Abstract
$(Ba_{0.5}Sr_{0.5)/TiO_3$(BST) thin films were prepared for the application of 256 Mb DRAM by RF magnetron sputtering. The crystallinity of BST thin films increased with increasing deposition tempera lure. The composition of thin films was $(Ba_{0.48}Sr_{0.48)/TiO_{2.93}$ Pt/Ti barrier layer suppressed the diffusion of Si into BST layer. The films showed a dielectric constant of 320 and a dissipation factor of 0.022 at 100 kHz. the change of capacitance of the films with applied voltage was small, showing paraelectric property. The charge storage density and leakage current density were 40fC/$\mu \textrm{m}^{2}$ and 0.8$\mu A/\textrm{cm}^2$, respectively at a field of 0.15 MV/cm. The BST films obtained by RF magnetron sputtering appeared to be potential thin film capacitors for 256 Mb DRAM application.
256Mb DRAM에서 박막 커패시터로의 적용을 위해서$(Ba_{0.5}Sr_{0.5)/TiO_3$(BST)박막이 RF Magnetron Sprttering방법에 의해 제조되었다. BST박막의 결정화도는 기판온도가 높아짐에 따라 증가하였고 증착된 박막의 조성은 $(Ba_{0.48}Sr_{0.48)/TiO_{2.93}$이었다. 이때 Pt/Ti장벽층은 Si의 BST계면으로의 확산을 억제하였다. 100kHz에서의 유전상수 및 유전손실은 각각 320 및 0.022이었다. 인가전계도 (Charge Storage Density)는 40fC/$\mu \textrm{m}^{2}$, 누설전류밀도(Leakage Current Density)는 0.8$\mu A/\textrm{cm}^2$ 로서 RF Matnetron sputtering방법에 의해 제조된 BST 박막이 256Mb DRAM 적용 가능함을 보였다.
