Abstract: A semiconductor processing system is provided. The semiconductor processing system includes a chamber. The chamber includes a gas inlet, a top electrode configured to strike a plasma inside the chamber, and a support for holding a substrate. A controller configured to detect a passivation starved condition during an etching operation is provided. The controller is further configured to introduce a passivation enhancing gas through the gas inlet during the etching operation in response to detecting the passivation starved condition.

Abstract: A method for etching a polysilicon gate structure in a plasma etch chamber is provided. The method initiates with defining a pattern protecting a polysilicon film to be etched. Then, a plasma is generated. Next, substantially all of the polysilicon film that is unprotected is etched. Then, a silicon containing gas is introduced and a remainder of the polysilicon film is etched while introducing a silicon containing gas. An etch chamber configured to introduce a silicon containing gas during an etch process is also provided.

Abstract: A process for pre-tapering features in a material, such as silicon, prior to etching shallow trenches in the material includes opening a hard mask over the material such that first pre-tapered features are formed in the material. The process can include a hard mask overetch step, which modifies the profile of the first pre-tapered features to form second pre-tapered features in the material. Shallow trench isolation features are formed in the pre-tapered material.