Hardware for uniformly distributing active nuclides for semiconductor film processing.

Abstract

A substrate processing system having a processing chamber is provided. The processing chamber includes a lid plate, one or more chamber sidewalls, and a chamber base that collectively define a processing volume. An annular plate is coupled to the lid plate, and an edge manifold is fluidly coupled to the processing chamber through the annular plate and the lid plate. The substrate processing system includes a central manifold coupled to the lid plate.

Description

Technical Field

[0001] Embodiments of the present specification relate to a system used in the manufacture of electronic devices, and more particularly, to a gas distribution system used to form a structure including tungsten and molybdenum in a semiconductor device.

Background Art

[0002] Tungsten (W) is widely used in the manufacture of integrated circuit (IC) devices to form conductive features where relatively low electrical resistance and relatively high resistance to electromigration are desired. For example, tungsten can be used as a metal filling material to form source contacts, drain contacts, metal gate fills, gate contacts, interconnects (e.g., horizontal features formed on the surface of a dielectric material layer), and vias (e.g., vertical features formed through a dielectric material layer to connect other interconnect features disposed above or below the dielectric material layer). Tungsten is also generally used to form bit lines and word lines used to address individual memory cells in a memory cell array of a dynamic random access memory (DRAM) device due to its relatively low resistance and high melting point.

[0003] As circuit density increases and device features continue to shrink to meet the requirements of next-generation semiconductor devices, it is becoming increasingly difficult to reliably fabricate tungsten features. Advances in integrated circuit technology require improved methods for depositing high melting point metals, particularly tungsten, to enhance uniform deposition across the substrate. Conventional deposition methods using point source distribution of active nuclei on the substrate cannot adjust the active nuclei between the center and the edge of the substrate. The uniformity of the layer thickness from the center to the edge of the substrate is affected by the inability to adjust the deposition gas.

[0004] Therefore, a system for adjusting the gas distribution of radical nuclei from the center to the edge of the substrate is needed. [Overview of the project]

[0005] In some embodiments, a substrate processing system having a processing chamber is provided. The processing chamber includes a lid plate, one or more chamber sidewalls, and a chamber base that collectively define a processing volume. An annular plate is coupled to the lid plate, and an edge manifold is fluidly coupled to the processing chamber through the annular plate and the lid plate. The substrate processing system includes a central manifold coupled to the lid plate.

[0006] In some embodiments, a gas supply system is provided that includes a lid plate having a first main surface and a second main surface opposite the first main surface. An annular plate is coupled to the first main surface of the lid plate. The gas supply system includes a blocker plate coupled to the second main surface of the lid plate. The gas supply system includes a central manifold fluidly coupled to an opening in the lid plate. An edge manifold is fluidly coupled to the central manifold and the annular plate.

[0007] In some embodiments, a method for processing a substrate is provided, which includes depositing a nucleation layer by exposing the substrate to a high-melting-point metal-containing gas using a gas supply system. The method involves exposing the substrate to a radical nuclide, wherein the radical nuclide is supplied to an edge region of a blocker plate positioned above the substrate, and the edge region is fluidly isolated from the inner region of the blocker plate.

[0008] To allow for a more detailed understanding of the features described above in this disclosure, a more detailed description of this disclosure, which has been briefly summarized above, can be given with reference to embodiments, some of which are shown in the accompanying drawings. However, it should be noted that the accompanying drawings show only exemplary embodiments and should not be considered to limit the scope of this disclosure, as other equally effective embodiments are possible. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic side view of a processing system according to several embodiments. [Figure 2A] This is a top view of a gas supply system according to several embodiments. [Figure 2B] This is a cross-sectional bottom view of an annular plate of a gas supply system according to several embodiments. [Figure 2C] This is a top view of the lid according to several embodiments. [Figure 3] This is a top view of a blocker plate according to several embodiments. [Figure 4] This is a process flowchart of a method for processing a substrate according to several embodiments. [Modes for carrying out the invention]

[0010] For ease of understanding, where possible, the same reference numerals are used to designate identical elements common to the figures. Elements and features of one embodiment are intended to be usefully incorporated into other embodiments without further detail.

