Some implementations provide an interposer that includes a substrate, a via in the substrate, and an oxidation layer. The via includes a metal material. The oxidation layer is between the via and the substrate. In some implementations, the substrate is a silicon substrate. In some implementations, the oxidation layer is a thermal oxide formed by exposing the substrate to heat. In some implementations, the oxidation layer is configured to provide electrical insulation between the via and the substrate. In some implementations, the interposer also includes an insulation layer. In some implementations, the insulation layer is a polymer layer. In some implementations, the interposer also includes at least one interconnect on the surface of the interposer. The at least one interconnect is positioned on the surface of the interposer such that the oxidation layer is between the interconnect and the substrate.