System for collecting, recovering and recycling chemical off-gas from semiconductor processing chamber

Abstract

Chemical precursor recovery systems and methods for recovering and reusing semiconductor manufacturing chemicals are disclosed. The recovery system includes a cold trap inlet line and a cold trap outlet line in fluid communication with a plurality of cold traps. The plurality of cold traps are configured to condense the chemical precursor and are arranged based on semiconductor manufacturing process conditions.

Description

TECHNICAL FIELD

[0001] Embodiments of the present disclosure generally relate to apparatuses and methods for collecting, recovering, and recycling chemical compounds from a waste gas stream of a semiconductor manufacturing process chamber. In particular, embodiments of the present disclosure relate to apparatuses and methods for separating, condensing, and reusing chemical species associated with deposition and etching processes in semiconductor manufacturing. BACKGROUND

[0002] Reliably producing sub-micron and smaller features is one of the key requirements of very large scale integration (VLSI) and ultra large scale integration (ULSI) of semiconductor devices. However, as circuitry technology continues to shrink in size, the size and pitch of circuit features, such as interconnects, place additional demands on processing capabilities. Various semiconductor components, e.g., interconnects, vias, capacitors, transistors, require precise placement of high aspect ratio features. Reliable formation of these components is critical to further increasing device and density.

[0003] Additionally, the electronics device industry and semiconductor industry continue to strive for greater throughput while increasing uniformity of layers deposited on substrates having increasingly larger surface areas. These same factors combined with new materials also provide for higher integration of circuitry per unit area on the substrate.

[0004] During semiconductor manufacturing, expensive and potentially hazardous precursors and reactants are used. For example, chemical vapor deposition (CVD), atomic layer deposition (ALD), and etching processes often employ expensive chemical precursors, which are used in excess to ensure complete reaction. These excess reactants and waste gases are sent to scrubbers for abatement and disposal. As a result, expensive chemicals are lost and potentially harmful greenhouse gases are released into the atmosphere. Currently, the semiconductor industry does not use such chemical recovery systems.

[0005] Accordingly, there is a need for apparatuses and methods that recover semiconductor manufacturing process gases and reduce the environmental impact of semiconductor manufacturing. SUMMARY

[0006] One or more embodiments of the present disclosure relate to a chemical precursor recovery system including a cold trap inlet line, a plurality of cold traps, and a cold trap outlet line. The plurality of cold traps is positioned downstream of and in fluid communication with the inlet line. Each of the cold traps is configured to condense a chemical precursor. The cold trap outlet line is positioned downstream of and in fluid communication with the plurality of cold traps.

[0007] Further embodiments of the disclosure relate to a chemical precursor recovery system for an atomic layer deposition process chamber. The chemical precursor recovery system includes a cold trap inlet line, a cold trap outlet line, and a plurality of cold traps. The cold trap inlet line is configured to be connected to an exhaust line of the atomic layer deposition process chamber. The cold trap outlet line is downstream of the cold trap inlet line. The plurality of cold traps is downstream of and in fluid communication with the inlet line. Each of the cold traps is configured to condense a chemical precursor. The plurality of cold traps is arranged in parallel with an inlet junction connected to and in fluid communication with the cold trap inlet line and an outlet junction connected to and in fluid communication with the cold trap outlet line downstream of the plurality of cold traps. Each of the cold traps has one or more of an upstream pneumatic valve or an upstream manual valve and one or more of a downstream pneumatic valve or a downstream manual valve to isolate each of the cold traps separately from the plurality of cold traps. A bypass line is in fluid communication with the inlet line upstream of the inlet junction and with the outlet line downstream of the outlet junction. The bypass line includes an upstream bypass valve and a downstream bypass valve to isolate the bypass line from the plurality of cold traps.

