Integration of Piezoelectric Nanowires Matrix onto a Microelectronics Chip

Our work focuses on a new technology dedicated to very high-resolution fingerprint sensors based on a matrix of interconnected piezoelectric ZnO nanowires (NWs), reaching level 3 of fingerprint details (pores, ridge edges). Using the local deformation of an array of individually contacted piezoelectric NWs, we aim at reconstructing an image from the generated potentials, whose amplitudes are proportional to the NW displacement. We focus on one possible configuration where the ZnO charges are collected with top-bottom contacts. Heterogeneous integration of nano-piezotronic objet onto microelectronics chips, considering process compatibility at the wafer scale, contacting and encapsulation steps are among the CEA-Leti fabrication challenges. We report on the results of chip processing in clean-room and on the successful growth of interconnected ZnO nanowires on chip.