Reduction of br2 and cl2 in semiconductor processes

Abstract

The one or more embodiments described herein relate to the use of Br in semiconductor processing to reduce Br 2 and Cl 2. Reduction System. In the embodiments described in this case, the semiconductor etching process is performed within a processing chamber. Subsequently, fluorinated greenhouse gases (F-GHG), HBr, and Cl... 2. The gas leaves the processing chamber and enters the plasma reactor. The reagent gas is transferred from the reagent gas transfer device to the plasma reactor to mix with the processing gas. Radio frequency (RF) power is applied to the plasma reactor, adding energy and "exciting" the gas in the processing chamber. When HBr is excited, it forms Br₂. 2. Br 2 and Cl 2. It is corrosive and toxic. However, adding H to the plasma reactor... 2O terminates Br 2 and Cl The emission of H2 occurs because H atoms recombine with Br and Cl atoms to form HBr and HCl. HBr and HCl are readily soluble in water and can be removed by a wet scrubbing machine.

Description

Technical Field

[0001] One or more embodiments described herein generally relate to abatement systems for semiconductor processing, and more particularly, to abatement systems for abatement of Br 2 and Cl 2 in semiconductor processing. Prior Art

[0002] Process gases used in semiconductor processing facilities include many compounds that must be reduced or disposed of before being discarded due to regulatory requirements and environmental issues. For example, etching processes, etc. often use fluorinated greenhouse gases (F-GHGs), such as CF4, SF6, C4F8, and CHF3. Along with F-GHGs, process gases such as HBr and Cl2 are often used to improve selectivity and reduce oxidation damage to the substrate surface during the etching process. Under energetic conditions, HBr is known to balance H2+Br2.

[0003] The processing chamber plasma has sufficient energy to cause the formation of Br2. Conventional abatement systems also have sufficient energy to cause the formation of Br2. Br2 and Cl2 are corrosive and toxic, causing environmental problems. Br2 is liquid at room temperature and can accumulate in exhaust pipes under certain conditions. In addition, Br2 and Cl2 are not water soluble and therefore cannot be adequately abated in wet scrubbers. With the increase in the flow of HBr and Cl2 in the etch process due to the use of larger substrates in semiconductor processing, the increased Br2 and Cl2 emissions cause problems.

[0004] Additionally, there is a need for an abatement system to reduce Br 2 and Cl 2 in semiconductor processing. Summary of the invention

[0005] One or more embodiments described herein relate to methods for abatement of a process gas.

[0006] In one embodiment, a method for abatement of a process gas comprises the following steps: performing a semiconductor etching process in a process chamber using a process gas, the process gas comprising a fluorinated greenhouse gas (F-GHG), HBr and Cl2, wherein the process gas is configured to flow from the process chamber into a plasma reactor; introducing a reagent gas from a reagent gas delivery system into the plasma reactor to react with the process gas; and applying RF power to the plasma reactor; wherein a ratio of the reagent gas flow rate to the HBr flow rate is greater than 2:1.

[0007] In another embodiment, a method for abatement of a process gas includes the following steps: performing a semiconductor etching process in a process chamber using a process gas, the process gas including a fluorinated greenhouse gas (F-GHG), HBr, and Cl2, wherein the process gas is configured to flow from the process chamber into a plasma reactor; introducing a reagent gas from a reagent gas delivery system into the plasma reactor to react with the process gas; and applying RF power to the plasma reactor; wherein a ratio of the reagent gas flow rate to the Br2 byproduct gas is greater than 8:1.

[0008] One or more embodiments described herein relate to a system for abatement of a process gas.

[0009] In one embodiment, a processing system includes: a processing chamber; a plasma reactor positioned downstream of the processing chamber; a reagent gas delivery device positioned between the processing chamber and the plasma reactor; a vacuum pump positioned downstream of the plasma reactor; a wet scrubber positioned downstream of the vacuum pump; a passivation gas delivery device positioned between the plasma reactor and the vacuum pump; and a controller configured to receive information from the processing system and perform operations when executed by a processor, the operations including the following actions: performing a semiconductor etching process in the processing chamber using a processing gas, the processing gas including a fluorinated greenhouse gas (F-GHG), HBr, and Cl2, wherein the processing gas is configured to flow from the processing chamber into the plasma reactor; introducing water vapor (H2O) from the reagent gas delivery system into the plasma reactor to react with the processing gas; and applying RF power to the plasma reactor; wherein a ratio of the H2O flow rate to the HBr flow rate is greater than 2:1; and a ratio of the H2O flow rate to the Br2 byproduct gas is greater than 15:1. Simple diagram description

[0010] By way of detailed understanding of the features of the present disclosure described above, a more detailed description of the present disclosure briefly summarized above can be obtained by reference to the embodiments, some of which are illustrated in the accompanying drawings. However, it should be understood that the accompanying drawings only illustrate typical embodiments of the present disclosure and therefore should not be considered as limiting the scope thereof, as the present disclosure recognizes other equally effective embodiments.

