Negative differential resistance characteristics of nanoscale in‐plane gate devices

Nanoscale in-plane gate devices are fabricated by electron beam lithography followed by electron cyclotron resonance reactive ion etching. We investigate the negative differential resistance (NDR) of the InGaAs/InAlAs in-plane gate devices. In our nanoscale devices, the NDR phenomenon is most likely caused by a real space transfer of electrons from the high mobility channel to the low mobility layer. The NDR characteristics are related to the effective channel width of in-plane gate devices and get more pronounced when the channel conductance is enhanced by applying the gate voltages. In addition, the NDR effect depends on the channel geometry. The NDR onset voltage shifts toward lower drain-source voltages when the channel length or width is decreased. Furthermore, high drain-source voltage characteristics are found to be affected considerably by the channel shape. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)