Forming a bit line configuration for semiconductor memory

Abstract

A new interdigitated folded bit line (IFBL) architecture for a future generation high density semiconductor memory design is disclosed. In the architecture, the basic cross-point memory cells are organized orthogonally in rows and columns to form an array matrix. The bit lines run in a row direction while the word lines run in a column direction. Transfer transistors are designed to be shared with the same drain junction and the same bit line contact in order to save area. A choice of at least two described embodiments are provided. In one embodiment, referred to as the offset bit line structure, the bit lines are constructed by using two layers of interconnection lines to connect the interdigitated cells associated to it. By connecting the bit line contacts and with two different interconnecting layers and in an alternating row order, the true and complement bit lines and will run parallel to both sides of the memory array. In another embodiment, referred to as the side wall bit line structure, the bit lines are constructed by using the conductive side wall spacer rails to connect the interdigitated cells associated to it. By connecting the side wall bit line contacts with two sided-side wall spacer rails in an alternating row order, the true and complement bit lines will run parallel to both sides of the memory array.

Dependencies are inferred from the claim text.