LED have become the main light sources of the future as they open the path for intelligent use of light in time, intensity
and color. In many usages, strong energy economy is done by adjusting these properties. The smart lighting has three
dimensions, energy efficiency brought by GaN blue emitting LEDs, integration of electronics, sensors, microprocessors
in the lighting system and development of new functionalities and services provided by the light.
Monolithic LED arrays allow two major innovations, the spatial control of light emission and the adjustment of the
electrical properties of the source.
With a long experience in optoelectronics, CEA-LETI has focused on Light Emitting Diode (LED) lighting since 2006. Today, all the technical challenges in the implementation of GaN LED based solid state lighting (SSL) are addressed at CEA-LETI who is now an RandD player throughout the entire value chain of LED lighting. The SSL Line at CEA-LETI first deals with the simulation of the active structures and LED devices. Then the growth is addressed in particular 2D growth on 200 mm silicon substrates. Then, technological steps are developed for the fabrication of LED dies with innovative architectures. For instance, Versatile LED Array Devices are currently being developed with a dedicated μLED technology. The objective in this case is to achieve monolithical LED arrays reported and interconnected through a silicon submount. In addition to the required bonding and 3D integration technologies, new solutions for LED chip packaging, thermal management of LED lamps and luminaires are also addressed. LETI is also active in Smart Lighting concepts which offer the possibility of new application fields for SSL technologies. An example is the recent development at CEA LETI of Visible Light Communication Technology also called LiFi. With this technology, we demonstrated a transmission rate up to 10 Mb/s and real time HD-Video transmission.
EUV lithography is expected to be inserted for the 32/22 nm nodes with possible extension below.
EUV resist availability remains one of the main issues to be resolved. There is an urgent need to provide suitable tools to accelerate resist development and to achieve resolution, LER and sensitivity specifications simultaneously.
An interferometer lithography tool offers advantages regarding conventional EUV exposure tool. It allows the evaluation of resists, free from the deficiencies of optics and mask which are limiting the achieved resolution.
Traditionally, a dedicated beam line from a synchrotron, with limited access, is used as a light source in EUV interference lithography.
This paper identifies the technology locks to develop a stand alone EUV interferometer using a compact EUV source. It will describe the theoretical solutions adopted and especially look at the feasibility according to available technologies.
EUV sources available on the market have been evaluated in terms of power level, source size, spatial coherency, dose uniformity, accuracy, stability and reproducibility. According to the EUV source characteristics, several optic designs were studied (simple or double gratings). For each of these solutions, the source and collimation optic specifications have been determined.
To reduce the exposure time, a new grating technology will also be presented allowing to significantly increasing the transmission system efficiency. The optical grating designs were studied to allow multi-pitch resolution print on the same exposure without any focus adjustment.
Finally micro mechanical system supporting the gratings was studied integrating the issues due to vacuum environment, alignment capability, motion precision, automation and metrology to ensure the needed placement control between gratings and wafer. A similar study was carried out for the collimation-optics mechanical support which depends on the source characteristics.
When projected with a scanner, the latent image intensity in the photoresist has a slope that can be much lower than
with an interferometer. To study finely the lithographic process and to be predictive, the Normalized image slope of 193
nm immersion interferometer built at LETI has to be controlled. The exposure latitude (EL), the Normalized Image Log
Slope (NILS) and the interference contrast are closely related.
In this paper, we present an immersion interferometer specially designed to be used with a commercial ArF excimer laser. Different configurations are presented enabling the printing of dense lines with a pitch down to 65 nm with an acceptable depth-of-focus. Photoresist patterns are shown at a half-pitch down to 40 nm with nice squared profiles. First polarization studies at high-numerical aperture (NA) have been performed and we noticed a good correlation between roughness and polarization variation at high NA.
This document shows the modelization of the vibration effects on a hyper NA immersion interferometer at 193 nm, and their consequences on the image contrast. Finally we propose to use a active tabletop anti vibration unit and show its benefits.
The automatic damage test benches allow to obtain more data in less time but also to imagine new laser damage tests. Thereby, new questions can be asked and more answers can be provided. In this paper, the 3 YAG automatic damage test facilities build up at the laboratory will be shown. There are based on well-known principles : an half wave plate to adjust the wished peak fluence and a scattered light measurement in real time to detect the damage appearances. Many tests are developed around these benches as the usual hon-i, N-on-i, R-on-1, S-on-i tests and raster scans previously proposed by other laboratories. On all our test benches, these standard tests are driven by the same software designed at the laboratory : "Wintfl". But new tests and characterizations are also added. Indeed, on these thcilities the aging ofthe optics at various repetition rate under constant fluence (like S-on-i with or without a limit number of shots) are carried out. An automatic defect count has been also implemented. This tool is able to evaluate the number of defects after cleaning or after coating but also between laser irradiation. New tests are also imagined. The so-called HR-on-i test (High Ramp), which is a R-on4 (Ramp) test without beginning at zero has been achieved. It allows to compare 1-on-I and R-on-1 distributions performed with exactly the same damage criterion. Other parameters can be investigated as the speed of the motor ramp during the R-on-1 test, the pulse repetition frequency during the S-on-i test,... In this article, after a short presentation of our test bench facilities, the convenient possibilities of automatic YAG test benches are illustrated with experimental results.