[0011] FIG. 1 is a schematic diagram of a processing system according to at least one embodiment of the present invention; and

[0012] FIG. 2 is a flow chart of a method according to at least one embodiment of the present invention. Implementation

[0013] In the following description, several specific details are mentioned to provide a more thorough understanding of the embodiments of the present disclosure. However, it is obvious to those skilled in the art that one or more embodiments of the present disclosure can be performed without one or more of these specific details. In other instances, well-known features are not described in order to avoid obscuring one or more embodiments of the present disclosure.

[0014] One or more embodiments described herein relate to an abatement system for abatement of Br2 and Cl2 in semiconductor processing. In the embodiments described herein, a semiconductor etching process is performed in a processing chamber. During certain semiconductor processes such as etching processes, F-GHG such as at least one of CF4, SF6, C4F8 and / or CHF3 are often used. Along with F-GHG, other process gases such as HBr and Cl2 are often used to improve selectivity and reduce oxidation damage to the substrate surface during the etching process. After the etching process, the F-GHG, HBr and Cl2 gases leave the processing chamber and enter a plasma reactor.

[0015] In certain embodiments, a reagent gas including hydrogen and oxygen atoms is delivered from a reagent gas delivery device to a plasma reactor to be mixed with a process gas. Radio frequency (RF) power is applied to the plasma reactor to add energy and "excite" the gas within the plasma reactor. When the gas within the plasma reactor is excited, the gas dissociates into an atomic level. Thereafter, the atomic elements recombine to form more stable, water-soluble compounds, helping to substantially reduce or eliminate F-GHGs that often cause environmental problems if present in the environment. When HBr is excited within the processing chamber and plasma reactor, it is known to balance H2+Br2. As discussed above, Br2 is corrosive and toxic. Additionally, Cl2 is corrosive and toxic. However, the addition of H2O within the plasma reactor stops the emission of Br2 and Cl2 because the H atoms recombine with the Br atoms and the Cl atoms to form HBr and HCl. HBr and HCl are readily soluble in water and are removed by a wet scrubber, however, Br2 and Cl2 cannot be effectively reduced in a wet scrubber.

[0016] Thus, the embodiments described herein provide advantages over conventional abatement systems. In conventional abatement systems, H atoms cannot be effectively recombined to form HBr and HCl, typically leaving behind large amounts of toxic Br2 and Cl2 that cannot be abated via a wet scrubber. Additionally, in conventional abatement systems, Br2 is liquid at room temperature and can accumulate in the exhaust pipe of the treatment system under certain conditions. In the embodiments described herein, Br2 and Cl2 are converted to water-soluble HBr and HCl, respectively, thereby reducing or eliminating the above problems. Additionally, F-GHG is also significantly reduced and / or eliminated.

[0017] FIG. 1 is a schematic diagram of a processing system 100 according to at least one embodiment described herein. The processing system 100 includes a processing chamber 102. The processing chamber 102 is configured to perform a semiconductor etching process to process a substrate. In certain embodiments, the processing chamber 102 may be a plasma enhanced chemical vapor deposition (PECVD) chamber configured to perform deposition or etching of a processing material. However, other chambers may also be used or modified with the embodiments described herein. During the etching process, a potentially harmful F-GHG such as CF4, SF6, C4F8 and / or CHF3 is often used with the processing chamber 102. The F-GHG gas is used to achieve the necessary anisotropy required in the etching process, particularly for deep trench etching processes. Along with the F-GHG, other processing gases such as HBr and Cl2 are often used to improve selectivity and reduce oxidation damage to the substrate surface during the etching process.

[0018] After the etching process, the F-GHG, HBr, and Cl2 gases are configured to flow out of the processing chamber 102 and into the plasma reactor 106. The plasma reactor 106 is positioned downstream of the processing chamber 102. RF power is applied to the plasma reactor 106 via a remote plasma source 107. The plasma source 107 may be an inductively coupled plasma source and may include a solid-state matching network. In some embodiments, the amount of RF power applied may be between about 2000 watts and about 4000 watts, but other amounts of RF power are possible. The processing system 100 also includes a reagent gas delivery device 104 configured to deliver a reagent gas to the plasma reactor 106, such as water vapor (H2O), H2, and / or O2, to mix with the processing gas leaving the processing chamber 102. In some embodiments, the reagent gas delivery device 104 may be a water delivery system configured to introduce water vapor to supply hydrogen and oxygen atoms to the plasma.

