Laurent Roux

Fluorescence of Ta 2 O 5 thin films doped by kilo-electron-volt Er implantation: application to microcavities

Luminescent layers are prepared by the implantation of kilo-electron-volt Er ions into tantalum pentoxide (Ta(2)O(5)) thin films made by ion plating. The implantation fluences range from 3.3 × 10(14) to 2 × 10(15) ions/cm(2), and the energies range from 190 to 380 keV. Refractive index, extinction coefficient, and losses on guided propagation are investigated. We show that these Er-implanted layers present an absorption as low as that of the nonimplanted films. When optically pumped with an Ar(+) laser (λ = 0.488 μm) beam, implanted films show peaked fluorescence spectra centered near 1.53 and 0.532 μm. We show that the fluorescence intensity is correlated with the intensity of the pump beam in the region where Er ions are implanted. Radiation patterns of Er ions located inside a single layer or inside a Ta(2)O(5)/SiO(2) dielectric stack made by ion plating are also investigated. We show that, in any case, spontaneous emission of Er ions can be spatially controlled.

Titanium implantation in bulk and thin film amorphous silica

Both bulk and thin film amorphous silica implanted with titanium were investigated. We studied the induced modifications of the microstructure and the consequences on the optical properties. We determined the refractive index profile of implanted materials from guided wave measurements and we show that it matches the distribution of titanium. An increase in refractive index of up to 0.9 can be obtained by high dose implantation. A study of thermal annealing in air shows that the implanted materials exhibit low optical losses.

Enhanced diffraction efficiency of gratings in multilayers

Computations with the rigorous differential method show that single gratings made by ion implantation have a diffraction efficiency in the +1 transmitted order under TE illumination of only 0.78%. The insertion of such gratings into multilayer dielectric Fabry-Perot cavities leads to an enhancement of the free-space diffraction efficiency. Different designs for the multilayer are considered. An 18.8% efficiency is reached with 11-layer mirrors. This result is obtained by optimization of the thickness of the spacer of the Fabry-Perot cavity that contains the grating and centering of the wavelength of the mirrors. The dependence of optical properties of the structure on the various optogeometrical parameters of the structure is discussed.

Plasma doping of silicon fin structures

Plasma doping has been explored for many implant applications for over two decades and is now being used in semiconductor manufacturing for two applications: DRAM polysilicon counter-doping and contact doping. Recently it has become an attractive implant technique for multiple gate and FinFET devices, since the directionality of the conventional beam-line implant processes used to form the source and drain junctions in planar devices is not well suited for use on non-planar devices. In this paper, we investigate the use of plasma doping to dope the sidewalls of fins, with particular attention to the dopant uniformity and residual damage after anneal.

Consequences of Ti-, Li-, and Er-ion implantations on the optical properties of single layers of Ta 2 O 5

Tantalum pentoxide (Ta(2)O(5)) layers made by ion plating are implanted with a high fluence of keV Ti, Li, and Er ions. The resulting refractive-index profiles are given from the analysis of guided-wave propagation conditions. A comparison with spectrophotometric measurements is presented. All the implanted layers present low losses (extinction coefficient of some 10(-6)) after thermal annealing in air. Ti-implanted layers exhibit an increase in refractive index, whereas Li- and Er-implanted layers present a slight decrease in refractive index. Er-implanted layers present photoluminescent properties.

Ion implanted integrated optics (I3O) technology for planar lightwave circuits fabrication

The Ion Implanted Integrated Optics (I3O) technology, using titanium ion implantation in bulk silica to fabricate passive compact planar lightwave circuits (PLCs), is presented in this paper. Its advantages are described and compared with other waveguide fabrication technologies. It is demonstrated that the guided electromagnetic field can be tailored by adjusting the titanium ion dose either to fit the guided mode of standard single-mode fibers or to allow a sharp radius of curvature of bent waveguides.

Fabry–Perot multilayers for enhancing the diffraction efficiency of ion-implanted gratings

Enhancement of the free-space diffraction efficiency of gratings made by titanium-ion implantation is demonstrated both theoretically and experimentally. Indeed, by insertion of a grating into a multilayer dielectric Fabry-Perot cavity, the diffraction efficiency can be increased to as much as 24 times that of a single grating. The sensitivity of the diffraction efficiency to the optogeometrical parameters of the grating or of the Fabry-Perot cavity is discussed. Moreover, a process for performance of a phase grating inside a Fabry-Perot cavity is described, and experimental results concerning efficiency measurements are compared with computed values for various grating periods.

Transmission enhancement through square coaxial aperture arrays in metallic film: when leaky modes filter infrared light for multispectral imaging.

The diffractive behavior of arrays of square coaxial apertures in a gold layer is studied. These structures exhibit a resonant transmission enhancement that is used to design tunable bandpass filters for multispectral imaging in the 7-13 μm wavelength range. A modal analysis is used for this design and the study of their spectral features. Thus we show that the resonance peak is due to the excitation of leaky modes of the open photonic structure. Fourier transform infrared (FTIR) spectrophotometry transmission measurements of samples deposited on Si substrate show good agreement with numerical results and demonstrate angular tolerance of up to 30 degrees of the fabricated filters.

Down to 2 nm Ultra Shallow Junctions : Fabrication by IBS Plasma Immersion Ion Implantation Prototype PULSION®

Classical beam line implantation is limited in low energies and cannot achieve P+/N junctions requirements for <45nm node. Compared to conventional beam line ion implantation, limited to a minimum of about 200 eV, the efficiency of Plasma Immersion Ion Implantation (PIII) is no more to prove for the realization of Ultra Shallow Junctions (USJ) in semiconductor applications: this technique allows to get ultimate shallow profiles (as implanted) thanks to no lower limitation of energy and offers high dose rate. In the field of the European consortium NANOCMOS, Ultra Shallow Junctions implanted on a semi‐industrial PIII prototype (PULSION®) designed by the French company IBS, have been studied. Ultra shallow junctions implanted with BF3 at acceleration voltages down to 20V were realized. Contamination level, homogeneity and depth profile are studied. The SIMS profiles obtained show the capability to make ultra shallow profiles (as implanted) down to 2nm.

Optimization of Etching/Deposition Phenomena for BF3 and B2H6 Plasma Doping using PULSION®

Plasma doping has been accepted into semiconductor manufacturing for two low energy, high dose implant applications. The p‐type polysilicon counter‐doping and contact doping for DRAM devices can be carried out using BF3 or B2H6 precursor gas. The choice between these two precursors depends on the benefits and constraints of each one. The capability of the PULSION plasma doping tool to minimize these key constraints, the amount of silicon etching, enhanced oxidation, and/or boron deposition, has been studied and is reported in this paper.Plasma doping has been accepted into semiconductor manufacturing for two low energy, high dose implant applications. The p‐type polysilicon counter‐doping and contact doping for DRAM devices can be carried out using BF3 or B2H6 precursor gas. The choice between these two precursors depends on the benefits and constraints of each one. The capability of the PULSION plasma doping tool to minimize these key constraints, the amount of silicon etching, enhanced oxidation, and/or boron deposition, has been studied and is reported in this paper.