Konrad Seidel

Konrad Seidel
Fraunhofer Institute for Photonic Microsystems IPMS | IPMS · Center Nanoelectronic Technologies (IPMS-CNT)

About

57
Publications
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278
Citations

Publications

Publications (57)
Conference Paper
This paper reports a semi-empirical, SPICE compatible and computationally efficient compact model of ferroelectric capactitors (Fe-CAP). This compact model is inspired by the Jiles-Atherton model of ferroemagnts, which has much smaller computation time than other state-of-the-art models. This model successfully reproduces the evolution of memory wi...
Conference Paper
Full-text available
CMOS compatibility and the low process temperature of hafnium oxide (HfO2) make HfO2-based ferroelectric FETs an excellent candidate for logic, memory, and neuromorphic devices. This article discusses the challenges and opportunities of using hafnium oxide-based ferroelectric memory for in-memory-computing applications. Finally, we try to draw the...
Article
Full-text available
Novel devices based on ferroelectric hafnium oxide comply with the increasing demand for highly scalable embedded non-volatile memory devices, especially for in-memory computing applications. However, due to the polycrystalline nature of these hafnium oxide films, highly scaled devices face variability concerns. In order to enable smaller grains to...
Article
The discovery of ferroelectric hafnium oxide enabled a variety of non-volatile memory devices, like ferroelectric tunnel junctions or field-effect transistors. Reliable application of hafnium oxide based electronics in space or other high-dose environments requires an understanding of how these devices respond to highly ionizing radiation. Here, th...
Article
Full-text available
Devices based on ferroelectric hafnium oxide are of major interest for sensor and memory applications. In particular, Si-doped hafnium oxide layers are investigated for the application in the front-end-of-line due to their resilience to high thermal treatments. Due to its very confined doping concentration range, Si:HfO2 layers based on thermal ato...
Article
Full-text available
Ferroelectric (FE) and antiferroelectric (AFE) materials are used for several memory-related and energy-related applications. Perovskite materials (e.g., bulk ceramics) remain the most common materials for many applications. However, due to large deposition thickness, these materials are not appropriate for future miniaturized devices. In 2011, FE...
Presentation
The presence of ferroelectricity in hafnium oxide thin films can be controlled via doping. Since those layers are usually deposited via atomic layer deposition, the doping element (like Zr, Al, Si, La) is supplied via monolayers. This way, the metastable ferroelectric phase can be stabilized. However, often wake-up effects and asymmetries like impr...
Conference Paper
In our work we describe and demonstrate an alternative approach of integrating 1T-1C FeFET having separated transistor (1T) without modifying frontend CMOS technology and an additional gate-coupled ferroelectric (FE) capacitor (1C) embedded in the interconnect layers. Starting from the results of FE capacitor integration and 1T-1C single cell chara...
Preprint
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p>Interfacial Layer Engineering to Enhance Endurance and Noise Immunity of FeFETs for IMC Applications</p
Preprint
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This article reports an improvement in the endurance and low-frequency noise characteristics in hafnium oxide-based (HfO2) ferroelectric field-effect transistors (FeFET) by interfacial layer (IL) engineering. FeFET devices with silicon dioxide (SiO2) and silicon oxynitride (SiON) as IL were fabricated and charac�terised. FeFETs with SiON interfaces...
Preprint
Full-text available
p>This paper reports back-end-of-line (BEoL) compatible indium gallium zinc oxide (IGZO) based multibit one-time programmable (OTP) ferroelectric thin-film transistors (FeTFT) with lifelong retention capability. The maximum temperature of the entire fabrication process was limited to 350oC. The gate-stack engineering by varying the thickness ratio...
Conference Paper
Recently, hafnium oxide based ferroelectric memories gained great attention due to good scalability, high speed operation, and low power consumption. In contrast to the FRAM concept, the FeFET offers non-destructive read-out. However, the integration of the FeFET into an established CMOS technology entails several challenges. Herein, an 1T1C FeFET...
Preprint
div>This paper reports high precision, highly linear MAC operation conducted on 28nm ferroelectric (Fe) FET (FeFET) based 4Kb computing-in-memory (CIM) core with 1FeFET-1T structure. The CIM-macro consists of 4 Kbit ultra-high precision FeFET based synaptic core, ADCs, and peripheral components for data processing. The crossbar array in the synapti...
Conference Paper
Hafnium oxide-based ferroelectric tunnel junctions (FTJs) are novel nonvolatile memory devices with promising advantages such as non-destructive readout in comparison to conventional ferroelectric random access memories (FRAMs). Reliability aspects of FTJ devices need to be investigated, including their endurance, retention, ferroelectric switching...
Conference Paper
In recent years various emerging memory concepts are in discussion for versatile application as low power solution in edge devices or as high performance memory in novel computing architectures. Among others, ferroelectric memories based on CMOS compliant hafnium oxide are promising candidates for fulfilling the application requirements. In our pap...
