Design And Optimization Of The Reverse Re-covery Characteristic Of SOI-FRD For Intelli- Gent Power Driver Chip

In recent years, intelligent power driver chip gains an increasing concern as its high efficiency and high reliability. In intelligent power driver chip, Fast Recovery diode works as the freewheel diode of high voltage switch transistor LIGBT (Lateral Insulated Gate Bipolar Transistor). The reverse recovery proper-ties of FRD (Fast Recovery Diode) have significant influence on the whole intelligent power driver chip. At the present, the domestic study of FRD pays more attention on vertical structures, while focus less on the SOI-FRD (Silicon On Insulator Fast Recovery Diode) and its reverse recovery characteristics. There-fore, optimizing the reverse recovery characteristics of SOI-FRD is in an urgent need.First of all, the research status and the dynamic characteristics of fast recovery diode is discussed in this thesis. With the study of the reverse recovery mechanism, a new PT-IDDOT (Irregular Dual Deep oxide Trench with Ptop Layer) FRD structure is proposed. The key feature of the new structure is that, in order to cut down the reverse recovery time, two additional separated deep oxide trenches are added to the n-drift regions to improve the device efficiency. In the meantime, the two additional separated deep oxide trenches can help to trap holes and the Ptop layer can provide holes during reverse recovery, therefore the new thick SOI-FRD structure successfully suppresses waveform oscillation.According to the 2-D TCAD simulation, the reverse recovery time of the proposed structure is 69ns. Comparing with the tranditonal PiN diode, the proposed device brings a 37.5% reduction in trr with no waveform oscillation. The chip probing test results are shown that the reverse recovery time of the new PT-IDDOT FRD is 150ns which meets the application requirements of Intelligent Power Driver Chip.