
21GaN High-Voltage Power Devices
1.3.4 counterMeAsures towArd oPtiMized Power switching
1.3.4.1 Optimized Epitaxial Buffer Design
As discussed earlier, design and composition of the buffer structure signicantly inu-
ence dynamic properties. High values of breakdown strength, for example, 170 V/µm,
have already been obtained in the past [47]. However, due to the high R
on_dyn
these
devices were not useful for switching applications. Therefore, different epitaxial
Source
(a)
(b)
Drain
Time
Time
Time
Off-state: steady,
biased at 300 V
Partially on, immediately afte
switching from off-state
On-state, steady
I
D
V
DS
I
D
V
DS
I
D
V
DS
Gate
–4V
Source
Drain
Gate
+1V
Electri ...