Dielectric properties of amorphous Zr–Al–O and Zr-Si-O thin films

Abstract

We have systematically studied the composition dependence of the dielectric properties of Zr 1Àx Al x O 2Àx=2 and Zr 1Àx Si x O 2 . An essentially linear variation of the static dielectric constant, " s , was observed as a function of composition, x, for compositions rich in the p-block element, i.e., x > 0:4, for both chemical systems. However an abrupt change in " s is found near x % 0:35, associated with the onset of crystallinity in as-deposited films. Breakdown fields do not show a comparable composition dependence. Measurements of the index of refraction at optical frequencies, combined with a simple Clausius-Mossotti interpretation, indicates that low-frequency (ionic) contributions to the polarizability exhibit systematic deviation with respect to values linearly interpolated from the endmembers. These trends are not consistently affected by the presence of crystalline order, but are related to changes associated with heterogeneous local oxygen coordination and bonding.

Solution processable amorphous hafnium silicate dielectrics and their application in oxide thin film transistors

“…To develop amorphous high-k dielectrics, some research groups have investigated different multicomponent dielectrics based on a mixture of high-k dielectrics (ZrO 2 , HfO 2 , TiO 2 ) and different dopants, such as Al, 10,11 La 12 and Si, [13][14][15] to increase the crystalline temperature. Among them, silicon oxide has a wide bandgap, small ion radius and high Si-O band energy.…”