Patent Publication Number: US-2022220613-A1

Title: Substrate processing apparatus having exhaust gas decomposer, and exhaust gas processing method therefor

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a divisional of U.S. patent application Ser. No. 17/024,675, filed on Sep. 17, 2020, which is a divisional of U.S. patent application Ser. No. 15/766,000, filed on 4 Apr. 2018, now U.S. Pat. No. 10,808,315, issued on Oct. 10, 2020, which claims priority under 35 U.S.C. § 371 to International Patent Application No. PCT/KR2016/011045, filed on Oct. 4, 2016, and to 35 U.S.C. § 119 to Korean Patent Application No. 10-2015-0139794, filed on Oct. 5, 2015, in the Korean Intellectual Property Office, the contents of both which are herein incorporated by reference in their entireties. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a substrate processing apparatus having exhaust gas decomposer and an exhaust gas processing method therefor, which decompose a source gas emitted from a process chamber to prevent an exhaust pump from being damaged by an exhaust gas. 
     DESCRIPTION OF THE RELATED ART 
     Semiconductor devices, flat panel display devices, or solar cells are manufactured by a thin film deposition process of depositing a source material on a substrate such as a silicon wafer or glass, a photolithography process of exposing or covering a selected area in thin films which are deposited by using a photosensitive material, and an etching process of removing a thin film in a selected area to perform desired patterning. 
     Examples of the thin film deposition process include a physical vapor deposition (PVD) process, a chemical vapor deposition (CVD) process, and an atomic layer deposition (ALD) process. 
     The thin film deposition process deposits a thin film on a substrate by using various materials. In this case, only the small amount of a source gas which is a precursor flowing into a process chamber including a space for processing a substrate is used in a deposition process, and most of the source gas is emitted to outside the process chamber along with a byproduct which occurs in the deposition process. 
     A source gas and a byproduct of the process chamber which are not used in the deposition process are emitted to outside the process chamber by an exhaust line and an exhaust pump. That is, the source gas and the byproduct of the process chamber which are not used in the deposition process are extracted by the exhaust pump and are emitted to outside the exhaust pump through the exhaust line and the exhaust pump. 
     Moreover, the source gas which is not used in the deposition process is decomposed by reacting with heat occurring in the exhaust pump and a reactant gas emitted from the process chamber, and the decomposed source gas is deposited on an inner surface of the exhaust pump to form a thin film. In this case, clearance between elements configuring the exhaust pump is changed, and for this reason, the exhaust pump is damaged. 
     When a source gas which is for a low temperature and is emitted to outside the process chamber is piled in the exhaust pump, the source gas can be exploded by heat which occurs in the exhaust pump. 
     SUMMARY 
     An aspect of the present invention is directed to provide a substrate processing apparatus having exhaust gas decomposer and an exhaust gas processing method therefor, which solve all of the above-described problems of the related art. 
     Another aspect of the present invention is directed to provide a substrate processing apparatus having exhaust gas decomposer and an exhaust gas processing method therefor, which decompose a source gas which is emitted from a process chamber and is not used in a deposition process, and emit the decomposed source gas through an exhaust pump, thereby preventing the exhaust pump from being damaged by the source gas and perfectly preventing the source gas from being exploded. 
     Technical Solution 
     A substrate processing apparatus including: a process chamber including a space where a substrate is processed; a substrate supporting means installed in the process chamber, the substrate being disposed on the substrate supporting means; a source gas distribution means distributing a source gas to the substrate; a reactant gas distribution means distributing a reactant gas to the substrate; a source gas exhaust line guiding the source gas of the process chamber to be emitted to outside the process chamber; a reactant gas exhaust line guiding the reactant gas of the process chamber to be emitted to outside the process chamber; an exhaust pump communicating with each of the source gas exhaust line and the reactant gas exhaust line to respectively exhaust the source gas and the reactant gas to the source gas exhaust line and the reactant gas exhaust line; and an exhaust gas decomposition module installed in the source gas exhaust line between the process chamber and the exhaust pump to decompose the source gas which flows into the exhaust pump through the source gas exhaust line. 
     In another aspect of the present invention, there is provided an exhaust gas processing method of a substrate processing apparatus, exhausting and processing a source gas and a reactant gas, which are not used in a deposition process, in a source gas and a reactant gas which are distributed to a process chamber where a substrate is processed and deposit a thin film on the substrate, including: respectively exhausting a source gas and a reactant gas to a source gas exhaust line and a reactant gas exhaust line by using an exhaust pump, one side of the source gas exhaust line communicating with the process chamber, the other side of the source gas exhaust line communicating with the exhaust pump, one side of the reactant gas exhaust line communicating with the process chamber, the other side of the reactant gas exhaust line communicating with the exhaust pump; decomposing the source gas flowing into the source gas exhaust line; and emitting a mixed gas, which is generated by mixing the decomposed source gas of the source gas exhaust line with the reactant gas of the reactant gas exhaust line, through the inside of the exhaust pump. 
