Substrate processing apparatus

A substrate processing apparatus, comprising:

• a processing space, defined by a reaction tube made of quartz, to provide a space in which a substrate is to be processed;
• a buffer space provided at an inner wall of the reaction tube and partitioned from the processing space;
• an electrode provided inside the buffer space, the electrode being used when a first processing gas is plasma-excited, and a high frequency voltage being applied to the electrode;
• a heating member to heat the processing space;
• a gas supply member to supply at least the first processing gas and a second processing gas to the processing space;
• an exhaust member to exhaust an atmosphere in the processing space;
• and a control member to control the electrode, the heating member, the gas supply member and the exhaust member, the control member including a film forming mode to form a desired film on the substrate and a coating mode to coat a desired film on a surface of an inner wall of the processing space, wherein a sequence of operations includes:
• in the film forming mode, the desired film is formed on the substrate in a state where the processing space loaded with the substrate is heated to a first temperature, by repeating the following a plurality of times in order:
• supplying a first processing gas to the processing space, removing the first processing gas remaining in the processing space, supplying the second processing gas to the processing space and removing the second processing gas remaining in the processing space in the coating mode, the desired film is coated on the surface of an inner wall of the processing space in a state where the processing space not loaded with the substrate is heated to a second temperature higher than the first temperature by supplying both the first processing gas and the second processing gas to the processing space at the same time, in the film forming mode, the first processing gas is excited by plasma and a high frequency voltage is applied to the electrode and in the coating mode, the first processing gas is not excited by plasma and a high frequency voltage is not applied to the electrode, the first processing gas is supplied to the processing space through the buffer space, and the coating is also formed on a surface of an inner wall of the bufferspace.