Method of forming layer by ALD

Abstract

A method of forming a layer of material on one or more substrates by ALD is disclosed. Embodiments of the presently described methods include performing a plurality of deposition cycles including at least two precursor pulses and an intervening purge pulse to form a layer of material on one or more substrates. During each deposition cycle, a ratio of the process chamber pressure during each of the at least two precursor pulses to the process chamber pressure during the intervening purge pulse is equal to or different from each other.

Description

Technical Field

[0001] The present disclosure relates to semiconductor processing. More particularly, the present disclosure relates to a method of forming a layer on a substrate by atomic layer deposition (ALD), and to a substrate processing system including an ALD apparatus for forming a layer. Background Art

[0002] Material deposition for forming layers on substrates remains one of the important process steps in semiconductor device manufacturing. In particular, atomic layer deposition offers the advantage of forming conformal layers that can also allow controlled adjustment of layer thickness.

[0003] One of the challenges associated with ALD can be related to the growth per cycle, as this can also have an impact on the yield of the deposition process. This can have a negative impact on the cycle time of manufacturing as well as the cost of operation.

[0004] Additionally, with equipment tailored for batch processing, whereby multiple substrates can be processed at once, upcoming challenges associated with ALD may involve thickness uniformity. Lack of thickness uniformity during the deposition process may present further challenges that may be associated with subsequent processing that needs to take place in semiconductor manufacturing.

[0005] Therefore, improvements to the ALD process may be needed. Summary of the invention

[0006] This summary is provided to introduce some concepts in a simplified form. These concepts are further described in detail in the detailed description of the exemplary embodiments of the present disclosure below. This summary is not intended to identify the key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0007] It is an object of the present disclosure to improve the ALD process. More specifically, it is an object to provide an optimized growth rate per cycle and an optimized yield, improved thickness uniformity and improved electrical properties of ALD formed layers. Another object is to provide a layer formed by ALD with a reduced contamination level. In order to at least partially achieve these objects, the present disclosure may provide a method of forming a layer on one or more substrates by ALD as defined in the independent claims and a substrate processing system including an ALD device for forming a layer. Further embodiments are provided in the dependent claims.

[0008] In a first aspect, the present disclosure relates to a method for forming a material layer on one or more substrates by atomic layer deposition (ALD). The method may include providing one or more substrates in a process chamber. The method may further include performing a plurality of deposition cycles to form a material layer on the one or more substrates. Each deposition cycle may include at least two precursor pulses and an intervening purge pulse. The process chamber pressure during each deposition cycle may be in the range of about 0.1 Torr to about 10 Torr. During each deposition cycle, the ratio of the process chamber pressure during each precursor pulse of at least two precursor pulses to the process chamber pressure during the intervening purge pulse may be equal to or different from each other.

[0009] The method according to the embodiment of the first aspect of the present disclosure may allow a material layer to be formed on one or more substrates by ALD. In particular, the method according to the embodiment of the first aspect of the present disclosure may allow a material layer to be formed on multiple substrates by ALD.

[0010] An advantage of embodiments of the first aspect is that an increased growth rate of the layer may be obtained. The increased growth rate may further improve the throughput of the deposition process.

[0011] Another advantage of the embodiments of the first aspect is that the intra-wafer non-uniformity of the substrate can be reduced. This may be more advantageous when forming layers on multiple substrates. This may allow for an increase in the uniform thickness of the layer on the substrate surface on which the layer is deposited. This may advantageously help increase the yield of subsequent processes in semiconductor manufacturing, such as further layer deposition, photolithography, and etching.

[0012] Another advantage of embodiments of the first aspect is that the reliability of a fabricated semiconductor device including a layer formed by an ALD process may be improved due to improved thickness uniformity.

[0013] An advantage of embodiments of the first aspect is also that the level of contamination in the layer may be reduced. This may advantageously involve, for example, a reduction in carbon contamination or hydrogen contamination.

[0014] Another advantage of embodiments of the first aspect is that the electrical characteristics of a fabricated semiconductor device including a layer formed by an ALD process may be improved due to reduced contamination.

[0015] In a second aspect, the present disclosure relates to a substrate processing system. The substrate processing system may include an atomic layer deposition (ALD) device. The ALD device may include a controller, which may be configured to execute instructions stored in a non-transitory computer-readable medium and cause the ALD device to form a material layer on one or more substrates according to a method according to an embodiment of the first aspect of the present disclosure.

[0016] The substrate processing system according to the embodiment of the second aspect of the present disclosure may allow for an increase in the throughput of a deposition process. This may help reduce the cycle time of the deposition process. In the semiconductor industry, this may be reflected as a reduction in the chip production cycle time. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] It should be understood that the elements in the drawings are shown for simplicity and clarity and are not necessarily drawn to scale. For example, the size of some elements in the drawings may be exaggerated relative to other elements to help improve the understanding of the illustrated embodiments of the present disclosure.

[0018] Unless otherwise stated, the same reference numerals in the drawings will be used for the same elements. Reference numerals in the claims shall not be construed as limiting the scope.

