Tuned atomic layer deposition

Abstract

The invention provides methods and apparatus for depositing thin films using long and short switch times during alternating cycles of atomic layer deposition (ALD). Embodiments involve alternating the switch duration of ALD cycles in one or more cycles of a multi-cycle ALD process. Some embodiments involve adjustments in dosing, purging, pressure, plasma power, or plasma energy in two or more ALD cycles.

Description

[0001] Incorporated by Reference

[0002] The PCT Application Transfer Table as a part of this application is filed concurrently with the specification. Each of the applications from which this application claims benefit or priority, as identified in the concurrently filed PCT Application Transfer Table, is incorporated by reference in its entirety and for all purposes. BACKGROUND

[0003] Films of various materials including silicon oxide films are used in semiconductor processing for various applications. Silicon oxide films can be deposited using different techniques such as plasma enhanced atomic layer deposition. As technology advances, it becomes challenging to deposit high quality films.

[0004] The background description provided here is for the purpose of generally presenting the context of the disclosure. The work of the presently named inventors, to the extent the work is described in this background section as well as in this description and the accompanying drawings, neither is, nor is submitted to be, prior art against the application in its entirety. SUMMARY

[0005] Provided herein are methods and apparatuses for depositing films. One embodiment relates to a method of depositing a film, the method comprising: providing a substrate to a processing chamber; depositing a first amount of a material on the substrate in a first atomic layer deposition (ALD) cycle, the cycle comprising: exposing the substrate to a precursor under conditions that allow adsorption of the precursor on a surface of the substrate, thereby forming a first adsorbed layer of the precursor; and exposing the first adsorbed layer of the precursor to a reactive species for a first duration to form the first amount of the material; and depositing a second amount of the material on the first amount of the material using a second ALD cycle, the cycle comprising: exposing the substrate to the precursor under conditions that allow adsorption of the precursor on a surface of the substrate, thereby forming a second adsorbed layer of the precursor; and exposing the second adsorbed layer of the precursor to a reactive species for a second duration to form the second amount of the material, wherein the first duration and the second duration are different durations.

[0006] In various embodiments, the second duration is between about 1.1 times and about 15 times as long as the first duration.

[0007] In various embodiments, the second duration is between about 1.1 times and about 10 times as long as the first duration.

[0008] In various embodiments, the second duration is between about 1.1 times and about 5 times as long as the first duration.

[0009] The method can also include igniting a plasma to generate the reactive species. The plasma can be generated in situ. In some embodiments, the plasma can be generated remotely.

[0010] In various embodiments, the reactive species is introduced along with argon.

[0011] The method can also include repeating the first ALD cycle two or more times prior to depositing the second amount of the material.

[0012] In some embodiments, the method further includes repeating the second ALD cycle two or more times.

[0013] The method can also include alternating between the first and second ALD cycles.

[0014] In some embodiments, the method further includes, in at least one of the first and the second ALD cycles, performing a purge after exposing the substrate to the precursor.

[0015] In various embodiments, the precursor is an aminosilane. For example, in some embodiments, the aminosilane is diisopropylaminosilane (DIPAS).

[0016] In various embodiments, the material includes silicon oxide.

[0017] Another aspect relates to a method of depositing silicon oxide, the method comprising: providing a substrate to a processing chamber; and depositing a conformal silicon oxide film on the substrate by exposing the substrate to two or more plasma enhanced atomic layer deposition (PEALD) cycles, the two or more PEALD cycles including at least a first PEALD cycle and a second PEALD cycle, wherein the first PEALD cycle includes introducing a silicon-containing precursor to form an adsorbed layer of the silicon-containing precursor on a surface of the substrate, exposing the adsorbed layer of the silicon-containing precursor to an oxygen-containing reactant and argon and igniting a first plasma at a first plasma energy, and wherein the second PEALD cycle includes introducing the silicon-containing precursor to form an adsorbed layer of the silicon-containing precursor on a surface of the substrate, exposing the adsorbed layer of the silicon-containing precursor to an oxygen-containing reactant and argon and igniting a second plasma at a second plasma energy, wherein the second plasma energy is at least three times greater than the first plasma energy.

[0018] In various embodiments, the first plasma energy is between about 200 Joules and about 500 Joules per substrate.

[0019] In various embodiments, the first and second PEALD cycles are performed in continuously alternating exposures.

[0020] In various embodiments, the second PEALD cycle is performed for each repetition of the first PEALD cycle, wherein n is an integer greater than or equal to 2.

[0021] The method can further include a third PEALD cycle performed at a third plasma energy, wherein the first plasma energy is less than the second plasma energy and the second plasma energy is less than the third plasma energy.

[0022] In various embodiments, the plasma power used to generate the first and second plasma energies is the same.

[0023] In some embodiments, the silicon-containing precursor is an aminosilane. For example, the aminosilane can be diisopropylaminosilane (DIPAS).

[0024] In various embodiments, the second plasma is generated using a plasma power of between about 125 Watts to about 1625 Watts per substrate.

[0025] In some embodiments, the conformal silicon oxide film has a wet etch rate of less than 1 Angstrom / second in 200: 1 diluted hydrofluoric acid.

[0026] Another aspect relates to an apparatus for processing a substrate, the apparatus comprising: one or more processing chambers; one or more gas inlets and associated flow control hardware into the one or more processing chambers; and a controller having at least one processor and a memory, wherein the at least one processor and the memory are communicatively connected to each other, the at least one processor is at least operatively connected to the flow control hardware, and the memory stores computer-executable instructions for controlling the at least one processor to at least control the flow control hardware to: cause a substrate to be inserted into at least one of the one or more processing chambers; cause a first set of alternating flows of a silicon-containing precursor and an oxidant to be introduced into the at least one of the one or more processing chambers via the one or more gas inlets for a first duration; and cause a second set of alternating flows of the silicon-containing precursor and the oxidant to be introduced into the at least one of the one or more processing chambers via the one or more gas inlets for a second duration; and wherein the second duration is at least 1.1 times longer than the first duration.

[0027] The apparatus can further comprise a plasma generator.

[0028] In various embodiments, the at least one of the one or more processing chambers comprises a powered showerhead and a grounded pedestal for holding the substrate.

[0029] In various embodiments, the at least one of the one or more processing chambers comprises a grounded showerhead and a powered pedestal for holding the substrate.

[0030] Another aspect relates to an apparatus for processing a substrate, the apparatus comprising: one or more process chambers; one or more gas inlets and associated flow control hardware into the one or more process chambers; a plasma generator; and a controller having at least one processor and a memory, wherein the at least one processor and the memory are communicatively coupled to each other, the at least one processor is at least operatively coupled to the flow control hardware, and the memory stores computer-executable instructions for controlling the at least one processor to at least control the flow control hardware to: cause a substrate to be inserted into at least one of the one or more process chambers; cause a first set of alternating silicon-containing precursor flows to be introduced into the at least one process chamber; causing a second alternating set of the silicon-containing precursor flows and the oxidant flows to be introduced into the at least one of the one or more processing chambers through the one or more gas inlets for a first duration; causing a plasma having a first plasma energy to be generated when the oxidant is introduced during the first set of periods to form a conformal silicon oxide material; and causing a second alternating set of the silicon-containing precursor flows and the oxidant flows to be introduced into the at least one of the one or more processing chambers through the one or more gas inlets for a second duration; and causing a plasma having a second plasma energy at least 1.1 times greater than the first plasma energy to be generated when the oxidant is introduced during the second set of periods to form a conformal silicon oxide material.

[0031] In various embodiments, the at least one of the one or more processing chambers includes a powered showerhead and a grounded pedestal for holding the substrate.

[0032] In various embodiments, the at least one of the one or more processing chambers includes a powered pedestal to hold the substrate and a grounded showerhead.

[0033] These and other aspects will be described below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1A and 1B is a flow chart depicting the operations of a method performed in accordance with certain disclosed embodiments.

[0035] Figure 2 is a timing diagram showing exemplary cycles in a method according to certain disclosed embodiments.

[0036] Figure 3A and 3B is a process flow diagram depicting the operation of a method according to certain disclosed embodiments.

[0037] Figure 4 is a schematic diagram of an example processing chamber for carrying out the disclosed embodiments.

[0038] Figure 5 is a schematic diagram of an example processing tool for carrying out the disclosed embodiments.

[0039] Figure 6 is a graph comparing wet etch rates and step coverage of silicon oxide films deposited using various plasma energy depositions.

[0040] Figure 7 is a graph comparing wet etch rates of silicon oxide films deposited using different plasma enhanced atomic layer deposition processes at various constants and alternating the conversion time at a given plasma power.

[0041] Figure 8 is a graph comparing wet etch rates of films deposited using certain disclosed embodiments at the bottom, sides, and top of a feature. DETAILED DESCRIPTION

[0042] In the following description, numerous specific details are set forth to provide a thorough understanding of the presented embodiments. The disclosed embodiments can be practiced without some or all of these specific details. In other instances, well known process operations have not been described in detail, so as not to unnecessarily obscure the disclosed embodiments. While the disclosed embodiments will be described in conjunction with the specific embodiments, it will be understood that the disclosed embodiments are not limited to those specific embodiments.

[0043] Semiconductor processing is performed on a variety of substrates, including patterned substrates having high aspect ratio topographies. Certain processing operations involve film deposition that can present various challenges. For example, as technology advances, techniques for depositing high quality films on complex topographies become challenging. One particular technique for depositing high quality films on such topographies is to use conformal deposition, such as atomic layer deposition (ALD). ALD can be used to deposit different types of materials, including depositing dielectrics, metals, and other films. One particular example film that can be deposited by ALD is silicon oxide.

[0044] While silicon oxide is described herein as a particular type of film that can be deposited by ALD, it should be understood that other types of materials can also be deposited using ALD, with silicon oxide provided as an example only.

