Patent ID: 7541291

Claim:
A method for forming a feature in a layer, comprising: forming a photoresist layer over the layer; patterning the photoresist layer to form photoresist features with photoresist sidewalls, where the photoresist features have a first critical dimension; depositing a conformal layer over the sidewalls of the photoresist features to reduce the critical dimensions of the photoresist features, comprising: a first deposition with a first gas chemistry to form a first deposition plasma; comprising: providing a flow of the first deposition gas; forming the first deposition gas into a plasma; and stopping the flow of the first deposition gas; and a second deposition with a second gas chemistry to form a second deposition plasma, wherein the first gas chemistry is different than the second gas chemistry, comprising: providing a flow of a second deposition gas different than the first deposition gas; forming the second deposition gas into a plasma; and stopping the flow of the second deposition gas, so that the flow of the first deposition gas and the flow of the second deposition gas alternates instead of being simultaneous; and etching features into the layer, wherein the layer features have a second critical dimension, which is less than the first critical dimension.