Research And Realization Of The CMOS Terahertz Thermal Detector Based On The 0.18-?m Process

Terahertz(THz)wave is a kind of electromagnetic wave located from 0.3 THz to 30 THz,between the spectrum and the millimeter and infrared bands.Because of the low energy,high penetrability,fingerprint characteristics,safety and other characteristics of terahertz waves,it has been extensive developed in military,medical,aerospace and other fields.The most rencent studies of terahertz detectors almost are electronic detectors,which are limited by the cutoff frequency of semiconductor devices and cannot detect the higher frequency bands of terahertz.Therefore,this paper proposes a new CMOS-based terahertz thermal detector that overcomes the problems above.The CMOS terahertz thermal detector proposed in this paper is a structure of "antenna-thermistor-temperature sensing circuit".By adjusting the size of the antenna,it is possible to cover the entire frequency band of the terahertz in theory.The detection process of the detector is divided into three processes: antenna electromagnetic energy absorption,wave-thermal conversion and thermo-electric conversion.The modeling of the detector is built and analyzed by combining the modeling for each process.The detector structure coupled by the optimal loop antenna and NMOS temperature sensing circuit is determined by the model and the chip is designed according to the modeling summarized and measured.The "loop antenna-polysilicon resistor-NMOS temperature sensor" terahertz thermal detector designed in this paper is simulated with the responsivity of 193.88V/W when operating at 2.9 THz,and the equivalent noise power obtained by simulation is 1.4 nW/ ? Hz,which can be verified by the measured responsivity of 180 V/W.The tested result confirmed the correctness of the modeling we built.