A germanium p-channel Schottky barrier metal–oxide–semiconductor field-effect transistor (SB-MOSFET) with germanium–platinum Schottky contacts is demonstrated experimentally. The fabrication process has a low thermal budget of C and requires neither intentional doping nor ion implantation. At a temperature of 4 K, the p-channel SB-MOSFET turns on at a gate voltage of −1.6 V and shows a peak mobility of 500 cm2/V s at a carrier density of 3 × 1012 cm–2. Under high drain–source bias voltages, the device operates in an unconventional mode where the current is limited by the source contact. Injection of carriers from the source contact to the germanium channel is controlled by the gate bias, which modulates the Schottky barrier capacitively. The transconductance in this mode deviates from and is significantly higher than the value expected for a conventional MOSFET with the same geometry, mobility, and capacitance. Based on four-point current–voltage measurements, we present a theoretical band diagram of the device and give a physical picture for the observed high currents and transconductances.
REFERENCES
1.
G.
Scappucci
,
C.
Kloeffel
,
F. A.
Zwanenburg
,
D.
Loss
,
M.
Myronov
,
J.-J.
Zhang
,
S.
De Franceschi
,
G.
Katsaros
, and
M.
Veldhorst
, “
The germanium quantum information route
,” Nat. Rev. Mater.
6
, 926
(2020
).2.
N.
Hendrickx
,
D.
Franke
,
A.
Sammak
,
M.
Kouwenhoven
,
D.
Sabbagh
,
L.
Yeoh
,
R.
Li
,
M.
Tagliaferri
,
M.
Virgilio
,
G.
Capellini
et al, “
Gate-controlled quantum dots and superconductivity in planar germanium
,” Nat. Commun.
9
, 2835
(2018
).3.
W.
Lawrie
,
H.
Eenink
,
N.
Hendrickx
,
J.
Boter
,
L.
Petit
,
S.
Amitonov
,
M.
Lodari
,
B.
Paquelet Wuetz
,
C.
Volk
,
S.
Philips
et al, “
Quantum dot arrays in silicon and germanium
,” Appl. Phys. Lett.
116
(8
), 080501
(2020
).4.
H.
Bonet
,
A.
Bonhomme
,
C.
Buck
,
K.
Fülber
,
J.
Hakenmüller
,
G.
Heusser
,
T.
Hugle
,
J. B.
Legras
,
M.
Lindner
,
W.
Maneschg
,
V.
Marian
,
T.
Rink
,
T.
Schröder
,
H.
Strecker
, and
R.
Wink
, “
Large-size sub-keV sensitive germanium detectors for the conus experiment
,” Eur. Phys. J. C
81
, 267
(2021
).5.
E.
Armengaud
,
C.
Augier
,
A.
Benoit
,
L.
Berge
,
O.
Besida
,
J.
Blümer
,
A.
Broniatowski
,
A.
Chantelauze
,
M.
Chapellier
,
G.
Chardin
et al, “
First results of the EDELWEISS-II WIMP search using Ge cryogenic detectors with interleaved electrodes
,” Phys. Lett. B
687
, 294
(2010
).6.
E.
Armengaud
,
C.
Augier
,
A.
Benoit
,
L.
Bergé
,
J.
Blümer
,
A.
Broniatowski
,
V.
Brudanin
,
B.
Censier
,
G.
Chardin
,
M.
Chapellier
et al, “
Final results of the EDELWEISS-II WIMP search using a 4-kg array of cryogenic germanium detectors with interleaved electrodes
,” Phys. Lett. B
702
, 329
(2011
).7.
C. I. Collaboration
, “
Dark matter search results from the CDMS II experiment
,” Science
327
, 1619
(2010
).8.
M. J.
Curry
,
T. D.
England
,
N.
Bishop
,
G.
Ten-Eyck
,
J. R.
Wendt
,
T.
Pluym
,
M.
Lilly
,
S. M.
Carr
, and
M. S.
Carroll
, “
Cryogenic preamplification of a single-electron-transistor using a silicon-germanium heterojunction-bipolar-transistor
,” Appl. Phys. Lett.
