Depression filling method and processing apparatus

A processing apparatus comprising:

• a vessel;
• a gas supply part configured to supply a first gas which forms a first thin film made of a semiconductor material substantially not containing an impurity, a second gas which forms a second thin film made of a semiconductor material substantially not containing an impurity, a third gas which etches the first thin film and a fourth gas for use in gas phase doping, into the vessel;
• a heating device configured to heat an internal space of the vessel;
• and
• a control part configured to control the gas supply part and the heating device,
• wherein the control part is configured to execute a first control which causes the gas supply part to supply the first gas into the vessel, a second control which causes the heating device to heat the internal space of the vessel after the first control is executed, a third control which causes the gas supply part to supply the third gas into the vessel after the second control is executed, a fourth control which causes the gas supply part to supply the fourth gas into the vessel after the third control is executed, a fifth control which causes the gas supply part to supply the second gas into the vessel after the fourth control is executed, a sixth control which causes the heating device to heat the internal space of the vessel after the fifth control is executed, and a seventh control which causes the gas supply part to supply the fourth gas into the vessel after the sixth control is executed.