Design and fabrication of micro RF coil for MRI

The design and novel fabrication of micro RF receiver coil with high aspect ratio for miniature magnetic resonance imaging (MRI) system is presented. This micro coil is realized using micro-electro-mechanical system (MEMS) technique combining deep reactive ion etching (deep-RIE) process and copper electroplating. The inner diameter of the fabricated coil is 100 μm, the wire thickness is up to 200 μm, the wire width is approximately 30 μm and the aspect ratio is about 6. On-wafer electrical characterization shows the quality factor is about 4 at 100 MHz, which suggests an alternative method to fabricate metal microstructures with a high aspect ratio.