Batch fabrication of micro-coils for MR spectroscopy on silicon

Abstract

A process for batch fabrication of low-cost microcoils for magnetic resonance (MR) spectroscopy of clinical biopsy samples is demonstrated. Conductors are fabricated on oxidized, intrinsic silicon substrates by electroplating metals inside a deep photoresist mould. Through-wafer deep reactive ion etching (DRIE) is used to define precise sample volumes and stencil cuts around each die, and dies are separated by snap-out. Single- and multiple-coil (Helmholtz-type) sensors are formed, by stacking parts on silicon baseplates. MR imaging and spectroscopy are both demonstrated on model samples, with high SNR