A flexible logic circuit based on a MOS-NDR transistor in standard CMOS technology

A MOS-NDR (negative differential resistance) transistor which is composed of four n-channel metal-oxide-semiconductor field effect transistors (nMOSFETs) is fabricated in standard 0.35 μm CMOS technology. This device exhibits NDR similar to conventional NDR devices such as the compound material based RTD (resonant tunneling diode) in current-voltage characteristics. At the same time it can realize a modulation effect by the third terminal. Based on the MOS-NDR transistor, a flexible logic circuit is realized in this work, which can transfer from the NAND gate to the NOR gate by suitably changing the threshold voltage of the MOS-NDR transistor. It turns out that MOS-NDR based circuits have the advantages of improved circuit compaction and reduced process complexity due to using the standard IC design and fabrication procedure. (semiconductor integrated circuits)