Bonding Constraints at Interfaces Between Crystalline Si and Stacked Gate Dielectrics

1999 ◽  
Vol 567 ◽  
Author(s):  
G. Lucovsky ◽  
J.C. Phillips
Keyword(s):  
Metal Oxides ◽  
Transition Metal Oxides ◽  
Chemical Bonding ◽  
Gate Dielectrics ◽  
Nuclear Charge ◽  
Dielectric Materials ◽  
Band Offset ◽  
High K ◽  
Dielectric Interfaces ◽  
Mechanical Bonding

ABSTRACTThis paper discusses chemical bonding effects at Si-dielectric interfaces that are important in the implementation of alternative gate dielectrics including: i) the character of interfacial bonds, either isovalent with bond and nuclear charge balanced as in Si-SiO2, or heterovalent, with an inherent mismatch between bond and nuclear charge, ii) mechanical bonding constraints related to the average number of bonds/atom, Nay, and iii) band offset energies that are reduced in transition metal oxides due to the d-state origins of the conduction band states. Applications are made to specific classes of dielectric materials including i) nitrides and oxide/nitride stacks and ii) alternative high-K gate materials.

Materials and Physical Properties of Novel High-k and Medium-k Gate Dielectrics

2001 ◽  
Vol 670 ◽  
Author(s):  
Ran Liu ◽  
Stefan Zollner ◽  
Peter Fejes ◽  
Rich Gregory ◽  
Shifeng Lu ◽  
...  
Keyword(s):  
Thin Film ◽  
Transition Metal Oxides ◽  
Gate Dielectrics ◽  
Low Leakage ◽  
Low Leakage Current ◽  
High K ◽  
Compositional Properties ◽  
Sharp Interfaces ◽  
Selection Of

ABSTRACTRapid shrinking in device dimensions calls for replacement of SiO2 by new gate insulators in future generations of MOSFETs. Among many desirable properties, potential candidates must have a higher dielectric constant, low leakage current, and thermal stability against reaction or diffusion to ensure sharp interfaces with both the substrate Si and the gate metal (or poly-Si). Extensive characterization of such materials in thin-film form is crucial not only for selection of the alternative gate dielectrics and processes, but also for development of appropriate metrology of the high-k films on Si. This paper will report recent results on structural and compositional properties of thin film SrTiO3 and transition metal oxides (ZrO2and HfO2).

scholarly journals High-K dielectric sulfur-selenium alloys

2019 ◽  
Vol 5 (5) ◽  
pp. eaau9785 ◽  
Author(s):  
Sandhya Susarla ◽  
Thierry Tsafack ◽  
Peter Samora Owuor ◽  
Anand B. Puthirath ◽  
Jordan A. Hachtel ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Metal Oxides ◽  
High Dielectric Constant ◽  
Dielectric Material ◽  
Dielectric Strength ◽  
Dielectric Materials ◽  
High K ◽  
Device Applications ◽  
High K Dielectric ◽  
High Dielectric

Upcoming advancements in flexible technology require mechanically compliant dielectric materials. Current dielectrics have either high dielectric constant, K (e.g., metal oxides) or good flexibility (e.g., polymers). Here, we achieve a golden mean of these properties and obtain a lightweight, viscoelastic, high-K dielectric material by combining two nonpolar, brittle constituents, namely, sulfur (S) and selenium (Se). This S-Se alloy retains polymer-like mechanical flexibility along with a dielectric strength (40 kV/mm) and a high dielectric constant (K = 74 at 1 MHz) similar to those of established metal oxides. Our theoretical model suggests that the principal reason is the strong dipole moment generated due to the unique structural orientation between S and Se atoms. The S-Se alloys can bridge the chasm between mechanically soft and high-K dielectric materials toward several flexible device applications.

