| 摘要 |
PROBLEM TO BE SOLVED: To provide an improved HEMT formed from a GaN material system which has reduced gate leakage current.SOLUTION: A HEMT device is formed of a GaN material system. One or more GaN based materials 44, 48 and 49 are layered and etched to form a gate mesa 50, and step discontinuities 52 and 54 define source and drain regions. The step discontinuities 52 and 54 are back-filled with an insulating material 56, such as silicon nitride (SiN), a flat surface is formed relative to the source and drain regions, and gate metal 58 can be formed flatly. By back-filling the source and drain regions with an insulating material, leakage currents between a gate and a source and between the gate 58 and a drain 62 are greatly reduced. In addition, current constrictions resulting from the deposition of gate metal 58 over the step discontinuities 52 and 54 are virtually eliminated. |
