Patent Publication Number: US-2019198296-A1

Title: Plasma Processing Apparatus and Method of Manufacturing Semiconductor Device Using the Same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This U.S. non-provisional application claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2017-0181247 filed on Dec. 27, 2017, in the Korean Intellectual Property Office, the entire contents of which are hereby incorporated by reference. 
     BACKGROUND 
     Inventive concepts relate to apparatus and method of manufacturing a semiconductor device, and more particularly, to a plasma processing apparatus and a method of manufacturing a semiconductor device using the same. 
     In general, a plurality of unit processes may be performed to manufacture a semiconductor device. The unit processes may include a deposition process, a diffusion process, a thermal process, a photolithography process, a polishing process, an etching process, an ion implantation process, a cleaning process, and the like. The etching process may include a dry etching process and a wet etching process. A plasma reaction may be used to perform the deposition process and the dry etching process. 
     SUMMARY 
     Some embodiments of inventive concepts provide a plasma processing apparatus capable of minimizing window deformation. 
     Some embodiments of inventive concepts provide a plasma processing apparatus capable of minimizing power delivery loss. 
     According to exemplary embodiments of inventive concepts, a plasma processing apparatus may include: a chamber including a lower housing and an upper housing on the lower housing; a window in the upper housing; an antenna for generating a plasma of a first gas, wherein the antenna is disposed on the window and in the upper housing; a first pump for exhausting the first gas between the window and the lower housing, wherein the first pump is associated with the lower housing; a power supply for providing a power output, wherein the power supply is connected with the antenna through a first cavity of the upper housing; and a second pump for pumping a second gas between the window and the upper housing so as to hold the antenna and the window onto an inside wall of the upper housing, wherein the second pump is associated with a second cavity of the upper housing, wherein the second cavity is different from the first cavity, and wherein second pump is associated independently of the power supply. 
     According to exemplary embodiments of inventive concepts, a plasma processing apparatus may include: a chamber; a window in the chamber; an antenna for generating plasma, wherein the antenna is disposed on the window and in the chamber; and a power supply for delivering power to the antenna, wherein the power supply includes a power feed, wherein the power feed passes through the antenna and extends to the window and wherein the window may have a central groove receiving an end of the power feed. 
     According to exemplary embodiments of inventive concepts, a method of manufacturing a semiconductor device may include: providing a substrate into a lower housing of a chamber; and processing the substrate using microwave power output provided through an antenna and a window that are in an upper housing on the lower housing. The step of processing the substrate may include: pumping a first gas between the lower housing and the window; pumping a second gas on the window and in the upper housing; and generating plasma of the first gas by providing the antenna with the microwave from a power supply. The step of pumping the second gas may include exhausting the second gas independently of the power supply. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a schematic diagram showing a plasma processing apparatus according to exemplary embodiments of inventive concepts. 
         FIG. 2  illustrates a cross-sectional view showing an example of a power feed and a connection part in section A of  FIG. 1 . 
         FIG. 3  illustrates a perspective view showing an example of a lower connection part of  FIG. 2 . 
         FIG. 4  illustrates a flow chart showing a method of manufacturing a semiconductor device, according to exemplary embodiments of inventive concepts. 
         FIG. 5  illustrates a flow chart showing an example of a substrate processing step of  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       FIG. 1  shows a plasma processing apparatus  100  according to exemplary embodiments of the inventive concepts. 
     Referring to  FIG. 1 , the plasma processing apparatus  100  of the inventive concepts may be a substrate etching apparatus or a thin-layer deposition apparatus. Alternatively, the plasma processing apparatus  100  may be an ion implantation apparatus. In an embodiment, the plasma processing apparatus  100  may include a chamber  10 , a chuck  20 , a dielectric window  30 , an antenna  40 , a dielectric plate  50 , a first pump  60 , a power supply  70 ; a connection part  80 , and a second pump  90 . 