XAS Studies of Chemical Bonding of Nitrogen and Oxygen Atoms in Ti/Zr/Hf High-K Gate Dielectrics

2007 ◽  
Author(s):  
Hyungtak Seo ◽  
Sanghyun Lee ◽  
Byoung Ju ◽  
Gerald Lucovsky ◽  
Jan Lüning
Keyword(s):  
Chemical Bonding ◽  
Gate Dielectrics ◽  
High K ◽  
Oxygen Atoms

First Principles Modeling Of High-K Dielectric Materials

2002 ◽  
Vol 745 ◽  
Author(s):  
Gyuchang Jun ◽  
Kyeongjae Cho
Keyword(s):  
Metal Oxide ◽  
Metal Oxides ◽  
First Principles ◽  
Density Functional ◽  
Oxide Thickness ◽  
Dielectric Materials ◽  
Interface Layer ◽  
Dielectric Constants ◽  
High K ◽  
Interface Layers

ABSTRACTFirst-principles calculations are performed for high-K gate dielectric materials using model bulk and interface systems. Detailed electronic structures and atomic configurations are investigated for transition metal (Hf and Zr) oxide, metal doped silicate bulk system and a model Si-silicate interface system. Pseudo polymorphs of metal oxides are investigated to elucidate the underlying driving mechanisms in microscopic configurations of metal oxides and silicates in amorphous structures. We studied energetics and electronic structure of metal oxide pseudo morph with varying oxygen coordination. Dielectric constants of metal oxide and silicate materials are also investigated using the density functional perturbation theory method implemented in the ABINIT code. Electronic and dielectric properties of silica interface layers between high-κ dielectric and Si substrate are investigated leading to a confirmation that 1 nm is the physical limit of gate oxide thickness. Furthermore silica interface layer is found to have small dielectric constant of 3.4∼3.9.

Methods to Improve Properties of Gate Dielectrics in Metal-Oxide-Semiconductor

2012 ◽  
Vol 463-464 ◽  
pp. 1341-1345 ◽  
Author(s):  
Chong Liu ◽  
Xiao Li Fan
Keyword(s):  
Gate Dielectric ◽  
Gate Dielectrics ◽  
Dielectric Materials ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Physical Limitation ◽  
Low Leakage ◽  
Mos Devices ◽  
Low Leakage Current ◽  
High K

This essay aims to introduce development of gate dielectrics. In present-day society, Si-based MOS has met its physical limitation. Scientists are trying to find a better material to reduce the thickness and dimension of MOS devices. While substrate materials are required to have a higher mobility, gate dielectrics are expected to have high k, low Dit and low leakage current. I conclude dielectrics in both Si-based and Ge-based MOS devices and several measures to improve the properties of these gate dielectric materials. I also introduce studies on process in our group and some achievements we have got. Significantly, this essay points out the special interest in rare-earth oxides functioning as gate dielectrics in recent years and summarizes the advantages and problems should be resolved in future.

PART I: BOND STRAIN AND DEFECTS AT Si-SiO2 AND DIELECTRIC INTERFACES IN HIGH-k GATE STACKS

2006 ◽  
Vol 16 (01) ◽  
pp. 241-261 ◽  
Author(s):  
GERALD LUCOVSKY
Keyword(s):  
Gate Dielectric ◽  
Field Effect Transistors ◽  
Dielectric Materials ◽  
Buffer Layers ◽  
Gate Stacks ◽  
High K ◽  
Interfacial Defects ◽  
Dielectric Interfaces ◽  
Bond Strain ◽  
High K Dielectric

The performance and reliability of aggressively-scaled field effect transistors that include deposited high-k dielectrics and interfacial SiO 2 buffer layers are determined in large part by electronically-active defects and defect precursors at the Si - SiO 2, and internal SiO 2-high-k dielectric interfaces. A crucial aspect of reducing interfacial defects and defect precursors is associated with bond-strain driven bonding self-organizations that take place during high temperature annealing in inert ambients. These interfacial self-organizations, and intrinsic interface defects are addressed through an extension of bond constraint theory from bulk glasses to interfaces between non-crystalline SiO 2, and i) crystalline Si , and ii) non-crystalline and crystalline alternative gate dielectric materials.

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