scholarly journals Radiation Tolerance and Charge Trapping Enhancement of ALD HfO2/Al2O3 Nanolaminated Dielectrics

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 849
Author(s):  
Dencho Spassov ◽  
Albena Paskaleva ◽  
Elżbieta Guziewicz ◽  
Vojkan Davidović ◽  
Srboljub Stanković ◽  
...  
Keyword(s):  
Charge Trapping ◽  
Atomic Layer ◽  
Information Storage ◽  
Radiation Tolerance ◽  
Leakage Currents ◽  
High K ◽  
60Co Source ◽  
Retention Characteristics ◽  
High K Materials ◽  
High K Dielectric

High-k dielectric stacks are regarded as a promising information storage media in the Charge Trapping Non-Volatile Memories, which are the most viable alternative to the standard floating gate memory technology. The implementation of high-k materials in real devices requires (among the other investigations) estimation of their radiation hardness. Here we report the effect of gamma radiation (60Co source, doses of 10 and 10 kGy) on dielectric properties, memory windows, leakage currents and retention characteristics of nanolaminated HfO2/Al2O3 stacks obtained by atomic layer deposition and its relationship with post-deposition annealing in oxygen and nitrogen ambient. The results reveal that depending on the dose, either increase or reduction of all kinds of electrically active defects (i.e., initial oxide charge, fast and slow interface states) can be observed. Radiation generates oxide charges with a different sign in O2 and N2 annealed stacks. The results clearly demonstrate a substantial increase in memory windows of the as-grown and oxygen treated stacks resulting from enhancement of the electron trapping. The leakage currents and the retention times of O2 annealed stacks are not deteriorated by irradiation, hence these stacks have high radiation tolerance.

Design, Simulation and Testing of High Density, High Current Micro-machined Embedded Capacitors

2013 ◽  
Vol 2013 (DPC) ◽  
pp. 000515-000534
Author(s):  
Aubrey Beal ◽  
C. Stevens ◽  
T. Baginski ◽  
M. Hamilton ◽  
R. Dean
Keyword(s):  
Integrated Circuits ◽  
Hafnium Oxide ◽  
Implementation Strategies ◽  
Atomic Layer ◽  
High Density ◽  
Embedded Capacitors ◽  
Passive Devices ◽  
Layer Deposition ◽  
High K ◽  
High K Materials

Due to increasing speed, density and number of signal paths in integrated circuits, motivations for high density capacitors capable of quickly sourcing large amounts of current have led to many design and fabrication investigations. This work outlines continued efforts to achieve devices which meet these stringent requirements and are compatible with standard silicon fabrication processes as well as silicon interposer technologies. Previous work has been further developed resulting in devices exhibiting greater capacitance values by employing geometries which maximize surface area. The Atomic Layer Deposition (ALD) of thin layered high K materials, such as Hafnium Oxide, as opposed to previous silicon-dioxide based devices effectively increased the capacitance per unit area of the structures. This paper outlines the design, fabrication, and testing of high density micro-machined embedded capacitors capable of quickly sourcing (i.e. risetimes greater than 100A/nsec) high currents (i.e. greater than 100A). These devices were successfully simulated then tested using a standard ringdown procedure. Generally, the resulting device characterization found during testing stages strongly correlates to the expected simulated device behavior. Subsequent descriptions and design challenges encountered during fabrication, testing and integration of these passive devices are outlined, as well as potential device integration and implementation strategies for use in silicon interposers. The modification and revision of several device generations is documented and presented. Increased device capacitive density, maximized current capabilities and minimized effects of series inductance and resistance are presented. These resulting thin, capacitive structures exhibit compatibility with Si interposer technology.

scholarly journals Conformal High-K Dielectric Coating of Suspended Single-Walled Carbon Nanotubes by Atomic Layer Deposition

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1085 ◽  
Author(s):  
Kemelbay ◽  
Tikhonov ◽  
Aloni ◽  
Kuykendall
Keyword(s):  
Carbon Nanotubes ◽  
Atomic Layer Deposition ◽  
Field Effect Transistors ◽  
Atomic Layer ◽  
Oxide Thickness ◽  
Ambient Conditions ◽  
Nucleation Layer ◽  
Layer Deposition ◽  
High K ◽  
High K Dielectric

