In-situ control of film properties during atomic layer deposition

Abstract

This invention provides a method for controlling film properties during atomic layer deposition using in-situ intermittent plasma processing. The method includes adjusting the gas flow rate ratio used to generate the plasma, switching the plasma power, and regulating the chamber pressure during intermittent plasma processing.

Description

[0001] By incorporating references

[0002] The PCT application form is filed together with this specification as part of this application. Each application claiming a benefit or priority under this application, as identified in the concurrently filed PCT application form, is incorporated herein by reference in its entirety for all purposes. Background Technology

[0003] Many semiconductor device manufacturing processes involve the formation of films, including silicon-containing films such as silicon nitrides and silicon oxides. Some depositions of silicon-containing films involve plasma-enhanced chemical vapor deposition (PECVD) and / or atomic layer deposition (ALD), but in some cases it can be difficult to obtain high-quality films.

[0004] The background description provided herein is for the purpose of presenting the general context of this disclosure. The work of the currently designated inventors, within the scope described in this background section and in the various aspects of the specification that could not be identified as prior art at the time of filing, neither expressly nor impliedly acknowledges that it is prior art to this disclosure. Summary of the Invention

[0005] This document provides methods and apparatus for processing a substrate. One aspect relates to a method for processing a substrate, the method comprising: providing a semiconductor substrate to a reaction chamber; performing a cycle of atomic layer deposition to deposit a film, each cycle comprising: guiding a first reactant in a gaseous phase into the reaction chamber to adsorb the first reactant onto a surface of the semiconductor substrate; guiding a second reactant in a gaseous phase into the reaction chamber for a dispensing time; and generating a first plasma in the reaction chamber while the second reactant in a gaseous phase is in the reaction chamber; and after every n cycles of the atomic layer deposition, exposing the film to a second plasma generated by flowing argon and a second gas, wherein either: (1) the second gas is selected from the group consisting of hydrogen, oxygen and combinations thereof, and the flow rate ratio of argon to the second gas is between about 50:1 and about 1:1, or (2) the second gas is nitrous oxide, and the flow rate ratio of argon to the second gas is between about 10:1 and about 20:1.

[0006] In some embodiments, the method further includes: during the exposure of the membrane to the second plasma, circulating one or more additional gases, said additional gases being any one or more of oxygen, nitrous oxide, and helium.

[0007] On the other hand, a method for processing a substrate is provided, the method comprising: providing a semiconductor substrate to a reaction chamber; performing a cycle of atomic layer deposition to deposit a film, each cycle comprising: guiding a first reactant in a gaseous phase into the reaction chamber to adsorb the first reactant onto the surface of the semiconductor substrate; guiding a second reactant in a gaseous phase into the reaction chamber for a dispensing time; and generating a first plasma in the reaction chamber while the second reactant in a gaseous phase is in the reaction chamber; and after every n cycles of the atomic layer deposition, exposing the film to a second plasma, the second plasma being generated by flowing argon and a second gas, the ratio of the argon flow rate to the second gas flow rate being between about 50:1 and about 1:1, to achieve a flow rate of less than approximately 1:1 in 100:1 HF. The wet etching rate.

[0008] In various embodiments, the second gas is one or more of hydrogen, oxygen, and combinations thereof. The method may also include: during exposure of the membrane to the second plasma, flowing a third gas, wherein the third gas is one or more of nitrous oxide, helium, and combinations thereof. In some embodiments, the flow rate of argon to the flow rate of the third gas is between about 10:1 and about 20:1.

[0009] In some embodiments, the second plasma is generated at a power between about 750 W and about 1625 W per substrate. In some embodiments, the method further includes exposing the deposited film to the second plasma, which also includes introducing an argon-oxygen mixture with an argon-to-oxygen flow rate ratio of about 12:1.

[0010] On the other hand, a method for processing a substrate is disclosed, the method comprising: providing a semiconductor substrate to a reaction chamber; performing a cycle of atomic layer deposition to deposit a film, each cycle comprising: guiding a first reactant in a gaseous phase into the reaction chamber to adsorb the first reactant onto the surface of the semiconductor substrate; guiding a second reactant in a gaseous phase into the reaction chamber for a dispensing time; and generating a first plasma in the reaction chamber while the second reactant in a gaseous phase is in the reaction chamber; and after every n cycles of the atomic layer deposition, exposing the film to a second plasma generated using a power between about 1000 W and about 2000 W at a chamber pressure between about 1 Torr and about 10 Torr, to reduce the stress of the film to below about -290 MPa to 55 MPa.

[0011] On the other hand, a method for processing a substrate is provided, the method comprising: providing a semiconductor substrate to a reaction chamber; performing n cycles of atomic layer deposition to deposit a film, each cycle comprising: guiding a first reactant in a gaseous phase into the reaction chamber to adsorb the first reactant onto the surface of the semiconductor substrate; guiding a second reactant in a gaseous phase into the reaction chamber for a dispensing time; and generating a first plasma in the reaction chamber while the second reactant in a gaseous phase is in the reaction chamber; and after every n cycles of atomic layer deposition, exposing the deposited film to a second plasma using a power between about 3000 W and about 6500 W at a chamber pressure between about 1 Torr and about 5 Torr, to reduce electrical leakage to below about 1 E-9 A / cm at a 2 MV electric field. 2 .

[0012] On the other hand, a method for processing a substrate is disclosed, the method comprising: providing a semiconductor substrate to a reaction chamber; performing n cycles of atomic layer deposition to deposit a film, each cycle comprising: guiding a first reactant in a gaseous phase into the reaction chamber to adsorb the first reactant onto the surface of the semiconductor substrate; guiding a second reactant in a gaseous phase into the reaction chamber for a dispensing time; and generating a first plasma in the reaction chamber while the second reactant in a gaseous phase is present in the reaction chamber; and after every n cycles of atomic layer deposition, exposing the deposited film to a second plasma using a power between about 3000 W and about 6500 W at a chamber pressure between about 1 Torr and about 5 Torr to produce a treated film, wherein the treated film has a breakdown voltage greater than 10 MW / cm.

[0013] On the other hand, a method for processing a substrate is disclosed, the method comprising: providing a semiconductor substrate to a reaction chamber; performing n cycles of atomic layer deposition to deposit a silicon-containing film, each cycle comprising: guiding a first reactant in a gaseous phase into the reaction chamber to adsorb the first reactant onto the surface of the semiconductor substrate; guiding a second reactant in a gaseous phase into the reaction chamber for a dispensing time; and generating a first plasma in the reaction chamber while the second reactant in a gaseous phase is in the reaction chamber; exposing the deposited silicon-containing film to a second plasma after every n cycles of atomic layer deposition; and introducing a fluorine-containing reactive material to form a fluorine-terminated silicon surface.

[0014] On the other hand, a method for processing a substrate is provided, the method comprising: providing a semiconductor substrate to a reaction chamber; performing n cycles of atomic layer deposition to deposit a film, each cycle comprising: guiding a first reactant in a gaseous phase into the reaction chamber under conditions allowing a first reactant to adsorb onto the surface of the semiconductor substrate; guiding a second reactant in a gaseous phase into the reaction chamber for a dispensing time; and generating a plasma in the reaction chamber while the second reactant in a gaseous phase is in the reaction chamber; and introducing the second reactant dispensing during the nth cycle of atomic layer deposition for an extended dispensing time at least 1.5 times longer than the dispensing time for the first to n-1th cycles of atomic layer deposition.

[0015] For any of the above aspects, the deposited film may be silicon oxide. In some embodiments, the deposited film is silicon oxide nitride. In some embodiments, the deposited film is boron-doped silicon oxide. In some embodiments, the deposited film is doped silicon oxide to form an n-type semiconductor. In some embodiments, the deposited film is doped silicon oxide to form a p-type semiconductor.

[0016] For any of the above aspects, the first reactant can be a silicon-containing precursor.

[0017] For any of the above aspects, the second reactant may contain more than one oxygen-containing gas. The oxygen-containing gas may be any one of oxygen, nitrous oxide, water, carbon dioxide, and combinations thereof.

[0018] For any of the above aspects, n can be an integer between 5 and 10, inclusive. For any of the above aspects, the second plasma can be generated by igniting an inert gas. For any of the above aspects, the cycle of exposing the membrane to the second plasma and performing the atomic layer deposition can be performed in the same chamber. For any of the above aspects, the cycle of exposing the membrane to the second plasma and performing the atomic layer deposition can be performed without breaking the vacuum. For any of the above aspects, exposing the membrane to the second plasma may involve pulsed second plasma.

[0019] For any of the above aspects, the second plasma can be between approximately 0.4421 W / cm². 2 With approximately 1.7684 W / cm 2 The plasma density between them is generated.

[0020] On the other hand, an apparatus for processing a substrate is disclosed, the apparatus comprising: one or more processing chambers, each processing chamber including a chuck; one or more gas inlets leading to the processing chambers and associated flow control hardware; and a controller having a memory and at least one processor, 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: introduce a first reactant in a gaseous phase from the one or more gas inlets into the one or more processing chambers; introduce a second reactant in a gaseous phase from the one or more gas inlets into the one or more processing chambers; stop the introduction of the first reactant; stop the introduction of the second reactant; and after stopping the introduction of the first reactant and stopping the introduction of the second reactant, cause the following operation to be performed: generate plasma using a combination of the inert gas and the additional gas in a flow rate ratio between about 50:1 and about 1:1. In some embodiments, the controller includes instructions to introduce the inert gas and the additional gas after stopping the introduction of the first reactant and the second reactant, without disrupting the vacuum that allows the first reactant in gaseous phase to be introduced into the more than one processing chamber from the more than one gas inlet and the second reactant in gaseous phase to be introduced into the more than one processing chamber from the more than one gas inlet.

[0021] On the other hand, an apparatus for processing a substrate is disclosed, the apparatus comprising: one or more processing chambers, each processing chamber including a chuck; one or more gas inlets leading to the processing chambers and associated flow control hardware; and a controller having a memory and at least one processor, 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: introduce a first reactant in a gaseous phase from the one or more gas inlets into the one or more processing chambers; introduce a second reactant in a gaseous phase from the one or more gas inlets into the one or more processing chambers; stop the introduction of the first reactant; stop the introduction of the second reactant; and after stopping the introduction of the first reactant and stopping the introduction of the second reactant, cause the following operation to be performed: generate plasma using a combination of an inert gas and an additional gas in a flow rate ratio between about 10:1 and about 20:1. In some embodiments, the controller includes instructions to introduce the inert gas and the additional gas after stopping the introduction of the first reactant and the second reactant, without disrupting the vacuum that allows the first reactant in gaseous phase to be introduced into the more than one processing chamber from the more than one gas inlet and the second reactant in gaseous phase to be introduced into the more than one processing chamber from the more than one gas inlet.

[0022] For any of the foregoing aspects, the apparatus may include four processing chambers, and the controller may include instructions for generating plasma using a plasma power between approximately 3000 W and approximately 6500 W.

[0023] These and other aspects will be described below with reference to the accompanying drawings. Attached Figure Description

[0024] Figure 1 and 2 A flowchart is provided to depict the operation of a method performed according to certain publicly disclosed implementation schemes.

[0025] Figure 3 A timing diagram showing an exemplary loop in a method according to some disclosed implementation.

[0026] Figure 4 This is a schematic diagram of an example processing chamber used to implement some of the disclosed implementation schemes.

[0027] Figure 5 This is a schematic diagram of an exemplary processing tool used to perform certain disclosed implementations.

[0028] Figure 6 It is a graph showing the wet etching rate within the top, middle, and bottom features of various films.

[0029] Figure 7 It is a graph showing the stress of films deposited using different treatments.

[0030] Figure 8 It is a graph depicting the relationship between the fluorine concentration of the membrane and the normalized depth for different durations of plasma exposure.

[0031] Figure 9 It is a graph depicting the dielectric k-values ​​of films deposited by plasma-enhanced atomic layer deposition (PEALD) and films deposited by PEALD with intermittent plasma treatment.

[0032] Figure 10 It is a graph depicting the breakdown voltage of films deposited by plasma-enhanced atomic layer deposition (PEALD) and films deposited by PEALD with intermittent plasma treatment.

