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 on 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. Advancements in integrated circuit technology require improved methods for depositing high melting point metals, particularly tungsten, to enhance uniform deposition across the entire substrate. Conventional deposition methods that use 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 is needed that can adjust the gas distribution of radical nuclei from the center to the edge of the substrate.

Summary of the Invention

[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 including a lid plate having a first major surface and a second major surface opposite the first major surface is provided. An annular plate is coupled to the first major surface of the lid plate. The gas supply system includes a blocker plate coupled to the second major surface of the lid plate. The gas supply system includes a central manifold fluidly coupled to an opening in the lid plate. The edge manifold is fluidly coupled to the central manifold and the annular plate.

[0007] In some embodiments, a method of processing a substrate is provided, the method including depositing a nucleation layer by exposing the substrate to a high melting point metal-containing gas using a gas supply system. The method includes exposing the substrate to radical nucleating species, where the radical nucleating species are supplied to an edge region of a blocker plate disposed above the substrate, and the edge region is fluidly isolated from an inner region of the blocker plate.

[0008] To enable a more detailed understanding of the features described above of the present disclosure, a more detailed description of the present disclosure briefly summarized above can be made with reference to the 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 as limiting the scope of the present disclosure, and other equally effective embodiments can be recognized.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2A

Figure 2B

Figure 2C

Figure 3

Figure 4

DETAILED DESCRIPTION OF THE INVENTION

[0010] For ease of understanding, where possible, the same reference numbers are used to designate the same elements common to the figures. It is intended that the elements and features of one embodiment may be beneficially incorporated into other embodiments without further elaboration.

[0011] FIG. 1 schematically shows a processing system 100 that can be used to execute the processing methods described herein. Here, the processing system is configured to provide processing conditions for processing a substrate and processing conditions for cleaning the interior of the processing chamber 102.

[0012] As shown in FIG. 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 sidewalls 112, and a chamber base 114, which collectively define a processing volume 115. The processing volume 115 is fluidly coupled to an exhaust section 117, such as one or more vacuum pumps, used to maintain the processing volume 115 at near-atmospheric pressure conditions and to exhaust processing gases and processing by-products from the processing volume 115.

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

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

[0015] The edge gas holes 204 are channels that extend 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 approximating the shape of an annular plate, for example, circular. In some embodiments, about 15 to about 25, for example, about 17 to about 20 edge gas holes 204 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 outlet of the edge gas holes 204 on the inner surface of the lid plate 116 forms a second shape having a size different from the first shape on the outer surface of the lid plate. It has been discovered that angling the edge gas holes allows for a space in which components can be fixed to the lid plate 116 within the opening of an annular plate 129 such as the central manifold 107. It has further been discovered that angling the edge gas holes allows for gas to be supplied to a specific volume, such as adjacent to the edge of a substrate disposed within the 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 disposed between the central gas inlet 123 and the showerhead 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 showerhead 118, provides a more uniform or desired distribution of the gas flow to the processing region 121.

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

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

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

[0020] The substrate 130 is transferred to and from the substrate support 122 through a door 171, such as a slit valve disposed in one of the one or more side walls 112. Here, one or more openings in the region surrounding the door 171, such as the opening of the door housing, are fluidly coupled to a purge gas source 137, such as an argon (Ar) gas source. The purge gas is used to prevent the process gas and the cleaning gas from contacting 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 receiving surface, such as 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 respective power supplies 193A to 193B, such as a radio frequency (RF) power supply. The power supplies 193A to 193B are used to ignite and maintain the plasma delivered to the plasma chamber volume using the gas supplied from the 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 the processing plasma from the 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 the cleaning radicals used in the chamber cleaning process by igniting and maintaining the cleaning plasma from the halogen-containing mixed gas (e.g., HCl, Cl 2 , F 2 ) 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 the memory 196 (e.g., non-volatile memory) and support circuits 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 circuits 197 conventionally include 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 the memory 196 are in the form of a program product such as a program for implementing 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 functions of the embodiments (including the methods described herein). Thus, a computer-readable storage medium is an embodiment of the present disclosure when it holds computer-readable instructions that direct the functions of the methods described herein.

