A.Y. Kovalgin

Langmuir-probe Characterization of an Inductively-Coupled Remote Plasma System intended for CVD and ALD

We measured electron density and electron energy distribution function (EEDF) vertically through our reactor for a range of process conditions and for various gases. The EEDF of Ar plasma could largely be described by the Maxwell-Boltzmann distribution function, but it also contained a fraction (~ 1E-03) of electrons which were faster (20-40 eV). At low pressures (6.8-11 µbar), the fast-electron tail shifted to higher energies (Emax ~ 50 eV) as we measured more towards the chuck. The fast-electron tail shifted to lower energies (Emax ~ 30 eV) when we increased pressure to 120 µbar or applied an axial magnetic field of 9.5 µT. Addition of small amounts of N2 (1-10%) or N2O (5%) to Ar plasma lowered the total density of slow electrons (approx. by a factor of two) but did not change the shape of the fast-electron tail of the EEDF. The ionization degree of Ar-plasma increased from 2.5E-04 to 5E-04 when a magnetic field of 9.5 µT was applied.

On the verification of EEDFs in plasmas with silane using optical emission spectroscopy

We measured the electron density and electron energy distribution function (EEDF) of plasmas in our reactor which is intended for silicon oxide and nitride deposition. Langmuir-probe measurements showed that the EEDF of Ar plasma could largely be described by the Maxwell-Boltzmann (MB) distribution function, but it also contained a fraction (~0.5 %) of fast electrons in the energy range between 20 and 40 eV, strongly deviating from the MB distribution. We also measured relative mean electron temperatures (kTe) by optical emission spectroscopy (OES) which were calibrated by the absolute Langmuir-probe measurements. The kTe as measured by OES in Ar plasma decreased from 1.7 eV at 1.1 Pa to 1.4 eV at 12 Pa, while Langmuir-probe measurements showed a decrease from 1.7 eV to 0.8 eV. This difference is caused by the OES method, which is especially sensitive to the fraction of fast electrons in the plasma. OES can be used instead of Langmuir-probe measurements when depositing plasmas are used. Combining both methods, we demonstrated that EEDFs as measured by the Langmuir probe in Ar-N2, and Ar-N2O plasmas, resemble EEDFs in plasmas with small additions of silane, provided that (a) precursor fractions in plasma are small (SiH4 {less than or equal to} 0.8 % and N2O {less than or equal to} 15 %), and (b) total pressure does not exceed 3.6 Pa (27 mTorr). As such, the measured EEDF without silane can be used as input for chemical modeling and optimization of deposition processes in plasmas containing silane.

Materials and integration schemes for above-IC integrated optics

A study is presented on silicon oxynitride material for waveguides and germanium-silicon alloys for p-i-n 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 inductively-coupled-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 are discussed.

Green laser crystallization of GeSi thin films and dopant activation

Laser-crystallization of amorphous

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

Ge_{0.85}Si_{0.15}

Characterization of Green Laser Crystallized GeSi Thin Films

films is studied, using green laser scanning and preformed topography to steer the crystallization. Large crystals (8x2

Realization of Silicon-Nanodots-Based CMOS Backend-Compatible Electrical SPP Source

mu m^2

In-situ monitoring of growth and oxidation of ALD TiN layers followed by reduction in atomic hydrogen

) are formed with location-controlled grain boundaries. The obtained films were characterized using Scanning Electron Microscopy, Transmission Electron Microscopy, Atomic Force Microscopy, X-Ray Photoelectron spectroscopy, X-Ray Diffraction and Spectroscopic Ellipsometry. In addition, the activation of ion-implanted poly-

Low temperature TFTs with poly-stripes

Ge_{0.85}Si_{0.15}

Thermal atomic layer deposition and oxidation of TiN monitored by in-situ spectroscopic ellipsometry

films is compared after furnace annealing, rapid thermal annealing and green-laser annealing