Nathan Marchack, Hiroyuki Miyazoe, et al.
JVSTB
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.
Nathan Marchack, Hiroyuki Miyazoe, et al.
JVSTB
Guohan Hu, J.H. Lee, et al.
IEDM 2015
Pouya Hashemi, Karthik Balakrishnan, et al.
PRiME/ECS Meeting 2016
Dominik Metzler, Chen Li, et al.
Journal of Chemical Physics