[0008] Further embodiments of the disclosure relate to a chemical precursor recovery system for a chemical vapor deposition process chamber. The chemical precursor recovery system includes a cold trap inlet line, a plurality of cold traps, and a cold trap outlet line. The plurality of cold traps is downstream of and in fluid communication with the inlet line. Each of the cold traps is configured to condense a chemical precursor. The plurality of cold traps is arranged in series with a decreasing temperature gradient, ending with a cold trap of lowest temperature. The cold trap closest to the inlet line has one or more of an upstream manual valve or an upstream pneumatic valve and one or more of a downstream pneumatic valve or a downstream manual valve to isolate the cold trap. A pneumatic valve is between each of the cold traps. One or more of a pneumatic valve or a manual valve is downstream of the last cold trap. The cold trap outlet line is downstream of and in fluid communication with the plurality of cold traps. Each of the cold traps is connected to a downstream collection system by a collection line with a valve. The collection system includes one or more of a compressor or a gas cylinder. BRIEF DESCRIPTION OF DRAWINGS

[0009] In order to enable a detailed understanding of the above-mentioned features of the present disclosure, it can be described more specifically with reference to the embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings only show typical embodiments of the present disclosure and therefore should not be considered to limit the scope thereof, as the present disclosure can allow other equivalent embodiments.

[0010] Figure 1 A schematic diagram of a chemical precursor recovery system with cold traps arranged in parallel is shown in accordance with one or more embodiments of the present disclosure;

[0011] Figure 2 A cross-sectional schematic diagram of a cold trap is shown in accordance with one or more embodiments of the present disclosure; and

[0012] Figure 3 A schematic diagram showing a portion of a chemical precursor recovery system having cold traps arranged in series with a temperature gradient is shown in accordance with one or more embodiments of the present disclosure. DETAILED DESCRIPTION

[0013] Before several exemplary embodiments of the present disclosure are described, it is to be understood that the present disclosure is not limited to the details of construction or processing steps set forth in the following description. The present disclosure is capable of other embodiments and of being practiced or being carried out in various ways.

[0014] As used in this specification and the appended claims, the term "substrate" refers to a surface upon which processing is performed and / or a portion of a surface upon which processing is performed. Those skilled in the art will appreciate, in light of the disclosure herein, that reference to a substrate can also refer to only those surfaces of the substrate that are processed unless otherwise specifically stated. In addition, reference to depositing on a substrate can mean both bare substrates and those that have had one or more films or features deposited or formed thereon.

[0015] As used herein, "substrate" refers to any substrate or material surface formed on a substrate upon which film processing is performed during a fabrication process. For example and without limitation, the substrate surface on which processing is performed includes materials such as silicon, silicon oxide, strained silicon, silicon on insulator (SOI), carbon doped silicon oxides, amorphous silicon, doped silicon, germanium, gallium arsenide, glass, sapphire, and any other suitable materials and / or combinations of materials as will occur to one skilled in the art. Substrates include, but are not limited to, semiconductor wafers. Substrates can be exposed to a pretreatment process to polish, etch, reduce, oxidize, hydroxylate, anneal, UV cure, e-beam cure, and / or bake the substrate surface. In addition to film processing directly on the surface of the substrate itself, in the present disclosure, any of the thin film processing steps disclosed can also be performed on an underlayer formed on the substrate, as disclosed in more detail below, and the term "substrate surface" is intended to include such underlayer as the context indicates. Thus, for example, when a film / layer or partial film / layer has been deposited onto a substrate surface, the exposed surface of the newly deposited film / layer becomes a substrate surface.

[0016] As used in this specification and the appended claims, the terms "substrate support" and "substrate support pedestal" are used interchangeably.

[0017] As used in this specification and the appended claims, the use of relative terms such as "above" and "below" should not be construed as limiting the scope of the present disclosure to physical orientation in space. Thus, the use of relative terms should not be limited to the direction designated by gravity.

[0018] One or more embodiments of the present disclosure provide a scrubberless system to collect, recover, and / or recycle chemicals from the exhaust of a semiconductor manufacturing process chamber. As used in this manner, the term "scrubberless" means that a chemical scrubber is not required to collect and recycle the active species. However, the scrubberless system can include a scrubber as a precaution to ensure that harmful chemicals are not released into the environment.

