Constructing drain surrounded double gate structure in AlGaN/GaN HEMT for boosting breakdown voltage.

AlGaN/GaN high electron mobility transistors (HEMTs) play an important role in the field of high-voltage and high-frequency power devices. However, the current collapse effect of the HEMTs under high voltage greatly limits the development of AlGaN/GaN HEMTs. In this work, a breakdown performance enhanced drain surrounded double gate (DSDG) AlGaN/GaN HEMT is investigated. This structure has two separate gates located on the right and the left of the drain. The optimized off-state characteristics are analyzed by the Sentaurus TCAD simulation tool. The additional gate contributes to restraining the movement of electrons injected by the source therefore reducing the source-to-drain punch-through current. Moreover, the energy band pulled up by the relatively low voltage of the right gate helps to alleviate the drain induced barrier lower (DIBL) effect. As a result, DSDG-HEMT could postpone the breakdown by approximately 100 V through suppressing buffer leakage.