Introduction of infrared spectroscopic ellipsometry in a semiconductor production environment

IRSE proposes a complementary type of characterization to widely accepted UV-VIS ellipsometry. IRSE is sensitive to absorption bands (vibrational and rotational states of molecules) and free carriers. IRSE reduces also sensitivity to scattering due to roughness or very small CDs. We present here an IRSE production tool integrated in clean-room class 1: the SOPRA IRSE200. Our first objective is to assess IRSE capabilities for better sensitivity, stability and throughput for thin epilayers (20 nm-120 nm) thickness monitoring. A production strategy is developed on this topic.