Fabrication and properties of GeSi and SiON layers for above-IC integrated optics

Abstract

a b s t r a c tA study is presented on silicon oxynitride material for waveguides and germanium-silicon alloys for p-in diodes. The materials are manufactured at low, CMOS-backend compatible temperatures, targeting the integration of optical functions on top of CMOS chips. Low-temperature germanium-silicon deposition, crystallization and doping are studied for integrated photo detection up to $1500 nm wavelength. An investigation of the process window for laser crystallization is presented aiming toward the localization control of crystal boundaries and the achievement of crystals larger than 2 lm. Further, an inductivelycoupled-plasma chemical vapor deposition process is presented for silicon oxynitride manufacturing at 150°C wafer temperature, yielding low-loss material in a wide optical spectral range. Integration schemes for an optical plane on top of CMOS using these materials are discussed.

Nitrogen Nanobubbles in a-SiOxNy Coatings: Evaluation of Its Physical Properties and Chemical Bonding State by Spatially Resolved Electron Energy-Loss Spectroscopy

“…15 Through these 2D spectroscopic maps at the nanoscale, we have been able to demonstrate that He is located inside the nanopores of the coatings in a condensed state, with densities as high as tens of He atoms/nm 3 and pressure close to the GPa range.…”

“…(NH 3 ). However, the high hydrogen content in these plasma-enhanced chemical vapor deposition films in the form of Si-H or N-H bonds causes optical losses at wavelengths around 1500nm.…”

“…However, the high hydrogen content in these plasma-enhanced chemical vapor deposition films in the form of Si-H or N-H bonds causes optical losses at wavelengths around 1500nm. [3][4]9 Additional annealing steps between 1000 and 1150°C, or plasma treatments at 300°C have been proposed to reduce the H content [3][4]10 however limiting the type of substrates to be used.…”

Photo-sensitive Ge nanocrystal based films controlled by substrate deposition temperature

“…It is crucial to significantly lower the temperature for structuring Ge-NCs into SiO 2 matrix in order to use these materials in Si-based optoelectronics on a chip, where low processing temperature is needed to preserve the functionality of the adjacent Si electronics [26]. There have been attempts to structure Ge-NCs at temperatures below 400 • C, but the technological methods employed (ultra-high vacuum chemical vapor deposition or wet chemical synthesis) are either too expensive and/or incompatible with the current highly developed silicon technology [27,28].…”

Transport properties of Si based nanocrystalline films investigated by c-AFM

“…Silicon oxy-nitride (SiO x N y ) is an innovative material for different applications. For example, SiO x N y layers are employed as dielectric in metal-insulator-metal capacitors [1], as core layer in integrated optics devices [2,3] as well as in the photovoltaic field, as rear passivation layer in monocrystalline silicon solar cells [4].…”