TY - GEN
A1 - Niu, Gang
A1 - Capellini, Giovanni
A1 - Lupina, Grzegorz
A1 - Niermann, Tore
A1 - Salvalaglio, Marco
A1 - Marzegalli, Anna
A1 - Schubert, Markus Andreas
A1 - Zaumseil, Peter
A1 - Krause, Hans-Michael
A1 - Skibitzki, Oliver
A1 - Lehmann, Michael
A1 - Montalenti, Francesco
A1 - Xie, Ya-Hong
A1 - Schröder, Thomas
T1 - Photodetection in hybrid single layer graphene/fully coherent Ge island nanostructures selectively grown on Si nano-tip patterns
T2 - ACS Applied Materials and Interfaces
Y1 - 2016
SN - 1944-8252
VL - 8
IS - 3
SP - 2017
EP - 2026
ER -
TY - GEN
A1 - Zaumseil, Peter
A1 - Schubert, Markus Andreas
A1 - Yamamoto, Yuji
A1 - Skibitzki, Oliver
A1 - Capellini, Giovanni
A1 - Schröder, Thomas
T1 - Misfit dislocation-free epitaxial growth of SiGe on compliant nanostructured Silicon
T2 - Solid State Phenomena
Y1 - 2016
U6 - https://doi.org/10.4028/www.scientific.net/SSP.242.402
SN - 1662-9779
SN - 0377-6883
VL - 242
SP - 402
EP - 407
ER -
TY - GEN
A1 - Taoka, Noriyuki
A1 - Capellini, Giovanni
A1 - Driesch, Nils von den
A1 - Buca, Dan
A1 - Zaumseil, Peter
A1 - Schubert, Markus Andreas
A1 - Klesse, Wolfgang Matthias
A1 - Montanari, Michele
A1 - Schröder, Thomas
T1 - Sn Migration Control at High Temperature Due to High Deposition Speed for Forming High Quality GeSn Layer
T2 - Applied Physics Express
Y1 - 2016
U6 - https://doi.org/10.7567/APEX.9.031201
SN - 1882-0786
SN - 1882-0778
VL - 9
IS - 3
SP - 031201
ER -
TY - GEN
A1 - Niu, Gang
A1 - Capellini, Giovanni
A1 - Schubert, Markus Andreas
A1 - Niermann, Tore
A1 - Zaumseil, Peter
A1 - Katzer, Jens
A1 - Krause, Hans-Michael
A1 - Skibitzki, Oliver
A1 - Lehmann, Michael
A1 - Xie, Ya-Hong
A1 - Känel, Hans von
A1 - Schröder, Thomas
T1 - Dislocation-free Ge nano-crystals via pattern dependent selective Ge heteroepitaxy on Si nano-tip wafers
T2 - Scientific Reports
Y1 - 2016
U6 - https://doi.org/10.1038/srep22709
SN - 2045-2322
VL - 6
SP - 22709
ER -
TY - GEN
A1 - Niu, Gang
A1 - Capellini, Giovanni
A1 - Hatami, Fariba
A1 - Bartolomeo, Antonio di
A1 - Niermann, Tore
A1 - Hameed, Hussein Emad
A1 - Schubert, Markus Andreas
A1 - Krause, Hans-Michael
A1 - Zaumseil, Peter
A1 - Skibitzki, Oliver
A1 - Masselink, William T.
