Plasma etching with metal sputtering

A method of etching a substrate, the method comprising:

• loading the substrate into a plasma etch chamber, the substrate comprising a patterned hard mask layer and an underlying layer, the plasma etch chamber comprising:
• a focus ring having a surface comprising a refractory metal;
• and
• a first electrode;
• flowing a process gas comprising fluorine and carbon into the plasma etch chamber;
• while flowing the process gas, applying a source power to the first electrode of the plasma etch chamber to generate a plasma in the plasma etch chamber;
• and
• etching the underlying layer, the etching comprising
• exposing the surface of the focus ring to the plasma to sputter the refractory metal from the surface of a chamber part of the plasma etch chamber, and
• exposing the substrate to the plasma to form a recess in the underlying layer, wherein a conductive polymer layer comprising the refractory metal is deposited over the substrate with a radial gradient such that a concentration of the refractory metal in the conductive polymer layer near an edge portion of the substrate is higher than a central portion of the substrate.

A method of etching a substrate, the method comprising:

• loading the substrate into a plasma etch chamber, the substrate comprising a patterned hard mask layer and an underlying layer, the plasma etch chamber comprising
• a top electrode having a surface comprising a first refractory metal,
• a bottom electrode,
• a first radio frequency (RF) power source connected to the bottom electrode,
• a second radio frequency (RF) power source connected to the bottom electrode,
• a direct current (DC) voltage source connected to the top electrode, and
• a focus ring having a surface comprising a second refractory metal;
• flowing a process gas comprising fluorine and carbon into the plasma etch chamber;
• while flowing the process gas, applying a source power to the bottom electrode using the first RF power source to generate a plasma in the plasma etch chamber;
• applying a bias power to the bottom electrode using the second RF power source;
• applying a DC voltage to the top electrode using the DC voltage source;
• and
• etching the underlying layer, the etching comprising
• sputtering the first and second refractory metals from the top electrode, and
• exposing the substrate to the plasma to form a recess in the underlying layer, wherein a conductive polymer layer comprising the first and second refractory metals is deposited on sidewalls of the patterned hard mask layer and the underlying layer.