Nondestructive measurement of thickness and carrier concentration of GaAs epitaxial layer using infrared spectroscopic ellipsometry

This article reports a method for evaluating thickness and the carrier concentration of n type GaAs epitaxial layers simultaneously by employing nondestructive, contactless infrared spectroscopic ellipsometry. The carrier concentration Nc and layer thickness d were correctly measured for carrier concentration over 5×1017 cm−3 with the method by simply assuming the plasma oscillation of free carriers and a step function carrier profile.