| AVS 62nd International Symposium & Exhibition | |
| Plasma Science and Technology | Monday Sessions |
| Session PS-MoM |
| Session: | Advanced FEOL/Gate Etching |
| Presenter: | Nathan Marchack, IBM T.J. Watson Research Center |
| Authors: | N.P. Marchack, IBM T.J. Watson Research Center S.U. Engelmann, IBM T.J. Watson Research Center E.A. Joseph, IBM T.J. Watson Research Center R.L. Bruce, IBM T.J. Watson Research Center H. Miyazoe, IBM T.J. Watson Research Center E.M. Sikorski, IBM T.J. Watson Research Center T. Suzuki, ZEON Chemicals L.P. M. Nakamura, ZEON Chemicals L.P. A. Itou, ZEON Chemicals L.P. H. Matsumoto, Zeon Corporation, Kawasaki, Japan |
| Correspondent: | Click to Email |
Image reversal has been utilized in semiconductor manufacturing to invert line/space [US6221562 B1] and hole/pillar [US6358856 B1] patterns. Since this process requires the ability to remove one material with high selectivity to another, traditionally either contrasting dielectrics (such as SiN/SiOx) or complementary types of photoresist (e.g. positive/negative tone) have been used. While carbon-based soft materials are easier to deposit than dielectric films, lack of selectivity and physical integrity can potentially hinder successful image reversal processes when they are combined with hard materials, e.g. metals, dielectrics.
We present an image reversal process by depositing an organic planarizing layer (OPL) material into a hole array patterned in SiN to create pillars, which are a commonly required shape for a variety of emerging technologies. By using a gas chemistry with an extremely high selectivity to OPL, plasma etch removal of the SiN is possible, allowing pattern fidelity to be maintained at pitches below 100nm. We demonstrate control of the pillar CD by controlling the time of the OPL etchback step.
For applications requiring minimal mask budget, we utilize the same chemistry’s selectivity to SiOx to demonstrate patterning of SiN hard mask features with reduced LER/LWR and iso/dense loading ratio. We demonstrate hard mask patterning of 80nm thick SiN with 35nm SiOx hard mask for 50nm pitch lines, with potential applications for advanced technology nodes. The results were achieved in both RLSA and ICP plasma sources.