Gas processing apparatus and method and computer storage medium storing program for controlling same

Abstract

A processing apparatus includes a processing vessel, a gas introduction unit, a processing gas supply unit, a nonreactive gas supply unit, a vacuum pumping unit, a pressure gauge and a control unit. The control unit controls a valve opening ratio of a pressure control valve based on a detection value of the pressure gauge while making a processing gas flow to a flow rate controller of the processing gas supply unit at a constant flow rate when performing a process in which a partial pressure of the processing gas is important. Meanwhile, when performing a process wherein the partial pressure of the processing gas is relatively unimportant, the control unit fixes the valve opening ratio of the pressure control valve at a predetermined value, and operating a flow rate controller of the nonreactive gas supply unit to control a flow rate based on the detection value.

1 . A processing apparatus comprising: 
 a processing vessel having therein a mounting table for mounting an object to be processed;    a gas introduction unit for introducing a gas towards the mounting table inside the processing vessel;    a processing gas supply unit, connected to the gas introduction unit and provided with a flow rate controller, for supplying a processing gas;    a nonreactive gas supply unit, connected to the gas introduction unit and provided a flow rate controller, for supplying a nonreactive gas;    a vacuum pumping unit connected to the processing vessel and provided with a pressure control valve having a variable valve opening ratio and a vacuum pump;    a pressure gauge installed at the processing vessel; and    a control unit for controlling the valve opening ratio of the pressure control valve based on a detection value of the pressure gauge while making the processing gas flow to the flow rate controller of the processing gas supply unit at a constant flow rate when performing a process wherein a partial pressure of the processing gas is important; and for fixing the valve opening ratio of the pressure control valve at a predetermined value, and at the same time, operating the flow rate controller of the nonreactive gas supply unit to control a flow rate based on the detection value of the pressure gauge when performing a process wherein the partial pressure of the processing gas is relatively unimportant.    
   
   
       2 . The processing apparatus of  claim 1 , further comprising one or more additional processing gas supply units, wherein the control unit is configured to set the valve opening ratio of the pressure control valve at a fully opened state during a predetermined process; and in that state, to let the flow rate controller of each processing gas supply unit control each flow rate based on the detection value of the pressure gauge while maintaining a flow rate ratio at a substantially constant state.  
   
   
       3 . The processing apparatus of  claim 1 , wherein the vacuum pumping unit is provided with an additional vacuum pump; and a bypass exhaust path bypassing the pressure control valve of the vacuum pumping unit and the second vacuum pump, wherein a converting opening/closing valve is installed in the bypass exhaust path.  
   
   
       4 . A processing method for performing a process on an object by using a processing apparatus, which includes a processing vessel having therein a mounting table for mounting the object to be processed; a gas introduction unit for introducing a gas towards the mounting table inside the processing vessel; a processing gas supply unit, connected to the gas introduction unit and provided with a flow rate controller, for supplying a processing gas; a nonreactive gas supply unit, connected to the gas introduction unit and provided with a flow rate controller, for supplying a nonreactive gas; a vacuum pumping unit connected to the processing vessel and provided with a pressure control valve having a variable valve opening ratio and a vacuum pump; and a pressure gauge installed at the processing vessel, 
 wherein the valve opening ratio of the pressure control valve is controlled based on a detection value of the pressure gauge while a flow rate of the processing gas flowing to the processing gas supply unit is maintained constant when performing a first process in which a partial pressure of the processing gas is important; and    wherein the valve opening ratio of the pressure control valve is fixed at a predetermined value, and at the same time, a flow rate of the nonreactive gas flowing to the nonreactive gas supply unit is controlled based on the detection value of the pressure gauge when performing a second process in which the partial pressure of the processing gas is relatively unimportant.    
   
   
       5 . The processing method of  claim 4 , wherein the processing apparatus includes one or more additional processing gas supply units; and 
 wherein the valve opening ratio of the pressure control valve is set at a fully opened state during a predetermined process; and in that state, each flow rate is controlled based on the detection value of the pressure gauge while a flow rate ratio of the processing gas flowing through each processing gas supply unit is maintained at a substantially constant state.    
   