106
(20
), 203505
(2015
).9.
L. A.
Tracy
,
D. R.
Luhman
,
S. M.
Carr
,
N. C.
Bishop
,
G. A.
Ten Eyck
,
T.
Pluym
,
J. R.
Wendt
,
M. P.
Lilly
, and
M. S.
Carroll
, “
Single shot spin readout using a cryogenic high-electron-mobility transistor amplifier at sub-Kelvin temperatures
,” Appl. Phys. Lett.
108
(6
), 063101
(2016
).10.
L. A.
Tracy
,
J. L.
Reno
,
S.
Fallahi
, and
M. J.
Manfra
, “
Integrated high electron mobility transistors in GaAs/AlGaAs heterostructures for amplification at sub-Kelvin temperatures
,” Appl. Phys. Lett.
114
(5
), 053104
(2019
).11.
B.
Banerjee
,
S.
Venkataraman
,
Y.
Lu
,
Q.
Liang
,
C.-H.
Lee
,
S.
Nuttinck
,
D.
Heo
,
Y.-J.
Chen
,
J. D.
Cressler
,
J.
Laskar
et al, “
Cryogenic operation of third-generation, 200-GHz peak-f/sub T/, silicon-germanium heterojunction bipolar transistors
,” IEEE Trans. Electron Devices
52
, 585
(2005
).12.
L. E.
Stehouwer
,
A.
Tosato
,
D.
Degli Esposti
,
D.
Costa
,
M.
Veldhorst
,
A.
Sammak
, and
G.
Scappucci
, “
Germanium wafers for strained quantum wells with low disorder
,” Appl. Phys. Lett.
123
(9
), 092101
(2023
).13.
N. D.
Foster
,
A. J.
Miller
,
T. A.
Hutchins-Delgado
,
C. M.
Smyth
,
M. C.
Wanke
,
T.-M.
Lu
, and
D. R.
Luhman
, “
Thermal activation of low-density Ga implanted in Ge
,” Appl. Phys. Lett.
120
(20
), 201902
(2022
).14.
G.
Impellizzeri
,
S.
Mirabella
,
A.
Irrera
,
M.
Grimaldi
, and
E.
Napolitani
, “
Ga-implantation in Ge: Electrical activation and clustering
,” J. Appl. Phys.
106
(1
), 013518
(2009
).15.
T.
Nishimura
,
K.
Kita
, and
A.
Toriumi
, “
Evidence for strong fermi-level pinning due to metal-induced gap states at metal/germanium interface
,” Appl. Phys. Lett.
91
, 123123
(2007
).16.
A.
Dimoulas
,
P.
Tsipas
,
A.
Sotiropoulos
, and
E.
Evangelou
, “
Fermi-level pinning and charge neutrality level in germanium
,” Appl. Phys. Lett.
89
(25
), 252110
(2006
).17.
L.
Calvet
,
H.
Luebben
,
M.
Reed
,
C.
Wang
,
J.
Snyder
, and
J.
Tucker
, “
Subthreshold and scaling of PtSi Schottky barrier MOSFETs
,” Superlattices Microstruct.
28
, 501
(2000
).18.
C.
Wang
,
J. P.
Snyder
, and
J.
Tucker
, “
Sub-40 nm ptsi Schottky source/drain metal–oxide–semiconductor field-effect transistors
,” Appl. Phys. Lett.
74
, 1174
(1999
).19.
S.-J.
Choi
,
C.-J.
Choi
,
J.-Y.
Kim
,
M.
Jang
, and
Y.-K.
Choi
, “
Analysis of transconductance
in Schottky-Barrier MOSFETs
,” IEEE Trans. Electron Devices
58
, 427
(2011
).20.
J.
Kedzierski
,
P.
Xuan
,
E. H.
Anderson
,
J.
Bokor
,
T.-J.
King
, and
C.