[0033] Figure 11 It is a graph depicting the stress and wet etching rate of films treated with pulsed and continuous intermittent plasma processes. Detailed Implementation

[0034] The following description sets forth numerous specific details to provide a thorough understanding of the presented implementation schemes. The disclosed implementation schemes may be implemented without some or all of these specific details. In other cases, well-known processing operations have not been described in detail to avoid unnecessarily obscuring the disclosed implementation schemes. While the disclosed implementation schemes are described in conjunction with specific implementation schemes, it should be understood that this is not intended to limit the disclosed implementation schemes.

[0035] Semiconductor manufacturing processes typically involve the fabrication of silicon-containing films, such as silicon oxide, silicon nitride, and silicon carbide films. Sometimes such films are deposited onto patterned substrates to form conformal films for various applications, such as barrier layers for contacts. Silicon nitride and silicon carbide layers are used as encapsulation films, spacers, and barrier films in advanced devices with logic and memory structures, such as FinFETs, MRAMs, 3DXPoints, ReRAMs, and PCRAMs. As devices shrink and technology advances, higher quality, denser, and more conformal films are desired. Conventional techniques for depositing conformal films involve atomic layer deposition (ALD), but efforts to modify the final properties of films deposited through this process often result in trade-offs with wafer yield, especially when quality requirements such as low wet etch rates or high breakdown electric fields are desired. Some approaches involve using secondary chemical processes to influence anisotropic deposition within the structure, but this process cannot modulate or control the final contamination in the film.

[0036] This document provides a method for performing intermittent plasma treatment during the ALD of thin films to control desired physical properties of the resulting films. In various embodiments, the deposited film is silicon oxide. The thickness of the silicon oxide film is less than approximately... The plasma used in such operations can be generated using the same chemicals and processing conditions as the plasma used in the activation operation of silicon oxide deposition via ALD, or it can incorporate additional chemicals, frequencies, and / or power levels to achieve desired film properties, details of which are provided here as examples. Physical properties that can be altered using this process can include, but are not limited to, film wet etch rate, breakdown electric field, film dielectric, atomic composition, and density. Depending on the chemicals used during intermittent plasma treatment, improvements in sidewall wet etch rates can also be achieved by more actively bombarding incident ions onto a surface perpendicular to the wafer plane. Intermittent plasma treatment can also be used to influence the conformal properties of films on patterned structures through sputtering at the top of the structure. For deposition processes that include a suppression operation as part of an ALD cycle or after thin-film ALD, intermittent plasma exposure can help tune the properties of certain films, resulting in high-quality films and reduced contaminant accumulation.

[0037] Intermittent plasma treatment can be performed after any number of ALD cycles. In some examples, plasma treatment is performed every n cycles, where n is between 1 and 200 and inclusive, for example, n=5, n=10, n=15, or n=20. The plasma composition, power, and treatment time depend on the desired membrane properties and can be adjusted to provide specific physical properties; preferred critical ranges are provided here.

[0038] As described above, the embodiments described herein relate to deposition via ALD. ALD is a technique for depositing thin layers of material using a sequential, self-limiting reaction. Typically, an ALD cycle includes the following operations: delivering and adsorbing at least one reactant onto a substrate surface, and then reacting the adsorbed reactant with one or more reactants to form at least a partial film layer. As an example, a silicon oxide deposition cycle may include the following operations: (i) delivering / adsorbing a silicon precursor, (ii) purging the silicon precursor from the chamber, (iii) delivering an oxygen-containing reactant with an optional plasma, and (iv) purging the oxygen-containing reactant and / or plasma from the chamber. In some embodiments, when plasma is used during the delivery of a second reactant, this is referred to as plasma-enhanced atomic layer deposition (PEALD). The delivery or adsorption of the silicon precursor may be referred to as a “feeding” operation, and the delivery of the second reactant to react with the adsorbed precursor may be referred to as a “conversion” operation.

[0039] Unlike chemical vapor deposition (CVD), ALD processes use surface-mediated deposition reactions to deposit films layer by layer. In one example of an ALD process, a substrate surface comprising a number of surface-active sites is exposed to a first precursor (e.g., a silicon precursor) in a gaseous distribution of a feedstock provided to a chamber containing the substrate. Molecules of this first precursor (including chemisorbed and / or physisorbed molecules of the first precursor) are adsorbed onto the substrate surface. It should be understood that when a compound is adsorbed onto a substrate surface as described herein, the adsorbed layer may include the compound and derivatives thereof. For example, an adsorbed layer of a silicon precursor may include the silicon precursor and derivatives thereof. After the first precursor feedstock is prepared, the chamber is then evacuated to remove most or all of the first precursor remaining in the gaseous phase, leaving primarily or only the adsorbed material. In some embodiments, the chamber may not be completely evacuated. For example, the chamber may be evacuated to make the partial pressure of the gaseous first precursor sufficiently low to mitigate the reaction. A second reactant, such as an oxygen-containing reactant, is introduced into the chamber such that some of these molecules react with the first precursor adsorbed on the surface. In some processes, the second precursor reacts immediately with the adsorbed first precursor. In other embodiments, the second reactant reacts only after a temporary application of the activation source. In some embodiments, the plasma is ignited during the second reactant feeding. The chamber can then be purged again to remove unbound second reactant molecules. As described above, in some embodiments, the chamber may not be completely purged. Additional ALD cycles can be used to build up the film thickness.

[0040] In some embodiments, the first precursor feed for ALD is partially saturated on the substrate surface. In some embodiments, the feeding phase of the ALD cycle ends before the precursor contacts the substrate to ensure uniform saturation on the surface. Typically, the precursor flow is shut off or diverted at this point, and only purge gas flows. By operating under this subsaturated condition, the ALD process reduces cycle time and increases yield. However, because precursor adsorption is unsaturation-limited, the adsorbed precursor concentration may vary slightly across the entire substrate surface. U.S. Patent Application No. 14 / 061,587 (now U.S. Patent No. 9,355,839), filed October 23, 2013, entitled "SUB-SATURATED ATOMICLAYER DEPOSITION AND CONFORMAL FILM DEPOSITION," provides an example of an ALD method operating under subsaturated conditions, the entire contents of which are incorporated herein by reference.

[0041] As described, in some implementations, the ALD method includes plasma activation. As discussed herein, the ALD methods and apparatus described herein can be conformal film deposition (CFD) methods, which are generally described in the following patent documents: U.S. Patent Application No. 13 / 084,399 (now U.S. Patent No. 8,728,956), filed April 11, 2011, entitled “PLASMA ACTIVATED CONFORMAL FILM DEPOSITION”; and U.S. Patent Application No. 13 / 084,305, filed April 11, 2011, entitled “SILICON NITRIDE FILMS AND METHODS”, the entire contents of which are incorporated herein by reference.

[0042] Figure 1 A processing flowchart is shown, which depicts the operations performed according to certain publicly available implementation schemes.

[0043] In operation 110, the first ALD cycle is performed. An ALD cycle involves alternating between reactants of two or more reactants, with a purge step in between to remove excess reactants / byproducts. The following... Figure 2Operations 211-214 describe an example. In some embodiments, the ALD cycle is a PEALD cycle. In operation 120, a second ALD cycle is performed. The second ALD cycle can be performed such that it is the same as the first ALD cycle used in operation 110. The ALD can be performed using plasma with a plasma power between about 150 W and about 6000 W. In some embodiments, the plasma power in operation 110 is different from the plasma power used in operation 140. In some embodiments, the plasma power in operation 110 is the same as the plasma power used in operation 140.

[0044] In operation 130, the nth ALD cycle can be executed after potentially multiple intermediate cycles. That is, according to the disclosed embodiments, any n cycles, or any two or more ALD cycles, can be executed. In various embodiments, each of the first, second, ..., nth ALD cycles can be different from each other. In some embodiments, each of the first, second, and nth ALD cycles is identical, having the same ingredients, cleaning and conversion chemicals, and treatment conditions. In the disclosed embodiments, n can be any integer greater than or equal to 2.

[0045] In operation 140, intermittent plasma treatment is performed. Intermittent plasma treatment involves exposure to one or more treatment gases provided using specific gas mixture chemicals and treatment conditions to achieve specific membrane properties. The one or more treatment gases include argon. The one or more treatment gases may also include one or more of the following gases: hydrogen, oxygen, nitrous oxide, and helium. In one non-limiting example, the gas used to generate the plasma for intermittent plasma treatment includes argon and hydrogen. In one non-limiting example, the gas used to generate the plasma for intermittent plasma treatment includes argon, hydrogen, and oxygen. In one non-limiting example, the gas used to generate the plasma for intermittent plasma treatment includes argon, hydrogen, oxygen, nitrous oxide, and helium. In one non-limiting example, the gas used to generate the plasma for intermittent plasma treatment includes argon, oxygen, nitrous oxide, and helium. In one non-limiting example, the gas used to generate the plasma for intermittent plasma treatment includes argon, nitrous oxide, and helium.

[0046] In some embodiments, the ratio of argon flow rate to hydrogen flow rate is between about 50:1 and about 1:1. In some embodiments, the ratio of argon flow rate to oxygen flow rate is between about 50:1 and about 1:1. In some embodiments, the ratio of hydrogen flow rate to nitrous oxide flow rate is between about 10:1 and about 20:1. In some embodiments, the ratio of argon flow rate to helium flow rate is between about 10:1 and about 20:1.

[0047] Typically, the number of ALD cycles performed in each intermittent plasma treatment, as well as the conditions used during the intermittent plasma treatment, can influence the properties of the film in a way that allows certain properties to be tailored to the application of the deposited film.

[0048] In some implementations, intermittent plasma is pulsed. The pulses of intermittent plasma can be executed with a specific duty cycle (the duration the plasma is on during one cycle). It should be understood that plasma pulses can include repetitions of cycles, each cycle lasting a certain duration T. The duration T includes the duration of the pulse on (ON) time (the duration the plasma is in the ON state) and the duration of the plasma off (OFF) time (the duration the plasma is in the OFF state) during a given cycle. The pulse frequency will be understood as 1 / T. For example, for a plasma pulse cycle T = 100 μs, the frequency is 1 / T = 1 / 100 μs, or 10 kHz. The duty cycle, or load ratio, is the proportion or percentage of the plasma in the ON state during cycle T, such that the duty cycle or load is the pulse ON time divided by T. For example, for a plasma pulse cycle T = 100 μs, if the pulse ON time is 70 μs (making the duration the plasma is in the ON state during one cycle 70 μs) and the pulse OFF time is 30 μs (making the duration the plasma is in the OFF state during one cycle 30 μs), then the duty cycle is 70%.

[0049] In some embodiments, the intermittent plasma is pulsed between an ON state and an OFF state, wherein the voltage applied during the OFF state is 0W. In various embodiments, for example, the pulsed intermittent plasma is pulsed between a 0W OFF state and a 1250W ON state for a specific duration (e.g., 10 seconds).

[0050] The chamber pressure during operation 140 can be used to regulate stress, form a compression film or a stretching film, or reduce contaminants. For example, a lower pressure (e.g., less than about 6 Torr) can be used to form a compression film, form a film with a reduced wet etching rate, remove contaminants, or all of the above. A higher pressure (e.g., greater than about 6 Torr) can be used to form a stretching film, form a film with a higher wet etching rate, remove contaminants, or all of the above. Operation 140 can be performed at a chamber pressure between about 2 Torr and about 10 Torr.

[0051] The chamber pressure during operation 140 may differ from the chamber pressure during operation 110. For example, the chamber pressure during operation 140 may be between about 2 Torr and about 6 Torr, while operation 110 may be performed at a chamber pressure between about 0.6 Torr and about 20 Torr. In some embodiments, the chamber pressure during operation 140 may be the same as the chamber pressure during operation 110.

[0052] Below is a set of exemplary processing conditions for implementing certain features.