[0019] Some embodiments of the present disclosure provide systems and methods to separate, collect, and / or recover precursors and byproducts of deposition processes in ALD, CVD, and etch chambers. Some embodiments employ a set of cold traps, pneumatic (manual or other type) valves, and gas separation membranes (GSMs) to condense unreacted precursors, byproducts, and other chemicals separately, rather than disposing of them en masse through abatement systems. After processing, the collected chemicals can be isolated and, in some cases, reused.

[0020] In some embodiments, the semiconductor manufacturing process chamber includes one or more of a chemical vapor deposition (CVD) chamber, an atomic layer deposition (ALD) process chamber, or an etch chamber. Exhaust from other process chambers can also be directed through the recovery system and is within the scope of the present disclosure. The main difference between ALD and CVD / etch chambers is the composition of the exhaust components. ALD chambers typically have a mixture of precursors and carrier gas constituents that become exhaust, while CVD / etch chambers typically have a mixture of active species and carrier gas. In some embodiments, the recovery system separates the active species from the carrier gas. In some embodiments, the recovery system separates a mixture of active species into individual active species. In some embodiments, the recovery system separates the carrier gas / diluent / inert gas from the reactive gas.

[0021] Some embodiments of the present disclosure allow for the recovery of expensive precursors (e.g., noble metal precursors) and gases (e.g., helium, hydrogen), which can then be reused within the facility, or sent for purification. Some embodiments reduce the operating costs of a semiconductor manufacturing facility by allowing for the reuse of expensive chemical precursors. Some embodiments allow for the recovery of warm chamber gases (e.g., methane, carbon dioxide, nitrous oxide), thereby reducing the environmental impact of a semiconductor manufacturing facility.

[0022] Some embodiments provide a system that uses cold traps (CTs) and gas separation membranes in series or in parallel. The system can be arranged to receive exhaust from a semiconductor manufacturing process chamber or tool.

[0023] In ALD mode, as Figure 1As shown and discussed further below, the cold traps are arranged in parallel with a bypass line. In some embodiments, each cold trap has a manual valve followed by a pneumatic valve. The bypass line has a pneumatic valve. The pneumatic valves can be operated by chamber software to synchronize the processing steps with a particular cold trap (or bypass line). The manual valves can be used to isolate the cold traps from the system and subsequently recover chemicals. Although the term "pneumatic valve" is used herein, one skilled in the art will recognize that the present disclosure is not limited to pneumatic control valves. The term "pneumatic valve" is used herein to describe any valve that can be controlled by an automated system, as opposed to a manual valve that can only be controlled by manual operation.

[0024] In the CVD / etch mode, as Figure 3 As shown and discussed further below, the cold traps are arranged in series to reduce temperature to achieve fractional condensation of the effluent vapor. The cold traps are separated by pneumatic valves, and each cold trap is connected to a compressor and gas cylinder. After the processing pneumatic valves are closed, the cold traps are preheated and collect the chemicals contained therein. The first cold trap has a manual valve to isolate and recover the precursors from the system.

[0025] The cold traps can be followed by gas separation membranes. In the illustrated embodiment, there are two GSMs. The first GSM separates small molecules (e.g., H2, He, CO2, CH4) that are then fed to the second GSM to recover H2and He.

[0026] An activated carbon filter can be added to capture additional chemicals (e.g., H2S, volatile organic chemicals (VOCs)) that can be recovered by thermal disposal.

[0027] One or more embodiments of the present disclosure relate to a chemical precursor recovery system 100. The chemical precursor recovery system 100 includes a cold trap inlet line 110, a plurality of cold traps 130, and a cold trap outlet line 120. The cold trap inlet line 110 of the chemical precursor recovery system 100 is positioned downstream of a processing chamber 102 such that exhaust gas flow from the processing chamber 102 flows into the chemical precursor recovery system 100 through the cold trap inlet line 110. As shown in the figures, the plurality of cold traps 130 includes at least one cold trap 150 and at least one pneumatic valve 140 and / or manual valve 145.

