Precursor supply tank

Abstract

To provide a device and a method for supplying a precursor.SOLUTION: A precursor supply vessel is disclosed. The precursor supply vessel comprises a top wall, a bottom wall and a side wall, a top wall heater constructed and arranged to heat the top wall, a bottom wall heater constructed and arranged to heat the bottom wall, and a side wall heater constructed and arranged to heat the side wall. Each of the heaters is independently controllable.SELECTED DRAWING: Figure 1a

Description

[Technical Field]

[0001] The present invention relates generally to semiconductor processing, and more particularly to a device and method for delivering precursors. [Background technology]

[0002] In the semiconductor industry, various processes are used to form thin films of materials on substrates, such as silicon wafers. In chemical vapor deposition (CVD), reactant gases (also referred to herein as precursor gases) of different reactants are supplied to one or more substrates in a reaction chamber. The reactant gases react with each other in the reaction chamber to form a thin film on one or more substrates. In atomic layer deposition (ALD) processes, gaseous precursors are alternately and repeatedly supplied to a substrate or wafer to form a thin film of material on the wafer. One reactant adsorbs on the wafer in a self-limiting process. A different pulse of reactant then reacts with the adsorbed material to form a monolayer of the desired material.

[0003] In some cases, vapors of source chemicals ("precursors") (e.g., molybdenum oxychloride) that are liquid or solid at ambient pressure and temperature are used. For some solid materials, the vapor pressure at room temperature is so low that they must be heated to produce sufficient reactant vapor (vapor drawing). Typically, semiconductor processing tools in clean rooms are connected to bulk precursor supplies located below the clean room floor to deliver gaseous precursors to the reaction chamber.

[0004] In applications where the reaction chamber contains multiple substrates with high surface enhancement, where the effective surface area onto which the precursor is deposited can be 400 times or more that of a flat substrate, it is necessary to provide large amounts of precursor in gaseous form within a specific period of time. In such cases, direct delivery of precursor gas from the sub-fab to the reaction chamber may not provide the necessary amount and flow rate of precursor to result in acceptable deposition conditions and / or throughput. Summary of the Invention

[0005] According to a first aspect of the present invention, there is provided a precursor supply vessel comprising a top wall, a bottom wall, and a side wall, a top wall heater configured and arranged to heat the top wall, a bottom wall heater configured and arranged to heat the bottom wall, and a side wall heater configured and arranged to heat the side wall, wherein each of the heaters is independently controllable.

[0006] Providing an individually controllable heater for each wall can provide a high level of control over precursor behavior within the chamber. For example, by appropriately selecting the power supply to each heating element, precursor can be selectively deposited on the bottom wall while preventing deposition on the side and top walls. This can allow for a more even and uniform layer of precursor to be delivered into the chamber and may provide a more consistent and reliable flow of precursor out of the chamber.

[0007] The top wall may include an inlet port for supplying precursor gas to the vessel. The top wall may include an outlet port for removing precursor gas from the vessel. By providing the inlet and / or outlet ports in the top wall, deposition of precursor on the inlet and / or outlet ports may be substantially reduced or avoided because the top wall may be maintained at a higher temperature than the sidewalls due to being further removed from the bottom wall, which in some embodiments may need to be heated to a temperature suitable for deposition of precursor on the bottom wall.

[0008] By providing the tank with inlet and outlet ports for gas injection / exhaust, precursors can be supplied to the tank in gaseous form, which may have advantages over supplying precursors to the tank in solvent or powder form. For example, using a solvent to supply precursors to the tank, followed by evaporation of the solvent in the tank, requires an additional drying step in the precursor refill process, can result in solvent contamination of the precursor extracted from the tank, and limits capacity. Supplying precursors in powder form can cause clogging, and a transport gas may be required to remove the precursor from the tank. By providing a gas supply inlet in the tank, precursor refilling can be performed without removing the tank from its installed location.

[0009] The vessel may include a single gas port in a top wall, the single gas port configured to function as an inlet for supplying precursor gas to the vessel and an outlet for removing precursor gas from the vessel. The vessel may include a selector valve for connecting the port to an inlet gas line when the port functions as an inlet, and to an outlet gas line when the port functions as an outlet, the inlet gas line being separate from the outlet gas line.

[0010] The inlet and outlet ports may be separate ports that may be spaced apart along a dimension of the top wall. By providing separate, spaced apart inlet and outlet ports, a flow of purge gas may be provided into the vessel from the inlet port and out the outlet port.

[0011] The top wall, bottom wall, and side walls may form a container. The container may have a rectangular cross-section in a plane parallel to the bottom wall. This may allow for more efficient use of space within a gas cabinet that needs to accommodate multiple vessels.

[0012] The vessel may include a housing enclosing the vessel and heater, the housing having a higher thermal conductivity than the vessel walls, which may allow for more even heating of the walls due to heat redistribution by the housing.

[0013] The housing may be arranged to provide an air gap between the housing and the bottom wall, which may allow for a larger temperature gradient between the bottom wall and the housing, which may be advantageous in applications where the bottom wall temperature needs to be changed quickly.

[0014] The housing may include a set of spacers for spacing the housing from the bottom wall to provide an air gap.

[0015] The housing may have a water-cooled bottom wall. The vessel may include a water-cooled conduit in or on the bottom wall of the housing through which water can flow to cool the bottom wall of the housing. By providing water cooling to the bottom wall of the housing, the time required for a temperature change in the bottom wall of the vessel may be reduced because active cooling may be provided.

[0016] Each wall may include a recessed channel, and the heater may include a wire fitted within the recessed channel of the respective wall configured to heat, which may allow for more efficient heat transfer to the walls and reduce the footprint of the vessel.

