Dielectric and Phase Engineering of Van der Waals Sb2O3 Films via PLD

Van der Waals dielectrics are broadly utilized to retain the intrinsic properties of two-dimensional (2D) electronic devices. As a 2D inorganic molecular crystal, Sb2O3 have attracted many research interests as a promising high k gate dielectric with low-cost and CMOS compatibility. However, fabricating 2D Sb2O3 film with controllable dielectric constant and crystal phase is challenging. Here, we designed an oxygen-assisted PLD method for the phase-selective growth of α- and β- Sb2O3 thin films with super-high κ (>100) and good homogeneity by PLD. This is realized by tuning the oxygen gas pressure in the growth products to obtain two phases Sb2O3. This phase-controlled bottom-up synthesis offers a simple and efficient way for manipulating the relevant device structures and provides a general approach for producing other multi-phase materials with unique properties and allows us to characterize their intrinsic optical and electrical properties. Using dielectric and electrical measurements, we show that α phases exhibit good dielectric performance. Our Sb2O3 dielectric film not only show higher κ than other conventional dielectrics in terms of compatibility to CMOS processes, but also keeps their comparative advantages in the fabrication of high-performance electronic devices over conventional dielectrics. Our approach of fabricating Sb2O3 dielectrics using PLD may open promising opportunities to promote such unprecedented 2D devices to industry applications.