As one of the highest mobility semiconductor materials, carbon nanotubes (CNTs) have been extensively studied for use in field effect transistors (FETs). To fabricate surround-gate FETs— which offer the best switching performance—deposition of conformal, weakly-interacting dielectric layers is necessary. This is challenging due to the chemically inert surface of CNTs and a lack of nucleation sites—especially for defect-free CNTs. As a result, a technique that enables integration of uniform high-k dielectrics, while preserving the CNT’s exceptional properties is required. In this work, we show a method that enables conformal atomic layer deposition (ALD) of high-k dielectrics on defect-free CNTs. By depositing a thin Ti metal film, followed by oxidation to TiO2 under ambient conditions, a nucleation layer is formed for subsequent ALD deposition of Al2O3. The technique is easy to implement and is VLSI-compatible. We show that the ALD coatings are uniform, continuous and conformal, and Raman spectroscopy reveals that the technique does not induce defects in the CNT. The resulting bilayer TiO2/Al2O3 thin-film shows an improved dielectric constant of 21.7 and an equivalent oxide thickness of 2.7 nm. The electrical properties of back-gated and top-gated devices fabricated using this method are presented.

Growth and interfacial properties of atomic layer deposited Al0.7Ti0.3O y high-k dielectric on Ge substrate

2014 ◽  
Vol 117 (3) ◽  
pp. 1479-1484 ◽  
Author(s):  
Hong-Liang Lu ◽  
Zhang-Yi Xie ◽  
Yang Geng ◽  
Yuan Zhang ◽  
Qing-Qing Sun ◽  
...  
Keyword(s):  
Atomic Layer ◽  
Interfacial Properties ◽  
High K ◽  
High K Dielectric

scholarly journals Atomic layer deposition of crystalline SrHfO3 directly on Ge (001) for high-k dielectric applications

2015 ◽  
Vol 117 (5) ◽  
pp. 054101 ◽  
Author(s):  
Martin D. McDaniel ◽  
Chengqing Hu ◽  
Sirong Lu ◽  
Thong Q. Ngo ◽  
Agham Posadas ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Layer Deposition ◽  
High K ◽  
High K Dielectric

Charge Trapping Memories With Atomic Layer Deposited High-k Dielectrics Capping Layers

2010 ◽  
Vol 1250 ◽  
Author(s):  
Nikolaos Nikolaou ◽  
Panos Dimitrakis ◽  
Pascal Normand ◽  
Konstantinos Giannakopoulos ◽  
Konstantina Mergia ◽  
...  
Keyword(s):  
Charge Trapping ◽  
Atomic Layer ◽  
Dielectric Strength ◽  
Precursor Chemistry ◽  
Memory Window ◽  
Trapping Efficiency ◽  
Zirconium Oxides ◽  
Metal Precursors ◽  
High K ◽  
Memory Structures

AbstractIn this work, we examine the influence of hafnium and zirconium oxides ALD precursor chemistry on the memory properties of SiO2/Si3N4/ZrO2 and SiO2/Si3N4/HfO2 non-volatile gate memory stacks. Approximately 10 nm thick ZrO2 and HfO2 layers were deposited on top of a SiO2/Si3N4 structure, functioning as blocking oxides. Both metal oxides were deposited using either alkylamides or cyclopentadienyls as metal precursors, and ozone as the oxygen source. In the case of the ZrO2 gate stacks a memory window of 6 V was determined, comprised of 4 V write window and 2 V erase window. Although no dramatic differences were evident between the ZrO2 layers, ZrO2 grown from alkylamide provided structures with higher dielectric strength. The memory structures with HfO2 blocking layers indicate that the memory window and the dielectric strength are significantly affected by the precursor. The structures with the HfO2 formed from alkylamide showed a write window of 7 V, while the films grown from cyclopentadienyl possessed window of 5 V. Comparison between the memory windows obtained using ZrO2 and HfO2 as control oxides reveals that the former provides memory structures with higher electron trapping efficiency.

Sign in / Sign up

Export Citation Format

Share Document