[0053] To regulate the wet etching rate (measured by immersion in 100:1 dilute hydrofluoric acid (HF) for 60 seconds), intermittent plasma treatment can be performed by introducing an argon-oxygen mixture, wherein the argon is supplied at a flow rate between approximately 5 slm and approximately 50 slm, and the oxygen is supplied at a flow rate between approximately 500 sccm and approximately 10000 sccm, using an argon-to-oxygen ratio between approximately 50:1 and approximately 1:10, or between approximately 50:1 and approximately 100:1, or approximately 36:1; and igniting the plasma using a plasma power between approximately 50 W and approximately 6500 W for a 4-station tool, or between approximately 3000 W and approximately 6500 W, or approximately 5000 W for a 4-station tool for high-frequency plasma. For low-frequency plasma, the plasma power for a 4-station tool can be between approximately 50 W and approximately 4500 W, or between approximately 50 W and approximately 2000 W. In some embodiments, the plasma power during operation 110 is less than the plasma power during operation 140. The chamber pressure can be set to between about 0.6 Torr and about 20 Torr, or between about 1 Torr and about 5 Torr, and the intermittent plasma treatment can be performed for a duration of about 0.1 seconds to about 30 seconds. The longer the duration of the intermittent plasma treatment, the lower the wet etching rate. In various embodiments, this intermittent plasma treatment is performed every 15 ALD cycles or less. In a 100:1 HF, the achieved wet etching rate can be less than approximately or as low as approximately

[0054]

[0055] In a non-limiting example of adjusting the wet etching rate (measured by immersion in 100:1 dilute HF for 60 seconds), intermittent plasma processing can be performed by introducing a mixture of argon, hydrogen, and oxygen, wherein the ratio of the argon flow rate to the hydrogen flow rate is between approximately 50:1 and approximately 1:1, and the ratio of the argon flow rate to the oxygen flow rate is between approximately 50:1 and approximately 1:1.

[0056] In a non-limiting example of adjusting the wet etching rate (measured by immersion in 100:1 dilute HF for 60 seconds), intermittent plasma processing can be performed by introducing a mixture of argon, oxygen, nitrous oxide, and helium, wherein the argon to oxygen flow rate ratio is between about 50:1 and about 1:1, the argon to nitrous oxide flow rate ratio is between about 10:1 and about 20:1, and the argon to helium flow rate ratio is between about 10:1 and about 20:1.

[0057] In a non-limiting example of adjusting the wet etching rate (measured by immersion in 100:1 dilute HF for 60 seconds), intermittent plasma processing can be performed by introducing a mixture of argon, oxygen, and nitrous oxide, wherein the ratio of the argon flow rate to the oxygen flow rate is between about 50:1 and about 1:1, and the ratio of the argon flow rate to the nitrous oxide flow rate is between about 10:1 and about 20:1.

[0058] To regulate membrane stress, intermittent plasma treatment can be performed by introducing a mixture of argon and oxygen, and optionally one or more inert gases (e.g., hydrogen or nitrous oxide). In some embodiments for regulating membrane stress, the delivered gas mixture does not include ammonia. The achieved membrane stress can be less than about -290 MPa, less than about 55 MPa, or between about -290 MPa and about 55 MPa. Argon can be delivered at a flow rate between about 5 slm and about 50 slm, and oxygen can be delivered at a flow rate between about 1000 sccm and about 10000 sccm, wherein an argon-to-oxygen ratio between about 50:1 and about 1:10, or between about 50:1 and about 100:1, or about 36:1 is used, and the plasma is ignited using a plasma power between about 1000 W and about 2000 W for a 4-station tool or about 1200 W for a 4-station tool. The chamber pressure can be set from about 1 to about 20 Torr, or about 10 Torr, and the intermittent plasma treatment can be performed for a duration of from about 1 second to about 20 seconds, or from about 5 seconds to about 10 seconds. In various embodiments, this intermittent plasma treatment is performed every 15 ALD cycles or every fewer than 15 ALD cycles. The combination of reduced plasma power and chamber pressure contributes to achieving a lower stress film.

[0059] In a non-limiting example of regulating membrane stress, intermittent plasma treatment can be carried out by introducing a mixture of argon, oxygen and nitrous oxide, wherein the ratio of the argon flow rate to the oxygen flow rate is between about 50:1 and 1:1, and the ratio of the argon flow rate to the nitrous oxide flow rate is between about 10:1 and about 20:1.

[0060] To modulate the electrical properties of the deposited film, intermittent plasma treatment can be performed by introducing one or more of argon, helium, oxygen, and hydrogen and nitrous oxide. The electrical properties of the film can be determined by using a mercury probe microanalysis tool to determine current leakage and breakdown voltage. Some disclosed embodiments are capable of depositing films with breakdown voltages greater than about 10 MW / cm. During intermittent plasma treatment, hydrogen can be used to improve specific properties and reduce leakage and increase breakdown voltage in films such as thermally oxidized films. Argon is supplied at a flow rate of about 5 slm to about 50 slm, and oxygen is supplied at a flow rate of about 500 sccm to about 10000 sccm, wherein an argon-to-oxygen ratio between about 50:1 and about 1:10, or between about 50:1 and about 100:1, or about 36:1 is used, and the plasma is ignited using a plasma power of about 3000 W to about 6500 W for a 4-station tool, or about 5000 W for a 4-station tool. The chamber pressure can be set from about 1 Torr to about 5 Torr, and the duration of intermittent plasma treatment can be from about 0.1 seconds to about 30 seconds. This specific combination of plasma power and chamber pressure helps to reduce leakage and increase breakdown voltage.

[0061] In a non-limiting example of adjusting the electrical properties of the deposited film, intermittent plasma treatment can be carried out by introducing a mixture of argon, oxygen and nitrous oxide, wherein the ratio of the argon flow rate to the oxygen flow rate is between about 50:1 and about 1:1, and the ratio of the argon flow rate to the nitrous oxide flow rate is between about 10:1 and about 20:1.

[0062] The longer the duration of the intermittent plasma treatment, the lower the wet etching rate. In various implementations, this intermittent plasma treatment is performed every 15 ALD cycles or less.

[0063] To tune membrane impurities (e.g., impurities of carbon, nitrogen, and / or fluorine atoms), intermittent plasma treatment can be performed by introducing a mixture of argon, hydrogen, and optionally oxygen. Membrane impurities can be determined by obtaining the IR spectrum of the deposited membrane.

[0064] In a non-limiting example of conditioning membrane impurities, intermittent plasma treatment can be carried out by introducing a mixture of argon, hydrogen, and oxygen, wherein the ratio of the argon flow rate to the hydrogen flow rate is between about 50:1 and 1:1, and the ratio of the argon flow rate to the oxygen flow rate is between about 50:1 and about 1:1.

[0065] In a non-limiting example of regulating membrane impurities, intermittent plasma treatment can be carried out by introducing a mixture of argon, oxygen, nitrous oxide and helium, wherein the argon to oxygen flow rate ratio is between about 50:1 and about 1:1, the argon to nitrous oxide flow rate ratio is between about 10:1 and about 20:1, and the argon to helium flow rate ratio is between about 10:1 and about 20:1.

[0066] To adjust the elemental composition of the deposited film, intermittent plasma treatment can be combined with suppression or passivation operations using fluorine-containing gases. Suppression or passivation operations can provide greater control over the ALD deposition filling process. See below for reference. Figure 2 Operation 260 describes the details of an exemplary process. Intermittent plasma processing can be performed by introducing a mixture of process gases.

[0067] The process gas mixture may include one or more of argon, oxygen, and hydrogen, along with helium. The helium flow rate may be between approximately 1000 sccm and approximately 10000 sccm, the argon flow rate between approximately 500 sccm and approximately 20000 sccm, the oxygen flow rate between approximately 1000 sccm and approximately 10000 sccm, and the hydrogen flow rate between approximately 500 sccm and approximately 5000 sccm. The process gas mixture is introduced, and for a 4-station tool, the plasma is ignited using a plasma power between approximately 1000 W and approximately 1500 W. The chamber pressure may be set between approximately 5 Torr and approximately 10 Torr, or approximately 6 Torr, and intermittent plasma processing may be performed for a duration between approximately 1 second and approximately 10 seconds.

[0068] The processing gas mixture may include argon, hydrogen, and oxygen, with an Ar:H2:O2 gas flow rate ratio of approximately 50:1:1 to approximately 1:1:1, such as approximately 5:1:1, and without nitrous oxide or helium.

[0069] The processing gas mixture may include argon, nitrous oxide, and helium, wherein the gas flow ratio of Ar:N2O:He is approximately 1:1:0.2 to approximately 0.2:0.5:0.2, for example approximately 0.2:0.5:0, and there is no hydrogen or oxygen.

[0070] To achieve void-free material filling, intermittent plasma treatment can be performed by introducing a mixture of argon and oxygen. Argon can be supplied at a flow rate between approximately 10 slm and approximately 150 sccm, or approximately 50 slm, and oxygen can be supplied at a flow rate between approximately 1 slm and approximately 10 slm, using an argon-to-oxygen ratio of approximately 1.5:1, and the plasma is ignited using a plasma power between approximately 1000 W and approximately 2000 W for a 4-station tool, or approximately 1200 W for a 4-station tool. The chamber pressure can be set from approximately 1 Torr to approximately 10 Torr, and the intermittent plasma treatment can be performed for a duration of approximately 1 second to approximately 20 seconds, or approximately 5 seconds to approximately 10 seconds.

[0071] In operation 150, operations 110-140 can be repeated. That is, operation 150 is performed every n ALD cycles, and all n cycles of ALD and intermittent plasma processing can be repeated. The disclosed embodiments are applicable to the deposition of any material using ALD, such as oxides, nitrides, and carbides of silicon.

[0072] Further examples of in-situ regulated ALD processing loops are provided here. Figure 2 An exemplary processing cycle is shown, which includes an ALD cycle with intermittent plasma processing and optional suppression operation that can be used in some embodiments. Figure 3 Corresponding to Figure 2 An exemplary timing diagram is provided, in which no optional suppression operation is performed; in Figure 3 The timing diagrams in the diagrams provide various pulses and flow rates for ALD cycles and for periodic intermittent plasma treatments that are repeated once.

[0073] The implementation scheme described here refers to the deposition of silicon oxide; however, it should be understood that similar processes can be used to deposit other silicon-containing films.

[0074] exist Figure 2 In operation 211, the substrate is exposed to the deposition precursor. In various embodiments, the substrate is provided to the chamber prior to exposure to the deposition precursor, such that the deposition precursor is introduced into the chamber to expose the substrate to the deposition precursor. In various embodiments, the chamber itself includes a controller, as described below relative to... Figure 4 Further described, the controller includes machine-readable instructions for delivering the deposition precursor into the chamber containing the substrate.

[0075] The substrate may be a semiconductor substrate. The substrate may be a silicon wafer, such as a 200mm, 300mm, or 450mm wafer, including wafers on which one or more layers of material (e.g., dielectric, conductive, or semiconductive) are deposited. In various embodiments, the substrate is patterned. The patterned substrate may have “features” such as vias or contact holes, which may be narrow and / or recessed openings, contractions within features, and one or more of various aspect ratios including high aspect ratios. One or more features may be formed in one or more of the aforementioned layers. One example of a feature is a hole or via in a semiconductor substrate or a layer on the substrate. Another example is a trench in a substrate or layer. In various embodiments, the feature may have an underlying layer, such as a barrier layer or an adhesion layer. Non-limiting examples of underlying layers include dielectric layers and conductive layers, such as silicon oxide, silicon nitride, silicon carbide, metal oxide, metal nitride, metal carbide, and metal layers.

[0076] In some embodiments, the feature may have an aspect ratio of at least about 1:1, at least about 2:1, at least about 4:1, at least about 6:1, at least about 10:1, or higher. The feature may also have dimensions close to the opening, for example, an opening diameter or linewidth between about 10 nm and 10 μm, for instance, between about 25 nm and about 1 μm. The disclosed methods can be performed on a substrate having features with openings less than about 250 nm. Vias, trenches, or other recessed features may be referred to as unfilled features or features. According to various embodiments, the feature profile may gradually narrow and / or include overhangs at the feature opening. A concave profile is a profile that narrows from the bottom, closed end, or interior of the feature toward the feature opening. A concave profile may produce overhangs due to asymmetric etch kinetics during patterning and / or due to non-conformal film steps covering the previous film deposition (e.g., deposition of diffusion barriers). In various examples, the width of the feature in the opening at the top of the feature may be smaller than the width of the feature at the bottom.