   
       6 . The processing method of  claim 4 , wherein the number of revolutions in the process wherein the partial pressure of the processing gas is important is controlled by the vacuum pump to be different from that in the process in which the partial pressure of the processing gas is unimportant.  
   
   
       7 . The processing method of  claim 4 , wherein the process in which the partial pressure of the processing gas is important is a film forming process, and the process in which the partial pressure of the processing gas is relatively unimportant is a cleaning process.  
   
   
       8 . The processing method of  claim 4 , wherein the processing vessel is pumped during the first and the second process by the vacuum pumping unit.  
   
   
       9 . A processing apparatus comprising: 
 a processing vessel having therein a mounting table for mounting an object to be processed;    a gas introduction unit for introducing a gas towards the mounting table inside the processing vessel;    a processing gas supply unit, connected to the gas introduction unit and provided with a flow rate controller, for supplying a processing gas;    a nonreactive gas supply unit, connected to the gas introduction unit and provided with a flow rate controller, for supplying a nonreactive gas;    a vacuum pumping unit connected to the processing vessel and provided with a pressure control valve having a variable valve opening ratio and a first vacuum pump;    a pressure gauge installed at the processing vessel; and    a control unit for fixing the valve opening ratio of the pressure control valve at a predetermined value, and at the same time, performing a first control for controlling a flow rate by using the flow rate controller of the nonreactive gas supply unit based on a detection value of the pressure gauge.    
   
   
       10 . The processing apparatus of  claim 9 , wherein the control unit performs a second control for controlling the valve opening ratio of the pressure control valve based on the detection value of the pressure gauge while making the processing gas flow to the flow rate controller of the processing gas supply unit at a constant flow rate, and 
 wherein the second control is used for a process wherein a partial pressure of the processing gas is important.    
   
   
       11 . The processing apparatus of  claim 9 , wherein the first control is used for a process in which a partial pressure of the processing gas is relatively unimportant.  
   
   
       12 . The processing apparatus of  claim 9 , wherein the first control is used for a case when a process is performed at a low pressure where a passing flow rate is not substantially changed even though the valve opening ratio of the pressure control valve is changed.  
   
   
       13 . A processing method for performing a process on an object by using a processing apparatus, which includes a processing vessel having therein a mounting table for mounting the object to be processed; a gas introduction unit for introducing a gas towards the mounting table inside the processing vessel; a processing gas supply unit, connected to the gas introduction unit and provided with a flow rate controller, for supplying a processing gas; a nonreactive gas supply unit, connected to the gas introduction unit and provided with a flow rate controller, for supplying a nonreactive gas; a vacuum pumping unit connected to the processing vessel and a pressure control valve having a variable valve opening ratio and a first vacuum pump; and a pressure gauge installed at the processing vessel, 
 wherein the valve opening ratio of the pressure control valve is fixed at a predetermined value; and    wherein a first control for controlling a flow rate is performed by using the flow rate controller of the nonreactive gas supply unit based on a detection value of the pressure gauge.    
   
   
       14 . The processing method of  claim 13 , wherein a second control for controlling the valve opening ratio of the pressure control valve is further performed based on the detection value of the pressure gauge while making the processing gas flow to the flow rate controller of the processing gas supply unit at a constant flow rate, the second control being used for a process in which a partial pressure of the processing gas is important.  
   
   
       15 . The processing method of  claim 13 , wherein the first control is used for a process in which a partial pressure of the processing gas is relatively unimportant.  
   
   
       16 . The processing method of  claim 15 , wherein the process in which the partial pressure of the processing gas is relatively unimportant is a cleaning process.  
   
   
       17 . The processing method of  claim 13 , wherein the first control is used for a case when a process is performed at a low pressure where a passing flow rate is not substantially changed even though the valve opening ratio of the pressure control valve is changed.  
   
