Integrated RF micro-coils on porous silicon

Porous silicon (PS) of up to 400 /spl mu/m with high porosity (70%) has been studied to integrate high-performance micro-coils on heavily doped Si substrates (7-15 m/spl Omega/cm). 2 /spl mu/m-thick Au spiral inductors with L/spl sim/15 nH were fabricated; they demonstrate a quality factor Q up to 8 in the 0,1 to 2 GHz frequency range. Substrate loss is greatly lowered, down to /spl sim/12 /spl Omega/ at 400 MHz, which offers attractive potentialities for high resolution RMN (80-500 MHz) spectroscopy integrated devices.