ETCH CHARACTERISTICS OF AN AMORPHOUS REFRACTORY ABSORBER

An ECR etch process for defining sub-0.25 mu m features in a TaSiN abs orber layer has been developed. A 2000 Angstrom PECVD oxide layer serv ed as a hard mask during the etch. The effect on feature profile has b een determined as a function of both rf power and back side temperatur e. Etch rate uniformity is excellent, with 3 sigma deviations of less than 4% over the center 40 mm of the substrate. Micro-loading issues a ssociated with the etch process have also been characterized. Minimal line edge roughness is observed, and the feasibility for defining 0.10 mu m features has been demonstrated.