Metal deposition

Abstract

Various showerheads and methods are provided. A showerhead may include a panel partially defined by a front surface and a back surface; the back plate is provided with a gas inlet, a first cone frustum surface and a second cone frustum surface; an inflation volume fluidly connected to the gas inlet and defined at least in part by the gas inlet, the back surface of the panel, the first cone frustum surface, and the second cone frustum surface; and a baffle plate located within the plenum volume and having a plurality of baffle plate through holes extending through the baffle plate. The second cone frustum surface may be positioned radially outward from the first cone frustum surface relative to a central axis of the showerhead, and the second cone frustum surface may be positioned further away from the gas inlet than the first cone frustum surface along the central axis.

Description

This application is a divisional application of the invention patent application with application number 202080075633.2, application date August 19, 2020, and invention name “Metal Deposition”. Incorporated by Reference

[0001] 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

[0002] Tungsten (W) film deposition using chemical vapor deposition (CVD) technology is an integral part of semiconductor manufacturing processes. For example, tungsten films can be used as low-resistivity electrical connectors in horizontal interconnect forms, vias between adjacent metal layers, and contacts between the first metal layer and the device on the silicon substrate. Tungsten films can also be used in a variety of memory applications, including the formation of buried word lines (bWL) architectures for dynamic random access memory (DRAM), the formation of word lines for 3D NAND, and logic applications. However, the continued reduction in feature size and film thickness brings various challenges, including higher resistivity of thinner films. Other metals such as molybdenum (Mo) are being evaluated as low-resistivity substitutes for W.

[0003] 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

[0004] Details of one or more implementations of the subject matter described in this specification are set forth in the accompanying drawings and the following description. Other features, aspects, and advantages will become apparent from the description, drawings, and claims. The following non-limiting implementations are considered part of this disclosure; other implementations will be apparent from the entire disclosure and the drawings.

[0005] In some embodiments, a showerhead may be provided. The showerhead may include: a faceplate partially defined by a front surface and a back surface and having a plurality of faceplate through holes extending from the front surface through the faceplate to the back surface; a backplate having a gas inlet, a first frustoconical surface, and a second frustoconical surface; a plenum volume fluidly connected to the gas inlet and at least partially defined by the gas inlet, the back surface of the faceplate, the first frustoconical surface, and the second frustoconical surface; and a baffle located within the plenum volume and partially defined by a top surface and a bottom surface and having a plurality of baffle through holes extending from the top surface through the baffle to the bottom surface. The second frustoconical surface can be positioned radially outward from the first frustoconical surface relative to the central axis of the nozzle, the second frustoconical surface can be positioned along the central axis farther away from the gas inlet than the first frustoconical surface, the first frustoconical surface can form a first angle relative to the central axis, and the second frustoconical surface can form a second angle relative to the central axis.

[0006] In some embodiments, the inner circumference of the second frustoconical surface may be located radially outward from the outer circumference of the first frustoconical surface relative to the central axis.

[0007] In some embodiments, the first angle may be greater than the second angle.

[0008] In some such embodiments, the first angle is between about 50° and about 90°, and the second angle is between about 45° and about 85°.

[0009] In some embodiments, the back plate further includes a third surface spanning between the first truncated cone surface and the second truncated cone surface.

[0010] In some embodiments, the third surface may include a planar portion that is perpendicular to the central axis.

[0011] In some embodiments, the backplate may also include a third frustoconical surface, which is positioned radially outward from the second frustoconical surface relative to the center axis, so that the second frustoconical surface is radially inserted between the first frustoconical surface and the third frustoconical surface, and the third frustoconical surface can be positioned to form a third angle relative to the center axis.

[0012] In some such embodiments, the third angle may be greater than the first angle and the second angle.

[0013] In some embodiments, the outer edge of the baffle may be located radially outward from the first frustoconical surface relative to the central axis.

[0014] In some such embodiments, the outer edge of the baffle may be positioned relative to the central axis to be radially interposed between an inner circumference of the second frustoconical surface and an outer circumference of the second frustoconical surface.

[0015] In some embodiments, the baffle may be positioned along the central axis such that the first frustoconical surface is closer to the gas inlet than the baffle.

[0016] In some such embodiments, the top surface of the baffle can face the gas inlet and the bottom surface of the baffle can face the panel, and the baffle can also be positioned along the central axis so that the top surface of the baffle is between the inner circumference of the second frustum of the conical surface and the outer circumference of the second frustum of the conical surface along the central axis.

[0017] In still other embodiments, the baffle may be further positioned along the central axis such that the bottom surface of the baffle is further away from the gas inlet than the outer circumference of the second frustoconical surface.

[0018] In some embodiments, the baffle further comprises a baffle frustum cone surface facing the backing plate.

[0019] In some such embodiments, the baffle frustoconical surface may be offset from the central axis by a fourth angle, wherein the fourth angle is complementary to the second angle.

[0020] In some embodiments, the plurality of baffle through holes may have outer diameters that increase as the radial position increases relative to the central axis.

[0021] In some such embodiments, a first number of baffle through holes can be positioned in a first section of the baffle and have a first outer diameter, a second number of baffle through holes can be positioned in a second section of the baffle and have a second outer diameter, the second outer diameter is greater than the first outer diameter, and the second section can be radially offset outward from the first section relative to the center axis.

[0022] In still some such embodiments, the first outer diameter may be between about 0.3 mm and about 0.65 mm, and the second outer diameter is between about 0.5 mm and about 0.75 mm.

[0023] In some such embodiments, a third number of baffle through holes can be positioned in a third section of the baffle and have a third outer diameter, the third outer diameter is greater than the second outer diameter, and the third section can be radially offset from the second section relative to the central axis.

[0024] In some embodiments, the third outer diameter is between about 0.7 mm and about 1.1 mm.

[0025] In some embodiments, an inner circumference of the first frustoconical surface may partially define the gas inlet.

[0026] In some embodiments, the panel may further include a panel frustum conical surface, the panel frustum conical surface being positioned radially outward from the front surface of the panel relative to the central axis and offset from the central axis by a fifth angle, the fifth angle being greater than 90°.

[0027] In some embodiments, the nozzle may also include: a port including a first end and an opening at a second end and extending through the panel, and the opening may be located in the panel and radially outward from the front surface, and a window portion positioned adjacent to the first end of the port.

[0028] In some such embodiments, the showerhead may further include a sensor positioned adjacent to the window such that the window is between the first end and the sensor.

[0029] In still some such embodiments, the sensor may be configured to determine one or more of: a distance of an object external to the opening, a temperature external to the opening, and a type of gas external to the opening.

[0030] In some such embodiments, the window may be made of a material comprising sapphire.

[0031] In some such embodiments, the showerhead may further include three ports and three windows. Each window may be positioned adjacent to the first end of a corresponding port, and the three ports may be substantially equally spaced about the central axis.

[0032] In some embodiments, the outer diameters of the panel through holes may all be the same.

[0033] In some such embodiments, the outer diameter of each of the panel through holes may be between about 0.03 inches and 0.05 inches.

[0034] In some embodiments, a method may be provided. The method may include introducing sequential doses of reactant gases into a processing chamber via a showerhead to deposit a film on a substrate by an atomic layer deposition process. The showerhead may include: a faceplate, which is partially defined by a front surface and a back surface and has a plurality of faceplate through holes, the plurality of faceplate through holes extending from the front surface through the faceplate to the back surface; a backplate, which has a gas inlet, a first frustoconical surface, and a second frustoconical surface; a plenum volume, which is fluidly connected to the gas inlet and is at least partially defined by the gas inlet, the back surface of the faceplate, the first frustoconical surface, and the second frustoconical surface; and a baffle, which is located within the plenum volume and is partially defined by a top surface and a bottom surface and has a plurality of baffle through holes, the plurality of baffle through holes extending from the top surface through the baffle to the bottom surface. The second frustoconical surface can be positioned radially outward from the first frustoconical surface relative to the central axis of the nozzle, the second frustoconical surface can be positioned along the central axis farther away from the gas inlet than the first frustoconical surface, the first frustoconical surface can form a first angle relative to the central axis, and the second frustoconical surface can form a second angle relative to the central axis.

[0035] In some embodiments, a method may be provided. The method may include exposing a structure to a plurality of deposition cycles to fill features of the structure with a bulk conductive layer in the features of the structure, and each deposition cycle may include sequentially delivering a dose of hydrogen (H2) and a dose of a metal-containing precursor co-flowed with nitrogen (N2).

[0036] In some implementations, the structure can be a partially processed three-dimensional (3D) NAND structure including sidewalls and a plurality of openings in the sidewalls leading to a plurality of features having a plurality of interior regions that are fluidically accessible via the openings.

[0037] In some embodiments, the metal-containing precursor may be a metal halide.

[0038] In some embodiments, the metal-containing precursor may be a metal oxyhalide.

[0039] In some embodiments, the metal-containing precursor may be a tungsten-containing precursor.

[0040] In some such embodiments, the tungsten-containing precursor can be tungsten hexafluoride (WF6), tungsten hexachloride (WCl6), tungsten pentachloride (WCl5), tungsten tetrachloride (WCl4), tungsten dichloride (WCl2), tungsten oxychloride (WOCl4), or tungsten dichloride (WO2Cl2).

[0041] In some embodiments, the metal-containing precursor may be a molybdenum-containing precursor.

[0042] In some such embodiments, the molybdenum-containing precursor may be molybdenum pentachloride (MoCl5), molybdenum hexafluoride (MoF6), molybdenum dioxide dichloride (MoO2Cl2), molybdenum oxytetrachloride (MoOCl4), and molybdenum oxytetrafluoride (MoOF4).

[0043] In some embodiments, the method may further include an NH 3 soak treatment prior to the plurality of deposition cycles.

[0044] In some embodiments, the plurality of deposition cycles may include introducing at least one of a dose of hydrogen (H 2 ) and a dose of a metal-containing precursor co-flowed with nitrogen (N 2 ) through a showerhead provided in any of the above embodiments.

