Methods for assessing semiconductor structures

A method for assessing a quality of a semiconductor structure, the semiconductor structure having a front surface and a back surface generally parallel to the front surface and comprising a charge trapping layer, the method comprising:

• illuminating the semiconductor structure to generate charge carriers in the semiconductor structure;
• measuring an initial electrostatic parameter of the semiconductor structure, the initial electrostatic parameter being selected from the group consisting of (1) a capacitance of the semiconductor structure and (2) a difference in voltage potential between the front surface of the semiconductor structure and an electrode;
• measuring an excited electrostatic parameter of the semiconductor structure during illumination of the semiconductor structure to generate charge carriers in the semiconductor structure, the excited electrostatic parameter being a same parameter as the initial electrostatic parameter;
• and
• assessing an efficiency of the charge trapping layer based on the measured electrostatic parameter of the semiconductor structure, the charge trapping layer being selected from the group consisting of polycrystalline silicon, amorphous silicon, silicon germanium, silicon doped with carbon, and germanium.