Nanoscale in-plane structure devices are fabricated by electron beam lithography followed by electron cyclotron resonance reactive ion etching. We investigate the negative differential resistance (NDR) of InGaAs/InAlAs in-plane structure devices. The NDR appears in the current–voltage (I–V) characteristics of simple two-terminal in-plane short-channel devices. NDR characteristics depend on the effective channel width of in-plane gate transistors and become more pronounced when the channel conductance is increased by applying gate voltages. In a short-channel in-plane gate transistor, a more prominent NDR is observed and the NDR appears even at room temperature. In addition, the NDR onset voltage shifts to lower voltages when the channel length decreases. The NDR phenomenon is most likely caused by the real-space transfer of electrons from a high mobility channel to a low mobility layer.

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)

Logic devices based on in‐plane gate (IPG) transistors are realized and their electrical characteristics are investigated. An IPG transistor connected in series with a resistance functions as a logic device. In this work, we present logic devices based on lateral gate structures using an additional IPG transistor as a variable resistance. The logic device is formed by an in‐plane double gate transistor connected in series with a self‐gating transistor as a variable resistance. It shows clear input‐output characteristics as a logic device. Either NAND or NOR operation can be achieved by changing the width of the self‐gating transistor. The operation of IPG logic devices depends on the resistance ratio of the two transistors. By using IPG transistors as variable resistances, the Hi/Low ratio is high enough for reliable logic operations. Furthermore, it is shown that the number of terminals and wiring are considerably reduced by using our IPG logic devices compared to logic devices based on CMOS transistors. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)