Article
Full-text available
The properties of hybrid ferroelectric (FE) and antiFE (AFE) films integrated in a single capacitor stack is reported. The stack lamination (4 × 5 nm) or (2 × 10 nm) using an Alumina (Al2O3) interlayer, material type (Si-doped HfO2 (HSO) and Zr doped HfO2 (HZO)), precursor condition (TEMA-Hf and Hf/ZrCl4), or dopant concentration (Si and Zr) are in...
Article
Nonvolatile memories especially the ferroelectric (FE)-based ones such as ferroelectric tunnel junctions (FTJs) and ferroelectric field-effect transistors (FeFETs) have recently attracted a lot of attention. FTJs have been intensively researched for the last decade and found to be very promising memory devices due to their significant nondestructiv...
Article
Full-text available
A novel system-on-a-chip compatible one-transistor one-capacitor ferroelectric random-access memory array (1T1C FeRAM) based on ferroelectric Hf0.5Zr0.5O2 with a capacitor under bitline (CUB) structure was experimentally demonstrated. The CUB structure facilitates the application of post-metallization annealing on metal/ferroelectric/metal capacito...
Article
Full-text available
Ferroelectricity in crystalline hafnium oxide thin films is strongly investigated for the application in non-volatile memories, sensors and other applications. Especially for back-end-of-line (BEoL) integration the decrease of crystallization temperature is of major importance. However, an alternative method for inducing ferroelectricity in amorpho...
Article
Full-text available
Non-volatile memories based on ferroelectric hafnium oxide, especially the ferroelectric field-effect transistor (FeFET), have outstanding properties, e.g. for the application in neuromorphic circuits. However, material development has focused so far mainly on metal–ferroelectric–metal (MFM) capacitors, while FeFETs are based on metal–ferroelectric...
Conference Paper
Hafnium oxide based ferroelectric FETs (FeFETs) are highly suitable for in-memory computing applications like neuromorphic hardware due to their CMOS compatibility, high dynamic range, low power consumption and good linearity. Device-to-device and die-to-die variability play an important role, especially due to the polycrystalline nature of ferroel...
Article
Full-text available
Reliability is a central aspect of hafnium oxide-based ferroelectric field effect transistors (FeFETs), which are promising candidates for embedded non-volatile memories. Besides the device performance, understanding the evolution of the ferroelectric behaviour of hafnium oxide over its lifetime in FeFETs is of major importance for further improvem...
Article
Full-text available
A multi-level cell (MLC) operation as a 1–3 bit/cell of the FeFET emerging memory is reported by utilizing optimized Si doped hafnium oxide (HSO) and hafnium zirconium oxide (HZO) based on ferroelectric laminates. An alumina interlayer was used to achieve the thickness independent of the HSO and HZO-based stack with optimal ferroelectric properties...
Article
Full-text available
The discovery of ferroelectricity in the fluorite structure based hafnium oxide (HfO2) material sparked major efforts for reviving the ferroelectric field effect transistor (FeFET) memory concept. A Novel metal-ferroelectric-metal-ferroelectric-insulator-semiconductor (MFMFIS) FeFET memory is reported based on dual ferroelectric integration as an M...
Conference Paper
Advanced non-volatile memory concepts such as the 1T1C ferroelectric (FE) random-access memory (FeRAM) and the 1T1C FE field-effect transistor (FeFET) can be realized by connecting a metal-ferroelectric-metal (MFM) capacitor placed in the back end of line (BEoL) of a microchip to the drain and gate contacts of a standard logic device, respectively....
Cover Page
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With the help of transmission Kikuchi diffraction the major physical mechanism of antiferroelectric-like behavior as well as of the wake-up effect is determined by Maximilian Lederer, Konrad Seidel, and co-workers in article number 2100086. Furthermore, guidelines on how to influence this behavior by crystallographic texture and adjacent layers, as...
Conference Paper
The back-end-of-line (BEoL) integration of ferroelectric hafnium zirconium oxide (HZO) has many advantages for applications like non-volatile memories and sensors. Using transmission Kikuchi diffraction (TKD), the influence of process parameters like annealing conditions and Zr content on the microstructure are investigated here. TKD analysis allow...
Conference Paper
Recently, ferroelectric field-effect transistors (Fe-FETs) based on hafnium oxide (HfO 2 ) have been shown to be promising candidates for synaptic devices in neuromorphic applications. The polycrystalline structure of the ferroelectric layer strongly impacts the memory storage as well as the synaptic device performance, especially for highly scaled...
Article
Full-text available
Thin-film transistors (TFTs) based on amorphous indium-gallium-zinc-oxide (a-IGZO) have attracted vast attention for use in organic light-emitting diode (AMOLED) displays due to their high electron mobility and large current on–off ratio. Although amorphous oxide semiconductors show considerably less threshold voltage (Vth) variation than poly-sili...
Article
Full-text available
Ferroelectric hafnium oxide (HfO2) is considered as a very prospective material for applications in integrated devices, due to its considerably large spontaneous polarization and superior thickness scaling. In fact, the evolution of the ferroelectric hysteresis upon field cycling plays the important role in most applications; especially the so‐call...
