Event: December 11, 2008 - 11:00am to December 11, 2008 - 12:00pm (US/Pacific)
12/11/2008 - 11:00am
12/11/2008 - 12:00pm
US/Pacific
Host: Karen Gleason, Massachusetts Institute of Technology
Presentation by: Nathan J. Trujillo, Department of Chemical Engineering, Massachusetts Institute of Technology
Title: "Depositing and Patterning a Robust and Dense Low-k Polymer by iCVD"
Abstract: The new millennium has brought fourth many technological innovations made possible by the advancement of high speed integrated circuits. As the average feature size in integrated circuits continues to decrease, reducing the dielectric constant of the interconnect dielectric (ILD) becomes crucial to minimizing RC delay, power consumption and cross talk noise. Common methods for reducing the dielectric constant involve reducing the film density by incorporating void space and using precursors with inherently open structures. Void space can be induced by copolymerization of the low-k matrix with a thermally sensitive porogen molecule, which is removed in a post-processing anneal. The mechanical properties of SiCOH dielectrics generally decrease with lower k values and typically scale with porosity as (1-p)3 until the percolation point, where pores coalesce. Therefore, there is a need to improve the properties of the as-deposited "dense" films, before porogens are incorporated. Initiated Chemical Vapor Deposition (iCVD) is a low-energy, one step, solvent-free process for producing polymeric thin films from one or more monomer species and an initiator species. iCVD is an attractive technique for creating low-k films from cyclic siloxane precursors. The low-energy process produces polymeric thin films that fully retain the organic functionality of their monomer precursor. In this talk we will discuss the deposition of a novel low-k iCVD precursor, 1,3,5,7-Tetravinyltetramethylcylcotetrasiloxane (V4D4). Dense films are deposited at low substrate temperatures and are subsequently annealed in air. The high degree of organic content in the as-deposited films affords the ability to systematically tune the film properties by annealing. The incorporation of atmospheric oxygen, at high temperatures, enhances the mechanical and electrical properties of the films. These "dense" annealed films provide favorable mechanical and electrical properties for incorporating thermally sensitive porogen molecules. The structural evolution of the films was characterized by FT-IR, XPS, and TGA/RGA, and the mechanical, electronic, and optical properties were characterized by Nano-Indentation, Hg-Probe, and VASE, respectively. Furthermore, using non conventional lithography, we patterned the novel low dielectric constant polymer down to 25 nm, without the need for environmentally harmful solvents or expensive lithography tools.
Back to list
Previous
Next
.jpg_thumb_50.png)
