STACKED SHORT AND LONG CHANNEL FINFETS

摘要

An analog integrated circuit is disclosed in which short channel transistors are stacked on top of long channel transistors, vertically separated by an insulating layer. With such a design, it is possible to produce a high density, high power, and high performance analog integrated circuit chip including both short and long channel devices that are spaced far enough apart from one another to avoid crosstalk. In one embodiment, the transistors are FinFETs and the long channel devices are multi-gate FinFETs. In one embodiment, single and dual damascene devices are combined in a multi-layer integrated circuit cell. The cell may contain various combinations and configurations of the short and long-channel devices. A high density cell can be made by simply shrinking the dimensions of the cells and replicating two or more cells in the same size footprint as the original cell.

主权项

1. A method of fabricating an integrated circuit having finFET transistors therein, the method comprising:
forming, overlying a silicon substrate, long channel epitaxial fin; forming an insulating layer overlying the long channel epitaxial fin; forming, overlying the insulating layer, short channel epitaxial fin; implanting source and drain regions while a gate region for the transistors is covered by a mask; etching recesses in the silicon substrate while the source and drain regions of the transistors are covered by a mask; depositing a gate dielectric layer over the epitaxial fins; and depositing metal into the recesses to form a recessed metal gate for the long channel fin and a recessed metal gate for the short channel fin, the long and short channel transistors having portions that vertically overlap each other.