Ex situ ellipsometry characterization of excimer laser annealed amorphous silicon thin films grown by low pressure chemical vapor deposition

Spectroscopic ellipsometry was used to monitor excimer laser annealed thin (∼100 nm) amorphous silicon (a-Si) films grown on quartz substrates by low pressure chemical vapor deposition (LPCVD). The peak position of the imaginary part of the complex dielectric function ε2 was used to determine the degree of crystallization of the a-Si. The amplitude of ε2 at the Si E1 transition energy is found to be a good indicator of the polycrystalline silicon (poly-Si) grain size after laser annealing with good correlation between ex situ ellipsometric data and poly-Si grain sizes being observed. Spectroscopic ellipsometry provides a contactless, nondestructive, and simple technique for monitoring laser annealing both in situ during the annealing process or ex situ after annealing.