[0019] The amount of each of the process gases in the plasma reactor 106 may vary, and the ratio of each of the different gases in the plasma reactor 106 may vary. In some embodiments, the ratio of the H 2 O vapor flow rate to the HBr chamber flow rate is greater than 2:1. In other embodiments, the ratio of the H 2 O vapor flow rate to the HBr chamber flow rate is greater than 5:1. In some embodiments, the ratio of the H 2 O vapor flow rate to the Br 2 by-product gas is greater than 8:1. In other embodiments, the ratio of the H 2 O vapor flow rate to the Br 2 by-product gas is greater than 15:1. In some embodiments, the amount of H 2 O may be higher than the F-GHG gas, and vice versa. In other embodiments, the amount of H 2 and / or O 2 may be higher than the F-GHG gas, and vice versa. In other embodiments, the amounts of some or all of the gases in the plasma reactor 106 may be substantially similar.

[0020] Water vapor supplied from the reagent gas delivery device 104 is mixed with the process gas exiting the processing chamber 102 in the plasma reactor 106. The plasma source 107 adds energy to dissociate the process gas into an atomic level. Thereafter, the atomic elements recombine with the water vapor to form more stable, water-soluble compounds, helping to substantially reduce or eliminate F-GHGs that often cause environmental problems if present in the environment. When HBr is excited in the processing chamber and the plasma reactor, it is known to balance H2+Br2. As discussed above, Br2 is corrosive and toxic. Additionally, Cl2 is corrosive and toxic. However, the addition of H2O in the plasma reactor 107 stops the emission of Br2 and Cl2 because the H atoms recombine with the Br atoms and the Cl atoms to form HBr and HCl. HBr and HCl provide advantages over conventional abatement systems in which the H atoms do not recombine efficiently to form HBr and HCl, typically leaving behind large amounts of toxic Br2 and Cl2. Additionally, in conventional abatement systems, Br is liquid at room temperature and can accumulate in the exhaust pipe of the processing system 100 under certain conditions.

[0021] In some embodiments, the processing system 100 includes an inert gas delivery device 108, which is positioned downstream of the plasma reactor 106. The inert gas can be delivered to the processing system 100 through the inert gas delivery device 108. Furthermore, a vacuum pump 110 is positioned downstream of the inert gas delivery device 108. Therefore, the inert gas delivery device 108 is positioned between the plasma reactor 106 and the vacuum pump 110. The vacuum pump 110 can be used to pump the gas leaving the plasma reactor 106 and the inert gas delivery device 108 to a wet scrubber 112. The wet scrubber 112 is positioned downstream of the vacuum pump 110. In some embodiments, the wet scrubber 112 can be a bubble column, a packed bed column, or a scrubber. Any suitable wet scrubber can be used. The wet scrubber 112 functions to reduce the residual gas in the processing system 100 before the residual gas leaves the environment. The wet scrubber 112 cannot reduce Br2 and Cl2 well because they are not water soluble. However, wet scrubber 112 abates HBr and HCl well because they are water soluble. Therefore, the embodiments described herein provide the advantage of converting Br2 and Cl2 into HBr and HCl so that they can be more easily abated by wet scrubber 112 before leaving the environment.

[0022] In certain embodiments, the processing system 100 is controlled by a controller 114. The controller 114 communicates with the hardware included throughout the processing system 100 and functions to control processing parameters within the processing system 100. The controller 114 may include a central processing unit (CPU) 114A, a memory 114B, and support circuits (or I / O) 114C. The CPU 114A may be one of any type of computer processor used in an industrial setting to control various processes and hardware and monitor the processor. The memory 114B is connected to the CPU 114A and may be one or more immediately accessible memories, such as random access memory (RAM), read-only memory (ROM), a floppy disk, a hard disk, or any other form of digital storage, whether local or remote. Software instructions, algorithms, and data may be encoded and stored in the memory 114B for instructing the CPU 114A. The support circuits 114C are also connected to the CPU 114A for supporting the processor in a conventional manner. Support circuits 114C may include conventional caches, power supplies, clock circuits, input / output circuits, subsystems, and the like. What tasks are performed in processing system 100 is determined by a program (or computer instructions) readable by the controller. The program may be software readable by controller 114 and may include code to monitor and control processing parameters in processing system 100.