     The chamber  10  may provide a substrate W in a space hermetically sealed from the outside. In an embodiment, the chamber  10  may include a lower housing  12  and an upper housing  14 . The lower housing  12  may accommodate the chuck  20 . For example, the lower housing  12  may include an aluminum alloy. The upper housing  14  may be disposed on the lower housing  12 . When the lower housing  12  is separated from the upper housing  14 , the substrate W may be loaded into the chamber  10 . The substrate W may also be unloaded from the chamber  10 . When the lower housing  12  and the upper housing  14  are combined with each other, the substrate W may be processed with a plasma  24 . For example, the substrate W may be etched or a thin layer deposited thereon. 
     The chuck  20  may be installed in the lower housing  12 . The substrate W may be held on the chuck  20 . The chuck  20  may fix and/or heat up the substrate W. For example, the chuck  20  may include an electrostatic chuck, a heater, or a susceptor. 
     The dielectric window  30  may be disposed in the upper housing  14 . The dielectric window  30  may separate and/or insulate the antenna  40  from the plasma  24  generated on the substrate W. For example, the dielectric window  30  may include a disc of quartz (e.g., SiO 2 ). 
     The antenna  40  may be disposed on the dielectric window  30 . The antenna  40  may be installed in the upper housing  14 . The antenna  40  may have a sidewall spaced apart from an inner wall of the upper housing  14 . A first gas  22  may be converted into the plasma  24  beneath the dielectric window  30  when the antenna  40  is provided with a microwave power output  72 . The antenna  40  may include a metal plate (e.g., Cu, Ni, or Au). In an embodiment, the antenna  40  may include a plurality of slots  42 . The microwave power output  72  may be irradiated through the slots  42  onto the dielectric window  30 . The microwave power output  72  may induce formation of the plasma  24  of the first gas  22  between the dielectric window  30  and the lower housing  12 . 
     The dielectric plate  50  may be disposed on the antenna  40 . The dielectric plate  50  may insulate the antenna  40  from the upper housing  14 . The dielectric plate  50  may include a disc of quartz (e.g., SiO 2 ). In an embodiment, the dielectric plate  50  may have the same diameter as that of the antenna  40 . The diameter of the dielectric plate  50  may be smaller than that of the dielectric window  30 . The dielectric plate  50  and the antenna  40  may each have a sidewall spaced apart from an inside wall of the upper housing  14 . For example, the sidewalls of the antenna  40  and the dielectric plate  50  may be spaced apart at a predetermined gap  28  from the inside wall of the upper housing  14 . 
     The first pump  60  may be associated with the lower housing  12 . When the lower housing  12  and the upper housing  14  are combined with each other, the first pump  60  may exhaust the first gas  22  through a lower cavity  13  of the lower housing  12 . The first gas  22  may include an etching gas or a deposition gas. When the first pump  60  pumps the first gas  22 , the first gas  22  may have a pressure ranging from about 1 mTorr to about 1 Torr in the chamber  10 . For example, the first pump  60  may include a dry pump (e.g., rotary pump, screw pump, or turbo pump). 
     The power supply  70  may supply the antenna  40  with the microwave power output  72 . When the first gas  22  is exhausted and/or pumped, the antenna  40  may be provided with the microwave power output  72 . In an embodiment, the power supply  70  may include a power source  74 , a waveguide  76 , and a power feed  78 . 
     The power source  74  may use electrical power to produce the microwave power output  72 . For example, the power source  74  may produce the microwave power output  72  ranging from about 100 W to about 1 MW. The microwave power output  72  may generate the plasma  24  at frequency less than that of a radio frequency power output. A damage rate of the substrate W may be proportional to frequency and/or magnitude of power. In an etching process, the substrate W may be less damaged from the microwave power output  72  than that of a radio frequency power output. 
