Patent Application
20160111257
The invention relates to gas delivery systems for semiconductor substrate processing apparatuses. More particularly, the invention relates to a gas delivery substrate for mounting gas supply components of a gas delivery system for a semiconductor processing apparatus.
Semiconductor substrate processing apparatuses are used for processing semiconductor substrates by techniques including, but not limited to, plasma etching, physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), plasma enhanced atomic layer deposition (PEALD), ion implantation, and resist removal. Semiconductor substrate processing apparatuses include gas delivery systems through which process gas is flowed and subsequently delivered into a processing region of a vacuum chamber of the apparatus by a gas distribution member such as a showerhead, gas injector, gas ring, or the like. For example, the gas delivery system can be configured to supply process gas to a gas injector positioned in the chamber above a semiconductor substrate so as to distribute process gas over a surface of the semiconductor substrate being processed in the chamber. Current gas delivery systems are constructed from many individual components, many of which have conduits therein through which process gas flows.
Conventional semiconductor processing systems typically utilize gas sticks. The term “gas sticks” refers, for example, to a series of gas distribution and control components such as a mass flow controller (MFC), one or more pressure transducers and/or regulators, a heater, one or more filters or purifiers, and shutoff valves. The components used in a given gas stick and their particular arrangement can vary depending upon their design and application. In a typical semiconductor processing arrangement, over seventeen gases may be connected to the chamber via gas supply lines, gas distribution components, and mixing manifolds. These are attached to a base plate forming a complete system known as a “gas panel” or “gas box” which serves as a mounting surface and does not play a role in gas distribution.
In general, a gas stick comprises multiple integrated surface mount components (e.g., valve, filter, etc.) that are connected to other gas control components through channels on a substrate assembly or base plate, upon which the gas control components are mounted. Each component of the gas stick is typically positioned above a manifold block in a linear arrangement. A plurality of manifold blocks form a modular substrate, a layer of manifold blocks that creates the flow path of gases through the gas stick. The modular aspect of conventional gas sticks allow for reconfiguration, much like children's LEGO® block toys. However, each component of a gas stick typically comprises highly machined parts, making each component relatively expensive to manufacture and replace. Each component is typically constructed with a mounting block, which in turn is made with multiple machine operations, making the component expensive. In addition, conventional gas sticks require a substantial amount of space, long connections between components, multiple seals between components, and comprise multiple potential failure points and contamination points. Also, the long connections result in gas delivery delays, which adversely affect gas pulsing times and switching times. Thus, there is a need for an improved substrate for mounting gas supply components for a semiconductor processing apparatus.
Disclosed herein is a gas delivery substrate for mounting gas supply components of a gas delivery system for a semiconductor processing apparatus. The substrate includes a plurality of layers having major surfaces thereof bonded together forming a laminate. The laminate includes openings configured to receive and mount at least a first gas supply component, a second gas supply component, a third gas supply component, and a fourth gas supply component on an outer major surface of at least one of the layers. The substrate includes a first gas channel extending at least partially into an interior major surface of one of the layers, a second gas channel extending at least partially into a different interior major surface of one of the layers, wherein the first gas channel is at least partially overlapping the second gas channel. In addition, the substrate includes a first gas conduit including the first gas channel configured to connect the first gas supply component to the second gas supply component, and a second gas conduit including the second channel configured to connect the third gas supply component to the forth gas supply component.
Also disclosed herein is a system for a gas block that includes the gas delivery substrate. The system includes gas supply components mounted on at least one major surface. In one embodiment, the gas supply components can be mounted on opposed major surfaces. In another embodiment, the system includes an on/off gas valve connected to an MFC through a gas conduit within the substrate, another on/off gas valve connected to a mixing manifold through a gas conduit within the substrate, and a mixing manifold exit connected to one or more openings on the laminate.