[0011] Figure 1 schematically shows a processing system 100 that can be used to carry out the processing method described herein. Here, the processing system is configured to provide processing conditions for processing the substrate and processing conditions for cleaning the inside of the processing chamber 102.

[0012] As shown in Figure 1, the processing system 100 includes a processing chamber 102, a gas supply system 104 fluidly coupled to the processing chamber 102, and a system controller 108. The processing chamber 102 includes a chamber lid assembly 110, one or more side walls 112, and a chamber base 114, which together define a processing volume section 115. The processing volume section 115 is fluidly coupled to an exhaust section 117, such as one or more vacuum pumps, used to maintain the processing volume section 115 under near-atmospheric pressure conditions and to discharge processing gases and processing by-products from the processing volume section 115.

[0013] The chamber lid assembly 110 includes a lid plate 116 and a shower head 118 coupled to the lid plate 116, which define a gas distribution volume 119. The shower head 118 faces a substrate support assembly 120 located in the processing volume 115. As will be discussed below, the substrate support assembly 120 is configured to move a substrate support 122, and therefore a substrate 130 located on the substrate support 122, between a raised substrate processing position (as shown in the figure) and a lowered substrate transfer position (not shown). When the substrate support assembly 120 is in the raised substrate processing position, the shower head 118 and the substrate support 122 define a processing region 121.

[0014] The gas supply system 104 is fluid-coupled to the processing chamber 102 through a central manifold 107 and an edge manifold 103. The central manifold 107 is coupled to the lid plate 116 and fluid-coupled to the processing chamber 102 through a central gas inlet 123 located through the lid plate 116. The processing gas or cleaning gas supplied by the use of the gas supply system 104 flows through the central gas inlet 123 into the gas distribution volume section 119 and is distributed to the processing area 121 through a showerhead 118. In some embodiments, the processing gas or cleaning gas flows through an edge manifold 103. The edge manifold 103 is coupled to an annular plate 129 located on the outer surface of the lid plate 116. The edge manifold 103 is fluid-coupled to the processing chamber 102 through an opening 210 in the annular plate 129 and an edge gas hole 204 in the lid plate 116. An isolation valve 105 is located in the edge manifold 103 and is configured to control the gas flow ratio through the edge manifold 103. An opening 210 in the annular plate 129 is fluid-coupled to the edge manifold 103 and to a channel 212 located within the annular plate 129. The channel 212 is fluid-coupled to an edge gas hole 204 located in the lid plate 116.

[0015] The edge gas holes 204 are channels extending from the outer surface to the inner surface of the lid plate 116. In some embodiments, the edge gas holes 204 are arranged in a first shape that approximates the shape of an annular plate, for example, in a circular shape. In some embodiments, about 15 to 25 edge gas holes 204, for example, about 17 to 20, are arranged around the lid plate 116. In some embodiments, the edge gas holes 204 are angled radially inward from the outer surface to the inner surface of the lid plate 116. The outlets of the edge gas holes 204 on the inner surface of the lid plate 116 form a second shape having a different size from the first shape on the outer surface of the lid plate. It has been found that angling the edge gas holes allows for a space in which components can be fixed to the lid plate 116 within an opening in an annular plate 129, such as a central manifold 107. It has been further found that angling the edge gas holes allows for the supply of gas to specific volumetric areas, such as adjacent to the edges of substrates placed in a processing chamber. In some embodiments, the diameter of the first shape is the same as or larger than the diameter of the second shape, for example, about 1% larger, for example, about 2% larger, for example, about 5% larger, for example, about 8% to about 10% larger.

[0016] In some embodiments, the chamber lid assembly 110 further includes a perforated blocker plate 125 positioned between the central gas inlet 123 and the shower head 118. In those embodiments, the gas flowing into the gas distribution volume 119 is first diffused by the blocker plate 125, and together with the shower head 118, provides a more uniform or desired distribution of gas flow to the processing area 121.

