Thomas Oszinda

Improved characterization of Fourier transform infrared spectra analysis for post-etched ultra-low-κ SiOCH dielectric using chemometric methods

The structural changes due to post-ash and post-ash treatments on chemical vapor deposited ultra-low-κ (ULK) SiOCH dielectric films were studied by Auger electron spectroscopy (AES) and Fourier transform infrared spectroscopy (FTIR). Changes in the ULK layer with respect to the carbon content were analyzed. For the application of different plasma gases for photoresist removal and further post-clean and anneal treatments first a reduction of carbon was observed. Using AES it was found that the carbon was removed up to ∼140nm. Accompanied with the carbon loss a modification of chemical bonds was observed with FTIR, whereas the analysis of FTIR spectra was improved by means of chemometric methods. A principle component analysis was applied for qualitative analysis, which focuses on changes of infrared vibration peaks. This provides a fast assessment of chemical bond modifications. A partial least square regression was used to correlate the carbon loss with the infrared spectra. It is shown that the regressio...

Characterization of plasma damaged porous ULK SiCOH layers in aspect of changes in the diffusion behavior of solvents and repair-chemicals

The diffusion behavior of different solvents and repair chemicals in a porous SiCOH with pores of ∼ 1,5 nm was studied. It was found for molecule with a size ≤ 1/3 of the pore size the diffusion coefficient (De) depends mainly on the size of the molecule, while a size ≫ 1/3 of the pore size does not show a linear dependency of De on the molecules size. In this regime De is mainly a function of the surface diffusion which depends on the surface energies of the solid and the liquid and adsorption effects. This study show that the porosity and the surface energies influencing the diffusion need to study in order to perform satisfactory cleaning and repair process for ULK dielectric layers.

Aqueous Fluoride Residue Removers for 32 nm and beyond Copper Ultra Low-κ Technologies

Mallinckrodt Baker, Inc. (MBI) has developed an aqueous fluoride-based cleaner (AFC1) that shows improved ultra-low k (ULK) and cobalt tungsten phosphide (CoWP) compatibility over dilute hydrofluoric acid (dHF) and a simple solvent based cleaner (SFC1). Performance and compatibility testing was performed with beaker tests at MBI and on 45 nm wafers by GLOBALFOUNDRIES. Our results indicate that AFC1 may be a good alternative to dHF for future Cu technologies.