[0019] Figure 1a is a flowchart of an exemplary method according to an embodiment of the first aspect of the present disclosure.

[0020] Figure 1b is a flow chart of an embodiment according to the first aspect of the present disclosure.

[0021] Figure 2 is a schematic diagram of an ALD device included in a substrate processing system according to an embodiment of the second aspect of the present disclosure. DETAILED DESCRIPTION

[0022] Although certain embodiments and examples are disclosed below, it will be appreciated by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments and / or uses of the present invention and their obvious modifications and equivalents. Therefore, it is intended that the scope of the disclosed invention should not be limited by the specifically disclosed embodiments described below.

[0023] As used herein, the term "substrate" may refer to any one or more underlying materials, including any one or more underlying materials that may be modified or on which a device, circuit, or film may be formed. A "substrate" may be continuous or non-continuous; rigid or flexible; solid or porous; and combinations thereof. A substrate may be in any form, such as a powder, a plate, or a workpiece. A plate-like substrate may include wafers of various shapes and sizes. A substrate may be made of semiconductor materials, including, for example, silicon, silicon germanium, silicon oxide, gallium arsenide, gallium nitride, and silicon carbide.

[0024] For example, a substrate in powder form can be used in drug manufacturing. The porous substrate can include a polymer. Examples of workpieces can include medical devices (such as stents and syringes), jewelry, tool equipment, components for battery manufacturing (such as anodes, cathodes, or separators), or components of photovoltaic cells, etc.

[0025] The continuous substrate may extend beyond the boundaries of the processing chamber in which the deposition process occurs. In some processes, the continuous substrate may be moved through the processing chamber so that the process continues until the end of the substrate is reached. The continuous substrate may be provided by a continuous substrate feeding system to allow the continuous substrate to be manufactured and output in any suitable form.

[0026] Non-limiting examples of continuous substrates may include sheets, nonwoven films, rolls, foils, meshes, flexible materials, bundles of continuous filaments or fibers (eg, ceramic fibers or polymer fibers). Continuous substrates may also include carriers or sheets on which discontinuous substrates are mounted.

[0027] The illustrations presented herein are not intended to be actual views of any particular material, structure, or device but are merely idealized representations used to describe embodiments of the present disclosure.

[0028] The specific embodiments shown and described are illustrations of the present invention and its best mode and are not intended to limit the scope of these aspects and embodiments in any way. In fact, for the sake of brevity, the traditional manufacturing, connection, preparation and other functional aspects of the system may not be described in detail. In addition, the connecting lines shown in the various figures are intended to represent exemplary functional relationships and / or physical connections between various elements. Many alternative or additional functional relationships or physical connections may exist in actual systems, and / or may not exist in some embodiments.

[0029] It should be understood that the configurations and / or methods described herein are exemplary in nature, and these specific embodiments or examples should not be considered restrictive, as many variations are possible. The specific routines or methods described herein may represent one or more of any number of processing strategies. Therefore, the various actions shown may be performed in the order shown, in other orders, or may be omitted in some cases.

[0030] The subject matter of the present disclosure includes all novel and nonobvious combinations and subcombinations of the various processes, systems and configurations, and other features, functions, acts and / or properties disclosed herein, and any and all equivalents thereof.

[0031] It should be noted that the term "comprising" used herein should not be interpreted as being limited to the means listed thereafter. It does not exclude other elements or steps. Therefore, it should be interpreted as specifying the presence of the features, steps or components mentioned. However, this does not prevent the presence or addition of one or more other steps, components or features or combinations thereof.

[0032] References to "embodiment" in various places in the specification do not necessarily refer to the same embodiment, but may refer to the same embodiment. In addition, in one or more embodiments, the particular features, structures or characteristics may be combined in any suitable manner, which is obvious to those of ordinary skill in the art.

[0033] References to "some embodiments" throughout the specification mean that the specific structures, features, and steps described in conjunction with these embodiments are included in some embodiments of the present invention. Therefore, phrases such as "in some embodiments" appearing in different places throughout the specification do not necessarily refer to the same set of embodiments, but may refer to the same set of embodiments.

[0034] References throughout this specification to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment is included in at least one embodiment of the present disclosure. Therefore, the phrases "in one embodiment" or "in an embodiment" appearing in various places in this specification do not necessarily all refer to the same embodiment, but may refer to the same embodiment.

[0035] It should be noted that the term "essentially comprising" used in the claims means that in addition to those specifically mentioned components, other components may be present but are not required to be present, that is, those components that do not substantially affect the basic characteristics of the material, compound or composition involved.

[0036] The terms first, second, third, etc. in the specification and claims are used to distinguish similar elements. They are not necessarily used to describe a sequence in time, space, order, or any other manner. It should be understood that the terms so used are interchangeable where appropriate, and that the embodiments of the present disclosure described herein are capable of operating in other sequences than those described or shown herein.

[0037] The following terms are used only to aid in understanding the present disclosure.

[0038] As used herein, unless otherwise specified, the term "intervening purge pulse" may refer to providing an inert gas between precursor pulses. An intervening purge pulse may also be referred to as an "intervening evacuation pulse" so that the precursors provided to the process chamber do not contact each other in the gas phase.

