Terahertz Metamaterial Absorbers Implemented in CMOS Technology for Imaging Applications: Scaling to Large Format Focal Plane Arrays

Abstract

We present the design and fabrication of terahertz (THz) metamaterial (MM) absorbers and their monolithic integration into a commercial CMOS technology along with its respective readout electronics to produce a low-cost, uncooled, and high resolution THz camera. We first describe the work done on single band and broadband MM absorbers on custom substrates, then progress with a description of the integration of such resonators into a six metal layer 180 nm CMOS process and its coupling with two types of microbolometer sensors: Vanadium oxide (VOx) and silicon (Si) pn diode. Additionally, we demonstrate the integration of the THz sensors with readout electronics to form a monolithic THz focal plane array (FPA). Reflection images of a metallic object hidden in a manila envelope are recorded using both the VOx and Si pn diode detectors, demonstrating the suitability of the technology for stand-off detection of concealed objects. Finally, we present the current work toward scaling this technology into a 64 × 64 FPA.