[0045] ALD is a technique that uses sequential self-limiting reactions to deposit thin layers of material. ALD processing uses surface-mediated deposition reactions to deposit films in a layer-by-layer fashion in cycles. For example, an ALD cycle can include the following operations: (i) delivery / adsorption of a precursor (also referred to as "dosing"); (ii) purging the chamber of the precursor; (iii) delivery of a second reactant and optional plasma generation (also referred to as "switching"); and (iv) purging the chamber of byproducts. In some cases the purging steps can be optional. Further, dosing can not necessarily be performed prior to switching; in some cases, delivery of the second reactant can be performed prior to delivery of the precursor. For purposes of illustration herein, an ALD cycle will mean: dosing, purging, switching, and purging, but it is understood that other variations can also be utilized.

[0046] When plasma is used during delivery of the second reactant, the process can be referred to as plasma-enhanced atomic layer deposition (PEALD). The reaction between the second reactant and the adsorbed precursor for forming a film on the substrate surface affects the film composition and properties, such as stress, wet etch rate, dry etch rate, electrical properties (e.g., dielectric constant, breakdown voltage, and leakage current), incorporation of impurities, and the like. Further, non-uniformity of the deposited film can also be determined, and in some cases, it can be desirable to reduce non-uniformity.

[0047] In one particular example of an ALD process, in a dose provided to a chamber housing a substrate, a substrate surface comprising a population of surface active sites is exposed to a first precursor (e.g., a silicon-containing precursor) distributed in the gas phase. The first precursor molecules comprising chemisorbed species and / or physisorbed molecules of the first precursor are adsorbed on the substrate surface. It should be understood that when a compound is adsorbed on a substrate surface as described herein, the adsorbed layer can comprise the compound and derivatives of the compound. For example, an adsorbed layer of a silicon-containing precursor can comprise the silicon-containing precursor and derivatives of the silicon-containing precursor. Following the first precursor dose, the chamber can then be pumped down to remove a substantial portion or all of the first precursor that is still in the gas phase, leaving a substantial portion or only the adsorbed species. For example, the chamber can be pumped down such that the partial pressure of the first precursor in the gas phase is substantially reduced to slow the reaction. In some embodiments, the chamber can not be completely pumped down. A second reactant, such as an oxygen-containing gas, is introduced into the chamber such that some of the second reactant molecules react with the adsorbed first precursor on the surface of the substrate. In some processes, the second reactant immediately reacts with the adsorbed first precursor. In some embodiments, the second reactant only reacts after an activation source, such as a plasma, is applied. Such a plasma exposure can be applied for a time. The chamber can then be pumped down again to remove unbound second reactant molecules. As described above, in some embodiments, the chamber can not be completely pumped down. The exposure described above can be part of a time ALD process, whereby the substrate is exposed to each exposure in a time separated exposure step. Additional ALD cycles can be used to build up the film thickness.

[0048] Embodiments herein can also be related to spatial ALD processes. In spatial ALD, the gases used for each exposure step are continuously flowed into spatially distinct locations or "zones" in a processing chamber. Each zone comprises a gas injection point - for example, one zone can comprise a first precursor, one zone can comprise a first purge gas, one zone can comprise a second reactant, and a fourth zone can comprise a second purge gas. The substrate is rotated between the zones to expose the substrate surface to the different exposures to carry out the surface reactions described above with respect to time ALD. That is, the multiple exposures are separated by location, rather than separating the multiple exposures in time.

[0049] In certain implementations, the ALD method includes plasma activation. As described herein, the ALD methods and apparatus described herein can be conformal film deposition (CFD) methods, which are generally described in U.S. Patent Application No. 13 / 084,399, filed April 11, 2011, entitled "PLASMA ACTIVATED CONFORMAL FILM DEPOSITION," now U.S. Patent No. 8,728,956, the entire contents of which are incorporated herein by reference. Plasma activation can be performed by generating a plasma in-situ or in a chamber to generate reactive species in a chamber containing a substrate, and contacting a surface of the substrate with the adsorbed precursor with the reactive species. In certain cases, plasma activation can be performed by generating a plasma in a remote region or generator, and the reactive species from the plasma can then be delivered to a chamber containing a substrate, thereby contacting a surface of the substrate with the reactive species. In various embodiments, a plasma generator that can be suitable for PEALD is a capacitively coupled plasma generator. In various embodiments, a plasma generator that can be suitable for PEALD is an inductively coupled plasma generator. Although some ALD and PEALD embodiments are described herein, it should be understood that various disclosed embodiments can be applied to ALD or PEALD processing.

[0050] Although ALD can be used to deposit thin films conformally in high aspect ratio features, certain ALD processes can result in reduced throughput due to the duration of each ALD cycle. As a result, certain processes can be too expensive to implement in high volume manufacturing.

[0051] Densification of the film occurs in the conversion operation. Since ALD is a layer-by-layer growth process, each half-reaction (adsorption and conversion) can be modulated to achieve desired film quality and throughput. However, for certain ALD processes, there is a tradeoff between throughput and desired film properties; although longer conversion times can result in higher quality films, longer conversion times extend the overall ALD cycle time, thereby reducing throughput. Likewise, although throughput can be improved by reducing the conversion time of the ALD cycle, shorter conversion times result in lower quality films.

[0052] Certain techniques can be used to increase throughput during processing of large quantities of semiconductor films, but some techniques have drawbacks. For example, one technique is to reduce the cycle time or the time for each ALD cycle to increase throughput. Existing techniques for increasing throughput modify the dose, purge, or transition operations of each ALD cycle; however, shortening of these operations in each cycle can be limited by the saturation of the deposited reactants, and can result in poor film quality, defect issues, and / or underfilling, and the appearance of voids in high aspect ratio structures in gap fill applications. Thus, certain existing techniques are unable to achieve high quality film formation at high throughput.

[0053] Provided herein are techniques for depositing high quality films at high throughput by using long transition times in certain ALD cycles and short transition times in other ALD cycles to reduce the overall cycle time. The short transition times reduce the average cycle time for depositing the film, while the long transition times form deposited films with certain desirable properties. That is, N cycles of ALD cycles with short transition times are performed with M cycles of ALD cycles that are otherwise identical except for the long transition time, without sacrificing film quality or defect performance. Generally, in various embodiments, M is less than N.

[0054] It should be understood that the term "transition time" as used herein is used to mean the duration of time during which an adsorbed precursor is exposed to a second reactant to convert the adsorbed precursor to a film material such as silicon oxide. Long transition times and short transition times are relative terms used herein to mean the duration of the transition. For PEALD embodiments, the long transition times and short transition times are transitions performed at the same plasma power - that is, the process of N cycles with short ALD transition time cycles and M cycles with long ALD transition time cycles are performed using the same plasma power during the transition - only the duration of plasma exposure is adjusted between the N cycles and the M cycles. These are examples of binary cycles involving exposure of two separate deposition reactants, but it should be understood that certain disclosed embodiments can be performed with other types of cycles including ternary cycles and quaternary cycles.

[0055] In various embodiments, the long transition time is about 1.5 times to about 15 times longer than the short transition time. In various embodiments, the long transition time is about 1.5 times to 10 times longer than the short transition time. In various embodiments, the long transition time is about 1.5 times to 5 times longer than the short transition time. In various embodiments, the long transition time is about 1.5 times longer than the short transition time.

[0056] In certain embodiments, a single long-pulse ALD cycle can be used with every 1 to 20 or more short-pulse ALD cycles. In certain embodiments, the number of short-pulse ALD cycles that can be used for each long-pulse ALD cycle depends on the film thickness deposited by the short-pulse ALD cycles and the duration of the short- and long-pulse times - that is, the number of cycles of short-pulse ALD cycles to be performed for each long-pulse ALD cycle is defined by the maximum film thickness that can be densified by one long-pulse ALD cycle from the film thickness deposited by the short-pulse ALD cycles.

[0057] In certain embodiments, the benefits of processing at a particular or longer long-pulse time can diminish; that is, while film quality can be improved compared to performing only short-pulse ALD cycles, using very long-pulse ALD cycles can exhibit less reduction in processing time while obtaining higher quality films than short-pulse ALD cycles.

[0058] In some embodiments, for blanket films, there can be a saturation point where no adjustment in wet etch rate is observed at a particular or higher pulse duration. In certain cases, based on a particular processing condition, the saturation point is 0.75 seconds for a four-station chamber system with a 13.56 MHz RF generator.

[0059] Certain disclosed embodiments can be performed with thermal, spatial, or plasma-enhanced ALD processing. In certain embodiments, the pulse time is adjusted while maintaining the same plasma power during the pulses of all ALD cycles. In certain embodiments, the pulse time and plasma power, as well as other processing conditions, are adjusted to achieve desired film properties.

[0060] Certain disclosed embodiments can be used to deposit a variety of films, including but not limited to: silicon oxide, silicon nitride, metal oxides, metal nitrides, metal carbides, other oxides, nitrides, carbides, oxynitrides, oxycarbides, and the like.

[0061] Adjusting the purge time can be used to achieve various types of desired film properties. Different metrics can be used to determine film quality. For silicon oxide films, one exemplary metric of film quality is the wet etch rate, which can be evaluated by immersing the substrate in a dilute hydrofluoric acid bath (e.g., for 180 seconds in a 200: 1 bath). Increased purge time allows the surface reactions to proceed long enough to produce the desired reactants and to densify the deposited film. Thus, the wet etch rate of the deposited film is reduced. Even having one longer purge ALD cycle for every two short purge ALD cycles significantly improves throughput and surprisingly achieves better film quality. In fact, the surprising result of using a longer purge time that is only 1.1 times longer than the short purge time results in improved film quality while significantly reducing cycle time.

[0062] Other metrics of film quality on the sidewalls of high aspect ratio structures (which can be different than the film quality on a silicon blanket wafer or field region) are sidewall thickness (step coverage) or sidewall wet etch rate. Step coverage can be calculated by comparing the average film thickness deposited at the bottom of the trench (or other location on the sidewall) to the average film thickness deposited at the top of the feature or trench.

