Fluorine-doped silicate glass hard mask to improve metal line etching profile

A method of forming metal lines having a vertical profile in the fabrication of an integrated circuit comprising:

• providing semiconductor device structures in and on a semiconductor substrate;
• covering said semiconductor device structures with an insulating layer;
• depositing a barrier layer overlying said insulating layer;
• depositing a metal layer overlying said barrier layer;
• depositing an antireflective coating layer overlying said metal layer;
• depositing a layer of fluorine-doped silicate glass overlying said antireflective coating layer wherein said fluorine-doped silicate glass layer acts as a hard mask;
• covering said hard mask with a layer of photoresist;
• exposing said photoresist layer to actinic light and developing and patterning said photoresist layer to form the desired photoresist mask;
• etching away said hard mask where it is not covered by said photoresist mask leaving a patterned hard mask;
• etching away said metal layer not covered by said patterned hard mask to form said metal lines whereby fluorine ions released from said patterned hard mask form a passivation layer on the sidewalls of said metal lines thereby preventing undercutting of said metal lines resulting in said metal lines having said vertical profile wherein said etching away does not use SF.sub.6 chemistry;
• removing said photoresist mask;
• and
• completing said fabrication of said integrated circuit.

A method of forming metal lines having a vertical profile in the fabrication of an integrated circuit comprising:

• providing semiconductor device structures including gate electrodes and source and drain regions in and on a semiconductor substrate;
• covering said semiconductor device structures with an insulating layer;
• depositing a barrier layer overlying said insulating layer;
• depositing a metal layer overlying said barrier layer;
• depositing an antireflective coating layer overlying said metal layer;
• depositing a layer of fluorine-doped silicate glass overlying said antireflective coating layer wherein said fluorine-doped silicate glass layer acts as a hard mask;
• covering said hard mask with a layer of photoresist;
• exposing said photoresist layer to actinic light and developing and patterning said photoresist layer to form the desired photoresist mask;
• etching away said hard mask where it is not covered by said photoresist mask leaving a patterned hard mask;
• etching away said metal layer not covered by said patterned hard mask to form said metal lines whereby fluorine ions released from said patterned hard mask form a C.sub.x F.sub.y passivation layer on the sidewalls of said metal lines thereby preventing undercutting of said metal lines resulting in said metal lines having said vertical profile wherein said etching away does not use SF.sub.6 chemistry;
• removing said photoresist mask;
• and
• completing said fabrication of said integrated circuit.