     The waveguide  76  may couple the power source  74  to the upper housing  14 . The microwave power output  72  may be provided along the waveguide  76  into the upper housing  14 . In an embodiment, the waveguide  76  may include an outer waveguide  73  and an inner waveguide  75 . The outer waveguide  73  may couple the power source  74  onto a center of the upper housing  14 . For example, the outer waveguide  73  may include a metal tube. The microwave power output  72  may be provided into the inner waveguide  75  along air (e.g., N 2 ) in the outer waveguide  73  and along an inner wall of the outer waveguide  73 . The inner waveguide  75  may be installed within the outer waveguide  73  on a center of the dielectric plate  50 . The inner waveguide  75  may be inserted into a first upper cavity  16  of the upper housing  14 . For example, the inner waveguide  75  may have a screw shape. The inner waveguide  75  may include metal (e.g., Cu, Ni, or Au). In an embodiment, the inner waveguide  75  may receive the microwave power output  72  in the outer waveguide  73 , and provide the power feed  78  with the received microwave power output  72 . 
       FIG. 2  shows an example of the power feed  78  and the connection part  80  in section A of  FIG. 1 . 
     Referring to  FIG. 2 , the power feed  78  may be provided within the inner waveguide  75  inserted into the first upper cavity  16 . The power feed  78  may extend from the inner waveguide  75  via the dielectric plate  50  and the antenna  40  to a central groove  32  of the dielectric window  30 . For example, the power feed  78  may include metal (e.g., Cu, Ni, or Au). The power feed  78  may have a screw shape. In an embodiment, the power feed  78  may include a screw rod  77  and a screw head  79 . The screw rod  77  may couple the inner waveguide  75  to the screw head  79 . The screw rod  77  may pass through a center of each of the dielectric plate  50  and the antenna  40 . The screw head  79  may be disposed in the central groove  32  of the dielectric window  30 . The screw head  79  may be connected to a lower portion of the screw rod  77 . 
     The connection part  80  may be disposed around the screw rod  77  between the inner waveguide  75  and the screw head  79 . The connection part  80  may couple the screw head  79  to the antenna  40 . The connection part  80  may provide the antenna  40  with the microwave power output  72  of the power feed  78 . The connection part  80  may seal between the upper housing  14  and the inner waveguide  75 . In such a configuration, the connection part  80  may prevent and/or minimize gas inflow and/or air inflow from outside the upper housing  14 . In an embodiment, the connection part  80  may include a lower connection part  82  and an upper connection part  84 . The lower connection part  82  may be disposed between the antenna  40  and the screw head  79  around the screw rod  77 . The lower connection part  82  may electrically connect the screw head  79  with the antenna  40 . 
     When the microwave power output  72  is provided through the screw rod  77  to the antenna  40 , the microwave power output  72  may heat up the screw rod  77 . When the screw rod  77  is heated up, the screw rod  77  may increase in length. For example, the screw rod  77  may expand and/or contract in a longitudinal direction. The screw head  79  and the antenna  40  may have a variable distance therebetween. The central groove  32  of the dielectric window  30  may have a floor depth D equal to or greater than a sum of a thickness T of the screw head  79  and a maximum length L between the screw head  79  and the antenna  40 . The central groove  32  may prevent the dielectric window  30  from being deformed due to the expansion of the screw rod  77  in the longitudinal direction. 
       FIG. 3  shows an example of the lower connection part  82  of  FIG. 2 . 
     Referring to  FIGS. 2 and 3 , the lower connection part  82  may include a cup spring washer  81 . The cup spring washer  81  may turn at least once. The cup spring washer  81  may stretch in the longitudinal direction of the screw rod  77 . The cup spring washer  81  may accordingly couple the screw head  79  to the antenna  40 , regardless of the expansion and/or contraction of the screw rod  77  in the longitudinal direction. 
