(Invited) Germanium Nanostructures in High-K Materials

Seidel, Peter; Geyer, Maximilian; Lehninger, David; Schneider, F.; Klemm, Volker; Heitmann, Johannes

doi:10.1149/05301.0237ecst

Cited by 3 publications

(10 citation statements)

References 7 publications

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“…The PL in the visible range with a varying energy between 2.2 and 2.5 eV was attributed to matrix‐related defects. Another PL band at about 2.9 eV was related to defects at the interfaces nanocrystal/matrix . Furthermore, the infrared band at around 0.85 eV was attributed to substrate interface defects.…”

Section: Influence Of Different Matrix Materialsmentioning

confidence: 97%

“…Ge‐rich ZrO 2 films (GeZrO x ) were deposited by MS and Ge ion implantation . Thin ZrO 2 films crystallize at higher temperatures than thin films of Ge .…”

Section: Influence Of Different Matrix Materialsmentioning

confidence: 99%

“…For this material system, the non‐volatile memory and PL characteristics were investigated. Non‐volatile memories with a ZrO 2 tunneling‐ and control oxide reach memory windows of up to 3 V .…”

Section: Influence Of Different Matrix Materialsmentioning

confidence: 99%

“…The formation of elemental Ge is further supported by the change in the Gibbs-free energy, which is much smaller by forming GeO 2 (À111.8 kcal mol À1 ) than by forming ZrO 2 (À248 kcal mol À1 ). [150] Ge-rich ZrO 2 films (GeZrO x ) were deposited by MS [18,19,[151][152][153][154][155][156] and Ge ion implantation. [157] Thin ZrO 2 films [158][159][160] crystallize at higher temperatures than thin films of Ge.…”

Section: Zirconium Oxide and Zirconium-tantalum Oxidementioning

confidence: 99%

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A Review on Ge Nanocrystals Embedded in SiO₂ and High‐k Dielectrics

Lehninger

Beyer

Heitmann

2018

Physica Status Solidi (a)

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In this article, the work on Ge nanocrystals embedded in dielectric films formed by phase separation from supersaturated solid solutions is reviewed. Different methods to synthesize supersaturated solid solutions are covered, e.g., magnetron sputtering, ion implantation, and chemical vapor deposition. The phase separation is activated by subsequent high temperature annealing. Important parameters that influence the formation and properties of the Ge nanocrystals are discussed. Various matrix materials like SiO2, Al2O3, HfO2, HfAlOx, Lu2O3, ZrO2, TaZrOx, and Si3N4 are reported in the literature. The influence of the matrix on the formation and properties of the Ge nanocrystals is addressed in this review. Ge nanocrystals are investigated for applications such as charge storage nodes in nonvolatile memory devices or as silicon technology compatible light emitters. A key to establish these applications seems to be embedding the Ge nanocrystals in still amorphous matrices. This could help to avoid grain boundaries that act as leakage paths for electrical charges (unfavorable for nonvolatile memories) and facilitate defects, which could act as recombination centers (unfavorable for light emitters). A further important point is the synthesis of size and position controlled Ge nanocrystals. Both aspects are reviewed for Ge nanocrystals embedded in the mentioned matrix materials.

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Section: Influence Of Different Matrix Materialsmentioning

confidence: 97%

“…Ge‐rich ZrO 2 films (GeZrO x ) were deposited by MS and Ge ion implantation . Thin ZrO 2 films crystallize at higher temperatures than thin films of Ge .…”

Section: Influence Of Different Matrix Materialsmentioning

confidence: 99%

Section: Influence Of Different Matrix Materialsmentioning

confidence: 99%

Section: Zirconium Oxide and Zirconium-tantalum Oxidementioning

confidence: 99%

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A Review on Ge Nanocrystals Embedded in SiO₂ and High‐k Dielectrics

Lehninger

Beyer

Heitmann

2018

Physica Status Solidi (a)

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“…Most applications of semiconductor nanocrystals require tight control of the nanocrystal shape, size, areal density and spatial distribution within the matrix. Attempts have been made to transfer this approach to other material systems, such as Ge nanocrystals embedded in insulating materials with high dielectric constants (high-k materials) like ZrO 2 [13,14] and TaZrO x [15]. Attempts have been made to transfer this approach to other material systems, such as Ge nanocrystals embedded in insulating materials with high dielectric constants (high-k materials) like ZrO 2 [13,14] and TaZrO x [15].…”

Section: Introductionmentioning

confidence: 99%

Size and Shape Controlled Semiconductor Nanocrystals Synthesized by RF‐Sputtering Techniques for Electronic and Optoelectronic Applications

Lehninger

Beyer

Schneider

et al. 2015

Contrib. Plasma Phys.

