Determining dopant content of doped amorphous semiconductor layer on carrier comprises use of spectral ellipsometry and reference Tauc curve

摘要

Determining the dopant content of a doped amorphous semiconductor layer (10) on a carrier (1) comprises preparing a reference Tauc curve relating dopant concentration to the slope (b) of the linear region. The square root of the product of absorption coefficient (alpha ) and photon energy (E) (y axis) is plotted against photon energy and the slope (b) equals delta y/delta (E -Et) where Et is the band gap. The plot is repeated for the dopant layer to be tested using spectral ellipsometry, the slope (b) is found and thus the dopant concentration.