[0045] In some embodiments, a method may be provided. The method may include providing a structure to be filled with a metal, and exposing the structure to a plurality of deposition cycles. Each deposition cycle may include sequentially delivering a dose of hydrogen (H2) and a dose of a metal-containing precursor co-flowed with nitrogen (N2). BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Various implementations disclosed herein are described by way of example and not limitation.In the figures of the accompanying drawings, like reference numerals refer to like elements.

[0047] Figure 1A and 1B are illustrative examples of material stacks that may be formed using the methods and apparatus described herein.

[0048] Figure 2 Depicted is a schematic example of a dynamic random access memory (DRAM) structure including buried word lines (bWLs) located in a silicon substrate.

[0049] Figure 3A A schematic example of a word line 310 in a 3D NAND structure formed on a substrate is depicted.

[0050] Figure 3B Details of the interface between the word lines and the oxide layer are depicted.

[0051] Figure 3C Depicted is a cross-sectional side view of a partially processed 3D NAND structure.

[0052] Figure 3D Depicted Figure 3C A cross-sectional top view of the same 3D NAND structure shown in FIG.

[0053] Figures 4A-4C Techniques that can be used to fill 3D NAND structures with metal are depicted.

[0054] Figure 5 A comparison of the fluorine concentration (in atoms / cc) of the deposited tungsten films is depicted.

[0055] Figure 6 Depicted is a schematic diagram of a processing system suitable for performing a deposition process in accordance with an embodiment.

[0056] Figure 7 An exemplary deposition station is depicted.

[0057] Figure 8 A schematic diagram of an exemplary gas manifold system is depicted.

[0058] Fig. 9 Depicted is an isometric view of an exemplary spray head according to the disclosed embodiments.

[0059] Fig.10 Depicted Fig. 9 A cross-sectional side view of a sprinkler head.

[0060] Fig.11A Depicted Fig.10 Cross-sectional view of .

[0061] Fig. 11B Only a cross-sectional cut through the center axis of the nozzle is depicted of the plenum volume.

[0062] Fig. 11C A cross-sectional side view depicting a partial profile of the backplate.

[0063] Fig.11D A plan view of the underside of the back plate is depicted.

[0064] Fig.11E Depicted Fig. 11C of the right side of the surface.

[0065] Fig.12 An illustrative frustum of a cone surface is depicted.

[0066] Fig.13A A side view of the baffle is depicted.

[0067] Fig. 13B A top view of the baffle is depicted.

[0068] Fig. 13C Depicted Fig. 13B Magnified image of .

[0069] Fig.14 Depicted Fig.10 An enlarged portion of the right half of the cross-sectional view of the sprinkler head.

[0070] Fig.15A A plan view of the panel is depicted.

[0071] Fig. 15B Depicted Fig.15A A partial enlargement of the middle of the panel.

[0072] Fig. 15C Depicted are some panel through-hole specifications.

[0073] Fig.16A A cross-sectional side view of a showerhead and an exemplary base is depicted.

[0074] Fig. 16B Depicted Fig.16A The enlarged part.

[0075] Fig.17A and 17B The resistance inhomogeneity measurement results of two deposited films are depicted.

[0076] Fig. 17C and 17D The resistance inhomogeneity measurements of two other deposited films are depicted. DETAILED DESCRIPTION

[0077] In the following description, numerous specific details are set forth to provide a full understanding of the embodiments presented. The disclosed embodiments may be implemented 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. Although the disclosed embodiments will be described in conjunction with specific embodiments, it should be understood that they are not intended to limit the disclosed embodiments.

[0078] Tungsten (W) filling of features is often used in semiconductor device processing to form electrical contacts. In conventional methods of depositing tungsten films, a nucleated tungsten layer is first deposited in a via or contact. Generally speaking, the nucleation layer is a thin conformal layer that is used to facilitate the subsequent formation of the bulk material thereon. The tungsten nucleation layer can be deposited to conformally coat the sidewalls and bottom of the feature. The conformality of the bottom and sidewalls of the underlying feature can be critical to maintaining high quality deposition. Atomic layer deposition (ALD) or pulsed nucleation layer (PNL) methods are typically used to deposit the nucleation layer.

[0079] In ALD or PNL techniques, pulses of reactants are sequentially injected and purged from the reaction chamber, typically by pulses of purge gas between reactants. A first reactant may be adsorbed on the substrate, which may react with the next reactant. The process is repeated in a cyclical manner until the desired thickness is achieved. In the context of the disclosed embodiments, chemical vapor deposition (CVD) includes processes in which reactants are introduced together into a reactor for vapor phase or surface reactions. PNL and ALD processes are different from CVD processes, and vice versa.

[0080] After the tungsten nucleation layer is deposited, a bulk tungsten may be deposited by a CVD process using a reducing agent such as hydrogen (H2) to reduce tungsten hexafluoride (WF6). The bulk tungsten is different from the tungsten nucleation layer. As used herein, bulk tungsten refers to tungsten used to fill most or all of the features (e.g., at least about 50% of the features). Unlike the nucleation layer (which is a thin conformal film used to facilitate the subsequent formation of the bulk material thereon), the bulk tungsten is used to carry current. The bulk tungsten may have features with larger grain sizes and lower resistivity than the nucleation film. In many embodiments, the bulk tungsten is deposited to at least Similarly, deposition of molybdenum may involve first depositing a nucleation layer and then depositing a lower resistivity bulk layer.

[0081] As devices shrink to smaller technology nodes and use more complex patterned structures, there are many challenges in filling conductive films. One of the challenges is to perform conformal deposition in these structures so that the material is evenly distributed throughout the structure. The distribution of materials within a feature or structure can be characterized by its step coverage. For the purpose of explanation, "step coverage" is defined as the ratio of two thicknesses. For example, step coverage can be the thickness of the material inside the feature divided by the thickness of the material near the opening. For the purpose of explanation, the term "inside the feature" is represented as the middle part of the feature near the midpoint of the feature along the feature axis (e.g., along the distance between about 25% and 75% of the feature depth measured from the feature opening (or in some implementations, the distance between about 40% and 60%)), or the end part of the feature located along the feature axis measured from the opening. The term "near the opening of the feature" or "near the feature opening" means the top of the feature that is within 25% (or more specifically, within 10%) of the edge of the opening (or other elements representing the edge of the opening). For example, step coverage in excess of 100% can be achieved by filling a wider feature near the middle or bottom of the feature than at the feature opening.

[0082] Another challenge is to reduce the fluorine concentration or content in the deposited film, which can be a problem when using fluorine-containing metal precursors. Smaller features with the same fluorine concentration in the film as larger features have a more significant impact on device performance than larger features. For example, the smaller the feature, the thinner the deposited film. Therefore, fluorine in the deposited film is more likely to diffuse through the thinner film, potentially causing device failure. Roughness, including sidewall roughness, is also a challenge for devices such as 3D NAND devices.

[0083] Another challenge with feature fill and other deposition and non-deposition processes is uniformity. Non-uniform processing across a wafer or other substrate can lead to integration challenges and device failure.

[0084] Methods and apparatus for filling structures with conductive films are provided herein. These methods involve utilizing an atomic layer deposition (ALD) process to deposit a bulk layer using hydrogen (H2) as a reducing agent. The ALD process involves sequential dosing of a metal-containing precursor and H2, and flowing nitrogen (N2) with the metal-containing precursor. Also provided is an apparatus configured to perform the method.

[0085] According to a number of embodiments, one or more advantages may be achieved. In some embodiments, flowing N2 with the metal-containing precursor enables good filling at higher deposition temperatures, which allows deposition of lower stress films. The use of nitrogen may also provide a smooth morphology of the deposited film. In some embodiments, this enables the bulk metal film to be deposited directly on the oxide surface without an intermediate nucleation layer.

[0086] Also provided is a low volume showerhead that can be used in an apparatus for deposition and other substrate processing. In some embodiments, the showerhead includes a plenum volume partially defined by a plurality of frustum cone surfaces of a backing plate, and a baffle having through holes located within the plenum volume. These features can result in one or more of the following: a reduced internal volume of the showerhead, a more uniform flow within the showerhead, and reduced particle generation within the showerhead. According to many embodiments, one or more advantages can be achieved. In some embodiments, reactant consumption and sweep time are reduced. In some embodiments, uniform flow within the showerhead improves uniformity of the deposited film.

[0087] Figure 1A-8 Methods and apparatus for filling structures with conductive films are described. Figure 9-17D Low volume showerheads for substrate processing are described. In some embodiments, low volume showerheads are used to perform the methods.

[0088] First, regarding conductive film deposition, Figure 1A and 1B are illustrative examples of material stacks that may be formed using the methods and apparatus described herein. Figure 1A and 1B The order of materials in a particular stack is shown and can be used with any suitable architecture and application, such as the following for Figure 2 , 3A , and 3B are further described. Figure 1A In the example of , substrate 102 has a nucleation layer 108 deposited thereon. Substrate 102 can be a silicon or other semiconductor wafer (e.g., a 200-mm wafer, a 300-mm wafer, a 450-mm wafer), including a wafer having one or more layers of material (e.g., a dielectric, conductive, or semiconductive material) deposited thereon. These methods can also be applied to form metallization stacks on other substrates (e.g., glass, plastic, etc.).

[0089] exist Figure 1A In the embodiment of the present invention, dielectric layer 104 is located on substrate 102. Dielectric layer 104 can be deposited directly on the semiconductor (e.g., silicon) surface of substrate 102, or there can be any number of intermediate layers. Examples of dielectric layers include doped and undoped silicon oxide, silicon nitride, and aluminum oxide layers, with specific examples including doped or undoped layers SiO2 and Al2O3. Figure 1A In the embodiment of the present invention, a diffusion barrier layer 106 is disposed between a nucleation layer 108 and a dielectric layer 104. Examples of diffusion barrier layers include titanium nitride (TiN), titanium / titanium nitride (Ti / TiN), tungsten nitride (WN), and tungsten carbonitride (WCN). A metal layer 110 is deposited on the nucleation layer 108 and is the main conductor (also referred to as the main conductor or main layer) of the structure, and the nucleation layer 108 provides a template for metal growth. Examples of metal layers include tungsten (W) and molybdenum (Mo) layers. The nucleation layer 108 may include the same or different metal as the metal layer 110.

