Plasma reactor and method

Abstract

A plasma reactor is provided for achieving extension of etching parameters to reduce charge-up shape anomaly and to improve selectivity, uniformity and workability in a dry etching process. An RF power fluctuates in cycles, each one of the cycles including first and second subcycles (25), (26) with different frequencies. The RF power in the first subcycles (25) is higher in frequency than that in the second subcycles (26). A charge accumulated during the first subcycles (25) in which the RF power of high frequency is applied can be relieved during the second subcycles (26) in which the RF power of low frequency is applied. At the same time, deterioration in an etching rate occurring with the application of only the RF power of low frequency can be relieved by applying the RF power of high frequency during the first subcycles (25).

Dependencies are inferred from the claim text.