Symmetrical precursor delivery

Abstract

A gas delivery system for a processing chamber includes a first channel for delivering a first chemical and a second channel for delivering a second chemical. The first channel includes a first outlet valve, and the second channel includes a second outlet valve. A trickle gas source is connected to both the first channel and the second channel. A first junction is coupled to the first outlet valve, and a second junction is connected to the second outlet valve. A common conduit connects the first junction and the second junction. The first junction includes an input for providing push gas from a push gas source, and the second junction includes an output to the processing chamber. During operation, either the first channel or the second channel is active at any given time. Trickle gas from the trickle gas source flows into the active channel and the inactive channel of the first channel or the second channel. Push inert gas from the push gas source flows into the first junction, through the common conduit, and from the second junction to the processing chamber.

Description

Technology Field

[0001] The present embodiments relate to semiconductor substrate processing, and more specifically, to a gas delivery tool for providing different chemical precursors to a process chamber for testing. Background Technology

[0002] Description of related technology

[0003] There are many types of film deposition processes commonly used in the semiconductor manufacturing field to define different types of features. Some exemplary deposition processes for creating thin films on a substrate include PVD (Physical Vapor Deposition), CVD (Chemical Vapor Deposition—e.g., plasma-enhanced CVD), or ALD (Atomic Layer Deposition).

[0004] In the PVD process, a pure source material in liquid form is converted into a vapor precursor and delivered to a process chamber. The liquid precursor is converted into a vapor precursor in a controlled manner by employing techniques using high-power electricity and laser ablation. When applied to a substrate, the vapor precursor condenses on the surface of the substrate to create a target layer. There are no chemical reactions occurring throughout the entire process.

[0005] In the CVD process, a source material is mixed with a volatile precursor that acts as a carrier. The mixture is injected in a gaseous phase into a process chamber in which substrates are accommodated to deposit films on the substrates. The reactants of the mixture react with the surface of the substrate to cause the deposition of thin films.

[0006] The ALD process is a subclass of CVD. ALD is a cyclic process performed by dividing the conventional CVD process into a repeated sequence of self-saturating deposition cycles. The resulting films are highly conformal, smooth, and possess excellent physical properties. Unlike CVD, where reactive gases are introduced into the chamber simultaneously, the reactive gases (i.e., precursors) in ALD are introduced sequentially to allow the gases to react with the surface of the substrate instead of one another. The ALD process involves a series of pulsing and purging steps in which the layers are formed by alternately pulsing precursors and reactive gases into the process chamber one at a time, and purging with an inert gas between each pulse. For example, during the first pulsing step, a first precursor is introduced as a gas and is absorbed (or adsorbed) onto the surface of the substrate contained within the process chamber. This is followed by a purging step in which the process chamber purges the first gas precursor using an inert gas. A subsequent pulsing step involves introducing a second precursor as a plasma that reacts with the absorbed precursor to form a monolayer of the target material. A second purge step is performed to remove the second precursor along with all byproducts from the process chamber. By controlling the sequence of pulses and purges, films generated by ALD are deposited as one at a time by repeatedly switching the sequential flow of two or more precursors / reactive gases on the substrate.

[0007] When a new chemical is to be tested for any of the aforementioned deposition processes, a significant amount of overhead time must be consumed. A significant portion of this time is due to hardware configuration. For example, to test the behavior of a new precursor within a process chamber, the new precursor must be tested under the same process conditions as the first precursor currently in use so that the results from the test are comparable.

[0008] In conventional systems, when different chemicals need to be tested, they are supplied through individual channels without considering the influence of the hardware layout (e.g., number of fittings, line length, number of bends, etc.) in the path to the process chamber. However, differences in pressure drop due to the hardware layout do not allow for easy process transparency testing. Therefore, to have similar process conditions, the process recipes used for the first precursor must be adjusted to match the process recipes for testing the new precursor. At these operating pressure regimes and flow rates, differences in pressure drop (a key factor affecting test results) are primarily due to differences in line layout (i.e., types, number of fittings, number of bends, line lengths, and line widths). One method of testing the behavior of the new precursor using the same process recipes as the first precursor while taking into account the differences in pressure drop is to move the ampoule supplying the new precursor to the location of the first precursor ampoule. This change typically results in at least significant tool downtime (e.g., about 5 days) due to the equipment safety measures that must be followed.

[0009] Inventions occur in this context.

[0010] Embodiments of the present disclosure include a gas delivery system that enables different chemical precursors (or simply referred to as chemicals) to be tested without causing significant tool downtime. The gas delivery system accommodates multiple channels, each having an ampoule for containing the chemicals and an individual conduit for delivering the chemicals to a process chamber. The layouts of the individual conduits are matched so that the chemicals are supplied to a manifold within the process chamber using the same process recipe. Because each of the chemicals follows a similar delivery path to the manifold of the process chamber, different chemicals can be easily tested using the same process recipe without tweaking the process recipes. Furthermore, different chemicals are tested without causing significant tool downtime. The only downtime that must occur during the testing of different chemicals is due to the purge operation that must be performed between applications of different chemicals. This downtime is significantly shorter than conventional methods of testing different chemicals.

[0011] In one embodiment, a gas delivery system for a processing chamber is disclosed. The gas delivery system includes a first channel for delivering a first chemical to the processing chamber and a second channel for delivering a second chemical to the processing chamber. The first channel has a first outlet valve, and the second channel has a second outlet valve. A trickle gas source is connected to both the first channel and the second channel. A first junction is coupled to the first outlet valve, and a second junction is coupled to the second outlet valve. A common conduit connects the first junction and the second junction. The first junction has an input connected to a push gas source, and the second junction has an output connected to the processing chamber. During operation, either the first channel, which carries the first chemical, or the second channel, which carries the second chemical, is active at one time. The active channel among the inert channel and the first channel or the second channel causes the trickle inert gas from the trickle gas source to flow to the first junction and the second junction. When the first chemical or the second chemical is output by the first channel or the second channel, the push gas source causes the push inert gas to flow into the first junction, through a common conduit, and from the second junction to the processing chamber.

[0012] In some embodiments, the first channel comprises a first ampoule having a first inlet for receiving a first chemical from a first chemical source and a second inlet for receiving a trickle inert gas from a trickle gas source. The second channel comprises a second ampoule having a first inlet for receiving a second chemical from a second chemical source and a second inlet for receiving a trickle inert gas from a trickle gas source.

[0013] In some embodiments, the first channel further comprises a first valve block coupled to a first ampoule, and the second channel comprises a second valve block coupled to a second ampoule. Each of the first valve block and the second valve block has one or more valves for controlling the flow of the first chemical or the second chemical from the first chemical source or the second chemical source into the first ampoule or the second ampoule.

[0014] In some embodiments, the first ampoule and the second ampoule each include one or more level sensors coupled to a spill detector valve. The one or more level sensors are configured to generate a signal to the spill detector valve indicating the level of the first chemical or the second chemical in the first ampoule or the second ampoule. The spill detector valve is configured to control the flow of the first gas chemical or the second gas chemical to the corresponding first ampoule or second ampoule.

