Substrate processing apparatus, substrate detection method of substrate processing apparatus and storage medium

A substrate detection method of a substrate processing apparatus, where the substrate processing apparatus includes:

• a substrate holding and rotating unit provided with a rotatable rotating plate and a substrate support unit configured to support a substrate above a rotating plate;
• and
• a substrate processing unit configured to process the substrate supported by the substrate support unit, and
• in which a ring-shaped retro-reflective sheet is disposed below the substrate supported by the substrate support unit, and
• a light projecting part configured to project incident light having a predetermined incident angle to the retro-reflective sheet from a slanted upper side and a light receiving part configured to receive reflected light reflected from the retro-reflective sheet in the same direction as the incident angle are provided above the substrate supported by the substrate support unit, and
• the substrate detection method comprising:
• projecting the incident light from the slanted upper side to the retro-reflective sheet by the light projecting part;
• receiving the reflected light from the retro-reflective sheet by the light receiving part;
• and
• detecting presence or absence of the substrate by the substrate detection unit based on an intensity of the reflected light received by the light receiving part.

A computer-readable storage medium storing a computer executable program that, when executed, causes a computer to perform a substrate detection method of a substrate processing apparatus, where the substrate processing apparatus includes:

• a substrate holding and rotating unit provided with a rotatable rotating plate and a substrate support unit configured to support a substrate above the rotating plate;
• and
• a substrate processing unit configured to process the substrate supported by the substrate support unit,
• wherein a ring-shaped retro-reflective sheet is disposed in the central part below the substrate supported by the substrate support unit, and
• a light projecting part configured to project incident light having a predetermined incident angle to the retro-reflective sheet from a slanted upper side and a light receiving part configured to receive reflected light reflected from the retro-reflective sheet in the same direction as the incident angle are provided above the substrate supported by the substrate support unit, and
• the substrate detection method comprising:
• projecting the incident light from the slanted upper side to the retro-reflective sheet by the light projecting part;
• receiving the reflected light from the retro-reflective sheet by the light receiving part;
• and
• detecting presence or absence of the substrate by the substrate detection unit based on an intensity of the reflected light received by the light receiving part.