[0077] During operation 211, the substrate is exposed to the deposition precursor. In various embodiments, the exposure time is sufficient to adsorb the deposition precursor onto the substrate surface. In some embodiments, the substrate may be exposed to the precursor for a duration sufficient to saturate less than 100% of the substrate surface. Example durations depend on the wafer's chemistry, the type of precursor, the precursor flow rate, the patterning on the wafer, and other factors. The duration can be selected based on the desired properties of the material. In some embodiments, the substrate may be exposed during operation 211 for less than about 5 seconds, or for a duration between about 0.05 seconds and about 3 seconds. For oxide deposition, the feeding time can be between about 0.05 seconds and about 0.5 seconds. The deposition precursor is selected based on the type of material to be deposited. For example, a silicon-containing precursor may be used during operation 211 for depositing silicon nitride or silicon oxide films.

[0078] During operation 211, one or more process gases may be introduced. In some embodiments, the deposition precursor is a silicon-containing precursor, such as a silane. The silicon-containing precursor used in some of the methods described herein may have the following structure:

[0079]

[0080] R1, R2, and R3 can be the same or different substituents, and can include silanes, amines, halides, hydrogen, or organic groups such as alkylamines, alkoxy groups, alkyl groups, alkenyl groups, alkynyl groups, and aromatic groups.

[0081] Exemplary silicon-containing precursors include polysilanes (H3Si-(SiH2)). n -SiH3), where n>1, for example silane, disilane, trisilane, tetrasilane, and trisilylamine:

[0082]

[0083] In some embodiments, the silicon-containing precursor is an alkoxysilane. Alkoxysilanes that can be used include, but are not limited to, the following:

[0084] H x -Si-(OR) y Where x = 1-3, x+y = 4, and R is a substituted or unsubstituted alkyl group; and

[0085] H x (RO) y -Si-Si-(OR) y H x, where x = 1-2, x+y = 3, and R is a substituted or unsubstituted alkyl group.

[0086] Examples of silicon-containing precursors include: methylsilane; trimethylsilane (3MS); ethylsilane; butylsilane; pentalosilane; octylsilane; heptylsilane; hexylsilane; cyclobutylsilane; cycloheptylsilane; cyclohexylsilane; cyclooctylsilane; cyclopentylsilane; 1,4-dioxa-2,3,5,6-tetrasilacyclohexane; diethoxymethylsilane (DEMS); diethoxysilane (DES) ); dimethoxymethylsilane; dimethoxysilane (DMOS); methyldiethoxysilane (MDES); methyldimethoxysilane (MDMS); octamethoxydodecylsiloxane (OMODDS); tert-butoxydisilane; tetramethylcyclotetrasiloxane (TMCTS); tetraoxomethylcyclotetrasiloxane (TOMCTS); triethoxysilane (TES); triethoxysiloxane (TRIES); and trimethoxysilane (TMS or TriMOS).

[0087] In some embodiments, the silicon-containing precursor may be an aminosilane having hydrogen atoms, such as bis(diethylaminosilane), diisopropylaminosilane, tert-butylaminosilane (BTBAS), or tris(dimethylamino)silane. Aminosilane precursors include, but are not limited to, the following: H x -Si-(NR) y Where x = 0-3, x+y = 4, and R is an organic or hydride group. In some embodiments, the silicon-containing precursor is a tetraaminosilane, such as tetra(dimethylamino)silane (4DMAS).

[0088] In some implementations, halogenated silanes may be used, such that the silane includes at least one hydrogen atom. Such silanes may have the chemical formula SiX. a H y , where y > 1. For example, dichlorosilane (H2SiCl2) may be used in some embodiments.

[0089] In addition to the silicon-containing precursor, one or more other gases may be flowed, including inert gases such as argon, nitrogen, helium, hydrogen, or combinations thereof. In various embodiments, argon may be introduced at a flow rate between about 1 slm and about 20 slm. In some embodiments, nitrogen may be introduced at a flow rate between about 0 slm and about 30 slm (it should be understood that 0 slm means no nitrogen flow). In some embodiments, hydrogen may be introduced at a flow rate between about 0 slm and about 5 slm (it should be understood that 0 slm means no hydrogen flow). During operation 211, the chamber pressure may be between about 0.6 Torr and about 10 Torr, and the temperature of the pedestal holding the substrate to be processed may be set between about 150°C and about 650°C, or between about 150°C and about 550°C, or between about 200°C and about 650°C, or between about 550°C and about 650°C.

[0090] In operation 212, the chamber containing the substrate is optionally purged to remove excess precursor molecules of the gaseous phase that have not been adsorbed onto the substrate surface. Purging may involve a purge or purging gas, which may be a carrier gas or other gas used in other operations. In some embodiments, the purge gas may be nitrogen, argon or other inert gases, oxygen, nitrous oxide, a combination of inert gases, or a combination of the above. In some embodiments, hydrogen is introduced at a flow rate between about 1 slm and about 20 slm, and nitrogen may flow in at a flow rate between about 0 slm and about 30 slm. Hydrogen may flow in at a flow rate between about 0 slm and about 5 slm, and in some embodiments, some oxygen may also flow at a flow rate between 0.5 slm and about 5 slm. In some embodiments, nitrous oxide may also flow at a flow rate between about 0 slm and about 5 slm.

[0091] In some embodiments, the purge gas has the same chemical composition as the carrier gas used during precursor feeding. In some embodiments, the purge gas is the same gas flowing during plasma operation, as further described below. In some embodiments, the purge gas exits from the same gas source as the carrier gas (from which the carrier gas exits). In some embodiments, purging may involve venting a processing station. In some embodiments, purging may include one or more venting purgings for venting a processing station. In some embodiments, purging may be performed for any suitable duration, such as between about 0 seconds and about 60 seconds, or between about 0 seconds and about 0.8 seconds. In some embodiments, increasing the flow rate of one or more purge gases can reduce the duration of purging. For example, the flow rate of the purge gas can be adjusted based on various reactant thermodynamic and / or geometric properties of the processing station and / or processing station piping to modify the duration of operation 212. In a non-limiting example, the duration of the purging phase can be adjusted by regulating the purge gas flow rate. This can reduce the deposition cycle time, thereby potentially increasing the substrate yield. After cleaning, some precursor molecules may remain adsorbed on the substrate surface.

[0092] The chamber pressure during operation 212 can be between approximately 0.6 Torr and approximately 10 Torr, and in some embodiments can be the same as during operation 211. The temperature of the base can be set between approximately 50°C and approximately 650°C, or between approximately 50°C and approximately 550°C, between approximately 150°C and approximately 650°C, or between approximately 150°C and approximately 550°C, or between approximately 200°C and approximately 650°C, or between approximately 550°C and approximately 650°C. In some embodiments, the temperature is the same as during operation 211.

[0093] In operation 213, the substrate is exposed to a second reactant plasma, which can be generated by introducing a second reactant and igniting the plasma. In various embodiments, the second reactant is an oxygen-containing reactant. The oxygen-containing reactant can be oxygen, nitrous oxide, water, carbon dioxide, or a combination thereof. The substrate can be exposed to a second reactant capable of reacting with the precursor to form a material on the substrate surface, while the plasma is ignited to catalyze the reaction. The second reactant can be selected depending on the type of film to be deposited. For silicon oxide films, in operation 213, the substrate can be exposed to an oxygen-containing reactant or an oxidant while the plasma is ignited to deposit the silicon oxide film. In various embodiments, the second reactant is oxygen. In some embodiments, the second reactant comprises two or more gases, such as a mixture of oxygen and nitrous oxide gases.

[0094] In some embodiments, argon is introduced at a flow rate between about 1 slm and about 20 slm, and nitrogen can be introduced at a flow rate between about 0 slm and about 30 slm, hydrogen can be introduced at a flow rate between about 0 slm and about 5 slm, and in some embodiments, some oxygen can also be introduced at a flow rate between 0.5 slm and about 5 slm. In some embodiments, nitrous oxide can also be introduced at a flow rate between about 0 slm and about 5 slm.

[0095] Plasma energy can be provided to activate the second reactant into ions and free radicals, as well as other activated substances, which react with the adsorbed layer of the deposition precursor. In various embodiments, the plasma is in-situ plasma, such that the plasma forms directly above the substrate surface in the chamber. This can be achieved at approximately 0.2122 W / cm². 2 With approximately 2.122 W / cm 2 Between or at approximately 0.4421 W / cm 2 With approximately 1.7684 W / cm 2 The power / substrate area is used to ignite the in-situ plasma. For example, the power for a single wafer can range from about 150 W to about 6000 W, or from about 500 W to about 6000 W, or from about 600 W to about 6000 W, or from about 800 W to about 4000 W, or from about 310 W to about 1250 W. The power range for four 300 mm wafers can range from about 150 W to about 6000 W, or from about 1250 W to about 5000 W. The ranges described herein include their endpoints.

[0096] Plasma for ALD processing can be generated by applying a radio frequency (RF) field to a gas using two capacitively coupled plates. The gas between the plates is ionized by the RF field, igniting the plasma and generating free electrons in the plasma discharge region. These electrons are accelerated by the RF field and can collide with gaseous reactant molecules. These collisions with reactant molecules may form free radical material that participates in the deposition process. It should be understood that the RF field can be coupled via any suitable electrode. In various embodiments, high-frequency plasmas with frequencies 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 are used. In some embodiments, microwave-based plasmas can be used. Non-limiting examples of electrodes include process gas distribution nozzles and substrate support bases. It should be appreciated that plasma for ALD processing can be formed by one or more suitable methods different from the method of capacitively coupling the RF field to the gas. In some embodiments, the plasma is a remote plasma, such that a second reactant is ignited in a remote plasma generator upstream of the chamber and then transported to the chamber containing the substrate.

[0097] The chamber pressure during operation 213 can be between about 0.6 Torr and about 10 Torr, and in some embodiments can be the same as during operations 211 and 212. The temperature of the base can be set to between about 50°C and about 650°C, or between about 150°C and about 650°C, or between about 150°C and about 550°C, or between about 200°C and about 650°C, or between about 550°C and about 650°C. In some embodiments, the temperature is the same as during operations 211 and 212.

[0098] In operation 214, the room is optionally cleaned again. In some embodiments, the cleaning conditions may be the same as those in operation 212. In some embodiments, the cleaning conditions may be changed. For the purposes of this example, the cleaning conditions may be the same as those in operation 212.

[0099] In operation 215, operations 211-214 are optionally repeated for n cycles, where n is an integer equal to or greater than 1, for example, between 1 and 200 cycles. The number of cycles may depend on the desired thickness of the film to be deposited. Operations 211-214 can constitute an ALD cycle.

[0100] In operation 240, the substrate is exposed to intermittent plasma processing. The above information regarding... Figure 1 Operation 140 describes the processing conditions and chemical properties used to perform intermittent plasma treatment. In various embodiments, depending on the specific application, intermittent plasma treatment is performed every 5 to 10 ALD cycles. For example, in some embodiments, intermittent plasma treatment every 10 ALD cycles can be used to adjust film stress, fluorine content, and breakdown voltage. In some embodiments, intermittent plasma treatment every 5 ALD cycles can be used to improve wet etching rate.

[0101] The processing conditions for intermittent plasma treatment, including the duration of the treatment, the processing frequency based on the number of ALD cycles, and the gas flow rate used during the treatment, can be adjusted to achieve desired results, including reduced stress, reduced wet etch rate, reduced fluorine content, reduced dielectric k-value, and improved breakdown voltage tolerance. The achievable wet etch rate in 100:1 HF can be less than approximately [missing value]. or as low as approximately

[0102] In some embodiments, argon is introduced at a flow rate between about 1 slm and about 20 slm, and nitrogen can be introduced at a flow rate between about 0 slm and about 30 slm, hydrogen can be introduced at a flow rate between about 0 slm and about 5 slm, and in some embodiments, some oxygen can also be introduced at a flow rate between 0.5 slm and about 5 slm. In some embodiments, nitrous oxide can also be introduced at a flow rate between about 0 slm and about 5 slm.