A1 - Lehmann, Michael
A1 - Xie, Ya-Hong
A1 - Schröder, Thomas
T1 - Selective Epitaxy of InP on Si and Rectification in Graphene/InP/Si Hybrid Structure
T2 - ACS Applied Materials and Interfaces
Y1 - 2016
U6 - https://doi.org/10.1021/acsami.6b09592
SN - 1944-8244
SN - 1944-8252
VL - 8
IS - 40
SP - 26948
EP - 26955
ER -
TY - GEN
A1 - Skibitzki, Oliver
A1 - Capellini, Giovanni
A1 - Yamamoto, Yuji
A1 - Zaumseil, Peter
A1 - Schubert, Markus Andreas
A1 - Schröder, Thomas
A1 - Ballabio, Andrea
A1 - Bergamaschini, Roberto
A1 - Salvalaglio, Marco
A1 - Miglio, Leo
A1 - Montalenti, Francesco
T1 - RP-CVD growth of isolated Ge crystals and suspended layers on micrometric Si pillars
T2 - ACS Applied Materials and Interfaces
Y1 - 2016
U6 - https://doi.org/10.1021/acsami.6b07694
SN - 1944-8244
SN - 1944-8252
VL - 8
IS - 39
SP - 26374
EP - 26380
ER -
TY - GEN
A1 - Schlykow, Viktoria
A1 - Klesse, Wolfgang Matthias
A1 - Niu, Gang
A1 - Taoka, Noriyuki
A1 - Yamamoto, Yuji
A1 - Skibitzki, Oliver
A1 - Barget, M. R.
A1 - Zaumseil, Peter
A1 - Känel, Hans von
A1 - Schubert, Markus Andreas
A1 - Capellini, Giovanni
A1 - Schroeder, Thomas
T1 - Selective growth of fully relaxed GeSn nano-islands by nanoheteroepitaxy on patterned Si(001)
T2 - Applied Physics Letters
Y1 - 2016
U6 - https://doi.org/10.1063/1.4967500
SN - 1077-3118
VL - 109
IS - 20
SP - 202102
ER -
TY - GEN
A1 - Lukosius, Mindaugas
A1 - Dabrowski, Jarek Marek
A1 - Lisker, Marco
A1 - Kitzmann, Julia
A1 - Schulze, Sebastian
A1 - Lippert, Gunther
A1 - Fursenko, Oksana
A1 - Yamamoto, Yuji
A1 - Schubert, Markus Andreas
A1 - Krause, Hans-Michael
A1 - Wolff, Andre
A1 - Mai, A.
A1 - Schröder, Thomas
A1 - Lupina, Grzegorz
T1 - Metal-free, CVD Graphene synthesis on 200 mm Ge / Si(001) substrates
T2 - ACS Applied Materials and Interfaces
Y1 - 2016
U6 - https://doi.org/10.1021/acsami.6b11397
SN - 1944-8244
SN - 1944-8252
VL - 8
IS - 49
SP - 33786
EP - 33793
ER -
TY - GEN
A1 - Grzela, Tomasz
A1 - Capellini, Giovanni
A1 - Koczorowski, Wojciech
A1 - Schubert, Markus Andreas
A1 - Czajka, Ryszard
A1 - Curson, Neil J.
A1 - Heidmann, Inga
A1 - Schmidt, Thomas
A1 - Falta, Jens
A1 - Schröder, Thomas
T1 - Growth and evolution of nickel – germanide nanonstructures on Ge(001)
T2 - Nanotechnology
Y1 - 2015
SN - 1361-6528
SN - 0957-4484
VL - 26
IS - 38
SP - 385701
ER -
TY - GEN
A1 - Morales, Carlos
A1 - Mahmoodinezhad, Ali
A1 - Schubert, Andreas Markus
A1 - Wenger, Christian
A1 - Henkel, Karsten
A1 - Flege, Jan Ingo
T1 - Functional ultra-thin oxide films deposited by atomic layer deposition on structured substrates
T2 - Verhandlungen der DPG - SurfaceScience21
N2 - In the last decades, atomic layer deposition (ALD) has gained prominence in the materials and surface science communities owing to its high potential for integration as a scalable process in microelectronics. ALD's largest strengths are its well-controlled layer-by-layer deposition and growth conformity on 3D structures. Yet, the ALD technique is also well known to lead to amorphous and defective, non-stoichiometric thin films, resulting in modified materials properties that may even preferentially be used in certain applications. To study these issues, we have developed an in-situ ALD reactor attached to an X-ray photoelectron spectroscopy (XPS) system, capable of switching between both pump and flow-type operation. This novel tool allows to cover the entire range of compounds and recipes used in ALD, thus clarifying the role of such defects at different deposition stages, growth conditions and film/substrate interfaces. To exemplify these sorts of studies, we show the deposition of Al2O3 5-10 nm films on nanostructured Si, and their use as substrates for functional CeOx ALD deposits.