Hu
, “
Complementary silicide source/drain thin-body MOSFETs for the 20 nm gate length regime
,” in International Electron Devices Meeting 2000 Technical Digest IEDM (Cat. No. 00CH37138)
(
IEEE
, 2000
), pp. 57
–60
.21.
Y.
Han
,
J.
Sun
,
F.
Xi
,
J.-H.
Bae
,
D.
Grützmacher
, and
Q.-T.
Zhao
, “
Cryogenic characteristics of UTBB SOI Schottky-Barrier MOSFETs
,” Solid-State Electron.
194
, 108351
(2022
).22.
H.
Yang
,
D.
Wang
,
H.
Nakashima
,
H.
Gao
,
K.
Hirayama
,
K.-i.
Ikeda
,
S.
Hata
, and
H.
Nakashima
, “
Influence of top surface passivation on bottom-channel hole mobility of ultrathin SiGe- and Ge-on-insulator
,” Appl. Phys. Lett.
93
(7
), 072104
(2008
).23.
M.
Kobayashi
,
A.
Kinoshita
,
K.
Saraswat
,
H.-S. P.
Wong
, and
Y.
Nishi
, “
Fermi level depinning in metal/Ge Schottky junction for metal source/drain Ge metal-oxide-semiconductor field-effect-transistor application
,” J. Appl. Phys.
105
(2
), 023702
(2009
).24.
D. D.
Zhao
,
C. H.
Lee
,
T.
Nishimura
,
K.
Nagashio
,
G. A.
Cheng
, and
A.
Toriumi
, “
Experimental and analytical characterization of dual-gated germanium junctionless p-channel metal–oxide–semiconductor field-effect transistors
,” Jpn. J. Appl. Phys., Part 1
51
, 04DA03
(2012
).25.
T.
Shimura
,
Y.
Suzuki
,
M.
Matsue
,
K.
Kajimura
,
K.
Tominaga
,
T.
Amamoto
,
T.
Hosoi
, and
H.
Watanabe
, “
Fabrication of high-quality Ge-on-insulator structures by lateral liquid phase epitaxy
,” ECS Trans.
69
, 305
(2015
).26.
T.
Hosoi
,
Y.
Suzuki
,
T.
Shimura
, and
H.
Watanabe
, “
Mobility characterization of Ge-on-insulator metal-oxide-semiconductor field-effect transistors with striped Ge channels fabricated by lateral liquid-phase epitaxy
,” Appl. Phys. Lett.
105
(17
), 173502
(2014
).27.
R.
Böckle
,
M.
Sistani
,
B.
Lipovec
,
D.
Pohl
,
B.
Rellinghaus
,
A.
Lugstein
, and
W. M.
Weber
, “
A top-down platform enabling Ge based reconfigurable transistors
,” Adv. Mater. Technol.
7
, 2100647
(2022
).28.
H.
Yang
,
J.
Gao
, and
H.
Nakashima
, “
Investigation of ZrGe Schottky source/drain contacts for Ge p-channel MOSFETs
,” Mater. Sci. Semicond. Process.
26
, 614
(2014
).29.
F.
Gao
,
S.
Lee
,
L.
Rui
,
S.
Wang
,
B.
Cho
,
S.
Balakumar
,
C.-H.
Tung
,
D.
Chi
, and
D.
Kwong
, “
Sige on insulator MOSFET integrated with Schottky source/drain and HfO2/TaN gate stack
,” Electrochem. Solid-State Lett.
9
, G222
(2006
).30.
R.
Li
,
H.
Yao
,
S.
Lee
,
D.
Chi
,
M.
Yu
,
G.
Lo
, and
D.
Kwong
, “
Metal-germanide Schottky source/drain transistor on germanium substrate for future CMOS technology
,” Thin Solid Films
504
, 28
(2006
).31.
T.
Sadoh
,
H.
Kamizuru
,
A.
Kenjo
, and
M.
Miyao
, “
Ge-channel thin-film transistor with Schottky source/drain fabricated by low-temperature processing
,” Jpn. J. Appl. Phys., Part 1
46
, 1250
(2007
).32.
