Fast flushing and cleaning during atomic layer deposition

Abstract

Provided herein are methods and related apparatus for purging a process chamber during an atomic layer deposition (ALD) process. The method involves flowing a purge gas from one or more gas reservoirs to remove the process gas from the process chamber. After the purge gas flows, additional reactants may be introduced into the process chamber to continue the ALD cycle.

Description

[0001] Incorporated by Reference

[0002] The PCT application form is filed concurrently with this specification as a part of this application. Each application to which this application claims the benefit or priority as identified in the concurrently filed PCT application form is incorporated herein by reference in its entirety and for all purposes. Background Art

[0003] Tungsten (W) film deposition using atomic layer deposition (ALD) technology is an integral part of the semiconductor manufacturing process. For example, tungsten films can be used as low-resistivity electrical connections in the form of horizontal interconnects, vias between adjacent metal layers, and contacts between the first metal layer and devices on the silicon substrate. Tungsten films can also be used in various memory applications and logic applications, including embedded word line (bWL) structures for dynamic random access memory (DRAM) and the formation of word lines for 3D NAND. However, the continued reduction in feature size and film thickness has brought various challenges, including the deposition of void-free and low-stress films.

[0004] The background description provided here is for the purpose of generally presenting the context of the present disclosure. The work of the presently designated inventors is neither explicitly nor implicitly admitted to be prior art against the present disclosure to the extent that it is described in this background section and in aspects of the specification that were not determined to be prior art at the time the application was filed. Summary of the invention

[0005] Atomic layer deposition (ALD) methods including rapid purges of reactant gases are disclosed herein. During an ALD cycle, reactant gas doses flow sequentially into a chamber to react on a substrate surface. Successive reactant gas doses are separated by purge operations, in which an inert gas flows through the chamber to remove residual reactant gas from the previous dose. Rapid purge purge uses two or more gas reservoirs to flow pressurized purge gas sequentially into the chamber during a single purge operation. Rapid purge purge increases the overall mass flow rate, reduces purge time, and improves throughput. For ALD of films such as tungsten, rapid purge purge can improve the material properties of the deposited film.

[0006] In one aspect of the embodiments herein, a method is disclosed, the method comprising: providing a semiconductor substrate to a chamber having a chamber pressure of less than 100 Torr, wherein the semiconductor substrate comprises a partially fabricated three-dimensional (3-D) NAND structure comprising sidewalls and a plurality of openings in the sidewalls leading to a plurality of features, the features having a plurality of interior regions accessible by fluid through the openings; depositing material on the semiconductor substrate through a plurality of ALD cycles, wherein each cycle comprises sequentially flowing a reducing agent; a first sweep gas; a tungsten precursor; and a second sweep gas into the chamber; and wherein flowing the first sweep gas and the second sweep gas comprises flowing the sweep gas from a first reservoir having a first charge pressure, followed by flowing the sweep gas from a second reservoir having a second charge pressure within 5 seconds of flowing the sweep gas from the first reservoir, the first charge pressure and the second charge pressure being between about 400 Torr and about 1000 Torr.

[0007] In another aspect of the embodiments herein, a method is disclosed, the method comprising: providing a semiconductor substrate to a chamber having a chamber pressure; depositing material on the semiconductor substrate through multiple ALD cycles, wherein each cycle comprises flowing reactants; and a purge gas into the chamber in sequence; wherein flowing the purge gas comprises flowing the purge gas from a first reservoir having a first boost pressure, and subsequently flowing the purge gas from a second reservoir having a second fill pressure.

[0008] In some embodiments, the first boost pressure and the second boost pressure are at least twice the chamber pressure. In various embodiments, the chamber pressure before flowing the sweep gas or the second sweep gas is less than about 100 Torr. In some embodiments, the first boost pressure and the second boost pressure are between about 400 Torr and about 1000 Torr.

[0009] In various implementations, the sweep gas is helium, nitrogen, argon, or xenon. In some embodiments, the reactant includes a reducing agent. In certain embodiments, the reducing agent is B 2 H 6 、SiH 4 or H 2 In some embodiments, the reactant comprises a metal precursor. In some embodiments, the metal precursor is a metal halide. In various implementations, the metal precursor is a metal oxyhalide. In certain embodiments, the metal precursor is a tungsten precursor. In various embodiments, the tungsten precursor is tungsten hexafluoride (WF 6 ), tungsten hexachloride (WCl 6 ), tungsten pentachloride (WCl 5 ), tungsten tetrachloride (WCl4 ), tungsten dichloride (WCl 2 ), tungsten oxychloride (WOCl 4 ) or tungsten dioxide dichloride (WO 2 Cl 2 )

[0010] In some embodiments, the metal precursor is a molybdenum precursor. In certain embodiments, the molybdenum precursor is one of: molybdenum pentachloride (MoCl 5 ), molybdenum hexafluoride (MoF 6 ), molybdenum dioxide and dichloride (MoO 2 Cl 2 ), molybdenum oxychloride (MoOCl4) and molybdenum oxychloride (MoOF 4 ).

[0011] In various implementations, flowing the purge gas is a choked flow. In some implementations, flowing the purge gas from the first accumulator is at least partially a choked flow. In certain embodiments, flowing the purge gas from the second accumulator occurs during the choked flow portion of flowing the purge gas from the first accumulator. In some embodiments, flowing the purge gas from the second accumulator occurs less than 5 seconds after flowing the purge gas from the first accumulator.

[0012] In various embodiments, the semiconductor substrate includes a partially fabricated three-dimensional (3-D) NAND structure including sidewalls and a plurality of openings in the sidewalls leading to a plurality of features having a plurality of interior regions fluidly accessible through the openings.

[0013] These and other features of the disclosed embodiments will be described in detail below with reference to the associated drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A flow chart of the operation of an exemplary embodiment is presented.

[0015] Figure 2A and 2B A pressure-time graph of the disclosed embodiments is presented.

[0016] Figures 3A-3C Diagrams of 3D NAND structures that may be populated using embodiments of the methods described herein are presented.

[0017] Figure 4A and 4B A flow chart of the operation of an exemplary embodiment is presented.

[0018] Figure 5 is a diagram of the fluid connections of an exemplary embodiment.

[0019] Figure 6 and Figure 7 is a schematic diagram of an example of a processing chamber for performing methods according to disclosed embodiments. DETAILED DESCRIPTION

[0020] In the following description, numerous specific details are set forth to provide a thorough understanding of the embodiments presented. The embodiments disclosed herein may be practiced without some or all of these specific details. In other instances, well-known processing operations are not described in detail to avoid unnecessarily obscuring the disclosed embodiments. In addition, while the disclosed embodiments will be described in conjunction with specific embodiments, it should be understood that the specific embodiments are not intended to limit the disclosed embodiments.

