Characterization of GaAs devices by a versatile pulsed I-V measurement system

On the redox origin of surface trapping in AlGaN/GaN high electron mobility transistors

“…12 More recently, it was likewise applied to AlGaN/GaN HEMTs leading to a major improvement in the pulsed I-V characteristics and microwave power performance of these devices. 13 Although it is believed that the SiN x passivation prevents surface trapping by passivating surface states and blocking the injection of electrons from the gate, 2,13 the details of this mechanism remain unclear.…”

Trapping effects in GaN and SiC microwave FETs

“…This prevented device and circuit designers from obtaining accurate device information to use in small-and large-signal models. The use of pulsed current-voltage ( -) test systems [16], which pulsed both gate and drain voltage with submicrosecond pulsewidths, yielded the drain characteristics that more accurately represented the device characteristics under high-frequency conditions, especially for those systems for which an arbitrary quiescent bias could be set [17]. It was demonstrated that device performance could be accurately predicted by using the pulsed -characteristics in smalland large-signal models [17].…”

“…The use of pulsed current-voltage ( -) test systems [16], which pulsed both gate and drain voltage with submicrosecond pulsewidths, yielded the drain characteristics that more accurately represented the device characteristics under high-frequency conditions, especially for those systems for which an arbitrary quiescent bias could be set [17]. It was demonstrated that device performance could be accurately predicted by using the pulsed -characteristics in smalland large-signal models [17]. The provision for setting a quiescent bias is an important feature in that the bias establishes steady-state trap populations, which generally could not follow the short pulses or high-frequency signals.…”

“…This difference between the static and pulsed drain characteristics is directly related to the limitation in the large signal performance of these devices. Devices fabricated with silicon nitride passivation were shown to exhibit better agreement between the dc and pulsed -drain characteristics, as well as improved microwave power performance, suggesting the role of surface trapping in these effects [17].…”

Dynamics of the kink effect in InAlAs/InGaAs HEMTs

“…Besides providing insight about the origin of the kink, pulsed characterization has been proven to be a good predictor of large-signal high-frequency performance [14]. In this work we have carried out the first experimental characterization of the dynamics of the kink effect in InAlAs/InGaAs HEMT's with nanosecond resolution.…”