Backthinning of image sensors is a very well established process for achieving high Quantum Efficiency for high-specification space and science applications. To optimize the QE performance in various spectral bands, the AR coating need to be adjusted. A new multilayer low thickness UV AR coating has been developed by e2v and CEA-Leti with very high transmission at 266 nm and 355 nm laser wavelengths. It is compatible with CCD and CMOS backthinned image sensor process. We describe hereafter the first results obtained on glass and silicon substrates for this AR coating. The manufacturing of backthinned CCD and CMOS image sensors samples is ongoing. This development is supported by Minalogic project (financed by French FUI-DGCIS).
A silicon photonics platform that uses a CMOS foundry line is described. Fabrication process is following a modular integration scheme which leads to a flexible platform, allowing different device combinations. A complete device library is demonstrated for 1310 nm applications with state of the art performances. A PDK which includes specific photonic features and which is compatible with commercial EDA tools has been developed allowing an MPW shuttle service. Finally platform evolutions such as device offer extension to 1550 nm or new process modules introduction are presented.
We demonstrate the feasibility of producing advanced silicon photonic devices for future data communication nodes at 40Gbps using CMOS compatible processes in a 300mm wafer fab. Basic building blocks are shown together with various wavelength division multiplexing solutions. All the devices presented are integrated on 220nm SOI or locally grown epitaxial germanium.
We present a scheme for the realization of high performances, large tuning range, fully integrated and possibly low cost mid infrared laser source based on quantum cascade lasers and silicon based integrated optics. It is composed of a laser array and a laser combiner. We show that our metal grating approach gives many advantages for the fabrication yield of those laser arrays. We show the results of such a fabrication at 1350 cm<sup>-1</sup> with 60 cm<sup>-1</sup> tuning range. The silicon is a low cost option for the size consuming combiner. In the development of the SiGe platform, we present the loss measurement set up and we show losses below 1dB/cm at 4.5μm.
The Laboratoire Infrarouge (LIR) of the Laboratoire d'Electronique et de Technologie de l'Information (LETI) has been
involved in the development of microbolometers for over fifteen years. Two generations of technology have been
transferred to ULIS and LETI is still working to improve performances of low cost detectors. Simultaneously,
packaging still represents a significant part of detectors price. Reducing production costs would contribute to keep on
extending applications of uncooled IRFPA to high volume markets like automotive. Therefore LETI develops an onchip
packaging technology dedicated to microbolometers.
The efficiency of a micropackaging technology for microbolometers relies on two major technical specifications. First,
it must include an optical window with a high transmittance for the IR band, so as to maximize the detector absorption.
Secondly, in order to preserve the thermal insulation of the detector, the micropackaging must be hermetically closed to
maintain a vacuum level lower than 10<sup>-3</sup>mbar.
This paper presents an original microcap structure that enables the use of IR window materials as sealing layers to
maintain the expected vacuum level. The modelling and integration of an IR window suitable for this structure is also
presented. This zero level packaging technology is performed in a standard collective way, in continuation of
bolometers' technology. The CEA-LETI, MINATEC presents status of these developments concerning this innovating
technology including optical simulations results and SEM views of technical realizations.
This numerical study focused on the errors that can occur when ellipsometric spectroscopic scatterometry programs are used for critical dimension (CD) control and other significant geometrical parameters. The role of the number of wavelengths, the measurements noise and the spectral range is analyzed in terms of CD precision. Conversely, an important part is devoted to the effect of a bad shaping modelling of the lines (corner rounding, foot and notch effects) and bad characterization of the index. We show that the scatterometry technique is very resistant to measurement noise, even for a small number of wavelengths, although the spectral range has an important role on the CD calculation. We also give quantitative data about the accuracy needed on refractive index of the diffracting
material must. Excepted for profiles with additional feet, the CD found is very close to the original line without geometrical defects (corner rounding and notches).
This paper deals with the realization of a 1.3/1.55 micrometers duplexer integrated on a silica on silicon substrate. The design consists of two cascaded directional couplers in order to enhance the rejection bandwidth. Fabrication is based on plasma enhanced chemical vapor deposition and reactive ionic etching of silica films. The channel guide structure has been optimized to comply with the small distance between guides along the coupler, that would still ensure low loss fiber coupling. The results show an excellent spectral response: insertion loss lower than 3 dB on a 150 nm bandwidth at both wavelengths, crosstalk as low as 20 dB on a 100 nm bandwidth. Moreover, quite a total independence on polarization and temperature has been checked, for the required 1.3/1.55 micrometers separation.