KW - Atomic layer deposition
KW - sensors
KW - structured substrates
KW - in-situ X-ray photoelectron spectroscopy
Y1 - 2021
UR - https://www.dpg-verhandlungen.de/year/2021/conference/surfacescience/part/o/session/74/contribution/5
VL - 2021
PB - Deutsche Physikalische Gesellschaft e.V.
CY - Bad Honnef
ER -
TY - GEN
A1 - Pérez-Bosch Quesada, Emilio
A1 - Romero-Zaliz, Rocío
A1 - Pérez, Eduardo
A1 - Mahadevaiah, Mamathamba Kalishettyhalli
A1 - Reuben, John
A1 - Schubert, Markus Andreas
A1 - Jiménez-Molinos, Francisco
A1 - Roldán, Juan Bautista
A1 - Wenger, Christian
T1 - Toward Reliable Compact Modeling of Multilevel 1T-1R RRAM Devices for Neuromorphic Systems
T2 - Electronics (MDPI)
N2 - In this work, three different RRAM compact models implemented in Verilog-A are analyzed and evaluated in order to reproduce the multilevel approach based on the switching capability of
experimental devices. These models are integrated in 1T-1R cells to control their analog behavior by means of the compliance current imposed by the NMOS select transistor. Four different resistance
levels are simulated and assessed with experimental verification to account for their multilevel capability. Further, an Artificial Neural Network study is carried out to evaluate in a real scenario the viability of the multilevel approach under study.
KW - RRAM
KW - multilevel switching
KW - compact modeling
KW - Verilog-A
Y1 - 2021
U6 - https://doi.org/10.3390/electronics10060645
SN - 2079-9292
VL - 10
IS - 6
ER -
TY - GEN
A1 - Franck, Max
A1 - Dabrowski, Jaroslaw
A1 - Schubert, Markus Andreas
A1 - Wenger, Christian
A1 - Lukosius, Mindaugas
T1 - Towards the Growth of Hexagonal Boron Nitride on Ge(001)/Si Substrates by Chemical Vapor Deposition
T2 - Nanomaterials
N2 - The growth of hexagonal boron nitride (hBN) on epitaxial Ge(001)/Si substrates via high-vacuum chemical vapor deposition from borazine is investigated for the first time in a systematic manner. The influences of the process pressure and growth temperature in the range of 10−7–10−3 mbar and 900–980 °C, respectively, are evaluated with respect to morphology, growth rate, and crystalline quality of the hBN films. At 900 °C, nanocrystalline hBN films with a lateral crystallite size of ~2–3 nm are obtained and confirmed by high-resolution transmission electron microscopy images. X-ray photoelectron spectroscopy confirms an atomic N:B ratio of 1 ± 0.1. A three-dimensional growth mode is observed by atomic force microscopy. Increasing the process pressure in the reactor mainly affects the growth rate, with only slight effects on crystalline quality and none on the principle growth mode. Growth of hBN at 980 °C increases the average crystallite size and leads to the formation of 3–10 well-oriented, vertically stacked layers of hBN on the Ge surface. Exploratory ab initio density functional theory simulations indicate that hBN edges are saturated by hydrogen, and it is proposed that partial de-saturation by H radicals produced on hot parts of the set-up is responsible for the growth
KW - Boron nitride
KW - 2d materials
KW - Chemical vapour deposition
Y1 - 2022
U6 - https://doi.org/10.3390/nano12193260
SN - 2079-4991
VL - 12
IS - 19
ER -
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 - Fritscher, Markus
A1 - Uhlmann, Max
A1 - Ostrovskyy, Philip
A1 - Reiser, Daniel
A1 - Chen, Junchao
A1 - Schubert, Andreas
A1 - Schulze, Carsten
A1 - Kahmen, Gerhard
A1 - Fey, Dietmar
A1 - Reichenbach, Marc
A1 - Krstic, Milos
A1 - Wenger, Christian
T1 - Area-efficient digital design using RRAM-CMOS standard cells
T2 - 2024 IEEE Computer Society Annual Symposium on VLSI (ISVLSI)
N2 - Extending the scalability of digital integrated circuits through novel device concepts is an attractive option. Among these concepts, resistive random access memory (RRAM) devices allow fast and nonvolatile operation. However, building large memristive systems is still challenging since large analog circuits have to be designed and integrated. In this paper, we propose a novel solution - the implementation of digital standard cells by the means of RRAM devices. While this methodology is universal, with applications ranging from few-device-circuits to large macroblocks, we demonstrate it for a 2T2R-cell. The benefits of using RRAM devices are demonstrated by implementing a NAND standard cell merely consuming the area of two transistors. This cell is about 25 % smaller than the equivalent CMOS NAND in the same technology. We use these cells to implement a half adder, beating the area of the equivalent CMOS implementation using more sophisticates gates by 15 %. Lastly, we fully integrate this novel standard cell into a digital standard cell library and perform a synthesis and layout of a RISC-V CPU core.
