Modeling the infrared reflectance of n–/n+ SiC layers on top of n+ SiC substrates for epitaxy control application

Abstract

Infrared reflectance is a powerful tool to control, rapidly and non-destructively, complex active layer stacks for electronic devices applications. The case of interest which is considered in this work concerns 4H-SiC Schottky diode structures. They are made of a lightly doped layer (drift zone, ≈5 × 1015 cm–3) on top of a heavily doped n+ substrate (5 × 1018 cm–3). In between is a thin (buried) SiC layer used as field stop (or buffer). From model calculations performed in the range 1000–4000 cm–1, we show that the shape of the interference spectra is very sensitive to the doping and thickness of the buried (buffer) layer.