Uncooled CMOS 2.5THz detector comprising a metamaterial absorber loaded with resistors and a PTAT sensor

Abstract

Terahertz (THz) detectors have shown a multitude of important prospects in the fields of THz technology. This paper presents an innovative metamaterial (MM) absorber combined with a temperature sensor, leading to a new type of room-temperature CMOS THz thermal detector. The innovative MM absorber implemented in the 55 nm CMOS process is presented across the THz frequency range for the first time. It is based on a loop resonator loaded with four polysilicon resistors for higher responsivity. The theoretical analysis, multi-physics simulations and experimental validations of the detector are presented in detail. Experimental results of detectors loaded with polysilicon resistors and without polysilicon resistors are obtained at 2.5 THz for comparison. The proposed detector loaded with resistors shows a DC responsivity of 57.1 V/W and a noise equivalent power (NEP) of 0.21 μW/√Hz. The detector without resistors achieves a DC responsivity of 20.18 V/W with a NEP of 0.59 μW/√Hz at 30 Hz. The presented novel detector could be easily scaled to array formats, showing significant potentials toward room-temperature, compact, inexpensive, easy-integration and high-yield THz detection systems.