Monte Carlo study of a self-aligned dual 50nm-gate InAlAs/InGaAs HEMT exhibiting high performances without short-channel effects

The authors present a theoretical study of a self-aligned dual-gate InAlAs/InGaAs/InAlAs high electron mobility transistor (HEMT) using two-dimensional Monte Carlo simulation. The gate closer to the source (G1) is used to modulate the electron injection. The second gate (G2) is biased to a constant voltage V_G2S greater than all possible values of the control-gate voltage V_G1S. Its role is to favor the occurrence of a screening effect between the drain contact and the first gated region of the channel. As soon as the domain of k-space transferred electrons grows between the two gates, the second gated-region becomes so resistive as to absorb the additional drain voltage. The potential barrier that controls the electron injection is then screened from drain potential variations. This screening effect allows restoration of an excellent saturation behavior while retaining high transconductance and cutoff frequency. Its role is to favor the occurrence of a screening effect between the drain contact and the first gated-region becomes so resistive as to absorb the additional drain voltage. The potential barrier that controls the electron injection is then screened from drain potential variations. This screening effect allows restoration of an excellent saturation behavior while retaining high transconductance and cutoff frequency