Methods and system for precursor recycling

Abstract

To provide a technology comprising, in various embodiments, a reactor, a first container with an inlet connected to the reactor inlet, a second container with an inlet connected to the reactor inlet, an exhaust line connected to the reactor outlet, an inlet of the first container, and an inlet of the second container.SOLUTION: A first vessel and a second vessel may be configured to receive vapor via an exhaust line and to recondense the vapor into a solid material reused in a precursor pulse process.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application is a non - provisional application of U.S. Provisional Patent Application No. 63 / 623,940, filed on January 23, 2024, entitled "METHODS AND SYSTEM FOR PRECURSOR RECYCLING", claiming the priority and benefit thereof, and is incorporated herein by reference in its entirety.

[0002] The present disclosure generally relates to methods and systems for semiconductor devices. More specifically, the present disclosure relates to methods and systems for precursor recycling.

Background Art

[0003] During a typical ALD process, precursors are pulsed and purged over several cycles to deposit a thin film on a substrate such as a wafer. During the purge step, any residual precursors that have not reacted with the surface of the substrate are purged out with an inert gas and removed through an exhaust system. In conventional systems, during the purge step, residual precursors are not recycled but rather are dispersed into the atmosphere.

Summary of the Invention

Means for Solving the Problems

[0004] Various embodiments of the present technology may provide a reactor, a first container having an inlet connected to an inlet of the reactor, a second container having an inlet connected to the inlet of the reactor, an exhaust line connected to an outlet of the reactor, an inlet of the first container, and an inlet of the second container. The first and second containers may be configured to receive vapor through the exhaust line and re - condense the vapor in a solid material that is reused during the precursor pulsing step.

[0005] According to one aspect, the system includes a reactor having an inlet and an outlet, a first vessel having a first inlet and a first outlet connected to the inlet of the reactor, a second vessel having a second inlet and a second outlet connected to the inlet of the reactor, and an exhaust line connected to the outlet of the reactor, the first inlet of the first vessel, and the second inlet of the second vessel. The first and second vessels are configured to receive steam through the exhaust line and re-condense the steam into the solid material.

[0006] The present technology can be more fully understood by referring to the detailed description in view of the following exemplary drawings. In the following figures, like elements and steps are denoted by like reference numerals throughout the figures.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0008] The present technology may be described with respect to components of functional blocks and various processing steps. Such functional blocks may be realized by any number of components configured to perform a specified function and to achieve various results. For example, the present technology may employ various vessels, reaction chambers, pipes, pumps, valves, and heating elements.

[0009] Referring to FIG. 1, an exemplary system 100 may include a first container 135, a second container 140, and a reactor 105. In an exemplary embodiment, the reactor 105 may be configured to process a substrate such as a wafer 115. The reactor 105 may include a susceptor 110 for supporting the wafer, a reaction space 112, and a showerhead 120 positioned above the reaction space 112 and the susceptor 110 and configured to deliver a chemical substance to the reaction space 112 and the wafer 115.

[0010] The system 100 may further include an exhaust system that may be partially integrated within the reactor 105 and / or disposed outside the reaction chamber 105. In various embodiments, the system 100 may be configured to recycle precursors from the reactor 105 that are reused during the processing step.

[0011] In an exemplary embodiment, the reactor 105 may include an inlet 125 and an exhaust outlet 130. The first container 135 may be connected to the inlet 125. For example, the outlet 160 of the first container 135 may be connected to the inlet 125 via a first conduit 150. Further, the second container 140 may be connected to the inlet 125. For example, the outlet 165 of the second container 140 may be connected to the inlet 125 via a second conduit 155. The first conduit 150 and the second conduit 155 may be configured to allow the flow of vapor from their respective containers 135, 140 to the inlet 125 of the reactor 105. Further, the first conduit 150 and the second conduit 155 may be actively heated to a temperature that prevents the vapor from the first container 135 and the second container 140 from recondensing inside the first conduit 150 and the second conduit 155. For example, the second conduit 155 may be heated by any suitable heating element such as a heater jacket, a printed heater, convective heating, and the like.

[0012] In an exemplary embodiment, the exhaust outlet 130 may be connected to the inlet 170 of the first container 135 and the inlet 175 of the second container 140. The exhaust outlet 130 may also communicate with the atmosphere.

