Method for simultaneously forming local interconnect with silicided elevated source/drain MOSFET's
AssigneeNational Science Council
InventorTiao-yuan Huang
Life of this patent
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Abstract
A method for formation of both local innerconnection and silicidation of source/drain transistors using the deposition of a blanket silicon layer over the entire top surface of the transistors and selectively stripping of unwanted portions of the silicon layer is disclosed. The method includes the step of applying a photoresist mask to map out where the local interconnection and source/drain are to be located. The final recited step is to deposit a thin metal layer to provide for the silicidation to complete the transistor. The silicon layer that is deposited has a thickness of 20 to 300 millimeters, and the thin metal layer is either cobalt or titanium having a thickness of 10 millimeters to 100 millimeters.
Claims7
A method to provide both local interconnection and silicidation of source/drain transistors comprising the steps of:
- photolithographic patterning and etching to form a gate structure,
- forming a sidewall spacer around the gate structure,
- forming a blanket silicon layer in which single crystal silicon is disposed on an exposed source/drain and polycrystal silicon is disposed on top of an oxidized layer, said gate structure, and side wall spacer,
- applying a photoresist mask in implanting n.sup.+ and p.sup.+ source/drain ions to form a LDD region,
- selectively stripping off unwanted portions of the silicon layer not protected by photoresist in a local interconnection photomask, wherein the remaining portions are used for local interconnection and source/drain, and
- depositing a metal layer in which a silicide layer is formed on said polycrystal silicon to form a local interconnection and a silicide is formed on said single crystal silicon of said source/drain to form a silicided source/drain.
Dependencies are inferred from the claim text.