For fabricating a memory device, spacers are formed to sides of word-line gates. In addition, aluminum oxide is formed as one of a liner layer or a cover layer to the spacers. The aluminum oxide has a chemical composition of Al.sub.2O.sub.3 for example. Such aluminum oxide may be used as an etch stop layer in a periphery region, a metal silicide block, and a hydrogen block for enhanced performance of the memory device.