[0028] Figure 2A schematic of a cold trap 150 according to one or more embodiments of the present disclosure is shown. The cold trap 150 shown has a cooled and / or insulated wall 151. The cold trap inlet line 110 allows gas flow into the cold trap 150 through a pneumatic valve 140 and an inlet line 152. The embodiment shown has one pneumatic valve 140 on the inlet end of the cold trap 150. However, one skilled in the art will recognize that one or more different types of valves can be present at the inlet end of the cold trap 150 and the scope of the present disclosure is not limited to having one pneumatic valve 140. The gas flows to the interior 156 of the cold trap 150 where condensation occurs based on the temperature of the cold trap 150 and the particular chemical species to be condensed. The gas flow can then exit the interior 156 of the cold trap 150 through an outlet line 153, a pneumatic valve 140, and the cold trap outlet line 120 to downstream components of the chemical precursor recovery system 100.

[0029] When a certain amount of condensate has collected in the cold trap 150, the pneumatic valve 141 can be opened allowing the condensate to flow from the interior 156 of the cold trap 150 through a collection line 154 into the collection system 170. One skilled in the art will recognize that the pneumatic valve 141 shown can be any appropriate valve or combination of valves without departing from the scope of the present disclosure. Additionally, one skilled in the art will recognize that the location of the collection line 154 can be at any appropriate location. For example, it can be advantageous to position the collection line 154 at the bottom of the cold trap 150.

[0030] Referring again to Figure 1 , a plurality of cold traps 130 are positioned downstream of and in fluid communication with the cold trap inlet line 110. The plurality of cold traps 130 are positioned upstream of and in fluid communication with the cold trap outlet line 120. In other words, the cold trap outlet line 120 is positioned downstream of and in fluid communication with the plurality of cold traps 130.

[0031] Each cold trap 150 of the plurality of cold traps 130 is configured to condense a chemical precursor. As used in this manner, the cold trap 150 is configured to condense a chemical precursor by maintaining the cold trap at a predetermined temperature based on the chemical precursor of interest. In some embodiments, any cold trap 150 is maintained at a temperature that is less than or equal to the boiling or sublimation point of the chemical precursor of interest.

[0032] In Figure 1 the embodiment shown, the cold traps 150 of the plurality of cold traps 130 are arranged in parallel with an inlet junction 132 and an outlet junction 134. The inlet junction 132 is connected to and in fluid communication with the cold trap inlet line 110. The outlet junction 134 is connected to and in fluid communication with the cold trap outlet line 120.

[0033] Figure 1The illustrated embodiment has three independent cold trap lines; a first cold trap line 155a, a second cold trap line 155b, and a third cold trap line 155c. For ease of description, Figure 1 A collection system 170 is not shown in FIG. 1, although the collection system 170 can be integrated into the chemical precursor recovery system 100 or can be a separate component. As a separate component, the cold traps 150 can be removed from the plurality of cold traps 130 and then connected to the collection system 170 for emptying.

[0034] Each cold trap line 155a, 155b, 155c in the illustrated embodiment has a pneumatic valve 140 and a manual valve 145 upstream of the cold trap 150 and in fluid communication with the cold trap. In addition, each cold trap line 155a, 155b, 155c has a manual valve 145 and a pneumatic valve 140 downstream of the cold trap 150 and in fluid communication with the cold trap 150. In the illustrated embodiment, the manual valve 145 is closer to the cold trap 150 than the pneumatic valve 140. In some embodiments, the pneumatic valve 140 is closer to the cold trap 150 than the manual valve 145.

