| abstract |
Etch profile control with pulsed gas flow and its applications to etching such as anisotropic etching of high aspect ratio features and etching of self-aligned contact structures in various processes. Pulsing can be applied according to this invention to the flow rate of a gas such as an etchant gas, a gas that leads to the deposition of a protective layer, a gas that modifies the deposition of a protective layer, and a gas that modifies etching. |