Method for producing gate stack sidewall spacers

A method for forming a sidewall spacer for a gate electrode, comprising:

• placing a substrate having a gate structure in a plasma process chamber;
• flowing process gas(es) into the plasma process chamber;
• creating a plasma in the plasma process chamber;
• and
• depositing one or more layers of silicon containing materials on the gate structure in the presence of the plasma, wherein the one or more layers of silicon containing materials have an overall dielectric constant value of about 3.0 to about 5.0, and the one or more layers of silicon containing materials are selected from the group consisting of silicon carbide, oxygen doped silicon carbide, nitrogen doped silicon carbide, carbon doped silicon nitride, nitrogen doped silicon oxycarbide, and combinations thereof.

A method for forming a sidewall spacer for a gate electrode, comprising:

• placing a substrate having a gate structure in a plasma process chamber;
• flowing process gas(es) into the plasma process chamber;
• creating a plasma in the plasma process chamber;
• and
• depositing one or more layers of silicon containing materials on the gate structure at a temperature equaling to or below 450° C. in the presence of the plasma, wherein the one or more layers of silicon containing materials have an overall dielectric constant value of about 3.0 to about 5.0, and the one or more layers of silicon containing materials are selected from the group consisting of silicon carbide, oxygen doped silicon carbide, nitrogen doped silicon carbide, carbon doped silicon nitride, nitrogen doped silicon oxycarbide, and combinations thereof.