[0039] As used herein, unless otherwise specified, the term "reduced WIWNU" may refer to a reduction in layer thickness variation across a substrate surface, such as from the center to the edge of the substrate.

[0040] The present disclosure will now be described by a detailed description of a plurality of embodiments of the present disclosure. Obviously, other embodiments of the present disclosure can be configured according to the knowledge of those skilled in the art without departing from the technical teachings of the present disclosure. The present disclosure is limited only by the terms of the claims included herein.

[0041] Figure 1a and Figure 1b A flowchart of an exemplary method according to an embodiment of the first aspect of the present disclosure is shown.

[0042] A method 100 of forming a material layer on one or more substrates by ALD is described herein.

[0043] The method 100 may include providing 110 one or more substrates in a processing chamber.

[0044] In some embodiments, one or more substrates may be provided together to a processing chamber.

[0045] Therefore, in some embodiments, the one or more substrates may be a plurality of substrates. The plurality of substrates may be arranged in a substrate carrier extending in a longitudinal direction. The substrate carrier may be accommodated in a processing chamber. In some embodiments, the longitudinal direction may be a horizontal direction. In some embodiments, the longitudinal direction may be a vertical direction.

[0046] Thus, in some embodiments, the process chamber may be contained in a semiconductor device that extends in a vertical direction relative to a ground surface on which the device is located. In some embodiments, the semiconductor device may be a vertical furnace. This may provide the advantage of performing each ALD deposition cycle in a duration on the order of minutes, so that switching between pulses may be performed more slowly than for ALD deposition cycles of shorter duration.

[0047] In some embodiments, one or more substrates may be provided to the process chamber one at a time, whereby the one or more substrates may be arranged on a substrate support constructed and arranged to hold a single substrate. Thus, the process chamber may be one of at least two process chambers included in a semiconductor processing apparatus.

[0048] In some embodiments, the process chamber may be a single process chamber contained in a semiconductor processing apparatus.

[0049] The method 100 may further include performing 120 a plurality of deposition cycles to form a material layer on one or more substrates. Each deposition cycle may include at least two precursor pulses 121 , 122 and an intervening purge pulse 123 .

[0050] Each of the at least two precursor pulses may include providing a precursor gas. Each precursor gas may be provided in the presence of a carrier gas. In an embodiment, the carrier gas may include N2 and a rare gas such as Ar, Ne, He, Xe, and Kr.

[0051] In some embodiments, the carrier gas may primarily include N2, Ar, He, Ne, Xe, Kr, or a combination thereof.

[0052] In an embodiment, each of the at least two precursor pulses may be different from each other.

[0053] like Figure 1bAs schematically shown in , an intervening purge pulse may be provided between at least two precursor pulses 121, 122 in each deposition cycle 120 and before completing each deposition cycle 120 after the precursor pulse. The intervening purge pulse may include providing an inert gas to the process chamber between precursor pulses.

[0054] In some embodiments, each intervening purge pulse 123 can be provided to the process chamber in a substantially identical manner, such as providing the same inert gas at the same flow rate, the same process chamber temperature, and the same process chamber pressure.

[0055] In some embodiments, each intervening purge pulse 123 can be provided to the process chamber differently from one another. The duration of each intervening purge pulse can, for example, be different from one another depending on which precursor gas needs to be purged. In this regard, an intervening purge pulse performed after providing an oxygen-containing precursor gas (e.g., H2O) can be longer than a precursor gas for providing a material.

[0056] The chamber pressure during each deposition cycle may be in the range of about 0.1 Torr to about 10 Torr. During each deposition cycle, the ratio of the chamber pressure during each precursor pulse to the chamber pressure during the intervening purge pulse may be equal to or different from one another.

[0057] Thus, in some embodiments, the change in chamber pressure within each deposition cycle, and in particular the change in chamber pressure between each precursor pulse and the intervening purge pulse, may be the same.

[0058] In another exemplary embodiment, the formation of the layer can be performed using two precursor pulses that are different from each other, separated by an intervening purge pulse. During the intervening purge pulse, the process chamber pressure can be set to 0.1 Torr. During the first precursor pulse and the second precursor pulse, the process chamber pressure can be set to a pressure value in the range of 1.5 Torr to 5 Torr.

[0059] In an embodiment, during the first precursor pulse and the second precursor pulse, the process chamber pressure may be set to a pressure value within the range of from at least 1.5 Torr to at most 2 Torr, or from at least 2 Torr to at most 2.5 Torr, or from at least 2.5 Torr to at most 3 Torr, or from at least 3 Torr to at most 3.5 Torr, or from at least 3.5 Torr to at most 4 Torr, or from at least 4 Torr to at most 4.5 Torr, or from at least 4.5 Torr to at most 5 Torr.

[0060] In some embodiments, the variation of chamber pressure within each deposition cycle, and in particular the variation of chamber pressure between each precursor pulse and the intervening purge pulse, can be different from one another.

