Investigation of Ge nanocrytals in a metal-insulator-semiconductor structure with a HfO2∕SiO2 stack as the tunnel dielectric

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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“…GeHfO x layers were synthesized by MS, Ge‐ion implantation, EBE, and CVD . Annealing is usually performed between 600 and 900 °C .…”

Section: Influence Of Different Matrix Materialsmentioning

confidence: 99%

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

Lehninger

Beyer

Heitmann

2018

Physica Status Solidi (a)

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“…The use of a physically thicker high-permittivity oxide ensures good retention characteristics. On the other hand, thin-tunneling barriers due to the low equivalent oxide thickness allow high currents across the tunneling oxide at low control gate voltages during programming and erasing cycles [9,14-16]. For Ge nanocrystals embedded in a high dielectric constant [high-k] material, the electrostatic energy is much higher due to the difference in the static dielectric constant of SiO 2 and high-k oxides [17].…”

Section: Introductionmentioning

confidence: 99%

Optical and electrical properties of undoped and doped Ge nanocrystals

et al. 2012

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Size-dependent photoluminescence characteristics from Ge nanocrystals embedded in different oxide matrices have been studied to demonstrate the light emission in the visible wavelength from quantum-confined charge carriers. On the other hand, the energy transfer mechanism between Er ions and Ge nanocrystals has been exploited to exhibit the emission in the optical fiber communication wavelength range. A broad visible electroluminescence, attributed to electron hole recombination of injected carriers in Ge nanocrystals, has been achieved. Nonvolatile flash-memory devices using Ge nanocrystal floating gates with different tunneling oxides including SiO2, Al2O3, HfO2, and variable oxide thickness [VARIOT] tunnel barrier have been fabricated. An improved charge storage characteristic with enhanced retention time has been achieved for the devices using VARIOT oxide floating gate.

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“…Germanium is interesting due to its use in flash memories. 19 Thus, we demonstrate growth of ordered Ge nanoparticle arrays on the HfO 2 surface during CVD at elevated temperatures. 19 Further, Ge nanocrystals on hafnium dioxide have been shown to have promising electrical characteristics.…”

Section: Introductionmentioning

confidence: 72%

Directed nucleation of ordered nanoparticle arrays on amorphous surfaces

Coffee¹,

Stanley²,

Ekerdt³

2006

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

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Germanium nanoparticle nucleation was studied in organized arrays on HfO2 using a SiO2 thin film mask with ∼20–24nm pores and a 6×1010cm−2 pore density. Poly(styrene-b-methyl methacrylate) diblock copolymer was employed to pattern the SiO2 film. Hot wire chemical vapor deposition at 800K produced Ge nanoparticles using 6–19 monolayer Ge exposures. By seeding adatoms on HfO2 at room temperature before growth, nanoparticle density is approximately one particle per pore.

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Investigation of Ge nanocrytals in a metal-insulator-semiconductor structure with a HfO2∕SiO2 stack as the tunnel dielectric

Cited by 20 publications

References 16 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

Optical and electrical properties of undoped and doped Ge nanocrystals

Directed nucleation of ordered nanoparticle arrays on amorphous surfaces

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Investigation of Ge nanocrytals in a metal-insulator-semiconductor structure with a HfO2∕SiO2 stack as the tunnel dielectric

Cited by 20 publications

References 16 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

Optical and electrical properties of undoped and doped Ge nanocrystals

Directed nucleation of ordered nanoparticle arrays on amorphous surfaces

Contact Info

Product

Resources

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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