Research And Application Of Random Telegraph Noise In Nano-Scale Field-Effect Transistors

In the development of human society in the past fifty years,semiconductor technology has played a pivotal role,which has promoted human society to rapidly enter the information age and is one of the cornerstone technologies of modern human society.Over the past fifty years,the size of semiconductor devices has been scaling down along Moore’s Law,the number of field-effect transistors on a single microprocessor chip has grown from the earliest few thousand to tens of billions today,and highly integrated semiconductor devices have profoundly changed the history of human development and everyone’s lifestyle.As the most common semiconductor device in practical applications,field-effect transistors are the core devices in static random access memory,dynamic random access memory,and central processing unit.With the development of semiconductor technology in new materials,new structures,and new principles,the size of field-effect transistors continues to decrease,but at the same time,there are more reliability issues,and some small disturbances will make semiconductor chips fail.There are many reliability issues in nano-scale devices,including leakage current,bias temperature instability,hot carrier injection,and random telegraph noise.This article focuses on the random telegraph noise in the reliability issues of nano-scale field-effect transistors.International research on random telegraph noise began in the late 1980s,and in recent years,as the size of devices has been further reduced,parameters related to field-effect transistors,such as channel current,threshold voltage,etc.,have become more sensitive to disturbances.Channel charge capture and emission caused by defects in the gate dielectric layer in field-effect transistors can cause transient changes in the channel current,that is,random telegraph noise,which will have a huge impact on the normal operation of the circuit.In this paper,the properties of random telegraph noise in nano-scale field-effect transistor are systematically studied,and a true random number generation scheme based on random telegraph noise is proposed by using its physical randomness.The first part of this paper is a systematic study of the basic properties of random telegraph noise in nano-scale field-effect transistors under the fixed gate voltage,including the time constant statistical distribution,gate voltage dependency,drain-source voltage dependency,temperature dependency,defect distribution,frequency dependency,and in-depth analysis and understanding of the results.The second part of this paper extends the research of random telegraph noise through two unfixed gate voltage measurement methods(dual-point method and periodic AC voltage method).Due to the detectable window of random telegraph noise under fixed gate voltage,the properties of random telegraph noise in a wide range of gate voltage cannot be obtained,which limits further exploration of the random telegraph noise.In this paper,the current amplitude fluctuation characteristics of random telegraph noise in a large range of gate voltage outside the detectable window are studied based on the dual-point method,and the periodic AC voltage method is used to study the time constant characteristics of random telegraph noise outside the detectable window.The third part of this paper proposes a true random number generation scheme based on the randomness of random telegraph noise under unfixed gate voltage.In the process of studying the effect of the periodic AC voltage on the random telegraph noise,this paper found that the pre-voltage applied before the measurement voltage will make a clear change in the state of the defect,if the pre-voltage is low,the defect will be in the release state when the measurement voltage is first applied,that is,the amplitude of the random telegraph noise will be at a high value,and drop after a period of time,which is closely related to the time constant of the device after the measurement voltage is applied,and its value is random.Based on this randomness,true random numbers can be generated by determining the level of the measured current value under certain conditions.Through the systematic study of the random telegraph noise in nano-scale field-effect transistors,this paper provides the basic core data for clarifying the mechanism of random telegraph noise and exploring the strategy of suppressing the noise,and provides important measurement methods for in-depth study of random telegraph noise in nano-scale transistors;beyond that,this paper proposes a noise-based true random number generation scheme by using the physical randomness of random telegram noise,which provides a new idea for expanding the application of random telegraph noise.