     Advantageous Effects 
     In the substrate processing apparatus and the method of processing an exhaust gas according to an embodiment of the present invention, the exhaust gas decomposition module may decompose a source gas exhausted from the process chamber to decompose a ligand of the source gas. Also, the ligand and the source gas of which the ligand has been decomposed may be put in a stabilized state by reacting with separately supplied O 2 , N 2 O, or O 3 , and then, may be changed to a mixed gas including a reactant gas mixed therewith. Subsequently, the mixed gas may flow into the exhaust pump and may be emitted. Alternatively, the ligand and the source gas may be mixed with the reactant gas and may be emitted. Therefore, the ligand and the source gas of which the ligand has been decomposed may not react with the reactant gas or heat which occurs in the exhaust pump, and thus, the ligand-decomposed source gas and the ligand flowing into the exhaust pump are not deposited on an inner surface of the exhaust pump. Also, the ligand-decomposed source gas and ligands piled in the exhaust pump are not exploded. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view illustrating a configuration of a substrate processing apparatus according to an embodiment of the present invention. 
         FIG. 2  is a plan cross-sectional view of  FIG. 1 . 
         FIG. 3  is a schematic view illustrating a configuration of a substrate processing apparatus according to another embodiment of the present invention. 
         FIG. 4  is a flowchart illustrating an exhaust gas processing method of a substrate processing apparatus according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
     In the specification, in adding reference numerals for elements in each drawing, it should be noted that like reference numerals already used to denote like elements in other drawings are used for elements wherever possible. 
     The terms described in the specification should be understood as follows. 
     As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “first” and “second” are for differentiating one element from the other element, and these elements should not be limited by these terms. 
     It will be further understood that the terms “comprises”, “comprising,”, “has”, “having”, “includes” and/or “including”, when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     The term “at least one” should be understood as including any and all combinations of one or more of the associated listed items. For example, the meaning of “at least one of a first item, a second item, and a third item” denotes the combination of all items proposed from two or more of the first item, the second item, and the third item as well as the first item, the second item, or the third item. 
     The term “and/or” should be understood as including any and all combinations of one or more of the associated listed items. For example, the meaning of “a first item, a second item, and/or a third item” denotes the combination of all items proposed from two or more of the first item, the second item, and the third item as well as the first item, the second item, or the third item. 
     It will also be understood that when an element is referred to as being ‘on’ another element, it can be directly on the other element, or intervening elements may also be present. Further, it will be understood that when an element is referred to as being ‘under’ another element, it can be directly under, and one or more intervening elements may also be present. In addition, it will also be understood that when an element is referred to as being ‘between’ two elements, it can be the only element between the two elements, or one or more intervening elements may also be present. Other terms for describing a relationship between elements, for example, “between” and “directly between” may be understood likewise. 
     In each of steps, reference numerals (for example, S 100 , S 110 , S 120 , etc.) are used for convenience of description, and do not define the order of the steps. Also, the steps may be performed in order different from a described order unless a specific order is clearly described contextually. That is, the steps may be performed in the described order, may be simultaneously performed, or may be performed in reverse order. 
     Hereinafter, a substrate processing apparatus having exhaust gas decomposer and an exhaust gas processing method therefor according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. 
     First, a substrate processing apparatus according to an embodiment of the present invention will be described. 
       FIG. 1  is a diagram illustrating a schematic configuration of a substrate processing apparatus according to an embodiment of the present invention, and  FIG. 2  is a plan cross-sectional view of  FIG. 1 . 
     As illustrated, the substrate processing apparatus according to an embodiment of the present invention may include a process chamber  110  including a space into which a substrate  50  such as a silicon wafer, glass, or the like is loaded and processed. The process chamber  110  may include a body  111 , which includes an opened top and is disposed on a relatively lower side, and a lid  115  which is coupled to the opened top of the body  111  and is disposed on a relatively upper side. 
     A substrate supporting means  120  on which the substrate  50  is mounted and supported may be installed on an inner lower surface of the process chamber  110 . The substrate supporting means  120  may include a supporter  121 , which is disposed in the process chamber  110  and includes a top on which the substrate  50  is mounted and supported, and a supporting shaft  125  which includes an upper end coupled to a bottom of the supporter  121  and a lower end exposed to the outside of a bottom of the process chamber  110  and connected to a driving part  130 . 
     The substrate  50  may be provided in plurality. The plurality of substrates  50  may be radially mounted and supported on the supporter  121  with respect to a center of the supporter  121 . The driving part  130  may raise, lower, or rotate the substrate supporting means  120 . That is, the driving part  130  may raise, lower, or rotate the supporter  121  by raising, lowering, or rotating the supporting shaft  125 . Therefore, the substrate  50  mounted and supported on the supporter  121  may be raised, lowered, or rotated. 
