Si-SiO Interface Research Articles

Understanding Early Failure Behavior in 3D-Interconnects: Empirical Modeling of Broadband Signal Losses in TSV-Enabled Interconnects

We develop an empirical model for measured frequency-dependent insertion loss ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\vert {S}_{{21}}\vert $ </tex-math></inline-formula> ). The model parameters are determined with a stochastic optimization implementation of the Levenberg–Marquard method. We compare measured <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\vert {S}_{{21}}\vert $ </tex-math></inline-formula> on through silicon via (TSV)-interconnects, from two different providers, as a function of the extent of thermal annealing. The frequency-dependent changes in the electrical characteristics of the interconnect are attributed to silanol (Si-OH) and other dangling bond polarizations at the Si–SiO interface between the silicon substrate and the lateral silicon oxide that isolates the coaxial metal core from the silicon substrate. The changes in the polarizations are traceable to changes in the chemistry of the isolation dielectric during thermal annealing. The data also suggest that the evolution of the chemical defects inherent in the “as-manufactured” products may be responsible for some of the signal integrity degradation issues and other early reliability failures observed in TSV-enabled 3-D devices.

Light Emission from Intrinsic and Doped Silicon-Rich Silicon Oxide: from the Visible to 1.6 ΜM

AbstractSilicon-rich silicon oxide (SRSO) films were prepared by thermal oxidation (700°C-950°C) of electrochemically etched crystalline silicon (c-Si). The annealing-oxidation conditions are responsible for the chemical and structural modification of SRSO as well as for the intrinsic light-emission in the visible and near infra-red spectral regions (2.0–1.8 eV, 1.6 eV and 1.1 eV). The extrinsic photoluminescence (PL) is produced by doping (via electroplating or ion implantation) with rare-earth (R-E) ions (Nd at 1.06 μm, Er at 1.5 μm) and chalcogens (S at ∼1.6 μm). The impurities can be localized within the Si grains (S), in the SiO matrix (Nd, Er) or at the Si-SiO interface (Er). The Er-related PL in SRSO was studied in detail: the maximum PL external quantum efficiency (EQE) of 0.01–0.1% was found in samples annealed at 900°C in diluted oxygen (∼ 10% in N2). The integrated PL temperature dependence is weak from 12K to 300K. Light emitting diodes (LEDs) with an active layer made of an intrinsic and doped SRSO are manufactured and studied: room temperature electroluminescence (EL) from the visible to 1.6 μmhas been demonstrated.

Microvoids and defect chemistry at the Si-SiO interface studied by positron annihilation depth profiling

Microvoids and defect chemistry at the Si-SiO interface studied by positron annihilation depth profiling