A 4.8mW 22nm CMOS Fully-Integrated 60-GHz $3\times 3\times 2$ 3D Frequency-Shift Biosensor Array Using Vertically-Stacked LC Oscillators

Given demands for biosensors that have high spatial resolution and energy efficiency, many frequency-shift bioimaging techniques by detecting electromagnetic with CMOS technology have been proposed. Although the most recent work has accomplished label-free bio-sensing in two-dimension, the label-free bio-imaging two-dimensionally cannot detect some biological phenomena that occur in three-dimension. To tackle this challenge, this paper presents a 3D frequency-shift biosensor array using vertically stacked LC oscillators in 22nm CMOS technology. By combining two techniques for bio-sensing arrays that have been demonstrated, two-dimensional LC oscillators array and stacked LC oscillators array, the 3×3×2 3D frequency-shift with 60GHz can emerge. It enables horizontal and vertical bio-molecule detection and the lowest power operation comparing prior arts. The implemented chip of 0.0026 mm2 achieved horizontally- 60 μm and vertically- 4 μm spatial resolution and 73% fill factor with 4.8 mW under 1.2V.