Etch chamber having three independently controlled electrodes

摘要

An etch chamber for anisotropic and selective etching of a semiconductor wafer contains a dielectric window (34) and an externally located first electrode member (36) adjacent to the dielectric window for generating a plasma within the chamber. A second electrode member (42) is located within the chamber for exciting the plasma generated by the first electrode member. A third electrode (48) is located between the first electrode member and the dielectric window for sputtering the dielectric window to provide sidewall passivation for anisotropic and selective etching of a semiconductor wafer located within said chamber. Each electrode member is powered by its own separate RF generator. This arrangement enables the independent control of each of the three electrode members to optimize the etching of the semiconductor wafer located within the chamber. <IMAGE>