Patent Publication Number: US-2020276622-A1

Title: Powder removing apparatus and powder removing system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2019-037643, filed on Mar. 1, 2019; the entire contents of which are incorporated herein by reference. 
     FIELD 
     Embodiments described herein relate generally to a powder removing apparatus and a powder removing system. 
     BACKGROUND 
     Deposition apparatuses may use gas containing a poisonous component in a deposition process on substrates. In such a case, an exhaust gas from the deposition apparatus is decomposed (and removed) by a abatement system. 
     Such a abatement system produces, for example, silicon dioxide powder through decomposition of a gas. The powder may deposit in a duct, located subsequent to the abatement system, through which a decomposed gas is exhausted to outside. Hence, the abatement system includes a scrubber that captures the powder with water, for example, and prevents the powder from depositing in the duct. 
     However, the abatement system may produce a large amount of powder, and the scrubber may not be able to capture all of the powder. The powder may then flow into the duct and deposit therein, causing blockage of the duct. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram schematically illustrating an example of a configuration of a system including a powder removing system and a powder removing apparatus according to an embodiment; 
         FIG. 2  is a schematic diagram illustrating an example of a abatement system according to the embodiment; 
         FIG. 3  is a schematic diagram illustrating another example of the abatement system according to the embodiment; 
         FIG. 4  is a diagram schematically illustrating a modification of the system illustrated in  FIG. 1 ; and 
         FIG. 5  is a diagram schematically illustrating a modification of the system illustrated in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     According to an embodiment, in general, a powder removing apparatus includes a first tank in which a powder produced by burning a process gas is collected; a duct with a hollow to which the powder is carried and to which a flow of a liquid is supplied, the duct being connected to the first tank and allowing the powder to flow from the hollow into the first tank by the flow of the liquid; and a pump that supplies the liquid to the hollow. 
     Hereinafter, a powder removing apparatus and a powder removing system according to the embodiment will be described in detail with reference to the accompanying drawings. In the embodiment, the powder removing apparatus includes a duct  4 , a tank  5 , and a pump  7  as illustrated in  FIG. 1 , and a powder removing system includes a abatement system  3  in addition to the powder removing apparatus, by way of example. The embodiment is merely exemplary and not intended to limit the scope of the present invention. 
       FIG. 1  is a diagram schematically illustrating an example of a configuration of a system including the powder removing system and the powder removing apparatus according to the present embodiment. As illustrated in  FIG. 1 , the system includes a deposition apparatus  1 , a vacuum pump  2  (pump), a abatement system  3  (unit), the duct  4 , and the tank  5  (first tank). 
     The deposition apparatus  1  forms a thin film on a substrate. In the deposition apparatus  1 , the chamber is placed in a certain vacuum state to allow a gas to flow in the chamber for a deposition process. A gas (process gas) used in a deposition process contains one or more poisonous components such as monosilane (SiH 4 ), titanium chloride (TiCl 4 ), and tungsten fluoride (WF 6 ). Different kinds of gas are used depending on thin films to form. In the embodiment, as one example, the deposition apparatus includes three deposition apparatuses  1   a ,  1   b , and  1   c . The deposition apparatus  1   a  employs monosilane as a deposition gas. The deposition apparatus  1   b  employs titanium chloride as a deposition gas. The deposition apparatus  1   c  employs tungsten fluoride as a deposition gas. Hereinafter, the deposition apparatus  1   a , the deposition apparatus  1   b , and the deposition apparatus  1   c  will be generically referred to as the deposition apparatus  1 . 
     The vacuum pump  2  is located subsequent to the deposition apparatus  1 . The vacuum pump  2  is connected to the deposition apparatus  1  via a pipe  12 . The vacuum pump  2  applies a negative pressure to the chamber of the deposition apparatus  1  to exhaust a gas from the chamber. In the embodiment, as one example, the vacuum pump  2  includes a vacuum pump  2   a , a vacuum pump  2   b , and a vacuum pump  2   c . The vacuum pump  2   a  is connected to the deposition apparatus  1   a . The vacuum pump  2   b  is connected to the deposition apparatus  1   b . The vacuum pump  2   c  is connected to the deposition apparatus  1   c . The vacuum pump  2   a , the vacuum pump  2   b , and the vacuum pump  2   c  will hereinafter be generically referred to as the vacuum pump  2 . 