[0015] In some implementation examples, the components of the first channel and the second channel, respectively, are positioned symmetrically with respect to each other within the gas delivery system.

[0016] In some implementation examples, the layout of the first channel matches the layout of the second channel.

[0017] In some embodiments, the layout is defined by the total line length, the number of bends, the line width, and the number of fittings. The total line length is calculated as the sum of the lengths of the line segments of each conduit of the first channel or the second channel, and the line segments are defined between pairs of consecutive bends. Matching the layout of each conduit includes matching the total line length, the number of bends, the number of fittings, and the line width of each conduit of the first channel and the second channel.

[0018] In some embodiments, the length of the common conduit between the first junction and the second junction is defined to prevent the diffusion of the first chemical or the second chemical from the active channel of the first channel or the second channel into the inactive channel.

[0019] In some implementation examples, the length of the common conduit between the first junction and the second junction is derived from the Peclet number.

[0020] In another embodiment, a gas delivery system for testing a plurality of gases within a process chamber is disclosed. The gas delivery system includes a first channel for delivering a first chemical to a processing chamber. The first channel includes a first ampoule coupled to a first chemical source and a trickle gas source. The first ampoule includes a first inlet for receiving the first chemical from the first chemical source and a second inlet for receiving an inert gas from an inert gas source. The first channel includes a first outlet valve. The gas delivery system also includes a second channel for delivering a second chemical to a processing chamber. The second channel includes a second ampoule coupled to a second chemical source and a trickle gas source. The second ampoule includes a first inlet for receiving the second chemical from a second gas source and a second inlet for receiving an inert gas from an inert gas source. The second channel includes a second outlet valve. The first junction has an input coupled to a first outlet valve and connected to a push gas source. The second junction has an output coupled to a second outlet valve and connected to a processing chamber. A common conduit connects the first junction and the second junction. During operation, either the first channel, which carries the first chemical, or the second channel, which carries the second chemical, is active. Trickle inert gas from the trickle gas source flows to the first junction and the second junction through the inert channel and the active channel of the first channel or the second channel. When the first chemical or the second chemical is output by the first channel or the second channel, the push gas source pushes inert gas into the first junction, through the common conduit, and from the second junction to the processing chamber.

[0021] In some embodiments, the first channel includes a first valve block positioned between a first chemical source and a first ampoule. The first valve block has one or more valves to control the flow of the first chemical from the first chemical source into the first ampoule. The second channel includes a second valve block positioned between a second chemical source and a second ampoule. The second valve block has one or more valves to control the flow of the second chemical from the second chemical source into the second ampoule.

[0022] In some embodiments, the first ampoule and the second ampoule each include one or more level sensors coupled to a spill detector valve. The one or more level sensors are configured to monitor the levels of gaseous chemicals in the first ampoule or the second ampoule and to generate a signal to the spill detector valve indicating the level of the first chemical or the second chemical in the first ampoule or the second ampoule. The spill detector valve is configured to control the flow of the first chemical or the second chemical to the corresponding first ampoule or the second ampoule.

[0023] In some embodiments, the first ampoule and the second ampoule are each coupled to a manometer. The manometer is configured to control the pressure of the first chemical or the second chemical flowing from the first ampoule or the second ampoule toward the first outlet valve or the second outlet valve.

[0024] Various implementation examples provide a simple and easily implementable method for testing multiple precursor gases by providing a gas delivery system design that accommodates multiple ampoules for storing different chemicals, and each ampoule is coupled to a separate conduit to supply the respective precursor gas to the manifold of the processing chamber. The design of the gas delivery system allows various chemicals to be tested using the same valve times for all chemicals without causing significant tool downtime.

[0025] Some advantages of the gas delivery system described herein are the ability to test various chemicals (also referred to as precursors or gases) using the same process recipes without the need to break any lines to switch ampoules. The ampoules independently supply various gases to a manifold within a process chamber using individual conduits having a matching layout. The only delay when testing different chemicals is due to a purging operation in which the first gas supplied to the manifold within the process chamber must be completely purged before the second gas is supplied to the same manifold. Additionally, by matching the overall layout of each conduit, valve timings are maintained during the testing of different chemicals while preventing pressure drop differences resulting from line layout mismatch. A diffusion distance between the first and second conduits is maintained to prevent the first chemical flowing through the active first channel from diffusing into the inactive second channel, or the second chemical flowing through the active second channel from diffusing into the inactive first channel. To further protect the chemical flowing through the active channel from diffusing into the inert channel, a sufficient amount of trickle inert gas trickles through the inert channel to provide momentum to the chemical supplied through the active channel while preventing any diffusion of the chemical into the inert channel. The momentum assists in pushing the chemical toward the manifold while ensuring that the flow or chemical composition of the chemical supplied by the active channel is not negatively affected by the inert gas. Additional inert gas may also be supplied through a common conduit to further assist the chemical supplied through the first or second channel to flow toward the manifold of the processing chamber.

[0026] These and other advantages will be discussed below and will be recognized by those skilled in the art upon reading the specification, drawings, and claims. Brief explanation of the drawing

[0027] FIG. 1a illustrates a simplified block diagram of an ampoule delivery system used to test different chemical precursors in one embodiment. FIG. 1b illustrates a simplified block diagram of an ampoule delivery system used to test different chemicals in one alternative implementation example. FIG. 2 illustrates a simplified block diagram of a gas delivery system used to provide gas precursors to a process chamber for testing in one embodiment. FIG. 3 illustrates a simplified block diagram of outlet valves used to control the flow of gaseous chemicals toward a process chamber in one embodiment. FIG. 4 illustrates a simplified block diagram of the geometry of conduits used to supply different gases from an ampoule delivery system to a process chamber in one embodiment. FIG. 5 illustrates a control module for controlling systems according to one embodiment. Specific details for implementing the invention

[0028] In the following description, numerous specific details are provided to provide a complete understanding of the features of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without some or all of these specific details. In other examples, known process operations have not been described in detail so as not to unnecessarily obscure the present invention.

[0029] Embodiments of the present disclosure provide details of a gas delivery system used to provide gases for testing within a process chamber. The gas delivery system comprises separate channels having ampoules for storing different gas precursors and a set of inlet and outlet valves for controlling the flow of gas precursors into the process chamber for testing. Conduits provided within the gas delivery system are used to supply gas precursors to a manifold within the process chamber. The manifold supplies the gas precursors to a showerhead, which ultimately supplies the gas precursors to a processing area within the process chamber. The conduits are designed with a matching layout to ensure that there are no pressure drop differences between two or more gas precursors being tested using the gas delivery system. Additionally, the layout design of the conduits provides sufficient separation distance between conduits supplying different chemicals to handle any dead-legs that may be caused by the intermittent flow of chemicals and to prevent backflow diffusion into inert conduits. Since the only downtime is for purging the manifold of the previously supplied precursor and the downtime is not due to the switching of ampoules, the gases can be tested with a minimum downtime. It should also be noted that gas precursors are referred to herein as gas chemicals or first chemicals, second chemicals.

