So if I understood correctly:
You have data from 2 sensors in time: Ar flow and BackGas Flow (SCCM, what is that?)
You have that data for multiple products.
1 - Since it is relatively low dimensional, you may try using raw data with K-Means or Self Organizing Maps.
2 - If you searching for anomalies in time, you might try using feature engineering with ...
If your anomalies are simply peaks, why should you be using machine learning methods? You could use peak detection algorithms for the purpose.
If you still insist on ML, isolation forest is a good try.