A Study On Self-heating Effect And Model Of FinFET

The 3D structure of FinFETs has limited heat dissipation compared with the planar MOSFET.The FinFET has poor heat dissipation conditions due to the structure of the Fin.New channel materials also reduce thermal conductivity.Therefore,the self-heating effect is more obvious in the FinFET than in planar technology.The temperature rise of the device can reach several tens of degrees in circuit applications,which will change the actual temperature of the device,shorten the service life of the device,and affect the performance and reliability of the device.The carrier saturation rate and mobility of device are reduced at higher temperature,so that self-heating is harmful to the operating device.Self-heating can also result in non-uniform temperature distribution,timing errors and reduced reliability.Model is the bridge between the device and the circuit design,so it is very important to characterize the self-heating effect of the device and dstablish the relevant model.In this thesis,a small-signal model of FinFETs is established.The theory and derivation method of the two-port network parameters for active devices with self-heating effect are studied.According to this theory,a small-signal model of FinFETs that can characterize the self-heating effect is established.Finally,the theory and model are verified by the actual test data of FinFET.The main work of this thesis is as follows:(1)The structure,working mechanism,manufacturing and performance of FinFETs are described.In addition,the self-heating effect of the device is introduced in detail.(2)A small signal equivalent circuit model of FinFETs is established based on the study of the traditional small signal model of MOSFETs and taking into account the substrate and external resistance parasitics.A method for extracting model parameters is given.(3)A model method for characterizing the self-heating effect of FinFETs is proposed through theoretical analysis.Based on this theory,a small-signal model of FinFETs that can characterize self-heating effect is established.At the same time,the method of extracting model thermal parameters wal proposed.(4)The small-signal model parameters and thermal network model parameters of FinFETs are extracted based on the network parameter test data.By comparing the simulation and test data of the model,the accuracy and precision of the small signal model of FinFETs with self-heating effect proposed in this thesis are verified.