US Patent 11654461 Plasma ashing method using residue gas analyzer

A plasma ashing method is provided. The plasma ashing method includes analyzing the process status of each of a number of semiconductor substrate models undergoing a tested plasma ash process by a residue gas analyzer. The tested plasma ash processes for the semiconductor substrate models utilize a plurality of tested recipes. The plasma ashing method further includes selecting one of the tested recipes as a process recipe for a plasma ash process.