[0061] In an exemplary embodiment, the formation of the layer can be performed using two precursor pulses that are different from each other, separated by an intervening purge pulse. The process chamber pressure during the intervening purge pulse can be set to 0.1 Torr. The process chamber pressure during the first precursor pulse can be set to 1 Torr, and the process chamber pressure during the second precursor pulse can be set to 10 Torr.

[0062] In an embodiment, the process chamber pressure during each of the at least two precursor pulses and during each intervening purge pulse may be selected such that a change in process chamber pressure when going from a precursor pulse to a subsequent intervening purge pulse produces a process chamber pressure swing of, for example, at least a factor of 5. This may be advantageous in promoting nucleation of the layer, which may be achieved at a higher process chamber pressure during the provision of the precursor pulses than during the process chamber pressure during the intervening purge pulses.

[0063] Without wishing to be bound by theory, it can be said that film formation by ALD at lower process pressure values ​​(e.g., below 1 Torr) can result in reduced growth per cycle, which can result in reduced yield of the process. In addition, differences in saturation levels between the edge and the center of the substrate can result in poor WIWNU. For example, this can occur when O3 is used as an oxygen-containing precursor gas. On the other hand, film formation by ALD at higher process pressure values ​​(e.g., above 1 Torr) can help to increase growth per cycle, thereby increasing the yield of the process. In addition, the higher saturation levels obtained between the edge and the center of the substrate can result in a reduction in the thickness variation of the formed layer, thereby improving WIWNU. For example, this can occur when O3 is used as an oxygen-containing precursor gas. However, film formation by ALD at higher process pressure values ​​can result in particle formation. It may also be necessary to increase the purge time.

[0064] Thus, performing film formation by ALD by implementing a pressure swing may allow for an increased growth rate per cycle (GPC) of the deposited layer when going from a precursor pulse to a subsequent intervening purge pulse. For example, the increased growth rate may be higher than 100% per cycle. This in turn may result in an increased yield of the deposition process. It may also provide the advantage of reducing the WIWNU per substrate. This may therefore allow a uniform thickness of the layer to be achieved across the surface of the substrate on which the layer is deposited.

[0065] In an embodiment, atomic layer deposition may be performed at a temperature below 700° C. This may allow the possibility to form layers with increased growth rates per cycle.

[0066] In some embodiments, atomic layer deposition may be performed at a temperature in a range of 20° C. to 700° C. This process window may allow formation of layers to be performed at lower process temperatures as well as higher process temperatures, thereby enabling increased growth rates per cycle.

[0067] In some embodiments, atomic layer deposition can be performed at a temperature within the range of from at least 20°C to at most 100°C, or from at least 100°C to at most 200°C, or from at least 200°C to at most 300°C, or from at least 300°C to at most 400°C, or from at least 400°C to at most 500°C, or from at least 500°C to at most 600°C, or from at least 600°C to at most 700°C.

[0068] In an embodiment, a first ratio of the process chamber pressure during a first precursor pulse of the at least two precursor pulses to the process chamber pressure during an intervening purge pulse may be lower than a second ratio of the process chamber pressure during a second precursor pulse of the at least two precursor pulses to the process chamber pressure during an intervening purge pulse.

[0069] This may further allow for enhanced variations in process chamber pressure within each deposition cycle. This may therefore further contribute to an increase in the GPC of the deposited layer.

[0070] In an embodiment, the process chamber pressure during the intervening purge pulse may be the same and may be lower than the process chamber pressure during the first precursor pulse and during the second precursor pulse. This helps to generate a pressure swing in the process chamber from a precursor pulse to a subsequent intervening purge pulse within a deposition cycle. In addition, the process chamber pressure during the second precursor pulse may be higher than the process chamber pressure during the first precursor pulse. In this way, a higher process chamber pressure change may be generated when purging after providing the second precursor pulse than after providing the first precursor pulse.

[0071] In an embodiment, the first precursor pulse may be different from the second precursor pulse.

[0072] In an embodiment, the change in chamber pressure between the first precursor pulse and the second precursor pulse may be configured to increase the growth rate per cycle.

[0073] Thus, in some embodiments, the process chamber pressure during the second precursor pulse is at least two times higher than the process chamber pressure during the first precursor pulse.

[0074] In some embodiments, the process chamber pressure during the second precursor pulse is at least five times higher than the process chamber pressure during the first precursor pulse.

[0075] In some embodiments, the process chamber pressure during the second precursor pulse is at least ten times higher than the process chamber pressure during the first precursor pulse.

[0076] A higher process chamber pressure during the second precursor pulse compared to during the first precursor pulse can help improve uniformity of layer thickness across the substrate surface. This can also help reduce decomposition of the precursor. Additionally, particle formation can be reduced. During the ALD process, layer formation can also occur on the interior surfaces of the process chamber. Flaking or cracking of this layer can lead to particle formation.

[0077] In an embodiment, the first precursor pulse may include providing a precursor gas of a material, and the second precursor pulse may include providing an oxygen-containing precursor gas or providing a nitrogen-containing precursor gas.

