Methods of forming and using topological etch selectivity materials

Abstract

Methods of forming a topographic etch selectivity material are disclosed. An exemplary method includes forming a layer overlying a substrate and anisotropically processing the layer to form a topographic etch selectivity material. An exemplary method can also include selectively removing portions of the topographic etch selectivity material. Structures formed using the methods and systems for performing the methods are also disclosed.

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 for forming topologically etched 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 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. Furthermore, conventional techniques for depositing spacer material can result in inhomogeneous or non-conformal films, including material overhangs at the top surface of the patterned features. These overhangs can lead to undesirable variations in the pattern transferred using the spacer as a template. Therefore, improved methods for forming patterned structures on the substrate surface are needed. In addition, improved device structures incorporating patterned structures are 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 or other 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 by forming a topologically etch-selective material. The methods described herein, including the formation of a topologically etch-selective material, allow for the formation of patterned structures with relatively small pitch using a relatively fast etching process, and / or allow for the use of isotropic etching, which may be desirable in the prior art for anisotropic etching. Additionally, the methods described herein can be used to reduce overhangs in the initial deposited material, thereby improving the resolution of pattern transfer.

[0009] According to examples of this disclosure, a method for forming a topologically etch-selective material is disclosed. An exemplary method includes: providing a substrate comprising at least one feature, the at least one feature including a top, a bottom, and sidewalls therebetween; conformally depositing a Group 13 metal oxide on the at least one feature; and anisotropically processing the Group 13 metal oxide. According to various examples, the anisotropic processing step includes providing a nitrogen-containing reactant to a reaction chamber, 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 processing step forms the topologically etch-selective material. According to aspects of these examples, the second frequency is less than the first frequency. According to another aspect, the steps of providing the first plasma power and providing the second plasma power substantially overlap (i.e., the steps begin and / or end at approximately the same time). According to another aspect, the first power is greater than the second power. According to another aspect, the second power is pulsed on and off (or from high to low) with a duty cycle between about 30% and about 70% within a plurality of cycles. The frequencies of the plurality of cycles may be, for example, between about 1 kHz and about 30 kHz. According to another aspect, the step of conformally depositing Group 13 metal oxides includes (e.g., cyclically) providing a Group 13 metal precursor and providing an oxygen-containing reactant. Exemplary methods may also include etching a topologically selective material to selectively remove the topologically selective material from the top and bottom relative to the sidewalls. In some cases, the step of etching the topologically selective material includes removing overhanging material from the top of the feature. According to various aspects, the etching step may be or includes an isotropic etching process. According to another aspect, the method includes providing a dilution gas during the steps of conformally depositing the Group 13 metal oxide and anisotropically processing the Group 13 metal oxide. As described in more detail below, to obtain the desired pattern transfer, the flow rate of the dilution gas during the anisotropic processing of the Group 13 metal oxide is less than the flow rate of the dilution gas during the conformal deposition of the Group 13 metal oxide.

[0010] According to another embodiment of this disclosure, a structure is provided. This structure can be formed according to the methods described herein. The 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 the structures described herein.

[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] Figure 3 Another timing sequence according to at least one embodiment of the present disclosure is shown.

[0017] Figures 4 to 10 The structure according to an exemplary embodiment of the present disclosure is shown.

[0018] Figure 11 A reactor system according to at least one embodiment of the present disclosure is shown.

[0019] Figure 12 Another reactor system according to at least one embodiment of the present disclosure is shown.

[0020] Figure 13 The removal of the overhang is shown in other examples according to this disclosure.

[0021] 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

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] A feature can refer to a protrusion on the surface of a substrate or a recess extending into the substrate. Protrusions can be pillars, lines, etc. Recesses can be vias, trenches, etc. In some cases, the terms patterned features and patterned structures are used interchangeably.

