GaN high electron mobility transistors with localized Mg doping and Drain Metal Extension

A Magnesium Doped Layer (MDL) under the 2-DEG channel and a Drain Metal Extension (DME) are proposed to provide a new degree of freedom in the optimization between breakdown voltage (BV) and specific-on-resistance (R
_on-sp
) in AlGaN/GaN HEMTs. The surface electric field of the proposed structure is distributed more evenly when compare to the MDL-only structure with the same dimensions. A breakdown voltage of 1390V with specific-on-resistance of 4mΩ·cm
²
was obtained with L
_M
= 1μm, a peak concentration of 8×10
¹⁷
cm
^-3
, L
_pd
= 3μm and a drift region length of 10μm. Comparing with the conventional MDL-only HEMT structure, the MDL-DME is shown to deliver comparable specific-on-resistance while featuring a 54% BV improvement without any area overhead penalty.