[0078] Providing the first precursor may result in chemical adsorption of the substrate surface where layer formation occurs, such that a monolayer of the first precursor covers the substrate surface. Providing an oxygen-containing precursor gas may result in the formation of an oxide layer, while providing a nitrogen-containing precursor gas may result in the formation of a nitride layer.

[0079] In an embodiment, the precursor gas of the material may be obtained from a liquid source precursor or a solid source precursor. Thus, one of the at least two precursor storage modules and the corresponding connection from the precursor storage module to the process chamber 1040 may be constructed and arranged to generate and deliver the precursor gas of the material.

[0080] In an embodiment, the precursor gas of the material may be a metal organic precursor.

[0081] In some embodiments, the precursor gas of the material may include a transition metal. In some embodiments, the precursor gas of the material may include vapor of a transition metal chloride. The vapor of the transition metal chloride may be provided to the processing chamber with the aid of a carrier gas. In some embodiments, the precursor gas of the material may substantially include vapor of a transition metal chloride.

[0082] In some embodiments, the precursor gas of the material may include vapor of HfCl4, TaCl5, TiCl4, MoCl5, ZrCl4, MoO2Cl2, VCl4.

[0083] In some embodiments, the precursor gas of the material may include a Group III element or a Group IV element.

[0084] In an embodiment, the precursor gas of the material may include Al(CH 3 ) 3 or AlCl 3. Depending on whether the second precursor pulse is an oxygen-containing precursor gas or a nitrogen-containing precursor gas, an aluminum nitride or aluminum oxide layer may be formed.

[0085] In an embodiment, the precursor gas of the material may include a Si-containing gas. Depending on whether the second precursor pulse is an oxygen-containing precursor gas or a nitrogen-containing precursor gas, a silicon nitride or silicon oxide layer may be formed.

[0086] In an embodiment, the Si-containing gas may be a metal-organic silicon precursor.

[0087] In an embodiment, the Si-containing gas may be a silicon halide. This may result in the formation of a silicon-containing layer by ALD. The silicon halide may be of the formula Si Si n X 2n+2 wherein X is a halogen and n is an integer of at least 1 to 5.

[0088] In some embodiments, the precursor gas of the material may include octachlorotrisilane, hexachlorodisilane, or silicon tetrachloride. In other words, the silicon halide may be octachlorotrisilane, hexachlorodisilane, or silicon tetrachloride.

[0089] In an embodiment, the process chamber pressure of the precursor gas of the material may be in a range from about 0.1 Torr to about 5.0 Torr.

[0090] In an embodiment, the processing chamber pressure of the precursor gas of the material can be in the following range: from at least about 0.1 Torr to at most about 0.5 Torr, or from at least about 0.5 Torr to at most about 1.0 Torr, or from at least about 1 Torr to at most about 1.5 Torr, or from at least about 1.5 Torr to at most about 2.0 Torr, or from at least about 2.0 Torr to at most about 2.5 Torr, or from at least about 2.5 Torr to at most about 3.0 Torr, or from at least about 3.0 Torr to at most about 3.5 Torr, or from at least about 3.5 Torr to at most about 4.0 Torr, or from at least about 4.0 Torr to at most about 4.5 Torr, or from at least about 4.5 Torr to at most about 5.0 Torr.

[0091] In some embodiments, the process chamber pressure of the precursor gas of the material may be in a range from about 0.2 Torr to about 0.5 Torr.

[0092] In an embodiment, the process chamber pressure of each intervening purge pulse may be in a range from about 0.1 Torr to about 1.0 Torr.

[0093] In an embodiment, the process chamber pressure of each intervening purge pulse can be in the range of from at least about 0.1 Torr to at most about 0.2 Torr, or from at least about 0.2 Torr to at most about 0.3 Torr, or from at least about 0.3 Torr to at most about 0.4 Torr, or from at least about 0.4 Torr to at most about 0.5 Torr, or from at least about 0.5 Torr to at most about 0.6 Torr, or from at least about 0.6 Torr to at most about 0.7 Torr, or from at least about 0.7 Torr to at most about 0.8 Torr, or from at least about 0.8 Torr to at most about 0.9 Torr, or from at least about 0.9 Torr to at most about 1.0 Torr.

[0094] In an embodiment, at least one of the first precursor pulse and the second precursor pulse may last from 1 second to 5 minutes.

[0095] In some embodiments, at least one of the first precursor pulse and the second precursor pulse may last from 2 seconds to 5 seconds.

[0096] In some embodiments, each deposition cycle may include three precursor pulses. This may be advantageous in being able to form layers including: ternary compounds, doped layers, nitride layers, doped nitride layers, oxide layers, doped oxide layers, carbide layers, or doped carbide layers. Thus, in these embodiments, at least one of the three precursor pulses may include a precursor gas that provides a material. Depending on the layer to be formed, the remaining precursors to be provided may be selected from an oxygen-containing precursor gas, a nitrogen-containing precursor gas, a gas containing a dopant, or a combination thereof.

