Proximity Gettering Design of Hydrocarbon–Molecular–Ion–Implanted Silicon Wafers Using Dark Current Spectroscopy for CMOS Image Sensors

We developed silicon epitaxial wafers with high gettering capability by using hydrocarbon−molecular−ion implantation. These wafers also have the effect of hydrogen passivation on process-induced defects and a barrier to out-diffusion of oxygen of the Czochralski silicon (CZ) substrate bulk during Complementary metal-oxide-semiconductor (CMOS) device fabrication processes. We evaluated the electrical device performance of CMOS image sensor fabricated on this type of wafer by using dark current spectroscopy. We found fewer white spot defects compared with those of intrinsic gettering (IG) silicon wafers. We believe that these hydrocarbon−molecular−ion−implanted silicon epitaxial wafers will improve the device performance of CMOS image sensors

Reduction of White Spot Defects in CMOS Image Sensors Fabricated Using Epitaxial Silicon Wafer with Proximity Gettering Sinks by CH₂P Molecular Ion Implantation

Using a new implantation technique with multielement molecular ions consisting of carbon, hydrogen, and phosphorus, namely, CH2P molecular ions, we developed an epitaxial silicon wafer with proximity gettering sinks under the epitaxial silicon layer to improve the gettering capability for metallic impurities. A complementary metal-oxide-semiconductor (CMOS) image sensor fabricated with this novel epitaxial silicon wafer has a markedly reduced number of white spot defects, as determined by dark current spectroscopy (DCS). In addition, the amount of nickel impurities gettered in the CH2P-molecular-ion-implanted region of this CMOS image sensor is higher than that gettered in the C3H5-molecular-ion-implanted region; and this implanted region is formed by high-density black pointed defects and deactivated phosphorus after epitaxial growth. From the obtained results, the CH2P-molecular-ion-implanted region has two types of complexes acting as gettering sinks. One includes carbon-related complexes such as aggregated C–I, and the other includes phosphorus-related complexes such as P4–V. These complexes have a high binding energy to metallic impurities. Therefore, CH2P-molecular-ion-implanted epitaxial silicon wafers have a high gettering capability for metallic impurities and contribute to improving the device performance of CMOS image sensors. (This manuscript is an extension from a paper presented at the 6th IEEE Electron Devices Technology & Manufacturing Conference (EDTM 2022))

TEM Image Analysis and Simulation Physics for Two-Step Recrystallization of Discretely Amorphized C₃H₅-Molecular-Ion-Implanted Silicon Substrate Surface

In this study, we investigate the initial rapid recrystallization of a discretely amorphized C3H5-molecular-ion-implanted silicon (Si) substrate surface in the subsequent thermal annealing treatment through the analysis of plan-view transmission electron microscopy (TEM) images and technology computer-aided design (TCAD) process simulation. In the approach of the analysis of the plan-view TEM image of the Si substrate surface, we found that initial rapid recrystallization occurs in the intermediate regions between the residual crystalline and discrete amorphous regions formed in the C3H5-molecular-ion-implanted Si substrate surface. In addition, the TCAD process simulation results indicate that the intermediate regions correspond to the amorphous pockets formed around the discrete amorphous regions in the C3H5-molecular-ion-implanted Si substrate surface and are recrystallized preferentially during the short thermal annealing time. These plan-view TEM image analysis and TCAD process simulation results reveal a two-step recrystallization of the discretely amorphized C3H5-molecular-ion-implaned Si substrate surface. After the initial rapid recrystallization of amorphous pockets in the 1st step, the recrystallization of discrete amorphous regions starts in the 2nd step. The incubation period between the 1st and 2nd steps is the time required to recrystallize the amorphous pockets around the discrete amorphous regions completely and redefine the amorphous/crystalline interface

Le dispositif de VAE militante entre rescolarisation et transformations de l'engagement

La validation des acquis de l'expérience (VAE) est un dispositif public créé en 2002, qui permet aux individus d'obtenir des diplômes en faisant reconnaître par des institutions éducatives des activités et des pratiques comme équivalentes aux savoirs et aux savoir-faire acquis dans les formations qui mènent à ces diplômes. La VAE apparaît alors comme un élément de la transformation plus générale de la conception de la formation continue, en ce sens qu'elle met plutôt en scène une conception économiciste, individualiste et instrumentale de la formation, et tout particulièrement parce qu'elle s'appuie sur les deux " outils " socio-cognitifs qui en sont aujourd'hui le cœur : les compétences et le projet. L'étude de la mise en valeur dans les dossiers de VAE des expériences d'engagement montre de quelle manière ce dispositif contribue à développer une conception du militantisme en termes de compétences, en même temps qu'il permet d'insister sur les logiques de rattrapage scolaire qu'il induit

Ultrahigh-Flux Concerting Materials

ORCID　0000-0002-5000-1269The purpose of the research unit UlCoMat (Ultrahigh-flux Concerting Materials) is creation of novel materials for advanced engineering systems, such as fusion and fission reactors, aerospace craft, rockets and chemical plants, based on understanding and control of the metastable phase and the self-organization induced in materials under extreme conditions. The UlCoMat will accelerate a paradigm shift from stable and resistant materials to metastable but adaptive ones. It focuses also on the science of life to seek long-life materials and a precise estimation of their existence for the development of robust engineering systems using the minimum materials compatible with economical and safety requirements