Semiconductor memory device and method of arranging signal and power lines thereof

Abstract

Method and apparatus for use, e.g., with Synchronous Dynamic Random Access Memory (SDRAM) circuits are disclosed. In one described embodiment, three metal layers are deposited and patterned in turn overlying a memory array portion of an SDRAM. Relatively wide power conductors are routed on a third metal layer, allowing power conductors to be reduced in size, or in some cases eliminated, on first and second metal layers. The relatively wide power conductors thus can provide a more stable power supply to the memory array, and also free some space on first and/or second metal for routing of additional and/or more widely spaced signal conductors. Other embodiments are described and claimed.