Performance Optimization Of High Voltage LDMOS Power Devices Based On RESURF Technology

In recent years,with the sharp increase in the market demand of China and the strong support of the government,there is a rapid development in IC industry,greatly shortening the gap with the counterparts around the world.As an integrated power device,Lateral Double Diffused Metal Oxide Transistor(LDMOS)has numerous advantages;for instance,high breakdown voltage,low specific on-resistance as well as compatibility with CMOS and BCD processes.Therefore,it have a pivotal position in various fields such as lighting system drive,smart car electronics,switching power supply,etc.However,the specific on-resistance of the high-voltage LDMOS device increases with the increase of the breakdown voltage at a speed of 2.5 power,which results in a great limitation of its application in the high-voltage field.As the power device needs to withstand higher withstand voltage value,the specific on-resistance(R_on,sp)of the device is also higher and higher,and the power consumption generated in the circuit therefore increasing,which is contrary to the slogan of sustainable development and low-carbon environmental protection.So the development of an LDMOS device with high withstand voltage and low on-resistance is of great significance to the development of contemporary science and technology.In this paper,the performance optimization of 500 V high voltage LDMOS devices based on 0.35?m technology is studied by the combination of TCAD simulation.The goal is to make the breakdown voltage greater than 500 V and the on-resistance less than 7.5?·mm².In order to meet the index of high withstand voltage and low on-resistance of integrated circuits,various improved LDMOS devices have emerged.This paper improves the performance of LDMOS devices from the perspective of new structures.Five kinds of step-optimized high-voltage LDMOS devices are proposed:ordinary RESURF LDMOS structure,RESURF LDMOS structure with field limiting ring,RESURF LDMOS structure with N-type and P-type double-doped top region,RESURF LDMOS structure with HVBN region,and RESURF LDMOS structure with PB buried layer.Among them,the RESURF LDMOS device with PB buried layer has a withstand voltage of 593 V and a specific on-resistance as low as 7.1?·mm².Compared with the ordinary RESURF LDMOS device,the withstand voltage is increased by 52%,and the on-resistance is reduced by 15%,which achieves the optimization goal.