[0017] The processing gas and processing by-products are exhausted radially outward from the processing area 121 through an annular channel 126 surrounding the processing area 121. The annular channel 126 may be formed in a first annular liner 127 positioned radially inward of one or more sidewalls 112 (as shown), or it may be formed in one or more sidewalls 112 used to protect the inner surface. In some embodiments, the processing chamber 102 includes one or more sidewalls 112 or one or more second liners 128 of the chamber base 114 derived from corrosive gases and / or undesirable material deposits.

[0018] In some embodiments, the purge gas source 137 includes a first connection that fluidly communicates with the processing volume 115, and as a result, the purge gas source 137 can be used to flow a chemically inert purge gas, such as argon (Ar), into a region positioned around the substrate and / or under the substrate positioned on the substrate support 122, for example, through an opening in the chamber base 114 surrounding the support shaft 162 of the substrate support assembly 120. The purge gas can be used to create a region of positive pressure above the substrate 130 positioned on the substrate support 122 (compared to below the substrate) during substrate processing. In some configurations, the purge gas is introduced through the chamber base 114, and as a result, the purge gas flows upward from the chamber base 114 and around the edge of the substrate support 122, and is discharged from the processing volume 115 through the annular channel 126. In this configuration, the purge gas reduces unwanted material deposition on the surface beneath the substrate support 122 by reducing and / or preventing the flow of material precursor gas beneath the substrate support 122.

[0019] The substrate support assembly 120 includes a movable support shaft 162 that extends in a sealed manner through the chamber base 114, such as being surrounded by a bellows 165 in the region below the chamber base 114, and a substrate support 122 positioned on the movable support shaft 162. To facilitate the transfer of substrates to and from the substrate support 122, the substrate support assembly 120 includes a lift pin assembly 166 which includes a plurality of lift pins 167 coupled to or positioned engaged with the lift pin hoop 168. The plurality of lift pins 167 are movably positioned in an opening formed through the substrate support 122.

[0020] The substrate 130 is transferred to and from the substrate support 122 through a slit valve located in the door 171, for example, one of the one or more side walls 112. Here, one or more openings in the area surrounding the door 171, for example, an opening in the door housing, are fluidly coupled to a purge gas source 137, for example, an argon (Ar) gas source. The purge gas is used to prevent the processing gas and cleaning gas from coming into contact with and / or degrading the seal surrounding the door, thereby extending the service life of the seal.

[0021] The substrate support 122 is configured for vacuum chucking, and the substrate 130 is fixed to the substrate support 122 by applying a vacuum to the interface between the substrate 130 and the substrate support surface, for example, using a vacuum source 172.

[0022] In some embodiments, the processing chamber 102 is configured directly for plasma processing. In those embodiments, the showerhead 118 can be electrically coupled to a first power source 131, such as an RF power source, that supplies power to form and maintain capacitively coupled plasma using a process gas flowing through the showerhead 118 into the processing region 121. In some embodiments, the processing chamber 102 instead includes an inductively coupled plasma generator (not shown), and the plasma is formed by inductively coupling RF power to a process gas disposed in the processing volume 115 by an antenna disposed in the processing chamber 102.

[0023] The processing system 100 is advantageously configured to perform each of the tungsten nucleation and bulk tungsten deposition processes without removing the substrate 130 from the processing chamber 102. Gases used to perform the individual processes and to clean residues from the inner surfaces of the processing chamber are delivered to the processing chamber 102 using a gas supply system 104 fluidly coupled to the processing chamber 102.

[0024] Generally, the gas supply system 104 includes one or more remote plasma sources, here, first and second radical generators 106A-106B, deposition gas sources 187A, 187B, and a conduit system 194 fluidly coupling the radical generators 106A-106B and the deposition gas source 140 to the lid assembly 110. The gas supply system 104 further includes a plurality of isolation valves, here, first and second valves 190A-190B respectively disposed between the radical generators 106A-106B and the lid plate 116, and the plurality of isolation valves can be used to fluidly isolate each of the radical generators 106A-106B from the processing chamber 102 and from each other. Deposition gases, such as tungsten-containing precursors, molybdenum-containing precursors, and reducing agents, are delivered from the deposition gas source 140 to the processing chamber 102 using the conduit system 194.