     The abatement system  3  is located subsequent to the vacuum pump  2 . The abatement system  3  is connected to the vacuum pump  2  via a pipe  23 . The abatement system  3  decomposes the gas used in forming a thin film on the substrate by the deposition apparatus  1 . The abatement system  3  decomposes an exhaust gas from the deposition apparatus  1  through the vacuum pump  2 . The abatement system  3  decomposes the exhaust gas from the deposition apparatus  1   a  by, for example, burning. 
     The abatement system  3  produces a product from burning a gas. For example, silicon dioxide (SiO 2 ) is produced from burning monosilane. Titanium oxide (TiO 2 ) is produced from burning titanium chloride. Tungsten oxide (WO 3 ) is produced from burning tungsten fluoride. Such products in the embodiment are in the form of powder T. Hereinafter, exemplary products produced by the abatement system  3  as silicon dioxide, titanium oxide, and tungsten oxide will be generically referred to as powder T. 
     In the embodiment, as one example, the abatement system  3  includes three abatement systems  3   a ,  3   b , and  3   c . The abatement systems  3   a  is connected to the vacuum pump  2   a . That is, the abatement systems  3   a  is connected to the deposition apparatus  1   a  via the vacuum pump  2   a . The abatement system  3   b  is connected to the vacuum pump  2   b . That is, the abatement system  3   b  is connected to the deposition apparatus  1   b  via the vacuum pump  2   b . The abatement system  3   c  is connected to the vacuum pump  2   c . That is, the abatement system  3   c  is connected to the deposition apparatus  1   c  via the vacuum pump  2   c . Additionally, in a modification as will be later described with reference to  FIG. 3 , a abatement system  3   d  is used in place of the abatement system  3   a , a abatement system  3   e  is used in place of the abatement system  3   b , and a abatement system  3   f  is used in place of the abatement system  3   c.    
     The abatement system  3   a  decomposes monosilane used in the deposition apparatus  1   a  by burning. The abatement system  3   a  produces silicon dioxide from burning monosilane. The abatement system  3   b  decomposes titanium chloride used in the deposition apparatus  1   b  by burning. The abatement system  3   b  produces titanium oxide from burning titanium chloride. The abatement system  3   c  decomposes tungsten fluoride used in the deposition apparatus  1   c  by burning. The abatement system  3   c  produces tungsten oxide from burning tungsten fluoride. The abatement system  3   a , the abatement system  3   b , and the abatement system  3   c  (the abatement system  3   d , the abatement system  3   e , and the abatement system  3   f ) may hereinafter be generically referred to as the abatement system  3 . 
     The duct  4  is connected to the tank  5  and includes a hollow  41 . The powder T is carried to the hollow  41  into which flows of water are supplied. The duct  4  works to allow the powder T to flow into the tank  5  by a water flow. More specifically, the duct  4  is a tube with the hollow  41  being a space penetrating inside the duct  4 . The duct  4  and the hollow  41  have a rectangular prism shape, for example. The hollow  41  has a rectangular cross section. The duct  4  is located subsequent to the abatement system  3 . The duct  4  includes a connection P 1 , a connection P 2 , and a connection P 3 . At the connection P 1 , the duct  4  is connected to the abatement system  3   a  via a pipe  34 . At the connection P 2 , the duct  4  is connected to the abatement system  3   b  via the pipe  34 . At the connection P 3 , the duct  4  is connected to the abatement system  3   c  via the pipe  34 . The duct  4  includes a first end P 4  and a second end P 5 . 
     In the tank  5  (first tank), the powder T, produced by burning the gas used in a deposition on the substrate, is collected. More specifically, the tank  5  has a rectangular parallelepiped shape with a cavity, for example. The tank  5  stores water as an exemplary liquid. The tank  5  accommodates and collects the deposited powder T inside. 
     A bottom part of the tank  5  is connected to the first end P 4  of the duct. The top part of the tank  5  is connected to the second end P 5  of the duct. Water stored in the tank  5  is supplied from the first end P 4  to the duct  4 , flows in the hollow  41  of the duct  4 , and is drained or discharged to the tank  5  from the second end P 5 . The tank  5  is provided with a fan  8  at the top part. The fan  8  emits the decomposed gas, exhausted to the tank  5  from the duct  4 , to the outside. 
