A High-Frequency Transconductance Method for Characterization of High- $\kappa$ Border Traps in III-V MOSFETs

Abstract

A novel method that reveals the spatial distribution of border traps in III-V metal-oxide-semiconductor field-effect transistors (MOSFETs) is presented. The increase in transconductance with frequency is explored in a very wide frequency range (1 Hz-70 GHz) and a distributed RC network is used to model the oxide and trap capacitances. An evaluation of vertical InAs nanowire MOSFETs and surface-channel InGaAs MOSFETs with Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> /HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> high-κ gate dielectric shows a deep border-trap density of about 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">20</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> eV <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> and a near-interfacial trap density of about 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">21</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> eV <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> . The latter causes an almost steplike increase in transconductance at 1-10 GHz. This demonstrates the importance of high-frequency characterization of high-κ dielectrics in III-V MOSFETs.