[0021] Described herein are methods of atomic layer deposition (ALD) and related systems and devices. Examples of applications include logic and memory contact filling, DRAM buried word line filling, vertical integrated memory gate / word line filling, and 3-D integration with through silicon vias (TSVs). In some embodiments, the method can be used for tungsten feature filling. Such features can include vertical features, such as vias, and horizontal features, such as vertical NAND (VNAND) word lines.

[0022] Atomic layer deposition (ALD) methods including rapid purge of reactant gases are disclosed herein. During an ALD cycle, reactant gas doses flow sequentially into a chamber to react on a substrate surface. Successive reactant gas doses are separated by a purge operation, in which an inert gas flows through the chamber to remove the remaining reactant gas of the previous dose. Rapid purge purge uses two or more gas reservoirs to cause pressurized purge gas to flow sequentially into the chamber during a single purge operation. In some embodiments, one or more of the following advantages can be achieved. In some embodiments, the total mass flow rate increases, which can result in reduced purge time and increased throughput. In some embodiments, the internal stress of the deposited film is reduced. In some embodiments, impurities in the deposited film are reduced.

[0023] ALD is a technique for depositing thin layers of material using continuous self-limiting reactions. The concept of "ALD cycle" is relevant to the discussion of various embodiments herein. Typically, an ALD cycle is a minimum set of operations for performing a surface deposition reaction. The result of a cycle is the production of at least a portion of a film layer on a substrate surface. Typically, an ALD cycle includes the operation of delivering and adsorbing at least one reactant to a substrate surface, and then reacting the adsorbed reactant with one or more reactants to form a portion of the film layer. In the method described herein, the cycle also includes at least one rapid rinse sweep as further described below. Typically, a cycle contains an instance of a unique sequence of operations. For example, an ALD cycle may include the following operations: (i) delivering / adsorbing reactant A, (ii) sweeping reactant A from a chamber, (iii) delivering reactant B, and (iv) sweeping reactant B from a reaction chamber.

[0024] Figure 1 1 is a process flow chart of the steps of the method according to various embodiments. The cycles and exposure times described herein may depend on the device and platform used, and those of ordinary skill in the art may adjust the cycles and exposure times accordingly. In operation 102, reactant A is introduced into the processing chamber. For the deposition of the conductive film, reactant A may be a metal-containing precursor or a reducing agent or other co-reactant. Although the following description mainly describes thermal atomic layer deposition (ALD) of metals, these methods may also be implemented to deposit any material by thermal ALD.

[0025] After operation 102, the processing chamber is cleaned by a rapid rinse sweep in operation 104. Typically, sweeping removes gas phase reactants from the processing chamber and typically occurs only after the delivery of such reactants is completed. In other words, the reactant is no longer delivered to the reaction chamber during the sweep. However, during the sweeping process, the reactant is still adsorbed on the substrate surface. Typically, after the reactant is adsorbed on the substrate surface to a desired level, sweeping is used to remove any residual gas phase reactants in the chamber. Sweeping can also remove weakly adsorbed substances (e.g., certain precursor ligands or reaction byproducts) from the substrate surface. In ALD, sweeping can prevent the gas phase interaction of two reactants or the interaction of a reactant with thermal or other driving forces to perform surface reactions. Sweeping can also make the volume of the fluid flowing through the chamber several times the volume of the chamber to reduce the amount of residual gas phase reactants remaining in the chamber. The sweeping stage described herein includes flowing an inert gas such as argon (Ar), xenon (Xe), helium (He) or nitrogen (N) into the processing chamber. The rapid rinse sweep is further explained below.

[0026] In operation 106, reactant B is introduced into the chamber. Reactant B can be, for example, a metal-containing precursor, or a reducing agent or other co-reactant. Reactant B can react with the adsorbed species of reactant A to form at least one sub-monolayer film. Reactant B and the adsorbed species of reactant A can also produce gas-phase products.

[0027] After operation 106, the process chamber is purged by a rapid purge in operation 108. Similar to operation 104, the purge removes gas phase reactant B and any gas phase products resulting from the reaction of reactant B with adsorbed reactant A from the process chamber by flowing an inert gas (e.g., argon) into the process chamber.

[0028] The result of operations 102-108 is the formation of at least one sub-monolayer film. For example, a tungsten film can be formed. Operations 102-108 include a single ALD cycle and can be repeated one or more times to increase the thickness of the film. Each ALD cycle deposits additional material to form a substantially uniform film layer. In some embodiments, the film composition may include undesirable compounds, such as fluorine. The presence of undesirable chemicals in the film may affect the properties of the film, such as resistivity.

[0029] exist Figure 1 In some embodiments, only one of operations 104 and 108 is a fast purge, and the other is a purge by a different method (e.g., continuous flow or using a single accumulator). In some embodiments, a fast purge may be used for a single reactant ALD cycle, where operations 102 and 104 are repeated using a single reactant and a single purge operation.

[0030] Figure 2A and 2B represents the pressure of the volume in one or more accumulators as a function of time for two different ways of performing a sweeping operation. Figure 2A In FIG. 2 , a gas reservoir 200 is used to build up a pressurized volume of purge gas, which is then flowed into the process chamber. The gas reservoir 200 has an initial pressure 202, which serves as a baseline pressure for the gas reservoir. A slope 204 shows the increase in volume pressure in the gas reservoir 200 as the purge gas is pressurized. Figure 2A, the accumulator reaches a maximum pressure of about 550 Torr before the purge gas flows into the chamber, but the pressure in the accumulator can vary from about 400 Torr to about 1000 Torr. Then, at time 206, the purge gas flows into the chamber, and the pressure decreases rapidly as the purge gas flows out of the accumulator 200. The decrease in pressure of the accumulator 200 corresponds to an increase in the flow rate of the purge gas into the chamber. As the purge volume flows into the chamber, the pressure in the accumulator 200 returns to the baseline value 202. The accumulator can then increase in pressure and flow the purge gas into the chamber for a second purge step (not shown).

[0031] Figure 2B Indicates rapid flushing and sweeping. The first gas reservoir 210 and the second gas reservoir 211 are used to allow the sweeping gas to flow into the chamber. Similar to Figure 2A , both accumulators have a baseline pressure 212. Then, the first accumulator 210 is pressurized, as shown by slope 214. At time 216, the purge gas from the first accumulator flows into the chamber, causing the pressure in the first accumulator to decrease rapidly. The reduction in accumulator pressure corresponds to an increase in the mass flow rate of the purge gas entering the chamber. As the pressure in the first accumulator decreases, the mass flow rate of the purge gas entering the chamber will also decrease. Then, at time 217, the second accumulator 211 causes the purge gas to flow into the chamber. The second flow of pressurized purge gas increases the mass flow rate of the purge gas entering the chamber again. By using two accumulators, the average mass flow rate of the chamber entering increases, thereby increasing the removal rate of the reactant gas and reducing the total time required to purge the chamber. In some embodiments, an additional accumulator can be used to continuously maintain a high pressure flow of the purge gas entering the chamber, so that the purge gas flows out of any number of additional accumulators in a manner similar to the second accumulator. In some embodiments, during a single fast flush purge operation, each reservoir is pressurized and purge gas flows into the chamber multiple times, for example, the first reservoir flows purge gas into the chamber two or more times during a single purge operation. In some embodiments, additional reservoirs or repeated flows from the same reservoir can be used for large chambers, or where the volume of each reservoir is less than 300cc. As described above, the pressure in the first and second reservoirs is about 550 Torr, but in various embodiments, the pressure can vary from about 400 Torr to about 1000 Torr. The pressure between the first and second reservoirs can also vary, with the first reservoir having a pressure between about 400 Torr and about 1000 Torr, and the second reservoir having a different pressure between about 400 Torr and about 1000 Torr.