Disclosed herein is a method of producing the gas delivery substrate. The method includes creating a first gas channel extending into an interior major surface of at least one layer of a plurality of layers having major surfaces thereof, creating a second gas channel extending at least partially into a different interior major surface, and creating openings on an outer major surface. At least some of the openings are mounting holes configured to receive and mount at least a first gas supply component, a second gas supply component, a third gas supply component, and a fourth gas supply component. The method further includes bonding the layers together to form a laminate such that the first gas channel is at least partially overlapping the second gas channel, the first gas channel forms part of a first gas conduit connecting the first gas supply component to the second gas supply component, and the second gas channel forms part of a second gas conduit connecting the third gas supply component to the fourth gas supply component.
Disclosed herein is a method of delivering gas through the gas delivery substrate, wherein gases are supplied through the openings of the laminate. The method includes delivering a first gas from the first gas supply component to the second gas supply component through the first gas channel, and delivering the first gas from the second gas supply component to a mixing manifold within the substrate through a third gas channel in the substrate. The method further includes delivering a second gas from the third gas supply component to the fourth gas supply component through the second gas channel, and delivering the second gas from the fourth gas supply component to the mixing manifold within the substrate through a fourth gas channel in the substrate. The method includes mixing the first gas and the second gas in the mixing manifold to create a first gas mixture and delivering the first gas mixture through one or more gas channels in the substrate and/or one or more outlets on the substrate to a semiconductor processing chamber downstream.
Disclosed herein is a gas delivery substrate for mounting gas supply components of a gas delivery system for a semiconductor processing apparatus and methods for producing and using the same. The semiconductor substrate processing apparatus can be used for processing semiconductor substrates by techniques including, but not limited to, plasma etching, physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), plasma enhanced atomic layer deposition (PEALD), ion implantation, or resist removal. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present embodiments. It will be apparent, however, to one skilled in the art that the present embodiments may be practiced without some or all of these specific details. In other instances, well known process operations have not been described in detail in order not to unnecessarily obscure present embodiments disclosed herein. Additionally, as used herein, the term “about” when used with reference to numerical values refers to ±10%.
As integrated circuit devices continue to shrink in both their physical size and their operating voltages, their associated manufacturing yields become more susceptible to contamination. Consequently, fabricating integrated circuit devices having smaller physical sizes requires that the level of contamination be less than previously considered to be acceptable. In addition, the wafers and processing equipment used in semiconductor processing are becoming more complex and larger in size, in order to produce more dies per wafer. Accordingly, producing and maintaining the equipment and manufacturing the wafers is becoming more expensive.
Gas distribution systems of semiconductor substrate processing apparatuses can utilize gas sticks which are a series of gas distribution and control components such as a mass flow controller (MFC), one or more pressure transducers and/or regulators, one or more heaters, one or more filters or purifiers, manifolds, gas flow adaptors, and shutoff valves. The components used and their particular arrangement in a gas stick can vary depending upon their design and application. For example, in a semiconductor substrate processing arrangement, over seventeen process gases can be supplied to the chamber via gas supply lines and gas distribution system components. The gas distribution system components are attached to a base plate (i.e. gas pallet) forming the system which is also known as a “gas panel” or “gas box.”
As discussed above, gas delivery system components are made from metals such as stainless steel or other metal alloys wherein constituent components are assembled together, requiring interfaces and seals between the constituent components, in order to achieve a desired conduit path for process gas. However, the constituent components typically comprise highly machined parts, making each component relatively expensive to manufacture, maintain and replace. Each component is typically constructed with a mounting block, which in turn is made with multiple machine operations, making the component expensive. Interchangeable components require a substantial amount of space and longer connections to connect the components with each other. Thus, the interchangeable components have multiple potential failure points, contamination points, and introduce gas delivery delays.
Corrosion, erosion, and/or corrosion/erosion in environments, such as those formed in the interior of gas delivery systems may contain oxygen, halogens, carbonyls, reducing agents, etching gases, depositing gases, and/or hydro-fluorocarbon process gas, or process gases which may be used in semiconductor substrate processing such as but not limited Cl2, HCl, BCl3, Br2, HBr, O2, SO2, CF4, CH2F2, NF3, CH3F, CHF3, SF6, CO, COS, SiH4 H2. In addition inert gases, such as but not limited Ar and N2, may be supplied to said environments.
