Interconnect processes
What problem must be watched for when etching or ashing low-k films?
- AThe film becomes far too hard
- BPlasma damages the film, for example by removing carbon, raising its dielectric constant
- CThe film emits light
Show answer and explanation
Answer: B. Plasma damages the film, for example by removing carbon, raising its dielectric constant
SiOC low-k films achieve low permittivity by containing carbon and methyl groups, but exposure to oxygen plasma and similar treatments removes them, making the film absorb moisture and raising its dielectric constant. Low-damage ashing conditions and treatments that repair the damage are needed.