[0028] In this disclosure, "continuous" can refer to one or more of the following: without breaching the vacuum, without interruption as a timeline, without any material intervention step, without alteration of 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 and / or processing cycles.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] As used herein, a metal oxide refers to a material comprising at least one metal and oxygen. Metal oxides can be defined by formula MO. xThe 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] Now turn to the attached image. Figure 1 A method 100 for forming 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 including at least one feature (step 102), depositing a metal oxide (step 104), anisotropically processing the deposited metal oxide (step 106), etching (step 108), removing mandrel / core material (step 110), and etching an underlying layer (step 112). Although steps 102-112 are shown, the exemplary method does not need to include all of these steps, but may include any subset of these steps. Figure 2 and Figure 3Timing 200 and 300 for steps 104 and 106 of method 100 are shown.

[0037] During step 102, a substrate comprising a surface having at least one characteristic is provided (e.g., in the reaction chamber of a reactor system). Figure 4 An exemplary substrate 400 used during step 102 is illustrated. In this example, the substrate includes a first layer or bulk material 404, a second layer 406 (e.g., a layer to be etched), and a surface 402 including patterned features 408, 410. The first layer or bulk material 404 may include, for example, silicon or other semiconductor materials; the second layer 406 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 408, one or more features may include a top 412, a bottom 414, and (e.g., across) a sidewall 416 therebetween. Features 408, 410 may be recesses, trenches, vias, etc., and may be at least partially defined by mandrels 418, 420, 422. Mandrels 418, 420, 422 may be formed of or include one or more of, for example, photoresist, carbon hard mask material, amorphous silicon, amorphous carbon, polycrystalline silicon, etc.

[0038] Return to Figure 1 The reaction chamber used during step 102 and / or other steps (e.g., steps 104, 106, 108) of method 100 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. An exemplary reaction chamber suitable for step 102 is described in more detail below.

[0039] 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 104-108, 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.

[0040] During step 104, a layer (e.g., conformal or substantially conformal) is formed on the substrate provided in step 102. Figure 5 Layer 502 shown is used to form structure 500. In some cases, the layer deposited during step 104 may include overhangs, as shown below. Figure 13 To describe in more detail. Layer 502 can be, or includes, for example, a metal oxide, such as a Group 13 metal oxide. Layer 502 can be relatively thin, for example, less than about 20 nm. Compared to layer 406, layer 502 can exhibit high etch selectivity.

[0041] According to an example of this disclosure, step 104 includes providing a Group 13 metal precursor and providing an oxygen-containing reactant. (Reference) Figure 2 The time series 200, including deposition sequence 202 and processing sequence 204, is shown. Figure 3 The time sequence 300 shown similarly includes a deposition sequence 302 and a processing sequence 304. Deposition sequence 202 and deposition sequence 302 may be the same or similar, and both are suitable for use as step 104 of method 100.

[0042] In the example shown, deposition sequence 202 is a cyclic process that includes a precursor provision step 206, a dilution gas provision step 208, a reactant gas provision step 210, and a first plasma power provision step 212. Deposition sequence 302 similarly includes a precursor provision step 306, a dilution gas provision step 308, a reactant gas provision step 310, and a first plasma power provision step 312. Steps 306-312 may be the same as or similar to steps 206-212. For brevity, a separate description of steps 306-312 is omitted.

[0043] During step 206, a Group 13 metal precursor is provided (e.g., to the reaction chamber) for the metal precursor pulse. Exemplary Group 13 metal precursors may include metal alkoxides and / or alkylamino compounds. Group 13 metal precursors may include titanium. 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+1The 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 durations of steps 206 and 306 can be in the range of about 0.05 to about 5 seconds.

[0044] During step 208, a dilution gas may optionally be supplied to the reaction chamber. Exemplary dilution gases include argon, helium, other inert gases, or mixtures thereof. The flow rate of the dilution gas may be, for example, between about 1 SLM and about 20 SLM. In some cases, the dilution gas may also be a carrier gas used to supply the precursor during precursor pulse 206. As shown, step 208 may begin prior to step 206.