[0035] In operation, the exhaust gas stream exiting the process chamber 102 and flowing through the cold trap inlet line 110 into the plurality of cold traps 130 is split at the inlet junction 132 to one of the plurality of cold traps 130. In some embodiments, the inlet junction 132 includes a proportional valve (not shown) to control the exhaust gas stream to each individual cold trap 130. In some embodiments, the inlet junction 132 is a split fitting that allows the exhaust gas stream to be split into a plurality of exhaust gas streams, each of which passes through one of the cold traps 150. When one of the cold traps 150 has accumulated condensate to a predetermined volume, the controller 190 closes the pneumatic valve 140 on either side of the cold trap 150. A manually operating operator can then close the manual valve 145 on either side of the target cold trap 150, allowing the cold trap 150 to be removed from the plurality of cold traps 130 for emptying or replacement. In some embodiments, all of the valves before and after any given cold trap 150 in the plurality of cold traps 130 are pneumatic valves 140. In some embodiments, all of the valves before and after any given cold trap 150 in the plurality of cold traps 130 are manual valves 145. In some embodiments, each cold trap 150 has one or more upstream pneumatic valves 140 or upstream manual valves 145, and one or more downstream pneumatic valves 140 or downstream manual valves 145 to isolate each cold trap 150 from the plurality of cold traps 130.

[0036] In some embodiments, the chemical precursor recovery system 100 includes a bypass line 160 in fluid communication with the cold trap inlet line 110 and the cold trap outlet line 120. The bypass line 160 is connected to the cold trap inlet line 110 upstream of the inlet junction 132 and to the cold trap outlet line 120 downstream of the outlet junction 134.

[0037] The bypass line 160 of some embodiments includes an upstream bypass valve 162 and a downstream bypass valve 164 to isolate the bypass line 160 from the plurality of cold traps 130. The upstream bypass valve 162 and the downstream bypass valve 164 shown in Figure 1

[0038] Figure 1 The illustrated embodiment is particularly useful when one precursor or chemical species needs to be recovered. For example, hafnium-containing precursors are flowed in an inert gas, where the hafnium-containing precursor is to be recovered and the inert gas is irrelevant. In some embodiments, the process chamber 102 is an atomic layer deposition (ALD) process chamber, and the cold trap inlet line 110 is in fluid communication with an atomic layer deposition (ALD) process chamber exhaust.

[0039] Figure 3 A portion of the chemical precursor recovery system 100 is shown, where the plurality of cold traps 130 and the collection system 170 are shown. In this embodiment, the plurality of cold traps 130 are arranged in series, with the cold trap inlet line 110 connected to the cold trap outlet line 120 through each of the cold traps 150 in the plurality of cold traps 130.

[0040] In some embodiments, the plurality of cold traps 130 are arranged to have a decreasing temperature gradient from the cold trap inlet line 110 to the cold trap outlet line 120. The coldest trap is the first or closest to the cold trap inlet line 110, and the warmest trap is the last or closest to the cold trap outlet line 120.

[0041] While the illustrated embodiment has six cold traps arranged in series, this represents only one possible configuration and should not be considered limiting the scope of the disclosure. In some embodiments, there are more or less than six cold traps arranged in series in the plurality of cold traps 130.

[0042] In some embodiments, each of the plurality of cold traps 130 is maintained at a different temperature during use. By way of example only, the first cold trap 150a is held at a higher temperature than the second cold trap 150b, the second cold trap 150b is held at a higher temperature than the third cold trap 150c, the third cold trap 150c is held at a higher temperature than the fourth cold trap 150d, the fourth cold trap 150d is held at a higher temperature than the fifth cold trap 150e, and the fifth cold trap 150e is held at a higher temperature than the sixth cold trap 150f.

[0043] ​In some embodiments, two or more of the plurality of cold traps 130 are maintained at substantially the same temperature. As used in this manner, the term "substantially the same temperature" means that the target cold trap is maintained at a temperature at which the same components of the effluent condense and no additional compounds condense. For example, if the temperature of a first cold trap 150a is 5 degrees Celsius higher than a second cold trap 150b, but no additional gas species in the effluent condense at that temperature difference, then the first cold trap 150a and the second cold trap 150b are considered to be at substantially the same temperature. In some embodiments, at least one cold trap 150 of the plurality of cold traps 130 is maintained at a substantially different temperature than at least one other cold trap 150 of the plurality of cold traps 130, creating a temperature gradient.

[0044] In some embodiments, the plurality of cold traps 130 includes one or more of an upstream manual valve 145a or an upstream pneumatic valve 140a positioned upstream of one or more of the cold traps 150. In some embodiments, the plurality of cold traps 130 includes one or more of a downstream pneumatic valve 140b or a downstream manual valve 145b positioned downstream of one or more of the cold traps 105.