[0017] The tank must be at least 0.01 m 3 The container may have an internal volume of at least 0.2 m. The bottom wall may have a width at least five times the height of the side walls. The container may have an internal volume of at least 0.2 m in a plane parallel to the bottom wall. 2 Each of these dimensions can allow for the supply of large quantities of precursor within the bath, which can be particularly advantageous in applications where large quantities of precursor need to be supplied to processing equipment containing multiple semiconductor wafers for processing, especially when the wafers have a high degree of surface enhancement. In such applications, direct supply of precursor from a sub-fab bulk supply to the process chamber of the semiconductor device may not provide sufficient volume or flow rate. Baths according to embodiments of the present invention allow for large quantities of precursor to be stored and made available to the process chamber.

[0018] Each heater can be individually controllable, thereby allowing each heater to output a power that is different from the power output by the other heaters. This can be advantageous in applications where the walls have different thermal characteristics, such that a particular power input to a first heater for a first wall will result in the wall achieving a first temperature and not the same temperature as would be achieved by a second wall with a second heater receiving the same power input.

[0019] The vessel may include a valve in fluid communication with the inlet port to control the flow of precursor gas into the vessel. The vessel may include a valve in fluid communication with the outlet port to control the flow of precursor gas out of the vessel.

[0020] The top wall heater may include at least two individually controllable heating elements. The bottom wall heater may include at least two individually controllable heating elements. The side wall heater may include at least two individually controllable heating elements. Providing multiple individually controllable heating elements per wall allows for finer control of the temperature of each wall, for example, in embodiments where the wall can be divided into zones, each having a different thermal capacity and therefore would not achieve the same temperature when heated by heaters with the same input power.

[0021] The tank may include a controller configured to independently control the top, side, and bottom wall heaters. The controller may be configured to heat the top and side walls to a temperature above a deposition temperature of the precursor supplied to the tank and to heat the bottom wall to a temperature below the deposition temperature in a precursor tank refill mode. This can prevent deposition of precursor on the top and side walls and result in a more uniform monolayer of precursor on the bottom wall.

[0022] The controller may be configured, in a precursor bath delivery mode, to cause the bottom wall, side wall, and top wall to be heated to a temperature above the sublimation temperature of the precursor delivered from the bath.

[0023] The bottom wall may be heated to a lower temperature than the temperature to which the top and side walls are heated.

[0024] The vessel may be equipped with booster heaters that are individually controllable and separate from the bottom wall heater, side wall heater, and top wall heater.

[0025] According to a second aspect of the present invention, there is provided a method of operating a precursor bath according to the first embodiment, comprising performing a precursor filling step that includes closing the outlet port and flowing precursor gas through the inlet port while maintaining the bottom wall at a temperature below the deposition temperature of the precursor gas and heating the top and side walls to a temperature above the deposition temperature of the precursor gas, thereby preventing deposition of precursor on the top and side walls and resulting in a more uniform monolayer of precursor on the bottom wall.

[0026] The method may include performing a precursor supply step after the precursor filling step, the precursor supply step including closing the inlet port and opening the outlet port while heating the bottom wall, side wall, and top wall to a temperature equal to or greater than the sublimation temperature of the precursor supplied from the tank.

[0027] The method may include performing a reflow step after the precursor filling step and before the precursor supplying step, the reflow step including heating at least one wall to a temperature above the melting point of the precursor for a predetermined duration while closing the inlet and outlet ports, thereby allowing the precursor in the bath to melt and reflow to form a more uniform layer on the bottom wall.

[0028] According to a third aspect of the present invention, there is provided a semiconductor processing apparatus comprising a vessel according to the first aspect in fluid communication with a process chamber.

[0029] The process chamber may be configured to receive and process multiple substrates simultaneously.

[0030] This Summary is provided to introduce a selection of concepts in a simplified form that are described in more detail below in the Detailed Description of Example Embodiments of this Disclosure. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. [Brief explanation of the drawings]

[0031] Specific embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

[0032] [Figure 1a] 1 is a schematic perspective view of a precursor supply vessel according to an embodiment of the invention, with components on the non-visible side of the vessel shown in dashed lines; [Figure 1b] 1 is a schematic perspective view of a precursor supply tank according to an embodiment of the present invention, with components on the non-visible side of the tank omitted for clarity, but still remaining part of the tank. FIG. [Figure 2a] FIG. 1 is a schematic plan view of a wall contained within a vessel according to an embodiment of the present invention, the wall including a channel for receiving a heater wire. [Figure 2b] FIG. 1 is a schematic plan view of a wall contained within a vessel according to an embodiment of the present invention, the wall comprising an undulating channel and a heater wire received within the channel. [Figure 2c] FIG. 1 is a schematic plan view of a wall contained within a vessel according to an embodiment of the present invention, the wall comprising two L-shaped channels and a heater wire received within the channels. [Figure 3a] 1 is a schematic plan view of a wall contained within a vessel and a plurality of heaters arranged to heat at least a portion of the wall in accordance with an embodiment of the present invention; FIG. [Figure 3b] 1 is a schematic plan view of a top wall contained within a vessel in accordance with an embodiment of the present invention, the top wall being divided into multiple zones, each zone having an associated heater configured to heat that zone. [Figure 4] 1 is a schematic cross-sectional view of a vessel according to an embodiment of the present invention, comprising a housing. [Figure 5] FIG. 2 is a schematic plan view of the bottom wall of the housing including the water-cooling conduits. [Figure 6] FIG. 1 is a schematic diagram of a vessel according to an embodiment of the present invention, including a controller. [Figure 7] 1 is a schematic diagram of a semiconductor processing apparatus including a bath according to an embodiment of the present invention; [Figure 8] 1 is a flowchart of a method of using a bath according to an embodiment of the present invention. [Figure 9] 9a-9d are schematic illustrations of a vessel according to an embodiment of the invention in precursor (re)fill mode. [Figure 10] 1 is a flowchart of a method of using a bath according to an embodiment of the present invention. [Figure 11] 11a and 11b are schematic diagrams of a chamber according to an embodiment of the invention in precursor delivery mode. [Figure 12a] 1 is a schematic cross-sectional view of a vessel according to an embodiment of the present invention, the bottom wall of which is provided with ribs; [Figure 12b] 1 is a schematic cross-sectional view of a vessel according to an embodiment of the present invention, comprising a precursor tray including ribs. [Figure 13] 1 is a schematic cross-sectional view of a vessel according to an embodiment of the present invention, including a booster heater;

[0033] It will be understood that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of the illustrated embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0034] While certain specific embodiments and examples are disclosed below, it will be understood by those skilled in the art that the scope of the invention extends beyond the specifically disclosed embodiments and / or uses of the invention, and obvious variations and equivalents thereof. It is therefore not intended that the scope of the disclosed invention should be limited by the specific disclosed embodiments described below.