[0025] Each of the radical generators 106A to 106B is coupled to a respective power source 193A to 193B, such as a radio frequency (RF) power source. The power sources 193A to 193B are used to ignite and maintain the plasma delivered to the plasma chamber volume using the gas supplied from a corresponding first gas source 187A or second gas source 187B fluidly coupled to the plasma chamber volume. In some embodiments, the first radical generator 106A can be used to ignite and maintain a processing plasma from a non-halogen-containing mixed gas delivered from the first gas source 187A to the first plasma chamber volume. The second radical generator 106B can be used to generate cleaning radicals used in the chamber cleaning process by igniting and maintaining a cleaning plasma from a halogen-containing mixed gas (e.g., HCl, Cl2, F2) delivered from the second gas source 187B to the second plasma chamber volume.

[0026] The operation of the processing system 100 is facilitated by the system controller 108. The system controller 108 includes a programmable central processing unit, herein the CPU 195, operable by a memory 196 (e.g., non-volatile memory) and support circuitry 197. The CPU 195 is one of any form of general-purpose computer processor used in industrial environments, such as a programmable logic controller (PLC), for controlling various chamber components and sub-processors. The memory 196 coupled to the CPU 195 facilitates the operation of the processing chamber. The support circuitry 197 conventionally includes a cache, clock circuit, input / output subsystem, power supply, etc., and combinations thereof, coupled to the CPU 195 and to various components of the processing system 100 to facilitate the control of substrate processing operations.

[0027] The instructions in memory 196 are in the form of a program product, such as a program that implements the method of the present disclosure. In one example, the present disclosure may be implemented as a program product stored on a computer-readable storage medium for use in a computer system. The program of the program product defines the function of the embodiment (including the method of the present specification). Thus, a computer-readable storage medium is an embodiment of the present disclosure if it holds computer-readable instructions that direct the function of the method of the present specification.

[0028] Figure 2A is a top view of the gas supply system 104, and Figure 2B is a cross-sectional bottom view of the gas supply system 104. The gas supply system 104 includes an edge manifold 103 extending from a central manifold 107 to an annular plate 129. The edge manifold 103 is in fluid communication with the annular plate 129 through an opening 210 located in the annular plate 129. Figures 2A and 2B show a single edge manifold 103 coupled to a single opening 210 in the annular plate 129, but additional edge manifolds extending from the central manifold 107 to additional openings in the annular plate 129 are also conceivable. The additional manifolds can be spaced equally apart from each other to provide enhanced gas distribution. Gas is supplied through the edge manifold 103 to the opening 210 and through an outer channel 212 located in the edge manifold 103. The outer channel 212 distributes the gas to one or more points along an inner channel 206. In some embodiments, the outer channel 212 is coupled to a first intermediate channel 208a and a second intermediate channel 208b. The first intermediate channel 208a and the second intermediate channel 208b are each coupled to two or more points along the inner channel 206. Figures 2A and 2B show four points along the inner channel 206 coupled to the outer channel 212, but additional or fewer points, such as two to ten points, for example, three or four points, may be spaced around the inner channel 206.

[0029] Figure 2C shows a top view of the lid plate 116. The lid plate 116 includes a plurality of edge gas holes 204 arranged in a circular pattern similar to that of the annular plate 129. The inner channel 206 of the annular plate 129 is fluidly coupled to the edge gas holes 204 of the lid plate 116.