[0032] The timing of the purge gas flowing out of the first and second accumulators may vary depending on the implementation. In some embodiments, the second accumulator flows before the pressure of the first accumulator returns to the baseline 212. In other embodiments, the second accumulator may flow when the first accumulator returns to the baseline pressure or after the first accumulator has returned to the baseline pressure. In some embodiments, the second accumulator flows only after the first accumulator, regardless of the pressure of the first accumulator. In some embodiments, the second accumulator flows within 5 seconds, 3 seconds, 1 second, 0.5 seconds, or 0.1 seconds of the first accumulator flowing.

[0033] The purge gas flow from the accumulator may be a choked flow. Choked flow occurs if the pressure ratio between the high pressure environment and the low pressure environment is large enough. The velocity of the fluid flow does not increase with further reduction of the pressure in the low pressure environment, and the flow is considered to be choked. The minimum pressure ratio for choked flow depends on the specific gas used, but is typically about 2:1. Choked flow can be modeled using only the conditions of the high pressure environment, including temperature, pressure, and gas density, which may be ideal when the parameters of the low pressure environment are unknown or vary. Specifically, when purging a process chamber, choked flow is relevant as a factor in reducing the time required to fully purge the process chamber.

[0034] During ALD processing, exemplary chamber pressure ranges are about 3 Torr to 100 Torr, about 3 Torr to 40 Torr, or about 3 Torr to 10 Torr. Meanwhile, the pressure of the gas reservoir used for the purge step can be about 400 Torr to 1000 Torr. Therefore, the initial flow of the purge gas from the gas reservoir into the chamber is typically blocked. However, if the purge gas from the gas reservoir is Figure 2B As can be seen in Figure 1, the pressure in the accumulator will decay rapidly. As the pressure ratio between the accumulator and the process chamber decreases, the flow may become unobstructed. This will reduce the velocity and mass flow of the purge gas entering the chamber, thereby increasing the time required for purge. Figure 2B As shown, by flowing the purge gas from the second accumulator 211, the flow will remain blocked and the chamber will require less time to purge. The time to flow the purge gas from the second accumulator may vary between embodiments, where in some embodiments, the purge gas from the second accumulator flows while the purge gas flow into the chamber is blocked. In other embodiments, the purge gas from the second accumulator may flow after the purge gas flow into the chamber stops being blocked. In this case, the purge gas flow from the second accumulator may cause the purge gas flow into the chamber to be blocked.

[0035] According to various embodiments, use of a fast rinse sweep can result in deposited materials with lower stress, lower impurity (e.g., fluorine) content, reduced cycle time for deposition, and improved sweep efficiency. For example, when filling complex features such as word lines of a 3D NAND structure, a fast rinse sweep can maintain fill quality while reducing cycle time and improving film properties.

[0036] Figure 3A A schematic example of word lines 310 in a 3D NAND structure 323 formed on a substrate 300 is depicted. The word lines 310 are separated by oxide layers 311. Figure 3B A cross-sectional side view of a partially fabricated 3-D NAND structure 333 is presented and illustrates the challenges of metal filling. The structure 330 is formed on a semiconductor substrate 300 and includes a 3D NAND stack (left 325 and right 326), a central vertical structure 330, and a plurality of stacked word line structures 320 having openings 322 on opposite sidewalls 340 of the central vertical structure 330. Note that Figure 3B Two stacks 325 and 326 of a partially fabricated 3-D NAND structure 333 are shown, which together form a trench-shaped central vertical structure 330. However, in some embodiments, there may be more than two stacks arranged in sequence and extending parallel to each other in space, with the gap between each adjacent pair of stacks forming a central vertical structure 330, similar to Figure 3B In Figure 3B In the example of FIG. 3 , word line features 320 can be fluidly accessed from central vertical structure 330 through opening 322. Although not explicitly indicated in the figure, Figure 3B The horizontal features 320 present in both the 3-D NAND stacks 325 and 326 (i.e., the left 3-D NAND stack 325 and the right 3-D NAND stack 326) shown in the figure can also be accessed from the other sides of the stack (the leftmost and rightmost sides, respectively) through similar vertical structures formed by other 3-D NAND stacks (located at the far left and rightmost sides, but not shown). In other words, each 3-D NAND stack 325, 326 contains a stack of word line features that can be fluidly accessed from both sides of the 3-D NAND stack through the central vertical structure 330.

[0037] The wordline features in the 3-D NAND stack may be formed by depositing a stack of alternating silicon oxide and silicon nitride layers, and then selectively removing the nitride layers, leaving a stack of oxide layers 311 with gaps between them. These gaps are wordline features 320. Any number of wordlines may be stacked vertically in such a 3-D NAND structure, provided there are techniques available to form the wordlines, and techniques available for any wordline that successfully accomplish substantially gap-free fill of the vertical features. Thus, for example, a 3D-NAND stack may include between 2 and 256 horizontal wordline features, or between 8 and 128 horizontal wordline features, or between 16 and 64 horizontal wordline features, and so forth (the listed ranges being understood to include the stated endpoints).

[0038] Figure 3C Shown in Figure 3B A cross-sectional top view of the same 3-D NAND structure shown in FIG. Figure 3B The horizontal portion 360 shown by the horizontal dotted line in FIG. Figure 3B The cross section of FIG. 3 shows several rows of pillars 355 extending vertically from the base of the semiconductor substrate 300 to the top of the 3-D NAND stack. In some embodiments, these pillars 355 are made of polysilicon material and are structurally and functionally important to the 3-D NAND structure 333. In some embodiments, such polysilicon pillars can be used as gate electrodes for stacked memory cells formed within the pillars. Figure 3C The top view of FIG. 35 shows that pillar 355 forms a constriction in opening 322 of word line feature 320, ie, the fluid accessibility of word line feature 320 from central vertical structure 330 via opening 322 (eg, Figure 3C ) is inhibited by pillars 355. In some embodiments, the horizontal gap between adjacent polysilicon pillars has a size between about 1 and 20 nm. The reduction in fluid accessibility increases the difficulty of uniformly filling word line features 320 with conductive material.