[0063] One example of step coverage can be calculated by dividing the average film thickness deposited on the sidewall by the average film thickness deposited at the top of the feature and multiplying the resulting quotient by 100 to obtain a percentage. The closer this percentage is to 100%, the denser the film is inside the feature. Step coverage and uniformity of film properties along the sidewall are particularly dependent on the delivery of the deposition precursors, reactive ions and / or radicals (e.g., those produced by igniting the reactant gases in a plasma), and byproducts. As the purge time of the ALD process is increased, the step coverage improves and approaches 100%. In some cases, sidewall step coverage can be a useful metric of film quality, but in some cases, different methods can be used to detect changes in film quality or density. One such method involves evaluating the sidewall wet etch rate, which can be determined by immersing a patterned wafer or small sample thereof in a dilute acid bath and measuring the amount etched. The smaller the amount etched in a given immersion time, the better the quality of the sidewall film.

[0064] Certain disclosed embodiments described herein reduce overall processing time and increase the yield of deposited silicon oxide films on some substrates in batch processing. Batch processing can mean herein continuous processing of multiple substrates in a processing chamber, which can include one or more stations, each station used for processing wafers for various purposes, such that in certain embodiments a single wafer is transferred into and out of each chamber and cycled between stations. Certain disclosed embodiments are suitable for depositing thick silicon oxide films by PEALD using a mixture of oxygen and argon during plasma conversion without sacrificing film quality. Certain disclosed embodiments are suitable for depositing thick silicon oxide films by PEALD using a mixture of nitrous oxide, oxygen, and argon during plasma conversion without sacrificing film quality.

[0065] For silicon oxide films deposited using certain disclosed embodiments, without being bound by a particular theory, it is believed that silicon oxide films deposited using short conversion times result in lower quality films due to insufficient time for the bonds in each deposited silicon oxide layer formed during the conversion operation to rearrange to convert adsorbed silicon precursors to silicon oxide. Conversely, films deposited using longer conversion times have higher quality because they allow the surface reactions sufficient time to proceed to produce the desired ALD reaction products. For example, one particular improvement can be a reduced etch rate in 200: 1 hydrofluoric acid such that higher quality films can withstand more aggressive wet etch rate conditions without being etched.

[0066] For PEALD embodiments, the plasma conversion time can be adjusted between each cycle. The plasma generated reaction species can be a function of time in nature; thus, increased plasma conversion time can generate sufficient reaction species to penetrate deposited material layers and rearrange bonds or adjust the properties of the deposited material to adjust the properties of the deposited film. In some embodiments, the properties of the reaction species can be related to the ion penetration depth in a blanket film. In some embodiments, the properties of the reaction species can be related to the plasma energy; that is, for example, higher plasma energy can result in reaction species with increased plasma density. In some embodiments, the same plasma power is used during long and short durations, but due to their different durations, the reaction species can behave differently.

[0067] In both thermal and plasma enhanced ALD processing, longer durations can result in increased diffusion into high aspect ratio features for deposition into high aspect ratio features, depositing higher quality films deeper into the features.

[0068] A "super cycle" is described herein as comprising one or more long-transition ALD cycles and one or more short-transition ALD cycles. The super cycle can be repeated multiple times to deposit the desired film.

[0069] Switching duration modulation can be used to adjust the desired film quality. One example of switching duration modulation is switching between short and long switching durations from ALD cycle to ALD cycle. A long switching duration ALD cycle can be performed between short-duration ALD cycles, or every n cycles of short-duration ALD cycles. Another example of switching duration modulation is using multiple switching durations of an ALD cycle in a super-cycle and repeating the super-cycle. For example, in certain embodiments, a "gradient" process can be used, where the gradient refers to the degree of change in the switching duration used from cycle to cycle. In such an example, a super-cycle comprises three or more ALD cycles, and each cycle comprises first, second, and third durations, each of which increases by an amount greater than the previous cycle. For example, a super-cycle may comprise a first switching time ALD cycle, followed by a second, longer switching time ALD cycle (such as an ALD cycle having a switching time 1.5 times that of the first switching time), followed by a third, longer switching time ALD cycle (such as an ALD cycle having a switching time 1.5 times that of the second switching time). Variations in the switching time can be used in various embodiments, depending on the desired film quality and process cycle time tolerances. Further embodiments are described in detail below with reference to the accompanying drawings.

[0070] Figure 1A A process flow diagram depicting operations performed according to certain disclosed embodiments. Figure 1A The operations in can be performed in a process chamber having one or more stations. In various embodiments, the process chamber has four stations. Suitable tools are further described in the apparatus section below.

[0071] exist Figure 1A The operations in can be performed at a chamber pressure between 1 mTorr and about 10 Torr, or between 1 mTorr and 500 mTorr, or between about 1 Torr and about 10 Torr. Figure 1A The operations in the embodiment may be performed at a substrate temperature between about −50° C. and about 900° C., or between about 100° C. and about 400° C., or between about 200° C. and about 300° C., or between about 400° C. and about 550° C., or between about 400° C. and about 600° C., or between about 400° C. and about 700° C., or between about 400° C. and about 800° C. It should be understood that the substrate temperature is defined as the temperature set for the susceptor holding the substrate so as to heat the substrate to a desired temperature.

[0072] In operation 132, a substrate is provided to the processing chamber. The substrate can be a silicon wafer, such as a 200-mm wafer, a 300-mm wafer, or a 450-mm wafer, containing one or more layers of material deposited thereon, such as dielectric, conductor, or semiconductor material. Non-limiting examples of underlayers include dielectric layers and conductor layers, such as silicon oxide, silicon nitride, silicon carbide, metal oxides, metal nitrides, metal carbides, and metal layers.

[0073] In various embodiments, the substrate can be patterned. The pattern can include topography, which can include vias, holes, and trenches. Such features can have a high aspect ratio. For example, the aspect ratio of the features can be between at least about 5: 1, or at least about 10: 1, or at least about 15: 1, or at least about 170: 1, or between about 10: 1 and about 300: 1, such as about 180: 1. In various embodiments, the feature openings of the features can be in the range of between about 10 nm and about 10 μιη, or between about 100 nm and about 10 μιη, or less than about 10 nm.

[0074] In operation 113, the substrate is exposed to the precursor for a duration sufficient to adsorb the precursor on the surface of the substrate to form a precursor adsorption layer.

[0075] The duration sufficient to adsorb the precursor depends on the precursor used and the partial pressure of the precursor. Other process conditions that can be relevant to the duration sufficient to adsorb the precursor include, but are not limited to, substrate temperature, chamber pressure, presence of other gases in the chamber, precursor flow rate, selected precursor, surface chemistry of the substrate, and surface topography of the substrate.

[0076] In some embodiments, certain disclosed embodiments can involve alternating short and long durations of any of the following non-limiting operations in an ALD cycle: dosing, purging, pressure, RF power, and / or RF energy. In certain disclosed embodiments, the alternating operations between short and long transition durations can be performed without, or in conjunction with, adjusting other operations of the ALD cycle to reduce the overall cycle time and improve throughput while achieving desired film properties, such as properties consistent with films deposited using only long transition times.

[0077] In various embodiments, the precursors can be delivered to the processing chamber containing the substrate using a carrier gas, which can be an inert gas such as argon. In some embodiments, the carrier gas is diverted prior to flowing into the chamber.

[0078] In operation 134, the processing chamber is optionally purged. The processing chamber containing the substrate can be purged to remove precursors that are not adsorbed on the surface of the substrate. Purging the chamber can involve flowing a purge gas or a sweep gas, which can be the carrier gas used in other operations or can be a different gas. Exemplary purge gases include argon, nitrogen, hydrogen, and helium. In various embodiments, the purge gas can be an inert gas. Exemplary inert gases include argon, nitrogen, and helium. In some embodiments, purging can involve evacuating the chamber. In some embodiments, the purge gas is the same as the carrier gas used to deliver the precursor to the chamber. In some embodiments, operation 104 can include one or more evacuation sub-stages that evacuate the processing chamber. Alternatively, it should be appreciated that in some embodiments operation 104 can be omitted. Operation 104 can have any suitable duration, such as between about 0.1 seconds and about 2 seconds.

[0079] In operation 135, the substrate is exposed to a second reactant using a short conversion time to convert the adsorbed precursor into a film. In some embodiments, a plasma is optionally generated during operation 135. In various embodiments, the short conversion time is between about 0.05 seconds and about 0.3 seconds.

[0080] In the case of PEALD, a reactive species is provided to activate the second reactant, such as an oxygen-containing gas or oxidant, into ions and radicals and other activated species that react with the adsorbed layer of the first precursor. For example, a plasma can directly or indirectly activate an oxygen-containing gas-phase molecule to form oxygen radicals or ions.

[0081] The reactive species can have a specific plasma energy that can be determined by the duration of the radio frequency plasma on (RF time) and the radio frequency plasma power (RF power). The plasma power of a 4-station tool can be between about 500 watts and about 6500 watts; that is, the plasma power per substrate can be between about 125 watts and about 1625 watts.

[0082] In operation 135, the substrate is exposed to the specific plasma power for a short duration. The plasma power can depend on tool limitations and sputtering risks. In one example, a stable plasma with as low as 300 Joules is generated by applying 2000 watts for 0.15 seconds using a 13.56 MHz generator. The RF time of a low energy plasma depends on the RF generator and the RF power used, and thus varies according to these parameters.

[0083] The amount of reactant species present in the chamber during deposition can also be adjusted by varying the plasma power or plasma time. However, it should be understood that in the various embodiments described herein, when PEALD is adjusted from cycle to cycle, the amount of reactant species can be adjusted to maximize throughput by varying only the RF time while maintaining the same maximum RF power allowed by the RF generator.

