WSix/WN/polysilicon DRAM gate stack with a 50 Å WN layer as a diffusion barrier and an etch stop

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

A new DRAM gate stack of WSix/WN/polysilicon with a 50 Å WN layer was studied as a gate stack of future technologies. With the 50 Å WN layer inserted between the WSix and polysilicon, the tungsten silicide etch was able to be very selective to the thin WN layer, and the thickness of the polysilicon underneath can be minimized. The etch selectivity of WN to silicide using the Cl2-based chemistry was approximately 1:13.2. The sheet resistivity of the new gate stack could be reduced significantly by using a thicker WSix and a thinner polysilicon while the aspect ratio of the gate stack remains the same. The thin WN layer seemed to work well as a diffusion barrier, as is shown by secondary ion mass spectroscopy analysis. The new gate stack with a low resistance and aspect ratio and without the diffusion problem seems a good candidate as a future DRAM gate and can extend the use of WSix gates to future technologies.

Original languageEnglish
Pages (from-to)602-607
Number of pages6
JournalMaterials Science in Semiconductor Processing
Volume8
Issue number5
DOIs
Publication statusPublished - 2005 Oct 1

Fingerprint

Diffusion barriers
Dynamic random access storage
Polysilicon
Aspect ratio
Tungsten
aspect ratio
Spectroscopy
Ions
low resistance
tungsten
mass spectroscopy
selectivity
chemistry
electrical resistivity

Keywords

  • DRAM
  • Etching
  • Tungsten nitride
  • Tungsten silicide

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials

Cite this

@article{7f08d3e90899473a8583823c60d63dff,
title = "WSix/WN/polysilicon DRAM gate stack with a 50 {\AA} WN layer as a diffusion barrier and an etch stop",
abstract = "A new DRAM gate stack of WSix/WN/polysilicon with a 50 {\AA} WN layer was studied as a gate stack of future technologies. With the 50 {\AA} WN layer inserted between the WSix and polysilicon, the tungsten silicide etch was able to be very selective to the thin WN layer, and the thickness of the polysilicon underneath can be minimized. The etch selectivity of WN to silicide using the Cl2-based chemistry was approximately 1:13.2. The sheet resistivity of the new gate stack could be reduced significantly by using a thicker WSix and a thinner polysilicon while the aspect ratio of the gate stack remains the same. The thin WN layer seemed to work well as a diffusion barrier, as is shown by secondary ion mass spectroscopy analysis. The new gate stack with a low resistance and aspect ratio and without the diffusion problem seems a good candidate as a future DRAM gate and can extend the use of WSix gates to future technologies.",
keywords = "DRAM, Etching, Tungsten nitride, Tungsten silicide",
author = "Heon Lee and Donghwan Kim and Huh, {Joo Youl} and Kim, {Deok Kee}",
year = "2005",
month = "10",
day = "1",
doi = "10.1016/j.mssp.2005.08.001",
language = "English",
volume = "8",
pages = "602--607",
journal = "Materials Science in Semiconductor Processing",
issn = "1369-8001",
publisher = "Elsevier Limited",
number = "5",

}

TY - JOUR

T1 - WSix/WN/polysilicon DRAM gate stack with a 50 Å WN layer as a diffusion barrier and an etch stop

AU - Lee, Heon

AU - Kim, Donghwan

AU - Huh, Joo Youl

AU - Kim, Deok Kee

PY - 2005/10/1

Y1 - 2005/10/1

N2 - A new DRAM gate stack of WSix/WN/polysilicon with a 50 Å WN layer was studied as a gate stack of future technologies. With the 50 Å WN layer inserted between the WSix and polysilicon, the tungsten silicide etch was able to be very selective to the thin WN layer, and the thickness of the polysilicon underneath can be minimized. The etch selectivity of WN to silicide using the Cl2-based chemistry was approximately 1:13.2. The sheet resistivity of the new gate stack could be reduced significantly by using a thicker WSix and a thinner polysilicon while the aspect ratio of the gate stack remains the same. The thin WN layer seemed to work well as a diffusion barrier, as is shown by secondary ion mass spectroscopy analysis. The new gate stack with a low resistance and aspect ratio and without the diffusion problem seems a good candidate as a future DRAM gate and can extend the use of WSix gates to future technologies.

AB - A new DRAM gate stack of WSix/WN/polysilicon with a 50 Å WN layer was studied as a gate stack of future technologies. With the 50 Å WN layer inserted between the WSix and polysilicon, the tungsten silicide etch was able to be very selective to the thin WN layer, and the thickness of the polysilicon underneath can be minimized. The etch selectivity of WN to silicide using the Cl2-based chemistry was approximately 1:13.2. The sheet resistivity of the new gate stack could be reduced significantly by using a thicker WSix and a thinner polysilicon while the aspect ratio of the gate stack remains the same. The thin WN layer seemed to work well as a diffusion barrier, as is shown by secondary ion mass spectroscopy analysis. The new gate stack with a low resistance and aspect ratio and without the diffusion problem seems a good candidate as a future DRAM gate and can extend the use of WSix gates to future technologies.

KW - DRAM

KW - Etching

KW - Tungsten nitride

KW - Tungsten silicide

UR - http://www.scopus.com/inward/record.url?scp=27844503616&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=27844503616&partnerID=8YFLogxK

U2 - 10.1016/j.mssp.2005.08.001

DO - 10.1016/j.mssp.2005.08.001

M3 - Article

AN - SCOPUS:27844503616

VL - 8

SP - 602

EP - 607

JO - Materials Science in Semiconductor Processing

JF - Materials Science in Semiconductor Processing

SN - 1369-8001

IS - 5

ER -