Back to results
US 4,736,233 AGranted
Interconnect and contact system for metal-gate MOS VLSI devices
AssigneeTexas Instruments Incorporated
InventorJames M. McDavid
Life of this patent
Estimating the term…
Abstract
A simplified process for metal gate and contact/interconnect system for MOS VLSI devices employs a refractory metal structure for the gate, including a thick layer of tungsten alone, with stress and adhesion controlled by the deposition conditions. The metal gate receives sidewall oxide spacers during a metal-cladding operation for the source/drain areas. Contacts to the source/drain region include a molybdenum/tungsten stack and a top layer of gold.
Claims4
A gate, contact and interconnect structure for an MOS integrated circuit, comprising:
- a metal gate on a face of a silicon body comprising a layer of tungsten overlying and adhered to a thin layer of silicon oxide, and a coating of oxide on the sidewalls of said gate totally encapsulating said gate;
- heavily-doped source/drain regions in said face self-aligned with said oxide on the sidewalls of the metal gate,
- a tungsten metal layer formed on the surface of said source/drain regions self-aligned with said oxide on the sidewalls of the metal gate,
- a thick deposited insulator coating on said face over said metal gate and over said tungsten metal layer and source/drain regions,
- a metal contact and interconnect strip extending along said face overlying said insulator coating and extending into a contact hole in said insulator coating to make electrical connection to said tungsten metal layer, and comprising:
- a thin layer of molybdenum over said insulator coating, a thicker layer of tungsten over said molybdenum, and a layer of gold over said thicker layer of tungsten.
3 more elements
Dependencies are inferred from the claim text.