The present disclose provides in some embodiments an array substrate and a method for fabricating the same, and a display device. The array substrate includes a source-drain metal layer formed on a base substrate and including copper, an alloy layer formed on the source-drain metal layer and including copper alloy, non-copper metal in the copper alloy being easier to be oxidized than copper in the copper alloy, a passivation layer formed on the alloy layer, and an oxide layer formed between the alloy layer and the passivation layer.