Optimal Design And Experiments Of Lateral High Voltage Device With Complementary Homogenization Field Voltage Sustaining Layer

In the design of high-voltage power devices,there has been a paradoxical relationship between high breakdown voltage VB and low specific on-state resistance Ron,sp.In order to increase the breakdown voltage while reducing the specific on-state resistance,researchers have designed a variety of voltage sustaining layer structures.From the lightly doped drift region to the reduced surface field RESURF(REduce SURface Field)technology,and then to the SJ(Super Juction)technology,the voltage sustaining layer has undergone the development of resistive to junction type.The proposed HOF(Homogenization Field)voltage sustaining layer breaks through the PN junction depletion mode of resistive and junction type voltage sustaining layers,divides the device voltage into n HOF cells equally,and introduces a new MIS(Metal Insulator Silicon)full domain depletion mechanism.In order to further optimize the surface electric field and depletion continuity of the HOF,thesis proposes a new complementary depletion homogenization field C-HOF(Complementary Homogenization Field)sustaining layer and applies it to a Lateral Double-Diffused MOSFET(LDMOS).The main research contents and results of this topic are as follows.First,a novel complementary depletion homogeneous field C-HOF sustaining layer is proposed.Structurally,the intrinsic PN junction between the P-top layer and the N-type drift region and the multiple complementary depletion of the P/N-MIS constitute the basic structure of the C-HOF.The periodically distributed HOF cells distribute the voltage drop on the drift region uniformly on each cell,so that the electric field in each HOF cell is periodically distributed to realize the uniform field sustaining;in the depletion mechanism,during the reverse sustaining,the MIS in terms of depletion mechanism,the equivalent charge in the metal electrode achieves double charge self-balancing with the dominant ionized negative charge and the dominant ionized positive charge in the silicon layer during the reverse sustaining voltage,which can achieve depletion continuity at high concentrations.Then,LDMOS devices with C-HOF sustaining layer are proposed.The C-HOF sustaining layer is applied to the transverse power device,and the simulation shows that the C-HOF device has higher sustaining voltage concentration range and stronger depletion continuity compared with N-HOF,and the C-HOF LDMOS has more uniform surface electric field.LDMOS devices,and the layout design and mapping were carried out.Finally,the device design is experimentally verified.Based on a company’s 0.5μm BCD platform for C-HOF LDMOS device fabrication,experimental results show that the optimized device characteristics at 400 V level are breakdown voltage VB=426 V and specific on-resistance Ron,sp=19.7 mΩ·cm~2,and the specific on-resistance is 42.8%lower than the theoretical limit of the conventional Triple RESURF device under the same breakdown voltage condition.The experimental optimal value of the device FOM reaches 9.2 MW/cm~2.