Ulrich Schmid

Silver Metallization on Porosified LTCC Deposited by Pulse Plating Technique

Present microelectronic devices especially when including high frequency applications are in need of highly integrated metallization technologies. Silver is considered as a future interconnection material for such devices and systems due to its low bulk resistivity of about 1.6 μΩ·cm at 20°C. Conventional thick film metallization techniques on low temperature co-fired ceramics such as screen printing are only partly capable of meeting the requirements in terms of lateral resolution and precision. Furthermore, on advanced surfaces such as porosified composite LTCC, also thin film metallization techniques (e.g. sputtering) meet their limits due to a poor coverage and hence, a low electrical conductivity. In this study, it is shown, that bipolar pulse plating of silver is capable of bridging the pores of the surface of the porosified substrate without penetrating them. The plated metallizations feature very fine grains with an average diameter of approx. 90 nm and a maximum up to 250 nm. The film resistivity...