[0084] In various embodiments, the plasma is an in-situ plasma such that the plasma is formed in the chamber directly above the substrate surface. The plasma of the ALD process can be generated by applying a radio frequency (RF) field to the gas using two capacitively coupled plates. The plasma generates reactant species. The reactant species can include electrons, ions, radicals, and neutral species. The plasma is ignited by ionization of the gas between the plates by the RF field, generating free electrons in the plasma discharge region. These electrons are accelerated by the RF field and can collide with gas phase reactant molecules. The collisions of these electrons with the reactant molecules can form radical species that participate in the deposition process. It should be understood that the RF field can be coupled via any suitable electrode. In various embodiments, a high frequency plasma is used, having a frequency of at least about 13.56 MHz, or at least about 27 MHz, or at least about 40 MHz, or at least about 60 MHz. In some embodiments, a microwave-based plasma can be used. Non-limiting examples of electrodes include: a process gas distribution showerhead and a substrate support pedestal. In various embodiments, the pedestal is a powered pedestal and the chamber includes a grounded showerhead. In some embodiments, the pedestal is grounded and the showerhead is powered. It should be understood that the plasma of the ALD process can be formed by one or more other suitable methods besides capacitively coupling an RF field to the gas. In certain embodiments, the plasma is a remote plasma such that the second reactant is ignited in a remote plasma generator upstream of the chamber and then delivered to the chamber containing the substrate.

[0085] In some embodiments, no plasma is used, but instead thermal ALD is performed such that the duration of exposure to the second reactant during the transition is adjusted from cycle to cycle.

[0086] In some embodiments, operation 135 can also be performed by adjusting the processing chamber in addition to or instead of the transition time. That is, in some embodiments, a low pressure is used during operation 135 while a higher pressure is used during operation 145 described further below. The low pressure used during operation 135 can be a processing chamber pressure of between about 1 Torr and about 5 Torr. In some embodiments, the pressure can be in the millitorr range, depending on the tool used. For example, in some embodiments, an ICP plasma processing chamber can be set at a chamber pressure of about 1 millitorr.

[0087] In operation 136, the processing chamber is again optionally purged to remove any excess byproducts from the reaction between the precursor and the second reactant. The processing conditions of operation 106 can be any of those described above with respect to operation 104. In some embodiments, an inert gas flowing at a flow rate between about 5 standard liters per minute (slm) and about 70 slm is used to purge the chamber.

[0088] Operations 133-136 can be optionally repeated multiple times, each constituting a cycle of short conversion ALD. The desired film properties, such as reduced wet etch rate, are achieved by performing operations 133-136 as described further below.

[0089] After repeating one or more cycles of operations 133-136, operations 143-146 can be performed. It should be understood that although operations 133-136 are depicted in FIG. 1 as being performed prior to operations 143-146, one skilled in the art will understand that operations 143-146 can also be performed prior to operations 133-136, and any combination of operations 133-136 and 143-146 can be performed in any order.

[0090] In operation 143, the substrate is exposed to the precursor to adsorb the precursor onto the substrate surface. This operation can be the same as operation 133 described above. In operation 144, the processing chamber is optionally purged. This operation can be the same as operation 134 described above. In operation 145, the substrate is exposed to the second reactant for a duration that is longer than the duration of operation 135.

[0091] For PEALD embodiments, without being bound by a particular theory, it is believed that the long conversion operation produces a reactive species (e.g., ions or radicals) that provides energy that facilitates stabilizing bonds or increasing cross-linking in a large depth of the deposited film, thereby improving the film quality at the surface. In the case where ions are the reactive species, the depth of ion penetration depends on the size of the ions - that is, heavier ions can be able to penetrate a greater depth.

[0092] How frequently the long conversion time cycle is performed is determined by the deposited film quality of the lower quality film deposited in the short conversion time ALD cycle, as well as the relative duration of the short and long conversion times.

[0093] For PEALD implementations, the increased RF time can be performed using the same RF power as used in operation 135. In some implementations, this can result in a high plasma energy, which can range from about 600 Joules to about 6000 Joules, or about 1500 Joules for four substrates. In some cases, the substrates can be exposed to the reactive species for a long transition duration of 0.3 seconds to 3 seconds using 2000 Watts of RF power. In various implementations, the high plasma energy per substrate is between about 150 Joules and about 1500 Joules. The high plasma energy can be limited by the RF time to ensure an industrially acceptable throughput, and by tool limitations for RF time and RF power.

[0094] As with operation 135 above, in some implementations, operation 145 can also be performed by adjusting the processing chamber instead of or in addition to the transition time. That is, in some implementations, a high pressure is used during operation 145, while a low pressure is used during operation 135, which is described further above. The high pressure used during operation 145 can be a processing chamber pressure between about 10 Torr and about 15 Torr. Without being bound by a particular theory, it is believed that a higher pressure increases the radical density, but decreases the ion energy. Thus, alternating between low pressure and high pressure ALD cycles, or PEALD cycles, can result in a film with particular desired properties, such as reduced wet etch rate. The frequency of high pressure ALD cycles performed in a series of low pressure ALD cycles depends on the number of layers for the higher and lower pressure conditions. In one particular example, one high pressure ALD cycle can be performed for every 1 to 20 low pressure ALD cycles.

[0095] In operation 146, the processing chamber is again optionally purged, which can use the same processing conditions and / or chemicals described above with respect to operation 134.

[0096] Operations 143-146 can be repeated in a multi-cycle of long transition time ALD. The number of long transition time cycles (M cycles) for every N cycles of short transition time ALD can depend on how many short transition time ALD cycles are used, where N is any integer greater than or equal to 1. Further, the transition duration used in each of the repeated cycles of long transition time ALD can vary from cycle to cycle. For example, a supercycle can include N short transition ALD cycles, followed by one long transition ALD cycle with 1.1 times the duration of the short transition, followed by N short transition ALD cycles, followed further by one long transition ALD cycle with 5 times the duration of the short transition, and so on.

[0097] Figure 1BTo depict a process flow diagram for performing an example operation for depositing silicon oxide by alternating conversion time PEALD according to certain disclosed embodiments. Figure 1B The operations in

[0098] In Figure 1B The operations in Figure 1B The operations in

[0099] In operation 102, a substrate is provided to the processing chamber. The substrate can be any of those described above with respect to Figure 1A

[0100] In operation 103, the substrate is exposed to a silicon-containing precursor for a duration of time sufficient to adsorb the precursor onto the substrate surface to form a precursor adsorption layer.

[0101] Suitable silicon-containing precursors for use according to the disclosed embodiments include polysilanes (H3Si-(SiH2) n SiH3), where n > 0. Examples of silanes are silane (SiH4), disilane (Si2H6), and organosilanes such as methylsilane, ethylsilane, isopropylsilane, t-butylsilane, dimethylsilane, diethylsilane, di-t-butylsilane, allylsilane, sec-butylsilane, thexylsilane, isoamylsilane, t-butylsilane, di-t-butylsilane, and the like.

[0102] Halo-silanes include at least one halogen group and can or can not include hydrogen and / or carbon groups. Examples of halo-silanes are iodo-silanes, bromo-silanes, chloro-silanes, and fluoro-silanes. While halo-silanes, especially fluoro-silanes, can form reactive halide species that can etch silicon materials when the plasma is ignited, in some embodiments, the halogenated silane can not introduce the chamber when the plasma is ignited, thus mitigating the formation of reactive halide species from the halo-silane. Specific chloro-silanes are tetrachlorosilane, trichlorosilane, dichlorosilane, monochlorosilane, chloroallylsilane, chloromethylsilane, dichloromethylsilane, chlorodimethylsilane, chloroethylsilane, t-butylchlorosilane, di-t-butylchlorosilane, chloroisopropylsilane, chlorosec-butyisilane, t-butyldimethylchlorosilane, t-hexyldimethylchlorosilane, and the like.

[0103] ​Aminosilanes include at least one nitrogen atom bonded to a silicon atom, but can also contain hydrogen, oxygen, halogen, and carbon. Examples of aminosilanes are mono-, di-, tri-, and tetra-aminosilanes (H3Si(NH2), H2Si(NH2)2, HSi(NH2)3, and Si(NH2)4, respectively) and substituted mono-, di-, tri-, and tetra-aminosilanes, such as t-butylaminosilane, methylaminosilane, t-butylsilylamine, bis(t-butylamino)silane, (SiH2(NHC(CH3)3)2 (BTBAS), tert-butyl silylcarbamate, SiH(CH3)-(N(CH3)2)2, SiHCl-(N(CH3)2)2, (Si(CH3)2NH)3, and the like. Another example of an aminosilane is trisilylamine (N(SiH3)).

[0104] In various embodiments, the silicon precursor is diisopropylaminosilane (DIPAS).

[0105] In operation 104, the process chamber is optionally purged. Purging can be performed using any of the chemicals and process conditions described above with respect to operation 134. Figure 1A of operation 134.

[0106] In operation 105, the substrate is exposed to an oxygen-containing plasma and an inert gas with a short conversion time to convert the adsorbed silicon precursor to silicon oxide. The particular conversion time for short conversion depends on the type of film to be deposited, the chemicals used, and process conditions such as temperature and pressure. The short conversion time can be between about 0.05 seconds and about 0.3 seconds in some embodiments.

[0107] The oxygen-containing plasma can be generated by introducing an oxidizing agent and igniting a plasma. The plasma can be generated in situ or in a remote generator. The reactive species can be delivered to the substrate surface with the oxygen-containing plasma to react with the silicon-containing precursor adsorbed on the substrate surface to form silicon oxide. Examples of oxidizing agents include oxygen, water, carbon dioxide, nitrous oxide, hydrogen peroxide, and combinations thereof. In various embodiments, the substrate is simultaneously exposed to the oxidizing agent and the inert gas upon ignition of the plasma. For example, in one embodiment, a mixture of oxygen and argon is introduced to the substrate upon ignition of the plasma.

[0108] For particular PEALD embodiments, the low plasma energy used in operation 105 can be between about 200 Joules and about 500 Joules, or in some embodiments, about 300 Joules.

[0109] In operation 106, the process chamber is again optionally purged to remove any excess byproducts from the reaction between the silicon precursor and the oxygen-containing plasma. The process conditions and chemicals used during the purge may be those described above with respect to Figure 1A Any one of those of operation 134.

[0110] Operations 103 through 106 can optionally be repeated multiple times, each time forming a cycle of short-switch PEALD. Such a layer can result in a lower-quality silicon oxide film, including a potentially less densified layer, and thus this film alone can have a high wet etch rate. However, short-switch PEALD cycles have short cycle times and can improve throughput.