[0103] The chamber pressure during operation 240 can be between approximately 0.6 Torr and approximately 10 Torr, and in some embodiments can be the same as during operations 211-214. In some embodiments, the chamber pressure during operation 240 is between approximately 2 Torr and approximately 10 Torr, or between approximately 2 Torr and approximately 6 Torr. The temperature of the base can be set between approximately 50°C and approximately 650°C, between approximately 150°C and approximately 650°C, or between approximately 150°C and approximately 550°C, or between approximately 200°C and approximately 650°C, or between approximately 550°C and approximately 650°C. In some embodiments, the temperature is the same as during operations 211-214.

[0104] The duration of operation 240 can be between approximately 0.02 seconds and approximately 120 seconds.

[0105] In some embodiments, intermittent plasma treatment can be used in conjunction with ALD and intermittent plasma treatment to suppress deposition in small features. In such embodiments, in operation 260, the substrate is optionally exposed to a fluorine-containing plasma material to suppress deposition. An exemplary processing scheme can be used to fill features on a substrate as follows: ALD is performed by exposing the substrate to alternating pulses of a silicon precursor and an oxygen-containing reactant to deposit silicon oxide partially filling the feature, followed by intermittent plasma treatment on the deposited ALD film, then suppressing the surface at or near the feature opening by exposing the substrate to fluorine ions and radical feedstock generated by fluorine plasma to form a fluorine-terminated silicon surface that prevents deposition in subsequent ALD cycles, and then cyclically repeating the above processing scheme (multiple ALD cycles, followed by intermittent plasma treatment, then suppression) to deposit silicon oxide into the feature.

[0106] like Figure 2 As shown, operations 211-240 can be optionally repeated, and operations 211-260 (which may include multiple loops of operations 211-214) can be repeated in multiple loops.

[0107] In embodiments involving inhibition, intermittent plasma treatment can be used to control the degree of inhibition caused by exposure to fluoride ions and free radicals; that is, intermittent plasma treatment can balance the inhibition to allow more active sites and provide an additional knob to fine-tune the deposition process, especially in embodiments where the inhibition may excessively slow down deposition but can still be used to ensure bottom-up filling of features.

[0108] Figure 3 This is an example timing diagram illustrating a process with a deposition scheme involving suppression of feature-filling applications. Process 300 shows a complete cycle comprising multiple deposition cycles in deposition phase 310, followed by periodic intermittent plasma treatment phase 340, and a selective suppression phase 360. These lines indicate when the flow and / or plasma is appropriately turned on and off. Although in Figure 3 Some processing conditions are described, but it should be understood that other processing parameters can be adjusted depending on the specific application of the deposited film. It should also be understood that, although... Figure 3 The example in the text involves suppression phase 360, but this phase may be absent in some implementations. Although Figure 3 The process 300 in the diagram consists of only one cycle, but it should be understood that the cycle shown can be repeated in multiple cycles to deposit a film.

[0109] Figure 3 The deposition stage 310 can correspond to Figure 1 Any one of operations 110, 120, or 130, or which may correspond to the execution of Figure 2 Operations 211-214 are described. During deposition stage 310, an inert gas can flow, and alternating pulses of the silicon precursor and oxygen-containing reactants are performed, while plasma is generated during the oxygen-containing reactant pulses. During this operation, the suppressor gas flow is shut off. Although many pulses are shown for the deposition stage, it should be understood that the number of pulses can vary depending on the film to be deposited.

[0110] During the periodic intermittent plasma processing phase 340, the inert gas can flow continuously, while the silicon precursor gas flow and the oxygen-containing gas flow are shut off. The plasma is turned on and continuously ignited in the presence of the inert gas to process the deposited film, while the suppressor gas flow remains shut off.

[0111] In the optional suppression phase 360, in some embodiments, the inert gas can be shut off (however, it should be understood that in some cases, the inert gas flow can remain on). The silicon precursor flow and the oxygen-containing gas flow remain off, and the plasma is shut off. Here, the suppression gas flow is then turned on.

[0112] Although not shown, the loop shown in process 300 can be repeated multiple times as needed.

[0113] Although silicon oxides have been described, it should be understood that the disclosed embodiments are equally applicable to forming doped silicon oxides, n-type semiconductors, p-type semiconductors, silicon nitride oxides, boron-doped silicon oxides, and other materials.

[0114] In this application, the terms “semiconductor wafer,” “wafer,” “substrate,” “wafer substrate,” and “partially manufactured integrated circuit” are used interchangeably. Those skilled in the art will understand that the term “partially manufactured integrated circuit” can refer to a silicon wafer at any stage of the many stages of integrated circuit manufacturing described above. Wafers or substrates used in the semiconductor device industry typically have diameters of 200 mm, 300 mm, or 450 mm. Unless otherwise stated, the processing details described herein (e.g., flow rate, power level, etc.) relate to processing a 300 mm diameter substrate or to a processing chamber configured to process a 300 mm diameter substrate and may be appropriately scaled down for substrates or chambers of other sizes.

[0115] Device

[0116] Figure 4 A schematic diagram depicts an embodiment of an atomic layer deposition (ALD) processing station 400 having a processing chamber body 402. In some embodiments, the ALD processing station 400 is suitable for processing substrates in a low-pressure environment. In some embodiments, one or more hardware parameter values ​​of the ALD processing station 400, including those discussed in detail below, can be programmatically adjusted by one or more computer controllers 450. In many embodiments, after film deposition in the ALD processing station as described herein, intermittent plasma processing is performed in situ. Parameter values ​​can be varied either by measurement or based on real-time feedback. Additional examples and further embodiments are described below.

[0117] The ALD processing station 400 is in fluid communication with a reactant delivery system 401a to deliver the process gas to the dispensing nozzle 406. The reactant delivery system 401a includes a mixing container 404 for mixing and / or regulating the process gas for delivery to the nozzle 406. For example, the reactant delivery system 401a may include a mass flow controller and a liquid flow controller as described below. One or more mixing container inlet valves 420 can control the introduction of the process gas into the mixing container 404. In various embodiments, the delivery of one or more process gases to the nozzle 406 or to the processing chamber body 402 can be varied across cycles. For example, the duration of one or more process gas dosings can be varied. In the disclosed embodiments, the controller 450 can control the delivery of one or more process gases by controlling one or more inlet valves 420.

[0118] For example, Figure 4 The implementation includes a vaporization point 403 for vaporizing liquid reactants to be supplied to a mixing vessel 404. In some implementations, the vaporization point 403 may be a heated evaporator. Saturated reactant vapors generated from such an evaporator condense in a downstream delivery line. Exposure of incompatible gases to the condensed reactants produces small particles. These particles may clog the line, impede valve operation, contaminate the substrate, etc. Some methods for addressing these problems involve purging and / or evacuating the delivery line to remove residual reactants. However, purging the delivery line increases processing station cycle time and reduces processing station throughput. Therefore, in some implementations, the delivery line downstream of the vaporization point 403 may be thermally tracked. In some examples, the mixing vessel 404 may also be thermally tracked. In a non-limiting example, the line downstream of the vaporization point 403 has an increased temperature distribution extending from about 30°C to about 150°C at the mixing vessel 404.

[0119] In some embodiments, the liquid precursor or liquid reactant can be vaporized at a liquid ejector. For example, the liquid ejector can pulse the liquid reactant into a carrier gas flow upstream of the mixing vessel. In one embodiment, the liquid ejector can vaporize the reactant by flashing the liquid from a higher pressure to a lower pressure. In another example, the liquid ejector can atomize the liquid into dispersed microdroplets that are subsequently vaporized in a heated delivery tube. Smaller droplets vaporize faster than larger droplets, thus reducing the delay between liquid injection and completion of vaporization. Faster vaporization can reduce the pipe length downstream of vaporization point 403. In one embodiment, the liquid ejector can be directly mounted to the mixing vessel 404. In another embodiment, the liquid ejector can be directly mounted to the nozzle 406.

[0120] In some implementations, a liquid flow controller (LFC) can be positioned upstream of the vaporization point 403 to control the mass flow rate of the liquid used for vaporization and delivery to the treatment station 400. For example, the LFC may 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 electrically communicating with the MFM. However, feedback control may be used for one second or longer to stabilize the liquid flow. This can extend the time for dispensing the liquid reactants. Therefore, in some implementations, the LFC can dynamically switch between a feedback control mode and a direct control mode. In some implementations, this can be achieved by disabling the PID controller and the sensing pipe of the LFC.

[0121] In some embodiments, flow-over-vapor treatment can be used. This treatment is discussed in U.S. Patent Application Publication No. 2019 / 0024233, filed September 20, 2018, entitled "DYNAMIC PRECURSOR DOSING FOR ATOMIC LAYER DEPOSITION". In some embodiments of flow-over-vapor treatment, the timing of valve operation can be set using line aeration time, adsorption time, or some other time. Furthermore, the reference coordinates for valve operation can be the start of the batching step, the stop of the batching step, any other event during the batching step, and / or any event during the ALD cycle.

[0122] In some implementations, the amount of precursor can be sent via a gas line, which may be more than necessary for the desired adsorption amount. This additional precursor can also be sent such that it arrives before the start of the dosing step, after the dosing step, and / or after the desired adsorption / saturation has been reached. In some such implementations, some precursor may be dumped into the foreline before and / or after the dosing step. In some such implementations, the duration for which the ampoule valve can be open, the sequence of when the ampoule valve can be opened and / or closed, the duration for which the chamber valve can be open, and / or the sequence of when the chamber valve can be opened may vary. However, to reduce waste, the excess precursor can be limited to about 20% or less (or about 10% or less) of the amount required for adsorption / saturation.

[0123] Furthermore, in some implementations, each event (e.g., opening of the ampoule valve, closing of the chamber valve) may not occur precisely at the expected time.

[0124] Furthermore, the valve timing may not be exactly equal to the pipeline charging time and / or adsorption time. Timing delays may also exist to account for system latency, such as the time spent opening or closing the valve. In some implementations, ALD valves with a timing delay of up to 25 milliseconds may be used. An error tolerance of 25 milliseconds may also exist in the implementation described here.

[0125] In some implementations, a dynamic feedback loop can be created to deliver exactly the same number of precursor moles per cycle required for each cycle, which can be less than, equal to, or greater than the adsorption amount. As described herein, the amount of precursor delivered through the vapor flow system can depend on several factors, including ampoule temperature, headspace pressure, and driving gas flow. If one or more of these parameters deviate from the expected setpoint during the deposition period (e.g., due to varying precursor levels in the ampoule), the amount of precursor delivered at each ampoule valve opening time will deviate accordingly. The feedback loop can be established using sensor data (e.g., measurements) particularly from ampoule thermocouples, pressure gauges, and MFCs, as well as a controller. In one example, a pressure gauge (e.g., a fluid pressure gauge) is located at the inlet of the processing chamber (e.g., via one of inlet valves 420). The arrival of precursor in the processing chamber can be signaled by pressure changes detected by the pressure gauge. By dynamically controlling the opening / closing sequence of the ampoule based on such a feedback loop, precursor delivery can be made more robust and repeatable between cycles. Feedback loops can be formed during the batching / deposition step, between steps in a cycle, between cycles, and / or between processes to perform measurements and / or adjustments.

[0126] Nozzle 406 distributes the processing gas toward substrate 412. Figure 4 In the illustrated embodiment, the substrate 412 is located below the nozzle 406 and is shown placed on the base 408. The nozzle 406 can have any suitable shape and can have any suitable number and arrangement of ports for distributing process gas to the substrate 412.

[0127] In some embodiments, the microvolume 407 is located below the nozzle 406. Implementing the disclosed embodiments in a microvolume, rather than within the entire volume of the treatment station, can reduce reactant exposure and purge time, reduce time spent changing treatment conditions (e.g., pressure, temperature, etc.), and may limit the exposure of the treatment station's robotic arms to the treatment gases, etc. Exemplary microvolume sizes include, but are not limited to, volumes between 0.1 liters and 2 liters. This also affects productivity. In some embodiments, the disclosed embodiments are not performed in a microvolume.

