Influence of Si surface roughness on electrical characteristics of MOSFET with HfON gate insulator formed by ECR plasma sputtering

Dae Hee Han, Shun Ichiro Ohmi, Tomoyuki Suwa, Philippe Gaubert, Tadahiro Ohmi

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

To improve metal oxide semiconductor field effect transistors (MOSFET) performance, flat interface between gate insulator and silicon (Si) should be realized. In this paper, the influence of Si surface roughness on electrical characteristics of MOSFET with hafnium oxynitride (HfON) gate insulator formed by electron cyclotron resonance (ECR) plasma sputtering was investigated for the first time. The surface roughness of Si substrate was reduced by Ar/4.9%H 2 annealing utilizing conventional rapid thermal annealing (RTA) system. The obtained root-mean-square (RMS) roughness was 0.07 nm (without annealed: 0.18 nm). The HfON was formed by 2 nm-thick HfN deposition followed by the Ar/O2 plasma oxidation. The electrical properties of HfON gate insulator were improved by reducing Si surface roughness. It was found that the current drivability of fabricated nMOSFETs was remarkably increased by reducing Si surface roughness. Furthermore, the reduction of Si surface roughness also leads to decrease of the 1/f noise.

Original languageEnglish
Pages (from-to)413-418
Number of pages6
JournalIEICE Transactions on Electronics
VolumeE97-C
Issue number5
DOIs
Publication statusPublished - 2014 May

Keywords

  • 1/f noise
  • ECR plasma sputtering
  • HfON gate insulator
  • Plasma oxidation
  • Si surface roughness
  • TDDB

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering

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