The disclosure relates to an array substrate and a method for fabricating an array substrate. The array substrate includes a base substrate, a cover layer on the base substrate, an opening at least partially passing through the cover layer, a stress buffer structure adjacent to the opening and on a side of the cover layer facing the base substrate, wherein the stress buffer structure includes a phase change material, wherein a height of a portion of the cover layer on the phase change material is lower than a height of a portion of the cover layer adjacent to the phase change material.