Reduction of Sodium Migration in Polymers by Addition of 15-Crown-5 Ether as Getter Substance

Abstract

Already small amounts of ion contamination within sensitive areas of high voltage transistors can cause severe damage to semiconductor devices. Therefore, it is of utmost importance to hinder mobile ions from reaching critical regions (e.g., the gate oxide layer). To protect semiconductor devices from environmental influences and contamination, polymers are used for chip encapsulation. Reduction of ion migration within these polymers can increase the reliability of the semiconductor device. Crown ethers are well known to form stable complexes with alkali cations. Within this work the influence of 15-crown-5 ether on the sodium migration in poly-methyl methacrylate and polyimide will be evaluated by means of ion conductivity measurements.

Study on the Ion Migration of Silver Ions from Aqueous Solution in Epoxy-Based Molding Compounds by TOF-SIMS Measurements

“…The initial 5-10 data points of each measurement are unreliable due to the roughness of the sample surface and typical surface effects of TOF-SIMS measurements. As shown in previous publications,, 19,20 the diffusion coefficient in molding compounds can be determined by fitting with the inverse error function (Equation 1) by Crank 21 to the graphs (atoms/cm 2 vs. cm). An example fit can be seen in Fig.…”

“…-SH, -NH 2 or -OH) may have an impact on Ag mobility. 19,27 Functional groups are mostly electron pair donors and can therefore alter primarily the water uptake and secondarily the pH-value. Unbound valence electrons may interact directly with available ions.…”