Characterization of ScAlN/GaN Toward Electronic Device Application

Scandium Aluminum Nitride (ScAIN) is an attractive material as a barrier layer of GaN HEMTs owing to its ultrawide bandgap, strong polarization and ferroelectric. In the paper, the recent progress in the characterization of ScAlN/GaN heterostructure prepared by low-temperature sputtering method is presented. Structural and optical properties of epitaxial pseudomorphic ScAIN with Sc compositions of 6,10 and 14% on GaN are investigated by AFM, XRD and spectroscopic ellipsometry. Consistent thicknesses of $\mathbf{\sim 2 0} \mathbf{~ n m}$ were obtained by XRD and spectroscopic ellipsometry. Dielectric function and optical bandgap are determined.