Patent ID: 9428828
Filing Date: 2016-08-30
CPC Classification: C23C,H01J

Claim Text:
1. A film forming method for forming a film on a substrate by sputtering a target using a film forming apparatus comprising a chamber shield that is grounded and disposed on an inner surface of a vacuum chamber: a target holder that is disposed in the vacuum chamber holding the target; a substrate holder that is disposed in the vacuum chamber so as to face the target holder and having a substrate holding surface for holding the substrate; a first shielding member that is disposed in an upper part of the chamber shield and in a vicinity of the target holder, and having an opening; and a second shielding member that is disposed in a lower part of the chamber shield and in a vicinity of the substrate holder, the method comprising: a first step of applying a first power to the target holder to cause discharge in a first discharge space that is formed when the first shielding member is located at a first position, at a same time with shielding the substrate by locating the second shielding member at a third position such that the second shielding member covers the substrate holding surface on which the substrate is held, the first power being lower than a film forming power applied upon film formation from a power source connected to the target holder, the first shielding member being movable between the first position that shields between the target holder and the substrate holder and a second position that does not shield between the target holder and the substrate holder, the second shielding member being movable between the third position that shields between the target holder and the substrate holder and a fourth position that does not shield between the target holder and the substrate holder; a second step of changing a location of discharging from the first discharge space to a second discharge space larger than the first discharge space by moving the first shielding member from the first position to the second position such that the opening of the first shielding member makes the target and the second discharge space communicate with each other, while continuing the discharge caused in the first step and locating the second shielding member at the third position such that the second shielding member covers the substrate holding surface; a third step of applying a second power higher than the first power to the target holder from the power source in the second discharge space, while locating the first shielding member at the second position such that the first shielding member does not shield between the target holder and the substrate holder, and locating the second shielding member at the third position such that the second shielding member covers the substrate holding surface; and a fourth step of exposing the substrate, which is shielded against the second discharge space by the second shielding member, to the second discharge space by moving the second shielding member from the third position to the fourth position such that the second shielding member does not cover the substrate holding surface, while locating the first shielding member at the second position such that the first shielding member does not shield between the target holder and the substrate holder.