[0028] FIG. 2A is a top view of the gas supply system 104, and FIG. 2B is a bottom cross-sectional view of the gas supply system 104. The gas supply system 104 includes an edge manifold 103 that extends from the central manifold 107 to the annular plate 129. The edge manifold 103 is in fluid communication with the annular plate 129 through an opening 210 disposed in the annular plate 129. FIGS. 2A and 2B show a single edge manifold 103 coupled to a single opening 210 of the annular plate 129, but additional edge manifolds extending from the central manifold 107 to additional openings of the annular plate 129 are also contemplated. The additional manifolds are equally spaced from each other and can provide enhanced gas distribution. Gas is supplied to the opening 210 through the edge manifold 103 and is supplied through an outer channel 212 disposed in the edge manifold 103. The outer channel 212 distributes gas at one or more points along the 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 of the points along the inner channel 206. FIGS. 2A and 2B show four points along the inner channel 206 coupled to the outer channel 212, but additional or fewer points, such as from 2 to 10 points, such as 3 points or 4 points, etc., may be spaced around the inner channel 206.

[0029] FIG. 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 shape similar to the shape 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] FIG. 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 fluidly coupled to the edge region 302 of the blocker plate 125. The central manifold 107 is fluidly 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 apertures 306. The apertures 306 are in fluid communication with the gas distribution volume 119 and are diffused to the processing region 121 through the showerhead 118. The gas supply system described herein enables adjustment of the process gas between the inner region and the edge region of the substrate disposed below the showerhead 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 discovered that adjustment between the inner region and the edge region enables uniform film deposition across the entire substrate. In contrast, conventional gas distribution assemblies such as point source systems deliver process gas using an asymmetric radical species delivery path. Conventional point source systems include a single point such as a central region for guiding gas to the center of a gas diffuser such as a showerhead with a blocker plate or a showerhead without a blocker plate. As a result, the film thickness near the peripheral portion of the substrate is reduced compared to the portion disposed radially inward.

[0031] In some embodiments, adjusting the process gas includes switching the gas flow between the edge manifold 103 and the edge region 302 and the gas flow between the central manifold 107 and the inner region 304. In some embodiments, adjusting the process gas includes co-flowing the gas between the edge manifold 103 and the edge region 302 and the gas between the central manifold 107 and the inner region 304. The gas flow to the edge region 302 to 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, etc. In some embodiments, the total volume flow rate is about 100 sccm to about 500 sccm of a process gas such as a mixed gas of nitrogen gas and argon gas. In some embodiments, the process gas is flowed for about 5 seconds to about 20 seconds, for example, about 10 seconds to about 15 seconds, etc. 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. In some embodiments, the gas flow to the inner region 304 is about 100 sccm to about 200 sccm, and the gas flow to the edge region 302 is about 300 sccm to about 400 sccm.

[0032] The edge region 302 is formed between an outer peripheral edge 312 and an inner peripheral partition 310 that separates the inner region 304 from the edge region 302. The annular width of the edge region 302 between the outer peripheral edge 312 and the inner peripheral partition 310 is about 0.25 inches to about 1.0 inch. The inner region 304 includes a diameter in a ratio of about 5:2. The edge region 302 is separated into segments between a plurality of segment dividers 308, for example, about 2 segments to about 8 segments, for example, about 4 segments to about 6 segments, etc. The segment divider 308 has been found to provide a location for mounting holes for fixing the blocker plate 125 and 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 treatment gas like 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, for the gas flow through the central manifold 107, the ratio of the components of two or more gases can be controlled. The central manifold 107 and the edge manifold 103 can be controlled independently of each other. Although the figure shows the gas source being coupled to the edge manifold 103 through the central manifold 107, additional gas sources may also be coupled to the edge manifold 103 at other locations along the edge manifold 103. [Examples]

[0034] Figure 4 shows a process flow diagram of a method 400 for processing a substrate in some 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 species. In some embodiments, exposing the substrate to radical species includes exposing the central portion of the substrate to radical species. The inner region can be exposed for a period of about 5 seconds to about 15 seconds, such as about 10 seconds, at a pressure of about 0.5 Torr to about 2 Torr. The radical species can be generated and delivered from a remote plasma source. In some embodiments, while the central portion is being exposed to the radical species, 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 species for a period of about 5 seconds or less, such as about 2 seconds to about 4 seconds. The radical species are delivered to the substrate from the central manifold using the central opening of the lid plate.

