Yoshihiko Isobe

Investigation of Reoxidation and Phosphorus Behavior in HF-Treated Heavily Doped Silicon Surfaces

The thermally stimulated desorption (TSD) from aqueous HF-treated heavily phosphorus-doped Si(100) and polycrystalline Si surfaces was studied by Auger electron spectroscopy (AES), electron energy loss spectroscopy (EELS) and mass spectroscopy. Desorption analyses indicated that reoxidation takes place slightly, to the same extent in the doped Si(100) and polycrystalline Si surfaces owing to hydrogen desorption. Moreover, a large quantity of phosphorus segregates to the top few layers in the desorption process of the oxides. It was clarified that the HF-treated polycrystalline silicon surface is terminated by hydrogen and resists oxidation similarly to a single-crystal one.

Gate insulator characteristics on the bonded thick SOI wafers for automotive IC applications

For the robustness of harsh environments around automotive ICs, such as negative surge and ESD, the authors have committed the thick SOI BiCDMOS process with trench dielectric isolations. This paper focuses on causes degrading reliability of gate insulators such as silicon dioxides and ONO (Oxide Nitride Oxide) films induced by the process.