[0039] Figure 4A-4B Describes methods by which 3D NAND structures can be filled with metal. First, turn to Figure 4A ,implement Figure 4A The operations 402-410 are performed to deposit the nucleation layer by ALD. In some embodiments described herein, the operations 402-410 are performed at a lower pressure than the subsequent bulk deposition in operation 480. For example, the operations 402-410 can be performed at a low pressure of less than about 10 Torr. In some examples, the operations 402-410 are performed at a pressure of about 10 Torr or a pressure of about 3 Torr.

[0040] In operation 402, the substrate is exposed to a metal-containing precursor. This operation may be referred to as a "pulse" or a "dose," which are used interchangeably herein. The metal-containing precursor contains a metal that will be the major component of the nucleation layer and, in many embodiments (although not necessarily), the major component of the subsequently deposited bulk layer.

[0041] Examples of the nucleation layer include a tungsten-containing nucleation layer and a molybdenum-containing nucleation layer, which use a tungsten-containing precursor and a molybdenum-containing precursor, respectively. Examples of the tungsten-containing precursor include tungsten halides and tungsten oxyhalides. Examples of tungsten halides include tungsten hexafluoride (WF 6 ), tungsten chloride (WClx), including tungsten hexachloride (WCl 6 ), tungsten pentachloride (WCl 5 ), tungsten tetrachloride (WCl 4 ), tungsten dichloride (WCl 2 ), and tungsten oxychloride (WO x Cl y ), such as tungsten oxychloride (WOCl 4 ) and tungsten dioxide dichloride (WO 2 Cl 2 ). Further examples include tungsten hexacarbonyl W(CO) 6 and organic tungsten precursors such as MDNOW (methylcyclopentadienyl-dicarbonylnitrosyl-tungsten) and EDNOW (ethylcyclopentadienyl-dicarbonylnitrosyl-tungsten).

[0042] Examples of molybdenum-containing precursors include molybdenum halides and molybdenum oxyhalides. Examples of molybdenum halides include molybdenum pentachloride (MoCl 5 ) and molybdenum hexafluoride (MoF 6 Examples of molybdenum oxyhalides include molybdenum dioxide dichloride (MoO 2 Cl 2 ), molybdenum oxychloride (MoOCl 4 ) and molybdenum oxychloride (MoOF 4 ).

[0043] The metal-containing precursor may include a combination of these compounds. In some embodiments, a carrier gas, such as nitrogen (N 2 ), argon (Ar), helium (He) or other inert gas flows.

[0044] Operation 402 can be performed for any suitable duration and at any suitable temperature. In some examples, operation 402 can be performed for a duration between about 0.25 seconds to about 30 seconds, about 0.25 seconds to about 5 seconds, or about 0.5 seconds to about 3 seconds. In some embodiments, the operation can be performed for a duration sufficient to saturate the active sites on the substrate surface.

[0045] In operation 404, the chamber is purged to remove excess precursor that is not adsorbed to the substrate surface. As described above, purging can be performed as a fast flush purge utilizing two or more gas accumulators. Purge gas may flow into the chamber from a first gas accumulator having a pressure higher than the chamber pressure, and then additional purge gas may flow into the chamber from a second gas accumulator. Operation 404 may be performed for any suitable duration. Exemplary durations include between about 0.5 seconds and about 25 seconds or between about 0.5 seconds and about 5 seconds. Purge gas from the second gas accumulator may flow about 2 seconds, about 1 second, or about 0.5 seconds after the purge gas flows out of the first gas accumulator. After the purge gas flows out of each gas accumulator, the chamber may be re-pressurized.

[0046] In operation 406, the substrate is exposed to a co-reactant to deposit a nucleation layer. In some embodiments, the co-reactant is a reducing agent, such as hydrogen (H 2 ), borane, silane or germane. Exemplary boranes include borane (BH 3 ), diborane (B 2 H 6 ), triborane, alkylborane, aminoborane, carborane and haloborane. Exemplary silanes include silane (SiH 4 ), disilane (Si 2 H 6 ), trisilane (Si 3 H 8 ), alkylsilanes, aminosilanes, carbosilanes and halogenated silanes. Germanes include Ge n H n+4 ,Ge n H n+6 ,Ge n H n+8 and Ge n H m , where n is an integer from 1 to 10, and n is an integer different from m. Other germanes, such as alkylgermanes, aminogermanes, carbogermanes, and halogenated germanes, may also be used. In general, halogenated germanium may not have significant reduction potential, but there may be processing conditions and precursors suitable for forming films using halogenated germanium.

[0047] In some embodiments, a metal halide or metal oxyhalide precursor and a nitrogen-containing reducing agent such as ammonia (NH 3 ) deposits an amorphous nucleation layer. Such a nucleation layer is described in U.S. Provisional Patent Application No. 62 / 797,860 filed on January 28, 2019, and can be characterized as a metal oxynitride or metal nitride nucleation layer. The metal oxynitride or metal nitride nucleation layer can be converted to a metal layer in subsequent processing (including during deposition of the bulk layer).

[0048] Operation 406 may be performed for any suitable duration. Exemplary durations include between about 0.25 seconds to about 30 seconds, about 0.25 seconds to about 5 seconds, or about 0.5 seconds to about 3 seconds. In some embodiments, this operation may be sufficient to react with the adsorbed layer of metal-containing precursor on the substrate surface. Operation 406 may be performed for durations outside of these example ranges. In some embodiments, a carrier gas such as argon (Ar), helium (He), or nitrogen (N 2 ).

[0049] After operation 408, there is a sweeping step to sweep the excess co-reactants that are still in the gas phase that are not reacted with the metal-containing precursor on the surface of the feature. As mentioned above, sweeping can be performed as a fast flushing sweep utilizing two or more gas accumulators. Purge gas can flow into the chamber from the first gas accumulator having a pressure higher than the chamber pressure, and then additional purge gas is made to flow into the chamber from the second gas accumulator. Operation 404 can perform any suitable duration. Exemplary duration is included between about 0.5 seconds and about 25 seconds or between about 0.5 seconds and about 5 seconds. Purge gas from the second gas accumulator can flow in about 2 seconds, about 1 second or about 0.5 seconds after purge gas flows out from the first gas accumulator. After purge gas flows out from each gas accumulator, the chamber can be re-pressurized.

[0050] Each repetition of operations 402-408 may be referred to as an ALD cycle. It should be understood that the order of operations 402 and 406 may be reversed so that the co-reactant is introduced first in a particular cycle while sweeping optionally separates the metal-containing precursor and co-reactant doses. In operation 410, it is determined whether the nucleation layer has been deposited to a sufficient thickness or a preset number of cycles. If not, operations 402-408 are repeated.

