Finding the optical constants of zinc arsenide (Zn₃As₂) via spectroscopic ellipsometry

Zinc oxide is a wide band gap semiconductor with the potential to supplement gallium nitride for violet and UV optoelectronic applications. Renlund et al. have fabricated stable p-type zinc oxide material through magnetron sputtering deposition in oxygen onto a zinc arsenide (Zn₃As₂) layer. Understanding the thickness and optical properties of the zinc arsenide layer is critical in controlling this process. We report some success using spectroscopic ellipsometry to determine the thickness of evaporated zinc arsenide layers. Determining the optical constants of this layer has been more challenging. We will discuss these difficulties, as well as potential solutions.