Clemens Mart

Clemens Mart
Infineon Technologies

Dr. rer. nat.

About

56
Publications
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417
Citations

Publications

Publications (56)
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
In this article, we present the capacitance-voltage (C-V) characteristics of HfₓZr₁₋ₓO₂metal-ferroelectric-metal (MFM) thin-film capacitors with various Zr doping, thicknesses, and annealing temperatures. The influence of doping, electric field cycling, and annealing temperature on tuning characteristics (tunability) was analyzed and an optimized b...
Article
Full-text available
The hafnium oxide material class is characterized by the coexistence of several polymorphs between which phase transitions are induced by means of composition and external electric fields. Pyroelectric materials, which convert heat into electrical energy, exhibit the largest response at such morphotropic or field-induced phase transitions. The hafn...
Cover Page
Full-text available
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...
Article
Full-text available
Pyroelectric infrared sensors are often based on lead-containing materials, which are harmful to the environment and subject to governmental restrictions. Ferroelectric Hf1−xZrxO2 thin films offer an environmentally friendly alternative. Additionally, CMOS integration allows for integrated sensor circuits, enabling scalable and cost-effective appli...
Conference Paper
Ferroelectric and antiferroelectric Hf/Zr-based oxide films have recently gained interest for memory and AI applications due to their promise of low power and CMOS compatibility. As Hf/Zr-based oxides are not ‘new’ materials, this paper will start with an overview of past learning on this material system. Recent results on fundamental understanding...
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
Full-text available
The hafnium oxide (HfO2) material system offers a unique combination of outstanding physical properties, that enable a manifold of novel integrated ferroelectric, piezoelectric, and pyroelectric applications. Long‐term stability is an essential concern for non‐volatile memory devices, sensors, and nano‐electromechanical systems (NEMS). Here, we rep...
Article
Piezoelectric thin films are of current interest in science and industry for highly integrated nano-electro-mechanical-systems and sensor devices. In this study, the dependence of the piezoelectric properties on the doping concentration in Si:HfO2 thin films and their crystallographic origin are investigated. The Si:HfO2 films with a thickness of 2...
Article
Full-text available
In this Letter, we report the percentage of the ferroelectric phase in a 10-nm-thick Hf 0.5 Zr 0.5 O 2 (HZO) film deposited in a metal-insulator-metal stack by atomic layer deposition. The ferroelectric behavior was confirmed by polarization measurements and piezoresponse force microscopy. Ferroelectric behavior in this material has been attributed...
Conference Paper
Full-text available
We demonstrate the feasibility of thermal energy recovery in the back end of line (BEoL) employing CMOS-compatible ferroelectric hafnium oxide. Efficient pyroelectric energy harvesting with a sizable power density of 92 mWcm-3 under typical thermal conditions is achieved. Our energy harvesting approach exceeds the efficiency limit of commonly-used...
Conference Paper
We demonstrate the feasibility of thermal energy recovery in the back end of line (BEoL) employing CMOScompatible ferroelectric hafnium oxide. Efficient pyroelectric energy harvesting with a sizable power density of 92 mWcm-3 under typical thermal conditions is achieved. Our energy harvesting approach exceeds the efficiency limit of commonly used t...
Article
Full-text available
The accurate determination of electrocaloric coefficients in nanometer-thin, polycrystalline doped HfO2 is challenging and has led to very different values reported in the literature. Here, we apply two different methods in order to compare and analyze reversible and irreversible or metastable contributions to the electrocaloric effect. The indirec...
Article
We report on the temperature-dependent operation of fluorite-structure-based ferroelectric FET (FeFET) emerging memory. A temperature range (-40 °C to 40 °C) is used to explore the FeFET characteristic relation to operating temperature. The memory window (MW) shows a modulated response that features a reciprocal MW dependence on temperature, such t...
Article
We report on the high-temperature operation and reliability of the Si-doped hafnium oxide (HSO) ferroelectric FET (FeFET) emerging memory. In this study, we explore the role of high-temperature operation of the ferroelectric (FE) material on the FeFET in the temperature range of 40-120 °C. The inverse memory window (MW) dependence on temperature le...
