Impact of Buffer Composition on the Dynamic On-State Resistance of High-Voltage AlGaN/GaN HFETs

Published in:
24th Int. Symp. on Power Semiconductor Devices and ICs, Bruges, Belgium, Jun. 3-7, pp. 345-348 (2012).
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Abstract:
Switching experiments with normally-off GaN-HFETs using a carbon-doped GaN buffer or an AlGaN buffer showed very different magnitudes of increased dynamic on-state resistance. The dynamic on-state resistance is analyzed for variations in buffer composition and set into relation to the buffer voltage-blocking strength. Also, the impact of p-GaN gate normally-off and Schottky-gate normally-on device technologies on the dispersion is studied. It is concluded that a buffer with less trap sites and lower breakdown strength is more favorable for high-voltage switching than a buffer with incorporated acceptors to increase the buffer breakdown strength.

Keywords:
GaN; normally off; dynamic on-state resistance; dispersion; switching.

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