the device structure 600, such as... Figure 6 As shown.

[0057] During step 120, spacers 514-518 can be used as template masks to etch layer 306 to form device structure 700, such as Figure 7 As shown. Device structure 700 includes a bulk material / substrate 304 and patterned structures 702-706 formed thereon. Structures 702-706 include regions 708-712 and regions 714-718, regions 708-712 comprising material from layer 306, and regions 714-718 comprising spacer material (e.g., Group 13 metal oxide). Structures 702-706 can be formed using any suitable etching process and will generally depend on the composition of layer 306.

[0058] Finally, although not in Figure 1 As shown separately, however, any remaining spacer material can be removed using appropriate etching to form Figure 8 The structure 800 shown is a feature 802 formed from material from layer 306.

[0059] Figure 9 The present invention illustrates a reactor system 900 according to an exemplary embodiment of the present disclosure. The reactor system 900 may be used to perform one or more steps or sub-steps as described herein and / or to form one or more structures or portions thereof as described herein.

[0060] The reactor system 900 includes a pair of parallel, facing conductive plate electrodes 914, 918 within the interior 901 (reaction zone) of a reaction chamber 902. Plasma can be excited within the reaction chamber 902 by applying plasma power, for example from a plasma power source (i.e., at least one power source) 908, to one electrode (e.g., electrode 918) and electrically grounding the other electrode (e.g., electrode 914). The power source 908 can be coupled to the electrode 918 via a transmission line 929 and an RF filter 931. As described above, the power source 908 can be suitably configured to provide plasma power at a first frequency and a second frequency, coupled to the reaction chamber. As described above, the first frequency can be additionally pulsed.

[0061] Temperature regulator 903 can be disposed in lower platform 914 (lower electrode), and the temperature of substrate 922 placed thereon can be maintained at a desired temperature, such as the temperature described above. Electrode 918 can be used as a gas distribution device, such as a spray plate or spray head. One or more gas lines (e.g., reactant gas line 904 and precursor gas line 906 connected to reactant source and precursor source respectively) can be used to introduce precursor gas, reactant gas, and carrier gas or inert gas (if any) into reaction chamber 902. For example, line 904 can be used to introduce inert gas and reactant from at least one reactant source 915 (including container 905 and reactant 907 therein) into reaction chamber 902, and / or line 906 can be used to introduce precursor and carrier gas (e.g., inert gas as described above) from precursor source 909 (including first container 911 and Group 13 metal precursor 913 therein, connected to reaction chamber) into reaction chamber 902. Although two inlet gas lines 904 and 906 are shown, the reactor system 900 may include any suitable number of gas lines.

[0062] In reaction chamber 902, a circular pipe 920 with an exhaust line 921 can be formed within a pipe plate 930, through which gas in the interior 901 of reaction chamber 902 can be discharged to exhaust source 910. Additionally, transfer chamber 923 may be provided with a sealing gas line 932 to introduce sealing gas into the interior 901 of reaction chamber 902 via the interior of transfer chamber 923 (transfer zone). A separation plate 925 (omitted in this figure, through which the substrate is transferred in and out of transfer chamber 923) for separating reaction zone 901 and transfer chamber 923 may be provided in transfer chamber 923. Transfer chamber 923 may also be provided with an exhaust line 927 connected to exhaust source 910. In some embodiments, a flow-through system (FPS) can be used to achieve continuous flow of carrier gas to reaction chamber 902.

[0063] Reactor system 900 may include one or more controllers 912, which are programmed or otherwise configured to cause one or more method steps as described herein to be performed. As those skilled in the art will understand, controller 912 is coupled to various power sources, heating systems, pumps, robots, and gas flow controllers or valves of the reactor. For example, controller 912 may be configured to control gas flows of precursors, reactants, and inert gases into at least one of one or more reaction chambers to form a layer on the surface of a substrate. Controller 912 may be further configured to provide power to, for example, form a plasma within reaction chamber 902. Controller 912 may similarly be configured to perform additional or alternative steps as described herein. For example, controller 912 may be configured to provide a precursor for a precursor pulse to the reaction chamber, provide at least one reactant to the reaction chamber, and provide plasma power at a first frequency and at a second frequency for plasma pulses to form a topology-etch-selective material on the surface of the substrate.

[0064] The controller 912 may include electronic circuitry and software to selectively operate valves, manifolds, heaters, pumps, and other components included in the system 900. Such circuitry and components operate to introduce precursors, reactants, and purge gases from appropriate sources. The controller 912 may control the timing of gas pulse sequences, the temperature of the substrate and / or reaction chamber, the pressure within the reaction chamber, and various other operations to provide appropriate operation of the system 900.

[0065] Controller 912 may include control software to electrically or pneumatically control valves to control the inflow and outflow of precursors, reactants, and / or purge gases from reaction chamber 902. Controller 912 may include modules, such as software or hardware components, like FPGAs or ASICs, that perform certain tasks. Modules may be advantageously configured to reside on addressable storage media of the control system and configured to perform one or more processes.

