Trap density of GeNx/Ge interface fabricated by electron-cyclotron-resonance plasma nitridation

• Published in: Applied physics letters Vol. 99; no. 2
• Main Authors: Fukuda, Yukio, Otani, Yohei, Toyota, Hiroshi, Ono, Toshiro
• Format: Journal Article
• Language: English
• Published: 11-07-2011
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.3611581

We have investigated GeNx/Ge interface properties using Si3N4(7 nm)/GeNx(2 nm)/Ge metal-insulator-semiconductor structures fabricated by the plasma nitridation of Ge substrates using an electron-cyclotron-resonance-generated nitrogen plasma. The interface trap density (Dit) measured by the conductance method is found to be distributed symmetrically in the Ge band gap with a minimum Dit value lower than 3 × 1011 cm−2eV−1 near the midgap. This result may lead to the development of processes for the fabrication of p- and n-Ge Schottky-barrier (SB) source/drain metal-insulator-semiconductor field-effect transistors using chemically and thermally robust GeNx dielectrics as interlayers for SB source/drain contacts and high-κ gate dielectrics.