[0051] After the nucleation layer is deposited to a sufficient thickness, in operation 480, the bulk metal is deposited as described below. In various embodiments, operation 480 can be performed at a pressure greater than the pressure during operations 402-410. For example, operation 480 can be performed at a pressure greater than or equal to about 3 Torr, such as about 10 Torr, about 40 Torr, or about 100 Torr. In some embodiments, the pressure during the deposition of the nucleation layer and the bulk layer can be about 3-40 Torr, or 10 Torr. In other embodiments, the same pressure can be used in operation 480 and / or a lower pressure can be used.

[0052] Figure 4B A process flow diagram of the operations that may be performed during operation 480 is provided. Note that the Figure 4A Execute in case of operation Figure 4B That is, in some embodiments, the operation can be performed without first depositing a nucleation layer. Figure 4B method.

[0053] exist Figure 4B In operation 482, the substrate is exposed to a co-reactant. In some embodiments, this is a reducing agent such as H 2 , which can be pulsed without flowing another reactant. Although the co-reactant pulse is described as the first pulse in the cycle defined by operations 482-488, in some embodiments, the order of operations 482 and 486 can be reversed so that the metal-containing precursor can be first. Operation 482 can involve H 2 The molecules adsorb on the surface and / or react with metal-containing precursor molecules to form a monolayer or sub-monolayer film.

[0054] In some embodiments, a carrier gas may be flowed. The carrier gas may be Figure 4A Any of those described in operation 404 of . Operation 482 can be performed for any suitable duration. In some examples, exemplary durations include between about 0.25 seconds to about 30 seconds, about 0.25 seconds to about 5 seconds, or about 0.5 seconds to about 3 seconds.

[0055] return Figure 4B , in operation 484, the chamber is purged. This purging operation can remove excess co-reactants remaining in the gas phase. As described above, purging can be performed by rapid flushing purging, and then the chamber is re-pressurized before starting another gas exposure. The chamber can be purged of any suitable duration, such as a duration between about 0.1 seconds and about 3 seconds. In operation 486, the substrate is exposed to a metal-containing precursor. This can form a sub-monolayer or monolayer film on the substrate. In various embodiments, the metal-containing precursor flows into the chamber during this operation for a duration between about 0.1 seconds and about 3 seconds or about 0.5 seconds. In some embodiments, the metal-containing precursor can be turned to fill gas lines and pipeline changes before batching.

[0056] Examples of metal precursors include WF 6 , WCl x , which includes WCl 6 、WCl 5 、WCl 4 、WCl 2 and WO x Cl y , such as WOCl 4 and WO 2 Cl 2 Other examples include W(CO) 6 and MDNOW and EDNOW. Other examples include molybdenum-containing precursors such as molybdenum halides and molybdenum oxyhalides. Examples of molybdenum halides include MoCl 5 and MoCl 6Examples of molybdenum oxyhalides include MoO 2 Cl 2 and MoOCl 4 .

[0057] exist Figure 4B In operation 488, the chamber is purged to remove the byproducts of the reaction and the gas-phase metal-containing precursor from the chamber. The purge can be a fast flush purge as described above. In some embodiments, the purge duration is between about 0.1 seconds and about 2 seconds.

[0058] exist Figure 4B In operation 490, it is determined whether the main metal has been deposited to a sufficient thickness or whether a preset number of cycles have been completed. If not, operations 482-488 are repeated until the desired thickness is deposited. In some embodiments, operations 482-488 are repeated until the feature is filled.

[0059] The metal-containing precursor used in operation 480 can be the same or different from the precursor used for nucleation layer deposition. If different, it can contain the same or different metals, for example, in some embodiments, a tungsten bulk layer can be deposited on a tungsten nucleation layer or in some embodiments, on a molybdenum nucleation layer.

[0060] Example

[0061] The following example is provided to further illustrate aspects of various embodiments. This example is provided to illustrate and more clearly illustrate various aspects and is not intended to be limiting. The following table illustrates various aspects of ALD tungsten deposition using embodiments disclosed herein.

[0062] Tables 1 and 2 below are timing diagrams for depositing a tungsten nucleation layer without and with a fast purge, respectively. Divert indicates that the reactants flow somewhere outside the chamber, such as a low pressure vessel. LC stands for line charge, which refers to the buildup of pressure in the reservoir that provides gas to the chamber. In some embodiments, each gas, including the reactants and the purge gas, has its own reservoir. Dosage indicates the reactant diborane / silane or WF 6 Flowing into the reaction chamber. Sweeping means that a sweep gas flows into the chamber. Vertically aligned processing means that two operations occur simultaneously.

[0063] The total time for a single ALD cycle for a nucleation layer without a fast rinse sweep is 54 seconds, of which 39 seconds include sweeping the chamber. In comparison, a single ALD cycle with a fast rinse sweep as described herein takes 25 seconds, which is a 54% improvement in cycle time for depositing a sub-monolayer. Each ALD cycle takes only 10 seconds with a fast rinse sweep, a significant improvement over not using a fast rinse sweep.

[0064]

[0065] Table 1: Timing diagram of tungsten deposition without fast rinse sweep.

[0066]

[0067]

[0068] Table 2: Timing diagram for tungsten deposition using fast rinse sweep.

[0069] Table 3 is a flow chart of an embodiment in which fast flushing scavenging involves flowing scavenging gas from two accumulators multiple times during a single scavenging operation. 2 Dose or WF 6 After the dose, the purge gas may flow from the first accumulator, followed by the second accumulator, and then again from the first accumulator and the second accumulator. Each accumulator may be used to provide a dose of the purge gas multiple times before the next reactant flows into the chamber. In some embodiments, the accumulators are cycled to repeatedly flow the purge gas into the chamber. In some embodiments, the purge gas flows out of one accumulator n times and the purge gas flows out of another accumulator m times, where n may be equal to or not equal to m.

[0070]

[0071] Table 3: Flowchart for tungsten deposition with rapid flush sweep using multiple doses from each reservoir.

[0072] Table 4 shows a comparison of material properties of tungsten where the nucleation layer was deposited with and without a fast purge. The time for each deposition process was the same as shown in Tables 1 and 2 above. In both nucleation deposition processes, different reservoirs with each reactant gas were also used to pressurize the reactant gases. The nucleation layer deposition was different for the fast purge and non-fast purge processes, while the bulk layer deposition processes were the same for both and no fast purge was used. Argon was used as the purge gas. The ALD cycle for the nucleation layer was repeated 5 times, while the bulk layer deposition cycle was repeated 1200 times. As shown in the table, tungsten deposited using a fast purge resulted in reduced resistivity, increased stress, and increased thickness, all of which resulted in a reduced deposition time range. Ar1 and Ar2 refer to flowing gas from the first or second reservoir, respectively.

[0073]

[0074]

[0075] Table 4: Processing conditions and material properties of deposited films where the nucleation process was varied while the bulk process remained constant.