[0066] In some embodiments, a dual-chamber reactor (for processing two portions or compartments of a substrate disposed close to each other) may be used, wherein reactant gases and rare gases may be supplied via a common line, while precursor gases may be supplied via a non-common line.

[0067] During operation of system 900, a substrate, such as a semiconductor wafer, is transferred from, for example, substrate transport region 923 to reaction region 901. Once the substrate is transferred to reaction region 901, one or more gases (e.g., precursors, reactants, carrier gases, and / or purge gases) are introduced into reaction chamber 902.

[0068] Figure 10 A reactor system 1000 is shown comprising multiple reaction chambers 1002-1008, each reaction chamber being... Figure 9An example of reaction chamber 902 may be included, or it may be part of a dual-reaction-chamber module or a four-reaction-chamber module. Reaction chambers 1002-1008 may be disposed around and / or coupled to transfer chamber 1010, which includes transfer tools 1012 for transferring a substrate between reaction chambers 1002-1008 and load-locking chamber 1014, and between reaction chambers 1002-1008 (e.g., through transfer chamber 1010). For example, substrate 922 may be disposed in different chambers for different steps of the methods described herein.

[0069] The exemplary embodiments disclosed above do not limit the scope of the invention, as these embodiments are merely examples of embodiments of the invention. Any equivalent embodiments are intended to fall within the scope of the invention. In fact, various modifications to this disclosure, such as alternative useful combinations of the described elements, will become apparent to those skilled in the art from the description, in addition to the embodiments shown and described herein. These modifications and embodiments are also intended to fall within the scope of the appended claims.

Claims

1. A method for depositing a topologically etch-selective material, the method comprising the following steps: A substrate is provided in the reaction chamber of the reactor, the substrate including at least one feature, the at least one feature including a top, a bottom and a sidewall therebetween; The reaction chamber is supplied with at least one reactant containing nitrogen and oxygen; A Group 13 metal precursor is supplied to the reaction chamber for metal precursor pulses; A first plasma power having a first frequency and a first power is provided in the reaction chamber for the first plasma power pulse; as well as A second plasma power with a second frequency and a second power is provided in the reaction chamber for the second plasma power pulse. The first frequency is less than the second frequency.

2. The method according to claim 1, wherein, The steps of providing the first plasma power and providing the second plasma power are substantially the same.

3. The method according to claim 1, wherein, The second frequency is ten times or more, or twenty times or more, of the first frequency.

4. The method according to claim 1, wherein, The first frequency is less than 1MHz.

5. The method according to claim 1, wherein, The second frequency is greater than 1MHz.

6. The method according to claim 1, wherein, The first power is between about 50W and about 1500W or at least 50W.

7. The method according to claim 1, wherein, The second power is between about 50W and about 1500W or at least 50W.

8. The method according to claim 1, wherein, The second power is greater than the first power.

9. The method according to claim 1, wherein, The second power is at least 1.5 times or at least 2.5 times greater than the first power.

10. The method according to claim 1, wherein, The first power is pulsed on and off with a duty cycle between approximately 30% and approximately 70% over multiple cycles.

11. The method according to claim 10, wherein, The frequencies of the multiple cycles are between approximately 1 kHz and approximately 30 kHz.

12. The method according to claim 1, wherein, Providing at least one reactant includes: Provide nitrogen-containing reactants; and Provides oxygen-containing reactants.

13. The method according to claim 12, wherein, The flow rate of the nitrogen-containing reactant is greater than the flow rate of the oxygen-containing reactant.

14. The method according to claim 13, wherein, The flow rate of the nitrogen-containing reactant is at least 5 times greater than the flow rate of the oxygen-containing reactant.

15. The method according to claim 1, wherein, The Group 13 metal precursors include titanium.

16. The method according to claim 1, wherein, The method does not include additional trimming steps to remove the topology-etched selective material from the top or the bottom.

17. The method of claim 1, further comprising etching the topology etch-selective material to selectively remove the topology etch-selective material from the top and the bottom relative to the sidewall.

18. The method according to claim 17, wherein, The etching process includes isotropic etching.

19. A structure formed by the method according to claim 1.

20. A reactor system, comprising: Reaction chamber; A precursor source, comprising a container and a Group 13 metal precursor therein, is connected to a reaction chamber; At least one reactant source is connected to the reaction chamber; At least one plasma power source configured to provide plasma power at a first frequency and a second frequency, the at least one plasma power source being coupled to the reaction chamber; as well as The controller is configured as follows: Provide the reaction chamber with a precursor for the precursor pulse; Provide at least one reactant to the reaction chamber; and Plasma power is provided at a first frequency and at a second frequency to form a topological etching selective material on the surface of the substrate.

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