     A heating unit (not shown) such as a heater or the like for heating the substrate  50  may be installed near the supporter  121  on which the substrate  50  is mounted and supported. 
     In order to deposit a thin film on the substrate  50 , a source gas which is a material deposited on the substrate  50  and a reactant gas which helps the source gas to be easily deposited on the substrate  50  may be supplied to the process chamber  110 . To this end, a source gas distribution means  141  for distributing a source gas to the substrate  50  mounted on the supporter  121  and a reactant gas distribution means  145  for distributing the reactant gas to the substrate  50  may be installed on an inner upper surface of the process chamber  110 . 
     The source gas distribution means  141  and the reactant gas distribution means  145  may each be provided as a shower head and may be mutually divided and installed. Also, the source gas distributed from the source gas distribution means  141  may be distributed to only a source gas area  121   a  opposite to the source gas distribution means  141 , and the reactant gas distributed from the reactant gas distribution means  145  may be distributed to only a reactant gas area  121   b  opposite to the reactant gas distribution means  145 . In this case, the source gas distributed from the source gas distribution means  141  and the reactant gas distributed from the reactant gas distribution means  145  may be distributed without being mixed with each other in the middle of being distributed to the substrate  50 . 
     Therefore, as the substrate supporting means  120  rotates, the plurality of substrates  50  mounted and supported on the substrate supporting means  120  may be sequentially located in the source gas area  121   a  and may be sequentially located in the reactant gas area  121   b . That is, when the substrate  50  which is located in the source gas area  121   a  and is supplied with the source gas is located in the reactant gas area  121   b  and is supplied with the reactant gas according to a rotation of the substrate supporting means  120 , the source gas may be deposited on the substrate  50  by reaction between the source gas and the reactant gas. 
     Only the small amount of each of the source gas and the reactant gas supplied to the process chamber  110  may be used in a deposition process, and most of each of the source gas and the reactant gas may be emitted to outside the process chamber  110  along with a byproduct which occurs in the deposition process 
     A source gas exhaust line  151 , a reactant gas exhaust line  153 , and an exhaust pump  155  may be provided for emitting the source gas and the reactant gas, which are not used in the deposition process, to outside the process chamber  110  along with the byproduct. 
     One end of the source gas exhaust line  151  may communicate with a bottom of the process chamber  110 , and the other end of the source gas exhaust line  151  may communicate with the exhaust pump  155 . One end of the reactant gas exhaust line  153  may communicate with the bottom of the process chamber  110 , and the other end of the reactant gas exhaust line  153  may communicate with the exhaust pump  155 . In this case, the one end of the source gas exhaust line  151  and the one end of the reactant gas exhaust line  153  may each communicate with the bottom of the process chamber  110  disposed just under the source gas area  121   a  and the reactant gas area  121   b.    
     Therefore, when the exhaust pump  155  provided as a vacuum pump or the like is driven, a source gas which is distributed to the source gas area  121   a  but is not used in the deposition process may be extracted and may flow into the source gas exhaust line  151 , and a reactant gas which is distributed to the reactant gas area  121   b  but is not used in the deposition process may be extracted and may flow into the reactant gas exhaust line  153 . Subsequently, the source gas and the reactant gas may be changed to a mixed gas and may flow into the exhaust pump  155 , and the mixed gas may be emitted to outside the exhaust pump  155  through the inside of the exhaust pump  155 . 
     A source gas which is not used in the deposition process and flows into the exhaust pump  155  through the exhaust line  151  may react with heat occurring in the exhaust pump  155  or a reactant gas which flows into the exhaust pump  155  through the reactant gas exhaust line  153 , and may be deposited on an inner surface of the exhaust pump  155 . For this reason, the exhaust pump  155  can be damaged. Particularly, when a source gas is for a low temperature, a source gas piled in the exhaust pump  155  can be exploded by heat which occurs in the exhaust pump  155 . 
     In order to prevent such problems, the substrate processing apparatus according to an embodiment of the present invention may include an exhaust gas decomposition module  160  which decomposes a source gas flowing into the source gas exhaust line  151 . 
     The exhaust gas decomposition module  160  may be installed near the source gas exhaust line  151  between the process chamber  110  and the exhaust pump  155  and may decompose the source gas flowing into the source gas exhaust line  151 . In this case, the exhaust gas decomposition module  160  may decompose a ligand of the source gas, and the ligand-decomposed source gas may be supplied to the exhaust pump  155 . 
