A dielectric layer containing a Zr--Sn--Ti--O film and a method of fabricating such a dielectric layer produce a reliable dielectric layer having an equivalent oxide thickness thinner than attainable using SiO.sub.2. In an embodiment, forming the Zr--Sn--Ti--O film on a substrate includes depositing materials of the Zr--Sn--Ti--O film substantially as atomic monolayers. In an embodiment, electronic devices include a dielectric layer having a Zr--Sn--Ti--O film such that Zr--Sn--Ti--O material is configured as substantially atomic monolayers. Dielectric layers containing such Zr--Sn--Ti--O films may have minimal reactions with a silicon substrate or other structures during processing.