[0111] After repeating one or more cycles of operations 103-106, operations 113-116 may be performed. It should be understood that although operations 103-106 are described in FIG1 as being performed before operations 113-116, those skilled in the art will appreciate that operations 113-116 may also be performed before operations 103-106, and any combination of operations 103-106 and operations 113-116 may be performed in any order.

[0112] In operation 113, the substrate is exposed to a precursor to adsorb the precursor onto the substrate surface. This operation can be the same as operation 103 described above. In operation 114, the process chamber is optionally purged. This operation can be the same as operation 104 described above. In operation 115, the substrate is exposed to an oxygen-containing plasma and an inert gas for a long conversion duration to convert the adsorbed silicon precursor into silicon oxide while improving the overall quality of the silicon oxide film. In some embodiments, a plasma energy of 1500 joules is used to penetrate 10 layers of silicon oxide deposited using approximately 10 cycles of low plasma energy PEALD at 300 joules, such that one cycle of 1500 joule PEALD is performed for every 10 cycles of 300 joule PEALD to result in a film having a wet etch rate quality similar to a film deposited using only 1500 joule PEALD cycles.

[0113] The high plasma energy can range from about 600 joules to about 6,000 joules, or about 1,500 joules for four substrates. This means that for an RF power of 2,000 watts, the RF time ranges from 0.3 seconds to 3 seconds. In various embodiments, the high plasma energy for each substrate is between about 150 joules and about 1,500 joules.

[0114] In some cases, a long transition duration is used such that the transition duration is about 1.1 times to about 15 times longer than the short transition duration.

[0115] In operation 116 , the process chamber is optionally purged again, which may use the same process conditions and / or chemistries as described above with respect to operation 104 .

[0116] Operations 113-116 may be repeated over multiple cycles of the long conversion step ALD. The number M of long conversion time cycles used and the frequency with which the long conversion time cycles are performed may depend on how many cycles of the short conversion time ALD are used, where M is any integer greater than or equal to 1. Furthermore, the conversion duration used in each of the repeated cycles of the long conversion ALD may vary from cycle to cycle.

[0117] Figure 2 A timing diagram illustrating an example of a process 200 having two super cycles 290A and 290B in a method according to certain disclosed embodiments is shown. Super cycle 290A includes a short switching cycle 230A and a long switching cycle 240A, while super cycle 290B includes a short switching cycle 230B and a long switching cycle 240B. In this example, a super cycle having one short switching cycle and one long switching cycle is repeated. However, those skilled in the art will appreciate that more than one short switching cycle or long switching cycle may be used in a single super cycle, and further that more than one type of switching duration cycle may be used (e.g., one or more short switching cycles and one or more medium switching duration cycles and one or more long switching cycles, to name a specific non-limiting example).

[0118] In this particular example of PEALD, the short transition cycle 230A includes four phases—a silicon precursor exposure phase 203A, a sweep phase 204A, a short transition phase 205A, and a sweep phase 206A. During the silicon precursor exposure phase 203A, the silicon precursor flow is turned on, the argon flow as a carrier gas is turned on, the oxygen flow is turned off, and the plasma power is 0 watts. The silicon precursor exposure phase 203A may correspond to Figure 1B Operation 103.

[0119] During the sweep phase 204A, the silicon precursor flow is turned off, the argon flow is continued to purge the chamber, the oxygen flow remains off, and the plasma power remains at 0 watts. The sweep phase 204A may correspond to Figure 1B Operation 104.

[0120] During the short transition phase 205A, the silicon precursor flow is maintained off, the oxygen flow is turned on, the argon flow is maintained on, and the plasma power is turned on to a specific plasma power. The short transition phase 205A may correspond to Figure 1B Operation 105.

[0121] During the sweep phase 206A, the silicon precursor flow remains off, the argon flow continues to purge the chamber, the oxygen flow is turned off, and the plasma power is 0 watts. The sweep phase 206A may correspond to Figure 1B Operation 106.

[0122] The long conversion cycle 240A includes four phases: a silicon precursor exposure phase 213A, a sweep phase 214A, a long conversion plasma phase 215A, and a sweep phase 216A. During the silicon precursor exposure phase 213A, the silicon precursor flow is turned on, the argon flow is turned on as a carrier gas, the oxygen flow is turned off, and the plasma power is 0 watts. The silicon precursor exposure phase 213A may correspond to Figure 1B Operation 113.

[0123] During the sweep phase 214A, the silicon precursor flow is turned off, the argon flow is continued to purge the chamber, the oxygen flow remains off, and the plasma power remains at 0 watts. The sweep phase 214A may correspond to Figure 1B Operation 114.

[0124] During the long transition plasma phase 215A, the silicon precursor flow is maintained off, the oxygen flow is turned on, the argon flow is maintained on, and the plasma power is turned on to a specific plasma power, which in this example is the same as the plasma power of the short transition phase 205A, but the plasma on time is longer to correspond to the longer transition plasma. The long transition plasma phase 215A may correspond to Figure 1B Operation 115.

[0125] During the sweep phase 216A, the silicon precursor flow is maintained off, the argon flow continues to flow to purge the chamber, the oxygen flow is turned off, and the plasma power is 0 watts. The sweep phase 216A may correspond to Figure 1B Operation 116.

[0126] The short switching cycle 230A and the long switching cycle 240A are repeated in a second super cycle 290B, which includes the short switching cycle 230B and the long switching cycle 240B.

[0127] The short transition cycle 230B includes four phases: a silicon precursor exposure phase 203B, a sweep phase 204B, a short transition plasma phase 205B, and a sweep phase 206B. During the silicon precursor exposure phase 203B, the silicon precursor flow is turned on, the argon flow is turned on as a carrier gas, the oxygen flow is turned off, and the plasma power is 0 watts. The silicon precursor exposure phase 203B may correspond to the silicon precursor exposure phase 203B. Figure 1B The operation 103 is performed by repeating the operations 103-116.

[0128] During the sweep phase 204B, the silicon precursor flow is turned off, the argon flow is continued to purge the chamber, the oxygen flow remains off, and the plasma power remains at 0 watts. The sweep phase 204B may correspond to the Figure 1B The operation 104 is performed by repeating the operations 103-116.

[0129] During the short transition plasma phase 205B, the silicon precursor flow is maintained off, the oxygen flow is turned on, the argon flow is maintained on, and the plasma power is turned up to a specific plasma power. The short transition plasma phase 205B may correspond to the period of Figure 1B The operation 105 is performed by repeating the operations 103-116.

[0130] During the sweep phase 206B, the silicon precursor flow remains off, the argon flow continues to flow to purge the chamber, the oxygen flow is turned off, and the plasma power is 0 watts. The sweep phase 206B may correspond to the Figure 1B The operation 106 is performed by repeating the operations 103-116.

[0131] The long conversion cycle 240B includes four phases: a silicon precursor exposure phase 213B, a sweep phase 214B, a long conversion plasma phase 215B, and a sweep phase 216B. During the silicon precursor exposure phase 213B, the silicon precursor flow is turned on, the argon flow is turned on as a carrier gas, the oxygen flow is turned off, and the plasma power is 0 watts. The silicon precursor exposure phase 213B may correspond to the Figure 1B The operation 113 is performed by repeating the operations 103-116.

[0132] During the sweep phase 214B, the silicon precursor flow is turned off, the argon flow is continued to purge the chamber, the oxygen flow remains off, and the plasma power remains at 0 watts. The sweep phase 214B may correspond to the Figure 1B The operation 114 is performed by repeating the operations 103-116.

[0133] During the long conversion plasma phase 215B, the silicon precursor flow is maintained off, the oxygen flow is turned on, the argon flow is maintained on, and the plasma power is turned on to a specific plasma power, which in this example is the same as the plasma power of the short conversion plasma phase 205B, but the plasma on time is longer to correspond to the long conversion plasma. The long conversion plasma phase 215B may correspond to the plasma power of the short conversion plasma phase 205B. Figure 1B The operation 115 is performed by repeating the operations 103-116.

[0134] During the sweep phase 216B, the silicon precursor flow remains off, the argon flow continues to flow to purge the chamber, the oxygen flow is turned off, and the plasma power is 0 watts. The sweep phase 216B may correspond to the Figure 3A The operation 116 is performed in the repeated operations 103-116.

[0135] Figure 3A and 3B is a process flow diagram depicting the operation of a method according to certain disclosed embodiments. Figure 1B An example of a variation of certain disclosed embodiments is shown, whereby multiple layers of silicon oxide are deposited using different conversion durations during conversion to form an overall silicon oxide layer having certain desired properties. In this particular example, a "gradient" plasma power scheme is used. In operation 302, a substrate is provided to a processing chamber. This operation may be similar to the above-described operation with respect to Figure 1B The operation 102 is the same.

[0136] In operation 330, one or more layers of silicon oxide are deposited by short transition PEALD, which may correspond to Figure 1B Operations 103-106 of FIG. 104 and a short transition such as about 0.15 seconds may be used during the transition.

[0137] In operation 340, one or more layers of silicon oxide are optionally deposited by medium transition time PEALD, which may involve introduction of a silicon precursor, an optional purge, introduction of oxygen and argon, and plasma ignition for a duration, eg, about 0.45 seconds, and an optional purge.

[0138] In operation 350, one or more layers of silicon oxide are deposited by long transition PEALD, which may correspond to Figure 3B Operations 113-116 of FIG. 114 and a long transition such as approximately 0.75 seconds may be used during the transition.

[0139] This is described herein as a "gradient" approach, with incremental transition times of 0.15 seconds, 0.45 seconds, and 0.75 seconds being used as a specific example of incremental transition times within a supercycle. Operations 330-350 may then be repeated in multiple cycles as desired.

[0140] Figure 3A Another alternative embodiment is shown in which a long switching PEALD cycle is performed every nth cycle of a short switching PEALD cycle, where n is an integer greater than or equal to 1.

[0141] Operation 302 and Figure 3A Operation 330 is consistent with operation 302. Figure 4 The process is consistent with operation 330 of FIG. In operation 360, one or more layers of silicon oxide are deposited by performing long-transition PEALD for every nth cycle of short-transition PEALD. A super-cycle may include both N cycles of short-transition PEALD and M cycles of long-transition PEALD, such that the super-cycle is repeated a plurality of times, where N and M are each integers greater than or equal to 1. Furthermore, N and M may be different or the same integers. Operations 330 and 360 may then be repeated in a cycle.