[0030] FIG. 1a illustrates a simplified block diagram of a process system (100) used to test a chemical B precursor in one embodiment. The process system (100) includes a process chamber (150) that receives different gases, including the gas precursors to be tested. The process chamber (150) may be a single-station or multi-station chamber. The top portion (or top plate—not shown) of the process chamber (150) includes a showerhead (not shown) connected to a manifold (not shown). The manifold receives gases from different gas sources and supplies these gases to the showerhead for continuous delivery to a processing area defined over a station within the process chamber (150). A gas delivery system (AMPDS) (110) within the process system (100) is used to provide different gas precursors for testing within the process chamber (150). The AMPDS (110) comprises a plurality of ampoules that receive gas precursors from different gas sources and supply them to the manifold of the process chamber (150). In the embodiment illustrated in FIG. 1a, the AMPDS comprises a first channel (channel A or Ch-A) (110-A) for delivering a first chemical (chemical A) and a second channel (channel B or Ch-B) (110-B) for delivering a second chemical (chemical B). The first channel (110-A) comprises a first ampoule (not shown) connected to a first gas source (120-A) to receive the first chemical via a chemical A feed and to a trickle gas source (130) to receive a trickle inert gas via a first inert gas feed. The first channel includes a first outlet valve coupled to a first ampoule and configured to receive a first chemical provided through a chemical A feed and a trickle inert gas provided through a first inert gas feed.The first outlet valve is coupled to the first joint (145-A).

[0031] Similarly, the second channel (110-B) includes a second ampoule (not shown) connected to a second gas source (120-B) to receive a second chemical via a chemical B feed and to a trickle gas source (130) to receive a trickle inert gas via a second inert gas feed. The second channel includes a second outlet valve coupled to the second ampoule and configured to receive a second chemical supplied via the chemical B feed and a trickle inert gas provided via the second inert gas feed. The second outlet valve is coupled to a second junction (145-B). The first channel and the second channel are selectively maintained as active or inactive when specific chemicals among the chemicals need to be tested.

[0032] A plurality of inlet valves and outlet valves provided within the AMPDS regulate the flow of the first chemical and the second chemical supplied through the corresponding first and second channels. The first junction (145-A) is connected to the second junction (145-B) via a common conduit (155). The first junction includes an input portion coupled to a push gas source (160) to receive a push inert gas. The second junction (145-B) includes an output portion connected to the processing chamber (150) to supply the chemicals to the processing chamber (150).

[0033] An embodiment illustrated in FIG. 1a illustrates the flow of different chemical feeds when chemical B is being tested. In this embodiment, channel A (110-A) is deactivated by turning off the flow of the first chemical (Ch-A) to the first outlet valve (140-A) through the chemical A feed (112-A) and the first ampoule. At the same time, the trickle inert gas flows from the trickle gas source (130) toward the first junction (145-A) through the first inert gas feed (114-A) and the first outlet valve (valve 51) (140-A). Channel B is kept active by turning on the flow of the second chemical (Ch-B) through the second outlet valve (valve 55) (140-B) and the chemical B feed (112-B) toward the second junction (145-B). Additionally, the trickle inert gas flows from the trickle gas source (130) through the second inert gas feed (114-B) to the second outlet valve (140-B). The trickle inert gas provided through the second channel is mixed with the second chemical and acts as a carrier providing momentum to the second chemical flowing toward the second junction (145-B) through the second outlet valve (140-B). A push gas source (160) is activated to cause push inert gas from the push gas source (160) to flow toward a second junction (145-B) through a first junction (145-A) and a common conduit (155). At the first junction, the push inert gas is mixed with trickle inert gas from a first channel and a second chemical / tricle inert gas mixture flowing from channel B (110-B) into the second junction (145-B). The combined mixture of the second chemical and inert gas flows through the second junction (145-B) to a manifold (not shown) of a processing chamber (150).The manifold supplies the mixture to a defined processing area on the substrate support surface of the processing chamber (150) station through a showerhead available in the upper chamber portion of the processing chamber (150).

[0034] The trickle inert gas flowing through the first inert gas feed fills the path extending from the first ampoule and the first valve 51 to the first junction (145-A) to prevent any dead-legs along the path of the first channel. Dead-legs usually occur in the inert channels of the zones along the path used to deliver the chemical (e.g., the first chemical or the second chemical) due to the intermittent use of the conduits. By flowing the trickle inert gas, sufficient positive pressure is provided to the dead zones of the inert channel that cause the dead-legs. The amount of trickle inert gas flowing through the inert channel is minimal to provide sufficient push force while ensuring that the chemical composition of the gas chemical flowing through the active channel is not adversely affected.

[0035] The distance between the first junction and the second junction is defined to prevent backflow of chemicals from the active channel to the inactive channel. In the example illustrated in FIG. 1a, the first junction is spaced apart from the second junction to prevent chemicals B supplied through the second channel from diffusing into the flow path defined in the first channel. The push inert gas introduced through the first channel substantially fills the common conduit up to the second junction and flows toward the second junction, further preventing backflow diffusion of the second chemicals into the first junction of the first channel. Additionally, the push inert gas from the push gas source (160) provides a pushing force to the second chemicals flowing into the second junction so that the push inert gas flows together with the second chemicals from the second junction toward the processing chamber (150). In some embodiments, the push inert gas and the trickle inert gas are both the same. In other embodiments, the push inert gas is different from the trickle inert gas. In some embodiments, both the push inert gas and the trickle inert gas are argon. In other embodiments, other inert gases may be used.

[0036] FIG. 1b illustrates an alternative implementation example of the flow of different chemical feeds within the process system exemplified in FIG. 1a when chemical A is being tested. In this implementation example, channel B (110-B) is deactivated by turning off the flow of the first chemical (Ch-B) to the second outlet valve (140-B) through the chemical B feed and the second ampoule. At the same time, the trickle inert gas flows from the trickle gas source (130) toward the second junction (145-B) through the second inert gas feed and the second outlet valve (valve 55) (140-B). Channel A is kept active by turning on the flow of the first chemical (Ch-A) toward the first junction (145-A) through the first outlet valve (140-A) and the chemical A feed from the first gas source (120-A). The trickle inert gas flows from the trickle gas source (130) through the first inert gas feed to the first outlet valve (valve 51) (140-A). The trickle inert gas is mixed with the first chemical (Ch-A) and acts as a carrier to provide momentum to the first chemical flowing toward the first junction (145-A) through the first outlet valve (140-A). The push gas source (160) is activated to cause the push inert gas from the push gas source (160) to flow toward the first junction (145-A) and to push the first chemical outward from the first junction (145-A) toward the second junction (145-B) through the common conduit (155). The first chemical / trickle inert gas mixture is mixed with the push inert gas flowing into the first junction (145-A) and the trickle inert gas flowing from the second outlet valve (140-B) of channel B (110-B) to the second junction (145-B).A combined mixture of the first chemical and an inert gas is pushed into a manifold in the processing chamber (150) through the second junction (145-B). The manifold supplies the first chemical to a defined processing area on the substrate support surface of a station in the processing chamber (150) through the showerhead of the processing chamber (150).

