LOCALLY FOLDED SPLIT LEVEL BITLINE WIRING

摘要

A method for fabricating a semiconductor memory with a split level folded bitline structure consisting of three contact levels, in accordance with the present invention, includes forming gate structures (204) for transistors in an array region (212) and a support region (214) of a substrate (202). First contacts (222) are formed down to diffusion regions between the gate structures in the array region. The first contacts have a height which is substantially the same for all first contacts in the array region. Second contacts (232) are formed between first level bitlines (234) in the array region and a first portion of the first contacts, while forming second contacts (236 and 260) to a first metal layer (233, 264) from the gate structures (204) and diffusion regions (262) in the support region. Third contacts (246) are formed between second level bitlines in the array region and a second portion of the first contacts, while forming third contacts to a second metal layer (251, 268) from the first metal layer in the support region.