[0030] Figure 3 shows a top view of the blocker plate 125. The blocker plate 125 includes an edge region 302 and an inner region 304. Each of the edge gas holes 204 is fluid-coupled to the edge region 302 of the blocker plate 125. The central manifold 107 is fluid-coupled to the inner region 304 of the blocker plate 125. Each of the inner region 304 and the edge region 302 includes a plurality of openings 306. The openings 306 are in fluid communication with the gas distribution volume 119 and diffused to the processing region 121 through the shower head 118. The gas supply system described herein allows for the adjustment of process gas between the inner region and the edge region of the substrate, which is located below the shower head 118. The inner region and the edge region of the substrate correspond to the inner region 304 and the edge region 302 of the blocker plate 125. It has been found that the adjustment between the inner region and the edge region allows for uniform film deposition across the entire substrate. In contrast, conventional gas distribution assemblies, such as point source systems, deliver process gases using asymmetric radical nuclide delivery paths. Conventional point source systems include a single point, such as a central region for directing gas to the center of a gas diffuser, such as a showerhead with or without a blocker plate. As a result, the film thickness near the periphery of the substrate is reduced compared to the portion located radially inward.

[0031] In some embodiments, process gas adjustment includes switching between a gas flow from the edge manifold 103 to the edge region 302 and a gas flow from the central manifold 107 to the inner region 304. In some embodiments, process gas adjustment includes co-flowing the gas from the edge manifold 103 to the edge region 302 and the gas from the central manifold 107 to the inner region 304. The gas flow to the edge region 302 versus the gas flow to the inner region 304 is about 1:4 to about 4:1, for example, about 1:3 to about 1:2 or about 2:1 to about 3:1. In some embodiments, the total volumetric flow rate is about 100 sccm to about 500 sccm of process gas, such as a mixture of nitrogen and argon gases. In some embodiments, the process gas flows for about 5 seconds to about 20 seconds, for example, about 10 seconds to about 15 seconds. In some embodiments, the gas flow to the edge region 302 is about 100 sccm to about 200 sccm, and the gas flow to the inner region 304 is about 300 sccm to about 400 sccm.

[0032] The edge region 302 is formed between the outer edge 312 and the inner partition 310 that separates the inner region 304 from the edge region 302. The annular width of the edge region 302 between the outer edge 312 and the inner partition 310 is approximately 0.25 inches to approximately 1.0 inch. The inner region 304 has a diameter ratio of approximately 5:2. The edge region 302 is separated into segments between multiple segment dividers 308, for example, approximately 2 segments to approximately 8 segments, or for example, approximately 4 segments to approximately 6 segments. The segment dividers 308 were found to provide locations for mounting holes for fixing the blocker plate 125 and to enable enhanced flow uniformity through the edge region 302 of the blocker plate 125.

[0033] In some embodiments, two or more gases, such as an incubation gas including a nitrogen radical-containing gas and an argon-containing gas, are simultaneously flowed through the edge manifold 103. The ratio of the nitrogen-containing gas to the argon-containing gas is adjusted based on predetermined process parameters for film deposition. Similarly, the ratio of the two or more gas components can be controlled for the gas flow through the central manifold 107. The central manifold 107 and the edge manifold 103 can be controlled independently of each other. Although the figure shows a gas source coupled to the edge manifold 103 through the central manifold 107, additional gas sources may be coupled to the edge manifold 103 at other locations along the edge manifold 103. [Examples]

[0034] Figure 4 shows a process flowchart of method 400 for processing a substrate in several embodiments. This method includes depositing a nucleation layer by exposing the substrate to a gas precursor using a gas supply system in activity 402.

[0035] In activity 404, the nucleation layer on the substrate is exposed to radical nuclides. In some embodiments, exposure of the substrate to radical nuclides includes exposure of the central region of the substrate to radical nuclides. The inner region can be exposed at a pressure of about 0.5 Torr to about 2 Torr for about 5 seconds to about 15 seconds, for example, about 10 seconds. Radical nuclides can be generated and delivered from a remote plasma source. In some embodiments, while the central region is exposed to radical nuclides, a purge gas, such as argon gas, is supplied to the edge portion of the substrate.

[0036] In some embodiments, the remote plasma source may be blocked or bypassed so that the substrate is not exposed to additional radical nuclides for about 5 seconds or less, for example, for about 2 to 4 seconds. The radical nuclides are delivered to the substrate from the central manifold using the central opening of the lid plate.