[0045] During step 210, at least one reactant is provided to the reaction chamber. Exemplary reactants include oxygen. Exemplary reactants including oxygen include, for example, O2, O3, CO, CO2, N2O, N2O2, NO2, mixtures thereof, etc. In some cases, providing at least one reactant includes providing an oxygen-containing reactant and providing a nitrogen-containing reactant. Oxygen-containing reactants may include, for example, O2, O3, CO, CO2, N2O, N2O2, NO2, mixtures thereof, etc. Nitrogen-containing reactants may include, for example, N2, NH3, N2H2, N2O, N2O2, NO2, mixtures thereof, etc. The reactant may be provided continuously during one or more deposition cycles 202 and processing cycles 204, 304 (e.g., before, during, and after). The reactant gas flow rate may be in the range of about 100 to about 10,000 sccm. Furthermore, as shown, step 210 may begin before step 206.

[0046] During step 212, a first plasma power is provided in the reaction chamber for a first plasma power pulse. The first plasma power has a first frequency and a first power.

[0047] As an example, the first frequency can be greater than 1 MHz or greater than 10 MHz or between about 10 MHz and about 100 MHz. The first power can be between about 50 W and about 1000 W or between about 100 W and about 500 W. The duration of the first plasma power pulse can be between about 0.1 seconds and about 10 seconds or between about 0.2 seconds and about 0.5 seconds.

[0048] The deposition sequence 202 may include one or more purging steps 214, 216. In the example shown, purging steps 214 and 216 involve the flow of dilution gas and one or more reactants.

[0049] As shown in loops 218 and 114, steps 206-216 can be repeated. For example, steps 206-216 can be repeated 0 to about 50 times or about 1 to about 20 times to form a layer 502 of the desired thickness before proceeding to step 106 / processing sequence 204.

[0050] Once the desired number of cycles 218 have been executed, timing 200 proceeds to processing sequence 204. During step 106 / processing sequence 204, the layer (e.g., a Group 13 metal oxide) is processed to form a topology-etch-selective material. Processing sequence 204 may include a first gas transition step 220, a plasma processing step 222, and a second gas transition step 232. Processing sequence 204 can be used as loop 116 to anisotropically process the (e.g., Group 13) metal oxide deposited using deposition sequence 202.

[0051] Processing sequence 204 (i.e., anisotropic processing) may begin with gas transition step 220. During gas transition step 220, the flow rate of one or more reactant gases supplied during step 210 is reduced or stopped, the flow rate of the process gas is started or increased, and the flow rate of the dilution gas supplied during step 208 may be reduced. For example, the flow rate of one or more reactant gases may be reduced to 0. The flow rate of the process gas may be increased from, for example, 0 to, for example, about 20 slm. The flow rate of the dilution gas may be reduced to maintain a desired chamber pressure—for example, by keeping the total flow rate of gas to the reaction chamber approximately the same. The process gas supplied during step 220 may be a nitrogen-containing reactant. The nitrogen-containing reactant may be or include nitrogen-containing reactants as described above. The duration of gas transition step 220 may be between about 0.1 and about 10 seconds.

[0052] Once the gas flow rate is at its desired level (e.g., steps 228, 229, 230), plasma treatment step 222 can begin. Plasma treatment step 222 includes providing a first (e.g., treatment) plasma power with a first frequency and a first power within the reaction chamber for a first plasma power pulse 224, and providing a second plasma power with a second frequency and a second power within the reaction chamber for a second plasma power pulse 226. According to various examples, the second frequency is less than the first frequency.

