Sc. Huang et al., Time dependent dielectric breakdown of paraelectric barium-strontium-titanate thin film capacitors for memory device applications, J APPL PHYS, 84(9), 1998, pp. 5155-5157
Barium-strontium-titanate (BST) is an important material for dynamic random
access memory capacitor applications. In this work, BST thin films are pre
pared by the sol-gel method and metal-BST-metal capacitors are fabricated.
The time dependent dielectric breakdown (TDDB) of the BST capacitors is mea
sured and analyzed. A new extrapolation method is developed to obtain the T
DDB lifetime from the time to breakdown (t(BD)) data. The leakage current i
s found to depend on the applied electric field in a power law relationship
. The exponent in the power law relation is close to 1 in the low field reg
ion (lower than 16 MV/m) and is about 16.5 in the high field region (larger
than 16 MV/m). A correlation between the leakage current and the TDDB life
time is established. The extrapolated lifetime is about 10(12) s at 3.3 V f
or 330-nm-thick films. (C) 1998 American Institute of Physics. [S0021-8979(
98)08820-3].