[0090] Figure 1B Another example of a material stack is shown. In this example, the stack includes a substrate 102, a dielectric layer 104, and a nucleation layer 108 deposited directly on the dielectric layer 104 without an intermediate diffusion barrier layer. Figure 1A In the example of FIG. 1 , the metal layer 110 is deposited on the nucleation layer 108 and is the main conductor of the structure.

[0091] Although Figure 1A and 1B An example of a metallization stack is shown, but the method and resulting stack are not so limited. For example, in some embodiments, the nucleation layer 108 can be omitted and the main conductor can be deposited directly on the underlying layer. In some embodiments, the nucleation layer can be deposited directly on a Si or other semiconductor substrate to serve as a template for metal growth. The methods described herein are performed on a substrate that can be contained in a chamber.

[0092] The material stacks described above and further below may be implemented in various configurations. Figure 2 , 3A and 3B provide examples of structures that may employ stacked pieces. Figure 2 An illustrative example of a DRAM structure is depicted that includes a buried word line (bWL) 210 located in a silicon substrate 202. The bWL 210 is formed in a trench etched in the silicon substrate 202. A conformal nucleation layer 208 and an insulating layer 204 line the trench, with the insulating layer 204 disposed between the conformal nucleation layer 208 and the silicon substrate 202. Figure 2 In the example of FIG. 2 , the insulating layer 204 can be a gate oxide layer formed of a high-k dielectric material (eg, silicon oxide or silicon nitride material). In some embodiments, a conformal barrier layer (eg, TiN or a tungsten-containing layer) can be inserted between the nucleation layer 208 and the insulating layer 204 .

[0093] Figure 3A A schematic illustration 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 , details of the interface between word line 310 and oxide layer 311 are shown, which includes aluminum oxide (Al2O3) 304 and nucleation layer 308. In some embodiments, nucleation layer 308 can be deposited directly on oxide layer 311, or on TiN or other barrier layers described herein. The nucleation layer can be, for example, between about to between or to For depositing word line 310 with a thickness between about 10 nm and 100 nm.

[0094] Figure 3C 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 3C 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 3C In Figure 3CIn 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 3C The horizontal features 320 present in both the 3-D NAND stacks 325 and 326 shown in the figure (i.e., the left 3-D NAND stack 325 and the right 3-D NAND stack 326) can also be accessed from the other sides of the stack (the leftmost and rightmost sides, respectively) through similar vertical structures formed by additional 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 are fluidly accessible from both sides of the 3-D NAND stack through the central vertical structure 330.

[0095] 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).

[0096] Figure 3D Shown in Figure 3C A cross-sectional top view of the same 3-D NAND structure shown in FIG. Figure 3C The horizontal portion 360 shown by the horizontal dotted line in FIG. Figure 3C The cross-section of FIG. 3 shows several rows of pillars 355 extending vertically from the base of 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 3D 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 3D) 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.

[0097] Figures 4A-4C Methods that may be performed to fill a 3D NAND structure with metal are described. Turning first to Figure 4A ,implement Figure 4A Operations 402-410 are performed to deposit a nucleation layer by ALD. In some embodiments described herein, operations 402-410 are performed at a lower pressure than the subsequent bulk deposition in operation 480. For example, for tungsten deposition, operations 402-410 can be performed at a low pressure of less than about 10 Torr. In some examples, for tungsten deposition, operations 402-410 are performed at a pressure of about 10 Torr or a pressure of about 3 Torr. Deposition of the molybdenum nucleation layer can use higher pressures, such as 10-60 Torr. Pressures at the lower end of this range can be used to mitigate fluorine incorporation effects.

[0098] In some embodiments, performing operations 402-410 at low pressure results in a reduced fluorine concentration in the deposited film due to a lower partial pressure of the fluorine-containing precursor (if used) in the chamber when depositing the film, resulting in less fluorine being incorporated into the film.

[0099] In operation 402, the substrate is exposed to a metal-containing precursor. This operation may be referred to as "pulsing" or "dosing," 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.

[0100] Examples of nucleation layers include tungsten-containing nucleation layers and molybdenum-containing nucleation layers, which use tungsten-containing precursors and molybdenum-containing precursors, respectively. Examples of tungsten-containing precursors include tungsten halides and tungsten oxyhalides. Examples of tungsten halides include tungsten hexafluoride (WF6), tungsten chlorides (WClx), including tungsten hexachloride (WCl6), tungsten pentachloride (WCl5), tungsten tetrachloride (WCl4), tungsten dichloride (WCl2), and tungsten oxychloride (WO x Cl y ), such as tungsten tetrachloride (WOCl4) and tungsten dichloride (WO2Cl2). Further examples include tungsten hexacarbonyl W(CO)6 and organic tungsten precursors, such as MDNOW (methylcyclopentadienyl-dicarbonylnitrosyl-tungsten) and EDNOW (ethylcyclopentadienyl-dicarbonylnitrosyl-tungsten).

[0101] Examples of molybdenum-containing precursors include molybdenum halides and molybdenum oxyhalides. Examples of molybdenum halides include molybdenum pentachloride (MoCl5) and molybdenum hexafluoride (MoF6). Examples of molybdenum oxyhalides include molybdenum dioxide dichloride (MoO2Cl2), molybdenum oxytetrachloride (MoOCl4) and molybdenum oxytetrachloride (MoOF4).

[0102] The metal-containing precursor may include a combination of these compounds. In some embodiments, a carrier gas, such as nitrogen (N2), argon (Ar), helium (He), or other inert gas may be flowed during operation 402.

[0103] 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.

[0104] The chamber is optionally purged to remove excess precursor that is not adsorbed to the substrate surface in operation 404. The purge operation can be performed by flowing an inert gas at a fixed pressure, thereby reducing the pressure of the chamber and re-pressurizing the chamber before starting another gas exposure step.

[0105] 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 (H2), borane, silane, or germane. Exemplary boranes include borane (BH3), diborane (B2H6), triborane, alkylborane, aminoborane, carborane, and haloborane. Exemplary silanes include silane (SiH4), disilane (Si2H6), trisilane (Si3H8), alkylsilane, aminosilane, carbosilane, and halosilane. 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. Generally, halogenated germanium may not have significant reduction potential, but there may be processing conditions and precursors suitable for forming films using halogenated germanium.

[0106] In some embodiments, an amorphous nucleation layer can be deposited using a metal halide or metal oxyhalide precursor and a nitrogen-containing reducing agent such as ammonia (NH3). 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 the deposition of the bulk layer).

[0107] 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 an adsorbed layer of a metal-containing precursor on the surface of the substrate. Operation 406 may be performed for a duration outside of these example ranges. In some embodiments, a carrier gas such as argon (Ar), helium (He), or nitrogen (N2) may be used.

[0108] After operation 408, there may be an optional purge step to purge excess co-reactant that has not reacted with the metal-containing precursor on the surface of the feature and is still in the gas phase. The purge operation may be performed by flowing an inert gas at a fixed pressure, thereby reducing the pressure of the chamber and re-pressurizing the chamber before starting another gas exposure step.

[0109] 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.

[0110] 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 280 can be performed at a pressure greater than the pressure during operations 202-210. For example, for a tungsten bulk layer, operation 280 can be performed at a pressure greater than or equal to about 10 Torr, such as about 10 Torr, or about 40 Torr. In some embodiments, the pressure during the deposition of the nucleation layer and the bulk layer can be about 5-20 Torr, or 10 Torr. In other embodiments, the same pressure can be used in operation 280 and / or a lower pressure can be used. For molybdenum deposition, the pressure can be about 10-60 Torr, or 30-60 Torr in some embodiments.

[0111] Figure 4B A process flow diagram of the operations that may be performed during operation 480 is provided. Note that the Figure 4AExecute 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. Figure 4C A timing diagram describing an exemplary ALD cycle in process 400 is provided.

[0112] exist Figure 4B In operation 482, the substrate is exposed to a co-reactant. In some embodiments, this is a reducing agent, such as H2, 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 adsorption of H2 molecules on the surface and / or reaction with the metal-containing precursor molecules to form a sub-monolayer film of a monolayer.

[0113] 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.

[0114] 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, a purging operation can be performed by flowing an inert gas at a fixed pressure, thereby reducing the pressure in the chamber and re-pressurizing the chamber 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 between about 0.1 seconds and about 3 seconds or about 0.5 seconds during this operation. In some embodiments, the metal-containing precursor can be turned to fill gas pipelines and pipeline changes before batching.

[0115] Examples of metal precursors include tungsten hexafluoride (WF6), tungsten chloride (WCl X ) (including tungsten hexachloride (WCl6), tungsten pentachloride (WCl5), tungsten tetrachloride (WCl4), tungsten dichloride (WCl2)), and tungsten oxychloride (WO x Cl y)(e.g., tungsten tetrachloride (WOCl4) and tungsten dichloride (WO2Cl2)). Further examples include tungsten hexacarbonyl (W(CO)6) and organic tungsten precursors, such as MDNOW (methylcyclopentadienyl-dicarbonylnitrosyl-tungsten) and EDNOW (ethylcyclopentadienyl-dicarbonylnitrosyl-tungsten). Further examples include molybdenum-containing precursors, such as molybdenum halides and molybdenum oxyhalides. Examples of molybdenum halides include molybdenum pentachloride (MOCl5) and molybdenum hexachloride (MOCl6). Examples of molybdenum oxyhalides include molybdenum dichloride (MOO2Cl2) and molybdenum oxytetrachloride (MOOCl4)

[0116] exist Figure 4B In operation 488, the chamber is purged to remove the byproducts of the reaction and the vapor-phase metal-containing precursor from the chamber. In some embodiments, the purge duration is between about 0.1 seconds and about 2 seconds.

[0117] 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.

[0118] 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.

[0119] The method involves in an ALD cycle (e.g., Figure 4A Operation 402 and / or Figure 4B In operation 486) nitrogen (N2) is co-flowed with the metal-containing precursor. Figure 4C A timing diagram is provided that depicts an exemplary cycle of ALD using a H2 reducing agent and a metal-containing precursor in process 400. The timing diagram is similar to Figure 4B and includes co-flowing N2 during dosing of the metal precursor. In particular, Figure 4C H2 dosing 420A in deposition cycle 411A is shown, which may correspond to Figure 4B Operation 482. During H2 dosing 420A, the carrier gas may be flowed, the H2 reducing agent may be pulsed, and the flow of the metal-containing precursor and N2 may be turned off. This may be followed by a purge phase 440A. Deposition cycle 411A also includes metal-containing precursor + N2 dosing 460A and a purge phase 470A. Figure 4CAs shown, during sweep phases 440A and 470A, the carrier gas is flowed and other flows are turned off. In subsequent deposition cycles, these operations are repeated, as shown in 420B, 440B, 460B, and 470B.

