Carbon doped GaN layers grown by Pseudo‐Halide Vapour Phase Epitaxy

Pseudo-Halide Vapour Phase Epitaxy (PHVPE) was utilized to grow thick carbon doped GaN layers to study their suitability as semi-insulating (SI) substrates. With in-situ waste gas analysis by FTIR spectroscopy, the carbon doping from the HCN precursor gas was indirectly controlled in a wide range up to 5 × 1019 cm–3. The grown layers were characterized by Scanning Electron Microscopy (SEM), Secondary Ion Mass Spectroscopy (SIMS), Photoluminescence (PL), Micro-Raman-Spectroscopy, Hall effect measurement, and High Resolution X-Ray Diffractometry (HRXRD). Similar to the impurity incorporation (O, Si, Mg and Zn), carbon distribution proved to be inhomogeneous, due to its increased incorporation on facets of so-called V-pits.