1. A method of forming a plurality of layers comprising forming a first layer on a substrate, wherein the first layer comprises a first compound comprising Me 1 w Me 2 x Si y O z , wherein Me 1 and Me 2 are metals, w≧0, x≧0, y≧0, and z>0, and at least one of w, x, and y is greater than zero; and forming a second layer on a substrate, wherein the second layer comprises a second compound comprising Me 1 a Me 2 b Si c O d , wherein a≧0, b≧0, c≧0, and d>0, and at least one of a, b, and c is greater than zero; wherein one of the first or the second layers has linear resistance and substoichiometric composition, and the other of the first or the second layer has bistable resistance and near-stoichiometric composition, wherein the sum of the first layer thickness and the second layer thickness is between about 20 Å and about 100 Å; wherein the layer with bistable resistance has a thickness between about 25% and about 75% of the total thickness; and wherein at least one of the first compound or second compound further comprises nitrogen.