Process Optimization And Fabrication Of Plating Doped Fast Recovery Diode

In recent years,the development of electronic power technology has promoted the continuous expansion of the application market of frequency conversion circuits,automotive electronics,and switching power supplies.In these applications,power diodes,as the most commonly used basic components,play a very critical role.With the development and progress of the technical level,the frequency of switching devices has increased,which has put forward faster requirements for the switching speed of the diode in the circuit,and thus the fast recovery diode was born.At present,in actual production,platinum doping is generally used to reduce the minority carrier life of fast recovery diodes and increase the switching speed of the device.This is because platinum is an ideal recombination center and the cost of the platinum doping process is low,which is suitable for mass production.This thesis first analyzes the platinum energy level theory and lifetime theory to verify the feasibility of platinum-doped technology to control the minority carrier lifetime of fast recovery diodes.Then,the structure principle and main electrical parameter theory of the fast recovery diode are analyzed,and the structure design adopted by the fast recovery diode and the most optimal scheme of the raw material of the fast recovery diode device are determined.Then introduced the manufacturing process of fast recovery diodes,and analyzed and studied the main processes such as high temperature diffusion,platinum diffusion,LPCVD and mesa forming.Through theoretical calculation and comparison of process test results,the production process conditions of platinum-doped fast recovery diodes were adjusted.Determine its process optimization plan,and prepare fast recovery diode samples according to the optimized process plan.Finally,through the analysis and research of experimental process data and sample test data,it is evaluated and confirmed that the fast recovery diode samples prepared by the optimized process have electrical parameters and reliability that meet the design goals of platinum-doped fast recovery diodes in this thesis.Based on the company's existing platinum-doped fast recovery diode production process,this thesis analyzes the relationship between reverse recovery time t_rr,forward voltage drop V_F,reverse breakdown voltage V_BR,and reverse leakage current I_R of the platinum-doped fast recovery diode through experimental research,and the use of lower cost 4-inch N-type Czochralski silicon wafers to replace the epitaxial silicon wafers used by foreign counterparts,The samples prepared in the experiment not only meet the electrical specifications of t_rr?75ns@I_F=0.5A,I_R=1A,I_REC=0.25A;V_F?1.5V@I_F=1A;V_BR?1000V@I₁=5?A;I_R?1?A@V_R=1000V design requirements,it also meets the reliability requirements,and the cost is lower,and it has strong market competitiveness.Through the research on the electrical parameters and process principles of platinum-doped fast recovery diodes,the theoretical knowledge combined with actual production is gradually established,which has certain reference value for the development and design of follow-up fast recovery diodes and other similar products.