Selective phase growth of van der Waals high-κ Sb2O3 films

Abstract

Van der Waals (vdW) dielectric film is characterized by its dangling-bond free interface and thus promising to use as the gate in the next-generation field effect transistor devices. Emergent molecular crystal Sb2O3 has been proved as an effective high-κ vdW dielectric with low-cost and CMOS compatibility. However, fabricating wafer-scale Sb2O3 film with controllable dielectric constant and crystal phase is challenging. Based on the result of first-principle study, we designed an oxygen-assisted low temperature pulsed laser deposition (PLD) method for the phase-selective growth of α- and β-Sb2O3 thin films with super-high κ (> 100) and good homogeneity. The phase control is experimentally demonstrated by tuning the oxygen gas pressure during the growth process. Dielectric analysis on pure phase α-Sb2O3 shows excellent dielectric properties and reveals the physics of the transport mechanism and dielectric relaxation process.