[0120] For illustrative purposes, Figure 4C The amounts of each dosing in are roughly the same. Ar or other carrier gas can have the highest flow rate.

[0121] Although the carrier gas is depicted as being constant throughout the procedure, it may be provided independently with the H2 flow and / or the metal-containing precursor-N2 co-flow. For example, H2 (or other co-reactants) may be provided in dosing 420A and 420B without providing a carrier gas flow.

[0122] In some embodiments, N 2 may be flowed during H 2 dosing phases 420A and 420B and / or during sweep phases 440A and 440B in addition to during dosing of the metal-containing precursor.

[0123] In some embodiments, the metal-containing precursor is a fluorine-containing precursor, such as WF6. By co-flowing N2 with the fluorine-containing precursor, the fluorine concentration in the metal layer is reduced. Figure 5 Shown is a comparison of the F concentration (in atoms / cc) of tungsten films deposited by the following processes: N2 H2 co-flow: N2+H2 / sweep / WF6 / sweep N2 WF6 co-flow: H2 / sweep / N2+WF6 / sweep

[0124] In particular, the concentration at 1-10 nm shows the F content in the deposited film, and the concentration in the N2 WF6 co-flow treatment is more than one order of magnitude lower than that in the N2 H2 co-flow treatment (1×10 17 For 6×10 18 ).

[0125] In addition, a lower resistivity is achieved, where for For the membrane, the resistivity is improved by about 10% compared with the N2H2 co-flow.

[0126] In some embodiments, the consumption of metal-containing precursors is reduced. The consumption of metal-containing precursors in the above-mentioned N2WF6 co-flow process is 17% less than that in the N2H2 co-flow process.

[0127] In some embodiments, the deposition rate and productivity are improved. Although the amount of WF6 is constant in both procedures (300 sccm), the deposition rate of N2 WF6 co-flow is 30% higher than that of N2 H2 co-flow. In some embodiments, the roughness is significantly reduced by co-flowing N2 with the metal-containing precursor.

[0128] ALD deposition of bulk layers may result in high stress films. This may be mitigated by using high temperatures, however, high temperatures may result in poor filling. In some embodiments, low stress films may be deposited by co-flowing N2 with metal-containing precursors as described herein. The temperature during ALD of tungsten may be between 200°C and 550°C, for example, between 300°C and 450°C. The temperature during ALD of molybdenum may be between 450°C and 800°C, for example, between 600°C and 750°C.

[0129] In some embodiments, a nitrogen soak, particularly an NH 3 soak, may be performed prior to deposition. experiment

[0130] High temperature ALD process is used to deposit Mo in linerless 3D NAND structures. Mo is deposited on Al2O3. Base temperature (℃) <![CDATA[NH3 immersion]]> <![CDATA[Co-flow of N2]]> Growth rate (angstroms / cycle) Nucleation delay (cycle) 650 no no 0.74 41 650 no yes 0.63 21 650 yes no 0.66 23 650 yes yes 0.58 0

[0131] The lowest roughness was observed for the NH3 / N2 co-flow treatment, while the highest roughness was observed for the no-immersion / no-co-flow treatment. Device

[0132] Any suitable chamber may be used to implement the disclosed embodiments. Exemplary deposition apparatus include various systems such as and Max, which is 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 (H2) and tungsten hexafluoride (WF6) or other metal-containing precursors can be introduced to the substrate surface at the first station in alternating pulses using a separate gas supply system that creates a local atmosphere on 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 processing manner. Alternatively, the wafer can be transposed to perform operations sequentially on two or more stations.

[0133] Figure 66 is a schematic diagram of a processing system suitable for performing deposition processing according to an embodiment. System 600 includes a transport module 603. The transport module 603 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.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] The computer program code for controlling the germanium-containing reducing agent pulses, hydrogen gas flow, and tungsten-containing precursor pulses 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.

[0141] 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.

[0142] 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.

[0143] The system software can be designed or configured in many different ways. For example, multiple chamber component subroutines or control objects can 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.

[0144] In some embodiments, the controller 629 is part of a system, which can be part of the above examples. Such a system includes semiconductor processing equipment, 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 delivery tools and / or delivery of load locks connected to a specific system or interfaced with the system.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] The apparatus may include a gas manifold system that provides line filling to various gas distribution lines, such as Figure 8 Schematically shown. Manifold 804 has inputs from a source 801 of a metal-containing precursor gas, a source 802 of nitrogen (N2), and a source 803 of argon (Ar) or other carrier gas. Manifold 811 has an input 809 from a source (not shown) of hydrogen (H2) or other reducing gas. As described above, there may or may not be an input from a carrier gas to manifold 811. Manifold 821 has an input from a source 819 of an inert purge gas. Manifolds 804, 811, and 821 provide metal-containing precursor gas and N2 co-flow gas, co-reactant gas, and purge gas to the deposition chamber via valved distribution lines 805, 813, and 825, respectively. Various valves can be opened or closed to provide pipeline filling, that is, to pressurize the distribution lines. For example, in order to pressurize the distribution line 805, valve 806 is closed toward vacuum, and valve 808 is closed. After an appropriate time increment, valve 808 is opened and the co-flow gas is delivered to the chamber. After an appropriate time for the gas to be delivered, valve 808 is closed. The chamber can then be purged to vacuum by opening valve 806 toward vacuum.

[0152] Similar processes can be used to deliver reducing gas and purge gas. To introduce reducing gas, for example, distribution line 813 is filled by closing valve 815 toward vacuum and closing valve 817. The opening of valve 815 enables the delivery of reducing gas to the chamber. Similarly, to introduce purge gas, distribution line 825 is filled by closing valve 827 toward vacuum and closing valve 823. The opening of valve 827 enables the delivery of argon or other inert purge gas to the chamber. The amount of time allowed for line filling changes the amount and timing of the initial delivery of gas.

[0153] Figure 8 A vacuum pump is also shown, where valves 806, 817 and 823 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.

[0154] 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.

[0155] Pulses containing metal precursor gases can be generated as follows. Initially, the system transfers WF6 to a vacuum pump for a period of time while the MFC or other flow control devices are stable. In one example, this can be performed over a period of about 0.5 to 5 seconds. Next, the system pressurizes the tungsten gas delivery manifold by closing both the diverting outlet 606 and the outlet 608 leading to the deposition chamber. For example, this can be performed over a period of about 0.1 seconds to 5 seconds to produce an initial pulse of reagent when the outlet leading to the deposition chamber is opened. In one example, this is achieved by opening an outlet 808 for about 0.1 to 10 seconds. Afterwards, a suitable purge gas is used to purge the tungsten-containing gas from the deposition chamber. The pulsed flow of other reagents can be performed in a similar manner.

[0156] As described above, in some embodiments, the apparatus described herein may include a low volume showerhead. In semiconductor processing apparatus, showerheads are often used to distribute process gases across a semiconductor substrate. The showerhead may include a plenum volume defined by a back plate and a face plate, wherein the face plate has a plurality of gas distribution holes leading to the exterior of the showerhead. The face plate faces a substrate reaction area within a semiconductor processing chamber or other reaction chamber, and the substrate is disposed within the semiconductor processing chamber, below the face plate, such as on a pedestal supporting a wafer.

[0157] The reactants used in the deposition process can be expensive, and reducing their consumption reduces the costs associated with processing each wafer. Various processing steps can also have minimum completion times, and reducing some of these times (such as the time to purge the showerhead between multiple processing steps in the ALD deposition cycle as described above) can increase production capacity. Increasing the flow uniformity of the reactant delivery in the gas phase can improve the uniformity of the deposited film. Especially during dosing and (if performed) plasma operation. However, increasing the purge flow uniformity within the showerhead can also improve film uniformity by more effectively purging the showerhead and removing non-needed gases (including gases that may react) from the showerhead.

[0158] The low volume showerhead may include an external geometry configured to reduce the gap between the showerhead and the pedestal (hereinafter referred to as the "gap" or "showerhead-pedestal gap"). Reducing the gap reduces gas consumption and improves the uniformity of the deposited film. Some pedestals can position a substrate in a cavity that is partially defined by a substrate support surface (on which the substrate is positioned) and an outer wall that extends around and above the substrate support surface. This external structure of the showerhead enables a portion of the showerhead to be positioned within this pedestal cavity. In some embodiments, the external geometry may include sizing the outer diameter of the front surface of the showerhead to be smaller than the inner diameter of the outer wall of the pedestal, wherein the front surface of the showerhead faces the wafer and includes a through hole for distributing gas to the wafer; the external geometry may also include an outer frustoconical surface (e.g., a chamfer) that extends around the front surface of the showerhead and provides a gap between the showerhead and the outer wall to further enable the front surface to be positioned within the pedestal cavity.

[0159] In some embodiments, the spray head may be configured with one or more sensors for measuring various aspects of the chamber. The spray head may have a port with an opening in the panel, a window near the port or at one end of the port, and a sensor near the window, which can detect conditions outside the spray head via the window, the port, and the opening. For example, the port may be located above the base, and a sensor with a laser may be located in the spray head so that the laser can emit a beam through the window, the port, and the opening to the base to measure the distance between the spray head and the base. In some cases, the base may be configured to move in multiple directions, including vertical, horizontal (e.g., x and y directions), and angular rotation around one or more axes, and tilting movement relative to a point. The base can be adjusted based on the measurement results provided by the sensor of the spray head so that the base is aligned with the spray head, including making the base support surface parallel or more parallel to the front surface of the spray head.

[0160] The spray heads described herein can be considered low volume spray heads, such that they have an internal plenum volume equal to or less than 250 ml (including about 214 ml). In contrast, most conventional spray heads have a total internal volume greater than 500 ml.

