Dynamics of the kink effect in InAlAs/InGaAs HEMTs

A physical model for the kink effect in InAlAs/InGaAs HEMTs

“…In order to test our model we have used lattice-matched, MBE-grown, HEMT's fabricated at MIT as a vehicle for this study [16], [18]. We examine devices with relatively long gate lengths ( m to m).…”

“…Additionally, simulations show that the kink disappears if the impact ionization mechanism is turned off in the simulator [3], [4], [15]. Finally, we have reported sidegate measurements establishing a direct relationship between impact ionization and the kink [16], [17], as well as transient measurements showing that the time constants associated with the kink are strongly correlated with the impact ionization rate [18].…”

“…• kink's dynamic behavior (particularly the bias-dependence of the time constants associated with the kink) [18]; • relationships between the kink and the recess (for example, why is the kink strengthened as the width of the source-side recess is increased?) [22], [25]; • kink's dependence on aging and surface treatments [5], [26].…”

“…[22], [25]; • kink's dependence on aging and surface treatments [5], [26]. We have recently carried out a several studies of the kink, including dc characterization [16], sidegate measurements [17], and large-signal transient measurements with nanosecond resolution [18]. In this work, we have combined the results of these measurements, as well as new measurements of the kink's temperature and illumination dependence, to develop a comprehensive picture of the kink.…”

Active current modeling for GaN HEMT devices

“…The alpha term which models the triode region of the I DS plots is a function of a hyperbolic tangent function with the midpoint and the magnitude term having V GS dependence. The alpha function used in this work is capable of modeling the kink phenomenon at the triode region and has a limiting function to prevent a negative range value.…”