     Referring back to  FIG. 2 , the upper connection part  84  may be disposed around the screw rod  77  between the inner waveguide  75  and the antenna  40 . The upper connection part  84  may include a gasket. The upper connection part  84  may seal between the inner waveguide  75  and an inner wall of the upper housing  14  in the first upper cavity  16 . The upper connection part  84  may also seal between a bottom surface of the inner waveguide  75  and a top surface of the dielectric plate  50 . The upper connection part  84  may further seal between a bottom surface of the dielectric plate  50  and a top surface of the antenna  40 . In an embodiment, the upper connection part  84  may include a first sealing member  86 , a second sealing member  88 , and a third sealing member  89 . 
     The first sealing member  86  may be disposed between the antenna  40  and the dielectric plate  50 . The first sealing member  86  may provide a seal between the bottom surface of the dielectric plate  50  and the top surface of the antenna  40  around the screw rod  77 . 
     The second sealing member  88  may be disposed within the first upper cavity  16  on the first sealing member  86 . The second sealing member  88  may be disposed between the dielectric plate  50  and the inner waveguide  75 . The second sealing member  88  may provide a seal between the bottom surface of the inner waveguide  75  and the top surface of the dielectric plate  50  around the screw rod  77 . 
     The third sealing member  89  may surround the second sealing member  88  and the inner waveguide  75  within the first upper cavity  16 . The third sealing member  8 - 9  may provide a seal between an outer wall of the inner waveguide  75  and the inner wall of the upper housing  14  in the first upper cavity  16 . The second sealing member  88  and third sealing member  89  may suppress air inflow into the upper housing  14  from the outer waveguide  73 . For example, the second sealing member  88  and third sealing member  89  may prevent inflow of a second gas (see  26  of  FIG. 1 ) from outside the upper housing  14 . 
     Referring back to  FIG. 1 , independently of the power supply  70 , the second pump  90  may be associated with the upper housing  14 . For example, the second pump  90  may be connected with a second upper cavity  18  of the upper housing  14 . The second upper cavity  18  may partially expose the dielectric plate  50 . The second pump  90  may pump a second gas  26  on or over the dielectric window  30 . The second pump  90  may pump and/or exhaust the second gas  26  through the second upper cavity  18  and the gap  28 . Since the upper housing  14  is hermetically sealed with the upper connection part  84 , the pumping of the second pump  90  may rigidly hold or adsorb the dielectric window  30 , the antenna  40 , and the dielectric plate  50  onto the inside wall of the upper housing  14 . The dielectric window  30 , the antenna  40 , and the dielectric plate  50  may be cooled down with coolant (not shown) flowing through a coolant hole  17  of the upper housing  14 . When the second pump  90  does not pump the second gas  26 , the dielectric window  30  may deform convexly toward the lower housing  12 . In some embodiments, since the second pump  90  pumps the second gas  26 , the dielectric window  30  may be rigidly held or adsorbed onto the inside wall of the upper housing  14 , with the result that the dielectric window  30  may be prevented from being deformed. 
     The second pump  90  has a pumping pressure lower than the atmosphere pressure. When the second pump  90  pumps the second gas  26 , the second gas  26  may have a pressure ranging from about 100 Torr to about 400 Torr. For example, the second pump  90  may include a venturi pump. In an embodiment, the second pump  90  may include an air supply  92 , an air exhaust  94 , and a venturi tube  96 . The air supply  92  may provide air  99  under a pressure greater than atmospheric pressure. The air exhaust  94  may discharge the air  99 . The venturi tube  96  may couple the air supply  92  to the air exhaust  94 . The venturi tube  96  may have an air nozzle  98 . The air nozzle  98  may be engaged with the second upper cavity  18 . The air nozzle  98  may use the air  99  to pump the second gas  26  in the second upper cavity  18 . When the air  99  expands in the air nozzle  98 , the second gas  26  may be pumped along with the air  99  into the air nozzle  98 . The second gas  26  in the upper housing  14  may then have a pressure ranging from about 100 Torr to about 400 Torr lower than atmospheric pressure. 
     It will be described below a method of manufacturing a semiconductor device using the plasma processing apparatus  100  configured as described above. 
       FIG. 4  shows a method of manufacturing a semiconductor device according to exemplary embodiments of inventive concepts. 