Accordingly, disclosed herein is a gas delivery substrate for mounting gas supply components of a gas delivery system for a semiconductor processing apparatus and methods for producing and using the same. The substrate can be formed from laminated layers which are bonded together to create a uniform monolithic structure having gas tight channels that can be in fluid communication with each other. The substrate can be configured to receive and mount gas supply components such that the gas supply components are in fluid communication with each other via channels within the substrate. The layered structure of the substrate can allow channels or connections to be created of any size, in any direction, in three dimensional space (e.g., X-direction, Y-direction, and Z-direction) within the substrate. In this way, gas supply components of a gas delivery system can be housed closer together and the connections between components can be made shorter, which reduces the size of the gas delivery system. In addition, gas supply components and their connections often need to be made from high quality materials, such as expensive metal alloys (e.g., Hastelloy®), glass or ceramics. In an embodiment, all of the metallic surfaces which may contact process gases (i.e. become chemically wetted) can be eliminated or reduced so as to comply with on wafer (i.e. substrate) purity requirements. This compact design allows for reduced material costs while also reducing the number of possible contamination and failure points, and faster gas delivery pulsing and switching times for a gas delivery system.
Once process gases are introduced into the interior of vacuum chamber 200, they are energized into a plasma state by an antenna 18 supplying energy into the interior of vacuum chamber 200. Preferably, the antenna 18 is an external planar antenna powered by a RF power source 240 and RF impedance matching circuitry 238 to inductively couple RF energy into vacuum chamber 200. However, in an alternate embodiment, the antenna 18 may be an external or embedded antenna which is nonplanar. An electromagnetic field generated by the application of RF power to the antenna energizes the process gas in the interior of the vacuum chamber 200 to form high-density plasma (e.g., 109-1012 ions/cm3) above substrate 214. During an etching process, the antenna 18 (i.e. a RF coil) performs a function analogous to that of a primary coil in a transformer, while the plasma generated in the vacuum chamber 200 performs a function analogous to that of a secondary coil in the transformer. Preferably, the antenna 18 is electrically connected to the RF impedance matching circuitry 238 by an electrical connector 238b (i.e. lead) and the RF power source 240 is electrically connected to the RF impedance matching circuitry 238 by an electrical connector 240b.
Substrate 322 is of a modular design which comprises multiple interchangeable parts which are connected to each other with seals, which introduce potential failure points. Since substrate 332 is made up of multiple parts, it allows for a LEGO® type construction. However, this design causes the flow path between gas supply components to become long, which increases size, introduces multiple failure points and delays when delivering gas.
Accordingly, disclosed herein is a gas delivery substrate for mounting gas supply components of a gas delivery system that can be formed from stacked layers which are bonded together to create a uniform monolithic structure that is configured to receive and mount gas supply components such that the gas supply components are in fluid communication with each other via channels within the substrate. The layered structure of the substrate can allow gas channels or conduits to be created of any size, in any direction. In addition, the layered substrate can include channels or conduits for running electrical wire connections between gas supply comments. Also, the substrate can include channels or conduits for carrying air between gas supply components. For example, the channels or conduits within the substrate can provide air supply connections between a pneumatic manifold and diaphragm values (e.g., on/off valves). For example, the diaphragm valves can include a solenoid which is actuated by air, in order to control the flow of gas. Thus, gas supply components can be housed closer together on the substrate and the connections between components can made shorter than the connections within substrate 322, as shown in
As shown in
In addition, vertical through holes 410 can take any shape, pattern or direction. Vertical through holes 410 can extend partially and/or completely through a layer. Also, vertical through holes 410 can be configured to create a gas tight connection with vertical through holes and/or horizontal channels of another layer when multiple layers are bonded together. Vertical through holes 410 can be set perpendicular to a plane of a layer or at any angle which respect to the plane of the layer. Vertical through holes 410 can be tapered in size. For example, vertical through holes 410 can be wider at one end and smaller at another end. In other words, vertical through holes 410 can extend vertically or at an angle in any direction within the three dimensional space of a layer (e.g., X-direction, Y-direction, and Z-direction).
