Al2O3 buffer in a ZnO thin film transistor with poly-4-vinylphenol dielectric

Seokhwan Bang, Seungjun Lee, Sunyeol Jeon, Semyung Kwon, Wooho Jeong, Honggyu Kim, Iksup Shin, Ho Jung Chang, Hyung-Ho Park, Hyeongtag Jeon

Research output: Contribution to journalArticle

27 Citations (Scopus)

Abstract

We compared the characteristics of bottom-gate ZnO-thin film transistors using poly-4-vinylphenol (PVP) and PVP/Al2O3 dielectrics. The PVP dielectric is more hydrophobic than the PVP/Al2O3 dielectric and is not useful for TFT devices because of its high leakage current density, but this leakage current density can be significantly reduced by inserting Al2O3. We deposited ZnO and Al2O 3 films by atomic layer deposition (ALD) because it is a low-temperature process. The ZnO-TFTs with either a PVP or a PVP/Al 2O3 dielectric exhibit typical field-effect transistor characteristics with n-channel properties. The ZnO-TFT containing PVP/Al 2O3 exhibits clear pinch-off and excellent saturation with an enhanced mode operation. The on/off ratio of 7.9 × 104 for the device containing the hybrid dielectric is about three orders of magnitude higher than the ratio of 47 for the device containing PVP. The subthreshold gate swings are 12 V/decade for the TFT containing PVP and 1.2 V/decade for the TFT containing PVP/Al2O3. The density of the interface trap state is significantly lower in the device containing PVP/Al2O 3 than in the ZnO-TFT containing PVP. The saturation mobility was 0.05 and 0.8 cm2 V-1 s-1, respectively, in the TFTs containing PVP and PVP/Al2O3.

Original languageEnglish
Article number025008
JournalSemiconductor Science and Technology
Volume24
Issue number2
DOIs
Publication statusPublished - 2009 Apr 16

Fingerprint

Thin film transistors
Buffers
transistors
buffers
thin films
Leakage currents
leakage
Current density
current density
saturation
Atomic layer deposition
atomic layer epitaxy
Field effect transistors
field effect transistors
poly(4-vinylphenol)
traps
Temperature

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering
  • Materials Chemistry

Cite this

Bang, Seokhwan ; Lee, Seungjun ; Jeon, Sunyeol ; Kwon, Semyung ; Jeong, Wooho ; Kim, Honggyu ; Shin, Iksup ; Chang, Ho Jung ; Park, Hyung-Ho ; Jeon, Hyeongtag. / Al2O3 buffer in a ZnO thin film transistor with poly-4-vinylphenol dielectric. In: Semiconductor Science and Technology. 2009 ; Vol. 24, No. 2.
@article{0213c24aeabe46adac796c491a1d2580,
title = "Al2O3 buffer in a ZnO thin film transistor with poly-4-vinylphenol dielectric",
abstract = "We compared the characteristics of bottom-gate ZnO-thin film transistors using poly-4-vinylphenol (PVP) and PVP/Al2O3 dielectrics. The PVP dielectric is more hydrophobic than the PVP/Al2O3 dielectric and is not useful for TFT devices because of its high leakage current density, but this leakage current density can be significantly reduced by inserting Al2O3. We deposited ZnO and Al2O 3 films by atomic layer deposition (ALD) because it is a low-temperature process. The ZnO-TFTs with either a PVP or a PVP/Al 2O3 dielectric exhibit typical field-effect transistor characteristics with n-channel properties. The ZnO-TFT containing PVP/Al 2O3 exhibits clear pinch-off and excellent saturation with an enhanced mode operation. The on/off ratio of 7.9 × 104 for the device containing the hybrid dielectric is about three orders of magnitude higher than the ratio of 47 for the device containing PVP. The subthreshold gate swings are 12 V/decade for the TFT containing PVP and 1.2 V/decade for the TFT containing PVP/Al2O3. The density of the interface trap state is significantly lower in the device containing PVP/Al2O 3 than in the ZnO-TFT containing PVP. The saturation mobility was 0.05 and 0.8 cm2 V-1 s-1, respectively, in the TFTs containing PVP and PVP/Al2O3.",
author = "Seokhwan Bang and Seungjun Lee and Sunyeol Jeon and Semyung Kwon and Wooho Jeong and Honggyu Kim and Iksup Shin and Chang, {Ho Jung} and Hyung-Ho Park and Hyeongtag Jeon",
year = "2009",
month = "4",
day = "16",
doi = "10.1088/0268-1242/24/2/025008",
language = "English",
volume = "24",
journal = "Semiconductor Science and Technology",
issn = "0268-1242",
publisher = "IOP Publishing Ltd.",
number = "2",

