Mechanism of mobility enhancement in Ge p-channel metal-oxide-semiconductor field-effect transistor due to introduction of Al atoms into SiO2/GeO2 gate stack

Yuta Nagatomi, Tomoki Tateyama, Shintaro Tanaka, Wei Chen Wen, Taisei Sakaguchi, Keisuke Yamamoto, Liwei Zhao, Dong Wang, Hiroshi Nakashima

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

In this paper, we present comprehensive results on Al-postmetallization annealing (Al-PMA) effect for the SiO2/GeO2 gate stack on a Ge substrate, which were fabricated by a physical vapor deposition method. The effective oxide thickness of metal-oxide-semiconductor (MOS) capacitor (CAP) was ~7 nm, and the Al-PMA was performed at a temperature in the range of 300–400 °C. The flat band voltage (VFB), the hysteresis (HT), the interfacial states density (Dit), and the border traps density (Dbt) for MOSCAPs were characterized by a capacitance–voltage method and a constant-temperature deep-level transient spectroscopy method. The MOSCAP without Al-PMA had an electrical dipole of ~−0.8 eV at a SiO2/GeO2 interface, which was disappeared after Al-PMA at 300 °C. The HT, Dit, and Dbt were decreased after Al-PMA at 300 °C and were maintained in the temperature range of 300–400 °C. On the other hand, the VFB was monotonically shifted in the positive direction with an increase in PMA temperature, suggesting the generation of negatively charged atoms. Structural analyses for MOSCAPs without and with Al-PMA were performed by a time-of-flight secondary ion mass spectroscopy method and an X-ray photoelectron spectroscopy method. It was confirmed that Al atoms diffused from an Al electrode to a SiO2 film and reacted with GeO2. The dipole disappearance after Al-PMA at 300 °C is likely to be associated with the structural change at the SiO2/GeO2 interface. We also present the device performances of Al-gated p-channel MOS field-effect transistors (FET) with PMA treatments, which were fabricated using PtGe/Ge contacts as source/drain. The peak field-effect mobility (μh) of the p-MOSFET was reached a value of 468 cm2/Vs after Al-PMA at 325 °C. The μh enhancement was explained by a decrease in the total charge densities at/near the GeO2/Ge interface.

Original languageEnglish
Pages (from-to)246-253
Number of pages8
JournalMaterials Science in Semiconductor Processing
Volume70
DOIs
Publication statusPublished - Nov 1 2017

Fingerprint

MOSFET devices
metal oxide semiconductors
field effect transistors
Annealing
Atoms
annealing
augmentation
atoms
Hysteresis
hysteresis
dipoles
Temperature
Deep level transient spectroscopy
temperature
germanium oxide
Physical vapor deposition
Charge density
borders
Oxides
capacitors

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Cite this

Mechanism of mobility enhancement in Ge p-channel metal-oxide-semiconductor field-effect transistor due to introduction of Al atoms into SiO2/GeO2 gate stack. / Nagatomi, Yuta; Tateyama, Tomoki; Tanaka, Shintaro; Wen, Wei Chen; Sakaguchi, Taisei; Yamamoto, Keisuke; Zhao, Liwei; Wang, Dong; Nakashima, Hiroshi.

In: Materials Science in Semiconductor Processing, Vol. 70, 01.11.2017, p. 246-253.

Research output: Contribution to journalArticle

@article{dde85fb89ae643c59b944f93b1dc53b1,
title = "Mechanism of mobility enhancement in Ge p-channel metal-oxide-semiconductor field-effect transistor due to introduction of Al atoms into SiO2/GeO2 gate stack",
abstract = "In this paper, we present comprehensive results on Al-postmetallization annealing (Al-PMA) effect for the SiO2/GeO2 gate stack on a Ge substrate, which were fabricated by a physical vapor deposition method. The effective oxide thickness of metal-oxide-semiconductor (MOS) capacitor (CAP) was ~7 nm, and the Al-PMA was performed at a temperature in the range of 300–400 °C. The flat band voltage (VFB), the hysteresis (HT), the interfacial states density (Dit), and the border traps density (Dbt) for MOSCAPs were characterized by a capacitance–voltage method and a constant-temperature deep-level transient spectroscopy method. The MOSCAP without Al-PMA had an electrical dipole of ~−0.8 eV at a SiO2/GeO2 interface, which was disappeared after Al-PMA at 300 °C. The HT, Dit, and Dbt were decreased after Al-PMA at 300 °C and were maintained in the temperature range of 300–400 °C. On the other hand, the VFB was monotonically shifted in the positive direction with an increase in PMA temperature, suggesting the generation of negatively charged atoms. Structural analyses for MOSCAPs without and with Al-PMA were performed by a time-of-flight secondary ion mass spectroscopy method and an X-ray photoelectron spectroscopy method. It was confirmed that Al atoms diffused from an Al electrode to a SiO2 film and reacted with GeO2. The dipole disappearance after Al-PMA at 300 °C is likely to be associated with the structural change at the SiO2/GeO2 interface. We also present the device performances of Al-gated p-channel MOS field-effect transistors (FET) with PMA treatments, which were fabricated using PtGe/Ge contacts as source/drain. The peak field-effect mobility (μh) of the p-MOSFET was reached a value of 468 cm2/Vs after Al-PMA at 325 °C. The μh enhancement was explained by a decrease in the total charge densities at/near the GeO2/Ge interface.",
author = "Yuta Nagatomi and Tomoki Tateyama and Shintaro Tanaka and Wen, {Wei Chen} and Taisei Sakaguchi and Keisuke Yamamoto and Liwei Zhao and Dong Wang and Hiroshi Nakashima",
year = "2017",
month = "11",
day = "1",
doi = "10.1016/j.mssp.2016.11.014",
language = "English",
volume = "70",
pages = "246--253",
journal = "Materials Science in Semiconductor Processing",
issn = "1369-8001",
publisher = "Elsevier Limited",