T.
Yamamoto
,
Y.
Yamashita
,
M.
Harada
,
N.
Taoka
,
K.
Ikeda
,
K.
Suzuki
,
O.
Kiso
,
N.
Sugiyama
, and
S-i
Takagi
, “
High performance 60 nm gate length germanium p-MOSFETs with Ni germanide metal source/drain
,” in 2007 IEEE International Electron Devices Meeting
(
IEEE
, 2007
), pp. 1041
–1043
.33.
C.-C.
Hsu
,
Y.-H.
Tsai
,
C.-W.
Chen
,
J.-H.
Li
,
Y.-H.
Lin
,
Y.-J.
Lee
,
G.-L.
Luo
, and
C.-H.
Chien
, “
High-performance Schottky contact quantum-well germanium channel pMOSFET with low thermal budget process
,” IEEE Electron Device Lett.
37
, 8
(2016
).34.
R.
Zhang
,
J.
Li
,
F.
Chen
, and
Y.
Zhao
, “
High-performance germanium pMOSFETs with NiGe metal source/drain fabricated by microwave annealing
,” IEEE Trans. Electron Devices
63
, 2665
(2016
).35.
X.
Yu
,
J.
Kang
,
R.
Zhang
,
M.
Takenaka
, and
S.
Takagi
, “
Characterization of ultrathin-body germanium-on-insulator (GeOI) structures and MOSFETs on flipped smart-cut™ GeOI substrates
,” Solid-State Electron.
115
, 120
(2016
).36.
C.-C.
Hsu
,
W.-C.
Chi
,
Y.-H.
Tsai
,
C.-H.
Chou
,
C.-W.
Chen
,
H.-P.
Chien
,
S.-S.
Chuang
,
G.-L.
Luo
,
Y.-J.
Lee
, and
C.-H.
Chien
, “
Experimental realization of a ternary-phase alloy through microwave-activated annealing for Ge Schottky pMOSFETs
,” IEEE Trans. Electron Devices
63
, 2714
(2016
).37.
W.
Wu
,
H.
Wu
,
J.
Zhang
,
M.
Si
,
Y.
Zhao
, and
D. Y.
Peide
, “
Carrier mobility enhancement by applying back-gate bias in Ge-on-insulator MOSFETs
,” IEEE Electron Device Lett.
39
, 176
(2018
).38.
Y.
Sun
,
W.
Schwarzenbach
,
S.
Yuan
,
Z.
Chen
,
Y.
Yang
,
B.-Y.
Nguyen
,
D.
Gao
, and
R.
Zhang
, “
Impact of channel thickness on the NBTI behaviors in the Ge-OI pMOSFETs with Al2O3/GeOx gate stacks
,” IEEE J. Electron Devices Soc.
11
, 210
(2023
).39.
Y.
Park
,
A.
Hanbicki
,
S.
Erwin
,
C.
Hellberg
,
J.
Sullivan
,
J.
Mattson
,
T.
Ambrose
,
A.
Wilson
,
G.
Spanos
, and
B.
Jonker
, “
A group-IV ferromagnetic semiconductor: MnxGe1-x
,” Science
295
, 651
(2002
).40.
J.
Tang
,
C.-Y.
Wang
,
M.-H.
Hung
,
X.
Jiang
,
L.-T.
Chang
,
L.
He
,
P.-H.
Liu
,
H.-J.
Yang
,
H.-Y.
Tuan
,
L.-J.
Chen
et al, “
Ferromagnetic germanide in Ge nanowire transistors for spintronics application
,” ACS Nano
6
, 5710
(2012
).41.
T.
Maeda
,
K.
Ikeda
,
S.
Nakaharai
,
T.
Tezuka
,
N.
Sugiyama
,
Y.
Moriyama
, and
S.
Takagi
, “
High mobility Ge-on-insulator p-channel MOSFETs using Pt germanide Schottky source/drain
,” IEEE Electron Device Lett.
26
, 102
(2005
).42.
