Study of photoluminescence of SiOxNy films implanted with Ge+ ions and annealed under the conditions of hydrostatic pressure

The influence of hydrostatic pressure on photoluminescence of SiO_xN_y (x=0.25 and y=1) films grown on the Si substrates and implanted with Ge⁺ ions, with pressure applied during annealing of the films, was studied for the first time. It is shown that hydrostatic compression leads to a tenfold increase in the photoluminescence intensity of the implanted SiO_xN_y films compared to that obtained as a result of postimplantation annealings at atmospheric pressure. The observed increase in the photoluminescence intensity is attributed to accelerated formation of radiative-recombination centers in the metastable-phase zones in the implanted silicon oxynitride. These centers are tentatively related to ≡Si-Si≡ centers and to complexes involving Ge atoms (of ≡Si-Ge≡ and ≡Ge-Ge≡ types).     

Anodic Oxidation of Hydrogen-Transferred Silicon-on-Insulator Layers

Semiconductors - The anodic oxidation rate of silicon-on-insulator films fabricated by hydrogen transfer is studied as a function of the temperature of subsequent annealing. It is established that...     

Diffusion and Interaction of In and As Implanted into SiO2 Films

Semiconductors - By means of Rutherford backscattering spectrometry, electron microscopy, and energy-dispersive X-ray spectroscopy, the distribution and interaction of In and As atoms implanted...     

Diffusion of In Atoms in SiO2 Films Implanted with As+ Ions

Semiconductors - The diffusion of indium atoms in silicon-dioxide films previously implanted with arsenic ions with different energies is studied in relation to the temperature of postimplantation...     

Structural Changes in Nanometer-Thick Silicon-on-Insulator Films During High-Temperature Annealing

Semiconductors - The thermal stability of silicon-on-insulator films with a thickness of 4.7  and 2.2 nm is studied as a function of annealing temperature in the range of...     

Phase Transformations and Consolidation of Si3N4 Ceramics Activated with Yttrium and Silicon Oxides in Spark Plasma Sintering

Powder Metallurgy and Metal Ceramics - The effect of Y2O3 and Y2O3–SiO2 additions on the spark plasma sintering (SPS) of α-Si3N4 was studied. The interaction of oxides with silicon...     

Quantum-confinement effect in silicon-on-insulator films implanted with high doses of hydrogen ions

280-nm-thick silicon-on-insulator films are implanted with high doses of hydrogen with the energy 24 keV and the dose 5 × 10¹⁷ cm^?2. Peaks corresponding to optical phonons localized in the silicon nanocrystals 1.9?C2.5 nm in size are observed in the Raman spectra. The fraction of the nanocrystal phase is ??10%. A photoluminescence band with a peak at about 1.62 eV is detected. The intensity of the 1.62 eV band nonmonotonically depends on the measurement temperature in the range from 88 to 300 K. An increase in the radiative recombination intensity at temperatures <150 K is interpreted in the context of a two-level model for the energy of strongly localized electrons and holes. The activation energy of photoluminescence enhancement is 12.4 meV and corresponds to the energy of splitting of the excited state of charge carriers localized in the silicon nanocrystals.     

Photoluminescence of Si3N4 films implanted with Ge+ and Ar+ ions

The room-temperature photoluminescence emission and excitation spectra of Si₃N₄ films implanted with Ge⁺ and Ar⁺ ions were investigated as a function of the ion dose and temperature of subsequent annealing. It was established that the implantation of bond-forming Ge atoms during annealing right up to temperature T _a=1000 °C stimulates the formation of centers emitting in the green and violet regions of the spectrum. Implantation of inert Ar⁺ ions introduces predominantly nonradiative defect centers. Comparative analysis of the photoluminescence spectra, Rutherford backscattering data, and Raman scattering spectra shows that the radiative recombination is due not to quantum-well effects in Ge nanocrystals but rather recombination at the defects ≡Si-Si≡, ≡Si-Ge≡, and ≡Ge-Ge≡. Fiz. Tekh. Poluprovodn. 33, 559–566 (May 1999)     

Properties of Ge nanocrystals formed by implantation of Ge<Superscript>+</Superscript> ions into SiO<Subscript>2</Subscript> films with subsequent annealing under hydrostatic pressure

The influence of hydrostatic compression on the implantation-induced synthesis of Ge nanocrystals in SiO₂ host was studied. It is found that high-temperature annealing under pressure leads to retardation of Ge diffusion in SiO₂. It is shown that unstressed Ge nanocrystals are formed as a result of conventional annealing (under atmospheric pressure). Annealing under pressure is accompanied by formation of hydrostatically stressed Ge nanocrystals. The stress in Ge nanocrystals was determined from optical-phonon frequencies in the Raman spectra. The shift of Raman resonance energy (E₁, E₁ + Δ₁) corresponds to the quantization of the ground-state energy for a two-dimensional exciton at the critical point M₁ of germanium. It is ascertained that a photoluminescence band peaked at 520 nm is observed only in the spectra of the films which contain stressed Ge nanocrystals.     

Behavior of germanium ion-implanted into SiO<Subscript>2</Subscript> near the bonding interface of a silicon-on-insulator structure

The properties of germanium implanted into the SiO₂ layers in the vicinity of the bonding interface of silicon-on-insulator structures are studied. It is shown that, under conditions of high-temperature (1100°C) annealing, germanium nanocrystals are not formed, while the implanted Ge atoms segregate at the Si/SiO₂ bonding interface. It is established that, in this case, Ge atoms are found at sites that are coherent with the lattice of the top silicon layer. In this situation, the main type of traps is the positive-charge traps; their effect is interpreted in the context of an increase in the surface-state density due to the formation of weaker Ge-O bonds. It is found that the slope of the drain-gate characteristics of the back MIS transistors increases; this increase is attributed to an increased mobility of holes due to the contribution of an intermediate germanium layer formed at the Si/SiO₂ interface.