Bath Systems and Methods Thereof

A bath processing tool comprising:

• a bath chamber for wet processing wafers in a bath solution, the bath chamber comprising wafer loading arms extending along a first direction;
• a light sensor to capture light from a bath solution in the bath chamber;
• a plurality of light sources disposed within a plurality of gas injectors,
• the plurality of light sources being configured to project light of different wavelengths from each of the plurality of gas injectors towards the wafers,
• the plurality of light sources comprising a first light source emitting light at a first wavelength towards a first zone and a second light source emitting light at a second wavelength towards a second zone, the second wavelength being different from the first wavelength, the first zone and second zone being different volume of the bath solution along the first direction;
• a processor;
• and
• a non-transitory memory storing a program and coupled to the processor, the program to be executed in the processor and comprising instructions to:
• immerse the wafers into the bath solution contained in the bath chamber;
• hold the wafers inside the bath solution with the wafer loading arms, adjacent ones of the wafers being held along the first direction, each of the wafers having a diameter along a second direction orthogonal to the first direction;
• generate gas bubbles in the bath solution from a plurality of gas injectors oriented along the first direction;
• first filter;
• capture light of the first wavelength from the first zone using a first light sensor and a capture light of the second wavelength from the second zone using a second light sensor and a second filter;
• generate light sensor data based on the captured light of the first wavelength and of the second wavelength;
• and
• convert the light sensor data into a metric for the bath solution.

A method of processing a plurality of substrates, the method comprising:

• immersing the plurality of substrates into a bath solution contained in a bath chamber, the bath chamber comprising wafer loading arms extending along a first direction;
• holding the plurality of substrates inside the bath solution with the wafer loading arms, adjacent ones of the plurality of substrates being held along the first direction, each of the plurality of substrates having a diameter along a second direction orthogonal to the first direction;
• generating gas bubbles in the bath solution from a plurality of gas injectors oriented along the first direction;
• generating, at a light sensor, light sensor data based on capturing electromagnetic (EM) light emanating off the gas bubbles in the bath solution;
• and
• terminating the processing of the plurality of substrates based on the captured EM light.