     The powder removing apparatus includes a filter  6  that removes the floating powder T from the water, near the first end P 4  of the duct  4 . The powder removing apparatus also includes a pump  7  near the first end P 4  of the duct  4  and subsequent to the filter  6 . The pump  7  serves to supply the water to the hollow  41 . More specifically, the pump  7  supplies water from the tank  5  to the hollow  41  of the duct  4  through the first end P 4 , and the filter  6  removes the floating powder T from the water at the same time. That is, the water is supplied from the first end P 4  of the tank  5 , circulates through the duct  4  in a direction indicated by an arrow Y, is drained from the second end P 5 , and returns to the tank  5 . An amount of water to flow in the hollow  41  of the duct  4  is equal to an amount occupying a lower half of the hollow  41 , for example. 
     The powder T produced by the abatement system  3  is carried through the pipe  34  to the hollow  41  of the duct  4  from the connection P 1 , the connection P 2 , or the connection P 3 . The powder T is then carried toward the tank  5  by the flow of water in the hollow  41 . Then, along with the water drainage to the tank  5  through the second end P 5 , the carried powder T flows into the tank  5 . That is, the duct  4  allows the powder T to flow into the tank  5 . The powder T then settles and is collected in the water at the bottom of the tank  5 . 
     Also, the gas decomposed by the abatement system  3  flows into the duct  4  from the connection P 1 , the connection P 2 , or the connection P 3 . The decomposed gas is exhausted to the tank  5  through the hollow  41 . The exhaust gas is emitted to the outside by the fan  8 . 
     Silicon dioxide, as the powder T produced by the abatement system  3   a , is carried to the hollow  41  of the duct  4  via the pipe  34  at the connection P 1 , is carried by water flowing through the hollow  41  into the tank  5 . The Silicon dioxide then settles and is collected at the bottom of the tank  5 . Titanium oxide, as the powder T produced by the abatement system  3   b , is carried to the hollow  41  of the duct  4  via the pipe  34  at the connection P 2 , and is carried by water flowing through the hollow  41  into the tank  5 . The Titanium oxide then settles and is collected at the bottom of the tank  5 . Tungsten oxide, as the powder T produced by the abatement system  3   c , is carried to the hollow  41  of the duct  4  via the pipe  34  at the connection P 3 , and is carried by water flowing through the hollow  41  into the tank  5 . The tungsten oxide then settles and is collected at the bottom of the tank  5 . 
     As described above, the powder T is removed from the hollow  41  of the duct  4  by the flow of water, so that the duct  4  is prevented from being blocked by the powder T. To prevent the blockage of the hollow  41 , it is possible to dry the powder T carried to the hollow  41  by heating and blow the dried powder T toward the tank  5 , for example. However, the powder T carried to the hollow  41  may be sprayed with misty water droplets by a later-described water scrubber  35  and contain a large amount of water. Drying such powder T requires great energy. In contrast, according to the embodiment, the flow of water sweeps away and removes the powder T from the duct  4  into the tank  5 , so that the duct  4  can be prevented from being blocked at a lower amount of energy than drying the powder T. 
     In the meantime, the collected powder T is to be removed from the tank  5  regularly, for example, once a month. In addition, the tank  5  is cleaned up regularly. Hence, the powder removing apparatus preferably includes a plurality of tanks  5 . 
     In the embodiment, the powder removing apparatus includes two tanks  5 , i.e., a tank  5   a  and a tank  5   b . The tank  5   a  and the tank  5   b  have the same structure. The duct  4  includes a switch  9  in the middle. The switch  9  switches passages of the water containing the powder T in the duct  4  in order to allow the powder T carried to the duct  4  to flow into any of the tanks  5 . By switching with the switch  9 , the duct  4  is connected to the tank  5   a  and the tank  5   b  alternately. Each of the tank  5   a  and the tank  5   b  includes the filter  6  and the pump  7 . 
     While the switch  9  switches the passage of the hollow  41  to a passage K 1  in the duct  4  to connect the duct  4  to the tank  5   a , the pump  7  supplies water from the tank  5   a  into the duct  4 . The duct  4  drains the water from the hollow  41  to the tank  5   a , to sweep away the powder T into the tank  5   a.    
     Also, while the switch  9  switches a passage of the hollow  41  to a passage K 2  in the duct  4  to connect the duct  4  to the tank  5   b , the pump  7  supplies water from the tank  5   b  to the duct  4 . The duct  4  drains the water from the hollow  41  to the tank  5   b , to sweep away the powder T into the tank  5   b.    
     According to the embodiment, while the duct  4  is connected to the tank  5   a  to sweep away and collect the powder T from the duct  4  into the tank  5   a , for example, the tank  5   b  can be cleaned. While the duct  4  is connected to the tank  5   b  to sweep away and collect the powder T from the duct  4  into the tank  5   b , the tank  5   a  can be cleaned. 