[0097] In some embodiments, the chamber pressure during the intervening purge pulse can be the same and can be lower than the chamber pressure during any of the three precursor pulses. This helps create a pressure swing in the chamber from a precursor pulse to a subsequent intervening purge pulse within a deposition cycle.

[0098] In some embodiments, each intervening purge pulse 123 can be provided to the process chamber in substantially the same manner, such as providing the same inert gas at the same flow rate, at the same process chamber temperature, and at the same process chamber pressure.

[0099] In some embodiments, each intervening purge pulse 123 can be provided to the process chamber differently from one another. The duration of each intervening purge pulse can, for example, be different from one another depending on which precursor gas needs to be purged. In this regard, an intervening purge pulse performed after providing an oxygen-containing precursor gas (e.g., H2O) can be longer than any of the three precursor pulses.

[0100] In some embodiments, the chamber pressure during any one precursor pulse may be higher than the chamber pressure during any other precursor pulse, further helping to create a pressure swing, whereby the chamber pressures during the other precursor pulses may be the same or different from each other.

[0101] In some embodiments, the chamber pressure during the three precursor pulses may be the same.

[0102] In an exemplary embodiment, a first precursor pulse may include providing octachlorotrisilane (Si3Cl8-OCTS) as a precursor gas for the material. A second precursor pulse may include NH3 as a nitrogen-containing precursor gas. There may be a third precursor pulse, which may include providing an organoborane, such as triethylborane ((CH3CH2)3B-TEB). In each deposition cycle, each of the three precursor pulses may be followed by an intervening purge pulse.

[0103] In some embodiments, each deposition cycle may include four precursor pulses. This may be advantageous in enabling the formation of layers comprising quaternary compounds.

[0104] In an embodiment, at least one of the four precursor pulses may include a precursor gas providing a material. Depending on the layer to be formed, the remaining precursors to be provided may be selected from an oxygen-containing precursor gas, a nitrogen-containing precursor gas, a gas containing a dopant, or a combination thereof.

[0105] In some embodiments, during the intervening purge pulse, the chamber pressure may be the same and may be lower than during any of the four precursor pulses. This helps create a pressure swing in the chamber from a precursor pulse to a subsequent intervening purge pulse within a deposition cycle.

[0106] In some embodiments, each intervening purge pulse 123 can be provided to the process chamber in substantially the same manner, such as providing the same inert gas at the same flow rate, at the same process chamber temperature, and at the same process chamber pressure.

[0107] In some embodiments, each intervening purge pulse 123 can be provided to the process chamber differently from one another. The duration of each intervening purge pulse can, for example, be different from one another depending on which precursor gas needs to be purged. In this regard, an intervening purge pulse performed after providing an oxygen-containing precursor gas (e.g., H2O) can be longer than providing any of the four precursor pulses.

[0108] In some embodiments, the chamber pressure during any one precursor pulse may be higher than the chamber pressure during any other precursor pulse, further helping to create a pressure swing, whereby the chamber pressures during the other precursor pulses may be the same or different from each other.

[0109] In some embodiments, the chamber pressure during the four precursor pulses may be the same.

[0110] In an embodiment, the method may further include performing a heat treatment process after performing multiple deposition cycles. The heat treatment process may be at least one of an in-situ and ex-situ heat treatment process. Depending on the environment, temperature, and pressure of the heat treatment process, it may be advantageous to allow for reduced contamination in the layer.

[0111] The thermal treatment process may be performed in an environment that may include at least one of O 3 , O 2 , H 2 O, and N 2 . The thermal treatment process may help reduce contamination in the ALD layer, such as carbon contamination or hydrogen contamination.

[0112] In some embodiments, the thermal treatment process may be performed after forming the desired ALD layer thickness. Therefore, the method 100 may further include performing a thermal treatment after performing a plurality of deposition cycles to help obtain the desired thickness. In other words, the thermal treatment process may be performed after completing the formation of the ALD layer having the desired thickness.

[0113] In some embodiments, the method 100 may further include repeatedly performing multiple deposition cycles and performing at least one of an in-situ and an ex-situ thermal treatment process. This is not only beneficial for gradually completing the formation of the desired ALD layer, but also for subsequently removing contaminants in each incremental layer.

[0114] In an embodiment, atomic layer deposition may be performed at a temperature in the range of 200°C to 450°C, and the precursor gas of the material may include trimethylaluminum (TMA), expressed as Al(CH3)3. The deposition cycle may further include an oxygen-containing precursor gas to form an aluminum oxide layer. In an embodiment, the oxygen-containing gas may be O3, H2O, O2, H2O2, N2O, or a combination thereof. When a combination is used, the flow of different oxygen-containing gases may be performed sequentially, in other words, the flow of one type of oxygen-containing gas follows the flow of another type of oxygen-containing gas. This may provide the advantage of forming an aluminum oxide layer at a lower processing temperature, thereby achieving an increased cycle growth rate.

[0115] In certain example embodiments, a combination of H2O and O3 may be used.

