Session 4A-1

High Mobility Ge pMOSFETs with ~1nm Thin EOT
using Al₂O₃/GeOx/Ge Gate Stacks
Fabricated by Plasma Post Oxidation

 

Abstract

A novel plasma post oxidation method has been proposed to form an Al2O3/GeOx/Ge gate stack by using oxygen plasma through a thin ALD Al2O3 layer. This Ge gate stack is shown to simultaneously realize both thin EOT of ~1 nm and low Dit of <1011cm-2eV-1. Ge pMOSFETs, fabricated by employing this method, have demonstrated superior device operation with high hole mobilities of 437, 526 and 345 cm2/Vs on (100), (110) and (111) Ge substrates, respectively. These mobilities on (100) and (110) are the highest under ~1 nm EOT among the results reported so far. Also, this is the first demonstration of (110) and (111) Ge pMOSFET operations in this ultrathin EOT range.