     In the following, an exemplary configuration of the abatement system  3  will be described. Herein, the abatement system  3   a  is described as a representative example. The abatement system  3   b  and the abatement system  3   c  have the same structure as the abatement system  3   a .  FIG. 2  is a schematic diagram illustrating an example of the abatement system  3   a  according to the embodiment. As illustrated in  FIG. 2 , the abatement system  3   a  includes a burner  31 , a pipe  32 , a tank  33  (a second tank), and the water scrubber  35 . The burner  31  works for decomposing monosilane, used by the deposition apparatus  1   a  and exhausted from the vacuum pump  2 , by burning. In the pipe  32 , powdery silicon dioxide, produced by the burner  31 , floats. The tank  33  serves to capture the silicon dioxide. 
     The water scrubber  35  sprays water droplets in the form of a shower into the pipe  32 . The pipe  32  is provided with a plurality of water scrubbers  35 . The water scrubbers  35  each spray misty water droplets in a direction opposite to a flowing direction of floating silicon dioxide, that is, toward an upstream side of the flowing direction in the pipe  32 , and captures the floating silicon dioxide in the pipe  32  into the tank  33 . In addition, the water scrubbers  35  work to lower the temperature of water vapor or silicon dioxide carried through the pipe  32  by spraying water droplets. The pipe  32  is connected to the pipe  34 . 
     In the example of  FIG. 2 , the monosilane, used by the deposition apparatus  1   a , is exhausted to the abatement system  3   a  by the vacuum pump  2   a . The burner  31  of the abatement system  3   a  burns the exhausted monosilane. The burner  31  burns the monosilane and produces silicon dioxide. The produced silicon dioxide floats as powder T in the gas. The water droplets sprayed by the water scrubbers  35  capture the floating silicon dioxide in the tank  33  while absorbing moisture. However, part of the silicon dioxide is not captured in the tank  33  but carried to the duct  4  through the pipe  32  and the pipe  34 . The silicon dioxide is then carried and swept away from the duct  4  into the tank  5  along with the flow of water in the hollow  41 . 
     In the example in  FIG. 2 , in order to reduce influences on the surroundings from leakage of the water from the duct  4  to the outside, it is preferable to place the duct  4  in a lower position than the pipe  32 , for example, to bury the duct  4  under the floor level. People are likely to stumble upon the duct  4  installed under the floor level. 
     Next, a modification of the abatement system  3  will be described.  FIG. 3  is a schematic diagram illustrating the modification of the abatement system  3  according to the embodiment. The modification in  FIG. 3  includes the abatement system  3   d  in place of the abatement system  3   a . As illustrated in  FIG. 1 , the modification includes the abatement system  3   e  in place of the abatement system  3   b , and the abatement system  3   f  in place of the abatement system  3   c . Herein, the abatement system  3   d  is described as a representative example. As illustrated in  FIG. 3 , the abatement system  3   d  includes the burner  31  and the pipe  32 , excluding the tank  33  and the water scrubber  35  of the abatement system  3   a . The burner  31  serves to supply oxygen to decompos monosilane by burning. The pipe  32  is connected to the pipe  34 . Silicon dioxide, produced by the burner  31 , is carried to the duct  4  through the pipe  32  and the pipe  34 . 
     Although not illustrated in  FIG. 3 , the abatement system  3   e  does not include the tank  33  and the water scrubber  35  which are included in the abatement system  3   b . The abatement system  3   f  does not include the tank  33  and the water scrubber  35  which are included in the abatement system  3   c . The abatement system  3  illustrated in  FIG. 3  carries all of the silicon dioxide produced by the burner  31  to the hollow  41  of the duct  4  through the pipe  34 . 
     Such a abatement system  3  illustrated in  FIG. 3  is simpler in structure than the abatement system  3  illustrated in  FIG. 2 , and can be manufactured at a lower cost. 
     In the example in  FIG. 3 , the monosilane used by the deposition apparatus  1   a  is exhausted to the abatement system  3   d  by the vacuum pump  2   a . The burner  31  of the abatement system  3   d  burns the exhausted monosilane. The burner  31  produces silicon dioxide while burning. The produced silicon dioxide is carried to the duct  4  through the pipe  34 . The silicon dioxide is then carried and swept away from the duct  4  into the tank  5  by the water flowing in the hollow  41 . 
