Bi-layer photoresist dry development and reactive ion etch method

A method for etching a semiconductor device feature using a bi-layer photoresist to improve an operating etching resolution and reduce particulate contamination comprising the steps of:

• providing a non-silicon containing photoresist layer over a dielectric insulating layer to form a first resist layer;
• providing a silicon containing photoresist layer on the first resist layer to form a second resist layer thinner than the first resist layer;
• patterning the second resist layer according to a photolithographic exposure process comprising a wavelength selected from the group consisting of 157 nm and 193 nm;
• wet developing the second resist layer to form a patterned second resist layer;
• dry developing the first resist layer according to a dry etching chemistry formed by supplying gases consisting essentially of nitrogen, oxygen, and argon, to reveal the dielectric insulating layer to form an etching mask;
• plasma etching in-situ an opening in the dielectric insulating layer according to the etching mask;
• then carrying out an in-situ oxygen ashing process to remove overlying resist layers comprising at least the first resist layer;
• wherein, during the in-situ oxygen ashing process a simultaneous in-situ plasma cleaning process is performed comprising adding a component selected from the group consisting of fluorine and nitrogen to clean plasma reactor contact surfaces.

A method for etching a semiconductor device feature using a bi-layer photoresist to improve an opening etching resolution and reduce particulate contamination comprising the steps of:

• providing a non-silicon containing photoresist layer over a dielectric insulating layer to form a first resist layer;
• providing a silicon containing photoresist layer over the first resist layer to form a second resist layer thinner than the first resist layer;
• patterning the second resist layer according to a photolithographic exposure process comprising a wavelength selected from the group consisting of 157 nm and 193 nm;
• wet developing the second resist layer to form a patterned second resist layer;
• dry etching the first resist layer according to a dry etching chemistry comprising nitrogen, oxygen, and argon, to reveal the dielectric insulating layer to form an etching mask;
• then carrying out a first in-situ oxygen ashing process to remove the second resist layer;
• then plasma etching in-situ an opening in the dielectric insulating layer;
• then carrying out a second in-situ oxygen ashing process to remove the first resist layer;
• then plasma etching in-situ through a bottom etch stop layer comprising the substrate;
• and,
• then carrying out an in-situ plasma cleaning process comprising a component selected from the group consisting of fluorine and nitrogen to clean plasma reactor contact surfaces.