[0037] In some embodiments, each station of the processing chamber includes a separate manifold, and different chemicals may be tested by supplying different chemicals to the manifold. Different chemicals may also be tested by sequentially activating a first channel, followed by a second channel. After the application of each chemical, a purge operation is performed to completely purge the manifold of the previous chemical before applying the next chemical. For example, referring to FIGS. 1a and 1b, after testing chemical B, the flow of chemical B is blocked, and an inert gas flows into the manifold to completely purge chemical B from the manifold. After the purge operation, the flow of chemical A is turned on, and chemical A is tested.

[0038] Channels A and B include individual conduits used to supply the first chemical and the second chemical to the first and second junctions, respectively. To prevent pressure drop differences, the layout of the conduit in Channel A is matched to the layout of the conduit in Channel B so that Chemical A and Chemical B are tested using the same process recipes (i.e., process parameters). Some of the process parameters considered during the testing of different chemicals include the processing chamber operating temperature, the processing chamber operating pressure, the flow rates of different chemicals, valve timing, etc. The design of the gas delivery system must consider one of the key parameters—namely, valve timing—to prevent pressure drop differences across the conduits during the testing of different chemicals. To maintain consistent valve timing in the conduits used to test different chemicals, the layout of the conduits in the channels must be kept identical so that the different chemicals follow similar paths to the processing chamber. The layout of the conduit is defined by the geometry of the conduit and includes the total line length, line width, number of bends, and number and type of fittings for each conduit. The total line length of each conduit is defined as the sum of the line segments constituting the total conduit line, and each line segment is defined between any two consecutive bends. Using similar process recipes, the results from the tests of the first chemical and the second chemical are similar.

[0039] Various implementation examples are discussed with reference to a gas delivery system including two channels for testing two different chemicals without significant tool downtime due to tuning processes and facility maintenance protocols, but it should be noted that the implementation examples can be easily extended to include n channels for testing n different chemicals.

[0040] FIG. 2 illustrates various components of a gas delivery system used in the process system of FIG. 1 to test different chemicals within a processing chamber (150) in one embodiment. The gas delivery system comprises a plurality of channels, each channel having an ampoule used to contain a different chemical to be tested. A gas delivery system having ampoules is otherwise referred to as an ampoule delivery system (AMPDS). In the embodiment illustrated in FIG. 2, a pair of channels, Channel A and Channel B, are provided to test two chemicals, Chemical A and Chemical B. When three or more chemicals are tested, the AMPDS may include an ampoule for each channel and a corresponding number of channels.

[0041] Each of the first and second channels of the pair of channels (channel A (110-A), channel B (110-B)) includes an ampoule (first ampoule (135-A) in channel A, second ampoule (135-B) in channel B) for supplying the first chemical or the second chemical to the processing chamber (150). Each of the ampoules (135-A, 135-B) is connected to a corresponding chemical source (first chemical source (120-A), second chemical source (120-B)) through a corresponding valve block (first valve block (115-A), second valve block (115-B)). A valve block (115-A, 115B) positioned between a corresponding chemical source (120-A, 120-B) and an ampoule (135-A, 135-B) includes one or more valves for controlling the flow of chemicals from the corresponding chemical source (120-A, 120-B) to the ampoule (135-A, 135-B). Each of the ampoules (135-A, 135-B) is also connected to a trickle gas source (130). A trickle control unit (116-A, 116-B) positioned between the trickle gas source (130) and the corresponding valve block (115-A, 115-B) controls the flow of a trickle inert gas, such as argon, into the ampoule (135-A, 135-B). Each of the ampoules (135-A, 135-B) includes a pair of inlets and outlets. Chemicals (chemical A, chemical B) from the corresponding chemical source (120-A, 120-B) are supplied to each ampoule (135-A, 135-B) through the first inlet, and trickle inert gas is supplied through the second inlet. The trickle inert gas supplied to the ampoules (135-A, 135-B) provides momentum to the chemical (first chemical or second chemical) contained within each ampoule (135-A, 135-B) to push the chemical into the manifold of the processing chamber (150) through the corresponding outlet.The outlets of each ampoule (135-A, 135-B) are connected to a common conduit (155). The first joint (145-A) and the second joint (145-B) connect the AMPDS to the processing chamber (150) through the common conduit.

[0042] Connections from the respective outlets of the ampoules (135-A, 135-B) to the corresponding joints (145-A, 145-B) pass through the corresponding outlet valves (valve (51) (140-A), valve (55) (140-B)). Manometers (139-A, 139-B) are provided along the connections to control the pressure of the chemicals (first chemical A, second chemical B) supplied to the corresponding joints (145-A, 145-B). Each connection of the channel is in the form of a conduit, and each conduit has a defined layout. Each of the outlet valves (valve 51 (140-A), valve 55 (140-B)) is used to control the flow of chemicals flowing through the respective conduits to the common joint.

[0043] The layout of each conduit may be based on the location of the ampoules and the layout of different modules in relation to the ampoules within the gas delivery system (AMPDS). For example, due to the presence and location of other connections / pipes / control modules / components, etc., within the AMPDS and the location of each conduit, one or more segments of each conduit may need to be routed to surround some of the existing connections. The layout of each conduit is defined by the number of bends, the line segments between consecutive pairs of bends, the number of fittings, and the line width of each line segment of the conduit. The line width of each conduit is maintained uniformly over the entire length of the conduit. To prevent pressure drop differences in the conduits, the layout of the first conduit providing the first chemical is matched with the layout of the second conduit providing the second chemical. Matching the layouts includes matching the number of bends, the number of segments, the total line length of the conduit, the number of fittings, and the line width. The total line length of the conduit is calculated as the sum of the line lengths of the line segments, and each line segment is defined between any consecutive pair of bending sections. In some embodiments, because the path taken by the first chemical toward the processing chamber includes the length of the segment of the common conduit between the first joint and the second joint, the total line length of the first conduit may also include the length of the segment of the common conduit between the first joint and the second joint.