[0161] Generally speaking, there are two main types of showerheads: chandelier type and flush mounted type. A chandelier type showerhead module has a stem attached to the top of the chamber at one end and to a panel or backplane at the other end. A portion of the stem may protrude from the top of the chamber to connect gas lines and RF power. Flush mounted showerheads are integrated into the top of the chamber and typically do not have a stem. Although the depicted figures generally refer to flush mounted showerheads, it should be understood that the present disclosure may also be applied to chandelier type showerheads. In addition, although the showerheads described herein may be implemented for thermal or plasma enhanced ALD processing, they may also be implemented in other processing techniques where reactant consumption and processing uniformity are of concern. These processing techniques include chemical vapor deposition (CVD), plasma enhanced CVD, and etching, including atomic layer etching (ALE) processing.

[0162] Fig. 9 An isometric view of an exemplary showerhead according to the disclosed embodiments is depicted. In this figure, the showerhead 900 includes a backing plate 902 having a gas inlet 904 , and a face plate 906 connected to the backing plate 902 .

[0163] Fig.10 Depicted Fig. 9 A cross-sectional side view of a nozzle; the cross-sectional view is taken along Fig. 9 The back plate 902 and the face plate 906 together partially define a plenum volume 908 within the showerhead 900, and a baffle 910 is positioned within the plenum. The back plate 102 and the face plate 104 can be positioned relative to each other in the showerhead so that they have surfaces facing each other. Generally speaking, the first surface 130 of the plenum volume can have a diameter that is similar or substantially similar to a diameter of a substrate for which the showerhead is configured. The face plate 906 includes a back surface 912 that partially defines the plenum volume 908 and faces the back plate 902, and a front surface 914 that is configured to face a substrate positioned in a processing chamber. The face plate 906 also includes a plurality of through holes 916 (in Fig.10 9), which extends from the back surface 912 through the faceplate 906 to the front surface 914 and enables fluid to flow from the plenum volume 908 to the exterior of the showerhead 902 and onto the substrate.

[0164] like Fig.10As further shown in FIG. 1 , a panel 906 is located below and connected to the back plate 902, and a through hole 916 passes through the panel 906 from the back surface 912 to the front surface 914. The arrangement and configuration of these through holes 916 are described in more detail below. The plenum volume 908 is fluidly connected to the gas inlet 904 and the through holes 916, so that the fluid can flow through the gas inlet 904 into the plenum volume 908 and flow through the panel 906 via the through holes 916. The plenum volume can be supplied with gas, such as reactant gas or purge gas, via the gas inlet. The gas inlet can be connected to one or more gas supply sources for gas delivery. The gas inlet can include a rod (not shown).

[0165] use Figures 11A-11E Further describe the volume of the gas-filled portion. Fig.11A middle, Fig.10 The cross-sectional view of FIG. 1 depicts the plenum volume 908, which is shown in dark shading, but the baffle 910 is removed along with the cross-hatching of the face plate 906 and the back plate 902 for purposes of illustration and clarity. Fig. 11B In FIG. 1 , only a cross-sectional cut through the central axis of the nozzle of the plenum volume is depicted. The back surface 914 of the panel 906 partially defines the plenum volume 908, as shown in FIG. Fig.11A and 11B In some embodiments, Figures 10 to 11E As shown, the back plate 902 includes a plurality of surfaces that also partially define the plenum volume 908; the plurality of surfaces may include one or more frustoconical surfaces.

[0166] A frustum of a cone is a conical surface without a tip; a plane parallel to the base of the frustum of the cone cuts off or removes the tip. Fig.12 An illustrative frustum of a cone surface is depicted. It can be seen that the frustum of a cone surface S is defined by a first circumference C1 having a first radius R1 and a second circumference C2 having a second radius R2, wherein the second radius R2 is greater than the first radius R1; the two circumferences are offset from each other by a height H. The length L of the frustum of a cone surface spans between the first circumference C1 and the second circumference C2. The frustum of a cone surface also has a central axis, and the frustum of a cone surface is offset from the central axis by a first angle θ1.

[0167] In some embodiments, such as Figure 9-11E As shown, the back plate may include three frustum of cone surfaces. The description herein is not limited to three frustum of cone surfaces; in some embodiments, the back plate may have two frustum of cone surfaces, and in other embodiments may have more than three frustum of cone surfaces. Fig. 11B Two cut surfaces of the first frustum of cone surface 918 , two cut surfaces of the second frustum of cone surface 920 , and two cut surfaces of the third frustum of cone surface 922 are identified. Fig. 11CA cross-sectional side view depicting a partial profile of a back plate. Here, the profile is shown in bold. Fig. 11B The three frustum surfaces 918, 920, and 922 are shown in FIG. 1 , and the other surfaces of the back plate are depicted in dashed lines. Each of the three frustum surfaces 918, 920, and 922 has a length L1, L2, and L3, respectively, and is also Fig. 11C The central axis 924 of the nozzle shown in FIG. 1 is offset by a first angle θ1, a second angle θ2, and a third angle θ3, respectively. The inner radius and the outer radius of each frustum surface are also depicted in FIG. Fig. 11C Middle: The first frustum surface 918 has an inner radius R 1A and outer radius R 2A The second frustum surface 920 has an inner radius R 1B and outer radius R 2B , and the third truncated cone surface 922 has an inner radius R 1C and outer radius R 2C .

[0168] Fig.11D A plan view of the underside of the back plate 902 is depicted. Three frustoconical surfaces 918, 920, and 922 are identified with shading. The three frustoconical surfaces extend completely around a central axis 924 (indicated by an "X") of the back plate 902; the central axes of each of these frustoconical surfaces are co-linear with each other and with the central axis 924 of the back plate 902. Each of the three frustoconical surfaces has a first circumference defined by an inner radius of the surface, and a second circumference defined by a larger outer radius of the surface, such that the second circumference is larger than the first circumference. Fig.11D The first circumference C of the first frustum of cone surface 918 is included. 1A and the second circle C 2A , the first circumference C of the second truncated cone surface 920 1B and the second circle C 2B , and the first circumference C of the third truncated cone surface 922 1C and the second circle C 2C .

[0169] In some embodiments, such as Figures 11B-11E As shown, the frustoconical surfaces of the backing plate can be positioned radially outward from and around the gas inlet 904; these surfaces can also be spaced apart at various radial locations and apart from the central axis of the backing plate. Figures 11B-11E, the first frustoconical surface 918 is shown adjacent to the gas inlet 904, and in some cases, the inner radius of the first frustoconical surface may form a boundary of the gas inlet 904. The second frustoconical surface 920 is radially offset outward from the first frustoconical surface 918 relative to the central axis 924 of the backing plate 902, such that, for example, when viewed along the central axis and in a cross-section perpendicular to the central axis, the first frustoconical surface 918 is interposed between the gas inlet 904 and the second frustoconical surface 920, as shown in FIG. Figures 11B-11E In some such embodiments, the outer radius R of the first frustum of cone surface 918 is 1B smaller than the inner radius R of the second truncated cone surface 920 2A .

[0170] In some embodiments, one or more other surfaces may span between the first and second frustum surfaces 918 and 920. For example, Fig. 11B As shown, surface 926 (not shaded) spans the outer radius R of first frustum surface 918. 2A The inner radius R of the second truncated cone surface 920 is 1B In some cases, this surface may include one or more portions that are planar and perpendicular to the central axis 924 of the backing plate 902. Due to, for example, manufacturing tolerances and imperfections, this perpendicularity may not be exact and may be considered to be substantially vertical. The surface 926 may also include one or more curved portions to create a smooth transition between a planar surface and a truncated conical surface, and may also include a truncated conical surface to achieve smooth fluid flow along these surfaces. This surface is also shown in Fig. 11C middle.

[0171] In some other embodiments, although not depicted Figure 9-11E However, the first truncated cone surface 918 and the second truncated cone surface 920 may be adjacent to each other, so that the outer radius R of the first truncated cone surface 918 is 2B The inner radius R of the second truncated cone surface 920 is 1B In some such cases, the second circumference C of the first frustum of cone surface 918 is 2A The first circumference C of the second truncated cone surface 920 may be 1B same.

[0172] Return to reference Figures 11B-11E , the third frustum of cone surface 922 can be positioned radially outward from the second frustum of cone surface 920 relative to the central axis 924 of the back plate 902, so that when viewed along the central axis 924 or viewed in a cross section perpendicular to the central axis, the second frustum of cone surface 920 is inserted between the first frustum of cone surface 918 and the third frustum of cone surface 922, as shown in FIG. Fig. 11C and 11EIn certain such embodiments, Fig.11D As shown, the outer radius R of the second truncated cone surface 920 is 2B smaller than the inner radius R of the third truncated cone surface 922 1C . Similar to the above, in some embodiments, another surface 928 may span between the second truncated cone surface 920 and the third truncated cone surface 922. The other surface may have one or more planar portions perpendicular to the central axis 924 (like surface 926), and it may also include one or more curved surfaces connected to the truncated cone surfaces to achieve smooth flow along these surfaces. Exemplary curved surfaces 930A, 930B, and 930C are shown in Fig. 11C and 11D middle.

[0173] In some embodiments, the frustoconical surfaces of the backing plate may be vertically offset from each other along the central axis of the backing plate. In some cases, the first frustoconical surface may be positioned closest to or adjacent to the gas inlet along the central axis and may be positioned at the same location as the gas inlet along the central axis. Fig.11E In it, it depicts Fig. 11C The surfaces on the right side of the figure show the vertical deviation of these surfaces. Here, the first circumference C of the first truncated cone surface 918 is 1A The second circumference C of the first truncated cone surface 918 is located at the same position as the gas inlet 904 along the central axis 924. 2A The second frustoconical surface may be vertically offset along the central axis to be farther from the gas inlet than the first frustoconical surface. In some such cases, the second circumference of the first frustoconical surface may be located at the same position along the central axis as the first circumference of the second frustoconical surface; in other embodiments, the first circumference of the second frustoconical surface may be farther away from the gas inlet along the central axis than the second circumference of the first frustoconical surface. Fig.11E In the embodiment, the first circumference C of the second truncated cone surface 920 is 1B The second circumference C of the first truncated cone surface 918 is located along the central axis 924. 2A The second circumference C of the second truncated cone surface 920 2B The second height H2 is offset along the central axis 924. In certain such embodiments, the first frustoconical surface can be considered to be interposed between the gas inlet and the second frustoconical surface along the central axis.

