Memories are categorized as embedded memories (e-memories) and stand-alone memories. E-memories favor high speed rather than low cost. In addition, they must maintain compatibility with the logic process, because they must be cofabricated on the same chip as the logic. In contrast, stand-alone memories give the first priority to low cost and thus high density rather than high speed. Over the course of such memory development, memory designers have faced several challenges to cope with problems involved in the e-memories. This article discusses those challenges and examines the likely development path they will take.