Masato Sone, Tso-Fu Mark Chang and Kazuya Masu
Scientific Tracks Abstracts: Biol Syst Open Access
The flexible properties of polymeric material make bio-MEMS promising candidates for the next generation of micro devices. However there have been many difficulties to overcome in fabrication process. Supercritical carbon dioxide (sc- CO2) is generally viewed as a replacement for harmful organic solvents used in extractions, separations, chemical reactions, molding, and many other applications because CO2 is non-polar and the tunable physical properties between a gas and a liquid. Especially for application of sc-CO2 in fine wiring technology, transfer of materials into and out of fine nano-space can be improved to allow proper cleaning and complete filling of the nano-spaces. Thus we have studied an application of sc-CO2 into integration of bio-compatible MEMS. We examined sc-CO2 for washing of photoresist pattern on substrate and completed washing the pattern with strengthening the adhesion. We have also proposed a washing process using emulsion of sc-CO2 in water for eliminating the resist pattern from the substrate. We now have studied metalizing of gold on polyimide, which is composed of catalyzation process on/into polymer using sc-CO2 of Pd-organic complex and electroless plating using sc-CO2 emulsion (ELP-SCE), which is composed of an aqueous electrolyte, sc-CO2, and a surfactant. ELP-SCE enabled the penetration of Pd into deep-inside of polymer. So Pd seed-layer can be deposited on polyimide. We also have studied gold electroplating method using sc-CO2 emulsion (EP-SCE). Metal film obtained by this technique was uniform and without pinhole, because sc-CO2 has low viscosity and compatibility of hydrogen. Thus, we have proposed and examined a void-free gold wiring on the Pd seed layers/polyimide. This method is applicable into bio-compatible MEMS.
Masato Sone completed his Doctors degree of Engineering at the age of 28 years old at Tokyo Institute of Technology. He worked as a Researcher in Nippon Oil Company from 1996-2000. He was an Assistant Professor and then a Research Associate Professor at Tokyo University of Agriculture and Technology from 2000 to 2005, and he got the position of Associate Professor at Tokyo Institute of Technology from 2005 until present time. He has published more than 110 papers in scientific journals. His majorities are microelectronics, surface finishing, chemical engineering, liquid crystal and polymer science. His recent topic has been novel nano wiring process using supercritical carbon dioxide for integrated circuit technology.