Electrical characteristics of Ge-based metal-insulator-semiconductor devices with Ge3N4 dielectrics formed by plasma nitridation

J Nanosci Nanotechnol. 2011 Apr;11(4):2856-60. doi: 10.1166/jnn.2011.3900.

Abstract

We have fabricated pure germanium nitrides (Ge3N4) using high-density plasma nitridation and investigated electrical properties of Au/Ge3N4/Ge capacitors. We achieved equivalent oxide thickness (EOT) of 1.4 nm, and dielectric constant of Ge3N4 was estimated to be 9.7. The gate leakage current density of 4.3 A/cm2 in the accumulation condition at V(fb)-1 V, where V(fb) is the flatband voltage, was one order of magnitude lower than that of conventional poly-Si/SiO2/Si stacks. The interface state density (D(it)) of Ge3N4/Ge interfaces evaluated by a low-temperature conductance method exhibited a minimum value of 9.4 x 10(11) cm(-2)eV(-1) at E - E(v) = 0.27 eV. Furthermore, the insulating property and interface quality of Ge3N4/Ge system was found to be thermally stable up to 650 degrees C. These results indicate that Ge3N4 is a promising candidate for either a gate insulator or an interfacial layer under high-k dielectrics for Ge-MIS devices.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Electric Capacitance
  • Electric Conductivity
  • Equipment Design
  • Equipment Failure Analysis
  • Germanium / chemistry*
  • Materials Testing
  • Nanostructures / chemistry*
  • Nanostructures / ultrastructure*
  • Nanotechnology / instrumentation*
  • Nitrogen / chemistry*
  • Particle Size
  • Plasma Gases / chemistry
  • Semiconductors*

Substances

  • Plasma Gases
  • Germanium
  • Nitrogen