Hot Carrier Reliability of High Voltage MOSFET for Different Lightly Doped Drain Doping Concentration

Abstract

In the thesis we study the reliability analysis of different lightly doped drain (LDD) doping concentrations device and mainly research the characteristics of the high voltage metal-oxide-semiconductor field effect transistor (HV-MOSFET) devices with different LDD doping concentrations and the device degradation after the hot carrier stress and the prediction and discussion of device lifetime First the application and the advantages of HV-MOSFET were illustrated This thesis motivation of high-voltage device with different LDD dosage was presented For the different LDD dosage caused the phenomenon of different substrate current (ISUB) magnitude so for this aspect will be more detailed study In this thesis the mechanism of substrate current generation hot carrier effect and reliability analysis were performed Also the use of technology computer aid design (TCAD) simulation to analyze the internal electrical characteristics of devices After the introduction of the basic characteristics the structure of the devices defined the internal region of the device and the measurement setup and methodology were also described Including device current ID-VG ID-VD substrate current ISUB-VG off-state breakdown voltage VBD and sheet resistance RS This study will mainly investigate the hot carrier reliability analysis of different LDD dosage devices and compare the lifetime of devices with different LDD dosage This thesis will introduce our measurement setup of hot carrier stress and bias conditions and the TCAD simulation was used to confirm the measurement data The results show that the device with higher LDD dosage has a longer lifetime but the substrate current also has a high trend The TCAD was used to simulate the current flowline and put the interface state (Nit) to different devices in the most serious region of the impact ionization rate and to explain the higher LDD dosage of the device has a longer lifetime but also has a large substrate current phenomenon

Date of Award	2017 Jun 30
Original language	English
Supervisor	Jone-Fang Chen (Supervisor)