[0035] As used herein, the term "substrate" can refer to any single or multiple underlying materials, including any single or multiple underlying materials that may be modified or upon which a device, circuit, or film may be formed. A "substrate" can be continuous or discontinuous, rigid or flexible, solid or porous, and combinations thereof. A substrate can be in any form, such as a powder, a plate, or a workpiece. A substrate in the form of a plate can include wafers of various shapes and sizes. A substrate can be made from semiconductor materials, including, for example, silicon, silicon germanium, silicon oxide, gallium arsenide, gallium nitride, and silicon carbide.

[0036] The continuous substrate may extend beyond the boundaries of the process chamber in which the deposition process occurs. In some processes, the continuous substrate may move through the process chamber so that the process continues until the end of the substrate is reached. The continuous substrate may be supplied from a continuous substrate supply system to enable the production and output of the continuous substrate in any suitable form.

[0037] The illustrations presented herein are not meant to be actual representations of any particular materials, structures, or devices, but merely idealized representations used to describe embodiments of the present disclosure.

[0038] The specific implementations shown and described are illustrative of the invention and its best mode and are in no way intended to otherwise limit the scope of aspects and implementations. Indeed, for the sake of brevity, conventional manufacturing, association, preparation, and other functional aspects of the systems may not be described in detail. Furthermore, connecting lines shown in the various figures are intended to represent example functional relationships and / or physical couplings between the various elements. Many alternative or additional functional relationships or physical connections may be present in an actual system and / or may not be present in some embodiments.

[0039] It should be understood that the configurations and / or approaches described herein are exemplary in nature, and that these specific embodiments or examples are not to be construed in a limiting sense, as numerous variations are possible. The specific routines or methods described herein may represent one or more of any number of processing strategies. As such, various illustrated operations may be performed in the order illustrated, in other orders, or omitted in some cases.

[0040] The subject matter of the present disclosure includes all novel and non-obvious combinations and subcombinations of the various processes, systems, and configurations, and other features, functions, operations and / or properties disclosed herein, as well as all equivalents thereof.

[0041] 1a and 1b, a precursor supply tank 1, also referred to herein as tank 1, according to an embodiment of the present invention comprises a top wall 2, a bottom wall 3, and a side wall 4 extending between the top wall 2 and the bottom wall 3, wherein the walls 2, 3, 4 form a vessel 5 enclosing an interior volume 6. The top wall 2, the bottom wall 3, and the side wall 4 may be substantially planar, i.e., have little or no curvature, thus providing the vessel 5 with a substantially cubic shape having an interior volume 6 with a rectangular cross-section in a plane parallel to the bottom wall 3. The side wall 4 may comprise, for example, four substantially planar portions 41, 42, 43, 44, each extending between the top wall 2 and the bottom wall 3 and arranged in opposing pairs.

[0042] The vessel 1 includes an inlet port 7 for supplying a precursor gas to the vessel 1. The inlet port 7 may be located in the top wall 2. In some embodiments, the inlet port 7 may be located in (one of) the side wall 4. A supply gas line 8 for supplying the precursor gas to the vessel 1 may be connected in fluid communication with the inlet port 7. The supply gas line 8 may include a valve 9 upstream of the inlet port 7 and configured to control the flow rate and / or amount of the precursor gas supplied in gaseous form to the vessel 1. The valve 9 may be, for example, a flow control valve or a mass flow controller. The valve 9 may be a surface-mounted valve mounted on the top wall 2. The valve 9 may be a diaphragm valve.

[0043] The vessel 1 includes an outlet port 10 for removing precursor gas from the vessel 1. The outlet port 10 may be located in the top wall 2. In some embodiments, the outlet port 10 may be located in one of the portions of the side wall 4. An extraction gas line 11, which provides a flow path for precursor gas removed from the vessel 1, may be connected in fluid communication with the outlet port 10. The extraction gas line 11 may include a valve 12 downstream of the outlet port 10 and configured to control the flow rate and / or amount of precursor gas extracted from the vessel 1. The valve 12 may be, for example, a flow control valve or a mass flow controller. The valve 12 may be a surface-mounted valve mounted on the top wall 2. The valve 12 may be a diaphragm valve.

[0044] The precursor supply tank 1 includes a top-wall heater 13, a bottom-wall heater 14, and a side-wall heater 15. The top-wall heater 13 is constructed and arranged to heat the top wall 2. The bottom-wall heater 14 is constructed and arranged to heat the bottom wall 3. The side-wall heater 15 is constructed and arranged to heat the side wall 4. The heaters 13, 14, and 15 are individually controllable. That is, a first power may be supplied to the top-wall heater 13, while a second power may be supplied to the side-wall heater 14, and a third power may be supplied to the bottom-wall heater 15. Because the heaters 13, 14, and 15 are individually controllable, the three power values ​​may be different or the same. One or more of the three power values ​​may be individually varied over time, while the other power values ​​remain constant or vary in different ways. Independent controllability may be achieved, for example, by having separate power inputs for each heater 13, 14, and 15. The sidewall heater 15 may comprise multiple sidewall heaters 151, 152, 153, 154, each disposed on a respective sidewall portion 41, 42, 43, 44. The multiple sidewall heaters 151, 152, 153, 154 may each be individually controllable or may be controllable as a unit, i.e., the same power input is supplied to each of the multiple sidewall heaters.

