Understanding of Etching Mechanism of Si3N4Film in H3PO4Solution For The Fabrication of 3D NAND Devices

Taegun Park, Changjin Son, Taehyeon Kim, Sangwoo Lim

Research output: Chapter in Book/Report/Conference proceedingConference contribution


The etching mechanism of the Si3N4 in H3PO4 solution is proposed. The effect of H3PO4 concentrations on Si3N4 etching rate is investigated. The Si3N4 etching rate is not simply proportional to H3PO4. Both H3PO4 and H2O participate in the Si3N4 etching reaction and play their roles. First, H2PO4- which is a weak nucleophile generated from H3PO4 replaces -NH2 on the Si3N4 surface with -H2PO4 by an SN1-like reaction. Next, N-Si which is backbone of Si3N4 network is substituted by H2O with Si-OH by an SN2-like reaction. From the Si3N4 etching mechanism and kinetic studies, it is concluded that the Si3N4 etching rate is proportional to product of concentration of H2O and H3PO4. These results suggest that consumption of H3PO4 can be reduced by using a lower concentration of H3PO4 between two H3PO4 concentrations that can produce a similar Si3N4 etching rates.

Original languageEnglish
Title of host publicationECS Transactions
PublisherInstitute of Physics
Number of pages6
ISBN (Electronic)9781607685395
Publication statusPublished - 2022
Event241st ECST Meeting - Vancouver, Canada
Duration: 2022 May 292022 Jun 2

Publication series

NameECS Transactions
ISSN (Print)1938-6737
ISSN (Electronic)1938-5862


Conference241st ECST Meeting

Bibliographical note

Publisher Copyright:
© 2022 ECS - The Electrochemical Society.

All Science Journal Classification (ASJC) codes

  • Engineering(all)


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