Patent ID: 8591657

Claim:
A substrate processing apparatus comprising: a process chamber configured to process a substrate; a substrate holder configured to hold the substrate; a cover part having a first penetration hole extending from an inside to an outside of the process chamber, the cover part configured to close and open the process chamber while loading and unloading the substrate holder into and from the process chamber; a substrate holder stage whereon the substrate holder is placed, wherein at least a portion of the substrate holder stage is made of a metal; a rotary mechanism installed at a side of the cover part opposite to the process chamber so as to rotate the substrate holder stage; a rotation shaft inserted through the first penetration hole and connected to the substrate holder stage and the rotary mechanism; a first gas ejection port defined by an inner circumferential surface of the cover part and the rotation shaft; a first gas stagnant part surrounded by the rotary mechanism, the rotation shaft and the cover part, the first gas stagnant part communicating with the process chamber via the first gas ejection port; a second gas ejection port comprising at least a second penetration hole extending from a surface of the substrate holder stage whereon the substrate holder is placed to an opposite surface thereof facing the rotary mechanism; a second gas stagnant part disposed at the rotation shaft and communicating with the process chamber via the second gas ejection port; and a flow port disposed at the rotation shaft, the flow part connecting the first gas stagnant part and the second gas stagnant part, wherein a ratio of a volume of the second gas stagnant part to that of the second gas ejection port is equal to or greater than a ratio of a volume of the first gas stagnant part to a sum of volumes of the first gas ejection port and the flow port.