Methodology for in-situ and real-time chamber condition monitoring and process recovery during plasma processing

A method for controlling a seasoning process in a plasma chamber comprising:

• injecting a seasoning gas into a plasma chamber, the seasoning gas comprising a source of free radicals, and wherein the seasoning gas includes an inert gas and at least one of Br, Cl, O or F, the inert gas accounting for 5–10 percent of the seasoning gas;
• striking the seasoning gas into a seasoning plasma;
• seasoning the processing chamber;
• measuring a density of the free radicals in the seasoning plasma, wherein the density of the free radicals is defined as a ratio of emission intensities of the free radicals and the inert gas and wherein the density of the free radicals is compared with a predefined level;
• determining when the plasma chamber is seasoned according to the measured density of the free radicals;
• and
• extinguishing the seasoning plasma when the density of the free radicals is above the predefined level.

A method for detecting process drift in a plasma chamber comprising:

• injecting a process gas into a plasma chamber, the process gas comprising a source of free radicals and an inert gas, the inert as accounting for 5–10 percent of the process gas;
• striking the process gas into a process plasma, wherein the process plasma includes an inert gas;
• measuring a density of the free radicals in the process plasma, wherein the density of the free radicals is defined as the ratio of emission intensities of the free radicals and the inert gas;
• determining an extent of process drift according to the measured density of the free radicals, wherein the density of the free radicals is compared with a predefined level;
• and
• deeming the plasma chamber unsuitable for production when the density of the free radicals is below the predefined level.