[0128] In some embodiments, the base 408 may be raised or lowered to expose the substrate 412 to the microvolume 407 and / or the volume of the microvolume 407 may be altered. For example, during the substrate transfer phase, the base 408 may be raised to position the substrate 412 within the microvolume 407. In some embodiments, the microvolume 407 may completely surround the substrate 412 and a portion of the base 408 to create a region of high flow resistance.

[0129] Optionally, the base 408 may be lowered and / or raised during a portion of the treatment to regulate the treatment pressure, reactant concentration, etc., within the microvolume 407. Lowering the base 408 may allow the microvolume 407 to be evacuated if the treatment chamber body 402 is maintained at the baseline pressure during treatment. Exemplary ratios of microvolume to treatment chamber volume include, but are not limited to, volume ratios between 1:500 and 1:10. It should be understood that in some embodiments, the base height may be programmably adjusted by a suitable computer controller 450. In some embodiments, the position of the base 408 may vary between cycles. For example, in some ALD cycles, the base 408 may be raised, and in some ALD cycles, the base 408 may be lowered. The variations described herein may depend on real-time feedback or a determined formulation.

[0130] In another scenario, adjusting the height of pedestal 408 can allow for variations in plasma density during plasma activation and / or deposition cycles included in the disclosed multi-cycle ALD process. At the end of the processing phase, pedestal 408 can be lowered during another substrate transfer phase to allow removal of substrate 412 from pedestal 408.

[0131] Although the exemplary microvolume changes described herein involve a height-adjustable base, it should be understood that in some embodiments, the position of the nozzle 406 can be adjusted relative to the base 408 to change the volume of the microvolume 407. Furthermore, it should be understood that the vertical position of the base 408 and / or the nozzle 406 can be changed by any suitable mechanism within the scope of this disclosure. In some embodiments, the base 408 may include a rotation 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 programmably performed by one or more suitable computer controllers 450.

[0132] In some embodiments where plasma can be used as described above, nozzle 406 and base 408 are electrically connected to radio frequency (RF) power source 414 and matching network 416 to power the plasma. In some embodiments, the energy of the plasma can be controlled by controlling one or more of the following: pressure of the processing station, gas concentration, RF source power, RF source frequency, and plasma power pulse timing. Such parameter values ​​can vary from ALD cycle to ALD cycle in a multi-cycle ALD process as described herein. For example, RF power source 414 and matching network 416 can operate at any suitable power to form a plasma with the desired free radical composition during one or more ALD cycles. Examples of suitable power have been included above. Similarly, RF power source 414 can provide RF power at any suitable frequency. In some embodiments, RF power source 414 can be configured to control a high-frequency RF power source and a low-frequency RF power source that are independent of each other. Exemplary low-frequency RF frequencies may include, but are not limited to, frequencies between 50 kHz and 500 kHz. Exemplary high-frequency RF frequencies may include, but are not limited to, frequencies between 1.8 MHz and 2.45 GHz. It should be understood that any suitable parameter value can be adjusted discretely or continuously to provide plasma energy for the surface reaction. In a non-limiting example, plasma power can be delivered intermittently in pulses to reduce ion bombardment of the substrate surface compared to continuously powered plasma. In some embodiments, the plasma power can be between about 50 W and about 6000 W. In many embodiments, RF power or RF frequency, or both, can be used for deposition and intermittent plasma processing. The RF power and / or frequency can be adjusted to change the properties of the deposited film, such as wet etch rate, stress, fluorine concentration, dielectric k-value, and breakdown voltage tolerance.

[0133] In some embodiments, the plasma can be monitored in situ by one or more plasma monitors. In one case, plasma power can be monitored by one or more voltage and current sensors (e.g., VI probes). In another case, plasma density and / or the concentration of the process gas can be measured by one or more optical emission spectrometers (OES). In some embodiments, one or more plasma parameter values ​​can be programmed to adjust based on measurements from such in-situ plasma monitors. For example, OES sensors can be used in feedback loops to provide programmable control of plasma power. It should be understood that in some embodiments, other monitors can be used to monitor the plasma and other process characteristics. Such monitors may include, but are not limited to, infrared (IR) monitors, acoustic monitors, and pressure sensors.

[0134] In some implementations, instructions for the controller 450 can be provided via input / output control (IOC) sequencing instructions. In one example, instructions for setting conditions for a treatment phase can be included in a corresponding formulation phase of the treatment formulation. In some cases, the treatment formulation phases can be arranged sequentially such that all instructions for a treatment phase are performed concurrently with that treatment phase. In some implementations, instructions for setting one or more reactor parameter values ​​can be included in the formulation phase. For example, a first formulation phase may include: instructions for setting the flow rate of an inert gas and / or reactant gas (e.g., a first precursor, such as silane), instructions for setting the flow rate of a carrier gas (such as nitrogen or argon), and time delay instructions for the first formulation phase. A subsequent second formulation phase may include: instructions for adjusting or stopping the flow rate of the inert gas and / or reactant gas, instructions for adjusting the flow rate of the carrier gas or purge gas, and time delay instructions for the second formulation phase. The third formulation stage may include: instructions for setting the flow rate of the inert and / or reactant gas, which may be the same as or different from the gas used in the first formulation stage (e.g., a second precursor, such as oxygen); instructions for setting the plasma RF power; instructions for adjusting the carrier gas flow rate (which may be the same as or different from the flow rate in the first formulation stage); plasma conditions; and time delay instructions for the third formulation stage. The fourth formulation stage may include instructions for adjusting or stopping the flow rate of the inert and / or reactant gas, instructions for adjusting the flow rate of the carrier or purge gas, and time delay instructions for the fourth formulation stage. The fifth formulation stage may include instructions for setting the flow rate of the inert and / or reactant gas (e.g., oxygen and / or argon), instructions for setting different or the same plasma RF power, instructions for adjusting the carrier gas flow rate, plasma conditions, and time delay instructions for performing intermittent plasma treatment in the fifth formulation stage. In some cases, the formulation stage may also include instructions for pulsed plasma between ON and OFF states. More formulation stages may also be used. It should be understood that, within the scope of this disclosure, these formulation stages may be further subdivided and / or iterated in any suitable manner.

[0135] In some embodiments, the base 408 can be temperature-controlled via a heater 410. Additionally, in some embodiments, pressure control of the processing station 400 can be provided via a butterfly valve 418. Figure 4 As shown in the embodiments, butterfly valve 418 regulates the vacuum provided by a downstream vacuum pump (not shown). However, in some embodiments, the pressure control of processing station 400 can also be adjusted by changing the flow rate of one or more gases introduced into processing station 400. Processing station 400 may include a controller 450 for controlling the exemplary formulations described above.

[0136] In some implementations, system controller 450 is part of a system, which may be part of the examples described above. Such a system may include semiconductor processing equipment comprising one or more processing tools, one or more processing chambers, one or more platforms for processing, and / or specific processing components (wafer pedestals, airflow systems, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after processing semiconductor wafers or substrates. The electronics may be referred to as a “controller”, which can control various elements or sub-components of one or more systems. Depending on the processing requirements and / or the type of system, controller 450 may be programmed to control any of the processes disclosed herein, including the delivery of processing gases and / or variations in different batching times for the delivery of processing gases (including the diversion of more than one gas), temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings and / or variations in RF power settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, position and operation settings, wafer transfer tools and other transfer tools, and / or loading locks connected to or interfaced with a specific system.

[0137] In a broad sense, controller 450 can be defined as an electronic device with various integrated circuits, logic, memory, and / or software that receives instructions, issues instructions, controls operations, enables cleaning operations, enables endpoint measurements, etc. Integrated circuits can include chips in the form of firmware storing 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 transmitted to controller 450 in the form of various individual settings (or program files) that define operating parameters for performing specific processes on or for a semiconductor wafer or system. In some embodiments, operating parameters can be part of a recipe defined by a process engineer for completing one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies.

[0138] In some implementations, controller 450 may be part of or coupled to a computer integrated with, coupled to, or network-connected to the system, or a combination thereof. For example, controller 450 may be in the “cloud” or a whole or part of a fab host system, allowing remote access to wafer processing. The computer may enable remote access to the system to monitor the current progress of manufacturing operations, examine the history of past manufacturing operations, examine trends or performance criteria of multiple manufacturing operations, change parameters of the current process, set processing steps to follow the current process, or start a new process. In some examples, a remote computer (e.g., a server) may provide processing recipes to the system via a network, which may include a local network or the Internet. The remote computer may include a user interface that allows input or programming of parameters and / or settings, which are then transmitted from the remote computer to the system. In some examples, controller 450 receives instructions in the form of data specifying parameters for each processing step to be performed during one or more operations. It should be understood that the parameters may be specific to the type of processing to be performed and the type of tool, to which controller 450 is configured to connect to or control. Therefore, as described above, controller 450 can be distributed, for example, by including one or more discrete controllers connected together via a network and operating toward a common goal (e.g., the processing and control described herein). An example of a distributed controller for these purposes could be one or more integrated circuits on a room that communicate with one or more remote integrated circuits (e.g., at the platform level or as part of a remote computer) to control room processing.

[0139] The system in the example may include, but is not limited to, plasma etching chambers or modules, deposition chambers or modules, spin cleaning chambers or modules, metal plating chambers or modules, cleaning chambers or modules, chamfering edge etching chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, atomic layer deposition (ALD) chambers or modules, atomic layer etching (ALE) chambers or modules, ion implantation chambers or modules, orbital chambers or modules, and any other semiconductor processing systems that may be associated with or used in the fabrication and / or manufacturing of semiconductor wafers.

[0140] As described above, depending on one or more processing steps the tool is to perform, the controller 450 can communicate with one or more other tool circuits or modules, other tool components, combined tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout the plant, a host, another controller, or tools used in material handling for moving wafer containers to and from tool locations and / or loading ports in a semiconductor manufacturing plant.

[0141] As mentioned 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, the tool having an inbound loading lock 502 and an outbound loading lock 504, one or both of which may contain a remote plasma source. An atmospheric pressure manipulator 506 is configured to move a wafer from a cassette loaded via a crystal boat 508 through an atmospheric port 510 into the inbound loading lock 502. The wafer is placed by the manipulator 506 onto a base 512 within the inbound loading lock 502, the atmospheric port 510 is closed, and the loading lock is evacuated. When the inbound loading lock 502 contains a remote plasma source, the wafer may be exposed to remote plasma processing in the loading lock before being introduced into the processing chamber 514. Additionally, the wafer may also be heated in the inbound loading 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 manipulator (not shown) places the wafer into a reactor on a base at the first station shown in the reactor diagram for processing. Figure 5 The implementation shown in the figure includes a loading lock, but it should be understood that in some implementations, the substrate can be allowed to go directly into the processing station.

[0142] The drawn processing room 514 contains 4 processing stations. Figure 5 The embodiments shown are numbered 1 to 4. Each station has a heated base (shown as 518 for station 1) and a gas line inlet. It should be understood that in some embodiments, each processing station may have different or multiple uses. For example, in some embodiments, the processing station may be switchable between ALD and plasma-enhanced ALD processing modes. Additionally or alternatively, in some embodiments, processing chamber 514 may contain a matched pair of one or more ALD and plasma-enhanced ALD processing stations. Although the illustrated processing chamber 514 contains four stations, it is to be understood that a processing chamber according to this disclosure may have any suitable number of stations. For example, in some embodiments, the processing chamber may have five or more stations, while in other embodiments, the processing chamber may have three or fewer stations.

[0143] Figure 5 An embodiment of a wafer handling system 590 for transferring wafers within a processing chamber 514 is illustrated. In some embodiments, the wafer handling system 590 can transfer wafers between various processing stations and / or between a processing station and a loading lock. It should be understood that any suitable wafer handling system can be employed. Non-limiting examples include wafer turntables and robotic arms for handling wafers. Figure 5An embodiment of a system controller 550 used to control the processing conditions and hardware status of the processing tool 500 is also illustrated. The system controller 550 may include one or more memory devices 556, one or more mass storage devices 554, and one or more processors 552. The processor 552 may include a computer or CPU, analog and / or digital input / output connections, a stepper motor controller board, etc.

