Non-elastomeric, non-polymeric, non-metallic membrane valves for semiconductor processing apparatus

Abstract

To provide an apparatus which includes a substrate having one or more microfluidic valve structures.SOLUTION: An apparatus 100 may be provided which includes a substrate 102 having one or more microfluidic valve structures 106. The valve structures 106 are non-elastomeric, non-polymeric, non-metallic membrane valves for use in high-vacuum applications. Such a valve is functional even when the fluid-control side of the valve is exposed to a sub-atmospheric pressure field which may generally act to collapse / seal conventional elastomeric membrane valves.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] [Incorporated by reference] PCT applications are being filed contemporaneously herewith as a part of this application. Each application to which this application claims the benefit or priority of a contemporaneously filed PCT application is hereby incorporated by reference in its entirety for all purposes.

[0002] Semiconductor processing operations often require the provision of many gases in various combinations, at various flow rates, and at various times that can be flowed into a semiconductor processing chamber. In some semiconductor processing tools, it is not uncommon to have as many as 15-20 different gases being fed into the tool, with each gas typically being controlled separately. Semiconductor processing tools typically include a "gas box" that houses many different computer-controlled valves, mass flow controllers, and / or other gas flow components that can be controlled to provide desired gas mixtures at various times during a semiconductor processing operation.

[0003] Such gas boxes are typically assembled from relatively large individual components (e.g., surface mounted valves, manifold passages, seals) that feature, for example, 1.5 inch (3.81 centimeter) square mounting flanges for connecting the gas flow components with their respective manifolds. Such components may be assembled together into a "gas stick" to allow control of each gas, which may then be mounted to a cabinet to form a "gas box." A gas stick may include multiple surface mounted components (e.g., 5-10 such components), and a semiconductor processing tool may include multiple (e.g., 10 or 20) such gas sticks.

[0004] Presented herein are new designs for semiconductor process gas flow control components that can be used to provide a more compact valve system. Summary of the Invention

[0005] The details of one or more embodiments of the subject matter described herein are set forth in the accompanying drawings and the following detailed description. Other features, aspects, and advantages will become apparent from the detailed description, the drawings, and the claims. The following non-limiting embodiments are considered part of this disclosure, and other embodiments will likewise be apparent from the disclosure as a whole and the accompanying drawings.

[0006] In some embodiments, an apparatus may be provided that includes a substrate having one or more microfluidic valve structures, each of the one or more microfluidic valve structures having a nominal diameter D d a diaphragm having a first surface and a second surface opposite the first surface; a base; and an orifice in the base, the orifice having a cross-sectional area A in a plane parallel to the base. o and an orifice having a nominal outside diameter D o and nominal inner diameter D i For each microfluidic valve structure of such a device, the diaphragm may be made of a non-elastomeric material, the raised seat structure may extend from a base of the diaphragm toward the first face, and a surface of the raised seat structure facing the diaphragm may be spaced apart from the first face of the diaphragm by a gap distance d when the microfluidic valve structure is in a non-operated state, and D i is 0.2 D d A may be: o teeth

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[0007] In some such embodiments, for one or more microfluidic valve structures, A o teeth

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[0008] In some embodiments, for a first micro-fluidic valve structure of the one or more micro-fluidic valve structures, a maximum distance along a first axis between a first surface of the diaphragm of the first micro-fluidic valve structure and a surface of the raised sheet structure of the first micro-fluidic valve structure may be 40 μm or less, and the first axis may be perpendicular to the surface of the raised sheet structure of the first micro-fluidic valve structure.

[0009] In some embodiments of the device, when a first microfluidic valve structure of the one or more microfluidic valve structures is in a non-operating state, a first surface of a diaphragm of the first microfluidic valve structure may be exposed to a pressure below atmospheric pressure and a second surface of the diaphragm of the first microfluidic valve structure may be exposed to atmospheric pressure.

[0010] In some embodiments of the device, the first pressure in the first microfluidic valve structure may be greater than atmospheric pressure.

[0011] In some embodiments of the device, the diaphragm of at least one of the one or more microfluidic valve structures may be made of silicon or silicon dioxide.

[0012] In some embodiments of the device, at least one of the one or more microfluidic valve structures may be made of multiple silicon or silicon dioxide layers.

[0013] In some embodiments of the device, the device may be configured to be connected to a gas source such that at least a first microfluidic valve structure of the one or more microfluidic valve structures is part of a flow path within the device, the flow path being configured to be fluidly connected to the gas source such that the raised seat structure of the first microfluidic valve structure is fluidly disposed between the gas source and a diaphragm of the first microfluidic valve structure.

[0014] In some such embodiments of the device, the device may further include a gas source and may be connected to the gas source such that the raised sheet structure of the first microfluidic valve structure is fluidly disposed between the gas source and the diaphragm of the first microfluidic valve structure.

[0015] In some embodiments of the device, the device may further comprise a diaphragm layer, an actuator plenum layer, and a valve plenum layer. In such embodiments, a diaphragm of a first microfluidic valve structure of the one or more microfluidic valve structures may be provided by the diaphragm layer, a first surface of the diaphragm layer may provide a first surface of the diaphragm of the first microfluidic valve structure, a second surface of the diaphragm layer may provide a second surface of the diaphragm of the first microfluidic valve structure, the first surface of the diaphragm layer may be coupled to the valve plenum layer, and the second surface of the diaphragm layer may be coupled to the actuator plenum layer, the actuator plenum layer having a diameter D through the actuator plenum layer centered on the diaphragm of the first microfluidic valve structure. apl The valve plenum layer may also have a hole of diameter D through the valve plenum layer centered on the diaphragm of the first microfluidic valve structure. vpl D vpl D apl It can be smaller than . [Brief description of the drawings]

[0016] Various embodiments disclosed herein are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings, in which like reference numbers refer to similar elements and in which:

[0017] [Figure 1] Exemplary devices having non-elastomeric, non-polymeric, and non-metallic microfluidic valve structures.

