Fill on demand ampoule refill

A substrate processing apparatus, comprising:

• an ampoule configured to be fluidically connected to a precursor delivery system and a precursor source and configured to contain liquid precursor;
• and
• one or more controllers configured to:
• (a) determine that an ampoule fill start condition for filling the ampoule with a liquid precursor is met;
• (b) fill the ampoule with precursor, wherein filling the ampoule with the precursor is performed concurrent with at least one other substrate processing operation;
• (c) determine that a sensor level in the ampoule indicates that the ampoule is not full, wherein a primary fill stop condition is met when the sensor level in the ampoule indicates that the ampoule is full;
• (d) maintain a cumulative time of filling the ampoule, wherein the cumulative time of filling the ampoule is all of the time that the precursor is flowing to the ampoule since the cumulative time of filling the ampoule was last reset, wherein the cumulative time of filling the ampoule is reset when the sensor level in the ampoule indicates that the ampoule is full
• (e) determine that a secondary fill stop condition is met, wherein the secondary fill stop condition comprises determining that the cumulative time of filling exceeds a threshold;
• and
• (f) in response to determining that the secondary fill stop condition is met and in response to determining that the sensor level in the ampoule indicates that the ampoule is not full, cease the filling of the ampoule with the precursor.