[0053] The first frequency and / or power in step 224 may be the same as or similar to the first frequency and / or power in step 212. The second frequency provided during step 226 may be less than 1 MHz or less than 500 kHz. For example, the second frequency of the power provided during step 226 may be approximately 430 kHz. According to another example, the power provided during step 226 may additionally or alternatively pulse on and off and / or pulse high and low (e.g., 20% or less of a high power value). For one or more (e.g., multiple) cycles, the duty cycle of the pulsed power may be between approximately 30% and approximately 70%, or between approximately 1% and 50%. 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 multiple cycles may be between approximately 1 kHz and approximately 30 kHz. In some cases, the first frequency is ten times or more, or twenty times or more, than the second frequency.

[0054] According to another example, the second power is between approximately 50W and approximately 1000W, or between approximately 50W and approximately 300W. In some cases, the first power is greater than the second power. For example, the first power may be at least 1.5 times or at least 2.5 times greater than the second power.

[0055] like Figure 2 As shown, in some cases, the steps of applying the first plasma power 224 and applying the second plasma power 226 overlap. In some cases, steps 224 and 226 substantially coincide (e.g., starting and / or ending 0.1 seconds or less from each other). In some cases, sequences 202 and 204 can be repeated as shown in loop 234.

[0056] Figure 6Structure 600 is shown after steps 102-106 or timing 200. Structure 600 is similar to structure 500, except that structure 600 includes a topology-etch-selective material layer 602 formed by layer 502 during processing sequence 204. The topology-etch-selective material layer 602 includes regions 604-612 with relatively poor film quality, and regions 614-620 with relatively good or higher film quality and / or relatively unchanged quality from layer 502. As shown, topology-etch-selective regions 604, 608, 612 may be located on top of features 622, 624, topology-etch-selective regions 606, 610 may be located on the bottom of features 622, 624, and relatively etch-resistant regions 614-620 may be formed along (e.g., across) the sidewalls (e.g., sidewall 416) of the respective features. The thickness of layer 602 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 602 is not conformal. For example, the etching rates of regions 606, 410 and / or regions 604, 608, 612 (e.g., using the etching process described below) can be 2, 3, 5 or more times greater than the etching rate of layer 602 in regions 614-620.

[0057] Refer again Figure 3 Processing sequence 304 may be the same as or similar to processing sequence 204, except that processing sequence 304 may not be repeated before method 100 proceeds to step 108 and / or timing sequence 300 may not be repeated. Timing sequence 300 may be particularly suitable for removing overhangs from material deposited during step 104.

[0058] Figure 13 A structure 1300 following step 104 is shown as an example according to this disclosure. Structure 1300 includes a substrate 1302, a feature 1304, and a Group 13 metal oxide layer 1306 deposited on the feature 1304. The Group 13 metal oxide layer 1306 may include a droop 1310 in a region 1308 at the top of the feature 1304. During step 106, layer 1306 and the droop 1310 are anisotropically processed such that during step 108 (e.g., a wet etching step), more material is removed from the thicker region of the droop 1310 / layer 1306 compared to the non-droop region, thereby producing a conformal layer 1312. Layer 1312 can be processed using processing sequence 1204 and steps 106-112.

[0059] Exemplary process conditions for timings 200 and 300 are listed in Table 1 below.

[0060]

[0061] return Figure 1 Once steps 104 and 106 (e.g., timing 200) are completed, during step 108, portions of layer 602 (e.g., in regions 604, 606, 608, 610, and 612) are selectively removed to form structure 700 including patterned structures 702-706, as shown below. Figure 7 As shown. Patterned structures 702-706 include mandrels or cores 708-712 (e.g., as shown above in combination). Figure 4 (as described) and spacers 714-718 on the corresponding sidewalls of the mandrel / core 708-712.

[0062] Any suitable wet or dry etching can be used to selectively remove portions of layer 602. Step 108 may include etching a 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 dilute HF, SCl (NH4OH and H2O2). For films of uniform mass (not layer 602), 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 604, 606, 608, 610, and 612 have different film masses than regions 614-620, typical isotropic etching (for films of uniform mass) can be used to selectively remove portions of layer 602 in regions 604, 606, 608, 610, and 612 relative to regions 614-620.