Cover Page
Full-text available
Hafnium Zirconium Oxide Films So far, the ferroelectric phase of prior amorphous hafnium zirconium oxide (HZO) films is achieved by using rapid thermal annealing. In article number 1900840 by David Lehninger and co‐workers, it is shown that a dedicated annealing step is not needed for the integration of ferroelectric HZO films into the back‐end‐of‐...
Conference Paper
The impact of the ferroelectric (FE) wakeup phenomenon on the reliability of fluorite structure-based laminated Si-doped hafnium oxide (HSO) FeFET memory cells is reported. The post wakeup cycling shows a strong change in the optimal program/erase (PG/ER) write conditions. A shift towards lower PG/ER switching conditions at a higher memory window (...
Article
Full-text available
The in‐plane piezoelectric response of 20 nm thick Si‐doped HfO2 is examined by exploiting thermal expansion of the substrate upon rapid temperature cycling. The sample is heated locally by a deposited metal film, and the subsequently registered pyroelectric current is found to be frequency dependent in the observed range of 5 Hz to 35 kHz. While t...
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
Full-text available
The local crystal phase and orientation of ferroelectric grains inside TiN/Hf0.5Zr0.5O2/TiN have been studied by the analysis of the local electron beam scattering Kikuchi patterns, recorded in transmission. Evidence was found that the ferroelectric phase of the layers is derived from an orthorhombic phase, most likely of space group Pca21. The ori...
Article
We employ a modified atomic layer deposition process utilizing in-situ mixing of precursors to obtain doped hafnium oxide thin films with improved ferroelectric properties. The method is demonstrated with aluminum, silicon, and lanthanum doping, where film composition and crystal structure are analyzed. With the modified process, low dopant concent...
Article
Full-text available
Low‐grade heat sources are abundant yet challenging to use for energy harvesting. In this work, we exploit the pyroelectric effect in Si‐doped HfO2 thin films to demonstrate thermal‐electric energy conversion. The 20 nm thin films are grown on an area‐enhanced substrate via atomic layer deposition, which enhances the power output by a factor of 19...
Article
Full-text available
Wireless power distribution is demonstrated using an infrared laser and an area‐enhanced Si‐doped HfO2 pyroelectric receiver, where Brayton‐style thermodynamic cycles are employed to significantly enhance the efficiency compared to simple resistive harvesting. More details can be found in article number 1900515 by Clemens Mart and co‐workers.
Cover Page
Full-text available
Wireless power distribution is demonstrated using an infrared laser and an area‐enhanced Si‐doped HfO2 pyroelectric receiver, where Brayton‐style thermodynamic cycles are employed to significantly enhance the efficiency compared to simple resistive harvesting. More details can be found in article number 1900515 by Clemens Mart and co‐workers.
Conference Paper
Full-text available
Ferroelectric thin films can be used for various applications such as non-volatile memories or infrared sensors. A very promising material for integrated devices hereby is ferroelectric HfO2, due to its CMOS compatibility. For such integrated devices a small variability in the ferroelectric characteristics such as the local coercive field as well a...
Presentation
Full-text available
Doped-HfO2 based ferroelectrics have been widely studied for the application in advanced CMOS technologies such as ferroelectric random-access memory (FeRAM) or ferroelectric field effect transistor (FeFET). Studies show that there is a strong link between the ferroelectric properties with the highest remanent polarization value of the doped-HfO2 a...
Poster
Full-text available
Since the discovery of ferroelectricity in HfO2 thin films [1], it obtained great research interest for the implementation into various integrated devices e.g. non-volatile memories or infrared sensors, due to its CMOS compatibility. As the ferroelectricity in HfO2 is assigned to the orthorhombic Pca21 phase [2], its phase fraction and orientation...
Poster
Ferroelectric HfO2 is a promising material for integrated devices due to its CMOS compatibility. For such applications, small variability in ferroelectric characteristics such as local coercive field is required. PFM can retrieve such information in ultra-thin films by switching spectroscopy (SS-PFM) with high lateral resolution. However, artefacts...
Conference Paper
Full-text available
