Use of NH 3 etchant for voids suppression to enhance set cycles in CGeSbTe-based phase change memory devices

J. H. Park, J. H. Kim, Dae Hong Ko, Z. Wu, D. H. Ahn, S. O. Park, K. H. Hwang

Research output: Contribution to journalArticle

Abstract

As the cell size of phase change memory devices decreases to less than 100 nm, the dry etch used for cell patterning becomes extremely critical because of its impact on the properties of memory cells. HBr gas has been known as the etchant that can minimize surface etching damage to GeSbTe-based phase change materials. However, the findings reported herein show that the HBr etch of CGeSbTe (CGST) films causes voids after annealing at temperatures below 400 °C due to the vaporization of volatile bromides (GeBr 4 , SbBr 2 , and TeBr 2 ) that form when bromine diffuses during the etch. In this investigation, we report on the use of NH 3 etchants to suppress the formation of volatile compounds and thereby eliminate void formation in CGST materials. The properties of NH 3 etchants were compared to those of HBr etchants as a function of both etch rate and profiles. The effects of void suppression as observed in transmission electron microscopy images of as-etched CGST film after annealing indicate that phase change memory devices etched using an NH 3 exhibited enhanced set cycles that were over 10 8 superior to results of HBr etchants by 2 orders of magnitude.

Original languageEnglish
Pages (from-to)502-506
Number of pages5
JournalThin Solid Films
Volume616
DOIs
Publication statusPublished - 2016 Oct 1

Fingerprint

Phase change memory
etchants
voids
retarding
Data storage equipment
cycles
Annealing
Bromine
Phase change materials
Bromides
Vaporization
cells
Etching
Gases
annealing
phase change materials
Transmission electron microscopy
bromine
bromides
etching

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Materials Chemistry

Cite this

Park, J. H. ; Kim, J. H. ; Ko, Dae Hong ; Wu, Z. ; Ahn, D. H. ; Park, S. O. ; Hwang, K. H. / Use of NH 3 etchant for voids suppression to enhance set cycles in CGeSbTe-based phase change memory devices In: Thin Solid Films. 2016 ; Vol. 616. pp. 502-506.
@article{09eca0dd49f54cf1a05324d8cc211108,
title = "Use of NH 3 etchant for voids suppression to enhance set cycles in CGeSbTe-based phase change memory devices",
abstract = "As the cell size of phase change memory devices decreases to less than 100 nm, the dry etch used for cell patterning becomes extremely critical because of its impact on the properties of memory cells. HBr gas has been known as the etchant that can minimize surface etching damage to GeSbTe-based phase change materials. However, the findings reported herein show that the HBr etch of CGeSbTe (CGST) films causes voids after annealing at temperatures below 400 °C due to the vaporization of volatile bromides (GeBr 4 , SbBr 2 , and TeBr 2 ) that form when bromine diffuses during the etch. In this investigation, we report on the use of NH 3 etchants to suppress the formation of volatile compounds and thereby eliminate void formation in CGST materials. The properties of NH 3 etchants were compared to those of HBr etchants as a function of both etch rate and profiles. The effects of void suppression as observed in transmission electron microscopy images of as-etched CGST film after annealing indicate that phase change memory devices etched using an NH 3 exhibited enhanced set cycles that were over 10 8 superior to results of HBr etchants by 2 orders of magnitude.",
author = "Park, {J. H.} and Kim, {J. H.} and Ko, {Dae Hong} and Z. Wu and Ahn, {D. H.} and Park, {S. O.} and Hwang, {K. H.}",
year = "2016",
month = "10",
day = "1",
doi = "10.1016/j.tsf.2016.08.065",
language = "English",
volume = "616",
pages = "502--506",
journal = "Thin Solid Films",
issn = "0040-6090",
publisher = "Elsevier",

}

Use of NH 3 etchant for voids suppression to enhance set cycles in CGeSbTe-based phase change memory devices . / Park, J. H.; Kim, J. H.; Ko, Dae Hong; Wu, Z.; Ahn, D. H.; Park, S. O.; Hwang, K. H.

In: Thin Solid Films, Vol. 616, 01.10.2016, p. 502-506.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Use of NH 3 etchant for voids suppression to enhance set cycles in CGeSbTe-based phase change memory devices

AU - Park, J. H.

AU - Kim, J. H.

AU - Ko, Dae Hong

AU - Wu, Z.

AU - Ahn, D. H.

AU - Park, S. O.

AU - Hwang, K. H.

PY - 2016/10/1

Y1 - 2016/10/1

N2 - As the cell size of phase change memory devices decreases to less than 100 nm, the dry etch used for cell patterning becomes extremely critical because of its impact on the properties of memory cells. HBr gas has been known as the etchant that can minimize surface etching damage to GeSbTe-based phase change materials. However, the findings reported herein show that the HBr etch of CGeSbTe (CGST) films causes voids after annealing at temperatures below 400 °C due to the vaporization of volatile bromides (GeBr 4 , SbBr 2 , and TeBr 2 ) that form when bromine diffuses during the etch. In this investigation, we report on the use of NH 3 etchants to suppress the formation of volatile compounds and thereby eliminate void formation in CGST materials. The properties of NH 3 etchants were compared to those of HBr etchants as a function of both etch rate and profiles. The effects of void suppression as observed in transmission electron microscopy images of as-etched CGST film after annealing indicate that phase change memory devices etched using an NH 3 exhibited enhanced set cycles that were over 10 8 superior to results of HBr etchants by 2 orders of magnitude.

AB - As the cell size of phase change memory devices decreases to less than 100 nm, the dry etch used for cell patterning becomes extremely critical because of its impact on the properties of memory cells. HBr gas has been known as the etchant that can minimize surface etching damage to GeSbTe-based phase change materials. However, the findings reported herein show that the HBr etch of CGeSbTe (CGST) films causes voids after annealing at temperatures below 400 °C due to the vaporization of volatile bromides (GeBr 4 , SbBr 2 , and TeBr 2 ) that form when bromine diffuses during the etch. In this investigation, we report on the use of NH 3 etchants to suppress the formation of volatile compounds and thereby eliminate void formation in CGST materials. The properties of NH 3 etchants were compared to those of HBr etchants as a function of both etch rate and profiles. The effects of void suppression as observed in transmission electron microscopy images of as-etched CGST film after annealing indicate that phase change memory devices etched using an NH 3 exhibited enhanced set cycles that were over 10 8 superior to results of HBr etchants by 2 orders of magnitude.

UR - http://www.scopus.com/inward/record.url?scp=84988025733&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84988025733&partnerID=8YFLogxK

U2 - 10.1016/j.tsf.2016.08.065

DO - 10.1016/j.tsf.2016.08.065

M3 - Article

VL - 616

SP - 502

EP - 506

JO - Thin Solid Films

JF - Thin Solid Films

SN - 0040-6090

ER -