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

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

[0039] By flowing a single point source of plasma, such as using a conventional method, to the center of the substrate, the bulk film thickness is deposited at the center of the substrate but tapers towards the edge of the substrate, such that the film thickness can be significantly thinner at the edge of the substrate compared to the center of the substrate. For example, in a substrate having a 150 mm radius, in the outermost 50 mm of the substrate radius of the comparative sample, the thickness was about 25% to about 45% thinner than the thickness measured at the center of the substrate. In contrast, substrates processed using the systems and methods provided herein demonstrated a substantially uniform substrate thickness across the entire substrate. The stack film described herein (a combination of the nucleation layer from 402, the plasma treatment from 404, and the deposited bulk layer from 406) demonstrated a difference in thickness of less than 25%, such as about 5% to about 20%, between the outermost 50 mm of the substrate radius and the thickness at the center of the substrate.

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

Claims

Claim 1 A substrate processing system, comprising: A processing chamber including a lid plate, one or more chamber sidewalls, and a chamber base that collectively define a processing volume; An annular plate coupled to the lid plate; An edge manifold fluidly coupled to the processing chamber through the annular plate and the lid plate; A central manifold coupled to the lid plate A substrate processing system comprising the above. Claim 2 The substrate processing system according to claim 1, further comprising a blocker plate coupled to the lid plate on a side facing the annular plate. Claim 3 The substrate processing system according to claim 2, wherein the annular plate includes one or more channels in fluid communication with the edge manifold and edge gas holes disposed through the lid plate. Claim 4 The substrate processing system according to claim 3, wherein the edge gas holes of the lid plate are fluidly coupled to an edge region of the blocker plate, and the blocker plate further includes a central region fluidly isolated from the edge region. Claim 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. Claim 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 a lid interface surface of the annular plate. Claim 7 A gas supply system, comprising: A lid plate having a first major surface and a second major surface facing the first major surface; An annular plate coupled to the first major surface of the lid plate; A blocker plate coupled to the second major surface of the lid plate; A central manifold fluidly coupled to an opening of the lid plate; An edge manifold fluidly coupled to the central manifold and the annular plate A gas supply system comprising the above. Claim 8 The gas supply system according to claim 7, further comprising a shower head coupled to the blocker plate. Claim 9 The gas supply system according to claim 7, wherein the lid plate includes a plurality of edge gas holes extending from the first major surface to the second major surface of the lid plate. Claim 10 The gas supply system according to claim 9, wherein the plurality of edge gas holes are angled radially inward from the first major surface to the second major 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 an outer peripheral edge of the blocker plate and an 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 dividers.

14. A method of processing a substrate, comprising: depositing a nucleation layer by exposing the substrate to a high melting point metal-containing gas using a gas supply system; and exposing the substrate to radical nuclides, wherein the radical nuclides are supplied to an edge region of a blocker plate disposed above the substrate, and the edge region is fluidly isolated from an inner region of the blocker plate. A method of processing a substrate, comprising the steps of:

15. The method according to claim 14, wherein depositing the nucleation layer includes supplying the high melting point metal-containing gas to the inner region of the blocker plate.

16. The method according to claim 15, wherein exposing the substrate to the radical nuclides includes exposing the substrate to nitrogen-containing nuclides and non-reactive nuclides.

17. The method according to claim 14, further comprising opening a valve to flow the radical nuclides from a central manifold to an edge manifold of the gas supply system.

18. The method according to claim 14, wherein exposing the substrate to the radical nuclides includes supplying the radical nuclides to the inner region of the blocker plate before supplying the radical nuclides to the edge region of the blocker plate.

19. The method according to claim 14, further comprising depositing a bulk layer on the nucleation layer.

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