[0045] 2a and 2b, the walls 2, 3, and 4 of the vessel 1 may include recessed channels 16 for receiving heater wires 17. The recessed channels 16 may have an undulating shape. The heater wires 17 may be press-fit within the channels 16. The heater wires 17, which form part of the heaters 13, 14, and 15, may include terminals 19 and 20 at both ends for supplying current to the heater wires 17. Providing separate terminals 19 and 20 for each heater 13, 14, and 15 allows each heater to be individually controllable. The vessel 1 may include one or more temperature sensors, such as thermocouples 18, located on each wall 2, 3, and 4 to measure the temperature of the respective wall.

[0046] The recessed channel 16 may have a shape other than an undulating shape. For example, referring to FIG. 2c, the recessed channel 16 may have an L-shaped shape. Two recessed channels 161, 162 may be provided in the walls 2, 3, and 4, one inverted relative to the other to receive the heater wire 17. The heater wire 17 may then be arranged in a broken rectangular configuration. In some embodiments, two L-shaped channels 161, 162 may be provided in the side wall 4, and undulating channels may be provided in the top wall 2 and the bottom wall 3. In some embodiments, the L-shaped channels and corresponding heater wires 17 may be provided in all the walls 2, 3, and 4. The L-shaped channels may still allow for heating of a large area of ​​the walls 2, 3, and 4 if the size of the walls 2, 3, and 4 is insufficient to allow for the placement of the undulating channels.

[0047] Referring to Figures 3a and 3b, each heater 13, 14, 15 on each wall 2, 3, 4 may include multiple heating elements 13, each of which is individually controllable. The multiple heating elements 13 may each be arranged to heat a different zone A of the respective wall. This may be advantageous when different zones have different heater power requirements to maintain all zones of the wall at the same temperature. The multiple heating elements 13 may each be formed with a channel 16 and a wire 17 press-fit into the channel 16. Each channel 16 may be separate from or adjacent to the channel 16 of an adjacent heating element 13. Each zone A may include one or more temperature sensors 18, such as thermocouples, for measuring the temperature of the portion of the wall within that zone.

[0048] 3b, the heater 13 of the top wall 2 may include a first top wall heating element 131 arranged to heat the first top wall zone A1, a second top wall heating element 132 arranged to heat the second top wall zone A2, a third top wall heating element 133 arranged to heat the third top wall zone A3, and a fourth top wall heating element 134 arranged to heat the fourth top wall zone A4. The vessel 1 may include a first thermocouple 181 for measuring the temperature of the first top wall zone A1, a second thermocouple 182 for measuring the temperature of the second top wall zone A2, a third thermocouple 183 for measuring the temperature of the third top wall zone A3, and a fourth thermocouple 184 for measuring the temperature of the fourth top wall zone A4.

[0049] Different zones may be adjacent to each other. Different zones may be selected to target specific areas of the respective walls. For example, the first zone A1 may include an inlet port 7. The fourth zone A4 may include an outlet port 10. The second and third zones A2, A3 may be located between the first and fourth zones A1, A4. Each heating element 131, 132, 133, 134 may have separate input / output terminals 19, 20 so that each heating element can receive individually controllable input power. The first top wall heating element 131 may require a higher input power than the second top wall heating element 132 to maintain the first and second zones A1, A2 at the same temperature due to the presence of the inlet port 7 in the first zone A1, which may increase the thermal capacity of the first zone A1. A similar requirement may apply to the fourth top wall heating element 134 due to the presence of the outlet port 10 in the fourth zone A4. It will be appreciated that the bottom wall 3 and side walls 4 may be provided with zones and associated individually controllable heating elements in a similar manner.

[0050] In some embodiments, the sidewall heaters comprise separate heaters 151, 152, 153, 154. In such embodiments, each of the separate heaters 151, 152, 153, 154 may comprise multiple individually controllable heating elements, each arranged to heat a separate zone of a respective wall 41, 42, 43, 44.

[0051] Referring to FIG. 4 , in some embodiments, the vessel 1 includes a housing 21 disposed to surround the vessel 5 and heaters 13, 14, and 15. The housing 21 may have a higher thermal conductivity than the walls 2, 3, and 4 of the vessel 5. For example, the walls 2, 3, and 4 of the vessel 5 may be made of stainless steel, and the housing 21 may be made of aluminum. The housing 21 may help improve the temperature uniformity of the walls 2, 3, and 4 of the vessel 5. The housing 21 may be spaced from the bottom wall 3 of the vessel 5 and, optionally, from the side wall 4 of the vessel 5 by a gap 22. By providing the gap 22 between the housing 21 and the bottom wall 3 of the vessel 5, a higher temperature gradient can be provided between the housing 21 and the bottom wall 3. This may be advantageous in applications where a rapid change in temperature of the bottom wall 3, and optionally the side wall 4, is required, for example, to efficiently cycle from a deposition temperature in a precursor refill mode to a sublimation temperature in a precursor delivery mode. Preferably, there is no gap between the top wall 2 and the housing 21. This can help enable the top wall to quickly and uniformly achieve and maintain the required temperature. The housing 21 may include a spacer 23 for spacing the housing 21 and the bottom wall 3 to provide an air gap 22.

