| 摘要 |
AlGaN/GaN HEMTs are disclosed having a thin AlGaN layer to reduce trapping and also having additional layers to reduce gate leakage and increase the maximum drive current. One HEMT according to the present invention comprises a high resistivity semiconductor layer 20 with a barrier semiconductor layer 18 on it. The barrier layer 18 has a wider bandgap than the high resistivity layer 20 and a 2DEG 22 forms between the layers. Source and drain contacts 13,14 contact the barrier layer 18, with part of the surface of the barrier layer 18 uncovered by the contacts 13,14. An insulating layer 24 is included on the uncovered surface of the barrier layer 18 and a gate contact 16 is included on the insulating layer 24. The insulating layer 24 forms a barrier to gate leakage current and also helps to increase the HEMT's maximum current drive; The invention also includes methods for fabricating HEMTs according to the present invention. In one method, the HEMT and its insulating layer are fabricated using metal-organic chemical vapor deposition MOCVD. In another method the insulating layer is sputtered onto the top surface of the HEMT in a sputtering chamber. |
