Blocking voltage design consideration for deep trench MOS gate high power devices

This paper describes, for the first time, the possibility of realizing a deep trench gate device with high blocking voltage. For a trench gate device with 4.5 kV blocking voltage, the influence of the trench gate geometrical parameters on the breakdown voltage is analyzed using the two-dimensional breakdown voltage simulator TONADDE II B. The breakdown voltage decreases as the p-base width increases. On the other hand, the breakdown voltage increases as the trench gate width increases. The breakdown voltage is independent of the trench gate depth from the p-n junction in the region from 8 to 20 μm. Assuming that the trench gate width is 1 μm, the maximum p-base width to realize 4.5 kV blocking voltage is about 6 μm. Therefore, it is concluded that a 4.5 kV blocking voltage of a deep trench gate device is attainable by the present process technology