Synthesis and Characteristics of Transferrable Single-Crystalline AlN Nanomembranes

Abstract

Single-crystalline inorganic semiconductor nanomembranes (NMs) have attracted great attention over the last decade, which poses great advantages to complex device integration. Applications in heterogeneous electronics and flexible electronics have been demonstrated with various semiconductor nanomembranes. Single-crystalline aluminum nitride (AlN), as an ultrawide-bandgap semiconductor with great potential in applications such as high-power electronics has not been demonstrated in its NM forms. This very first report demonstrates the creation, transfer-printing, and characteristics of the high-quality single-crystalline AlN NMs. This work successfully transfers the AlN NMs onto various foreign substrates. The crystalline quality of the NMs has been characterized by a broad range of techniques before and after the transfer-printing and no degradation in crystal quality has been observed. Interestingly, a partial relaxation of the tensile stress has been observed when comparing the original as-grown AlN epi and the transferred AlN NMs. In addition, the transferred AlN NMs exhibits the presence of piezoelectricity at the nanoscale, as confirmed by piezoelectric force microscopy. This work also comments on the advantages and the challenges of the approach. Potentially, the novel approach opens a viable path for the development of the AlN-based heterogeneous integration and future novel electronics and optoelectronics.