[0018] [Diagram 2] 1 is a graph showing the Mach number at the orifice of a non-elastomeric, non-polymeric, and non-metallic valve structure under various flow conditions for two different configurations of the valve structure; [Diagram 3] 1 is a graph showing the Mach number at the orifice of a non-elastomeric, non-polymeric, and non-metallic valve structure under various flow conditions for two different configurations of the valve structure; [Figure 4] 1 is a graph showing the Mach number at the orifice of a non-elastomeric, non-polymeric, and non-metallic valve structure under various flow conditions for two different configurations of the valve structure;

[0019] [Diagram 5] 1 is a simplified perspective view of various elements of a microfluidic valve structure.

[0020] [Figure 6] FIG. 1 is a diagram of a distributor for controllably mixing multiple gases.

[0021] [Figure 7] An example of a two-source splitter.

[0022] The figures herein are generally not drawn to scale; however, various aspects of the figures, as described below, may be drawn to scale. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Modern semiconductor processing tools often use a number of different gases introduced into the semiconductor processing chamber at different times, in different combinations, and at different flow rates. In some modern semiconductor processing tools, several reactant gases may be alternated, and each of the series of reactant gas flows may be followed by an inert or purge gas flow used to remove residues of that reactant before the next reactant flow. This prevents mixing of the two reactants in the gas distribution system, which can cause undesirable side effects (although such mixing is desirable once the reactant gases enter the semiconductor processing chamber). One problem with the use of conventional gas control components is that the flow paths are often long, and can include a significant length between the last controllable fluid component of a given gas source and the point at which the gas flows into the semiconductor processing chamber. Gas trapped in such flow paths may be wasted.

[0024] In order to provide a more compact and low-cost solution for gas flow control in semiconductor processing tools, the inventors have come up with a new type of non-elastomeric, non-polymeric, non-metallic membrane valve. Such a membrane valve may in some respects resemble somewhat elastomeric microfluidic membrane valves used, for example, in microfluidic cartridges or other liquid analytical systems. However, due to the operating pressures typically found in semiconductor processing systems, and the toxic or reactive gases typically handled by such systems, microfluidic valve technology commonly used in liquid microfluidic processing, such as those used in gene sequencing systems, is not suitable. For example, elastomeric microfluidic valves typically used in microfluidic applications for chemical and biological analysis may be susceptible to chemical corrosion or gas permeation through the elastomeric membranes used in such valves. Moreover, because most semiconductor processing chambers operate at sub-atmospheric pressures, the pressure environment downstream of such valves, and thus the side of such elastomeric membrane that provides the seal for such valves, is often at a lower pressure than the other side of such membrane. This would typically cause such elastomeric membranes to deform into a "sealed" state, making them difficult or impossible to reliably open.

[0025] To address this issue, the inventors have come up with a non-elastomeric, non-polymeric, and non-metallic membrane valve, in which the valve is made of layers of non-elastomeric, non-polymeric, and non-metallic materials bonded to form a laminate. Such materials may be selected to be non-reactive with the gases flowing through such valves (e.g., silicon such as glass, or silicon dioxide such as quartz). Avoiding the use of polymeric and elastomeric materials avoids potential gas permeation problems through such valve membranes, and avoiding the use of metallic materials reduces the risk of adverse chemical reactions between the valve materials and process gases that may be handled by the valve.

[0026] In an elastomeric membrane valve, the elastomeric membrane layer is typically placed on a substrate having an inlet and an outlet that can be sealed by the elastomeric membrane when the thin elastomeric layer is in contact with the substrate. Some such valves may have a spacer layer between the elastomeric membrane and the substrate, which provides a gap between the elastomeric membrane and the substrate when the elastomeric membrane is in an undeformed state, allowing liquid or gas to flow from one port to the other. When pressure is applied to the elastomeric membrane side opposite the gap, the elastomeric membrane deflects towards the inlet and outlet ports, contacting and sealing them. In other such valves, the elastomeric membrane may seal the inlet and outlet ports by sealing against the substrate when in an undeformed state. When the side of the elastomeric membrane opposite the side sealed to the inlet and outlet ports is exposed to reduced pressure, the elastomeric membrane may expand upwards, allowing fluid to flow from the inlet to the outlet. When the actuation pressure (or negative pressure) is removed, the elastomeric membrane returns to its undeformed state. Such valves are typically made of elastomeric materials (e.g., silicone). Such materials are liquid-tight (most microfluidic systems are used to transport liquids), strong, and can undergo large strains without permanent deformation or tearing. In most cases, such elastomeric membranes are the best choice because their flexibility allows them to conform to the inner surface of the valve structure, providing very good sealing against the inlet and outlet ports, and they can withstand repeated movements and relatively large deformations. Microfluidic valves with elastomeric membrane valves may have a general rigid structural layer in addition to the elastomeric membrane layer that provides rigidity to the entire valve structure. Such a rigid structural layer may be provided, for example, by a non-elastomeric polymeric material (e.g., acrylic or polycarbonate) or a non-elastomeric non-polymeric material (e.g., glass).

[0027] However, in the non-elastomeric, non-polymeric, and non-metallic membrane valves of the present application, the entire wet valve structure, including the membrane (i.e., the portion of the valve that contacts the fluid flow that the valve is designed to control), may be made of non-elastomeric, non-polymeric, and non-metallic materials. In particular, materials such as silicon (glass) or silicon dioxide (quartz) may be used, either of which reacts poorly with most semiconductor processing gases. While such materials offer excellent resistance to chemical attack, both glass and quartz are very brittle materials, significantly limiting their usefulness in the context of membrane valves.