}

TY - JOUR

T1 - Mechanism of mobility enhancement in Ge p-channel metal-oxide-semiconductor field-effect transistor due to introduction of Al atoms into SiO2/GeO2 gate stack

AU - Nagatomi, Yuta

AU - Tateyama, Tomoki

AU - Tanaka, Shintaro

AU - Wen, Wei Chen

AU - Sakaguchi, Taisei

AU - Yamamoto, Keisuke

AU - Zhao, Liwei

AU - Wang, Dong

AU - Nakashima, Hiroshi

PY - 2017/11/1

Y1 - 2017/11/1

N2 - In this paper, we present comprehensive results on Al-postmetallization annealing (Al-PMA) effect for the SiO2/GeO2 gate stack on a Ge substrate, which were fabricated by a physical vapor deposition method. The effective oxide thickness of metal-oxide-semiconductor (MOS) capacitor (CAP) was ~7 nm, and the Al-PMA was performed at a temperature in the range of 300–400 °C. The flat band voltage (VFB), the hysteresis (HT), the interfacial states density (Dit), and the border traps density (Dbt) for MOSCAPs were characterized by a capacitance–voltage method and a constant-temperature deep-level transient spectroscopy method. The MOSCAP without Al-PMA had an electrical dipole of ~−0.8 eV at a SiO2/GeO2 interface, which was disappeared after Al-PMA at 300 °C. The HT, Dit, and Dbt were decreased after Al-PMA at 300 °C and were maintained in the temperature range of 300–400 °C. On the other hand, the VFB was monotonically shifted in the positive direction with an increase in PMA temperature, suggesting the generation of negatively charged atoms. Structural analyses for MOSCAPs without and with Al-PMA were performed by a time-of-flight secondary ion mass spectroscopy method and an X-ray photoelectron spectroscopy method. It was confirmed that Al atoms diffused from an Al electrode to a SiO2 film and reacted with GeO2. The dipole disappearance after Al-PMA at 300 °C is likely to be associated with the structural change at the SiO2/GeO2 interface. We also present the device performances of Al-gated p-channel MOS field-effect transistors (FET) with PMA treatments, which were fabricated using PtGe/Ge contacts as source/drain. The peak field-effect mobility (μh) of the p-MOSFET was reached a value of 468 cm2/Vs after Al-PMA at 325 °C. The μh enhancement was explained by a decrease in the total charge densities at/near the GeO2/Ge interface.

AB - In this paper, we present comprehensive results on Al-postmetallization annealing (Al-PMA) effect for the SiO2/GeO2 gate stack on a Ge substrate, which were fabricated by a physical vapor deposition method. The effective oxide thickness of metal-oxide-semiconductor (MOS) capacitor (CAP) was ~7 nm, and the Al-PMA was performed at a temperature in the range of 300–400 °C. The flat band voltage (VFB), the hysteresis (HT), the interfacial states density (Dit), and the border traps density (Dbt) for MOSCAPs were characterized by a capacitance–voltage method and a constant-temperature deep-level transient spectroscopy method. The MOSCAP without Al-PMA had an electrical dipole of ~−0.8 eV at a SiO2/GeO2 interface, which was disappeared after Al-PMA at 300 °C. The HT, Dit, and Dbt were decreased after Al-PMA at 300 °C and were maintained in the temperature range of 300–400 °C. On the other hand, the VFB was monotonically shifted in the positive direction with an increase in PMA temperature, suggesting the generation of negatively charged atoms. Structural analyses for MOSCAPs without and with Al-PMA were performed by a time-of-flight secondary ion mass spectroscopy method and an X-ray photoelectron spectroscopy method. It was confirmed that Al atoms diffused from an Al electrode to a SiO2 film and reacted with GeO2. The dipole disappearance after Al-PMA at 300 °C is likely to be associated with the structural change at the SiO2/GeO2 interface. We also present the device performances of Al-gated p-channel MOS field-effect transistors (FET) with PMA treatments, which were fabricated using PtGe/Ge contacts as source/drain. The peak field-effect mobility (μh) of the p-MOSFET was reached a value of 468 cm2/Vs after Al-PMA at 325 °C. The μh enhancement was explained by a decrease in the total charge densities at/near the GeO2/Ge interface.

UR - http://www.scopus.com/inward/record.url?scp=85006995545&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85006995545&partnerID=8YFLogxK

U2 - 10.1016/j.mssp.2016.11.014

DO - 10.1016/j.mssp.2016.11.014

M3 - Article

AN - SCOPUS:85006995545

VL - 70

SP - 246

EP - 253

JO - Materials Science in Semiconductor Processing

JF - Materials Science in Semiconductor Processing

SN - 1369-8001

ER -