Also shown in
In addition, horizontal channels 420 can follow any path (e.g., winding or curved) within a layer. Horizontal channels 420 can extend in any direction within the layer. For example, horizontal channels 420 can extend radially from a common point or curve around a common point in the axial direction. In other words, horizontal channels 420 can extend any in direction in the three dimensional space of a layer (e.g., X-direction, Y-direction, and Z-direction). In addition, horizontal channels 420 can extend partially into an interior major surface of a layer or completely through an interior major surface of a layer within the substrate.
Referring now to
Also shown in
The substrate can be formed such that it is configured to receive and mount gas supply components on both the top layer and bottom layer. In addition, the substrate can be formed with three sides or more sides (e.g., a triangular shape, a rectangle, pentagon, hexagon, etc.), such that the one or more sides of the substrate are configured to receive and mount gas supply components. Alternatively, the layered substrate can be formed in a circular, oval or curvy shape (e.g., a single vertical side). Also, the substrate can be formed with a mixture of flat angular sides and curved sides (e.g., a “D” shape). In addition, the substrate can be formed such that it is configured with one or more gas inlets and one or more gas outlets. The gas inlets and outlets can be included in any layer or across more than one layer of the substrate. The gas outlets can be configured to connect to one or more gas lines and/or a processing chamber downstream.
As shown in
Referring now to
The gas delivery substrate can be configured to receive and mount gas supply components such that different components can be shared between different gas lines. This design can save space and reduce costs while also reducing gas pulsing and switching times. In addition,
For example, a mixing manifold within the substrate can include a cylindrical mixing chamber housed within one or more layers or on a surface of the substrate, and the gas inlets may be located at circumferentially spaced locations on any side of the substrate. Arranging all gases in a cylindrical arrangement in this way collapses a linear tubular design into a single mixing point—that is to say, by arranging all gases in a circular arrangement such that the length scale approaches zero (or is zero), high and low flow gases can be mixed instantly, and co-flow effects (i.e., gas mixing delays due to gas position or location) can be eliminated.
In embodiments, a manual valve may be mounted on the gas delivery substrate for carrying out the supply or isolation of a particular gas supply. The manual valve may also have a lockout/tagout device above it. Worker safety regulations often mandate that plasma processing manufacturing equipment include activation prevention capability, such as a lockout/tagout mechanism. A lockout generally refers, for example, to a device that uses positive means such as a lock, either key or combination type, to hold an energy-isolating device in a safe position. A tagout device generally refers, for example, to any prominent warning device, such as a tag and a means of attachment that can be securely fastened to an energy-isolating device in accordance with an established procedure.
A regulator may be mounted on the gas delivery substrate to regulate the gas pressure of the gas supply and a pressure gas may be used to monitor the pressure of the gas supply. In embodiments, the pressure may be preset and need not be regulated. In other embodiments, a pressure transducer having a display to display the pressure may be used. The pressure transducer may be positioned next to the regulator. A filter may be used to remove impurities in the supply gas. A primary shut-off valve may be used to prevent any corrosive supply gases from remaining in the substrate. The primary shut-off valve may be, for example, a two-port valve having an automatic pneumatically operated valve assembly that causes the valve to become deactivated (closed), which in turn effectively stops gas flow within the substrate. Once deactivated, a non-corrosive purge gas, such as nitrogen, may be used to purge one or more portions within the substrate. The purge gas component and the substrate may have, for example, three ports to provide for the purge process (i.e., an entrance port, an exit port, and a discharge port).
A mass flow controller (MFC) may be located adjacent the purge valve. The MFC accurately measures the flow rate of the supply gas. Positioning the purge valve next to the MFC allows a user to purge any corrosive supply gases in the MFC. A mixing valve next to the MFC may be used to control the amount of supply gas to be mixed with other supply cases on the substrate. In an embodiment, a portion of the MFC can be built into one or more layers of the substrate. For example, a flow restrictor (e.g., a filter with one or more small holes) or a flow diverter can be built into one or more layers of the substrate.