[0174] Similarly, the third frustoconical surface may be vertically offset along the central axis further from the gas inlet than the first and second frustoconical surfaces. In some such cases, the second circumference of the second frustoconical surface may be located at the same position along the central axis as the first circumference of the third frustoconical surface; in other embodiments, the first circumference of the third frustoconical surface may be further away from the gas inlet along the central axis than the second circumference of the second frustoconical surface. Fig.11E In the embodiment, the first circumference C of the third truncated cone surface 922 is 1C The second circumference C of the second truncated cone surface 920 is located along the central axis 924. 2B The second circumference C of the third truncated cone surface 922 2C The third height H3 is offset along the central axis 924. In certain such embodiments, the second frustoconical surface can be considered to be between the first and third frustoconical surfaces along the central axis.

[0175] In some embodiments, the inner radius R of the first frustum of cone surface 918 is 1A The outer radius R of the first frustum surface 918 may be between about 0.20 inches and 0.045 inches (including 0.3 inches). 2A The inner radius R of the second frustum surface 920 may be between about 1.25 inches and 3.0 inches (including 1.5 inches); 1B The outer radius R of the second frustum surface 920 may be between about 2.00 inches and 3.75 inches (including 3.0 inches). 2B The inner radius R of the third frustum surface 922 may be between about 2.5 inches and 4.25 inches (including 3.5 inches); and 1C The outer radius R of the third frustum surface 922 may be between about 4.25 inches and 5.75 inches (including about 5.00 inches). 2CIt may be between about 4.75 inches and 6.25 inches (including 5.75 inches). In some embodiments, the length L1 of the first frustum of cone surface 918 may be between about 1.15 inches and 2.5 inches (including about 1.5 inches), the length L2 of the second frustum of cone surface 920 may be between about 0.25 inches and 1.5 inches (including 0.5 inches), and the length L3 of the third frustum of cone surface 922 may be between about 0.25 inches and 1.75 inches (including 0.75 inches). In some embodiments, the first angle θ1 of the first frustum of cone surface 918 may be between about 50° and 95°, the second angle θ2 of the second frustum of cone surface 920 may be between about 45° and 85°, and the third angle θ3 of the third frustum of cone surface 922 may be between 65° and 89°. In some embodiments, the first height H1 of the first frustoconical surface 918 may be between about 0.1 inches and 0.5 inches (including 0.17 inches), the second height H2 of the second frustoconical surface 920 may be between about 0.1 inches and 0.3 inches (including 0.17 inches), and the third height H3 of the third frustoconical surface 922 may be between about 0.005 inches and 0.25 inches (including 0.04 inches). The inventors have determined that these dimensions improve flow uniformity within the showerhead and outside the panel in some embodiments while advantageously reducing the volume of the plenum of the showerhead.

[0176] Various aspects of the baffle will now be discussed. Fig.10 , a baffle 910 is positioned within the plenum volume 908 of the showerhead 900. The baffle includes a top surface facing the gas inlet 904 of the back plate 902, a bottom surface facing the face plate 906, and baffle through holes extending from the top surface through the baffle 910 to the bottom surface. The baffle 910 is positioned within the plenum volume 908 to direct gas outwardly throughout the plenum volume 908 and downwardly through the baffle 910 toward the face plate 906. Fig.13A A side view of the baffle is depicted, and Fig. 13B A top view of the baffle is depicted. Fig.13A , the top surface 932 and the bottom surface 934 of the baffle 910 are identified. In some embodiments, the top and bottom surfaces of the baffle can be planar and parallel to each other (including substantially parallel to each other given manufacturing tolerances and other tolerances). The baffle 910 can also be centered on the gas inlet 904 to provide uniform gas flow within the showerhead.

[0177] In some embodiments, such as Fig.13AAs shown, the baffle 910 may have a frustoconical surface 936 surrounding an outer region of the baffle. The frustoconical surface 936 may face the back plate 902; may have an angular component parallel to the central axis; and in some cases may face the second frustoconical surface 920 of the back plate 908. The first circumference of the frustoconical surface 936 may be defined by the outer diameter 938 of the top surface 932. In some cases, the second circumference of the frustoconical surface 936 may intersect with another surface, such as the curved surface 940 that may form the outer diameter 942 of the baffle 910. Similarly, there may be a curved surface between the top surface 932 and the frustoconical surface 936, which is at Fig.13A and 13B In some embodiments, the outer diameter 942 may be between about 140 mm and 200 mm. These surfaces and configurations achieve uniform fluid flow around the baffle edge, which can reduce shear forces on the baffle, thereby reducing particle generation.

[0178] In some embodiments, the angle θ4 of the frustum surface 936 of the baffle plate (measured from an axis parallel to the central axis of the baffle plate 910) can be complementary to the angle of the second frustum surface 920 of the backing plate 902. This can make the second frustum surface 920 of the backing plate 902 and the frustum surface of the baffle plate parallel to each other. Fig.14 Depicted Fig.10 . An enlarged portion of the right half of a cross-sectional view of a nozzle of . The baffle 910 is positioned inside the plenum volume 908; the frustoconical surface 936 of the baffle, the angle θ4 between it and the central axis 924, the second frustoconical surface 920 of the back plate 902, and the second angle θ2 are identified. These surfaces and angles are configured so that the angle θ4 and the second angle θ2 are complementary to each other and total 180°. In some embodiments, given manufacturing deviations and tolerances, these angles may not be exactly complementary, but may be very close to complementary and substantially complementary, for example within + / - 5° of 180°. In some embodiments, the angle θ4 may be approximately 110°, while the second angle θ2 may be approximately 70°. Return to reference Fig. 13B In the top view of the baffle in FIG. 9 , the frustum of the cone surface 936 highlighted with shaded area is shown to extend around the entire baffle 910 .

[0179] The through holes of the baffle can be configured to at least partially achieve uniform flow throughout the plenum volume (including across and through the baffle). In some embodiments, the number of through holes in the baffle 910 can affect the uniformity of the flow across and through the baffle 910. Generally speaking, gas flows along the path of least resistance, so if the through holes of the baffle 910, for example, cause a low pressure drop, the gas flow may be ejected through the through holes in the central area of ​​the baffle 910 and the through holes in the central area of ​​the panel; however, a higher pressure drop will push the gas flow more outward toward the edges of the baffle 910 and the edges of the panel. These potential results may cause uneven gas flow out of the panel, which may cause increased non-uniformity on the substrate. To promote a higher pressure drop, the number of through holes in the baffle 910, the diameter of the through holes, or both can be reduced to accompany the reduced internal volume compared to conventional showerheads. Otherwise, if the number of through holes in the baffle 910 is too large, if the through hole diameter is too large, or both, the pressure drop may be too low and the flux will be uneven across the baffle 910 from the center to the edge. Therefore, the number of through holes in the baffle and their diameters are configured to provide uniform flow through and across the baffle. Fig.14 , exemplary flow vectors are shown as black arrows showing gas flow from gas inlet 904 , across portions of baffle 910 , toward the edge of face plate 906 and through baffle through-holes 946 .

[0180] Return to Fig. 13B , a plurality of baffle through holes extending through the baffle 910 from the top surface to the bottom surface can be seen. In some embodiments, as Fig. 13B As depicted, some through-holes may have an outer diameter that is different from the outer diameters of other through-holes. In some such cases, the size of the outer diameter of a through-hole may increase as its radial distance from the center of the baffle increases. For example, a first segment of the baffle may have a first number of through-holes, each having a first outer diameter, and a second segment radially offset from the first segment relative to the center axis of the baffle may have a second number of through-holes, each having a second outer diameter, wherein the second outer diameter is greater than the first outer diameter.

[0181] Fig. 13C Depicted Fig. 13B951 . Here, the various segments of the baffle 910 are shaded, and the central axis 951 of the baffle is depicted as an "X"; as described above, the central axis 951 of the baffle can be colinear with the central axis 924 of the showerhead. The first segment 944 of the baffle (shown in dark shading) is located closest to and surrounds the central axis 951 of the baffle; a first number of through holes 946A are located in this segment, and they all have a first outer diameter. These through holes 946A are also arranged in a ring extending around the central axis 951 of the baffle. The second segment 948 (shown in light shading) is radially offset outward from the first segment 944 relative to the central axis 951 and is adjacent to the first segment; the second segment 948 is farther from the central axis 951 than the first segment 944. The second segment 948 contains a second number of through holes 946B, and they all have a second outer diameter, which is greater than the first diameter of the first number of through holes 946A in the first segment 944. A third segment 950 (shown in darker shading) is radially offset outward from both the first segment 944 and the second segment 948 and is adjacent to the second segment 948; the third segment 950 is further from the central axis 951 than the first and second segments. The third segment 950 includes a third number of through holes 946C, each having a third outer diameter that is greater than both the first diameter of the first number of through holes 946A in the first segment 944 and the second diameter of the second number of through holes 946B in the second segment 946. The third number of through holes 946C is also arranged along three rings around the central axis 951; the first and second segments have two rings of holes.

[0182] Three additional sections of the baffle are also highlighted with shading. A fourth section 952 is located radially outward from the third section 950 and includes a fourth number of through holes (not labeled) having a fourth outer diameter greater than the third outer diameter; this section also includes three rings of through holes. Similarly, a fifth section 954 is located radially outward from the fourth section 952 and includes a fifth number of through holes (not labeled) having a fifth outer diameter greater than the fourth outer diameter; this section also includes three rings of through holes. A sixth section 956 includes a sixth number of through holes (not labeled) having a sixth outer diameter greater than the fifth outer diameter; this section also includes two rings of through holes. In some embodiments, the first diameter may be between about 0.30 mm and 0.65 mm, the second diameter may be between about 0.50 mm and 0.75 mm, the third diameter may be between about 0.60 mm and 0.9 mm, the fourth diameter may be between about 0.7 mm and 1.1 mm, the fifth diameter may be between 0.8 mm and 1.25 mm, and the sixth diameter may be between about 0.9 mm and 1.4 mm. The configuration of the baffles provides uniform flow through the volume of the plenum, including through, across, and around the baffles.