   
       18 . The processing method of  claim 17 , wherein the low pressure process where the passing flow rate is not substantially changed even though the valve opening ratio of the pressure control valve is changed is a plasma etching process.  
   
   
       19 . The processing method of  claim 14 , wherein the process in which the partial pressure of the processing gas is important is a film forming process.  
   
   
       20 . A processing apparatus including a processing vessel having therein a mounting table for mounting an object to be processed; a gas introduction unit for introducing a gas towards the mounting table inside the processing vessel; a gas supply unit, connected to the gas introduction unit and provided with a flow rate controller, for supplying a predetermined gas; a vacuum pumping unit connected to the processing vessel and provided with a first vacuum pump, a second vacuum pump and a pressure control valve having a variable valve opening ratio; and a pressure gauge for detecting a pressure of the processing vessel, the processing apparatus comprising: 
 a bypass exhaust path installed to bypass the pressure control valve and the second vacuum pump;    a soft start valve mechanism installed in the bypass exhaust path, the soft start valve mechanism having a function of buffering an impact of a vacuum exhaust when exhausting an inside of the processing vessel from an atmospheric pressure to vacuum; and    a control unit installed to control an inner pressure of the processing vessel by adjusting the valve opening ratio of the pressure control valve based on a detection value of the pressure gauge during a relatively low processing pressure process; and to stop an exhaust toward the pressure control valve, and at the same time, to flow an exhaust gas to the bypass exhaust path while maintaining the soft start valve mechanism at a low pumping conductance state during a relatively high processing pressure process.    
   
   
       21 . The processing apparatus of  claim 20 , wherein the control unit adjusts a flow rate by using the flow rate controller based on the detection value of the pressure gauge during the relatively high processing pressure process, to thereby control the inner pressure of the processing vessel.  
   
   
       22 . The processing apparatus of  claim 20 , wherein the soft start valve mechanism includes: 
 a first bypass opening/closing valve installed in a bypass exhaust line of the bypass exhaust path;    an auxiliary bypass exhaust line installed to bypass the first bypass opening/closing valve;    a second bypass opening/closing valve installed in the auxiliary bypass exhaust line; and    an orifice mechanism installed in the auxiliary bypass exhaust line.    
   
   
       23 . The processing apparatus of  claim 22 , wherein the control unit turns the first bypass opening/closing valve into a closed state and turns the second bypass opening/closing valve into an opened state, in order to realize the low pumping conductance state.  
   
   
       24 . The processing apparatus of  claim 20 , wherein the soft start valve mechanism is formed of a soft start valve.  
   
   
       25 . A processing method for performing a process on an object by using a processing apparatus, which includes a processing vessel having therein a mounting table for mounting an object to be processed; a gas introduction unit for introducing a gas towards the mounting table inside the processing vessel; a gas supply unit, connected to the gas introduction unit and provided with a flow rate controller, for supplying a predetermined gas; a vacuum pumping unit connected to the processing vessel and provided with a first vacuum pump, a second vacuum pump and a pressure control valve having a variable valve opening ratio; and a pressure gauge for detecting a pressure of the processing vessel, 
 wherein a bypass exhaust path bypassing the pressure control valve and the second vacuum pump is installed; wherein a soft start valve mechanism in the bypass exhaust path is installed, the soft start valve mechanism having a function of buffering an impact of a vacuum exhaust when exhausting an inside of the processing vessel from an atmospheric pressure to vacuum; and    wherein an inner pressure of the processing vessel is controlled by adjusting the valve opening ratio of the pressure control valve based on a detection value of the pressure gauge during a relatively low processing pressure process; and an exhaust toward the pressure control valve is stopped, and at the same time, an exhaust gas flows to the bypass exhaust path while the soft start valve mechanism is maintained at a low pumping conductance state during a relatively high processing pressure process.    
   
   
       26 . A computer readable storage medium storing therein a program for controlling the processing method of  claim 4 ,  13  or  25 .