Optical Probing of Charge Retention Time in Semiconductor/Dielectric Structure

In this work, we demonstrate a noninvasive and contactless optical metrology technique to assess the quantitative electron trapping-detrapping in a semiconductor/dielectric structure and examine its correlation with oxide thickness. The experimental measurements are conducted with a home-built instrument that captures the time-dependent optical second-harmonic signal from the Si/SiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> interface. A numerical model is implemented to analyze the quantitative charge trapping-detrapping over time and determine charge retention time in the Si/SiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> structure while correlating it with experimental results.