[0028] The most significant problem with using non-elastomeric, non-polymeric, and non-metallic materials is that such materials are typically much stiffer than elastomeric materials, thereby limiting the amount of movement that a membrane made of such materials can undergo in response to the application of a given pressure differential. Moreover, most such materials suitable for use with various gases used in semiconductor processing equipment (e.g., materials that react poorly with such gases, such as silicon and quartz) have very low plasticity and can crack if bent excessively. In contrast, elastomeric materials, due to their stretchy and compliant nature, can withstand severe deformation without tearing.

[0029] FIGURE 1 depicts an exemplary device having a non-elastomeric, non-polymeric, and non-metallic microfluidic valve structure. In FIGURE 1, device 100 is mounted on a substrate 102 having a plurality of patterned layers 104 (e.g., layers 104a-104g) arranged to provide a microfluidic valve structure 106. It will be understood that the number and arrangement of layers 104 may vary from that shown, and any arrangement of layers that results in a structure having similar characteristics to those described herein falls within the scope of the present disclosure. The layers may be bonded using any suitable bonding technique (diffusion bonding, fusion bonding, etc.).

[0030] The layer 104 of the substrate 102 may be configured to provide a diaphragm 108 (e.g., a thin circular region) that may function as a flexible membrane interposed between the actuator plenum 132 and the valve plenum 138. The diaphragm 108 has a first surface 110 and a second surface 112, and a nominal diameter D vpl The valve plenum 138 may generally be defined as an open volume sandwiched between the first face 110 and the base 114 and bounded by the periphery of the diaphragm 108. The valve plenum 138 may include a raised seat structure 120 that may project upwardly from the base 114 and extend toward the first face 110 of the diaphragm 108. The raised seat structure 120 may, for example, form a continuous wall around its central region and have a surface 122 that faces the first face 110 of the diaphragm 108. In some embodiments, the raised seat structure 120 may be an annular wall that extends upwardly from the base 114 toward the first face 110 of the diaphragm 108, as shown in FIG.

[0031] The orifice 118 may be located within the central region of the raised seat structure 120 (e.g., at the center of the central region of the raised seat structure 120) and may extend through the base 114. The orifice 118 may be located at other locations within the central region of the raised seat structure 120 (e.g., at a location within the central region of the raised seat structure 120 that is not at the center of the raised seat structure 120). The orifice 118 may fluidly connect a gas inlet 124, which may be used to supply semiconductor processing gases from a gas source (not shown) to the microfluidic valve structure 106, to a valve plenum 138. The valve plenum 138 may be fluidly connected to an exhaust port 116 through which processing gases may flow when the microfluidic valve structure 106 is in an open state, and the gas inlet 124 is fluidly connected to a source of such processing gas. The orifice 118 may have any desired cross-sectional shape, but in the example described herein, the orifice 118 has a circular cross-sectional shape with a diameter D.

[0032] Control of the microfluidic valve structure 106 may be provided by any suitable mechanism for expanding and contracting the diaphragm 108. For example, the actuator plenum 132 may be connected to a controllable air pressure source (e.g., a valve attached to a pressurized air source) that controllably pressurizes the actuator plenum 132 to expand and contract the diaphragm 108 to inflate into the valve plenum 138, thereby moving the first surface 110 of the diaphragm 108 toward the surface 122. When the diaphragm 108 is sufficiently inflated, the first surface 110 of the diaphragm 108 may contact the surface 122, thereby sealing the raised seat structure 120 and preventing further gas flow out of the raised seat structure 120 through the orifice 118. When the microfluidic valve structure is in a non-operated state, the first surface 110 and the surface 122 may be separated by a gap 126 of a distance d.

[0033] The microvalve structure shown in FIG. 1 may be used regardless of flow direction (e.g., gas flowing in the direction of the figure or gas flowing in the reverse direction). However, if the orifice 118 is fluidly located between the gas source and the diaphragm 108, it may provide significant advantages to have the orifice 118 located upstream relative to the diaphragm 108. As used herein, the term "fluidically located between" refers to a first structure of a fluid flow system located relative to two second structures of the fluid flow system such that fluid flowing from one of the second structures to the other of the second structures must contact or flow near the first structure before reaching the other of the second structures. For example, a kitchen sink would be described as being fluidly located between the kitchen faucet for that sink and the drain for that sink. Similarly, a home's main water stop valve would be described as being fluidly located between the street water main and the home's interior water main.

[0034] As gas flows through the microfluidic valve structure 106 as shown, two general regions of high flow resistance may be encountered. The first region is the orifice 118, which may generally be sized to act as a sonic flow restrictor configured, for example, such that gas flowing through the orifice 118 develops into a sonic fully choked flow (i.e., M=1) within the orifice 118. If the diameter of the orifice 118 is tightly controlled, as may be achieved by lithographic techniques, then a very accurate orifice diameter may be achieved. Such precise dimensional control with fully choked flow may enable very accurate time-based measurement of gas flow through the microfluidic valve structure.

[0035] The second region is an annular region sandwiched between surface 122 and first face 110 and having a height defined by gap 126. This region is primarily defined by an inner dimension (D i ) and outer dimensions (D o ) (e.g., the inner and outer diameters of the raised sheet structure 120, and the gap distance d).

