Enhanced dielectric properties of Zr-Sn-Ti oxynitride thin films

Zr0.26Sn0.23Ti0.51OxNy (ZSTON) and Zr0.26Sn0.23Ti0.51O2-(delta) (ZSTO) film s have been prepared on Pt coated silicon substrates by pulsed laser deposi tion technique using a Zr-Sn-Ti oxide target at a substrate temperature of 650 degreesC in N-2 and O-2 ambient, respectively. TEM observation showed t hat both kinds of films are amorphous. XPS analysis showed that the N/O rat io in ZSTON is 0.08/0.92. With the help of a comparative study of the diele ctric properties of ZSTON and ZSTO films, it has been found that incorporat ion of nitrogen can increase the dielectric coefficient and decrease the di electric loss of the multicomponent oxide films remarkably. Optical transmi ttance measurements showed that incorporation of nitrogen can slightly decr ease the width of the bandgap and increase the refractive index of the film s. It is proposed that amorphous Zr-Sn-Ti oxynitride stable at 650 degreesC is a potential dielectric material for DRAM applications.