[0023] FIG. 2 is a flow chart of a method 200 according to at least one embodiment described herein. In these embodiments, the method 200 is performed with the apparatus described in FIG. 1, but is not limited to such apparatus and may be performed with other similar apparatus. In block 202, a semiconductor manufacturing process is performed in the processing chamber 102. The semiconductor manufacturing process may be an etching process, in which F-GHG such as CF4, SF6, C4F8 and / or CHF3 are often used. Along with F-GHG, other process gases such as HBr and Cl2 are often used to improve selectivity and reduce oxidation damage to the substrate surface during the etching process.

[0024] At block 204, a reagent gas is introduced from the reagent gas delivery device 104 into the plasma reactor 106. The reagent gas is mixed with the process gas exiting the process chamber 102. In certain embodiments, the reagent gas delivery device 104 may be a water delivery system configured to introduce water to supply hydrogen and oxygen atoms to the plasma reactor 106.

[0025] As discussed above, the amount of each of the process gases in the plasma reactor 106 may vary, and the ratio of each of the different gases in the plasma reactor 106 may vary. In some embodiments, the ratio of the H 2 O vapor flow rate to the HBr chamber flow rate is greater than 2:1. In other embodiments, the ratio of the H 2 O vapor flow rate to the HBr chamber flow rate is greater than 5:1. In some embodiments, the ratio of the H 2 O vapor flow rate to the Br 2 by-product gas is greater than 8:1. In other embodiments, the ratio of the H 2 O vapor flow rate to the Br 2 by-product gas is greater than 15:1. In some embodiments, the amount of H 2 O may be higher than the F-GHG gas, and vice versa. In other embodiments, the amount of H 2 and / or O 2 may be higher than the F-GHG gas, and vice versa. The ratio of HBr and Cl 2 may also be compared to other gases in the plasma reactor 106. For example, in some embodiments, the ratio of the H 2 O vapor flow rate to the Cl 2 by-product gas is greater than 8:1. In other embodiments, the ratio of H 2 O vapor flow rate to Cl 2 byproduct gas is greater than 15: 1. In other embodiments, the amounts of some or all gases in the plasma reactor 106 may be substantially similar.

[0026] At block 206, RF power is applied to the plasma reactor 106. The RF power may be applied via the remote plasma source 107. In some embodiments, the amount of RF power applied may be from about 2009 watts to about 4000 watts, but other amounts of RF power are possible. At optional block 208, the inert gas is delivered to the processing system 100 via the inert gas delivery device 108.

[0027] The embodiments described by the method 200 provide superior results compared to conventional abatement processes. For example, after performing the method 200, F-GHGs such as CF4 and SF6 were reduced by 95%. In addition, Br2 emissions from the processing chamber 102 were reduced by approximately 30% to 40% compared to conventional processes, and Cl2 emissions from the processing chamber 102 were reduced by approximately 90% compared to conventional processes. Thus, when performing the method 200, smaller amounts of destructive F-GHG, Br2, and Cl2 gases exit the processing system 100. Reducing these potentially harmful emissions becomes even more important because larger amounts of HBr and Cl2 are used to etch larger substrates within the processing chamber 102 during semiconductor processing.

[0028] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the present invention may be devised without departing from the basic scope thereof, and the scope of the present invention is determined by the following claims.

[0029] 100: Processing system 102: Processing chamber 104: Reagent gas transmission device 106: Plasma Reactor 107: Plasma Source 108: Inert gas transmission device 110: Vacuum pump 112: Wet scrubber 114: Controller 114A:CPU 114B: Memory 114C: Support circuit 200: Method 202: Block 204: Block 206: Block 208: Block

[0030] Domestic storage information (please note the order of storage institution, date and number) none Overseas deposit information (please note the order of deposit country, institution, date and number) none

Claims

1. A processing system comprising: a processing chamber; a plasma reactor positioned downstream of the processing chamber; a reagent gas transfer device positioned between the processing chamber and the plasma reactor; a vacuum pump positioned downstream of the plasma reactor; a wet scrubber positioned downstream of the vacuum pump; a passivation gas transfer device positioned between the plasma reactor and the vacuum pump; and a controller configured to control an operation performed in the processing system, the operation comprising: performing a semiconductor etching process in the processing chamber using processing gases including fluorinated greenhouse gases (F-GHG), HBr, and Cl2, wherein the processing gases are configured to flow from the processing chamber into the plasma reactor; Water vapor (H2O) is introduced into the plasma reactor from the reagent gas transport system to react with the treatment gases; and RF power is applied to the plasma reactor; wherein the ratio of an H2O flow rate to an HBr flow rate is greater than 2:1; and the ratio of an H2O flow rate to a Br2 byproduct gas is greater than 15:

1.