[0036] 1 (i.e., when the diaphragm 108 is fluidly disposed between the gas source and the orifice 118), the diaphragm 108 and the annular gap between the diaphragm 108 and the surface 122 of the raised seating structure 120 will be upstream of the orifice. In such a situation, if choked flow occurs in the region between the diaphragm 108 and the surface 122 of the raised seating structure 120, choked flow will generally not develop downstream at the orifice 108. In such a situation, the orifice 118 is no longer an effective mechanism for controlling or metering the gas flow and is unnecessary. The mass flow rate through the annular gap with choked flow is determined by the gap distance d between the diaphragm 108 and the surface 122 of the raised seating structure 120, the inner diameter D of the raised seating structure 120, and the gap distance d between the diaphragm 108 and the surface 122 of the raised seating structure 120. i , and the radial thickness of the raised sheet structure 120 (0.5·(D o -D i)) Two of these factors may be controlled by manufacturing tolerances, but it is difficult to control the gap distance d because the value of the gap distance d varies during use depending on, for example, pressure conditions in the valve plenum 138 and / or atmospheric pressure conditions.

[0037] Additionally, it may generally be desirable to reduce the gap distance d because the smaller the distance d, the smaller the gap the diaphragm must move through to contact surface 122 of raised seal structure 120. Given the limited flexibility of non-elastomeric, non-polymeric, and non-metallic materials (e.g., quartz or glass), the range of movement that a diaphragm 108 made from such materials may provide for a given size diaphragm may be significantly limited.

[0038] Thus, for configurations in which the diaphragm 108 is fluidly disposed between the gas source and the orifice 118, a microfluidic valve structure may either require a larger diameter diaphragm but use a larger gap size that avoids potential choked flow in the annular gap, or a smaller diameter diaphragm is possible but use a smaller gap size that may increase the likelihood of choked flow occurring in the annular gap rather than the orifice 118 (attempts may be made to size the gap "just right," but such attempts may not produce reliable performance because gap sizes vary with environmental conditions (e.g., atmospheric pressure environments)).

[0039] However, when the diaphragm 108, orifice 118, and gas source are configured as suggested in FIG. 1 such that the orifice 118 is fluidly located between the gas source and the diaphragm 108, choked flow through the orifice 118 may be produced for a given flow regime having a gap distance d that is much smaller than when used in the inverted configuration.

[0040] For example, for an argon flow of 10 standard cubic centimeters per minute (SCCM), an exemplary orifice 118 with diameter d=0.3 mm and diameter D i Fluid simulations performed on a raised sheet structure 120 having a Mach number of 1 mm showed that when the orifice was fluidly placed between the gas source and the diaphragm, the Mach number of the flow through the orifice 118 remained relatively constant at 1 for a range of gap sizes from 0.005 to 1 mm, but in the same configuration with a diaphragm fluidly placed between the gas source and the orifice, the Mach number of the flow through the orifice 118 similarly remained constant at 1 for gap sizes greater than 0.2 mm, but dropped rapidly to 0.01 for gap sizes from 0.005 to 0.2 mm. Figure 2 shows a plot of such a response (orifice upstream = orifice fluidly placed between the gas source and the diaphragm, orifice downstream = diaphragm fluidly placed between the gas source and the orifice). The data from this simulation shows that placing the orifice fluidly between the gas source and the diaphragm allows for the use of a gap distance d as small as about 0.005 mm without loss of choked flow at the orifice 118, while placing the diaphragm fluidly between the gas source and the orifice requires a gap distance d of about 0.2 mm or more to ensure that choked flow occurs within the orifice.

[0041] Figures 3 and 4 show similar plots of the simulation data. Figure 3 shows a plot of a simulation similar to that of Figure 2, except that the exemplary orifice 118 has a diameter d = 0.5 mm and the raised sheet structure 120 has a diameter D i = 1 mm and a 30 standard cubic centimeters per minute (SCCM) flow of argon was introduced through the microfluidic valve structure 106. Similarly, Figure 4 shows a plot of a simulation similar to that of Figure 2, but with the exemplary orifice and raised seat structure 120 both having a diameter D iand D=1 mm, with a 120 standard cubic centimeters per minute (SCCM) argon flow being introduced through the microfluidic valve structure 106. In these two additional cases, a similar response may be observed: placing the orifice fluidically between the gas source and the diaphragm allows for the use of a much smaller gap distance d (e.g., 0.01-0.05 mm) while still maintaining a choked flow condition in the orifice 118, whereas placing the diaphragm fluidically between the gas source and the orifice requires that the gap distance d be maintained at, for example, 2.5 mm or more (in the situations of FIG. 3 and FIG. 4, full choked flow never actually develops for the simulated situations).

[0042] In the non-elastomeric, non-polymeric, and non-metallic microfluidic valve structures described herein, the membrane / diaphragm of the microfluidic valve structure may be configured to have a very small operating gap (i.e., the distance the diaphragm must move to seal the orifice of the valve structure and block fluid flow). The operating gap is generally determined by the size of the diaphragm, with larger diaphragms allowing for larger movements and therefore allowing for larger operating gaps. For example, a microfluidic valve structure having a silicon-based diaphragm with an effective diameter of 5 mm may be configured to only allow for a deflection of 0.04 mm before sealing the orifice of the valve structure. However, as previously mentioned, for microfluidic valve structures intended to function with semiconductor processing equipment where gas flowing through the microfluidic valve structure may flow into a sub-atmospheric environment, the diaphragm may be exposed to a pre-existing pressure differential (e.g., sub-atmospheric pressure on the first side of the diaphragm and atmospheric pressure (or a pressure greater than sub-atmospheric pressure on the first side of the diaphragm)) when in a non-actuated state. As a result, the diaphragm may be in a partially expanded or deflected state even when not actively actuated. Actuation by increasing pressure on the second side of the diaphragm may simply deflect or expand the diaphragm further until the first side of the diaphragm contacts the raised seat structure.