[0052] Referring to FIG. 5 , in some embodiments, the vessel 1 includes a water-cooled conduit 24 arranged to cool a bottom wall 25 of the housing 21. The water-cooled conduit 24 may have an undulating configuration to distribute the water-cooling effect across the bottom wall 25. For example, the water-cooled conduit 24 may include a set of straight sections S connected by curved sections B. The water-cooled conduit 24 includes an inlet 26 for supplying cooled water to the conduit 24 and an outlet 27 for removing water from the conduit 24. The bottom wall 25 of the housing 21 may include a recessed channel (not shown) for receiving the conduit 24. Receiving the conduit 24 within the recessed channel, rather than providing the conduit 24 on the plane of the bottom wall 25, may increase the water-cooling effect. Cooling the bottom wall 25 of the housing 21 may also cool the bottom wall 3 of the vessel 5, thereby enabling a more rapid temperature change between the deposition temperature and the sublimation temperature. The housing 21 may include one or more thermal pads P, comprising a relatively high thermal conductivity material such as silicone or thermal paste / cement, disposed between the conduit 24 and the bottom wall 25 of the housing 21, which may help improve thermal contact between the conduit 24 and the housing 21. In embodiments in which the thermal conduit 24 has an undulating configuration, the thermal pads P may be disposed under the straight portions S, under the curved portions B, or both.

[0053] Referring to FIG. 6 , the vessel 1 may include a controller 28 connected to the top wall heater 13, the bottom wall heater 14, and the side wall heater 15 such that the power supplied to each of the heaters 13, 14, and 15 can be individually controlled. The controller 28 may include one or more inputs 29 for receiving data, for example, from a central control module described in more detail below and / or from the thermocouples 18. The controller 28 may include three controllers 281, 282, and 283 configured to control the top wall heater 13, the bottom wall heater 14, and the side wall heater 15, respectively. In some embodiments, one or more of the top wall heater 13, the bottom wall heater 14, and the side wall heater 15 may include two or more individually controllable heaters, for example, as described above with respect to the top wall heater 13 (but equally applicable to the bottom and side wall heaters 14, 15). In such embodiments, the controller 28 may be configured to individually control each heater within the set of heaters for a particular wall of the vessel 1. In some embodiments, controller 28 may be configured to control the flow of water into / out of water-cooled conduit 24, for example, by controlling valves to open or close flow lines connected to inlets 26. Controller 28 may be configured to receive temperature data (e.g., temperature values, or voltage or current or other data values ​​representing temperature values) from one or more thermocouples 18, optionally convert the received data into temperature values, for example, in a processor (not shown) included in controller 28, and use the received data or temperature values ​​to control one or more heaters or heating elements 13, 14, 15, for example, to control heaters that are closest to and / or adjacent to thermocouple 18. Controller 28 may be configured to implement a control loop, such as, for example, a proportional-integral-derivative control loop, and maintain the wall temperature at a particular setpoint using the received or converted data as input to the control loop.

[0054] Tank 1 is configured to contain precursor 30. Precursor 30 may be in solid, liquid, and / or gaseous form depending on the particular operating mode of tank 1, the operation of which is described in more detail below. For illustrative purposes, in FIG. 6, precursor 30 is shown in solid form in a layer at the bottom of container 5. Precursor 30 may be a solid source precursor, i.e., a source chemical that is solid under standard conditions (room temperature and atmospheric pressure). Non-limiting examples of solid source precursors include molybdenum oxychloride, hafnium chloride, and molybdenum chloride. Precursor 30 may also be a liquid source precursor, i.e., a source chemical that is liquid under standard conditions. Tank 1 is particularly suited for delivering gas-phase reactants used in gas-phase reaction chambers. Gas-phase reactants can be used for deposition, such as chemical vapor deposition or atomic layer deposition (ALD).

[0055] Still referring to FIG. 6, the internal volume 6 is at least 0.005 m 3 , preferably at least 0.01 m 3 , or at least 0.015m 3 , or at least 0.02 m 3The vessel 1 may have a volume of 1000 sq ft or 1000 sq ft. By providing a large interior volume 6, a large amount of precursor can be stored within the vessel 1, which can be particularly advantageous in applications where a large amount of vapor-phase precursor needs to be delivered to a process chamber of a semiconductor processing equipment, for example, when the process chamber contains many highly surface-enhanced substrates. A vessel 1 having such dimensions can be capable of delivering a precursor gas at a flow rate of at least 1 standard liter per minute through the outlet port 10. The bottom wall 3 may have a width w that is at least 5 times the height h of the side wall 4, preferably at least 10 times the height h of the side wall 4. The width w may be the smaller or larger of the two dimensions of the bottom wall 3 in the xy plane. By providing a vessel 1 with such a width-to-height ratio, a large interior volume 6 may be provided while maintaining a low profile in the vertical direction of the vessel 1. This can allow for vertical space savings when the vessel 1 is fitted, for example, into a gas cabinet of a semiconductor processing equipment, especially when multiple vessels 1 may be installed in the semiconductor processing equipment. The interior volume 6 may have a cross-sectional area in a plane parallel to the bottom wall 3, the cross-sectional area being at least 0.1 m. 2 , preferably at least 0.15 m 2 , or at least 0.2 m 2 , or at least 0.3 m 2 is.

[0056] Referring to FIG. 7 , tank 1 may be included in a semiconductor processing apparatus 31 for processing semiconductor wafers. The semiconductor processing apparatus 31 may be a single-wafer processing tool or a batch processing tool, such as a vertical furnace, as illustrated in FIG. 7 . The semiconductor processing apparatus 31 is shown in FIG. 7 in an accumulator-feed mode, as described in more detail below. The semiconductor processing apparatus includes a process chamber 32 for receiving one or more wafers 33 on a wafer support 34. The process chamber 32 and tank 1 are adapted to be in selective fluid communication with each other through a first conduit 35 to feed a vapor-phase precursor from tank 1 to the process chamber 32. An accumulator 36 may be provided between and in fluid communication with tank 1 and the process chamber 32. The first conduit 35 includes one or more shut-off valves 37 a, 37 b that may be used to separate the gas spaces of tank 1, accumulator 36 (if present), and process chamber 32. Accumulator 36 is configured to receive the vapor-phase precursor from tank 1 and store the precursor in a gaseous state until a sufficient amount is collected in accumulator 36. The vapor-phase precursor may then be released into process chamber 32 at a high flow rate. Accumulator 36 can advantageously allow for a higher precursor flow rate into process chamber 32 compared to directly supplying the precursor gas from tank 1 to process chamber 32, which can help improve throughput and the quality of the deposited film.