[0045] In the illustrated embodiment, the first cold trap 150a, which is the cold trap closest to the inlet line 110, has one or more of an upstream manual valve 145a or an upstream pneumatic valve 140a and one or more of a downstream pneumatic valve 140b or a downstream manual valve 145b to isolate the first cold trap 150a. When the upstream pneumatic valve 140a, the upstream manual valve 145a, the downstream pneumatic valve 140b, and the downstream manual valve 145b are all closed, the first cold trap 150a can be removed from the plurality of cold traps 130 without disrupting the pressure maintained within the chemical precursor recovery system 100.

[0046] In some embodiments, the plurality of cold traps 130 further includes pneumatic valves positioned between each of the cold traps 150 and one or more of a pneumatic valve or a manual valve downstream of the last cold trap. For example, in the illustrated embodiment, a downstream pneumatic valve 140b (relative to the first cold trap 150a) is upstream of the second cold trap 150b, and a pneumatic valve 140c is downstream of the second cold trap 150b and upstream of the third cold trap 150c. A pneumatic valve 140d is downstream of the third cold trap 150c and upstream of the fourth cold trap 150d. A pneumatic valve 140e is downstream of the fourth cold trap 150d and upstream of the fifth cold trap 150e. A pneumatic valve 140f is downstream of the fifth cold trap 150e and upstream of the sixth cold trap 150f. A pneumatic valve 140g is downstream of the sixth cold trap 150f.

[0047] In some embodiments, as Figure 3As shown, each cold trap 150a-f is connected to a downstream collection system 170 by a collection line 154a-f having a valve (not shown). In some embodiments, the collection system 170 includes one or more of a compressor 172 or a gas cylinder 174. In some embodiments, the collection system 170 includes both a compressor 172 and a gas cylinder 174, the compressor 172 compressing gas from the cold traps and filling the gas cylinder 174 with compressed gas.

[0048] Figure 3 The illustrated embodiments are particularly useful when more than one precursor or chemical species is to be recovered from the effluent. For example, hafnium-containing precursors and tantalum-containing precursors are flowed in an inert gas, where the hafnium-containing precursors and tantalum-containing precursors are to be recovered and the inert gas is irrelevant. The temperature gradient of the cold traps allows for the two precursors from the same effluent stream to be condensed separately. In some embodiments, the process chamber 102 is one or more of a chemical vapor deposition (CVD) process chamber or an etch chamber, and the cold trap inlet line 110 is in fluid communication with one or more of a chemical vapor deposition (CVD) process chamber or an etch chamber exhaust.

[0049] Referring again to Figure 1 The chemical precursor recovery system 100 of some embodiments further includes one or more gas separation modules (GSM) located downstream of and in fluid communication with the cold trap outlet line 120. In the illustrated embodiment, there are two gas separation modules arranged in series downstream of the cold trap outlet line 120. The effluent in the cold trap outlet line 120 enters a first gas separation module 180a, where small molecules are separated from the effluent. The separated small molecules flow into a second gas separation module 180b, while other effluent constituents continue downstream to an activated carbon filter 182. The first gas separation module 180a of some embodiments separates small molecules from the effluent, such as methane (CH4), carbon monoxide (CO), carbon dioxide (CO2), molecular nitrogen (N2), nitrous oxide (N2O), argon (Ar), molecular hydrogen (H2), helium (He), krypton (Kr), etc. In some embodiments, the second gas separation module 180b separates molecular hydrogen (H2) and / or helium (He) from the effluent exiting the first gas separation module 180a.

[0050] The effluent exiting the first gas separation module 180a that was not separated by the first gas separation module 180a flows into an activated carbon filter 182 located downstream of the first gas separation module 180a. The activated carbon filter 182 of some embodiments can be effective to collect or remove volatile organic compounds (VOCs) and / or hydrogen sulfide (H2S) from the effluent stream. The activated carbon filter 182 can be baked at an elevated temperature to release compounds bound to the activated carbon and to recover the activated carbon filter 182 for further use.

