Christin Bartsch

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...

Surface Energy and Wetting Behaviour of Plasma Etched Porous SiCOH Surfaces and Plasma Etch Residue Cleaning Solutions

The removal of plasma etch residues by wet cleaning is an alternative or additional process to plasma processes, which are known to degrade low-k and ultralow-k dielectric materials. Besides Cu/low-k compatibility wetting is an important issue for wet cleaning. Surface energy of solid and liquid is the key to understand the wetting behaviour. In this study we examined the energetic character of plasma etched/stripped solid surfaces, etch polymers and several cleaning solutions by contact angle measurements. The results show, that variations of the etching process can heavily change the energetic character of the solid. Calculating the surface energies of solid and liquid provides the possibility to make a prediction if a cleaning liquid will wet the surface which has to be cleaned.