[0013] In various embodiments, the exhaust system may further include a pump 197 configured to facilitate pumping vapor or gas from the reactor 105. The pump 197 may comprise any device or system suitable for promoting the flow of vapor. Further, the exhaust system may further include a plurality of valves, such as a first valve 180 and a second valve 181. The first valve 180 may be disposed downstream from the exhaust outlet 130, and the pump 197 may be disposed downstream from the first valve 180. The second valve 181 may be disposed downstream from the pump 197.

[0014] In various embodiments, the exhaust system may further include a return conduit 199. The return conduit 199 may be connected between the pump 197 and the second valve 181. The return conduit 199 may connect the exhaust outlet 130 to the inlets of the first vessel 135 and the second vessel 140.

[0015] In an exemplary embodiment, the first vessel 135 may be configured to contain or otherwise hold a solid material 195 (e.g., a chemical of a solid precursor). In various embodiments, the solid precursor may be in the form of a powder. The solid precursor may be a Group 2, Group 13, Group 14, or Group 15 element and a transition metal halide, or a Group 2, Group 13, Group 14, or Group 15 element and a transition metal organometallic that is solid at room temperature (e.g., 20° C. to 25° C.) and has a melting point above 50° C. In an exemplary embodiment, the solid precursor includes a molybdenum compound, such as a solid molybdenum halide (e.g., MoCl2 or MoOCl4).

[0016] In this embodiment, the first vessel 135 may be formed from a metallic material, such as stainless steel, Hastelloy®, aluminum, or the like.

[0017] The first container 135 may be configured to maintain the solid material 195 at a first temperature, for example, at about 20 to 25 degrees Celsius, so that the solid material 195 is also maintained at the first temperature. Further, the first container 135 may be configured to sublime the solid material 195. For example, the first container 135 may include a heating device 194 configured to heat the first container 135 and the solid material 195 to a temperature at which the solid material 195 sublimes and transforms into vapor. For example, the heating device 194 may include a suitable heating system or method such as a heater jacket or a heating appliance having a heating rod embedded in the heating appliance and in direct contact with the outer surface of the first container 135. Alternatively, the heating device 194 may provide indirect heat to the first container 135, for example, by convective heating. In some embodiments, the first container 135 may include a sublimator.

[0018] In various embodiments, the first container 135 may further include a cooling device 190 configured to cool the first container 135 from a higher temperature (e.g., above 25 degrees Celsius) to the first temperature. The cooling device 190 may be in direct contact with the outer surface of the first container 135 and may include any suitable cooling system or method such as a cooling coil through which a cooling fluid flows, a cooling gas flowing through a coil, a thermoelectric module configured to cool the first container 135, or the like.

[0019] In various embodiments, the second container 140 may be configured to contain or otherwise hold the solid material 195 (e.g., a chemical substance of a solid precursor). In various embodiments, the solid precursor may be in the form of a powder. The solid precursor is solid at room temperature (e.g., 20 to 25 degrees Celsius) and has a melting point above 50 degrees Celsius and may include Group 2, Group 13, Group 14, or Group 15 elements and transition metal halides, or Group 2, Group 13, Group 14, or Group 15 elements and transition metal organometallics. In an exemplary embodiment, the solid precursor includes a molybdenum compound, such as a solid molybdenum halide (e.g., MoCl2 or MoOCl4).

[0020] In this embodiment, the second container 140 may be formed of a metallic material such as stainless steel, Hastelloy®, aluminum, or the like.

[0021] The second container 140 may be configured to maintain the solid material 195 at a first temperature, for example, at about 20 to 25 degrees Celsius, so that the solid material 195 is also maintained at the first temperature. Further, the second container 140 may be configured to sublimate the solid material 195. For example, the second container 140 may include a heating device 196 configured to heat the second container 140 and the solid material 195 to a temperature at which the solid material 195 sublimates and transforms into vapor. For example, the heating device 196 may include a suitable heating system or method such as a heater jacket or a heating appliance having a heating rod embedded in the heating appliance and in direct contact with the outer surface of the first container 135. Alternatively, the heating device 196 may provide indirect heat to the second container 140, for example, by convective heating. In some embodiments, the second container 140 may include a sublimator.