[0037] In some embodiments, after the central part of the substrate is exposed and the plasma source is shut off, the edge portion of the substrate is exposed to a gas for about 1 second to about 5 seconds, for example, about 2 seconds to about 3 seconds. In some embodiments, the gas is a non-reactive gas such as argon. In some embodiments, after the edge portion is exposed to the gas, the edge portion of the substrate may be exposed to radical nuclides at a pressure of about 0.5 Torr to about 2 Torr for about 5 seconds to about 15 seconds, for example, about 10 seconds. The radical nuclides are delivered from the edge manifold to the substrate using multiple edge holes in the lid plate. In some embodiments, while the edge portion is exposed to radical nuclides, a purge gas such as argon is supplied to the central part of the substrate.

[0038] In activity 406, the bulk layer is deposited on top of the plasma-treated nucleated layer. In some embodiments, the bulk layer is deposited by supplying the process gas through a central manifold of the assembly. In some embodiments, the process gas is supplied through a periphery manifold in addition to the central manifold.

[0039] By applying a single-point source plasma to the center of a substrate using conventional methods, it was discovered that the bulk film thickness could be deposited in the center of the substrate but tapered towards the edges, resulting in a significantly thinner film thickness at the edges compared to the center. For example, in a substrate with a radius of 150 mm, the thickness at the outermost 50 mm of the substrate radius in a comparison sample was approximately 25% to 45% thinner than the thickness measured at the center of the substrate. In contrast, substrates treated using the systems and methods provided herein demonstrated substantially uniform substrate thickness throughout the substrate. The stacked films described herein (a combination of a nucleation layer from 402, plasma treatment from 404, and a deposited bulk layer from 406) demonstrated a difference of less than 25% in thickness at the outermost 50 mm of the substrate radius compared to the substrate thickness at the center, e.g., approximately 5% to 20%.

[0040] While the foregoing applies to embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope of the present disclosure, and the scope of the present disclosure is determined by the following claims.

Claims

1. A substrate processing system, A processing chamber comprising a lid plate, one or more chamber sidewalls, and a chamber base that collectively define the processing volume section, An annular plate connected to the lid plate, An edge manifold fluidly coupled to the processing chamber through the annular plate and the lid plate, The central manifold connected to the lid plate and A substrate processing system, including a substrate processing system.

2. The substrate processing system according to claim 1, further comprising a blocker plate coupled to the lid plate on the side facing the annular plate.

3. The substrate processing system according to claim 2, wherein the annular plate includes one or more channels that are in fluid communication with the edge manifold and edge gas holes arranged through the lid plate.

4. The substrate processing system according to claim 3, wherein the edge gas holes of the lid plate are fluid-coupled to the edge region of the blocker plate, and the blocker plate further includes a central region fluid-isolated from the edge region.

5. The substrate processing system according to claim 4, further comprising a valve assembly capable of switching the gas flow supplied to the edge region and the central region of the blocker plate.

6. The substrate processing system according to claim 1, wherein the annular plate includes channels disposed around the annular plate, and the channels are fluidly coupled to edge gas holes on the lid interface surface of the annular plate.

7. A gas supply system, A lid plate having a first main surface and a second main surface facing the first main surface, An annular plate bonded to the first main surface of the lid plate, A blocker plate bonded to the second main surface of the lid plate, A central manifold is fluidly coupled to the opening of the lid plate, The central manifold and the edge manifold fluidly coupled to the annular plate and A gas supply system, including a gas supply system.

8. The gas supply system according to claim 7, further comprising a shower head coupled to the blocker plate.

9. The gas supply system according to claim 7, wherein the lid plate includes a plurality of edge gas holes extending from the first main surface of the lid plate to the second main surface.

10. The gas supply system according to claim 9, wherein the plurality of edge gas holes are angled radially inward from the first main surface to the second main surface.

11. The gas supply system according to claim 9, wherein each inlet of each edge gas hole is in fluid communication with one or more channels of the annular plate.

12. The gas supply system according to claim 7, wherein the blocker plate includes an edge region defined between the outer peripheral edge of the blocker plate and the inner peripheral partition of the blocker plate.

13. The gas supply system according to claim 12, wherein the edge region includes a plurality of segments separated by a divider.

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