[0044] Each of the ampoules (ampoul A (135-A), ampoule B (135-B)) includes one or more level sensors (for ampoule A (136-A1, 136-A2), for ampoule B (136-B1, 136-B2)) to detect the level of a chemical within each ampoule when each channel is active. A first level sensor may be provided near the top of each ampoule to detect when the ampoule is full, and a second level sensor may be provided near the bottom of each ampoule to detect when the ampoule is empty. Eventually, each of the level sensors is connected to a spill detector (138) (138-A, 138-B) to detect when each ampoule is full and to generate a signal to block the chemical feed supplying the chemical (chemical A to ampoule A, chemical B to ampoule B). For example, when channel A is active, the spill detector (138-A) may use signals generated from level sensors (136-A1 and 136-A2) to determine the level of chemical A in ampoule A (135-A). Based on the signals, the spill detector (138-A) may provide signals to one or more valves in the channel A valve block (115-A) to control the flow of chemical A into ampoule A (135-A). In some embodiments, flow control may include blocking the flow of chemical A into ampoule A (135-A).

[0045] In the embodiment illustrated in FIG. 2, the outlet valves (valve 51 (140-A), valve 55 (140-B)) are shown as being outside the gas delivery system (AMPDS (110)). In alternative embodiments, the outlet valves may be located inside the AMPDS (110). A push gas source (160) is connected to a common conduit (155) at an inlet defined in the first junction. The push gas source (160) is configured to provide push inert gas to the first junction (145-A). A preheater (165) located between the push gas source and the first junction is used to heat the push inert gas before it is supplied to the first junction (145-A). When the first channel is active, the heated push inert gas is used to push the first chemical supplied to the first junction by the first channel into the processing chamber (150) through the common conduit and the second junction. When the first channel is inactive and the second channel is active, the push inert gas is used to fill the common conduit (155) and push the second chemical supplied by the second channel toward the processing chamber (150) through the second junction (145-B).

[0046] It should be noted that the various modules / components of the two channels are positioned symmetrically within the AMPDS to provide identical process parameters for the chemicals to be tested. For example, the two ampoules (Ampoule A, Ampoule B) are positioned symmetrically to each other. The two outlets and conduits leading from the two outlets to the corresponding outlet valves (first outlet valve (145-A), second outlet valve (145-B)) are also positioned symmetrically to each other to ensure that the chemicals supplied by the two channels follow a similar path into the processing chamber. In one embodiment, the total line length of the conduit leading from Ampoule A of Channel A includes the diffusion distance 'd' separating the first junction and the second junction. Details of the total line length calculation will be discussed in detail with reference to FIG. 4.

[0047] When the first chemical is tested, Channel A is activated and Channel B is deactivated. As a result, one or more valves from the Channel A valve block (115-A) are kept open to allow the first chemical, Chemical A, to flow from the first chemical source (120-A) into the Chemical A feed (112-A) and through the first inlet into Ampoule A (135-A). At the same time, the trickle control unit A (116-A) is turned on to allow the trickle inert gas to flow from the Channel A valve block (115-A), the first inert gas feed (114-A), and the second inlet into Ampoule A (135-A). A first level sensor (136-A1) near the top of ampoule A and a second level sensor (136-A2) near the bottom of ampoule A provide signals to a first outflow detector (138-A). Based on the signals, the first outflow detector (138-A) may transmit control signals to one or more valves of the first valve block to control the flow of the first chemical into ampoule A. The first chemical / inert gas mixture in ampoule A flows from the outlet toward the first junction (145-A) through the first conduit and the first outlet valve 51 (140-A). At the same time, the push inert gas from the push gas source (160) is supplied to a preheater (165), where it is heated, and the heated push inert gas is supplied to the first junction (145-A). The push inert gas pushes the first chemical supplied by channel A toward the second junction (145-B) through the common conduit (155).

[0048] Setting channel B to inert involves turning off the flow of chemical B from the second chemical source (120-B) while allowing the flow of trickle inert gas from the trickle gas source (130). Accordingly, one or more valves of the channel B valve block (115-B) controlling the flow of chemical B from the second chemical source (120-B) are blocked, and the second trickle control unit B (116-B) is kept active to allow the trickle inert gas to flow from the trickle gas source (130) to ampoule B (135-B) through the channel B valve block (115-B), the second inert gas feed (114-B), and the second inlet. The trickle inert gas fills ampoule B (135-B) and flows from the outlet toward the second junction (145-B) through the second conduit and the second outlet valve 55 (140-B). The trickle inert gas flowing from the second channel (110-B) fills the second conduit to prevent dead-leg blockage.

[0049] The forward momentum of the push inert gas from channel A and the chemical A / trickle inert gas mixture is further aided by the trickkle inert gas flowing from channel B at the second junction. The trickkle inert gas supplied from channel A acts as a carrier for chemical A flowing toward the processing chamber (150), and the push inert gas and trickkle inert gas supplied from channel B provide sufficient momentum to chemical A as it flows toward the processing chamber. The amount of trickkle inert gas and push inert gas supplied by both channel A and channel B provides sufficient momentum to move chemical A toward the processing chamber without negatively affecting the composition of chemical A being tested within the processing chamber.

[0050] The first junction (i.e., the entry point for the first chemical from the AMPDS first channel into the common conduit) is spaced sufficiently far from the second junction to prevent or minimize backflow diffusion of the chemical flowing from the active channel into the conduits within the inactive channel. The length of the common conduit between the first and second junctions (i.e., the diffusion distance separating the conduits from the first and second channels) is derived by the Peclet number. Pe (Peclet number) is defined as the ratio of the advection rate of the physical quantity due to flow to the diffusion rate of an equal amount driven by an appropriate gradient. For example, the Peclet number for bulk transfer of chemical bulk is defined as follows:

[0051] Pe L = Lu / D , where L is the characteristic length, u is the flow rate of the chemical, and D is the mass diffusion coefficient.

[0052] From the above Peclet number formula, in one embodiment, the optimal diffusion distance to prevent backflow diffusion was determined to be about 1''. Backflow diffusion occurs when a lower pressure region encounters a chemical along the flow path of a chemical flowing from a higher pressure region toward a lower pressure region. For example, when channel A is active, the ampoules and conduits of channel A are at higher pressure, but the processing chamber is at lower pressure. This causes chemical A supplied by channel A to flow toward the processing chamber. Along the path toward the processing chamber, chemical A may pass through a lower pressure region toward ampoule B—for example, a second junction and conduits—due to the inactive channel B. To prevent diffusion of chemical A toward the second junction and over the conduits of the second channel leading to the second ampoule, a sufficient separation distance is maintained between the first junction and the second junction. In addition, the trickle inert gas flows through the second channel to fill the conduit of the second channel leading to the second junction including the second outlet valve. Similarly, when channel B is kept active and channel A is kept inactive, the flow of the trickle inert gas through the diffusion distance 'd' and the conduit of the inactive channel A fills the conduit leading from ampoule A to the first junction including the first outlet valve, and the conduit of the inactive channel A, to prevent backflow diffusion into the first outlet valve.