[0022] In various embodiments, the second container 140 may further include a cooling device 191 configured to cool the second container 140 from a higher temperature (e.g., above 25 degrees Celsius) to the first temperature. The cooling device 191 may include any suitable cooling system or method such as a cooling coil in direct contact with the outer surface of the container 140 through which a cooling fluid flows, a cooling gas flowing through a coil, a thermoelectric module configured to cool the second container 140, or the like.

[0023] In various embodiments, system 100 may further include a plurality of valves, for example, a first valve 180, a second valve 181, a third valve 182, a fourth valve 183, and a fifth valve 184. In particular, the plurality of valves may be arranged along the flow path of the exhaust system. For example, the first valve 180 may be arranged downstream from the exhaust outlet 130, and the second valve 181 may be arranged downstream from the first valve 180. In an exemplary embodiment, the pump 197 may be arranged between the first valve 180 and the second valve 181.

[0024] In various embodiments, system 100 may further include additional valves such as a sixth valve 156 arranged along the first conduit 150 and a seventh valve 157 arranged along the second conduit 155. The sixth valve 156 and the seventh valve 157 may be operated to pulse steam from their respective containers to the reactor 105.

[0025] In an exemplary embodiment, the exhaust system may include a feedback portion 187 fluidly coupled to the exhaust outlet 130. For example, the feedback portion 187 may be connected between the pump 197 and the second valve 181 at the junction 199.

[0026] In an exemplary embodiment, the feedback portion 187 may include the second valve 181 and the third valve 182. Further, the feedback portion 187 may further include a filter 185. The filter 185 may be configured to remove contaminants in the exhaust steam or neutralize them in another way. For example, the filter 185 may include a porous filter or any other filter suitable for capturing particles or contaminants in the steam. The filter may be arranged upstream of the fourth valve 183 and the fifth valve 184 and downstream of the third valve 182.

[0027] In various embodiments, the feedback portion 187 of the exhaust system may be connected to the first container 135 and the second container 140. For example, the feedback portion 187 may be coupled to the inlet 170 of the first container 135 and the inlet 175 of the second container 140. The feedback portion 187 may include a junction 198 such as a T-junction having one leg coupled to the inlet 170 of the first container 135 and a second leg coupled to the inlet 175 of the second container 140. The fourth valve 183 may be coupled to one leg (to regulate the flow to the inlet 170 of the first container 135), and the fifth valve 184 may be coupled to the second leg (to regulate the flow to the inlet 175 of the second container 140). The filter 185 may be disposed upstream of the junction 198.

[0028] In various embodiments, the system 100 may further include a third container 145 configured to hold or otherwise contain a chemical substance, such as the same chemical substance, within the first container 135 and the second container 140. The third container 145 may be coupled to the second inlet of the first container 135 and the second inlet of the second container 140. The third container 145 may be used to refill the first container 135 and the second container 140 with the desired chemical substance when the first container 135 and the second container 140 have depleted substantially or completely of the desired chemical substance.

[0029] In various embodiments, the first container 135, the second container 140, and the reactor 105 may all be located within a processing area such that they are physically located near each other or are enclosed within a particular tool or area (i.e., cleanroom, semiconductor manufacturing area). However, the third container 145 may be located in a non-processing area that is remote from the processing area, such as an area physically below the processing area (i.e., sub-fab).

[0030] In various embodiments, system 100 may further include a controller 138 configured to generate and transmit various control signals. For example, controller 138 may be communicatively coupled to a plurality of valves (e.g., valves 156, 157, 180, 181, 182, 183) and transmit control signals to each valve. The control signals may indicate the operation or state (e.g., open or closed) of each valve. Controller 138 may also control the operation of heating devices 194, 196 and cooling devices 190, 191. Heating devices 194, 196 may be controlled independently of each other. Similarly, cooling devices 190, 191 may be controlled independently of each other.

