Masuichi Eguchi

Stress in polyimide films having a rodlike molecular skeleton formed on a silicon substrate

Stress measurements of polyimide films deposited on silicon wafers were performed in situ during the curing and cooling cycles. The films were constructed from a single polyimide having a rodlike molecular skeleton. The stress in the film varied with film thickness. The stress before curing decreased with increasing film thickness. On the other hand, the stress after the thermal cycle increased with increasing film thickness, resulting from the increasing thermal coefficient of expansion. This phenomenon was thought to be caused by the decrease in the degree of the in‐plane orientation of the polyimide molecular chain with decreasing stress before the curing process.

Stress measurement Of BPDA/PDA Polyimides From Poly(Amic Acid) And Photosensitive Polyimide Precursors On Silicon

The intrazeolite chemistry of the two germylene complexes Cl 2 (THF)GeM(CO) 5 (M = Mo, W) was studied with x-ray absorption spectroscopy (Ge, Mo, W edge EXAFS) and in-situ FTIR/TPD-MS techniques. The slightly decarbonylated GeMo complex interacts with the framework of NaY zeolite at room temperature and retains the Ge-Mo bond up to about 100° C. In proton-loaded HY zeolite, framework interactions increase at elevated temperature, and the attached complex retains the Ge-Mo bond up to about 120° C. The Ge-Mo bond is cleaved at higher temperatures. MoC1 x and Mo-Mo species are formed in NaY and HY zeolite, respectively, while GeCl x fragments are anchored to the zeolite framework. The complex Cl 2 (THF)GeW(CO) 5 retains all five CO ligands up to about 100° C in both NaY and the proton form. Detectable anchoring occurs at room temperature in NaY and at about 80° C in the proton form. WC1 x species are formed upon cleavage of the Ge-W bond at higher temperatures.