Semiconductor device fabrication with removal of accumulation of material from sidewall

A method for fabricating a semiconductor device, comprising:

• forming a plurality of layers over a semiconductor substrate, comprising:
• forming a first metal layer over a semiconductor substrate;
• forming a first layer over the first metal layer and contacting the first metal layer;
• forming a second metal layer over the first layer and contacting the first layer;
• etching the plurality of layers to expose a sidewall of the first metal layer, a sidewall of the first layer, and a sidewall of the second metal layer, wherein the etching creates an accumulation of material on the sidewall of the first metal layer, the sidewall of the first layer, and the sidewall of the second metal layer;
• and
• etching the accumulation using a first etchant comprising fluorine to remove at least some of the accumulation.

A method for fabricating a semiconductor device, comprising:

• forming a first metal layer over a semiconductor substrate;
• forming a first dielectric layer over the first metal layer;
• etching the first dielectric layer and the first metal layer to expose a sidewall of the first dielectric layer and a sidewall of the first metal layer, wherein the etching disburses a portion of the first metal layer to create an accumulation of material on at least one of the sidewall of the first dielectric layer or the sidewall of the first metal layer;
• etching the accumulation using an etchant comprising fluorine to remove at least some of the accumulation;
• and
• forming a second dielectric layer adjacent the sidewall of the first dielectric layer after etching the accumulation.