T.
Maeda
,
K.
Ikeda
,
S.
Nakaharai
,
T.
Tezuka
,
N.
Sugiyama
,
Y.
Moriyama
, and
S.
Takagi
, “
Thin-body Ge-on-insulator p-channel MOSFETs with Pt germanide metal source/drain
,” Thin Solid Films
508
, 346
(2006
).43.
R.
Li
,
S.
Lee
,
H.
Yao
,
D.
Chi
,
M.
Yu
, and
D.-L.
Kwong
, “
Pt-Germanide Schottky Source/Drain Germanium p-MOSFET with HfO2 Gate Dielectric and TaN Gate Electrode
,” IEEE Electron Device Lett.
27
, 476
(2006
).44.
T.
Uehara
,
H.
Matsubara
,
R.
Nakane
,
S.
Sugahara
, and
S-i
Takagi
, “
Ultrathin Ge-on-insulator metal source/drain p-channel metal–oxide–semiconductor field-effect transistors fabricated by low-temperature molecular-beam epitaxy
,” Jpn. J. Appl. Phys., Part 1
46
, 2117
(2007
).45.
S.
Dissanayake
,
K.
Tomiyama
,
S.
Sugahara
,
M.
Takenaka
, and
S.
Takagi
, “
High performance ultrathin (110)-oriented Ge-on-insulator p-channel metal–oxide–semiconductor field-effect transistors fabricated by Ge condensation technique
,” Appl. Phys. Express
3
, 041302
(2010
).46.
P.
Ponath
,
A. B.
Posadas
,
R. C.
Hatch
, and
A. A.
Demkov
, “
Preparation of a clean Ge(001) surface using oxygen plasma cleaning
,” J. Vac. Sci. Technol., B: Nanotechnol. Microelectron.: Mater., Process., Meas., Phenom.
31
, 031201
(2013
).47.
G. D.
Wilk
,
R. M.
Wallace
, and
J.
Anthony
, “
High-κ gate dielectrics: Current status and materials properties considerations
,” J. Appl. Phys.
89
, 5243
(2001
).48.
M.
Ťapajna
,
L.
Válik
,
F.
Gucmann
,
D.
Gregušová
,
K.
Fröhlich
,
Š.
Haščík
,
E.
Dobročka
,
L.
Tóth
,
B.
Pécz
, and
J.
Kuzmík
, “
Low-temperature atomic layer deposition-grown Al2O3 gate dielectric for GaN/AlGaN/GaN MOS HEMTs: Impact of deposition conditions on interface state density
,” J. Vac. Sci. Technol. B
35
(1
), 01A107
(2017
).49.
M. A.
Botzakaki
,
G.
Skoulatakis
,
N.
Xanthopoulos
,
V.
Gianneta
,
A.
Travlos
,
S.
Kennou
,
S.
Ladas
,
C.
Tsamis
,
E.
Makarona
,
S. N.
Georga
et al, “
Influence of the atomic layer deposition temperature on the structural and electrical properties of Al/Al2O3/p-Ge MOS structures
,” J. Vac. Sci. Technol. A
36
(1
), 01A120
(2018
).50.
T. A.
Hutchins-Delgado
,
A. J.
Miller
,
R.
Scott
,
P.
Lu
,
D. R.
Luhman
, and
T.-M.
Lu
, “
Characterization of shallow, undoped Ge/SiGe quantum wells commercially grown on 8-in. (100) Si wafers
,” ACS Appl. Electron. Mater.
4
, 4482
(2022
).51.
T.
Ando
,
A. B.
Fowler
, and
F.
Stern
, “
Electronic properties of two-dimensional systems
,” Rev. Mod. Phys.
54
, 437
(1982
).52.
R. R.
Troutman
, “
VLSI limitations from drain-induced barrier lowering
,” IEEE J. Solid-State Circuits
14
, 383
(1979
).© 2024 Author(s). Published under an exclusive license by AIP Publishing.
2024
Author(s)
You do not currently have access to this content.