[0076] Table 5 shows a comparison of the material properties of deposited tungsten, where the nucleation layer treatment remained the same, but the bulk layer treatment was changed as shown. The 0.9 second fast flush bulk ALD process used a fast flush purge after hydrogen flowed into the process chamber, while the 1.1 second fast flush purge used a fast flush purge after hydrogen flowed into the process chamber and the tungsten precursor flowed into the process chamber. Ar1 and Ar2 refer to the first and second gas reservoirs, respectively. Each ALD cycle of the bulk treatment required 0.77 seconds, 0.9 seconds, or 1.1 seconds per cycle. The resulting stress, fluorine content, and void percentage of each film showed that the use of the fast flush treatment as described herein reduced each of those properties of the deposited films, all of which are desirable.

[0077]

[0078] Table 5: Processing conditions and material properties of deposited films where bulk processing was varied and nucleation processing remained constant

[0079] Device

[0080] Any suitable chamber may be used to implement the disclosed embodiments. Exemplary deposition apparatus include various systems such as and Max, available from Lam Research Corp. of Fremont, California, or any of a variety of other commercially available processing systems. In some embodiments, atomic layer deposition (ALD) can be performed at a first station, which is one of two, five, or even more deposition stations located in a single deposition chamber. Thus, for example, hydrogen (H 2 ) and tungsten hexafluoride (WF 6 ) or other metal-containing precursors can be introduced to the surface of the semiconductor substrate at the first station in alternating pulses using a separate gas supply system that creates a local atmosphere at the surface of the semiconductor substrate. Another station can be used for tungsten bulk layer deposition. Two or more stations can be used to deposit tungsten in a parallel process. Alternatively, the wafer can be transposed to perform operations sequentially on two or more stations.

[0081] The apparatus may include a gas manifold system that provides line fill to various gas distribution lines, such as Figure 5 Manifold 504 has an input from a source 501 of a metal-containing precursor gas, which may include a gas reservoir (not shown). Manifold 511 has an input from hydrogen (H 2) or other reducing gas (not shown) source input 509, which may include a gas reservoir (not shown). As described above, there may or may not be an input from a carrier gas to manifold 511. Manifold 521 has an input from a first gas reservoir 519 and a second gas reservoir 520. The first gas reservoir 519 and the second gas reservoir 520 have an input 518 from an inert purge gas source. Manifolds 504, 511 and 521 provide metal-containing precursor gas, co-reactant gas and purge gas to the deposition chamber through valved distribution lines 505, 513 and 525, respectively. Various valves can be opened or closed to provide pipeline filling, that is, pressurizing the distribution lines. For example, in order to pressurize the distribution line 505, valve 506 is closed toward vacuum, and valve 508 is closed. After an appropriate time increment, valve 508 is opened and the co-flow gas is delivered to the chamber. After an appropriate time of delivering the gas, valve 508 is closed. The chamber may then be purged to vacuum by opening valve 506 toward vacuum.

[0082] A similar process is used for delivering reducing gas. To introduce reducing gas, for example, distribution line 513 is filled by closing valve 515 towards the vacuum and closing valve 517. Opening of valve 515 enables the delivery of reducing gas to the chamber.

[0083] Similarly, to introduce a purge gas, the distribution line 525 is filled by closing valve 527 and closing valve 523 toward the vacuum. The opening of valve 527 enables the delivery of argon or other inert purge gas to the chamber. Valves 528 and 530 can be opened or closed to introduce purge gas from inert purge gas source 518 into accumulators 519 and 520. The amount of time allowed for the line filling changes the amount and timing of the initial delivery of gas. Valves 530 and 531 can be opened or closed to introduce purge gas from accumulators 519 and 520, respectively. Opening valve 530 and / or valve 531 changes the amount and timing of the delivery of purge gas, as described above with reference to various embodiments.

[0084] Figure 5 A vacuum pump is also shown, where valves 506, 517 and 523 can be opened respectively to purge the system. The supply of gas through the various distribution lines is controlled by a controller (e.g., a mass flow controller) controlled by a microprocessor, digital signal processor, etc., which is programmed with flow rates, flow durations, and sequencing of treatments.

[0085] Note that the above process may require precise timing of valves and mass flow controllers (MFCs) that supply reagent pulses to the semiconductor substrate during deposition. In one way that this is possible, valve and MFC commands are delivered to an embedded digital input-output controller (IOC) in discrete packets containing instructions for all time-critical commands for all or part of a deposition sequence. Lam Research's ALTUS system provides at least one IOC sequence. The IOC can be physically located in various locations in the device, for example, within a processing module or on a separate power rack located at a certain distance from the processing module. There can be multiple IOCs in each module (for example, 3 IOCs per module). Regarding the actual instructions contained in the sequence, all commands for controlling valves and setting the flow of MFCs (for all carrier and reactive gases) can be contained in a single IOC sequence. This ensures that the timing of all equipment is strictly controlled from an absolute perspective as well as relative to each other. There are usually multiple IOC sequences running at any given time. For example, this enables ALD to be run at station 1-2, where all timing for all hardware components required to deposit the ALD nucleation layer on these workstations is controlled. A second sequence can be run simultaneously to deposit bulk metal at other deposition stations in the same module using a timing sequence as described above. Controlling the relative timing of the equipment delivering reagents to stations 3-4 is important in this group of equipment, but the relative timing of the ALD process at stations 1-2 can deviate from the relative timing of stations 3-4. The IOC converts the information in a packaged sequence and passes digital or analog command signals directly to the MFC or pneumatic solenoid group that controls the valve.

[0086] Pulses of metal-containing precursor gas may be generated as follows. Initially, the system will place WF 6 Transfer to the vacuum pump for a period of time. In one example, this can be done for a period of time between about 0.5 and 5 seconds. Next, the system pressurizes the tungsten gas delivery manifold by closing both valve 506 to the vacuum and valve 508 to the deposition chamber. For example, this can be done for a period of time between about 0.1 seconds and 5 seconds to generate an initial pulse of reagent when the valve to the deposition chamber is opened. In one example, this is achieved by opening valve 508 for about 0.1 to 10 seconds.

[0087] Thereafter, the tungsten-containing gas is purged from the deposition chamber using a suitable purge gas. Similar to the above, the system can pressurize the purge gas delivery manifold by closing valve 523 and valve 527. Valve 530 and valve 531 are also closed to enable accumulators 519 and 520 to be pressurized. For example, this can be performed for a period of time between about 0.1 and 5 seconds to quickly flush the reagent from the deposition chamber when the valve leading to the deposition chamber is open. When valve 527 leading to the deposition chamber is opened, valve 530 is opened at the same time or immediately thereafter to increase the mass flow rate of the purge gas flowing into the deposition chamber. Valve 531 is then opened between about 0.1 and 5 seconds after valve 530 is opened to increase the mass flow rate of the purge gas entering the deposition chamber. Pulsed flows of other reagents can be performed in a similar manner.