}

Bang, S, Lee, S, Jeon, S, Kwon, S, Jeong, W, Kim, H, Shin, I, Chang, HJ, Park, H-H & Jeon, H 2009, 'Al2O3 buffer in a ZnO thin film transistor with poly-4-vinylphenol dielectric', Semiconductor Science and Technology, vol. 24, no. 2, 025008. https://doi.org/10.1088/0268-1242/24/2/025008

Al2O3 buffer in a ZnO thin film transistor with poly-4-vinylphenol dielectric. / Bang, Seokhwan; Lee, Seungjun; Jeon, Sunyeol; Kwon, Semyung; Jeong, Wooho; Kim, Honggyu; Shin, Iksup; Chang, Ho Jung; Park, Hyung-Ho; Jeon, Hyeongtag.

In: Semiconductor Science and Technology, Vol. 24, No. 2, 025008, 16.04.2009.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Al2O3 buffer in a ZnO thin film transistor with poly-4-vinylphenol dielectric

AU - Bang, Seokhwan

AU - Lee, Seungjun

AU - Jeon, Sunyeol

AU - Kwon, Semyung

AU - Jeong, Wooho

AU - Kim, Honggyu

AU - Shin, Iksup

AU - Chang, Ho Jung

AU - Park, Hyung-Ho

AU - Jeon, Hyeongtag

PY - 2009/4/16

Y1 - 2009/4/16

N2 - We compared the characteristics of bottom-gate ZnO-thin film transistors using poly-4-vinylphenol (PVP) and PVP/Al2O3 dielectrics. The PVP dielectric is more hydrophobic than the PVP/Al2O3 dielectric and is not useful for TFT devices because of its high leakage current density, but this leakage current density can be significantly reduced by inserting Al2O3. We deposited ZnO and Al2O 3 films by atomic layer deposition (ALD) because it is a low-temperature process. The ZnO-TFTs with either a PVP or a PVP/Al 2O3 dielectric exhibit typical field-effect transistor characteristics with n-channel properties. The ZnO-TFT containing PVP/Al 2O3 exhibits clear pinch-off and excellent saturation with an enhanced mode operation. The on/off ratio of 7.9 × 104 for the device containing the hybrid dielectric is about three orders of magnitude higher than the ratio of 47 for the device containing PVP. The subthreshold gate swings are 12 V/decade for the TFT containing PVP and 1.2 V/decade for the TFT containing PVP/Al2O3. The density of the interface trap state is significantly lower in the device containing PVP/Al2O 3 than in the ZnO-TFT containing PVP. The saturation mobility was 0.05 and 0.8 cm2 V-1 s-1, respectively, in the TFTs containing PVP and PVP/Al2O3.

AB - We compared the characteristics of bottom-gate ZnO-thin film transistors using poly-4-vinylphenol (PVP) and PVP/Al2O3 dielectrics. The PVP dielectric is more hydrophobic than the PVP/Al2O3 dielectric and is not useful for TFT devices because of its high leakage current density, but this leakage current density can be significantly reduced by inserting Al2O3. We deposited ZnO and Al2O 3 films by atomic layer deposition (ALD) because it is a low-temperature process. The ZnO-TFTs with either a PVP or a PVP/Al 2O3 dielectric exhibit typical field-effect transistor characteristics with n-channel properties. The ZnO-TFT containing PVP/Al 2O3 exhibits clear pinch-off and excellent saturation with an enhanced mode operation. The on/off ratio of 7.9 × 104 for the device containing the hybrid dielectric is about three orders of magnitude higher than the ratio of 47 for the device containing PVP. The subthreshold gate swings are 12 V/decade for the TFT containing PVP and 1.2 V/decade for the TFT containing PVP/Al2O3. The density of the interface trap state is significantly lower in the device containing PVP/Al2O 3 than in the ZnO-TFT containing PVP. The saturation mobility was 0.05 and 0.8 cm2 V-1 s-1, respectively, in the TFTs containing PVP and PVP/Al2O3.

UR - http://www.scopus.com/inward/record.url?scp=64249092247&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=64249092247&partnerID=8YFLogxK

U2 - 10.1088/0268-1242/24/2/025008

DO - 10.1088/0268-1242/24/2/025008

M3 - Article

AN - SCOPUS:64249092247

VL - 24

JO - Semiconductor Science and Technology

JF - Semiconductor Science and Technology

SN - 0268-1242

IS - 2

M1 - 025008

ER -