[0031] During operation, and referring to FIGS. 1 and 2, during process 200, the precursor from the first vessel 135 may be pulsed into the reactor 105 (during the pulse step) (205). In an exemplary embodiment, only one vessel is used for processing while the other vessel is idle and not processed. During the idle state, the vessel is not at the processing temperature or does not sublime the precursor. For example, the idle vessel is at room temperature or any other temperature that allows the precursor to remain in a solid state. During the pulse step (205), the controller 138 may operate the sixth valve 156 to flow vapor from the first vessel 135 into the reactor 105. After the pulse step, the unused precursor may be purged from the reaction space 112 (during the purge step) (210). During the purge step (215), the inert gas 177 may flow through the showerhead 120 into the reaction space 112, and as the inert gas 177 flows, the unused precursor may flow from the reactor 105 to the exhaust system along with the inert gas. For example, the pump 197 may be activated and the first valve 180 may be opened. If the unused precursor is recycled, the second valve 181 is closed and the unused precursor flows into the feedback portion 187 of the exhaust system. Since the first vessel 135 is currently being used for processing, the unused precursor flows into the second vessel 140. For example, the pump 197 may be on, and the controller 138 may open the first valve 180, close the second valve 181, open the third valve 182, close the fourth valve 183, and open the fifth valve 184. The second vessel 140 is set to a temperature that allows the vapor precursor to recondense into a solid state. The system 100, such as the controller 138, and other sensors, such as a level sensor (not shown), may monitor the level of the precursor 195 in the first vessel 135 (220). The system 100 continues to use the precursor from the first vessel 135 for processing as long as the precursor in the first vessel 135 does not drop below a predetermined minimum threshold. When the precursor in the first vessel 135 drops below the minimum threshold, the system 100 utilizes the precursor in the second vessel 140 for processing (225).During the purge process (230), the inert gas 177 may flow into the reaction space 112 through the shower head 120, and the unused precursor flows through the exhaust system and is diverted into the first container 135, which is at a temperature lower than the processing temperature and allows the vapor precursor to re-condense within the first container 135. For example, the pump 197 may be on, and the controller 138 may open the first valve 180, close the second valve, open the third valve 182, open the fourth valve 183, and close the fifth valve 184.

[0032] The system 100, such as the controller 138 and other sensors (not shown), may monitor the level of the precursor within the second container 140 (240). The system 100 continues to use the precursor from the second container 140 for processing as long as the precursor within the second container 140 does not drop below a predetermined minimum threshold. When the precursor within the second container 140 drops below the minimum threshold, the system 100 utilizes the precursor within the first container 135 for processing (205).

[0033] The above-described process may continue periodically. Further, during processing, the container used to receive the recycled precursor vapor may also be refilled with chemicals from the third container 145.

[0034] When the precursor exhaust flows through the filter 185 into the first container 135 or the second container 140, the filter 185 may remove or neutralize contaminants such as water and organic materials.

[0035] In some cases where precursor recycling is not desired, the exhaust system may facilitate the flow of the exhaust vapor into the atmosphere. For example, the pump 197 is on, the first valve 180 and the second valve 181 are open, and the third valve 182 is closed.

[0036] In the foregoing description, the present technology has been described with reference to specific exemplary embodiments. The specific examples illustrated and described are illustrative of the present technology and its best mode, and are not intended to limit the scope of the present technology in any way. Also, for the sake of brevity, conventional manufacturing, connection, preparation, and other functional aspects of the present method and system may not be described in detail. Further, the connecting lines shown in the various figures are intended to represent exemplary functional relationships and / or steps between the various elements. Many alternative or additional functional relationships, or physical connections, may exist in the actual system.

[0037] The present technology has been described with reference to specific exemplary embodiments. However, various modifications and changes can be made without departing from the scope of the present technology. The present description and drawings are to be regarded in an illustrative, rather than a restrictive, sense, and are intended to include any variations within the scope of the present technology. Accordingly, the scope of the present technology should be determined not by the specific examples described above alone, but by the described general embodiments and their legal equivalents. For example, the steps described in an embodiment of a method or process may be executed in any order, unless specifically specified otherwise, and are not limited to the explicit order presented in the specific examples. Further, the components and / or elements described in an embodiment of any device may be assembled or operably configured in various forms to produce substantially the same results as the present technology, and thus are not limited to the specific configurations described in the specific examples.

[0038] Advantages, other benefits, and solutions to problems have been described above with reference to specific embodiments. It should be noted that any element that may give rise to or make more prominent any advantage, benefit, solution to a problem, or any specific advantage, benefit, or solution is not to be construed as an important, required, or essential feature or component.