[0051] In some embodiments, the chemical precursor recovery system 100 further includes a pump 184 downstream of the activated carbon filter 182 and a scrubber 186 downstream of the pump 184. The pump 184 of some embodiments effectively ensures that the effluent continues to flow downstream to exit the chemical precursor recovery system 100. The scrubber 186 of some embodiments serves as a precaution in the event that hazardous chemicals are not separated from the effluent after passing through the chemical precursor recovery system 100.

[0052] In some embodiments, as shown in FIG. 1, a controller 190 is coupled to the chemical precursor recovery system 100 and / or the processing chamber 102 for controlling the processing chamber 102, the chemical precursor recovery system 100, or components thereof. For example, the system controller 190 can control the operation of the processing chamber 102, pneumatic valves (or other computer controlled valves), and any monitoring components included in the system as known to one skilled in the art. In operation, the system controller 190 enables data and feedback to be collected from the processing chamber 102 and / or the chemical precursor recovery system 100 to coordinate system performance. Figure 1

[0053] The system controller 190 typically includes a central processing unit (CPU) 192, memory 194, and support circuits 196. The CPU 192 can be one of any form of a general purpose processor that can be used in an industrial setting. The memory 194 (or non-transitory computer readable medium) is accessible by the CPU 192 and can be one or more of a readily available memory, such as random access memory (RAM), read-only memory (ROM), a disk drive, a hard drive, or any other form of local or remote digital storage. The support circuits 196 are coupled to the CPU 192 and can include cache, clock circuits, input / output subsystems, power supplies, and the like. The various methods disclosed herein can generally be implemented by the CPU 192 executing computer instruction code stored in the memory 194 (or the memory of a particular processing chamber) as software routines under the control of the CPU 192. When the CPU 192 executes the computer instruction code, the CPU 192 controls the chamber or valve to perform processing according to the various methods.

[0054] ​References in this description to "one embodiment," "certain embodiments," "one or more embodiments" or "an embodiment" mean that a particular feature, structure, material, or characteristic being described is included in at least one embodiment of the disclosure. Thus, the appearances of such phrases in various places in the description are not necessarily referring to the same embodiment of the disclosure. Furthermore, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments.

[0055] While the application has been described with reference to particular embodiments, it will be understood by those skilled in the art that various changes in form and details can be made therein without departing from the spirit and scope of the disclosure. It is therefore intended that the disclosure not be limited to the particular embodiments described herein, but that the disclosure will include all embodiments falling within the scope of the appended claims, and their equivalents.

Claims

1. A chemical precursor recovery system, the chemical precursor recovery system comprising: Cold trap inlet piping; A plurality of cold traps, located downstream of and in fluid communication with the inlet line, each cold trap being configured to condense the chemical precursor; and A cold trap outlet pipeline, which is located downstream of the plurality of cold traps and is in fluid communication with the plurality of cold traps.

2. The chemical precursor recovery system of claim 1, wherein the plurality of cold traps are arranged in parallel with an inlet junction connected to and in fluid communication with the inlet line and an outlet junction connected to and in fluid communication with the outlet line.

3. The chemical precursor recovery system of claim 2, further comprising a bypass line in fluid communication with the inlet line upstream of the inlet junction and with the outlet line downstream of the outlet junction.

4. The chemical precursor recovery system of claim 3, wherein the bypass line further comprises an upstream bypass valve and a downstream bypass valve to isolate the bypass line from the plurality of cold traps.

5. The chemical precursor recovery system of claim 2, wherein each cold trap has one or more of an upstream pneumatic valve or an upstream manual valve, and one or more of a downstream pneumatic valve or a downstream manual valve to isolate each cold trap separately from the plurality of cold traps.

6. The chemical precursor recovery system of claim 2, wherein the inlet line is in fluid communication with the exhaust device of the atomic layer deposition (ALD) processing chamber.

7. The chemical precursor recovery system of claim 1, wherein the plurality of cold traps are arranged in series with a gradually decreasing temperature gradient, wherein the cold trap with the lowest temperature is last.