[0088] Figure 6 6 is a schematic diagram of a processing system suitable for performing deposition processing according to an embodiment. System 600 includes a transport module 603 that provides a clean, pressurized environment to minimize the risk of contamination of the processed substrate as it moves between the various reactor modules. According to various embodiments, a multi-station reactor 609 capable of performing ALD and CVD is mounted on the transport module 603. The multi-station reactor 609 can include a plurality of stations 611, 613, 615, and 617, which can perform operations sequentially according to the disclosed embodiments. For example, the multi-station reactor 609 can be configured so that station 611 performs nucleation layer deposition using a metal halide or a metal oxyhalide, and station 613 performs an ALD deposition operation according to various embodiments.

[0089] The station may include a heated pedestal or substrate support, one or more gas inlets or showerheads, or a dispersion plate. An example of a deposition station 700 is shown in FIG. Figure 7 , which includes a substrate support 702 and a showerhead 703. A heater may be disposed within the base portion 701.

[0090] Back to Figure 6 , which may also be mounted on the transfer module 503, are one or more single or multi-station modules 607 that can perform plasma or chemical (non-plasma) pre-cleaning, other deposition operations, or etching operations. The modules can also be used for a variety of processes, such as preparing substrates for deposition processes. The system 600 also includes one or more wafer source modules 601, where wafers are stored before and after processing. An atmospheric robot (not shown) in the atmospheric transfer chamber 619 can first move the wafer from the source module 601 to the load lock 621. The wafer transfer device (usually a robot arm unit) in the transfer module 603 moves the wafer from the load lock 621 to the modules mounted on the transfer module 603 and moves the wafer between these modules.

[0091] In various embodiments, a system controller 629 is used to control the process conditions during the deposition process. The controller 629 will typically include one or more memory devices and one or more processors. The processor may include a CPU or computer, analog and / or digital input / output connections, a stepper motor controller board, etc.

[0092] The controller 629 can control all deposition device activities. The system controller 629 runs system control software, which includes instruction sets for controlling timing, gas mixture, chamber pressure, chamber temperature, wafer temperature, radio frequency (RF) power level, wafer chuck or pedestal position, and other parameters of a particular process. In some embodiments, other computer programs stored on a memory device associated with the controller 629 may be used.

[0093] Typically, there will be a user interface associated with the controller 629. The user interface may include a display screen, a graphical software display of the device and / or processing conditions, and a user input device such as a pointing device, keyboard, touch screen, microphone, or the like.

[0094] The system control logic may be configured in any suitable manner. In general, the logic may be designed or configured in hardware and / or software. The instructions for controlling the drive circuit may be hard-coded or provided as software. The instructions may be provided by "programming". Such programming is understood to include any form of logic including hard-coded logic in digital signal processors, application specific integrated circuits, and other devices having specific algorithms implemented as hardware. Programming is also understood to include software or firmware instructions that can be executed on a general purpose processor. The system control software may be encoded in any suitable computer readable programming language.

[0095] The computer program code for controlling the reducing agent pulses, hydrogen flow, and metal-containing precursor pulses, inert gas flow, and other processes in the process sequence can be written in any conventional computer-readable programming language: for example, assembly language, C, C++, Pascal, Fortran, or others. The compiled object code or script is executed by the processor to perform the tasks identified in the program. As also indicated, the program code can be hard-coded.

[0096] Controller parameters relate to process conditions such as, for example, process gas composition and flow rate, temperature, pressure, cooling gas pressure, substrate temperature and chamber wall temperature. These parameters are provided to the user in the form of a recipe and can be input using a user interface.

[0097] Signals for monitoring the process may be provided through analog and / or digital input connections of the system controller 629. Signals for controlling the process are output through analog and digital output connections of the deposition apparatus 600.

[0098] The system software may be designed or configured in many different ways. For example, a plurality of chamber component subroutines or control objects may be written to control the operation of chamber components required to perform deposition processes according to the disclosed embodiments. Examples of programs or program segments for this purpose include substrate positioning code, process gas control code, pressure control code, and heater control code.

[0099] In some embodiments, the controller 629 is part of a system, which can be part of the above-described embodiments. Such a system includes a semiconductor processing device, which includes one or more processing tools, one or more chambers, one or more platforms for processing, and / or specific processing components (wafer pedestals, gas flow systems, etc.). These systems can be integrated with electronic devices to control the operation of these systems before, during, or after the processing of semiconductor wafers or substrates. The electronic device can be referred to as a "controller", which can control various components or sub-parts of one or more systems. Depending on the processing requirements and / or the type of system, the controller 629 can be programmed to control any of the processes disclosed in the present invention, including controlling the delivery of process gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings in some systems, RF matching circuit settings, frequency settings, flow rate settings, plasma pulse frequency settings, fluid delivery settings, position and operation settings, wafer entry and exit tools and other transport tools and / or delivery of load locks connected to a specific system or interfaced with the system.

[0100] Broadly speaking, a controller 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. The integrated circuit may include a chip storing program instructions in the form of firmware, a digital signal processor (DSP), a chip defined as an application specific integrated circuit (ASIC), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). Program instructions may be instructions delivered to a controller or system in the form of various different settings (or program files), and different settings (or program files) define operating parameters for specific processing on or for semiconductor wafers. In some embodiments, the operating parameters may be a part of a recipe defined by a process engineer to complete one or more processing steps in the manufacturing process of one or more (kinds) layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or bare chips of a wafer.

[0101] In some embodiments, the controller 629 can be a part of or coupled to a computer that is integrated with the system, coupled, or connected to the system or a combination thereof through a network. For example, the controller 629 can be in the "cloud" or all or part of a wafer factory (fab) main computer system, which can allow remote access to wafer processing. The computer can enable remote access to the system to monitor the current progress of the manufacturing operation, check the history of past manufacturing operations, check the trends or performance standards of multiple manufacturing operations, change the parameters of the current processing, set the processing steps to follow the current processing or start a new processing. In some embodiments, a remote computer (e.g., a server) can provide a processing recipe to the system through a network, which can include a local network or the Internet. The remote computer can 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, the controller receives instructions in the form of data, which specify the parameters of each processing step to be performed during one or more operations. It should be understood that these parameters can be for the type of processing to be performed and the type of tool, and the controller is configured to connect or control the tool type. Thus, as described above, the controller may be distributed, for example, by including one or more discrete controllers that are networked together and work toward a common goal (e.g., the processing and control described herein). An example of a distributed controller for these purposes would be one or more integrated circuits in the room that communicate with one or more remote integrated circuits (e.g., at the platform level or as part of a remote computer) that combine to control the processing in the room.