[0142] Silicon oxide films deposited using the alternating conversion time ALD technique described herein can achieve a wet etch rate of less than about 0.5 Angstroms per minute in 200: 1 hydrofluoric acid or between about 0.5 and about 1 Angstroms per minute for 180 seconds.

[0143] It should be understood that although silicon oxide films are described herein, the application of certain disclosed embodiments can be used to deposit other silicon-containing films including, but not limited to: silicon nitride, silicon carbide, silicon oxynitride, silicon carboxynitride, silicon oxycarbide, and polysilicon.

[0144] Although PEALD is described herein as an example, certain disclosed embodiments can be applied to any ALD technique, including thermal and spatial ALD, and although conversion times are described herein, dosing, purging, RF power, and / or pressure can also be adjustable.

[0145] Apparatus

[0146] Figure 5 A schematic diagram of one embodiment of an atomic layer deposition (ALD) processing station 400 having a process chamber body 402 for maintaining a low pressure environment is depicted. Multiple ALD processing stations 400 can be included in a generally low pressure processing tool environment. For example, Figure 4 One embodiment of a multi-station processing tool 500 is depicted. In some embodiments, one or more hardware parameters of the ALD processing station 400, including those discussed in detail below, can be programmatically adjusted by one or more controllers 450.

[0147] The ALD processing station 400 is in fluid communication with a reactant delivery system 401a for delivering process gases to the showerhead 406. The reactant delivery system 401a includes a mixing vessel 404 for mixing and / or conditioning process gases, such as a silicon precursor gas, or a second reactant gas (e.g., oxygen and argon), delivered to the showerhead 406. One or more mixing vessel inlet valves 420 can control the introduction of process gases to the mixing vessel 404. Argon plasma can also be delivered to the showerhead 406 or can be generated in the ALD processing station 400.

[0148] For example, Figure 4 ​Embodiments include a vaporization point 403 for vaporizing liquid reactants to be supplied to the mixing container 404. In some embodiments, the vaporization point 403 can be a heated evaporator. The saturated reactant vapors produced from such an evaporator will condense in the downstream delivery pipe. Incompatible gases exposed to the condensed reactants will produce small particles. These small particles may block the pipes, hinder valve operation, contaminate the substrate, etc. Some methods for dealing with these problems involve cleaning and / or emptying the delivery pipes to remove residual reactants. However, cleaning the delivery pipes will increase the processing station cycle time and reduce the processing station throughput. Therefore, in some embodiments, the delivery pipes downstream of the vaporization point 403 can be heat traced. In some examples, the mixing container 404 can also be heat traced. In a non-limiting example, the pipes downstream of the vaporization point 403 have an increased temperature distribution, extending from about 100°C to about 150°C at the mixing container 404.

[0149] In some embodiments, the liquid precursor or liquid reactant can be vaporized at the liquid injector. For example, the liquid injector can eject a pulse of liquid reactant into the carrier gas flow upstream of the mixing vessel. In one embodiment, the liquid injector can vaporize the reactant by flashing the liquid from a higher pressure to a lower pressure. In another example, the liquid injector can atomize the liquid into dispersed droplets that are then vaporized in a heated delivery pipe. Smaller droplets can vaporize faster than larger droplets, thereby reducing the delay between liquid injection and completion of vaporization. Faster vaporization can reduce the length of the pipeline downstream of the vaporization point 403. In one embodiment, the liquid injector can be directly loaded into the mixing vessel 404. In another embodiment, the liquid injector can be directly mounted on the spray head 406.

[0150] In some embodiments, a liquid flow controller (LFC) can be provided upstream of the vaporization point 403 to control the mass flow of the liquid being vaporized and delivered to the ALD processing station 400. For example, the LFC can include a thermal mass flow meter (MFM) located downstream of the LFC. The plunger valve of the LFC can then be adjusted in response to a feedback control signal provided by a proportional-integral-derivative (PID) controller in electrical communication with the MFM. However, it may take one second or more to use feedback control to stabilize the liquid flow. This can extend the time for dosing the liquid reactants. Therefore, in some embodiments, the LFC can dynamically switch between a feedback control mode and a direct control mode. In some embodiments, this can be done by disabling the PID controller and the sensing conduit of the LFC.

[0151] The showerhead 406 distributes the process gas toward the substrate 412. Figure 4In the illustrated embodiment, the substrate 412 is positioned below the showerhead 406 and is shown disposed on a pedestal 408. The showerhead 406 can have any suitable shape and can have any suitable number and arrangement of ports to distribute process gas to the substrate 412.

[0152] In some embodiments, the pedestal 408 can be raised or lowered to expose the substrate 412 to the volume between the substrate 412 and the showerhead 406. It should be appreciated that in some embodiments, the pedestal height can be adjusted programmatically via a suitable computer controller 450.

[0153] In another case, in embodiments where the plasma is ignited, adjusting the height of the pedestal 408 can cause the plasma density to change during the plasma activation cycle in the process. At the end of the processing phase, the pedestal 408 can be lowered for another substrate transfer phase to enable the substrate 412 to be removed from the pedestal 408.

[0154] In some embodiments, the pedestal 408 can be temperature controlled by the heater 410. In some embodiments, during deposition of a silicon oxide film as described in the disclosed embodiments, the pedestal 408 can be heated to a temperature of at least about 250 °C (or in some embodiments, less than about 300 °C, such as about 250 °C). In some embodiments, the pedestal is set to a temperature between about -50 °C and about 900 °C, or between about 50 °C and 300 °C, for example, a temperature between about 200 °C and about 275 °C. In some embodiments, the pedestal is set to a temperature between about 50 °C and 300 °C. In some embodiments, the pedestal is set to a temperature between about 200 °C and about 275 °C.

[0155] Further, in some embodiments, pressure control for the ALD processing station 400 can be provided by a butterfly valve 418. As shown in the embodiments of Figure 5 As shown in the embodiments of the butterfly valve 418 throttles a vacuum provided by a downstream vacuum pump (not shown). However, in some embodiments, pressure control for the ALD processing station 400 can also be adjusted by varying the flow rate of one or more gases introduced to the ALD processing station 400.

[0156] In some embodiments, the position of the showerhead 406 can be adjusted relative to the pedestal 408 to vary the volume between the substrate 412 and the showerhead 406. Further, it should be understood that the vertical position of the pedestal 408 and / or the showerhead 406 can be varied by any suitable mechanism within the scope of the present disclosure. In some embodiments, the pedestal 408 can include a rotational axis for rotating the orientation of the substrate 412. It should be understood that in some embodiments, one or more of these exemplary adjustments can be made programmatically by one or more controllers 450.

[0157] In some embodiments in which plasma can be used as described above, the showerhead 406 and the pedestal 408 are electrically connected to a radio frequency (RF) power source 414 and a matching network 416 to power the plasma. In various embodiments, the pedestal is an electrically powered pedestal and the chamber includes a grounded showerhead. In some embodiments, the pedestal is grounded and the showerhead is powered. The duration of the plasma used during the short and long transition times can be controlled using the controller 450. In some embodiments, the energy of the plasma is adjusted using a combination of plasma power and transition duration. In some embodiments, the energy of the plasma can be controlled by controlling one or more of the pressure of the processing station, the concentration of the gas, the RF source power, the RF source frequency, and the plasma power pulse timing. For example, the RF power source 414 and the matching network 416 can operate at any suitable power to form a plasma having a desired composition of radical species. Examples of suitable powers have been included above. Likewise, the RF power source 414 can provide RF power at any suitable frequency. In some embodiments, the RF power source 414 can be configured to control a high frequency RF power source and a low frequency RF power source independently of one another. Exemplary low frequency RF frequencies can include, but are not limited to, frequencies between 0 kHz and 500 kHz. Exemplary high frequency RF frequencies can include, but are not limited to, frequencies between 1.8 MHz and 2.45 GHz, or frequencies greater than about 13.56 MHz, or greater than 27 MHz, or greater than 40 MHz, or greater than 60 MHz. It should be understood that any suitable parameters can be adjusted discretely or continuously to initiate surface reactions.

[0158] In some embodiments, the plasma can be monitored in situ by one or more plasma monitors. In one case, the plasma power can be monitored by one or more voltage, current sensors (e.g., VI probes). In another case, the plasma density and / or concentration of process gases can be measured by one or more optical emission spectroscopy sensors (OES). In some embodiments, one or more plasma parameters can be adjusted programmatically based on measurements from such in situ plasma monitors. For example, an OES sensor can be used in a feedback loop to provide programmed control of the plasma power. It should be appreciated that in some embodiments, other monitors can be used to monitor the plasma and other process characteristics. Such monitors can include, but are not limited to, infrared (IR) monitors, acoustic monitors, and pressure sensors.