[0116] This may be more advantageous in obtaining an aluminum oxide layer with reduced WIWNU across the substrate. The pressure swing of the process chamber when going from a precursor pulse at a higher process chamber pressure to a subsequent intervening purge pulse at a lower process chamber pressure may result in a reduced WIWNU. In particular, the reduced WIWNU may be due to the process chamber pressure being higher during the oxygen-containing precursor pulse than during the TMA precursor pulse.

[0117] In an embodiment, atomic layer deposition may be performed at a temperature in the range from at least 200°C to at most 250°C, or from at least 250°C to at most 300°C, or from at least 300°C to at most 350°C, or from at least 350°C to at most 400°C, or from at least 400°C to at most 450°C.

[0118] In an embodiment, the heat treatment process may be an in-situ heat treatment process, an ex-situ heat treatment process, or a combination of both.

[0119] Therefore, in some embodiments, the heat treatment process can be performed in situ at a temperature in the range of 450° C. to 1000° C. In these embodiments, the process chamber pressure can be in the range of 0.1 Torr to 10 Torr, and the duration can be in the range of 15 minutes to 5 hours. The in situ heat treatment process can be performed in an environment including O3, O2, H2O and N2.

[0120] In embodiments, the temperature may be from at least 450°C to at most 550°C, or from at least 550°C to at most 650°C, or from at least 650°C to at most 750°C, or from at least 750°C to at most 850°C, or from at least 850°C to at most 1000°C.

[0121] In some embodiments, the heat treatment process may be performed ex situ at a temperature of about 1000° C. The ex situ heat treatment may be performed for a duration ranging from 1 minute to 5 minutes. The ex situ heat treatment process may be performed in an environment including N 2 and O 2 .

[0122] In an exemplary embodiment, an aluminum oxide layer may be formed by ALD at a process temperature of 200° C. using TMA as a precursor gas and a combination of O 3 and H 2 O as an oxygen-containing precursor gas in each deposition cycle of a plurality of deposition cycles. After the desired layer is formed, the in-situ thermal treatment disclosed herein may be performed at a temperature of about 600° C. in an environment including O 3 , O 2 , H 2 O, and N 2 .

[0123] Further described herein are substrate processing systems including atomic layer deposition apparatus. Figure 2 An ALD apparatus that may be included in a substrate processing system is schematically shown.

[0124] The ALD apparatus 1000 may include a process chamber 1040, which may be configured to form a layer on one or more substrates. The apparatus 1000 may also include a heater 1060, which may be configured to heat and maintain a process temperature in the process chamber 1040. The process temperature may be measured using a thermocouple located within the process chamber. The thermocouples may be placed in different regions along the longitudinal axis to achieve multi-region temperature measurement.

[0125] The device 1000 may also include a pressure controller 1070, which may be configured to obtain and maintain a process pressure in the process chamber 1040. The process pressure may be measured by using a pressure sensor. The device 1000 may further include at least two precursor storage modules 1010, 1020. The precursors stored in each of the at least two precursor storage modules may be different from each other. One of the at least two precursor storage modules 1010 may be constructed and arranged to hold a precursor gas of a material, while the other precursor storage module 1020 may be constructed and arranged to hold an oxygen-containing precursor gas or a nitrogen-containing precursor gas. The device 1000 may also include a controller, which may be configured to execute instructions stored in a non-transitory computer-readable medium, and according to an embodiment of the method according to the first aspect of the present disclosure, cause the atomic layer deposition device to form a material layer on one or more substrates.

[0126] In an embodiment, the precursor gas of the material can be obtained from a liquid source precursor or a solid source precursor. Therefore, one of the at least two precursor storage modules can be constructed and arranged to at least generate and maintain the precursor gas of the material. The corresponding connection from the precursor storage module to the processing chamber 1040 can be constructed and arranged to transfer the precursor gas of the material to the processing chamber 1040.

[0127] The apparatus 1000 may further include an exhaust outlet 1050. The exhaust outlet 1050 may be constructed and arranged to remove a portion of the at least two precursor gases from the process chamber 1040. The portion of the at least two precursor gases to be removed from the process chamber 1040 may be an additional monolayer formed on the substrate by physical adsorption.

[0128] In an embodiment, the ALD apparatus 1000 may be a vertical furnace batch ALD apparatus.A plurality of substrates may be accommodated in a process chamber 1040 arranged in a substrate boat.

[0129] The apparatus 1000 may further include a gas injector (not shown) constructed and arranged to provide at least two precursor gases and an intervening purge gas to the process chamber 1040. In an embodiment, the gas injector may be a multi-port gas injector.

[0130] The embodiments of the present disclosure do not limit the scope of the present invention, because these embodiments are defined by the claims attached hereto and their legal equivalents. Any equivalent embodiments are within the scope of the present invention. In addition to the content disclosed herein, modifications different from each other of the present disclosure will be apparent to those skilled in the art. Such modifications and embodiments derived therefrom are also intended to fall within the scope of the claims attached hereto.

