Erbium and Germanium Profiles in Si1 – xGe x Layers Grown by Silicon Sublimation-Source Molecular-Beam Epitaxy in GeH4

The Ge and Er depth profiles in Si_{1 – x} Ge _x layers grown on Si(100) substrates by Si sublimation-source molecular-beam epitaxy in GeH₄ were studied by secondary ion mass spectrometry. The results demonstrate that Ge facilitates Er incorporation into the growing Si–Ge layer. The Er dopant profile becomes sharper with increasing Ge content. The Ge profile also has rather sharp boundaries, indicating that there is no Ge surface segregation, which is attributable to the presence of adsorbed hydrogen, acting as a surfactant.     

A random telegraph signal in tunneling silicon p–n junctions with GeSi nanoislands

Technical Physics Letters - We have experimentally discovered random telegraph signal generation in tunneling silicon p +–n + junctions with embedded self-assembled GeSi nanoislands. The...     

Erbium Segregation in Silicon Layers Grown by Molecular-Beam Epitaxy

In the course of molecular-beam epitaxy of Er-doped Si on Si(100) substrates at 450–650°C, the dopant tends to segregate in the surface layer at doping levels from 10¹⁷ to above 10¹⁹ cm^–3. The introduction of oxygen into the growing epilayer—either from the gas phase at an oxygen pressure of 6.7 × 10^–6 Pa or from an SiO₂ layer on the substrate surface—suppresses the surface segregation of Er.     

Growth of n-Si layers by molecular-beam epitaxy on the substrates heavily doped with boron

Epitaxial n-Si layers doped with phosphorus or erbium have been grown by sublimation molecularbeam epitaxy at 500°C on heavily boron-doped p ⁺-type substrates with resistivity ρ = 0.005 Ω cm. Distribution profiles of the B, Er, and O impurity concentrations in the samples were determined by secondary-ion mass spectrometry. A thermal annealing of the substrate in vacuum at 1300°C for 10 min and growth at a very low substrate temperature made it possible to obtain an extremely abrupt profile for doping impurities at the layer-substrate interface. This method for growth of n-p ⁺ junctions considerably improves their electrical and luminescent characteristics.     

A Substrate Heater for an Ultrahigh Vacuum

A device for the uniform heating of substrates to a temperature of 1450°C for subsequent molecular-beam epitaxy is described.     

Enhanced Photoluminescence of Heavily Doped n-Ge/Si(001) Layers

Semiconductors - The photoluminescence spectra of epitaxial n+-Ge:P/Si(001) structures are studied. The structures are grown by hot-wire chemical vapor deposition and doped with phosphorus to the...     

Low-temperature growth of silicon epitaxial layers codoped with erbium and oxygen atoms

The fabrication technology and properties of light-emitting Si structures codoped with erbium and oxygen are reported. The layers are deposited onto (100) Si by molecular beam epitaxy (MBE) using an Er-doped silicon sublimation source. The partial pressure of the oxygen-containing gases in the growth chamber of the MBE facility before layer growth is lower than 5 × 10^?10 Torr. The oxygen and erbium concentrations in the Si layers grown at 450°C is ～1 × 10¹⁹ and 10¹⁸ cm^?3, respectively. The silicon epitaxial layers codoped with erbium and oxygen have high crystal quality and yield effective photoluminescence and electroluminescence signals with the dominant optically active Er-1 center forming upon postgrowth annealing at a temperature of 800°C.     

Resistive Switching in Memristors Based on Ge/Si(001) Epitaxial Layers

Semiconductors - The Ag/Ge/Si(001) stacks with threading dislocations growing through the Ge epitaxial layers (ELs) manifested bipolar resistive switching (RS) between two metastable resistance...     

Simultaneous doping of silicon layers with erbium and oxygen in the course of molecular-beam epitaxy

Epitaxial silicon layers codoped with erbium and oxygen were grown by molecular-beam epitaxy using a silicon sublimation source. For growing the erbium-doped silicon layers, two types of impurity sources were used: (i) erbium-doped silicon plates were used as a source of fluxes of Er and Si atoms; and (ii) metallic erbium plates were used as an impurity-vapor source in combination with the silicon sublimation source. If gaseous oxygen was used for in situ codoping with erbium and oxygen, then concentrations ranging from 10¹⁸ to 10²⁰ cm^?3 were attained. When oxygen is in the growth chamber, the erbium-entrapment efficiency of a layer increases substantially, with the surface segregation of erbium also being suppressed by oxidation.