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Dry etching of niobium using CCl sub 2 F sub 2 and CF sub 4 : A comparison

Journal Article · · Journal of Applied Physics; (USA)
DOI:https://doi.org/10.1063/1.347026· OSTI ID:6003057
 [1]
  1. Hypres Incorporated, Elmsford, NY (USA)

Freon 12 is compared to freon 14 as an etchant for patterning of high density superconductive circuits. Both reactive ion and plasma regimes are examined. CCl{sub 2}F{sub 2} is observed to be an excellent niobium etchant, offering significant advantages over similar CF{sub 4} processes. Improvements include a six-fold increase of Nb:photoresist selectivity, while Nb:SiO{sub 2} selectivity is increased by over 1400%. Critical dimension control was also enhanced through the reduction of photo to etch bias from between 1.09 and 0.5 {mu}m to 0.14 {mu}m. Diminished photoresist loss and the elimination of photoresist undercut are the reasons for this improvement. SiO{sub 2} surface texturing is not observed with either of the two etchants. Finally, data are presented that demonstrate the importance of electrode cooling in obtaining etch rate repeatability.

OSTI ID:
6003057
Journal Information:
Journal of Applied Physics; (USA), Journal Name: Journal of Applied Physics; (USA) Vol. 68:10; ISSN 0021-8979; ISSN JAPIA
Country of Publication:
United States
Language:
English