Film formation apparatus and method for semiconductor process

Abstract

A film formation apparatus for a semiconductor process includes a source gas supply circuit to supply into a process container a source gas for depositing a thin film on target substrates, and a mixture gas supply circuit to supply into the process container a mixture gas containing a doping gas for doping the thin film with an impurity and a dilution gas for diluting the doping gas. The mixture gas supply circuit includes a gas mixture tank disposed outside the process container to mix the doping gas with the dilution gas to form the mixture gas, a mixture gas supply line to supply the mixture gas from the gas mixture tank into the process container, a doping gas supply circuit to supply the doping gas into the gas mixture tank, and a dilution gas supply circuit to supply the dilution gas into the gas mixture tank.

1 . A film formation apparatus for a semiconductor process, comprising: 
 a process container configured to accommodate a plurality of target substrates stacked at intervals;    a support member configured to support the target substrates inside the process container;    a heater configured to heat the target substrates inside the process container;    an exhaust system configured to exhaust gas inside the process container;    a source gas supply circuit configured to supply a source gas into the process container, the source gas being for depositing a thin film on the target substrates;    a mixture gas supply circuit configured to supply a mixture gas into the process container, the mixture gas containing a doping gas for doping the thin film with an impurity and a dilution gas for diluting the doping gas; and    a control section configured to control an operation of the apparatus including the mixture gas supply circuit,    wherein the mixture gas supply circuit comprises    a gas mixture tank disposed outside the process container and configured to mix the doping gas with the dilution gas to form the mixture gas,    a mixture gas supply line configured to supply the mixture gas from the gas mixture tank into the process container,    a doping gas supply circuit configured to supply the doping gas into the gas mixture tank, and    a dilution gas supply circuit configured to supply the dilution gas into the gas mixture tank.    
   
   
       2 . The apparatus according to  claim 1 , wherein the mixture gas supply circuit includes a merged gas line for the doping gas and the dilution gas from the doping gas supply circuit and the dilution gas supply circuit to be merged therein and then supplied into the gas mixture tank.  
   
   
       3 . The apparatus according to  claim 1 , wherein the mixture gas supply circuit further comprises a first switching valve disposed on the mixture gas supply line, and the control section is configured to keep the first switching valve closed so as to store the doping gas and the dilution gas from the doping gas supply circuit and the dilution gas supply circuit within the gas mixture tank, and to then open the first switching valve so as to supply the mixture gas into the process container.  
   
   
       4 . The apparatus according to  claim 3 , wherein the mixture gas supply circuit further comprises a pressure meter configured to measure pressure inside the gas mixture tank, and the control section is configured to open and close the first switching valve, based on measurement values by the pressure meter.  
   
   
       5 . The apparatus according to  claim 1 , wherein the gas mixture tank has a volume of 200 to 5,000 cc.  
   
   
       6 . The apparatus according to  claim 1 , wherein the mixture gas supply circuit further comprises a first switching valve disposed on the mixture gas supply line, and the control section is configured to pulse-wise open and close the first switching valve while the doping gas and the dilution gas are continuously supplied from the doping gas supply circuit and the dilution gas supply circuit into the gas mixture tank.  
   
   
       7 . The apparatus according to  claim 6 , wherein the mixture gas supply circuit further comprises a pressure meter configured to measure pressure inside the gas mixture tank, and the control section is configured to pulse-wise open and close the first switching valve, based on measurement values by the pressure meter.  
   
   
       8 . The apparatus according to  claim 6 , wherein the source gas supply circuit comprises a source gas supply line configured to supply the source gas into the process container, and a second switching valve disposed on the source gas supply line, and the control section is configured to pulse-wise open and close the second switching valve in synchronism with operation to pulse-wise open and close the first switching valve.  
   
   
       9 . The apparatus according to  claim 8 , wherein the apparatus further comprises a purge gas supply circuit configured to supply a purge gas into the process container, the purge gas supply circuit comprises a purge gas supply line configured to supply the purge gas into the process container, and a third switching valve disposed on the purge gas supply line, and the control section is configured to pulse-wise close and open the third switching valve in synchronism with operation to pulse-wise open and close the first and second switching valves.  
   
   
       10 . The apparatus according to  claim 9 , wherein the purge gas supply line is connected to the mixture gas supply line downstream from the first switching valve.  
   
   
       11 . A film formation method for a semiconductor process, comprising: 
 heating a plurality of target substrates stacked at intervals inside a process container;    supplying a source gas into the process container, the source gas being for depositing a thin film on the target substrates; and    supplying a mixture gas from a gas mixture tank disposed outside the process container into the process container, while supplying a doping gas for doping the thin film with an impurity and a dilution gas for diluting the doping gas into the gas mixture tank to form the mixture gas.    
   
   
       12 . The method according to  claim 11 , comprising performing operation to pulse-wise supply the mixture gas from the gas mixture tank into the process container, while continuously supplying the doping gas and the dilution gas into the gas mixture tank.  
   
   
       13 . The method according to  claim 12 , comprising performing operation to pulse-wise supply the mixture gas, based on measurement values by a pressure meter configured to measure pressure inside the gas mixture tank.  
   
   
       14 . The method according to  claim 12 , comprising performing operation to pulse-wise supply the source gas in synchronism with operation to pulse-wise supply the mixture gas.  
   
   
       15 . The method according to  claim 14 , comprising performing operation to pulse-wise supply a purge gas into the process container in synchronism with an operation to pulse-wise supply the mixture gas and the source gas, in opposite phase.  
   
   
       16 . A computer readable medium containing program instructions for execution on a processor, which, when executed by the processor, cause a film-formation apparatus for a semiconductor process to execute 
 heating a plurality of target substrates stacked at intervals inside a process container;    supplying a source gas into the process container, the source gas being for depositing a thin film on the target substrates; and    supplying a mixture gas from a gas mixture tank disposed outside the process container into the process container, while supplying a doping gas for doping the thin film with an impurity and a dilution gas for diluting the doping gas into the gas mixture tank to form the mixture gas.    
   
   
       17 . The medium according to  claim 16 , wherein the program instructions, when executed by the processor, cause the film-formation apparatus to execute 
 performing operation to pulse-wise supply the mixture gas from the gas mixture tank into the process container, while continuously supplying the doping gas and the dilution gas into the gas mixture tank.    
   
   
       18 . The medium according to  claim 17 , wherein the program instructions, when executed by the processor, cause the film-formation apparatus to execute 
 performing operation to pulse-wise supply the mixture gas, based on measurement values by a pressure meter configured to measure pressure inside the gas mixture tank.    
   
   
       19 . The medium according to  claim 17 , wherein the program instructions, when executed by the processor, cause the film-formation apparatus to execute 
 performing operation to pulse-wise supply the source gas in synchronism with operation to pulse-wise supply the mixture gas.    
   
   
       20 . The medium according to  claim 19 , wherein the program instructions, when executed by the processor, cause the film-formation apparatus to execute 
 performing operation to pulse-wise supply a purge gas into the process container in synchronism with an operation to pulse-wise supply the mixture gas and the source gas, in opposite phase.