Stress-generating structure for semiconductor-on-insulator devices

摘要

A stack pad layers including a first pad oxide layer, a pad nitride layer, and a second pad oxide layer are formed on a semiconductor-on-insulator (SOI) substrate. A deep trench extending below a top surface or a bottom surface of a buried insulator layer of the SOI substrate and enclosing at least one top semiconductor region is formed by lithographic methods and etching. A stress-generating insulator material is deposited in the deep trench and recessed below a top surface of the SOI substrate to form a stress-generating buried insulator plug in the deep trench. A silicon oxide material is deposited in the deep trench, planarized, and recessed. The stack of pad layer is removed to expose substantially coplanar top surfaces of the top semiconductor layer and of silicon oxide plugs. The stress-generating buried insulator plug encloses, and generates a stress to, the at least one top semiconductor region.

主权项

1. A method of forming a semiconductor structure comprising:
providing a semiconductor-on-insulator (SOI) substrate including a handle substrate consisting of a single crystalline semiconductor material, a buried insulating layer present on said handle substrate, and a top semiconductor layer present on said buried insulating layer; forming a trench extending from a top surface of said SOI substrate to a depth beneath a bottom surface of said buried insulating layer of said SOI substrate to physically expose a portion of said handle substrate at a bottom of said trench, wherein said trench laterally abuts and encloses at least one top semiconductor portion formed in said top semiconductor layer of said SOI substrate; and forming a stack of an insulator stressor plug and a silicon oxide plug in said trench, wherein said insulator stressor plug abuts said portion of said handle substrate exposed at said bottom of said trench, wherein said silicon oxide plug is substantially coplanar with a top surface of said at least one top semiconductor portion and has sidewalls in direct contact with sidewalls of said trench, and wherein an interface between said insulator stressor plug and said silicon oxide plug is coplanar with said bottom surface of said buried insulating layer.