[0144] In some implementations, system controller 550 controls all activities of processing tool 500. System controller 550 executes system control software 558 stored in mass storage device 554, loaded into memory device 556, and executed by processor 552. Alternatively, control logic can be hard-coded in controller 550. Application-specific integrated circuits, programmable logic devices (e.g., field-programmable gate arrays, or FPGAs) can be used for these purposes. In the following discussion, whether "software" or "code" is used, functionally equivalent hard-coded logic can be substituted. System control software 558 may contain instructions for controlling timing, gas mixing, subsaturated gas flow rate, chamber and / or station pressure, chamber and / or station temperature, wafer temperature, target power level, RF power level, substrate pedestal, chuck and / or pedestal position, and other parameters for specific processes performed by processing tool 500. 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 the operation of processing tool components used to perform various processing tool processes. The system control software 558 can be coded in any suitable computer-readable programming language.

[0145] In some embodiments, system control software 558 may include input / output control (IOC) sequencing instructions for controlling the various parameters described above. In some embodiments, other computer software and / or programs associated with system controller 550 and stored in mass storage device 554 and / or memory device 556 may be employed. Examples of programs or program segments used for this purpose include substrate positioning programs, process gas control programs, pressure control programs, heater control programs, and plasma control programs.

[0146] The substrate positioning procedure may include program code for a processing tool assembly that loads the substrate onto the base 518 and controls the spacing between the substrate and other parts of the processing tool 500.

[0147] The process gas control program may include code for controlling the gas composition (e.g., silane, nitrogen, and purge gas as described herein) and flow rate, and optionally code for directing the gas into one or more processing stations prior to deposition to stabilize the pressure within the processing station. For example, the process gas control program may include code for varying the duration of the process gas feed across cycles in a multi-cycle ALD process. The pressure control program may include code for controlling the pressure within the processing station by adjusting, for example, throttling valves in the processing station's exhaust system, the airflow into the processing station, etc.

[0148] The heater control program may contain code for controlling the current flowing to the heating unit used to heat the substrate. Alternatively, the heater control program may control the delivery of a heat transfer gas (such as helium) toward the substrate.

[0149] The plasma control program may include code for setting the RF power level applied to one or more processing electrodes within the processing station, according to embodiments described herein. For example, the plasma control program may include code for changing the RF power level across cycles.

[0150] The pressure control program may contain code for maintaining the pressure within the reaction chamber according to the implementation scheme described herein.

[0151] In some implementations, a user interface may be associated with the system controller 550. The user interface may include a display screen, a graphical software display of the device and / or processing conditions, and user input devices such as pointing devices, keyboards, touch screens, microphones, etc.

[0152] In some implementations, the parameter values ​​regulated by the system controller 550 relate to processing conditions. Non-limiting examples include variations in the composition and flow rate of the processing gas, as well as dosing time, temperature, pressure, plasma conditions (e.g., RF power level), and one or more parameter values ​​throughout the ALD cycle. These parameter values ​​can be provided to the user in the form of a recipe, which can be input using the user interface.

[0153] Signals used for monitoring the processing can be provided from various processing tool sensors via analog and / or digital input connections of the system controller 550. Signals used for controlling the processing can be output via analog and digital output connections of the processing tool 500. Non-limiting examples of processing tool sensors that can be monitored include mass flow controllers, pressure sensors (e.g., pressure gauges), thermocouples, and the like. Appropriately programmed feedback and control algorithms can be used with data from these sensors to maintain processing conditions.

[0154] The system controller 550 can provide program instructions for performing the above-described deposition process. These program instructions can control various processing parameters, such as DC power level, RF bias power level, pressure, and temperature. The instructions can control these parameter values ​​to operate the in-situ deposition of the film stack according to various embodiments described in this invention.

[0155] System controller 550 will typically include one or more memory devices 556 and one or more processors configured to execute instructions to cause the device to perform the methods described according to the disclosed embodiments. A machine-readable medium containing instructions for controlling processing operations according to the disclosed embodiments may be coupled to the system controller. Controller 550 may have the above-mentioned references. Figure 4 Any characteristic described.

[0156] Suitable apparatus for carrying out the methods disclosed herein is further discussed and described in U.S. Patent Application No. 13 / 084,399, entitled "PLASMA ACTIVATED CONFORMAL FILM DEPOSITION," filed April 11, 2011, and U.S. Patent Application No. 13 / 084,305, entitled "SILICON NITRIDE FILMSAND METHODS," filed April 11, 2011, each of which is incorporated herein by reference in its entirety.

[0157] The apparatus / processes described herein can be used in conjunction with photolithographic patterning tools or processes, for example, for the fabrication or manufacture of semiconductor devices, displays, LEDs, photovoltaic panels, etc. Typically, although not necessarily, these tools / processes will be used together or operated in a common manufacturing facility. Photolithographic patterning of films typically involves some or all of the following operations, each of which enables multiple feasible tools: (1) applying a photoresist to a workpiece (i.e., substrate) using a spin coater or spray coater; (2) curing the photoresist using a hot plate or oven or a UV curing tool; (3) exposing the photoresist to visible light or ultraviolet or X-rays using a tool such as a wafer stepper; (4) developing the photoresist to selectively remove the photoresist and thereby pattern it using a tool such as a wet stage; (5) transferring the photoresist pattern onto the underlying film or workpiece using a dry or plasma-assisted etching tool; and (6) removing the photoresist using a tool such as an RF or microwave plasma stripper.

[0158] experiment

[0159] Experiment 1

[0160] Experiments were conducted on two silicon oxide films to determine the wet etch rate for each. Both silicon oxide films were deposited into features with an aspect ratio of 7:1. Both silicon oxide films were deposited using atomic layer deposition (ALD) with alternating pulses of a silicon precursor and a mixture of oxygen and nitrous oxide, which was used to generate a plasma at a power of 5000 W. Argon and nitrogen gases were also flowed during deposition. The flow rates were 5000 sccm for oxygen, 5000 sccm for nitrous oxide, 5000 sccm for argon, and 25000 sccm for nitrogen. A carrier gas with a flow rate of 1500 sccm was used. The plasma pulses used during ALD had a duration of 0.3 seconds, and the films were deposited in a chamber with a pressure of 6 Torr.

[0161] A first silicon oxide film was deposited without intermittent plasma treatment, and the wet etch rate was determined for the top, middle, and bottom of the feature. The wet etch rate measured in 100:1 hydrofluoric acid over 30 seconds was... Figure 6 The center is represented by solid bars.

[0162] A second silicon oxide film was deposited using intermittent plasma processing, which involved circulating oxygen, argon, helium, and hydrogen gases and generating plasma at a power of 1500 W for 10 seconds in a 2 Torr chamber. The oxygen flow rate was 2000 sccm, the argon flow rate was 3200 sccm, the helium flow rate was 2000 sccm, and the hydrogen flow rate was 2000 sccm. This intermittent plasma processing was performed every 5 ALD cycles. The wet etching rates for the top, middle, and bottom features were measured over 30 seconds in 100:1 hydrofluoric acid. Figure 6 It is depicted as a diagonal shaded bar.

[0163] like Figure 6 As shown, the wet etching rate of the film subjected to intermittent plasma treatment is much lower than that of the film without intermittent plasma treatment.

[0164] Experiment 2

[0165] An experiment was conducted on seven different membranes. Each membrane was deposited by atomic layer deposition (ALD) using a cycle of silicon precursor exposure, purge, oxygen and nitrous oxide gas mixture, and 1250 W plasma and purge. Argon and nitrogen were used as inert carrier gases and were employed during purge. The oxygen flow rate was 5000 sccm, the nitrous oxide gas flow rate was 5000 sccm, the argon flow rate was 5000 sccm, and the nitrogen flow rate was 25000 sccm. The carrier flow rate was 1500 sccm. The plasma was turned on for 0.3 seconds during the oxygen and nitrogen exposure. ALD was performed using a chamber pressure of 6 Torr.

[0166] A first silicon oxide film was deposited via this ALD process without intermittent plasma treatment, and the stress of the film was measured. Figure 7 It is described as processing 1.

[0167] The second to seventh silicon oxide films were deposited by ALD processing under intermittent plasma treatment every 10 cycles, and... Figure 7 Processes 2-7 are described in the table below. The processing conditions for each of these processes are provided in Table 1. The pressure during the intermittent plasma treatment for all processes is 10 Torr, and the RF ON time is 10 seconds. For cyclic processes 4 and 7, for 100 cycles of pulsed plasma treatment, the RF is turned on for 10 seconds and then off.

[0168] Table 1. Treatment conditions for treatments 2-7

[0169]

[0170] The results show that the stress of the membrane can be adjusted by switching various processing conditions of the individual intermittent plasma treatment, including changing the RF frequency, RF power, helium flow rate, argon flow rate and pulse scheme.

[0171] Experiment 3

[0172] Experiments were conducted on silicon oxide films deposited via atomic layer deposition (ALD), which involved a cycle of silicon precursor preparation, purging, oxygen and nitrous gas plasma (with argon and nitrogen), and purging. The plasma was generated using a 1250 W plasma power for 0.3 seconds, with a carrier gas flow rate of 1500 sccm. The oxygen flow rate was 5000 sccm, the nitrous oxide flow rate was 5000 sccm, the argon flow rate was 5000 sccm, and the nitrogen flow rate was 25000 sccm. The chamber pressure was 6 Torr.

[0173] These membranes are subjected to fluorine-based suppression by using a dual-frequency plasma generated at 750W for high-frequency plasma and 1000W for low-frequency plasma, and ignited in an environment in which oxygen, argon, helium, and nitrogen trifluoride gas flow for 1 second at 500 sccm, 3200 sccm, 6000 sccm, and 35 sccm flow for nitrogen trifluoride gas.

[0174] Next, the membranes were subjected to intermittent plasma treatments of varying durations. These intermittent plasma treatments involved exposing the substrate to 2 Torr of oxygen at 2000 sccm, argon at 3200 sccm, helium at 2000 sccm, and hydrogen at 2000 sccm in a chamber ignited with a 1500 W plasma. The three different intermittent plasma treatment durations were 5 seconds, 10 seconds, and 20 seconds. Intermittent plasma treatments were performed every 10 ALD cycles. The fluorine concentration was determined for each of these membranes as a function of the normalized depth of the membrane. Figure 8 The following diagrams illustrate the process. Line 801 represents the result of a 5-second intermittent plasma treatment, line 802 represents the result of a 10-second intermittent plasma treatment, and line 803 represents the result of a 15-second intermittent plasma treatment. The results indicate that longer plasma post-treatment can be used to reduce fluorine concentration in silicon oxide films deposited using ALD with suppression.

[0175] Experiment 4

[0176] Experiments were conducted to measure the k-values ​​of silicon oxide films deposited by ALD, comparing films without intermittent plasma treatment with those treated with intermittent plasma treatment. The experiments also involved determining the breakdown electric field for both films.

[0177] These films were deposited using multiple cycles of silicon precursor exposure, purge, oxygen and nitrous oxide plasma exposure (using argon and nitrogen), and purge. Plasma was generated at a power of 1250 W for 0.3 seconds. The flow rates were 5000 sccm for oxygen, 5000 sccm for nitrous oxide, 5000 sccm for argon, 25000 sccm for nitrogen, and 1500 sccm for the carrier gas. The chamber pressure was 6 Torr.

[0178] The film deposited using this process without intermittent plasma treatment is for a dielectric k value ( Figure 9 ) and breakdown electric field ( Figure 10 An evaluation will be conducted.

[0179] Following this film deposition, another film was exposed to an intermittent plasma treatment, which involved exposure to a 1250W plasma for 10 seconds. This plasma was generated every 10 ALD cycles by igniting 2000 sccm of oxygen, 3200 sccm of hydrogen, 2000 sccm of helium, and 2000 sccm of hydrogen. The film deposited using the above treatment with intermittent plasma treatment showed a dielectric k-value of ( Figure 9 ) and breakdown electric field ( Figure 10 An evaluation was conducted.