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Group IV (Ge and Si) nanocrystals embedded in a dielectric matrix were prepared via rf magnetron sputtering by the deposition of superlattices of stoichiometric and substoichiometric oxide layers and subsequent annealing. By this way Ge nanocrystals in a (Ta)ZrO x and Si nanocrystals in an SiO2 matrix were prepared in a size and shape controlled manner. In case of the Ge-ZrO2 system, elongated Ge nanocrystals in a crystallized ZrO2 matrix were formed for annealing temperatures above 660 • C. Starting from a Si3N4 interface of the Si wafer, a preferential orientation between the Ge and ZrO2 lattice can be stated. Doping the ZrO2 matrix additionally with Ta increases the crystallization temperature of the ZrO2 matrix and leads to the formation of Ge nanocrystals embedded in an amorphous TaZrOx matrix. The Ge nanocrystals were investigated by photoluminescence measurements and implemented into metal-insulator-semiconductor capacitor to investigate their potential for charge trapping devices. The prepared nano floating gate devices show good charging characteristics with a maximum memory window of 5 V and a slope of the writing voltage vs. memory window characteristics of 0.8-1. All luminescence centers seen in the Ge-(Ta)ZrOx system can be attributed to defects either from the Ge nanocrystal surface, the (Ta)ZrOx matrix or the Si substrate itself. Si nanocrystals were fabricated in the same way in an amorphous SiO2 film after annealing above 900 • C. The formed Si nanocrystals act as superior sensitizer for Er 3+ ions which were ion implanted into the films followed by an additional subsequent anneal, varied between 700 and 1000 • C. The Si nanocrystal -Er 3+ system was successfully implemented into a slot waveguide structure showing a strong polarization dependent field enhancement in both emission and excitation geometry.

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Size- and position-controlled Ge nanocrystals separated by high-k dielectrics

et al. 2022

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Germanium nanocrystals embedded in high-k dielectric matrices are of main interest for infrared sensing application, as a role model for Ge-based nanoelectronics passivation or for nonvolatile memory devices. The capability of the size control of those nanocrystals via rapid thermal processing of superlattice structures is shown for the [Ge–TaZrOx/TaZrOx]n, [Ge–TaZrOx/SiO2/TaZrOx]6, and [TaZrOx/Ge–SiO2]n superlattice systems. All superlattices were deposited by radiofrequency magnetron sputtering. Transmission electron microscopy (TEM) imaging confirms the formation of spherically shaped nanocrystals. Raman scattering proved the crystallization of Ge above 700°C. The TaZrOx crystallizes above 770°C, associated with a phase separation of Ta2O5 and ZrO2 as confirmed by x-ray diffraction. For the composite layers having 3 nm and 6 nm thickness, the size of the Ge nanocrystals correlates with the deposited layer thickness. Thicker composite layers (above 9 nm) form two fractions of nanocrystals with different sizes. An additional SiO2 layer in the [Ge–TaZrOx/SiO2/TaZrOx]6 superlattice stacks facilitates the formation of larger and better separated Ge nanocrystals. The deposition of Ge-SiO2 composite layers separated by pure TaZrOx illustrates the barrier effect of TaZrOx against Ge diffusion. All three material systems allow the controlled formation of Ge nanocrystals in amorphous matrices at temperatures above 700 and below 770°C. Graphical abstract

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(Invited) Germanium Nanostructures in High-K Materials

Cited by 3 publications

References 7 publications

A Review on Ge Nanocrystals Embedded in SiO₂ and High‐k Dielectrics

A Review on Ge Nanocrystals Embedded in SiO₂ and High‐k Dielectrics

Size and Shape Controlled Semiconductor Nanocrystals Synthesized by RF‐Sputtering Techniques for Electronic and Optoelectronic Applications

Size- and position-controlled Ge nanocrystals separated by high-k dielectrics

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(Invited) Germanium Nanostructures in High-K Materials

Cited by 3 publications

References 7 publications

A Review on Ge Nanocrystals Embedded in SiO2 and High‐k Dielectrics

A Review on Ge Nanocrystals Embedded in SiO2 and High‐k Dielectrics

Size and Shape Controlled Semiconductor Nanocrystals Synthesized by RF‐Sputtering Techniques for Electronic and Optoelectronic Applications

Size- and position-controlled Ge nanocrystals separated by high-k dielectrics

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A Review on Ge Nanocrystals Embedded in SiO₂ and High‐k Dielectrics

A Review on Ge Nanocrystals Embedded in SiO₂ and High‐k Dielectrics