[0053] FIG. 3 illustrates a diagram of control units used to operate different outlet valves (140-A, 140-B) of the gas delivery system illustrated in FIG. 1 and FIG. 2 in one embodiment. It should be noted that while the sizes of the various parts of the gas delivery system may be exaggerated to provide a clear view of the various parts, the actual sizes of the various parts may differ from those illustrated. As illustrated, the first outlet valve (valve 51 (140-A)) controls the flow of the first chemical (chemical A) from the first chemical source to the first junction (145-A), and the second outlet valve (valve 55 (140-B)) controls the flow of the second chemical (chemical B) from the second chemical source to the second junction (145-B). Each of the first outlet valve and the second outlet valve is coupled to a control mechanism (141-A, 141-B) for controlling the flow of the first chemical and the second chemical through the respective outlet valves (140-A, 140-B). The control mechanism may be a pneumatic control mechanism, or any other type of control mechanism including mechanical, electrical, etc. Each of the control mechanisms (141-A, 141-B) is coupled to a controller (170) used to control the operation of the processing chamber (150). The controller (170) may be coupled to a computer (not shown) to allow remote control of the outlet valves (140-A, 140-B) by providing inputs to the control mechanisms (141-A, 141-B). FIG. 3 illustrates two different controllers (170), but the two controllers may be part of a single controller coupled to a computer, or they may be coupled to a computer separately. Other parts of the gas delivery system illustrated in FIG. 3 are similar to the parts discussed with reference to FIG. 1 and FIG. 2 and are indicated using the same reference numerals.

[0054] FIG. 4 illustrates an exemplary gas delivery system illustrating the layout of two channels (channel A, channel B - (110-A, 110-B)) that supply different chemicals to a processing chamber (150) in one embodiment. Each of the channels (110-A, 110-B) includes a conduit extending to a junction on a common conduit (155) that supplies different chemicals to the processing chamber from a corresponding ampoule (120-A, 120-B) through an outlet valve. In the exemplary layout illustrated in FIG. 4, channel A includes a chemical A ampoule (120-A) and a conduit extending to a first junction (145-A) defined on the common conduit (155) leading from the chemical A ampoule to the processing chamber (150) through an outlet valve 51 (140-A) (i.e., chemical A feed (112-A)). Similarly, channel B includes a chemical B ampoule (120-B) and a conduit (i.e., chemical B feed (112-B)) extending from the chemical B ampoule to a second joint (145-B) defined on the common conduit (155) through the outlet valve 55 (140-B).

[0055] The gas delivery system is designed to match the layout of the conduit (112-A) of Channel A with the layout of the conduit (112-B) of Channel B. The layout of the conduits is defined by various conduit properties such as line width, the number of bends, the number of fittings, total line length, etc. The line width of each of the conduits (112-A, 112-B) of Channel A and Channel B is maintained uniformly throughout their lengths. Additionally, the line width of the conduit (112-A) of Channel A matches the line width of the conduit (112-B) of Channel B. The conduits of Channel A and Channel B include a plurality of line segments and a plurality of bends along their lengths. Each line segment is defined between any pair of consecutive bends or between a fitting and a module of the gas delivery system (e.g., ampoule, outlet valve, joint, etc.) and has a line length. Matching the layout of conduit (112-A) with the layout of conduit (112-B) involves matching the number of bends of conduit (112-A) with the number of bends of conduit (112-B) of channel B. In the example illustrated in FIG. 4, the total number of bends along the length of conduit (112-A) of channel A (i.e., A b1 , A b2 , A b3 , A b4 , A b5 , and A b6 The 6 bending sections represented by) is the total number of bending sections along the length of channel B's conduit (112-B) (i.e., B b1 , B b2 , B b3 , B b4 , B b5 , and B b6It matches the six bending sections shown in ( ). The length of each line segment of conduit (112-A) may or may not match the length of the corresponding line segment of conduit (112-B). If each line segment of conduit (112-A) does not match the corresponding line segment of conduit (112-B), the total line length of conduit (112-A) of channel A matches the total line length of conduit (112-B) of channel B. The total line length is calculated as the sum of the line lengths of each line segment. Thus, in the example illustrated in FIG. 4, line segment A of conduit (112-A) of channel A l1 The length of the corresponding line segment B of channel B's conduit (112-B) is l1 It may not be the same as the length of line segment A l2 The length of line segment B l2 These include, which may not be the same as the length of. However, (A l1 + A l2 + A l3 + A l4 + A l5 + A l6 + A l7 Total line length of conduit (112-A) of channel A, represented by ), A tl 은 (B l1 + B l2 + B l3 + B l4 + B l5 + B l6 + B l7 Total line length of channel B conduit (112-B), represented as the sum of ), B tlIt is designed in the same way as. In some implementation examples, the calculation of the total line length of the conduit (112-A) may also take into account the separation distance between the two conduits (i.e., the diffusion distance between the first junction (145-A) and the second junction (145-B) along the common conduit) when a chemical from channel A flows through the length of the common conduit connecting the two junctions.

[0056] A gas delivery system may be designed to test three or more chemicals by including an equal number of channels, each equipped with an ampoule. The chemicals are supplied through their respective chemical feeds (i.e., conduits). Each conduit includes defined line segments between multiple bends and pairs of consecutive bends, or between fittings and modules (e.g., ampoules, joints, outlet valves, etc.). Due to the layout of the various components of the gas delivery system, the conduits of each channel may be routed differently. As a result, the length of each line segment of Channel A may differ from the length of the corresponding line segment of Channel B.

[0057] When testing two chemicals while keeping all other remaining process parameters, such as operating temperature, flow rate, and pressures of different chemicals, constant, differences in the layouts of the conduits in the two channels can cause variations in valve timings. A new design of the gas delivery system allows the use of identical timing sequences (i.e., valve timings) to test different chemicals by matching the total line lengths of the conduits in Channel A and Channel B. Matching the conduit layouts helps maintain valve timing across the two conduits, which is one of the major process parameters causing uneven pressure drops in the two conduits.

[0058] A sample table, Table 1, illustrating various process parameters used to obtain similar results when testing different chemicals within a gas delivery system is shown below. The table shows, for example, the width of the conduits of Channel A and Channel B (0.402 inches), the processing chamber operating pressure of Torr (50.00 Torr), the processing chamber operating temperature (333.15 K), the flow rate of the chemicals in sccm (standard cubic centimeter per minute) (approx. 0.10 sccm), and the Peclet number derivative (0.01) used to determine the diffusion distance separating the two conduits (i.e., delta distance - approx. 1''), among other process parameters used during the testing of different chemicals.

[0059]

[0060] The various embodiments described herein provide a simple and easily implementable method for testing multiple chemicals using the same process parameters. A gas delivery system is designed to accommodate multiple channels, each channel having an ampoule coupled to a separate conduit to supply different chemicals to the manifold of a process chamber. The layouts of the conduits of the different channels are matched to prevent pressure drop differences between the different conduits. Inert gases trickle through the inert channels to prevent dead-leg blockage, while the active channels are used to supply the chemicals to be tested. The different conduits are separated by a diffusion distance to prevent the chemicals supplied through the active channels from back-diffused into the inert channels. Push inert gas is supplied through a common conduit to push the chemicals to be tested toward the processing chamber and prevent back-diffusion.