[0043] This problem is specific to microfluidic valves in semiconductor processing tools and imposes some implementation limitations on such valves that are not encountered in typical microfluidic systems (e.g., microfluidic systems for liquid handling may be used for genetic, chemical, or biological fluid analysis). For example, diaphragm deflection increases nonlinearly with increasing diaphragm diameter as a function of constant pressure. Thus, increasing the diaphragm diameter may provide more potential movement in the diaphragm, but at the expense of increasing the "static" deflection due to atmospheric pressure, which serves to reduce the gap size between the diaphragm 108 and the available raised sheet structure surface 122, and also results in increased stresses in the diaphragm, which may cause early failure. Another detriment to increasing the diaphragm diameter is that fewer microfluidic valve structures can be fabricated at one time. As previously mentioned, lithographic techniques may be used to fabricate layers of the microfluidic devices described herein. With such techniques, multiple microfluidic valve structures may be fabricated on a single wafer (e.g., a silicon wafer). Such fabrication techniques are expensive to implement and are more cost effective when multiple microfluidic valve structures are fabricated simultaneously on a single wafer. Thus, as the diameter of the diaphragm 108 increases, fewer microfluidic valve structures can fit on a wafer of a given size, so in many embodiments it may be beneficial to reduce or minimize the diameter of the diaphragm. Specifically, the inventors have found that in some embodiments, the diameter D vpl to a value of about 1 centimeter or less (e.g., 10 mm, 9 mm, 8 mm, 7 mm, 6 mm, 5 mm, 4 mm, 3 mm, 2 mm, 1 mm, or any value in between).

[0044] The diameter of the diaphragm, as well as the nature of the material used to provide the diaphragm, may effectively determine the maximum amount of movement the diaphragm can provide (without failing) when the second surface of the diaphragm is exposed to a predetermined pressure environment. This maximum amount of movement may then determine the size of the gap distance d, taking into account pre-operational movement due to atmospheric pressure effects, if necessary. For example, a microfluidic valve structure having a 5 mm diameter and 85 μm thick diaphragm may have a gap distance of 0.040 mm, although this gap distance is conservative and in some instances larger gap distances (e.g., up to 0.125 mm in some embodiments) may be used.

[0045] The orifice may generally be selected depending on the gas flow characteristics desired for a given semiconductor processing tool in which the microfluidic valve structure is to be used. The orifice may have dimensions selected to produce a choked flow in a flow rate range desired for the semiconductor processing operation provided by the semiconductor processing tool. For example, in various embodiments, orifice diameters of 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, or values ​​therebetween may be used.

[0046] The dimensions of the raised seat structure may be selected depending on the size of the orifice, the gap distance, and the diameter of the diaphragm. For example, the inner diameter D of the raised seat structure i is 0.2 D d may be chosen to be (D d is the nominal diameter of the diaphragm (e.g., D vpl )) Inner diameter D i , the gap distance d, and the diameter D of the orifice are A o is (π / 2) d D i may be chosen to be (A o is the cross-sectional area of ​​the orifice (e.g., A for a circular orifice) o =π D 2 / 4)). In various embodiments,

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[0047] The various layers of the microfluidic valve structures disclosed herein may be configured in a variety of different ways. For example, some embodiments may feature a layer having a through feature that is subsequently bonded to a layer without a corresponding through feature to form a blind hole or internal chamber in the stack. In other embodiments, the blind hole may be formed directly in the layer without the need for bonding, for example, by etching or machining the feature to a depth less than the thickness of the layer. The thickness of the various layers may be selected as desired depending on the needs of a particular application. For example, in some microfluidic valve structures, the diaphragm may be 15-120 μm thick (e.g., about 0.085 mm thick), with the thickness of the diaphragm naturally determining, at least in part, the movement that may be achieved by the diaphragm during operation.

[0048] In some embodiments, the base may be 100-1000 μm thick (e.g., 0.725 mm thick), and the thickness of the base may be selected so that the structure can support the raised seat structure and withstand the operating pressures within the valve structure, but the thickness of the base may determine the length of the orifice, and an orifice that is too long may suffer from an undesirable increase in flow resistance.

[0049] FIG. 5 provides a simplified perspective view of the various elements of the microfluidic valve structure described above. In FIG. 5, a raised seat structure 520 is shown with a diameter D d 5A, a diaphragm 508 is shown having a raised seat structure 520 with a surface 522 facing a first side 510 of the diaphragm 508 and separated from the first side 510 by a gap of distance d. A second side 512 of the diaphragm 508 (the top side in FIG. 5 ) may be pressurized to move the diaphragm 508 into contact with the surface 522 of the raised seat structure 520. The raised seat structure 520 has an inner diameter D i and outer diameter D oeach having an area A with gap distance d, e.g., by multiplying the circumference associated with the respective diameter by the gap distance d. g1 and area A g2 The orifice 518 may be located at the base of the microfluidic valve structure (not shown) and defines a cylindrical reference surface of cross-sectional area A o Generally, A g1 A o may be selected to be greater than twice the

[0050] In some embodiments, the diaphragm 108 may be implemented in a particular manner, for example, where different diameters are used to define the first surface 110 and the second surface 112. For example, as shown in FIG. AA, the first surface 110 of the diaphragm 108 and the valve plenum 138 may be spaced apart by a nominal diameter D vpl and the second surface 112 of the diaphragm 108 and the actuator plenum 132 may be defined by a nominal diameter D apl As can be seen, the actuator plenum 132 may be defined by a diameter D vpl Similarly, the valve plenum 138 may be provided in the actuator plenum layer 134 (layer 140a) which may have holes of diameter D apl The valve plenum layer 140 (layer 140c) may have holes of D. vpl and D. apl By avoiding structures where the layers are the same, stresses at the corners where layer 140b, which provides diaphragm 108, meet layers 140a and 140c may be significantly reduced, providing stronger valve action and reducing the chance of valve failure.

