Methods for in-situ chamber monitoring

A method for monitoring maintenance requirements of a preclean process chamber, the method comprising:

• forming a metal film on a substrate, followed by,
• forming an oxide film from the metal film with an H2O plasma in the preclean process chamber;
• measuring a thickness of the oxide film formed on the substrate by a reflectivity obtained from the oxide film;
• after forming the oxide film and measuring the thickness of the oxide film, reducing the oxide film to form a reduced metal film or surface modified film on the substrate, wherein forming the oxide film and reducing the oxide film to the reduced metal film occur within the same preclean process chamber and without an air break;
• measuring a thickness of the reduced metal film or surface modified film by a reflectivity obtained from the reduced metal film or surface modified film;
• determining an amount of oxide film removed from the substrate by comparing the thickness of the oxide film with the thickness of the reduced metal film or surface modified film;
• and
• determining whether preventative maintenance on the preclean process chamber is to be performed based on the amount of oxide film removed from the substrate obtained from a standard for the maintenance requirements determined by a reference thickness obtained from the reflectivity of the oxide film, and performing the preventative maintenance on the preclean process chamber when the reflectivity of the reduced metal film or surface modified film does not meet the standard.