In embodiments, a discrete MFC may independently control each gas supply. Exemplary gas component arrangements, and methods and apparatuses for gas delivery are described, for example, in U.S. Patent Application Publication No. 2010/0326554, U.S. Patent Application Publication No. 2011/0005601, U.S. Patent Application Publication No. 2013/0255781, U.S. Patent Application Publication No. 2013/0255782, U.S. Patent Application Publication No. 2013/0255883, U.S. Pat. No. 7,234,222, U.S. Pat. No. 8,340,827, and U.S. Pat. No. 8,521,461, each of which are commonly assigned, and the entire disclosures of which are hereby incorporated by reference herein in their entireties.
In other embodiments, MFCs may be used to initiate the desired flow set point for each gas and then release the respective gases for immediate mixing in a mixing manifold within the gas delivery substrate. Individual gas flow measurement and control may be performed by each respective MFC. Alternatively, a single MFC controller can operate multiple gas lines.
In embodiments, MFCs may be controlled by a remote server or controller. Each of the MFCs may be a wide range MFC having the ability to perform as either a high flow MFC or a low flow MFC. The controller may be configured to control and change the flow rate of a gas in each of the MFCs.
The present disclosure further provides, in embodiments, a method of using a gas delivery substrate for mounting gas supply components of a gas delivery system for a semiconductor processing apparatus for supplying process gas to a processing chamber of a plasma processing apparatus. Such a method may include, for example, delivering different gases between gas supply components mounted on the substrate through conduits within the substrate to a mixing manifold or chamber within the substrate. Initially, the gases are delivered to the substrate through a plurality of gas inlets on a surface thereof. After mixing within a mixing manifold, the gases exit the substrate through one or more outlets. The gas inlets can be equally spaced from a center mixing chamber of the mixing manifold, such that the length scale of each gas species is the same and when gas is flowed from gas supplies to the mixing manifold within the substrate, the gas delivery time for each gas is the same. Alternatively, the gas supply components and gas inlets can be spaced in linear or non-linear arrangements.
Such a method may further include, for example, delivering gas through a gas delivery substrate including a first layer having vertical through holes, a second layer having vertical through holes and horizontal gas channels, and a third layer having vertical through holes, some of which are gas conduits. The first, second and the third layers of the substrate being bonded together such that the horizontal gas channels of the second layer are in fluid communication with at least some of the vertical through holes in the first layer and/or the third layer. The method further includes delivering the gas between a plurality of gas supply components via the second layer and the first layer and/or the third layer of the substrate. In addition, the gas delivery substrate includes one or more openings for allowing gas to exit the substrate to one or more gas lines or to a downstream processing chamber.
In addition, the present disclosure provides a method of supplying process gas through a gas delivery substrate for mounting gas supply components to a processing chamber of a plasma processing apparatus. Such a method may include, for example, delivery gases from a plurality of gas supplies in fluid communication with a plurality of gas inlets on a surface of a substrate for mounting gas supply components having at least one mixing manifold outlet; flowing at least two different gases from the plurality of gas supplies to the substrate to create a gas mixture; and supplying the gas mixture to a plasma processing chamber coupled downstream of the substrate. In an embodiment, the gas mixture can be combined with a tuning gas before delivery to a processing chamber downstream.
In embodiments, mass flow controllers can initiate flow set points for each of the at least two different gases and release them simultaneously for immediate mixing in a mixing manifold within the substrate. One of the gases may be a tuning gas which may be delivered to the mixing manifold of combined to the gas mixture downstream from a mixing manifold.
In an embodiment, gas enters the substrate via a plurality of gas inlets/openings on a surface of the substrate and enters a mixing manifold within the substrate. The gas mixture may then exit the substrate via one or more exit outlets/openings. After exiting the substrate, the gas may be delivered to one or more gas lines, or directly to a processing chamber. The mixing manifold may be provided within one or more layers of the substrate or be external to the substrate. In other embodiments, the gas may be added to another array of gases or mixed gases, another substrate mounted with gas supply components or a gas stick.
While embodiments disclosed herein have been described in detail with reference to specific embodiments thereof, it will be apparent to those skilled in the art that various changes and modifications can be made, and equivalents employed, without departing from the scope of the appended claims.
