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Method for fabricating conductive wires with self-assembled organic molecules as templates

IP.com Disclosure Number: IPCOM000029750D
Publication Date: 2004-Jul-09
Document File: 5 page(s) / 40K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for fabricating conductive wires with self-assembled organic molecules (SAMs) as templates. Benefits include improved functionality, improved performance, and improved reliability.

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Method for fabricating conductive wires with self-assembled organic molecules as templates

Disclosed is a method for fabricating conductive wires with self-assembled organic molecules (SAMs) as templates. Benefits include improved functionality, improved performance, and improved reliability.

Background

              A reliable method is required to fabricate conductive wires with feature sizes smaller than 20 nm. The use of lithography is limited by wave length and smaller wavelengths become more expensive, especially for deep ultraviolet (UV).

      Conventionally, the problem is solved by using lithography and damascene metals. However, optical lithography does not print features smaller than 20 nm. Additionally, deep UV lithography is expensive.

General description

              The disclosed method fabricates conductive wires deposited on self-assembled organic molecules between the sidewalls of functionalized contacts (vias) plugs. The organic molecules include deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and proteins.

              The key elements of the method include:

•             Self-assembly of organic molecules between functionalized contacts (vias) plugs with top caps followed by activation with palladium (Pd) and electroless metal deposition

•             Interconnect structures containing capped contacts (vias) with metal wires between the contacts

•             Self-assembly of functionalized carbon nanotubes (or nanowires) between the sidewalls of the vias

Advantages

              The disclosed method provides advantages, including:

•             Improved functionality due to enabling the formation of metal wires with sub-20 nm feature sizes using self-assembled techniques without lithography

•             Improved functionality due to enabling carbon nanotubes (nanowires) to self-assemble with low-contact resistance to metal contacts (vias) through chemical bonding

•             Improved reliability due to eliminating lithography

•             Improved cost effectiveness due to eliminating lithography

Detailed description

 

              The disclosed method includes a process flow to fabricate conductive wires on self-assembled organic molecules. The process includes the following steps:

1.           Deposit a dielectric layer on top of substrate, such as silicon, with or without active devices.

2.           Form contact (via) plugs to active devices by using selective metal deposition or damascene process to fill contacts/vias. The selective metal deposition can use W, Ni, or Co in chemical vapor deposition (CVD) or electroless metal deposition. A damascene process can include barrier/seed deposition followed by metal plating, such as CVD or atomic-level deposition (ALD). Physical vapor deposition (PVD) can be used with a Ta/TaN, TiN, TiSiN, or TaSiN barrier with electroplated/electroless Cu, Au, or Ag and chemical mechanical polishing to remove excess metal from the field (see Figure 1).

3.           Cap the contacts (<100 nm thick) with met...