[0051] The non-elastomeric, non-polymeric, and non-metallic microfluidic valve structures as disclosed herein may be used in various ways in semiconductor processing equipment. Figures 6 and 7 depict exemplary embodiments in which such microfluidic valve structures may be used. Figure 6 depicts a diagram of a distributor for mixing multiple gases in a controllable manner. In Figure 6, multiple gas sources 630a-630f are provided. Each gas source 630 may receive gas, for example, from a pressurized gas source or tube. The gas sources 630 may then each be fluidly connected to an inlet gallery 642. For example, gas source 630a may be fluidly connected to inlet gallery 642a, and gas source 630b may be fluidly connected to inlet gallery 642b. Each inlet gallery 642 may then be fluidly connected to a corresponding branch passage 646 by a corresponding plurality of non-elastomeric, non-polymeric, and non-metallic micro-fluidic valve structures 606 (although only three are shown with callouts in FIG. 6, it is readily apparent that there are seven such micro-fluidic valve structures 606 in each inlet gallery 642). In this example, each inlet gallery is fluidly connected to seven micro-fluidic valve structures, but it will be understood that more or fewer such micro-fluidic valve structures may be provided and that two or more gas sources 630 may be coupled to their respective branch passages 642 by different numbers of micro-fluidic valve structures 606 (rather than the same number of micro-fluidic valve structures for each). The branch passages 646 then all merge at a common outlet passage 644, which may lead to a mixed gas outlet 648.

[0052] 6, the microfluidic valve structures 606 may be kept in a closed state, for example, by pressurizing a diaphragm using a pneumatic valve and compressed air to prevent process gases provided by the gas sources 630 from flowing into the branch passages 646. When a particular mixture of process gases is required at a particular mixing ratio and / or flow rate, an appropriate number of the microfluidic valve structures 606 for each of these gas sources 130 may be actuated to an open state, thereby allowing these process gases to flow into the respective branch passages 646 and the common outlet passage 644. For example, if a 1:3:7 ratio of gas is desired from gas source 630a, gas source 630c, and gas source 630d, respectively, one microfluidic valve structure 606 fluidly connecting inlet gallery 642a to branch passage 646a may be opened, three microfluidic valve structures 606 fluidly connecting inlet gallery 642c to branch passage 646c may be opened, and seven microfluidic valve structures 606 fluidly connecting inlet gallery 642d to branch passage 646d may be opened. Assuming the orifices of each microfluidic valve structure 606 are the same size, the fully choked flow that may be provided through each orifice of each microfluidic valve structure in an open state may provide the desired gas ratio.

[0053] FIG. 7 illustrates an example of a two-source distributor. In FIG. 7, two gas sources 730a and 730b are connected to respective pressurized gas sources to supply corresponding process gases to inlet galleries 742a and 742b, respectively. Each inlet gallery 742 is in turn fluidly connected to a common outlet passage 744 by a corresponding plurality of microfluidic valve structures 706a and 706b. The common outlet passage 744 leads to a mixed gas exhaust port 748. In this particular example, the examples A and B of the microfluidic valve structure 706a are in an open state (which may be a default non-operational state in some embodiments), and the examples C, D, E, F, and G of the microfluidic valve structure 706a are in a closed state. Similarly, the examples A, B, C, and D of the microfluidic valve structure 706b are in an open state, and the examples E, F, and G of the microfluidic valve structure 706a are in a closed state. Thus, the mixture ratio of gas from gas source 730a to gas source 730b may be 1:2.

[0054] It will be appreciated that many other embodiments of the microfluidic valve structure may be implemented using the microfluidic valve structure disclosed herein. For example, one such embodiment is a showerhead for semiconductor processing (e.g., a gas distributor that distributes process gases over a semiconductor wafer during processing operations). The showerhead typically has a large number (e.g., hundreds or thousands) of gas distribution ports across its underside (typically an area at least as large as the diameter of the wafer being processed). Process gas flow through the showerhead is typically controlled by a valve located outside the showerhead. For an external valve, there can be a large delay (e.g., several seconds) between when the valve opens and when the gas flowing therethrough is released by the showerhead (this delay is due to the need for gas to flow from the valve, through the showerhead, and through the gas distribution ports in the underside (or faceplate) of the showerhead). There may also be a large amount of exhaust gas trapped within the showerhead after each gas flow.

[0055] A more effective showerhead may be provided by implementing a microfluidic valve structure as disclosed herein within the showerhead (e.g., at each gas distribution port) as described in U.S. Patent Application No. 15 / 346,920, filed November 11, 2016. In this manner, the flow path from each microfluidic valve structure to the gas distribution port may generally be as short as practicable, thereby reducing the transit time of the released gas. In some embodiments, each microfluidic valve structure or a group of such valve structures may be individually operable, which may allow for operation or non-operation of a group of valves and may allow for different flow regimes of gas delivered by the showerhead. The microfluidic valve structures described herein may be used to provide the valves of the active showerhead described in U.S. Patent Application No. 15 / 346,920, the entire contents of which are incorporated herein by reference.

