Large in-plane permittivity of Ba0.6Sr0.4TiO3 thin films crystallized using excimer laser annealing at 300 °C

We demonstrated a way to fabricate the crystalline Ba0.6Sr0.4TiO3 (BST) thin films using excimer laser annealing technique on the amorphous BST thin films fabricated by sol-gel process. The grain size of the laser-annealed films is larger than that of the conventionally thermal-annealed films. However, an uncrystallized, amorphous layer was observed near the film/substrate interface due to the limited laser absorption depth. The uncrystallized layer has a critical influence on out-of-plane dielectric property of BST films. The significant difference of the relative dielectric permittivity (εr) between in-plane (1383) and out-of-plane (184) directions is observed.