Epitaxial growth of III-nitrides on silicon substrates

Hetero epitaxial structures with strained layers are widely used in electronic and optoelectronic semiconductor devices. Over the last decades the group III-Nitride semiconductor materials have been extensively used for light emitting applications and are nowadays emerging as promising candidates for high power electronic applications. Unlike the "classical" semiconductor materials (based on Si, Ge, GaAs, InP), group III-Nitrides crystallize in the wurtzite structure and thus have a hexagonal lattice. We will discuss the impact of the large differences in lattice constant between AlN and GaN with respect to thicknesses, compositions and strain in epitaxial hetero structures. Furthermore, as no native substrates are available for the III-Nitrides, growth is performed on foreign substrates such as sapphire, silicon carbide or silicon. III-Nitride epi layers grown on Silicon substrates offer a lower cost technology compared to other substrates because of the scalability towards larger wafer size and the leverage on Si technology. However, the large thermal mismatch between III-Nitrides and Silicon requires advanced deposition schemes to allow compensating for the huge tensile thermal stresses and to reduce the dislocation density of these materials. ©The Electrochemical Society.

ISBN:9781566778251

Publication year:2010