[0063] During step 110, the mandrel / core 708-712 may be removed. For example, an ashing process may be used to remove the mandrel 708-712 to form a device structure 800 including patterned structures 814-818, such as... Figure 8 As shown.

[0064] During step 112, patterned structures 814-818 can be used as template masks to etch layer 406 to form structure 900, such as Figure 9 As shown. Structure 900 includes a bulk material / substrate 404 and patterned structures 902-906 formed thereon. Structures 902-906 include regions 908-912 and regions 914-918, regions 908-912 comprising material from layer 406, and regions 914-918 comprising spacer material (e.g., Group 13 metal oxide). Structures 902-906 can be formed using any suitable etching process and will generally depend on the composition of layer 406.

[0065] Finally, although not in Figure 1 As shown separately, however, any remaining spacer material can be removed using appropriate etching to form Figure 10 The structure 1000 shown is included. The structure 1000 includes a feature 1002 formed from material from layer 406.

[0066] Figure 11 The present invention illustrates a reactor system 1100 according to an exemplary embodiment of the present disclosure. The reactor system 1100 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.

[0067] The reactor system 1100 includes a pair of parallel, facing conductive plate electrodes 1114, 1118 within the interior 1101 (reaction zone) of a reaction chamber 1102. Plasma can be excited within the reaction chamber 1102 by applying plasma power, for example from a plasma power source (i.e., at least one power source) 1108, to one electrode (e.g., electrode 1118) and electrically grounding the other electrode (e.g., electrode 1114). The power source 1108 can be coupled to the electrode 1118 via a transmission line 1129 and an RF filter 1131. As described above, the power source 1108 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.

[0068] Temperature regulator 1103 can be located in lower platform 1114 (lower electrode), and the temperature of substrate 1122 placed thereon can be maintained at a desired temperature, such as the temperature described above. Electrode 1118 can be used as a gas distribution device, such as a spray plate or spray head. Precursor gas, reactant gas, and carrier gas or inert gas (if any) can be introduced into reaction chamber 1102 using one or more gas lines (e.g., reactant gas line 1104 and precursor gas line 1106 connected to reactant source and precursor source, respectively). For example, line 1104 can be used to introduce inert gas and (deposited) reactants from at least one reactant source 1115 (including container 1105 and reactants 1107 therein) into reaction chamber 1102, and / or line 1106 can be used to introduce precursor and carrier gas (e.g., inert gas as described above) from precursor source 1109 (including first container 1111 and Group 13 metal precursor 1113 therein, coupled to reaction chamber) into reaction chamber 1102. Alternatively, line 1104 can be used to introduce processed reactants from at least one processed reactant source 1134 comprising container 1135 and processed reactants 1136 therein into reaction chamber 1102. Although two inlet gas lines 1104, 1106 are shown, reactor system 1100 may include any suitable number of gas lines.

[0069] In reaction chamber 1102, a circular pipe 1120 with an exhaust line 1121 can be formed within a pipe plate 1130, through which gas in the interior 1101 of reaction chamber 1102 can be discharged to exhaust source 1110. Additionally, transfer chamber 1123 can be provided with a sealing gas line 1132 to introduce sealing gas into the interior 1101 of reaction chamber 1102 via the interior of transfer chamber 1123 (transfer zone). A separation plate 1125 (omitted in this figure, through which the substrate is transferred in and out of transfer chamber 1123) can be provided for separating reaction zone 1101 and transfer chamber 1123. Transfer chamber 1123 may also be provided with an exhaust line 1127 connected to exhaust source 1110. In some embodiments, a flow-through system (FPS) can be used to achieve continuous flow of carrier gas to reaction chamber 1102.