8. The chemical precursor recovery system of claim 7, wherein each of the plurality of cold traps is at a different temperature.

9. The chemical precursor recovery system of claim 7, further comprising one or more upstream manual valves or upstream pneumatic valves upstream of one or more of the cold trap, and one or more downstream pneumatic valves or downstream manual valves downstream of one or more of the cold trap.

10. The chemical precursor recovery system of claim 7, wherein the cold trap closest to the inlet line has one or more upstream manual or upstream pneumatic valves and one or more downstream pneumatic or downstream manual valves to isolate the cold trap.

11. The chemical precursor recovery system of claim 10, further comprising one or more pneumatic valves between each of the cold traps and a pneumatic or manual valve downstream of the last of the cold traps.

12. The chemical precursor recovery system of claim 7, wherein each cold trap is connected to a downstream collection system via a collection line having a valve, the collection system comprising one or more compressors or gas cylinders.

13. The chemical precursor recovery system of claim 7, wherein the inlet line is in fluid communication with the exhaust device of the chemical vapor deposition (CVD) processing chamber.

14. The chemical precursor recovery system of claim 1, wherein the chemical precursor recovery system further comprises one or more gas separation modules (GSMs) located downstream of and in fluid communication with the cold trap outlet line.

15. The chemical precursor recovery system of claim 14, wherein two GSMs are connected in series downstream of the cold trap outlet line, the first GSM separating small molecules from the effluent in the cold trap line, and the second GSM separating hydrogen (H2) and helium (He) from the effluent leaving the first GSM.

16. The chemical precursor recovery system of claim 14, wherein the chemical precursor recovery system further comprises an activated carbon filter located downstream of the GSM.

17. The chemical precursor recovery system of claim 16, wherein the chemical precursor recovery system further comprises a pump located downstream of the activated carbon filter.

18. The chemical precursor recovery system of claim 17, wherein the chemical precursor recovery system further comprises a scrubber located downstream of the pump.

19. A chemical precursor recovery system for an atomic layer deposition processing chamber, the chemical precursor recovery system comprising: A cold trap inlet line, the cold trap inlet line being configured to connect to an exhaust line of the atomic layer deposition processing chamber; A cold trap outlet pipeline, wherein the cold trap outlet pipeline is located downstream of the cold trap inlet pipeline; A plurality of cold traps are located downstream of and in fluid communication with the inlet line, each of the cold traps being configured to condense the chemical precursor. The plurality of cold traps are arranged in parallel with an inlet junction connected to and in fluid communication with the cold trap inlet line and an outlet junction connected to and in fluid communication with the cold trap outlet line downstream of the plurality of cold traps. Each cold trap has one or more upstream pneumatic or upstream manual valves and one or more downstream pneumatic or downstream manual valves to isolate each cold trap separately from the plurality of cold traps. and A bypass line is in fluid communication with the inlet line upstream of the inlet junction and with the outlet line downstream of the outlet junction. The bypass line includes an upstream bypass valve and a downstream bypass valve to isolate the bypass line from the plurality of cold traps.

20. A chemical precursor recovery system for a chemical vapor deposition processing chamber, the chemical precursor recovery system comprising: Cold trap inlet piping; Multiple cold traps are located downstream of and in fluid communication with the inlet line. Each cold trap is configured to condense the chemical precursor. The multiple cold traps are arranged in series with a gradually decreasing temperature gradient, wherein the cold trap with the lowest temperature is last. The cold trap closest to the inlet line has one or more upstream manual or pneumatic valves and one or more downstream pneumatic or manual valves to isolate the cold trap. The pneumatic valves are located between each of the cold traps, and one or more pneumatic or manual valves are located downstream of the last cold trap. A cold trap outlet pipeline, wherein the cold trap outlet pipeline is located downstream of the plurality of cold traps and is in fluid communication with the plurality of cold traps; and Each cold trap is connected to a downstream collection system via a collection line with a valve, the collection system comprising one or more compressors or gas cylinders.

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