Film formation method in vertical batch cvd apparatus

A vertical batch CVD apparatus comprising:

• a process container having a process field configured to accommodate a plurality of target substrates at intervals in a vertical direction;
• a support member configured to support the target substrates inside the process field;
• a heater configured to heat the target substrates inside the process field;
• an exhaust system configured to exhaust the process field;
• a source gas supply circuit configured to supply a source gas to the process field;
• a reactive gas supply circuit configured to supply a reactive gas to the process field;
• a control section configured to control an operation of the apparatus,
• wherein the control section is preset to execute a film formation method for forming a reaction product film on the target substrates by a reaction between the source gas and the reactive gas within the process field, the method being preset to repeat a cycle a plurality of times to laminate thin films formed by respective times, the cycle alternately comprising
• an adsorption step of performing supply of the source gas to the process field, thereby adsorbing the source gas onto a surface of the target substrates, and
• a reaction step of performing supply of the reactive gas to the process field, thereby causing the reactive gas to react with the source gas adsorbed on the surface of the target substrates,
• wherein the adsorption step is arranged to make a plurality of times a supply sub-step of performing supply of the source gas to the process field with an intermediate sub-step of stopping supply of the source gas to the process field interposed therebetween, while maintaining a shut-off state of supply of the reactive gas to the process field, and
• wherein the reaction step is arranged to continuously perform supply of the reactive gas to the process field, while maintaining a shut-off state of supply of the source gas to the process field.