Sister Mary Regina Donovan, S.S.J. (Nora Donovan)

Thin silicon dioxide layers (40-100 A) can be successfully produced by anodization of silicon in pure water. The resulting layers are very homogeneous and pinhole free. The monitoring of the SiO2 thickness is accurately achieved by simple coulometry. The electrical properties of the oxide layers and the associated Si/SiO2 interface have been investigated by forming metal-oxide-semiconductor (MOS) capacitors using the anodically grown oxide as the dielectric and aluminium or chromium as the metal. This investigation shows a low charge density at the Si/SiO2 interface (≤ 10 11 charges. cm-2) and an interface states density comparable to that obtained with thermally grown SiO2 (1011 cm -2eV-1). The dielectric breakdown occurs at high fields (11 to 14 MW . cm-1). These results show that there is no pollution during the electrolysis. Furthermore, the metal to oxide barrier heights remained high (2.5 to 2.8 eV) even for thin (44 A) SiO2 layers

First-Principles Study of the Band Gap Structure of Oxygen-Passivated Silicon Nanonets

A net-like nanostructure of silicon named silicon nanonet was designed and oxygen atoms were used to passivate the dangling bonds. First-principles calculation based on density functional theory with the generalized gradient approximation (GGA) were carried out to investigate the energy band gap structure of this special structure. The calculation results show that the indirect–direct band gap transition occurs when the nanonets are properly designed. This band gap transition is dominated by the passivation bonds, porosities as well as pore array distributions. It is also proved that Si–O–Si is an effective passivation bond which can change the band gap structure of the nanonets. These results provide another way to achieve a practical silicon-based light source

Post-Oxidation Enhanced Diffusion of Low-Energy Implanted Boron in Ultra-Shallow P⁺/N Junctions Formation

AbstractIn this paper, we report for the first time the effect of sacrificial oxide (sacox) on the boron diffusion in ultra-shallow P+/N junctions. It is shown that the boron diffusivity is enhanced when low energy implantations are performed through sacrificial oxide. The various experimental data lead to conclude that the Post-Oxidation Enhanced Diffusion (POED) is due to a « mirror effect » seen by the Si interstitials incoming into the sacox layer. POED occurs even for sacox as thin as 1.5 nm. From a simple model, the reflection coefficient is estimated to be about 100 % for a 2.5 nm-thick sacox.</jats:p

SiON based antireflective coating for 193nm lithography

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