Research On The Technology And New Structure Of Terminal In The High Voltage Power Devices

High voltage power device is the foundation and core of power electronics technology, which has a high voltage, high current density of conduction characteristics, improving the ability to withstand the power of the device is one of the most important device design tasks. Design of junction termination has a great effect on the performance of high voltage power device, therefore, this paper studied the junction termination and drew some conclusions, the main contents and conclusions include the following:1. This article described what was terminal technology, the present situation of the research at home and abroad, the three factors influencing the device breakdown voltage and the four(including field limiting ring technology, field plate technology, junction termination extension technology, bevel edge terminal technology) typical junction terminal technology theory, and finally it analyzed the influence of the terminal structure on device.2. Researched and compared two types of terminal structure and reverse simulated the terminal structure of chips. Firstly, compared the extending type terminal and truncated terminal, we can found that the former occupied a large area terminal but the process is relatively simple, and the later occupied by the terminal area is smaller but the process is relatively complex. Then considering the needs of the project, according to the SEM test results of Fuji chip to realize reverse simulation by Sentaurus TCAD software and analyze its terminal structure. SEM results showed that the terminal consisted of common field limiting ring and field plate, but the simulation results showed that it would achieve the desired breakdown voltage by only field limiting ring structure. Finally, studied a failure chip that researched and developed by the company, based on the data provided by company, we used Sentaurus TCAD to simulate. Analysis of simulation results showed the flow sheet is failed, the main reasons are that the junction is much deep and the distance between rings is too small. By optimizing the distances between rings, the simulation results achieved the ideal results.3. A new study of the terminal structure, the terminal has a P- buried layer and the trench is filled by a different K material, simulation results showed that the high-K material is suitable for filling shallow and wide trench, but the low-K material is suitable for deep and narrow trench. Introducing P- buried layer will improve the breakdown voltage whether it is shallow and wide trench or deep and narrow trench.4. Firstly, finished chip corrosion, readied for landscape observation of the chip and the testing in SEM. Then assisted and summarized a set of failure analysis process. Finally, discussed the main work of this paper and the follow-up recommendations.This study covered the whole process of chip junction termination design, focusing on reverse analysis of chips and the trench junction termination structure with P- buried layer. The next step is to apply this structure in FS-IGBT and achieve good compatibility with the cellular. This type of junction termination is universal and it suits many semiconductor power devices, such as IGBT. What we have done may contribute to the future design and manufacture of junction terminations.