[0061] The design of the gas delivery system allows various chemicals to be tested with identical valve timings without causing significant tool downtime. The only delay when testing different chemicals may be due to a purge operation in which the first chemical supplied to the manifold within the process chamber is completely purged from the manifold before the second chemical can be supplied to the manifold. Since chemicals supplied by various ampoules are tested using the same process parameters, there is no need to destroy any lines to switch the ampoules. Additional advantages can be envisioned by those skilled in the art by reading various implementation examples.

[0062] FIG. 5 illustrates a control module (500) for controlling a process input and a control unit of a process chamber. In one embodiment, the control module may include some exemplary components. For example, the control module (or controller) (500) may include a processor, memory, and one or more interfaces. The controller illustrated in FIG. 5 is similar to the control module (170) illustrated in FIG. 3. The control module (500) may be employed to process recipes and partially control the devices of the process chamber based on sensed values. Only, for example, the control module (500) may control one or more of valves (502) (including valves in valve blocks of a gas delivery system, outlet valves, trickle controllers, etc.), filter heaters (504), pumps (506), and other devices (508) based on sensed values ​​and other control parameters. The controller (500) receives values ​​sensed from, for example, pressure manometers (510) (e.g., manometers (139) of FIG. 2), flow meters (512), temperature sensors (514), level sensors (136), and / or other sensors (516). The control module (500) may also be employed to control process conditions during precursor delivery and film deposition. The control module (500) will typically include one or more memory devices and one or more processors.

[0063] The control module (500) may control the activities of the precursor delivery system and the deposition apparatus. The control module (500) executes computer programs including sets of instructions for controlling process timing, delivery system temperature, pressure differences across filters, valve positions, mixture of gases, chamber pressure, chamber temperature, wafer temperature, RF power levels, wafer chuck or pedestal position, flow rates, and other parameters of a specific process. The control module (500) may also monitor pressure differences and automatically switch vapor precursor delivery from one or more paths to one or more other paths. Other computer programs stored on memory devices associated with the control module (500) may be employed in some embodiments.

[0064] Typically, there will be a user interface associated with the control module (500). The user interface may include a display (518) (e.g., a display screen of device and / or process conditions and / or graphic software displays), and user input devices (520) such as pointing devices, keyboards, touch screens, microphones, etc.

[0065] Computer programs for controlling the transfer, deposition, and other processes of precursors in a process sequence may 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 a processor to perform tasks identified in the program.

[0066] Control module parameters are related to plasma conditions such as filter pressure differences, process gas composition and flow rates, temperature, pressure, RF power levels and low-frequency RF frequency, cooling gas pressure, and process conditions such as chamber wall temperature.

[0067] System software may be designed or configured in many different ways. For example, various chamber component subroutines or control objects may be written to control the operation of chamber components necessary to perform the deposition processes of the present invention. Examples of programs or sections of programs for this purpose include substrate positioning code, process gas control code, pressure control code, heater control code, and plasma control code.

[0068] A substrate positioning program may include program code for controlling chamber components used to load the substrate onto a pedestal or chuck and to control the gap between the substrate and other parts of the chamber, such as a gas inlet and / or target. A process gas control program may include code for controlling gas composition and flow rates, and optionally code for flowing gas into the chamber before deposition to stabilize the pressure within the chamber. A filter monitoring program may include code for comparing measured difference(s) with predetermined value(s) and / or code for switching paths. A pressure control program may include code for controlling the pressure within the chamber, for example, by adjusting a throttle valve in the chamber's exhaust system. A heater control program may include code for controlling the current to heating units to heat components within the precursor delivery system, the substrate, and / or other parts of the system. Alternatively, a heater control program may control the delivery of a heat transfer gas, such as helium, to the wafer chuck.

[0069] Examples of sensors that may be monitored during deposition include, but are not limited to, mass flow control modules, pressure sensors such as pressure manometers (510) (manometers (139)), level sensors (136), and thermocouples, pedestals, or chucks located within the transfer system (e.g., temperature sensors (514)). Appropriately programmed feedback and control algorithms may be used in conjunction with data from these sensors to maintain targeted process conditions. The foregoing describes examples of implementations of embodiments of the present invention in a single or multi-chamber semiconductor processing tool or process chamber.

[0070] The foregoing description of the embodiments is provided for illustrative and technical purposes only. It is not intended to encompass or limit the present disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment and, even if not specifically illustrated or described, may be interchangeable and used in selected embodiments where applicable. The same may also be varied in many ways. Such variations are not to be considered as departing from the invention, and all such modifications are intended to be included within the scope of the invention.

[0071] Although the foregoing embodiments have been described in some detail for the sake of clarity of understanding, it will be apparent that specific changes and modifications may be made within the scope of the appended claims. Accordingly, the embodiments shall be regarded as illustrative rather than limiting, and the embodiments shall not be limited to the details provided herein but may be modified within the scope and equivalents of the claims.

