Plasma processing method and post-processing method

Claim 1

A plasma processing method for performing a plasma process on a target object in a plasma processing apparatus, the plasma processing apparatus comprising a chamber configured to accommodate the target object, a gas supply system configured to supply a process gas into the chamber, an exhaust system configured to exhaust gas from inside the chamber, an upper electrode and a lower electrode disposed to face each other in the chamber, the lower electrode being configured to support the target object, a first RF (radio frequency) power supply configured to supply the upper electrode with a first RF power for generating plasma of a process gas inside the chamber, and a second RF power supply configured to supply the lower electrode with a second RF power for providing the target object with a bias for attracting ions in plasma toward the target object, the plasma processing method comprising: consecutively performing a first plasma process, a second plasma process, and a third plasma process in this order in the chamber while keeping the target object placed in the chamber, such that the first plasma process is arranged to supply both of the first RF power and the second RF power while supplying a first gas containing a halogen element selected from the group consisting of chlorine and bromine into the chamber, thereby generating first plasma from the first gas to perform an etching process on the target object while attracting ions in the first plasma toward the target object, the second plasma process is arranged to supply the first RF power and not to supply the second RF power while supplying a second gas containing O 2 gas into the chamber, thereby generating second plasma containing O 2 , plasma from the second gas and using the O 2 plasma to sputter and thereby remove a gas component including the halogen element and physically adsorbed on an inner wall of the chamber, a component inside the chamber, and the target object, and the third plasma process is arranged to supply the first RF power and not to supply the second RF power while supplying a third gas containing fluorine into the chamber, thereby generating third plasma containing F radicals from the third gas and using the F radicals to etch and thereby remove a reaction product including the halogen element, generated by the first plasma process, and deposited on the target object, wherein the first gas is a gas selected from the group consisting of hydrogen bromide gas, hydrogen chloride gas, chlorine gas, and a mixture gas thereof, the second gas is a gas selected from the group consisting of O 2 gas and a mixture gas of O 2 gas with an inactive gas, and the third gas is a fluorine-containing gas selected from the group consisting of CF 4 and a mixture of CF 4 and O 2 .