Shower head structure and cleaning method thereof

Abstract

There is disclosed a shower head structure, disposed on a ceiling portion of a process chamber for subjecting a material to be treated to a film forming process, for supplying a predetermined gas, the structure comprising a head main body formed in a cup shape having a bottom with a plurality of gas injection holes opened therein, and formed integrally with a joining flange portion to be attached to the ceiling portion of the process chamber on an opening side of the cup shape, and a head heating portion, disposed on the bottom of the head main body, for adjusting the head main body at a desired temperature, so that the film forming process for enhancing reproducibility under a low temperature is performed and a reactive byproduct is removed under a high temperature.

1 . A shower head structure provided on a ceiling portion of a process chamber for subjecting a material to be treated to a film forming process, for supplying a predetermined gas into the process chamber, said shower head structure comprising: 
 a head main body formed in a cup shape having a gas injection portion with a plurality of gas injection holes opened therein in a bottom, and formed integrally with a joining flange portion to be attached to the ceiling portion of said process chamber on an opening side of the cup shape; and    a head heating portion, disposed on the bottom of said head main body, for adjusting the head main body at a desired temperature.    
   
   
       2 . The shower head structure according to  claim 1 , further comprising a seal surface for holding a vacuum state with an insulating material in a contact surface of said joining flange portion contacting said ceiling portion of said process chamber when the shower head structure is mounted on the process chamber.  
   
   
       3 . The shower head structure according to  claim 1 , wherein a seal member attached to the ceiling portion is compressed and a hermetic property is held by said seal surface when the shower head structure is attached to said ceiling portion, and a contact surface of said joining flange portion on a vacuum side is formed to be lower than that on an atmospheric side so that a gap is made between the contact surface on the vacuum side and the ceiling portion.  
   
   
       4 . The shower head structure according to  claim 1 , further comprising a bracket portion for reducing a sectional area of the side wall of said head main body disposed above said head heating portion and for increasing a heat resistance to a propagated heat on said side wall.  
   
   
       5 . The shower head structure according to  claim 1 , further comprising a head heating/cooling portion, disposed on said joining flange portion, for cooling said head main body during the film forming process of said material to be treated, and heating said head main body during a cleaning process in said process chamber.  
   
   
       6 . The shower head structure according to  claim 5 , wherein said head heating/cooling portion comprises: 
 a Peltier element disposed such that one temperature adjustment surface contacts said joining flange portion; and    a controller for driving/controlling said Peltier element.    
   
   
       7 . The shower head structure according to  claim 6 , further comprising: a medium channel, disposed to contact the other temperature adjustment surface of said Peltier element, for passing a heat transfer medium for propagating a warm heat or a cool heat generated by the temperature adjustment surface to the outside.  
   
   
       8 . The shower head structure according to  claim 6 , wherein said heat transfer medium comprises a first heat transfer medium for cooling said Peltier element during the film forming process, and a second heat transfer medium for heating said Peltier element during the cleaning process in said process chamber, and 
 said first heat transfer medium and the second heat transfer medium contact the temperature adjustment surface of said Peltier element via respective different medium channels, and either one of the first heat transfer medium and the second heat transfer medium is selected by switching a valve.    
   
   
       9 . A shower head structure, disposed on a ceiling portion of a process chamber for subjecting a material to be treated to a film forming process, for supplying a predetermined gas into the process chamber, said shower head structure comprising: 
 a head main body formed in a cup shape having a gas injection portion with a plurality of gas injection holes opened therein in a bottom, and formed integrally with a joining flange portion to be attached to the ceiling portion of said process chamber on an opening side of the cup shape;    a head heating portion, disposed on the bottom of said head main body, for adjusting the head main body at a desired temperature; and    a head heating/cooling portion, disposed on said joining flange portion, for cooling said head main body during the film forming process of said material to be treated, and heating said head main body during a cleaning process in said process chamber,    wherein the temperature of said head main body is controlled in a range of 50 to 300° C. by the head heating portion and said head heating/cooling portion.    
   
   
       10 . The shower head structure according to  claim 9 , which is mounted on a film forming apparatus comprising the process chamber for depositing a reactive byproduct on the surface of the heated material to be treated in a process gas atmosphere.  
   
   
       11 . The shower head structure according to  claim 9 , which is mounted on a plasma film forming apparatus comprising the process chamber for depositing a reactive byproduct on the surface of the heated material to be treated in a process gas atmosphere under generation of a plasma.  
   
