Details

Autor(en) / Beteiligte

• Marchack, Nathan
• Papalia, John M.
• Engelmann, Sebastian
• Joseph, Eric A.

Titel

Cyclic Cl2/H2 quasi-atomic layer etching approach for TiN and TaN patterning using organic masks

Ist Teil von

• Journal of vacuum science & technology. A, Vacuum, surfaces, and films, 2017-09, Vol.35 (5)

Erscheinungsjahr

2017

Quelle

AIP Scitation Journals Complete

Beschreibungen/Notizen

• A plasma-enhanced cyclic etch process utilizing sequential cycles of Cl2 (deposition) and He/H2 (etch) chemistries separated by purge steps was used to pattern TiN and TaN lines using an organic planarization layer mask at a 100 nm critical dimension and a 200 nm pitch. Etch rates (ERs) were found to vary from 3.5 to 7 nm per cycle for TaN and 5–7.3 nm per cycle for TiN, depending on the addition of H2 to the etch step. The cyclic etch process displayed several key advantages over a continuous wave plasma process, such as no residual material in TiN patterning and reduced veiling due to redeposition in the TaN features. Analysis of the optical emission spectra collected indicated a key mechanistic difference between etching of the two materials, with TiN etching mainly controlled by the residence time of Cl species and TaN etching rate-limited by physical bombardment to facilitate Ta-Cl formation. Tailoring of the feature profiles and control of the etch rate per cycle (ER/cycle) were demonstrated through manipulation of the Cl and H2 residence times.