Abstract: Methods for etching a substrate in a plasma etch reactor may include (a) depositing polymer on surfaces of a feature formed in substrate disposed in the etch reactor using first reactive species formed from a first process gas comprising a polymer forming gas; (b) etching the bottom surface of the feature of the substrate in the etch reactor using a third reactive species formed from a third process gas including an etching gas; and (c) bombarding a bottom surface of the feature with a second reactive species formed from a second process gas comprising one or more of an inert gas, an oxidizing gas, a reducing gas, or the polymer forming gas while at least one of depositing the polymer to remove at least some of the polymer disposed on the bottom surface or etching the bottom surface to at least one of chemically or physically damage the bottom surface.

Abstract: Methods and apparatus for gas delivery into plasma processing chambers are provided herein. In some embodiments, an apparatus for processing a substrate includes a process chamber having a processing volume, a substrate support disposed in the processing volume, an inductively coupled plasma source to generate an electric field within the processing volume that includes one or more regions of local maxima in the magnitude of the electric field, and one or more gas injectors to selectively direct a predominant portion of a process gas flowed through the one or more gas injectors into the one or more regions of local maxima.

Abstract: Methods for etching a substrate in a plasma etch reactor may include (a) depositing polymer on surfaces of a feature formed in substrate disposed in the etch reactor using first reactive species formed from a first process gas comprising a polymer forming gas; (b) etching the bottom surface of the feature of the substrate in the etch reactor using a third reactive species formed from a third process gas including an etching gas; and (c) bombarding a bottom surface of the feature with a second reactive species formed from a second process gas comprising one or more of an inert gas, an oxidizing gas, a reducing gas, or the polymer forming gas while at least one of depositing the polymer to remove at least some of the polymer disposed on the bottom surface or etching the bottom surface to at least one of chemically or physically damage the bottom surface.

Abstract: Plasma processing apparatus that provide an asymmetric plasma distribution within the processing apparatus are provided herein. In some embodiments, a plasma processing apparatus may include a process chamber having a processing volume with a substrate support disposed therein; and a first RF coil disposed above the substrate support to couple RF energy into the processing volume, wherein an electric field generated by RF energy moving along the first RF coil is asymmetric about a central axis of the substrate support. In some embodiments, a pump port is disposed asymmetrically with respect to the processing volume to remove one or more gases from the processing volume. In some embodiments, the first RF coil is asymmetrically disposed about the central axis of the substrate support.