Claims

Claim 1 A gas delivery system for a processing chamber, comprising: a first channel for delivering a first chemical to the processing chamber and a second channel for delivering a second chemical to the processing chamber, wherein the first channel has a first inlet valve, a second inlet valve, and a first outlet valve coupled to a first chemical source, and the second channel has a third inlet valve, a fourth inlet valve, and a second outlet valve coupled to a second chemical source; a trickle gas source connected to both the first channel through the second inlet valve and the second channel through the fourth inlet valve; a first junction coupled to the first outlet valve and a second junction coupled to the second outlet valve; a common conduit connecting the first junction and the second junction, wherein the first junction is an input connected to a push gas source for receiving a push inert gas. The common conduit having an output portion connected to the processing chamber, wherein the second joint above has;and a controller coupled to the first channel and the second channel, wherein the controller receives values ​​sensed from a plurality of sensors distributed within the first channel and the second channel and is programmed to control the operation of the first channel and the second channel, and during operation, the controller (a) opens only one of the first inlet valve of the first channel flowing the first chemical or the third inlet valve of the second channel flowing the second chemical as an active channel at one time, and keeps the other of the first inlet valve of the first channel or the third inlet valve of the second channel flowing the second chemical closed as an inactive channel, and (b) keeps the second inlet valve and the fourth inlet valve corresponding to both the inactive channel and the active channel open and the flow of trickle inert gas from the trickle gas source toward both the first junction and the second junction A gas delivery system programmed to control such that both the first junction and the second junction receive the trickle inert gas and only one of the first junction or the second junction receives the first chemical or the second chemical, and (c) keep the push gas source turned on so that the push inert gas flows into the first junction, through the common conduit, and out of the second junction while pushing the trickle inert gas and one of the first chemical or the second chemical toward the processing chamber.; Claim 2 A gas delivery system according to claim 1, wherein the first channel comprises a first ampoule having a first inlet for receiving the first chemical from a first chemical source and a second inlet for receiving the trickle inert gas from the trickle gas source, and the second channel comprises a second ampoule having a first inlet for receiving the second chemical from a second chemical source and a second inlet for receiving the trickle inert gas from the trickle gas source. Claim 3 A gas delivery system according to claim 2, wherein the first channel further comprises a first valve block coupled to the first ampoule, and the first valve block has at least the first inlet valve to control the flow of the first chemical from the first chemical source into the first ampoule, and the second channel further comprises a second valve block coupled to the second ampoule, and the second valve block has at least the third inlet valve to control the flow of the second chemical from the second chemical source and the flow of the trickle inert gas from the trickle gas source into the second ampoule. Claim 4 A gas delivery system according to claim 2, wherein the first channel comprises a first trickle control unit positioned between the trickle gas source and the first ampoule, and the second channel comprises a second trickle control unit positioned between the trickle gas source and the second ampoule, wherein the first trickle control unit comprises at least the second inlet valve and the second trickle control unit comprises at least the fourth inlet valve to control the flow of the trickle inert from the trickle gas source into the first ampoule and the second ampoule. Claim 5 A gas delivery system according to claim 2, wherein each of the first ampoule and the second ampoule comprises one or more level sensors coupled to a spill detector valve, the one or more level sensors are configured to generate a signal to the spill detector valve indicating the level of the first chemical and the second chemical in the corresponding first ampoule and the second ampoule, and the spill detector valve is configured to control the flow of the first chemical or the second chemical into the corresponding first ampoule or the second ampoule. Claim 6 A gas delivery system according to claim 2, wherein the components of the first channel and the second channel, respectively, are positioned symmetrically with respect to each other within the gas delivery system. Claim 7 A gas delivery system according to claim 1, wherein the layout of the first channel matches the layout of the second channel. Claim 8 A gas delivery system according to claim 7, wherein the layout is defined by the total line length, the number of bending sections, the line width, and the number of fittings of each of the conduits of the first channel and the second channel, the total line length of the conduits is calculated as the sum of the lengths of each line segment, the line segments are defined between pairs of consecutive bending sections, and matching the layout of the conduit of the first channel to the conduit of the second channel comprises matching the total line lengths, the number of fittings, the number of bending sections, and the line width. Claim 9 A gas delivery system according to claim 8, wherein the total line length of the conduit of the first channel includes the length of the line segment of the common conduit between the first joint and the second joint. Claim 10 A gas delivery system according to claim 1, wherein the flow of the trickle inert gas into the inert channel of one of the first channel or the second channel is intended to prevent an internal dead-leg. Claim 11 A gas delivery system according to claim 1, wherein the length of the common conduit between the first joint and the second joint is defined to prevent the diffusion of the first chemical or the second chemical into the inert channel of one of the first channel or the second channel. Claim 12 In claim 11, the gas delivery system, wherein the length is derived from the Peclet number. Claim 13 A gas delivery system according to claim 1, wherein the trickle inert gas and the push inert gas are argon. Claim 14 A gas delivery system for a processing chamber, comprising: a first channel for delivering a first chemical to the processing chamber, wherein the first channel comprises a first ampoule coupled to a first chemical source and a trickle gas source, wherein the first ampoule comprises a first inlet operated by a first inlet valve for receiving the first chemical from the first chemical source and a second inlet operated by a second inlet valve for receiving a trickle inert gas from the trickle gas source, and wherein the first channel comprises a first outlet valve; a second channel for delivering a second chemical to the processing chamber, wherein the second channel comprises a second ampoule coupled to a second chemical source and the trickle gas source, wherein the second ampoule comprises a first inlet operated by a third inlet valve for receiving the second chemical from the second chemical source and a fourth inlet valve A second channel comprising a second inlet for receiving the trickle inert gas from the trickle gas source, wherein the second channel has a second outlet valve; a first junction having an input portion coupled to the first outlet valve and connected to a push gas source for receiving the push inert gas, and a second junction having an output portion coupled to the second outlet valve and connected to the processing chamber; a common conduit connected between the first junction and the second junction;and a controller coupled to the first channel and the second channel, wherein the controller receives values ​​sensed from a plurality of sensors distributed within the first channel and the second channel and is programmed to control the operation of the first channel and the second channel, and during operation, the controller (a) opens only one of the first inlet valve of the first channel flowing the first chemical or the third inlet valve of the second channel flowing the second chemical as an active channel at one time, and keeps the other of the first inlet valve of the first channel or the third inlet valve of the second channel flowing the second chemical closed as an inactive channel, and (b) keeps the second inlet valve and the fourth inlet valve corresponding to both the inactive channel and the active channel open and the flow of trickle inert gas from the trickle gas source toward both the first junction and the second junction A gas delivery system programmed to control such that both the first junction and the second junction receive the trickle inert gas and only one of the first junction or the second junction receives the first chemical or the second chemical, and (c) keep the push gas source turned on so that the push inert gas flows into the first junction, through the common conduit, and out of the second junction while pushing the trickle inert gas and one of the first chemical or the second chemical toward the processing chamber.; Claim 15 A gas delivery system according to claim 14, wherein the first channel further comprises a first valve block positioned between the first chemical source and the first ampoule, and the first valve block has at least a first inlet valve to control the flow of the first chemical from the first chemical source into the first ampoule, and the second channel further comprises a second valve block positioned between the second chemical source and the second ampoule, and the second valve block has at least a second inlet valve to control the flow of the second chemical from the second chemical source into the second ampoule. Claim 16 A gas delivery system according to claim 14, wherein each of the first ampoule and the second ampoule comprises one or more level sensors coupled to a leak detector valve, the one or more level sensors are configured to generate a signal to the leak detector valve indicating the level of the first chemical and the second chemical in the first ampoule and the second ampoule, and the leak detector valve is configured to control the flow of the first chemical or the second chemical into the corresponding first ampoule or the second ampoule. Claim 17 A gas delivery system according to claim 14, further comprising a manometer coupled to each of the first ampoule and the second ampoule, wherein the manometer is configured to control the pressure of the first chemical or the second chemical flowing from the first ampoule or the second ampoule toward the first outlet valve or the second outlet valve. Claim 18 A gas delivery system according to claim 14, wherein each of the first channel and the second channel comprises a conduit, the conduit of the first channel connects the first ampoule to the first junction and the conduit of the second ampoule connects the second ampoule to the second junction, and the layout of the conduit of the first channel matches the layout of the conduit of the second channel. Claim 19 A gas delivery system according to claim 18, wherein the layout of each of the conduits is defined by a total line length, a number of bending sections, a line width, and a number of fittings, wherein the total line length is calculated as the sum of the lengths of the line segments of each of the conduits, and each of the line segments is defined between a pair of consecutive bending sections, and matching the layout of the conduit of the first channel to the layout of the conduit of the second channel comprises matching the total line length, the number of fittings, the number of bending sections, and the line width. Claim 20 A gas delivery system according to claim 14, wherein the trickle inert gas and the push inert gas are argon.

Images