TY - GEN
A1 - Weißhaupt, David
A1 - Sürgers, Christoph
A1 - Bloos, Dominik
A1 - Funk, Hannes Simon
A1 - Oehme, Michael
A1 - Fischer, Gerda
A1 - Schubert, Markus Andreas
A1 - Wenger, Christian
A1 - van Slageren, Joris
A1 - Fischer, Inga Anita
A1 - Schulze, Jörg
T1 - Lateral Mn5Ge3 spin-valve in contact with a high-mobility Ge two-dimensional hole gas
T2 - Semiconductor Science and Technology
N2 - Abstract
Ge two-dimensional hole gases (2DHG) in strained modulation-doped quantum-wells represent a promising material platform for future spintronic applications due to their excellent spin transport properties and the theoretical possibility of efficient spin manipulation. Due to the continuous development of epitaxial growth recipes extreme high hole mobilities and low effective masses can be achieved, promising an efficient spin transport. Furthermore, the Ge 2DHG can be integrated in the well-established industrial complementary metal-oxide-semiconductor (CMOS) devices technology. However, efficient electrical spin injection into a Ge 2DHG—an essential prerequisite for the realization of spintronic devices—has not yet been demonstrated. In this work, we report the fabrication and low-temperature magnetoresistance (MR) measurements of a laterally structured Mn5Ge3/Ge 2DHG/ Mn5Ge3 device. The ferromagnetic Mn5Ge3 contacts are grown directly into the Ge quantum well by means of an interdiffusion process with a spacing of approximately 130 nm, forming a direct electrical contact between the ferromagnetic metal and the Ge 2DHG. Here, we report for the first time a clear MR signal for temperatures below 13 K possibly arising from successful spin injection into the high mobility Ge 2DHG. The results represent a step forward toward the realization of CMOS compatible spintronic devices based on a 2DHG.
KW - two-dimensional hole gas
Y1 - 2024
U6 - https://doi.org/10.1088/1361-6641/ad8d06
SN - 0268-1242
VL - 39
IS - 12
SP - 1
EP - 10
PB - IOP Publishing
ER -
TY - GEN
A1 - Mai, Christian
A1 - Marschmeyer, Steffen
A1 - Peczek, Anna
A1 - Kroh, Aleksandra
A1 - Jose, Josmy
A1 - Reiter, Sebastian
A1 - Fischer, Inga Anita
A1 - Wenger, Christian
A1 - Mai, Andreas
T1 - Integration Aspects of Plasmonic TiN-based Nano-Hole-Arrays on Ge Photodetectorsin a 200mm Wafer CMOS Compatible Silicon Technology
T2 - ECS Transactions
N2 - In this work we present the progress in regard to the integration of a surface plasmon resonance refractive index sensor into a CMOS compatible 200 mm wafer silicon-based technology. Our approach pursues the combination of germanium photodetectors with metallic nanohole arrays. The paper is focused on the technology development to fabricate large area photodetectors based on a modern design concept. In a first iteration we achieved a leakage current density of 82 mA/cm2 at reverse bias of 0.5 V and a maximum optical responsivity of 0.103 A/W measured with TE polarized light at λ = 1310 nm and a reversed bias of 1 V. For the realization of nanohole arrays we used thin Titanium nitride (TiN) layers deposited by a sputtering process. We were able to produce very homogenous TiN layers with a thickness deviation of around 10 % and RMS of 1.413 nm for 150 nm thick TiN layers.
KW - plasmonics
KW - nanohole array
KW - germanium detector
Y1 - 2022
U6 - https://doi.org/10.1149/10904.0035ecst
SN - 1938-5862
VL - 109
IS - 4
SP - 35
EP - 46
ER -
TY - GEN
A1 - Mai, Christian
A1 - Peczek, Anna
A1 - Kroh, Aleksandra
A1 - Jose, Josmy
A1 - Reiter, Sebastian
A1 - Wenger, Christian
A1 - Fischer, Inga Anita
T1 - Towards a CMOS compatible refractive index sensor: cointegration of TiN nanohole arrays and Ge photodetectors in a 200 mm wafer silicon technology
T2 - Optics Express
N2 - In this work, we present the monolithic integration of a TiN nanohole array and a Ge photodetector towards a CMOS compatible fabrication of a refractive index sensor in a 200 mm wafer silicon technology. We developed a technology process that enables fabrication with high yields of around 90%. Ge photodetectors with a Ge layer thickness of 450 nm and an area of 1600 µm2 (40 µm x 40 µm) show dark current densities of around 129 mA/cm2 and responsivities of 0.114 A/W measured by top illumination (TE polarization; λ = 1310 nm; angle of incidence = 14 °) at a reverse bias of 1 V. Nanohole arrays were structured in a 150 nm thick TiN layer. They were integrated into the back end of line and placed spatially close to the Ge photodetectors. After the metallization, passivation, and pad opening, the nanohole arrays were released with the help of an amorphous silicon stop layer. A significant impact of the TiN nanohole arrays on the optical behavior of the photodetector could be proven on the wafer level. Photocurrent measurements by top illumination confirm a strong dependence of optical properties on the polarization of the incident light and the nanohole array design. We demonstrate very stable photocurrents on the wafer level with a standard deviation of σ < 6%.
KW - plasmonics
KW - sensor
KW - nano hole array
Y1 - 2024
U6 - https://doi.org/10.1364/OE.530081
SN - 1094-4087
VL - 32
IS - 17
SP - 29099
EP - 29111
PB - Optica Publishing Group
ER -
TY - GEN
A1 - Schlipf, Jon
A1 - Cutolo, Maria Alessandra
A1 - Manganelli, Costanza Lucia
A1 - Reiter, Sebastian
A1 - Seibold, Götz
A1 - Skibitzki, Oliver
A1 - Wenger, Christian
A1 - Fischer, Inga Anita
T1 - Fabrication and optical characterization of CMOS-compatible honeycomb-like large-scale lattices of near-field coupled plasmonic TiN nanotriangles
T2 - Advanced optical materials
N2 - Honeycomb-like plasmonic titanium nitride nanotriangle arrays defined by photolithography and fabricated in a modified silicon-germanium electronic–photonic integrated circuit process in a state-of-the-art pilot line. The nanotriangle arrays are characterized in experiments and simulations. The momentum-dependent reflectance spectra exhibit not only features that are consistent with surface lattice resonances in the honeycomb lattice but also minima governed by near-field coupling of the individual nanotriangles. The optical characterization results in combination with simulation-based predictions indicate that such nanotriangle arrays are capable of supporting collective plasmonic resonances that can be described as massless Dirac particles. The fabrication approach opens up the possibility of integrating the structures into device fabrication processes, and avenues toward near-infrared sensing and communication applications are predicted.
KW - Plasmonic Nanostructures
KW - Optics of Nanostructures
Y1 - 2025
UR - https://advanced.onlinelibrary.wiley.com/doi/epdf/10.1002/adom.202403408
U6 - https://doi.org/10.1002/adom.202403408
SN - 2195-1071
VL - 2025
SP - 1
EP - 8
PB - Wiley-VCH
CY - Weinheim
ER -