Claims

1. A method for forming a material layer on one or more substrates by atomic layer deposition, the method comprising: - providing one or more substrates in a process chamber, - performing a plurality of deposition cycles to form a material layer on one or more substrates, wherein each deposition cycle comprises at least two precursor pulses and an intervening purge pulse, in, The process chamber pressure during each deposition cycle is in a range from about 0.1 Torr to about 10 Torr, and wherein, during each deposition cycle, a ratio of the process chamber pressure during each of at least two precursor pulses to the process chamber pressure during an intervening purge pulse is equal to or different from one another.

2. The method according to claim 1, wherein: A first ratio of chamber pressure during a first of the at least two precursor pulses to chamber pressure during the intervening purge pulse is lower than a second ratio of chamber pressure during a second of the at least two precursor pulses to chamber pressure during the intervening purge pulse.

3. The method according to claim 2, wherein: The process chamber pressure during the intervening purge pulse is the same and lower than the process chamber pressure during the first precursor pulse and during the second precursor pulse, and wherein the process chamber pressure during the second precursor pulse is higher than the process chamber pressure during the first precursor pulse.

4. The method according to claim 2 or 3, wherein: The process chamber pressure during the second precursor pulse is at least two times higher than the process chamber pressure during the first precursor pulse.

5. The method according to claim 4, wherein: The process chamber pressure during the second precursor pulse is at least five times higher than the process chamber pressure during the first precursor pulse.

6. The method according to claim 5, wherein: The process chamber pressure during the second precursor pulse is at least ten times higher than the process chamber pressure during the first precursor pulse.

7. The method according to any one of claims 2 to 6, wherein: The first precursor pulse includes providing a precursor gas of the material, and the second precursor pulse includes providing an oxygen-containing precursor gas or providing a nitrogen-containing precursor gas.

8. The method according to any one of claims 1 to 7, wherein: The process chamber pressure of the precursor gas of the material is in a range of about 0.1 Torr to about 5.0 Torr.

9. The method according to any one of claims 1 to 8, wherein: The process chamber pressure for each intervening purge pulse is in a range from about 0.1 Torr to about 1.0 Torr.

10. The method according to any one of claims 2 to 9, wherein: At least one of the first precursor pulse and the second precursor pulse has a duration of 1 second to 5 minutes.

11. The method according to any one of claims 7 to 10, wherein: The precursor gas of the material includes a transition metal.

12. The method according to claim 11, wherein: The precursor gas of the material includes vapor of a transition metal chloride.

13. The method according to claim 11 or 12, wherein: The precursor gas of the material includes vapors of HfCl4, TaCl5, TiCl4, MoCl5, MoO2Cl2, and VCl4.

14. The method according to any one of claims 7 to 10, wherein: The precursor gas of the material includes a Group III element or a Group IV element.

15. The method according to claim 14, wherein: The precursor gas of the material includes Al(CH3)3 or AlCl3.

16. The method according to claim 14, wherein: The precursor gas of the material includes a Si-containing gas.

17. The method according to claim 16, wherein: The Si-containing gas is silicon halide.

18. The method according to claim 17, wherein: The precursor gas of the material includes octachlorotrisilane, hexachlorodisilane or silicon tetrachloride.

19. The method according to any one of claims 1 to 18, wherein: The atomic layer deposition is performed at a temperature below 700°C.

20. The method according to any one of claims 1 to 19, wherein: The method further includes, after performing the plurality of deposition cycles, performing at least one of an in-situ and an ex-situ thermal treatment process, the thermal treatment process being performed in an environment including at least one of O 3 , O 2 , H 2 O, and N 2 .

21. The method according to claim 19 or 20, wherein: The atomic layer deposition is performed at a temperature in the range of 200° C. to 450° C., and wherein a precursor gas of the material includes Al(CH 3 ) 3 .

22. The method according to claim 21, wherein: The thermal treatment process is performed in-situ at a temperature ranging from 450° C. to 1000° C. and a process chamber pressure ranging from 0.1 Torr to 10 Torr for a duration ranging from 15 minutes to 5 hours.

23. The method according to claim 21, wherein: The heat treatment process is performed ex situ at a temperature of about 1000° C. for a duration ranging from 1 minute to 5 minutes.

24. The method according to any one of claims 20 to 23, wherein: The method further includes repeatedly performing the plurality of deposition cycles and performing at least one of the in-situ and ex-situ thermal treatment processes.

25. The method according to any one of claims 1 to 24, wherein: The one or more substrates are a plurality of substrates arranged in a substrate carrier extending in a longitudinal direction, and the substrate carrier is receivable in the process chamber.

26. A substrate processing system comprising an atomic layer deposition apparatus, wherein the atomic layer deposition apparatus comprises: - a processing chamber configured to form a layer on one or more substrates, - a heater configured to heat and maintain a process temperature in the process chamber, - a pressure controller configured to obtain and maintain a process pressure in the process chamber, - at least two precursor storage modules, - A controller configured to execute instructions stored in a non-transitory computer readable medium and cause an atomic layer deposition apparatus to form a material layer on one or more substrates according to a method according to any one of claims 1 to 25.

27. The substrate processing system according to claim 26, wherein: The atomic layer deposition equipment is a vertical furnace batch atomic layer deposition equipment.

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