Title :
Processing and dielectric property evaluation of barium strontium titanate thin films prepared by a sol-gel technique [DRAM capacitors]
Author :
Tahan, D.M. ; Klein, L.C. ; Safari, A.
Author_Institution :
Dept. of Ceramic Sci. & Eng., Rutgers Univ., Piscataway, NJ, USA
Abstract :
Barium strontium titanate (BST) thin films of the compositions Ba xSr1-xTiO3 with x ranging from 0 to 1 were prepared by a sol-gel spin coating technique. BST solutions were optimized in terms of stability, film crystallization and film quality. Films were deposited on Si (100) and Pt/Ti/SiO2/Si (100) substrates and the corresponding microstructures were evaluated using techniques such as X-ray diffraction, SEM, FESEM, and TEM. The dielectric breakdown strength was also determined. Grain size was proven to be on the order of 50 nm and had a marked effect on the electrical properties of the films. A dielectric constant ranging from 200 to 625 was obtained for BST thin films with x=0.6 over a thickness range of 100 to 900 nm. The leakage current density of the films remained below 1.1 μA/cm2 for extended time periods when measured at an applied field of 75 kV/cm
Keywords :
DRAM chips; X-ray diffraction; coating techniques; electric breakdown; electric strength; ferroelectric capacitors; ferroelectric thin films; grain size; leakage currents; permittivity; scanning electron microscopy; sol-gel processing; transmission electron microscopy; (BaSr)TiO3; 100 to 900 nm; DRAM capacitors; FESEM; Pt-Ti-SiO2-Si; SEM; Si; TEM; X-ray diffraction; applied field; dielectric breakdown strength; dielectric constant; ferroelectric thin films; film crystallization; film quality; grain size; leakage current density; sol-gel technique; spin coating technique; Barium; Binary search trees; Coatings; Crystallization; Dielectric substrates; Dielectric thin films; Semiconductor films; Stability; Strontium; Titanium compounds;
Conference_Titel :
Applications of Ferroelectrics, 1996. ISAF '96., Proceedings of the Tenth IEEE International Symposium on
Conference_Location :
East Brunswick, NJ
Print_ISBN :
0-7803-3355-1
DOI :
10.1109/ISAF.1996.602794