     Referring to  FIG. 4 , according to exemplary embodiments of inventive concepts, a method of manufacturing a semiconductor device may include a step S 10  of providing the substrate W into the chamber  10 , a step S 20  of processing the substrate W, and a step S 30  of unloading the substrate W. 
     When the lower housing  12  is separated from the upper housing  14 , a robot arm (not shown) may provide the substrate W onto the chuck  20  installed in the lower housing  12  (S 10 ). 
     When the lower housing  12  is combined with the upper housing  14 , a controller (not shown) may use the plasma  24  to process the substrate W (S 20 ). 
       FIG. 5  shows an example of the step S 20  of processing the substrate W of  FIG. 4 . 
     Referring to  FIG. 5 , the step S 20  of processing the substrate W may include a step S 22  of pumping the first gas  22 , a step S 24  of pumping the second gas  26 , and a step S 26  of providing the microwave power output  72 . 
     The first pump  60  may pump the first gas  22  (S 22 ). The first gas  22  may include a purge gas (e.g. N 2 ), an inert gas (e.g., Ar or He), or a reaction gas (e.g., H 2 , O 2 , CH 4 , SF 6 , SiH 4 , or NH 3 ). The first gas  22  may be provided into the chamber  10  from a gas supply (not shown). For example, the first gas  22  may have a pressure ranging from about 1 mTorr to about 100 mTorr in the lower housing  12 . 
     The second pump  90  may pump the second gas  26  (S 24 ). The second gas  26  may be pumped to have a pressure ranging from about 100 Torr to about 400 Torr in the upper housing  14 . The second gas  26  may be substantially different than the first gas  22 . The second gas  26  may be the air. 
     The power supply  70  may provide the antenna  40  with the microwave power output  72  to generate the plasma  24  on the substrate W (S 26 ). Independently of the outer waveguide  73 , the second pump  90  may pump the second gas  26 . Under atmospheric pressure, the outer waveguide  73  of the power supply  70  may transfer the microwave power output  72  to the inner waveguide  75 . The microwave power output  72  may be delivered via air in the outer waveguide  73 . When the outer waveguide  73  has atmospheric pressure larger than vacuum pressure, the microwave power output  72  may increase in transfer efficiency. When the microwave power output  72  is provided to the antenna  40 , the plasma  24  may be generated on the substrate W. When the gas supply (not shown) provides the first gas  22  into the chamber  10 , the first pump  60  may cause the first gas  22  to have a pressure ranging from about 1 mTorr to about 100 mTorr in the lower housing  12 . The plasma  24  may process and/or work on the substrate W. For example, in some embodiments, when the first gas  22  is the reaction gas, the plasma  24  may etch the substrate W. In other embodiments, a thin layer may be deposited on the substrate W. 
     Referring back to  FIG. 4 , when an etching process and/or a thin-layer depositing process on the substrate W are complete, the robot arm (not shown) may operate such that the substrate W is unloaded from the chuck  20  to outside the lower housing  12  (S 30 ). Before the substrate W is unloaded, the lower housing  12  may be separated from the upper housing  14 . 
     In a plasma processing apparatus according to inventive concepts, a second gas above a window may be pumped to a pressure less than the atmosphere pressure such that the window may be rigidly held or adsorbed onto an upper inside wall of a chamber, and this mechanism may minimize and/or prevent deformation of the window. The second gas may be pumped independently of a power supply, and thus it may be possible to prevent power delivery loss of the power supply. 
     The exemplary embodiments have been described in the specification and drawings. Although specific terms are used herein, they are merely used for the purpose of describing inventive concepts rather than limiting technical meanings or scopes of inventive concepts disclosed in the claims. Therefore, it will be appreciated by a person of ordinary skill in the art that various modifications and equivalent embodiments can be made from inventive concepts. In conclusion, the authentic technical scope of inventive concepts to be protected shall be determined by the technical concepts of the accompanying claims.