[0056] As mentioned above, the microfluidic valve structures described herein may be actuated by any suitable mechanism, such as the operation of a pneumatic valve that may be used to pressurize a diaphragm of such a valve structure. Such pneumatic valves may be controlled by a controller of a semiconductor processing tool. The controller may be part of a system that includes semiconductor processing equipment, including processing tools, chambers, processing platforms, and / or specific processing components (wafer pedestals, gas flow systems, etc.). These systems may be integrated with electronics for controlling pre-, during, and post-processing operations of a semiconductor wafer or substrate. These electronics may be referred to as a "controller" that may control various components or subcomponents of the system. The controller may be programmed to control any of the processes disclosed herein as well as various parameters affecting semiconductor processing, such as process gas supplies, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid supply settings, position motion settings, wafer loading and unloading from the tool and other transport tools and / or load locks connected or coupled to a particular system, depending on the processing requirements and / or type of system.

[0057] In general, a controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operations, enable cleaning operations, enable endpoint measurements, etc. Integrated circuits may include chips in firmware format that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). Program instructions may be instructions communicated to the controller in the form of various personalizations (or program files) that define operational parameters for performing a particular process on or for a semiconductor wafer or for a system. In some embodiments, the operational parameters may be part of a recipe defined by a process engineer to accomplish one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or one or more processing steps during the manufacture of a wafer die.

[0058] In some embodiments, the controller may be part of or coupled to a computer that is integrated or coupled with the system, or otherwise networked or combined with the system. For example, the controller may be in the "cloud" that allows remote access of wafer processing, or may be all or part of a fab host computer system. The computer may allow remote access to the system to monitor the progress of a manufacturing operation, review the history of past manufacturing operations, review trends or performance metrics from multiple manufacturing operations, modify parameters of a current process, set processing steps following a current process, or start a new process. In some examples, a remote computer (e.g., a server) may provide a process recipe to the system over a network that may include a local network or the Internet. The remote computer may include a user interface that allows entry or programming of parameters and / or settings that are then communicated from the remote computer to the system. In some examples, the controller receives instructions in the form of data that specifies parameters for each processing step to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process being performed and the type of tool that the controller is configured to couple to or control. Thus, as discussed above, the controller may be distributed, for example, by including one or more separate controllers networked together and cooperating toward a common purpose, such as a process or control as described herein. An example of a controller distributed for such purposes would be one or more integrated circuits on the chamber that are located remotely (e.g., at the platform level or as part of a remote computer) and that cooperate to control a process in the chamber.

[0059] Without being limited thereto, example systems may include plasma etch chambers or modules, deposition chambers or modules, spin rinse chambers or modules, metal plating chambers or modules, cleaning chambers or modules, bevel edge etch chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, ALD chambers or modules, atomic layer etch (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, and other semiconductor processing systems that may be related to or used in the fabrication and / or manufacturing of semiconductor wafers.

[0060] As described above, depending on the processing steps being performed by the tool, the controller may be in communication with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools installed throughout the factory, a main computer, another controller, or tools used to transport materials to and from tool locations and / or load ports in a semiconductor manufacturing factory.

[0061] As used herein, the term "wafer" may refer to a semiconductor wafer or substrate, or other similar types of wafers or substrates. As used herein, the term wafer station may refer to any location within a semiconductor processing tool where a wafer may be placed during various wafer processing or wafer transfer operations. As used herein, wafer support refers to any structure within a wafer station (e.g., pedestal, electrostatic chuck, wafer support shelf, etc.) configured to receive or support a semiconductor wafer.

[0062] It should also be understood that the use of ordinal indicators herein (e.g., (a), (b), (c), ...) is for organizational purposes only and is not intended to convey a particular order or importance to the items associated with each ordinal indicator. For example, "(a) obtaining information regarding velocity, and (b) obtaining information regarding position" would include obtaining information regarding position before obtaining information regarding velocity, obtaining information regarding velocity before obtaining information regarding position, and obtaining information regarding position simultaneously with obtaining information regarding velocity. Nevertheless, there may be instances where some items associated with ordinal indicators may inherently require a particular order. For example, in "(a) obtaining information regarding velocity, (b) determining a first acceleration based on the information regarding velocity, and (c) obtaining information regarding position," (a) would need to be performed before (b) because (b) is based on information obtained in (a). However, (c) may be performed before or after either (a) or (b).

[0063] It should be understood that when the term "each" is used herein (e.g., "for each <item> of one or more <items>" or "of each <item>"), it should be understood to include both a single item and a plurality of items. That is, the phrase "for each" is used in programming languages ​​to mean each and every item of the referenced collection of items. For example, if the referenced collection of items were a single item, "each" would refer to only that single item and would not imply that there must be at least two of those items (apart from the fact that dictionary definitions of "each" are often defined as terms that mean "every one of two or more things"). Similarly, if a selected item has one or more subitems, and when one of the subitems is selected, and the selected item has only one subitem, it will be understood that the selection of the one subitem is inherent to the selection of the item itself.

[0064] It will also be understood that, in general, reference to multiple controllers configured to perform various functions is intended to include situations in which only one of the controllers is configured to perform all of the disclosed or described functions, as well as situations in which each of the various controllers performs a subportion of the described functions. For example, an auto-calibration wafer may include a controller configured to control operation of various sensors of the auto-calibration wafer and communicate data therefrom to another controller associated with a semiconductor processing tool. The semiconductor processing tool controller may then analyze such data to determine various operating parameters for use with the semiconductor processing tool.

[0065] Various modifications of the embodiments described in this disclosure may be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Thus, the claims are not intended to be limited to the embodiments shown herein, but are intended to be accorded the widest scope consistent with this disclosure, the principles and novel features disclosed herein.

[0066] Certain features described herein as separate embodiments may be combined and implemented in one embodiment. Conversely, various features described as one embodiment may be implemented in multiple embodiments separately or in any suitable subcombination. Also, even if features are described above as functioning in a particular combination and initially claimed as such, in some cases one or more features from the combination of the invention may be implemented in that combination, and the combination of the invention may relate to a subcombination or variations thereof.

