Gas supply system, substrate processing apparatus and gas supply method

A gas supply system for supplying a gas into a processing chamber for processing a substrate to be processed, the system comprising:

• a processing gas supply unit for supplying a processing gas for processing the substrate to be processed;
• a processing gas supply line for allowing the processing gas from the processing gas supply unit to flow therein;
• a first and a second branch line branched from the processing gas supply line to be connected with different portions of the processing chamber;
• a branch flow control unit for controlling branch flows of the processing gas distributed from the processing gas supply line to the first and the second branch line based on inner pressures of the first and the second branch line, respectively;
• an additional gas supply unit having a plurality of additional gas lines respectively connected with additional gas sources, downstream sides of the additional gas lines being joined together;
• an additional gas supply line, joining the second branch line at a downstream side of the branch flow control unit, for allowing additional gases from the additional gas supply unit to flow therein;
• and
• a control unit for performing, before processing the substrate to be processed, a processing gas supply control and an additional gas supply control by using the processing gas supply unit and the additional gas supply unit, respectively,
• wherein the additional gas supply control includes a control that supplies an additional gas in each additional gas line at an initial flow rate greater than a set flow rate in each additional gas line and then at the set flow rate after a lapse of a period of time.

A substrate processing apparatus comprising:

• a processing chamber for processing a substrate to be processed;
• a gas supply system for supplying a gas into the processing chamber;
• and
• a control unit for controlling the gas supply system,
• wherein the gas supply system includes:
• a processing gas supply unit for supplying a processing gas for processing the substrate to be processed;
• a processing gas supply line for allowing the processing gas from the processing gas supply unit to flow therein;
• a first and a second branch line branched from the processing gas supply line to be connected with different portions of the processing chamber;
• a branch flow control unit for controlling branch flows of the processing gas distributed from the processing gas supply line to the first and the second branch line based on inner pressures of the first and the second branch line, respectively;
• an additional gas supply unit for supplying an additional gas;
• and
• an additional gas supply line, joining the second branch line at a downstream side of the branch flow control unit, for allowing the additional gas from the additional gas supply unit to flow therein, and
• wherein the control unit performs, before processing the substrate to be processed, a processing gas supply control and an additional gas supply control by using the processing gas supply unit and the additional gas supply unit, respectively, wherein the additional gas supply control includes a control that supplies the additional gas at an initial flow rate greater than a set flow rate and then at the set flow rate after a lapse of a period of time.

A gas supply method for use with a gas supply system for supplying a gas into a processing chamber for processing a substrate to be processed, wherein the gas supply system includes a processing gas supply unit for supplying a processing gas for processing the substrate to be processed;

• a processing gas supply line for allowing the processing gas from the processing gas supply unit to flow therein;
• a first and a second branch line branched from the processing gas supply line to be connected with different portions of the processing chamber;
• a branch flow control unit for controlling branch flows of the processing gas distributed from the processing gas supply line to the first and the second branch line based on inner pressures of the first and the second branch line, respectively;
• an additional gas supply unit for supplying an additional gas;
• and an additional gas supply line, joining the second branch line at a downstream side of the branch flow control unit, for allowing the additional gas from the additional gas supply unit to flow therein, the method comprising the steps of, before processing the substrate to be processed:
• performing a control of supplying the processing gas at a first set flow rate from the processing gas supply unit;
• and
• performing a control of supplying the additional gas at an initial flow rate greater than a second set flow rate and then at the second set flow rate after a lapse of a period of time.