Self-aligned laterally extended strap for a dynamic random access memory cell

摘要

A self-aligned strap structure can be formed by forming trench capacitors and overlying trench top conductive material portions. End portions of fin mask structures overlie portions of the trench top conductive material portions. A dielectric spacer is formed around each end portions of the fin mask structure to cover additional areas of the trench top conductive material portions. An anisotropic etch is performed to recess portions of the trench top conductive material portions that are not covered by the fin mask structures or dielectric spacers. Conductive strap structures that are self-aligned to end portions of semiconductor fins are formed simultaneously with formation of the semiconductor fins. Access fin field effect transistors can be subsequently formed.

主权项

1. A semiconductor structure comprising:
a semiconductor fin located on a substrate and including a region having a first width and an end portion having a second width that is greater than said first width; a trench capacitor located within said substrate and including an inner electrode, a node dielectric, and an outer electrode; and a conductive strap structure, wherein a lower portion of said conductive strap structure vertically contacts said inner electrode and an upper portion of said conductive strap structure laterally contacts said semiconductor fin and includes a portion having said second width, wherein a top surface of said semiconductor fin is coplanar with a top surface of said conductive strap structure.