InGaAs with embedded ErAs nano-particles is a promising material for thermoelectric applications. The incorporation of erbium arsenide metallic nanoparticles into the semiconductor can provide both charge carriers and create scattering centers for phonons. Electron filtering by heterostructure barriers can also enhance Seebeck coefficient by selective emission of hot electrons. 2.1μm-thick ErAs/InGaAs superlattices with a period of 10 nm InAlGaAs and 20 nm InGaAs were grown using molecular beam epitaxy, and the effective doping is from 2x10 18 to 1x10 19 cm 3. Special device patterns were developed for the measurement of the cross-plane Seebeck coefficient of the superlattice layers.. Using these device patterns, the combined Seebeck coefficient of superlattice and the substrate were measured and the temperature drops through the superlattice and InP substrate were determined with 3D ANSYS® simulations. The Seebeck coefficient of the superlattice layers is obtained based on the measurements and simulation results.