Method for removing metal impurity from quartz component part used in heat processing apparatus of batch type

Abstract

A method for removing a metal impurity from a quartz component part in a heat processing apparatus of a batch type includes placing a plurality of dummy substrates for allowing the metal impurity to be deposited thereon inside a process container with no product target substrates placed therein; then, supplying a chlorine-containing gas and water vapor into the process container and heating the quartz inner surface of the process container at a process temperature, thereby applying a baking process onto the quartz inner surface to discharge the metal impurity from the quartz inner surface and deposit the metal impurity onto the dummy substrates; and then, unloading the dummy substrates with the metal impurity deposited thereon from the reaction container.

1 . A method for removing a metal impurity from a quartz component part in a heat processing apparatus of a batch type,
 the apparatus comprising   a process container configured to accommodate a plurality of target substrates at intervals in a vertical direction and to form a heat process atmosphere therein, the process container including a quartz inner surface to be exposed to the heat process atmosphere,   a heater configured to heat an interior of the process container,   an exhaust system configured to exhaust gas from inside the process container, and   a process gas supply system configured to supply a process gas into the process container,   the method comprising:   placing a plurality of dummy substrates for allowing the metal impurity to be deposited thereon inside the process container with no product target substrates placed therein;   then, supplying a chlorine-containing gas and water vapor into the process container and heating the quartz inner surface of the process container at a process temperature, thereby applying a baking process onto the quartz inner surface to discharge the metal impurity from the quartz inner surface and deposit the metal impurity onto the dummy substrates; and   then, unloading the dummy substrates with the metal impurity deposited thereon from the reaction container.   
   
   
       2 . The method according to  claim 1 , wherein the metal impurity comprises aluminum or titanium. 
   
   
       3 . The method according to  claim 1 , wherein the metal impurity comprises aluminum. 
   
   
       4 . The method according to  claim 3 , wherein the process temperature is set to be 550° C. to 1,200° C. 
   
   
       5 . The method according to  claim 3 , wherein each of the dummy substrates comprises a silicon surface. 
   
   
       6 . The method according to  claim 1 , wherein the chlorine-containing gas comprises hydrogen chloride gas. 
   
   
       7 . The method according to  claim 1 , wherein the method comprises repeatedly applying the baking process onto the quartz inner surface while replacing the dummy substrates with new ones. 
   
   
       8 . The method according to  claim 7 , wherein the method comprises measuring a concentration of the metal impurity deposited on an unloaded dummy substrate, and repeatedly applying the baking process onto the quartz inner surface while replacing the dummy substrates with new ones until the concentration becomes lower than a target value. 
   
   
       9 . The method according to  claim 1 , wherein the method comprises purging the interior of the reaction container with oxygen gas after the baking process. 
   
   
       10 . The method according to  claim 1 , wherein the apparatus comprises a holder member configured to hold the target substrates and including a quartz portion, and the method comprises placing the holder member holding the dummy substrates inside the process container, and applying the baking process also onto the quartz portion of the holder member to discharge the metal impurity from the quartz portion and deposit the metal impurity onto the dummy substrates. 
   
   
       11 . The method according to  claim 1 , wherein the apparatus comprises a predetermined member including a quartz portion to be exposed to the heat process atmosphere, and the method comprises placing the predetermined member along with the dummy substrates inside the process container, and applying the baking process also onto the quartz portion of the predetermined member to discharge the metal impurity from the quartz portion and deposit the metal impurity onto the dummy substrates. 
   
   
       12 . A method for removing a metal impurity from a quartz component part in a heat processing apparatus of a batch type,
 the apparatus comprising   a process container configured to accommodate a plurality of target substrates at intervals in a vertical direction and to form a heat process atmosphere therein,   a predetermined member including a quartz portion to be exposed to the heat process atmosphere,   a heater configured to heat an interior of the process container,   an exhaust system configured to exhaust gas from inside the process container, and   a process gas supply system configured to supply a process gas into the process container,   the method comprising:   placing the predetermined member along with a plurality of dummy substrates for allowing the metal impurity to be deposited thereon inside the process container with no product target substrates placed therein;   then, supplying a chlorine-containing gas and water vapor into the process container and heating the quartz portion of the predetermined member at a process temperature, thereby applying a baking process onto the quartz portion to discharge the metal impurity from the quartz portion and deposit the metal impurity onto the dummy substrates; and   then, unloading the dummy substrates with the metal impurity deposited thereon from the reaction container.   
   
   
       13 . The method according to  claim 12 , wherein the metal impurity comprises aluminum or titanium. 
   
   
       14 . The method according to  claim 12 , wherein the metal impurity comprises aluminum. 
   
   
       15 . The method according to  claim 14 , wherein the process temperature is set to be 550° C. to 1,200° C. 
   
   
       16 . The method according to  claim 14 , wherein each of the dummy substrates comprises a silicon surface. 
   
   
       17 . The method according to  claim 12 , wherein the chlorine-containing gas comprises hydrogen chloride gas. 
   
   
       18 . The method according to  claim 12 , wherein the method comprises repeatedly applying the baking process onto the quartz portion while replacing the dummy substrates with new ones. 
   
   
       19 . The method according to  claim 18 , wherein the method comprises measuring a concentration of the metal impurity deposited on an unloaded dummy substrate, and repeatedly applying the baking process onto the quartz portion while replacing the dummy substrates with new ones until the concentration becomes lower than a target value. 
   
   
       20 . A method for removing a metal impurity from a holder member configured to hold a plurality of target substrates at intervals in a vertical direction and including a quartz portion, in a heat processing apparatus of a batch type, the method comprising:
 placing the holder member holding a plurality of dummy substrates for allowing the metal impurity to be deposited thereon inside a process container with no product target substrates placed therein;   then, supplying a chlorine-containing gas and water vapor into the process container and heating the quartz portion of the holder member at a process temperature, thereby applying a baking process onto the quartz portion to discharge the metal impurity from the quartz portion and deposit the metal impurity onto the dummy substrates; and   then, unloading the holder member along with the dummy substrates with the metal impurity deposited thereon from the reaction container.