An Experimental Demonstration of GaN CMOS Technology

An E-Mode p-Channel GaN MOSHFET for a CMOS Compatible PMIC

“…Compared to a of , reported by R. Chu et al [5] for their fabricated p-channel device, a significantly smaller is the result of much smaller on-resistance and load capacitor of and compared to their values of and estimated , respectively from their work. Our smaller onresistance is the result of higher on-current facilitated by lower access resistances and depletion beneath the channel, facilitated by the AlGaN cap.…”

“…In this work, the dependence of the electrical characteristics of a p-channel GaN MOSHFET on gate length is investigated on a platform that is fully compatible with a power device in PSJ technology. The substrate parameters are closely aligned to those reported in [5], [15]. Subsequently the switching speed of the inverter is evaluated.…”

“…The next challenge for GaN power devices is integration of the gate driver and power device, to reduce the parasitic loop inductance and facilitate high frequency switching in converters [4], [5]. Additionally, complementary logic with normally-off (E-mode) operation is preferred to reduce static power consumption, simplify circuitry and for fail-safe operation [6].…”

“…On the other hand, less attention has been paid to p-channel devices due to the low mobility of holes in GaN ( at room temperature [14]), which leads to poor on-current and switching speed. E-mode operation of p-channel HFETs has been attempted via recessed gate [5], [15], [16], an Al2O3 separated gate on a GaN/AlN heterostructure [17], or reducing the polarization charge in GaN/AlInGaN/GaN heterostructures by adjusting the Al or In mole fraction [18]. However, except for the recessed gate approach, the others have similar challenges associated with optimisation of the substrate layers for all other devices on the platform.…”

Extending the bounds of performance in E-mode p-channel GaN MOSHFETs

“…This high mobility, naturally occurring, conducting channel lends itself more easily to high performance depletion mode (D-mode) devices that find applications in high frequency and power. High performance p-channel heterostructure field-effect transistors (p-HFETs) in GaN, utilizing the two dimensional hole gas (2DHG) as carrier, are also highly desirable to enable complementary logic [1], [2] and allow integrated power convertor systems on a chip [3]. Despite the poor mobility of holes in GaN, at room temperature [4], the high density of 2DHG ( [5]) has resulted in an on-current of [1] in a normally-on D-mode p-HFET, however, the on/off current ratio was only 1.…”