Design On 100V Lateral Fast Recovery Diode Based On The Silicon Process

In order to give full play to the high-frequency switching advantages of Gallium Nitride(GaN)power devices,the operating frequency of the gate control driver chip should also be improved accordingly.Since the bootstrap diode characteristics affect the charging speed of the bootstrap circuit in the gate driver chip and thus limit the operating frequency of the driver chip,it is important to design and optimize a bootstrap diode with good switching characteristics.This thesis first analyzes the working principle of the traditional bootstrap lateral fast recovery diode.Through simulation analysis,it is pointed out that the diode drift region length and hole injection efficiency are important reasons for the reverse recovery characteristics.Then,the existing deep trench technology and Schottky technology are deeply analyzed.It is found that although the above two technologies can improve the reverse recovery characteristics,there are problems such as difficulty in process preparation and large leakage.Based on the above research,this thesis proposes a novel variable-doping bootstrap lateral fast recovery diode,which uses a doping method to increase the anode concentration in the anode region of the diode,and reduces the forward conduction characteristics and breakdown characteristics.Diode anode area;secondly,by adjusting the anode doping injection window to control the injection efficiency of the diode anode,adjusting the diode catenary carrier distribution to a linearly graded carrier distribution,greatly reducing the reverse recovery peak current and reverse recovery time,and the process is simple and the leakage is small.The simulation results show that: in this thesis,the design of variable doping bootstrap transverse fast recovery diode,the breakdown voltage is 172 V,the forward voltage drop is 0.76 V when the forward current is 0.1A,compared with the traditional structure,reverse recovery time shortened from 41 ns to 22 ns,improved by 45%,can satisfy the working frequency of 1MHZ GaN power device driver chip needs.