Conduction barrier offset engineering for DRAM capacitor scaling

Pešić, Milan; Knebel, S.; Cho, Kyuho; Jung, Changhwa; Chang, Jaewan; Lim, H.; Kolomiiets, Nadiia; Afanasʼev, Valeri; Mikolajick, Thomas; Schroeder, Uwe

doi:10.1016/j.sse.2015.08.012

Cited by 36 publications

(32 citation statements)

References 16 publications

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“…These interfacial regions consist of nonswitching transitional material (TM-HfO 2 ) ( Figure 5) and are parasitically grown during the deposition of the HfO x and the subsequent annealing step. [39,40] During deposition of the HfO 2 dielectric atop of TiN bottom electrode, a TiO x N y interfacial layer is formed, which pulls oxygen out of the HfO 2 whereas nitrogen diffuses into the dielectric. [39,40] Moreover, an additional growth of the bottom interface layer was reported during top electrode deposition, [39,40] which creates further asymmetry within the device.…”

Section: Modelingmentioning

confidence: 99%

Physical Mechanisms behind the Field‐Cycling Behavior of HfO₂‐Based Ferroelectric Capacitors

Pešić

Fengler

Larcher

et al. 2016

Adv Funct Materials

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708

461

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Novel hafnium oxide (HfO 2 )-based ferroelectrics reveal full scalability and complementary metal oxide semiconductor integratability compared to perovskite-based ferroelectrics that are currently used in nonvolatile ferroelectric random access memories (FeRAMs). Within the lifetime of the device, two main regimes of wake-up and fatigue can be identified. Up to now, the mechanisms behind these two device stages have not been revealed. Thus, the main scope of this study is an identification of the root cause for the increase of the remnant polarization during the wake-up phase and subsequent polarization degradation with further cycling. Combining the comprehensive ferroelectric switching current experiments, Preisach density analysis, and transmission electron microscopy (TEM) study with compact and Technology Computer Aided Design (TCAD) modeling, it has been found out that during the wake-up of the device no new defects are generated but the existing defects redistribute within the device. Furthermore, vacancy diffusion has been identified as the main cause for the phase transformation and consequent increase of the remnant polarization. Utilizing trap density spectroscopy for examining defect evolution with cycling of the device together with modeling of the degradation results in an understanding of the main mechanisms behind the evolution of the ferroelectric response.

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Section: Modelingmentioning

confidence: 99%

Physical Mechanisms behind the Field‐Cycling Behavior of HfO₂‐Based Ferroelectric Capacitors

Pešić

Fengler

Larcher

et al. 2016

Adv Funct Materials

Self Cite

708

461

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show abstract

“…In addition to the the TiO x N y and TiO x interfacial layer formation due to oxygen scavenging from the HfO 2 and nitrogen diffusion, results of the TEM study [55,58] revealed parasitic tetragonal regions of the HfO 2 film towards the electrodes. Due to their tetragonal nature, these regions consist of non-switching (from the ferroelectric point of view) transitional material (T-HfO 2 ) [55,60,61]. Therefore, the complete device stack consists of TiO x N y /TM-HfO x /FE-HfO 2 /TM-HfO x /TiO x sandwiched between two TiN electrodes (see Fig.…”

Section: Physical Mechanisms Model Behind Field Cycling Of Ferroelectmentioning

confidence: 99%

A computational study of hafnia-based ferroelectric memories: from ab initio via physical modeling to circuit models of ferroelectric device

et al. 2017

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Abstract. The discovery of ferroelectric properties of binary oxides revitalized the interest in ferroelectrics and bridged the scaling gap between the state-of-the-art semiconductor technology and ferroelectric memories. However, before hitting the markets, the origin of ferroelectricity and in-depth studies of device characteristics are needed. Establishing a correlation between the performance of the device and underlying physical mechanisms is the first step toward understanding the device and engineering guidelines for a novel, superior device. Therefore, in this paper a holistic modeling approaches which lead to a better understanding of ferroelectric memories based on hafnium and zirconium oxide is addressed. Starting from describing the stabilization of the ferroelectric phase within the binary oxides via physical modeling the physical mechanisms of the ferroelectric devices are reviewed. Besides, limitations and modeling of the multi-level operation and switching kinetics of ultimately scaled devices as well as the necessity for Landau-Khalatnikov approach are discussed. Furthermore, a device level model of ferroelectric memory devices that can be used to study the array implementation and their operational schemes are addressed. Finally, a circuit model of the ferroelectric memory device is presented and potential further applications of ferroelectric devices are outlined.