[0183] The baffle is also positioned within the plenum volume to provide faster and more uniform fluid flow through the nozzle. In some embodiments, this includes positioning the central axis of the baffle so that it is colinear with the central axis of the gas inlet of the backing plate. This may also include positioning the baffle along the central axis so that the baffle is farther away from the gas inlet along the central axis than the first frustum of the cone surface. This may also include positioning the baffle so that the top surface of the baffle is farther away from the gas inlet along the central axis than the first circumference of the second frustum of the cone surface; this may also include positioning the top surface of the baffle along the central axis between the first and second circumferences of the second frustum of the cone surface. In some cases, the bottom surface of the baffle may be positioned along the central axis to be farther away from the gas inlet than the first circumference of the third frustum of the cone surface. The bottom surface of the baffle may also be offset from the panel along the central axis.

[0184] Return to Fig.14 The baffle is positioned within the plenum volume such that the baffle 910 is further away from the gas inlet 904 along the central axis 924 than the first frustum surface 918; the top surface 932 of the baffle 910 is further away from the gas inlet 904 along the central axis 924 than the first circumference C of the second frustum surface 920 1B Further away from the gas inlet 904; the top surface 932 is also positioned along the central axis 924 on the first circumference C of the second frustum surface 920 1B With the second circle C 2B and the bottom surface 934 of the baffle 910 is positioned along the central axis 924 than the first circumference C of the third frustum of the cone surface 922 1c Further away from the gas inlet 904. Fig.14 It can also be seen that the second circumference C of the third truncated cone surface 922 2C 906 along the central axis and offset from the back surface 912 of the panel 906. These positioning arrangements of the baffles within the plenum volume achieve uniform, rapid, and efficient fluid flow through the showerhead while simultaneously reducing the volume of the showerhead, which results in reduced fluid consumption and reduced particle contamination. As described herein, the positioning and configuration of the baffles allows the gas flow to be directed not only through the baffle through-holes, but also outwardly throughout the plenum volume and toward the edge of the panel. By directing the gas flow through the through-holes and outwardly throughout the plenum volume, a more spatially uniform gas flow can be achieved despite the fact that the total internal volume of the showerhead is reduced compared to conventional showerheads.

[0185] As described above, the panel also includes a plurality of through holes that extend through the panel and enable gas to flow from the plenum volume to the exterior of the showerhead and onto the substrate. Similar to what is described above regarding the baffle through holes, the number of through holes in the panel 906 may also affect the uniformity of the flow across the panel 906. Here, in order to promote a higher pressure drop, the number of through holes in the panel 906 may be reduced to accompany the reduced internal volume compared to conventional showerheads. If the number of through holes in the panel 906 is too large, the pressure drop may be too low, and the flux may not be uniform across the entire panel 906 from the center to the edge. In some embodiments, the number of through holes in the panel 906 may be between about 1000 through holes to about 3,000 through holes, or between about 2,500 to about 2,750 through holes.

[0186] In some embodiments, the through holes may all have the same outer diameter, such as between about 0.015 inches and 0.1 inches. The panel through holes may also be provided throughout the panel to create a uniform flow out of the panel. Fig.15A A plan view of a panel is depicted, wherein the front surface (which is configured to face the substrate) and through holes are visible. It can be seen that through holes 916 of panel 906 extend through the panel and front surface 914. The through holes are also arranged along a plurality of circles centered about the central axis of the panel, and the holes are offset from each other. For example, the panel may have through holes centered about the central axis of the panel, which are Fig.11A 916 identified in . Immediately adjacent to the central through hole may be a plurality of holes arranged equally spaced along a first circle having a first diameter; radially outwardly from the circle may be another circle having a second plurality of holes, the second plurality of holes having more holes than the plurality of holes, and the second plurality of holes may be equally spaced along the second circle. The equally spaced spacing may not always be exact and may be considered to be substantially equally spaced (which may be due to manufacturing or other inconsistencies), such that the spacing may vary from equal values ​​to within about + / - 5%.

[0187] Fig. 15B Depicted Fig.15A916 is identified and a plurality of other through holes are shown. The central through hole may be centered about the central axis of the panel. A first reference circle 958 is shown extending around the central through hole 916, and six holes are equally spaced along the first reference circle. Two through holes are centered on a baseline 961. A second reference circle 960 is radially offset from the first reference circle 958 and extends around the first reference circle 958; 12 through holes are equally spaced around the second reference circle 960, but these through holes are offset from the baseline 961 by a first angle, such as 15°. A third reference circle 962 is radially offset from the second reference circle 960 and extends around the second reference circle 960; 18 through holes are equally spaced around the third reference circle 962, and these through holes are not offset from the baseline 961. The fourth reference circle 964 is radially offset from the third reference circle 962 and extends around the third reference circle 962; the 24 through holes are equally spaced around the fourth reference circle 964, but the through holes are offset from the baseline 961 by a second angle, for example, 7.5°. The spacing may be as shown in FIG. Fig. 15C Continuing as described in the table shown, the table depicts the specifications of the panel through holes, such that panel 906 includes a total of 2,610 through holes, each having a diameter of approximately 0.04 inches (+ / - 0.001 inches). In some embodiments, the diameter of the through holes may be between about 0.03 and 0.05 inches, including 0.04 inches. The angles provided may also not be exact and may be in the range of, for example, + / - 1° or 0.5° due to variability and manufacturing deviations.

[0188] The exterior of the faceplate may also be configured to be positioned closer to a substrate on a pedestal than conventional showerheads; this in turn may help reduce fluid consumption and improve uniformity. As described above, some substrate supports, such as pedestals and electrostatic chucks (ESCs), may position a substrate in a cavity defined in part by a substrate support surface on which the substrate is positioned and an exterior wall above the substrate support surface. Many showerheads are designed to reside above and outside of the cavity of a substrate support. The exterior geometry of the faceplate disclosed herein may enable a portion of it to be positioned in the pedestal cavity and thereby reduce the pedestal-showerhead gap.

[0189] Fig.16AA cross-sectional side view of a showerhead and an exemplary pedestal is depicted. The exemplary pedestal 1680 includes a substrate support surface 1682 configured to hold and support a substrate, an outer wall 1684 (surrounded by a dotted shape) having a wall top surface 1686, and a cavity 1688 (shown in shading and dashed lines), wherein the cavity 1688 is at least partially defined by the substrate support surface 1682 and the outer wall 1684. The front surface 914 of the panel 906 faces the pedestal 1680, and a pedestal-showerhead gap 1690 measured between the front surface 914 of the panel 906 and the substrate support surface 1682 is shown. It can also be seen that the front surface 914 of the panel 906, and a portion of the panel 906, are positioned within the cavity 1688 of the pedestal such that the front surface 914 is closer to the substrate support surface 1682, i.e., the pedestal-showerhead gap 1690 is smaller than the distance between the wall top surface 1686 and the substrate support surface 1682.

[0190] Fig. 16B Depicted Fig.16A The enlarged part of Fig.14 Similar, but different, Fig. 16B 1680. Here, the spacing between the showerhead 900 and the pedestal 1680 is shown. Again, the front surface 914 of the panel 906 faces the pedestal 1680 and the pedestal-showerhead gap 1690, and the front surface 914 of the panel 906 can be positioned closer to the substrate support surface 1682 than the distance between the wall top surface 1686 and the substrate support surface 1682. The panel 906 can be positioned further within the cavity 1688 of the pedestal 1680.

[0191] In some embodiments, the outer diameter of the front surface 914 of the faceplate 906 can be sized to be smaller than the inner diameter of the wall of the pedestal so that the faceplate can fit within the substrate support cavity. In addition, the faceplate can have a frustoconical surface extending around the central axis of the showerhead, which further enables the front surface of the faceplate to be positioned closer to the pedestal. Fig.11A , 14 16, a panel frustum conical surface 966 is identified. In FIG. 15, the panel frustum conical surface 966 is also shown in shading; the surface 966 extends around the entirety of the panel 906 and is radially offset from the front surface 914 relative to the central axis 924. In some embodiments, the frustum conical surface can have a length between about 0.05 inches and 0.4 inches, a height between about 0.02 inches and 1.0 inches, and an angle greater than about 90° with the central axis 924, including an angle between about 95° and 150°.

[0192] Some components of the showerhead may be made of metal or metal alloys. For example, the back plate, baffle, and face plate may be made of metal or metal alloys, such as aluminum, aluminum 6061, quartz, and stainless steel. The material may be compatible with remote cleaning and may be a material that passivates or is not easily reactive with ammonia / fluorine free radicals.

[0193] The showerhead may also have one or more ports extending through a portion of the showerhead to enable a sensor to acquire data from outside the showerhead. Each port may have an opening in a faceplate of the showerhead that is configured to face the substrate support. In some embodiments, a window may be positioned at one end or along the port to protect the sensor from the environment outside the showerhead while still enabling the sensor to collect data through the port. Fig.10 and 11A , the nozzle includes a port 968 (enclosed by a dotted shape) extending through the face plate 906 and the back plate 902, and having an opening 970 in the face plate 902; a window portion 972 is also located at the rear end 974 of the port 968; these features are also identified at Fig.14 The nozzle may also include two or more ports (e.g., three), such as Fig.15A 968 in the panel 906. The ports may be positioned radially outward from the front surface 914 of the panel, as shown. Fig.10 , 11A , 14, and 15. The ports may be equally spaced along the circumference of the panel. In some cases, the equally spaced spacing may not always be exact and may be considered substantially equally spaced (which may be due to manufacturing or other inconsistencies), such that the spacing may vary from equal values ​​to within about + / - 5%. Windows are also shown in these figures and may be made of materials such as sapphire and quartz that can withstand exposure to various process gases.