KW - RRAM
Y1 - 2024
SN - 979-8-3503-5411-9
SN - 979-8-3503-5412-6
U6 - https://doi.org/10.1109/ISVLSI61997.2024.00026
SN - 2159-3477
VL - 18
SP - 81
EP - 87
PB - IEEE
ER -
TY - GEN
A1 - Reiter, Sebastian
A1 - Han, Weijia
A1 - Mai, Christian
A1 - Spirito, Davide
A1 - Jose, Josmy
A1 - Zöllner, Marvin Hartwig
A1 - Fursenko, Oksana
A1 - Schubert, Markus Andreas
A1 - Stemmler, Ivo
A1 - Wenger, Christian
A1 - Fischer, Inga Anita
T1 - Titanium Nitride Plasmonic Nanohole Arrays for CMOS-compatible integrated refractive index sensing: influence of layer thickness on optical properties
T2 - Plasmonics
Y1 - 2023
U6 - https://doi.org/10.1007/s11468-023-01810-3
SN - 1557-1963
SP - 1
EP - 13
ER -
TY - GEN
A1 - Morales, Carlos
A1 - Mahmoodinezhad, Ali
A1 - Tschammer, Rudi
A1 - Kosto, Yuliia
A1 - Alvarado Chavarin, Carlos
A1 - Schubert, Markus Andreas
A1 - Wenger, Christian
A1 - Henkel, Karsten
A1 - Flege, Jan Ingo
T1 - Combination of Multiple Operando and In-Situ Characterization Techniques in a Single Cluster System for Atomic Layer Deposition: Unraveling the Early Stages of Growth of Ultrathin Al2O3 Films on Metallic Ti Substrates
T2 - Inorganics
N2 - This work presents a new ultra-high vacuum cluster tool to perform systematic studies of the early growth stages of atomic layer deposited (ALD) ultrathin films following a surface science approach. By combining operando (spectroscopic ellipsometry and quadrupole mass spectrometry) and in situ (X-ray photoelectron spectroscopy) characterization techniques, the cluster allows us to follow the evolution of substrate, film, and reaction intermediates as a function of the total number of ALD cycles, as well as perform a constant diagnosis and evaluation of the ALD process, detecting possible malfunctions that could affect the growth, reproducibility, and conclusions derived from data analysis. The homemade ALD reactor allows the use of multiple precursors and oxidants and its operation under pump and flow-type modes. To illustrate our experimental approach, we revisit the well-known thermal ALD growth of Al2O3 using trimethylaluminum and water. We deeply discuss the role of the metallic Ti thin film substrate at room temperature and 200 °C, highlighting the differences between the heterodeposition (<10 cycles) and the homodeposition (>10 cycles) growth regimes at both conditions. This surface science approach will benefit our understanding of the ALD process, paving the way toward more efficient and controllable manufacturing processes.