     The powder removing apparatuses of the embodiment and the modification includes the tank  5  in which the powder T, produced by burning a gas used in the deposition on a substrate, is collected; the duct  4  that is provided with the hollow  41 , is connected to the tank  5 , and allows the powder T carried to the hollow  41  to flow into the tank  5  by flows of water supplied to the hollow  41 ; and the pump  7  that supplies the water to the hollow  41 . Hence, the duct  4  is prevented from being blocked by the powder T. 
     The powder removing systems of the embodiment and the modification include the abatement system  3  that decomposes a gas used in the deposition on a substrate by burning, and produces the powder T along with burning the gas; the tank  5  in which the powder T is collected; the duct  4  that is provided with the hollow  41 , is connected to the tank  5 , and allows the powder T carried to the hollow  41  to flow into the tank  5  by flows of water supplied to the hollow  41 ; and the pump  7  that supplies the water to the hollow  41 . Thus, the duct  4  is prevented from being blocked by the powder T. 
     The above embodiment has described the example of using water as a liquid. However, the liquid is not limited to water, and any liquid may be used in addition to water as long as it has a relatively high specific gravity sufficient to sweep away the powder T into the tank  5 . 
     The above embodiment has described the example of using two tanks  5 . However, the number of the tanks is not limited thereto. One tank  5  or three or more tanks  5  may be applied. 
     Further, the above embodiment has described the example of the duct  4  and the hollow  41  both having a rectangular prism shape. However, the shape thereof is not limited to such an example. The duct  4  and the hollow  41  may have a columnar, polygonal prism, or an elliptic columnar shape, for example. 
     The above embodiment has described the exemplary system including the plurality of deposition apparatuses  1  and the vacuum pump  2  and the abatement system  3  for each of the deposition apparatuses  1 . However, the system is not limited to such an example. One vacuum pump  2  and one abatement system  3  may be provided for the deposition apparatuses  1 , for example. Alternatively, one abatement system  3  may be provided for the deposition apparatuses  1  and a plurality of vacuum pumps  2 . Whether one vacuum pump  2  is provided for each of the deposition apparatuses  1  or for all the deposition apparatuses  1 , and whether two or more abatement systems  3  are provided for the deposition apparatuses  1  and two or more vacuum pumps  2  or one abatement system  3  is shared thereby, depend on the amount of a gas used by the deposition apparatus  1 , for example. 
       FIGS. 4 and 5  schematically illustrate modifications of the system illustrated in  FIG. 1 . For example, as illustrated in  FIG. 4 , the deposition apparatus  1   a , the deposition apparatus  1   b , and the deposition apparatus  1   c  are connected to one vacuum pump  2  and one abatement system  3  via the pipe  12 . As illustrated in  FIG. 5 , the deposition apparatus  1   a , the deposition apparatus  1   b , and the deposition apparatus  1   c  may be connected to the vacuum pump  2   a , the vacuum pump  2   b , and the vacuum pump  2   c  via the pipes  12   a ,  12   b ,  12   c , respectively. The vacuum pump  2   a , the vacuum pump  2   b , and the vacuum pump  2   c  may be connected to one abatement system  3  via the pipe  23 . In each of the systems illustrated in  FIGS. 4 and 5 , the abatement system  3  is connected to the duct  4  via the pipe  34  at a connection P. The abatement system  3  decomposes monosilane used by the deposition apparatus  1   a  and produces powder, e.g., silicon dioxide. In addition, the abatement system  3  decomposes titanium chloride used by the deposition apparatus  1   b  and produces powder, e.g., titanium oxide. The abatement system  3  decomposes tungsten fluoride used by the deposition apparatus  1   c  and produces powder, i.e., tungsten oxide. 
     The above embodiment has described the powder T as an exemplary product. However, a product is not limited thereto. Any material can be applied as a product in addition to powder as long as it can flow into the tank  5  by a liquid. Examples of the product may include a sand-like substance, such as the one containing particles greater in size than the powder T. 
     The above embodiment has described the pump  7  configured to supply water from the tank  5  to the duct  4  and circulate the water by way of example. However, the pump  7  is not limited thereto. The pump  7  may be configured to supply the water to the duct  4  from a location other than the tank  5  and drain the water to the tank  5 . In other words, the circulation of water described in the embodiment is not essential. 
     The above embodiment has described the gas used in the deposition process of the system including the deposition apparatus  1  as an exemplary process gas. However, a process gas is not limited thereto. As long as a process gas, which produces the powder T when decomposed by a subsequent abatement system, is supplied, the powder removing apparatus according to the embodiment may be applied to a system including a semiconductor manufacturing apparatus other than a deposition apparatus. 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.