Dry isotropic removal of inorganic anti-reflective coating after poly gate etching

A method of fabricating a conductor structure on a first workpiece, comprising:

• forming a polysilicon film on the first workpiece;
• forming an anti-reflective coating on the polysilicon film;
• forming a photoresist mask on a first portion of the anti-reflective coating, while leaving a second portion unmasked;
• etching the second portion of the anti-reflective coating and the polysilicon film;
• and
• removing the photoresist mask and the anti-reflective coating by isotropic plasma etching;
• measuring a width of the etched polysilicon film;
• comparing the measured width with a predicted width;
• and
• adapting the isotropic plasma etch for a second workpiece to reduce differences between the measured width and the predicted width.

A method of fabricating a conductor structure on a first workpiece, comprising:

• forming a polysilicon film on the first workpiece;
• forming a silicon oxynitride anti-reflective coating on the polysilicon film;
• forming a photoresist mask on a first portion of the silicon oxynitride anti-reflective coating, while leaving a second portion unmasked;
• etching the second portion of the silicon oxynitride anti-reflective coating and the polysilicon film;
• removing the photoresist mask;
• removing the silicon oxynitride anti-reflective coating by isotropic plasma etching;
• and
• measuring a width of the etched polysilicon film and comparing the measured width with a predicted width and adapting the isotropic plasma etch for a second workpiece to reduce differences between the measured width and the predicted width.