@article{somashekhar_ying_smith_aldrich_nemanich_1999, title={Hydrogen plasma removal of post-RIE residue for backend processing}, volume={146}, ISSN={["0013-4651"]}, DOI={10.1149/1.1391933}, abstractNote={Reactive ion etching of a patterned silicon dioxide layer leaves behind a uniform fluorocarbon layer which must subsequently be removed. Both surface and via polymeric residues form during the reactive ion etch step and their removal using H 2 -based plasma clean processes is reported here. X-ray photoelectron spectroscopy was used to determine the composition of the residue. Scanning electron microscope images were taken before and after the dry clean treatment to determine the effectiveness of the residue removal process. A radio-frequency-generated hydrogen plasma was used in the dry clean experiments. Power, temperature, and pressure were varied while gas flow was kept constant at 75 sccm and the process time was 5-10 min. The surface residue (on the oxide) was most efficiently removed at 400 W, 450°C, and 15 mTorr when exposed to the plasma for 10 min. The in-via residue was best removed following a 5 min plasma exposure at 100 W, 450°C and 15 mTorr.}, number={6}, journal={JOURNAL OF THE ELECTROCHEMICAL SOCIETY}, author={Somashekhar, A and Ying, H and Smith, PB and Aldrich, DB and Nemanich, RJ}, year={1999}, month={Jun}, pages={2318–2321} }
 @article{wang_aldrich_nemanich_sayers_1997, title={Electrical and structural properties of zirconium germanosilicide formed by a bilayer solid state reaction of Zr with strained Si1-xGex alloys}, volume={82}, ISSN={["0021-8979"]}, DOI={10.1063/1.366043}, abstractNote={The effects of alloy composition on the electrical and structural properties of zirconium germanosilicide (Zr–Si–Ge) films formed during the Zr/Si1−xGex solid state reaction were investigated. Thin films of Zr(Si1−yGey) and C49 Zr(Si1−yGey)2 were formed from the solid phase reaction of Zr and Si1−xGex bilayer structures. The thicknesses of the Zr and Si1−xGex layers were 100 and 500 Å, respectively. It was observed that Zr reacts uniformly with the Si1−xGex alloy and that C49 Zr(Si1−yGey)2 with y=x is the final phase of the Zr/Si1−xGex solid phase reaction for all compositions examined. The sheet resistance of the Zr(Si1−yGey)2 thin films was higher than the sheet resistance of similarly prepared ZrSi2 films. The stability of Zr(Si1−yGey)2 in contact with Si1−xGex was investigated and compared to the stability of Ti(Si1−yGey)2 in contact with Si1−xGex. The Ti(Si1−yGey)2/Si1−xGex structure is unstable when annealed for 10 min at 700 °C, with Ge segregating from Ti(Si1−yGey)2 and forming Ge-rich Si1−zGez precipitates at grain boundaries. In contrast, no Ge segregation was detected in the Zr(Si1−yGey)2/Si1−xGex structures. We attribute the stability of the Zr-based structure to a smaller thermodynamic driving force for germanium segregation and stronger atomic bonding in C49 Zr(Si1−yGey)2. Classical thermodynamics were used to calculate Zr(Si1−yGey)2–Si1−xGex tie lines in the Zr–Si–Ge ternary phase diagram. The calculations were compared with previously calculated Ti(Si1−yGey)2–Si1−xGex tie lines.}, number={5}, journal={JOURNAL OF APPLIED PHYSICS}, author={Wang, Z and Aldrich, DB and Nemanich, RJ and Sayers, DE}, year={1997}, month={Sep}, pages={2342–2348} }