[0070] Reactor system 1100 may include one or more controllers 1112, 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 1112 is coupled to various power supplies, heating systems, pumps, robots, and gas flow controllers or valves of the reactor. For example, controller 1112 may be configured to control the flow of gas, including 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 1112 may be further configured to provide power to, for example, form a plasma within reaction chamber 1102. Controller 1112 may similarly be configured to perform additional or alternative steps as described herein. For example, controller 1112 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 a second frequency for the plasma pulse to form a topology-etch-selective material on the surface of the substrate.

[0071] Controller 1112 may include electronic circuitry and software to selectively operate valves, manifolds, heaters, pumps, and other components included in system 1100. Such circuitry and components operate to introduce precursors, reactants, and purge gases from appropriate sources. Controller 1112 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 system 1100.

[0072] Controller 1112 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 1102. Controller 1112 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.

[0073] 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.

[0074] During operation of system 1100, a substrate, such as a semiconductor wafer, is transferred from, for example, substrate transport region 1123 to reaction region 1101. Once the substrate is transferred to reaction region 1101, one or more gases (e.g., precursors, reactants, carrier gases, and / or purge gases) are introduced into reaction chamber 1102.

[0075] Figure 12 A reactor system 1200 is illustrated, comprising multiple modules 1202-1208, each module including one or more (e.g., 1, 2, or 4) reaction chambers, such as reaction chamber 1102 described above. Modules 1202-1208 may be disposed around and / or coupled to transfer chamber 1210, and include transfer tools 1212 for transferring substrates between modules 1202-1208 and load locking chamber 1214, and between modules 1202-1208 (e.g., through transfer chamber 1210). For example, substrates may be disposed in different chambers or modules for different steps of the method described herein. Modules may include one or more controllers as described herein.

[0076] 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 comprising forming a topologically etch-selective material, the method comprising the steps of: A substrate is provided that includes at least one feature, wherein the at least one feature includes a top, a bottom, and a sidewall therebetween; Conformally depositing Group 13 metal oxides at at least one feature; Anisotropic treatment of Group 13 metal oxides, wherein the anisotropic treatment steps include: Provide nitrogen-containing reactants to the reaction chamber; A first plasma power having a first frequency and a first power is provided in the reaction chamber for a first plasma power pulse; and 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 second frequency is less than the first frequency, and Among them, anisotropic treatment of Group 13 metal oxides forms topological etching selective materials.

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 first frequency is ten times or more, or twenty times or more, than the second frequency.

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

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

6. The method according to claim 1, wherein, The first power is between about 50W and about 1000W or between about 100W and about 500W.

7. The method according to claim 1, wherein, The second power is between about 50W and about 1000W or between about 50W and about 300W.

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

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

10. The method according to claim 1, wherein, The second 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, The steps of conformally depositing the Group 13 metal oxides include: Provide Group 13 metal precursors; and Provides oxygen-containing reactants.

13. The method according to claim 12, wherein, The Group 13 metal precursors include titanium.

14. The method according to claim 12, wherein, Prior to the step of anisotropically processing the Group 13 metal oxide, the steps of providing the metal precursor and providing the oxygen-containing reactant are repeated multiple times.

15. 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.

16. The method of claim 14, wherein, The etching process includes isotropic etching.

17. The method of claim 1, further comprising providing a dilution gas during the steps of conformally depositing the Group 13 metal oxide and anisotropically treating the Group 13 metal oxide.

18. The method according to claim 17, wherein, The flow rate of the dilution gas during anisotropic processing of the Group 13 metal oxides is less than that during conformal deposition of the Group 13 metal oxides.

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

20. A reactor system comprising: Reaction chamber; A precursor source, comprising a first container and a Group 13 metal precursor therein, the precursor source being connected to a reaction chamber; At least one reactant source is connected to the reaction chamber; At least one processing gas 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 connected 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; Plasma power is provided at a first frequency during the deposition step; and During the processing steps, plasma power is provided at a first frequency during a first plasma power cycle and at a second frequency during a second plasma power cycle to form a topological etching selective material on the surface of the substrate.

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