| 摘要 |
Provided is a method for etching a layer in a plasma chamber with an inner injection zone gas feed and an outer injection zone gas feed. The layer is placed in the plasma chamber. Pulsed etch gas is provided from the inner injection zone gas feed at a first frequency, wherein the flow of pulsed etch gas from the inner injection zone gas feed is ramped down to zero. The pulsed etch gas is provided from the outer injection zone gas feed at the first frequency, and is simultaneous with and out of phase with the pulsed etch gas from the inner injection zone gas feed. The etch gas is formed into a plasma to etch the layer, simultaneously with the steps of providing the pulsed etch gas from the inner injection zone gas feed and providing the pulsed gas from the outer interjection zone gas feed. |
