Electronic structure of the interface of aluminum nitride with Si(100)

Abstract

The band alignment at the interfaces of Si(100) with amorphous (a-) and crystallized (c-) AlN layers was analyzed using internal photoemission and photoconductivity spectroscopy. The bandgap of thin a-AlN layers grown using atomic layer deposition is found to be 5.8±0.1 eV, widening to 6.5±0.2 eV after annealing induced crystallization into the wurtzite phase. Internal photoemission of electrons from the Si valence band to the AlN conduction band was found to exhibit the same energy threshold of 3.2±0.1 eV in amorphous and crystallized AlN. The energy band diagrams of a-AlN/Si(100) and c−AlN/Si(100) interfaces are established.