[0159] In some embodiments, instructions for controller 450 can be provided via input / output control (IOC) sequencing instructions. In one example, instructions for setting conditions of a processing phase can be included in a corresponding recipe phase of a process recipe. In some cases, the process recipe phases can be arranged in sequence, such that all instructions for a processing phase are performed concurrently with that processing phase. In some embodiments, instructions for setting one or more reactor parameters can be included in a recipe phase. For example, a first recipe phase can include instructions for setting a flow rate of an inert gas and / or a reactant gas (e.g., a first precursor), instructions for setting a flow rate of a carrier gas (such as argon), and a time delay instruction for the first recipe phase. A subsequent second recipe phase can include instructions for adjusting or stopping the flow rate of the inert gas and / or the reactant gas, and instructions for adjusting the flow rate of the carrier gas or a purge gas, and a time delay instruction for the second recipe phase. A third recipe phase can include instructions for adjusting the flow rate of a second reactant gas, instructions for adjusting a duration of the flow of the second reactant gas, instructions for adjusting the flow rate of the carrier gas or purge gas, and a time delay instruction for the third recipe phase. A subsequent fourth recipe phase can include instructions for adjusting or stopping the flow rate of the inert gas and / or the reactant gas, and instructions for adjusting the flow rate of the carrier gas or purge gas, and a time delay instruction for the fourth recipe phase. It should be appreciated that these recipe phases can be further subdivided and / or repeated in any suitable manner within the scope of the present disclosure. In some embodiments, controller 450 can include any of the features described below with respect to system controller 550 of Figure 5

[0160] As described above, one or more processing stations can be included in a multi-station processing tool. Figure 5 ​A schematic view of one embodiment of a multi-station processing tool 500 is shown having an inbound load lock 502 and an outbound load lock 504, either or both of which may contain a remote plasma source. A robot 506 at atmospheric pressure is configured to move wafers from a cassette loaded via a wafer boat 508 into the inbound load lock 502 via an atmospheric port 510. The wafer is placed on a pedestal 512 in the inbound load lock 502 by the robot 506, the atmospheric port 510 is closed, and the load lock is evacuated. When the inbound load lock 502 contains a remote plasma source, the wafer can be exposed to remote plasma treatment in the load lock before being introduced into the processing chamber 514. In addition, the wafer can also be heated in the inbound load lock 502, for example to remove moisture and adsorbed gases. Next, a chamber transfer port 516 leading to the processing chamber 514 is opened, and another robot (not shown) places the wafer into the reactor on a pedestal at the first station shown in the reactor for processing. Although in Figure 5 The embodiment depicted in FIG includes a load lock, but it should be understood that in some embodiments, substrates may be brought directly into a processing station.

[0161] The depicted processing chamber 514 contains four processing stations. Figure 5 In the illustrated embodiment, the stations are numbered 1 to 4. Each station has a heated susceptor (shown as 518 for station 1) and a gas line inlet. It should be understood that in some embodiments, each processing station can have different or multiple uses. For example, in some embodiments, the processing station can be switchable between ALD and plasma-enhanced ALD processing modes. Additionally or alternatively, in some embodiments, the processing chamber 514 can include one or more matched pairs of ALD and plasma-enhanced ALD processing stations. Although the processing chamber 514 is depicted as including 4 stations, it is understood that a processing chamber according to the present disclosure can have any suitable number of stations. For example, in some embodiments, the processing chamber can have 5 or more stations, while in other embodiments, the processing chamber can have 3 or fewer stations.

[0162] Figure 5 One embodiment of a wafer handling system for transporting wafers within process chamber 514 is depicted. In some embodiments, the wafer handling system can transport wafers between various processing stations and / or between a processing station and a load lock. It should be understood that any suitable wafer handling system can be employed. Non-limiting examples include a wafer turntable and a robot for handling wafers. Figure 6An embodiment of a system controller 550 used to control process conditions and hardware states of the multi-station processing tool 500 is also depicted. The system controller 550 can include one or more memory devices 556, one or more mass storage devices 554, and one or more processors 552. The processors 552 can include computers or CPUs, analog and / or digital input / output connections, stepper motor controller boards, etc.

[0163] In some embodiments, the system controller 550 controls all activities of the multi-station processing tool 500. The system controller 550 executes system control software 558 stored in the mass storage device 554, loaded into the memory device 556, and executed by the processor 552. Alternatively, control logic can be hard coded in the system controller 550. Application specific integrated circuits, programmable logic devices (e.g., field programmable gate arrays, or FPGAs), etc. can be used for these purposes. In the following discussion, whether using "software" or "code," functionally equivalent hard coded logic can be substituted therefor. The system control software 558 can include instructions for controlling timing, mixtures of gases, gas flow rates, chamber and / or station pressures, chamber and / or station temperatures, wafer temperatures, target power levels, RF power levels, substrate chucks, chuck and / or pedestal positions, and other parameters of the particular processing by the multi-station processing tool 500. The system control software 558 can be configured in any suitable manner. For example, various processing tool component subroutines or control objects can be written to control operation of the processing tool components for carrying out various processing tool processes. The system control software 558 can be coded in any suitable computer readable programming language.

[0164] In some embodiments, the system control software 558 can include input / output control (IOC) sequencing instructions for controlling the various parameters described above. Other computer software and / or programs stored in the mass storage device 554 and / or the memory device 556 associated with the system controller 550 can be employed in some embodiments. Examples of programs or program segments for these purposes include substrate positioning programs, process gas control programs, pressure control programs, heater control programs, and plasma control programs.

[0165] The substrate positioning programs can include program code for processing tool components used to load a substrate to the pedestal 518 and to control spacing between the substrate and other portions of the multi-station processing tool 500.

[0166] A process gas control program can include code for controlling gas composition (e.g., the iodine-containing silicon precursor gas, nitrogen-containing gas, carrier gas, and purge gas described herein) and flow rates, and optionally code for flowing the gases into one or more process stations prior to deposition to stabilize the pressure in the process stations. A pressure control program can include code for controlling the pressure in the process stations by adjusting, for example, a throttle valve in an exhaust system of the process stations, the gas flow into the process stations, and the like.

[0167] A heater control program can include code for controlling the current to a heating unit used to heat the substrate. Alternatively, the heater control program can control the delivery of a heat transfer gas, such as helium, toward the substrate.

[0168] A plasma control program can include code for setting the RF power level applied to a process electrode in one or more process stations according to the embodiments herein.

[0169] A pressure control program can include code for maintaining the pressure in the reaction chamber according to the embodiments herein.

[0170] In some embodiments, there can be a user interface associated with the system controller 550. The user interface can include a display screen, graphical software displays of devices and / or process conditions, and user input devices such as pointing devices, keyboards, touch screens, microphones, etc.

[0171] In some embodiments, the parameters adjusted by the system controller 550 can relate to process conditions. Non-limiting examples include process gas composition and flow rates, temperature, pressure, plasma conditions (e.g., RF bias power level), etc. These parameters can be provided to the user in the form of a recipe, which can be entered using the user interface.

[0172] Signals for monitoring the process can be provided by analog and / or digital input connections of the system controller 550 from various process tool sensors. Signals for controlling the process can be output on analog and digital output connections of the multi-station process tool 500. Non-limiting examples of process tool sensors that can be monitored include mass flow controllers, pressure sensors (e.g., manometers), thermocouples, etc. Appropriately programmed feedback and control algorithms can be used with data from these sensors to maintain process conditions.

[0173] The system controller 550 can provide program instructions for carrying out the deposition processes described above. The program instructions can control a variety of process parameters, such as DC power level, RF bias power level, pressure, temperature, etc. The instructions can control these parameters to operate in-situ deposition of film stacks according to the various embodiments described herein.

[0174] The system controller 550 will generally include one or more memory devices 556 and one or more processors configured to execute instructions to cause the apparatus to perform the methods described in accordance with the disclosed embodiments. Machine-readable media containing instructions for controlling processing operations in accordance with the disclosed embodiments can be coupled to the system controller 550.

[0175] In some implementations, the system controller 550 is part of a system, which can be part of the above-described examples. Such systems can include semiconductor processing equipment including one or more processing tools, one or more processing chambers, one or more platforms for processing, and / or specific processing components (wafer pedestals, gas flow systems, etc.). These systems can be integrated with electronics for controlling the operations of the systems before, during, and after processing of semiconductor wafers or substrates. The electronics can be referred to as the “controller,” which can control various elements or subparts of the system or systems. Depending on the processing requirements and / or the type of system, the system controller 550 can be programmed to control any of the processes disclosed herein, including control of process gas delivery, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, position and operation settings, wafer transfer into and out of a tool and other transfer tools and / or load locks connected to or interfaced with a specific system.

[0176] Broadly speaking, the system controller 550 can be defined as electronics having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operation, enable cleaning operations, enable endpoint measurements, and the like. The integrated circuits can include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors, or microcontrollers that execute program instructions (e.g., software). Program instructions can be instructions communicated to the system controller 550 in the form of various individual settings (or programs) of the various operating parameters for the various process techniques to be performed within the system, e.g., the various process techniques described above. The program instructions can be embodied in the form of firmware programming of the integrated circuits. The various settings of the program instructions can be provided to the system controller 550 via a number of different input interfaces, e.g., an electronic input interface, a wireless input interface, a memory device, a communication port, a USB connection, a network connection, or the like.

[0177] In some implementations, system controller 550 can be a part of, or coupled to, a computer that is integrated with, coupled to the system, otherwise networked to the system, or a combination thereof. For example, system controller 550 can be in a“cloud” or all or a part of a fab host computer system, which can allow for remote access of the wafer processing. Computer can enable remote access to the system to monitor current process progress, inspect a history of past manufacturing processes, examine performance statistics of

[0178] An example system can include, but is not limited to, a plasma etch chamber or module, a deposition chamber or module, a spin-rinse chamber or module, a metal plating chamber or module, a clean chamber or module, a bevel edge etch chamber or module, a physical vapor

[0179] As noted above, system controller 550 can communicate with one or more other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout a factory, a main computer, another controller, or tools used in material transport that bring containers of wafers to and from tool locations and / or ports in a semiconductor manufacturing factory, depending on the process steps to be performed by the tool.

[0180] Appropriate apparatus for carrying out the methods disclosed herein are further discussed and illustrated in U.S. Patent Application No. 13 / 084,399, filed April 11, 2011, entitled "PLASMA ACTIVATED CONFORMAL FILM DEPOSITION" (now U.S. Patent No. 8,728,956); U.S. Patent Application No. 13 / 084,305, filed April 11, 2011, entitled "SILICON NITRIDE FILMS AND METHODS," each of which is incorporated herein in its entirety.

[0181] The apparatus / process described herein can be used in conjunction with lithographic patterning tools or processes, e.g., for the fabrication or manufacture of semiconductor devices, displays, LEDs, photovoltaic cells, etc. Typically, though not necessarily, these tools / processes will be used or operated together at a common manufacturing facility. Lithographic patterning of a film typically involves some or all of the following operations, each of which enables a number of viable tools: (1) applying photoresist on a workpiece (i.e., substrate) using a spin-on or spray-on tool; (2) curing the photoresist using a hot plate or furnace or UV curing tool; (3) exposing the photoresist to visible or ultraviolet or x-rays using a tool such as a wafer stepper; (4) developing the resist so as to selectively remove resist and thereby pattern it using a tool such as a wet bench; (5) transferring the resist pattern into an underlying film or workpiece by using a dry or plasma- assisted etching tool; and (6) removing the resist using a tool such as a radio frequency or microwave plasma resist stripper.

