Grain Boundary Characterization in Polysilicon by Light Beam Induced Current Topography and Image Processing

Abstract

ABSTRACTA high performance light-beam-induced-current (LBIC) analyser has been used to determine the recombination velocity at the grain boundary (S) and the minority-carrier diffusion length (L). For this purpose a Schottky diode (Cr/Si) was fabricated using a p-type silicon bicrystal (1Ω cm, Σ13 grain boundary). The contacts were obtained by a “cold” technology. The diffusion length, determined by the method proposed by Ioannou, was subsequently fitted into the model proposed by Marek to evaluate the recombination velocity by the curve-fitting of the experimental and theoretical photocurrent profiles. A value of S = 2.104 cm/s was thus obtained. The influence of the thin oxide layer at the Cr/Si interface is also discussed.