Hafnium oxide thin films have proven to be a viable alternative to established ferroelectrics since their recent discovery. Reported applications include non-volatile memory and energy storage devices. Further, large pyroelectric coefficients, high scalability down to few nanometers, CMOS compatible manufacturing, and the low dielectric permittivit...
Presentation
Full-text available
Self-limiting nature of atomic layer deposition (ALD) proposes a unique deposition mechanism which can produce extremely good step coverage within high aspect ratio (HAR) structures. This layer-by-layer deposition method also provides fine control on different features of deposition techniques such as controlling the dopant distribution in the dire...
Article
Full-text available
For the analysis of thin films, with high aspect ratio (HAR) structures, time-of-flight secondary ion mass spectrometry (ToF-SIMS) overcomes several challenges in comparison to other frequently used techniques such as electron microscopy. The research presented herein focuses on two different kinds of HAR structures that represent different semicon...
Conference Paper
Full-text available
For the analysis of thin films, with high aspect ratio (HAR) structures, time-of-flight secondary ion mass spectrometry (ToF-SIMS) overcomes several challenges in comparison to other frequently used techniques such as electron microscopy. The research presented herein focuses on two different kinds of HAR structures that represent different semicon...
Conference Paper
Full-text available
Ferroelectric HfO2-based thin films receive research interest due to their large spontaneous polarization, scalability, and CMOS compatible manufacturing. In ferroelectrics, the remanent polarization exhibits a temperature dependence, which causes the pyroelectric response in such films. Recently, the pyroelectric effect of Si-doped HfO2 films has...
Conference Paper
Full-text available
Ferroelectric doped hafnium oxide thin films continue to spark research interest as they exhibit large spontaneous polarization in combination with scalable and CMOS compatible manufacturing. Since its recent discovery, the material has already found applications such as non-volatile memory [1], energy storage [2], and temperature sensing [3]. The...
Poster
Ferroelectricity in Si-doped HfO2 (HSO) was first discovered in 2011 [1]. Since then research was conducted to investigate the influence of different conditions such as doping, wake-up cycling and anneal conditions [2] for applications in highly scaled integrated devices. Hereby, a high grain texture and small variability in the ferroelectric prope...
Presentation
Ferroelectric HfO2-based thin films receive extensive research interest due to their large spontaneous polarization, scalability, and CMOS compatible manufacturing. As in ferroelectrics, the remnant polarization exhibits a temperature dependence, one can observe a strong pyroelectric response in such films. Recently, the pyroelectric effect of dope...
Article
Full-text available
Lanthanum has been identified as a promising dopant to achieve ferroelectricity in HfO2 thin films in recent theoretical and experimental studies. In this work, the pyroelectric properties of 10 nm thick polycrystalline La-doped HfO2 layers manufactured by thermal ALD are assessed employing a sinusoidal temperature profile. Compared to Si doping, L...
Article
Full-text available
Capacitors based on 10 nm antiferroelectric silicon-doped hafnium oxide (Si:HfO 2 ) thin films are investigated in terms of energy storage efficiency, cycling endurance, and reliability. Atomic layer deposition (ALD) on an area-enhanced substrate with large-scale arrays of deep-trench structures is used to significantly increase the energy density,...
Article
Full-text available
The pyroelectric response of polycrystalline, Si-doped HfO2 layers with a thickness of 20 nm is investigated in a frequency range of 2 Hz to 20 kHz. Local Joule heating of the pyroelectric material by a deposited nickel strip is used to achieve fast thermal cycles. Over the whole frequency range, a distinct pyroelectric response is registered. A py...
Article
Full-text available
The pyroelectric response of polycrystalline, Si-doped HfO2 layers in a thickness range of 10 nm to 50 nm is investigated employing the temperature oscillation method. The largest value of the pyroelectric coefficient is obtained for the 20 nm layer with p = 84 μC m−2 K⁻¹, which is similar to that of lithium niobate. Furthermore, the pyroelectric c...
Article
Full-text available
ZrO2-based metal-insulator-metal (MIM) capacitors are manufactured using atomic layer deposition. The impact of aluminum doping at the electrode interface on the electrical characteristics is evaluated using I-V, C-V and time dependent dielectric breakdown measurements. The aluminum doping profiles are examined using ToF-SIMS. Further, the impact o...