{"id":1463,"date":"2010-07-08T10:32:34","date_gmt":"2010-07-08T14:32:34","guid":{"rendered":"https:\/\/wpmu2.mit.local\/?p=1463"},"modified":"2010-07-08T10:32:34","modified_gmt":"2010-07-08T14:32:34","slug":"gan-power-electronics","status":"publish","type":"post","link":"https:\/\/wpmu2.mit.local\/gan-power-electronics\/","title":{"rendered":"GaN Power Electronics"},"content":{"rendered":"

Our group is focusing on the development of GaN power transistors grown on Si substrates. Si substrates are preferred to SiC due to their much lower cost; however, GaN devices on Si substrates suffer from lower breakdown. To increase the breakdown voltage of AlGaN\/GaN HEMTs grown on Si substrates, we have developed a new technology based on the removal of the original Si substrate and subsequent transfer of the AlGaN\/GaN HEMT structure to an insulating carrier wafer (e.g., glass or polycrystalline AlN) [1<\/a>]<\/sup>. By applying this new technology to standard AlGaN\/GaN HEMTs with a total epitaxial thickness of only 2 mm grown on a Si substrate, AlGaN\/GaN HEMTs transferred to a glass substrate with breakdown voltage above 1500 V and specific on-resistance of 5.3 m\u03a9\u00b7cm2<\/sup> has been achieved, as shown in Figure 1.<\/p>\n

The standard AlGaN\/GaN HEMTs are depletion-mode (D-mode) devices. However, enhancement-mode (E-mode) devices are highly desirable for power electronics as they can greatly simplify circuit designs and improve system reliability. We have recently demonstrated a new AlGaN\/GaN E-mode HEMT based on a dual-gate structure [2<\/a>]<\/sup>. The device utilizes an integrated gate structure with a narrow gate controlling the threshold voltage and a long gate supporting the high voltage drop from the drain. Using this new dual-gate technology, AlGaN\/GaN E-mode HEMTs grown on a Si substrate have demonstrated\u00a0 a high threshold voltage of 2.9 V with a maximum drain current of 434 mA\/mm and a breakdown voltage of 643 V (Figure 2).<\/p>\n