[0057] Semiconductor processing equipment 31 includes a second conduit 38 for providing a gas flow path between tank 1 and a bulk precursor supply tank 39. Bulk precursor supply tank 39 contains a precursor in solid (or liquid) form and is configured to supply the vapor-phase precursor to tank 1 via second conduit 38. Second conduit 38 includes one or more shut-off valves 40 for separating the gas spaces of tank 1 and bulk precursor supply tank 39. Bulk precursor supply tank 39 has an internal volume for storing precursor that is larger than the volume of tank 1, allowing for the storage of a large amount of precursor for refilling tank 1.

[0058] The semiconductor processing equipment 31 includes a gas exhaust line 41 in fluid communication with the process chamber 32 and an exhaust pump 42 for exhausting gas from the process chamber 32. The exhaust pump 42 may be configured to provide a low pressure or vacuum within the process chamber 32, which may create a pressure differential between the process chamber 32 and the bath 1 when the shut-off valves 37 a, 37 b are not closed, thereby drawing precursor gas from the bath 1 into the process chamber 32.

[0059] Referring to FIG. 8 , a method according to an embodiment of the present invention for supplying precursor to tank 1 can proceed as follows. The supply can be a resupply, i.e., tank 1 may have previously contained precursor, may be currently empty, or may contain a residual amount of precursor. The supply can also be an initial supply, i.e., tank 1 may not have previously contained precursor. For illustrative purposes, FIG. 9 a shows that tank 1 is empty of precursor before the precursor supply begins. Referring also to FIG. 9 b, in step S101, inlet valve 9 and, optionally, shutoff valve 40 (which may be the same valve in some embodiments) are set to an open position. In some embodiments, inlet valve 9 and / or shutoff valve 40 may be set to a position that is not fully open, e.g., to control the precursor flow rate. Outlet valve 12 is set to a closed position. In step S102, the bulk precursor supply tank 39 is controlled to supply precursor gas 30 to the second conduit 38, for example, by heating the bulk precursor supply tank 39 above the precursor sublimation temperature so that a portion of the precursor contained in the bulk precursor supply tank 39 transitions from a solid phase to a vapor phase and flows through the second conduit 38. The top wall heater 13 and the side wall heater 15 are controlled to maintain the temperatures of the top wall 2 and the side wall 4 above the precursor deposition temperature. The deposition temperature or anti-sublimation temperature is the wall temperature at which the vapor-phase precursor transitions to a solid phase and is deposited on the wall. The top wall heater 13 and the side wall heater 15 are controlled to maintain the respective wall temperatures above this temperature to avoid precursor deposition on the top wall 2 and the side wall 4. The bottom wall heater 14, and optionally a water-cooled conduit, are controlled to maintain the bottom wall temperature below the deposition temperature. By individually controlling the heaters in this manner, precursor can be directed to deposit on the bottom wall 3 of the vessel 1, but not on the top wall 2 or side walls 4 (FIG. 9c). This can provide a more uniform precursor layer within the vessel 5, which helps to result in a more consistent and uniform delivery of precursor to the process chamber 32. By heating the top wall 2 during (re)delivery, precursor deposition on or in the inlet and outlet ports 7 and 10 can be avoided, which can help prevent the ports from clogging with solidified precursor.

[0060] 9d, once the required amount of precursor has been delivered to tank 1, which may be measured by the time of delivery of precursor gas to tank 1, the flow rate of precursor into tank 1, the pressure in tank 1, the pressure in second conduit 38, or other parameters, shut-off valve 40 and inlet valve 9 are set to a closed position. Tank 1 can be maintained in this closed state until precursor gas is needed to be delivered to process chamber 32.

[0061] Optionally, after step S103, the top wall heater 13 and the side wall heater 15 may be controlled to heat the top wall 2 and the side wall 4 to a temperature higher than the melting point of the precursor. This may allow any precursor that was nevertheless deposited on the top wall 2 or the side wall 4 to melt and flow to the bottom of the tank 1, resulting in a more uniform layer of precursor at the bottom of the tank 1. Optionally, after step S103, the bottom wall heater 14 may be controlled to heat the bottom wall 3 to a temperature higher than the melting point of the precursor. In some embodiments, the top wall 2 and / or the side wall 4 may be heated by their respective heaters to a temperature above the melting point of the precursor at this step. This may allow the precursor at the bottom of the tank 1 to melt and reflow into a more uniform layer, reducing non-uniformities on the surface of the precursor layer at the bottom of the tank 1. Providing a more uniform layer of precursor at the bottom of the tank 1 may allow for better reproducibility in the delivery of precursor from the tank 1.

[0062] Referring to FIG. 10, delivery of precursor from tank 1 to process chamber 32 may proceed according to a precursor delivery method in accordance with an embodiment of the present invention. Referring also to FIG. 11a, in step S201, inlet valve 9 and optionally shut-off valve 40 are set to a closed position if they are not already in this state. Outlet valve 12 is set to a closed position. Shut-off valve 37a may be set to a closed or open position. In step S202, top wall heater 13 and side wall heater 15 are controlled to maintain the temperature of top wall 2 and side wall 4 above a deposition temperature of the precursor. In some embodiments, top wall heater 13 and side wall heater 15 may be controlled to maintain the temperature of top wall 2 and side wall 4 above a sublimation temperature of the precursor to sublimate any precursor that may nevertheless be deposited on top wall 2 or side wall 4. Bottom wall heater 14 is controlled to maintain the temperature of bottom wall 3 above a sublimation temperature of the precursor. In step S203, after a predetermined period during which the vapor pressure of the precursor in headspace H of vessel 1 increases due to sublimation of the solid-state precursor (see FIG. 11b), outlet valve 12 is opened, allowing the precursor gas to exit vessel 1 through outlet 10. Headspace H is the volume within vessel 1 above the surface of the solid-state precursor, which may be occupied by the vapor-phase precursor. Heaters 13, 14, and 15 are controlled to maintain the respective walls 2, 3, and 4 above the deposition or sublimation temperature (side and top walls) or above the sublimation temperature (bottom wall) so that the solid-state precursor continues to sublimate and the resulting vapor-phase precursor is extracted via outlet 10.

