Structure Design Of Epitaxial Layer For 150V VDMOS Device

As one of the new generation of integrated power electronic devices,VDMOS is important electronic components and indispensable to the modern life,its application areas include common household appliances,automotive electronic systems,smart grids,and various industrial equipment,power locomotive,aerospace,shipbuilding system.And at the present,all domestic power VDMOS device is made with silicon epitaxial wafer,so the performance of the VDMOS device is closely linked to the high-quality silicon epitaxial materials.At the same time,the detailed design of silicon epitaxial wafer structure for the specific device can improve its performance and the success rate of the development,which is urgent need for epitaxial manufacturers,therefore the research has a very high value.In this thesis,firstly the basic structure of epitaxial material for VDMOS device is introduced,and the design project of the epitaxial layer structure is given.Then,by Tsuprem4 and Medici simulation software platform the VDMOS devices made of different epitaxial layer structure are simulated and optimized.The simulation analysis of epitaxial layer resistivity and its uniformity affected on device performance is given to point out that there exists a standard linear relationship between the epitaxial layer resistivity and the breakdown voltage devices and on-resistance.The simulation analysis of epitaxial layer thickness and its uniformity affected on device performance is given to turn out that the epitaxial layer effective thickness must be greater than critical penetration thickness.The simulation analysis of epitaxial layer transition depth morphology affected on device performance is given to indicate that the device process is an important factor influencing the transition depth analysis and enriches the silicon epitaxial layer transition depth theory.In this thesis,the problem of epitaxial resistivity consistency is solved by the As substrate material research.Based on the theoretical optimal epitaxial layer parameters,in combination with the corresponding relation of VDMOS device features,a 150 V VDMOS device of silicon epitaxial material is designed and the best device performance is obtained by simulation.Finally,from the perspective of quality control,the growth process of the designed epitaxial layer is given.