Epitaxial Stress‐Free Growth of High Crystallinity Ferroelectric PbZr0.52Ti0.48O3 on GaN/AlGaN/Si(111) Substrate.

Abstract: Due to its physical properties gallium‐nitride (GaN) is gaining a lot of attention as an emerging semiconductor material in the field of high‐power and high‐frequency electronics applications. Therefore, the improvement in the performance and/or perhaps even extension in functionality of GaN based devices would be highly desirable. The integration of ferroelectric materials such as lead–zirconate–titanate (PbZr<italic>_x</italic>Ti_1‐<italic>_x</italic>O₃) with GaN has a strong potential to offer such an improvement. However, the large lattice mismatch between PZT and GaN makes the epitaxial growth of Pb(Zr_1‐<italic>_x</italic>Ti<italic>_x</italic>)O₃ on GaN a formidable challenge. This work discusses a novel strain relaxation mechanism observed when MgO is used as a buffer layer, with thicknesses down to a single unit cell, inducing epitaxial growth of high crystallinity Pb(Zr_0.52Ti_0.48)O₃ (PZT) thin films. The epitaxial PZT films exhibit good ferroelectric properties, showing great promise for future GaN device applications. [ABSTRACT FROM AUTHOR]