[0063] In some embodiments, the outlet valve 12 and the shut-off valve 37a (if previously closed) are opened simultaneously with the initial temperature change of the walls 2, 3, 4 of the chamber 1 caused by controlling the heaters 13, 14, 15, i.e. there is no waiting time between raising the temperature of the bottom wall 3 above the sublimation temperature of the precursor and opening the outlet valve 10.

[0064] The vapor-phase precursor then flows through first conduit 35 toward accumulator 36 (if present) or process chamber 32 (if no accumulator is present). In some embodiments, when accumulator 36 is present, shut-off valve 37b is kept closed, and shut-off valve 37a is kept open while precursor gas is delivered from reservoir 1 to accumulator 36 until the accumulator stores a predetermined amount of precursor gas, which can be determined, for example, by measuring the flow rate of gas through first conduit 35, and then shut-off valve 37a can be closed. When precursor gas needs to be delivered to process chamber 32, shut-off valve 37b can be opened to allow precursor gas to flow from accumulator 36 to process chamber 32.

[0065] Tank 1 may be maintained in the supply mode until substantially all of the solid-state precursor has sublimated and been extracted in gaseous form. Tank 1 may be maintained in the supply mode until a predetermined amount of solid-state precursor remains in the tank. This may be determined, for example, by providing a sensor 44, which may be, for example, a pressure sensor, a flow sensor, or another type of sensor capable of measuring gas properties, downstream of outlet port 10 to measure the amount of precursor gas extracted from tank 1. Sensor 43, which may be, for example, a pressure sensor, a flow sensor, or another type of sensor capable of measuring gas properties, may be provided upstream of inlet port 7 to measure the amount of precursor gas being supplied to tank 1. When no more precursor gas needs to be supplied from tank 1, outlet valve 12 is set to a closed position (step S204). In some embodiments, tank 1 may be supported by a load scale (not shown) that can measure the weight of tank 1 and thereby determine the amount of precursor remaining in the tank. A load scale may be provided in addition to or instead of sensors 43 and 44.

[0066] In some embodiments, a bypass valve may be provided between the supply gas line 8 and the extraction gas line 11. The bypass valve may be connected between a point on the supply gas line 8 between valve 9 and inlet port 7 and a point on the extraction gas line between valve 12 and outlet port 10. When in the open position, the bypass valve allows direct gas flow between the supply gas line 8 and the extraction gas line 11. The bypass valve may be set to the open position during the supply of precursor to the vessel 1, allowing both the inlet port 7 and the outlet port 10 to be used as conduits for the precursor gas flowing into the vessel 1. The bypass valve may be set to the open position during the extraction of precursor from the vessel 1, allowing both the inlet port 7 and the outlet port 10 to be used as conduits for the precursor gas flowing out of the vessel 1.

[0067] The substrate processing apparatus 31 may include a central control unit 50 configured to control various functions of the apparatus 31, such as the state of the valves, the temperature of the process chamber 32, the gas flow rates, the pressure in the process chamber 32, the opening and closing of the process chamber 32, the operation of the exhaust pump 42, etc. The central control unit 50 may be configured to receive data from various components of the apparatus 31, such as pressure and / or flow rate data from the valves 9, 12, 37a, 37b, 40, temperature data from one or more temperature sensors (not shown) in the process chamber 31, and pressure data from one or more pressure sensors (not shown) in the process chamber 31. Electrical connections to the components of the substrate processing apparatus 31 are not shown. The central control unit 50 may include a controller 28 for the heaters 13, 14, 15. The central control unit 50 may be configured to receive and send data from the controller 28, for example, to control the functions of the controller 28. For example, the central control unit 50 may store in memory a set of instructions for performing methods according to embodiments of the present invention and may load such instructions into a processor configured to execute the instructions for performing the methods. The method may be, for example, a precursor (re)fill method as described above with reference to FIG. 8 and / or a precursor delivery method as described above with reference to FIG.

[0068] Referring to FIG. 12a, in some embodiments, the bottom wall 3 includes a set of ribs 50 spaced apart along a first dimension in the plane of the bottom wall 3 and extending along a second dimension in the plane of the bottom wall 3, the second dimension being perpendicular to the first dimension. The ribs 50 project upward toward the top wall 2, providing a means for stiffening the bottom wall 3 in embodiments in which the vessel 1 is disposed in a low-pressure or vacuum environment. Referring to FIG. 12b, in some embodiments, the vessel 1 includes a tray 51 for receiving the precursor in a solid or liquid state. The tray 51 may be disposed on the bottom wall 3. In some embodiments, the tray 51 includes a set of ribs 52 spaced apart along a first dimension in the plane of the tray 51 and extending along a second dimension in the plane of the tray 51, the second dimension being perpendicular to the first dimension. The ribs 52 project upward toward the top wall 2, providing a means for stiffening the tray 51 in embodiments in which the vessel 1 is disposed in a low-pressure or vacuum environment.