2. The processing system as described in claim 1, wherein the F-GHG includes CF4, SF6, C4F8 and CHF3.

3. The processing system as claimed in claim 1, wherein the reagent gas transport system is configured to supply hydrogen (H) and oxygen (O) atoms to the plasma reactor.

4. The processing system as described in claim 3, wherein the amount of H and O atoms is greater than the amount of F-GHG.

5. The processing system as described in claim 3, wherein the amount of F-GHG is greater than the amount of H and O atoms.

6. The processing system as described in claim 5, wherein the amount of RF power is between about 2000 watts and about 4000 watts.

7. The processing system as described in claim 1, wherein the F-GHG includes at least one of the following: CF4, SF6, C4F8, or CHF3.

8. A processing system comprising: a processing chamber; a plasma reactor positioned downstream of the processing chamber; a reagent gas transfer device positioned between the processing chamber and the plasma reactor; a vacuum pump positioned downstream of the plasma reactor; a wet scrubber positioned downstream of the vacuum pump; a passivation gas transfer device positioned between the plasma reactor and the vacuum pump; and a controller configured to control an operation performed in the processing system, the operation comprising: performing a semiconductor etching process in the processing chamber using processing gases including fluorinated greenhouse gases (F-GHG), HBr, and Cl2, wherein the processing gases are configured to flow from the processing chamber into the plasma reactor; and introducing a reagent vapor from the reagent gas transfer system into the plasma reactor to react with the processing gases. RF power is applied to the plasma reactor, in which the processed gases are at least partially converted into a Br2 byproduct gas and the Br2 byproduct gas is reacted with the reagent vapor to form HBr, wherein the ratio of the reagent vapor flow rate to the HBr flow rate of the HBr gas in the processing chamber is greater than 2:1; and a passivation gas is introduced between the plasma reactor and a pump configured to pump the gas out of the plasma reactor.

9. The processing system as described in claim 8, wherein the ratio of an H2O flow rate to a Br2 byproduct gas is greater than 15:

1.

10. The processing system as described in claim 8, wherein the reagent vapor comprises H2O.

11. The processing system as described in claim 8, wherein the reagent vapor comprises hydrogen (H) and oxygen (O) atoms.

12. The processing system as described in claim 11, wherein the amount of F-GHG is greater than the amount of H and O atoms.

13. The processing system as described in claim 8, wherein the amount of RF power is between about 2,000 watts and about 4,000 watts.

14. A processing system comprising: a processing chamber; a plasma reactor positioned downstream of the processing chamber; a reagent gas transfer device positioned between the processing chamber and the plasma reactor; a vacuum pump positioned downstream of the plasma reactor; a wet scrubber positioned downstream of the vacuum pump; a passivation gas transfer device positioned between the plasma reactor and the vacuum pump; and a controller configured to control an operation performed in the processing system, the operation comprising: performing a semiconductor etching process in the processing chamber using processing gases including fluorinated greenhouse gases (F-GHG), HBr, and Cl2, wherein the processing gases are configured to flow from the processing chamber into the plasma reactor; and introducing a reagent vapor from the reagent gas transfer system into the plasma reactor to react with the processing gases. RF power is applied to the plasma reactor, whereby the processed gases are at least partially converted into an HCl byproduct gas and the Cl2 byproduct gas is reacted with the reagent vapor to form HCl; and a passivation gas is introduced between the plasma reactor and a pump configured to pump the gas away from the plasma reactor.

15. The processing system as described in claim 14, wherein the reagent vapor comprises H2O.

16. The processing system as described in claim 14, wherein the reagent vapor comprises hydrogen (H) and oxygen (O) atoms.

17. The processing system as described in claim 14, wherein the F-GHG includes at least one of the following: CF4, SF6, C4F8, or CHF3.

18. The processing system as described in claim 17, wherein the amount of F-GHG is greater than the amount of H and O atoms.

19. The processing system as described in claim 14, wherein the ratio of an H2O flow rate to a Br2 byproduct gas is greater than 15:

1.

20. The processing system as claimed in claim 14, wherein the operation further comprises pumping the gas leaving the plasma reactor and the passivation gas to the wet scrubber.

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