[0067] Similarly, although operations are depicted in the figures in a particular order, it should not be understood that such operations need to be performed in the particular order or sequence of the figures, or that all of the figure operations need to be performed, to achieve desired results. Furthermore, the figures may generally depict one or more exemplary processes in the form of flow diagrams. However, other operations not depicted may be incorporated into the generally depicted exemplary process. For example, one or more additional operations may be performed before, after, simultaneously with, or between the illustrated operations. In certain cases, multitasking and concurrent processing may be advantageous. Also, it should be understood that the separation of various system components in the above embodiments is not required for all embodiments, and that the described program components and systems may generally be integrated into a single software product or packaged into multiple software products. Additionally, other embodiments are within the scope of the following claims. In some cases, the operations recited in the claims may be performed in a different order to achieve desired results.

Claims

1. An apparatus comprising: A substrate having one or more microfluidic valve structures, each of the one or more microfluidic valve structures comprising: Nominal diameter D d a diaphragm having a first surface and a second surface opposite the first surface; A base and An orifice in the base having a cross-sectional area A in a plane parallel to the base. o and an orifice having Nominal outer diameter D o and nominal inner diameter D i and a substrate comprising a raised sheet structure having For each micro valve structure, the diaphragm is made of a non-elastomeric material; the raised sheet structure extends from the base toward the first surface of the diaphragm; a surface of the raised seat structure facing the diaphragm is separated from the first surface of the diaphragm by a gap of distance d when the microfluidic valve structure is in an unoperated state; D i is 0.2 D d is as follows: A o teeth, [0010] is as follows: the diaphragm, the raised seat structure, and the gap of the microfluidic valve structure are sized such that when the microfluidic valve structure is transitioned to an operative state by applying a first pressure to the second surface of the diaphragm, the position of the diaphragm elastically deforms toward the raised seat structure and seals against the raised seat structure.

2. 2. The apparatus of claim 1, For one or more of the microfluidic valve structures, A o teeth, [0010] The following is true: A o is 0.

9. [0010] That's it, the device.

3. 2. The apparatus of claim 1, For one or more of the microfluidic valve structures, A o teeth, [0010] The following is true: A o is 0.

8. [0010] That's it, the device.

4. 2. The apparatus of claim 1, For one or more of the microfluidic valve structures, A o teeth, [0010] The following is true: A o is 0.

7. [0010] That's it, the device.

5. 2. The apparatus of claim 1, For one or more of the microfluidic valve structures, A o teeth, [0010] The following is true: A o is 0.

6. [0010] That's it, the device.

6. 2. The apparatus of claim 1, For one or more of the microfluidic valve structures, A o teeth, [0010] The following is true: A o is 0.

5. [0010] That's it, the device.

7. 2. The apparatus of claim 1, For one or more of the microfluidic valve structures, A o teeth, [0010] The following is true: A o teeth, [0025] That's it, the device.

8. 2. The apparatus of claim 1, For a first microfluidic valve structure of the one or more microfluidic valve structures, a maximum distance along a first axis between the first surface of the diaphragm of the first microfluidic valve structure and the surface of the raised seat structure of the first microfluidic valve structure is less than or equal to 40 μm; The apparatus, wherein the first axis is perpendicular to the surface of the raised seat structure of the first microfluidic valve structure.

9. 2. The apparatus of claim 1, When a first of the one or more micro-fluidic valve structures is in the non-operating state, the first surface of the diaphragm of the first micro-fluidic valve structure is exposed to a pressure below atmospheric pressure and the second surface of the diaphragm of the first micro-fluidic valve structure is exposed to atmospheric pressure.

10. 10. The apparatus of claim 9, The apparatus, wherein the first pressure in the first microfluidic valve structure is greater than atmospheric pressure.

11. 2. The apparatus of claim 1, The apparatus, wherein the diaphragm of at least one microfluidic valve structure of the one or more microfluidic valve structures is made of silicon or silicon dioxide.

12. 2. The apparatus of claim 1, A device, wherein at least one of the one or more microfluidic valve structures is made of multiple silicon or silicon dioxide layers.

13. 2. The apparatus of claim 1, The device is configured to be connected to a gas source such that at least a first of the one or more microfluidic valve structures is part of a flow path within the device, the flow path being configured to be fluidly connectable to the gas source such that the raised seat structure of the first microfluidic valve structure is fluidly disposed between the gas source and the diaphragm of the first microfluidic valve structure.

14. 14. The apparatus of claim 13, further comprising: an apparatus comprising: a gas source, the apparatus being connected to the gas source such that the raised seat structure of the first microfluidic valve structure is fluidly disposed between the gas source and the diaphragm of the first microfluidic valve structure.

15. 2. The apparatus of claim 1, further comprising: A diaphragm layer; an actuator plenum layer; a valve plenum layer; the diaphragm of a first microfluidic valve structure of the one or more microfluidic valve structures is provided by the diaphragm layer; a first surface of the diaphragm layer providing the first surface of the diaphragm of the first microfluidic valve structure; a second surface of the diaphragm layer providing the second surface of the diaphragm of the first microfluidic valve structure; the first surface of the diaphragm layer is coupled to the valve plenum layer; the second surface of the diaphragm layer is coupled to the actuator plenum layer; The actuator plenum layer has a diameter D penetrating the actuator plenum layer located at the center of the diaphragm of the first microfluidic valve structure. apl having a hole of The valve plenum layer has a diameter D through the valve plenum layer, which is also located at the center of the diaphragm of the first microfluidic valve structure. vpl having a hole of D vpl D apl A device smaller than

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