[0102] Exemplary systems may include, but are not limited to, plasma etching chambers or modules, deposition chambers or modules, spin rinse chambers or modules, metal plating chambers or modules, cleaning chambers or modules, chamfer edge etching chambers or modules, physical vapor deposition (PVD) chambers or modules, CVD chambers or modules, ALD chambers or modules, atomic layer etching (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, and any other semiconductor processing system that may be associated with or used in the preparation and / or manufacture of semiconductor wafers.

[0103] As described above, depending on one or more processing steps to be performed by the tool, the controller can communicate with one or more other tool circuits or modules, other tool components, combination tools, other tool interfaces, adjacent tools, adjacent tools, tools located throughout the factory, a host computer, another controller, or tools used in material handling to move containers of wafers to and from tool locations and / or load ports in a semiconductor manufacturing facility.

[0104] The controller 629 may include different programs. The substrate positioning program may include program code for controlling chamber components that are used to load the substrate onto a pedestal or chuck and control the spacing between the substrate and other components of the chamber, such as a gas inlet and / or a target. The process gas control program may include code for controlling gas composition, flow rate, pulse time, and optionally for flowing gas into the chamber to stabilize the pressure in the chamber before deposition. The pressure control program may include code for controlling the pressure in the chamber by adjusting, for example, a throttle valve in an exhaust system in the chamber. The heater control program may include code for controlling the current of a heating unit for heating the substrate. Alternatively, the heater control program may control the delivery of a heat transfer gas, such as helium, to a wafer chuck.

[0105] Examples of chamber sensors that can be monitored during deposition include mass flow controllers, pressure sensors such as manometers, and thermocouples located in the pedestal or chuck. Appropriately programmed feedback and control algorithms can be used with data from these sensors to maintain desired processing conditions.

[0106] The foregoing describes implementations of the present invention as implemented in a single-chamber or multi-chamber semiconductor processing tool. The apparatus and processes described herein can be used in conjunction with lithography patterning tools or processes, for example, to prepare or manufacture semiconductor devices, displays, LEDs, photovoltaic panels, etc. Typically, although not necessarily, these tools / processes will be used or operated together in a common manufacturing facility. Photolithographic patterning of films typically includes some or all of the following steps, each of which enables multiple available tools: (1) coating a workpiece, i.e., a substrate, with photoresist using a spin coating or spray coating tool; (2) curing the photoresist using a hot plate or oven or a UV curing tool; (3) exposing the photoresist to visible light or UV light or X-rays using a tool such as a wafer stepper; (4) developing the resist to selectively remove the resist and thereby pattern it using a tool such as a wet cleaning station; (5) transferring the resist pattern to an underlying film or workpiece by using a dry or plasma assisted etching tool; and (6) removing the resist using a tool such as a radio frequency or microwave plasma resist stripper.

[0107] in conclusion

[0108] Although the above embodiments have been described in some detail for the purpose of clear understanding, it is apparent that certain variations and modifications may be implemented within the scope of the appended claims. It should be noted that there are many alternative ways of implementing the processes, systems, and devices of the embodiments of the present invention. Therefore, the embodiments of the present invention should be considered illustrative rather than restrictive, and these embodiments are not limited to the details given herein.

Claims

1. A method for rapid flushing and cleaning, comprising: providing a semiconductor substrate to a chamber having a chamber pressure of less than 100 Torr, wherein the semiconductor substrate comprises a partially fabricated three-dimensional (3-D) NAND structure comprising a sidewall and a plurality of openings in the sidewall leading to a plurality of features, the features having a plurality of interior regions fluidically accessible through the openings; A material is deposited on the semiconductor substrate by a plurality of ALD cycles, wherein each cycle comprises sequentially flowing into the chamber: reducing agent; first purge gas; Tungsten precursor; and a second purge gas; and wherein each of flowing the first purge gas and flowing the second purge gas comprises flowing purge gas from a first reservoir having a first boost pressure and into the chamber, and then flowing purge gas from a second reservoir having a second boost pressure and into the chamber within 5 seconds of flowing the purge gas from the first reservoir, the first boost pressure and the second boost pressure being between 400 Torr and 1000 Torr.

2. A method for rapid flushing and cleaning, comprising: providing a semiconductor substrate to a chamber having a chamber pressure; A material is deposited on the semiconductor substrate by multiple ALD cycles, wherein each cycle includes sequentially flowing the following substances into the chamber: reactants; and wherein flowing the purge gas comprises flowing the purge gas from a first accumulator having a first boost pressure and into the chamber, and then flowing the purge gas from a second accumulator having a second boost pressure and into the chamber.

3. The method according to claim 2, wherein: The first boost pressure and the second boost pressure are at least twice the chamber pressure.

4. The method of claim 2, wherein the chamber pressure prior to flowing the sweep gas is less than about 100 Torr.

5. The method of claim 2, wherein the first boost pressure and the second boost pressure are between about 400 Torr and about 1000 Torr.

6. The method according to claim 2, wherein: The purge gas is helium, nitrogen, argon or xenon.

7. The method according to claim 2, wherein: The reactants include a reducing agent.

8. The method according to claim 7, wherein: The reducing agent is B2H6, SiH4 or H2.

9. The method according to claim 2, wherein: The reactants include a metal precursor.

10. The method according to claim 9, wherein: The metal precursor is a metal halide.

11. The method according to claim 9, wherein: The metal precursor is a metal oxyhalide.

12. The method of claim 9, wherein the metal precursor is a tungsten precursor.

13. The method of claim 12, wherein the tungsten precursor is one of tungsten hexafluoride (WF6), tungsten hexachloride (WCl6), tungsten pentachloride (WCl5), tungsten tetrachloride (WCl4), tungsten dichloride (WCl2), tungsten oxychloride (WOCl4) or tungsten dioxide dichloride (WO2Cl2).

14. The method of claim 9, wherein the metal precursor is a molybdenum precursor.

15. The method of claim 14, wherein the molybdenum precursor is one of molybdenum pentachloride (MoCl5), molybdenum hexafluoride (MoF6), molybdenum dichloride dioxide (MoO2Cl2), molybdenum oxychloride tetrachloride (MoOCl4) and molybdenum oxychloride tetrachloride (MoOF4).

16. The method of any one of claims 2-15, wherein flowing the sweep gas is choked flow.

17. The method according to any one of claims 2 to 15, wherein: The flow of purge gas from the first accumulator is at least partially choked flow. 18 . The method of claim 17 , wherein flowing purge gas from the second accumulator occurs during the choked flow portion of flowing purge gas from the first accumulator.

19. The method of any one of claims 2-15, wherein flowing purge gas from the second accumulator occurs less than 5 seconds after flowing purge gas from the first accumulator.

20. The method of any one of claims 2-15, wherein the semiconductor substrate comprises a partially fabricated three-dimensional (3-D) NAND structure comprising sidewalls and a plurality of openings in the sidewalls leading to a plurality of features, the features having a plurality of interior regions accessible by fluid through the openings.

Images