[0194] The showerhead may include various sensors positioned adjacent to the window and configured to acquire data from the outside of the opening of the port in the showerhead. In some embodiments, the showerhead may include three lasers, each positioned adjacent to the port, so that the laser can emit lasers through the window, the port, and the opening. These lasers may be configured to detect the distance between the substrate support and the showerhead, and these distance measurements may be used for various advantageous adjustments. For example, the distance measurements from the lasers can more accurately and precisely detect the pedestal-showerhead gap, so that the gap can be reduced, which in turn can improve uniformity and reduce gas consumption. Conventional pedestal and showerhead configurations measure the pedestal-showerhead gap with an accuracy that cannot reach the level that can be obtained using laser measurements. In addition, these lasers can measure when the pedestal and showerhead are at high heat (e.g., 450°C) in a vacuum during processing (which may cause these components to warp). Accurately and precisely measuring the pedestal-showerhead gap to obtain the in-situ distance and state enables the showerhead and pedestal to be positioned and adjusted to the correct desired distance and position.

[0195] In some cases, these measurements also help determine if the showerhead is parallel to the pedestal. This can be considered the parallelism between the showerhead and the pedestal. The parallelism can be measured between the outer wall of the pedestal or the substrate supporting surface of the pedestal and the front surface of the showerhead. Deviations in parallelism between the pedestal and the showerhead can have a huge percentage impact on the gas flow to the wafer, including gas consumption and wafer uniformity. The smaller the pedestal-showerhead gap (which is achieved by the showerhead), the greater the percentage impact that parallelism can have on the gas flow to the wafer.

[0196] In some embodiments, the pedestal or ESC is adjustable in various directions, including a vertical z-direction parallel to the central axis of the showerhead, and in an xy plane perpendicular to the z-direction, and one or more tilted directions relative to one or more axes or points. When the substrate support is at a high operating temperature (e.g., 450° C.), the substrate support may warp and cause it to become misaligned with the showerhead, including the central axis becoming non-parallel, offset, and non-collinear. Measurements made by sensors on the showerhead can be used to determine the position of the substrate support relative to the showerhead and determine adjustments to the substrate support so that the showerhead can be more aligned with the pedestal. This can include, for example, measuring the substrate support, determining the plane of the substrate support, determining whether the plane of the substrate is within a specific threshold of alignment with the showerhead, and moving, rotating, or both the showerhead in one or more directions. For example, if three measurements of the distance between the substrate support and the showerhead are not equal or do not differ from each other within a specific threshold, it can be determined that the substrate support is not parallel to the showerhead. These measurements can be used to determine how the substrate support should be moved to become more aligned, such as rotating the substrate support about an axis, which may cause the substrate support to become more parallel to the showerhead, such as the distances at three points to become more equal to each other.

[0197] A controller as described herein may include instructions for controlling the substrate support to perform such movement, controlling the sensors, and making the determinations described above.

[0198] The showerheads described herein may provide one or more advantages. The configuration of the surface of the plenum volume (e.g., a frustum of a cone surface), the baffles, and the positioning of the baffles within the plenum volume allows the showerhead to have a reduced plenum volume, which reduces the amount of fluid consumed flowing through the showerhead and onto the substrate during precursor dosing and purging. This reduced volume also reduces the time flowing through the showerhead, which reduces purging time, and may also reduce dose (and plasma activation (if performed) time); these reduced times allow for increased throughput. The inventors found that in some experiments using the same process recipe (gas, flow rate, time, etc.), the use of a conventional showerhead resulted in the use of 10 L of precursor per substrate to produce a film of a certain thickness, while the use of the showerhead described herein resulted in the use of 6.5 L of precursor per substrate to produce a film of the same thickness.

[0199] The configuration of the nozzles described herein also improves flow uniformity, which in turn improves filling performance and film uniformity. One measure of deposition performance is the filling void fraction of the deposited film, where a lower filling void fraction indicates better filling and deposition. The use of the nozzles described herein improves the filling void fraction of the deposited film compared to conventional nozzles. As shown in Table 1 below, the inventors conducted four experiments in which the same gas formulation was flowed through the nozzles disclosed herein and conventional nozzles for a specific time. It can be seen that for the same process recipe, the use of the disclosed nozzles results in a lower filling void fraction, and therefore better deposition performance, compared to conventional nozzles.

[0200] Using the showerhead described herein also improves the uniformity of the deposited film. One measure of uniformity is the resistance non-uniformity of the deposited film, Rs NU, which is the inverse of the film uniformity. Fig.17A and 17B Plotted are the resistance non-uniformity measurements of two deposited films; the films were deposited using the same process recipe, but differed in that: Fig.17A The measurements shown in are for conventional sprinklers, while Fig. 17B The measurement results shown in are for the nozzle disclosed in this article. It can be seen from these two figures that Fig. 17B It is shown that the disclosed showerhead results in a more uniform resistance across the film, which indicates a more uniform film. Similarly, Fig. 17C and 17D Depicted are the resistance non-uniformity measurements of two other films deposited using the same process recipe (but with Fig.17A and 17B Different) for deposition, and the difference is that: Fig. 17C The measurements shown in the figure are for conventional sprinklers, while Fig.17D The measurements shown in are for the spray heads disclosed herein. Fig.17D The disclosed showerhead is shown to result in a more uniform resistance across the film and therefore a more uniform film.

[0201] The low volume showerhead of the present disclosure can be installed in a semiconductor processing chamber. The processing chamber may include a low volume showerhead mounted on the top of the chamber housing. The substrate support can support the semiconductor substrate in the processing chamber and below the low volume showerhead. A micro volume can be formed between the substrate support and the low volume showerhead. The micro volume can be used as a substrate reaction area and can assist in concentrating and maintaining the processing gas near the semiconductor substrate during processing. The substrate support can be configured to move up and down to facilitate loading and unloading operations. In some embodiments, the low volume showerhead can be suspended from the cover of the processing chamber by a rod, and the low volume showerhead may not itself constitute part of the "cover" of the processing chamber. In such an embodiment, the low volume showerhead can be configured to move up and down to facilitate substrate loading and unloading operations.

[0202] In some embodiments, one or more processing chambers may be provided as processing stations in a multi-station semiconductor processing tool. Figure 6 An example of a multi-station chamber is provided. In some embodiments, a single processing chamber may contain multiple processing stations, some or all of which may have their own showerhead assembly as described herein.

[0203] The foregoing describes embodiments 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. in conclusion

[0204] 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 back plate for a showerhead for semiconductor processing, the back plate comprising: Gas inlet; a first frustum of a cone surface extending around a central axis of the back plate; as well as a second frustum of a cone extending about the central axis, wherein: Relative to the central axis, the first truncated cone surface is located radially inside the second truncated cone surface, The first truncated cone surface is located closer to the gas inlet along the central axis than the second truncated cone surface, The first truncated cone surface is at a first angle relative to the central axis, and The second frustum of a cone surface is at a second angle relative to the central axis.

2. The backing plate of claim 1, further comprising a third frustum of a cone surface, wherein the third frustum of a cone surface is: Disposed radially outwardly from the second frustoconical surface relative to the central axis such that the second frustoconical surface is radially between the first frustoconical surface and the third frustoconical surface, and The center axis is disposed at a third angle relative to the center axis. The spray head according to claim 2 , wherein the third angle is greater than the first angle and the second angle.

4. The spray head according to claim 2, wherein: The second truncated cone surface has: an inner circumference disposed vertically along the central axis, and further away from the gas inlet outer circumference than the inner circumference and vertically offset from the inner circumference by a second height, and The third truncated cone surface has an inner circumference located at the same vertical position along the central axis as the outer circumference of the second truncated cone surface. The spray head of claim 1 , wherein the first angle is greater than the second angle.

6. The showerhead of claim 5, wherein the first angle is between about 50° and about 90°, and the second angle is between about 45° and about 85°. 7 . The spray head according to claim 1 , wherein an inner circumference of the second truncated cone surface is disposed radially outward from an outer circumference of the first truncated cone surface relative to the central axis.

8. The back plate according to claim 1, wherein: The first truncated cone surface has: a first circumference disposed vertically along the central axis, and a second circumference further away from the gas inlet than the first circumference and vertically offset from the first circumference by a first height, and The second truncated cone surface has an inner circumference located at the same vertical position along the central axis as the second circumference of the first truncated cone surface.

9. The backing plate of claim 1, further comprising a third surface spanning between the first frustoconical surface and the second frustoconical surface.

10. The backing plate of claim 9, wherein the third surface includes a planar portion perpendicular to the central axis.

11. The backing plate of claim 1, wherein an inner circumferential portion of the first frustoconical surface defines the gas inlet.

12. A nozzle, comprising: Gas inlet; a panel defined in part by a front surface and a back surface, and having a plurality of panel through holes extending through the panel from the front surface to the back surface; a backing plate fluidly connected to the gas inlet, the backing plate having a first frustoconical surface and a second frustoconical surface; as well as a plenum volume fluidly connected to the gas inlet and defined at least in part by the back surface of the panel, the first frustoconical surface, and the second frustoconical surface, wherein: The second truncated cone surface is disposed radially outward from the first truncated cone surface relative to the central axis of the nozzle, and The second truncated cone surface is disposed closer to the back surface of the panel along the central axis than the first truncated cone surface.

13. The spray head according to claim 12, wherein: The first truncated cone surface is at a first angle relative to the central axis, and The second frustum of a cone has a second angle relative to the central axis.

14. The sprayhead of claim 12, further comprising a baffle disposed within the plenum volume.

15. The spray head according to claim 14, wherein the baffle: The portion is defined by a top surface and a bottom surface, and A plurality of baffle through holes are provided extending through the baffle from the top surface to the bottom surface. 16 . The showerhead of claim 15 , wherein outer diameters of the plurality of baffle through-holes increase with increasing radial positioning relative to the central axis.

17. The spray head of claim 14, wherein an outer edge of the baffle is disposed radially outward from the first frustoconical surface relative to the central axis. 18 . The spray head according to claim 17 , wherein the outer edge of the baffle is radially disposed between an inner circumference of the second truncated cone surface and an outer circumference of the second truncated cone surface relative to the central axis.

19. The spray head of claim 12, wherein the faceplate further comprises a faceplate frustoconical surface disposed radially outward from a front surface of the faceplate relative to the central axis and offset from the central axis by a fifth angle greater than 90°.

20. The spray head according to claim 12, further comprising: a port including a first end and an opening at a second end and extending through the panel, wherein the opening may be located in the panel radially outward from the front surface, and A window portion is positioned adjacent to the first end of the port.

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