Article
A novel hybrid antiferroelectric (AFE)-based charge trap (CT) memory is reported focusing on an amplified tunnel oxide field (ETO) via the dynamic of an AFE hysteresis dipole switching. The role of dynamic permittivity increase and the saturated polarization at the instant of the write operation are explored for enhanced ETO. The hybrid CT concept...
Article
Full-text available
Applying transmission Kikuchi diffraction (TKD) allows us to fundamentally investigate the Si-doped-hafnium-oxide (HSO) microstructure that results from the interface layer present in ferroelectric field-effect transistors. In addition to the predominant orthorhombic phase, dendritic HSO grains larger than 100 nm govern the microstructure compositi...
Conference Paper
Full-text available
We report on antiferroelectric (AFE) hybrid charge trap (CT) memory with amplified tunnel oxide field via dynamic AFE hysteresis dipole switching. Memory window (4.5V), switching speed (<1μs), 10 years retention, and 10^5 endurance are reported. The HSO/HZO with tailored (FE,AFE) hysteresis are explored for low power and high-speed-boosted CT memor...
Article
Full-text available
Increasing demands for new computer archi-tectures may require embedded non-volatile memories as for example in-memory computing. Ferroelectric field-effect transistors (FeFETs) add further advantages besides their outstanding properties due to the availability of both n-type and p-type transistors. The latter favor a different channel materials, l...
Conference Paper
Full-text available
Hafnium based ferroelectric field effect transistors (FeFETs) are expected to be influenced by a high defect density of thick gate ferroelectric hafnium oxide. In order to quantify this noise source, we optimized noise and defect density investigation methods with respect to stable erase and program states of FeFETs. Understanding defect states and...
Conference Paper
Full-text available
The novel thin-film ferroelectric material hafnium oxide has revived the interest into ferroelectric memory concepts, which is due to the fact, that it facilitates CMOS and BEoL compatible integration. A major requirement hereby is the stability of the ferroelectric layer towards ionizing radiation, such as gamma and heavy ion exposure. In this stu...
Conference Paper
Full-text available
The discovery of ferroelectricity in thin films of doped hafnium oxide has led to a renaissance of ferroelectric (FE) memory concepts. Compared to all inspected dopants, zirconium doped hafnium oxide (HZO) crystallizes at the lowest temperatures. Thus, this material system is ideal for the implementation of FE functionalities into the back-end-of-l...
Article
Long data retention is a critical requirement for many of the potential applications of HfO₂-based ferroelectric field-effect transistors (FeFETs). However, methods for its rapid assessment are still missing. In this article, we report a detailed investigation of the retention and switching properties of FeFETs fabricated in the 28-nm high-k metal...
Patent
The present invention relates to an integrated electronic circuit comprising a first transistor (1) and a ferroelectric capacitor (2). The ferroelectric capacitor (2) comprises a first electrode layer composed of a non-ferroelectric material, a ferroelectric interlayer having a thickness that is less than the thickness of the first electrode layer,...
Patent
The present invention relates to a voltage-controllable capacitor comprising a first electrode layer (4) composed of a non-ferroelectric material, said first electrode layer being applied on a substrate (6), a ferroelectric interlayer (3) having a thickness that is less than the thickness of the first electrode layer (4), and a second electrode lay...
Article
Full-text available
The microstructure of ferroelectric hafnium oxide plays a vital role for its application, e.g., non-volatile memories. In this study, transmission Kikuchi diffraction and scanning transmission electron microscopy STEM techniques are used to compare the crystallographic phase and orientation of Si and Zr doped HfO2 thin films as well as integrated i...
Article
Full-text available
The discovery of ferroelectricity in thin doped hafnium oxide films revived the interest in ferroelectric memory concepts. Zirconium doped hafnium oxide (HZO) crystalizes at low rapid thermal annealing (RTA) temperatures (e.g. 400°C), which makes this material interesting for the implementation of ferroelectric functionalities into the back‐end‐of‐...
Article
This article presents a fully differential power-tuning heterodyne on-chip sensing readout system at 240 GHz. The chip enables the measurement of not only the transmission parameter but also the reflection parameter to sense the permittivity of different materials by using four heterodyne mixer-based receiving channels connected to a dielectric sen...
Presentation
Full-text available
Hardware based neuromorphic computing, which requires a synaptic memory capable of retaining a multitude of addressable conductance states, opens a possibility to bypass the von-Neumann bottleneck [1]. Ferroelectric field effect transistors (FeFETs) based on doped hafnium oxide have been demonstrated as viable candidates for neuromorphic synapses [...
Conference Paper
As the name suggests SPIDERNET (Sensor Platform for Intelligent aD-hoc wirEless Relaying NETwork) is a platform for a wireless sensor network developed at TU Dresden. We introduce the ad-hoc, multi-hop protocol implemented on our hardware platform. It combines ideas from known proposals: rotating cluster heads (CH) [1] ensure energy balancing, know...