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“…Both approaches (1) and (2) are suitable to create an internal (built‐in) bias field that essentially shifts the polarization–voltage characteristic of the anti‐ or field‐induced‐ferroelectric material along the voltage axis. Utilization of a high work function top or bottom electrode (e.g., Pt ≈ 5.6 eV) while maintaining a lower work function electrode on the other side would result in the required built in bias voltage and thus in the desired shift of the hysteresis.…”

Section: Antiferroelectric Zro2 For Nonvolatile Memoriesmentioning

confidence: 99%

“…Beside the lifetime and performance, scalability and integrability of novel material system is of high importance to achieve competitive products. For many years, dynamic random access memory (DRAM) capacitors comprising ZrO 2 based materials have been successfully scaled down . Metal‐insulator‐metal (MIM) capacitors with TiN electrodes and ZrO 2 /Al 2 O 3 /ZrO 2 (ZAZ) dielectric stacks were applied in commercial DRAM products from the 80 nm node to current 18 nm generations during the last decade .…”

Section: Introductionmentioning

confidence: 99%

Nonvolatile Random Access Memory and Energy Storage Based on Antiferroelectric Like Hysteresis in ZrO₂

Pešić

Hoffmann

Richter

et al. 2016

Adv Funct Materials

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190

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To date antiferroelectrics have not been considered as nonvolatile memory elements because a removal of the external field causes a depolarization, resulting in a loss of the stored information. In comparison to ferroelectrics, antiferroelectrics are known for their enhanced fatigue resistance. Therefore, the main scope of this study is the development of a new memory device concept that would enable the usage of antiferroelectrics as a nonvolatile material with improved wake‐up and enhanced endurance properties. Recent studies have shown antiferroelectric behavior in ZrO2, a material that is widely used in semiconductor industry, especially in dynamic random access memories. The basis of the new concept is the antiferroelectric hysteresis combined with the use of different workfunction electrodes that induce an internal bias field. Utilizing this approach, the field cycling endurance is drastically improved. Combining a comprehensive material study and electrical trap spectroscopy together with Landau–Ginzburg–Devonshire formalism, a proof of concept for a novel antiferroelectric random access memory is presented. For implementing a nonvolatile random access memory, the capacitors have to be realized in a 3D integrated version. These 3D integrated ZrO2 capacitors can be used as energy storage devices as well, showing record high energy storage density and very high energy efficiency values.

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Conduction barrier offset engineering for DRAM capacitor scaling

Cited by 36 publications

References 16 publications

Physical Mechanisms behind the Field‐Cycling Behavior of HfO₂‐Based Ferroelectric Capacitors

Physical Mechanisms behind the Field‐Cycling Behavior of HfO₂‐Based Ferroelectric Capacitors

A computational study of hafnia-based ferroelectric memories: from ab initio via physical modeling to circuit models of ferroelectric device

Nonvolatile Random Access Memory and Energy Storage Based on Antiferroelectric Like Hysteresis in ZrO₂

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Conduction barrier offset engineering for DRAM capacitor scaling

Cited by 36 publications

References 16 publications

Physical Mechanisms behind the Field‐Cycling Behavior of HfO2‐Based Ferroelectric Capacitors

Physical Mechanisms behind the Field‐Cycling Behavior of HfO2‐Based Ferroelectric Capacitors

A computational study of hafnia-based ferroelectric memories: from ab initio via physical modeling to circuit models of ferroelectric device

Nonvolatile Random Access Memory and Energy Storage Based on Antiferroelectric Like Hysteresis in ZrO2

Contact Info

Product

Resources

About

Physical Mechanisms behind the Field‐Cycling Behavior of HfO₂‐Based Ferroelectric Capacitors

Physical Mechanisms behind the Field‐Cycling Behavior of HfO₂‐Based Ferroelectric Capacitors

Nonvolatile Random Access Memory and Energy Storage Based on Antiferroelectric Like Hysteresis in ZrO₂