DUMMY GATE STRUCTURE FOR ELECTRICAL ISOLATION OF A FIN DRAM

摘要

Trench capacitors can be formed between lengthwise sidewalls of semiconductor fins, and source and drain regions of access transistors are formed in the semiconductor fins. A dummy gate structure is formed between end walls of a neighboring pair of semiconductor fins, and limits the lateral extent of raised source and drain regions that are formed by selective epitaxy. The dummy gate structure prevents electrical shorts between neighboring semiconductor fins. Gate spacers can be formed around gate structures and the dummy gate structures. The dummy gate structures can be replaced with dummy replacement gate structures or dielectric material portions, or can remain the same without substitution of any material. The dummy gate structures may consist of at least one dielectric material, or may include electrically floating conductive material portions.

主权项

1. A semiconductor structure comprising:
semiconductor fins located on a substrate, wherein each of said semiconductor fins is laterally bound by a pair of lengthwise sidewalls and a pair of widthwise sidewalls; trench capacitors located within said substrate, wherein an inner electrode of each trench capacitor is electrically shorted to a source region in one of said semiconductor fins; a gate structure straddling one of said semiconductor fins, said gate structure comprising a stack of a gate dielectric and a gate electrode; a gate spacer laterally surrounding said gate dielectric and said gate electrode; and a dummy gate structure including dielectric surfaces located between a widthwise sidewall of one of said semiconductor fins and a widthwise sidewall of another of said semiconductor fins and laterally extending along a same direction as said gate structure.