Cyclic etching of silicon oxide using NF3/H2 remote plasma and NH3 gas flow

You Jung Gill; Doo San Kim; Hong Seong Gil; Ki Hyun Kim; Yun Jong Jang; Ye Eun Kim; Geun Young Yeom

doi:10.1002/ppap.202100063

Cyclic etching of silicon oxide using NF₃/H₂ remote plasma and NH₃ gas flow

You Jung Gill, Doo San Kim, Hong Seong Gil, Ki Hyun Kim, Yun Jong Jang, Ye Eun Kim, Geun Young Yeom

Department of Advanced Materials Science and Engineering

Sungkyunkwan University

Research output: Contribution to journal › Article › peer-review

11 Scopus citations

Abstract

Selective isotropic cyclic dry etching of silicon oxide (SiO₂) was investigated using a three-step cyclic process composed of hydrogen fluoride (HF) adsorption by NF₃/H₂ remote plasma and reaction with NH₃ gas flow to form ammonium fluorosilicate ((NH₄)₂SiF₆), and desorption by heating. The variation of the ratio of NF₃:H₂ (2:1 to 1:3) and adsorption time (10–180 s) showed the highest etch selectivity of SiO₂ over Si₃N₄ at 1:2 ratio of NF₃:H₂ and with the adsorption time of 20 s. The etch selectivity higher than 40 was observed with 20 s of adsorption time with a 1:2 ratio of NF₃:H₂ remote plasma and the total etch depth was linearly increased with the increase of cycles with the SiO₂ EPC of ~7.5 nm/cycle.

Original language	English
Article number	2100063
Journal	Plasma Processes and Polymers
Volume	18
Issue number	11
DOIs	https://doi.org/10.1002/ppap.202100063
State	Published - Nov 2021

Keywords

cyclic etching
H
NF
remote plasma
SiO

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title = "Cyclic etching of silicon oxide using NF3/H2 remote plasma and NH3 gas flow",

abstract = "Selective isotropic cyclic dry etching of silicon oxide (SiO2) was investigated using a three-step cyclic process composed of hydrogen fluoride (HF) adsorption by NF3/H2 remote plasma and reaction with NH3 gas flow to form ammonium fluorosilicate ((NH4)2SiF6), and desorption by heating. The variation of the ratio of NF3:H2 (2:1 to 1:3) and adsorption time (10–180 s) showed the highest etch selectivity of SiO2 over Si3N4 at 1:2 ratio of NF3:H2 and with the adsorption time of 20 s. The etch selectivity higher than 40 was observed with 20 s of adsorption time with a 1:2 ratio of NF3:H2 remote plasma and the total etch depth was linearly increased with the increase of cycles with the SiO2 EPC of \textasciitilde{}7.5 nm/cycle.",

keywords = "cyclic etching, H, NF, remote plasma, SiO",

author = "Gill, \{You Jung\} and Kim, \{Doo San\} and Gil, \{Hong Seong\} and Kim, \{Ki Hyun\} and Jang, \{Yun Jong\} and Kim, \{Ye Eun\} and Yeom, \{Geun Young\}",

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year = "2021",

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doi = "10.1002/ppap.202100063",

language = "English",

volume = "18",

journal = "Plasma Processes and Polymers",

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T1 - Cyclic etching of silicon oxide using NF3/H2 remote plasma and NH3 gas flow

AU - Gill, You Jung

AU - Kim, Doo San

AU - Gil, Hong Seong

AU - Kim, Ki Hyun

AU - Jang, Yun Jong

AU - Kim, Ye Eun

AU - Yeom, Geun Young

PY - 2021/11

Y1 - 2021/11

N2 - Selective isotropic cyclic dry etching of silicon oxide (SiO2) was investigated using a three-step cyclic process composed of hydrogen fluoride (HF) adsorption by NF3/H2 remote plasma and reaction with NH3 gas flow to form ammonium fluorosilicate ((NH4)2SiF6), and desorption by heating. The variation of the ratio of NF3:H2 (2:1 to 1:3) and adsorption time (10–180 s) showed the highest etch selectivity of SiO2 over Si3N4 at 1:2 ratio of NF3:H2 and with the adsorption time of 20 s. The etch selectivity higher than 40 was observed with 20 s of adsorption time with a 1:2 ratio of NF3:H2 remote plasma and the total etch depth was linearly increased with the increase of cycles with the SiO2 EPC of ~7.5 nm/cycle.

AB - Selective isotropic cyclic dry etching of silicon oxide (SiO2) was investigated using a three-step cyclic process composed of hydrogen fluoride (HF) adsorption by NF3/H2 remote plasma and reaction with NH3 gas flow to form ammonium fluorosilicate ((NH4)2SiF6), and desorption by heating. The variation of the ratio of NF3:H2 (2:1 to 1:3) and adsorption time (10–180 s) showed the highest etch selectivity of SiO2 over Si3N4 at 1:2 ratio of NF3:H2 and with the adsorption time of 20 s. The etch selectivity higher than 40 was observed with 20 s of adsorption time with a 1:2 ratio of NF3:H2 remote plasma and the total etch depth was linearly increased with the increase of cycles with the SiO2 EPC of ~7.5 nm/cycle.

KW - cyclic etching

KW - H

KW - NF

KW - remote plasma

KW - SiO

UR - https://www.scopus.com/pages/publications/85111867121

U2 - 10.1002/ppap.202100063

DO - 10.1002/ppap.202100063

M3 - Article

AN - SCOPUS:85111867121

SN - 1612-8850

VL - 18

JO - Plasma Processes and Polymers

JF - Plasma Processes and Polymers

IS - 11

M1 - 2100063

ER -

Cyclic etching of silicon oxide using NF₃/H₂ remote plasma and NH₃ gas flow

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Keywords

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