A New Short Channel MOSFET with an Atomic-Layer-Doped Impurity-Profile (ALD-MOSFET)

Abstract

A new device structure with an atomic-layer-doped (ALD) impurity profile is proposed to decrease device size and to achieve high speed operation. Device performance is evaluated by computer simulation, and it is clarified that the potential and current flow distributions in MOSFETs with the ALD profile are effectively modulated. Punch-through in ALD MOSFETs is completely suppressed even for Leff=0.2 µm. The minimum channel length, Lmin, restricted by VTH lowering is extended into the submicron range, while the Lmin of conventional structure MOSFETs remains near 1 µm. Furthermore, it is shown that the process margin is sufficient to fabricate ALD MOSFETs by molecular beam epitaxy technology. Thus, it is concluded that the ALD structure is attractive and promising for developing devices with short channels.