[0182] Experiment

[0183] Experiment 1

[0184] Experiments were conducted at 200 °C on each of the silicon oxide films deposited at different conversion times to evaluate the wet etch rate ratio at 180 seconds in 200: 1 diluted HF and the step coverage at 2000 watt plasma power. The results thereof are depicted in Figure 6 .

[0185] RF conversion time was adjusted by varying the RF on time, increased conversion time is indicated by Figure 7The wet etch rate ratio (wet etch rate of the ALD oxide film normalized to the result of thermal oxidation) is represented by the circle plot, while the step coverage is represented by the square plot. As shown, for both the wet etch rate ratio and for achieving good step coverage, the RF transition time has a saturation point at about 0.75 seconds; at shorter transition times (e.g., lower RF budget), the wet etch rate ratio is higher and the step coverage substantially exceeds 100, while closer to 100 indicates improved step coverage. These results indicate that improved film quality can be achieved at longer RF transition times, but such transition times come at the cost of increased time.

[0186] Experiment 2

[0187] Experiments were performed at 300°C to compare the wet etch rate of each silicon oxide film deposited using various techniques. The plasma used here involved a plasma generator at a frequency of 13 MHz.

[0188] First silicon oxide film (SiO x #1) was deposited using multiple cycles of short transition (also referred to as low plasma energy) PEALD using repeating cycles of DIPAS dosing, purge, oxygen plasma with argon, purge. The RF transition time of the oxygen plasma with argon was 0.15 seconds, and the RF power was 2000 Watts. The duration of one ALD cycle was 0.95 seconds.

[0189] Second silicon oxide film (SiO x #2) was deposited using multiple cycles alternating between short and long transition PEALD using cycles of DIPAS dosing, purge, RF transition time of 0.15 seconds of oxygen plasma with argon, purge, DIPAS dosing, purge, RF transition time of 0.75 seconds of oxygen plasma with argon, purge. The RF power was 2000 Watts. The average duration of one ALD cycle was 1.25 seconds.

[0190] Third silicon oxide film (SiO x #3) was deposited using multiple cycles alternating between medium transition PEALD and long transition PEALD using cycles of DIPAS dosing, purge, RF transition time of 0.45 seconds of oxygen plasma with argon, purge, DIPAS dosing, purge, RF transition time of 0.75 seconds of oxygen plasma with argon, purge. The RF power was 2000 Watts. The average duration of one ALD cycle was 1.4 seconds.

[0191] Fourth silicon oxide film (SiO x#4) Deposition was performed using multiple cycles of long-transition PEALD using the following steps: DIPAS dosing, sweep, oxygen plasma with argon for 0.75 second RF transition time, sweep. RF power was 2000 W. The average duration of one ALD cycle was 1.55 seconds.

[0192] The wet etch rate of each of these silicon oxide films was evaluated in 200:1 hydrofluoric acid for 180 seconds. The wet etch rate values ​​are provided in Tables 1 and 2 below. Figure 7 middle.

[0193] Table 1. Wet etching rate of ALD silicon oxide film

[0194]

[0195] As shown in Table 1 and Figure 8 As shown in , the first technique results in an undesirably high wet etch rate. The fourth technique achieves a low wet etch rate but uses long transitions (also known as a high RF budget), which extends the cycle duration and reduces overall throughput. The second and third techniques achieve low wet etch rates comparable to the fourth technique but do not use long transition times in each ALD cycle, thereby reducing overall process duration and improving throughput.

[0196] The step coverages of the silicon oxide films deposited using the third and fourth techniques were obtained, which showed fairly similar step coverages between the third and fourth techniques, indicating that the use of alternating transition time PEALD cycles results in comparable high quality films.

[0197] Experiment 3

[0198] An experiment was performed to deposit a liner film in a through-hole used to make a contact. The films were deposited using the following cycles: a first cycle of ALD involving dosing, sweeping, a 0.25 second transition, and sweeping; and a second cycle of ALD involving dosing, sweeping, a 1.55 second transition, and sweeping. The two cycles were alternating using a 5500 watt switching plasma power for four substrates. The second film was deposited using only an ALD cycle involving dosing, sweeping, a 1.55 second transition, and sweeping. The final etch rates for the bottom, middle, and top of the features were evaluated and are shown in Figure 2. Figure 8 middle.

[0199] ​The film deposited using only the 1.55 second cycle is depicted as a diagonal hatched bar, while the film deposited using the alternating cycle of transition times is depicted as a fully hatched bar. As shown, both films exhibit similar wet etch rates at the bottom and middle, which indicates that similar film quality is achieved using all 1.55 second transition times versus alternating between 1.55 second and 0.25 second transition times, the latter of which can significantly increase throughput.

[0200] CONCLUSION

[0201] While the foregoing embodiments have been described in some detail for purposes of clarity and the actual details can vary considerably from the details provided, it is to be understood that certain changes and modifications can be practiced within the scope of the appended claims. It is expressly intended that all such changes and modifications that fall within the scope of the claims or their equivalents throw the claims should be covered by the claimed subject matter. It is to be understood that the use of certain specific language, words, or phrases mentioned herein is by way of descriptive example and should be understood not as a restriction on the scope of the claimed subject matter.

Claims

1. A method for depositing a film, the method comprising: providing a substrate to a processing chamber; Depositing a first amount of material on the substrate in a first atomic layer deposition (ALD) cycle, the first ALD cycle comprising: exposing the substrate to the precursor under conditions allowing the precursor to be adsorbed on the surface of the substrate, thereby forming a first adsorption layer of the precursor; as well as exposing the first adsorbed layer of the precursor to a reactive species for a first duration to form the first amount of the material; as well as After the first atomic layer deposition cycle, depositing a second amount of the material on the first amount of the material using a second ALD cycle, the second ALD cycle comprising: exposing the substrate to the precursor under conditions allowing the precursor to be adsorbed on the surface of the substrate, thereby forming a second adsorption layer of the precursor; and exposing the second adsorbed layer of the precursor to a reactive species for a second duration to form the second amount of the material, The second duration is longer than the first duration. 2 . The method of claim 1 , wherein the second duration is between 1.1 and 15 times as long as the first duration.

3. The method of claim 1, further comprising igniting a plasma to generate the reactive species. The method of claim 3 , wherein the plasma is generated in situ or remotely.

5. A method for depositing a film, the method comprising: providing a substrate to a processing chamber; and depositing a conformal film on the substrate by exposing the substrate to two or more plasma enhanced atomic layer deposition (PEALD) cycles, the two or more PEALD cycles comprising at least a first PEALD cycle and a second PEALD cycle, The first PEALD cycle comprises: introducing a precursor to form an adsorbed layer of the precursor on the surface of the substrate, exposing the adsorbed layer of the precursor to a reactant and argon and igniting a first plasma at a first plasma energy, and Wherein, after the first PEALD cycle, the second PEALD cycle comprises: introducing the precursor to form an adsorption layer of the precursor on the surface of the substrate, exposing the adsorbed layer of the precursor to a reactant and argon and igniting a second plasma at a second plasma energy, Wherein, the second plasma energy is at least three times greater than the first plasma energy. 6 . The method of claim 5 , further comprising a third PEALD cycle performed at a third plasma energy, wherein the first plasma energy is less than the second plasma energy and the second plasma energy is less than the third plasma energy. The method of claim 5 , wherein plasma powers used to generate the first plasma energy and the second plasma energy are the same.

8. An apparatus for processing a substrate, the apparatus comprising: one or more processing chambers; one or more gas inlets and associated flow control hardware into the one or more process chambers; as well as A controller having at least one processor and a memory, wherein the at least one processor and the memory are communicatively connected to each other, the at least one processor is at least operatively connected to the flow control hardware, and the memory stores computer-executable instructions for controlling the at least one processor to at least control the flow control hardware to: causing a substrate to be inserted into at least one of the one or more processing chambers; causing a first set of alternating precursor and reactant flows to be introduced into said at least one of said one or more processing chambers via said one or more gas inlets for a first duration; as well as causing a second alternating set of said precursor and reactant flows to be introduced into said at least one of said one or more processing chambers via said one or more gas inlets for a second duration subsequent to said first alternating set of precursor flows; and Wherein, the second duration is at least 1.1 times longer than the first duration.

9. The device of claim 8, further comprising a plasma generator.

10. An apparatus for processing a substrate, the apparatus comprising: one or more processing chambers; one or more gas inlets and associated flow control hardware into the one or more process chambers; plasma generator; as well as A controller having at least one processor and a memory, wherein the at least one processor and the memory are communicatively connected to each other, the at least one processor is at least operatively connected to the flow control hardware, and the memory stores computer-executable instructions for controlling the at least one processor to at least control the flow control hardware to: causing a substrate to be inserted into at least one of the one or more processing chambers; causing a first set of alternating precursor and reactant flows to be introduced into said at least one of said one or more processing chambers via said one or more gas inlets for a first duration; causing a plasma having a first plasma energy to be generated to form a conformal material when causing the reactant to be introduced during the first set of periods; as well as causing a second alternating set of said precursor and reactant flows to be introduced into said at least one of said one or more processing chambers via said one or more gas inlets for a second duration subsequent to said first alternating set of precursor flows; and When the reactant is introduced during the second set of periods, a plasma is caused to be generated having a second plasma energy at least 1.1 times greater than the first plasma energy to form a conformal material.

11. The apparatus of any one of claims 8 and 10, wherein the at least one of the one or more processing chambers comprises a powered showerhead and a grounded pedestal for holding the substrate.

12. The apparatus of any one of claims 8 and 10, wherein the at least one of the one or more processing chambers comprises a grounded showerhead and a powered pedestal for holding the substrate.

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