   
       12 . The shower head structure according to  claim 9 , wherein said head heating/cooling portion comprises a medium channel, disposed to contact said joining flange portion, for passing a heat transfer medium for propagating a warm heat or a cool heat generated by the joining flange portion to the outside.  
   
   
       13 . The shower head structure according to  claim 12 , wherein said heat transfer medium comprises a first heat transfer medium for cooling said Peltier element during the film forming process, and a second heat transfer medium for heating said Peltier element during the cleaning process in said process chamber.  
   
   
       14 . A film forming method by a shower head structure disposed on a ceiling portion of a process chamber for subjecting a material to be treated to a film forming process, said shower head structure comprising: 
 a head main body formed in a cup shape having a bottom comprising a gas injection portion with a plurality of gas injection holes opened therein, and formed integrally with a joining flange portion to be attached to the ceiling portion of said process chamber on an opening side of the cup shape; and    a head heating/cooling portion, disposed on the bottom of said head main body, for adjusting the head main body at a desired temperature, said method comprising steps of:    introducing a predetermined gas into said process chamber having a vacuum state from said shower head structure; subjecting said material to be treated in said process chamber to a film forming process; and maintaining the temperature of said gas injection portion to a constant temperature lower than the temperature of said material to be treated by said head heating/cooling portion.    
   
   
       15 . The film forming method according to  claim 14 , wherein when the temperature of said material to be treated during the film forming process is 420° C. or less by said head heating/cooling section, the temperature of said shower head structure is set to 95° C. or less.  
   
   
       16 . The film forming method according to  claim 14 , wherein when the temperature of said material to be treated during the film forming process is 500° C. or less by said head heating/cooling section, the temperature of said shower head structure is set to 110° C. or less.  
   
   
       17 . The film forming method according to  claim 14 , further comprising steps of adjusting the temperature of the surface of the gas injection portion generated during film formation, inhibiting heat from being propagated to said joining flange portion, and forming a film by a bracket formed on the side wall of said head main body disposed above said gas injection portion.  
   
   
       18 . A method of cleaning the interior of a film forming apparatus designed to form a reactive byproduct on a surface of a heated material in a process gas atmosphere and comprising a process chamber and a shower head structure mounted on the process chamber, for introducing a process gas into the process chamber, said method comprising: 
 passing a cleaning gas into said process chamber from said shower head structure; setting a temperature of the shower head structure to be higher than the temperature of the film forming process; and performing a cleaning process to remove the reactive byproduct generated during the film forming process.    
   
   
       19 . The cleaning method according to  claim 18 , where the temperature of said shower head structure is 130° C. or more.  
   
   
       20 . The cleaning method according to  claim 18 , wherein said film forming process is a film forming process of a tungsten metal, and comprises a step of removing the reactive byproduct containing a titanium fluoride (Ti gas Fx) based main component attached to said shower head structure.  
   
   
       21 . The cleaning method according to  claim 18 , wherein said cleaning process comprises steps of: judging whether a cumulative processing number of treated wafers, a cumulative process time, a measured film thickness of the reactive byproduct, or an electric property of the film formed on the wafer is within specifications as a standard; and starting the cleaning process when a preset standard value is exceeded.  
   
   
       22 . The cleaning method according to  claim 21 , wherein said cleaning process is executed in accordance with a predetermined sequence every time said reference value is exceeded.  
   
   
       23 . The cleaning method according to  claim 21 , wherein said cumulative processing number of treated wafers is in a range of 1 to 2500.  
   
   
       24 . The cleaning method according to  claim 21 , wherein the film thickness of said reactive byproduct deposited by the processing is 5 nm or more.  
   
   
       25 . The cleaning method according to  claim 21 , wherein the film thickness of said reactive byproduct is measured using a laser or a light flux (UV, infrared ray).  
   
   
       26 . A method of cleaning the interior of a film forming apparatus designed to form a reactive byproduct on a surface of a heated material in a process gas atmosphere and comprising a process chamber and a shower head structure mounted on the process chamber, for introducing a process gas into the process chamber, said method comprising: 
 passing a cleaning gas into said process chamber from said shower head structure; setting a temperature of the shower head structure in a range of 140 to 170° C. with respect to a range of 50 to 110° C. during the film forming process; and performing a cleaning process to remove the reactive byproduct generated during the film forming process.