KW - Atomic layer deposition (ALD)
KW - in-situ
KW - operando
KW - X-ray photoelectron spectroscopy
KW - ellipsometry
KW - quadrupol mass spectrometry (QMS)
Y1 - 2023
U6 - https://doi.org/10.3390/inorganics11120477
SN - 2304-6740
VL - 11
IS - 12
ER -
TY - GEN
A1 - Franck, Max
A1 - Dabrowski, Jarek
A1 - Schubert, Markus Andreas
A1 - Vignaud, Dominique
A1 - Achehboune, Mohamed
A1 - Colomer, Jean‐François
A1 - Henrard, Luc
A1 - Wenger, Christian
A1 - Lukosius, Mindaugas
T1 - Investigating Impacts of Local Pressure and Temperature on CVD Growth of Hexagonal Boron Nitride on Ge(001)/Si
T2 - Advanced Materials Interfaces
N2 - AbstractThe chemical vapor deposition (CVD) growth of hexagonal boron nitride (hBN) on Ge substrates is a promising pathway to high‐quality hBN thin films without metal contaminations for microelectronic applications, but the effect of CVD process parameters on the hBN properties is not well understood yet. The influence of local changes in pressure and temperature due to different reactor configurations on the structure and quality of hBN films grown on Ge(001)/Si is studied. Injection of the borazine precursor close to the sample surface results in an inhomogeneous film thickness, attributed to an inhomogeneous pressure distribution at the surface, as shown by computational fluid dynamics simulations. The additional formation of nanocrystalline islands is attributed to unfavorable gas phase reactions due to the radiative heating of the injector. Both issues are mitigated by increasing the injector‐sample distance, leading to an 86% reduction in pressure variability on the sample surface and a 200 °C reduction in precursor temperature. The resulting hBN films exhibit no nanocrystalline islands, improved thickness homogeneity, and high crystalline quality (Raman FWHM = 23 cm−1). This is competitive with hBN films grown on other non‐metal substrates but achieved at lower temperature and with a low thickness of only a few nanometers.
KW - Boron Nitride
KW - 2D material
Y1 - 2025
U6 - https://doi.org/10.1002/admi.202400467
SN - 2196-7350
VL - 12
IS - 1
PB - Wiley
ER -
TY - GEN
A1 - Morales, Carlos
A1 - Gertig, Max
A1 - Kot, Małgorzata
A1 - Alvarado, Carlos
A1 - Schubert, Markus Andreas
A1 - Zoellner, Marvin Hartwig
A1 - Wenger, Christian
A1 - Henkel, Karsten
A1 - Flege, Jan Ingo
T1 - In situ X‐ray photoelectron spectroscopy study of atomic layer deposited cerium oxide on SiO₂ : substrate influence on the reaction mechanism during the early stages of growth
T2 - Advanced materials interfaces
N2 - Thermal atomic layer deposition (ALD) of cerium oxide using commercial Ce(thd)4 precursor and O3 on SiO2 substrates is studied employing in‐situ X‐ray photoelectron spectroscopy (XPS). The system presents a complex growth behavior determined by the change in the reaction mechanism when the precursor interacts with the substrate or the cerium oxide surface. During the first growth stage, non‐ALD side reactions promoted by the substrate affect the growth per cycle, the amount of carbon residue on the surface, and the oxidation degree of cerium oxide. On the contrary, the second growth stage is characterized by a constant growth per cycle in good agreement with the literature, low carbon residues, and almost fully oxidized cerium oxide films. This distinction between two growth regimes is not unique to the CeOx/SiO2 system but can be generalized to other metal oxide substrates. Furthermore, the film growth deviates from the ideal layer‐by‐layer mode, forming micrometric inhomogeneous and defective flakes that eventually coalesce for deposit thicknesses above 10 nm. The ALD‐cerium oxide films present less order and a higher density of defects than films grown by physical vapor deposition techniques, likely affecting their reactivity in oxidizing and reducing conditions.
KW - Atomic Layer Deposition (ALD)
KW - Cerium oxide
KW - In-situ X-ray Photoelectron spectroscopy (in-situ XPS)
KW - Growth model
KW - Substrate influence
Y1 - 2025
U6 - https://doi.org/10.1002/admi.202400537
SN - 2196-7350
VL - 12
IS - 5
SP - 1
EP - 13
PB - Wiley
CY - Weinheim
ER -