[0180] like Figure 9As shown, the dielectric k-value of the film exposed to intermittent plasma treatment is significantly lower than that of the film not exposed to intermittent plasma treatment. The breakdown voltage of the film exposed to intermittent plasma treatment is also significantly higher than that of the film not exposed to intermittent plasma treatment. These results indicate that films deposited using intermittent plasma treatment yield better results compared to films deposited without intermittent plasma treatment.

[0181] Experiment 5

[0182] Experiments were conducted to compare the stress and wet etching rate of films deposited and treated using continuous and pulsed plasma. Figure 11 A graph depicting the change in film stress relative to the wet etching rate, plotted by modifying the percentage argon flow rate and the type of plasma applied during the process, is shown. Pulsed plasma was applied at a frequency of 10 Hz. The percentage argon flow rate is the percentage of the total available argon flow rate entering the chamber.

[0183] Point 1102 represents 80% argon flow rate under pulsed plasma conditions; point 1104 represents 100% argon flow rate under pulsed plasma conditions; point 1106 represents 60% argon flow rate under pulsed plasma conditions; point 1108 represents 40% argon flow rate under pulsed plasma conditions; point 1110 represents 20% argon flow rate under pulsed plasma conditions; and line 1101 represents the overall curve and trend of stress as a function of wet etching rate when treated with pulsed plasma.

[0184] In comparison, point 1112 represents 80% argon flow rate under continuous plasma conditions; point 1114 represents 100% argon flow rate under continuous plasma conditions; point 1116 represents 60% argon flow rate under continuous plasma conditions; point 1118 represents 40% argon flow rate under continuous plasma conditions; point 1120 represents 20% argon flow rate under continuous plasma conditions; and line 1111 represents the overall curve of the film treated with continuous plasma and the trend of stress versus wet etching rate.

[0185] As shown in the figure, the results are surprising because the trend of continuous plasma differs from that of pulsed plasma. At 40% argon flow rate and pulsed plasma, favorable results are observed with significantly reduced stress and wet etching rate, while the highest wet etching rate is achieved with 40% argon flow rate and continuous plasma compared to all other points. Given the known trends of stress and wet etching rate for various films, the observed differences are significant and unexpected.

[0186] in conclusion

[0187] While the above embodiments have been described in detail for clarity, it will be apparent that certain variations and modifications may be implemented within the scope of the appended claims. It should be noted that many alternative processes, systems, and apparatuses exist for carrying out embodiments of the invention. Therefore, embodiments of the invention should be considered illustrative rather than restrictive, and are not limited to the details given herein.

Claims

1. A method for processing a substrate, the method comprising: Provide a semiconductor substrate to the reaction chamber; Perform cycles of atomic layer deposition to deposit a film, each cycle comprising: The first reactant, which is in the gas phase, is guided into the reaction chamber to adsorb the first reactant onto the surface of the semiconductor substrate; The second reactant, in its gaseous phase, is introduced into the reaction chamber for the specified dispensing time; and When the second reactant, in its gaseous phase, is in the reaction chamber, a first plasma is generated in the reaction chamber; and After every n cycles of atomic layer deposition, the film is exposed to a second plasma generated by flowing argon and a second gas. in, There exists any of the following: (1) The second gas is selected from the group consisting of hydrogen, oxygen, and combinations thereof, and the ratio of the flow rate of argon to that of the second gas is between 50:1 and 1:1, or (2) The second gas is nitrous oxide, and the ratio of the flow rate of argon to that of the second gas is between 10:1 and 20:

1. During the exposure of the membrane to the second plasma, the second plasma pulses between ON and OFF states.

2. The method of claim 1, further comprising: during exposure of the membrane to the second plasma, circulating one or more additional gases, said additional gases being selected from the group consisting of oxygen, nitrous oxide and helium.

3. A method for processing a substrate, the method comprising: Provide a semiconductor substrate to the reaction chamber; Perform cycles of atomic layer deposition to deposit a film, each cycle comprising: The first reactant, which is in the gas phase, is guided into the reaction chamber to adsorb the first reactant onto the surface of the semiconductor substrate; The second reactant, in its gaseous phase, is introduced into the reaction chamber for the specified dispensing time; and When the second reactant, in its gaseous phase, is in the reaction chamber, a first plasma is generated in the reaction chamber; and After every n cycles of atomic layer deposition, the film is exposed to a second plasma generated by flowing argon and a second gas, the ratio of the argon flow rate to the second gas flow rate being between 50:1 and 1:1, to achieve a lower than 100:1 HF. The wet etching rate, and During the exposure of the membrane to the second plasma, the second plasma pulses between ON and OFF states.

4. The method of claim 3, wherein the second gas is selected from the group consisting of hydrogen, oxygen, and combinations thereof.

5. The method of claim 3, further comprising: During the exposure of the membrane to the second plasma, a third gas is circulated, wherein the third gas is selected from the group consisting of nitrous oxide, helium, and combinations thereof.

6. The method of claim 5, wherein the ratio of the argon flow rate to the flow rate of the third gas is between 10:1 and 20:

1.

7. The method of claim 1, wherein the second plasma is generated at a power between 750 W and 1625 W per substrate.

8. The method of claim 1, wherein exposing the deposited film to the second plasma further comprises: introducing an argon-oxygen mixture in which the argon-oxygen flow rate ratio is 12:

1.

9. A method for processing a substrate, the method comprising: Provide a semiconductor substrate to the reaction chamber; Perform cycles of atomic layer deposition to deposit a film, each cycle comprising: The first reactant, which is in the gas phase, is guided into the reaction chamber to adsorb the first reactant onto the surface of the semiconductor substrate; The second reactant, in its gaseous phase, is introduced into the reaction chamber for the specified dispensing time; and When the second reactant, in its gaseous phase, is in the reaction chamber, a first plasma is generated in the reaction chamber; and After every n cycles of atomic layer deposition, the membrane is exposed to a second plasma generated using a power between 1000 W and 2000 W at a chamber pressure between 1 Torr and 10 Torr to reduce the stress on the membrane to below -290 MPa to 55 MPa. During the exposure of the membrane to the second plasma, the second plasma pulses between ON and OFF states.

10. A method of processing a substrate, the method comprising: Provide a semiconductor substrate to the reaction chamber; Perform atomic layer deposition for n cycles to deposit a film, each cycle containing: The first reactant, which is in the gas phase, is guided into the reaction chamber to adsorb the first reactant onto the surface of the semiconductor substrate; The second reactant, in its gaseous phase, is introduced into the reaction chamber for the specified dispensing time; and When the second reactant, in its gaseous phase, is in the reaction chamber, a first plasma is generated in the reaction chamber; and After every n cycles of atomic layer deposition, the deposited film is exposed to a second plasma using a power between 3000 W and 6500 W at a chamber pressure between 1 Torr and 5 Torr to reduce electrical leakage to below 1 E-9 A / cm at a 2 MV electric field. 2 ,and During the exposure of the deposited film to the second plasma, the second plasma pulses between ON and OFF states.

11. A method for processing a substrate, the method comprising: Provide a semiconductor substrate to the reaction chamber; Perform atomic layer deposition for n cycles to deposit a film, each cycle containing: The first reactant, which is in the gas phase, is guided into the reaction chamber to adsorb the first reactant onto the surface of the semiconductor substrate; The second reactant, in its gaseous phase, is introduced into the reaction chamber for the specified dispensing time; and When the second reactant, in its gaseous phase, is in the reaction chamber, a first plasma is generated in the reaction chamber; and After every n cycles of atomic layer deposition, the deposited film is exposed to a second plasma using a power between 3000 W and 6500 W at a chamber pressure between 1 Torr and 5 Torr to produce a treated film. in, The treated membrane has a breakdown voltage greater than 10 MV / cm, and During the exposure of the deposited film to the second plasma, the second plasma pulses between ON and OFF states.

12. A method for processing a substrate, the method comprising: Provide a semiconductor substrate to the reaction chamber; Perform n cycles of atomic layer deposition to deposit a silicon-containing film, each cycle containing: The first reactant, which is in the gas phase, is guided into the reaction chamber to adsorb the first reactant onto the surface of the semiconductor substrate; The second reactant, which is in the gas phase, is guided into the reaction chamber for the specified dispensing time. as well as When the second reactant, which is in the gaseous phase, is in the reaction chamber, a first plasma is generated in the reaction chamber; After every n cycles of atomic layer deposition, the deposited silicon-containing film is exposed to a second plasma; as well as Fluorine-containing reactive materials are introduced to form a fluorine-terminated silicon surface. During the exposure of the silicon-containing film to the second plasma, the second plasma pulses between ON and OFF states.

13. The method according to any one of claims 1-12, wherein the membrane comprises silicon oxide.

14. The method according to any one of claims 1-12, wherein exposing the membrane to the second plasma and performing the atomic layer deposition cycle are performed without breaking the vacuum.

15. The method according to any one of claims 1-12, wherein the first reactant is a silicon-containing precursor.

16. The method according to any one of claims 1-12, wherein the second reactant comprises one or more oxygen-containing gases.

17. The method of claim 16, wherein the oxygen-containing gas is selected from the group consisting of oxygen, nitrous oxide, water, carbon dioxide, and combinations thereof.

18. The method according to any one of claims 1-12, wherein n is an integer between 5 and 10 and inclusive of 5 and 10.

19. The method according to any one of claims 1-12, wherein the second plasma is generated by igniting an inert gas.

20. The method according to any one of claims 1-12, wherein the second plasma uses a concentration between 0.4421 W / cm². 2 With 1.7684W / cm 2 The plasma density between them is generated.

21. An apparatus for processing a substrate, the apparatus comprising: More than one processing chamber, each processing chamber containing a chuck; One or more gas inlets leading to the processing chamber and associated flow control hardware; and The controller has memory and at least one processor. 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: The first reactant in gas phase is introduced into the one or more processing chambers through one or more gas inlets; The second reactant in gas phase is introduced into the one or more processing chambers through one or more gas inlets; The introduction of the first reactant is stopped; To stop the introduction of the second reactant; as well as After stopping the introduction of the first reactant and the second reactant, the following operation is performed: using a combination of the inert gas and the additional gas with a flow rate ratio between 50:1 and 1:1 to generate a plasma pulsed between ON and OFF states.

22. The apparatus of claim 21, wherein the controller includes instructions to: after stopping the introduction of the first reactant and stopping the introduction of the second reactant, introduce the inert gas and the additional gas without disrupting the vacuum that allows the first reactant in a gaseous phase to be introduced from the more than one gas inlet into the more than one processing chamber and the second reactant in a gaseous phase to be introduced from the more than one gas inlet into the more than one processing chamber.

23. An apparatus for processing a substrate, the apparatus comprising: More than one processing chamber, each processing chamber containing a chuck; One or more gas inlets leading to the processing chamber and associated flow control hardware; and The controller has memory and at least one processor. 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: The first reactant in gas phase is introduced into the one or more processing chambers through one or more gas inlets; The second reactant in gas phase is introduced into the one or more processing chambers through one or more gas inlets; The introduction of the first reactant is stopped; To stop the introduction of the second reactant; as well as After stopping the introduction of the first reactant and the second reactant, the following operation is performed: using a combination of the inert gas and the additional gas with a flow rate ratio between 10:1 and 20:1 to generate a plasma pulsed between ON and OFF states.

24. The apparatus of claim 23, wherein the controller includes instructions to: after stopping the introduction of the first reactant and stopping the introduction of the second reactant, introduce the inert gas and the additional gas without disrupting the vacuum that allows the first reactant in a gaseous phase to be introduced from the more than one gas inlet into the more than one processing chamber and the second reactant in a gaseous phase to be introduced from the more than one gas inlet into the more than one processing chamber.

25. The apparatus of any one of claims 21 and 23, wherein the one or more processing chambers comprises four processing chambers, and wherein the controller comprises instructions for generating plasma using plasma power between 3000W and 6500W.

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