STRUCTURE HAVING DUAL SILICIDE REGION AND RELATED METHOD

• US 20080230848A1
• Filed: 03/22/2007
• Published: 09/25/2008
• Est. Priority Date: 03/22/2007
• Status: Abandoned Application

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Wong, Keith Kwong Hon, Yang, Chih-Chao, Yang, Haining S.
• Application Number:
  US11/689,708
• Publication Number:
  US 20080230848A1
• Time in Patent Office: Days
• US Class Current: 257/388
• CPC Class Codes: H01L 21/28052 the conductor comprising a silicide layer formed by the silicidation reaction of silicon with a metal layer formed by metal ion implantation H01L21/28044
• CPC Class Codes: H01L 21/823835 silicided or salicided gate conductors
• CPC Class Codes: H01L 29/4933 with a silicide layer contacting the silicon layer, e.g. Polycide gate with a barrier layer between the silicide and silicon layers H01L29/4941
• CPC Class Codes: H01L 29/665 using self aligned silicidation, i.e. salicide formation of conductive layers comprising silicides H01L21/28518
• CPC Class Codes: H01L 29/7833 with lightly doped drain or source extension, e.g. LDD MOSFET's; DDD MOSFET's for thin film transistors H01L29/78618

Abstract

A structure including a dual silicide region and a related method are disclosed. The structure may include a doped silicon, and a dual silicide region in the doped silicon, the dual silicide region including a first silicide region including a mid band gap metal, and a second silicide region including a near band gap metal, wherein the second silicide region is immediately adjacent to the doped silicon. The method may include forming a first silicide portion in a doped silicon by depositing a first metal over the doped silicon, annealing and removing unreacted first metal; ion implanting a second metal into the doped silicon; and annealing to form a second silicide portion from the second metal, wherein the first metal is different than the second metal.

Claims

1. A structure comprising:

a doped silicon; and

a dual silicide region in the doped silicon, the dual silicide region including a first silicide region and a second silicide region;

wherein the second silicide region is immediately adjacent to the doped silicon.

2. The structure in claim 1, wherein the first silicide region has a lower sheet resistance than that of the second silicide region.

3. The structure in claim 1, wherein the second silicide region has a lower contact resistance than that of the first silicide region.

4. A structure comprising:

a doped silicon; and

a dual silicide region in the doped silicon, the dual silicide region including a first silicide region including a mid band gap metal, and a second silicide region including a near band gap metal,

wherein the second silicide region is immediately adjacent to the doped silicon.

5. The structure of claim 4, wherein the second metal includes platinum in the case that the doped silicon includes a p-type dopant, and the second metal includes one of erbium and ytterbium in the case that the doped silicon includes an n-type dopant.

6. The structure of claim 5, wherein the first metal includes one of cobalt and nickel.

7. A method comprising:

forming a first silicide portion in a doped silicon by depositing a first metal over the doped silicon, annealing and removing unreacted first metal;

ion implanting a second metal into the doped silicon; and

annealing to form a second silicide portion from the second metal,

wherein the first metal is different than the second metal.

8. The method of claim 7, wherein the first metal includes a mid band gap metal, and the second metal includes a near band gap metal.

9. The method of claim 7, wherein the second silicide region is immediately adjacent to the doped silicon.

10. The method of claim 7, wherein the second metal includes platinum in the case that the doped silicon includes a p-type dopant, and the second metal includes one of erbium and ytterbium in the case that the doped silicon includes an n-type dopant.

11. The method of claim 10, wherein the first metal includes one of cobalt and nickel.