Research On Key Techniques Of Terahertz Detection System Chips

Terahertz(THz)electromagnetic waves are generally composed of electromagnetic waves with frequencies of 0.1 THz–10 THz,which locates between millimeter waves and infrared light waves.Terahertz waves have many special properties and have great application potential in national security,high-frequency communication,human body perspective,security imaging,production inspection,art analysis,and so on.Terahertz detection technology is a major component of terahertz technology,and is one of the important foundations of various terahertz applications.At present,no matter in wireless communication or detection imaging,the low transmitting power of THz source and the poor sensitivity of detector are the technical bottlenecks restricting the development of THz technology.The transmitting power can be increased by the technology of electric vacuum traveling wave tube,and the receiver noise can be reduced by using low-temperature refrigeration.However,these technologies need complex external high-pressure,low-temperature Dewars and other equipments.It is a world-class problem in the field of terahertz that how to get high-power terahertz source and high-sensitivity detector at room temperature.The theory and experiment of RTD terahertz wave source are studied.The design and the tapeout of terahertz detector is realized with UMC 0.18-?m CMOS processing.The innovative work of this paper is as follows:(1)After two tape-outs,a planar RTD device in the THz frequency band was realized by Boron ion implantation.According to the resistance compensation effect,the function of 8 DC parameters of the first tape-out RTD chips with pulsed T-profile annealing times or total annealing time are calculated and analyzed.The RTD penetration probability model has been revised to make up for the shortcomings of the peak value of the current DC physical parameter model,improve the accuracy of the model,and make the fitted function image closer to the measured curve.This thesis clearly explained the principle of apparent positive resistance.(2)A THz source of RTD with graphene two-dimensional electron fluid(2DEF)is proposed.The power self amplification is realized by the negative differential resistance generated by RTD and graphene 2DEF.In this thesis,two ultra wideband graphene antennas are proposed for the first time to realize the transmission of high-order THz harmonics,and a distributed parameter equivalent circuit model is established.The output power of 22 m W at 1.9 THz and 20 m W at 6.1 THz is obtained by simulation.In theory,the output power of the system is two orders of magnitude higher than that of the traditional RTD terahertz source.Furthermore,the RTD oscillator has the potential to oscillate at 50 THz with a matching antenna.(3)The terahertz detector is analyzed in detail.A CMOS terahertz detector chip designed and was implemented by UMC 0.18-?m standard CMOS process.The chip has two high gain rectangular inset-feed patch antennas,two NMOSFETs,two on-chip amplifiers,and a catadioptric horn-like lens.The detector is tested at 250 GHz and achieves a responsivity up to 95.67 kV/W,a NEP of 12.8 pW/Hz^0.5,and a total gain of10.67 dB for the antenna and lens by calculation,reaching the international leading level.(4)A neuron transistor circuit based on NDR theory is designed and implemented by UMC 0.18-?m standard CMOS technology.This neuron transistor verifies the feasibility of NDR logic circuit,and realizes the basic functions of biological neurons("weighted sum and threshold"function).The neuron MOS transistor was analyzed at maximum frequency of 10 k Hz,and has extremely low power consumption,<10^-4?W.It can be combined with terahertz detector to realize on-chip processing of detector output signal.It is a new application of general artificial intelligence in the field of image processing.