[0039] The terms "comprises", "comprising", or any variation thereof are intended to mean a non-limiting inclusion, such that a process, method, article, composition, or apparatus that comprises the recited elements does not include only those elements that are recited, but may also include other elements not expressly recited or inherent to such a process, method, article, composition, or apparatus. In addition to what is specifically recited, the above-described structures, configurations, uses, ratios, elements, materials, or other combinations and / or variations of components used in the practice of this technology may be altered, or may be specifically adapted to particular environments, manufacturing specifications, design parameters, or other operating requirements without departing from their general principles.

[0040] This technology has been described above with reference to exemplary embodiments. However, modifications and alterations may be made to the exemplary embodiments without departing from the scope of this technology. These and other modifications or alterations are intended to be included within the scope of this technology as set forth in the following claims.

Claims

1. A system comprising: a reactor having an inlet and an outlet; a first vessel having a first inlet and a first outlet connected to the inlet of the reactor; a second vessel having a second inlet and a second outlet connected to the inlet of the reactor; an exhaust system connected to the outlet of the reactor, the first inlet of the first vessel, and the second inlet of the second vessel; wherein one of the first vessel and the second vessel is configured to sublime a solid precursor therein for processing, and the other of the first vessel and the second vessel is maintained in an idle state having a temperature that allows unreacted precursor received from the exhaust system to recondense therein.

2. The system of claim 1, wherein the exhaust system comprises a feedback portion connecting the reactor to the first vessel and the second vessel.

3. The system of claim 2, wherein the feedback portion comprises a junction including a first leg connected to the first vessel and a second leg connected to the second vessel.

4. The system of claim 3, wherein a first valve is connected to the first leg to regulate flow to the first vessel, and a second valve is connected to the second leg to regulate flow to the second vessel.

5. The system of claim 3, wherein the feedback portion comprises a filter.

6. The system of claim 5, wherein the filter is disposed upstream of the junction.

7. The system of claim 1, wherein each of the first vessel and the second vessel comprises a heating device and a cooling device.

8. A method comprising: flowing a precursor from a first vessel to a reactor for processing; flowing unreacted precursor from the reactor to an exhaust system connected to the reactor; flowing the unreacted precursor from the exhaust system to a second vessel; and condensing the unreacted precursor in the second vessel to a solid state for use as a precursor in future processing.

9. The method of claim 8, further comprising flowing the unreacted precursor from the reactor to a feedback portion of the exhaust system, the feedback portion of the exhaust system being connected between the reactor and the second vessel.

10. The method according to claim 8, wherein the first container is in a processing state configured to sublimate a solid precursor into the precursor, and the second container is in an idle state at a temperature that allows the precursor to remain in the solid state.

11. The method according to claim 10, further comprising monitoring a precursor level in the first container.

12. The method according to claim 11, further comprising changing the first container from the processing state to the idle state and changing the second container from the idle state to the processing state in response to the precursor level in the first container falling below a predetermined minimum threshold.

13. The method according to claim 12, further comprising flowing the precursor from the second container to the reactor for processing.

14. The method according to claim 13, further comprising flowing the unused precursor from the reactor to the exhaust system and into the first container.

15. The method according to claim 14, further comprising condensing the unused precursor in the solid state in the first container for use as the precursor in future processing.

16. The method according to claim 8, further comprising flowing the unused precursor through a filter while flowing the unused precursor to the second container.

17. The method according to claim 8, wherein flowing the unused precursor from the reactor to the exhaust system includes purging the reactor with an inert gas.

18. A method comprising: flowing a precursor from a first container to a reactor for processing; flowing an unused precursor from the reactor to a second container; and condensing the unused precursor in the solid state in the second container for use as the precursor in future processing.

19. The method according to claim 18, wherein the first container is in a processing state configured to sublimate a solid precursor into the precursor, and the second container is in an idle state at a temperature that allows the precursor to remain in the solid state.

20. monitoring a precursor level in the first container; In response to the level of the precursor in the first container falling below a predetermined minimum threshold value, changing the first container from the processing state to the idle state and changing the second container from the idle state to the processing state; Flowing the precursor from the second container to the reactor for processing; The method according to claim 19, further comprising flowing the unused precursor from the reactor to the first container.

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