     Since the ligand and the ligand-decomposed source gas are in an unstable state, it is required to stabilize the ligand and the ligand-decomposed source gas. To this end, O 2 , N 2 O, or O 3  may be supplied to source gas exhaust line  151  between the exhaust gas decomposition module  160  and the exhaust pump  155 . Therefore, the ligand and the ligand-decomposition module source gas may be put in a stabilized state by reacting with O 2 , N 2 O, or O 3 . 
     Subsequently, the ligand and the ligand-decomposed source gas may be changed to a mixed gas including a reactant gas of the reactant gas exhaust line  153  mixed therewith. Therefore, the ligand and the ligand-decomposed source gas may not react with the reactant gas or heat which occurs in the exhaust pump  155 , and thus, the ligand-decomposed source gas and the ligand flowing into the exhaust pump  155  are not deposited on an inner surface of the exhaust pump  155 . Also, the ligand-decomposed source gas and ligands piled in the exhaust pump  155  are not exploded. 
     In this case, the exhaust gas decomposition module  160  may be provided as a plasma generator, which generates plasma to decompose a source gas, or a heat source which heats and decomposes the source gas. 
       FIG. 3  is a diagram illustrating a schematic configuration of a substrate processing apparatus according to another embodiment of the present invention. Only a difference between  FIG. 3  and  FIG. 1  will be described below. 
     As illustrated, in the substrate processing apparatus according to another embodiment of the present invention, a ligand of a source gas exhaust line  251  decomposed by an exhaust gas decomposition module  260 , a ligand-decomposed source gas, and a reactant gas of a reactant gas exhaust line  252  may flow into an exhaust pump  255 , and then, may be mixed with each other in the exhaust pump  255 . Subsequently, the mixed gas may be emitted to outside the exhaust pump  255 . 
     Hereinafter, an exhaust gas processing method of a substrate processing apparatus according to the present embodiment will be described with reference to  FIGS. 1 to 4 .  FIG. 4  is a flowchart illustrating an exhaust gas processing method of a substrate processing apparatus according to an embodiment of the present invention. 
     As illustrated, a source gas and a reactant gas, which is not used in the deposition process of depositing a thin film on the substrate  50 , in a source gas and a reactant gas distributed to the process chamber  110  may be respectively supplied to the source gas exhaust line  151  and the reactant gas exhaust line  153  and may be emitted to outside the process chamber  110  in step S 110 . 
     As described above, one side of the source gas exhaust line  151  may communicate with the process chamber  110 , and the other side may communicate with the exhaust pump  155 . Also, one side of the reactant gas exhaust line  153  may communicate with the process chamber  110 , and the other side may communicate with the exhaust pump  155 . Therefore, when the exhaust pump  155  is driven, the source gas and the reactant gas of the process chamber  110  may be respectively extracted and exhausted to the source gas exhaust line  151  and the reactant gas exhaust line  153 . 
     Subsequently, in step S 120 , the source gas flowing into the source gas exhaust line  151  may be decomposed by the exhaust gas decomposition module  160 . Also, in step S 130 , the decomposed source gas of the source gas exhaust line  151  and the reactant gas of the reactant gas exhaust line  153  may be changed to a mixed gas through mixing. Subsequently, in step S 140 , the mixed gas may be emitted to the outside through the inside of the exhaust pump  155 . 
     In this case, the exhaust gas decomposition module  160  may be a plasma generator which generates plasma to decompose a source gas, or may be a heat source which heats and decomposes the source gas. Also, a ligand may be separated from the source gas of the source gas exhaust line  151 . 
     As described above, the ligand and the ligand-decomposed source gas may be put in a stabilized state by reacting with separately supplied O 2 , N 2 O, or O 3 , may be mixed with the reactant gas of the exhaust pump  155 , may flow into the exhaust pump  155 , and may be emitted. Alternatively, the ligand and the source gas may be mixed with the reactant gas of the reactant gas exhaust line  153  in the exhaust pump  155  and may be emitted. 
     In the substrate processing apparatus and the method of processing an exhaust gas according to the present embodiment, the exhaust gas decomposition module  160  ( 260 ) may decompose a ligand of a source gas. Subsequently, the ligand, the ligand-decomposed source gas, and a reactant gas of the reactant gas exhaust line  153  ( 253 ) which have been stabilized may be changed to a mixed gas. The mixed gas may flow into the exhaust pump  155  ( 255 ) and may be emitted, or the ligand and the ligand-decomposed source gas may be mixed with the reactant gas in the exhaust pump  155  ( 255 ) and may be emitted. Therefore, the ligand and the ligand-decomposed source gas may not react with the reactant gas or heat which occurs in the exhaust pump  155  ( 255 ), and thus, the ligand-decomposed source gas and the ligand flowing into the exhaust pump  155  ( 255 ) are not deposited on an inner surface of the exhaust pump  155  ( 255 ). Also, the ligand-decomposed source gas and ligands piled in the exhaust pump  155  ( 255 ) are not exploded. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.