[0069] Referring to FIG. 13 , in some embodiments, the vessel may include an individually controllable booster heater 53 controllable by the controller 28. The booster heater 53 may be located within the interior volume 6, for example, on the bottom wall 3 or on the side wall 4. The booster heater 53 may also be located on the exterior of the bottom wall 3 or side wall 4. The solid-state precursor may experience a temperature drop when sublimation occurs. This can increase the temperature stabilization time and affect throughput. The booster heater 53 functions to compensate for this temperature drop and reduce the temperature stabilization time. The controller 28 may be configured to have the booster heater heat the solid-state precursor in a predictive manner, for example, by increasing the power to the booster heater when the precursor delivery process is initiated, so as to already add additional heat to the solid-state precursor at the moment sublimation begins and the precursor temperature drops.

[0070] Throughout this specification, a reference to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrase "in one embodiment" or "in an embodiment" in various places throughout this specification do not necessarily all refer to the same embodiment. Furthermore, it is noted that particular features, structures, or characteristics of one or more embodiments may be combined in any suitable manner to form new embodiments not expressly described. The subject matter of this disclosure includes all novel and non-obvious combinations and subcombinations of the various processes, systems, and configurations, and other features, functions, operations, and / or characteristics disclosed herein, as well as any and all equivalents thereof. [Explanation of symbols]

[0071] 1 Precursor supply tank 2 Upper wall 3 Bottom wall 4 side wall 5 containers 6. Internal volume 7 Inlet Port 8 Supply Gas Line 9 Inlet valve 10 Exit Port 11 Extraction gas line 12 Outlet valve 13 Upper wall heater 14 Bottom wall heater 15 Sidewall heater 16 recessed channels 16 channels 17 Heater Wire 18 Thermocouple 19 Output terminal 20 Output terminal 21 Housing 22 void 23 Spacer 24 Water cooling conduit 25 Bottom Wall 26 Entrance 27 Exit 28 Controller 29 Input 30 Precursors 31 Semiconductor processing equipment 32 Process Chamber 33 wafers 34 wafer support 35 First Conduit 36 Accumulator 37a, 37b Shut-off valve 38 Second Conduit 39 Bulk precursor supply tank 40 Shut-off valve 41 Gas exhaust line 42 Exhaust pump 43, 44 Sensor 50 Central Control Unit 53 Booster heater

Claims

1. a top wall, a bottom wall, and a side wall; a top wall heater constructed and arranged to heat the top wall, a bottom wall heater constructed and arranged to heat the bottom wall, and a side wall heater constructed and arranged to heat the side walls; The precursor supply vessel, wherein each of the top wall heater, the bottom wall heater, and the side wall heater is independently controllable.

2. 10. The precursor supply tank of claim 1, wherein the top wall comprises an inlet port for supplying a precursor gas to the precursor supply tank.

3. 10. The precursor supply tank of claim 1, wherein the top wall comprises an outlet port for removing precursor gas from the precursor supply tank.

4. 10. The precursor supply tank of claim 1, wherein the top wall, the bottom wall, and the side wall form a vessel having a rectangular cross-section in a plane parallel to the bottom wall.

5. 5. The precursor supply tank of claim 4, further comprising a housing enclosing the vessel and the top, bottom and side wall heaters, the housing having a higher thermal conductivity than the vessel walls.

6. The precursor supply tank of claim 5 , wherein the housing is disposed to provide a gap between the housing and the bottom wall.

7. 6. The precursor supply tank of claim 5, comprising a conduit disposed in or on the bottom wall of the housing, through which water can be flowed to cool the bottom wall of the housing.

8. At least 0.01 m ３ The precursor supply tank of claim 1 having an internal volume of

9. 10. The precursor supply tank of claim 1, wherein each wall comprises a recessed channel, and the top wall heater, the bottom wall heater, and the side wall heater comprise wires fitted into the recessed channels of the respective walls configured to heat.

10. 10. The precursor supply tank of claim 1, wherein the bottom wall has a width at least five times the height of the side wall.

11. The container has a length of at least 0.2 m in a plane parallel to the bottom wall. ２ The precursor supply vessel of claim 5 having an interior volume with a cross-sectional area of

12. 10. The precursor supply tank of claim 1, wherein each heater is individually controllable to allow each heater to output a power that is different from the power output by the other heaters.

13. 10. The precursor supply tank of claim 1, wherein the top wall heater, the bottom wall heater, and the side wall heater each comprise at least two individually controllable heating elements.

14. 10. The precursor supply tank of claim 1, comprising a controller configured to individually control the top wall heater, the side wall heater, and the bottom wall heater.

15. 15. The precursor supply tank of claim 14, wherein the controller is configured to, in a precursor tank refill mode, cause the top wall and the side wall to be heated to a temperature above a deposition temperature of a precursor supplied to the precursor supply tank, and cause the bottom wall to be heated to a temperature equal to or less than the deposition temperature.

16. 15. The precursor supply tank of claim 14, wherein the controller is configured, in a precursor tank supply mode, to cause the bottom wall, the side wall, and the top wall to be heated to a temperature at or above a sublimation temperature of a precursor supplied from the precursor supply tank.

17. 10. The method of operating a precursor supply tank of claim 1, comprising performing a precursor filling step comprising closing an outlet port and flowing the precursor gas through an inlet port while maintaining the bottom wall at a temperature below a deposition temperature of the precursor gas and heating the top wall and the side wall to a temperature above the deposition temperature of the precursor gas.

18. 18. The method of claim 17, further comprising performing a precursor supplying step after the precursor filling step, the precursor supplying step comprising closing the inlet port and opening the outlet port while heating the bottom wall, the side wall, and the top wall to a temperature equal to or greater than a sublimation temperature of a precursor supplied from the precursor supply tank.

19. 20. The method of claim 18, comprising performing a reflow step after the precursor filling step and before the precursor supplying step, the reflow step comprising closing the inlet port and the outlet port while heating at least one wall to a temperature above the melting point of the precursor for a predetermined period of time.

20. 10. A semiconductor processing apparatus comprising the precursor supply tank of claim 1 in fluid communication with a process chamber, the process chamber configured to receive and process multiple substrates simultaneously.

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